| chromatographic evidence of the self-association of oxyhemoglobin in concentrated solutions: its biological implications. | expressions that take into account the effects of thermodynamic non-ideality, described in terms of a high-order virial expansion, are derived for the concentration-dependence of the weight-average partition coefficient in exclusion chromatography of a single solute and of a solute undergoing reversible self-association. comparison of the concentration-dependences predicted by those expressions with results obtained for bovine and human oxyhemoglobins on cpg-10-120 porous glass beads in 0.156 i ... | 1979 | 39647 |
| effect of immobilization on stability and properties of n-acetyl-beta-d-hexosaminidase from turbo cornutus. | a mixture of glycosidases from the liver of the gastropod turbo cornutus was co-immobilized with bovine serum albumin and glutaraldehyde, and then cast as membranes. the properties of immobilized n-acetyl-beta-d-hexosaminidase were studied. the recovery of n-acetyl-beta-d-hexosaminidase after immobilization was unaffected by increasing the concentration of glutaraldehyde, but was decreased by increasing the bovine serum albumin concentration. the immobilized enzyme showed enhanced resistance tow ... | 1979 | 39677 |
| the relative merits of polyethyleneglycol as a separating agent in the radioimmunoassay of thyroid hormones. | polyethyleneglycol (peg) has been recommended as a separating agent in the assay of some peptide hormones (desbuquois, b. and aurbach, g.d. (1971) j. clin. endocrinol. 33, 732) and several substances of low molecular weight (ratcliffe, j.g. (1974) br. med. bull. 30, 32). in the present study the peg-separation technique has been modified and adapted for the assay of thyroid hormones. separation with peg has the advantage of being cheap, rapid and relatively non-susceptible to disturbances as com ... | 1979 | 39694 |
| the aromatic residues of bovine pancreatic ribonuclease studied by 1h nuclear magnetic resonance. | 1. the aromatic proton resonances in the 360-mhz 1h nuclear magnetic resonance (nmr) spectrum of bovine pancreatic ribonuclease were divided into histidine, tyrosine and phenylalanine resonances by means of ph titrations and double resonance experiments. 2. photochemically induced dynamic nuclear polarization spectra showed that one histidine (his-119) and two tyrosines are accessibly to photo-excited flavin. this permitted the identification of the c-4 proton resonance of his-119. 3. the resona ... | 1979 | 39752 |
| albumin density gradient purification of canine hemopoietic blood stem cells (hbsc): long-term allogeneic engraftment without gvh-reaction. | long-term repopulation of the blood-forming organs of dogs, conditioned by wholebody x-irradiation (1200 r midplane dose), was achieved by transfusion of cryopreserved allogeneic blood mononuclear cells (mnc) without causing graft-versus-host-reaction (gvh-r). donor and recipient dogs were dl-a identical, mlc-negative, no siblings, non-related. the blood stem cells (cfuc) were procured by a 3- to 4-hour continuous-flow leukapheresis. to increase the cfuc concentration in the peripheral blood, de ... | 1979 | 39771 |
| on the possible hydrolysis of the alpha-l-iduronide linkage by beta-d-glucuronidase (ec 3.2.1.31). | | 1979 | 39779 |
| redox bohr-effects in the cytochrome system of mitochondria. | | 1979 | 39781 |
| low ph binding of vanadyl to bovine lactoferrin: electron spin resonance studies. | | 1979 | 39786 |
| evidence for the enzymic degradation of thyrotropin-releasing-hormone (trh) and pseudo-hormone (pyroglutamyl-histidyl-amphetamine) by calf liver pyroglutamine-amino-peptidase. | | 1979 | 39805 |
| purification and characterization of the cfa/i antigen of enterotoxigenic escherichia coli. | the fimbral colonization factor antigen cfa/i of enterotoxigenic escherichia coli was purified and characterized. the initial purification step was release of these fimbriae from the bacterial cells by homogenization with a waring blender. common fimbriae and flagellar antigen were avoided by careful control of growth conditions and the use of a nonmotile (h-) mutant of the prototype strain h-10407 (o78:h11). the essential purification steps were membrane filtration (millipore corp.), ammonium s ... | 1979 | 39896 |
| comparison of the substrate specificity of adenosine 3':5'-monophosphate- and guanosine 3':5'-monophosphate-dependent protein kinases. kinetic studies using synthetic peptides corresponding to phosphorylation sites in histone h2b. | the substrate specificities of cyclic gmp-dependent and cyclic amp-dependent protein kinases have been compared by kinetic analysis using synthetic peptides as substrates. both enzymes catalyzed the transfer of phosphate from atp to calf thymus histone h2b, as well as to two synthetic peptides, arg-lys-arg-ser32-arg-lys-glu and arg-lys-glu-ser36-tyr-ser-val, corresponding to the amino acid sequences around serine 32 and serine 36 in histone h2b. serine 38 in the latter peptide was not phosphoryl ... | 1979 | 39929 |
| collagen cross-linking. purification of lysyl oxidase in solvents containing nonionic detergents. | | 1979 | 39938 |
| effects of low electrolyte media on salt loss and hemolysis of mammalian red blood cells. | cation loss and hemolysis of various mammalian red cells suspended in isotonic non-electrolyte media were investigated. sucrose buffered with 10 mm tris-hepes, ph 7.4 was used as the non-permeable non-electrolyte. mammals from which the red cells were derived include the human, guinea pig, rat, rabbit, newborn calf, newborn piglet and pig, all of which contain k as the predominant cation species (hk type) and the dog, cat, sheep and cow, all of which possess na as the predominant cation species ... | 1979 | 39943 |
| nicotinamide adenine dinucleotide phosphate-decanaldehyde adduct as an inhibitor of beef brain nadp-linked aldehyde reductase. | the synthesis and characterization of the addition product of nadp and decanaldehyde are described. this adduct is an inhibitor of beef brain nadp-linked aldehyde reductase (ki = 2.3 x 10(-6) m) along with the nadp adducts of butyraldehyde, phenylpropionaldehyde, and phenylacetaldehyde. | 1979 | 40025 |
| structure of bovine beta-lactoglobulin at 6a resolution. | | 1979 | 40037 |
| calcium-activated neutral protease from bovine ventricular muscle: isolation and some of its properties. | | 1979 | 40039 |
| [3h]para-amino-clonidine: a novel ligand which binds with high affinity to alpha-adrenergic receptors. | | 1979 | 40089 |
| uv-endonuclease from calf thymus with specificity toward pyrimidine dimers in dna. | we describe the partial purification of an endonuclease from calf thymus that nicks phage pm2 dna irradiated with uv doses producing only a few pyrimidine dimers per molecule. it has much less activity on dna that has been subjected to enzymatic photoreactivation after uv irradiation. the calf thymus endonuclease is different from other mammalian uv-endonucleases so far described in that it seems to be dimer specific. the enzyme is stimulated by mg2+ and is inactive in the presence of edta. it b ... | 1979 | 40230 |
| cns benzodiazepine receptors: physiological studies and putative endogenous ligands. | the recent demonstration of benzodiazepine receptors in the mammalian cns has provided new information on the mechanism of action of this important class of drugs. in addition, the presence of these receptors has prompted studies on their physiological significance, including attempts at isolating an endogenous ligand. the isolation of a number of substances from bovine brain that competitively inhibit (3h)-diazepam binding to synaptosomal membrane suggests the presence of an endogenous ligand. ... | 1979 | 40256 |
| some characteristics of 17 beta-estradiol dehydrogenase from bovine placenta. | the activity of 17 beta-estradiol dehydrogenase (e.c. 1.1.1.62) was measured, and its distribution in the subcellular fractions of bovine placenta was compared. assay of activity was based on the formation of radioactive estrone from 17 beta[4(-14)c]-estradiol. either nad+ or nadp+ can serve as cofactor for the enzyme. the nuclear and microsomal fractions of the placental homogenate exhibited the highest specific enzymatic activities before and after treatment with triton x-100. electron microgr ... | 1979 | 40329 |
| iodoamino acid synthesis in thyroid lobes in vitro with excellent yield of iodothyronines. | thyroid lobes of male sprague-dawley rats on an iodine-sufficient diet were incubated in our improved in vitro system with 0.01 microm 127i and 5mu/ml of bovine tsh. thyroidal 131i-uptake and the relative incorporation of iodine into iodothyronines increased with time. the average yield of each iodoamino acid after 8 h of incubation was: monoiodotyrosine 28.0%, diiodotyrosine 46.5%, triiodothyronine 1.9% and thyroxine 13.9%, which showed a striking resemblance to the values obtained in vivo. the ... | 1979 | 40373 |
| quantitative and rapid assays of togaviruses by immunofluorescence. | for the quantitative assay of selected togaviruses, suspensions of bhk cells were inoculated with virus and grown in spinner cultures. at intervals, dependent on the growth characteristics of the viruses, about 10(3) cells were centrifuged on to microscope slides and then stained with fluorescent antibody. for rapid demonstration (2--3 hr) of specific viral antigens, virus was bound in successive dilutions onto microscope slides and stained. binding of specific anti-virus antibodies in both meth ... | 1979 | 40420 |
| purification of microtubule protein from beef brain and comparison of the assembly requirements for neuronal microtubules isolated from beef and hog. | | 1979 | 40455 |
| further studies on bovine serum amylase--the effect of gel buffer ph. | this paper describes the effect of gel buffer ph on the resolution of bovine serum amylase (amylase i) isozymes in starch gel and the consequences for the understanding of the genetics of this locus. the two main findings are: (1) the existence of a satellite isozyme e to isozyme c which at ph 7.3 has the same mobility as the b isozyme but which at ph 8.0 migrates slower than b, and (2) the finding of three alleles aml a, aml b and aml c in british cattle populations previously reported as havin ... | 1978 | 40464 |
| the mechanism of transmembrane delta muh+ generation in mitochondria by cytochrome c oxidase. | in rat liver mitochondria treated with rotenone, n-ethylmaleimide or oligomycin the expected alkalinization caused by proton consumption for aerobic oxidation of ferrocyanide was delayed with respect to ferrocyanide oxidation, unless carbonyl cyanide p-trifluoromethoxyphenylhydrazone was present. 2. when valinomycin or valinomycin plus antimycin were also present, ferricyanide, produced by oxidation of ferrocyanide, was re-reduced by hydrogenated endogenous reductants. under these circumstances ... | 1979 | 40546 |
| nuclear magnetic resonance study of solvent exchange and nuclear overhauser effect of the histidine protons of bovine superoxide dismutase. | | 1979 | 40594 |
| guanylate cyclase of isolated bovine retinal rod axonemes. | the guanylate cyclase activity of axoneme--basal apparatus complexes isolated from bovine retinal rods has been investigated. the mg2+ and mn2+ complexes of gtp4- serve as substrates. binding of an additional mole of mg2+ or mn2+ per mole of enzyme is required. among cations which are ineffective are ca2+, ni2+, fe2+, fe3+, zn2+, and co2+. the kinetics are consistent with a mechanism in which binding of mg2+ or mn2+ to the enzyme must precede binding of mggtp or mngtp. the apparent dissociation ... | 1979 | 40595 |
| light-induced permeability changes in sonicated bovine disks: arsenazo iii and flow system measurements. | | 1979 | 40596 |
| enzymatic characterization of the chondrocytic alkaline phosphatase isolated from bovine fetal epiphyseal cartilage. | purified chondrocytic alkaline phosphatase (orthophosphoric-monoester phosphohydrolase (alkaline optimum), ec 3.1.3.1) from bovine fetal epiphyseal cartilage hydrolyzes a variety of phosphate esters as well as atp and inorganic pyrophosphate. optimal activities for p-nitrophenyl phosphate, atp and inorganic pyrophosphate are found at ph 10.5, 10.0 and 8.5, respectively. the latter two substrates exhibit substrate inhibition at high concentrations. p-nitrophenyl phosphate demonstrates decreasing ... | 1979 | 40603 |
| stimulation of bull sperm hyaluronidase by polycations. | the activity of bull sperm hyaluronidase (hyaluronate 3-glycanohydrolase, ec 3.2.1.36) is increased by the inclusion of polycations in the assay mixture. at ph 3.8, bovine serum albumin and histone give the greatest stimulation, while protamine sulfate, spermine, spermidine and hyamine 2389 stimulate to a lesser extent. enzyme activity increases with serum albumin concentration to a nearly constant, high level at serum albumin concentrations greater than 1 mg/ml. other stimulatory compounds show ... | 1979 | 40604 |
| characterization of the active site of homogeneous thyroid purine nucleoside phosphorylase. | purine nucleoside phosphorylase (purine-nucleoside : orthophosphate ribosyltransferase, ec 2.4.2.1) has been purified approx. 4000-fold and to electrophoretic homogeneity from bovine thyroid glands. the isolated enzyme has a specific activity of 17 mumol . min-1 . mg-1. the native enzyme appears to have a molecular weight of 92 000 as determined by sedimentation equilibrum ultracentrifugation and is comprised of three subunits having a molecular weight of 31 000 each as shown by sodium dodecyl s ... | 1979 | 40614 |
| [radioimmunoassay of urinary oxytocin in man]. | a radioimmunoassay (ria) for oxytocin (ot) in urine is described. 125i-ot was prepared, and antibodies were raised in rabbits against ot coupled to bovine serumalbumine. this allowed us to set up of ria for ot which limit of detection is 1.25 pg/tube (0.6 microu). the use of an extraction procedure using cg50 amberlite is essential. the recovery after extraction reaches 70.5%. ph 5 is the optimum ph were urine samples must be stored. the superposition of the elution peak of endogenous ot on that ... | 1978 | 40675 |
| appearance of tyrosine hydroxylase, aromatic amino-acid decarboxylase, dopamine beta-hydroxylase and phenylethanolamine n-methyltransferase during the ontogenesis of the adrenal medulla: an immunohistochemical study in the rat. | the cellular localization of the enzymes tyrosine hydroxylase (th), aromatic amino-acid decarboxylase (or dopa decarboxylase, ddc), dopamine beta-hydroxylase (dbh) and phenylethanolamine n-methyltransferase (pnmt) in the adrenal medulla of adult rats and rat fetuses (14th, 17th, 18th, 19th and 21st day) was examined. in the prenatal stages the medullary blastema and an adjacent part of the primitive sympathetic trunk were also investigated. tissues were fixed in ice-cold 4% paraformaldehyde in 0 ... | 1979 | 40700 |
| isolation of the catalytic subunits of cyclic amp-dependent protein kinases from different mammalian tissues on the basis of charge differences of their subunits. | both, the experimental data and a literature survey presented reveal common charge differences in the subunit composition of camp-dependent protein kinases from a variety of mammalian tissues. in general, the holoenzymes (type i and ii) focus at ph 4.5-5.5, the camp-binding regulatory subunit below ph 4, whereas catalytic subunits are found at ph 6.7-9.1. for the purification of the catalytic subunits, the anionic holoenzymes of a variety of rat and rabbit organs as well as mouse and human-deriv ... | 1979 | 40861 |
| pathogenic species of the genus haemophilus and streptococcus pneumoniae produce immunoglobulin a1 protease. | thirty-seven strains of the genus haemophilus and five strains of streptococcus pneumoniae were examined for their ability to produce extracellular enzyme that cleaves immunoglobulin molecules. all strains of h. influenzae, h. aegyptius, and s. pneumoniae elaborated enzyme that selectively cleaved human immunoglobulin a1 (iga1) myeloma proteins but was inactive against a variety of other proteins including human iga2, igg, and igm, porcine and bovine secretory iga, human and bovine serum albumin ... | 1979 | 40878 |
| adherence of mycoplasma pneumoniae to glass surfaces. | attachment of m. pneumoniae to glass was quantitated in an experimental system enabling the settling down of [3h]palmitic acid-labeled cells onto glass cover slips. attachment of mycoplasmas suspended in buffer increased with temperature, decreased with higher ionic strength, and showed a maximum at about ph 5.5. the findings suggest a participation of ionic bonds in the attachment process. trypsin did not detach glass-bound mycoplasmas, and treatment of the cells with glutaraldehyde did not red ... | 1979 | 40883 |
| purification and properties of biliverdin reductases from pig spleen and rat liver. | biliverdin reductase was purified from pig spleen soluble fraction to a purity of more than 90% as judged by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. the enzyme was a monomer protein with a molecular weight of about 34,000. its isoelectric point was at 6.1-6.2. the enzyme was strictly specific to biliverdin and no other oxiodoreductase activities could be detected in the purified enzyme preparation. the purified enzyme could utilize both nadph and nadh as electron donors for th ... | 1979 | 40968 |
| the charge stoichiometry of cytochrome c oxidase in the reconstituted system. | purified cytochrome c oxidase was reconstituted into phospholipid vesicles having high internal ph buffering capacity. in the presence of valinomycin, 2 k+ ions were taken up by the vesicles per electron transferred from cytochrome c to oxygen. the charge stoichiometry of 2 was obtained from simultaneous measurement of changes of k+, h+, and oxygen in the medium after addition of the reductant ascorbate/tmpd (n,n,n',n'-tetramethyl-p-phenylenediamine). the changes in oxygen concentration were mea ... | 1979 | 40970 |
| biological amine transport in chromaffin ghosts. coupling to the transmembrane proton and potential gradients. | the effect of the transmembrane proton gradient (delta ph) and potential gradient (delta psi) upon the rate and extent of amine accumulation was investigated in chromaffin ghosts. the chromaffin ghosts were formed by hypo-osmotic lysis of isolated bovine chromaffin granules and extensive dialysis in order to remove intragranular binding components and dissipate the endogenous electrochemical gradients. upon atp addition to suspensions of chromaffin ghosts, a transmembrane proton gradient alone, ... | 1979 | 40978 |
| effects of thiols, sugars, and proteins on nitric oxide activation of guanylate cyclase. | purification of soluble guanylate cyclase from rat liver resulted in an apparent loss of enzyme activation by nitric oxide that could be restored by dithiothreitol. methemoglobin, bovine serum albumin, or sucrose. although hemoglobin also permitted some activation with nitric oxide, the effect of other agents to restore enzyme activation was prevented with hemoglobin. as a result of enzyme purification, there is an alteration of the dose-response relationship for nitric oxide activation. after p ... | 1979 | 40996 |
| humoral factor that specifically regulates factor x levels in rabbits (coagulopoietin-x). | a heat-stable humoral substance (coagulopoietin-x) is present in rabbits partially depleted of factor x, which is capable of raising factor x levels when injected into recipient rabbits. rabbits were partially depleted of factor x by slow infusion of a globulin fraction of goat anti-rabbit factor x antibody. this resulted in the reduction of factor x to 40--50% of normal at 1 h and 60--70% of normal at 6 h. no effect was noted on levels of factors ii, v, or vii. plasma from these animals, when i ... | 1979 | 41003 |
| inorganic constituents of milk: i. correlation of soluble calcium with citrate in bovine milk. | a high correlation was found between soluble calcium and citrate concentrations during a study of seasonal changes in the composition of the commercial milk supply to south-west scotland. a simple physicochemical model of the ion equilibria in the aqueous phase of milk suggests that the observed correlation is causal. this hypothesis was corroborated by an analysis of data on individual cow milks and by experiments involving the addition of citrate to milk at constant ph. | 1979 | 41007 |
| review of the progress of dairy science: the milk proteinase system. | | 1979 | 41008 |
| vitamin b12 absorption studied by vascular perfusion of rat intestine. | the study of vitamin b12 release from the ileal enterocyte has been hampered by the fact that b12 does not cross the serosa of traditional everted ileal sacs. we studied this release by perfusing the superior mesenteric arteries of starved, heparinized, etherized rats and collecting perfusate from the superior mesenteric vein. the rats were fed 57cob12 well before study. the standard perfusion medium was krebs-henseleit-nahco3 buffer containing glucose, dextran, albumin, propranolol, and dexamet ... | 1979 | 41023 |
| effects of sulfhydryl reagents on brain microtubule-associated atpase activity in vitro. | | 1979 | 41028 |
| alpha- and beta- adrenoceptors and pge2 in the modulation of catecholamine secretion from bovine adrenal medulla in vitro. | | 1979 | 41053 |
| variation in the heats of reaction of drugs and albumin with the source and pretreatment of the albumin. | | 1979 | 41083 |
| adrenergic antagonists and the presynaptic receptor hypothesis in vascular tissue. | | 1979 | 41086 |
| reactions of the sulfhydryl groups of membrane-bound bovine rhodopsin. | reactions of the sulfhydryl groups of bovine rhodopsin in rod outer segment membranes have been investigated using 4,4'-dithiopyridine. this reagent is uncharged at neutral ph and rapidly equilibrates across phospholipid bilayers. membrane-bound rhodopsin has two kinetically distinguishable sulfhydryl groups reactive to the reagent, this stoichiometry being unchanged by bleaching provided the sulfhydryl reactions themselves are carried out in the dark. the rates of the reactions, however, are su ... | 1978 | 41159 |
| effects of tannic acid and its related compounds upon chikungunya virus. | the present report describes not only the effects of tannic acid (ta; belonging to hydrolyzable tannins) and its related compounds upon the infectivity of chikungunya virus (chikv) but also the mechanism involved in this phenomenon. our data show that ta inactivates chikv in vitro. since the inactivating effect turned out to be ph-dependent and was suppressed by bovine serum albumin, it is most probable that the virus-inactivating capacity of ta is attributable to its preferential binding to pro ... | 1979 | 41164 |
| review: ethidium fluorescence assays. part 1. physicochemical studies. | dna and rna can be assayed rapidly and very sensitively by exploiting the enhanced fluorescence of ethidium intercalated into duplex regions. by assaying at different phs and introducing a heating/cooling cycle, a great many physicochemical aspects of dna and rna can be studied avoiding the use of radiolabels, and often giving information not otherwise readily obtainable. studies are described on duplex dna which involve measurement of extinction coefficients, cross-linking by chemicals, cot cur ... | 1979 | 41222 |
| ph-dependent migration of copper(ii) to the vacant zinc-binding site of zinc-free bovine erythrocyte superoxide dismutase. | bovine erythrocyte superoxide dismutase (cu(2)zn(2)sodase; superoxide:superoxide oxidoreductase, ec 1.15.1.1) consists of two identical subunits each containing cu(2+) and zn(2+) in close proximity. we describe here electron spin resonance (esr) and visible absorption spectroscopic studies of the zinc-free derivative of this protein, cu(2)e(2)sodase (e = empty) over the ph range 6-10. the esr spectrum of the zinc-free protein at 77 k is markedly ph dependent. at ph < 8.0 the esr spectrum is axia ... | 1979 | 41239 |
| characterization of the ph-dependent dimer-to-protomer transformation of cytochrome c oxidase at alkaline ph. | the ph-induced dissociation of cytochrome c oxidase from dimer to protomer has been studied in the ph range 7 to 11. findings are as follows: the heme a:copper ratio is 1.0 at both ph 7.4 and 10.6. the relative enzymatic activity is preserved at all ph values at which the dimer or protomer are found. the fraction of protomer, determined from sedimentation velocity profiles, increases from 0 to 1 as the ph is raised. the absorption and circular dichroism spectra in the soret region change in ways ... | 1979 | 41275 |
| the isoelectric point of thrombin and its behaviour compared to prothrombin at some solid surfaces. | we have shown that the isoelectric point of thrombin is high and that thrombin is a cation at the ph of blood. on the other hand, prothrombin has a low isoelectric point, being more anionic at the ph of blood. it was also found that thrombin adsorbs readily to surfaces, especially negatively charged surfaces, like behenic acid surfaces at ph 8.2. furthermore, thrombin adsorbed onto behenic acid was active in the sense that it coagulated fibrinogen. the significance of the electric charge of the ... | 1979 | 41337 |
| [isolation of anti-foot and mouth igg by means of affinity chromatography]. | the coupling of the f. m. d. antigen with unsoluble cnbr-activated sepharose (2b or 4b) induced the production of an active agent with which the specific f. m. d. antibody of the investigated solution may covalently couple. coupling procedures prove most effective with the use of buffer solutions of high ion strength that is necessary for the reduction of a protein-protein adsorption initiated by the polyoelectrolite nature of proteins. the produced complexes of the type cnbr activated sepharose ... | 1979 | 41359 |
| [breakdown of luliberin, somatostatin and substance p as an effect of hypothalamic endopeptidases]. | acid and neutral proteinases were isolated with the purpose of investigating their participation in the breakdown of hypothalamic peptides and proteins. the acid proteinase was purified about 1000-fold from hypothalamus by precipitation with acetone, chromatography on sp-sephadex g-50, gel filtration through column of g-100 and chromatography on deae-sephadex a-50. the molecular weight of the enzyme was approximately 50.000. maximal activity against hemoglobin was obtained at ph 3,2--3,5: serum ... | 1978 | 41363 |
| [heterogeneity and regulation of glutamate dehydrogenase activity in mammalian brain and liver]. | the present report concerns the study of the catalytic properties and the coenzyme affinity of glutamate dehydrogenase (gdh) and its isoenzymes in various preparations of the brain and liver as well as the different regulatory mechanisms controlling the ratio of the rates of biogenesis and breakdown of glutamate (glu). the investigations carried out showed that gdh activity of various preparations of brain and liver (crystalline enzymes, cellular extracts and mitochondria) are markedly different ... | 1978 | 41364 |
| [prostaglandins in the regulation of enzyme activity]. | | 1979 | 41375 |
| resistance of gram-negative bacteria to antibiotics in large calf agglomerations. | the antibiotic resistance of e. coli, citrobacter, enterobacter-klebsiella and pseudomonas aeruginosa strains isolated from calves was tested. a high proportion of multiresistance was found even in e. coli strains isolated from newborn calves. gram-negative bacteria isolated from animals in three large calfhouses were almost 100% resistant to ampicillin, tetracyclines and sulphonamides. multiresistance was general and varied from 5 to 12 antibiotics among different strains. initial high sensitiv ... | 1979 | 41425 |
| selective iga deficiency and circulating immune complexes containing bovine proteins in a child with chronic graft versus host disease. | we have previously shown that a selective absence of serum and secretory immunoglobulin a (iga) may lead to the development of circulating immune complexes which appear to contain bovine milk antigens. we report here that high levels of circulating immune complexes were found in the serum of a child who was treated for severe combined immunodeficiency by bone marrow transplantation but in whom the iga-producing cells subsequently failed. as increasing amounts of complexes appeared over a two yea ... | 1979 | 41453 |
| [effect of bismuth fluoride solution on bovine enamel surface (author's transl)]. | | 1978 | 41459 |
| blood and ruminal fluid profiles in carbohydrate-foundered cattle. | the relationships of acetylhistamine and histamine to the clinical signs of carbohydrate-induced acidosis were investigated in beef steers. blood ph and plasma l-lactic acid decreased and serum sodium, serum potassium, ruminal fluid l-lactic acid, ruminal fluid histamine, and ruminal fluid and blood acetylhistamine increased in carbohydrate-engorged steers as compared with the changes in the steers while feeding on pasture (forage-fed steers). twelve to 14 hours after the steers had become engor ... | 1979 | 41464 |
| a re-examination of the reaction between ox liver glutamate dehydrogenase and 1-fluoro-2,4-dinitrobenzene. | | 1979 | 41482 |
| amidino-substituted aromatic heterocycles as probes of the specificity pocket of trypsin-like proteases. | | 1979 | 41488 |
| activation of rotavirus rna polymerase by calcium chelation. | two types of particles were isolated during purification of rotavirus. dense (d) particles have a density of 1.38 in cscl and exhibit spontaneously a fully active endogenous transcriptase. light (l) particles (density of 1.36 in cscl) need to be treated with chelating agents to show a polymerase activity. the activation process of l particles was studied under strictly controlled monovalent, divalent, and hydrogen ion concentrations. these experiments demonstrate that i) activation is not affect ... | 1979 | 41504 |
| terminal transferase-like activity in human melanoma cells. | an enzyme activity, capable of attaching deoxynucleotides to single-stranded oligonucleotide primers, has been detected in extracts from cultured melanoma cells. the substrate preferences of this activity show it to be distinct from the calf thymus terminal transferase (ec 2.7.7.31). | 1979 | 41509 |
| perturbed angular correlation gamma ray (pac) spectroscopy of 111cd carboxypeptidase a alpha. | | 1979 | 41524 |
| solubilization and reconstitution of the catecholamine transporter from bovine chromaffin granules. | the catecholamine transporter from bovine chromaffin granules has been solubilized by using low concentrations of sodium cholate in the presence of phospholipids. the functional solubilized protein has been incorporated into liposomes after removal of the detergent either by gel filtration or by dialysis. reserpine-sensitive accumulation against a concentration gradient is achieved by artifically imposing a ph gradient across the membrane. in the reconstituted system adenosine 5'-triphosphate (a ... | 1979 | 41569 |
| the effect of ph on the oxygen kinetics of cytochrome c oxidase proteoliposomes. | the effect of ph on the oxygen kinetics of cytochrome c oxidase incorporated into phospholipid vesicles is studied. the ph profiles of the oxygen kinetics of energized and deenergized oxidase vesicles are similar. an effect of ph on the slope of the reciprocal plot of rate against oxygen concentration is observed, and this may indicate that protons are involved in the rate limiting step of the reaction between oxygen and reduced oxidase. in contrast to the ph dependence of the oxygen kinetics, t ... | 1979 | 41577 |
| skeletal keratan sulfate from different tissues. characterization and alkaline degradation. | keratan sulfate-rich peptides were isolated after digestion of proteoglycans from bovine nasal cartilage and bovine nucleus pulposus with chondroitinase abc, trypsin and chymotrypsin. the keratan sulfate enriched peptides from nucleus pulposus were larger than those from nasal cartilage. keratan sulfate chains were isolated after treatment of the keratan sulfate-rich peptides under alkaline, reductive conditions. proteoglycans from nucleus pulposus contain longer keratan sulfate chains, as is sh ... | 1979 | 41589 |
| studies on synaptic vesicles in mammalian brain characterization of highly purified synaptic vesicles from bovine cerebral cortex. | synaptic vesicles have been isolated from bovine cerebral cortex by sequential differential and density gradient centrifugations followed by chromatography on a sepharose 6b column. we have studied the morphology, enzymatic markers, neurotransmitter and atp contents and protein composition of the vesicles. the specific contents of acetylcholine, gamma-aminobutyric acid, aspartate, glutamate and catecholamines were 4--8-fold higher in the vesicle fraction compared to the crude synaptosomal pellet ... | 1979 | 41613 |
| noradrenaline inhibition of transmitter efflux in a renal artery preparation and the presynaptic receptor theory. | the effect of noradrenaline on the stimulation-induced efflux of tritium in cattle renal arteries preincubated with [3h]noradrenaline was determined. preparations were stimulated transmurally, with 300 shocks over a range of frequencies (1--15 hz) in the presence and absence of noradrenaline (3 x 10(-6) m). the agonist inhibited the efflux most at 1 hz but the extent of the inhibition did not vary with frequency between 2, 5, and 15 hz. it is concluded that a negative feedback system, modulating ... | 1979 | 41633 |
| bovine serum chitinase. | 1. a glycol-chitin-splitting enzyme without lysozyme (muramidase) activity has been found in calf serum. the enzyme also degrades colloidal chitin and is thus a true chitinase, 1,4-beta-poly-n-acetylglucosaminidase, without exo-beta-n-acetylglucosaminidase effect. 2. the enzyme is purified 1000-fold by ion-exchange chromatography and gel filtration. its optimal activity is between ph 1.5-2.0 with glycol chitin and between ph 3-6 in a rather broad optimum with colloidal chitin as substrate. the o ... | 1979 | 41711 |
| proton-nuclear-magnetic-resonance/ph-titration studies of the histidines of pancreatic phospholipase a2. | the study by means of 1h nuclear magnetic resonance (nmr) of the histidines of phospholipase a2 isolated from porcine, bovine and equine pancreas is reported. assignment of the histidine resonances was achieved by comparison of different enzymes and the use of paramagnetic probes. ph titration curves for various histidyl resonances were obtained and compared in the presence and absence of calcium. calcium is shown to lower the pka of the active site histidine. the nmr results are compared with t ... | 1979 | 41713 |
| ethanolamine attack of the bovine rhodopsin chromophore. | | 1979 | 41733 |
| comparative aspects of the energetics of oxidative phosphorylation in bacteria and mitochondria. | | 1979 | 41780 |
| ethyl bromoacetimidate, a nh2-specific heterobifunctional reagent. model reactions with ribonuclease. | ethyl bromoacetimidate was designed as a potential reagent for cross-linking protein nh2 groups with a vicinal nucleophile. the chemical properties of this compound were studied by model reactions with small molecules. ethyl bromoacetimidate amidinates lysine residues in ribonuclease at ph 9. in a second step, at lower ph values, one of the bromoacetamidino groups bound to the enzyme alkylates a proximal histidine residue. this substitution is ph-dependent with a sharp optimum at 5.6, the same a ... | 1979 | 41807 |
| adenosine triphosphate-dependent calcium uptake of synaptic vesicle fraction is largely due to contaminating microsomes. | ca2+ uptake by synaptic vesicle fractions isolated from bovine caudatolenticular nuclei and from rat brain was studied. the purified vesicle fractions from both materials took up very little ca2+ even in the presence of atp and mg2+, but the crude fractions took up ca2+ actively, showing the maximum uptake around ph 7.0. since the crude fractions were contaminated by microsomes, which are known to accumulate ca2+ actively (yoshida, h., kadota, k., & fujisawa, h. (1966) nature 212, 291--292; otsu ... | 1979 | 41841 |
| a growth factor from spinal cord. | mitogenic activity is present at a variety of sites in the central nervous system. a growth factor was purified from neonatal bovine spinal cord. it has a pi of 9.5-9.8 and a molecular weight of about 11,000 daltons. spinal cord growth factor is a basic polypeptide that is inactivated by extremely acid or basic conditions. its mobility on sds polyacrylamide gels suggests that this factor is different from pituitary fgf and brain fgf-1. | 1979 | 41845 |
| starter culture, temperature, and antibiotic residue in fermentation of mastitic milk to feed dairy calves. | | 1979 | 41855 |
| symposium on the chemical and nutritional aspects of dairy waste. 174th national meeting of the american chemical society, division of agricultural and food chemistry, chicago, illinois, august 1977. | | 1979 | 41863 |
| preliminary characterization of bovine pineal prolactin releasing (pprf) and release-inhibiting factors (ppif) activity. | bovine pineal glands were subjected to extraction with dilute acetic acid, gel filtration on sephadex g-25 and subsequent ultrafiltration through diaflo membranes pm10, um2 and um05. various fractions derived at each step were tested for the presence of substances which stimulate or inhibit prolactin secretion in vitro and in vivo. both prolactin releasing (pprf) and release-inhibiting (ppif) activities were observed. pprf activity was present in certain fractions derived from sephadex g-25 and ... | 1979 | 41886 |
| synthesis, assignment of absolute configuration, and receptor binding studies relevant to the neuroleptic activities of a series of chiral 3-substituted cyproheptadine atropisomers. | | 1979 | 41950 |
| dopamine receptors in bovine retina : characterization of the 3h-spiroperidol binding and its use for screening dopamine receptor affinity of drugs. | | 1979 | 41997 |
| divalent cation-induced aggregation of chromaffin granule membranes. | divalent cations induce the aggregation of chromaffin granule ghosts (cg membranes) at millimolar concentrations. monovalent cations produce the same effect at 100-fold higher concentrations. the kinetics of the dimerization phase were followed by light-scattering changes observed in stopped-flow rapid mixing experiments. the rate constant for ca2+-induced dimerization (kapp) is 0.86-1.0 x 10(9) m-1sec-1, based on the "molar" vesicle concentration. this value is close to the values predicted by ... | 1979 | 42003 |
| [thermal inactivation of milk lipoprotein lipase]. | the kinetics of thermal inactivation of cow's milk lipoprotein lipase (lpl) was studied. lpl inactivation can be described by the first order q equation. thermodynamic parameters of lpl inactivation were calculated. in the range of physiological temperatures lpl existed as two conformers. the temperature of conformation conversion was 41.5 degrees c. glycerol increased thermal stability of milk, whereas water dilution of milk, ph shift to the acid or alkaline zone, and glycine addition to milk d ... | 1979 | 42051 |
| the inhibitory effect of bovine rumen fluid on salmonella typhimurium. | the possible fate of salmonella typhimurium in the rumen was investigated by monitoring rumen volatile fatty acids (vfa), lactate concentrations and ph over periods which included regular feeding and 48 h starvation. preparations were made containing 50 per cent rumen fluid from the cow or vfa solutions, and then inoculated with s typhimurium. viable counts before and after incubation for 24 h at 37 degrees c were compared. incubation in broths with high concentrations of vfa and low ph resulted ... | 1979 | 42125 |
| [first european conference welfare of livestock animals]. | | 1979 | 42166 |
| serological evidence of ibr and bvd infection in caribou (rangifer tarandus) | | 1979 | 42188 |
| [organoleptic and biochemical changes in beef during refrigeration and storage]. | studies were carried out on the changes taking place in the organoleptic properties and the ph values of m. longissimus dorsi of carcass quarters of cattle, subjected to various ways of chilling and storage. it was found that in quickly chilled beef (immediately following slaughter) the processes of ripening were very slow, and the organoleptic indices were lower as against meat that was slowly cooled. the ph values of quickly chilled beef dropped at a very slow rate, and it was not until the ni ... | 1979 | 42194 |
| on serum as a mitogen in intact tissue. | | 1979 | 42202 |
| retinyl esterase activity of purified rat liver retinyl ester lipoprotein complex. | | 1979 | 42359 |
| comparisons between hog intestinal peroxidase and bovine lactoperoxidase-compound i formation and inhibition by benzhydroxamic acid. | | 1979 | 42360 |
| production, purification and characterization of rat interferon. | priming with heterologous mouse interferon, increased production of an antiviral substance induced in rat diploid fibroblasts by newcastle disease virus. this substance was characterized as an acid stable interferon. this rat interferon exhibited marked cross-species antiviral activity when tested in mouse l929b cells, guinea pig embryo fibroblasts, human fibroblasts and bovine cells but was not active on chick embryo cells. | 1979 | 42377 |
| interaction of calf brain tubulin with poly(ethylene glycols). | | 1979 | 42431 |
| variable proton conductance of submitochondrial particles. | the relationship between the rate of substrate oxidation and the protonmotive force (electrochemical proton gradient) generated by bovine heart submitochondrial particles has been examined. unexpectedly, oxidation of succinate generated a higher protonmotive force than the oxidation of nadh, although the rate of proton translocation across the membrane was inferred to be considerably lower with succinate as substrate. the data suggest that the flow of electrons through site 1 of the respiratory ... | 1979 | 42433 |
| on the mechanism of isotope exchange kinetics of single protons in bovine pancreatic trypsin inhibitor. | | 1979 | 42434 |
| activation of human brain galactosylceramidase by phosphatidylserine. | assays of sphingolipid hydrolases in vitro generally require bile salts or other detergents. a few 'activator proteins' have been reported that can partially replace the detergents in the assay mixture. we report here that phosphatidylserine from bovine brain is a relatively specific activator of human brain galactosylceramidase in the absence of sodium taurocholate (phosphatidylserine system). activity similar to that obtained with the conventional assay system containing taurocholate and oleic ... | 1979 | 42440 |
| the formation and thermal stability of in vitro assembled fibrils from acid-soluble and pepsin-treated collagens. | the role of the non-helical regions of the collagen molecule in fibrillogenesis has been investigated by comparing the kinetics of fibril formation of pepsin-treated acid-soluble collagen, acid-soluble collagen and mixtures of the two and by comparison of the thermal stabilities of the fibrils formed. the acid-soluble collagen was found to aggregate more rapidly than the pepsin-treated collagen under physiological conditions of ph and ionic strength. variations in ionic strength, at physiologica ... | 1979 | 42446 |
| [stability through the gastrointestinal tractus of newborns and tolerance of bovine immunoglobulines with a high agglutination titer against pathogenens e. coli given per os (author's transl)]. | | 1979 | 42509 |