| direct inhibition of tyrosine hydroxylase activity by catechol estrogens. | catechol estrogens, the 2-hydroxylated metabolites of estrogens, recently shown to be formed in brain, inhibit tyrosine hydroxylase, the enzyme that catalyzes the pivotal step in the biosynthesis of the neurotransmitters dopamine and norepinephrine. the nature of the inhibition is by competition with the pterin cofactor and thus resembles feedback inhibition of the enzyme by catecholamines. | 1978 | 27508 |
| metabolism of prostacyclin in blood vessels. | the activity of 15-hydroxyprostaglandin dehydrogenase has been shown to be high in both mesenteric arteries and veins; the present study suggests that it may be responsible for the inactivation of prostacyclin (pgi2). the cytoplasmic fractions of bovine mesenteric arteries and veins were incubated with radiolabeled pgi2 in the presence of nad+ or nadp+. the substrate was rapidly converted to a product, which was isolated and identified as 6,15-diketo prostaglandin f1alpha, (6,15-diketo-pgf1alpha ... | 1978 | 27516 |
| effects of acidified fetal bovine serum on the fibrinolytic activity and growth of cells in culture. | the fibrinolytic activity of cells in culture varied with the type of serum employed in the growth medium. degradation of iodinated fibrin occurred slowly when rous sarcoma virus-transformed chick embryo fibroblasts were grown in medium containing fetal bovine serum (fbs), and rapidly when chicken serum was employed. this difference reflected the low plasminogen and high inhibitor content of fbs. the inhibitors were found to be serum macromolecules that were precipitated with ammonium sulfate or ... | 1978 | 27528 |
| the modification of the dehydromyodesmone-induced hepatic lesion in cattle by microsomal drug metabolizing enzymes. | | 1978 | 27540 |
| effects of intravenous salmonella dublin on cattle at different stages of fasciola hepatica infection. | | 1978 | 27541 |
| persistence of foot-and-mouth disease virus in butter and butter oil. | | 1978 | 27543 |
| blood and tissue distribution of gamma glutamyl transferase in calves. | in five male and five female calves, we studied the tissue distribution of gamma-glutamyl transferase. the enzyme was mainly in kidney, pancreas, and liver; there was no sex-related difference. the relative hepatic and pancreatic specificity of the enzyme indicated that the measure of its activity in serum could be a test of hepatic or pancreatic damage in the calf. serum activity measured within 159 samples of apparently healthy calves was 15.3 +/- 3.7 u/liter, not differing significantly from ... | 1978 | 27544 |
| enrichment of in vitro and in vivo immunologic activity of purified fractions of calf thymic hormone. | thymus humoral factor (thf), a thymus hormone which participates in the processes leading to acquisition of immunocompetence of lymphoid cells has been isolated in our laboratory by a stepwise gel filtration through various sephadex columns. thf so isolated appears to be a polypeptide of 3,000 mol wt which contains approximately 30 amino acid residues. here we have tested the biological activity of thf fractions of successive degrees of purity upon lymphoid cells from both intact and neonatally ... | 1978 | 27568 |
| partial purification and kinetics of gamma-glutamyl transpeptidase from bovine choroid plexus. | | 1978 | 27580 |
| modulation of gamma-glutamyl transpeptidase activity from bovine choroid plexus. | | 1978 | 27581 |
| effect of lysolecithin on adenylate cyclase and guanylate cyclase activities in bovine adrenal medullary plasma membranes. | | 1978 | 27589 |
| increased binding of 3hapomorphine in caudate membranes after dopamine pretreatment in vitro. | | 1978 | 27612 |
| covalent coupling of calf brain prolidase. | calf brain prolidase covalently bound to cnbr-sepharose 4b, retained about 32% of the activity of the uncoupled enzyme. the free enzyme showed slightly greater stability than the bound preparation when stored at 20 degrees c or at 0 degrees c. however, in either case the free and bound enzymes were more stable at the lower temperature. greater thermal stability was shown by the free enzyme than by the bound preparation over a temperature range of 25 degrees c-60 degrees c. the free and bound pro ... | 1977 | 27644 |
| efficiency of protein production from yeast grown in liquor derived from anaerobically fermented tropical pasture. | | 1978 | 27726 |
| substance p: binding to lipids in the brain. | 1. substance p (sp) could be extracted from brain homogenates with chloroform-methanol by a method which extracts all lipids. 2. sp could be transferred form this total lipid extract (tle) into an aqueous solution at low ph values (2.0--3.0). 3. at higher ph values (5.5) sp could be transferred from an aqueous phase into an organic phase (chloroform:methanol, 2:1) and recombined with tle (which was previously freed from endogenous sp) contained in this phase. the binding capacity of tle for sp e ... | 1978 | 27728 |
| serum gamma glutamyltransferase in the diagnosis of liver disease in cattle. | | 1978 | 27739 |
| isolation of a low molecular weight ca2+ carrier from calf heart inner mitochondrial membrane. | a protein was isolated from calf heart inner mitochondrial membrane with the aid of an electron paramagnetic resonance assay based on the relative binding properties of ca2+, mn2+, and mg2+ to the protein. the molecular weight of this protein has been estimated to be about 3000 by urea/sodium dodecyl sulfate gel electrophoresis and amino acid analysis. the protein is shown to have two classes of binding sites for ca2+ by flow dialysis studies and can extract ca2+ into an organic phase. the selec ... | 1978 | 27784 |
| selective labeling of alpha-adrenergic receptors in caudate nucleus by 3h dihydroergocryptine in the presence of spiperone-blocked dopamine receptors. | because it was known that (3)hdihydroergocryptine can label alpha-adrenergic receptors as well as dopamine receptors, this study was done to establish the conditions under which (3)hdihydroergocryptine would be a reliable ligand for selective labeling of alpha-adrenergic receptors. the calf caudate was chosen because it contains both dopamine and adrenergic receptors, and 5 nm spiperone (spiroperidol) was used to block the neuroleptic/dopamine receptors. thus, in the presence of spiperone, (3)hd ... | 1978 | 27786 |
| inhibition of acute anaphylaxis in the chicken by anti-allergic drugs. | the anti-anaphylactic effects of four potential anti-allergic agents (dscg: disodium cromoglycate, prd-92-ea, m&b 22,948 and decc: diethylcarbamazine citrate) were studied on cardiovascular responses of acute systemic anaphylaxis and chemical mediators of immediate hypersensitivity in chickens. compounds m&b 22,948, prd-92-ea, dscg and decc all inhibited cardiovascular manifestations of systemic anaphylaxis in domestic fowl. high doses of compounds prd-92 ea, m&b 22,948 and decc also exhibited a ... | 1978 | 27847 |
| control of blood-sucking flies. | | 1978 | 27894 |
| effects of alpha-adrenergic stimulation and blockade of plasma parathyroid hormone concentrations in cows. | experiments were designed to investigate responses of immunoreactive parathyroid hormone (pth) during alpha-adrenergic stimulation and blockade in cows. alpha-adrenergic agonists (methoxamine, phenylephrine and noradrenaline, the beta-adrenergic action of which was blocked by propranolol) did not change pth and free fatty acid levels, whereas they characteristically increased the blood pressure and decreased the heart rate. in contrast, alpha-adrenergic blockade by phentolamine progressively inc ... | 1978 | 27932 |
| butanol extraction of serum and urinary gamma-glutamyltransferase and its application in clinical diagnosis. | gamma-glutamyltransferase (gamma-gt) activity was measured in serum and urine before and after extraction with n-butanol. residual gamma-gt activity after extraction of normal serum with butanol was more than 75%, whereas for normal urine the figure was less than 68%. the loss of activity from urine was not affected by prior dialysis, and the stabilisation which resulted from adding bovine serum albumin at a concentration of 40 g/l did not approach the residual activity with normal serum. in pat ... | 1978 | 28067 |
| the effect of pelleting cereal straw with naoh-addition on rumen fermentation in cows. | experiments with rumen-fistulated dairy cows were performed to study the effect of naoh-addition to cereal pellets. compared to straw-concentrate rations in which the straw pellets were free of naoh, cereal straw pellets containing 2.4 kg naoh per 100 kg straw caused the rumenal ph to go up from 6.21 to 6.47, the cellulotlytic activity to rise by some 20%, and the passage turnover rate of dry matter to increase from 0,039 to 0,056. the concentrations of volatile fatty acids and the fermentation ... | 1978 | 28109 |
| cooperative binding of folate to a protein isolated from cow's whey. | | 1978 | 28151 |
| comparison of bovine glial fibrillary acidic protein with bovine brain tubulin. | | 1978 | 28172 |
| separation and analysis of arylsulfatase isoenzymes in body fluids of man. | soluble arylsulfatase (ec 3.1.6.1) is present in the body fluids of man in the form of two isoenzymes, arylsulfatase a and b, which reportedly are useful biochemical markers for certain types of malignancy. however, rapid assay of the individual isoenzymes is extremely difficult; procedures based on differential inhibition or activation of the isoenzymes in a mixture yield only semiquantitative results. a feature of these isoenzymes is their inhibition by some common anions (notably phosphate) a ... | 1978 | 28185 |
| fecal chymotrypsin: study on some characteristics of the enzyme. | a lineweaver-burk plot demonstrated that the apparent michaelis constants are identical for chymotrypsin (ct) in duodenal juice and in feces of the same patient. ct in fecal homogenates exhibits exhibits a remarkable stability and is bound to particles to a considerable but variable extent. the ph optimum of ct in human feces is somewhat higher as compared to pure bovine pancreatic ct. all measurements of fecal ct activity should, therefore, be performed at ph 9.0. the distribution of ct among t ... | 1978 | 28261 |
| immunological nature of the inhibition of blv-induced early polykaryocytosis by bovine sera. | a quantitative in vitro assay (epi) was developed for the serological detection of bovine leukemia virus (blv) infection in cattle. positive sera inhibit early polykaryocytosis (ep) induced by blv. we report herein experiments which demonstrate that blv-induced antibodies are responsible for this inhibition. serum fractionation by gel filtration and affinity chromatography indicate that ep-inhibiting activity is mediated only by immunoglobulins of the igg class. furthermore, on the basis of thei ... | 1978 | 28296 |
| the dissociation of b-tsh. the effect of sodium dodecyl sulfate, ph, urea and temperature. | in the present study sds polyacrylamide gel electrophoresis was used to reinvestigate the conditions under which b-tsh dissociates into its constituent subunits. the effects of sds, itself, urea, acid ph and temperature were assessed by the decrease in the amount of undissociated tsh and the increase in the dissociated components as revealed by sds gel electrophoresis. in sds alone 25--30% dissociation occurred. pre-treatment with increasing concentrations of urea up to 7.1 m increased the degre ... | 1978 | 28297 |
| use of enzymolysis techniques in studying the mechanical properties of connective tissue components. | the optimum conditions for the selective removal of elastin from connective tissues are described. the process, elastolysis, consists of incubating small samples of connective tissue in buffered saline at ph=8.6 containing 300 microgram/me of a 50-50% mixture of elastase with trypsin inhibitor, for 5-6 hours at room temperature. this process, complimented with other processes for selective removal of lipids, or mucopolysaccharides, or collagen, enables one to examine the contribution of the vari ... | 1977 | 28317 |
| diffusion of fluoride ions in dental enamel at ph 7. | the penetration and uptake of both radioactive (18f) and stable fluoride (19f) in bovine enamel were investigated. buffered ph 7 naf solutions were employed. penetration profiles of both 18f and 19f in enamel were determined by using a sectioning technique. 18f and 19f concentrations decreased exponentially with increasing penetration distance. the uptake of 18f in enamel can be described by a power function of the immersion time, with an average power of 0.76. the results agree reasonably with ... | 1978 | 28318 |
| calcium binding properties of beef cardiac troponin. | | 1978 | 28322 |
| bovine thymus poly(adenosine diphosphate ribose) polymerase. | about 1,300-fold purification of poly(adenosine diphosphate ribose) polymerase has been achieved from the extract of bovine thymus with a recovery of 10 to 20%. the final preparation has a purity of 99%, and the enzyme is composed of a single peptide with a molecular weight of 130,000. the purified enzyme required nad+, mg2+, a thiol compound, dna, and histones for full activity. whereas dna is essential for activation of the enzyme, histones are not. the observed stimulation of the reaction by ... | 1978 | 28329 |
| separation of ciliary dyskinesia substances found in serum and secreted by cystic fibrosis leukocytes and lymphoid cell lines, using protein a--sepharose cl-4b. | | 1978 | 28374 |
| experimental cross infections of fasciola hepatica in lambs and calves. | the effects of experimental infections with fasciola hepatica of ovine and bovine origin in homologous and heterologous hosts and in uninfected controls were compared; groups comprised 5 animals each. the effects of the infections were monitored by biweekly determinations of packed cell volumes (pcv), serum glutamic oxaloacetic transaminase (sgot), serum glutamic pyruvic transaminase (sgpt), gamma glutamyl transpeptidase (ggt), serum iron, bilirubin levels, alkaline phosphatase (alp) and total s ... | 1978 | 28389 |
| a ph-dependent change in both the sedimentation coefficient and the molecular weight of z-component from 6 n hcl solubilized collagen. | | 1976 | 28430 |
| influence of ph on the interaction of cardiotonic steroids with sodium- and potasssium-dependent adenosine triphosphatase. | | 1978 | 28472 |
| acid proteinase of hypothalamus. purification, some properties, and action on somatostatin and substance p. | in a continuing study of the physiological role of protein breakdown in the hypothalamus, acid proteinase from bovine hypothalamus was purified about 1000-fold. the molecular weight of the enzyme was approximately 50,000. masimal activity against hemoglobin was obtained at ph 3.2-3.5; serum albumin was split much more slowly. hypothalamus acid proteinase was partially inhibited by beta-phenyl pyruvate, or benzethonium cl, and was completely inhibited by low concentrations of pepstatin. this prot ... | 1978 | 28491 |
| the effect of raised ph on pacemaker activity and ionic currents in cardiac purkinje fibers. | | 1978 | 28515 |
| porphyrin biosynthesis. immobilized enzymes and ligands. vii. studies on bovine liver porphobilinogenase. | bovine liver porphobilinogenase (pbgase) has been covalently attached to sepharose, and some of their properties have been studied. the optimal conditions for binding have been determined. the water-insoluble pbgase retained a high percentage of the activity of the soluble enzyme; the coupling yield was also high. sepharose-pbgase could be stored at 4 c for periods up to 5 weeks with 40% loss of activity; however, both by storage and repeated use, isomerase was inactivated and the percentage of ... | 1976 | 28632 |
| seroepidemiological investigations in domestic ruminants from egypt, somalia and jordan for the demonstration of complement fixing antibodies against rickettsia and chlamydia (author's transl). | 1450 random serum samples of domestic ruminants from egypt, somalia and jordan were investigated for complement fixing antibodies against rickettsia and chlamydia. between 1.5 and 3.4% of the samples from the animals investigated had antibodies against the rmsf-group of rickettsia, with exception of the sera from somalian cattle and sheep from jordan. antibodies against rickettsia of the typhus-group were found in 4 cattle and 1 goat from jordan and 2 sheep from egypt; by agglutination test with ... | 1978 | 28651 |
| a contribution to the biology of dicrocoelium hospes looss, 1907 (trematoda, dicrocoeliidae). | in this study, carried out in the ivory coast, dicrocoelium hospes looss, 1907 was shown for the first time to be a parasite of cattle and it was also detected in sheep by the presence of ova in the faeces. up to 50% of the sheep in some flocks were found to shed eggs. the adults, sporocysts, "slime balls" and cercariae of d. hospes are described and compared to the respective stages of d. dendriticum. this comparison shows that essential morphological structures are very similar, especially the ... | 1978 | 28656 |
| effects of xylazine hydrochloride on urine in cattle. | urine volume, urine ph, and urine glucose concentration were monitored for up to 24 hours after physiological saline or one of two dosage levels (0.22 mg/kg or 0.44 mg/kg) of xylazine was administered to cows. during the first 2 hours after xylazine was given, urine output was greatly increased (relative to the control animals), with the high dosage group having more output than the low dosage group. the influence of the drug on urine volume had ended by 5 hours after injection when urine output ... | 1978 | 28723 |
| a characterization of the nucleotide uptake of chromaffin granules of bovine adrenal medulla. | chromaffin granules isolated from bovine adrenal gland were incubated with (3)h-labelled nucleotides and (14)cnoradrenaline to study the uptake of these substances. (3)hatp, (3)hadp and (3)hamp are taken up by these organelles by the same temperature-dependent mechanism. the apparent k(m) for atp and adp is 1.4mm, and for amp it is 2.9mm. the uptake of atp has a flat ph optimum, whereas the catecholamine uptake increases with more alkaline ph. atractyloside and carboxyatractyloside are competiti ... | 1978 | 28725 |
| two distinct rhodopsin molecules within the disc membrane of vertebrate rod outer segments. | the kinetics of the metarhodopsin i-ii reaction have been measured over a wide range of temperatures (1-37c ) and ph values (4.5-8) with suspensions containing fragments of bovine rod outer segments. it was found that for all conditions the occurrence of metarhodopsin ii could be described by two independent first-order processes. the fast component: slow component amplitude ratio depends upon ph and temperature. the kinetics of the lumi-metarhodopsin i reaction show the same ph dependence for t ... | 1978 | 28757 |
| role of thiol group(s) in the enzymatic activity of the membrane-bound delta5-3beta-hydroxysteroid dehydrogenase from bovine adrenal cortex microsomes. | | 1978 | 28762 |
| immobilization of glutamate dehydrogenase into proteic films. stability and kinetic modulation by effectors. | | 1978 | 28764 |
| the two human trypsinogens: catalytic properties of the corresponding trypsins. | the catalytic properties of the two human trypsins obtained from purified trypsinogens have been studied. the catalytic rate constant kcat and the pk of the ionisable residue implicated in the active site have been determined with bz-arg-oet. the hydrolysis of tos-arg-ome by human trypsins does not follow the simple michaelis-menten scheme and indicates a difference in the conformational flexibility of the active site-regions of the two enzymes. both enzyme are readily autolyzed and calcium ion ... | 1978 | 28765 |
| nmr and enzymatic investigation of the interaction between elastase and sodium trifluoroacetate. | at ph 5.5, sodium trifluoroacetate is a potent competitive inhibitor of porcine elastase (ki = 2.6 mm) and human leukocyte elastase (ki = 9.3 mm). for both enzymes the ki increases strongly with ph. sodium fluoride is inactive on pancreatic elastase and sodium acetate is a weak inhibitor of this enzyme. trifluoroethanol inhibits both enzymes but is less active than trifluoroacetate in acidic ph conditions. bovine trypsin and alpha-chymotrypsin are resistant to the action of sodium trifluoroaceta ... | 1978 | 28776 |
| the isolation and identification of 2,4-diketones present in human and animal tissues and in urine. | the chemical isolation of 2,3-diketone fraction from hydrolysates of various mammalian tissues has been accomplished by the use of a modified girard t procedure. this fraction, which constitutes a new lipid class, has been resolved by gas chromatography into a number of homologous 2,4-diketones, ranging in chain length from c13 to c25. after separation by preparative gas chromatography, the following compounds have been unequivocally identified: 2,4-heptadecanedione, 2,4-nonadecanedione, 2,4-hen ... | 1978 | 28820 |
| remineralization of artificial enamel lesions in vitro. ii. determination of activation energy and reaction order. | | 1978 | 28847 |
| an "oncometer" of clinical measurement of colloid osmotic pressure of plasma. | measurement of colloid osmotic pressure complements measurements of pulmonary artery wedge pressure for assessing the risks of pulmonary edema and constitutes an increasingly important reference for purposes of guiding selection of colloid or crystalloid fluids in patients with acute cardiac disease. we describe a simple device for its routine clinical measurement. a membrane, selectively impermeable to molecules of relative molecular mass (mr) greater than 30000, is rigidly mounted between a sa ... | 1978 | 28860 |
| preparation and long-term cultivation of porcine tracheal and lung organ cultures by alternate exposure to gaseous and liquid medium phases. | conventional methods of organ culture have proved unsatisfactory for mammalian lung because of the rapid collapse of the tissue and the loss of its normal structure. in an effort to circumvent this problem and to provide a means for visualizing the cellular relationships throughout the culture period, respiratory organs consisting of trachea and lungs of fetal or hysterectomy-derived 1- to 4-week-old pigs were embedded in warm 3% noble agar in phosphate buffer silicone solution and cooled to fir ... | 1978 | 29005 |
| lipogenesis in isolated intramuscular adipose tissue from four bovine muscles. | | 1978 | 29026 |
| direct evidence of participation of rat lung carbonic anhydrase in co2 reactions. | isolated rat lungs were ventilated with air and perfused with a blood-free krebs-ringer bicarbonate solution under conditions of net co2 elimination in the lung. some of the effluent perfusate was drawn through a stop-flow ph electrode apparatus, arriving at the electrode within 4 s after passing through the pulmonary capillaries. ph and temperature of the fluid in the electrode chamber were continuously monitored both before and after withdrawal was suddenly stopped. little or no change was obs ... | 1978 | 29055 |
| hepatic lipid metabolism. age-related changes in triglyceride metabolism. | age-related changes in hepatic triglyceride formation have been described in developing rats. triglyceride formation was measured in vitro in the presence of 14cglycerol-3-phosphate, palmitate, atp, coa, and mg2+ by using liver homogenates and microsomal fractions derived from various age groups of animals. triglyceride formation was most active in one-day-old rats and then decrease with age. the increase in triglyceride formation following birth was prevented by the administration of puromycin ... | 1978 | 29075 |
| swelling and shrinkage of bovine eye-lens capsule and their effect on the membrane permeability (author's transl). | | 1978 | 29113 |
| selective labeling of pre-synaptic receptors by 3h-dopamine, 3h-apomorphine and 3h-clonidine; labeling of post-synaptic sites by 3h-neuroleptics. | | 1978 | 29197 |
| purification and characterization of protein methylase i (s-adenosylmethionine: protein-arginine methyltransferase; ec 2.1.1.23) from calf brain. | | 1978 | 29212 |
| electromechanical properties of articular cartilage during compression and stress relaxation. | | 1978 | 29231 |
| soluble bovine adrenal cortex guanylate cyclase: effect of sodium nitroprusside, nitrosamines, and hydrophobic ligands on activity, substrate specificity and cation requirement. | | 1978 | 29234 |
| the response of lymphatic smooth muscles to vasoactive substances. | a study was made of the isotonic response of bovine mesenteric lymphatics to several physiological vasoactive substances. contractions of lymphatic smooth muscles were induced by serotonin (5-ht), prostaglandin f2alpha (pgf2alpha), noradrenaline (na), histamine, dopamine and acetylcholine (ach). the smooth muscles were particularly sensitive to 5-ht. excepting pgf2alpha no other substances could equal 5-ht in the magnitude of the maximum response. the majority of 5-ht receptors seemed to be the ... | 1978 | 29277 |
| role of a transmembrane ph gradient in epinephrine transport by chromaffin granule membrane vesicles. | atp-driven transport and accumulation of epinephrine in chromaffin granule membrane vesicles isolated from bovine adrenal medulla is inhibited by the proton ionophores carbonylcyanide p-trifluoromethoxyphenylhydrazone and nigericin, but not by valinomycin. moreover, an artificially imposed ph gradient (interior acid) is able to drive this reserpine-sensitive transport system in the absence of atp. dicyclohexylcarbodiimide, an inactivator of the chromaffin granule membrane-bound atpase, completel ... | 1978 | 29292 |
| phenoxybenzamine induced pulmonary hypertension in calves. | | 1978 | 29298 |
| comparative characteristics of the free amino acid content in a pediatric sour milk product with an increased biological value and in biolact. | | 1978 | 29401 |
| the action of cathepsin b and collagenolytic cathepsin in the degradation of collagen. | cathepsin b and collagenolytic cathepsin were obtained from bovine spleen and human placenta and identified as thiol proteinases. both enzymes degraded insoluble fibrous collagen maximally at ph 3.5 and soluble monomeric collagen near ph 4.5. the response to activators and inhibitors was similar for both enzymes. collagenolytic cathepsin was unable to degrade the synthetic substrates of cathepsin b and was also shown to differ in its physico-chemical properties. minor differences were noted in t ... | 1977 | 29420 |
| influence of mild acid hydrolysis on the antigenic properties of phase i coxiella burnetii. | mild acid hydrolysis of phase i coxiella burnetii cells gradually cleaved off polysaccharide chains, which contain determinants of antigen 1, thus unmasking determinants of the diagnostically important antigen 2. this artificial phase i to phase ii conversion was reflected by changed serological activity in the complement-fixation (cf) test and by changed nonspecific phagocytosis. the product of mild acid hydrolysis can serve as a complex diagnostic preparation, because it reacts in the cf test ... | 1978 | 29469 |
| the growth of bovine ephemeral fever virus in primary cell cultures. | | 1978 | 29478 |
| determination of serum protein concentration in nanoliter blood samples using fluorescamine or 9-phthalaldehyde. | | 1978 | 29520 |
| storage quality of dark, firm, dry meat. | dark, firm, dry meat contains little or no glucose. therefore, spoilage bacteria growing on such meat immediately attack amino acids so that spoilage odors and ammonia are detectable at comparatively low cell densities (about 10(6)/cm2). | 1978 | 29565 |
| establishment of a heat inactivation curve for clostridium botulinum 62a toxin in beef broth. | a procedure is described for establishing a heat inactivation curve for the toxin of clostridium botulinum 62a in beef broth. the effect of toxin titer, ph, and the type of acid employed for ph adjustment on the heat stability of the toxin is described. | 1978 | 29566 |
| evidence for differently protonated forms of metarhodopsin ii as intermediates in the decay of membrane-bound cattle rhodopsin. | | 1978 | 29625 |
| the production and characterization of antibodies against beta-adrenergic antagonists. | | 1978 | 29641 |
| isolation and properties of bovine kidney aminopeptidase a. | aminopeptidase a, which specifically hydrolyses n-terminal dicarbonic amino acid residues containing free alpha-amino groups, is isolated from bovine kidney. the enzyme is 500-fold purified and is homogenous under electrophoresis and ultracentrifugation. aminopeptidase a has ph optimum of 7.5, it is activated with ca2+ and inactivated with edta. its molecular weight is 53000. the enzyme hydrolyses alpha-l-aspartyl-beta-naphtylamide and splits peptides having n-terminal glycine, lysine, arginine ... | 1978 | 29673 |
| the effect of magnesium on the hemolysis of calf and adult cattle erythrocytes. | | 1978 | 29680 |
| column-chromatographic separation of isoenzymes of aspartate aminotransferase. | we describe a column-chromatographic method for separating the mitochondrial and cytoplasmic isoenzymes of aspartate aminotransferase in human serum. bed height of the ion exchanger, ph, and salt concentrations in the eluting buffers are shown to be variables affecting the separation of the isoenzymes. under the optimized conditions selected for this study, a 30% increase in volume was observed in one fraction, associated with changing the salt concentration of the eluting buffer and attributed ... | 1978 | 29723 |
| investigations into the choice of immunogen, ligand, antiserum and assay conditions for the radioimmunoassay of conjugated cholic acid. | investigations into the choice of immunogen, ligand, antiserum and assay conditions for the radioimmunoassay of conjugated cholic acid have been performed with a view to producing optimal assay conditions. cholic acid-bsa was found to be the best immunogen to produce antibodies to conjugated cholic acid and the response was of an igg type. incorporating a spacer (hexanoic acid) between hapten and carrier protein resulted in a decrease in antiserum titre. optimal conditions for the assay were fou ... | 1978 | 29725 |
| effect of ph on photosensitivity of bull spermatozoa. | | 1978 | 29772 |
| time-dependent increase in the stability of collagen fibrils formed in vitro. i. effects of ph and salt concentration on the dissolution of the fibrils. | the time-dependent increase in stability, as measured in terms of the rate of dissolution, of collagen fibrils formed in vitro from pepsin-treated collagen was significantly affected only by temperature, and not by either ionic strength or ph. this is in contrast with collagen fibril formation, a process which is greatly affected by ionic strength and ph. within the range of temperature 29-37 degrees c, lower temperature caused slower fibril formation and faster fibril stabilization. these resul ... | 1978 | 29885 |
| chymotrypsin inhibitors from hemolymph of the silkworm, bombyx mori. | three new protease inhibitors were isolated and purified about 200-fold from hemolymph of silkworm larvae, bombyx mori, using ion-exchange and affinity chromatography. two of the three inhibitors were basic proteins (sci-i had pi 9.4 and sci-ii had pi 9.6) and one was acidic (sci-iii had pi 4.0). the molecular weight of each inhibitor was determined to be 7,000 by the sedimentation equilibrium method. the amino acid composition of the inhibitors were similar except for the contents of asp, glu, ... | 1978 | 29886 |
| ionic interactions between bovine chymotrypsinogen a and chondroitin sulfate a.b.c.. a possible model for molecular aggregation in zymogen granules. | the formation of large aggregates by ionic interactions between acidic glucosaminoglycans and cationic secretory proteins has been proposed as one of the critical steps in the concentration process in the condensing vacuoles of secretory cells. in this paper, this hypothesis was tested by studies on the interactions between bovine chymotrypsinogen a and chondroitin sulfate as a simplified model. small amounts of chondroitin sulfate were found able to induce chymotrypsinogen precipitation. like z ... | 1978 | 29905 |
| organic solvents and temperature effects on desorption from immunoadsorbents. dnp-bsa anti-dnp as a model. | conditions for desorbing a dnp carrier from its immunoadsorbent were studied in various hydro-organic media at different phs and temperatures, including the sub-zero range. it appeared that dnp--anti-dnp interaction is the result of a balance between various bonds and the best result (95% yield) was obtained in hydro-organic solvent at high ph and +30 degrees c. | 1978 | 29930 |
| comparative studies on glutamyl-trna synthetases isolated from cytoplasm and mitochondria of calf brain. | | 1978 | 29940 |
| peroxidases in the neural retina and pigment epithelium. | | 1978 | 29941 |
| purification of bovine pineal hydroxyindole o-methyltransferase by immunoadsorption chromatography. | | 1978 | 29942 |
| redistribution of hydrogen ion and chloride, and water shift across the red cell membrane of human and ruminant blood with changes in oxygen saturation. | | 1978 | 30065 |
| application of the sousa (john phillip) principles to medical research: the role of cyclic nucleotides in hormone and drug action. | | 1978 | 30205 |
| a simple and sensitive fluorometric assay for tyrosine hydroxylase. | | 1978 | 30333 |
| efficiency of beef extract for the recovery of poliovirus from wastewater effluents. | the efficiency of poliovirus elution from fiber glass cartridge filters (k27), epoxy-fiber glass-asbestos filters (m780), and pleated cartridge filters was assessed by using 3% beef extract (ph 9.0) or 0.1 m glycine (ph 11.5). poliovirus type i, strain lsc, was seeded into 20- to 25-gallon (ca. 75.6- to 95.6-liter) samples of treated sewage effluent and concentrated by using a filter adsorption-elution technique. virus elution was accomplished by using either two 600-ml portions of 3% beef extra ... | 1978 | 30391 |
| some properties of 3-hydroxy-3-methylglutaryl-coenzyme a synthase from ox liver. | mitochondrial 3-hydroxy-3-methylglutaryl-coa synthase (ec 4.1.3.5) was purified from ox liver, and obtained essentially free from 3-oxoacyl-coa thiolases. the kinetic behaviour, like that of the synthases from chicken liver and yeast, is compatible with a reaction pathway involving condensation of an acetyl-enzyme with acetoacetyl-coa. the km for acetoacetyl-coa, less than 1 micronm at ph 7.8, may possibly be low enough to permit rapid ketogenesis under physiological conditions without the need ... | 1978 | 30450 |
| proteoglycan-degrading enzymes of rabbit fibroblasts and granulocytes. | a neutral proteinase secreted by rabbit synovial fibroblasts in parallel with specific collagenase was partially purified by ion-exchange chromatography. at ph 7.6 this proteinase degraded 35s-labelled bovine nasal proteoglycan and azo-casein. the enzymic activity was inhibited by edta, 1,10-phenanthroline and serum, whereas di-isopropyl phosphorofluoridate and soya-bean trypsin inhibitor had little effect. by gel filtration the apparent mol.wt. of the enzyme was 25000. the fibroblast neutral pr ... | 1978 | 30451 |
| phosphorus-31 nuclear magnetic resonance studies of active proton translocation in chromaffin granules. | atp hydrolysis and proton translocation in chromaffin granules were followed using 31p nuclear magnetic resonance. the intragranular ph affects the resonance frequency of the gamma-phosphate of granular atp. by measuring frequency vs. ph in solutions which simulate the intragranular matrix, this may be calibrated to give quantitative ph measurements. the ph in the resting granule is 5.65 +/- 0.15. this drops by 0.4 to 0.5 ph unit when atp is added externally and protons are actively pumped into ... | 1978 | 30475 |
| proton-translocating cytochrome c oxidase in artificial phospholipid vesicles. | the proton translocating properties of cytochrome c oxidase have been studied in artificial phospholipid vesicles into the membranes of which the isolated and purified enzyme was incorporated. initiation of oxidation of ferrocytochrome c by addition of the cytochrome, or by addition of oxygen to an anaerobic vesicle suspension, leads to ejection of h+ from the vesicles provided that charge compensation is permitted by the presence of valinomycin and k+. proton ejection is not observed if the mem ... | 1978 | 30478 |
| the effect of bovine serum albumin on partial reactions of palmitoyl-coa chain elongation by rat liver microsomes. | in the absence of albumin, v/s curves for both condensation and overall chain elongation demonstrated that the specific activity for overall chain elongation was 3.7 times that of condensation. when the molar ratio of palmitoyl-coa to albumin was greater than 2 : 1, the specific activity of chain elongation exceeded that of condensation. at these low albumin concentrations, in the absence of nadph, the beta-ketostearoyl-coa was converted back to palmitate. this cleavage reaction is inhibited by ... | 1978 | 30485 |
| the involvement of one of the three histidine residues of cow kappa-casein in the chymosin-initiated milk clotting process. | cow kappa-casein has been modified by photo-oxidation in the presence of rose bengal and by the chemical reagents diethyl pyrocarbonate, 2-hydroxy-5-nitro-benzyl bromide and iodoacetic acid. photo-oxidation resulted in the destruction of histidine and tryptophan residues and all of the histidines could be ethoxy-formylated by treatment with diethyl pyrocarbonate. both procedures caused a loss in the susceptibility of the phe-met linkage of kappa-casein to chymosin hydrolysis. treatment of kappa- ... | 1978 | 30487 |
| symposium on freezing of gametes and spermatozoa-synopsis papers. | | 1978 | 30594 |
| partial purification and characterization of dihydropyrimidinases from calf and rat liver. | the partial purification of rat and calf liver dihydropyrimidinase (ec 3.5.2.2) is described. molecular weights of the native calf and rat liver enzymes were estimated by gel-filtration chromatography to be 252,000 and 266,000 daltons, respectively. subunit molecular weights of the calf and rat liver enzyme were estimated by sds-gel electrophoresis to be 59,000 and 62,000 daltons, respectively. the native enzyme in both species is thought to comprise four subunits. the purified enzyme from both ... | 1978 | 30611 |
| slow association-dissociation equilibrium of nadp-linked isocitrate dehydrogenase from beef liver in relation to catalytic activity. | in this paper experiments are reported which show evidence for a relation between quaternary structure and catalytic activity of cytoplasmic nadp-linked isocitrate dehydrogenase from beef liver. the inactivation of the enzyme occurring upon dilution and the plots of the catalytic activity versus the enzyme concentration indicate that the monomeric species is catalytically inactive and that the monomer-dimer equilibrium is shifted towards the dimer upon binding of the substrate magnesium isocitra ... | 1978 | 30630 |
| a 31p nmr study of phosphate in presence of cobalt(ii)- and copper(ii)- substituted bovine carbonic anhydrase b. | | 1978 | 30648 |
| bovine thyroidal xanthine oxidase. | | 1978 | 30660 |