Two-dimensional gel electrophoresis of membrane proteins. A high-resolution method for two-dimensional separation of membrane proteins is described. It involves a nondiscriminating solubilization of a membrane preparation with sodium dodecyl sulfate, followed by electrophoresis in the first dimension according to charge (by isoelectric focusing). The electrophoresis in the second dimension is in the presence of sodium dodecyl sulfate, thus separating proteins on the basis of molecular weight. Electrophoresis in the first dimension is either on a thin slab gel, or on a small-diameter tube; electrophoresis in the second dimension is on a thin slab gel. Up to 100 mug of protein can be analyzed. The two-dimensional system is a modification of the one recently described by O'Farrell (1975). About 150 different proteins can be visualized in Escherichia coli or Salmonella typhimurim cell envelopes; examples of differences between mutant and wild-type strains are presented. The method is applicable also to membrane preparations from other sources: a two-dimensional separation of plasma membrane proteins from HeLa cells is presented.


Behavior of colicins E1, E2, and E3 attached to sephadex beads. Colicins E1, E2, and E3 were covalently attached to Sephadex G-25 beads by cyanogen bromide activation. These immobilized colicins were still active in binding to specific receptors on sensitive and tolerant cells but not to resistant cells which lack such receptors. Bound colicin E3 also retained its ability to inhibit protein synthesis in vitro. Leakage of free colicin from these coated beads was negligible. Assays sensitive to free colicin activity of 1 part in 10(7) of the bound toxin failed to detect any soluble activity. The viability of different cell types bound specifically onto these colicin-Sephadex beads was assayed by using autoradiography based on labeled amino acid uptake. Immobilized E1 killed 90% of bound sensitive cells while less than 10% of sensitive cells bound to E2 and E3 were killed in this assay. These observations agree very well with previously suggested mechanisms which propose that E1, whose target site appears to be at the membrane level, can kill sensitive cells by binding to the cell surface, but that for E2 and E3 penetration of part or all of the molecule is necessary for killing action to be observed.


Synthesis and biological activity of pyrazolo[3,4,-d]pyrimidine nucleosides and nucleotides related to tubercidin, toyocamycin, and sangivamycin. The 6-aza analogues of toyocamycin and sangivamycin were prepared as potential cytotoxic agents. The toyocamycin analogue (4-amino-1-(beta-D-ribofuranosyl)pyrazolo[3,4-d]pyrimidine-3-carbonitrile) could not be obtained directly from its O-acetylated precursor but was accessible via 4-amino-1-(beta-D-ribofuranosyl)pyrazolo[3,4-d]pyrimidine-3-thiocarboxamide. The identity of the nitrile was verified by its ultraviolet, infrared, and mass spectra, and by its conversion to the corresponding 3-carboxamide and thiocarboxamide when treated with water or hydrogen sulfide, respectively. Bioassay of the synthetic compounds in comparison with 4-amino-1-(beta-D-ribofuranosyl)pyrazolo[3,4-d]pyrimidine (6-azatubercidin) and 4-amino-2-(beta-D-ribofuranosyl)pyrazolo[3,4-d]pyrimidine revealed that the 3-thiocarboxamido derivative was more cytotoxic to the growth of mouse fibroblasts than 6-azatubercidin, effecting killing of 3T6 cells at less than or equal to 1 mug/ml. 4-Amino-1-(beta-D-ribofuranosyl)pyrazolo[3,4-d]pyrimidine (but not its 2-ribofuranosyl isomer) was shown to act as a substrate for adenosine deaminase from calf intestinal mucosa with an apparent Km of 125 (vs. 20 for adenosine) and the corresponding 5'-diphosphate of 6-azatubercidin was polymerized by polynucleotide phosphorylase (Micrococcus luteus) in the presence of Mn2+ to afford a homopolymer and copolymers with adenosine. The copolymers directed the binding of [3H]lysyl-tRNA to the A-site of ribosomes from Escherichia coli, but could not be used for the synthesis of polylsine in a cellfree system. The copolymer consiting of adenosine and 6-azatubercidin in a 2:1 ratio was found to form a 1:1 complex with poly(uridylic acid) at 4degreesC.


Alteration of the allosteric properties of aspartate transcarbamoylase by pyridoxylation of the catalytic and regulatory subunits. Extension modification of aspartate transcarbamoylase from Escherichia coli with pyridoxal 5'-phosphate followed by reduction of the Schiff base with sodium borohydride caused only partial inactivation of the enzyme. Under comparable conditions, virtually complete loss of enzyme activity is obtained with the free catalytic subunits. The pyridoxylated, intact enzyme containing more than 60% of the bound pyridoxamine phosphate on the regulatory subunits exhibited considerable cooperativity, inhibition by CTP, and activation by ATP. When the modification was performed in the presence of the ligands which bind to the catalytic sites, the resulting product had virtually the same activity as the native enzyme, but it exhibited significantly reduced cooperativity and virtually no inhibition by CTP. The pyridoxylation of the regulatory subunits within the intact enzyme was enhanced markedly in the presence of ligands as compared with the reactivity of these subunits when the modificaiton was performed in the absence of the active site ligands. Both types of pyridoxylated derivatives exhibited the ligand-promoted conformational changes characteristic of the native enzyme. Spectrophotometric studies of inactive pyridoxylated catalytic subunits and intact enzyme showed that the substrate (carbamoyl phosphate) bound strongly but that the substrate analogue (succinate) did not bind. Both the pyridoxylation experiments in the presence and absence of ligands and the spectral behavior of a hybrid containing one native and one pyridoxylated catalytic subunit indicated that ligand binding was accompanied by a conformational change in the intact enzyme molecules.


Concerted allosteric transition in hybrids of aspartate transcarbamoylase containing different arrangements of active and inactive sites. Various hybrids of aspartate transcarbamoylase of Escherichia coli were constructed from native regulatory subunits and mixtures of active and inactive (pyridoxylated) catalytic chains in specific arrangements within the two catalytic subunits. The kinetic and physical properties of these well-defined hybrids were studied in order to determine the effects of reducing the number of substrate binding sites and distributing the active and inactive chains in different ways. Experiments on enzyme-like molecules containing six, four, three, two, and one active sites showed that the Hill coefficient decreased and the apparent Km increased as the number of active chains in the hybrids was reduced. The maximum inhibition and activation by the nucleotide effectors, CTP and ATP, were independent of the composition of the enzyme-like molecules. Two hybrids were of particular interest since one contained two active sites in one catalytic subunit and none in the other, and the second hybrid had one active site in each catalytic subunit. These two hybrids exhibited identical kinetic behavior despite the markedly different structural arrangements. The ligand-promoted conformational changes of the hybrids monitored both by sedimentation velocity measurements and the reactivity toward p-hydroxymercuribenzoate were similar to those of the native enzyme. These results indicate that there are no discrete "cooperative units" within the enzyme molecules but rather that the allosteric transition promoted by ligands is fully concerted. The various kinetic and physical properties can be accounted for satisfactorily in terms of the two-state model of Monod et al.


Influence of geometry on control of cell growth. The assembled evidence suggests that geometry plays an important role in regulation of cell growth, at least at two levels: (1) For non-transformed individual cells in culture, there may be a continuous range of shapes, from spherical all the way to extremely flat or extended, which correlates with increasing proliferative capacity or increasing ability to respond to serum growth factors. In other words, sensitivity to a variety of mitotic stimulators and growth factors may be modulated by cell conformation. Fully transformed cells appear to lose the modulating effect of shape, and thus are able to proliferate even when spherical. (2) For transformed cells which can grow in three-dimensional populations, the shape of the population itself eventually limits growth. The most likely mechanism is based upon the limiting effects of diffusion gradients of nutrients, oxygen and catabolites which build up across the surface of a three-dimensional population of cells. Tumor cells which are able to make tumour angiogenesis factor (TAF), induce new capillary blood vessels from the host. These vessels penetrate the tumor and permit further rapid growth. In this sense, tumor angiogenesis is a mechanism by which "successful" tumors escape the growth restriction imposed upon three-dimensional cell population by geometry [49].


Optical measurements reveal base-pairing in T4-specific mRNAs. Previous studies have shown that 60-70% of the nucleotides in rRNA, tRNA and the RNA of the RNA bacteriophages are involved in base pairing. To determine whether this is also true of mRNAs coded from double-stranded DNA, T4-specific mRNAs were purified using two different techniques: hybridization to T4 DNA or chromatography on benzoylated DEAE-cellulose columns followed by sucrose gradients. We have determined the optical melting curves of the purified mRNAs. The hypochromicities calculated from these melting curves were similar to those of rRNA, indicating comparable amounts of base pairing in rRNA and T4-specific mRNA. If this hypochromicity were due to random base pairing, we would have expected a less sharp melting curve and a lower Tm than for the rRNA controls. On the contrary, the mRNA samples had very high cooperativities and Tm values.


Action of phospholipases on the cytoplasmic membrane of Escherichia coli. Stimulation by melittin. The emission maximum of the single tryptophan residue of melittin was measured in the presence of phosphatidylethanolamine liposomes and Escherichia coli cytoplasmic membranes. In both cases, the fluorescence maximum was shifted to shorter wavelengths indicating a transfer of the indole ring to an apolar environment. E. coli membranes were labelled in position 2 of their phospholids with [14C]oleic acid. These membranes were used for measuring the activity of an endogenous phospholipase A2. A slow hydrolysis is observed, which can be accelerated by adding melittin. The extent of the stimulation depends on the molar ratio of melittin to membrane phospholipid. Under suitable conditions, the initial rate of hydrolysis is six to seven times higher in the presence than in the absence of melittin. The action of the phospholipase A2 from bee venom is also stimulated by melittin. An identical stimulation was observed with either E. coli membranes or pure phosphatidylethanolamine liposomes as substrate.


Ion etching of tobacco mosaic virus and T4 bacteriophage. A technique for the etching of biological materials by accelerated nitrogen ions is described. Upon exposure to such a beam, tobacco mosaic virus becomes thinner in diameter and the head of T4 becomes smaller. Experiments on radioactively labeled T4 suggest that the particle's protein is more susceptible to removal by the incident ions, and that the residual material is predominantly nucleic acid.


[The effect of hydrocortisone on individual stages of immunogenesis]. A study was made of the influence of hydrocortisone on the individual stages of immunogenesis: migration of the hemopoietic stem cells from the bone marrow, B-cell migration and cooperation between the T and B lymphocytes in the course of primary immune response to sheep red blood cells was studied. Experiments were carried out on (CBAXC57B1) F1 mice. In doses which failed to suppress the proliferation of hemopoietic cells hydrocortisone produced a marked immunosuppressive action which was a sum total result of its inhibition of various stages of immunogenesis--the stem cells and the B-cells migration and the T-B lymphocyte cooperation.


[The importance of the density of spleen cell suspensions in cultures for development of immune reactions]. A relationship was revealed between the number of cells in the suspension of the splenic tissue taken for induction of primary immunization of the reaction outside the organism and the number of the plaque-forming cells (PFC) formed by the end of incubation. It was shown that with increase of the cell density in the culture in the bottom of the incubation flask there was a 10-100 fold decrease of the PFC response; as to the cell viability--it was not affected or decreased but slightly. This effect was observed in using sheep red blood cells and water-soluble antigen extracted from them as an antigen. The effect was independent of shortage of the antigen or of the nutrient substances; it was accompanied by a general reduction of the 3H-thymidine incorporation into cultured cells.


[A comparative immunofluorescent study of carcino-embryonic antigen in pseudomucinous cystoma of the ovary and adenocarcinoma of the large intestine]. The indirect method of immunofluorescent analysis was applied to the study of the localization of the carcinoembryonic antigen (CEA) in pseudomucinous cystoma of the ovary and adenocarcinoma of the large intestine. CEA proved to be concentrated in the membranes and the basal part of the epithelial cells both in the pseudomucinous cystoma of the ovary and in the carcinoma of the large intestine.


[The influence of differences in the Rec-genotype of E. coli cells on the function of sex factor F']. Functions of the sex factor F' depended not only on damage of the genes, controlling the recombination capacity of bacterial cells, but also on suppression of the rec-gene mutations. Suppression of mutations of these genes was accompanied by the capacity of the sex factor to mobilize the chromosome for the transfer from the rec-bacterial cells. If it were demonstrated that the cells of the Jc 9604-131 strain actually carried the inverse mutation of the rec A gene, this would prove that these mutations resulted in the restoration of a recombination possibility between the sex factor F' and the bacterial chromosome.


Direct implantation of Ph1 chromosome-positive myeloblasts into newborn hamsters. Peripheral leukocytes from a male patient with chronic myelogenous leukemia in blast crisis were implanted directly into the intraperitoneal cavity of seven newborn hamsters treated with antilymphocyte serum. At sacrifice 17-19 days after implantation, three hamsters were found to have disseminated tumors. The other four hamsters were cannibalized. Chromosome analysis of cells from the enlarged lymph nodes revealed the presence of a human male karyotype. Most metaphase cells were pseudodiploid with the Ph1 chromosome and isochromosome 17, while a few metaphase cells were classically diploid. Identical chromosome constitutions were observed in the original peripheral leukocytes of the patient. The results strongly suggested simultaneous heterotransplantation of Ph1-positive leukemic and normal leukocytes.


Histochemical and immunohistochemical techniques on acrylate embedded bone biopsies. Till present the advantages of methacrylate embedded bone biopsies for the diagnosis of haemoblastic disorders have been somewhat restricted. This was a result of the impossibility to apply histochemical methods and other sensitive staining procedures to semithin sections. A routine method is described whereby enzyme activity, excellent fixation and good sectioning ability are retained. Fixation is carried out using 4% purified formaldehyde buffered in 0.1M sodium cacodylate. Dehydration is done with a water-miscible glycolmethacrylate. Naphthol-AS-D-chloroacetate esterase activity can be observed in granules of the entire neutropil cell lineage. By use of this method it becomes possible to demonstrate acid phosphatase activity and immunoglobulins in atypical plasma cells of multiple myeloma. A considerable decrease in processing time, as well as a preservation of enzyme activity during the postal mailing of fixed tissue samples from outside are further advantages.


Vaccination of schoolgirls against rubella. Assessment of serological status and a comparative trial of Wistar RA 27/3 and Cendehill strain live attenuated rubella vaccines in 13-year-old schoolgirls in Dudley. A total of 1525 schoolgirls aged 13 years from 21 schools in the County Borough of Dudley, were bled for titration of rubella haemagglutinating inhibiting antibody and then were immediately vaccinated with either Wistar RA 27/3 or Cendehill strain live attenuated. Both vaccines were administered subcutaneously by syringe and needle but the Wistar RA 27/3 vaccine was also given by multiple injection apparatus. Significnatly higher conversion rates and geometric mean haemagglutinating inhibiting antibody titres were obtained in girls initially seronegative given the Wister RA 27/3 than in those given the Cendehill vaccine, regardless of the method of vaccination. The RA 27/3 strain was associated with a small but significantly greater incidence of local pain immediately on injection. With this exception, differences in the occurrence of reactions were not found between vaccines, between those initially susceptible and immune or with the level of antibody response.


[Oxygen transport in shock (author's transl)]. This review considers functional repercussions of shock state on the different stages of oxygen transport from alveolus to mitochondria. At the pulmonary level, the decrease in perfusion pressure induces disturbances in the distribition of VA/Q ratio, and therefore leads to aerial hypoxaemia. Prolonged ischemia injures the air-blood barrier and reduces the area of exchange. Decrease in oxygen delivery to the tissue is related to a fall in cardiac output (hemorrhagic and cardiogenic shock) or to a primary disturbance in peripheral circulatory distribution (septic shock) or to a primary disturbance in peripheral circulatory distribution (septic shock). The intervention of compensating factors leads to a redistribution of the regional perfusion and probably to an easier oxygen delivery by haemoglobin. However circulatory inhomogeneity by itself produces a progressive deterioration of microcirculation. Decrease in intracapillary circulation. Decrease in intracapillary circulation and impairment in blood rheologic properties contribute to aggregates formation and intravascular coagulation. The result is a decrease in capillary diffusion capacity and in oxygen intracellular transport. When intracellular PO2 reaches a critical level, the functional exclusion of mitochondria involves a metabolic shift to anaerobiosis. The value of hyperlactacidemia as a sign of oxygen debt is discussed.


The pathogenesis of reflux nephropathy (chronic atrophic pyelonephritis). The relationship between vesico-ureteric reflux and coarse renal scarring (atrophic pyelonephritis) has been studied in swine. Scars were observed to develop where reflux took place into the kidney substance via the  renal papillae (intrarenal reflux). They were confined to these regions and were similar in size, distribution and other features peculiar to those found in the human from early childhood onwards. Intrarenal reflux was found to be related to the pressure within the urinary tract as well as to vesico-ureteric reflux. Infection was not an essential factor in scar-formation, but it appeared to intensify the scarring process. The histological findings were a progressive focal interstitial fibrosis confined to the zones of intrarenal reflux, extending from the capsule to the papillary tip, and varying in severity with pressure, time and the extent of intrarenal reflux. Nephron and tubular damage accompanied all grades of fibrosis, with the possible exception of the earliest. In many respects the histological changes closely resemble those due to obstruction, except they are focal in distribution. Added features are the early peripheral lymphocytic aggregations and interstitial fibrosis which appear to suggest that some "irritant"--possibly urine--reaches the interstitium and drains away via the lymphatic system. Many of the phenomena observed were strikingly similar to those present in children with the more severe grades of vesico-ureteric reflux. In some cases a mixture of generalized obstructive nephropathy and focal scarring developed; in others focal scarring took place with normal papillae elsewhere. The results are readily reproducible. The basic questions as to whether it is bladder pressure, or infection, or a mixture of the two which is responsible for scar-formation are discussed.


[Estimation of intrapulmonary shunt in resuscitation (use of a nomogram) (author's transl)]. Acutely ill patients often show rapid and sometimes concomitant changes in haemodynamics, pulmonary exchange and O2-uptake. PaO2 reflects the interrelationships between these three factors. The Qs/Qt shunt is computed by taking two simultaneous blood samples, one systemic arterial, the other mixed venous, with the patient inhaling pure O2 for twenty minutes. In estimating the fraction of total cardiac output unsaturated in pulmonary transit, Qs/Qt is practically used as a selective test for pulmonary gas exchange. We propose a nomogram, showing in terms of Qs/Qt shunt the variations of PaO2, of haemoglobin O2 saturation and of arterial-venous difference of O2 concentrations. Blood gas changes during treatment of shock or of acute respiratory insufficiency are explained by use of this nomogram.


Long survival after renal transplantation in man. The indications for transplantation, complications, management and results in 127 consecutive patients who had received renal transplants between October 1960 and December 1974 are presented. In 2 cases the donor was an identical twin, in 22 a living relative other than a twin, in 2 an unrelated individual in whom nephrectomy was performed for therapeutic reasons and in 101 a cadaver. At the end of the period under review there were 37 patients alive with grafts which had functioned for 6 months or more; of these, 28 had survived for more than 2 years, 13 for more than 5 years, 6 for more than 8 years and 2 for more than 12 years. Thirty-four patients were employed or doing routine housework or receiving full-time education. One patient fathered a child 4 years after transplantation; another gave birth to a healthy infant 3 years after transplantation.


Diverticular disease: threee studies. Part II - Treatment with bran. Forty patients with diverticular disease were treated with wheat bran 24g/day for at least six months. Thirty-three patients showed a very satisfactory clinical response. Sixty per cent of all symptoms were abolished, and a further 28% were relieved. After treatment the transit times accelerated in patients whose initial times were slower than 60 hours and slowed down in those whose initial transit times were faster than 36 hours. Stool weight increased significantly. The number of intracolonic high pressure waves decreased, especially during and after eating. Barium enema studies showed less spasm in eight patients and no diverticula in three patients after taking bran. As well as relieving the symptoms of diverticular disease a high-fibre diet may also prevent the condition from developing.


Cardiovascular effects of insulin.

Cardiovascular effects of insulin. Insulin increased the heart rates of seven diabetics with normal cardiovascular reflexes. This effect, which was not due to hypoglycaemia, was greater in the upright than in the supine position and was produced by as little as one unit given intravenously. This increase in heart rate may be a compensatory response to maintain cardiac output.


Failure of BCG immunostimulation to affect the clinical course of Burkitt's lymphoma. A controlled randomised trial was carried out to evaluate the efficacy of BCG immunotherapy in preventing relapse in patients with Burkitt's lymphoma in whom remission had been induced with cyclophosphamide. Twenty-one patients were treated with BCG, and 19 were controls. Eleven patients in each group relapsed during a follow-up period long enough to make it unlikely that further relapses would occur. There were no significant differences in the length of remission or the site of relapse that could be attributed to treatment. Eleven patients died: of these none of the six patients in the BCG group but all of the five in the control group had stage D lymphomas. BCG treatment increased the rate of recovery from tumour-induced immunosuppression, but within the BCG group immunocompetence improved most rapidly in the patients who relapsed-a finding that appears to contradict the tenet retionalising the use of immunological adjuvants as treatment.


Spironolactone in essential hypertension: evidence against its effect through mineralocorticoid antagonism. The effect of a six-week course of spironolactone 300 mg/day was examined in 25 unselected patients with essential hypertension. In the blood spironolactone produced a significant rise in urea and potassium concentrations and a fall in sodium and bicarbonate concentrations. In six patients blood pressure was normal at the end of the course, while in five patients there was almost no change. Studies of the effects of spironolactone on various indices usually affected by mineralocorticoids-namely, blood electrolytes, total body potassium, and rectal electrical properties-showed no differences between responding and non-responding patients. Mineralocorticoid excess therefore seems to be rarely responsible for essential hypertension and the influence of spironolactone cannot at present be fully explained.


Quantitative effects of unsaturated fatty acids in microbial mutants. IV. Lipid composition of Saccharomyces cerevisiae when growth is limited by unsaturated fatty acid supply. The Saccharomyces cerevisiae mutant KD46 (ole 2), which is unable to synthesize unsaturated fatty acids, was grown on limiting amounts of different added unsaturated fatty acids. The acyl chain composition of the cellular lipid classes was determined in these cultures at different stages or growth. During growth on added oleic acid, there was no marked change in the mole percentage of phosphatidylcholine, phosphatidylethanolamine. phosphatidylinositol, or phosphatidylserine among the total phospholipids. Cells grown on palmitoleic, oleic, or linoleic acid showed a steady decrease in their total phospholipid levels per cell concomitant with a decrease in growth rate approaching minimal levels at stationary phase. Furthermore, the mole percentage of the supplemented unsaturated fatty acid in the cellular phospholipids also decreased during growth and attained minimal values when growth ceased. At stationary phase the total phospholipid content per cell was similar for cells grown on a wide range of  fatty acids or mixtures thereof, whereas the composition of the fatty acids in the cellular phospholipids were strikingly different. The differences in efficiencies for supporting growth of most of the unsaturated fatty acids tested did not seem due to the extent of their corporation into cellular phospholipids, but rather to differences in the ability of the derived membrane phospholipids to support cellular functions. Palmitoleate, oleate, linoleate, linolenate, arachidonate, eicosapentaenoate, and docosahexaenoate all appeared to contribute to the functionality of cellular membranes in an additive linear manner. Thus, the contribution of these acids to cellular growth can be characterized by a functionality factor that seems independent of the mixtures of acids supporting growth. Use of the functionality concept allows the cumulative influence of many different acids to be summarized quantitatively by a single number rather than resorting to qualitative decriptions of the degree of unsaturation or 'fitness' of the membrane phospholipids.


Purification and properties of phenylalanyl-tRNA synthetase from baker's yeast. In an effort to avoid proteolytic fragmentation of enzymes extracted from yeast cells, the (L-phenylalanine:tRNAPhe ligase (AMP-forming) phenylalanyl-tRNA synthetase (EC6.1.1.20)) has been isolated from toluene lysates of baker's yeast in the presence of the protease inhibitor, phenylmethylsulfonyl fluoride. The procedure includes ammonium sulfate fractionation and chromatography on DEAE-cellulose and hydroxylapatite columns. Acrylamide gel electrophoresis of the enzyme in the presence of sodium dodecyl sulfate indicates a single subunit of 75 000; other isolations have led to two subunits of 75 000 and 63 000, respectively, in agreement with other workers. Steady state kinetic analysis of the enzyme has also been carried out. The apparent kinetic patterns resulting from application of Cleland's procedure, in which the substrates are varied pairwise in the presence of saturating concentrations of the third component, suggest a reaction mechanism in which ATP and phenylalanine enter the reaction in an obligatory ordered fashion but do not completely eliminate a random mechanism.


The conservation of amino acids in the n-terminal position of ribosomal and cytosol proteins from Escherichia coli, Bacillus stearothermophilus, and Halobacterium cutirubrum. Alanine, methionine, and serine are the predominant N-terminal residues in the cytosol and ribosomal protein fractions from the thermophile Bacillus stear othermophilus and the extreme halophile Halobacterium cutirubrum, a similar situation to that previously found in Escherichia coli. In all three bacteria the N-terminal residues of the 30S ribosomal proteins are mainly alanine greater than methionine greater than serine whereas in the 50S ribosomal proteins from E. coli and B. stearothermophilus the predominant residues are methionine greater than alanine greater than serine suggesting conservation of specific N-terminal residues in these ribosomal proteins. However, the 50S ribosomal proteins from H. cutirubrum showed serine as the major N-terminal residue.


[Identification of aerobic actinomycetes isolated from fresh water]. This paper presents the methods used for the study and identification of 172 actinomycetes strains isolated from samples of surface water and of sediments (soft water). For this analysis, two main criteria were used; the morphological and the biochemical study of the cellular constituents. A key for identification is proposed.


The survival of Escherichia coli from freeze-thaw damage: the relative importance of wall and membrane damage. When Escherichia coli is frozen rapidly in saline and thawed slowly, survival is very low; however, the inclusion of 3% glycerol or 1% Tween 80 in the saline freezing menstruum results in near complete survival. The release of material from, and penetration of, substances into the cell indicate that both membrane and wall damage occur during freezing and thawing. Glycerol, under these conditions, is able to reduce severely both the damage to the wall and membrane, whereas Tween 80 prevents only membrane damage. This indicates that freezing and thawing in saline results in membrane damage which is lethal to the cell whereas wall damage which occurs is not detrimental to cell survival.


Ingestion and survival of Y. pseudotuberculosis in HeLa cells. HeLa cells were infected with Yersinia pseudotuberculosis for 0.5-3 h. Intracellular bacteria could then be demonstrated by three different techniques: viable count, fluorescent-antibody staining and electron microscopy. Most of the bacteria seemed to be viable, since there was a good positive correlation (0.94) between viable and fluorescent bacteria. The bacterial uptake seemed to be mediated by a phagocytic-like procedure. The intracellular bacteria seemed to reside in vacuoles some of which increased in size as a function of time. The kinetics of infection was studied after addition of 10(7) or 10(9) bacteria per cell culture (2 X 10(6) cells). After a lag period of about 30 min there was a linear increase of intracellular bacteria, and this uptake proceeded for 1-2 h until most of the bacteria were ingested or an upper limit of ingested bacteria was reached. The upper limit was calculated to be a mean of 60 per infected cell in the cell culture. More than 90% of the cells could be infected and a reasonable number of the bacteria survive in the cells for at least 3 days, as demonstrated by the viable-count technique. The bacteria-cell system may be used to study, for example, the effect of antibiotics or antibodies on intracellular bacteria and pathogenicity of intracellular diseases.


Purification and characterization of tuberculin-active components from BCG. The tuberculin activity of protoplasmic extracts isolated from living BCG was purified successively by gel filtration on Sephadex G-100 and G-75, and by electrophoresis on 7.5% and on gradient (6-18%) polyacrylamide gels. The tuberculin-active fractions, as determined in BCG-sensitized guinea pigs, were used as the starting material for each of the following fractionation steps. The physicochemical properties and the antigenic activity of the biologically active fractions have shown that a single component, or only a few ones with similar properties, possessed high tuberculin activity. These active components were proteins having relatively high molecular weights (about 72,000) and could behave as antigens.


Pyruvate inhibition of the carbon dioxide fixation of the strict chemolithotroph Thiobacillus thiooxidans. A flow-through dialysis system used to decrease the concentrations of toxic organic materials excreted by Thiobacillus thiooxidans permitted an improved efficiency of carbon dioxide fixation when compared with cells taken from the usual shaken culture. The additions of various concentrations of pyruvic acid and succinic acid inhibited growth significantly. Pyruvate at a concentration of 5 X 10(-3) M completely inhibited the respiration of resting cells oxidizing sulfur. The toxicity of pyruvic acid was found to be permanent as evidenced by the inability to obtain satisfactory oxidation rates after washing the exposed cells twice in buffer. Both pyruvate (10(-3) M) and succinate (10(-3) M) inhibited carbon dioxide fixation by 84%.


[Study of various factors affecting the colonization of the digestive tract in white mice by Candida albicans]. This paper deals with the quantitative localization of Candida albicans in different parts of white micr gastrointestinal tract after oral inoculation of the yeast. Animals are previously treated with ampicillin, cortisone, or estradiol. Female pregnant and normal adult mice are also used. Our results show that the number of yeasts increases respectively in small intestine, stomach, caecum, and sigmoid. As compared with normal adult mice, C. albicans is more abundant in mice treated wtih ampicillin or cortisone whereas the yeast growth is lower in pregnant animals or in mice receiving estradiol. Moreover, male animals ordinarily show higher values than those found in female mice.


Detection of enteropathogenic Escherichia coli strains in wastewater by fluorescent antibody. Flourescent antibody (FA) techniques were used to evaluate fluorescein-labeled enteropathogenic Escherichia coli (EEC) OB globulins as a means of presumptively detecting these serogroups in wastewater. Four of the more prevalent and incriminated EEC serogroups were detected by FA and isolated from wastewater. A total of 317 sewage isolates biochemically defined as E. coli were tested by FA and agglutination tests. Only a small number of these isolates (9/317, 2.8%) were serologically groups as being enteropathogenic related strains. The frequency of occurrence of EEC organisms in a wastewater, as determined by FA, is reported. The use of highly specific OB fluorescent antibodies to monitor wastewater for the presence of EEC is discussed.


Massive pulmonary hemorrhage in neonatal infection. Of 35 newborn infants who died from an infection 19 had postmortem evidence of massive pulmonary hemorrhage. All but 1 of the 19 had evidence of antimortem formation of intravascular fibrin clots in lung tissue. Seventeen infants had low platelet counts. Of the 11 infants in whom coagulation studies were done, 8 had evidence of disseminated intravascular coagulation (DIC) during life. Vasculitis in the lungs, associated with fibrin clots and hemorrhages, was detected in two infants. It is postulated that sepsis is an important cause of hemorrhage in the newborn, probably as a result of the development of DIC.


Occupational asthma.

Occupational asthma. Occupational asthma is probably much more common than is generally realized. Though many causes have been described, undoubtedly many more are yet to be recognized. One of the diagnostic difficulties lies in the fact that in most forms of this disease a late asthmatic reaction occurs in the evening rather than at work. The pathogenetic mechanisms differ in various forms of occupational asthma. In some, an immunologic mechanism is likely; in others, a "pharmacologic" action of the offending agent is implicated. Asthma due to inhalation of dusts of western red cedar, isocyanates, detergent enzymes and textiles is considered in detail. Periodic examination of workers at risk is of value for early diagnosis and prevention of irrversible airway obstruction.


A phase II study of intravenously- administered methyl CCNU in the treatment of advanced sarcomas. Thirty-two patients with advanced, inoperable nonhematologic soft-tissue and osseous sarcomas were treated with Methyl CCNU administered via controlled intravenous infusion in doses of 130-170 mg/m2 every 6 weeks in a Phase II trial. All 28 evaluable patients were no longer responsive to adriamycin. Greater than 50% tumor regression was seen in one of two patients with chondrosarcoma and one of five patients with rhabdomyosarcoma. Less than 50% tumor regression occurred in one of five patients with rhabdomyosarcoma, one of two patients with malignant giant cell tumor, and one of three patients with malignant fibrous histiocytoma. Stabilization of previously advancing disease occurred in two of seven patients with leiomyosarcoma. The drug preparation was well tolerated. Nausea and vomiting occurring in three of 32 patients. Major toxicity was myelosuppression, characterized chiefly by thrombocytopenia with lesser degrees of leukopenia. This drug preparation appears to have activity in this group of tumors.


Intralesional BCG in the treatment of metastatic malignant melanoma. The therapeutic efficacy of intralesional BCG (Bacillus Calmette-Guerin; one immunizing dose every 2 weeks for a minimum of five treatments) was studied in 19 melanoma patients. Of 15 patients evaluable for response, five experienced significant objective improvement (two complete and three partial remissions). Objective improvement was limited to those patients with dermal metastatic disease. In vitro cytotoxicity in the presence of patient's serum bore, on average, a relationship to the clinical disease. In certain individual cases, serum blocking and/or lymphocyte stimulation may have had prognostic significance.


Squamous cell carcinoma of the skin and lip in renal homograft recipients. Forty-four squamous cell carcinomas (SCC) of the skin and lip were observed in 9 of 464 renal homograft recipients. Clinically and histologically the SCC's fell into two groups. Two patients with widespread warts, suggestive of epidermodysplasia verruciformis, showed multiple SCC's predominantly on the upper extremities which were associated with minimal solar elastosis of the adjacent dermis. The other seven patients did not have widespread warts; their SCC's occurred predominantly on the head and neck and were associated with prominent solar elastosis of the adjacent dermis. The degree of solar elastosis was particularly striking in view of the young age of this group (mean age: 37 years). Inflammatory cellular response to the transplant SCC's was significantly diminished in comparison with a group of control SCC's from non-immunosuppressed patients. In both transplant groups sunlight appears to be an important etiologic factor; in the first group viruses may also be important.


Febrile neutrophilic dermatosis in acute myelogenous leukemia. Three patients with acute myelogenous leukemia and adequate granulocyte reserves developed fever and painful indurated erythematous plaques on their extremities and faces. The plaques became studded with vesicles or bullae and occasionally became necrotic. Histologic examination revealed dermal edema, infiltration with granulocytes, and formation of intraepidermal vesicles. Efforts to relate the skin reaction to infiltration of leukemic cells, microorganisms, or allergic phenomena were unsuccessful. Empiric antibiotic therapy was without effect. The symptoms and signs responded dramatically to systemic administration of corticosteroids. These lesions, which may cause diagnostic confusion and needless therapy with potent antibiotics, may represent another previously uncharacterized nonspecific skin reaction in patients with acute myelogenous leukemia.


Primary reticulum cell sarcoma of testis in a 12-year-old. A 12-year-old boy with primary reticulum cell sarcoma of the testis who is alive and free of tumor 32 months after orchiectomy, radiation therapy to inguinal, iliac and retroperitoneal lymph nodes and chemotherapy is reported. Seven previously documented cases of childhood primary testicular lymphoma are reviewed. The patient with reticulum cell and one with lymphosarcoma were alive and tumor-free 4 and 18 months respectively. The other 5 with primary testicular lymphosarcoma died. Four survived for periods up to 1 year, 3 developing generalized lymphosarcoma and 1 leukemia. The fifth was tumor-free for 4 years and developed leukemia 2 weeks before death. The small number of cases precludes evaluation of survival in relation to various modes of therapy. Primary lymphoma of testis, no evidence of lymphoma elsewhere at time of orchiectomy, does exist. Its relatively benign biologic behavior in some remains an enigma.


The carcinogenicity of anticancer drugs: a hazard in man. The carcinogenic potential of anticancer drugs is discussed in the light of selected basic principles of chemical carcinogenesis. Anticancer drugs which act by alkylation and/or by binding tightly to DNA frequently cause cancer in experimental animals and may be carcinogenic in man. In addition, certain anticancer drugs act as cocarcinogens in experimental systems and augment the tumorigenicity of chemical carcinogens. Host determinants are important in chemical carcinogenesis. Many chemical carcinogens and anticancer drugs require metabolic activation by microsomal enzymes. Studies in twins have shown interindividual variation of drug metabolism in man is greater than intraindividual variation caused by exogenous factors. Therefore, certain individuals may be unusually susceptible to the carcinogenicity of anticancer drugs on a pharmacogenetic basis. Age is also a host determinant. At a given total dose level, age at first exposure to chemical carcinogens has been shown to be an important risk factor in experimental studies and in some epidemiologic investigations in man. Therefore, children may be especially susceptible to the carcinogenicity of anticancer drugs. These treated children have the potential of a normal lifespan; the latency period between initial exposure to a carcinogen and clinical evidence of cancer in man is long, usually 2-5 decades. The problems involved in extrapolating data of carcinogenicity in experimental animals to man are discussed. A single drug may have multiple consequences in experimental studies; for example, actinomycin D can act as an anticancer drug, an anticarcinogen, and a carcinogen. These uncertainities and the clinical results concerning second neoplasms following cancer therapy in both children and adults clearly indicate the need to follow carefully long-term survivors who have received cancer therapy.


Second malignant neoplasms associated with immunosuppressive medications. Previous studies have shown that immunosuppressive therapy permits the growth and spread of inadvertently transplanted malignant cells in man, and, in addition, is associated with a 5 to 6% incidence of de novo cancers in organ homograft recipients who were apparently free of cancer before and at the time of transplantation. In the present report two further groups of patients were studied. There was a 4% incidence of new tumors in 101 organ homograft recipient- who had had pre-existing cancers. The immunosuppressive effects of cancer chemotherapeutic agents may have been responsible for the development of 166 new malignancies in 160 patients who received treatment for 161 neoplasms. This does not contraindicate the use of chemotherapy in patients with advanced or widespread neoplasms, as the occasional development of new malignancies is far outweighed by the many months or years of control of the original tumors.


The effect of immunosuppressive chemotherapy on immune function in patients with malignant disease. This paper reviews studies previously conducted on the effect of anticancer drugs on immune function in man. It provides new data reporting on the effect of short intensive courses of cytotoxic drug therapy on B-lymphocyte and T-lymphocyte number in cancer patients. Both types of lymphocyte were found in this investigation to be equally sensitive to cytotoxic drugs. The degree of absolute cell number reduction and rate of recovery were similar for T-lymphocytes and B-lymphocytes. Other workers have demonstrated, however, that with prolonged administration of cytotoxic drugs B-lymphocyte number and function are more adversely affected than are T-lymphocyte number and function. Immune function which had been suppressed by continuous programs of chemotherapy for periods of up to 2-3 years will, in certain groups of patients, recover to normal or almost normal levels of function. Short courses of combination drug chemotherapy may be followed by "rebound-overshoot" recovery of immune function. This has been associated with a more favorable clinical course than in situations where it does not occur. Chemotherapy and chemoimmunotherapy programs in clinical oncology ought ideally to be initially evaluated for the effect that they have on immune function. This will permit the development of drug dose and time schedules which allow for recovery of immune function and may possibly lead to augmented antitumor responses.


Effects of chemotherapy on the central nervous system. A study of parenteral methotrexate in long-term survivors of leukemia and lymphoma in childhood. Twenty-three children surviving more than 5 years from the diagnosis of leukemia, lymphoma, or malignant histiocytosis were evaluated for clinical evidence of central nervous system disease. Severe impairment, consisting of seizures, paraplegia, and dementia was present in 4, all of whom received methotrexate (MTX) and other agents for 2 to 7 years. Brain biopsies in 3 of these children showed white-matter gliosis and no evidence of viral or other infections or leukemic infiltrates. Of the remaining children 10/19 were found to have mild clinical or EEG abnormalities. All had received i.v. MTX with other drugs for 2-6 years; 5 did not receive cranial irradiation. Common to all impaired patients was the administration of intravenous methotrexate in relatively high doses over a prolonged period of time. Impairment in nervous system function may present as a spectrum of deficiencies, with the most severe resulting in death, or as in the 4 patients described here, profound dementia and dependence. Less dramatic changes in functioning, may, however, result from various combinations of chemotherapy and radiation therapy. Methods of assessing their etiology and impact on survivors need now to be devised.


Late neoplastic changes following medical irradiation. New additions since 1968 to the literature on radiation carcinogenesis in man support the earlier conclusion of an approximately linear increase in cancer incidence in a broad intermediate dose range for most sites of cancer. Questions are raised regarding the nature of the dose-response relation at very low and at very high dose exposures. Analyses of some data on exposure to radiation from internal deposits of radioactive material suggest that the dose-response curve at low and intermediate ranges in concave up, implying a smaller effect per unit exposure at very low doses than at intermediate ranges. Data on exposure to the very high but anatomically limited doses of radiation used in cancer therapy give conflicting results, suggesting in one report a continuation of the linear relation into the high-dose range. Other reports suggest a lesser effect per unit dose at high doses than at intermediate doses. Extensive laboratory studies of exposure of experimental animals indicate that over broad dose ranges, exceptions to simple linear relations are the rule, and that factors of dose rate and fractionation also affect the dose-response relation.


The effects of gonadal irradiation in clinical radiation therapy: a review. Recent improvements in radiation therapy of some malignancies in lower abdominal sites are leading to a prolongation of life in persons of child-bearing age. These successes require an evaluation of the possible undersirable consequences of the unavoidable gonadal irradiation that occurs in these cases. A review of radiobiological data from experimental animal studies and retrospective clinical studies suggests that in most instances human gonadal exposures in both sexes are insufficient to cause permanent sterility, because the exposures are fractionated and the total gonadal dose is much less than 600 rads. As a consequence, return of fertility must be anticipated, and the worrison questions of radiation-induced genetic damage in subsequent pregnancies must be addressed. This review did not substantiate this fear, because no case reports could be found of malformed infants among the progeny of previously irradiated parents. Some experimental studies suggest that radiation-damaged spermatogonia are self-destructive, but any evidence for this phenomenon in the ovary is nonexistent. We suggest that the difference between fact and theory here may be the mathematical result of the interplay of low probability for occurrences and the few patients who until now have survived long enough for study.


Long-term effects on external radiation on the pituitary and thyroid glands. Chronic damage following external irradiation of the normal pituitary and thyroid glands, delivered incidentally during radiotherapy of neoplasms of the head and neck may be more common than has been appreciated in the past. A case of a child who developed pituitary dwarfism 5 1/2 years after radiation therapy has been delivered for an embryonal rhabdomyosarcoma of the naso-pharynx is described. A review of similar cases from the literature is presented. Likewise, external irradiation of the normal thyroid gland produces a spectrum of radiation-induced syndromes. Clinical damage to the pituitary and thyroid glands is usually manifested months to years after treatment and is preceded by a long subclinical phase. A careful exclusion of these glands from radiation treatment fields is recommended whenever possible. An early detection of endocrine function abnormalities in patients receiving radiation to these glands is desirable, since appropriate treatment may prevent the deleterious effects of external irradiation of the pituitary and thyroid glands.


Quantification of combined radiation therapy and chemotherapy effects on critical normal tissues. In order to determine the modification of radiation effects on critical normal tissues which occurs with combinations of radiation and cancer chemotherapy, a review of laboratory and clinical data has been carried out. Information on 10 different normal tissues is available. It is clear that the antibiotic cancer chemotherapeutic agents are the most likely to enhance radiation injury, with increased levels reported in all tissues except the central nervous system. The second most common type of injury with combination therapy appears to occur with drugs causing injury to the normal tissue on their own, such as adriamycin in the heart and methotrexate in the central nervous system. Quantification of the dose-effect factor is only available on a limited number of tissues, and, primarily, in experimental animals. From these limited data, it is clear that dose-effect factors between 1.1 and 1.8 are seen, indicating that radiation doses must be reduced by 10-80% for the same level of injury when combined with chemotherapy. The augmentation of radiation damage by cancer chemotherapeutic agents is a serious problem in a wide range of tissues, but a problem which can be dealt with by accurate knowledge as to the dose-effect factor and appropriate modification of the radiation treatment.


Prevention of Marek's disease: a review. Marek's disease (MD) is a highly infectious neoplastic condition of chickens caused by a herpesvirus. The virus is cell associated in tumors and in all organs except in the feather follicle where enveloped infectious virions egress from the body. From this source, infection is spread horizontally by the airborne route to the environment and to other chickens. Vertical transmission from dam to offspring does not occur or at best is very rare. The nonpathogenic herpesvirus of turkeys (HTV) is ubiquitous in turkeys and is probably spread horizontally by the airborne route. When chickens are inoculated with this virus, they do not subsequently develop MD even after infection with virulent Marek's disease virus. The Marek's disease virus, not the HVT, will spread horizontally from dually infected birds. The HVT vaccine is safe and highly effective in preventing MD under field conditions, and most chickens throughout the world are vaccinated with this vaccine. Other vaccines that have been used but have disadvantages over HVT include the following: (a) the highly pathogenic HPRS 16 strain of Marek's disease virus was attenuated by passage in cell culture. The attenuated virus protects against MD and does not spread, but "over-attenuated" virus does not protect; (b) naturally apathogenic strains virologically, immunologically, and epizootiologically similar to pathogenic strains will protect when adminstered before infection with the virulent strains; (c) virus preparations that have been chemically treated to inactivate infectivity protect only slightly. When a candidate vaccine virus for the prevention of herpesvirus-induced cancer in humans is developed, the purity of the vaccine preparations will be easily determined by modern techniques. However, measurements of safety and effectiveness are a significant problem. If, analogous to the MD model, the vaccine will have to be administered shortly after birth and the incubation period to development of neoplasms is long, then pathogenicity tests in nonhuman primates and other animals may be of limited valued. However, biochemical demonstration that the segment of the nucleic acid responsible for oncogenesis is absent from the vaccine virus may be the major indication that the vaccine is nonocogenic and therefore safe. Because of the low incidence of neoplasia and long incubation period, the effectiveness of the vaccine will be difficult to test. The vaccine possibly will protect against an acute manifestation of viral infection. Future research on MD will be directed to determining the mechanism of protection against disease, i.e., whether immunity is mediated by thymus- or bursa-dependent systems, and to identifying the protective antigen, i.e., which cell surface or an interior antigen induces the protective immunity. The prevention of MD by vaccination may become a very fruitful area for model studies on prevention of human cancer by vaccination.


Immunology of herpes simplex virus infection: relevance to herpes simplex virus vaccines and cervical cancer. The immunology of herpes simplex infections has been reviewed, particularly in relation to potential herpes simplex virus (HSV) vaccines, and to the association between HSV and cervical cancer. Relevant data from humans, experimental animals, and in vitro systems implicate both specific immune mechanisms and nonspecific factors in the course of HSV infections. There appear to be complex interactions between the various populations of mononuclear cells, marcrophages, and lymphokines or other humoral factors. It is not yet possible, however, to pinpoint the crucial factors determining the different manifestations of the viral infection (primary infection, endogenous recurrence, or exogenous reinfection) in the various human hosts, although genetic factors may be important. While numerous animal models of HSV infection are available for the evaluation of HSV vaccines, models of HSV-induced cervical cancer require further exploration.


Immune functions characteristic of SJL/J mice and their association with age and spontaneous reticulum cell sarcoma. Spontaneous reticulum cell sarcoma in SJL/J mice has been proposed as an animal tumor model for Hodgkin's lymphoma. The relationship of tumor progression and immune function is not clear, however, and has prompted a systematic evaluation of SJL/J immune competence. It was found that the ability to generate cell-mediated immunity and antibody response to allografts was not impaired in 2- to 12-month-old mice, regardless of their tumor status. All animals were capable of generating in vivo cytotoxic effector T-cells and both IgG and IgM classes of cytotoxic antibody to a tumor allograft. In addition to being able to respond, older mice showed an unexpected hyperresponsiveness to alloantigens, which suggested that escape from feedback control might be a characteristic of SJL/J mice. Loss of immune regulation was further indicated by the failure to induce tolerance to human gamma-globulin in mice 4 months and older, while 3-week-old SJL/J mice could be rendered unresponsive. Coincident with this apparent loss of regulation, circulating antibodies to synthetic double-stranded RNA, polyinosinis - polycytidylic acid, were first detected in unimmunized mice at 4 months of age, and titers remained elevated regardless of tumor status. It is suggested that tumor development as well as autoimmunity may result from an effective amplification of the immune response.


The effects of methyl (5-(2-thienylcarbonyl)-1H-benzimidazol-2-yl) carbamate, (R 17934; NSC 238159), a new synthetic antitumoral drug interfering with microtubules, on mammalian cells cultured in vitro. Ultrastructural investigations on mammalian cells cultured in vitro show that R 17934, a new synthetic anticancer drug, interferes with the structure and function of microtubules, both in interphase and mitotic cells. The activity of this compound in a wide range of experimental tumor systems can thus be explained partly as a direct antimitotic effect and partly as the disintegration of the normal subcellular organization of the nondividing cells. Preliminary investigations in experimental animals show that malignant cells are more susceptible to the antimicrotubular effect of R 17934 than are the nonmalignant cells of the host.


Inhibitory effect of endotoxin on the growth of plasma cell tumor. Small amounts (0.1 ng to 5.0 mug) of Escherichia coli endotoxin protect normal female BALB/c mice against challenge with low doses of syngeneic mineral oil-induced 315 plasma cell tumor. Significant protection was most evident when mice were treated with endotoxin 11 days and 5 days before inoculation with 50 to 100 tumor cells i.p., and endotoxin treatment continued twice a week for the entire experiment. Tumors induced by 10,000 cells s.c. were similarly affected by this treatment. The antitumor action of endotoxin was obliterated when higher challenges of tumor cells or solid tumor pieces were used. Omission of endotoxin pretreatment resulted in a loss of the effect against i.p.-induced tumors but not against s.c.-induced tumor.


Demonstration of the existence of a single morphological type of gonadotrophic cell in Ellobius lutescens (Microtinae) by an ultrastructural analysis of their development under various physiological and experimental conditions. Ultrastructural studies of pituitaries from Ellobius lutescens (immature males and females, adult hypogonadic males, and virgin and pregnant females) show that the gonadotrophic cells are characterized by a lamellar or vacuolar rough endoplasmic reticulum (RER), a spirally-arranged Golgi apparatus, elongated mitochondria and secretory granules of variable density and size (150-500 mmu). Ultrastructural differences between gonadotrophic cells previously determined by light microscopy correspond to changes in the development of the protein synthetic apparatus and in the intensity of hormonal discharge. Type 2 gonadotrophs always appear to be more active than type 1 gonadotrophs. After castration, all gonadotrophic cells develop into the same form of "castration cell", although type 1 gonadotrophs change more slowly than type 2 cells. Treatment with testosterone induces an inverse development of the gonadotrophic cells which take on the appearance of resting cells similar to those found in immature animals, where the two cell types are also identical. Thus, only one morphological type of gonadotrophic cell can be identified in Ellobius lutescens. Moreover, the gonadotrophic cells of the hypogonadic adult male have the same appearnance as those of the female two months after castration, whic proves that the negative feedback mechanism which regulates gonadtrophic function is defective in adult male Ellobius lutescens.


The mutagenicity of chloroethylene oxide, chloroacetaldehyde, 2-chloroethanol and chloroacetic acid, conceivable metabolites of vinyl chloride. Previous investigations have shown that the carcinogen vinyl chloride causes base-pair substitution in the bacterium Salmonella typhimurium. The ability of four conceivable metabolites-chloroethylene oxide, chloroacetaldehyde, 2-chloroethanol and chloroacetic acid-to cause base-pair substitution directly in Salmonella typhimurium TA1535 has been compared. The main comparison was performed at initial concentrations from 0.1 to 1.5 mM. In this region, however, a mutagenic effect was observed only with chloroethylene oxide and chloroacetaldehyde, the former being approximately 20 times more effective than the aldehyde when compared on a molar basis.2-Chloroethanol and chloroacetic acid were studied also at higher concentration (1 mM-1 M), and a weak mutagenic response was found with 1 M 2-chloroethanol solution. With chloroacetic acid no enhancement of the mutation frequency could be detected. Chloroethylene oxide was found to be approximately 450 times more effective as a mutagen than chloroacetaldehyde when the comparison is based on exposure doses, defined as the time-dependent concentrations of the compounds in the treatment solutions, integrated between the times of onset and termination of treatment. Similarly, chloroethylene oxide was 10,000-15,000 times more effective as a mutagen than ethylene oxide, used as a positive control.


Effects of metabolic and pharmacologic interventions on myocardial infarct size following coronary occlusion. A number of hemodynamic, pharmacologic, and metabolic interventions were found to change the extent of acute ischemic injury of the myocardium and subsequent necrosis following  experimental coronary artery occlusion. Reduction in myocardial damage occurred by decreasing myocardial oxygen demands (beta-adrenergic blocking agents, intra-aortic balloon counterpulsation, nitroglycerin, decreasing afterload in hypertensive patients, inhibition of lipolysis, and digitalis in the failing heart); by increasing myocardial oxygen supply either directly (coronary artery reperfusion or elevating arterial pO2), or through collateral vessels (evevation of coronary perfusion pressure by alpha adrenergic agonists, intra-aortic balloon counterpulsation); or by increasing plasma osmolality (manitol, hypertonic glucose); presumably by augmenting anaerobi metabolism (glucose-insulin-potassium, hypertonic glucoxe insulin potassium, hypertonic glucose); by enhancing transport to the ischemic zone of substrates utilized in energy production (hyaluronidase); by protecting against autolytic and heterolytic damage (hydrocortisone, cobra venom factor, aprotinin). Augmentation of myocardial ischemic damage occurred as a consequence of increasing myocardial oxygen requirements (isoproterenol, glucagon, ouabain, bretylium tosylate, tachycardia); by decreasing myocardial oxygen supply either directly (hypoxia, anemia), through reduction of collateral flow (hemorrhagic hypotension, minoxidil), or by decreasing substrate availability (hypoglycemia). Pilot studies have been carried out in patients with hyaluronidase, nitroglycerin intra-aortic balloon counterpulsation, beta-blocking agents and Arfonad and have shown that these interventions may also reduce myocardial damage, which suggests that the concept of reduction in infarct size following coronary occlusion is applicable clinically.


Mechanical and surgical interventions for the reduction of myocardial ischemia. To reduce myocardial ischemia effectively, mechanical or surgical interventions must achieve either augmentation in coronary blood flow, a reduction in myocardial oxygen demand, or a combination of both. Coronary bypass graft procedures can achieve an immediate augmentation in coronary blood flow distally through the involved vessel and thereby improve myocardial perfusion and oxygen delivery and thus have the potential for reversing myocardial ischemia both acutely and for the long term. Although myocardial revascularization may resolve the ventricular functional alterations associated with acute myocardial ischemia it remains uncertain whether revascularization can reverse ischemic myocardial cellular injury and in what time framework, as related to reversible vs. irreversible ischemic cellular changes. Mechanical circulatory assistance (MCA) using diastolic counterpulsation effectively reduces myocardial ischemia by the physiologic mechanisms of 1) decrease in left ventricular after-load and left ventricular wall tension, 2) improvement is cardiac output by diastolic counterpulsation and 3) augmentation of coronary blood flow by diastolic pressure augmentation. The most effective indication for either MCA or myocardial revascularization is for interruption of myocardial ischemia prior to the development of infarction. Clinical sudies have demonstrated that acute myocardial ischemia can be effectively interrupted by intraaortic balloon pumping (IABP) including reversal of left ventricular dysfunction associated with acute myocardial ischemia. In most instances, cessation of IABP resulted in recurrence of myocardial ischemia indicating the need for urgent revascularization surgery. In the management of medically refractory myocardial ischemia. IABP has been effective in complete suppression of ischemia in 80 percent and resulted in marked improvement in all, allowing safe revascularization surgery with an operative mortality in the range of 5% and perioperative myocardial infarction incidence of 2%. In patients with acute myocardial infarction and cardiogenic shock (AMI-CS), IABP can resolve CS in 75 percent. The combination of IABP and surgery has resulted in survival approaching 45 percent indicative of a significant improvement in salvage in this group of patients where expected mortality approaches 100 percent.


Platelet aggregation secondary to coronary obstruction. From many observations made at autopsy it is apparent that thrombosis in a coronary artery is usually, if not always, associated with rupture of an atheromatous plaque. The sequelae of such rupture include hemorrhage into the plaque with further narrowing of the lumen, formation of an occlusive thrombus or of a non-occlusive thrombus. A developing thrombus in an artery undergoes fragmentation with showering of the distal microcirculation by aggregates of platelets possibly with some admixture of fibrin. In many cases of sudden cardiac death associated with severe atherosclerotic stenosis of the coronary vessels, an occlusive thrombus is not found and the myocardium shows no morphological lesion or else focal patchy early damage in the subendocardial region. One possible mechanism that might explain these findings is microembolism from mural nonobstructing coronary thrombus. Such a mechanism is well established in transient ischemia of the brain and retina related to ulcerated atheroma of the internal carotid artery. Experimental observations indicate that platelet aggregates in the myocardial circulation cause arrhythmias, sudden death, vasculitis, and myocardial ischemic damage.  Induction of an occlusive coronary artery thrombus is associated with development of an infarct involving the full thickness of the myocardium. A nonocclusive thrombus is associated with either no myocardial damage or focal subendocardial ischemic injury. It is possible that further aggregation of platelets may facilitate the extension of infarction subsequent to an occlusive event, although there is little evidence on this point. A number of clinical studies show increased platelet reactivity to agents causing aggregation, such as norepinephrine or collagen, in subjects experiencing thromboembolic episodes. It seems unlikely, however, that in vitro tests of platelet function can identify or predict clinical arterial thrombotic disease, although studies of platelet survival and turnover may be more helpful. There is also evidence that platelet survival may be prolonged by drugs having a therapeutic benefit in coronary artery disease and arterial thromboembolism. There is a need for better designed and coordinated clinical trials and for better experimental approaches to explore the relationships among coronary thrombosis, embolsim of the myocardial microcirculation, myocardial ischemia, and sudden death.


Electorcardiographic ST-segment analysis in the characterization of myocardial ischemia and infarction. The ST segments of the electrocardiogram (ECG) become elevated within 20 to 30 seconds after the onset of acute coronary occlusion and, when persistent, such changes offer a possible indirect marker of the extent and severity of myocardial ischemic injury and of eventual cell death. When ST-segment elevation on the epicardial ECG is measured 15 minutes after an acute coronary occlusion in the dog, a general correlation exists with biochemical changes, regional myocardial blood flow, and myocardial electrolyte alterations measured at 15 minutes, although when an effort is made to correlate the degree of such alterations with the magnitude of the ST-segment change there is considerable scatter. On the other hand, when the ST-segment elevation at 15 minutes is correlated with myocardial blood flow, histologic changes, and creating phosphokinase (CPK) depletion 24 hours later, the correlation is good. Possible mechanisms underlying ST-segment elevation are discussed, and data are reviewed which indicate that the epicardial ECG my be relatively insentive to subendocardial injury; in the experimental setting this problem may be partially corrected by the use of intramyocardial ECG leads. The extension of direct epicardial ECG maps to precordial ST-segment mapping poses additional problems that include reduced sensitively, problems due to reciprocal changes in the ECG at the body surface, surface contact of the electrodes, pericarditis, and individual variability in the rate of spontaneous regression of ST-segment changes. Such mapping appears reliable only for infarctions of the anterior and lacteral wall. Further research is necessary on analysis of the QRS complex, and use of vector leads. Despite these problems experimental and clinical studies indicate that precordial electrocardiographic analysis may be useful for detecting acute changes in the severity of ischemic injury over relatively short periods of time (2 to 4 hours). This indirect measure clearly will require correlation with specific markers of ischemic damage, but with further improvements it seems likely that analysis of serial ECG changes will evolve into a valuable and reliable nonivasive clinical tool for characterizing myocardial ischemia and infarction.


Salt, volume and the prevention of hypertension. The evidence supporting the thesis that hypertension can be prevented by eliminating salt from the diet is based on four principal sources: (1) epidemiological studies in unacculturated peoples showing that the prevalence of hypertension is inversely correlated with the degree of salt intake; (2) hemodynamic studies suggesting that the development of chronic experimental hypertension is a homeostatic response to a maintained increase in extracellular fluid volume (ECF); (3) evidence that the ECF of "salt eaters" is expanded in comparison to that of "no-salt eaters"; and (4) investigations in hypertensive patients receiving either diets greatly restricted in salt or continuous diuretic therapy which correlate the fall in blood pressure with a reduction in ECF. Although this mechanism of essential hypertension is still obscure the evidence is very good if not conclusive that reduction of salt in the diet to below 2 g/day would result in the prevention of essential hypertension and its disappearance as a major public health problem.


Status report on instrumentation useful for craniofacial research. This report reviews briefly State-of-the-Art of certain bioengineering instrumentation useful in craniofacial research and assessment. Brief reviews are included in the areas of Radiography, Electromyography, Intra-oral air flow/pressure, Lingual/palatal pressure, Oral-sensory perception, Visualization techniques, Acoustic processing, and Digital Computers. It should be obvious, even from this limited effort, that the variety and quality of available equipment is expanding rapidly. While it is conceded that there probably have been no abrupt or profound instrumental breakthroughs in any of the areas discussed, the sum total of the advances being made in each of the cited areas, taken collectively, are impressive. It is quite evident that both the clinical and basic researcher now have at their command great quantities of equipment of excellent intrinsic quality that are appropriate for the types of assessment and research being carried out or contemplated. These devices are at a level of sophistication not dreamed of as little as 20 years ago. It is now necessary for the scientist and practitioner to exploit this wealth of facilities and to be prepared to utilize effectively the future instrumental advances that can be expected in this area.


Post-transplantation analgesic dependence in patients who formerly suffered from analgesic neophropathy. Twenty-two patients with functioning grafts who originally developed renal failure due to analgesic nephropathy ("analgesic" group), and 84 patients with various other causes of renal failure ("non-analgesic" group) were studied over one year to assess the extent of analgesic use and abuse. On each occasion that one of these patients reported to hospital a urine sample was collected and analyzed for N-acetylparaminophenol (NAPA). Of the "analgesic" group of patients, 14% had consistently negative urine samples while 41% showed NAPA in more than half the urines collected. In the "non-analgesic" group 29% of patients had entirely negative urine tests, and in only 7% were more than half of the urines NAPA-positive. Patients in the "non-analgesic" group readily admitted taking anaglesics at frequencies compatible with the observed number of positive tests. This contrasted with the "analgesic" group in which 14 of 19 patients with NAPA-positive urines denied analgesic intake. This is considered to be a guilt manifestation in patients who have developed a psychological dependence on analgesics and have recidivated with full knowledge of the possible harm these drugs may inflict on their grafts.


Avascular necrosis of bone in patients undergoing renal allotransplantation. Five to forty-three months after renal allotranplantation, thirteen patients (9 male, 4 female) developed avascular necrosis of one or more joints. The dose of corticosteroids used as part of the immunosuppressive therapy was compared to that used in similar patients who did not develop avascular necrosis. No significant difference could be found.


Mesangiocapillary glomerulonephritis with dense "deposits" in the basement membranes of the kidney. Amongst 125 patients with mesangiocapillary glomerulonephritis (MCGN), 19 showed continuous intramembranous dense "deposits" (IDD). Most were children or young adults. Two patients had partial lipodystrophy. Eleven had a consistently low plasma concentration of C3; only three, however, had an initial low plasma concentration of C4, which rose and then remained normal in two. Tests for the C3 nephritic factor were positive in thirteen patients, and plasma C1q was normal in 8 out of 11 cases investigated. Ten out of twelve (seven of them with low plasma C3) showed C3 deposition by immunofluorescence in the glomerular tuft. This was also demonstrated in some instances in Bowman's capsule and tubular basement membranes. Stains for IgG, IgA, C4 and C1q were negative in all, whereas stains for IgM and fibrin were weakly positive in the glomeruli of three and eight cases repectively. Eight patients went into terminal renal failure over an average of thirty-three months and required hemodialysis or transplantation. MCGN with IDD is an uncommon pattern of renal response to injury, which involves activation of the alternate pathway of the complement system and has a poor short term prognosis. The association with partial lipodystrophy and C3-splitting activity suggests a primary complement abnormality.


Management of postoperative infections in obstetrics and gynecology. A discussion of postoperative infections in obstetrics and gynecology has been presented with particular emphasis on soft tissue infections involving the operative site. It has been emphasized that the offending organisms are those normally found in the vagina and cervix and that mixed infections are common. The immediate life threats to the patient are endotoxin shock and clostridial sepsis; therefore, initial therapy should include coverage for those organisms. Because of the potential toxicity of clindamycin and chloramphenicol, as well as the usual protracted course of Bacteroides infections, the addition of one of these drugs can generally be deferred until its use is dictated by microbiologic data or a failure of clinical response. Persistent fever generally indicates a lack of the appropriate antibiotic, an undrained collection of pus, or concomitant pelvic thrombophlebitis, the latter being a special concern with anaerobic infections. Specific infections and their management have also been discussed as have urinary tract and pulmonary infections and drug fever.


Giant cell synovitis associated with failed polyethylene patellar replacements. Destroyed patellar articular surfaces were replaced with a high molecular weight polyethylene prosthesis in two patients. The patellofemoral articulation of the femur consisted of eburnated bone in one case and degenerative cartilage in the other. Both operations failed within one year because of a giant cell synovitis caused by a high volume (0.2 cc) of fine polyethylene (1-100 mu) wear particles. Ultra high molecular weight polyethylene should not be used as a prosthetic bearing surface to articulate against cortical, cancellous or eburnated bone or against degenerative articular cartilage in a major joint.


The surgical approach and source of bone graft for symptomatic nonunion of the scaphoid. In 2 groups of patients treated by bone grafting for scaphoid nonunions, one group had a dorsal or dorsolateral surgical approach with a bone graft from the radius while the other group had a volar approach with an iliac graft. The best results were obtained with an iliac graft. Through the volar approach it is relatively easy to avoid damage to the scaphoid arterial supply. A small proximal vascular pole led to a failure rate of 36%.


Immunotherapy for allergic disease.

Immunotherapy for allergic disease. Although immunotherapy initially was purely empirical, immunologic studies of treated patients in more recent years have shown several types of responses that might be beneficial to patients. Likewise, double-blind clinical trials have documented some clinical improvement if sufficiently large doses of certain allergens are administered to properly selected patients. The selection of patients for possible immunotherapy depends upon a large number of considerations, including the severity of their disease and response to simpler forms of treatment. More slowly absorbed allergen preparations may make immunotherapy less cumbersome and reduce risks. It is impressive that so many patients persist with such an inconvenient form of treatment. Perhaps this indicates that allergies are trivial only for those who don't have them.


Ethical considerations of study participants in dental caries clinical trials. During the past 30 years there has been increasing concern for ethical considerations that pertain to the conduct of human biomedical research. Consequently, many national and international medical and dental organizations and agencies have developed regulations, policies or ethical guidelines for the protection of human subjects who take part in clinical investigations. In the United States, more than 500 research institutions have established permanent committees to review research in humans conducted by their institutions. Members of these committees must represent a broad range of backgrounds, interests, and concerns. Prospective study subjects must be able to make an informed decision on whether to participate in any study, without any element of force, deceit, duress, or other form of constraint or coercion. Obtaining informed consent for studies of children, the mentally infirm, and persons with restricted civil freedom presents special problems. Ethical considerations also raise questions on appropriate designs for clinical studies, e.g. use of untreated controls. Dental studies, particularly those testing caries-preventive agents, raise special questions of design, informed consent, ethical procedures and the use of diagnostic radiographs. The director of a clinical study is responsible for the conduct of all personnel connected with the investigation.


A community health center dental program in Boston, U.S.A. In 1970, a community-based and federally funded dental program was established in Boston. The multiple objectives of this program included the following: provision of dental treatment; education of schoolchildren in dental health; support for community measures of prevention such as water fluoridation; support of job training programs in dental assisting for community residents; employment of community people; and sensitization and training in community health for dental students and auxiliaries. The program provided a number of dental services at a reasonable benefit-cost ratio of 0.87. Other endeavors included the development of a dental health program with community schools and the involvement of dental students in the delivery of care and in screening for children with dental treatment needs.


Animal behavior as a subject for veterinary students. Knowledge of animal behavior is an important asset for the veterinarian; therefore a course in veterinary animal behavior is offered at the New York State College of Veterinary Medicine as an elective. The course emphasizes the behavior of those species of most interest to the practicing veterinarian: cats, dogs, horses, cows, pigs and sheep. Dominance heirarchies, animal communication, aggressive behavior, sexual behavior and maternal behavior are discussed. Play, learning, diurnal cycles of activity and sleep, and controls of ingestive behavior are also considered. Exotic and zoo animal behaviors are also presented by experts in these fields. The critical periods of canine development are related to the optimum management of puppies. The behavior of feral dogs and horses is described. The role of the veterinarian in preventing cruelty to animals and recognition of pain in animals is emphasized. Whenever possible behavior is observed in the laboratory or on film.


Radiological signs of acute pancreatitis. Acute pancreatitis is commonly presented as a confusing and challenging diagnostic problem. This article is intended to show the increasingly important contribution radiology plays in the establishment of a correct initial diagnosis as well as in recognizing the serious complications of acute pancreatitis. A short discussion of the etiology and pathophysiology of pancreatitis is essential in understanding the mechanism of production of the X-ray findings. The most important recently published papers on this topic are reviewed together with a personal evaluation of the most significant and reliable radiographic changes. Statistical data, indications, and contraindications as well as the limitations of our radiographic procedures are discussed.


Photochemical inactivation of enzymes.

Photochemical inactivation of enzymes. The mechanisms of enzyme inactivation by ultraviolet light and visible light in the presence of sensitizing dyes are reviewed. Recent flash photolysis studies on amino acids and enzymes are summarized in terms of proposed models relating the initial photochemical reactions to permanent chemical and biological damage. The generation and reactions of singlet oxygen are discussed in connection with photodynamic processes. The photochemical results are compared with ionizing radiations, particularly pulse radiolytic methods employing radical anions as selective probes. The interrelationships between the various modes of enzyme inactivation are discussed, as well as the new information to be learned about the structure and functions of the native enzymes from selective radiation-induced alterations.


Inhibition of cell wall synthesis by sulfonamides and trimethoprim. The hypothesis that defective cell wall synthesis seems to represent a final common pathway of drug-induced injury either within the bacterial cell or on its surface was supported by two different findings: (1) sulfamethoxazole and trimethoprim, either alone or in combination, induced morphological findings in various Escherichia coli and Proteus mirabilis strains identical to those found after incubation with so-called cell-wall-active antibiotics (e.g., penicillin) and (2) cell-wall-defective bacteria (L forms, spheroblasts) were resistant to sulfonamides and/or trimethoprim as compared to their normal bacterial cells.


In vitro sensitivity of hospital strains of Serratia marcescens to chemotherapeutic agents. The susceptibility of 83 non-pigmented Serratia marcescens strains was determined by an agar dilution technique. They originated from miscellaneous pathological specimens submitted to the diagnostic laboratory during a nosocomial infection outbreak in 1974. All strains were completely resistant to 128 mug/ml of cephalothin, colistin sulphomethate, lincomycin and penicillin G. They were also resistant to clinically attainable concentrations of ampicillin, chloramphenicol, erythromycin, novobiocin and tetracycline. With regard to drugs with some activity 84% of the strains were susceptible to nalidixic acid, 48% to sulphamethoxazole, 57% to streptomycin, 60% to kanamycin, 61% to gentamicin, 85% to co-trimoxazole and 100% to amikacin. Environmental strains isolated from the infected units were strikingly more sensitive than the patient strains.


[Wandering of foreign bodies. (Grenate fragment in the common bile duct causing jaundice)]. This report deals with the "wandering" of foreign bodies and their cause. The rarity of such occurrences is emphasised. Two cases are presented, in the first patient a grenade splinter was removed from the common bile duct 33 years after injury; there are only seven instances in the literature of this condition. In the other case a mandrin was injected into an arm vein and travelled to the bifurcation of the abdominal aorta causing an aneurysm. According to the definition given by Schwaiger (1948) these 2 cases belong to the groups 2 and 3. In the case of the grenade splinter it is a secondary "wandering" from parenchymatous tissue to the biliary tract from where the splinter was able to descent the tract.


Electron microscopy of membrane-associated folded chromosomes of Escherichia coli. Membrane-associated folded chromosomes were purified from log-phase cultures of Escherichia coli 15 TAU-bar and prepared for electron microscopy by aqueous spreading techniques. A spectrum of structures was observed, ranging from condensed structures with no DNA fibers visible, to extended structures with DNA fibers. In the extended structures, loops of DNA radiated from residual envelope, the loops sometimes appeared supercoiled, and both their number and apparent contour length approximated previous estimates from physical and biochemical data. It is proposed that the structures with free DNA arose from the condensed structures.


The fine structure of human chromosomes isolated by shearing-sieving. Chromosomes isolated by the new technique of shearing-sieving, even if unstained, show a less degraded organisation than those prepared for the electron microscope by other techniques. The chromosomes are banded, may show more bands if stretched, and the centromere is a precisely defined structure. Appearances resulting from this technique are compared with those from other techniques.


Dysphoric response to neuroleptic treatment in schizophrenia and its prognostic significance. Data on the subjective responses to neuroleptic treatment and their prognostic implications are reported from a multidimensional double-blind study of the pharmacotherapeutic process in schizophrenia. From these data it seems that the occurrence of a dysphoric response in the course of neuroleptic treatment is associated with a less favorable therapeutic response and long-term prognosis. It is suggested that the dysphoric responders, many of whom belong to the category of nuclear or poor prognosis schizophrenia, may be fundamentally different from the others.


Psychotic reactions associated with childbirth. The literature on postpartum psychoses is reviewed. Clinical similarities and differences between patients with postpartum psychoses and those with nonpuerperal psychoses are described. The psychological and physiological precipitants of postpartum psychoses are discussed and a stress summation theory is proposed to explain the etiology of these reactions. Treatment considerations and factors pointing to favorable short-term and long-term prognoses are reviewed.


[Fatal thrombo-embolism after central-vein catheterisation (author's transl)]. Ten cases of fatal thromboembolism after central venous catheterisation were found among the autopsies of one year. The immediate causes of death were protracted pulmonary embolism (n = 8), cerebral embolism with defect of ventricular septum (n = 1), and central regulatory disturbance following complete thrombotic occlusion of the jugular veins (n = 1). The sources of the fatal embolisms were found in thrombi in the superior vena cava, the innominate veins or subclavian veins. The relation of these thrombi to catheter-dependent lesions in the venous walls was beyond doubt. The catheters had been left in position for periods of 2 to 56 days. In 40 further autopsies with different causes of death, catheter-dependent mural lesions of varying extent were found in the venous system near the heart. Local thrombi were identified after catheterisation of not more than 24 hours. Macroscopic and microscopic appearance of these thrombi was characterised by a groove-like structure corresponding to the apposition of thrombi around the plastic catheter.


[Clinical evaluation of simple hygienic measures for wearers of dental prostheses in a nursing home]. The simple treatment of dentures with bacteriostatic drugs withoug any additional treatment may result in a considerable improvement of inflamed mucosa on which a denture is resting. The question as to whether hygiene or other factors (e. g. trauma) are more important with regard to the etiology of denture stomatitis cannot be answered entirely by this study. Continuation of studies on the various causes of denture stomatitis and searching for improvements in its therapy by short and long-term investigations are recommended.


[Clinical evaluation of an hygiene program for patients with denture stomatitis]. 1. Daily thorough cleaning of dentures is the essential factor for the healing or prevention of denture stomatitis. 2. The denture-bearing base and its mucosal side should be shaped and prepared in such a manner that denture hygiene is facilitated. 3. In papillomatous stomatitis surgical and hygienic measures must be combined.


[The effects of occlusal changes on the supporting tissues]. Displacements of the condyle caused by preparations in the supporting area are reported. These displacements occur only if the second premolar is included in the preparations. They are ventrocranial in direction and increase in extent if the first premolar and the canine are included in the preparations. Values of up to 2.8 mm in carnial and of up to 2.8 mm in ventral direction can be observed.


Standardization of the instrumentation used in the preparation of the site for endosseous implantation. Special importance is attached to the standardization of the instrumentarium used for the preparation of a reception area of implants. When selecting and preparing the instrumentarium and the burs, the technical measurements must be in accordance with those of the implant. Also when selecting the various attachments for the dental mini-handpieces, the admissible r.p.m. numbers must be considered and a cooling system must be applied which excludes infections.


[Pre and postoperative determination of the gingival sulcus fluid for the control of the healing process after periodontal surgery]. To objectify the healing process after gingivectomy and flap operation, the gingival sulcus liquid was determined in 20 patients before and after the operation. It was drawn off in the labial part of the sulcus of anterior teeth by means of microcapillaries and then measured. At the same time, the gingival index (M-index) was checked and the depth, of the pocket was measured. Four weeks after the operation, a clear reduction in the amount of the gingival liquid, the index and the depth of the pocket was observed. The group of probands on which flap operations were performed, had twice as much sulcus liquid than those undergoing gingivectomy, and consequently the amount of exudate decreased considerably more within the first three weeks. After the third postoperative week, the average values converged and after the fourth week they were almost identical. The M-index changed accordingly, the average pocket depth was between 1 and 1.5 mm after four weeks.


[Dean's alveolotomy for the correction of maxillary protrusion with periodontal disease]. The method of intraseptal alveolotomy which was introduced by Dean and has meanwhile been further improved, enables us to correct maxillary protrusion when teeth cannot be retained. The various phases of the operation are described on the basis of our own experience. In many cases an additional excision of the labial frenulum with partial extension of the vestibulum appears to be indicated. This should, however, be performed in a second operation. Special attention is called to the simultaneous correction of a deep bite in the lower anteriors which is frequently the cause of periodontal damage of the maxillary teeth.


[Plastic-surgical problems in the removal of malignant facial skin neoplasms on the nose and ear]. The majority of malignant tumors of the skin on the head are found in the upper two thirds of the face. The oral surgeon who is active in the plastic surgery field is therefore frequently confronted with surgical problems exceeding the limited area of the jaws. In this respect nose and ear are regions presenting special problems with regard to esthetics and function.


[Electron microscopic study of preserved skin]. The ultrastructure of normal and preserved skin of rabbits breed "chin-chill" has been investigated. The authors state that when the skin is preserved under given conditions for 20 days, the intracellular changes of the epithelium and connective tissue have a reversible character, but after 30 day preservation under the same conditions the connective tissue shows deep pathological changes. The authors conclude that the electronic microscopic investigations give a more complete characteristics for the fitness of the tissues for transplantation, as compared with other methods.


[Hypothalamic mechanism of the antiovulatory action of sulpiride]. The antiovulatory effect of sulpiride is mediated via inhibition of the LH-RH release: when given during 10 days in guinea pigs, sulpiride is able to promote an increase of LH-RH immunoreactive substance in anterior hypothalamic and suprachiasmatic neurons. This storage probably related with inhibition of LH-RH release, is permitted by catecholamines, since metatyrosine administration prevent this sulpiride effect. On the other hand, when administered to hamsters sulpiride is able to promote stimulation of hypothalamic catecholaminergic neurons of tubero infundibular and anterior periventricularis nuclei. The hypothalamic aminergic action upon sulpiride antiovulatory effect is discussed.


Muscle structure and function--an explanation. The structure of vertebrate skeletal muscle is reviewed. The mechanism of muscular contraction and its control is then discussed from the point of view of molecular structure. Contraction takes place by a sliding filament mechanism produced by cross-bridges which form between thick and thin filaments. Control is exercised by tropomyosin and troponin. When the calcium concentration is low, these proteins interfere with the formation of cross-bridges and prevent contraction, but when the calcium concentration is increased, they no longer interfere and contraction proceeds.