Effects of changing levels of glucocorticosteroids on heat exposure in rabbit. Rabbits exposed for one hour to a temperature of 40degrees Cand 35-37% humidity showed elevated plasma osmolality and pH. Most of the animals were not able to withstand the heat. Dexamethasone-treated rabbits under the same conditions withstood the heat better and their plasma pH and osmolality remained constant. Metopirone-treated rabbits withstood the heat and showed a rise in plasma osmolality and a slight change in plasma pH. The highest rise in rectal temperature was observed in the metopirone-treated rabbits. Only the untreated animals were unable to regain pre-exposure rectal temperature. The results suggest that high levels of glucocorticosteroids enhance neurogenic and metabolic mechanisms which have protective functions during acute exposure to heat.


Changes in contractility and calcium binding of guinea pig taenia coli by treatment with enzymes which hydrolyze sialic acid. The effects of neuraminidase and phospholipase C on the contractility and the Ca++ -binding of guinea pig taenia coli were investigated. Potassium contracture or histamine-induced contracture of taenia coli was inhibited by treatment with neuraminidase, though acetylcholine-induced contracture was not. Treatment with phospholipase C markedly inhibited the contracture induced by isotonic potassium, histamine or acetylcholine. By treatment with neuraminidase for 4 hr, about 40 mumol/100 mg wer wt of sialic acid was released from taenia coli. This corresponded to two-fifths of total content of sialic acid. By treatment with phospholipase C for 2 hr, a similar amount of sialic acid to that produced  by neuraminidase treatment was released. The Scarchard plot of Ca++-binding was a biphasic pattern indicating the presence of two types ofthe Ca++ -binding site with different affinity constants. Neuraminidase produced a 57% decrease in the amount of bound Ca++. The Scatchard plot of Ca++ -binding changed to a monophasic pattern indicating the disapperance of thel ow affinity Ca++ -binding site. Phospholipase C caused a 59% decrease of bound Ca++. The Scatchard plot also indicated the disappearance of the low affinity Ca++ -binding site. From these results, we speculated that sialicacid residue of surface membrane of the muscle cell was first site in the Ca++ -influx mechanism.


[Treatment of acute respiratory insufficiency in cardiac surgery]. An analysis of the main causes of acute respiratory insufficiency as a frequently observed and severe complication of the early postoperative period after open-heart surgery is presented. To permit differentiated employment of respiratory resuscitation measures, subcompensated and decompensated forms of acute postoperative respiratory insufficiency were distinguished on the basis of clinical and laboratory data. The most efficient methods of treatment of this complication are described, including the employment of helium, ultrasonic inhalator, therapeutic intubation, bronchoscopy, long-term automated artificial pulmonary ventilation. A combined employment of the modified methods of respiratory resuscitation permitted to improve the course of acute respiratory insufficiency and to reduce the mortality nearly three-fold.


[Isoenzyme differentiation of gamma-glutamyltransferase by concanavalin A and Con- A-Sepharose (author's transl)]. In this investigation a new possibility of isoenzyme-differentiation of the gamma-glutamyl-transferase (GGT) (EC Nr.2.3.2.2.) was demonstrated by Concanavalin A and Con A-Sepharose. Because of the different sugar content of the glycoproteins distinction between liver- and kidney-GGT is possible. Furthermore it was possible for the first time to show a different precipitation behaviour of one glycoprotein to Concanavalin A in certain diseases. In cases of alcoholic hepatitis GGT looses its Concanavalin A-affinity because of increased neuraminic acid concentration. The possible reasons of the different behaviour to the binding affinity of Con A and Con A-Sepharose and GGT as well as additional use for enzyme-differentiation by Con A-Sepharose affinity chromatography are discussed.


Investigations on the function of the rat forestomach. The functions of the rat forestomach and upper digestive tract were studied. The pH values, alpha-amylase activity, quantitative estimates of microorganisms, and emptying rates were higher in the forestomach than in the glandular stomach. Rats with surgically removed forestomachs lived without complications for more than 1 yr. Their alimentary hyperglycemia was higher and shorter than in controls. The significance of rich microflora present in the conventional forestomach is not known, although in this function between man and ruminants were discussed.


Removal of basement membrane in the involuting breast. Morphologic and immunohistochemical studies by light and electron microscopy indicated that basement membrane was removed during the process of involution of the murine breast. Removal of the basement membrane started 2 days postweaning, was maximal at 4 days, and correlated with degeneration of epithelial cells. There was no evidence of phagocytosis of basement membrane, so the removal of this antigen was attributed to enzymatic hydrolysis. To determine the activity of breast homogenate on the specific basement membrane antigen, insoluble basement membrane embedded in agarose gels was incubated with breast liver and kidney homogenates. When basement membrane antigen was demonstrated by the specific antibody, it was found that breast homogenate solubilized basement membrane but liver and kidney failed to solubilize basement membrane. To quantify the reaction and determine some of the characteristics of the responsible enzyme(s), insoluble basement membrane was labeled with 125I and the release of radioactivity into the supernatant following incubation with extracts of involuting breast indicated hydrolysis of basement membrane. Extracts of breast homogenate extensively hydrolyzed labeled basement membrane if naturally occurring inhibitors were removed by previous washing, whereas liver or kidney extracts prepared in a similar manner were devoid of activity. The hydrolysis of basement membrane was time and concentration dependent and had a pH optimum. The reaction was blocked by prior heating of the extract at 100 degrees C. for 30 minutes, removal of divalent cations, and presence of diisopropylfluorophosphate (a specific serine esterase inhibitor); prolonged dialysis failed to remove the hydrolytic activity. It is concluded that an enzyme system present in the involuting breast is capable of basement membrane hydrolysis


The effects of dopamine and isoproterenol on the pulmonary circulation. Dopamine and isoproterenol, although used primarily for their inotropic effects, are also potent vasoactive substances. To determine their effects on the pulmonary circulation, we cannulated the left lower lobe bronchus in 20 dogs to permit ventilation with either air or a mixture of 95% nitrogen and 5% carbon dioxide; systemic oxygenation was maintained by venitlating the right lung with 95% oxygen. The lobe was perfused at a controlled flow rate and left atrial pressure was held constant. Hypoxic ventilation increased the lobar vascular resistance by 52% (p less than 0.001). Dopamine infusion (20 mcg. per kilogram per minute) during air ventilation also increased lobar vascular resistance by 50% (p less than 0.001). During hypoxic ventilation, dopamine increased the resistance by an additional 19% (p less than 0.001). In contrast, isoproterenol (0.2 mcg. per kilogram per minute) abolished the hypoxic pressor response (p less than 0.001). Combined alpha- and beta-adrenergic blockade did not alter hypoxia-induced vasoconstriction, whereas phentolamine blocked the dopamine response and propranolol abolished the isoproterenol-induced vasodilation. These results indicate the following: (1) The hypoxic pressor response is independent of sympathetic innervation; (2) dopamine in dogs is a pulmonary vasoconstrictor; and (3) isoproterenol is a pulmonary vasodilator. If these findings can be extrapolated to man, isoproterenol may be the preferred inotropic agent in patients with an elevated pulmonary vascular resistance.


Biochemistry of copper.

Biochemistry of copper. Copper, as a component of numerous cuproenzymes, plays a vital role in many physiologic functions in man and animals. From the stand-point of human health there are at least three functional areas of prime importance. Copper is involved in the development and maintenance of cardiovascular and skeletal integrity, central nervous system structure and function, and erythropoietic function including iron metabolism. Although there is no evidence for widespread copper deficiency in the human population, it does occur, owing to genetic defects and other precipitating factors. A clear understanding of the functions of copper and its mechanisms of action could prove highly beneficial in the solution of present and unforeseen problems in medicine.


Effects of dietary saturated and trans fatty acids on cholesteryl ester synthesis and hydrolysis in the testes of rats. Studies were made of the enzymic synthesis and hydrolysis of cholesteryl esters in rat testes. Weanling rats were fed for 14 weeks diets containing 5% by wt of hydrogenated coconut oil (HCO), a concentrate of ethyl elaidate and linolelaidate (TRANS), devoid of essential fatty acids (EFA), or safflower oil (SAFF). Cholesterol esterifying activity was localized in the soluble fraction, and cholesteryl ester hydrolase activity was distributed in both particulate and soluble fractions obtained from tissue homogenates. The optimum pH was 6.0 for esterification and 6.9-7.0 for hydrolysis. Neither esterifying nor hydrolytic activity was affected by freezing and thawing, but both reactions were inhibited by heat or sonication. The animals of both the HCO and TRANS groups had developed an EFA deficiency before they were sacrificed. The EFA deficiency produced upon feeding the HCO diet had no apparent effect on the synthesis and hydrolysis of cholesteryl esters in rat testes. The TRANS diet influenced the development of the testes as judged by their size, and cholesterol esterifying and cholesteryl ester hydrolyzing activities were suppressed in the testes of the animals of this group. A major difference in the effects of the HCO and TRANS diets on the lipids of the tests was the relatively minor amount of eicosatrienoic acid (20:3) and the elevated level of docosapentaenoic acid (22:5) in the cholesteryl esters of the testicular lipids of the TRANS group.


Defective lipid disposal mechanisms during bacterial infection in rhesus monkeys. Mechanisms producing hypertriglyceridemia during bacterial sepsis have not been well defined. In this study lipid disposal mechanisms were assessed in 76 infected and 19 control male rhesus monkeys by the ability to dispose of triglycerides after: (1) oral lipid loading; (2) intravenous lipid loading; and (3) by lipolytic enzyme activity tests as measured by postheparin lipolytic activity (PHLA). Studies were performed both before and 48 hr after intravenous inoculation with either Salmonella typhimurium or Diplococcus pneumoniae when illness was uniformly severe and fasting serum triglyceride elevations were increased maximally. S. typhimurium-infected monkeys demonstrated significant fasting hypertriglyceridemia (p is less than 0.001), reduced clearance of orally and intravenously administered lipid and markedly reduced PHLA. During this gram-negative sepsis, mild lethargy, slight diarrhea, and a 2% mortality were observed. During D. pneumoniae sepsis, average fasting triglyceride concentrations were slightly, but not significantly elevated. While oral lipid clearance was impaired, intravenous lipid clearance was unimpaired, and PHLA was slightly reduced. Marked lethargy, agitation, and a 20% mortality were present during this gram-positive infection. Results of this study support the concept that an impairment of lipid disposal mechanisms, particularly during gram-negative sepsis with S. typhimurium, may significantly contribute to the observed hypertriglyceridemia.


Sweetening agents from natural sources.

Sweetening agents from natural sources. Sweetness is an important taste sensation to humans. The absence of suitable sweeteners as alternatives to cyclamates and saccharin has led to a renewed interest in sweeteners form natural sources. A brief review of the history of sweetener usage provides a basis for understanding our present heavy consumption of sweet substances. The structure of naturally-occurring compounds possessing a sweet taste range from simple sugars to complex, intensely sweet proteins. The structural types include monoterpenes, diterpenes, triterpenes, flavonoids, steroid saponins, dipeptides, and proteins. Some of these substances are not, strictly-speaking, natural but are derived from natural sources by relatively minor chemical modification. The properties of two non-sweet substances, miraculin and gymnemic acid, are included because of their close relationship to the subject of sweeteners. Miraculin causes sour substances to taste sweet and gymnemic acid selectively blocks sweet taste perception. The second part of the paper presents some of the work on monellin, the intensely sweet protein from "serendipity berries" (Dioscoreophyllum cumminsii). The physico-chemical studies of monellin provide convincing evidence that it is, indeed, a protein. Structural studies using denaturants and specific chemical modifications have provided a beginning of our understanding of the molecular basis of the sweet taste of monellin.


[Mendelson's syndrome (author's transl)]. It is reported on 10 patients with the features of Mendelson's syndrome; 4 patients died. Diagnosis, therapy, course and prognosis of this severe complication following aspiration of gastric hydrochloric acid are discussed.


The effects of nalorphine and naloxone on maternal and fetal blood gas and pH. In the control trials on near-term pregnant women before the onset of labour, nalorphine was found to cause a mild respiratory acidosis in the mother and metabolic acidosis in the fetus. These effects were not apparent when naloxone was administered.


[Investigations of the lipase activity of a pancreatin compound (author's transl)]. In connection with the physiologic process of digestion, the requirements for an enzyme-based drug are stated. Quick release of highly active enzymes in the duodenum is a prerequisite of physiological stimulation of the pancreatic excretory function. Digestive potency is regarded as a suitable gauge for comparing of results in large-scale in vitro scanning. Our own in vitro and in vivo studies have borne out the possibility of transferring in vitro findings to the therapeutic value of this compound. As shown by our investigations, quick release of highly active enzymes in vitro is coupled with a high degree of bioavailability in Fermento duodenal. As a result, normalization or reduction of the lipid content of faeces--as a sign of therapeutic efficacy--is seen in patients with pancreatic excretory insufficiency. Statistical evaluation resulted in the following: 1 A statistically significant (p less than 0.1%) increase in lipase activity in the duodenal juice in vitro after addition of one capsule of Fermento duodenal. 2. Lipase activity in vivo after 15 minutes is significantly different from all other values. 3. A statistically significant (p less than 1%) drop in the amount and lipid content of faeces following the treatment with Fermento duodenal.


Characterisation of eukaryotic ribosomal proteins. A simple method of two-dimensional polyacrylamide gel electrophoresis is described which affords: (1) high resolution of eukaryotic ribosomal proteins; (2) good recovery of protein in the transfer from first to second dimension; and (3) characterisation of the separated proteins in terms of molecular weights and other electrophoretic properties. Using this method, we have characterised 70 proteins in rabbit reticulocyte ribosomes, 30 from the small subunit and 40 from the large subunit. The molecular weight distribution is compared with those obtained by other authors after fractionation of the proteins in two dimensions.


Study on proteins from yeast cytoplasmic ribosomes by two-dimensional gel electrophoresis. Proteins of yeast cytoplasmic ribosomes were analyzed by two different methods of two dimensional gel electrophoresis: run at pH 8.6 in 1-D1 and at pH 4.6 in 2-D (Method A); run at pH 5.0 in 1-D and in the presence of sodium dodecyl sulfate in 2-D (Method B). The numbers of proteins estimated were 28 (Method A) and 29 or 30 (Method B) in the 40S small subunit, and 40 (Method A) and 41 (Method B) in the 60S large subunit, respectively. Molecular weights of proteins in the small and the large subunits were found to be less than 40,000 and 60,000 respectively.


Conformational changes in cytochrome aa3 and ATP synthetase of the mitochondrial membrane and their role in mitochondrial energy transduction. 1. The thermodynamics and molecular basis of energy-linked conformational changes in the cytochrome aa3 and ATP synthetase complexes of the mitochondrial membrane have been studied with spectrophotometrical and fluorometrical techniques. 2. Ferric cytochrome aa3 exists in two conformations, high spin and low spin, the equilibrium between these states being controlled by the electrical potential difference across the mitochondrial membrane. The conformational change is brought about by an electrical field-driven binding of one proton per aa3 to the complex. At pH 7.2 the concentration of the two conformations is equal at a membrane potential of 170 mV corresponding to about 4 kcal/mole. 3. The high to low spin transition in ferric aa3 is also induced by hydrolysis of ATP in which case two molecules of aa3 are shifted per ATP molecule hydrolyzed. This is in accordance with translocation of two protons across the mitochondrial membrane coupled to hydrolysis of ATP as proposed in the chemiosmotic theory of oxidative phosphorylation. 4. The conformational transition in cytochrome aa3 is not an expression of the formation of a 'high-energy' intermediate or reversal of the energy-transducing pathway of oxidative phosphorylation, but is presumably the basis of allosteric control of the activity of cytochrome oxidase by the energy state of the mitochondrion. This control is exerted by a regulatory mechanism in which the electrical potential difference controls the conformation and redox properties of the heme centres and thereby the rate of oxygen consumption. 5. The synthesis of one molecule of ATP by oxidative phosphorylation is energetically equivalent to the work done in carrying two electrical charges across the entire mitochondrial membrane. 6. Fluorescence changes of aurovertin bound to ATP synthetase reveal that the electrical membrane potential induces a conformational change in the F1 portion of the enzyme which is probably associated with dissociation of the natural F1 inhibitor protein. This conformational change is energetically equivalent to the work done in carrying one electrical charge across the mitochondrial membrane. 7. A model is proposed for the mechanism of the electrical field-induced conformational changes in the cytochrome aa3 and ATP synthetase complexes, and the significance of these changes in the mechanism and control of mitochondrial energy conservation is discussed.


[Old and new dangers of blood transfusion (author's transl)]. The predominant danger of blood transfusion, even after the discovery of the ABO and Rh systems, is the immunological risk. This led in 1940 to a regulation of blood transfusion in Germany by official guidelines which were constantly adjusted in the light of new research results. The dangers due to deterioration on storage still receive too little attention although these may be of greater danger to the patient than immunisation risk. Also the assessment of other medical problems of transfusion is insufficiently applied to clinical routine.


Vinyl chloride dependent mutagensis: effects of liver extracts and free radicals. The mutagenic effects of vinyl chloride (VC) on Salmonella typhimurium strain TA1530 are enhanced by mouse or rat liver extracts. The extracts prepared from mice pretreated either with vinyl chloride or the microsomal enzyme inducer, Aroclor 1254, did not produce any greater stimulation of VC-dependent mutagenesis than extracts from untreated animals. These same extracts, however, differed markedly in their capacity to stimulate the mutagenicity of dimethylnitrosamine (DMN), a compound which is converted to a mutagen by an NADPH dependent microsomal mixed function oxidase. The order of activity of the extracts with DMN was Aroclor pretreated is greater than untreated is greater than VC pretreated. Furthermore, the stimulatory effect of the liver extracts on VC mediated mutagenesis did not require NADPH and was still evident in liver extracts in which the microsomal mixed function oxidase system had been heat inactivated. The mutagenic activity of VC also was found to be stimulated by riboflavin in the presence of light suggesting that free radicals may be involved in VC dependent mutagenesis.


Testicular function after orchiopexy for unilaterally undescended testis. Testicular function was determined in 29 men, 21 to 35 years old, who had undergone orchiopexy for unilaterally undescended testis at four to 12 years of age. Serum testosterone and dialyzable testosterone concentrations of these men were not significantly different from those of a control group of 30 normal men, and their basal serum luteinizing hormone concentrations and serum luteinizing hormone responses to synthetic gonadotropin-releasing hormone were only slightly higher than those of the normal men. The mean sperm density of the patients, however, was only one third of that of the normal men (p less than 0.001). The mean serum follicle stimulating hormone response ro gonadotropin-releasing hormone of the patients was doubled that of the normal men (p less than 0.001). The data indicate that spermatogenesis may be abnormal after orchipexy, and suggest that men with unilaterally undescended testis may have bilateral testicular abnormality.


[Isolation and characterization of main albumin fractions of seeds from sunflower (Helianthus annuus L.) and rape (Brassica napus L.)]. The main fractions of the albumins from sunflower and rapeseeds (isolated by means of precipitation with ammonium sulphate or tannin + caffeine and subsequent gel chromatography) are low-molecular, very basic proteins. Their molecular weights range from 10 000 to 16 000, and their isoelectric points (determined by isoelectric focusing and free electrophoresis) are situated at pH greater than 10.0. From the circular dichroism in the wavelength range from 200 to 240 nm it is deduced that the main fraction of the rape albumin is a well-structured protein with 40-46% alpha-helix in aqueous and salt-containing solutions. Denaturation by heating is achieved only at temperatures about 100 degrees C and pH values greater than 9. 20% alpha-helix are left after the action of 8 M urea. This conformational stability is explained by the presence of disulphide linkages in the molecule.


[Effect of acid polysaccharides on properties of pancreatic proteases]. The use of acid polysaccharides (sodium alginate, pectin, carrageenan, etc.) as gel-forming agents in the manufacture of artificial foods excites the interest in the study of their effects on the enzymes of the gastrointestinal tract. In this connection, the authors investigated the action of various acid polysaccharides on the kinetics of the hydrolysis of low-molecular substrates catalyzed by pancreatic proteinases. It was shown that the intereactions between acid polysaccharides and enzymes produce effects which can be fully explained by changes in the apparent ionization constants of the ionogenic groups which participate in the catalytic reaction. The extent of the effects observed in presumably determined by the strength of the electrostatic potential which is generated by polyanions.


[Interaction between proteins and acid polysaccharides]. The intereaction between proteins and acid polysaccharides is electrostatic in nature and leads to the formation of soluble charged and insoluble neutral complexes. The complex formation in the system casein-dextran sulphate is followed by means of turbidimetric titration. It depends on the pH value and the electrolyte concentration. On free electrophoresis, complexes formed below the isoelectric point of the protein exhibit anodic mobility, whereas pure casein migrates to the cathode. The protein in the complex is not able to bind amido black. Consequently, it cannot be detected electrophoretically by dyebinding. The results from viscosity and diffusion measurements are indicative of an increased hydrodynamic volume of the complexes.


[Isolation of proteins with complex forming agents]. Taking vegetable albumins for models, the authors report of the possibilities of isolating proteins (which cannot be precipitated isoelectrically) by using their property of forming complexes with tannin or poly-anions. The precipitation of proteins with dextran sulphate or polyphosphates, which is due to electrostatic interaction, depends on the pH value and the electrolyte content of the solution. Under appropriate experimental conditions, protein yields of 100% are achieved. By means of tannin, the proteins are completely precipitated in a wide range of pH. The protein component of the poly-anion-containing complexes is isolated by precipitation with salt or by thermal coagulation after dissolving of the complexes. The isolation of protein from the tannin complexes is preferably realized by reaction with coffeine.


[Technological directions for processing rape proteins into protein concentrates and isolates]. Rape-seeds or rape-seed meal are relatively cheap, but valuable raw materials for the manufacture of protein concentrates and isolates which may be used as constituents of foodstuffs. The high content of crude fibres and also of thioglucosides leads to considerable difficulties in the development of techniques for the manufacture of high-grade protein preparations. To describe the procedure, certain production-technological properties of rape proteins are discussed, such as extraction parameters, coagulating conditions, processing temperature, amount of solvent, etc. On the basis of these data, the following techniques for the manufacture of rape protein products are presented: - protein concentration by means of the water diffusion method; - protein isolation with the aid of one or multi-stage extraction. Finally, the author reports of a fermenting procedure for the manufacture of protein biomass from coarse colza meal. Furthermore, he presents some data about the nutritional value of rape protein.


[Mass transfer in production of milk protein coprecipitates]. During the last twenty years heat coagulation has become a more important technical procedure for the isolation of milk proteins because of its very efficient utilization of raw material. Experiments are reported to get approximation equations for the mass transfer in the production of milk protein coprecipitates from skim milk and mixtures of skim milk with rennet and acid whey by means of statistical planning and interpreting of experiments. Good exactness was reached. The coagula consist of casein fractions, whey protein fractions, calcium, and phosphates. The products are thermically rather stable, sensorically indifferent and contain water insoluble protein. They are suitable to improve the fat: protein ration of sausages, but also for the protein enrichment of other foods and for dietetic purposes.


[The effect of novocaine on the electrical activity of nodes of Ranvier in high  and low pH solutions]. The minimal concentrations of procaine which block the action potentials of a single Ranvier node were determined under decreased and increased pH in the bathing solution. The changes in concentrations of the basic [B] and cationic [BH+] form of procaine with pH were of monotonic character: [B] drops and [BH+] grows with pH increase. The dependence of membrane excitability (fraction of channels are able to excite)  on pH was nonmonotonic; it is low under increased and decreased pH. On the basis of these data the hypothesis that the membrane of the Ranvier node may interact with a definite form of procaine is rejected. T he quantitative analysis shows that the membrane interacts with both the basic and cationic forms of procaine but the efficiency of this interaction is different.


[The effect of the pH of the external solution on posttetanic hyperpolarization of a denuded nerve]. A decrease in pH of the external solution from 7.3 to 5.3 causes an increase in post-tetanic hyperpolarization, while an increase in pH to 9 causes its decrease. The time-course of the hyperpolarization was increased at low pH and reduced at high pH. The possibility of a change in the electrogenicity  of the sodium pump induced by changes in pH is discussed.


Kinetics of thymus-derived lymphocyte count changes in rats affected by graft-versus-host reaction. The effect of GVHR on thymus-dependent lymphocytes of various lymphoid organs has been followed autoradiographically and by scintillation technique in a temporal dependence on the induction of the reaction. GVHR was induced in (BD X Lw) F1 hybrid rats with parental spleen (BD) cells. As marker of the thymus-dependent lymphocytes the in vitro 3H-uridine incorporation was used. Compared to B cells, T lymphocytes of rats have a higher ability of incorporating labeled uridine. T lymphocytes in peripheral blood and the thoracic duct achieved their peak at 3 or 4 days following GVHR induction. On the fourth day, simultaneously with a GVH-altered thymus a rapid decline in the number of these cells was also observed. A mobilization of T lymphocytes from the spleen and lymph nodes into the circulation already in the very first days of the reaction might be responsible for the peak seen in PBL and TDL. The GVH-alteration lasting 21 days caused an evident reduction of thymus-dependent lymphocytes in all the organs studied here. The immunological attack of GVHR is considered to be primarily responsible for the exhaustion of T cells. The discussion bears on the possibility of a more progressive action of GVHR on the more mature T lymphocyte subpopulation.


Effect of chlorogenic acid in a casein diet for rats. Nutritional and pathological observations. 3-week-old male rats were fed on a casein diet containing 1% (w/w) of chlorogenic acid in order to find out if the ingestion of chlorogenic acid may be associated with a reduced utilization of dietary proteins or with causing other adverse effects. The protein efficiency ratio, biological value and digestibility of this diet did not differ from a corresponding casein diet free from chlorogenic acid. No change was observed in the nitrogen balance of the experimental rats. Neither did the rats show any change in hematological values or volumes and pH of the urine. Some deviation was noticed in the weights of kidneys and adrenals of the chlorogec acid-free casein diet. The findings that were made were normal in the microscopic examinations of various organs. Chlorogenic acid did not seem to influence the ultrastructure of the liver as revealed by electron microscopy.


Influence of experimental dietary conditions on hepatic enzymes of glutamic acid metabolism in rats. The lowering levels of dietary protein induced a significant fall of some hepatic enzymes associated with glutamic acid metabolism. The changes were later normalised during dietary rehabilitation of the protein-deprived rats. The levels of these enzymes were found to be increased as compared to those observed after starvation, on feeding a carbohydrate-free, protein-rich diet or by the dietary supplementation by glutamic acid.


[Methods of determination of the turnover rate of neuromediators (author's transl)]. For the study of the effect of a treatment on a neuromediator, the determination of the turnover rate is often more interesting than the determination of the endogenous level of the mediator. Many methods have been used and they are not always isotopic ones. The principal methods are summarized here, especially for catecholamines and serotonin.


Changes in tyrosine transaminase and phosphoenolpyruvate kinase activities during short term incubation of fetal liver. Incubation of fetal rat liver homogenates at 37 degrees for 2-3 hr increased PEPK activity in the 100,000 X g supernatant 5-fold and TTA activity 10-fold. At the same time, activity in the 100,000 X g pellet decreaed and no change was observed in the whole homogenate. It is concluded that during incubation of fetal liver pieces or homogenates in vitro, a redistribution of enzymes occurs between cell particles and cell sap. It is suggested that release of enzyme into the cell sap may be the first stimulus for subsequent enzyme synthesis which occurs after birth.


Oxygen transport in congenital heart disease: influence of fetal hemoglobin, red cell pH, and 2,3-diphosphoglycerate. In 48 individuals (age 1 day to 13 years) with congenital heart disease, blood oxygen transport function was studied in order to evaluate adaptive changes in shunt hypoxemia and to investigate the in vivo regulation of erythrocyte 2, 3-diphosphoglycerate concentration (RBC 2, 3-DPG) in the presence of fetal hemoglobin (HbF). Arterial pO2 and oxygen content, oxygen capacity, acid base status, oxygen affinity, HbF fraction, plasma pH, red cell pH, and RBC 2, 3-DPG were determined. During the first 50 days of life values of standard P50 (stdP50) (37, pH 7.4), actual in vivo P50 (actP50), RBC 2, 3-DPG, O2 capacity, arterial plasma pH, and red cell pH were scattered around the normal range, although tending to low values for stdP50 and arterial plasma pH and to high values for O2 capacity. After the third month, stdP50 actP50, RBC 2, 3-DPG, O2 capacity, and red cell pH were found to be elevated. Plasma pH and actP50 were scattered around the normal range (Figs. 1 and 2). Intraerythrocytic pH in hypoxemic infants was increased compared with normal children when related to plasma pH (Fig. 3). A close to normal intraerythrocytic pH was therefore found in the hypoxemic infants with low plasma pH, and an increased intraerythrocytic pH in the hypoxemic children with normal plasma pH (Fig. 1). A significant negative correlation exists between erythrocyte H+ ion and 2, 3-DPG concentration (Fig. 5); regression constants derived from data at high (mean 47%) and low (mean 9%) fractions of HbF are not significantly different (Regression Equations 8 and 11 in Table 1). Thus, the known difference in 2, 3-DPG binding to fetal or adult deoxyhemoglobin does not measurably influence the erythrocyte 2, 3-DPG concentration, indicating that in vivo the 2, 3-DPG synthesis in hypoxia is virtually regulated by the erythrocyte pH, which in turn is determined by plasma pH and the oxygenation state of hemoglobin.


Dual effect of 2,3-diphosphoglycerate on the Bohr effects of human blood. The influence of the red cell concentration of 2,3-diphosphoglycerate (2,3-DPG, 0.5-26 mumoles/g erythrocytes) on the "CO2-Bohr effect" (pH varied by CO2 at constant base excess) and the "fixed acid-Bohr effect" (pH varied by fixed acid or base at constant PCO2) was studied in human blood at plasma pH values ranging between pH 7.2 and pH 7.6. Elevation of red cell 2,3-DPG concentration leads to a numerical decrease of the "CO2-Bohr coefficient" referring to plasma pH. The "fixed acid-Bohr coefficients" are numerically smaller than the corresponding "CO2-Bohr coefficients" and exhibit a maximum at normal red cell 2,3-DPG concentrations. The Bohr coefficients referring to red cell pH are distinctly higher than those referring to plasma pH, especially at high 2,3-DPG levels. This is due on the one hand to the physico-chemical properties of the intact red cell membrane, and on the other hand to a 2,3-DPG-induced decrease in the ratio deltapHcell/deltapHplasma. From the results it is concluded that 2,3-DPG exerts a dual effect on the Bohr coefficients of whole blood which is mediated 1. by the direct effect of 2,3-DPG on the allosteric properties of hemoglobin (as reflected by changes of the Bohr coefficients referring to red cell pH), and 2. by the effect of 2,3-DPG on deltapHcell/deltapHplasma.


Influence of 2,3-diphosphoglycerate on the buffering properties of human blood: role of the red cell membrane. The effect of the concentration of red cell 2,3-diphosphoglycerate (2,3-DPG, 0.5-21 mumoles/g cells) on the buffering properties and on the slope of the relation between the extracellular and intracellular pH (deltapHi/deltapHe) of human blood was studied. The results were evaluated in connection with previous findings concerning the effect of 2,3-DPG on the Donnan ratio rH+ = H+e/H+i. deltapHi/deltapHe decreases with rising red cell 2,3-DPG content as well as with rising extracellular pH. deltapHi/deltapHe and rH+ can be related to each other by the empirical equation deltapHi/deltapHe = 1 + log rH+ = 1 + pHi - pHe. The validity of this equation appears to be restricted to conditions where the Donnan ratio rH+ is altered between 0.3 and 1 either by changes of the red cell concentration of buffering anions such as 2,3-DPG or by changes of the extracellular pH. As determined in suspensions of red cells with intact membranes, the 2,3-DPG-and pH-induced changes of deltapHi/deltapHe lead to proportional changes in the buffering power of the non-bicarbonate buffers of erythrocytes. Due to this effect the buffering power of suspensions of cells containing 5 times the normal concentration of the buffer 2,3-DPG is lower than that of cells with normal 2,3-DPG content (at extracellular pH values above 7). These findings demonstrate that the action of intracellular non-bicarbonate buffers in blood is effectively modulated by the physico-chemical properties of the red cell membrane.


Conformation and reactivity of DNA in the complex with proteins. III. Helix-coil transition and conformational studies of model complexes of DNA's with poly-L-histidine. Differences in the interaction of poly-L-histidine with DNA of various base composition have been demonstrated using melting and CD measurements. The two types of complexes formed with DNA at pH values below the pK of 5.9 and in the region of pH 6.5 are very different in their CD spectral properties. The binding effects with highly protonated poly-L-histidine are AT-dependent as reflected by large negative CD spectra indicating the formation of psi-DNA as a condensed state of the double helix. GC-rich DNA may, however, also form psi-DNA structures with poly-L-histidine under certain conditions. At pH 6.5 complex formation with the weakly protonated polypeptide is GC-dependent. From the results it is concluded that protonated poly-L-histidine interacts more specifically at AT base pairs, prabably along the small groove while the weakly protonated poly-L-histidine tends to interact preferentially with GC regions which seems to occur rather in the large groove.


Conformation and reactivity of DNA in the complex with protein. IV. Circular dichroism of poly-L-histidine model complexes with DNA polymers and specificity of the interaction. The CD study of the DNA-poly-L-histidine complex at high degree of protonation revealed that complex formation is already observable at 2 M NaCl. The influence of salt together with 5 M urea suggests that in addition to electrostatic interactions probably hydrogen bonding may favour specific complexes. Affinity of protonated histidines to AT-rich regions is strongly supported by the complexes formed with (dA.dT)-containing polymers. The psi-type structure occurs with poly(dA-dT)-poly(dA-dT) while poly(dA)-poly(dT) is restricted to form a similar psi-state on interaction with highly protonated poly-L-histidine. Differences in the helix winding properties due to variation in the sequence is suggested as a possible factor in the formation of the psi-type complexes. The mechanism of interaction including hydrogen bonding of histidine side-chains with an AT pair at high degree of protonation and with GC-regions at lower degree of protonation in the polypeptide structure is discussed.


Effect of excision of the Y-base on the interaction of tRNAPhe (yeast) with phenylalanyl-tRNA synthetase (yeast). The interaction between tRNAPhe (yeast), from which the Y-base has been removed by acid treatment, and phenylalanyl-tRNA synthetase (yeast) has been investigated by fluorescence competition titrations and sedimentation velocity runs. The binding parameters are given under various ionic conditions. The tRNAPhe-Y still can occupy the specific binding sites on the enzyme. Compared to unmodified tRNAPhe, the binding constant is lowered by more than one order of magnitude. It can be concluded that the Y-base is not necessary for specific recognition of tRNAPhe by the cognate synthetase, it rather may represent a point of attachment for the synthetase.


Distribution of histones in alkali-denatured chromatin studied by isopycnic centrifugation in alkaline metrizamide density gradients. Three types of density gradients - neutral metrizamide, alkaline NaOH-metrizamide and alkaline triethanolamine-metrizamide - were used for studying the distribution of histones between the two DNA strands in alkali-denatured chromatin. It was found possible to avoid both protein redistribution and dissociation by using triethanolamine-metrizamide density gradients at pH 10.5. Under these conditions an alkali-denatured mixture of DNA and chromatin was well separated into the original DNA and DNP. When native or sonicated chromatin was denatured at pH 12.2 and centrifuged in a triethanolamine-metrizamide density gradient at pH 10.5 no peak of free DNA appeared. These results show that both DNA strands remain associated with histone molecules upon alkaline denaturation of chromatin.


Pyrimidine nucleoside analogues.X. 5-Substituted 1-(1,3-dihydroxypropyl-2) uracils. A convenient method is suggested for synthesis of uracil-1-malonic acid diethyl ester by alkylating 2,4-bis(trimethylsilyl) uracil with bromo-malonic acid diethyl ester. This compound has been shown to hydrolyze with NaOH yielding either uracil or uracil-1-acetic acid, depending on reaction conditions. Similarly, thymine-1-malinic acid diethyl ester and 5-fluorouracil-1,3-dimalonic acid tetraethyl ester were obtained. 1-(1,3-Dihydroxypropyl)uracil has been obtained by reducing uracil-1-malonic acid diethyl ester with NaBH4.


Preparation and properties of poly 2'-O-ethylcytidylic acid. Poly 2'0-ethylcytidylic acid (poly (Ce)) was prepared by polymerization of 2'-0-ethylcytidine-5'-pyrophosphate with Escherichia coli polynucleotide phosphorylase in the presence of Mn++, and its properties compared with those of poly (rC), poly (Cm) and poly (dC). The neutral form of pOLY (Ce) exhibits properties similar to those of poly (rC) and poly (Cm). It also forms an acid twin-stranded helix with a transition pH of 5.9 in 0.1 M NaCl. The neutral form readily forms a double-stranded helical complex with poly (rI). Relative to poly (Cm), replacement of the 2'-0-methyl by 2-0-ethyl leads to increased enhancement of the thermal stabilities of both the acid helical form of poly (Ce) and its complex with poly (rI).


O2'-Methylinosine, a constituent of the ribosomal RNA of Crithidia fasciculata. A novel nucleoside, O2'-methylinosine (Im), has been identified as a constituent of the ribosomal RNA of Crithidia fasciculata, a hemoflaggelate protozoan. The nucleoside is released as part of an alkali-stable dinucleotide, Im-Up, by alkaline hydrolysis of Crithidia rRNA, and as a 5'-nucleotide, pIm, by snake venom hydrolysis of the same RNA. The Im-containing derivatives isolated from Crithidia rRNA were characterized by comparison with marker compounds prepared by chemical deamination of the corresponding adenosine analogues. O2'-Methylinosine prepared from either natural Im-Up or natural pIm had the same ultraviolet absorption spectra and chromatographic properties as marker Im. Characterization of the base and sugar components of Im as hypoxanthine and 2-O-methylribose, respectively, provided final confimration of structure. Control experiments have eliminated the possibility that Im arises from O2'-methyladenosine (Am), a known constituent of ribosomal RNA, by chemical or enzymatic deamination during hydrolysis of Crithidia rRNA.


Observations and interpretation of x-ray absorption edges in iron compounds and proteins. X-ray absorption spectra near the Kalpha edge have been measured in various iron group compounds using the intense synchrotron radiation at the Stanford Synchrotron Research Project. In the cubic compounds KMF3 where M = Mn+2, Fe+2, Co+2, Ni+2, and Zn+2, well resolved lines were observed and assigned to the 1s leads to 3d, 1s leads to 4s, and 1s leads to 4p transitions. The observed energies agreed rather well with the spectroscopic energy levels of the Z + 1 ion and the intensities are shown to agree with those expected on the basis of one electron transitions of the form Z 1s2dn(L,S) leads to (Z + 1)1s2dnn'l'(L",S). The energies of the intense 1s leads to 4p transition increase by about 5 V going from KFeF3 to K2NaFeF6, but only by about 1 V from K4Fe(CN)6 to K3Fe(CN)6. The transitions confirm that upon oxidation of the hexacyanides the iron electronic structure barely changes. In the iron sulfur protein rubredoxin, where the iron is bound to a tetrahedron of sulfurs, the 1s leads to 3d transition was about seven times more intense than the same transition in an octahedrally coordinated compound. These intensities parallel those observed in the d-d transitions of optical spectra, because in both types of spectra the intensities depend upon 4p admixture. In the heme protein cytochrome c, upon oxidation the 1s leads to 4p transition shifts only about 1 V to higher energies similar to the iron hexacyanides. These results are discussed in terms of covalent bonding.


Nuclear magnetic resonance studies of slowly exchanging peptide protons in cytochrome c in aqueous solution. The slowly exchanging protons in oxidized and reduced horse heart cytochrome c (D20, uncorrected pH meter reading 6.5 room temperature) have been monitored by recording the 270 and 360 MHz proton nuclear magnetic resonance spectra of the reduced protein between 5 and 11 parts per million downfield from 2,2-dimethyl-2-silapentane-5-sulfonate.


15N nuclear magnetic resonance investigations on amino acids. 15N nuclear magnetic resonance investigations of some amino acids were carried out in order to check the applicability of this method to biological problems. Because the natural abundance of the 15N isotope is not sufficient to get readable spectra in a reasonable time, 95% 15N isotope-enriched samples were used for the measurements. Besides the chemical shift values, the line widths, and the nuclear Overhauser enhancement factors, spin lattice relaxation times of the correspondent 15N resonances were measured as functions of pH had temperature.


Desensitization of beta-adrenergic receptors by beta-adrenergic agonists in a cell-free system: resensitization by guanosine 5'-(beta, gamma-imino)triphosphate and other purine nucleotides. Incubation of purified frog erythrocyte membranes with beta-adrenergic agonists at 25 degrees produces relatively rapid (half-time about 10 min) desensitization (inactivation) of about 60% of the beta-adrenergic receptor binding sites. The desensitized receptors no longer bind the specific beta-adrenergic ligand (-)[3H]dihydroalprenolol. The decrease in the number of functional beta-adrenergic receptors is also manifest as a decreased ability of isoproterenol to stimulate the membrane-bound adenylate cyclase.


An assay of ribonuclease H, endoribonucleases, and phosphatases. An assay for ribonuclease H (EC 3.1.4.34) is described which permits the estimation of the number and the type of cleavages produced by the enzyme when acting on the ribo moiety of a DNA-RNA hybrid substrate. With six different homopolymer hybrids tested, the number of enzymically induced breaks varied widely. The method is applicable to other endoribonucleases, phosphodiesterases, and phosphatases.


Bacteriophage T5-induced endonucleases that introduce site-specific single-chain interruptions in duplex DNA. Four site-specific endodeoxyribonucleases have been partially purified from extracts of bacteriophage T5-infected Escherichia coli by gel filtration and affinity chromatography on single- and double-stranded DNA. The enzymes were detected and characterized by agarose gel electrophoresis of alkali-denatured digestion products. None of the four is found in uninfected cells. In the presence of a divalent cation, all four endonucleases make ligase-repairable, single-chain interruptions at specific sites in the duplex DNA of several bacteriophages (lambda, T7, and T5) and a mammalian virus (adenovirus 2). These activities are not stimulated by ATP. None of the four is active on single-stranded DNA. The fragments produced by each enzyme from ligase-repaired T5 DNA do not correspond to those derived from mature T5 DNA. Each of the enzymes is able to cleave the intact strand of T5 DNA.


Regulation of guanylate and adenylate cyclase activities by lysolecithin. The guanylate cyclase activity [GTP pyrophosphate-lyase (cyclizing), EC 4.6.1.2] in membrane preparations from 3T3 mouse fibroblasts is stimulated approximately 5-fold by lysolecithin at concentrations of 100 mug/ml and above.


Abnormal ornithine carbamoyltransferase in mice having the sparse-fur mutation. Mice with the X-chromosomal sparse-fur (spf) mutation frequently have urinary bladder stones composed mostly of orotic acid, which was identified by the following criteria: ultraviolet and infrared absorption, spectra, chromatographic behavior, melting point, and reactivity in a specific color test. This clue led to the discovery that spf-bearing mice have an abnormal form of liver ornithine carbamoyltransferase (carbamoylphosphate:L-ornithine carbamoyltransferase, EC 2.1.3.3). Normal ornithine carbamoyltransferase has maximum activity at pH 7.6-8.0 and 80% of maximum activity at pH 10.0.


The structure and function of thoracic exopodites in the larvae of the lobster Homarus gammarus (L.). The first three larval stages of the lobster Homarus gammarus are pelagic swimming animals. A description is given of the exopodite apparatus of the thoracic appendages that provide lift and propulsive power in these stages. Setal arrangement and display provides greater surface area during power strokes. Musculature is peculiar to the exopodites and concerned with rotational movements of the appendage. Metachronal beating takes place with the segmental appendages moving in a variable sequence.


A quantitative analysis of exopodite beating in the larvae of the lobster Homarus gammarus (L.). Raw data on exopodite beating in the first three developmental stages of the lobster Homarus gammarus were collected and analysed for key beating parameters. The analysis was computer assisted and the main procedures used are described. Beating patterns are the same in all three stages and are usually very regular although perturbations do occur (figures 1, 2). When beating stops the deceleration and subsequent re-acceleration is very rapid (figure 1) and limb movement sequences usually start posteriorly and move forwards (figures 1, 2d). Ipsilateral phase relations are generally maintained at 0.4-0.6 (figures, 3,4) and while the coupling between adjacent exopodites is usually stronger than for those further apart various deviations from this are occasionally seen (figure 5). No significant correlation between the ipsilateral phase relations of adjacent exopodites and base cycle duration was detected for any of the stages (figure 6). Contralateral phase relations undergo a constant progression (figures 7, 9) and this was found to be due to a heterodyne effect (figure 8) also described as gliding coordination. The powerstroke/returnstroke ratio for all stages was approximately 0.5 (figure 10) and no significant correlation was found with cycle duration (figure 11). The only substantial difference between the three larval stages which was noted was that of cycle duration, the cycles of stage III being shorter than those of the first two stages. The exopodite beating pattern was discussed in context with other metachronously cycling systems in arthropods and the implications of the present study discussed.


A comparison of beating parameters in larval and post-larval locomotor systems of the lobster Homarus gammarus (L.). A study has been made of the interrelations between rhythmical exopodite beating in different larval stages and swimmeret beating in poast-larval stages of the lobster Homarus gammarus. Data on exopodite beat cycle durations have been used for statistical comparisons of exopodite performance within one larva, and also between different stages of larval development. Inter-exopodite comparisons reveal clear bilateral differences (table 1), although there is no consistently favoured relationship (tables 2 and 3). There are significant differences in cycle duration between the first three developmental stages, with a slight increase at the first moult, and a marked decrease at the second (table 4). However, within each stage the repeat frequency exhibits little change (table 5). Therefore it appears that changes in swimming behaviour occur discontinuously in development, and are associated with the larval moults. It is suggested that changes in beat frequency, and especially the faster beating in stage III, may represent responses to changed loading conditions (table 7). Measurements of swimmeret beating in post-larval lobsters have been analysed in terms of cycle durations, and inter- and intra-segmental phase relations. Swimmeret beating patterns are very regular (figure 1), but not restricted to a narrow range of frequencies (table 6a). Intersegmental phase lag remains constant around 0.2 (figure 3) independent of beat frequency (figure 4). Similarly the powerstroke/returnstroke ratio of approximately 0.5 (figure 5) shows no significant correlation with cycle duration (figure 6). Differences emerge in the performance of larval exopodites and post-larval swimmerets (table 6b), although the possibility cannot be excluded that the larval exopodite oscillator in some way influences the developing action of the post-larval swimmeret system.


The nervous system of Loligo. II. Suboesophageal centres. A well-marked hierarchy of centres can be recognized within the suboesophageal lobes and ganglia of the arms. The inputs and outputs of each lobe are described. There are sets of motoneurons and intermediate motor centres, which can be activated either from the periphery or from above. They mostly do not send fibres up to the optic or higher motor centres. However, there is a large set of fibres running from the magnocellular lobe to all the basal supraoesophageal lobes. The centre for control of the four eye-muscle nerves in the anterior lateral pedal lobe receives many fibres direct from the statocyst and from the peduncle and basal lobes, but none direct from the optic lobe. The posterior lateral pedal is a backward continuation of the oculomotor centre, containing large cells that may be concerned in initiating attacks by the tentacles. An intermediate motor centre in the posterior pedal lobe probably controls steering. It sends fibres to the funned and head retractors, and by both direct and interrupted pathways to the fin lobe. It receives fibres from the crista nerve and basal lobes, but none direct from the optic lobe. The jet control centre of the ventral magnocellular lobe receives fibres from the statocyst and skin and also from the optic and basal lobes. Some of these last also give extensive branches throughout the palliovisceral lobes. The branching patterns of the dendritic collaterals differ in the various lobes. Some estimates are given of the numbers of synaptic points. The dendritic collaterals of the motoneurons spread through large volumes of neuropil and they overlap. The incoming fibres spread widely and each presumably activates many motoneurons either together or serially. Many of the lobes contain numerous microneurons with short trunks restricted to the lobe, but there are none of these cells in the chromatophore lobes or fin lobes. The microneurons have only few dendritic collaterals, in contrast to the numerous ones on the nearby motoneurons.


Psychoactive drugs. Uses, misuses, and abuses. The source of knowledge about the use of psychoactive drugs is often biased--being the representative or literature of the pharmaceutical company. Psychotropic drugs and their appropriate usage are discussed, and the basic ingredients of good prescribing habits are examined by focusing on the nonchemical factors that can help determine outcome.


Understanding acid-base disturbances.

Understanding acid-base disturbances. The physiologic principles of blood pH, Pco2, and bicarbonate homeostasis provide a suitable basis for a systematic approach to the interpretation of acid-base disturbances. Pathogenesis, diagnosis, and management of the four classic acid-base disorders follows.


Dystonic reactions following neuroleptics: time course and proposed mechanisms. The occurrence of acute dystonic reactions was studied relative to drug pharmacokinetic parameters following a single dose of the phenothiazine, butaperazine. Dystonias occurred more than one half-life from peak butaperazine levels, 23 to 56 h after drug administration. The authors postulate that the appearance of dystonias on falling plasma concentrations may be due to disruption of dopaminergic-cholinergic balance caused by differential antidopaminergic and anticholinergic potencies of the drug.


Lysosomal and neutral hydrolase activity during the regression of cardiac hypertrophy. Cardiac hypertrophy was produced in rats by constriction of the ascending aorta. Removal of the constricting band 10 days after operation resulted in rapid decline in left ventricular (LV) weight and total ventricular RNA. Activities of acid RNase and beta-glucuronidase were elevated 3 days after aortic constriction. Activities of cathepsin D and alkaline RNase were unchanges. Activities of cathepsin  D and acid RNase were unchanged 1 and 3 days after removal of constricting band. Ca2+-activated, neutral protease (CAF) isolated from postmitochondrial muscle supernatant was partially purified and characterized. CAF specifically degrades alpha-actinin when incubated with isolated myofibriles in the presence of Ca2+.


Reduced myocardial ATP and creatine phosphate in diabetes: role of 2,3-diphosphoglycerate. Observations are presented which suggest that myocardial cellular hypoxia may account for the reduction in myocardial ATP and CP in the ketoacidotic diabetic state. It is suggested that reduced 2,3-diphosphoglycerate adversely affects oxygen release from the red blood cell, thereby leading to myocardial cellular hypoxia.


Early changes in myocardial hypoxia: relations among mechanical function, pH, and intracellular redox states. When rat hearts were subjected to abrupt hypoxia the onset of NADH changes as measured by epicardial fluorescence and of depressed contractility occurred at similar times. Direct measurements of changes in tissue metabolism lagged behind changes in fluorescence and contractility. Calculated NAD:NADH ratios became reduced more rapidly and to a greater extent in the cytoplasm than in the mitochondria, but did not necessarily signal greater changes in total NADH. The detection of depressed contractility before a fall in intracellular pH or a rise in intracellular lactate casts doubt on the postulate that an increase in hydrogen ion is the primary cause of hypoxic myocardial failure.


Inhibition of glycolysis in hearts during ischemic perfusion. Rates of glycolysis were determined in the isolated perfused rat heart under aerobic, anoxic, and ischemic conditions. The rate was accelerated in anoxic and was inhibited in ischemic tissue. Glycolytic inhibition developed at the level of glyceraldehyde-3-P dehydrogenase and was associated with accumulation of high levels of tissue lactate and H+.


Muscarinic stimulation of cardiac guanylate cyclase. Right ventricular kitten papillary muscles were incubated with dibutyryl adenosine 3',5'-monophosphate (db-cAMP) at varying concentrations from 1 X 10(-4) M to 1 X 10(-3) M. A positive inotropic effect was observed with all concentrations of db-cAMP. Concomitant administration of 5 X 10(-4) M monobutyryl guanosine 3',5'-monophosphate and 1--2 X 10(-4) M db-cAMP did not produce an inotropic response. At the biochemical level cardiac guanyl cyclase activity is enhanced 2--3 times with acetylcholine and this enhancement is completely blocked by atropine. This increased activity appears to be the result of a decrease in the Michaelis constant (Km) for GTP. Calcium also produces a significant activation of guanyl cyclase activity.


Distribution of lysosome populations in rat cardiac tissue. The post-nuclear fraction of rat heart tissue was fractionated by isopycnic zonal centrifugation in sucrose gradients, followed by differential centrifugation of the zonal fractions (rho-S fractionation). The distribution of 5 lysosomal acid hydrolases, a protease with neutral and alkaline activity and several marker enzymes for cell organelles (catalase, Ca2+-ATPase, cytochrome oxidase, glucose-6-phosphatase and muramidase) were studied. Three major lysosomal populations were described with equilibrium densities of 1.09, 1.17, and 1.23 gms cc-1 (omega2t = 1.54 X 10(11) rad2 sec-1), and a continuum in the size of these particles at the three different densities.


Phospholipase A and acid lipase activity during release of lysosomal hydrolases. Hydrolysis of cardiac and hepatic lysosomal phospholipids by endogenous phospholipase A occurs during incubation at 37 degrees C at pH 5.0. Lysophospholipids and free fatty acids accumulate in association with release of hydrolases from the lysosomes into the supernatant. Acid-active neutral lipid lipases contribute to the release of free fatty acids. Albumin inhibits the production of these surface-active lipids as well as the release of hydrolases. The soluble phospholipase A is inhibited by albumin, soluble protein (cytoplasmic), heparin, and protamine sulfate. Thus, hydrolysis of lysosomal lipids, catalyzed by endogenous phospholipases, as well as acid-active neutral lipid lipases, may contribute significantly to the increased permeability, swelling, and subsequent lysis of lysosomes. Stabilization of the lysosomal membrane is associated with integrity of the structural lipids of the membrane.


Some properties of rat myocardial ornithine decarboxylase and the in vitro effects of nucleotides. Myocardial ornithine decarboxylase appears to have characteristics similar to those of enzymes isolated from other tissues. Ornithine decarboxylase activity decreased very rapidly after the death of the animal. Storage of the cell sap fraction at 0 degrees C or -15 degrees C, however, led to only a small decrease in the enzyme activity up to 3 days after preparation. Pyridoxal phosphate at an optimum of 50 muM was essential for full enzyme activity. Thiol compounds did not increase the myocardial ornithine decarboxylase enzyme activity. The subcellular distribution of the enzyme in the myocardium was found to be different from that reported in other tissues. A partial purification of the enzyme was possible using the proteins precipitated at pH 5 from a cell-soluble fraction or by passing a soluble fraction through a Sephadex G 100 gel column. ATP, ADP, and AMP inhibited ornithine decarboxylase at high concentrations (5 mM), but GTP, CTP, and ITP inhibited at a 1 mM concentration and above.


Comparative aspects of buffering capacity in muscle. These findings are discussed in relation to the contention that a high buffer value is linked to a high work performance. This generalization does not extend to the "white" breast muscle of chicken. Its high buffer value is in part due to a high content of the dipeptides carnosine and anserine. Additionally, a hypothesis is advanced that muscle, e.g. pigeon breast muscle, can in part regulate intracellular pH by changes in the steady state concentrations of the glycolytic and citric acid cycle acids. Notably this form of pH regulation has no inherent energy requirement.


Cardiac and skeletal muscle acid-base composition during metabolic acidosis in dogs. Nephrectomized, open chested dogs were infused with 25-30 ml.kg(-1) body weight of 0.15 M NaCl (group I), 0.15 MHCl (Group II) or 0.3 M lactic acid (Group) III). Pulmonary ventilation was maintained constant in the three groups. Intracellular pH was calculated with the CO2 method. No significant intracellular or extracellular acid-base changes were produced in Group I. A similar degree of extracellular acidosis was achieved in Groups II and III. In spite of constant arterial PCO2, the PCO2 of mixed, coronary sinus and femoral vanous blood increased moderately after the infusion in Groups II and III. It was calculated that less than half of the HCl acid infused remained in the extracellular space. However, no significant changes were observed in the acid-base composition of skeletal muscle in either Group II or III. Comparison of the cardiac muscle cell acid-base composition of Group I with that of Groups II and III whows that metabolic acidosis of the degree and duration produced in these experiments does not produce appreciable myocardial acidosis.


Dependence of CSF on plasma bicarbonate during hypocapnia and hypoxemic hypocapnia. We have previoulsy shown pH compensation to be similar in CSF and arterial blood during chronic hypoxemic hypocapnia in man and pony, and postulated that the compensatory reduction in CSF [HCO3] was dependent upon corresponding changes in [HCO3]a. We tested this hypothesis in anesthetized, paralyzed dogs by determining the effects of 7 or 14 hours of hypocapnia (PaCO2 20 and 30 mm Hg), hypoxemia (PaO2 30, 38 and 48 mm Hg) and hypocapnic hypoxemia on CSF acid-base status. [hco3]a was either permitted to fall normally or was held near control levels by NaHCO3 infusion. In hypocapnia and hypoxemic hypocapnia, the decrease in [HCO3] and % pH compensation in CSF were less than or equal to that in arterial blood. Most (51-89%) of the compensatory decrease in CSF [HCO3] was prevented by preventing the corresponding reduction in [HCO3]a. This dependence of changes in CSF on plasma [HCO3] required a concurrent decrease in CSF PCO2, but was largely independent of variations in plasma pH. A minor but significant portion of the decrease in CSF [HCO3] was achieved independently of corresponding changes in [HCO3]a. The contribution of this local mechanism to CSF [HCO3] regulation increased with increasing severity of hypocapnia or hypoxemia and was usually associated with a selective increase in CSF lactate. It was concluded that [HCO3] regulation in the CSF during hypoxemic hypocapnia was primarily dependent upon, and therefore limited by, the concomitant decrease in plasma [HCO3].


Response to jejunal acidification in man. I. Changes in composition of perfusate. The jejunal disposal of perfused acid was studied in 11 control subjects and 12 patients with duodenal ulcer. It was found that the capacity to dispose of acid was saturable and was less than control in patients with duodenal ulcer. When the load of acid was small, all the acid disappeared from the jejunum and sodium bicarbonate could be aspirated. During acid perfusion there was secretion of water and electrolytes into the jejunum if the load of acid exceeded the dissipative capacity. Superimposed intravenous infusion of secretin and cholecystokinin increased acid disposal, particularly in patients with duodenal ulcer, and increased the associated rate of secretion of water and electrolytes or changed net absorption to net secretion. We conclude, firstly, that acid is removed from the jejunum by secreted bicarbonate, and secondly that the whole of the upper small intestine of patients with duodenal ulcer is functionally abnormal.


The hydrolysis and absorption of conjugated folates in man. After ingestion of synthetic PteGlu3 in physiological doses, the folate forms were studied in plasma obtained from human vena portae blood. Plasma conjugase was inhibited by rapid heat-denaturation. The folate forms were assayed with L. casei and S. faecalis and identified by thin-layer chromatography (biautography). Mono- and diglutamic folate was demonstrated in the portal plasma, indicating that intestinal hydrolysis precedes the absorption of conjugated folates. The pteroylpolyglutamate hydrolase activity in the human gastrointestinal tract was investigated. The activity was demonstrated in gastric juice, pancreatic juice, and intestinal mucosa. The highest activity was found in the pancreatic juice with a pH-optimum of 4.5. In gastric juice the pH-optimum for the enzyme was 3 and the activity half of that found in pancreatic juice. However, in view of the volumes of these fluids produced every day, the activity at physiological pH might be enough to hydrolyse the daily intake of conjugated folates in amounts of about 500 mug.


Erythroid differentiation of fetal, newborn and adult haemopoietic stem cells. Erythroid regeneration was studied in lethally irradiated mice given transplants containing equivalent numbers of haemopoietic stem cells (i.e. CFU) from fetal liver, neonatal marrow or adult marrow. Adult marrow was taken from normal control mice, whose CFU for the most part were not in active cell cycle, as well as from phenylhydrazine-treated groups whose CFU were in similar state of proliferation (i.e. approximately 40-50% in DNA SYNTHESIS) AS THOSE DERIVED FROM FETAL LIVER AND NEONATAL MARROW. Splenic and femoral radioiron (59Fe) incorporation were measured at intervals after transplantation and were found to begin earliest in mice given fetal liver, then in animals given neonatal marrow and latest in recipients of adult marrow. Peripheral reticulocytes showed a similar pattern of recovery. The data reported herein suggest that the differences in erythroid regeneration evoked by transplants of fetal liver, neonatal marrow or adult marrow, are not solely attributed to the degree of proliferation in the pluripotential stem cell compartment. These data may, however, suggest a shorter doubling time for cells comprising the fetal and newborn committed erythroid compartments.


Serological types of Diplococcus pneumoniae isolated from the respiratory tract of children with cystic fibrosis and children with other diseases. The distribution of serological types of D. pneumoniae was investigated in 40 strains isolated from 26 children with cystic fibrosis and 57 strains isolated from 39 children with other diseases. All strains were isolated from sputum or tracheal secretion. The strains from cystic fibrosis patients belonged to 14 different serological types, the most prevalent were 19F, 19A and 3. The strains from the other group of children belonged to 20 different serological types, the most prevalent were 23F, 19F and 11A. The differences between the two groups of patients as to the prevalences of types were small, and it is concluded that no special serological types of D. pneumoniae are associated with cystic fibrosis.


Catecholamine enzymes in the degenerative neurological disease idiopathic orthostatic hypotension. Discrete brain areas and sympathetic ganglia obtained at autopsy from patients with idiopathic orthostatic hypotension were assayed for tyrosine hydroxylase and dopamine beta-hydroxylase. Dopamine beta-hydroxylase activity was decreased 7.5-fold in sympathetic ganglia, while tyrosine hydroxylase activity was reduced more than 50-fold in the pontine nucleus locus coeruleus. These observations indicate that noradrenergic neurons of both brain and ganglion are affected in idiopathic orthostatic hypotension, but suggest that the central and peripheral biochemical deficits differ.


Lymphocyte-induced angiogenesis in tumor-bearing mice. The presence of a growing tumor can lead to a significant curtailment of a graft-versus-host reaction as measured by the ability of allogeneic spleen cells to induce a host vascular response. This interference with the normal pattern of immunological reactions may be a reason for the survival of tumors in an immunologically alien environment.


Clinical significance of the biotransformation of inhalation anesthetics. Inhalation anesthetics, a class of drugs formerly believed to be biologically inert, are now recognized to undergo considerable biotransformation. The viscerotoxicity of certain anesthetics on kidney and liver can be explained in terms of metabolism. The entity of "halothane hepatitis" remains mechanistically and diagnostically a mystery, but if it exists, it could be due to abnormalities of biotransformation.


Theoretical considerations in the vector control of filariasis. In order to assist in assessing progress of vector control of filariasis a theoretical model is constructed, using retrospective data on infected persons removed to a vector-free situation. This shows that the decrease of microfilaraemia is not regular, but is gradual for the first 3 years and then more rapid, reaching zero at about 10 years. An estimate is made of the level to which the vector must be reduced before transmission of filariasis ceases, showing that the degree of efficiency required is considerably less than for malaria.


Intensive care in a hospital for Blacks. A review of 300 consecutive admissions. Experinece with the first 300 patients in a new Intensive Care Unit for Blacks is presented. Causes of death and specific problems are considered in detail.


The management of hernias, hydroceles and undescended testes. The management of hernias, hydroceles and undescended testicles is reviewed on the basis of current practice as reported in recent literature and of the author's experience at Addington Hospital, Durban.


Experimental stimulation of cell-mediated immunity without concomitant stimulation of humoral immunity in graft-versus-host immunosuppressed mice. The immunosuppressive effect of the graft-versus-host (GVH) reaction was studied in CBA X A F1 (CAF1) mice which had been rendered immunologically unresponsive by the injection of parental A strain lymphoid cells (GVH mice). Suppression of both cell-mediated and humoral immune responses was demonstrated by the prolonged survival of C57BL/6 (B6) skin allografts and by the inability of GVH mice to produce detectable antibody following stimulation with sheep erythrocytes (SRBC). Appropriate stimulation of GVH mice induced cell-mediated immune reactions to xeno- and allogeneic antigens while the humoral immune responses to the same antigens remained suppressed. Multiple challenges of the GVH mice with B6 tissue caused a rapid rejection of subsequent B6 skin grafts but failed to stimulate the production of any detectable antibodies to B6 allotransplantation antigens. Sensitization of GVH mice with SRBC in Freund's complete adjuvant stimulated a delayed hypersensitivity response to SRBC, although no humoral response to SRBC could be detected, even after three challenges with SRBC. The experimental results are discussed in terms of a proposed model for GVH-induced immunosuppression.


[The hematopoietic colony-forming cell--object of experimental study]. Studies dealing with the colony-forming cell as a subject of experimental research are reviewed. The techniques of cultivation of colony-forming cells, their proliferation, differentiation and self-renewal have been considered.


Abnormal liver enzymes and human chorionic gonadotropin elevation in abdominal testicular seminoma. A case of seminoma in an abdominal testis is presented in which abnormal liver enzyme as well as elevated human chorionic gonadotropin levels were present which returned to normal after surgical extirpation of the primary lesion. A review of pertinent literature and implications of these unusual findings are presented.


[Clinical evaluation of the effectiveness of different surgical interventions in peptic ulcer]. The clinical status, secretory and motor activity of the stomach were studied in 213 patients showing ulcerous disease prior to surgery and in 153 operated patients. The most favourable results were noted after resection of two thirds of the stomach in Billroth I modification with preservation of the pyloric compressor. These patients along with suppression of acid-formation retained normal portional evacuation of the gastric content. Selective vagotomy with resection of the ulcer and pyloroplasty in a number of patients produced no considerable reduction in acid-formation both in the early postoperative period and in later terms.


[Comparative study of the optimum pH value of serum alkaline phosphatase in various species of farm animals]. Investigations were carried out on the alkaline phosphatase in the sera of cattle, horses, pigs, sheep, goats, and chickens, the pH value of the buffer used being 9.0-9.8-10.0-10.2-10.6 and 11.0, and the method applied--that of Richterich. The pH value at which the serum alkaline phosphatase in the various farm animals and birds was most active was found to vary to a large extent. Optimal values for the enzyme's activity usually range as follows: cattle, 10.2; pigs and goats, 10.0; sheep,--10.2; horses,--9.8; chickens,--10.6.


The electrolyte pattern of the gastric secretion from the vervet monkey. The output of acid, chloride, sodium and potassium in gastric washings from the Vervet monkey have been measured under basal conditions and while stimulating the secretion with two doses of pentagastrin (one dose submaximal, the other dose supramaximal). The output during washings with different weak electrolyte solutions (5 mEq/1 NaC1, KCl, or HCl or 0.36 M Glycine) are compared. The results show that the composition of the secretion was independent of the composition of the rinsing fluid in the stomach except that glycine stimulated acid and potassium secretion when the monkey was not stimulated by pentagastrin. These observations and the composition of the gastric secretion of the Vervet monkey are discussed in the light of the "two-component" and "exchange" models of gastric secretion, and which compared with the gastric juice obtained from humans under similar conditions.


[The acid-base balance in the CSF of normal subjects regulatory mechanisms (author's transl)]. 1. The acid-base balance (pH, pCO2 and HCO-3) of 23 normal subjects was determined both in arterialized capillary blood and in the CSF. 2. Statistically significant correlations (determined by means of Spearman's rank correlation) were found between: pCO2 in arterialized blood and CSF pH (Rs=--0.372, p is less than 0.05), pCO2 in the CSF and CSF pH (Rs=--0.421, p is less than 0.05), HCO-3 in the CSF and in arterialized blood (Rs=0.623, p is less than 0.05), blood pH and CSF pH (Rs=0.485, p is less than 0.025), pCO2 in the CSF and HCO-3 in the CSF (Rs=0.559, p is less than 0.005). 3. The regulatory mechanisms of the CSF acid-base balance in normal subjects and also in patients with extra-neural or CNS disturbances are discussed.


[The diagnosis of cholestasis: lipoprotein X (LP-X) (author's transl)]. The diagnostic specificity of a new method to detect obstructive jaundice by determination of lipoprotein X (LP-X) was tested in 144 patients with different kinds of hepatic diseases and compared with the usual chemical "obstructive jaundice specific" tests, such as bilirubin, SGOT, SGPT, alkaline phosphatase, LAP and gamma-GT. The LP-X test was performed by using all-in test kit LP-X Rapidophor" low-voltage electrophoresis of Immuno AG/Wien. The results were correlated with the histological classification of the liver biopsy specimen. In 82% of the histologically verified cases of obstructive jaundice the result of the LP-X test was positive, whilst in 98.5% of the histologically negative cases the result of the LP-X test was negative. Hence, this LP-X method proved superior to chemical methods in providing a clear-cut positive or negative answer to the presence of cholestasis. Furthermore, the LP-X test was suitable for long-term follow-up investigation of patients with obstructive jaundice.


[The effects of flunitrazepam (rohypnol) on respiration (author's transl)]. The effects of flunitrazepam (0.03 mg/kg administered intravenously over a two-minute period) was investigated in 11 healthy volunteers with normal pulmonary function. Spirometer tracings were recorded continuously by the Siregnost FD 40 and blood gas measurements were performed by the Harnoncourt AVL gas analyzer. Flunitrazepam produced a characteristic cyclical hypoventilation/hyperventilation pattern lasting 15 min., followed by quiet sleeping rhythms. The duration of action was 20 min. There was a significant fall in PCO2, whilst the  CO2 tension showed a significant rise. Changes in pH were in accordance with respiratory acidosis. Apnoea did not occur after the administration of flunitrazepam.


[Immunosuppressive therapy in renal disease (author's transl)]. Since immunological events were found to be pathogenetically involved in various forms of glomerulonephritis, corticosteroids and immunosuppressive drugs were introduced in the treatment of nephritis. However, as opposed to the findings in the paediatric nephrotic syndrome, controlled and multicentric trials with immunosuppressive therapy revealed disappointing results in the management of renal disease in adults. Significantly better results under immunosuppressive therapy, were seen only in the nephrotic syndrome based on the so-called "no changes" or "minimal changes" nephritis. In chronic membranous and proliferative glomerulonephritis the clinical course in the treated group was not statistically different from that of the untreated group. In some disorders of connective tissues, such as systemic lupus erythematosus, polyarteritis nodosa and Wegener's granulomatosis, corticosteroids and immunosuppressive agents seem to exert a favourable effect on the course of renal disease. Encouraging results concerning the combined use of immunosuppressive drugs, anticoagulants and platelet aggregation inhibitors in mesangiocapillary (membrano-proliferative) glomerulonephritis and rapidly progressive nephritis have also been presented. Several factors such as incomplete immunosuppression, druginduced antigen tolerance and increased immune complex formation as a consequence of inhibited antibody production may contribute to the fact that many patients with different forms of nephritis do not benefit from long-term immunosuppressive therapy.


[Infusion therapy with mif (melanocyte inhibiting factor) in Parkinson's disease (author's transl)]. On the basis of reports in the literature and of our own clinical experience it appears that melanocyte inhibiting factor (MIF) is a very promising therapeutic agent in the management of Parkinson's disease. Besides theoretical considerations relating to biochemical and pathophysiological spheres, the question of the current dosage for clinical usage seems to be of the utmost importance. We are of the opinion that the currently-employed dosage of 400 mg daily is still too low. Hence, the present investigation will be continued with a view to establishing the optimum dosage for maximal therapeutic effect.


Implication of rifampicin-quinone in the irreversible binding of rifampicin to macromolecules. 1. When [3H]rifampicin is incubated with rat liver microsomes or rat liver homogenate, minor amounts are bound irreversibly to protein. This effect does not depend on the presence of NAD, NADH, NADP or NADPH. 2. Rifampicin is autoxidized at physiological pH. The product of autoxidation, rifampicin-quinone, if incubated with albumin, shows a much greater irreversible binding to the protein than the parent compound rifampicin. Hence it is concluded that rifampicin may bind irreversibly to proteins in a non-enzymic reaction after autoxidation to rifampicin-quinone. 3. Rifampicin-quinone also binds irreversibly to RNA and poly-L-lysine, if incubated with these compounds. This suggests that free amino groups of protein or RNA are involved in the binding. 4. 48 h after dosage of [3H]rifampicin (33 mg/kg) to rats, 29-2 +/- 4-1 (S.D.) pmol are bound irreversibly to 1 mg liver RNA, 15.8 +/- 8-1 pmol to 1 mg liver protein and 5-0 +/- 0-47 pmol to 1 mg protein in brain tissue. 5. Microsomal NADPH-cytochromcin-quinone to rifampicin. The KM of this reaction is 10(-4) M. Induction of the NADPH-cytochrome c reductase by pre-treatment of rats with 20 mg/kg rifampicin over 5 days results in a corresponding increase of increase of rifampicin-quinone reduction. 6. These results suggest that microsomal NADPH-cytochrome c reductase prevents accumulation of higher amounts of possibly toxic rifampicin-quinone by reduction to rifampicin.


[Bacteriological examinations of bronchial secretion in children with non-specific bronchopulmonary disease (author's transl)]. One thousand specimens of bronchial secretion from children with non-specific respiratory diseases have been examined bacteriologically. In spite of the complex nature of acute and especially of chronic respiratory disease the role of bacterial infection should not be underestimated. Thirty per cent of the specimens were sterile. More than 20 per cent of the bacterial species isolated from bronchial secretion were pathogenic. Relatively frequent was the isolation of E. coli and of pathogenic staphylococci. Nearly 40 per cent of all isolated bacteria were alpha-haemolytic streptococci. The latter have been found more frequently in children with, than in children without bronchological alterations. The pathogenicity of alpha-haemolytic streptococci in the bronchial tree is discussed.


Biochemical and histochemical studies on non-specific phosphomonoesterases of swine kidney worm Stephanurus dentatus (Diesing, 1839). Biochemical and histochemical studies have been made on non-specific acid and alkaline phosphomonoesterases of S. dentatus. The two forms of acid phosphomonoesterases have been found active at pH 4.0 and 6.0. The pH optima for the two forms of aklaline phosphomonoesterases lie at 8.0 and 10.0. Studies on the distribution of acid and alkaline phosphomonoesterases in various tissues have revealed an abundance of acid phosphomonoesterase in various parts of the alimentary canal and various organs of the reproductive system. The excretory ducts show alkaline phosphomonoesterase activity only.


Reversal of dibromothymoquinone inhibition of photosynthetic electron flow by thiol compounds. Dibromothymoquinone inhibits photosynthetic NADP reduction by broken chloroplasts. The inhibition of electron flow and coupled ATP formation is effectively reversed by the addition of thiol compounds.


On the mechanism of the acridine orange sensitized photodynamic inactivation of lysozyme. I. Basic kinetics. The kinetics of the photodynamic desactivation of lysozyme in presence of acridine orange as the sensitizer have been investigated in detail varying oxygen, protein, dye concentration, ionic strength and pH value. The kinetics can be approximately described as an over all pseudo-first-order rate process. Changing the solvent from water to D2O or by quenching experiments in presence of azide ions it could be shown that the desactivation of lysozyme is caused exclusively by singlet oxygen. The excited oxygen occurs via the triplet state of the dye with a rate constant considerably lower than that to be expected for a diffusionally controlled reaction. Singlet oxygen react chemically (desactivation, k=2.9 X 10(7) m(-1) sec(-1)) and physically (quenching process, k=4.1 X 10(8) m(-1) sec(-1)) with the enzyme. The kinetical analysis shows that additional chemical reaction between singlet oxygen and lysozyme would have only little influence on the kinetics of the desactivation as long as their products would be enzymatically active and their kinetical constants would be less than about 1 X 10(8) m(-1) sec(-1)).


Photoreactions of cytochrome b6 and cytochrome f in chloroplast photosystem I fragments. Photosystem I fragments were prepared by digitonin treatment of spinach chloroplasts. The midpoint potential of cytochrome b6 in the fragments is close to 0V, showing a one electron transition. No cytochrome b559 was detectable, neither in difference absorption spectra nor in light-induced absorbance changes. In the absence of added cofactors only cytochrome b6 photoreduction can be observed. This photoreduction is stimulated by ferredoxin. Ferredoxin-NADP+ reductase appears not to be involved in cytochrome b6 reduction. Photooxidation of cytochrome b6 is dependent on plastocyanin addition and inhibited by DBMIB, a plastoquinone antagonist. Addition of plastocyanin restores cytochrome f photooxidation as well, reacting quite specifically in about equimolar concentrations to bound cytochrome f. The stimulation of cytochrome f oxidation is abolished by an antibody prepared against plastocyanin, indicating a surface location of plastocyanin in digitonin treated membranes. Biphasic kinetics of dark-reduction of cytochrome f by ascorbate indicate that part of this cytochrome f is relatively inaccessible in the membrane. After preillumination a monophasic reduction is observed and the slowly oxidized component is absent. Illumination in the presence of plastocyanin causes a fast and complete reduction of cytochrome f, suggesting equilibration of cytochrome f with added plastocyanin, residing in the membrane surface. It appears that actinic light causes conformation and/or structural changes in the membrane of these digitonin fragments, influencing cytochrome f asseccibility.


[Extraction and concentration of Clostridium botulinum toxins from specimens (author's transl)]. In order to detect minimal amounts of Clostridium botulinum toxins in animal tissue or food specimens it is necessary to use an extraction method which results in concentration of the botulinal toxins. In the present examinations, artificially contaminated canned beans were used to develop a suitable procedure for extraction and concentration of botulinal toxins A-E. The procedure consisted of 4 steps: 1. Canned beans were diluted 1:2 with 0.1 m phosphate buffer pH 6.0. 2. The diluted material was homogenised with an "Ultra-Turrax" homogeniser for 20 sec. 3. The monogenised material was centrifuged at 4000 rpm for 30 min. 4. 15 ml of supernatant was concentrated using a "Millipore ultrafiltration chamber" (with a membrane capable of excluding all material with a molecular weight above 25,000). A pressure of 1.5 atmospheres was applied until the terminal volume was 0.5 ml. Following extraction and concentration, the samples were assayed for botulinal toxin in mice. Using this assay the concentration of the five toxins were shown to be as follows: Type A toxin: 19.0-fold toxin concentration Type B toxin: 14.8-fold toxin concentration Type C toxin: 20.6-fold toxin concentration Type D toxin: 28.2-fold toxin concentration Type E toxin: 112.2-fold toxin concentration


Bacterial meningitis in infancy and childhood in Lusaka (One year prospective sturdy). In approximately 10,000 admissions in a 12 months period, at University Teaching Hospital, Lusaka 85 cases of meningitis were recorded. The signs and symptoms in these patients do not greatly differ from other similar studies in Africa. The commonest organism isolated was pneumococcus. There was high mortality rate which was to a large extent due to parents not bringing their children to hospital early enough for medical treatment to be instituted. This is borne out by the fact that 50% of the children with meningitis died within the first 24 hours. The C.S.F. protein and peripheral white blood count may be of prognostic value. Spasticity, cranial nerve palsises hydrocephalus and subdural effusion were the commonest complications.


Cerebral blood flow and exchange of oxygen, glucose, ketone bodies, lactate, pyruvate and amino acids in infants. Cerebral blood flow (CBF) and cerebral av-differences of oxygen and circulating substrates were measured in normocapnic infants during general anaesthesia before elective surgery in order to study possible age-dependent variations. CBF was determined by a minor modification of the Kety-Schmidt technique from desaturation curves of nitrous oxide (N2O) in arterial and cerebral venous blood (N2O analysed by gas chromatography on 15 mul blood samples) after reduction of inhaled N2O from 75 to 50%. The reproducibility was +/-4.6%. Lactate, pyruvate and oxygen were determined in whole blood and amino acids in plasma by ion-exchange chromatography. Reliable av-differences of glucose, acetoacetate and D-beta-hydroxybutyrate could be calculated from plasma values and hematocrits. Mean values from 12 infants (age 11 days-12 months) were: CBF 69 ml/100 g0min-1; cerebral uptake (in mumoles/100 g-min-1): oxygen 104, glucose 27, acetoacetate 0.9, D-beta-hydroxybutyrate 2.3; cerebral release: lactate 2.4 and pyruvate 0.8. Significant uptake of amino acids was found only for histidine 0.95 and arginine 0.7. Significant correlations between arterial concentration and cerebral exchange were found for: ornithine, arginine, phenylalanine, aspartic acid, serine, glutamine and acetoacetate. CBF and substrate exchange were unrelated to age within the group. Infants had higher mean CBF and greater uptake of ketone bodies than has been reported in adults.


Down's syndrome with X0/XY mosaicism.

Down's syndrome with X0/XY mosaicism. A 5-month-old Chinese infant with combined Down's syndrome and X0/XY mosaicism is presented. The phenotypical features of mongolism are classical and unmodified. The somatic effects of X0/XY mosaicism is that of incomplete masculinization with short phallus, hypospadias, bifid scrotum, urogenital sinus, and bilateral extra-abdominal infantile testicles. These features together with the absence of internal female organs and signs of Turner's syndrome in this patient are different from the previous reported cases of mixed gonadal dysgenesis.


Bile canalicular alkaline phosphatase and disease. The alkaline phosphatase reaction is normally absent in human bile canaliculi, but was found in 79 patients. In search for a common causal factor, these patients were further examined. Thirty-seven were autopsied. The conditions most ocmmonly associated with the phenomenon were malignant tumours with or without involvement of the liver, collagen diseases, long-standing partial obstruction of the common bile duct, and genetic variants of alpha-1-antitrypsin. No clinical or laboratory facts were common to all the patients.


Polyarteritis nodosa associated with nosematosis in blue foxes. The patho-morphological lesions in fox nosematosis (encephalitozoonosis) were studied in a material comprising 150 young blue foxes from 23 different farms. Disseminated nosematosis in blue fox pups was regularly accompanied by severe vasculitis, affecting medium-sized and small arteries in various organs. The acute damage has the form of a necrotizing angiitis, with mural necrosis and sometimes resultant thrombosis. The causative organism Nosema cuniculi, is frequently present in the freshly affected arterial walls, either in endothelial or in medial smooth muscle cells. Older lesions include nodular fibrous thickening of the arterial walls, and intimal proliferation, sometimes with luminal obliteration. The conclusion is drawn that the arterial lesions are morphologically equivalent to classical polyarteritis nodosa.


Some factors influencing the haemolysis of Bordetella bronchiseptica. Strain-dependent variations in the ability of Bordetella bronchiseptica to produce haemolysis on solid media exist. Haemolysis is strongest at an acid reaction and will not take place if the reaction is too alkaline. Peptone and glutamine inhibit haemolysis and favour growth. The vigorous growth rapidly produced an alkaline reaction which inhibits the haemolysis.


[Effects of acid-base changes upon the chronotropic response to norepinephrine (author's transl)]. The effect of changes in pH produced by changing NaHCO2 at constant pCO2 and by changing pCO2 at constant NaHCO2 concentration was studied in the spontaneous beating rat atrium. Alkalosis produced either by changes in pCO2 or in NaHCO2 concentration increased basal heart rate shifting dose-response curves to norepinephrine upwards. When these dose-response curves were analysed for a horizontal shift, it was found that the necessary dose to produce a given effect was lesser in alkalosis than in acidosis. This shift was significant at the ED10 and at ED30 when the pCO2 was lowered and at ED30, ED50 and ED70 when the NaHCO2 concentration was increased. Beta-adrenergic blockade did not prevent the rate increasing effect of alkalosis. Our results suggest that there is a sensitizing effect to norepinephrine in alkalosis superimposed to a direct effect of pH upon heart rate.


Blood changes in water deprived rats.

Blood changes in water deprived rats. To study the variations of blood constituents during water deprivation, rats were deprived of water from six to twelve days. Control and rehydrated animals were also included in the study. A significant increase was observed in sodium, chloride and hematocrit throughout the experiment. Calcium, bicarbonate and PCO2 increased at 10-11 days of treatment. Potassium, inorganic phosphorus, pH, base excess and blood buffer capacity did not change in the course of the experiment. Rehydrated animals recovered to control levels in all the studied components, except for pH and base excess, which increased somewhat. Plasma volume changes could explain only partially electrolyte variation. The "dehydration reaction" is considered to be the main mechanism responsible for these changes. Unchanged hematocrit levels in water deprived animals suggest that after 6 days of water deprivation there is no further loss of plasma water. Bicarbonate and PCO2 changes showed a good relationship and may account for unchanged pH and base excess values.