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Developmental protein malnutrition: influences on the central nervous system of the rat.
Our group has been carrying out interdisciplinary studies on the effects of prenatal and postnatal protein malnutrition on the developing rat brain. Anatomical, physiological, biochemical and behavioral approaches using the same animal model have revealed that protein malnutrition affects the brain at various levels, i.e., (1) anatomical, as revealed by Golgi findings of deranged dendritic trees on analysis of cortical and subcortical areas; (2) physiological, as revealed by delayed sleep pattern maturation, disturbances in seizure thresholds, slowing of sensory cortico-cortical and thalamocortical evoked potentials, and changed power in hippocampal theta activity; (3) biochemical, as revealed by marked increases in biogenic amines dating from birth, as well as modifications in tryptophan metabolism; and (4) behavioral, as revealed by various changes in responses to different kinds of aversive stimulation. Reversal studies have revealed that many changes are permanent and not amenable to nutritional rehabilitation even at birth, which is before the brain growth spurt in the rat. Our paradigm closely mimicks the human condition of low level, chronic protein undernutrition and thus reveals the underlying disturbances due to malnutrition. The dietary reversal studies are attempts at pin-pointing critical brain growth periods, beyond which recovery of functions is not possible.
0.929294
Toxic interaction between narcotic analgesics and inhibitors of catechol-O-methyltransferase.
A lethal synergism between morphine and tropolone, an inhibitor of catechol-O-methyltransferase, was previously noted in adult male Holtzman rats. The present research demonstrates that this phenomenon generalizes across factors of sex, age, strain (Sprague--Dawley, Wistar) and species (Swiss albino mice). Acute toxicity was also significantly increased (1.5--1.9 times) in the case of codeine, methadone, meperidine and levorphanol, but to a lesser extent than for morphine (4.0 times) in the S-D strain. Another COMT inhibitor, 3,5-dihydroxy-4-methoxybenzoic acid, interacted with morphine in S-D rats to an equal degree as did tropolone. Post-treatment with 1 mg/kg of naloxone in rats or naltrexone in mice reduced the high lethality associated with morphine plus tropolone. There was a pronounced lowering of whole brain norepinephrine (NE) level after morphine plus tropolone in Wistar rats with doses of each component that alone caused no change in NE. Brain dopamine (DA) was elevated by tropolone and by its combination with morphine. Each drug alone caused slight lowering of brain serotonin. Enhancement by tropolone of the toxicity of (+)-amphetamine in mice and rats was of similar magnitude as for morphine. The possible role of brain NE and/or DA in the sensitivity to acute toxic effects of opioids in rodents is suggested by these data, as well as a parallel in this regard with amphetamine-type stimulants.
0.821139
On the nature of basal vascular tone in cat skeletal muscle and its dependence on transmural pressure stimuli.
The aim of the present study was to elucidate in some detail the characteristics of the intrinsic basal vascular tone in the adrenergically blocked skeletal muscle with regard to its extent and site along the vascular bed, its dependence on arterial pressure via static and dynamic transmural pressure stimuli, and its sensitivity to local metabolic influence. Basal tone, which apparently is of myogenic nature, was pronounced in 'proximal arterial vessels' (greater than 25 mmicrometer i.d.) and in the 'microvessels' (less than 25 micrometers), but low in 'large veins'. Its functional characteristics, however, were different in the 'proximal arterial vessels' and the 'microvessels'. Normal basal tone in the 'microvessels' thus seemed to be intimately dependent on the arterial blood pressure level and, at least partly, initiated by its static mean pressure distension effect as well as by its dynamic pulse pressure oscillations. It could be virtually abolished by a transmural pressure decrease applied at fast rate ('strong inhibitory dynamic transmural pressure stimulus'). Basal tone in the 'proximal arterial vessels', on the other hand, was little affected by arterial pressure and almost irresponsive to transmural pressure stimuli. Basal tone in the 'microvessels' was much more sensitive to metabolic stimuli than that in the 'proximal arterial vessels'. The present results, viewed in the light of some recent electrophysiological studies on vascular smooth muscle, suggest that smooth muscle in the 'microvessels' is mainly of the spike-generating type, whereas that in the 'proximal arterial vessels' seems to be of different nature, possibly of the non-spike-generating type.
0.910708
Viral aggregation: mixed suspensions of poliovirus and reovirus.
The aggregation of mixtures of two dissimilar viruses, poliovirus I (Mahoney) and reovirus III (Dearing), was followed by electron microscopy under conditions known to induce either aggregation or dispersion of each virus separately. Neither virus aggregated at pH 7 in an appropriate buffer, and no mixed aggregates were formed. Under conditions of lowered ionic strength (by dilution into distilled water) poliovirus became aggregated, whereas reovirus did not, and again no mixed aggregates were formed. At pH 6, however, poliovirus again aggregated and, although reovirus did not, it attached to poliovirus aggregates. Thus, some inducement toward aggregation was necessary to cause formation of mixed aggregates. This inducement probably took the form of a reduction of the ionic double layer surrounding the particles, which is known to occur at low pH. At pH 5 and below both viruses aggregated severely, and large mixed aggregates were formed. These mixed aggregates could be broken up by neutralization of the suspension, although small aggregates of poliovirus remained. Reovirus showed a marked tendency to attach to large clumps of poliovirus, but the reverse tendency was not observed. The results indicate that mixed aggregates may be of significance in the isolation of viruses from water or wastewater.
0.903455
Structural elements in adenovirus cores. Evidence for a "core shell" and linear structures in "relaxed" cores.
"Freeze-fracture negative staining" of adenovirus type 5 revealed the virus cores as internal bodies with a fine granular surface which at high magnification shows reticular and ring-like patterns. This indicates that the virus protein V forms a thin surface layer for which a name "core shell" is proposed. Virus cores prepared by heating virus particles in sodium deoxycholate (DOC) relaxed into curved filaments or several rods by means of EGTA and high salt, respectively. High pH treatment had similar effects as high salt. Rod-like elements were also observed in ultrathin sections of the "DOC-cores". Fresh cores exhibited circular dichroism (C.D.) with similar features as described for nucleosomes (COWMAN and FASMAN, ref. 5). This indicates that the DNA has an orderly arrangement in the cores. EGTA had no effect on C.D. spectra but high salt treatment abolished the positive peak in 10 minutes. It is concluded that the adenovirus nucleocapsid is a linear structure, presumably a 120-150 Angstrom thick filament folded 5 to 6 times into "rods" as previously observed by freeze-fracturing.
0.891238
[Comparative study on the depressive action of several benzodiazepine minor tranquilizers (author's transl)].
The potencies of four benzodiazepine minor tranquilizers in depressing respiratory function were investigated in rats and cats anesthetized with pentobarbital. The effect of the drug on respiration was studied in the rat, and the effect on the phrenic nerve activity which reflects the activity of an inspiratory centre was investigated in the cat vagotomized bilaterally at the level of the neck. The change of blood pressure, heart rate and pCO2 in expiration were also recorded simultaneously in experiments with the cat, an infra-red CO2 gas analyzer (Model LB-1, Beckman) was used to measure the pCO2. Respiration in the rat was decreased by the oral administration of diazepam 10, 20 mg/kg or chloridazepoxide 20, 40 mg/kg. Although the pre-administration level of ventilation was not decreased by oxazolam or chloxazolam, both 20, 40 mg/kg, p.o., the level after administration was slightly lower than that after the administration of CMC alone. Diazepam, given intravenously either as a CMC-suspension or as the preparation Cercine, in the dose of 0.5 mg/kg, suppressed both the number of the burst discharges and the magnitude of the integrated signal of the discharge of the phrenic nerve of the cat. Chlordiazepoxide 1 mg/kg, i.v. also slightly decreased the magnitude of the integrated signal. Oxazolam 1 mg/kg, i.v. had little effect on the phrenic activity. Cloxazolam 1 mg/kg, i.v., on the other hand, tended to increase the magnitude of the integrated signal but only immediately after the administration. It is suggested that the potencies which depress the respiratory function vary for each minor tranquilizer, namely the ddpressive actions of oxazolan and cloxazolam are weaker than those of diazepam and chloridiazepoxide.
0.802815
Effect of phospholipase A2 on purified gastric vesicles.
The phospholipid and fatty acid composition and role of phospholipids in enzyme and transport function of gastric (H+ + K+)-ATPase vesicles was studied using phospholipase A2 (bee venom). The composition (%) was phosphatidyl-choline (PC) 33%; sphingomyelin (sph) 25%; phosphatidylethanolamine (PE) 22%; phosphatidylserine (PS) 11%; and phosphatidylinositol (PI) 8%. The fatty acid composition showed a high degree of unsaturation. In both fresh and lyophilized preparations, even with prolonged incubation, only 50% of phospholipids were hydrolyzed, but the amount of PE and PS disappearing was increased following lyophilization. There was a marked decrease in K+-ATPase activity (75%) but essentially no loss of the associated K+ p-nitrophenyl phosphatase was found. ATPase activity could be largely restored by various phospholipids (PE greater than PC greater than PS). There was also an increase in Mg2+-ATPase activity, partially reversed in fresh preparations by the addition of phospholipids (PE greater than PS greater than PC). Proton transport activity of the preparation was rapidly inhibited, initially due to a large increase in the HCl permeability of the preparation. Associated with these enzymatic and functional changes, the ATP-induced conformational changes, as indicated by circular dichroism spectra were inhibited.
0.862778
Purification and covalent coupling of calf brain prolidase.
We have investigated methods of stabilizing prolidase by chemical modification and covalent coupling to various supports, for use in protein hydrolysis and possible use in enzyme replacement therapy. Purified acetone powder of calf brain prolidase was further purified by gel filtration on Sephadex G-200 and chromatography on DEAE-Sephadex A25. Polyacrylamide gel electrophoresis showed that the number of bands was reduced from 11 to 2. Since yields were low, the purified (NH4)2SO4 fraction was used in all experiments. Thiolation of the enzyme reduced the amount of protein coupled to AH- or CH-Sepharose 4B. Activities were highest when the protein was linked through its carboxyl groups. The coupled enzyme showed much greater thermal stability than its free counterpart. Of the bound preparations, the thiolated was less stable than the untreated. Untreated and thiolated enzymes bound to either matrix showed higher activity at low pH and less at high pH than the free material. Thiolation shifted the pH maximum from 6.8 to 7.5. The free thiolated enzyme and that bound to activated SH-Sepharose 4B showed greater thermal stability and a broader pH range of optimal activity than the bound untreated enzyme. These results show that prolidase can be immobilized by coupling to an insoluble matrix through various types of covalent bonds with retention of activity and increased stability.
0.848748
Inhibition of photosynthetic electron transport in tobacco chloroplasts and thylakoids of the blue green alga Oscillatoria chalybea by an antiserum to synthetic zeaxanthin.
An antiserum to synthetic Zeaxanthin inhibits photosynthetic electron transport on the oxygen-evolving side of photosystem II in tobacco chloroplasts and thylakoids of the filamentous blue-green alga Oscillatoria chalybea. The inhibition site lies for both species between the site of electron donation of water or tetramethyl benzidine and that of diphenyl carbazide or manganese II ions. Typical photosystem I reactions are not impaired by the antiserum. The effect of the antiserum concerning the inhibition site is practically identical to that of the earlier described antiserum to violaxanthin. However, the degree of inhibition seems to be generally somewhat lower with the antiserum to Zeaxanthin, than with that to violaxanthin which hints at a lesser accessibility of zeaxanthin, in the tylakoid membrane in comparison to violaxanthin. In the course of these investigations new evidence was obtained that the oxygen-evolving side of the electron transport scheme is differently organized in Oscillatoria chalybea when compared to tobacco chloroplasts. Thus, the silicomolybdate reduction with water as the electron donor is sensitive to DCMU in these algae.
0.941158
Inactivation of Pasteurella multocida within the mouse peritoneal cavity.
Normal ICR mice were injected intraperitoneally with 0.5 ml of thioglycollate broth or 5 x 10(8) heat-killed Pasteurella multocida vaccine and the number of polymorphs, lymphocytes and macrophages in the peritoneal washout suspensions were determined at intervals up to 72 hours. The stimulated mice were challenged intraperitoneally with opsonized or unopsonized P. multocida at increasing time intervals and the rate of growth by the organisms in the washout suspension was determined up to 60 minutes later. The opsonized bacilli were taken up by the 6 hr. exudate cells (50-60% PMNs) and their growth inhibited more effectively than when the 72 hr exudate cells were tested (only 10% PMNs). When the challenge inoculum was introduced into the peritoneal cavities of mice stimulated 6 hrs previously with 5 x 10(8) heat-killed P. multocida vaccine, up to 80% of the bacilli were inactivated over a 30 minute period. However, when 72 or 250 hr peritoneal exudate cells were tested, the inoculum was not inactivated, but showed an increasingly lethal effect.
0.874039
Antimicrobial activity of crude juices of Allium ascalonicum, Allium cepa and Allium sativum.
Crude juices of garlic (Allium sativum), onion (Allium cepa) and shallots (Allium ascalonicum) were tested in an agar diffusion test for their growth inhibitory effect on five gram negative and three gram positive bacterial species and two yeast species. All test organisms were inhibited by garlic juice, whilst onion and shallot juice showed no effect upon gram negative bacteria. Garlic juice was investigated in more detail. Addition of complex-forming agents and organic matter to the crude juice reduced its activity on all test organisms. Volatile substances showed a strong inhibitory activity after exposure for 8 hours or longer at 23 degrees C or 37 degrees C. Minimal inhibition concentrations determined in a dilution test were found to be high for gram negative bacteria and low for both yeast species. The D-values of the different test organisms in undiluted garlic juice were calculated. P. aeruginosa had a very low D-value, whilst the bacteriostatic concentration was high. This indicates a large concentration exponent of crude garlic juice for this organism. The opposite was found for S. aureus. In view of the strong antibiotic properties and the complete absence of development of resistance further investigation upon the principles of the antimicrobial activity of juices from Allium species merits consideration.
0.84171
[Protective role of Salmonella R mutants in Salmonella infection in mice (author's transl)].
NMRI mice were immunized with acetone-killed bacteria of 6 salmonella R mutants, 5 homologous and 6 heterologous Salmonella S forms and 3 E. coli R mutants. The animals were then challenged with graded amounts of live S. typhimurium. The results show that the protection obtained was dependent on the number of immunizing injections and on the time interval between them. Thus in the case of Salmonella R-mutants two immunizations increased the LD50 of challenge by an index of two (log 10) compaired to one immunization. A third immunization led to only a small further increase, the protection however, was longer lasting. A 3 fold immunization with two Salmonella typhimurium mutants, one SR- and one Ra form, led to a protection comparable to that obtained with S form bacteria. In contrast to the R-mutants, with Salmonella typhimurium S form a high degree of long-lasting protection was achieved already after a single immunization, and was not increased significantly by repeated injections. In animals immunized with Salmonella typhimurium S form the difference between non-lethal and 100% lethal challenge dose varied by a factor of 10 (one injection dose). In contrast, in animals immunized with Salmonella R mutants the above differences were more gradual extending over 3, 4 or more infection doses. This was also true for animals immunized with lower doses of S. typhimurium S form and for the non-immunized control animals. For comparison the protective effect of heterologous Salmonella S forms and of E. coli R-mutants was studied. These were found to be less effective in affording protection to Salmonella typhimurium than the above Salmonella R forms. The various strains used for immunization may be placed in the following sequence in order of decreasing protection: Salmonella typhimurium S form, Salmonella R-mutants, heterologous Salmonella S forms, E. coli R mutants. In a parallel investigation the antibody inducing properties of Salmonella R mutants and heterologous Salmonella S forms were studied. In all cases homologous hemaglutinating antibodies to all the strains used for immunization were detectable. In immunization with Salmonella R mutants in addition to homologous titres, agglutinating antibodies to Salmonella typhimurium S form were also produced in significant amounts. There was, however, no correlation between the time of appearance of protection and that of appearance of antibodies nor between the hight of antibody titres and degree of protection. The detection of agglutinins to the infecting microorganisms represents therefore no valid criterium for the effectiveness of R mutants and heterologous Salmonella S forms as protective vaccines. From the present results it is concluded that in addition to the O antigen one or more further cell components exist which are involved in rendering animals immune to Salmonella typhimurium and probably also to other Salmonella S form bacteria.
0.860328
Effect of terbutaline, a beta 2-adrenergic receptor stimulating compound, on cutaneous reponses to histamine, allergen, compound 48/80, and trypsin.
The beta-adrenoceptor stimulating agent terbutaline (2 ng-2 microgram) injected intradermally in eight atopic subjects produced a dose-dependent inhibition of the skin reactions induced by subsequently injected allergen. After injection of 0.5 microgram terbutaline inhibition of the flare and weal responses was demonstrable throughout the observation period of 90 min. The flare response induced by histamine, the histamine liberator compound 48/80 and the proteolytic enzyme trypsin was not inhibited by terbutaline in the doses used, suggesting a selective action of terbutaline on the allergen-induced response. The weal response elicited by histamine and compound 48/80 was slightly reduced by 2 microgram terbutaline. It is suggested that pretreatment of the skin with terbutaline interferes with the ability of the cutaneous mast cells to respond to challenge with allergen and that terbutaline produces this effect in doses lower than those needed to counteract the permeability increasing effect of released mediator substances.
0.925255
Factors influencing adherence of group B streptococci to human vaginal epithelial cells.
Factors affecting the adherence of group B streptococci to human vaginal epithelial cells in vitro were examined. Maximal adherence was achieved within 15 min of incubation of bacteria with epithelial cells. Adherence was temperature and pH dependent; maximal adherence occurred at 37 degrees C and pH 5.5. Killing of streptococci with ultraviolet light or penicillin did not affect adherence. Similarly, adherence was not altered by preincubating epithelial cells at 65 degrees C for 30 min. Thus neither bacterial nor epithelial cell viability appears to be a prerequisite for adherence. Preincubation of streptococci at 65 degrees C for 30 min resulted in a marked decrease in adherence, whereas preincubation of group B streptococci with neuraminidase was associated with a significant increase in adherence. The adherence of strains belonging to five different group B streptococcal serotypes was not altered by group-specific or type-specific rabbit antisera. These findings suggest that the site for adherence on the bacterial cell wall is heat sensitive and is marked by sialic acid, but is not related to either group-specific or type-specific antigens.
0.917592
Hydrophobic high-performance liquid chromatography of hormonal polypeptides and proteins on alkylsilane-bonded silica.
Thirty-two hormonal polypeptides and nine proteins (8-65 kD) have been used to evaluate the potential of high-performance liquid chromatography on alkylsilane-bonded silica for separating and recovering biologically active compounds of this type. The basic method used was gradient elution with acetonitrile in an acid phosphate buffer. Variation of key chromatographic parameters demonstrated that low pH (less than 4.0) and high buffer molarity (greater than 0.1 M) are mandatory for reproducible high efficiency polypeptide chromatography. Simple NaCl-HCl mixtures of appropriate acidity and molarity could be substituted for the acid phosphate buffer, with the advantage of minimising non-physiological ion contributions to eluted materials. Minor selective effects were noted with different organic modifiers, but variation of other parameters, including choice of specific alkylsilane packings, did not materially influence separations. Under optimal conditions all of the polypeptides tested could be efficiently chromatographed, and many simultaneously resolved, as could most of the proteins tested. Three of the more hydrophobic proteins could not, however, be eluted from the alkylsilane packings. Retention orders of smaller compounds (less than 15 residues) generally correlated with the sum of the Rekker fragmental constants of their strongly hydrophobic residues. Larger polypeptides showed numerous anomalies when ranked by this means, however, limiting its predictive value. The separation of at least eighteen discrete components from a partially-purified posterior pituitary extract has demonstrated the capability of alkylsilane-type reversed-phase packings for the hydrophobic high-performance liquid chromatography of complex biological mixtures.
0.916093
[The monoamines in molluscs. I. Catecholamines: biosynthesis, disposition and inactivation (author's transl)].
The central nervous system of the mollusc Helix pomatia, like that of other molluscs, contains a very high level of dopamine. However, noradrenaline is weakly represented. These characteristics apply to the peripheral nervous system and more particularly to the heart. The study of the phenomena taking part in the synthesis and inactivation of catecholamines shows that these processes are not different in vertebrates and molluscs. Thus, in the particular case of Helix pomatia the synthesis of catecholamines is carried out by tyrosine hydroxylase, aromatic amino acid decarboxylase and dopamine-beta-hydroxylase. These enzymes are not only active in the ganglia and nerves, but also in the peripheral nervous system. The monoamines are associated with granules. The synthesized enzymes in the pericarya migrate due to the axonal flow and accumulate in the intracardiac nerve endings. In Helix pomatia, the enzymes participate actively in the local synthesis of catecholamines using the precursors tyrosine and DOPA. We have little information on the uptake of dopamine by nervous structures, but it would seem that this phenomenon seems to play an active role in the synaptic inactivation of dopamine. The glial elements also play a part in uptake and inactivation. In most species the nervous system has very little monoamine oxidase, and there is even less in the heart. The enzymic activity depends on substrates and is more active with dopamine than with 5-hydroxytryptamine. The exact localization of monoamine oxidase in the tissues is unknown. However, we believe that it plays a part in the neuronal regulation of dopamine levels and in its synaptic inactivation. The same applies for catechol O-methyltransferase.
0.883136
[The influence of a beta-adrenolytic premedication on cardiovascular parameters and plasma free fatty acids during esophago-gastro-duodenoscopy (author's transl)].
Three groups of patients with different premedications were examined for changes of blood pressure, heart rate, ECG and plasma free fatty acid levels during esophago-gastro-duodenoscopy: Group A was premedicated with Bunitrolol, group B was premedicated with Hyoscin-N-butyl-bromide and diazepam, group C was endoscopied without premedication. The pulse rate rose significantly less in group A than in groups A and C; the same phenomenon was observed with regard to the systolic blood pressure. Premature beats occurred in all 3 groups: 32 per cent of the patients in group A, 43 per cent in group B and 60 per cent in group C had at least occasional premature beats; an accumulation of premature beats however occurred significantly less frequently in group A than in groups B or C. A drop of the ST-part of the ECG occurred with about the same frequency in each group. An increase of the plasma free fatty acids, which was noted in groups B and C, could be observed in Group A. A pre-endoscopic medication of beta blocking agents could be a useful measure in patients with labile arterial hypertension, vegatative dysregulation and a hyperkinetic heart syndrome.
0.88295
[Comparison of four recently introduced cephalosporins with respect to probability of resistance in multiresistant strains of Escherichia coli, Proteus mirabilis and Klebsiella spec. (author's transl)].
Strains with the same number of resistances were arranged in so-called resistance classes. Nine classes of resistance (0 to greater to or equal to 8) were formed by means of ten standard chemotherapeutics; the four new cephalosporins were excluded. For every resistance class frequency of cephalosporinresistance was described as coefficient ranging from 0 to 1 (Fig. 1). In Cephalothin the coefficients were markedly rising only in 6 (7)-fold resistant strains of the species examined. Similar but somewhat reduced rising of coefficients was also observed in Cefaclor and Cefamandole. In Cefaclor this is particularly evident for E. coli, whereas in Cefamandole, it concerns Klebsiella spec. In the other species rising of coefficients of Cefaclor and Cefamandole are less marked. The probability of restance in multiresistant strains are therefore distinguished more clearly from that of Cephalothin. Cefuroxime and Cefoxitin take a special position because the probability of resistance does not rise in multiresistant strains. The coefficients of Cefoxitin do not show any recognizable dependance on multiresistance. For clinical purpose the following conclusions can be derived: Because of their effectiveness in multiresistant strains Cefoxitin and Cefuroxime are suitable for empiric use in intensive care units where many multiresistant Klebsiella-strains are to be expected. Cefamandole on the other hand is characterized by a rising probability of resistance in multiresistant strains. Therefore it should only be given after antibiotic testing. Cefaclor, a new oral cephalosporin, will be introduced specially for outpatients where multiresistant strains are rarely found.
0.892748
[Virological diagnosis of epidemic keratoconjunctivitis (author's transl)].
Among 180 patients with proved adenovirus infection of the eye, 144 infections with adenovirus 8 (Ad 8) were found. 11 or 7 patients were infected with Ad 19 or Ad 4 respectively; further 18 cases were associated with 6 other serotypes. The main symptoms of epidemic keratoconjunctivitis (EKC) (pronounced inflammatory swelling of the plica and caruncula, nummular corneal infiltations) are not confined to Ad 8 infections. For the virological diagnosis, a combination of virus isolation and serology is recommended. Virus isolation is mostly successful from conjunctival swabs obtained during the first week of the disease. For serological investigation, the first blood specimen should be taken as early as possible, the second not earlier than 15 days after onset of disease. The mere application of the group-specific adenovirus complement-fixation is insufficient; it should be supplied by neutralization and hemagglutination-inhibition with Ad 8 (or Ad 19) virus, although these reactions are not invariably type-specific. A swifter diagnosis of the adenovirus infection by immunofluorescence performed in cell cultures inoculated with conjunctival material, 3 or 7 days after inoculation, was often successful; however, this procedure proved to be less sensitive than virus isolation.
0.825014
Isolation of virus strains from mosquitoes collected in Queensland, 1972-1976.
171,348 mosquitoes and 4,353 other arthropods collected at three centres in Queensland in 1972-1976 yielded 151 strains of 18 viruses. Culex annulirostris was the major source of virus isolation but 42 strains from Aedes normanensis indicate it to be a vector of importance. Ross River and Kokobera viruses were isolated at Kowanyama in the dry season, a finding of interest as being compatible with year-round survival in vector-vertebrate cycles. Culex fatigans has in part replaced Culex annulirostris in peridomestic breeding sites at Kowanyama; the infrequency of virus isolation from it suggests that this replacement may lower arbovirus infection rates. Twelve strains were identified as viruses antigenically distinct from any previously isolated in Australia or New Guinea: Ch16129, showed by the International Reference Centre for Arboviruses to be a previously undescribed member of the Simbu Group (Facey's Paddock virus), Ch16313 (Murweh), Ch19520 (Parker's Farm) and Ch19546 (little Sussex). The remaining strains were identified as viruses previously known in Australia, but included many new host or geographical records.
0.870141
[Iatrogenic depression (author's transl)].
A number of drugs are traditionally blamed for causing depression: in general medicine, the antihypertensives, the oral contraceptives and the appetite suppressants; in psychiatry, the neuroleptics. The identification of iatrogenic depression is difficult methodologically, for two reasons: 1. Detection of the depression. 2. Linking convincingly that state of depression with the administration of a particular drug, given the presence of many non-pharmacological factors. The literature and the experience of clinicians provide fairly contradictory evidence, but an analysis of published work calls for the following observations: --the type and severity of depression are rarely specified;--a history of psychiatric disorder is commonly stressed;--the specific role of the disability caused by physical or mental illness and the need to use palliative rather than curative measures are usually underestimated;--biochemically, it is surprising that the effects which some of these drugs are known to have upon the cerebral amines do not cause more depression of mood. In fact, if we consider how widely the drugs incriminated are used, it is clear that real drug-caused depression is rather uncommon.
0.842383
Allogeneic marrow grafting for acute leukemia: a follow-up of long-term survivors.
We have reported 100 consecutive patients with refractory acute leukemia treated with chemotherapy, total body irradiation (TBI) and marrow from an HLA identical sibling. At the time of the report 17 patients were alive after 11-53 months. All patients have now been followed more than 3 years. At the time of the last report 4 of the 17 patients had relapsed: two in the marrow, one in the central nervous system and one in the testicle. Three of these four patients have died of their disease 27, 34 and 50 months following transplant. The patient with a solitary testicular relapse remains in complete remission 49 months after local irradiation without concomitant systemic therapy. One other patient died 26 months following transplantation from cardiopulmonary complications following multiple respiratory infections. Of the 13 surviving patients, three suffer from chronic graft-versus-host disease. Summaries of the problems encountered in these patients after the first 100 days are presented. Ten of the original 100 patients are living productive lives 36-80 months after transplantation. The data clearly demonstrate that long-term unmaintained remissions are possible in a small fraction of patients with terminal leukemia treated with various chemotherapy regimens and TBI followed by marrow transplantation.
0.835709
A redefinition of normal acid-base equilibrium in man: carbon dioxide tension as a key determinant of normal plasma bicarbonate concentration.
It has been shown recently that normal acid-base equilibrium in the dog is characterized by a strong positive correlation between plasma bicarbonate concentration and PCO2. The present study was undertaken to examine the possibility that a similar relationship between normal levels of PCO2 and plasma bicarbonate might be present in man. The results indicate that values for bicarbonate within the normal range are highly dependent upon the prevailing level of PCO2 ([HCO3-] = 0.36 PaVCO2 + 10.4; r = 0.73). Thus, approximately 50% of the normal variance in bicarbonate concentration is explained simply by the variance in PCO2. The joint confidence region for bicarbonate concentration and PCO2, that can be derived from these data provides a new and more rigorous definition of normal acid-base equilibrium in man.
0.905793
Chemical relaxation studies on the horse liver alcohol dehydrogenase system.
Chemical relaxation studies on the system horse liver alcohol dehydrogenase, nicotinamide adenine dinucleotide, and ethanol were conducted observing fluorescence changes between 400 and 500 nm. Temperature-jump experiments were performed at pH 6.5, 7.0, 8.0, and 9.0; concentration-jump experiments at pH 9.0. The reciprocal of the slowest relaxation time was found to be linearly dependent upon the enzyme concentration for relatively low enzyme concentrations, as predicted earlier. Use of the wide pH-range necessitated expression of the four apparent dissociation constants of the catalytic reaction cycle in terms of pH-independent constants. The system was described in terms of only one (or two) catalysis-linked protons not associated with the electron transfer. Protonic steps in a buffered system are in rapid equilibrium, too fast to be measured with the equipment available. Assuming only two of the four bimolecular reaction steps in the four-step cycle are fast compared to the remaining two, six cases may be considered with six expressions for the reciprocal of the slowest relaxation time. Comparison with the experimental data revealed that the bimolecular reaction steps governing the slowest relaxation time change with pH. Above the effective time resolution of the temperature-lump instrument with fluorescence detection (0.1 msec) only one other relaxation time was detectable and only at pH 9. This relaxation time, found to be independent of the concentration of all reactants within experimental error (r = 10 +/- 5 msec), is most likely due to an interconversion among ternary complexes.
0.904882
The role of adrenergic receptors in the regulation of gastric motility in the rat.
Gastric motility was investigated under the effect of adrenergic receptor agonist and antagonist substances in albino rats of both sexes and weighing 150 to 180 g. Gastric evacuation was studied, after introducing 2 ml/100 g of Novobarium suspension in the stomach, by radioscopy and radiography. Epinephrine (Tonogen) was found to inhibit gastric motility, this inhibition being effective even after pylorotomy. The dominantly alpha adrenergic agonist phenylephrine (Sympathomim) had not any effect; the alpha blocker phenoxybenzamine (Dibenzyline) slightly depressed gastric evaluation. A marked inhibitory influence was noted with stimulating the beta receptors by isoproterenol (Prophylon), while propranolol (Inderal) slightly accelerated gastric evacuation by blocking beta receptors. A pretreatment by phenoxybenzamine of the animals did not affect epinephrine influence whereas a pretreatment by propranolol completely abolished the inhibitory effect of epinephrine on gastric motility. These results suggest the presence of a slight beta receptor tone in gastric motility at rest, and indicate further that epinephrine exerts its inhibitory effect on gastric motility via adrenergic beta receptors.
0.881701
[Rabies specific IgM- and IgG-antibody response in persons immunized with HDCS vaccine according to the Essen postexposure vaccination schedule (author's transl)].
A solid phase enzyme immunoassay (ELISA) was applied for the determination of rabies virus antibodies of the immunoglobulin classes G and M in sera of 10 young adults. Vaccinations were carried out with the Essen post-exposure vaccination schedule, which is recommended by the W.H.O., with the rabies HDCS vaccine with an antigen value of 1.9. From these results the rabies virus IgM/IgG-conversion was derived. Furthermore a comparison was carried out of results obtained with the ELISA, the mouse neutralization test, the complement fixation test and the hemagglutination inhibition test. Rabies virus-IgM-antibodies were detected already three days after the first vaccination. The IgM-antibody concentration increased to a maximum at the 22nd day p.v. In sera of seven of eight vaccinees rabies virus IgM-antibody was still detectable until the 90th day p.v. Rabies virus antibodies of the IgG-class were found in the serum of 1/7 vaccinees at the 7th day p.v. A steep increase of the rabies virus IgG-antibodies was observed from day 10 p.v. to a maximum between the 30th and 40th day p.v.. The titer values varied between 1:10-1:1600. The rabies virus IgM/IgG-conversion was observed after the 10th day p.v.. More than 75% of the total antirabies virus globulin fraction belonged to the IgG-class in sera of 6 of 9 vaccinees between the 22nd and 30th day of p.v.. A preponderance of the rabies virus IgM-antibodies was seen in 3 of 9 vaccinees until the 90th day p.v.. Most sensitive for the early detection of rabies virus antibodies was the IgM-ELISA followed by the IgG-ELISA, mouse-neutralization test, hemagglutination inhibition test and complement fixation test.
0.881617
[Effect of bacterial infections and antibiotics on tsetse flies (Diptera, Glossinidae) (author's transl)].
The membrane feeding technique (in vitro feeding) used for the rearing of tsetse flies has advantages over the conventional method of feeding the flies on host animals. However, as long as blood remains the sole source of tsetse fly nutrition, the risk remains of blood being contaminated during collection, storage or feeding with bacteria pathogenic to the flies. The resulting high mortality of the tsetse flies endangers the success of this rearing. The experiments described here have shown that Glossina m. morsitans Westw. are more sensitive to Pseudomonas aeruginosa than G. p. palpalis Rob.-Desv. Rearing experiments over several years have confirmed this finding in that the latter species has never been threatened by high bacterial-induced mortality, whereas in 1973-74, due to contamination of the in vitro fed blood, a population of G. m. morsitans was difficult to colonize. The quantity of infected blood intake (14 to 70 mg) had no influence on the survival rate. However, when flies were infected once with Pseudomonas aeruginosa (dilution stage of 10(-3)), the organisms were eliminated after only nine days in living G. p. palpalis, but after 14 days in living G. m. morsitans. Females were infected at different stages of pregnancy but the same bacteria were not isolated in any puparia. Therefore, transmission of the bacteria to larvae growing in the uterus could not be demonstrated. All antibiotics used, to which bacteria isolated from tsetse flies in the laboratory were sensitive, caused a reduction in productivity. Parental females as well as females which emerged from larvae deposited by these flies (= F1-generation) 6 days after the administration of the drug to the pregnant females showed a similar loss in productivity. This corresponds with a degeneration of mesenteric symbionts. The most successful way to cope with bacterial infection in the membrane feeding technique in the rearing of tsetse flies has proved to be prophylactic measures, i.e. sterile membranes, sterile underlying aluminium trays and sterile blood. The methods employed at this laboratory, where up to 20 000 flies are being fed daily through membranes, have prevented dangerous bacterial infections in both species.
0.849744
[In vitro maturation of rabbit reticulocytes: oxygen consumption reaction].
With a simple experimental system the changes of endogenous, antimycin A-suppressed, oligomycin-suppressed and antimycin A-resistant oxygen consumption are studied during the maturation of intact cells of the 6th day of bleeding. All functional characteristics of oxygen consumption decrease during maturation. The rate of decrease is strongly increased by high inorganic phosphate concentrations (125 mM). This effect is most obvious for the oligomycin-suppressed and the endogenous respiration. The degree of uncoupling of non-incubated cells is 14%. During 24 h incubation it rises to 75%. Inorganic phosphate accelerates the increase of uncoupling during maturation. Reticulocytes of the 4th day of bleeding are characterized by a higher respiratory capacity and also by a higher rate of maturation of antimycin A-suppressed and endogenous respiration. The degree of uncoupling does not increase during maturation. This may be attributed to the low lipoxygenase activity of these cells. 25% of the endogenous oxygen consumption of unmatured cells are antimycin A-resistant. This type of respiration declines by 50% in 4 h incubation irrespective of inorganic phosphate concentrations and day of bleeding. In nitrogen all functional characteristics of respiration during the maturation decline more rapidly than in oxygen. The antimycin A-resistant respiration, however decreased more slowly and reached 50% after 12 h. A pH dependence of maturation (maximum at pH 8.4) was found for the endogenous and the antimycin A-suppressed respiration. The degree of uncoupling rises most quickly at pH 7.4. This is possibly related to the pH maximum of lipoxygenase.
0.787845
[2d-generation cephalosporins in the treatment of gram-negative superinfections].
The second generation cephalosporins are those drugs that are totally or partially resistant to betalactamases (cefamandole, cefuroxime) or the cephamycins (cefoxitine). This property allows them to destroy the enterobacteria resistant to cefalotine and they may have a place in the treatment of certain post-operative infections (abdominal, gynaecological, urinary) on their own or in combination with an aminoglycoside. They also may be of use in combination with an aminoglycoside in the management of secondary septicaemia infections. Outside of these indications which are dependent on the bacteriological findings, their use should be limited even when there is an absence of organisms that are Cefalotine sensitive on the antibiogram. This careful approach (which applies particularly for cefotaxine) may be abandoned once a certain quantity of resistant strains have emerged. For the time being, the second generation cephalosporins ought to be used only for specific indications, and as a general rule should not be first line antibiotic treatment.
0.794696
[Comparison of postoperative blood cortisol levels after neuroleptanalgesia and extradural anesthesia].
Postoperative plasma cortisol levels were measured in two series of surgical patients who had undergone a gynaecological operation, with respectively 17 and 16 subjects. Samples were drawn on D0 6pm, D1 8am, D2 8am and D3 8 am. A reference sample had been taken before the premedication on D0 at 8 am. The first series had been anaesthetised using a dextromoramidedroperidol type neuroleptanalgesia followed by postoperative analgesia by a noramidopyrine compound. The second series required epidural anaesthesia followed by postoperative analgesia by the injection of lidocaine at constant rate, interrupted between the last two samples. In the neuroleptanalgesia group: from a basal level of 470 nmol.l-1, plasma cortisol rose to 800 nmol.l-1 (p less than 0.01) on D0 at 6 pm to subsequently remain on a plateau between 500 and 550 nmol.l-1 (NS) within the normal physiological limits for the laboratory. In the epidural group, from a basal level of 420 nmol.l-1, plasma cortisol rose to 1000 nmol.l-1 (p less than 0.01) to return to basal levels only on D3: 450 nmol.l-1 (NS) with intermediate values of 700 and 630 nmol.l-1 (respectively: p less than 0.001 and p less than 0.05). Statistical comparison between the two groups showed that the increase in cortisol in the epidural group in relation to the other was significant throughout the period of administration of lidocaine at constant flow rate: p less than 0.05 on D0 at 6pm, D1 and D2. The results are discussed.
0.895546
Danger of haemodialysis using acetate dialysate in combination with a large surface area dialyser.
Large surface area, high mass transfer dialysers have recently come into widespread use, and it has been shown that they promote the loss of large amounts of bicarbonate when acetate is used in the dialysate. The present study was designed to confirm these metabolic consequences and quantitatively to compare two commonly used dialysers in this respect. Simultaneous measurement of arterial and venous blood gases has shown that there is a significant reduction in bicarbonate, carbon dioxide tension, and pH of blood returning to the patient from the dialyser. These changes were greatest with the 2,5-m2 hollow-fibre dialyser, and least with the 1,4-m2 coil dialyser. In the chronic dialysis patient in a steady state, these effects may be inconsequential but, in an acutely ill patient, the combination of a dialysate containing acetate and a high-efficiency dialyser may be extremely hazardous. A return to the use of bicarbonate as the source of base would avoid such hazards and would promote the more physiological correction of the metabolic acidosis of renal failure.
0.866708
Sperm quality in adult diabetic men.
In 65 adult diabetic men and 77 control men without diabetes, both groups without any problems as to fertility, the following characteristics of ejaculate have been compared: volume of seminal fluid, sperm concentration per milliliter, total sperm count, sperm morphology, and motility at 1, 3, and 5 hours after ejaculation. In the entire diabetic group, sperm morphology and motility at 1 hour after ejaculation was statistically significantly worse. In 15 diabetics without sexual disurbances only sperm morphology was statistically significantly worse compared with an equally large control groups. In 50 diabetics with erection disturbances, sperm volume and motility in three successive observations were statistically remarkably lower. In younger age subgroups, the differences between diabetics and nondiabetics were more marked than in older age subgroups. The patients' age, when diabetes was discovered in them, did not essentially influence the quality of the ejaculate where diabetes lasted 8 or more years. Diabetics over 40 years' age displayed a significantly lower sperm volume. The total sperm count and motility at 3 and 5 hours after ejaculation, with 12 or more years' duration of diabetes, differed from diabetes of 2 years' duration. On the basis of these observations a negative influence of diabetes on the quality of the ejaculate seems unquestionable. There exists great variability in the adverse effect on the individual diabetic. Also, the individual characteristics of the ejaculate are affected, usually, to a different extent: the most frequently and markedly affected being the sperm motility, then morphology and/or volume of ejaculate, and the least often and the least conspicuously, the sperm count.
0.889112
Spontaneous motility of isolated mesosalpinx-free isthmic and ampullar segments from human oviducts, and the influences of indomethacin and prostacyclin (PGI2).
The spontaneous contractile activity of isolated mesosalpinx-deprived isthmic and ampullar segments from estrogen dominated human oviducts and the influences of indomethacin, prostaglandin F2-alpha, (PGF2-alpha), E1 (PGE1), E2 (PGE2) and prostacyclin (PGI2) on their motility, were explored. Indomethacin enhanced significantly the Isometric Developed Tension (I.D.T.) of the isthmic but not the ampullar region. On the other hand, a single and identical concentration (10(-6) M) of PGE1 and PGI2 depressed the ampulla whereas PGE2 and PGF2-alpha enhanced its contractions. In the isthmus, PGE1, PGE2, and PGF2-alpha augmented whereas PGI2 diminished the I.D.T. Dose-response curves of PGI2 demonstrated a dose-dependent depression of I.D.T. and contractile frequency of both ampullar and isthmic regions. Furthermore, in the isthmus PGI2 resulted in a biphasic action on resting basal tone (depressing at low and augmenting at high concentrations), whereas in the ampulla only a progressive dose-dependent decline, was observed. The results suggest that a prostaglandin with inhibitory capacity, presumably PGI2, may be synthesized by the human isthmus and play some role in the reduced spontaneous activity observed under estrogenic dominance.
0.920457
Tumour promoter alone induces neoplastic transformation of fibroblasts from humans genetically predisposed to cancer.
Neoplastic transformation is a multi-phase process apparently caused by carcinogens and subject to the influence of promoters. The naturally occurring phorbol esters such as 12-O-tetradecanoyl phorbol-13-acetate (TPA) are potent tumour promoting agents. Through the use of phorbol esters a two-stage process of malignant transformation has been demonstrated in the mouse skin model and, more recently, in cell culture systems. Studies in vitro suggest that TPA reversibly inhibits terminal differentiation in most, but not all model systems, and that its function is presumably to increase the probability of expression of the malignant phenotype. We have studied the effects of TPA on mutant human fibroblast cell strains derived from individuals with hereditary adenomatosis of the colon and rectum (ACR), an autosomal dominant trait. We have previously demonstrated in these fibroblasts abnormal phenotypic expressions which often appear in transformed cells. In these studies, we have assumed that the ACR cell exists in an "initiated state" due to a dominant mutation and that expression of the malignant state might only require treatment with a promoting agent. This single experimental protocol provided a novel system for the study of cancer promotion in vitro. We have now demonstrated, for the first time, the growth in vivo of human mutant cells exposed to TPA alone.
0.809529
Serum prolactin levels following intramuscular chlorpromazine: two- and three-hour response as predictors of six-hour response.
Neuroendocrine studies that examine the changes in serum prolactin levels following intramuscular (im) neuroleptics have usually monitored prolactin levels before and for 90 minutes to 3 hours after neuroleptic injection. Recent studies have suggested that this may be an inadequate period of time. In the present study, six male and four female psychiatric inpatients, who had not received neuroleptic medication for at least 1 week before the study began, received an injection of chlorpromazine (CPZ) 25 mg im; serum prolactin levels were monitored for 6 hours after injection. Peak serum prolactin levels occurred at 60 minutes in one subject, 90 minutes in three subjects, 120 minutes in two subjects, 180 minutes in three subjects, and 240 minutes in one subject. Area under the serum prolactin curve at 2 hours and area under the curve at 3 hours after CPZ injection were found to be good predictors (r = 0.86; r = 0.95, respectively) of 6-hour area under the curve. Two-hour studies should therefore not be considered inadequate; however, a 3-hour study length results in more precise characterization of prolactin response to im CPZ.
0.904933
Interactions of pharmacological agents which alter biogenic amine metabolism and depression--an analysis of contributing factors within a primate model of depression.
The observation that the biogenic amine depleting agent, reserpine, could induce severe depression in a small proportion of the patients treated with it has proved to be seminal finding in what is now a much larger field of research relating the function brain biogenic amine systems to emotions and behavior. A review of the human reserpine literature suggests, however, that factors other than pharmacologically produced alterations in brain biogenic amine metabolism must have been critical determinants of the eventual mood alterations observed in conjunction with reserpine treatment. While some of these factors, such as previous history of depression, ongoing psychosocial and environmental stress, can be intuitively identified, there are practical as well as ethical problems involved in actually testing the relative contribution of these factors in precipitating human depression and thereby determining their importance in a quantitative fashion. In the present paper we have attempted to examine, in a nonhuman primate model of depression, the degree to which factors such as prior rearing condition, repeated peer separation, and housing environment can intact with the behavioral effects produced by biogenic amine depleting agents. Major emphasis will be placed on studies utilizing alpha-methyl-para-tyrosine, an inhibitor of tyrosine hydroxylase, to ostensively reduce levels of the catecholamine neurotransmitters norepinephrine and dopamine. The results of these studies provide quantitative estimates, in terms of dose-effect relationships, of the degree to which a number of factors can combine to produce despair-like behavior in rhesus monkeys. These data may be of practical importance in evaluating the contribution of similar factors to the precipitation of human depression. Analysis of some of the existing literature relating alterations in behavior to changes in biogenic amine metabolism in animals suggests that there are important differences between rodent and primate species. These differences, when fully established, may indicate that additional research examining the mechanisms whereby modest alterations in biogenic amine metabolism can interact with environmental and social stress is needed.
0.892684
Regulation of biosynthesis of aminoacyl-transfer RNA synthetases and of transfer-RNA in Escherichia coli.
We have isolated temperature resistant revertants from temperature sensitive E. coli strains containing either a thermolabile glutaminyl-tRNA synthetase or leucyl-tRNA synthetase. Among the revertants which still contained the thermolabile leucyl-tRNA synthetase we found two classes of regulatory mutants (leuX and leu Y) which have elevated levels of this enzyme. The leuX mutation specifies an operator-promoter region adjacent to the structural gene (leuS) for the enzyme. The leuY gene maps away from the leuS gene and codes for a protein. Using these mutants we demonstrated that the levels of leucyl-tRNA are related to the derepression of the leucine and isoleucine-valine operons. Among the revertants which still contained the thermolabile glutaminyl-tRNA synthetase were characterized three classes of mutants, glnT, glnU, and glnR. The glnT and glnU mutants contain elevated levels of tRNAgln, while the glnR mutant possesses elevated levels of glutaminyl-tRNA synthetase. The level of glutamine synthetase, the enzyme responsible for the formation of glutamine, is also derepressed in the glnT and glnR mutants.
0.789368
[Mechanisms of ovulation in mammalian females].
The aim of this review was to briefly recapitulate the most important mechanisms involved in ovulation in the Mammals. The rabbit served as a model for the study of reflex ovulation. The triggering of ovulation by coitus was shown to be dependent on the activation of the hypothalamo-pituitary axis by sensory signals of multiple origin. The fundamental aspects of the hormonal and nervous machinery that governs spontaneous ovulation have been envisaged. The timing of LH ovulatory release and the mechanisms of action of this hormone at the ovarian level have been defined. Evidence was given that steroid hormones from ovarian and/or adrenal origin could evoke or modulate ovulatory processes. The structures responsible for both the tonic and clonic secretion of LH in subprimate and in primate mammals have been localized in the hypothalamus. The nervous endocrine mechanisms involving interactions between LHRH, neurotransmitters, prostaglandins and steroid hormones have been elucidated. Short loop feed back effects of pituitary hormones were shown to control LHRH secretion. Several examples were given attesting that the limbic system, the thalamus and the neocortex on one hand, and the environmental factors, on the other hand, were capable of modulating the activity of the hypothalamic structures implicated in the control of either ovulation or estrous rhythm regulation. An unitarian conception of the ovulatory mechanisms, based on the fact that coital-induced ovulation and estrogen-induced ovulation could occur in spontaneous and reflex ovulators respectively, has been proposed.
0.862187
[Rheological effects of normovolemic hemodilution].
Blood viscosity depends essentially on two factors: shearing rate, since the blood is not a Newtonian liquid and the hematocrit, any fall in which tends to cause the blood to become closer in its behaviour to a Newtonian liquid. Furthermore, these two factors are interdependent. When the hematocrit falls, blood viscosity decreases in greater proportions at lower shearing rates than at high shearing rates. Whilst in vitro, in hemodilution, results vary in relation to the type of replacement solution, in vivo this factor would appear to be of little importance by virtue of the adapted variations in the deformability of the red cells. However, hemodilution results in the greatest relative decreases in blood viscosity at the highest hematocrits. Below a hematocrit of approximately 30 p. cent, the gain in terms of viscosity is very low. This figure would appear to be the ideal hematocrit level from a rheological standpoint. An additional rheological advantage is provided by hemodilution the instability of red cell rouleaux, which are in fact created more readily in areas where shearing rate is low. All of these rheological changes explain the hemodynamic consequences.
0.808319
Evidence for a strong non-adrenergic component in the motor transmission to the rabbit vas deferens.
Isolated vas deferens preparations from 16 rabbits of the New Zealand white strain were subjected to electrical and chemical excitability under physiological conditions and under the influence of drugs. Such smooth muscle fibres were strictly confined to the terminal 3 cm. segments of the distal 'urethral' portions of the vasa deferentia. Intermittent field stimulation, at 60 second intervals, was provided by a stimulator of low output impedance under constant parameters of voltage, pulse width and frequency. Results from this investigation revealed the undermentioned anomalous but distinct findings viz: (a) the presence of a minor adrenergic component which disappeared in phentolamine but remained unaffected by prolonged exposures to phenoxybenzamine; (b) the presence of a predominantly non-adrenergic component which was totally refractory to phenoxybenzamine but suffered a weak diminution in phentolamine; and (c) the picture of a phentolamine-insensitive but twitch-inhibiting effect shared by both tyramine and noradrenaline. Rabbit vasa consistently displayed a remarkable insensitivity to the motor effects of submicromolar concentrations of the putative neurotransmitter substance i.e. noradrenaline. The indirect sympathomimetic agent, tyramine failed to elicit any contractions when employed in doses as massive as 290 micrometers. i.e. 5 x 10(-5) g/ml, except in 2 out of 14 trials when a weak phentolamine-susceptible bursts of single contractions were produced. Thus, the adrenoceptors involved in the mediation of the twitch-inhibiting effects, appear not to behave towards conventional adrenoceptor antagonists in the classified manner. It seems appropriate therefore to invoke an unknown neurotransmitter for the non-adrenergic component in this motor transmission.
0.862826
Collection, storage and transfusion of blood stem cells for the treatment of hemopoietic failure.
Migration of hemopoietic stem cells via the blood to sites of stem cell need is a principle that becomes established during the embryonic development of hemopoiesis and can be observed in the adult whenever bone marrow transplantations are being performed. The regular presence of stem cells in the peripheral blood lends itself to the study of their collection, storage, and use for transfusion purposes in cases of bone marrow failure. Both in dog and in man, granulocyte-macrophage progenitor cells (CFU-C) can be collected by leukapheresis from the blood in large quantities, particularly if the yield is increased by the administration of mobilizing agents such as dextran sulfate, and appear to be an indicator for the presence of stem cells. For collection and storage, a closed plastic bag system has been developed that allows the safe handling of the cells. The loss of CFU-C from freezing and thawing with DMSO as a cryoprotective agent is only 10%-20%. If frozen and thawed mononuclear leukocytes are transfused into 1200 rad whole-body X-irradiated autologous or allogeneic recipient dogs, a hemopoietic take is observed when 0.2 X 10(5) CFU-C are present among the mononuclear leukocytes (MNC). Graft-versus-host disease can be avoided in the allogeneic situation when a purified CFU-C rich cell fraction is being transfused. In man collection and storage of MNC including CFU-C is feasible and may eventually become a therapeutic tool.
0.826404
Studies on experimental growth retardation in sheep. The effect of removal of a endometrial caruncles on fetal size and metabolism.
Experimental intrauterine growth retardation was studied in sheep. Endometrial caruncles (anlagen of maternal cotyledon) were removed before pregnancy and at a second operation, catheters were implanted into the ewe and fetus at 105-135 days of pregnancy. Three groups of fetuses were defined: low birthweight-for-dates (small-caruncle), normal birthweight-for-dates (normal-sized-caruncle) from ewes which had endometrial caruncles removed and the controls. The mean placental weights in these groups were 139 plus or minus 5 g, 283 plus or minus 46 g, 334 plus or minus 22 g respectively. The brains, kidneys and adrenals of the small-caruncle-fetuses were significantly greater in proportion to body weight than in the controls and the appearance of ossification centres was delayed. Arterial oxygen tension was lower and packed cell volume higher in the small-caruncle-fetuses (PaO2 15 plus or minus 0.6 mmHg; packed cell volume 37.3 plus or minus 1.6%) and normal sized caruncles (PaO2 20.7 plus or minus 1.2 mmHg; packed cell volume 35.2 plus or minus 0.7%) than in the controls (PaO2 23.2 plus or minus 0.7 mmHg; packed cell volume 29.8 plus or minus 0.7%). Plasma concentrations of glucose (0.65 plus or minus 0.12 micromol/ml), lactate (0.9 plus or minus 0.1 micromol/ml) and pyruvate (0.08 plus or minus 0.025 micromol/ml) were lower in small-caruncle fetuses than in the control fetuses (glucose 1.05 plus or minus 0.06 micromol/ml, lactate 1.83 plus or minus 0.7 micromol/ml, pyruvate 0.21 plus or minus 0.06 micromol/ml). The corresponding values for the normal-sized-caruncle fetuses were glucose 0.71 plus or minus 0.12, lactate 1.18 plus or minus 0.7 and pyruvate 0.12 plus or minus 0.03 micromol/ml. The plasma concentration of alanine in the small-caruncle-fetuses (0.25 plus or minus 0.09 micromol/ml) was higher than in the normal-sized-caruncle (0.073 plus or minus 0.009 micromol/ml) or control fetuses (0.12 plus or minus 0.013 micromol/ml). The results indicate that fetal growth retardation due to restriction of placental growth after removal of endometrial caruncles is associated with chronic hypoxaemia, polycythaemia and hypoglycaemia. The restriction of nutrient supply probably accounts for the altered pattern of fetal growth but the relative importance of the changes observed remains uncertain.
0.912444
Suppression of graft-versus-host reaction by preincubation of the graft with an antitumor protein, neocarzinostatin.
The immunosuppressive activity of neocarzinostatin, an antitumor antibiotic with a high molecular weight, was demonstrated, as measured by the local and systemic graft-versus-host reaction in rats. The preincubation of parental strain lymphocytes with doses more than 1 micrograms/ml of neocarzinostatin for at least 10 min at 37 degrees C resulted in the marked suppression of the popliteal lymph node enlargement, when injected subcutaneously into the hind footpads of F1 hybrid rats. The suppressive effect was temperature-dependent and irreversible, because the neocarzinostatin (1 microgram/ml) pretreatment of parental lymphocytes at 4 degrees C was not effective in the suppressive activity, and the reincubation of cells after the removal of the drug from the culture did not result in demonstrable changes in the degree of suppression. The neocarzinostatin pretreatment does not result in visible changes in the oxygen consumption rate and viability of cells in vitro or in the distribution pattern within a regional lymph node, indicating that treated cells may retain the same viability and migration capacity in vivo as do untreated cells. Furthermore, the drug pretreatment resulted in the complete prevention of runting syndrome, when treated parental lymphocytes were injected intravenously into F1 hybrid rats.
0.839035
Recovery of the gastric mucosa from bile-induced injury.
Bile salts are known to injure the gastric mucosa and may be involved in the pathogenesis of gastric stress ulceration, a feared sequela of shock. Although the induction of bile injury to the stomach has been extensively studied, recovery from such an injury has not. In the studies reported here the period after removal of bile was examined to see whether the mucosa could return to pre-bile-exposure status under various circumstances. Recovery from a bile salt-induced injury was studied in three mongrel dogs with Heidenhain pouches. Net acid back diffusion (NABD) was measured with a recirculating system incorporating a pH stat and was measured with a recirculating system incorporating a pH stat and autoburette, and transmucosal electrical potential difference (PD) was measured by usual methods. The effects of exposure to 5 mM taurodeoxycholate at pH 2 for 30 minutes were studied. This exposure increased net acid back diffusion from 23 +/- 5 to 184 +/- 16 micro Eq/10 min (P less than 0.01) and reduced PD from 56 +/- 2 to 18 +/- 2 mV (P less than 0.01). After injury the pouches were copiously irrigated with saline to remove bile, and then recovery was observed as the pouches were perfused with pH 1, 2, or 7 HCl solution made isotonic with NaCl. The recovery values were compared with the same dog's preinjury values at the same pH perfusion. The data showed that at pH 2 and pH 7, PD and NABD returned to preinjury levels within 90 minutes after bile injury. At pH 1, however, recovery did not occur. The pH dependence of recovery from bile-induced injury may have relevance to patients with episodic reflux of bile into the stomach.
0.897651
beta-Adrenoceptor blockers in the treatment of hypertension.
Clinical drug trials have shown that pindolol, timolol and sotalol are effective hypotensive agents in Nigerians with mild to moderate hypertension (standing diastolic blood pressure below 120 mmHg). There was no significant difference between the three beta-blockers with respect to their antihypertensive effect irrespective of differences in their other pharmacological actions. There was also no correlation between the hypotensive effect of the drugs and the initial blood pressure. Timolol at 30 mg daily had an additive effect to the hypotensive action of binazine, a peripheral vasodilator. Increasing the dose of timolol to 60 mg daily did not produce further fall in the blood pressure. Pindolol at a dose of 30 mg per day also had an additive effect to the hypotensive action of the thiazide diuretics, methyldopa and debrisoquine. There was no significant difference between the hypotensive effect of sotalol and that of methyldopa. The three beta-blockers produced no side effects. This was considered to be a distinct advantage over most of the drugs currently available for treatment of hypertension in Nigeria.
0.790638
GH secretion in two siblings with Laron's dwarfism: the effects of glucose, arginine, somatostatin, and bromocryptine.
The secretion of GH in two siblings with clinical dwarfism and high GH plasma levels (the mean of several basal values; 233.83 ng/ml in patient A and 178.16 in patient B has been studied with several dynamic tests. An arginine infusion increased GH levels in both cases (+193.55% for A, +140.27% for B). No significant modifications were obtained with oral glucose tolerance test +18.70% for A, +24.32% for B). A bolus of somatostatin almost completely prevented the rise in GH levels in response to arginine. Pretreatment with bromocryptine clearly increased basal GH plasma levels (A, +58.66%; B, +56.03%) and the response to arginine. As in the case of a normal hypothalamus, the hypothalamus of Laron's syndrome responds to arginine and bromocryptine, with GH elevations. Somatostatin suppresses GH levels. A lack of response to glucose can be considered as a nonspecific effect of the very low biological activity of the stimulus in a hyperstimulated hypothalamus. We suggest that GH secretion by the hypothalmo pituitary system in Laron's syndrome is normal, and that GH hyperproduction may be due to a generalized defect in GH receptors or to the low levels of somatomedin.
0.940107
Failure of total calcium corrected for protein, albumin, and pH to correctly assess free calcium status.
The clinical effectiveness of published algorithms in correcting serum total calcium (CaT) for the effects of protein, albumin, and pH was tested. Corrected calcium (CaC) values obtained by 13 of these methods were compared with values of measured free calcium (CaF) in 55 samples from normal controls and 404 samples from patients with various disorders of calcium metabolism. Three criteria were used to compare either CaC or CaT with measured CaF: 1) the correlation coefficient, 2) the average absolute deviation from measured CaF of the values of CaF predicted by the linear regression of CaF on each CaC, and 3) the number of samples in which CaC or CaT gave a different impression of normality than measured CaF. Application of the 13 published algorithms produced varied results, but none produced substantially better agreement between CaC and CaF than was found between CaT and CaF. The application of additional algorithms derived by multiple linear regression using our data base gave slightly better results than any of the published algorithms, but many values of CaC remained which were disparate from the measured value of CaF. Correction of measured total calcium by using other concurrently obtained chemistry values does not seem to adequately predict calcium status as measured by free calcium.
0.886916
Regulation of accumulation and turnover of an inducible glutamate dehydrogenase in synchronous cultures of Chlorella.
Earlier studies indicated that the gene of an ammonium-inducible glutamate dehydrogenase (GDH) was inducible throughout the cell cycle and was expressible shortly after replication early in the S-phase in synchronous Chlorella cells growing at a rate of 13% per h in the absence of inducer. In the present study, synchronous cells cultured at the same growth rate in the continuous presence of inducer accumulated this enzyme in a linear manner, with a positive rate change observed late instead of early in the S-phase. At a growth rate of 26% per h, the positive rate change appeared to be displaced to 1.5 h before the S-phase in the next cell cycle. With 2'-deoxyadenosine, an in vivo inhibitor of deoxyribonucleic acid (DNA) synthesis, the magnitude of the positive rate change was shown to be proportional to the relative increase in DNA in the previous cell cycle. Collectively, these data support the idea that expression of newly replicated genes of this enzyme can be delayed into the subsequent cell cycle in cells in the continuous presence of inducer. Studies with cycloheximide indicated that the inducible GDH and another GDH isozyme were stable in fully induced cells in the absence of protein synthesis. However, after ammonium was removed from the culture medium, the activity of the inducible GDH decreased rapidly in vivo, with a half-time of 5 to 10 min at 38.5 degrees C, whereas the rate of accumulation of the other GDH isozyme did not change. Addition of cycloheximide, at the time of inducer removal, prevented this loss in activity of the inducible GDH. The inability to rescue the activity of the inducible GDH, by readdition of ammonium during the deinduction period, indicates that this enzyme probably underwent irreversible inactivation and/or proteolytic degradation.
0.893782
Purification and properties of beta-lactamase from Bacteroides fragilis.
Beta-Lactamase activity was detected either biologically or using the chromogenic cephalosporin 87/312 in 20 clinical isolates of Bacteroides fragilis with penicillin G minimal inhibitory concentrations of 10 to 100 micrograms/ml. Strain AM78 (minimal inhibitory concentration, greater than 1,000 micrograms/ml) was used to optimize the conditions for production, assay, and storage of the enzyme. The enzymes are cell associated, with less than 1% of activity being found in culture fluids during growth, and can be released from the cell surface by modified osmotic shock procedure. This procedure causes concomitant release of cyclic phosphodiesterase activity. Substrate profiles and the effects of inhibitors were determined for enzymes partially purified by osmotic shock release and gel filtration. The enzymes are cephalosporinases with some penicillinase activity and are inhibited by p-chloromercuribenzoate, cloxacillin, and carbenicillin. The molecular weight, as determined by gel filtration, is 29,000 to 31,000. A method for the purification of the beta-lactamase from strain AM78 is described: the specific activity of the purified enzyme was 3,424 U/mg, about 3,000-fold that of the crude, cell-associated enzyme.
0.870505
Comparative study on the activity, pH optimum and thermal stability of some glycosidases and acid phosphatase from pig and mule leukocytes.
1. alpha-D-mannosidase, beta-D-galactosidase, alpha-L-fucosidase, beta-N-acetylgalactosaminidase, alpha-D-glucosidase and acid phosphatase activities were studied in circulating blood leukocytes from Sus scropha var. domestica L. (pig) and Equus asinus x caballus (mule) by spectrophotometric procedures using p-nitrophenyl derivatives as substrates and three different buffer solutions. 2. The highest specific activity corresponds to acid phosphatase. The specific activities of the glycosidases, all relatively close together in all cases, were low in comparison with that of phosphatase. 3. Generally, each of the above-mentioned enzymes shows one common peak for the pH optimum between 3.5 and 6.0, except alpha-D-glucosidase, which shows two peaks. 4. The pH optima values are generally similar in three buffer solutions employed. 5. Specific activities of the studied enzymes show a parallelism in leukocytes from both pig and mule. Also, this parallelism is observed in their pH optima values. 6. Thermal stability of alpha-D-mannosidase is high whereas that of acid phosphatase is low, in both materials. For other enzymes, differences in the thermal stability was observed according to their source.
0.910396
[Effect of antianginal drugs on the exertion electrocardiogram].
In order to evaluate the clinical efficacy on penbutolol (Hoe 893 d), a new adrenergic blocking agent, two groups of 10 patients (A & B) with ischemic heart disease were chosen. These were submitted to exercise testing for 3 minutes, and placebos, nitroglycerin, and propranolol were used as reference preparations. As an index of indirect consumption of oxygen we determined the maximum cardiac frequency (MCF), maximum systolic arterial pressure (MAP) and the maximum double product (MDP). An electrocardiographic control of the patients was also included to observe ST segment changes. The patients from group A received 0.8 mg. of nitroglycerin sublingual as the first treatment and 40 mg. of propranolol as the second. The patients from group B received initially a placebo P.O. and then 25 mg. of penbutolol P.O. In both groups the exercise testing was repeated 10 minutes after the administration of the first substance and 10 minutes after the second. The results showed that 25 mg. of penbutolol and 40 mg. of propranolol have similar therapeutic effects over the degree, intensity, and duration of the differences in elevation of the ST segment, MCF, MAP, and MDP when you compare the results of their own controls with those obtained with the active principle. There is no significant difference observed in the results obtained in each parameter studied between penbutolol and propranolol. During the period of this clinical study there were no undesirable collateral effects caused by the oral administration of the investigated drugs.
0.767426
Emergence of antibiotic resistance in hospitals, 1935-1975.
A limited review of the changes in susceptibility of common bacterial pathogens to available antibacterial agents is presented. Significant developments in recent years include the following: (1) the emergence of Streptococcus pneumoniae with decreased resistance to penicillin and of some strains resistant to several antibiotics; (2) a decline in prevalence of multi-drug-resistant Staphylococcus aureus after 1960 following their increasing prevalence in the preceding years (these changes were methicillin-resistant (and multi-drug-resistant) S. aureus and the marked differences in their prevalence in different areas (these changes also were related to appearance of new phages in those organisms); (4) an increasing resistance to multiple drugs among enterococci but not among viridans streptococci or among nonenterococcal group D streptococci; (5) the emergence of beta-lactamase-producing Neisseria gonorrhoeae; (6) the emergence and spread of sulfonamide-resistant Neisseria meningitidis; (7) the occurrence of beta-lactamase-producing strains of Haemophilus influenzae and occasional strains resistant to chloramphenicol; (8) the focal occurrence of chloramphenicol-resistant Salmonella typhi in Vietnam and in epidemic form in Mexico; (9) the demonstration of marked differences in prevalence of resistance to multiple drugs in common pathogens to the most widely used antibiotics in different geographic areas. The dominant factor in the emergence and spread of antibiotic-resistant bacterial pathogens, whether in hospital wards or in the community, is clearly the intensive use of the antibiotic agents to which resistance emerges and then spreads.
0.828209
Selective viral immunosuppression of the graft-versus-host reaction.
Graft-vs.-host (GVH) reactivity of parental lymph node (LN) cells was assayed by measurements of 3H-thymidine incorporation in vivo in spleens of irradiated F1 recipients. Preincubation of parental LN cells with vesicular stomatitis virus (VSV) for 2 h at 37 degrees C followed by washing resulted in an 85-90% reduction in splenic radioactivity, as did injection of VSV on days 0-2 after recipients received untreated parental LN cells. In contrast, 3H-thymidine incorporation in the spleens or irradiated F1 hosts was not affected by VSV when F1 bone marrow cells were incubated with the virus. In addition, preincubation of F1 B cells with VSV still allowed these syngeneic B cells to be recruited into proliferation by mitomycin-treated parental LN cells. The inhibitory effect of VSV, thus, seems to be specific for T-cell proliferation. These observations suggest that viral immunosuppression might be capable of being developed into a useful strategy for selective deletion of lymphocytes capable of reacting against histocompatibility antigens and initiating GVH reactions.
0.792274
Molecular characterization of the genomes of actinophages SH3, SH10, SH11, and SH12 infecting Streptomyces hygroscopicus.
Some physico-chemical properties of the DNAs released from the actinophages SH3, SH10, SH11, and SH12 are described. The four phage DNAs have a linear double-stranded secondary structure and are unique with respect to their high G.C contents which, from melting studies and buoyant density experiments, were found to be in the range of 68-73 mol-%. The DNA molecular weights were determined by sedimentation velocity experiments and by electron microscopic length measurements, the mean values of the two corresponding data sets being 34.0 x 10(6) (SH3), 26.7 x 10(6) (SH10), 26.1 x 10(6) (SH11), and 28.7 x 10(6) (SH12) with a mean relative error of +/- 5%. From different observations it was concluded that SH10 DNA, and possibly also SH11 and SH12 DNA, have cohesive ends and can undergo intramolecular or intermolecular association to form ring-like monomers or linear and ring-like multimers. Cleavage of the DNAs of SH3, SH10, SH11, and SH12 by EcoRI restriction endonuclease delivered two, one, zero, and two cleavage sites, respectively, and by BamHI restriction endonuclease eight, zero, zero, and zero cleavage sites, respectively.
0.791122
Histochemical and biochemical investigations of adenosine triphosphatase in vertebrate mixed muscles.
Mammalian and avian muscles were examined histochemically and biochemically to determine the relative contribution of membrane bound (mitochondrial and sarcotubular) ATPases under the same conditions employed for myofibrillar ATPase. For histochemically investigated Ca+(+)-ATPase activity following incubation at pH 9.4 according to the calcium-citro-phosphate technique, avian muscle displayed distinct mitochondrial localization in both dark and light staining fibres. However, mitochondrial localization did not occur in mammalian muscle fibres. Pretreatment of unfixed frozen sections with ouabain, cyanide and acetone did not prevent the reticular distribution in avian muscle fibres. The present study demonstrates that "myofibrillar" localization is achieved by the Ca+(+)-precipitation technique: provided frozen sections are pretreated with cold acetone, fixed in a fixative containing oligomycin or azide and then incubated in a medium containing glycine-NaO H as buffer. Mitochondria prepared by successive mechanical homogenization or by Nagarse treatment plus 2 min homogenization develop different ATPase activities at pH 9.4 7.4 6.0 and 4.35 as well as stimulation by 70 mM Ca++ at these pHs compared to those ATPase activities in the homogenate of mixed hamster hind leg muscles. Glycerol-3-phosphate dehydrogenase and creatine kinase (both located at the outer surface of the inner mitochondrial membrane) and succinate dehydrogenase and glutamate dehydrogenase (localized at the inner mitochondrial membrane and in the matrix resp.) also show different activities in both mitochondria preparations indicating different membrane properties of both mitochondria. Evidence is obtained that using the calcium-citro-phosphate technique at pH 9.4 oligomycin-sensitive and -insensitive ATPases are activated by Ca++ in both mitochondria preparations. Since in muscle homogenate less than 10% of Ca+(+)-stimulated ATPase activity is oligomycin-sensitive, mitochondrial ATPase exhibit only a small portion of total ATPase from mixed hamster hind leg muscles.
0.792667
Gasoline contact burns.
In the past four years, four cases of gasoline contact burns have been treated at the Detroit General Hospital Emergency Department. Signs are erythema and blister formation within 24 hours. Treatment is removal of contaminated clothing and washing the surface with soap and water plus open exposure of the wounds. Renal failure is not caused by skin absorption but may develop following inhalation.
0.822283
Improvement of pancreatic cancer model by modified treatment with N-nitroso-bis (2-oxopropyl) amine.
Comparative studies were conducted in 2 groups of Syrian golden hamsters treated with N-nitroso-bis (2-oxopropyl)amine (BOP) weekly for life (group A) or weekly for 6 weeks (group B), and sacrificed at 2-week intervals. Pancreatic neoplasms developed as early as 8 weeks (group B) and 10 weeks (group A); however, in group B there were fewer, smaller lesions, well-differentiated morphologically. Liver neoplasms occurred only in group A, while gallbladder and kidney tumors were seen in both groups. A lower incidence of pulmonary adenomas was found in group B than in group A, which also had pulmonary carcinomas. The results indicate a further advance in the development of a pancreatic cancer model.
0.81072
Quantitative comparisons of various biological responses of neutrophils to different active and inactive chemotactic factors.
The effects of chemotactic factors on rabbit neutrophils were evaluated measuring cell migration in modified Boyden chambers and under agarose, in lysosomal enzyme release, leukocyte aggregation, and in vivo neutropenia. Chemotactins employed included the complement-derived C3 and C5 fragments, the bacterial chemotactic factor from culture supernatant fluids of Escherichia coli, and the synthetic chemotactic factors Met-Leu-Phe and formyl-Met-Leu-Phe. A consistent parallelism was found in all the leukocyte responses to a given chemotactic factor. In no instance, with any of the five chemotactic factor preparations, did cells responding in one assay system fail to respond in the four other assay systems, suggesting a common event in all of the cell responses. Boyden chamber chemotaxis was consistently the most sensitive assay; the agarose assay was, in general, less sensitive by a factor of 100 fold. Enzyme release approached, in cell sensitivity to chemotactic factors, that of the Boyden chamber assay. In general, in vitro leukocyte aggregation and in vivo neutropenia were considerably less sensitive assays. Chemotactic factor inactivator (CFI) purified from human serum destroyed in parallel all biological activities of C3 and C5 chemotactic factors but had no effect on the bacterial chemotactic factor and the activities of synthetic chemotactic peptides.
0.885737
Enzyme immunoassay of a beta-adrenergic agent using beta-galactosidase as label.
Antisera against tetrahydronaphthalenols, which are conformationally rigid derivatives of adrenergic catecholamine, were produced in rabbits immunized with trans-5-amino-6-hydroxy-2-isopropylamino-1,2,3,4-tetrahydronaphthalene-1 -ol (I) conjugated to succinylated bovine serum albumin at the C5 position on the tetralin ring. Antisera were screened by immunodiffusion and further characterized by passive hemagglutination assay using erythrocytes sensitized with trans-I-ovalbumin conjugate and by enzyme immunoassay using trans-I-beta-galactosidase conjugate. Cross-reactivity studies indicated that the antiserum was highly specific for the tetralin structure and for substitution at the C2 position. The antiserum also selectively discriminated the stereoisomers about the C1-C2 bond. The anti-trans-I serum was used to develop EIA for trans-5-hydroxymethyl-6-hydroxy-2-isopropylamino-1,2,3,4-tetrahydronapht halene- 1-ol (IIb), which exhibited strong beta-stimulating activity fairly selective to tracheal muscle, since it recognized trans-IIb to the same degree as trans-I. The assay could detect as little as 100 pg of this compound. The mean recovery of trans-IIb added to plasma was 105%, and values for plasma trans-IIb determined by this immunoassay correlated well with those determined by gas chromatography-mass spectrometry.
0.786441
Effect of cardiotonic and vasoactive drugs on transmural flow distribution and ventricular volume in the fibrillating heart on cardiopulmonary bypass.
Subendocardial hemorrhagic necrosis in an important cause of death following cardiopulmonary bypass. The transmural distribution of flow across the left ventricle (LV), septum (SP), and right ventricle (RV) is a complex interaction of vascular resistance and myocardial compressive resistance. We studied the change in transmural blood flow in LV, SP, and RV, and left ventricular volume, following administration of cardiotonic and vasoactive drugs in the fibrillating heart. The drugs studied included calcium with and without ATP-induced vasodilation, isoproterenol, epinephrine, angiotensin, and ouabain. Calcium produced underperfusion of LV subendocardium with or without previous ATP vasodilation. Isoproterenol also caused underperfusion of LV subendocardium. Both calcium and isoproterenol decreased ventricular volume. Angiotensin increased resistance in the subepicardium and increased flow in the subendocardium, with no change in ventricular volume. Epinephrine and ouabain caused no consistent changes in transmural flow. The decreased ventricular volume produced by calcium and isoproterenol restricts flow in the subendocardium because of increased compressive resistance. Increased subendocardial flow with angiotensin indicates that subepicardial vasodilation in the fibrillating heart causes epicardial "steal," which contributes to subendocardial ischemia.
0.881035
Molecular organization of rat prolactin granules. I. In vitro stability of intact and "membraneless" granules.
Studies carried out on a number of secretory cell systems suggest that the specific cytoplasmic granules in which the secretion products are stored before their release are complex organelles which can possess a distinct molecular organization. For instance, it has been reported that in some granules the segregated secretion products are organized into crystalline structures (1-3) or large intermolecular aggregates (4-8). It is likely that all phenomena of this type are favorable to the economy of the cell, in the sense that they reduce the energy required for storage of the secretion products. The prolactin (LTH) granules of the rat pituitary possess a number of morphological features which strongly suggest that the molecules(s) of their content might be arranged in a relatively stable structure. Thus, these granules are remarkably polymorphic in shape, and their membrane is usually separated from their content by a clear space. Furthermore, identifiable LTH granules devoid of their membrane are often seen in the pericapillary space, suggesting that upon discharge by exocytosis they are dissolved only slowly (9). However, no studies specifically concerned with the mechanisms of LTH storage have been reported so far. In order to obtain some information on this question, we have studied the behavior of isolated granule fractions incubated in vitro under a variety of carefully controlled experimental conditions.
0.8637
Expression of specific clones during B cell development.
The expression of DNP- and TNP-specific B cells in spleens of neonatal BALB/c mice was analyzed by the in vitro splenic focus technique. B cells of these specificities were found to be present in slightly higher frequency in neonatal than in adult spleens. The parameters of stimulation of neonatal B cells were similar to those of adult B cells but the antibody-forming cell progeny of neonatal B cells produce predominantly gammaM rather than gammaG antibody and produce less antibody than the progeny of adult B cells. Isoelectric focusing analyses of monoclonal antibodies derived from neonatal B cells stimulated in vitro with DNP or TNP revealed that over 90 per cent of the antibodies could be identified as belonging to one of six predominant clonotypes, three specific for DNP and three for TNP. While individual neonates rarely expressed all of the predominant clonotypes, B cells of each of the six clonotypes were found in several donors. When B cells of a given predominant clonotype were present in an individual many such B cells could be found and in many cases the entire DNP- or TNP-specific B cell population of an individual could be accounted for by B cells of a single clonotype. These findings are discussed in terms of the diversity of clonotype specificities available in neonates, the kinetics of development of cells within a clonotype, and factors that may play a role in controlling the expression of B cell clones.
0.851808
Intracardiac electrography in children and young adults.
The interpretation of IE recorded in children has been hampered by a lack of agreement regarding normal values. We recorded IE in 158 children and young adults (ages, three days to 33 years) to define the various conduction intervals in normal and disease states. The HBP was recorded in 156 subjects. In 85 subjects with normal conduction indicated by surface ECG, including 19 subjects with normal hearts, there were no statistically significant age-related differences in internodal, A-V nodal, or His-Purkinje conduction intervals. Therapeutic levels of digitalis did not alter the conduction intervals. In 11 subjects with first degree A-V block and in five subjects with congenital complete A-V block, the site of block as determined by IE could not be predicted from the surface ECG. No abnormalities in conduction intervals were found in 18 subjects with right bundle branch block (surgically induced in 17 cases). Intracardiac electrography with recording of the HBP was found to be a safe, informative technique for electrophysiologic investigations in children and young adults.
0.824924
"Pure" monocytic or histiomonocytic leukemia: a revised concept.
In a series of 130 cases of acute leukemia studied by cytochemical staining techniques, 10 cases cytochemically diagnosed as "pure" monocytic leukemia were seen. Cytochemical staining of bone marrow aspirates from these patients revealed all leukemic cells to be Sudan black negative. No positive reactions were observed for peroxidase or naphthol AS-D chloroacetate esterase. All cases demonstrated strong alpha-naphthyl acetate esterase positivity; and fluoride-inhibited naphthol AS-D acetate esterase positivity was observed in 8 of 9 cases tested. The P.A.S. reaction showed diffuse fine to coarse granules. Oil red O stain was positive in 8 of 9 cases, and the beta-glucuronidase activity was strong in 5 of 9 cases. Light microscopy revealed cells with monocytic or histiocytic morphology. Electron microscopic studies in 2 cases demonstrated features consistent with leukemic monocytic or histiocytic morphology; none was suggestive of granulocytic or lymphocytic leukemia. Five of 6 patients treated with drug regimens including prednisone and vincristine entered a complete remission; the other obtained a partial remission. Two patients achieved complete remission after treatment with Adriamycin, 1 following a relapse. Three patients who received cytosine arabinoside as their only therapy died soon after treatment was commenced. It is suggested that the cytochemical similarity but morphological differences in those patients may be objectively used to group them as cases of histiomonocytic leukemia.
0.831313
Microfluorometric comparisons of heat-induced nuclear acridine orange metachromasia between normal cells and neoplastic cells from primary tumors of diverse origin.
Nuclear fluorescence metachromasia of heated fixed cells subsequently stained with acridine orange was compared in smears and isolated nuclei of various types of primary tumors and normal cells from the tissues that gave rise to the tumors. The ratios of fluorescence emission at 590 and 530 nm reflect the thermal stability of chromatin in situ. The results show that the mean thermal stability of the chromatin in neoplastic cells was lower than the stability of their normal counterparts in all cases. This was found in both spontaneous and chemically induced tumors as divergent in type as a dog vaginal tumor and murine lymphocytic leukemia. These data, together with our previous observations in other neoplastic systems, indicate that reduced chromatin thermal stability may be a general characteristic of cells that have undergone neoplastic transformation and is not confined to rapidly growing tumors. The present investigation identifies the sources of variability encountered in measuring fluorescence metachromasia in slide preparations, and methods of minimizing this variability for potential cytodiagnostic application are discussed.
0.878317
Comatose state maintained during eight years following a vascular ponto-mesencephalic lesion.
A 24-year-old man survived for 8 years after a vascular lesion of the pons and midbrain. During these years a subresponsive comatose state with neurological signs extending from the oculomotor nuclei to the trigeminal and facial nuclei levels was present. A decorticated type of rigidity, with bilateral paralysis of the limbs accompanied by pyramidal signs, was also present. The EEG during the first months showed slow activity which afterwards gradually changed towards fast and alpha activities, maintained in the course of the years. The pathological diagnosis was a fibrous endarteritis, mainly in the territory of the basilar and vertebral arteries. The pons and midbrain, presenting a large cystic infarct, were serially studied to determine the anatomical extent of the lesion. After reviewing other examples from the literature, the clinical features of our case are discussed. The evolution of the EEG is related to different structures of the ponto-mesencephalic region with different functional activities.
0.82485
On the relation between the EMG frequency spectrum and the duration of symptoms in lesions of the peripheral motor neuron.
Two samples of muscles, one with proved, the other with doubtful neurogenic lesions have been investigated with EMG frequency analysis. Confirming reports from previous authors it was possible to show that a large proportion of muscles with proved lesions have a displacement of the frequency spectrum towards low frequencies("bass" displacement). The displacements were principally found in cases with old lesions. In a group of cases in which the symptoms had lasted a few months only a displacement towards high frequencies ("descant" displacement) was revealed. In view of these findings it was surprising to note a relatively large number of spectra with bass displacement in a group of cases in which the symptoms had lasted less than one month. The probable explanation of this is to be found in the fact that the muscles with bass displacement in this group principally belonged to patients with systemic diseases such as diabetes, alcoholism, renal insufficiency, itc., who quite possibly might have had earlier neurogenic lesions with a subclinical course. In the group of muscles with doubtful neurogenic lesions there was also found a comparatively large number of bass-displaced spectra. It was possible to show that here also there was a large number of patients with systemic diseases.
0.835298
Far-field recorded frequency-following responses: correlates of low pitch auditory perception in humans.
The recent demonstration that auditory frequency-following responses (FFR) can be recorded by signal averaging from the human scalp, opened the way for studies correlating FFR with auditory experience. This report describes FFR amplitude changes as a function of stimulus intensity and the addition of masking noise. The first experiment revealed a high degree of consistency both within and across subjects in the latency, phase and waveform of averaged FFR. This experiment also demonstrated a monotonic relationship between average FFR amplitude and stimulus intensity between 40 and 65 dB SL. Results of the second experiment showed a close correlation between the detectability of a tone in a noise masker and FFR amplitude. FFR amplitude diminishes precipitously as noise intensity approaches or exceeds the threshold for masking of the tone. These results are interpreted as emphasizing the role of neural periodicity mechanisms in the preception of low frequencies.
0.860939
[An electrophysiological study of direct occipito-frontal connections in centrum semi-ovale of Papio papio].
1. Evoked responses to single visual stimuli (VEP) and driving by intermittent light stimulation (ILS) were recorded with macroelectrodes from the central white matter (centrum semiovale) of 12 Papio papio baboons. 2. Two types of VEP were identified: VEPs with constant morphology, localized in the long associative bundles connecting the occipital, temporal and frontal lobes; VEPs with variable morphology and without any preferential localization; these probably originate from other types of fibres also belonging to the centrum semi-ovale. 3. Concerning the long associative bundles which have been individualized, they might be the equivalent of the occipito-frontal and the superior and inferior longitudinal bundles well known in man. The fusion frequency observed in these bundles during ILS increases from the frontal to the occipital lobe, because of their involvement (particularly in the parieto-temporal region) with other fibres of the centrum semi-ovale also likely to be driven by ILS. The existence of driving by ILS in these bundles demonstrates an activation of the frontal lobe by visual impulses.
0.793642
Low-renin hypertension: nephrosclerosis?
A substantial group of patients with essential hypertension have abnormally low renin levels which respond poorly to stimulation. Important differences in response to therapy and in prognosis have been described between these and other hypertensive patients. It is suggested that the vascular changes of nephrosclerosis, which may be seen in both hypertensive and normal subjects, result in a reduction of afferent arteriolar distensibility, with impairment of basal renin secretion and responsiveness. This hypothesis accords with both of the known clinical characteristics of low-renin hypertension and with the known effect of arterial changes upon the activity of other baroreceptors.
0.878072
Leukaemia and lymphoma patients interlinked by prior social contact.
Patients with either leukemia or lymphoma were asked if they had close personal associations with other patients before the onset of disease. Iinitial interviews indicated that several patients could be interlinked into social clusters. Tumour-registry records were used to contact each patient (or a surviving relative) diagnosed during the years 1964-73 in three areas of West Virginia. Close personal associations, antedating the onset of disease in 1 or both individuals of each linkage pair, were detected in 14 of 23 (61%), 14 of 22 (68%), and 6 of 8 (75%) patients from these three areas during this ten-year period. In addition, among 28 randomly selected patients with Hodgkin's disease from various parts of the United States, 10 (36%) had direct or indirect close personal associations with 17 other patients with leukemia or lymphoma. Patients with leukemia or lymphoma frequently are interlinked by prior close personal associations to other patients with these diseases.
0.863501
Increased incidence of adenocarcinoma of uterine cervix.
A greater than expected incidence of adenocaricinoma of the uterine cervix is reported. Among 41 cases of cervical carcinoma, 14 (34%) were adenocarcinoma. Clinicopathologic data for these cases are summarized. Eleven of the 14 cases were pure adenocarcinomas; 3 were mixed adenosquamous carcinoma. The value of cytopathology is demonstrated in the 7 of 9 pretreatment cervical cytologies whereby adenocarcinoma was indicated (an accuracy rate of 78%). The other 2 revealed abnormal cells in which malignancy was a possibility. Three cases clinically were initially considered endometrial adenocarcinoma, but by our classification criteria, including Alcian blue staining for cervical mucin content of acid mucopolysaccharide, they were more specifically identified as primary endocervical in origin.
0.861021
Mucosal histochemistry in secretory otitis.
Mucosal biopsies were taken from 20 ears with secretory otitis media (glue ear) and histochemical stainings were made for comparison with data obtained from biochemical analysis of the fluids. Acid phosphatase, lactate dehydrogenase (LD), and malate dehydrogenase (MD), the activity of which in the ear fluids was 20 to 30 times higher than in serum, were found to appear as strong precipitates in the middle ear epithelium, particularly in the top layer. Alkaline phosphatase activity was only exceptionally seen in the epithelium but appeared in the capillaries and histiocytes. Nonspecific esterase appeared irregularly in the epithelium and regularly in histiocytes. The latter two had lower activities in ear fluids than in serum. Epithelial secretory cells and subepithelial glands and cysts showed strong alcian blue (AB)-positive staining. Positive material appeared also in the cytoplasm of the epithelial cells and in the intercellular substance. Distinct PAS-positive staining appeared in the columnar epithelium and particularly in the free mucus on top of the epithelium but was less promounced in the glandular structures and absent from the cysts.
0.823784
Corticothalamic neurons and thalamocortical terminal fields: an investigation in rat using horseradish peroxidase and autoradiography.
Subsequent to thalamic injections in rats of horseradish peroxidase (HRP) alone or HRP and [3H]leucine in combination, the cells of origin of the corticothalamic projections and the terminal fields of the thalamocortical projections were identified. HRP-labeled corticothalamic neurons were uniformly found in layers V and VI. They were medium to small in size and always pyramidal in shape with the larger neurons being found in layer V. On the other hand, 3 different patterns for the distribution of thalamocortical terminal fields were observed. The autoradiographic material indicated that in prefrontal cortex the bulk of thalamocortical fibers terminate in layer III while in motor cortex they terminate primarily in layer V. A third pattern was shared by temporal, occipital and parietal cortex where the bulk of thalamocortical fibers terminate preferentially in layer IV. The data derived from the rats which had received thalamic injections of HRP and [3H]leucine in combination indicated that the connections between cortex and thalamus are in general reciprocal. These results are discussed with regard to earlier studies using classical or more recently developed neuroanatomical methods.
0.915051
Purification, characterization and radioimmunoassay of thyrocalcitonin from rat thyroid glands.
A highly purified preparation of rat thyrocalcitonin (TCT) has been obtained from lyophilized thyroid glands by gel chromatography following acid-acetone extraction. Biological activity of Sephadex G-50 eluates appeared in two peaks. The TCT in the major peak was concentrated, and applied to a Bio-Gel P-6 column, and a major protein peak was eluted which coincided with TCT activity. Potency, estimated by bioassay in rats, increase approximately 3500-fold from 0.075 MRC U/mg lyophilized glands to 250-400 MRC U/mg in the final product. The overall yield of TCT activity was about 36%. The purified product was characterized by chemical procedures and evaluated for its antigenic properties and use for radioimmunoassay. The purified rat TCT was used both labeled with 125I and as unlabeled standard. The following results were obtained: 1) Guinea pig antisera to either human or rat TCT were capable of binding 125I-rat TCT or 125I-human TCT; 2) Using either 125I-human or 125I-rat TCT and antisera to either TCT, pg amounts of rat and human TCT reacted in the assay while ng to mug amounts of salmon calcitonin or porcine TCT failed to react; 3) Using 125I-rat TCT and antisera to human or rat TCT, synthetic C-terminal (10-32 or 22-32) fragments of human TCT reacted well, while N-terminal (1-18) or desamide (1-32) derivatives reacted poorly or not at all; 4) Rat TCT was easily detected in normal thyroid venous plasma (5-10 ng/ml) and thyroid gland extracts (similar to 1 mug/gland) but not in peripheral blood; 5) Bioassay and radioimmunoassay of rat thyroid extracts (N equals 18) showed good agreement (r equals 0.86, p less than 0.001). The results support the idea that rat TCT is closely related to human TCT, indicate that major antigenic determinants reside in the C-terminal portion of the molecule, and show that antisera to either human or rat TCT can be used to measure rat TCT.
0.906827
Serological analysis of human deoxyribonucleic acid polymerases. Preparation and properties of antiserum to deoxyribonucleic acid polymerase I from human lymphoid cells.
The preparation and properties of an antiserum to human DNA polymerase I (6 to 8 S) are described. Care was taken in the purification of the antigen to remove certain other DNA polymerases found in human cells. An incubation of antigen and antiserum lasting about 48 hours is necessary to achieve maximal inhibition. About 1 mug of the antipolymerase immunoglobulin G, prepared in rats, neutralizes 60% of the activity present in 54 ng of the enzyme. Tritrations varying both antiserum and enzyme demonstrate clear regions of antigen and antibody excess. Inhibition of enzyme activity is about the same whether the templateprimer is (dA)n-(dT)12-18, or partially digested DNA. An assay was developed which measures the remaining activity in the supernatant after precipitation of enzyme-antibody complexes with goat anti-rat immunoglobulin G. In this assay, 2.2 mug of the antipolymerase immunoglobulin G quantitatively bind 33 ng of DNA polymerase I. With use of the direct neutralization assay and the immuno-precipitation test, we found little, if any, antigenic relationship between DNA polymerase I and DNA polymerase II (3.4 S). Similarly, little, if any, relationship was found to the DNA polymerases from five RNA tumor viruses. The activities of RNA-directed DNA polymerases from the blood leukocytes of two patients with acute myelogenous leukemia and from the placentas of rhesus monkeys were not inhibited in neutralization assays which were shortened because these enzymes were thermolabile. In identically shortened neutralization assays, the antipolymerase immunoglobulin G neutralized up to 76% of the activity of DNA polymerase I. In addition to its utility in distinguishing cellular DNA polymerases, the rat antiserum should be useful reagent for testing of novel DNA polymerases isolated in small quantities from human tumors for contamination with DNA polymerase I. This enzyme is present in abundance in proliferating tissue and often confuses the biochemical characterization of these novel enzymes.
0.871295
Catabolism physical, and immunologic properties of endocytosed isologous and heterologous iota-globulins by mouse macrophages.
The catabolism of completely endocytosed isologous and heterologous gamma-globulins by mouse macrophages was studied in vitro. Mouse, human, and rabbit 125-I-IgG were coupled to mouse, human, or sheep erythrocytes either as antibodies or by covalent binding. They were exposed to macrophages for 1 hr and the non-endocytosed erythrocytes were then removed with a Ficoll gradient centrifugation. Catabolism was evaluated after 2, 5, and 18 hr in culture by measuring the radioactivity released into the culture medium as well as the radioactivity that remained associated with cells. It was found that all iota-globulins were catabolized in a similar fashion, and that the type of carrier erythrocytes (isologous or heterologous) had no influence on catabolism. Some of the material that remained associated with macrophages was on the cell membrane and could be removed by trypsin. Some of the material that was released by macrophages was completely degraded but some was either not degraded or only partially degraded. Sucrose density gradient analysis and SDS-polyacrylamide gel electrophoresis showed that this material had kept some physical properties of native iota-globulins. It was also found with the antigen-binding inhibition test and incubation with erythrocytes that the released material contained molecules carrying Fab determinants and was able to bind specifically to erythrocytic antigens. Taken together, these observations show that iota-globulins phagocytosed in the form of antigen-antibody complexes are only incompletely degraded and that the material associated with plasma membrane of macrophages or found in the culture medium is a product of cell catabolism.
0.928895
Comparison of the ocular effects of circulating endotoxin and immune complexes: role of vasoactive amines.
Both bacterial endotoxin and soluble immune complexes (BGG-anti BGG) injected i.v. in rabbits produce an alteration in ocular vascular permeability confined primarily to the vessels of the iridial portion of the ciliary processes. These effects have been measured by the ocular accumulation of 125I-albumin relative to cardiac plasma. Ten micrograms per kilogram of Escherichia coli bacterial endotoxin (055:B5) produce a consistent alteration in ocular vascular permeability over a 90-min period after injection. Fifty to 100 mmug/kg of endotoxin result in a prolonged effect that is maximum 4 hr after injection. Large quantities of immune complexes (BGG-antiBGG) prepared in 20 to 25 times antigen excess produce an anaphylaxis and approximately a 70% reduction in platelets and CH50. The alteration in ocular vascular permeability is half as great as that produced by 10 ug/kg of endotoxin over the 90-min period after their injection. A combined treatment with antihistamine, pyrilamine maleate, and antiserotonin, methysergide maleate, results in a significant reduction in ocular 125I-albumin in normal animals, virtually prevents the ocular effect of immune complexes, and reduces the average effect of endotoxin by 30%. Increasing the quantities of injected antihistamine and antiserotonin does not have a further effect on the response to 10 ug of endotoxin.
0.859546
Maturation of B lymphocytes in the rat. II. Subpopulations of virgin B lymphocytes in the spleen and thoracic duct lymph.
Thoracic duct and spleen cells of normal (unimmunized) adult rats were fractionated according to size by 1 times G velocity sedimentation. Fractions were tested for their ability to restore the adoptive antibody response of irradiated hosts to horse spleen ferritin. A constant source of T cells (small numbers of unfractionated thoracic duct cells) was added to each fraction in order to monitor the B cell activity of the latter. Although large and small cell fractions of the spleen showed restorative activity, only the small cell fractions of the thoracic duct lymph showed activity. The turnover rate of the spleen cell fractions was determined by treating donors with high specific-activity 3H-thymidine for 48 hr before splenectomy. Rapidly dividing cells are preferentially killed by this treatment. The results suggest that a considerable proportion of large, intermediate, and small virgin B cells turn over within 48 hr. The cell surface of the various spleen cell fractions was examined for the presence of immunoglobulin (Ig) and a receptor for complement. The percentage of Ig-bearing cells in the large cell fractions was similar to the percentage of cells bearing IgM and a receptor for complement. However, the majority of Ig-bearing cells in the small cell fractions did not show the latter two surface markers. Experiments with the fluorescence-activated cell sorter showed that the large functionally active B cells bore surface IgM. The experimental findings suggest that there are subpopulations of virgin B cells in the spleen of the adult rat which differ with respect to size, migration pattern, turnover rate, and cell surface characteristics. The relationship of these cells to one another is discussed in the framework of an antigen-independent model of B cell maturation in the rat.
0.84224
IgA and IgA diphtheria antitoxin responses from human tonsil lymphocytes.
Human tonsil lymphocytes were stimulated with diphtheria toxoid and then cultured in a Marbrook culture system so that antibodies could be measured in the culture supernatant. Specific antibodies were measured with excess radiolabeled antigen and antisera specific for each immunoglobulin class. Good IgG and IgA diphtheria antitoxin responses have been obtained and responding culture supernatants were shown to neutralize toxin. The relationship between antitoxin response in vitro and immunization of donors with toxoid was investigated. It was found that at least two immunizations after the age of 6 months were necessary to prime the tonsils for an in vitro antibody response. The IgG and IgA in culture supernatants were demonstrated by immunodiffusion and were measured by radioimmunoassay. By sucrose density gradient ultracentrifugation, it was shown that 40% of the IgA produced in the cultures was greater than 7S. Evidence was obtained that neither the IgA nor the specific IgA antitoxin bears secretory piece. It appears that human lymphocytes from tonsils produce polymer IgA in vitro without secretory piece.
0.911474
An attempt to identify the intestinal receptor for the K88 adhesin by means of a haemagglutination inhibition test using glycoproteins and fractions from sow colostrum.
The K88 antigen of Escherichia coli specifically adheres to the piglet intestinal cell; a solution of this antigen agglutinates guinea-pig red cells at 4 degrees C. The latter reaction was used as a model of the former, using inhibition of haemagglutination as an index of specific combination with the K88 adhesin. Inhibition was found with mucous glycoproteins and chemical modification of their heterosaccharide residues by mild acid hydrolysis, periodate oxidation or the Smith degradation procedure suggested that the terminal beta-D-galactosyl structure in a heterosaccharide sidechain of a glycoprotein might combine specifically with the K88 adhesin and inhibit haemagglutination. One serum glycoprotein (fetuin), after exposure of its subterminal beta-D-galactosyl residue, also inhibited haemagglutination, but high inhibitory activity was exhibited by some submaxillary glycoproteins in which this structure was absent or not prominent. It was concluded that in some cases inhibition of haemagglutination by glycoprotein was non-specific. No inhibition was found using glycosaminoglycans, glycogen or any simple sugar or glycoside. Sow colostrum was inhibitory but this was associated mainly with its gamma-globulin fraction. Some inhibitory activity was traced to a colostral glycopeptide fraction of low molecular weight but the smaller colostral oligosaccharides were not inhibitory; the composition of these components in sow colostrum is reported.
0.872193
Polysaccharides of metaplastic mucosa and carcinoma of the gallbladder.
The polysaccharide composition of the human gallbladder well was studied in carcinomas and metaplastic changes of various degrees, and the results obtained were compared with those for the normal material previously presented (Terho, T., and Laitio, M. Biochim. Biophys. Acta 338: 135, 1974). Elevated amounts of acid connective tissue polysaccharides (heparitin and dermatan sulfates as well as chondroitin 4- or 6-sulfate, or both, could be observed in carinomas. In histochemical stainings it was found that in carcinomas and in the two specimens classified as group III (containing the most extensive metaplastic changes at disposal), the intracellular mucin was mainly neutral or nonsulfated acidic. The amounts of sulfated mucin were relatively insignificant. This mucin polysaccharide material was isolated and its composition was determined. It was observed to be large polysaccharide material was isolated and its composition was determined. It was observed to be large molecular (approximate molecular sizes 1 to 2 times 10-6), and to be composed of fucose, galactose, glucosamine, and galactosamine as well as small amounts of sialic acid. The basic structure of these polysaccharides is thus similar to that of normal sulfated mucin. The almost total absence of acid groups, however, causes the polysaccharide material in question to stain in a manner identical with neutral mucin when investigated with histochemical methods. The carcinomas also contained some sulfomucin; its proportion, however, was small as compared with the amounts of nonsulfated acid and neutral mucin in biochemical characterization. A small molecular polysaccharide fraction, assumed to originate in membrane-bound glycoproteins, was isolated from the insoluble gallbladder tissue residue. The proportion of this fraction was larger in carcinomas than in normal material. This rise as well as the rise in the quantity of acid connective tissue polysaccharides is presumably due to the large number of cells in the carcinoma tissue as well as to fibrosis.
0.913313
Salmonella typhimurium resistant to silver nitrate, chloramphenicol, and ampicillin.
A strain of Salmonella typhimurium appeared sequentially in three patients in a burn unit, and epidemiological study suggested the occurrence of person-to-person spread. This organism was responsible for both colonisation and invasive infection in these patients whose burn surfaces were receiving topical treatment with 0.5% silver nitrate (AgNO3) solution. The antibiotic and metal ionsusceptibility pattern of this strain of S. typhimurium was unique and disturbing: resistant to silver nitrate, mercuric chloride, ampicillin, chloramphenicol, tetracycline, streptomycin, and sulphonamides. This pattern of multiple resistances could be transferred by invitro mating experiments to sensitive recipient strains of Escherichia coli and S. typhimurium. Further transfer of these resistances could be consumated between different strains of E. coli. A survey of other salmonella strains isolated from patients in this hospital without thermal burns did not reveal this pattern of resistance. Also, strains of S. typhimurium, isolated elsewhere and showing simultaneous resistance to both ampicillin and chloramphenicol, were not resistant to AgNO3 in vitro. The very real danger of this strain of S. typhimurium in burn units stems from its resistance to the two most effective antibiotics (ampicillin and chloramphenicol) available for systemic therapy; and this threat may be compounded through the selection effected by the widespread topical use of AgNO3 solutions and sulphonamide preparations on burned surfaces.
0.90072
Sudden death and sport.
Of 21 sudden deaths in sportsmen, 18 were thought to be caused by heart attacks either during or after sport. There was firm evidence of ischaemic heart-disease in 9, strongly suggestive evidence in 7, but in 2 there was only suggestive clinical evidence. As a group, these subjects were characterised by (1) a mean age above thirty (above twenty-five for rugby players); (2) a family history of early heart-attacks; and (3) antecedent symptoms of chest pain or pressure in 9, fatigue or blackout in 4, and minor complaints in 2. Most were known to their medical practitioners. Psychological factors were thought to be important in 8. Doctors, players and referees should be aware that severe sporting exertion as in rugby football involves a risk which for most players is relatively minor, but in the minority predisposed to heart-attacks by family history, smoking, or age (as in referees) the risk is more serious. To reduce hazard of sudden death in exercise, players and referees should be warned against smoking and informed of the serious implications of the development of chest pain, pressure, or undue tiredness before, during, or after sport.
0.854308
Reversible renal concentrating defect in shock.
The loss of renal concentrating power in haemorrhagic shock is reversible upon correction of the shock state. Shock resulting from acute hypovolaemia leads to the following sequence of events: (1) diminished renal blood-flow; (2) decreased superficial cortical nephron perfusion; (3) continued juxtamedullary nephron perfusion; (4) enhanced proximal reabsorption of Na, Cl, and H23; (5) decreased delivery of these ions to the ascending limb, which results in diminished hypertonicity of the medullary interstitium. This hypotonicity is worsened by the "washout" effect on the interstitial hypertonicity caused by continued perfusion of the juxtamedullary vasa recta which results in (6) diminished renal concentrating capacity due to elimination of medullary hypertonicity. Replenishing blood-loss and correcting the hypovolaemic state "regenerates" the hypertonic renal medullary interstitium by (a) diminishing proximal reabsorption and allowing presentation of greater quantities of Na and Cl to the ascending-limb "pump", (b) restoring superficial cortical nephron perfusion, thereby decreasing juxtamedullary perfusion and in this manner eliminating medullary "washout".
0.822527
Formation of cysteinyldopa from glutathionedopa in melanoma.
Glutathionedopa injected intravenously into mice is metabolized and excreted in the urine as a compound with the fluorescence characteristics of cysteinyldopa. Glutathionedopa incubated with a guinea-pig kidney homogenate is metabolized to a compound with the fluorescence characteristics of cysteinyldopa. Boiling of the kidney homogenate prevents the metabolism of glutathionedopa. Incubation of glutathionedopa with a homogenate of a melanoma metastasis led to the formation of a compound with the fluorescence characteristics of cysteinyldopa. Boiling of the melanoma homogenate prevented the metabolism of glutathionedopa. Large amounts of glutathione added to the incubate inhibited the reaction. Lung tissue and blood plasma had no detectable ability to metabolize glutathionedopa. The results show that human melanoma contains one or several enzymes capable of metabolizing glutathionedopa to a smaller dopathioether, probably cysteinyldopa. Such enzymes seem to be normally present in mice and guinea-pigs and have been demonstrated in the guinea-pig kidney.
0.879505
Morphological and histochemical studies on a PAS-positive granular leukocyte in blood and connective tissues of Catostomus commersonii Lacépède (teleostei:pisces).
This study was undertaken to identify an ubiquitous granular leukocyte found in Catostomus commersonni Lacépède. The cell contains large, numerous, strongly PAS-positive cytoplasmic granules, an eccentric nucleus and prominent, persistent juxtanuclear space. It develops in the hemopoietic tissue of the kidney, and mature cells are found not only in kidney and peripheral blood but also in areas of connective tissue where mast cells are usually located. Electron microscopy confirms the presence of a large Golgi apparatus, unlamellated cytoplasmic granules and extensive rough-surfaced endoplasmic reticulum. Histochemical studies show that the cytoplasmic granules are alcianophobic, non-metachromatic and unstained by acridine orange. Histamine is detectable spectrophotometrically in kidney tissue, but the PAS-positive granular leukocyte does not consistently degranulate after treatment with histamine liberator 48/80. The authors suggest that while the PAS-positive granular leukocyte is not identical with classical basophils/mast cells, which are absent in C. commersonnii, it may represent an evolutionary precursor of these cells.
0.918701
Uncontrolled diabetes mellitus and hyperglucagonemia associated with an islet cell carcinoma.
A 53 year old woman presented with diabetes mellitus, hyperglucagonemia (600 to 1,500 pg/ml), clinical hyperparathyroidism and an abdominal mass diagnosed on biopsy as an islet cell carcinoma. Glucagon content of the tumor was 0.78 mug/g wet weight. Hourly blood samples during a 24 hour period revealed a direct correlation between plasma glucose and glucagon. The oral administration of glucose paradoxically increased whereas the intravenous administration decreased plasma glucagon. Circulating glucagon levels were markedly increased with arginine and epinephrine infusion. Both short- and long-term administration of alpha adrenergic blockade depressed the glucagon response to epinephrine infusion. In contrast, long-term alpha adrenergic blockade increased glucagon secretion despite improved glucose tolerance during a second 24 hour study. Although the patient demonstrated overt clinical and chemical findings of hyperparathyroidism, parathyroid hormone (PTH) was not detected in her plasma. The pattern of tumor growth was consistent with an origin from pancreatic islets. We conclude that (1) the tumor was responsive to physiologic stimuli known to affect glucagon secretion; (2) elevations of plasma glucagon levels with oral and dietary glucose suggest regulation of secretion by intestinal factors; and (3) improvement of glucose tolerance with alpha adrenergic blockade may be related to increased insulin secretion.
0.816838
Genetic studies in the Markham Valley, northeastern Papua New Guinea: gamma globulin (Gm and Inv), group specific component (Gc) and ceruloplasmin (Cp) typing.
Genetic studies in the Markham Valley, northeastern Papua New Guinea; Gamma globulin (Gm and Inv), group specific component (Gc) and ceruloplasmin (Cp) typing. M. S. Schanfield, Eugene Giles and H. Gershowitz, Department of Human Genetics, University of Michigan, Ann Arbor, Michigan 48104. Immunoglobulin allotyping was carried out on 680 serum samples from inhabitants of the Markham Valley, Papua New Guinea (seven villages speaking the same Melanesian [PAP] speaking village). Family and population data verified the presence of Gm-ag, G-ab and Gm-afb among the MN speakers and Gm-ag, Gm-axg, Gm-ab and Gm-afb among the PAP speakers. The frequency of Gm-ag was between 0.048 and 0.235, while the frequency of Gm-ab was between 0.427 and 0.627 and the frequency of Gm-afb ranged between 0.261 and 0.424 among the seven MN villages; the single PAP village had frequencies of 0.568, 0.160, 0.213 and 0.059 for Gm-ag, Gm-axg, Gm-ab and Gm-afb respectively. The frequency of Inv1 ranged between 0.034 and 0.095 in the MN villages and 0.014 in the PAP village. The rare occurrence of Gm(x) without Gm(g) was explained by the presence of a Gm-axfb haplotype, while in two PAP families the presence of Gm(x) without Gm(g) was explained by the abnormally weak expression of Gm(g) in a Gm-axg haplotype. A total of 654 sera were typed for Gc, with the seven MN villages ranging between 0.350 and 0.650 for Gc-1, 0.312 and 0.575 for Gc-2 and between 0.017 and 0.112 for Gc-Ab; the single PAP village had a value of 0.627 for Gc-1, 0.165 for Gc-2 and 0.208 for Gc-Ab. A total of 693 sera were tested for ceruloplasmin type. All showed the common Cp(b) phenotype.
0.939039
Hemipelvectomy.
Hemipelvectomy was performed in 50 patients with malignant neoplasms of the upper part of the thigh and pelvis. Although not technically difficult, the operation is associated with considerable blood loss. Postoperative complications are frequent, the greatest morbidity resulting from skin flap necrosis. Symptomatic phantom limb is as occasional late problem. Of 37 patients resected for cure prior to 1969, 14 were alive five or more years postoperatively. Five of these long-term survivors subsequently died of metastases. Patients with fibrosarcoma and chondrosarcoma had the best survival. Six other patients underwent palliative hemipelvectomy for intractable pain, with gratifying results. Hemipelvectomy is an important, useful operative procedure in selected patients.
0.844238
Neutrophil alkaline phosphatase: comparison of enzymes from normal subjects and patients with polycythemia vera and chronic myelogenous leukemia.
To determine whether decreased alkaline phosphatase activity in the granules from neutrophils of patients with chronic myelogenous leukemia (CML) was due to an absence of enzyme or the production of defective enzyme, we compared the immunologic properties of granule alkaline phosphatase derived from patients with CML with that of normal subjects and patients with polycythemia vera (PRV). Antisera prepared in rabbits against granule alkaline phosphatase purified from the neutrophils of a patient with PRV produced a single precipitin line of antigenic identity when reacted with extracts of normal, PRV, and CML neutrophil granules. A histochemical stain for alkaline phosphatase activity (alpha-naphthyl acid phosphate coupled with Fast Blue RR) specifically stained the precipitin line. A variety of quantitative precipitin techniques failed to produce satisfactory precipitation of alkaline phosphatase activity. Comparative analyses were therefore performed by affinity chromatography using goat antirabbit-gammaglobulin linked to Sepharose 4B to adsorb alkaline phosphatase complexed with rabbit gamma globulin. With this method, 100% of CML, normal, and PRV alkaline phosphatase could be adsorbed. Using limiting concentrations of antibody, a proportionally smaller fraction of enzyme activity was absorbed as the concentration of PRV alkaline phosphatase or normal alkaline phosphatase was increased. Extracts of CML granules containing comparable amounts of protein but 200-fold less alkaline phosphatase activity per milligram did not specifically reduce adsorption. Thus, in CML, we found no evidence that the granulocytes contained a large amount of antigenically normal but enzymatically defective alkaline phosphatase. Examination of electron micrographs revealed no significant differences in the number or distribution of granules in the granulocytes of normal subjects or patients with PRV or CML. This suggests that the low level of neutrophil alkaline phosphatase in CML granulocytes is the result of decreased enzyme content and not a consequence of synthesis of catalytically defective enzyme.
0.883732
Transport of choline acetyltransferase and acetylcholinesterase in the central stump and isolated segments of a peripheral nerve.
Axonal transport of choline acetyltransferase (ChAc, E.E.:2.3.1.6) and acetyl cholinesterase (AChE, E.C.:3.1.1.7) was studied in the peroneal fascicles of rabbit sciatic nerves. The accumulation of ChAc in the central nerve stump proceeded 5 times more slowly than that of AChE and occurred at a distanct of 2-4 mm proximally from the end, whereas AChE accumulated in the last 2 mm of the stump. In double-ligated segments of the nerve in situ the activity of ChAc decreased at the proximal and increased at the distal end; the activity of AChE rose at both ends, The increase of ChAc activity did not cease until 22 h, whereas that of AChE stopped before 10 h. The intensity of ChAc transport is considerably diminished in the part of axon separated from the nerve cell body. Differences between the behavior of ChAc and AChE are interpreted by the assumption that the axonal transport of ChAc is slow, unidirectional, concerns all of the enzyme in the nerve, and that most of the transported enzyme is not associated with intraaxonal organelles. In contrast to ChAc, the transport of AChE is fast, bidirectional, and concerns a minor proportion of enzyme in the nerve; the transported enzyme is associated with organelles. The rate of proximodistal transport of ChAc is estimated at 4 mm/day (based on the assumption that 100% of the enzyme moves proximo-distally) and that of AChE at 480 mm/day (based on the extimate that 5% of enzyme moved proximo-distally in the present experiments).
0.879088
The morphology of murine oncornaviruses following different methods of preparation for electron microscopy.
The effect of different preparative procedures for electron microscopy on the size and shape of murine oncornaviruses has been studied. With conventional negative staining procedures using neutral sodium phosphotungstate, both murine mammary tumor virus and murine leukemia virus appeared in head-and-tail forms, with a peak head diameter of 122 and 130 nm, respectively. Negative staining with uranyl accetate gave round virions with peak diameters of 148 and 130 nm. Prefixed virus was round with peak diameters of 141 and 130 nm, respectively, in phosphotungstate, and 148 and 117 nm, respectively, in uranyl acetate. With thin sections, the peak diameters were 143 and 123 nm. The preservation of the spherical shape of the virus was obtained by glutaraldehyde fixation dehydration in alcholic solutions of uranyl acetate, and critical point drying. Under these conditions the viruses had peak diameters of 99 and 82 nm, respectively. The size of murine mammary tumor virus has always been found to be larger than murine leukemia virus in all preparations except for negative staining with neutral sodium phosphotungstate. Shadowing of the virion preparations revealed considerable flattening of the particles in all cases except for critical point drying. Negatively stained preparations did not cast any shadow, and thus thethickness of the particles could not be evaluated. Virus can be reversibly converted from spherical to head-and-tail forms by altering osmotic strength. Under most of the conditions used, murine mammary tumor virus gave a bimodal size distribution with significant numbers of particles that were smaller than the major virus size.
0.900117
Diagnostic value of routine liver tests.
In 131 patients on a medical service and 97 patients on a surgical service, in whom a diagnosis of hepatobiliary disease was verified in the hospital, the diagnostic value of routine liver tests performed soon after admission was evaluated by stepwise discriminant analysis. By measurements of alanine aminotransferase, alkaline phosphatases, gamma globulin, prothrombin time, bilirubin, and albumin, half of the medical patients were correctly classified into one of seven diagnostic categories. Aminotransferase contributed most to the classification, being twice as effective as random allocation. Decreasing the number of diagnostic categories to three (hepatitis, fatty liver, and chronic liver disease) increased the frequency of correct allocation to 80%. The allocation of all the patients to seven medical and four surgical diagnostic categories by means of four tests (aminotransferase, alkaline phosphatases, prothrombin time, and bilirubin) was significantly improved by each step with a misclassification rate of 55% when all tests were used. A reduction of the diagnostic groups to five (hepatitis, fatty liver, chronic liver disease, duct obstruction and tumor) increased the frequency of correct allocation to 63%. The analysis demonstrates the limited diagnostic effectiveness of routine liver tests when used alone. The absolute discrimination values depend on the a priori frequencies of the diagnostic groups investigated, and therefore may vary from time to time and from place to place.
0.866993
Synchronization of human motor units: possible roles of exercise and supraspinal reflexes.
Some normal human subjects show definite synchronization of the motor units in hand muscles (i.e., the impulses from two or more motor units coincide in time more frequently than expected for independent random processes). Subjects who show synchronization tend to use their hands to exert large, brief forces, either in their work (e.g., manual laborers) or recreational activities (e.g., weightlifters). In this study all seven weightlifters examined showed a significant degree of synchronization. Furthermore, after 6 weeks of using the first dorsal interosseus muscle of the hand to exert maximal, voluntary contractions, the level of synchronization increased substantially in four control subjects, and the average level became significantly different from zero. Weightlifters also showed greater late reflex responses than control subjects, but no significant difference in earlier spinal reflexes. Two late reflex waves are described which probably involve fast pathways to and from motor cortes. We suggest that supraspinal connections from motor cortex directly to spinal motoneurons may be enhanced as a result of training to the point where they produce a significant synchronization of motor units during steady, voluntary contractions.
0.906815
Intracortical transmission of specific evoked activity across the cerebral cortex.
The intracortical transmission of abnormally generated activity, like spreading depression and the direct cortical response, across the cortex is well known. In the experiments described here, the tangential transmission of a more normal type of cortical activity, the short latency response evoked by contralateral forepaw stimulation, was investigated. No evidence for tangential transmission was found from surface recordings. Various methods, such as passing polarizing currents, intravenous injection and topical application of strychnine, were used to alter the state of cortical excitation in order to induce a change in tangential transmission; none was found. The boundaries of the contralateral forepaw receiving area (CRA) appeared to be rigid, since the responses could not be induced beyond the perimeter by these manipulations of the cortex. Evoked responses in the centre of the CRA were shown to be unaffected by the excitation state of the cortex 2 mm or more away. The data support the hypothesis that the neural activity represented by the short latency surface evoked response is not transmitted laterally across the cortex and does not appear to be influenced by activity, beyond a range of about 2 mm or possibly less. The effectiveness of the methods used to alter cortical excitation, and to detect a spread of the evoked activity are discussed.
0.851332
An injury-induced diffuse slow potential from brain.
Three different slow potential (SP) changes resulting from focal brain injury are described. The first is an immediate, high amplitude (in excess of 25 mV)negative shift at the site of injury. The second is a biphasic negative-positive SP wave which spreads throughout the cortex ipsilateral to injury and is similar to spreading depression (SD). The third SP change, called here the injury-induced diffuse slow potential (IDSP)is a prolonged (lasting approx. 2h) negative shift occurring simultaneously in many brain areas, also in those far removed from the injured focus. The SD can be separated from IDSP by the size of focal injury; a 20 mu pucture of the parenchyma will trigger IDSP but not SD. An injury resulting from a larger puncture triggers both, SD and IDSP. IDSPcan not be induced by a re-entry of a previously damaged tissue. The magnitude of IDSP has anatomical specificity in that the largest amplitude occurrs in white as compared to gray of the cortex or of the caudate nucleus. Aso, the magnitude of the hypothalamic IDSP is larger when ipsilateral corpus callosum-commissural regions are injured. Electrical stimulation of the cortex in rats sufficiently strong to result in tonic-clonic convulsions triggers SD and IDSP; these two slow potential changes are similar to those induced by mechanical injury. A transpinnate electrical stimulus strong enough to elicit a grand-mal type of discharge results in a diffuse negative slow potential change similar to IDSP elicited by mechanical damage or direct cortical stimulation.
0.872234
Ontogeny of B-lymphocyte function with respect to the heterogeneity of antibody affinity-1,2.
Neonatal liver or adult spleen was used as a source of B-lymphocytes in reconstituting lethally irradiated, syngeneic mice. Recipients were all given excess adult, syngeneic thymus cells and were immunized with dinitrophenylated bovine gamma globulin. The distribution of avidities of plaque-forming cells produced by immunized recipients of neonatal liver was highly restricted in comparison with animals reconstituted with adult spleen indicating a restriction of B-lymphocyte heterogeneity in the neonatal mouse.
0.80079
Chemistry of allergens. XXII. Isolation and characterization of three new antigens from the dialysates of six successive pepsin hydrolyses of beta-lactoglobulin.
Twelve new antigens previously have been demonstrated in the pepsin digests of milk proteins. The term "new antigen" is defined as an antigen with a specificity distinct from that of the protein from which it was generated. Three new antigens (alpha-, beta-, and D2i) polypeptides and one nonantigenic gamma-polypeptide have been isolated from the dialysates of six successive pepsin hydrolyses of beta-lactoglobulin. The alpha- and beta-polypeptides were 1/5 and D2i was 1/10-1/20 as potent immunogens as precursor beta-lactoglobulin as determined by the Schultz-Dale technique. The minimum observed amounts of new antigen eliciting maximum response of uterine strips in the Schultz-Dale tests were: alpa-D2, 50 ng; beta-D2, 15 ng; beta-D3; 10 ng; and D2i, 1,000 ng. Except for the alpha-polypeptide, the amino acid contents of the polypeptides differed markedly from that of beta-lactoglobulin. The beta-polypeptide has been tentatively identified as a 33 amino acid fragment of beta-lactoglobulin (3,910 daltons). The gamma-polypeptide has been tentatively identified as a 12 amino acid fragment of beta-lactoglobulin (1,372 daltons).
0.85013
The demonstration of arylsulfatases with 4-nitro-1,2-benzenediol mono(hydrogen sulfate) by the formation of osmium blacks at the sites of copper capture.
A new method is described for the direct cytochemical demonstration of lysosomal arylsulfatases utilizing a synthetic substrate, 4-nitro-1,2-benzenediol mono(hydrogen sulfate), and a copper capture reaction. A small amount of Hatchett's brown (cupric ferrocyanide, Cu2Fe(CN)6-7 H2O) formed at the subcellular sites of copper capture is then utilized as a heterogeneous catalyst to effect the oxidative polymerization of 3,3'-diaminobenzidine which results in the formation of an insoluble, highly colored osmiophilic indamine polymer at the sites of enzymatic activity. The reaction product even at this stage prior to osmication is highly visible. It is readily seen with a light microscope in 50 mum sections of fixed tissues prepared with a mechanical chopper or in 10 micron cryostat sections treated for arylsulfatase activity. Upon osmication, an electron-opaque osmium black is formed which is much less soluble than the products of either the lead or barium capture reactions currently used for the demonstration of arylsulfatase with the electron microscope. The selection of areas of plastic-embedded tissues for ultrathin sectioning is facilitated by the ready visibility of these osmium black end products on 1-2 mum plastic sections which can be studied with the light microscope. This method gives permanent specimens demonstrating arylsulfatases A or B in lysosomes and autophagic vacuoles. In addition, enzyme activity is seen occasionally in the Golgi region or lamellae of certain cells believed to be elaborating sulfated products. In these instances, it may be demonstrating sulfotransferase activity.
0.876371