A preliminary controlled evaluation of the antihypertensive effect of indapamide. A controlled, single-blind trial was carried out in 10 hypertensive patients to compare the effectiveness of a single daily dose (2.5 mg to 5 mg) of indapamide with that of placebo. Blood pressure was measured with a bias-free sphygmomanometer. Indapamide produced a significant reduction in mean systolic and diastolic pressures in both supine and erect positions. It was generally well tolerated: few side-effects were reported and no significant changes were noted in laboratory tests. It is concluded that further long-term studies of indapamide are indicated in larger numbers of patients.


Cryptococcosis, with emphasis on the significance of isolation of Cryptococcus neoformans from the respiratory tract. Cryptococcus neoformans was isolated from 65 patients: 11 had meningitis, 11 had disseminated cryptococcosis without meningitis, and 43 had C neoformans isolated from the respiratory tract. Predisposing conditions and the diagnostic value of cultures from various sites and of the latex agglutination test on cerebrospinal fluid and serum are analyzed for patients with extrapulmonary disease. Nine patients had pleural effusions; the effusion was cultured in six and yielded C neoformans in four. None of 11 deaths among 43 patients with respiratory tract isolates could be attributed to cryptococosis. The 32 survivors were nor treated with antifungal agents. Twenty-six of 43 patients with respiratory isolates had various bronchopulmonary disorders, with chronic obstructive pulmonary diseases and asthma the most common (28 percent). Seven of 28 patients (25 percent) with roentgenographically detected lung lesions had carcinoma of the lung. Roentgenographic evidence of a lung lesion and C neoformans grown from the respiratory tract warrant a further search for carcinoma of the lung.


Short-term effects of smoked marihuana on left ventricular function in man. The short-term effects of smoking one to three marihuana cigarettes (900 mg of marihuana per cigarette; 2.2% delta9-tetrahydrocannabinol) on left ventricular performance were evaluated in 21 experienced users of cannabis at different times during a 94-day in-hospital study of the biologic effect of daily heavy smoking of marihuana. In six subjects, cardiac output was determined using the indocyanine-green dye-dilution technique; and in two of these individuals and 15 additional subjects, cardiac output, ejection fraction, preejection period (PEP), left ventricular ejection time (LVET), and the velocity of circumferential fiber shortening (Vcf) were determined using echocardiograms, phonocardiograms, and carotid pulse recordings. Following the smoking of one to three marihuana cigarettes, the heart rate rose 16 to 53 percent, cardiac output rose 4 to 9 percent, stroke volume did not change or fell slightly, and ejection fraction, PEP/LVET, and did not change, except for a slight increase in Vcf (15%) after three marihuana cigarettes, which could be accounted for by the associated increase in heart rate (53%). These findings suggest that in long-term heavy users of cannabis, marihuana has no significant effect on myocardial contractility independent of its effect on heart rate.


Children's services--past, present, future. Preventing, healing, and educating in various forms have always been major ingredients of clinical services for troubled children. Traditional services involving healing or prevention have been emphasized. Current times mandate a closer look at the value of an educationally oriented model to provide direction for clinical intervention. Case illustrations of such a model are presented.


Sulpiride: evaluation of antipsychotic activity in schizophrenic patients. Sulpiride is a new antipsychotic agent chemically different from recognized psychotropic compounds. The animal profile and the rapid urinary excretion without metabolism also distinguishes this drug from other neuroleptics. Previous studies have indicated therapeutic efficacy and few side effects. Sulpiride was evaluated in 10 hospitalized, chronic schizophrenic patients over a 10 week period. The overall findings support those studies reporting neuroleptic activity. Although no side effects were encountered, a mild leukocytosis was observed in one patient and broadening and flattening of T-waves  was observed in another when each received high doses. Toxic levels appear to be well beyond the therapeutic range.


[Failures in enosseous impantations].

[Failures in enosseous impantations]. It was possible to examine over 500 jaw implants which were anchored in bone after varying duration of wear. The average failure rate of these implants after up to seven years after insertion lies approximately 40% above the complication rate given in the majority of publications. The time of occurrence and the symptoms of failures are discussed as well as their possible causes.


[Needle implantations--clinical report]. In the last four years 27 patients with edentulous lower jaw were treated with implantation of rows of tantalum needles; 25 of them were followed up clinically and radiologically. After an average of two years and seven months where the success rate was found to be 72%. Reasons for failure were thought to be mistakes in operative technique, insufficient oral hygiene of the patients and less than optimal aftercare. These needle implants have proved their value also in cases with marked atrophy of the lower jaw where other prosthetic-surgical methods aimed at improving the prosthesis site have failed.


[Supported dentures in the periodontally damaged residual dentition in combination with enosseous implantations]. The use of implants in bone represents an extension of prosthetic possibilities. Clinical cases are used to demonstrate how additional supports can be created by means of implants of Linkow-blades which allow the incorporation of periodontally damaged teeth into prosthetic care. In addition the use of transdental fixation in  the stabilisation of badly loosened teeth is pointed out.


[Temporary bridging of defects in mandibular resections with osteosynthesis methods]. In a survey, the three conventional methods of bridging a defect (immediate rib transplant, extraoral Becker splinting and intraoral metal plate bridging) are studied. The advantages and disadvantages of the pertinent method are described. Although metal plate bridging has risks and disadvantages, clinical experience has shown the great advantages of this temporary method in extensive mandibular resections with soft tissue covering the defect.


Rapid determination of valproate sodium in serum by gas-liquid chromatography. A rapid and simple gas-liquid chromatographic procedure is described for the measurement of valproate sodium (sodium di-n-propylacetate) in serum. Valproate is extracted from serum by a micro-extraction method and chromatographed on a 10% Carbowax 6000 column using 2-ethyl-2-methyl-caproic acid as internal standard. The method is capable of measuring at least 2 microgram of valproate per milliliter serum.


A study of the action of valproic acid on the kindling effect. The effect of an antiepileptic drug, valproic acid (VPA), on an experimental form of epilepsy, the kindling phenomenon, is described. In cat, 50 mg/kg i.p. per day is sufficient to block the progressive establishment of generalized seizures produced normally by repetitive electrical stimulation of the amygdala. However, a focal afterdischarge persists during the entire treatment. Higher doses (75-150 mg/kg) are necessary to protect the animal against the generalized tonic-clonic seizure when the kindling phenomenon is established. These effects and the action of barbiturates, which was also tested, seem to attribute to VPA a complex role in the mechanism of this action.


T lymphocyte induction of non-T cell-mediated nonspecific cytotoxicity. I. Introduction mechanisms. Mononuclear cells (MNC) from normal humans consistently failed to give nonspecific cytotoxic responses. However, after removal of T cells by sheep erythrocyte (E) rosetting, the remaining non-RFC (rosette-forming cells) now gave significant nonspecific cytotoxic responses against both autologous and allogeneic target cells. Reconstitution experiments with T cell subpopulations failed to suppress these nonspecific non-E-RFC-mediated cytotoxic responses. There was also no evidence to indicate the involvement of antibody in this nonspecific cytotoxicity. The cytotoxic cells were characterized as non-E-rosetting, non-phagocytic, and glass adherent lymphocytes; no evidence of monocyte-macrophage participation was found. The inductive trigger of non-E-RFC-mediated cytotoxicity was found to be soluble factors released by T cells during E-rosette formation at 4 degrees C. Incubation of MNC with horse, marmoset and human erythrocytes under identical conditions failed to trigger cytotoxicity. The incubation of quiescent MNC with E-rosetting supernatants (ERS) induced nonspecific cytotoxic responses equivalent to those mediated by separated non-E-RFC. ERS-activated MNC destroyed both autologous and allogeneic target cells. The ERS supernatants themselves were not cytolytic. These findings suggested that cell separation procedures, and possibly in vivo events, which activate T cells may also induce non-T cell-mediated nonspecific cytotoxicity.


Ontogeny of the antibody-forming cell line in mice. III. The generation of mature anti-sheep red blood cell-specific B cells is antigen-dependent. A role for antigen in the generation of fully mature splenic type B cells has been shown. In adoptive transfer experiments, cells from bone marrow or fetal liver required a longer period to give an anti-sheep red blood cell plaque-forming cell (PFC) response than those from spleen. This delay was not overcome by allowing the cells a 7-day sojourn in the irradiated host before antigen challenge. A two-stage protocol was designed in which the in vivo generation of fully mature cells could be measured by their ability to give PFC in lipopolysaccharide-stimulated cultures in vitro. These experiments showed that a critical factor which influences the final differentiation of bone marrow or fetal liver cells into mature, splenic type B cells is exposure to antigen.


Induction of specific transplantation tolerance with blood serum in newborn and adult rats. Histocompatibility (H) antigens present in the serum of rats induce a relatively high degree of neonatal transplantation tolerance in the absence of cellular chimerism. With the non-H-1 difference, which is relatively strong in the rat strain combination used, skin grafts survive permanently in some animals. With the H-1 plus non-H-1 difference, only some animals show a slight prolongation of skin graft survival, but cytotoxic antibody production is inhibited for long periods of time. In adult animals, at least with the non-H-1 difference, allograft survival is very significantly prolonged after treatment with serum alone, or in combination with hydrocortisone. The nonspecific component(s) of the serum also contributes to a prolongation of graft survival. The data suggest that blood serum is a good source of H antigens which seem to be present in a tolerogenic active form.


Hypothalamic changes during the immune response. The immune system is subject to an array of identified autoregulatory processes, but immunoregulation may also have a further basis in a network of immune-neuroendocrine interactions. Two antigens each produced an increase of more than 100% in electrical activity of individual neurones in the ventromedial but not in the anterior nucleus of the rat hypothalamus. Animals that failed to respond to antigen manifested no increase in the firing rate. These findings constitute the first evidence for a flow of information from the activated immune system to the hypothalamus, suggesting that the brain is involved in the immune response.


Genetic defect in responsiveness to the B cell mitogen lipopolysaccharide. Splenic B cells C57BL/10ScCr mice fail to respond to the mitogenic principle of lipopolysaccharide (LPS), and do not express a serologically defined "LPS receptor". In contrast, polyclonal B cell responses to both purified protein derivative of tuberculin and lipoprotein are conserved.


Granulocyte transfusions in recovery of neutropenic rats from induced E. coli toxicemia. Rats made transiently neutropenic by intra-arterial administration of vinblastine (3 mg/kg) and infected with E. coli (6.02+/-0.45 X 10(8), per animal) have a mortality rate of 90% within 48 h post infection. Multiple transfusions of large numbers of granulocytes (harvested from Deca-Durabolin treated donor rats) protected the neutropenic animals from sepsis. Out of a group of 11 rats, 10 recovered completely after repeated granulocyte transfusions.


Quantitative aspects of an in vivo diffusion chamber assay for normal human hemopoietic colony forming units. The purpose of the present study was to definite some of the quantitative characteristics of the colonies formed by normal human hemopoietic cells in diffusion chambers in vivo. The cells were cultured in fibrin clots in diffusion chambers, which were implanted i.p. into 450 R irradiated mice, reimplanted into newly irradiated mice after 7 days and harvested by a previously described chamber centrifugation technique after a total of 14 days. At low cell doses per chamber, no colonies were observed; however when more than 3-8 X 10(4) cells were inoculated per chamber, the number of granulocytic colonies was proportional to the cell dose. Similar dose-reponse curves were obtained when the cells were harvested in suspensions from the chambers. The granulocytic colonies do not conform to a Poisson distribution when identically prepared chamberbeare compared, but show a more heterogeneous distribution. Evidence is presented that this heterogeneity is not due to technical errors in the process of chamber filling and harvesting. A host factor was found to influence the mean number of cells per neutrophilic colony, but the heterogeneity of the total number of neutrophilic or eosinophilic colonies of more than five cells could not be ascribed to variable host factors. There was a mean of 3.6 granulocytic colonies (of more than 30 cells) per 10(5) cells implanted in a series of 15 normal bone marrows cultured. The mean size of neutrophilic colonies was 23 cells. Determinations in duplicate suggest that the method may serve as an assay for certain classes of colony forming cells, provided the number of chambers in each assay is sufficiently high.


Growth and differentiation of normal and leukemic human bone marrow cells cultured in diffusion chambers. Bone marrow from healthy, normal volunteers and patients with acute myelocytic leukemia was cultured in diffusion chambers implanted into cyclophosphamide pretreated mice. Chambers were removed at regularly scheduled intervals over a period of 28 days. Total and differential cell counts were then done on the contents of each chamber. Normal human bone marrow showed an orderly pattern of growth and differentiation which was not found with leukemic bone marrow. Monocytes and macrophages were the predominant cell types in the diffusion chambers filled with normal marrow after day 10 of culture. Although leukemic specimens showed predominantly leukemic cells, a few mature polymorphonuclear leukocytes could be found throughout the entire culture period. Questions about the nature of the defect in acute myelocytic leukemia and the significance of the in vivo culture system are discussed. The results of these studies are compared and contrasted with studies of a similar type.


Substance abuse and family interaction.

Substance abuse and family interaction. The authors propose that substance use and abuse may be understood and effectively treated when the individual user or abuser is viewed in the context of his family or stable living group. This viewpoint attributes an important role in the maintenance of individual substance abuse to interactional processes within the family system. The theoretical assumptions implied by this viewpoint are discussed. A selective literature review examines the available evidence, from both experimental and clinical-descriptive studies, that is relevant to this proposal. The next step toward a more systematic investigation of these ideas is outlined, including testable hypotheses, methodological issues and problems, and potentially useful techniques.


The symbolic drawing of the family life space. Several innovative techniques have been developed in the last ten years for facilitating meaningful communication and interaction among family members. These techniques serve the purpose of highlighting relatively stable patterns of verbal and nonverbal communication among family members and bring to the surface various aspects of familial structure, thereby illuminating focal points for intervention. The purpose of the present article is to describe the technique of the Symbolic Drawing of the Family Life Space, to compare this technique with other techniques for facilitating communication and interaction among family members, and to illustrate the clinical use of this technique with case examples. In reviewing the literature, the authors extracted two types of symbolic and interactive procedures, which may be conveniently divided into those that tend to be task-centered and those that tend to be expressive modalities.


Inhibition of serotonin reuptake.

Inhibition of serotonin reuptake. An uptake system on the serotonin neuronal membrane apparently functions to inactivate serotonin that has been released into the synaptic cleft. Various inhibitors of this active transport system on serotonin neurons are known, and some are specific in the sense that they do not inhibit the active uptake system on norepinephrine neurons. The most widely studied specific inhibitor of the serotonin neuron pump is fluoxetine, 3-(p-trifluoromethylphenoxy-N-methyl-3-phenyl propylamine (Lilly 110140). When fluoxetine or other effective but less specific serotonin uptake inhibitors are given, a rapid decrease in serotonin turnover occurs and the rate of firing of single neural units in the serotonin rich raphe area of brain is reduced. This decrease in serotonin turnover and release may be a compensatroy mechanism in response to an enhanced action of serotonin on synaptic receptors. Through the use of fluoxetine and other serotonin uptake inhibitors, the role of serotonin neurons in various brain functions--behavior, sleep, regulation of pituitary hormone release, thermoregulation, pain responsiveness, and so on--can be studied.


Varicocele and male fertility.

Varicocele and male fertility. Over the past 25 years the association of varicocele with male subfertility has been repeatedly demonstrated and the beneficial effect of varicocele ligation in infertile men with oligoasthenospermia has been documented. Since the precise mechanisms by which a varicocele affects spermatogenesis are still unclear, the proper approach to the management of "asymptomatic" varicoceles is controversial.


The effect of gonadotropin-releasing hormone on blood glucose insulin, luteinizing hormone, and follicle-stimulating hormone levels. Sixteen women volunteers with menstrual irregularities were studied with an intravenous injection of 100 microgram of gonadotropin-releasing hormone (GNRH). Serial blood samples were obtained for 2 hours after the injection and assayed for their concentration of glucose, insulin, luteinizing hormone (LH), and follicle-stimulating hormone (FSH). There was a significant increase in the levels of both gonadotropins following the injection, with the peak for LH occurring at 30 minutes and the peak for FSH occurring at 90 minutes. There was a slight decrease in the glucose level at 45 minutes and in the insulin levels at 60 and 120 minutes. Because GNRH causes only minor changes in these parameters of carbohydrate metabolism, it would appear to be safe to use in women with ovulatory abnormalities secondary to diabetes mellitus.


The management vf essential hypertension with once daily administration of timolol maleate and bendrofluazide. A placebo controlled-blind study performed on new patients presenting with mild to moderate essential hypertension. A once daily combined dose of timolol maleate and bendrofluazide in a 4:1 ratio was administered ot each patient after a four week placebo period. The starting dose was timolol 10 mg and bendrofluazide 2-5 mg and this dose was increased in steps of timolol 10 mg and bendrofluazide 2-5 mg until blood pressure was controlled. Eleven out of twelve patients achieved normotension, the falls in diastolic and systolic blood pressure being highly significant on active treatment compared with placebo. The once daily regimen of timolol and bendrofluazide resulted in good control of blood pressure with no more side-effects than occurred on the placebo. A combination of these two drugs in one tablet would appear to be both practical and advantageous and should increase patient compliance in taking medication.


A clinical comparison of betamethasone 17,21-dipropionate and clobetasol propionate creams in dermatology. In a double-blind investigation, 36 patients suffering from various steroid-reponsive dermatoses were treated twice daily for three weeks either with 0-05% betamethasone 17,21-dipropionate cream or with 0-05% clobetasol propionate cream. Results showed both products to be highly effective in terms of onset of action and efficacy and no statistical differences were found (p greater than 0-1).


An open comparative trial of Vanquin tablets and pripsen granules in the treatment of threadworm infestation. Thirty-eight patients presenting to their general practitioner with threadworm infestation were admitted to an open, comparative, multicentre trial of Vanquin tablets and Pripsen granules. Efficacy and tolerance were assessed. Twelve of nineteen patients treated with Vanquin had positive results from a peri-anal skin test at the start of treatment, all results were negative after twenty-one days. Fourteen of nineteen patients treated with Pripsen had positive results at the start of treatment and two of these had positive results after twenty-one days. One patient treated with Vanquin and five treated with Pripsen reported side-effects.


A multicentre study comparing mazindol and placebo in obese patients. Mazindol is chemically unrelated to the phenethylamines and has not shown the side-effects or abuse potential of the amphetamine anorectics. To further define its potential for causing weight loss, a six-week double-blind placebo controlled study was undertaken in four centres. A common protocol was used except in one centre, behavioural modification also was employed, whereas in the other centres, no additional measures were used to cause weight loss. Two hundred and forty-five obese patients were assigned randomly to two mazindol groups and one placebo group in each centre. Ninety-eight and forty patients receiving mazindol and placebo respectively completed the protocol. The conclusions were: (a) no significant clinical or laboratory abnormalities occurred from mazindol therapy, (b) the placebo therapy patients did not lose weight without behavioural modification, (c) the placebo therapy group had a higher drop-out rate compared to the mazindol therapy group attributable to the patients' dissatisfaction with failure to lose weight, (d) mazindol therapy without behavioural modification and behavioural modification alone both resulted in a statistically significant mean weight loss of 1 pound/patient/week and (e) mazindol plus behavioural modification resulted in a greater mean weight loss of 1/2 pound/patient/week than with behavioural modification alone. Hence, mazindol is of value in the initial therapy of obesity.


Effect of cutaneous stimulation on the development of misdirected wiping reflexes in skin-grafted Discoglossus pictus. The frog, Discoglossus pictus, has been studied with respect to wiping reflex behavior developing after skin rotations performed at larval stages. Misdirected wiping reflexes were obtained only from belly skin-grafts placed on the animals' back; back skin-grafts on the belly failed to elicit any misdirected limb movements in this species. We found that misdirected reflexes occurred more readily in 3-week and older animals if not subjected to any previous test experience, than in younger naive frogs. Frogs that had been exposed to daily cutaneous stimulation between 2 to 4 weeks after metamorphosis showed a delayed development of misdirected responses.


C-peptide response to glucagon. A test for the residual beta-cell function in diabetes mellitus. Pancreatic beta-cell secretory activity was measured in 17 patients with insulin-dependent diabetes mellitus of less than 19 months' duration and in 10 nondiabetic subjects by means of the peripheral plasma C-peptide response to 1 mg. of glucagon I.V. The C-peptide response to a meal was also measured in the diabetic patients. Residual beta-cell function was present in all the diabetic patients as indicated by significant amounts of C-peptide in plasma. Significant increases in C-peptide were observed in 16 after glucagon stimulation and in 15 after the meal. Both absolute and relative increase in C-peptide were reduced in the diabetic patients. The increase in C-peptide was correlated to the fasting C-peptide concentration both after glucagon (r=0.86, p less than 0.001) and after the meal (r=0.66, p less than 0.01). The responses to the meal and to glucagon were correlated (r=0.77, p less than 0.005), indicating a high predictive value of the glucagon test as to how the beta-cells will respond during normal daily life.


Secretion of insulin in a perifusion system and conversion of proinsulin to insulin by pancreatic islets from hyperglycemic rats. The secretory pattern of insulin and the rate of conversion of proinsulin to insulin were studied in isolated pancreatic islets from normoglycemic (buffer-infused for 24 hours) and hyperglycemic (glucose-infused for 24 hours) rats. The profiles of insulin secretion obtained during one hour of perifusion were markedly different in the two groups. The rate of insulin secretion by islets from the hyperglycemic rats was initially very high but progressively declined during the late period of the perifusion. The reverse pattern was found with the islets from buffer-infused rats. For the estimation of the rate of proinsulin conversion, islets were pulse-labeled with L-[4,5-3H]-leucine for 15 minutes and "chase"-incubated for 30 and 60 minutes. Labeled rat proinsulin and rat insulins in the medium and in the islet extracts were separated by a validated SDS-urea electrophoretic acrylamide procedure following immunoprecipitation. The conversion rate was estimated from the radioactivity in the insulin band, expressed as a per cent of the radioactivity in the proinsulin + insulin bands. Islets from hyperglycemic rats converted newly synthesized proinsulin to insulin at significantly higher rates than did control islets.


Physiologic role of somatostatin. Insulin release from rat islets treated by somatostatin antiserum. In order to clarify the physiologic role of somatostatin in insulin release, rat pancreatic islets treated by somatostatin antiserum were incubated in media containing various concentrations of glucose. Insulin release from antiserum-treated islets was significantly elevated above that from nontreated ones at 3.3 and 8.3 mM glucose, while the former was not different from the latter at 16.7 mM glucose. It is suggested that somatostatin plays an important role in the regulation of insulin release in the physiologic range of glucose concentration.


[Idiopathic sick sinus syndrome with a-v and intraventricular conduction disturbances in a child. (first report in childhood) (author's transl)]. This report presents a ten-year old child suffering from sick sinus syndrome, in the "Bradycardia-tac hycardia-asystole" variant. A long observation and an ECG made when he was 7 have never shown a sinusal rhythm. An involvement of the A-V node is also present, made clear by a block of the second degree with not very high atrial rates and by prolonged refractory periods, as well as an involvement of the intraventricular conduction, made evident by an incomplete right bundle branch block and by a long refractory period of the anterior fascicle. The clinical, laboratory and hemodynamic data excluded either a congenital or an acquired cardiopathy. The ECGs of the patient's relatives excluded a familiar type of S.S.S. It is, therefore, an idiopathic S.S.S., which is very rare in children. The nosological set in the still vague field of the idiopathic degenerations of the conduction tissue is discussed.


Representational development of the human figure in familial retardates. Representational development of the human figure of normal and familially retarded children was examined. Five tasks were employed: Drawing a Person, Figure Completion, two Form Puzzles, and Drawing on Dictation. Ss included 34 normal children, ages 3-0 to 5-10, and 34 familially retarded children, ages 4-4 to 13-1. The two groups were matched for mental age, socioeconomic status, public school attendance, and intact family structure. Results indicate that familial retardates performed as well as normals and at times surpassed them. Performance on these representational tasks is, predominantly, a function of mental age which lends support to a "developmental" theory of familial retardation and refutes the "defect" hypothesis.


Escherichia coli serotypes throughout the gastrointestinal tract of patients with intestinal disorders. The O and H serotypes of Escherichia coli that were present along the entire length of the gastrointestinal tract of patients with small intestinal bacterial overgrowth were studied. Multiple sero- and biotypes were represented, although usually a single serotype predominated in each patient. In a number of cases the different O:H serotypes were antigenically related indicating that antigenic degradation was occurring. The serotypes isolated from the stomach and small intestine were represented in the faeces. In general, within the limitations of this study, there appears to be a stable ecosystem in each patient and it may require specific oral antibiotics to alter it.


Role of intestinal microflora in colonic pseudoobstruction complicating jejunoileal bypass. A double-blind crossover study using placebo and antibiotics effective against either aerobic or anaerobic organisms has been performed to elucidate the role of intestinal microflora in the pathogenesis of colonic pseudo-obstruction, which is now established as an important complication of jejunoileal bypass. Using strict Virginia Polytechnic Institute (VPI) technique, quantitative bacterial studies of the intestinal flora in the region of bypassed bowel have been correlated with symptoms of abdominal pain and distension. It has been shown that antibiotics effective against obligate anaerobes rapidly relieve the symptoms of pseudo-obstruction and this coincides with the disappearance of these organisms from this region of bowel. Symptoms rapidly recur when anaerobic organisms repopulate the bowel. It is concluded that obligate anaerobes may play a role in the pathogenesis of this complication.


Immunohistochemical identification of lysozyme in intestinal lesions in ulcerative colitis and Crohn's disease. Lysozyme (LZM) was identified in ulcerative colitis in granulocytes, monocytes, and macrophages of the intestinal lamina propria. In contrast with findings in normal colon or rectum, in ulcerative colitis LZM was also detected in some mucosal crypt cells and metaplastic Paneth cells. In both ulcerative colitis and Crohn's disease LZM was present in inflammatory cells of crypt abscesses. In Crohn's disease intense LZM staining was seen in epitheloid cell granulomas. The present observations permit one explanation for the raised concentration of serum-LZM in patients with ulcerative colitis and Crohn's disease.


Nocturnal metiamide treatment in the management of healed duodenal ulceration. This paper presents the results of a pilot study to investigate whether the administration of a nocturnal dose of metiamide (the first orally active H2 receptor antagonist) would prevent or delay the relapse of duodenal ulceration after initial ulcer healing. Sixteen patients took part in a double-blind trial to compare metiamide (400 mg) with placebo. Endoscopically confirmed duodenal ulcer relapses occurred in two out of eight on metiamide and six out of eight on placebo. There was a significant prolongation of remission in those in those on the active drug with an apparent reduction in duodenitis.


Lymphocyte populations in liver biopsy specimens from patients with chronic liver disease. The characterisation of lymphocytes from liver biopsies indicates that 'activated' T lymphocytes are present in the liver in alcohol induced hepatitis, chronic active hepatitis (HBS+ve and -ve), and in primary biliary cirrhosis but not in inactive cirrhosis, chronic persistent hepatitis, extrahepatic and drug induced cholestasis. A greater percentage of lymphocytes bear Fc-receptors in chronic active hepatitis than in alcohol induced hepatitis or cholestatic liver disease. The concentration of 'activated' T cells in the peripheral blood in all groups studied was within the normal range, suggesting that the 'activated' T cells found in the liver were reacting to either native or foreign antigens within the liver. The data on Fc-receptor bearing cells are consistent with the involvement of antibody assisted K cell mediated cytotoxicity in chronic active hepatitis.


Double-blind trial of cholestyramine in post-vagotomy diarrhoea. The effect of cholestyramine in post-vagotomy diarrhoea has been assessed under double-blind conditions. Cholestyramine produced a significant improvement in frequency, urgency, and consistency of stool as well as episodic diarrhoea. Faecal bile acid excretion was significantly higher in the post-vagotomy group when compared with normal controls. These findings confirm the effectiveness of cholestyramine and support the concept of a bile acid mediated aetiology in post-vagotomy diarrhoea.


Double-blind placebo-controlled study of loperamide (Imodium) in chronic diarrhoea caused by ileocolic disease or resection. Loperamide (R 18 553) was compared with placebo in a double-blind crossover study of 21 patients with chronic diarrhoea caused by ileocolic disease or resection. Eighteen patients completed the trial. At a median daily dose of 6 mg the new antidiarrhoeal preparation was found to be superior to placebo in controlling chronic diarrhoea. The frequency and weight of stools significantly decreased, the stools became more solid, and carmine transit time was prolonged during loperamide therapy. Loperamide was consistently preferred to placebo by the patients. Gastrointestinal side-effects were few and comparable during both treatment periods.


[Management of extensive avulsion injury of the hand]. The case of a 25 years old industrial worker is reported, who suffered an extensive avulsion of his left hand in a rubber roller injury. The middle and ring fingers hand to be amputated. The skin loss was covered simultaneously by an axillary pedicled flap for the thumb, two pedicle flaps from the upper arm for the index and small fingers and split thickness skin grafts for the dorsum of the hand. In a second stage, sensation of the tips of thumb and index finger was restored by two innervated full thickness skin grafts from the dorsum of the foot.


[Experimental principles of immunotherapy using microbial substances in malignant tumors. 1. Effect of streptococci on ascite retothelsarcoma in the mouse in vitro]. The experimental results of Okamoto and his group with the preparation PB-B-45 from a strain of beta-hemolytic streptococci, group A, could be confirmed. The in vitro-method they used gives good results in the screening for strains of streptococci, which have antitumoral activity. With an own strain (no. IC) a complete inhibition of the growth of an ascites-retothelsarcoma of the mouse could be achieved by this technique.


Chemical composition and potential 'genotoxic' aspects of polluted atmospheres. The chemical composition of the gaseous, vapour and particulate phases of the atmosphere has been reported in terms of background, urban and highly polluted levels. Too little is known about the chemical composition of polluted atmospheres and other environments, and the situation will worsen as a result of the steadily increasing production of a wide variety of chemicals. This and other evidence presented in this paper indicates that the human race has not yet felt the full impact of the burgeoning chemical environment in terms of genotoxic effects. Some highly suggestive data from the literature have been presented to indicate that carcinogenesis and mutagenesis in human beings involve not only the attack of a primary genotoxicant, but that genetic factors, cofactors, antifactors and sometimes precursors can play important roles in the process of genotoxicity. Evidence has been presented to indicate that genotoxic effects are much more prevalent among human beings than is commonly believed. Since inherited effects arise from mutation of a germ cell, cancer probably from mutation of a somatic cell, atherosclerosis possibly from some mutagenic effect and the debilitating effects of some aspects of ageing possibly from a somatic mutation of the metabolic type, then mutagenesis in these four postulated types could be the overwhelmingly major cause of death in modern society.


Cell size in aging monolayer cultures.

Cell size in aging monolayer cultures. Changes in the size of the area covered by individual cultured WI-38 cells as the cultures age have been studied by using a new microphotographic paper cutout technique. This method is nondestructive and noninstrusive and avoids a number of artifacts which can occur in the measurement of suspended cells. The measurements reveal that the decreased cell yield of late passage cultures reflects not only the appearance of a subpopulation of larger cells but also the failure of the cells to utilize all the growth surface available to them.


Culture of rat retinal pigment epithelium. A method of preparing monolayer cultures of retinal pigment epithelium from normal pigmented neonatal rats is described. Critical features include incubating the eyes in balanced salt solution and treating with trypsin before dissecting the eyes. The tissue also has been culured from RCS rats with inherited retinal degeneration. Since the pigment epithelium has been shown to be the primary site of action of the gene for retinal dystrophy in the RCS rat, the method should be usefull in studying the defect(s) associated with this mutation.


The appearance of non-specific antibody-forming cells in the efferent lymph draining antigen-stimulated single lymph nodes. Immunization of single lymph nodes with various antigens led to the appearance of cells in the efferent lymph that secreted antibody specific for the antigen which induced their formation and for a number of unrelated, non-crossreacting antigens. Immunization of single lymph nodes with mitogens led to the appearance of cells secreting antibodies specific for an even greater number of antigens, including one (TNP) that in all probability is not present in the animals' natural environment. When the node was primed with one antigen, a subsequent challenge with an unrelated antigen 12 weeks later led to the appearance of greater numbers of cells containing and secreting antibody against the previously experienced antigen, than was the case in unprimed lymph nodes. These findings indicate that the immune response to antigen provokes the maturation of lymphocytes of specificities unrelated to that of the injected immunogen. Such a mechanism may be important in maintaining immunological memory. Mitogens may directly activate lymphocytes into maturation and expression as antibody-secreting cells, whereas antigens appear to act indirectly.


Oral toxicities of Clostridium botulinum toxins in response to molecular size. Clostridium botulinum type A, B, and F toxins of different molecular sizes were fed to mice to compare the oral toxicities. The progenitor toxin, a complex of a toxic and nontoxic component, of any type was higher in oral toxicity to mice than the dissociated toxic component or the derivative toxin. The former may no doubt play a more important role in the pathogenesis of food-borne botulism. The higher oral toxicity possessed by the progenitor toxin, including the exceptionally high one found with type B-L toxin, can be explained solely by the protection afforded by the nontoxic component attached to the toxic component. The possibility of the highest oral toxicity of type B-L toxin to humans is discussed.


Capsule size of Cryptococcus neoformans: control and relationship to virulence. Capsule size of five isolates of Cryptococcus neoformans was controlled by cultivation in media containing varying amounts of sugar. High concentrations of sugar (e.g., 16%) suppressed encapsulation whereas low concentrations (e.g., 1%) allowed maximal encapsulation. Suppression of capsule size was attributed at least in part to the increased osmolarity of the medium because a medium with low sugar concentration but having high osmolarity (by virtue of added sodium chloride) also produced cells having small capsules. The extent of control was more marked with certain of the isolates than with others. Mice were intravenously inoculated with cells of a single isolate cultivated so as to have either small or large capsules, and virulence was measured by comparing death rates. Results indicate that virulence after such an inoculation is a constant characteristic of an isolate and is not affected by size of the capsule of the cells in the inoculum.


Vagal and adrenal influences on gastric secretion in Shay rats. The present experiment was planned to assess the role of vagus and adrenals in gastric secretion in the pylorus ligated rats. Vagotomy significantly reduced the volume of gastric juice but the reduction following adrenalectomy was not significant. Both vagotomy and adrenalectomy significantly reduced the free acid, total acid and pepsin contents of the gastric secretion, the reduction being more pronounced following vagotomy.


Susceptibility of lipopolysaccharide mutants to the bactericidal action of human neutrophil lysosomal fractions. Acetate extracts of purified human neutrophil granules (a mixed population containing specific and azurophil granules) were dialyzed against phosphate-buffered saline (pH 7.0) and tested for bactericidal activity against smooth parent and rough mutant, gram-negative bacteria. Rough (Re) mutants of Escherichia coli, Salmonella typhimurium, and Salmonella minnesota were exquisitely more sensitive to extracts of human polymorphonuclear leukocyte granules than were their smooth (S) parents. The mean lethal dose (LD(50)) for the parent strains was 25 to 50 mug of granule protein per ml. As much as 500 mug of extract per ml failed to kill 100% of the S parents. The LD(50) for the rough mutants was 1.5 to 2.0 mug of the same granule extract per ml; 100% killing occurred with 5 to 10 mug of lysosomal protein per ml. Conditions affecting the growth of the bacteria greatly affected their sensitivity to the granule extracts. Granule extract killed bacteria grown with aeration to log phase 10 to 15 times more efficiently than the same bacteria grown to stationary phase under static conditions. The bactericidal incubation mixture also influenced results, in that greater killing occurred with tryptone than with phosphate or N-2-hydroxyethyl piperazine-N'-2-ethanesulfonic acid-buffered saline. Bactericidal activity depended on lysosomal protein concentration, time, and temperature. Boiled lysosomal fractions failed to kill the S parents but retained 20 to 50% of their ability to kill the Re mutants. Parents (smooth) were killed more efficiently at pH 5 to 6, whereas their Re mutants were killed more efficiently at pH 7 to 8.


Immunological responsiveness to Escherichia coli during pregnancy. To determine whether immunological responsiveness to a bacterial antigen is altered during pregnancy and lactation, Swiss mice (gestation, 19 to 21 days) were studied during early, middle, and late pregnancy and in the early postpartum period. Pregnant and nursing mice, each along with a virgin female littermate control, were injected with 2 x 10(6) heat-killed Escherichia coli and sacrificed 4 days later for the enumeration of splenic anti-E. coli plaque-forming cells (PFC). For 72 4- to 10-day pregnant and control mice ranked together, total PFC per spleen ranged from 0 to 312,650, with 61% of the counts from pregnant animals ranking above the median of 12,700. The mean number of PFC for the pregnant animals was greater than for sister controls in 19 of 23 litters studied (P = 0.001). Responsiveness was also increased for 72 mice tested in later pregnancy. Counts of PFC of 72% of mice 11 to 18 days pregnant were above the median when ranked with those of their controls (P < 0.001). In 18 of 21 litters studied, pregnant animals responded better than littermate controls (P = 0.001). Responses of mice at term (19 to 21 days) were depressed when compared with those of controls, but nursing animals 6 to 9 postpartum responded like virgin animals. Previous studies suggested that low concentrations of estradiol stimulate the mitosis of PFC. To determine if progesterone also increases numbers of PFC, concentrations in a range physiological for pregnancy were added to cultures of spleen cells from male mice injected with E. coli 3 days before. After 24 h of incubation, numbers of PFC in these suspensions were compared to those of the same suspensions incubated without hormone. In 19 of 25 and 48 of 68 suspensions tested at concentrations of 500 pg and 50 ng of progesterone per ml, the numbers of PFC were increased over those of the same suspensions without hormone (P < 0.01). Geometric mean number of PFC for progesterone-treated cells was 45% greater than that for the controls. Findings suggest that female sex hormones, important for the normal growth and differentiation of fetal cells, may also enhance division and/or maturation of immunocompetent cells in the mother.


Inhibitory action of galactose on phagocytes from normal and hypergalactosemic chicks. The inhibitory effect of galactose on phagocyte function was investigated in normal and hypergalactosemic chicks by monitoring the in vitro killing of Escherichia coli by leukocytes and the in vivo clearance of colloidal 125I-labeled bovine serum albumin ([125I]BSA) from the circulation. Elevated levels of galactose (30 mM) significantly impaired the bactericidal activities of leukocytes from both control and hypergalactosemic chicks. However, the latter cells were more susceptible to the galactose-dependent inhibition. Leukocytes from hypergalactosemic chicks displayed near-normal bactericidal activity when assayed in vitro under simulated normal conditions in the absence of galactose. Mean corrected phagocytic indexes, obtained from data on the clearance of colloidal [125I]BSA, were calculated to be 0.358 and 0.299 for control and hypergalactosemic chicks, respectively. Moreover, increased concentrations of galactose significantly impaired the bactericidal activity of circulating leukocytes but did not significantly affect the phagocytic activity of the reticuoendothelial system.


Superoxide dismutase in anaerobic bacteria of clinical significance. Twenty-two anaerobic bacteria isolated from infected sites and normal fecal flora were assayed for superoxide dismutase (SOD). The organisms were also classified according to their oxygen tolerance into aerotolerant, intermediate, and extremely oxygen-sensitive groups. There was a correlation between the enzyme level and the oxygen tolerance, in that the aerotolerant and intermediate organisms had SOD, whereas the extremely oxygen-sensitive isolates had low or undetectable enzyme. Among the oxygen-tolerant organisms, gram-negative bacteria had higher levels of SOD than gram-positive organisms. Oxygen was shown to induce SOD production in a strain of Bacteriodes fragilis grown in minimal medium under continuous-culture conditions. Enzyme levels in this isolate grown under static conditions were lower in minimal medium than in complex medium, indicating that other components in the complex medium were stimulating the production of SOD. Our data suggest that the variation in oxygen tolerance of anaerobes is usually related to their level of SOD. It is postulated that SOD may be a virulence factor that allows pathogenic anaerobes to survive in oxygenated tissues until the proper reduced conditions are established for their growth.


Protective role of complement in experimental Escherichia coli endocarditis. Fourteen strains of Escherichia coli were tested for ability to cause infective endocarditis in rabbits prepared by prior placement of an intracardiac catheter. Strains that were resistant to the bactericidal action of serum caused E. coli endocarditis in 91.4% of rabbits, whereas serum-sensitive strains usually failed to cause persisting infection (11.3% infected, P less than 0.001). Although serum-sensitive E. coli lodged on heart valves within 1 h after intravenous injection, they survived less than 24 h in most normal rabbits. In contrast to normals, all five C6-deficient rabbits injected with a serum-sensitive strain of E. coli developed infective endocarditis (P less than 0.005). No correlation was found between the presence of K1 antigen and the incidence of experimental E. coli endocarditis. Thus, the ability of strains of E. coli to establish persisting endocardial infection in rabbits appears to be directly associated with resistance to the complement-mediated serum bactericidal system. These findings may explain in part the rarity of gram-negative bacillary endocarditis in patients; they also indicate that in certain special circumstances the serum bactericidal system can play a decisive role in host defense.


Interactions of radio-detoxified Escherichia coli endotoxin preparations with the complement system. Escherichia coli O89 lipopolysaccharide (LPS) was treated with different doses of gamma irradiation (5, 10, 15, and 20 Mrad). Various biological activities such as lethal effect, decrease in arterial blood pressure in dogs, and interaction with the complement system were determined for the parent and irradiated preparations. Irradiation of LPS significantly and in a dose-dependent manner decreased its lethal and blood pressure-depressing effects along with its ability to activate the complement system. In contrast, radio-detoxified LPS fixed more strongly the isolated human C1 than did the parent LPS. The possible connection between the toxicity of endotoxin and endotoxin-induced complement activation is discussed.


Possible dual function of M protein: resistance to bacteriophage A25 and resistance to phagocytosis by human leukocytes. Spontaneous phage A25-resistant (A25(R)) mutants of group A streptococci, strain K56, were isolated. The mutant cultures were unable to adsorb phage particles and hyperproduced M protein. Trypsin-digested A25(R) cells regained the ability to adsorb phage particles, but failed to become infectious centers. This failure indicated that the mutation created a double barrier to phage growth: (i) receptors were masked by M protein; (ii) irreversibly adsorbed phage were unable to multiply. Spontaneous variants of one A25(R) mutant, shown to be M negative (M(-)) by electron microscopy, serological tests, and sensitivity to phagocytosis, rapidly adsorbed phage and were able to become infectious centers. Therefore, it was concluded that the mutant phenotype, A25(R), arose by a single mutation and genes coding for this trait and M protein synthesis were either genetically linked, controlled by a common gene or were biochemically interdependent. The A25(R) phenotype was unstable and, as expected for plasmid-coded properties, acridine orange induced segregation of this phenotype. The parental M(+), A25-sensitive (A25(S)) cultures proved to be a mixed population. Infection at various multiplicities indicated that this culture was composed of phage A25(S) cells and cells more resistant to infection. Morphological comparison of thin sections of A25(R) and A25(S) cells by electron microscopy demonstrated striking differences. The A25(R) culture was composed entirely of cells uniformly covered with M protein, whereas the A25(S)M(+) wild-type culture was a mixed population, the majority of cells devoid of M protein. Phagocytosis by human blood enriched the culture for the latter cell type, suggesting that differences in phage sensitivity in the wild-type culture were also determined by the presence or absence of M protein. Thus M protein can serve a dual function for the streptococcal cell by allowing it to avoid infection by bacteriophage and ingestion by human leukocytes.


Cellular immune responses in guinea pigs immunized with cell walls of Histoplasma capsulatum prepared by several different procedures. Since guinea pigs immunized with water-washed cell walls of Histoplasma capsulatum developed cellular immune responses detectable with cytoplasmic substances, attempts were made to determine whether cytoplasmic contamination of the walls was responsible for the induction of the immune response. Cell walls were treated by several procedures designed to remove possible contamination, namely, extraction with lipid solvents, incubation with proteolytic enzymes, and washing with sodium dodecyl sulfate, and each of the treated preparations was compared with water-washed walls for its ability to induce cellular responses demonstrable with cytoplasmic substances. For comparison, wall glycoprotein was also used as a test antigen. Immune responses were assessed by gross and histological examinations of skin test sites and by assays for the production of migration inhibition factor. A portion of the material inducing the response detectable with cytoplasmic substances was apparently removed or altered by each of the purifying procedures. The cellular immune responses to wall glycoprotein were also altered, however, indicating that more than the mere removal of cytoplasmic substances had occurred. On the basis of the data collected from each of the cellular assays involving wall glycoprotein as the test antigen, the hypothesis is proposed that sodium dodecyl sulfate altered or removed protein from the wall and thus augmented its ability to induce a more intense immediate-type hypersensitivity, whereas incubation with Pronase altered the walls in such a way as to shift the balance toward a more intense delayed-type hypersensitivity. The latter effect was probably due to the removal of carbohydrate from the wall by glucanase or to mannosidase contaminating the Pronase preparation.


Bactericidal activity of the normal, cell-free hemolymph of silkworms (Bombyx mori). Cell-free hemolymph from silkworm (Bombyx mori) larvae can kill Escherichia coli B/SM. The bactericidal principle can be resolved into at least two factors. One is a lysozyme-like enzyme that can be absorbed on crab shell chitin and on bentonite, and the other (cofactor) is an anionic factor that is of low molecular weight, can pass through the chitin column and a carboxymethyl-cellulose column, and can be eluted from a diethylaminoethyl-cellulose column at mu = 0.15 and pH 7.5. Egg-white lysozyme cannot replace the silkworm lysozyme-like enzyme for restoring the bactericidal activity when it is mixed with the cofactor, although it can enhance the bactericidal activity of the mixture of silkworm enzyme and cofactor. Mg2+ and Ca2+ can inhibit the bactericidal activity.


Isolation of cryptic plasmid deoxyribonucleic acid from Kanagawa-positive strains of Vibrio parahaemolyticus. Twelve strains of Vibrio parahaemolyticus was examined for plasmid deoxyribonucleic acid (DNA) by dye-buoyant gradient centrifugation. Four Kanagawa-positive strains, all isolated from the same outbreak of gastroenteritis, contained multiple plasmid species of cryptic function. However, three Kanagawa-negative strains and five Kanagawa-positive strains were not found to contain demonstrable plasmid DNA. R-plasmids were successfully transferred from Escherichia coli to V. parahaemolyticus.


Colonization of porcine intestine by enterotoxigenic Escherichia coli: selection of piliated forms in vivo, adhesion of piliated forms to epithelial cells in vitro, and incidence of a pilus antigen among porcine enteropathogenic E. coli. In contrast to K88-positive porcine enterotoxigenic Escherichia coli (ETEC), K88-negative porcine ETEC strains did not adhere to isolated intestinal epithelial cells in vitro. However, they did adhere to intestinal epithelium in vivo. Growth of one such ETEC (strain 987) in pig small intestine consistently yielded a greater percentage of piliated cells than did growth in vitro. This increase was demonstrable by electron microscopy, by change in colonial morphology, and by agglutination in specific antisera against the pili of strain 987. In contrast to the stored stock culture (which contained very few piliated cells), richly piliated forms of strain 987 did adhere to isolated intestinal epithelial cells in vitro. A series of porcine E. coli strains was tested for agglutinability in antiserum against the pili of strain 987, and several K88-negative ETEC strains were agglutinated. These data are consistent with the hypothesis that pili facilitate intestinal adhesion and colonization by K88-negative ETEC strains.


Reduction of reactivity of Escherichia coli enterotoxins by intestinal mucosal components. Incubation studies involving rabbit and piglet small intestinal mucosal components and Escherichia coli and Vibrio cholerae enterotoxins were conducted at 37 and 4 degrees C. Mucosal homogenate cytosol from rabbits did not significantly alter the reactivities of either cholera enterotoxin (CT) or E. coli labile enterotoxin (LT). However, mucosal homogenate cytosol from piglets was capable of neutralizing LT, though it had no effect on E. coli stable enterotoxin. LT became bound to piglet and rabbit microvillous membranes at 4 degrees C in the presence of a protective protein. In rabbits, the binding of LT was not dependent upon an intact glycocalyx or free unbound CT-receptors, although some binding was apparently associated with the glycocalyx and CT-receptors. These results indicated the presence of two different LT-receptors in microvillous membranes one being associated with the membrane proper and the other with the glycocalyx. Stable enterotoxin did not bind to in vitro preparations of piglet mucosal components, which is evidence for a different mechanism for inducing intestinal secretion.


Catabolism of glucose and fatty acids by virulent Treponema pallidum. We describe a procedure which permits essentially full recovery of physiologically active Treponema pallidum from rabbit testicular extracts and greatly reduces contaminating tissue material. Such preparations were employed for investigations of the ability of T. pallidum to catabolize glucose and fatty acids. Radiorespirometric studies revealed that glucose and pyruvate, but not oleate or palmitate, could be degraded to CO2. The use of differentially labeled glucose, in conjunction with enzymatic analyses, indicated that glucose was catabolized by a combination of the Embden-Meyerhoff-Parnas and hexose monophosphate pathways. Pyruvate was degraded to CO2 from only the carboxyl position, suggesting the absence of a functioning Krebs cycle; this was substantiated by additional enzyme analyses and radiorespirometric experiments. Oleate and palmitate were incorporated but not catabolized by beta-oxidation. Glucose, although catabolized, was not incorporated. The potential significance of these findings is discussed.


Pathogenesis of neonatal Escherichia coli meningitis: induction of bacteremia and meningitis in infant rats fed E. coli K1. Escherichia coli K1 strains, isolated from human newborns with meningitis, were fed to pathogen-free Sprague-Dawley infant rats by an oral gastric tube. Feeding of 10(3) to 10(11) organisms colonized the intestine of approximately 70% of the animals. At 5 days postfeeding of 3- to 5-day-old rats, bacteremia was detected in 60%, and meningitis occurred in 15% of bacteremic animals. Colonization and bacteremia were age-related. Rats 15 days old had only 19 colonization and 10% bacteremia, and those 30 days old were almost completely resistant to colonization and bacteremia. The intranasal route was less effective in inducing colonization and bacteremia. Intralitter transmission from E. coli K1-fed rats occurred, with 52% of water-fed controls becoming colonized and 15% become bacteremic. Colonization of mothers from their fed infants occurred, but none of five tested developed bacteremia. Other E. coli capsular polysaccharide types were studied. A K92 strain isolated from a newborn with meningitis induced a 77% colonization rate, and 8% of these developed bacteremia without detectable meningitis. An E. coli K100 strain showed a 32% colonization rate, and 2% developed bacteremia. The age relation, relatively high virulence of K1 compared with other capsular types, spontaneous appearance of colonization, bacteremia, and meningitis, and intralitter transmission of colonization and disease in newborn rats closely parellel E. coli epidemiology in human neonates.


Non-encapsulated variant of Cryptococcus neoformans. II. Surface receptors for cryptococcal polysaccharide and their role in inhibition of phagocytosis by polysaccharide. The binding of cryptococcal polysaccharide to a non-encapsulated strain of Cryptococcus neoformans was studied. Binding of purified polysaccharide to the yeast was determined by inhibition of phagocytosis and by indirect immunofluorescence techniques. The ability of cryptococcal polysaccharide to prevent phagocytosis of the non-encapsulated strain appears to be directly related to adherence of polysaccharide to the yeast via specific receptors on the cell surface. Addition of varying doses of cryptococcal polysaccharide to non-encapsulated yeast cells inhibited phagocytosis only at polysaccharide concentrations at which the polysaccharide could be demonstrated on the yeast surface by immunofluorescence. Macrophages treated with cryptococcal polysaccharide had no detectable amounts of cryptococcal polysaccharide adherent to their surface, and they had a normal ability to phagocytize the yeast. Kinetic studies showed that inhibition of phagocytosis is directly related to the presence of cryptococcal polysaccharide at the yeast surface rather than to some indirect effect by the polysaccharide on serum components necessary for phagocytosis. Purified polysaccharide from C. neoformans serotypes A, B, C, and D bound to the yeast, but type III pneumococcal polysaccharide did not inhibit phagocytosis of the nonencapsulated yeast. Cryptococcal polysaccharide did not bind to cells of Candida albicans, C. pseudotropicalis, Torulopsis sp., Rhodotorula sp., or Saccharomyces cerevisiae.


Experiments on the passive sensitization of human basophils, using quantitative immunofluorescence microscopy. In previous experiments a correlation was found between the amount of IgE on human basophils and the IgE serum level. The results of these experiments are shown to fit a free exchange model with an approximately constant K-value. We investigated whether the free IgE-receptors on the basophils, which should be present according to this model, could be saturated by incubating the cell suspensions with IgE myeloma protein or with sera from patients with an elevated IgE serum level. Various incubation conditions were applied in sensitizing the leukocytes, and cells from both atopic and nonatopic subjects were used for testing, but no increase in basophil-bound IgE could be measured with the quantitative immunofluorescence technique. Nor could we demonstrate a significant dissociation of cell-bound IgE in a period of 24 h. Therefore another hypothesis is put forward, in which receptor turnover is taken into account: we assumed that that free receptors on the basophils had a shorter functional half-life, than the half-life of the IgE-receptor complexes. This model would explain the contradictory results mentioned above.


Tumor regression after intralesional injection of emulsified trehalose-6,6'-dimycolate (cord factor): efficacy increases with oil concentration. Injection of emulsified trehalose-6,6'-dimycolate (TDM), a mycobacterial glycolipid, into transplants of an established, syngeneic murine fibrosarcoma induced complete regression of tumor in a number of animals. The number of animals in wich tumor regressed completely depended on the amount of oil in the emulsion. The anti-tumor activity of the TDM emulsion containing the highest concentration of oil was equivalent to that of living BCG.


Immunological studies in methadone maintained patients. Rosettes formed by circulating T and B lymphocytes obtained from 30 methadone maintained narcotic addicts were compared with those of 23 normal control subjects. Abnormal percentages of T rosette-forming cells were found in 6 of 30 patients (20%) while the percentages of B rosette-forming cells were increased in 40% and reduced in 27% of methadone patients. It appears that alterations in the percentages of peripheral lymphocytes, particularly those with cell surface complement receptors, should be added to the list of immunological abnormalities evident in some methadone-treated narcotic additics.


On the interaction between the anti-inflammatory substance proquazone (RU 43-715) and phenprocoumone. In a double blind study on 20 anticoagulated patients, the influence of the anti-inflammatory drug 1-isopropyl-4-phenyl-7-methyl-2 (1H) quinazolone on the degree of hypocoagulability was examined. In comparison to a placebo group, there was no statistical difference in the Quick precentage, in coagulation factors II, VII, and X, and in platelet aggregation induced by collagen and by epinephrine respectively. In addition, no increased bleeding tendency could be observed during the study.


Papaverine hydrochloride: the evaluation of two new dosage forms. The bioavailability of papaverine, administered as sustained release capsules, an elixir, and soft gelatin capsules, was studied with volunteers. Blood samples were assayed for papaverine, using a gas chromatographic method, following the administration of single 150 mg doses of papaverine HC1. The elixir and the soft gelatin capsule resulted in nearly identical papaverine blood levels, while peak levels, area under the blood level-time curve, and plasma levels 0.5, 1.0, 1.5, and 2.0 hours after dosing with the sustained release capsule were significantly (p less than 0.01) lower.


[Psychopharmacologic studies on the combined effect of alcohol and oxazepam on reactivity pattern. II. Subjective feeling and reaction behavior]. Psychopharmacological investigations of the subjective state of being and the reactivity pattern of a group of 14 probands show a good agreement with the alterations of performance reported in the first part of this publication and with the data on polarity profiles. In addition to a sedative effect the interaction of alcohol and oxazepam in the oxazepam trial results in dysphoric changes of mood and related significant alterations of polarity profiles. A correlation of the changes of performance and the alterations of the polarity profiles with the respective blood levels of alcohol and oxazepam could be demonstrated.


Action of hydrogen peroxide on degradation of DNA after irradiation in Escherichia coli. Hydrogen peroxide (H2O2), which produces breaks in cellular DNA, has not hitherto been shown to cause degradation of DNA. In this investigation it is shown that if transcription is blocked with rifampin, treatment with H2O2 causes degradation of DNA to nearly the same extent as does gamma-radiation. Further, if cells are given a treatment with H2O2 and incubated for 50 min, the amount of degradation in a second treatment is markedly less. This is attributed to the induction of the inhibitor of post-irradiation degradation of DNA (prd) by the first treatment. There is thus a double action of H2O2: first, to induce inhibition, and second, to cause degradation of DNA to begin in non-induced cells. The genetic dependence of induction by H2O2 mimics that of ionizing radiation. Accordingly, the induction process does not occur in recA- and lex- cells, because they are not inducible and is absent in recB- cells because they lack exonuclease V, the major component of prd. Potassium iodide (KI), an OH radical scavenger, negates the action of peroxide on DNA. The results obtained in this study suggest a possible theory for the evolution of radiation response systems


The effect of U.V.-irradiation on lambda DNA transcription. The effect of U.V.-irradiation of template DNA has been studied in vitro in the E. coli RNA polymerase system with native and U.V.-treated lambda DNA. Lambda DNA is more susceptible to U.V. than is calf-thymus DNA, yet a residual activity is observed at a U.V. dose of 0-5+10(4) erg/mm2. From the kinetic analysis of the reaction and the incorporation of lambda 32P-labelled nucleoside triphosphates, it seems reasonable to conclude that U.V.-irradiation probably does not affect the DNA initiation sites, recognizable by RNA polymerase. The transcription products made with U.V.-irradiated lambda DNA are assymmetrical, and hybridized to the right half (R) and the left half (L) of lambda DNA with the ratio of R/L = 4/1, and they show a lower hybridizability than the transcripts with native lambda DNA. The initiation sites recognizable by RNA polymerase seem to be the same on both native and U.V.-irradiated lambda DNA though the transcription of U.V.-treated lambda DNA appears to terminate with rather short RNA chains.


Split-dose and liquid-holding recovery after X-irradiation on diploid yeast Saccharomyces cerevisiae. I. Dependence on growth-phase. Liquid-holding recovery (LHR) and the sparing effect of dose fractionation were investigated with 100 kVp-X-rays in diploid yeast from exponential and stationary phase. Exponential cells showed prompt and complete split-dose recovery. The ability to undergo LHR remained constant during 2-5 hours incubation after the first dose. Stationary-phase cells did not exhibit split-dose recovery (SDR) in a simple way: there was an increase in sensitivity after 3-5 hours followed by a gradual increases with time. It is suggested that stationary cells are starved of an essential co-factor which has to be synthesized de nova.


Significance of catheter tip cultures.

Significance of catheter tip cultures. Sixty-three patients were studied after renal transplantation to determine whether infection associated with use of the urethral catheter could be diagnosed reliably with catheter tip cultures. Catheter tip cultures correlated poorly with urine cultures aspirated from the catheter and follow-up voided urine cultures. Postoperative infectious complications did appear to be related to catheter contamination.


Macrophages and/or fibroblasts in hematopoietic diffusion chamber cultures. An ultrastructural study of diffusion chamber (DC) hematopoietic colonies derived from rat bone marrow is reported. The emphasis is placed on the structural features of macrophages and fibroblasts in cultures. The observations indicate that the two cell types are normal components of DC cultures. In older cultures both macrophages and fibroblasts contain large lipid droplets, sometimes causing difficulty in the precise characterization of the cell type. The possible origin of fibroblasts from adventitial cells if sinuses or of larger blood vessels of the bone marrow implanted in diffusion chambers is discussed. It is suggested that fibroblasts exert an enhancing influence on the growth of blood cells in DC cultures, comparable to feeder layers in in vitro cultures.


Cold injury in early infancy.

Cold injury in early infancy. Sixteen cases of neonatal cold injury, five of them fatal, were seen in the winter of 1974-75. The affected infants, who weighed from 2.5 to 3 kg. had developed symptoms when the ambient termperature was below 10 C. Few of them were referred as cases of hypothermia. Refusal to eat was the most common complaint and less often edema and/or apathy. No correlation was found between death and ethnic origin, sex, duration of illness or minimum temperature. Admission weight, however, tended to be lower in the infants who died. The consistent finding of thrombocytopenia and the suspected bleeding phenomena suggested that disseminated intravascular coagulation may have been a factor in the unfavorable outcome of some of the cases. Evidence supporting such a hypothesis and proposals for the prevention. Diagnosis and treatment of neonatal cold injury are presented.


[Serodiagnosis of syphilis from the viewpoint of the immunologist]. A review of the immunology of the serological diagnosis of syphilis is given and modern methods for the demonstration of treponema-specific antibodies are shown. The possible combinations of test results and interpretations of these are discussed. The importance of the demonstration of treponema-specific IgM-antibodies not only for diagnosis but also for basis of treatment is finally pointed out.


The laboratory diagnosis of Pneumocystis carinii pneumonia. In the diagnosis of Pneumocystis carinii infection in man, rather exacting methods of staining must be used for the organism to be visualized in lung tissue. Techniques for sample collection, which range from open lung biopsy to endobronchial brush methods or collection of sputum, are discussed. Recent advances in the serologic diagnosis and in the culture of the organism are also covered.


Specific direct fluorescent antibody detection of Treponema pallidum. In a study to determine the reliability of specific direct fluorescent antibody staining of Treponema pallidum (DFATP) in lesion exudate, and to evaluate it as a potential diagnostic test to be used in lieu of or as an adjunct to the darkfield and other laboratory tests as an aid in the diagnosis of early syphilis, two types of comparisons were made: Study A-Replicate specimens from each of 350 lesions were examined in the state laboratory by DFATP and in the field by darkfield microscopy and the results were compared; Study B--95 specimens of lesion exudate were tested by the DFATP test and compared with the Fluorescent Treponemal Antibody Absorption (FTA-ABS) test on patients' sera. The tests in each study were evaluated as to sensitivity, specificity, and agreement with each other. The DFATP proved to be as reliable as the darkfield, was advantageous in some instances, and can be valuable when a darkfield examination is not feasible. Much of the responsibility of an adequate DFATP or darkfield test rests on the one who takes the specimen.


Serologic study of specimens with borderline FTA-ABS test reactivity. The treponemal group-specific absorbed fluorescent antibody test (FTA-ABS) does not yield clearly positive or negative results in all instances. This study was designed to analyze those sera showing borderline reactivity, in order to determine whether additional tests may help to resolve serodiagnostic problem cases. FTA-ABS tests on 23,807 sera submitted to the Wisconsin State Laboratory of Hygiene yielded borderline results with 479 specimens (2%). Patients showing inconclusive FTA-ABS test reactivity were equally distributed among older and younger age groups, and 6% of borderline cases were women. Of all the 479 specimens, only five sera (1%) gave a non-specific hemagglutination with the Treponema pallidum microhemagglutination (MHA-TP) test, with 82.5% of the FTA-ABS test borderline sera yielding negative results with the MHA-TP test. Because recent findings had shown atypical false fluorescence with the FTA-ABS test on sera from patients with antinuclear antibody, the fluorescent antinuclear antibody test (FANA) was also performed on specimens inconclusive with the FTA-ABS test. Only seven sera (1.5%) were reactive by the FANA test, suggesting that antinuclear antibody was not a significant cause of borderline FTA-ABS reactions. The implications of these findings to venereal disease serology laboratory practice are discussed.


The impact of laboratory improvement programs on laboratory performance: the CLIA 67 experience. The experience acquired by the Center for Diseases Control during the past 7 years in the administration of the Clinical Laboratories Improvement Act of 1967 suggests that the key indicators of reliability have been identified and that sensitive measurement of those indicators is now possible and practical. The costs of assuring high quality are inconsequential compared to the costs to the patient and taxpaying public of inaccurate test results. This objective system for evaluating clinical laboratories has been applied to licensed interstate laboratories and has been shown to be effective. This proven system has been offered to the  Bureau of Health Insurance of the Social Security Administration for application to Medicare laboratories.


Substitutability among different types of care under Medicare. The question of whether Medicare coverage of outpatient services, nursing home care, and home health care reduced the use of short-term hospitals by Medicare beneficiaries, and whether reduced hospital use saved the Medicare program money, is reexamined by use of a simultaneous-equations model estimated by the two-stage least-squares method. It is argued that all alternative modes of care must be examined simultaneously for accurate results. The findings partly support and partly contradict results of previous studies: both outpatient care and nursing home care can substitute for hospital care, but a complementary relationship between outpatient and nursing home care indicates that the additional coverage resulted in greater, not less, expenditure by Medicare.


Mycoplasma and mycoplasma mastitis.

Mycoplasma and mycoplasma mastitis. Mastitis due to mycoplasma has been reported sporadically from several countries in Europe, Australia, Israel, New Zealand, and many states in the United States. Most reported occurrences are due to Mycoplasma bovis, but 5 other mycoplasmas are reported to cause mastitis. A total of 5 species of mycoplasma have been isolated from cows with mastitis in California. Therapy trials with M bovis infections have not been encouraging. Recovery is slow, and shedding of mycoplasma into milk of apparently recovered cows for an indefinite period is common.


Dying of gamma-irradiated Escherichia coli studied by the use of prophage. Loss of the biological activity of deoxyribonucleic acid in gamma-irradiated Escherichia coli cells was studied. The study is based on two sets of experimental data: (i) post-irradiation heat inducibility of the cells whose chromosomes were "labeled" with the thermoinducible lambdacI857ind prophage, and (ii) post-irradiation capacity of nonlysogenic cells to promote growth of the unirradiated lambdacI857ind phage. The results show that, at the beginning of incubation after irradiation, the number of plaques formed upon heat induction of lysogenic cells was much higher than the viable cell count of the nonheated culture. This high resistance of the heat inducibility gradually decreased during post-irradiation incubation. Finally, after a period of 4 h, there was no difference in sensitivity between the heat inducibility and the colony-forming ability of gamma-irradiated cells. The capacity of gamma-irradiated bacteria to support growth of unirradiated lambdacI857ind is radioresistant; this resistance, in contrast to that of heat inducibility, is much less affected during post-irradiation incubation. A continuous decrease in radioresistance of heat inducibility without a corresponding decrease in radioresistance of the capacity suggests that functional failure of initially undamaged and/or repaired parts of the chromosome gradually develops after irradiation. From the fact that after 4 h all colony formers are capable of being induced by heat, whereas no chromosomal activity can be detected in nonviable cells, two conclusions may be drawn: (i) gamma-irradiated E. coli cells destined to die reach their biological end point within 4 h of post-irradiation incubation; (ii) in most cells, functional failure of the whole chromosome is the immediate cause of death.


Characterization of methylated neutral amino acids from Escherichia coli ribosomes. The methylated neutral amino acids from both 30S and 50S ribosomal subunits of an Escherichia coli K strain were characterized. The 50S ribosomal subunit contains three methylated neutral amino acids: N-monomethylalanine, N-monomethylmethionine, and an as yet unidentified methylated amino acid found in protein L11. Both N-monomethylalanine and N-monomethylmethionine were found in protein L33. The amount of N-monomethylmethionine in this protein, however, is variable but not more than 0.25 molecules per protein. Thus protein L33 from this E. coli K strain has heterogeneity in its N-terminal amino acid and can start with either N-monomethylalanine or N-monomethylmethionine. The N-monomethylmethionine residue was not derived from the reduction of N-formylmethionine in the protein. The 30S ribosomal subunit contains only one methylated neutral amino acid: N-monomethylalanine.


Regulation of L-cystine transport in Salmonella typhimurium. A kinetic analysis of L-cystine uptake in wild-type Salmonella typhimurium indicates the presence of at least two, and possibly three, separate transport systems. CTS-1 accounts for the majority of uptake at 20 muM L-cystine, with a Vmax of 9.5 nmol/min per mg and a Km of 2.0 muM; CTS-2 is a low-capacity, higher-affinity system with a Vmax of 0.22 nmol/min per mg and a Km of 0.05 muM; a third, nonsaturable process has been designated CTS-3. We find that wild-type CTS-1 levels are at least 11 times higher in sulfur-limited cells than in L-cystine-grown cells. Pleiotropic cysteine auxotrophs of the types cysE (lacking serine transacetylase) and cysB- (lacking a regulatory element of positive control) have very low levels of CTS-1 even when grown under conditions of sulfur limitation, which response is analogous to that previously observed for cysteine biosynthetic enzymes (N . M. Kredich, J. Biol. Chem. 246:3474-3484, 1971). CTS-1 is induced in cysE mutants by growth in the presence of O-acetyl-L-serine (the product of serine transacetylase), again paralleling the behavior of the cysteine biosynthetic pathway. Strain DW25, a prototrophic cysBc mutant, which is constitutive for cysteine biosynthesis, is also derepressed for CTS-1 when grown on L-cystine. Since CTS-1 is regulated by sulfur limitation, O-acetyl-L-serine, and the cysB gene product, the same three conditions controlling cysteine biosynthesis, we propose that this transport system is a part of the cysteine regulon.


Origin of the heterogeneity of cell wall O-polysaccharides from Salmonella zuerich (1,9,12,(46),27). The heterogeneity of the cell wall O-polysaccharide of Salmonella zuerich (factor 1 present or absent) is probably not due to mutations in the stock since it was seen in essentially similar fashion (proportion one 1+ to four 1-forms) in four separate lots of polysaccharide extracted from separate culture batches. The results of indirect fluorescent antibody studies suggest that form variation of factor 1, occurring at an unusually high rate, is the most probable basis of the heterogeneity.


Analysis of genetic recombination between two partially deleted lactose operons of Escherichia coli K-12. Genetic recombination between a nontandem duplication of two partially deleted lactose operons (lacMS286phi80dIIlacBK1) in Escherichia coli K-12 has been examined. Since the deletions were nonoverlapping, rare lactose-fermenting (Lac+) recombinants occurred and were detected qualitatively on lactose tetrazolium agar indicator plates as white papillae growing on the surface of red colonies or quantitively on lactose minimal agar plates. Formation of Lac+ recombinants required the recA, recB, and recC gene products. Indirect suppression of recB21 by sbcB15 led to an increase in the frequency of Lac+ recombinants over wild-type levels. recF143 did not appreciably alter the number of Lac+ progeny, whereas recL152 and sbcB15 strains yielded increased numbers of Lac+ recombinants. The nature and formation of Lac+ recombinants was also examined. Respreading analysis indicated that formation of recombinants occurred primarily as the cells entered early stationary phase on the surface of the minimal agar plates and that over 90% of the recombinants contained a phi80dIIlac+ prophage. Time-of-entry experiments suggested that the region of deoxyribonucleic acid between the two operons was not inverted as a result of the recombinational event.


Properties of the relaxation complex of supercoiled deoxyribonucleic acid and protein of R plasmid NR1 in Escherichia coli. Some properties of the supercoiled deoxyribonucleic acid (DNA)-protein relaxation complex of the R plasmid NR1, which contains more than one origin for DNA replication, were examined. The percentage of complexed NR1 molecules that can be converted to the relaxed (nicked) form appeared to be unaffected by the conditions under which the host cells were cultured. However, the percentage of supercoiled NR1 DNA that can be relaxed was highly dependent on the method used to prepare the DNA and the agents used to induce relaxation. Our data suggest that 100% of NR1 molecules may exist in situ as DNA-protein relaxation complexes. An RTF-Tc segregant of NR1, which has deleted the r-determinants component of the NR1 and therefore does not contain the two origins of replication located in the r-determinants, has indistinguishable relaxation properties in comparison with NR1 itself.


Inactivation and partial degradation of phosphoribosylanthranilate isomerase-indoleglycerol phosphate synthetase in nongrowing cultures of Escherichia coli. The stability of tryptophan biosynthetic enzyme activities was examined in cultures of repressor-negative (trpR) strains of Escherichia coli K-12 incubated under conditions of nutrient starvation of chloramphenicol inhibition. The results show that four of the five activities examined are stable under most nongrowing conditions, whereas one activity, indoleglycerol phosphate (InGP) synthetase, carried by the trpC protein, is unstable under most conditions tested. Phosphoribosylanthranilate (PRA) isomerase activity, which is also carried by the trpC protein, is unstable during starvation for ammonium, cysteine, or sulfate but is stable under other nongrowing conditions where InGP synthetase is not. InGP synthetase activity but not PRA isomerase activity is also diminished about twofold in cultures using glycerol as a carbon-energy source. These results indicate that one or both activities of the trpC protein is specifically inactivated under several culture conditions. Experiments with antibodies to the trpC protein show that sulfate-starved and ammonium-starved cultures contain 20 to 40% less immunologically reactive trpC protein than unstarved cultures. This indicates that the trpC protein is probably partially degraded under these conditions. During recovery from sulfate starvation or ammonium starvation, cultures slowly regain normal levels of InGP synthetase and PRA isomerase activities, suggesting that inactivation may be reversible.


Molecular events associated with induction of arginase in Saccharomyces cerevisiae. Arginase, the enzyme responsible for arginine degradation in Saccharomyces cerevisiae, is an inducible protein whose inhibition of ornithine carbamoyl-transferase has been studied extensively. Mutant strains defective in the normal regulation of arginase production have also been isolated. However, in spite of these studies, the macromolecular biosynthetic events involved in production of arginase remain obscure. We have, therefore, studied the requirements of arginase induction. We observed that: (i) 4 min elapsed between the addition of inducer (homoarginine) and the appearance of arginase activity at 30 degrees C; (ii) induction required ribonucleic acid synthesis and a functional rna1 gene product; and (iii) production of arginase-specific synthetic capacity occurred in the absence of protein synthesis but could be expressed only when protein synthesis was not inhibited. Termination of induction by inducer removal, addition of the ribonucleic acid synthesis inhibitor lomofungin, or resuspension of a culture of organisms containing temperature-sensitive rna1 gene products in a medium at 35 degrees C resulted in loss of ability for continued arginase synthesis with half-lives of 5.5, 3.8, and 4.5 min, respectively. These and other recently published data suggest that a variety of inducible or repressible proteins responding rapidly to the environment may be derived from labile synthetic capacities, whereas constitutively produced proteins needed continuously throughout the cell cycle may be derived from synthetic capacities that are significantly more stable.


Incompatibility and surface exclusion properties of H1 and H2 plasmids. Plasmids of the H incompatibility group showed two types of surface exclusion and incompatibility interactions. Strong incompatibility and surface exclusion were evident between plasmids within the same subgroup, and recombination frequently occurred between these plasmids after antibiotic selection for the presence of two plasmids in the same cell. Weaker interactions were seen between plasmids of the different subgroups, H1 and H2, and recombination was not detected. Incompatibility between H1 and H2 plasmids led preferentially to the loss of the H1 plasmid, irrespective of the order of entry of the plasmids. These data are consistent with the hypothesis that incompatibility is negatively controlled.


Control of protein synthesis in Escherichia coli: analysis of an energy source shift-down. The energy source shift-down described in the preceding paper (Molin et al., J. Bacteriol. 131: 7-17, 1977) was used to study the effects of shift-down on protein synthesis. The overall rate of protein synthesis was reduced immediately, and to the same extent, in stringent and relaxed strains. The primary effect of the shift was a slowing down of the polypeptide chain growth rate, a finding not previously reported. In stringent strains the normal, preshift rate was reestablished within 2 to 3 min, whereas in relaxed strains the chain growth rate remained low for about 20 min before slowly returning to the normal value, which was reestablished some 50 to 60 min after the shift. Throughout this transition, the stability of messenger ribonucleic acid (mRNA) remained unchanged in both strains. We interpret these findings as evidence of the more rapid reduction of the mRNA pool in the stringent strain after shift-down: we believe that very soon after the shift, the stringent strain reduces its pool of mRNA and with it the number of ribosomes engaged in protein synthesis. In this manner the number of active ribosomes is adjusted to the availability of energy and carbon. The relaxed strain cannot rapidly reduce its mRNA pool, which thus remains large enough to engage a near-preshift number of ribosomes during a prolonged period; as a consequence its ribosomes must work at a reduced rate. The possibility that ppGpp is involved in the control of mRNA production is discussed. After shift-down, the initial part of beta-galactosidase (the auto-alpha fragment) was produced at a higher rate than complete beta-galactosidase in the relaxed strain, as expected when translation is impeded.


Effect of transient lambda prophage induction on ultraviolet light resistance and recombination in Escherichia coli. Transient induction of lambda prophage increases the ultraviolet light resistance of most exponentially growing Escherichia coli lysogens. Resistance is increased in wild-type, recB, recB recC, recB recC recF, and recB recC recL hosts. No enhancement in recA lysogens was found, nor was there enhancement in stationary cultures. Enhancement was dependent upon the lambdared recombination system. Transient induction also increases the genetic recombination rate in recB lysogens as measured in Hfr X F- matings.


Metabolism of arginine-specific messenger ribonucleic acid in Escherichia coli K-12. Ribonucleic acid-deoxyribonucleic acid (RNA-DNA) hybridization was employed for the determination of the level of messenger RNA (mRNA) transcribed from seven of the nine genes of the arginine regulon of Escherichia coli K-12. The quantity of RNA complexing with each of the separated DNA strands of the argA, argF, argE, and argCBH operons carried on specialized transducing phages was measured. The derepressed:repressed ratio of mRNA formed in vivo was found to vary between about 3 and 4 when measured by hybridization to DNA isolated from specialized transducing phages carrying the argA, argE, argCBH, argF, and argI operons.


Morphological analysis of the division cycle of two Escherichia coli substrains during slow growth. Morphological parameters of the cell division cycle have been examined in Escherichia coli B/r A and K. Whereas the shape factor (length of newborn cell/width) of the two strains was the same at rapid growth (doubling time, tau, less than 60 min), with decreasing growth rate the dimensions of the two strains did change so that B/r A cells became more rounded and B/r K cells became more elongated. The process of visible cell constriction (T period) lasted longer in B/r A than in B/r K during slow growth, reaching at tau = 200 min values of 40 and 17 min, respectively. The time between termination of chromosome replication and cell division (D period) was found to be longer in B/r A than in B/r K. As a result, in either strain completion of chromosome replication seemed always to occur before initiation of cell constriction. Nucleoplasmic separation did not coincide with termination as during rapid growth but occurred in both strains within the T period, about 10 min before cell division.


Temperature-sensitive cell division mutants of Escherichia coli with thermolabile penicillin-binding proteins. The thermostability of the penicillin-binding proteins (PBPs) of 31 temperature-sensitive cell division mutants of Escherichia coli has been examined. Two independent cell division mutants have been found that have highly thermolabile PBP3. Binding of [(14)C]benzylpenicillin to PBP3 (measured in envelopes prepared from cells grown at the permissive temperature) was about 30% of the normal level at 30 degrees C, and the ability to bind [(14)C]benzylpenicillin was rapidly lost on incubation at 42 degrees C. The other PBPs were normal in both mutants. At 30 degrees C both mutants were slightly longer than their parents and on shifting to 42 degrees C they ceased dividing, but cell mass and deoxyribonucleic acid synthesis continued and long filaments were formed. At 42 degrees C division slowly recommenced, but at 44 degrees C this did not occur. The inhibition of division at 42 degrees C was suppressed by 0.35 M sucrose, and in one of the mutants it was partially suppressed by 10 mM MgCl(2). PBP3 was not stabilized in vitro at 42 degrees C by these concentrations of sucrose or MgCl(2). Revertants that grew as normal rods at 42 degrees C regained both the normal level and the normal thermostability of PBP3. The results provide extremely strong evidence that the inactivation of PBP3 at 42 degrees C in the mutants is the cause of the inhibition of cell division at this temperature and identify PBP3 as an essential component of the process of cell division in E. coli. It is the inactivation of this protein by penicillins and cephalosporins that results in the inhibition of division characteristic of low concentrations of many of these antibiotics.


Genetics of the relB locus in Escherichia coli. A mutant of Escherichia coli with a delayed relaxed phenotype very similar to that of a previously described relB mutant has been obtained using a new selection procedure. The mutation giving rise to this phenotype has been shown to map at 34.5 min and to be 12% cotransducible with man. It is recessive, revertible, and most likely an allele of the relB gene.


Identification of lipopolysaccharides and phospholipids of Escherichia coli in polyacrylamide gels. Polyacrylamide gel electrophoresis of unfractionated lysates of radioactively labeled cells resolves not only proteins and polynucleotides into discrete bands but also cellular lipopolysaccharides and phospholipids. This allows a determination of the intracellular amounts of all of these macromolecules. In addition, this technique is sensitive enough to detect mutational alterations in lipopolysaccharide structure. Polyacrylamide gel electrophoresis is herein shown to be a useful tool for investigations into the structure of lipopolysaccharides and the synthesis of lipopolysaccharides and phospholipids.


Mucopeptide biosynthesis by minicells of Escherichia coli. Minicells produced by Escherichia coli chi925 incorporated amino acids and N-acetyl-d-glucosamine into mucopeptide.


Do cytochromes function as oxygen sensors in the regulation of nitrate reductase biosynthesis? The observation that oxygen represses nitrate reductase biosynthesis in a hemA mutant grown aerobically with or without delta-aminolevulinic acid indicates that cytochromes are not responsible for nitrate reductase repression in aerobically grown cells.


Fine-structure mapping and complementation analysis of the Escherichia coli cysB gene. Sixty-two point mutations were isolated in Escherichia coli by means of transduction with mutagenized phage P1. Twenty-two deletions extending into cysB but able to recombine with at least some of the point mutations were isolated on a transmissible E. coli plasmid. Mapping of the point mutations against the deletions divided the former into 16 deletion groups. Nine merodiploids were constructed in which the chromosome carried one of the three point mutations most distal to the trp operon and in which a plasmid carried one of the three point mutations most proximal to the trp operon. All of these showed a Cys-phenotype. It follows that mutations at the two extreme ends of the region belong to the same complementation group.