| effect of ammonia concentration on activity of enzymes of ammonia assimilation and on synthesis of amino acids by mixed rumen bacteria in continuous culture. | | 1977 | 18495 |
| fetal and maternal plasma electrolytes, blood gases, and ph in dairy cows during late gestation. | sodium, potassium, and chloride were determined in fetal and maternal plasma of six cows between 208 and 269 days of gestation. blood ph and partial pressures of oxygen and carbon dioxide also were measured in samples collected from the jugular vein of the cow and the caudal aorta and vena cava of the fetus. concentration of chloride in fetal plasma was generally lower than the corresponding maternal value, and fetal potassium was greater than maternal. potassium of fetal plasma increased toward ... | 1977 | 18496 |
| nature of the rabbit acrosome reaction-inducing activity of follicular fluid. | follicular fluid samples from rabbits, cats, pigs, women and cows had acrosome reaction-inducing activity (aria) on rabbit spermatozoa as determined by differential staining after incubation with these fluids. activity was retained after dialysis and at least 50% was found to be labile when heated to 56 degrees c for as little as 20 min. the induction of the acrosome reaction by bovine follicular fluid showed a dependence on the concentration of follicular fluid and spermatozoa and on calcium io ... | 1977 | 18603 |
| effects of sera of normal, anemic and leukemic rats on particle size distribution of 99mtechnetium-sulfur colloid in vitro. | | 1977 | 18605 |
| binding of trifluoperazine to the calcium-dependent activator of cyclic nucleotide phosphodiesterase. | | 1977 | 18661 |
| trisialoganglioside synthesis by a chicken brain sialyltransferase. comparative study with the similar reaction for the synthesis of disialoganglioside. | an enzyme preparation from embryonic chicken brain catalyzes the transfer of sialic acid from cmp-n-acetylneuraminic acid to ceramide-glc-gal(neuac-neuac)-galnac-gal (gdlb) to form ceramide-glc-gal(neuac-neuac)-galnac-gal-neuac (gtlb). the sialyltransferase activity was measured during the development of the embryo, the subcellular distribution of this activity was determined and several kinetic properties of the reaction were examined. a comparative study with the similar reaction involved in t ... | 1977 | 18668 |
| porphyrin biosynthesis. immobilized enzymes. iv. studies on aminolaevulate dehydratase attached to sepharose. | bovine liver aminolaevulate dehydratase (ala-d) has been chemically attached to sepharose 4b and its properties have been studied. the optimal conditions for coupling have been determined. it was found that the immobilized enzyme retained a significant percentage of the activity of the free enzyme. the coupling yield was rather high. the insolubilized enzyme requires both anaerobiosis and a thiol activator for maximal activity. it can be stored at 4 degrees c for long periods with little loss of ... | 1977 | 18669 |
| beta-adrenoceptor studies. 4. influence of albumin on in vitro beta-adrenoceptor blocking and antiarrhythmic properties of propranolol, pindolol, practolol and metoprolol. | | 1977 | 18685 |
| quantitative and visualization studies of the transport of rat and bovine igg and ferritin across the segments of the small intestine of the suckling rat. | | 1977 | 18740 |
| some mechanisms of carbohydrate metabolism regulation with nadp participation. | it is shown that in the presence of nadp in the myocardium extracts glucose-6-phosphate is transformed into fructose-6-phosphate, fructose-1,6-diphosphate and lactate. the intensity of this transformation is close to that when nad is introduced. the addition of crystalline glucose-6-phosphate dehydrogenase to the extracts is not accompanied by formation of lactate, but reduced nadp accumulates which oxidizes due to introduction of pyruvate or oxalacetate into the medium. this process is reconst ... | 1977 | 18829 |
| changes in enzyme activity induced by experimental aflatoxicosis in dairy cows. | the activities of got, gpt, ldh, gamma-glutamyltranspeptidase (gamma-gtp), alkaline phosphatase (ap), glutamate dehydrogenase (gldh) and the concentrations of bilirubin in blood plasma after a single intraruminal application of aflatoxins were studied in four dairy cows. the maximum changes in the activities of the enzymes and the maximum bilirubin concentration in plasma were obtained in the first two to three days following the application of aflatoxins. the statistically significant increase ... | 1977 | 18836 |
| chronic metabolic acidosis in dairy cows. | complex clinical and clinico-biochemical examination of the blood, urine and rumen liquor in a herd of dairy cows revealed chronical metabolic acidosis accompanied by rumen dysfunction and by a reduced butterfat content of milk. during the first examination of the acid-base state of the blood was almost at a standard level. an increased level of urea in blood plasma and a higher got transaminase activity testified to an excessive load on the liver. urine ph was considerably deviated towards the ... | 1977 | 18837 |
| significance of ruminal juice examination in the diagnosis of subclinical rumen dysfunction. | the suitability of the metabolic test of rumen liquor for the diagnosis of subclinical rumen dysfunction was tested. the test for the assessment of the metabolic profile of the rumen included: the determination of ph, total titration acidity in clinical units, lactic acid in mg%, fatty acids in mmol 1-1, ammonia n in mg%, urea n in mg% and the number of infusorians in 1 ml of rumen liquor. this test enabled, on the basis of the examination of rumen liquor, to determine not only the kind and form ... | 1977 | 18838 |
| on the enzymatic breakdown of tripolyphosphate and diphosphate in comminuted meat. xi. influence of heating and freezing (author's transl). | the tripolyphosphatase and diphosphatase activities of comminuted bovine muscle increase with rising temperature until at about 40 degrees c a denaturation of the enzyme proteins occurs. prae or post rigor frozen bovine muscle, which was stored at -18 degrees c, shows after thawing and mincing the same tripolyphosphatase activity as the non-frozen tissue post rigor. freezing and thawing under the same conditions cause a reversible inhibition of the diphosphatase activity of bovine muscle. the r ... | 1977 | 18858 |
| formation of dehydroalanine, lanthionine and lysinoalanine during heat treatment of beta-lactoglobuline a (author's transl). | solutions of beta-lactoglobulin a were heated at 97.5 degrees c at ph 6.9 and 9.8 80 min. the formation of dehydroalanine, lanthionine and lysinoalanine as well as changes in the levels of cysteine, cystine and the basic amino acids were recorded. lanthionine (equal amounts of the 1- and the mesoform) was formed only in small amounts, while the lysinoalanine levels were rather high. beside this, lysine was converted to unknown compounds. the main sources for the formation of dehydroalanine are t ... | 1977 | 18859 |
| improved methods of influenza virus propagation. i. enhancement of virus reproduction in cell cultures. | comparative studies on the reproduction of a set of influenza a and b virus strains in different cell cultures were carried out. a cultivation system yielding influenza virus with high infectivity, based on the use of roller cultures of bovine embryo kidney cells, of virus strains adapted to this culture, and of a maintenance medium of improved composition, was developed. | 1977 | 18922 |
| improved methods of influenza virus propagation. ii. characteristics of cell culture and allantoic virus preparations. | regular reproduction of influenza a virus with infectious titres of 7.4--8.5 log eid50/0.2 ml was observed in roller bovine embryo kidney cell cultures. the haemagglutinating activity of the cell culture preparations was 8-33-fold lower than that of the allantoic preparations, the infectivity being similar. cell culture preparations of influenza a/victoria/35/72 and a /leningrad/538/74 viruses were markedly immunogenic in laboratory animals and antigenically active in complement fixation (cf) te ... | 1977 | 18923 |
| variables of the rubella hemagglutination tests employing freeze-dried erythrocytes. | the variables which affect the interaction between freeze-dried one-day-old chick erythrocytes and rubella hemagglutinin prepared from rubella-infected porcine kidney cells were defined and evaluated. the sensitivity of the hemagglutination (ha) reaction is much greater at ph 6.0 to 6.2 than at ph 7.0 to 7.5 hepes (n-2-hydroxyethylpiperazine-n'-2'-ethanesulfonic acid) diluent with added ca+ or mg2+ ion gave four- to eightfold higher ha titers than one without divalent cations. the development of ... | 1977 | 19008 |
| interconversion of myo- and scyllo-inositol with simultaneous formation of neo-inositol by an nadp+ dependent epimerase from bovine brain. | | 1977 | 19018 |
| anesthetic action of membrane lipids. | | 1977 | 19041 |
| effect of low ph on neurophysin-peptide interactions: implications for the stability of the amino-carboxylate salt bridge. | | 1977 | 19050 |
| cyclic amp-dependent protein kinase phosphorylation of cardiac (na+ + k+)-atpases. effect on calcium binding. | 1. calcium binding to (na+ + k+)-atpase (atp phosphohydrolase, ec 3.6.1.3) preparations from beef and pig heart preparations of varying degrees of purity was measured. 2. binding was inhibited by mg2+, na+ and k+. inhibition by na+ and k+ appeared to be due to an ionic strength effect. 3. four classes of binding sites were identified with kd values for calcium of about 0.03, 1, 15 and 200 micrometer. 4. cyclic amp-dependent phosphorylation of the enzyme by protein kinase (atp: protamine o-phosph ... | 1977 | 19066 |
| 3'-phosphoadenylylsulfate:galactosylceramide 3'-sulfotransferase. an optimized assay in homogenates of developing brain. | an optimized in vitro assay of 3'-phosphoadenylysulfate:galactosylceramide 3'-sulfotransferase (ec 2.8.2.11, galactosylceramide sulfotransferase, formerly known as galactocerebroside sulfotransferase) activity is presented, that can be used in crude homogenate of brain tissue of various developmental stages. the enzyme activity is determined by measuring the 35ssulfatides formed by the enzymic transfer of 35ssulfate from 3'-phosphoadenoside 5'-phospho 35ssulfate to galactosylceramides. the sulfa ... | 1977 | 19067 |
| genetic independence of two forms of carbonic anhydrase from bovine erythrocytes. | the two major forms of bovine erythrocyte carbonic anhydrase have been designated as ci and cii because their high activity of the c type. separation of both forms and isolation of ci from the ethanol chloroform extract of the hemolysate were obtained by either column chromatography on deae-cellulose de 23 or on deae-sephadex a-50. but pure preparations of the cii form were only obtained from deae-sephadex a-50 which separated cii from a minor component civ1. comparative studies of the ci and ci ... | 1977 | 19093 |
| a serotonergic innervation of noradrenergic neurons in nucleus locus coeruleus: demonstration by immunocytochemical localization of the transmitter specific enzymes tyrosine and tryptophan hydroxylase. | immunocytochemical localization of the neurotransmitter synthesizing enzymes, tyrosine and tryptophan hydroxylase, was used to determine whether the noradrenergic neurons in the nucleus locus coeruleus of the rat are innervated by serotonergic (5-ht) neurons. specific antibodies were prepared to tyrosine hydroxylase, purified from the bovine adrenal medulla, and tryptophan hydroxylase, purified from rat midbrain. these were localized by both light and electron microscopy by the use of the peroxi ... | 1977 | 19125 |
| nuclear-magnetic-resonance-spectroscopic studies of the amino groups of insulin. | the amino groups of insulin have been studied by 1h and 13c nuclear magnetic resonance spectroscopy in insulin, zinc-free insulin and methylated insulin. by difference spectroscopy it is possible to follow the shift with ph of the epsilon-ch2 and delta-ch2 proton resonances of lysine-b29 in insulin. in methylated insulin the dimethyl proton resonances of glycine-a1, phenylalanine-b1 and lysine-b29 can be followed as a function of ph. in native insulin pkapp values of 6.7 and 8.0 are obtained for ... | 1977 | 19247 |
| lens glycosidases in human and bovine species. ii. the isozymes of beta-hexosaminidases in human and bovine lens. | | 1977 | 19273 |
| are some interactions between nadh oxidase and succinate oxidase in beef heart non-phosphorylating submitochondrial particles artifacts? | | 1977 | 19278 |
| generation of the superoxide radical during the peroxidatic oxidation of nadh by catalase at acid ph values. | | 1977 | 19298 |
| subcellular distribution of myosin (k+, edta)-atpase in bovine adrenal medulla. | | 1977 | 19300 |
| thermal denaturation of cytochromes c of horse cow, and candida krusei in aqueous guanidine hydrochloride. | thermal denaturation of cytochromes c of horse, cow, and candida krusei in aqueous guanidine hydrochloride in the neutral ph region was studied by means of absorption and optical rotation measurements. the values of standard free energy change upon denaturation were estimated over the temperature range from 3 to 51 degrees c. large differences in the heat capacity of the native and denatured states amounting to several kcal/mol-deg were obtained for all three kinds of cytochromes c. these lead t ... | 1977 | 19430 |
| regulation of protein synthesis in hen's oviducts. ii. extracellular ovalbumin as an inhibitor of ovalbumin synthesis in the oviducts. | washed, preincubated minced hen's oviducts, which contained low levels of extracellular and intracellular proteins, synthesized egg-white proteins actively. the addition of ovalbumin to the incubation medium resulted in inhibition of the synthesis of egg-white proteins by the washed, preincubated oviduct cells, while the addition of bovine serum albumin seemed to stimulate protein synthesis and hen's egg-white lysozyme had no effect. the inhibitory or stimulatory effect on protein synthesis was ... | 1977 | 19447 |
| bovine platelet myosin. | | 1977 | 19449 |
| preparation and characterization of highly acidic proteins from chick brain. | | 1977 | 19456 |
| effects of phthalate esters on the latent atpase and swelling of mitochondria. | phthalate esters have shown to stimulate the latent atpase ec 3.6.1.3 activity and induce mitochondrial swelling. among the tested phthalate esters, di-n-butyl phthalate (dbp) exhibited the greatest activity, and the activity decreased progressively as the alkyl chain was lengthened or shortened. the dbp-stimulated atpase was oligomycin-sensitive. the degree of stimulation of the atpase was proportional to the extent of mitochondrial swelling induced by dbp in 0.1 m tris-hcl (ph 7.2) containing ... | 1977 | 19458 |
| dimethyl sulfoxide-induced self-assembly of tubulin lacking associated proteins. | | 1977 | 19469 |
| platelet-aggregating factor and the aggregation of fixed washed platelets. | platelet-aggregating factor (paf) was removed from bovine plasma by human platelets fixed with 2% formaldehyde. the degree of adsorption was directly related to the platelet concentration and the length of incubation. fixed washed platelets (fwp) aggregated with bovine plasma could be deaggregated by 1m kcl, evans blue, and 8m urea but not by beta-galactosidase. incubation with 1m kcl eluted some but not all of the paf, as the deaggregated platelets spontaneously aggregated upon removal of the d ... | 1977 | 19545 |
| preferential hemolysis of postnatal calf red cells induced by internal alkalinization. | red blood cells from neonatal calves, but not from adult cows, rapidly hemolyze in buffered 300 mm solutions of a variety of nonelectrolytes and amino acids. of these compounds, sucrose is chosen to elucidate the mechanism by which this preferential hemolysis takes place. as in other mammalian red cells, both calf and cow cells are found to be impermeable to sucrose and, in an isosmolar sucrose solution, to undergo volume shrinkage caused by the net loss of chloride ions with concomitant increas ... | 1977 | 19557 |
| hallucinogen binding to dopamine/neuroleptic receptors. | | 1977 | 19605 |
| solubilization of neurofilaments from central nervous system myelinated nerve. | | 1977 | 19632 |
| statements concerning weights and measures by cow (cp/wasp (commission on world standered in clinical pathology of the world standered in clinical pathology of the world association of societies of (anatomic and clinical) pathology). | | 1977 | 19640 |
| atypical (relaxant) response to histamine in cat bronchus. | histamine, 2-methylhistamine (a specific h1-receptor agonist), 4-methylhistamine (a specific h2-receptor agonist), isoprenaline, bradykinin, prostaglandin e1, e2, and f 2alpha induce relaxation of carbachol-contracted isolated cat bronchial strips and tracheal chains. bovine srs-a contracts bronchus but not trachea. histamine-induced relaxation of cat bronchus is not blocked by mepyramine (a specific h1-receptor antagonist); metiamide or burimamide (specific h2-receptor antagonists); propranolo ... | 1977 | 19953 |
| an apparatus for the simultaneous performance of polyacrylamide-gel electrophoresis at multiple phs. | | 1977 | 19989 |
| simultaneous determination of superoxide dismutase and catalase in biological materials by polarography. | | 1977 | 19990 |
| natural ph gradients formed by amino acids: ampholyte distribution, time course, use in electrofocusing of protein, relation to ph gradients in isotachophoresis, and separator effects. | | 1977 | 19991 |
| bradshaw lecture, 1976. thyroid medullary carcinoma. | the main characteristics of medullary carcinoma of the thyroid are its non-follicular histological appearance, resulting from its origin from the parafollicular c cells, its secretion of calcitonin, providing a relatively simple diagnostic test, and its equal sex incidence, in contrast to all other diseases of the thyroid. sporadic cases are seen and it occurs in familial groups, with autosomal dominant inheritance, when it is associated with phaeochromocytoma and parathyroid hyperplasia to form ... | 1977 | 20027 |
| arthropod-borne viruses in australia, 1973-1976. | | 1977 | 20071 |
| generalized glycogenosis in beef shorthorn cattle--heterozygote detection. | a preliminary study of acidic alpha-glucosidase in a variety of tissues was carried out in an attempt to develop a test which might be used to detect individuals heterozygous for the genetype associated with generalized glycogenosis in beef shorthorn cattle. of the tissues readily available peripheral lymphocytes were chosen as being likely to be the most suitable. it was concluded that, when coupled with genealogical information, assays of alpha-glucosidase in extracts of lymphocytes were usefu ... | 1977 | 20072 |
| in vitro studies on parsalmide / bioavailability and protein binding (author's transl). | the values of the diffusion constants at the different ph-values obtained using stricker's apparatus, demonstrate that 2-propargyloxy-5-amino-n-(n-butyl)-benzamide(parsalmide, my 46-1) is characterized by a good absorption rate at gastric level and by a high absorption rate in the intestinal tract. the per cent of parsalmide bound to serum proteins, mainly to serum albumin, decreases with increasing concentration of parsalmide. human serum binds about 55--70%, whereas bovine and equine serum bin ... | 1977 | 20112 |
| neutral lipid biosynthesis in mycobacterium smegmatis. | the biosynthesis of neutral lipids in mycobacterium smegmatis was studied using cell free extracts. maximum neutral lipid production was obtained when the reaction mixture (400 microliter) consisted of 0.25 m potassium phosphate buffer (ph 7.5), 0.125 mm oleoyl-coa, 3.75 mm sn-glycerol-3-p, 10 mm mgcl2 and 1.85 mg bovine serum albumin. no magnesium dependency for the acylation of sn-glycerol-3-p was observed. a slight stabilizing effect seemed to occur due to this ion. the enzyme phosphatidate p ... | 1977 | 20150 |
| the binding of calcium to fibrinogen: some structural features. | experiments are described which suggest that structural features are related to the existence of three high affinity calcium-binding sites in the fibrinogen molecule. the circular dichroism spectra analysis shows that the binding of calcium to this protein does not entail an overall conformational change. however several calcium-induced protective effects may be observed: 1. at ph 5.0 calcium-free fibrinogen is slightly acid-denatured. this denaturation is counteracted by the presence of calcium ... | 1977 | 20154 |
| physicochemical evidence for the existence of two pyridoxal 5'-phosphate binding sites on glutamate dehydrogenase and characterization of their functional role. | kinetic studies of pyridoxal 5'-phosphate binding to glutamate dehydrogenase (ec 1.4.1.3) has provided evidence for two specific binding sites, chemically identified as lys 126 and lys 333. use of protecting ligands permitted the selective modification of only one of these lysines, and showed that (1) lys 333 modification results in depolymerisation of the enzyme into active hexamers; (2) lys 126-modified enzyme was 92% inactivated. the residual activity was desensitized to gtp. the inactivation ... | 1977 | 20155 |
| conformational stability and self-association of zinc-free bovine insulin at neutral ph. | | 1977 | 20156 |
| the isolation and characterization of a colony stimulating factor from human lung. | serum-free conditioned medium from human lung obtained at autopsy provides a rich source of colony stimulating factor which stimulates granulocytic and macrophagic colony growth in both mouse and human bone marrow. the appearance of the factor is enhanced by endotoxin and inhibited by either puromycin or actinomycin d. human lung colony stimulating factor is stable at the ph range of 6.5-10 and temperature of 56 degrees c for 30 min. it is resistant to trypsin and neuraminidase but is sensitive ... | 1977 | 20157 |
| peripheral vascular and cardiac effects of nitrous oxide in the bovine. | peripheral vascular and myocardial effects of increasing concentrations of nitrous oxide (0 to 70 per cent) in oxygen were determined in 15 unanaesthetized calves before and after replacement in their natural heart (nh) with a pneumatically driven artificial heart (ah). nitrous oxide produced concentration-related decreases in arterial and mixed venous ph and increases in minute ventilation and arterial and mixed venous carbon dioxide tensions in both nh and ah calves. nitrous oxide resulted in ... | 1977 | 20205 |
| the interaction of human glycophorin with 8-anilino-1-naphthalene sulfonate. | both the sialoglycoprotein of human erythrocyte membranes, glycophorin, and the sialic acid free protein, obtained by treatment of glycophorin with neuraminidase (ec 3.2.1.18), increase the fluorescence of 8-anilino-1-naphthalene sulfonate (ans). binding of ans to glycophorin is weak compared with the binding to bovine serum albumin (bsa). equilibrium dialysis gives an apparent binding constant of about 4 x 10(3) m(-1) at neutral ph, but ka increases 1.75 times when nacl or cacl2 are added and 1 ... | 1977 | 20208 |
| comparative biochemical studies of placental alkaline phosphatase in animals (author's transl). | biochemical properties of alkaline phosphatase (alp) from placenta were compared between man, dog, cat, rabbit and cattle. 1) optimum ph of the enzyme was essentially identical through the species of the animals but the inhibition of l-phenylalanine was clearly demonstrable with human alp but little with that of other animals. 2) alp of human placenta was not inactivated by heating at 65 degrees c for 15 min. but one of the other animals was thermolabile. such thermostability of human placental ... | 1977 | 20315 |
| hydrogen peroxide generation in trypanosoma cruzi. | homogenates from t. cruzi epimastigotes produced 3.4 pmoles h2o2/min 10(6) cells, as detected by the cytochrome c peroxidase assay. addition of nadh or nadph increased h2o2 production by a factor of 3 and 5, respectively. when supplemented with nadh and nadph, the mitochondrial, microsomal and supernatant fractions produced h2o2, the soluble fraction and the mitochondrial membranes being apparently the main generators of h2o2. the epimastigote homogenates showed cyanide-sensitive superoxide dism ... | 1977 | 20323 |
| xenogeneic neoplastic transplants in adult rats pretreated with thymic foetal extracts. | the paper deals with the effect of thymic extracts from young foetal pigs and calves on the development of tumour xenografts, i.e. mouse ascites ehrlich carcinoma and hamster malignant melanoma, in rats. the results of experiments showed that ehrlich carcinoma developed in 4 out of 72 animals, i.e., in those animals which had received thymic extracts from young foetal pigs, ehrlich carcinoma led to their death. ehrlich carcinoma assumed a solid form and the cells changed in their shape. it devel ... | 1977 | 20339 |
| uterine secretions in the cow and sheep. | | 1977 | 20367 |
| partial purification and some properties of acetyl-coenzyme a carboxylase from bovine mammary tissue proceedings. | | 1977 | 20377 |
| purification and molecular properties of nadp-linked isocitrate dehydrogenase from ox heart mitochondria proceedings. | | 1977 | 20382 |
| rna polymerase activity in bovine spermatozoa. | washed mature spermatozoa from bulls incorporate ribonucleoside triphosphates into rna using an endogenous template. maximum incorporation was observed at 31 degrees c in the presence of mgcl2, all four ribonucleoside triphosphates, beta-mercaptoethanol, and glycine sodium hydroxide buffer at ph 9.0. the amount of synthesis was linearly dependent upon the concentration of spermatozoa and continued for at least 4 h. digestion studies revealed the rna to be present in a protected (intracellular?) ... | 1977 | 20446 |
| chromatographic separations of alphavirus strains by hydroxylapatite. | hydroxylapatite column chromatography methods were developed to characterize selected alphavirus populations. different conditions of ph and phosphate molarity were required to obtain satisfactory elution profiles and separations for western equine encephalomyelitis virus strains, compared with eastern equine encephalomyelitis virus and semliki forest virus strains. raising the ph of the buffers effected earlier elutions of all viruses. selection of phosphate gradients with more gentle slopes an ... | 1977 | 20452 |
| blood and tissue distribution of gamma glutamyl transferase in the cow. | to test the hepatic specificity of gamma-glutamyl transferase in the cow, the tissue distribution of this enzyme was studied in 10 healthy adult cows. it was located mainly in kidney, pancreas, and liver. the relative hepatic specificity of this enzyme indicated that measurement of its activity in serum could be a valuable test of hepatic damage in the cow. the blood activity measured within 54 plasmas and 54 serums of apparently healthy animals was almost the same, 17.7 +/- 5.7 u/liter for plas ... | 1977 | 20454 |
| daily changes in the blood of conscious pigs with catheters in foetal and uterine vessels during late gestation. | 1. catheters were inserted into the foetal carotid artery and maternal middle uterine artery and vein in twenty foetuses from fifteen sows, 91-105 days pregnant. blood samples were collected from foetal and maternal circulations for periods of 7-21 days after surgery.2. blood gas tensions, ph, packed cell volume (pcv) and the levels of glucose, fructose and lactic acid in conscious pigs were followed in foetal and maternal bloods during late pregnancy.3. foetal blood gas tensions, ph, pcv, lacti ... | 1977 | 20500 |
| aminoacyl-trna synthetases from calf liver: optimized assay conditions and kinetic properties. | kinetic studies have been performed on the "family" of aminoacyl synthetases from calf liver. all assays were based on the esterification of amino acids to trna. optimized reaction conditions for each synthetase are reported. most of the synthetases show hyperbolic kinetics with respect to both amino acid and trna concentration, however a few show sigmoidal kinetics with respect to one substrate. arginine, methionine and proline synthetases show sigmoidal kinetics with respect to mixed trna solu ... | 1977 | 20569 |
| the role of the at pairs in the acid denaturation of dna. | it has been determined previously that the protonation of the gc pairs induces a dna conformation change which leads to a "metastable" structure. the role of the at pairs, however, is no well known because the protonation does not modify their spectral properties. by means of an indirect method based on the binding of proflavine, it has been determined that the at pairs are protonated before the acid-induced denaturation and that they seem to be unable to assume a conformation change when proton ... | 1977 | 20604 |
| purification and properties of a ribonuclease in human urine that hydrolyses polycytidylic acid. | human urine rnase was purified about 2000-fold. the preparation is free from phosphatase, phosphodiesterase and dnase activities. on electrophoresis through polyacrylamide gel at ph 8.3, it migrates toward the anode and stains with periodic acid-schiff reagent, suggesting that it is acidic and glycoprotein in nature. its isoelectric point is at ph 4.1. it has a molecular weight of about 21,500. it is thermostable at ph 4.2 and thermolabile at ph 8.5. it has a ph optimum at 6.5. it exhibits highe ... | 1977 | 20615 |
| primary photochemical event in vision: proton translocation. | picosecond studies of rhodopsin in low-temperature glasses have been carried out in order to observe directly the risetime of prelumirhodopsin, the first intermediate in the visual pathway. only at 20 k or below can the risetime of this intermediate be resolved and even at 4 k it is astoundingly rapid, about 36 psec. an examination of the arrhenius dependence on temperature of the rate of formation of prelumirhodopsin shows a strong deviation from linearity at low temperatures, i.e., non-arrheni ... | 1977 | 20620 |
| nitric oxide activates guanylate cyclase and increases guanosine 3':5'-cyclic monophosphate levels in various tissue preparations. | nitric oxide gas (no) increased guanylate cyclase gtp pyrophosphate-lyase (cyclizing), ec 4.6.1.2 activity in soluble and particulate preparations from various tissues. the effect was dose-dependent and was observed with all tissue preparations examined. the extent of activation was variable among different tissue preparations and was greatest (19- to 33-fold) with supernatant fractions of homogenates from liver, lung, tracheal smooth muscle, heart, kidney, cerebral cortex, and cerebellum. small ... | 1977 | 20623 |
| purification, characterization and insolubilization of bovine thrombin. | | 1977 | 20675 |
| platelet adhesion to foreign surfaces under controlled conditions of whole blood flow: human vs rabbit, dog, calf, sheep, pig, macaque, and baboon. | our results reveal significant differences between mammalian species with respect to platelet adhesion to foreign surfaces exposed to heparinized, flowing blood. in particular, we have demonstrated the following: 1) at a surface shear rate characteristic of shear rates in mammalian arteries, human platelet adhesion (and that of calf, baboon, macaque, hog or sheep) is negligible in comparison to dog or rabbit platelet adhesion after 10 mins of blood flow. 2) the species differences are biomateria ... | 1977 | 20686 |
| dynamics of acid-base changes in bovine venous blood in relation to time. | | 1977 | 20687 |
| the effect of feeding propionic acid on the health status of milk cows. | | 1977 | 20688 |
| purification of protease from staphylococcus aureus (author's transl). | 380 (80%) of 475 staphylococcus aureus cultures isolated from humans, cattle and dogs were proteolytically active either on casein or gelatin or both (table 1). protease-activity could also be demonstrated in experimental body-cavities of rabbits (fig. 1). the enzyme-activity was estimated with azocasein. protease from s. aureus, m 135 precipitated from the culture supernatant with ammonium sulfate at 65% saturation (table 2). it was purified by 2 filtrations on ultrogel aca 44 (fig. 2,3) and su ... | 1977 | 20720 |
| 35s-sulfide incorporation during alkaline treatment of keratin and its relation to lanthionine formation. | cattle hair exposed to solutions of 35s-sulfide ions at ph 12.5, hydrolyzed with acid, and analyzed for amino acids with simultaneous measurement of the radioactivity of the eluate from the analytical column showed 87 percent of the radioactivity incorporated in the hair in three amino acids: cysteic acid, lanthionine, and cystine. this and other evidence presented lend further support to the intermediacy of dehydroalanyl residues formed by a beta-elimination reaction in the conversion of cystin ... | 1977 | 20743 |
| reactions of proteins with dehydroalanines. | reactions of proteins with dehydroalanine or derivatives of dehydroalanine were studied as models for protein crosslinking. treatment of casein, bovine serum albumin, lysozyme, wool or polylysine with acetamido- and phenylacetamido acrylic acid methyl esters at ph 9-10 converted varying amounts of lysine to lysinoalanine residues. howver, complete transformation was not achieved. incomplete reaction is atributed to partial hydrolysis of the esters to the less reactive acrylic acids under the rea ... | 1977 | 20747 |
| structural proteins of infectious bovine rhinotracheitis virus. | infectious bovine rhinotracheitis (ibr) virus grown in bovine embryo kidney cell cultures was concentrated and purified in ficoll density gradients. the polypeptide composition of the virus was studied by polyacrylamide gel electrophoresis. the mature virion was found to contain 18 structural proteins with molecular weights from 250,000 to 29,000 daltons; 8 of them were glycosylated. the similarity of ibr virus protein composition to proteins of other herpetoviruses is discussed. | 1977 | 20761 |
| bruce and the african trypanosomes. | | 1977 | 20787 |
| stabilization of ph gradients in buffer electrofocusing on polyacrylamide gel. | | 1977 | 20813 |
| characterization of particulate d-apiosyl-and d-xylosyltransferase from lemna minor. | | 1977 | 20844 |
| the use of a maleimido spin label to detect conformational changes in cytochrome c oxidase. | | 1977 | 20848 |
| ph effects on ciliomotility and morphology of respiratory mucosa. | tracheal cilia of cows exposed, in vitro, for 20 hours to different acidities and alkalinities of sulfuric acid and sodium hydroxide, respectively, showed ciliomotility at ph values as low as 4.9, while the epithelial cells began to be expelled from the mucosa at ph 6.7, initiating a reduction of ciliary function around this ph value. in alkaline reactions, ciliostasis occurred at ph 9.76. destroyed cilia were found above ph 10.15, while they were morphologically unchanged at ph values as low as ... | 1977 | 20855 |
| evidence of exchangeable protons in the donor groups of the acidic form of cobalt bovine carbonic anhydrase b. | | 1977 | 20880 |
| determination of the km-value of the fumarase (e.c. 4.2.1.2) with bencyclan-hydrogenfumarate as the substrate (author's transl). | the michaelis-menten constant for fumarase (e.c. 4.2.1.2) has been determined by measuring the enzyme activity by the spectrophotometric method of racker, which depends on the formation or disappearance of the double bond of fumaric acid. when using na2-fumarate or bencyclan hydrogenfumarate (fludilat), respectively, as a substrate, a km-value of 1.3 x 10(-3) m was found for both substances. in a linked assay where the formation of nadh in the reaction of fumarate leads to malate leads to oxaloa ... | 1977 | 20899 |
| influence of the ionic strength on the effect of monomeric and dimeric rnase on poly(a). | | 1977 | 20909 |
| zinc(ii) and cobalt(ii) bovine carbonic anhydrases. comparative studies and esterase activity. | | 1977 | 20924 |
| steady-state kinetics of electron transfer through cytochrome chain of uncoupled submitochondrial particles. i. general kinetic analysis. | steady-state kinetics of electron transfer through the cytochrome chain of uncoupled ultrasonic submitochondrial particles at different ph values has been studied. rate constants calculated from the pring equation (ki' = v/pirpi+1ox) increased with the increase of the rate of the process. as in the previous work (saks, v. a., kupriyanov, v. v. and luzikov, v. n. (1972) biochim. biophys. acta 283, 42-53) this dependence was linear, but only at comparatively low rates of electron transfer. to expl ... | 1977 | 20946 |
| oxidation of hypoxanthines, bearing 8-aryl or 8-pyridyl substituents, by bovine milk xanthine oxidase. | 1. hypoxanthines, bearing at position 8 aryl or pyridyl substituents, are converted by bovine milk xanthine oxidase (xanthine: oxygen oxidoreductase, ec 1.2.3.2) into the corresponding xanthines at low rates. oxidation is accelerated considerably when the 8-pyridyl substituents are quaternised. 2. in the enzymic oxidation of quaternary 8-pyridylhypoxanthines a lag phase precedes the attainment of a constant, maximal reaction rate. it is assumed that the delay is due to a relatively slow conforma ... | 1977 | 20959 |
| proton magnetic resonance studies of histidines in human, rhesus monkey, and bovine carbonic anhydrases. | histidine c-2 proton resonances in rhesus monkey carbonic anhydrase b (carbonate hydro-lyase, ec 4.2.1.1) and bovine carbonic anhydrase were investigated using 270-mhz proton magnetic resonance. the results suggest that there are extensive three-dimensional homologies between the human b and rhesus b enzymes and between the human c and bovine enzymes. resonances from solvent exchangeable protons have been observed in the 11-16 ppm range in the nmr spectra of human carbonic anhydrases b and c and ... | 1977 | 20966 |
| kinetic analysis of calcium activation of brain acetylcholinesterase forms. | calcium activation of acetylcholine hydrolysis by bovine brain acetylcholinesterase (acetylcholine hydrolase, ec 3.1.1.7) forms has been analyzed in terms of changes in kinetic constants and thermodynamic activation parameters. de-acetylation was determined to be the major rate-influencing step in acetylcholine hydrolysis by both 60 000- and 240 000-dalton forms of the brain enzyme and 10 mm ca2+ increased the rate constant for this step (k+3) by approximately 30% for both forms. for the smaller ... | 1977 | 20967 |
| circular dichroism of porcine, bovine, and equine pancreatic phospholipases a2 and their zymogens. unusual conformations simulating helix content. | | 1977 | 20973 |
| oxidation-reduction potentials of cytochromes p-450 and ferredoxin in the bovine adrenal. their modification by substrates and inhibitors. | | 1977 | 20984 |
| generation of black foamy films of proteins. | | 1977 | 20985 |
| isolation and characterization of beta-d-galactosidase from gastric juice. | a method for beta-d-galactosidase isolation from cattle gastric juice has been developed. gastric juice mucus was removed by and addition of equimolar amounts of na2hpo4 and cacl2. the removal of proteases and other proteins was achieved by the treatment with resins kb-51x2 and an-22. the resulting preparation had specific activity of 0.14 units per mg of protein. gel filtration on sepharose 4b led to an increase of specific activity of the preparation up to 0,4 units per mg of protein. some pro ... | 1977 | 20988 |
| the use of tears for diagnosis of gm1 gangliosidosis. | the properties of beta-galactosidase of tears were investigated and the standard assay system was accomplished. the ph optimum was 4.2. the enzyme had a km of 8.3 x 10(-4) m. the activity was stimulated by chloride ions and slightly stabilized by bovine serum albumin. the activities of normal individuals were 205 +/- 80 (s.d.) nmol/h/ml. the activity in the tears of the patient with gm1 gangliosidosis decreased to about 20% of normal control and this disease could be diagnosed by the assay of be ... | 1977 | 21045 |
| influence of ions on the antigen-antibody complex formation as measured by radioimmunoassay. | in this study, using radioimmunoassay techniques, we found that ions at concentrations in the order of 0.1 molar influence the antigen-antibody complex formation. the angiotensin i/anti-angiotensin i reaction was studied in detail. particularly bivalent cations and anions with a strong chaotropic effect (scn-, i- and clo4-) were found to influence strongly the specific immunological reaction. however, no3- had also a remarkably strong influence. we found that the equilibrium constant, rather tha ... | 1977 | 21048 |
| substrate specificity via ternary complex formation with glutamate dehydrogenase. | very littly discrimination is observed in the binary binding of dicarboxylic acid substrate analogues to glutamate dehydrogenase as monitored by proton nuclear magnetic resonance. variation in length, charge, bulkiness and conformational rigidity resulted in only a factor of five variation in kd and apparent relaxation time, t2. upon titration of the binary enzyme-ligand complex with coenzyme to form the ternary enzyme-ligand-coenzyme complex strong discrimination is observed. coenzyme binds tig ... | 1977 | 21092 |
| energy-dependent contraction of swollen heart mitochondria. | | 1977 | 21185 |