Publications
| Title | Abstract | Year Filter | PMID(sorted descending) Filter |
|---|
| the g protein-gated atrial k+ channel is stimulated by three distinct gi alpha-subunits. | the guanine nucleotide-binding protein, gi, which inhibits adenylyl cyclase, has recently been shown to have three subtypes of the alpha-subunit, termed gi alpha-1, gi alpha-2 and gi alpha-3. they share 87-94% amino-acid sequence homology and so are difficult to separate from one another. among other functions, purified preparations activate k+ channels but there is confusion over which of the subtypes activates the muscarinic k+ channels of the atrial muscle of the heart: gi alpha-3, also terme ... | 1988 | 3143915 |
| effects of stroma-free hemoglobin solutions on isolated perfused rabbit hearts and isolated perfused rat kidneys. | "stroma-free" hemoglobin solutions (sfh) cause hemodynamic alterations indicative of vasoconstriction. we studied vasoconstrictor activity in isolated rabbit hearts and rat kidneys of unmodified sfh and of sfh modified by pyridoxylation or glyoxylation, with or without glutaraldehyde cross-linking. the purity and chemical composition of the solutions, all prepared by other laboratories, were not characterized by us. in isolated hearts sfh prepared by conventional methods had potent vasoconstrict ... | 1988 | 3140918 |
| effect of antiserum against aflatoxin b1-bovine serum albumin complex on aflatoxin b1-induced lysogenesis. | escherichia coli k12 bacteria lysogenic for the lambda phage were used to study the effect of antiserum against aflatoxin b1-induced lysogenesis. the antiserum was obtained from rabbits immunized with water in oil emulsion of aflatoxin b1-bovine serum albumin complex (afb1-bsa). a marked reduction in the degree of lysogenesis was observed when the antiserum was added to the reaction medium prior to microsomal enzyme activation of aflatoxin b1. there was no detectable effect when the antiserum wa ... | 1988 | 3140005 |
| expression of the bovine hypothalamic hormone oxytocin precursor in escherichia coli. | the bovine oxytocin precursor was expressed in escherichia coli as a fusion protein by cloning the hormone encoding cdna in frame behind the replicase gene of the rna phage ms2. by step-wise extraction with different urea concentrations, the fusion protein was enriched in the 7 m urea fraction and further purified by sephacryl s-300 chromatography. the oxytocin precursor was cleaved off the fusion protein by cyanogen bromide treatment, chromatographed on fplc columns and identified by western bl ... | 1988 | 3135840 |
| sites of termination of in vitro dna synthesis on cis-diamminedichloroplatinum(ii) treated single-stranded dna: a comparison between e. coli dna polymerase i and eucaryotic dna polymerases alpha. | we have compared the capacity of the large fragment of e. coli dna polymerase i and highly purified dna polymerases alpha from either drosophila melanogaster embryos or calf thymus to replicate single-stranded m13 mp10 dna treated with the antitumoral drug cis-diamminedichloroplatinum(ii) (cis-ddp). we report that: a) although prokaryotic and eukaryotic enzymes have different structural complexity and dissimilar in vivo functions, their synthesis was blocked in vitro at similar sites on cis-ddp ... | 1988 | 3132699 |
| chemical and immunological characterization of the 21-kda adp-ribosylation factor of adenylate cyclase. | the adp-ribosylation factor (arf) is a 21-kda gtp-binding protein cofactor in the cholera toxin-catalyzed adp-ribosylation of the stimulatory regulatory subunit of adenylate cyclase. purified bovine brain arf was digested with cyanogen bromide, and peptides were purified and sequenced. approximately 25-30% of the protein was sequenced in this manner. peptides contained consensus sequences for gtp-binding proteins but were distinct from any of the previously published gtp-binding proteins. antibo ... | 1988 | 3131341 |
| allosteric activation by purine nucleosides and nucleotides of the inactive by phosphatase ornithine decarboxylase of tetrahymena pyriformis. | ornithine decarboxylase (odc) of tetrahymena pyriformis is inactivated by e. coli or calf intestinal alkaline phosphatase. inactivated odc by e. coli alkaline phosphatase, form b, can be allosterically reactivated to form a by purine-nucleosides or -nucleotides at 10(-4) m concentration. inactivated odc by calf intestinal alkaline phosphatase bound to agarose can be converted to form a by purine-analogues with 10(-7) m concentration only if inorganic phosphate is included in the incubation mixtu ... | 1988 | 3130058 |
| binding and action of cecropin and cecropin analogues: antibacterial peptides from insects. | the mechanism of action of cecropin was studied by using liposomes as a model system. the bilayer was efficiently destroyed if the liposome net charge was zero or negative. cecropin analogues with an impaired n-terminal helix had reduced membrane disrupting abilities that correlate with their lower antibacterial activity. the reduced bactericidal activity of the analogues was rationalized in terms of reduced binding to bacteria. the stoichiometry of cecropin killing of bacteria suggests that amo ... | 1988 | 3128324 |
| antibody levels in milk of vaccinated and unvaccinated cows against organisms of neonatal diarrhoea. | 1987 | 3124412 | |
| inhibition of mammalian dna polymerases by recombinant alpha-interferon and gamma-interferon. | interferons (ifns) have been shown to suppress the growth of both normal and malignant cells. we examined the effect of gene-cloned ifn-alpha and ifn-gamma on the in vitro activities of human, calf, or rat dna polymerases. ifn-alpha strongly inhibited the reactions of dna polymerase alpha and beta at apparent ki values of 1.25 and 0.35 x 10(5) antiviral units/ml, respectively, but inhibited dna polymerase gamma only slightly. ifn-gamma inhibited the reaction of dna polymerase alpha more strongly ... | 1987 | 3117359 |
| selective alteration of substrate specificity by replacement of aspartic acid-189 with lysine in the binding pocket of trypsin. | to test the role of asp-189 which is located at the base of the substrate binding pocket in determining the specificity of trypsin toward basic substrates, this residue was replaced with a lysine residue by site-directed mutagenesis. both rat trypsinogen and lys-189 trypsinogen were expressed and secreted into the periplasmic space of escherichia coli. the proteins were purified to homogeneity and activated by porcine enterokinase, and their catalytic activities were determined on natural and sy ... | 1987 | 3111531 |
| identification of brucella abortus in formalin-fixed, paraffin-embedded tissues of cows, goats, and mice with an avidin-biotin-peroxidase complex immunoenzymatic staining technique. | an avidin-biotin-peroxidase complex immunoenzymatic staining technique was evaluated for light microscopic detection of brucella organisms in formalin-fixed, paraffin-embedded tissues. tissues from cows, goats, and mice inoculated with b abortus strain 2308 were examined, using rabbit antiserum to brucella cell surface protein as primary antibody. stained organisms were identified histologically in tissue sections containing b abortus, as detected by bacteriologic examination of duplicate nonpro ... | 1986 | 3096172 |
| cloning and sequence of a cdna coding for the human beta-migrating endothelial-cell-type plasminogen activator inhibitor. | a lambda gt11 expression library containing cdna inserts prepared from human placental mrna was screened immunologically using an antibody probe developed against the beta-migrating plasminogen activator inhibitor (beta-pai) purified from cultured bovine aortic endothelial cells. thirty-four positive clones were isolated after screening 7 x 10(5) phages. three clones (lambda 1.2, lambda 3, and lambda 9.2) were randomly picked and further characterized. these contained inserts 1.9, 3.0, and 1.9 k ... | 1986 | 3092219 |
| cloning, sequence, and expression of bovine interferon-gamma. | bovine interferon-gamma (ifn-gamma) sequences have been isolated by screening a cdna library with a human ifn-gamma cdna probe. the cdna library was constructed from rna isolated from concanavalin a-stimulated bovine lymph node cells. the open reading frame predicts that the bovine ifn-gamma precursor is composed of 166 amino acids with a predicted m.w. of 19,393. alignment of the amino acid sequence with human ifn-gamma indicates that mature bovine ifn-gamma is composed of 143 amino acids with ... | 1986 | 3086437 |
| relationship between serologic recognition of escherichia coli 0111:b4 (j5) and clinical coliform mastitis in cattle. | serum igg1 elisa titers recognizing gram-negative core antigens (escherichia coli [j5]) were studied at a large dairy in central california. population mean log10 titer was 2.7357 (equivalent to 1:544) with a se of 0.03843. titers increased with increased lactation number (unstandardized regression coefficient = 0.06733). changes in lactation number accounted for only 6.77% of titer variation. titers less than 1:240 were associated with 5.33 times the risk of clinical coliform mastitis. also, ol ... | 1988 | 3073679 |
| thermal inactivation of campylobacter species, yersinia enterocolitica, and hemorrhagic escherichia coli o157:h7 in fluid milk. | heat treatment of raw milk in an htst pasteurizer operated at 60.0 to 72.0 degrees c for a minimum holding time of 16.2 s rapidly inactivated mixtures of hemorrhagic escherichia coli o157:h7, yersinia enterocolitica and campylobacter spp. (c. fetus, c. coli, and c. jejuni). each of the three genera in the mixture was inoculated at a level of approximately 1.0 x 10(5) cfu/ml. at 60.0 degrees c, hemorrhagic e. coli showed a maximum 2 log10 reduction in counts and no viability at greater than or eq ... | 1988 | 3069886 |
| proteolytic cleavage of ada protein that carries methyltransferase and transcriptional regulator activities. | the 39-kda ada protein that carries two distinct methyltransferase activities and an activity to promote transcription of the ada and alka genes is cleaved to smaller polypeptides in the case of incubation with a crude extract of escherichia coli. a protease that specifically cleaves the ada protein was partially purified and characterized. the enzyme showed maximal activity at ph 7.8-8.0 and did not require specific ions or atp for the reaction. the activity was inhibited by p-chloromercuribenz ... | 1988 | 3058696 |
| colitis in calves: natural and experimental infection with a verotoxin-producing strain of escherichia coli o111:nm. | verotoxin-producing escherichia coli o111:nm were isolated from two five week old holstein calves with dysentery. on necropsy both calves had pseudomembranous ileitis, mucohemorrhagic colitis and proctitis. large numbers of e. coli o111:nm were isolated from the colon and lesions typical of attaching-and-effacing e. coli were evident. the isolates from both calves had identical biochemical reactions and antimicrobial resistance patterns. oral inoculation of a four day old colostrum deprived calf ... | 1988 | 3058279 |
| characters of escherichia coli 078 isolated from septicaemic animals. | twenty-one escherichia coli isolates of serogroup 078 from animal septicaemia were obtained from laboratories in france, england and canada. the bacteria were compared for outer membrane protein (omp) patterns, lipopolysaccharide patterns, surface proteins of fimbrial types, biotypes, antibiotypes, colicin production, hydroxamate production and virulence in mice. sixteen isolates from bovine, ovine, porcine and avian species in france and england had a similar omp pattern. this characteristic as ... | 1988 | 3055657 |
| [clinical and bacteriologic studies of the frequency of mastitis during and after parturition in heifers lactating for the first time]. | the udders of 100 heifers were examined for clinical changes during parturition. of each quarter colostral samples were taken and analyzed bacteriologically. 35 heifers (13.5% of the quarters) showed clinical changes of the quarters and/or of colostral samples. 14 of these animals (4.75% of the quarters) suffered from cellulitis-like mastitis. 13 (5.25% of the quarters) had acute catarrhalic mastitis and eight heifers (3.5% of the quarters) showed acute galactophoritis. in all milk samples of an ... | 1988 | 3055422 |
| pharmacokinetics of single doses of cefoxitin given by the intravenous and intramuscular routes to unweaned calves. | cefoxitin pharmacokinetics and bioavailability were studied in unweaned calves. the antibiotic was administered to nine calves intravenously (i.v.), to seven calves intramuscularly (i.m.) at 20 mg/kg and to eight calves i.m. at 20 mg/kg together with probenecid at 40 mg/kg. serum concentration versus time data were analysed using statistical moment theory (smt). the i.v. data were also fitted by a linear, open two-compartment model. the elimination half-life (t1/2) was 66.9 +/- 6.9 min (mean +/- ... | 1988 | 3054149 |
| evidence for interaction of an aminoacyl transfer rna synthetase with a region important for the identity of its cognate transfer rna. | recent experiments showed that a single base pair (g3:u70) in the amino acid acceptor helix is a major determinant for the identity of escherichia coli alanine transfer rna. experiments reported here show that bound alanine trna synthetase protects (from ribonuclease attack) seven consecutive phosphodiester linkages on the 3'-side of the acceptor-t psi c helix (phosphates 65-71) and a few additional sites that are in scattered locations. there is no evidence for interaction of the enzyme with th ... | 1988 | 3053691 |
| non-radioactive oligonucleotide probe for detection of clinical enterotoxigenic escherichia coli isolates of bovine origin. | oligonucleotides (32 or 34 mer) corresponding to enterotoxigenic escherichia coli stia (st-p) toxin gene were tailed with bio-11-dutp using terminal deoxynucleotidyl transferase. plasmids from clinical e. coli isolates were prepared by modified rapid alkaline lysis procedure and dot-spotted. biotinylated oligonucleotide probes were hybridized to detect the stia toxin gene. the results were in agreement with that obtained by radioactive oligonucleotide probes. of 135 clinical isolates (sampled fr ... | 1988 | 3052531 |
| triacylglycerol output by the isolated perfused liver of endotoxin-treated rats. | liver perfusion experiments were performed to further investigate the origin of hypertriacylglycerolemia associated with endotoxemia in rats. for this purpose male rats were treated with e. coli endotoxin in a dose of 0.5 mg/100 g b.w. intravenously, deprived of food (with free access to water), and used 18 h later for liver perfusion experiments. livers were isolated and perfused for 4 h with a medium consisting of krebs-ringer bicarbonate buffer containing bovine serum albumin (4%, w/v), gluco ... | 1988 | 3048767 |
| cdna cloning and sequence analysis of a chicken gene expressed during the gonadal development and homologous to mammalian cytochrome p-450c17. | a cdna clone, ploa0511, was isolated from the cdna library prepared from the left ovaries of one- to three-day-old chickens. the transcript corresponding to this cdna clone is approx. 1.9 kb in length and is present in steroidogenic tissues (ovary, testis and adrenal gland) but is undetectable in non-steroidogenic tissues. relative abundance of the transcript in the ovary and testis is high and developmentally regulated but is much lower in the adrenal gland. relative levels of this transcript i ... | 1988 | 3047010 |
| inhibition of parathyroid hormone bioactivity by human parathyroid hormone (pth)-(3-84) and pth-(8-84) synthesized in escherichia coli. | human pth (hpth)-(3-84) and hpth-(8-84) were synthesized in escherichia (e.) coli when the cells were transformed with a multicopy plasmid in which the transcription of human prepropth cdna is directed by the e. coli lac promoter. pth fragments were extracted from cells and purified by reverse phase hplc. pth bioactivity and pth antagonist activity were estimated in a renal cytochemical bioassay. hpth-(3-84) and hpth-(8-84) exhibited less than 1% and less than 0.1%, respectively, of the biologic ... | 1988 | 3046927 |
| effect of ph changes on the killing of staphylococcus aureus and other mastitis pathogens by bovine neutrophil granule extracts. | a partly purified extract of granules from bovine neutrophils was used to investigate killing of mastitis pathogens by the non-oxidative killing system of the neutrophil. eight strains of staphylococcus aureus, two of escherichia coli and two of streptococcus uberis were used. different strains of bacteria had different sensitivities to killing by the extract, three strains of staphylococci being particularly resistant. whereas e coli were killed most effectively at ph 6.0, little or no killing ... | 1988 | 3043603 |
| a glycolipid precursor of bacterial lipopolysaccharide (lipid x) lacks activity against endothelial cells in vitro and is not toxic in vivo. | lipid x (2,3-diacylglucosamine-1-phosphate) accumulates in mutants of escherichia coli incapable of assembling the disaccharide backbone of lipid a, the principle endotoxic moiety of bacterial lipopolysaccharide (lps). we compared the effects of lipid x on cultured bovine aortic endothelial cell (bec) viability and prostacyclin (pgi2) release with those of lipid a and lps. at 10(-5) m, both lps and lipid a produced significant bec cytotoxicity (percentage cytotoxicity 69 +/- 4 for lps and 51 +/- ... | 1988 | 3043110 |
| [epidemiology of diarrhea caused by escherichia coli and rotavirus in calves and lambs in morocco]. | an epidemiological survey on e coli and rotavirus associated diarrheas in one to twenty five days old calves and lambs was made in three regions: rabat-kenitra, marrakech and agadir. isolated e coli k99 stains have been studied of a biochemical, serotypical (o antigen) and antibiotypical point of view. the identification of rotavirus was made by elisa test. persistence of k99 antigen and heat stable toxin a was examined after a conservation of 5 weeks at - 18 degrees c. the frequency of e coli k ... | 1988 | 3041900 |
| effect of vaccination of the dam on rotavirus infection in young calves. | vaccination of cows with a combined, inactivated, adjuvanted rotavirus and escherichia coli vaccine resulted in increased neutralising antibody titres to rotavirus in serum and colostral whey. evidence was obtained that vaccination resulted in a decreased incidence of rotavirus shedding and of abnormal faeces or diarrhoea in young calves fed colostrum and milk from the vaccinated dams. the e coli component of the vaccine was not evaluated because no natural challenge was evident. | 1987 | 3033870 |
| shedding of enteric coronavirus in adult cattle. | electron microscopic examination of fecal specimens from adult dairy cows indicated seasonal coronavirus shedding. fifty-two cows from a 300 cow herd were monitored for shedding of coronavirus. approximately 50% to 60% of the cows monitored shed coronavirus during the winter months (november to march) of the first year of the study. during 2 subsequent years of monitoring the same cows, 20% to 30% of the cows shed coronavirus during the winter months. virus shedding was not detected during the s ... | 1987 | 3032023 |
| [a new polyvalent vaccine against enteral infections in newborn calves]. | the most frequent microbial causative agents of massive diarrheas in new-born calves kept on large cattle farms in the cssr are rotaviruses, coronaviruses and enterotoxigenic strains of e. coli, manifesting themselves as complicated virus-bacterial infections. an inactivated polyvalent adjuvant vaccine has been developed for the prevention and specific prophylaxis of these enteral infections; the vaccine contains bovine rotavirus, bovine coronavirus and three enterotoxigenic serotypes of e. coli ... | 1987 | 3029935 |
| a mutated bovine prochymosin zymogen can be activated without proteolytic processing at low ph. | as a first step towards understanding how the zymogen structure of prochymosin contributes to the process by which active enzyme is produced, we altered the nucleotide sequence which encodes the amino-terminal (or propeptide) region of the protein. of the two sites for autoproteolysis of prochymosin, one where pseudochymosin is formed at a ph of 2 and the other where chymosin is formed at ph 4-5, we changed the former by removing one codon and changing two other codons. this genetically modified ... | 1986 | 3023316 |
| probable occurrence of brain basic protein factor i, an activator of phosphoprotein phosphatases. | basic protein factor i (bpfi was purified to homogeneity from bovine brain by boiling and trichloroacetic acid-precipitation of tissue homogenate, followed by deae-cellulose, sephadex g-150, affi-gel-phenothiazine, and bio-gel p-6dg chromatographic procedures. the preparation appeared as a single protein band in the sds-polyacrylamide gel electrophoresis with a minimal mr of 13,200. the factor was a basic protein as indicated by an estimated isoelectric point of ph 8.3 and a high content of amin ... | 1986 | 3019610 |
| evaluation of a combined rotavirus and enterotoxigenic escherichia coli vaccine in cattle. | a vaccine of rotavirus and k99 antigen from enterotoxigenic escherichia coli was emulsified in oil adjuvant and administered intramuscularly to pregnant cows. calves born to and reared on vaccinated dams were protected against experimental rotavirus infection at five days old when compared with calves from unvaccinated control cows. field trials of the vaccine were carried out in 40 commercial herds, in which half the cows in each herd were selected at random for vaccination and half were left u ... | 1986 | 3018989 |
| biological activities and receptor binding of two human recombinant interferons and their hybrids. | two human recombinant lymphoblastoid interferon-alpha subtypes, lyifn-b (alpha 8) and lyifn-d (alpha 1), and 10 hybrids generated therefrom were produced in escherichia coli and purified. the antiviral and antiproliferative activities and the induction of (2'-5')oligoadenylate synthetase were compared to their receptor binding affinities. the ifn subtypes and their hybrids had similar specific antiviral activities on bovine cells. on human cells both the specific antiviral and antiproliferative ... | 1986 | 3016158 |
| catalytic properties of the hhaii restriction endonuclease. | the catalytic properties of the hhaii restriction endonuclease were studied using plasmid psk11 dna containing a single 5'-g-a-n-t-c hhaii cleavage site as substrate. reactions were followed by two methods: 1) gel electrophoretic analysis of nicked circular and linear dna products, or 2) release of 32p-labeled inorganic phosphate from specifically labeled hhaii sites in a reaction coupled with bacterial alkaline phosphatase. the enzyme is optimally active at 37 degrees c in 10 mm tris-hcl (ph 9. ... | 1985 | 2999112 |
| possible mechanism of the allosteric activation of camp receptor protein. | secondary structure of camp receptor protein of e. coli was predicted and compared to its crystal structure in the complex with camp solved by mckay and steitz. the two conformations coincide in the dna binding domain but strikingly differ in the other domain which binds camp and causes protein dimerization. the comparison indicates that camp destabilizes a very long helix instead of which sheets are formed creating a hydrophobic pocket where camp binds. consequently, the helix-sheets isomerizat ... | 1985 | 2996527 |
| the cytochrome c oxidase test for the rapid detection of psychrotrophic bacteria in milk. | a new, rapid, simple and cheap method for the detection of the predominant psychrotrophic bacteria in raw and pasteurized milks is described, using tetramethyl-p-phenylene-diamine dihydrochloride to detect cytochrome c oxidase which in general is not present in the non-psychrotrophic bacterial milk flora. the test is sensitive to samples containing over 10(4) organisms/ml. correlation coefficients of 0.92 and 0.84 between dye oxidation and viable counts for pasteurized and raw milk samples, resp ... | 1985 | 2995302 |
| high spontaneous mutation frequency of bpv shuttle vector. | a recombinant shuttle vector containing the entire bovine papillomavirus (bpv) genome, sequences from pbr322, and the escherichia coli gpt gene was used to transform mouse c127 cells. plasmid extracted from the transformed mouse cells was used to transform a gpt- derivative of e. coli hb101, and the relative frequency of plasmids carrying a mutation in the gpt gene was determined. approximate mutant frequencies of 3-16 x 10(-3) were observed for plasmid molecules which had been passaged through ... | 1985 | 2994240 |
| nucleotide sequence of yeast gdh1 encoding nicotinamide adenine dinucleotide phosphate-dependent glutamate dehydrogenase. | the yeast gdh1 gene encodes nadp-dependent glutamate dehydrogenase. this gene was isolated by complementation of an escherichia coli glutamate auxotroph. nadp-dependent glutamate dehydrogenase was overproduced 6-10-fold in saccharomyces cerevisiae bearing gdh1 on a multicopy plasmid. the nucleotide sequence of the 1362-base pair coding region and 5' and 3' flanking sequences were determined. transcription start sites were located by s1 nuclease mapping. regulation of gdh1 was not maintained when ... | 1985 | 2989290 |
| characterization of the dna of the hamster papovavirus: ii. a comparison of binding sites for escherichia coli- and calf thymus rna polymerase ii on the hamster papovavirus genome. | calf thymus (ct) rna polymerase ii bound to hamster papovavirus (hapv) dna was visualized by electron microscopy and compared to binding sites obtained after binding of escherichia coli rna polymerase to the hapv genome. thirteen binding sites were observed with ct polymerase ii at map positions 0.04-0.07; 0.11; 0.18; 0.30; 0.37; 0.47; 0.57; 0.65; 0.78; 0.83; 0.90 and 0.94 using the unique bamhi cleavage site as zero point on the hapv physical map. these binding sites correlate well with a + t r ... | 1985 | 2988523 |
| dna polymerase alpha and models for proofreading. | using a modified system to measure fidelity at an amber site in phi x174, we have employed dna polymerase alpha to test different mechanisms for proofreading. dna polymerase alpha does not exhibit the characteristics of "kinetic proofreading" seen with procaryotic polymerases. polymerase alpha shows no evidence for a "next nucleotide" effect, and added deoxynucleoside monophosphates do not alter fidelity. pyrophosphate, which increases error rates with a procaryotic polymerase, appears to weakly ... | 1985 | 2987791 |
| the dna restriction endonuclease of escherichia coli b. ii. further studies of the structure of dna intermediates and products. | the dna intermediates and final products formed by the type i restriction endonuclease, ecob, were further characterized. dna cleaved on only one strand (hemi-restricted dna) contains gaps of approximately 70-100 nucleotides, while the fully restricted products contain 3'-single-stranded tails averaging approximately 70-100 nucleotides for each strand cleaved. the gaps and tails are formed with the release of an equal number of nucleotides as small oligonucleotides that are soluble in acid. afte ... | 1985 | 2985610 |
| the dna restriction endonuclease of escherichia coli b. i. studies of the dna translocation and the atpase activities. | electron microscopic examination of dna intermediates formed by the restriction endonuclease of escherichia coli b revealed supercoiled loops that are presumably formed during an atp-dependent dna translocation process in which the enzyme remains bound to the recognition site while tracking along the dna helix to a cleavage site. the rate of dna translocation during this process is at least 5000 base pairs/min at 37 degrees c. even after all cleavages have been completed, complexes are seen that ... | 1985 | 2985609 |
| a field trial to evaluate the efficacy of a combined rotavirus-coronavirus/escherichia coli vaccine in dairy cattle. | a field trial was designed to determine the efficacy of a combination rotavirus-coronavirus/escherichia coli vaccine on dairy farms in southwestern ontario. in part a of the trial, 321 cows on 15 farms were randomly assigned to either vaccination or placebo groups. on eight farms, 50% of the dams were vaccinated, while on the other seven farms, 80% of the dams were vaccinated. in part b of the trial, 26 farms were randomly assigned to either a total vaccination program or to no vaccination progr ... | 1985 | 2985213 |
| virulence factors and markers in escherichia coli from calves with bacteremia. | relative pathogenicity of 151 escherichia coli isolates from 36 calves with bacteremia after necropsy was studied by measurement of the ld50 after mice were inoculated ip with e coli isolates. study of virulence factors and markers revealed that the pathogenicity of e coli was associated with the production of hydroxamate siderophores and with resistance to serum bactericidal effects. production of colicins, including colicin v, and of surface antigen 31a was correlated with virulence. the close ... | 1988 | 2973271 |
| isolation and characterization of the bos taurus beta-casein gene. | the expression of casein genes in the mammary cells is regulated by peptide and steroid hormones. to investigate the controlling mechanisms we have isolated and characterized the bovine beta-casein gene. the gene has the size of 8.6 kb, which is 7.8 times longer than the corresponding mrna composed of nine exons. the genomic clones include additional 8.5-kb and 4.5-kb sequences of the 5'- and 3'-flanking regions. we have determined the sequences of the 5' and 3' ends of the gene and compared the ... | 1988 | 2970989 |
| cloning and expression of cdna for human endonexin ii, a ca2+ and phospholipid binding protein. | endonexin ii is a member of the family of ca2+-dependent phospholipid binding proteins known as annexins. we cloned human endonexin ii cdna and expressed it in escherichia coli. the apparent size and ca2+-dependent phospholipid binding properties of purified recombinant endonexin ii were indistinguishable from those of the placental protein. a single mrna of approximately 1.6 kilobase pairs was found to be expressed in human cell lines and placenta and was in close agreement with the length of t ... | 1988 | 2967291 |
| differences in excretion and efficiency of the aerobactin and enterochelin siderophores in a bovine pathogenic strain of escherichia coli. | secretion of aerobactin is thought to play an important part in the virulence of invasive escherichia coli also capable of synthesizing enterochelin. why, despite its markedly lower affinity for iron than that of enterochelin, aerobactin proves to be the predominant active siderophore for bacterial growth in transferrin was investigated. we studied the action of two iron chelators, 2,2'-dipyridyl and transferrin, in expression of the aerobactin and enterochelin genes. specifically, we describe t ... | 1988 | 2962945 |
| lipocortin-like anti-phospholipase a2 activity of endonexin. | endonexin (protein ii, 32.5 kda) has been purified to homogeneity from bovine liver in the following steps: selective extraction by egta from membranes precipitated with triton x-100/calcium; chromatography on deaf-tsk 545 at ph 7.0, endonexin being eluted at 0.1 m nacl; affinity chromatography on polyacrylamide-immobilized phosphatidylserine; gel filtration on tsk 3000. the amino acid composition was essentially similar to that previously reported. using [3h]oleic acid-labelled escherichia coli ... | 1987 | 2953628 |
| dual-origin plasmids containing an amplifiable cole1 ori; temperature-controlled expression of cloned genes. | dual-origin plasmids comprising an inducible cole1-derived origin of replication controlled by the lambda pr promoter, the ci857 temperature-sensitive repressor gene and the psc101 origin of replication and its associated par sequence, were constructed. such plasmids carrying cloned genes were stably maintained at four copies per chromosome, and were readily amplifiable by thermal induction. cloned gene expression increased with copy number, and accumulation values of greater than 20% total cell ... | 1986 | 2952556 |
| in vitro biological activities of escherichia coli-derived bovine interferons-alpha, -beta, and -gamma. | the infectious yields of several bovine viruses were inhibited in bovine cells treated with purified preparations of e. coli-derived bovine interferons (boifns)-alpha, -beta, and -gamma. boifn-beta 2, encoded by one member of the boifn-multigene family, had more potent antiviral and antiproliferative activities than the product of one member of the class-i ifn-alpha gene family (boifn-alpha i1). boifn-beta 2 also completed more effectively than boifn-alpha i1 with huifn-alpha i2 for cell-surface ... | 1986 | 2939154 |
| nucleotide sequence of the gdh gene coding for the nadp-specific glutamate dehydrogenase of saccharomyces cerevisiae. | the isolation of the saccharomyces cerevisiae gene for nadp-dependent glutamate dehydrogenase (nadp-gdh) by cross hybridization to the neurospora crassa am gene, known to encode for nadp-gdh is described. two dna fragments selected from a yeast genomic library in phage lambda gt11 were shown by restriction analysis to share 2.5 kb of common sequence. a yeast shuttle vector (cv13) carrying either to the cloned fragments complements the gdh- strain of s. cerevisiae and directs substantial overprod ... | 1985 | 2932370 |
| flotation of mastitis pathogens with cream from subclinically infected quarters. prospects for developing a cream-rising test for detecting mastitis caused by major mastitis pathogens. | bacterial isolates, originating from 36 subclinically infected quarter milk samples, were labelled with 75se and checked for cream-rising at various temperatures in a system analogous to the abr test ("abortus bang ringprobe"; the cream-rising test based on stained brucella organisms for detection of brucellosis). diagnostic specificity and sensitivity were analyzed in experiments where labelled bacterial isolates were mixed with a number of quarter milk samples with known bacteriological status ... | 1989 | 2929195 |
| fimbria-like adhesive factor (eaf 44) from verocytotoxigenic escherichia coli of bovine origin. | an adhesin with fimbria-like properties was present in four strains of verocytotoxigenic escherichia coli isolated from diarrhoeic calves in brazil. | 1988 | 2905510 |
| the beta-subunit of the bovine mitochondrial f1 atpase specifically binds the amino terminal domain of parathyroid hormone. | a protein which specifically binds the amino terminal domain of parathyroid hormone (pth) on nitrocellulose blots of polyacrylamide gels was fragmented with cyanogen bromide (cnbr), and two fragments were sequenced through 20 residues. the sequence obtained was 100% homologous with the beta-subunit of bovine f1 mitochondrial atpase. purified f1 atpase from bovine heart and escherichia coli were obtained and the binding of pth examined on the blots. the beta-subunit of the bovine enzyme bound pth ... | 1988 | 2904385 |
| cs31a, a new k88-related fimbrial antigen on bovine enterotoxigenic and septicemic escherichia coli strains. | the nature of the common surface antigen of six hemagglutinating and adhesive piliated escherichia coli strains isolated from diarrheic or septicemic calves was studied. by electron microscopy studies, the e. coli surface antigen designated cs31a was found on bacterial cells and in purified form to consist of thin (2-nm) "fibrillar" fimbriae. e. coli 31a, which was cured of a 105-megadalton plasmid, failed to express cs31a fimbriae, but retained the ability to hemagglutinate and to adhere in vit ... | 1988 | 2899553 |
| protective antigens against enterotoxigenic escherichia coli o101:k99,f41 in the infant mouse diarrhea model. | protective antigens present in whole cells of bovine enterotoxigenic escherichia coli strains were tested in an infant mouse diarrhea model. reduction of mortality rates of infant mice suckling vaccinated mothers was measured 1, 2, and 5 days after oral challenge with strain b41 (o101:k99,f41:h-). vaccines consisted of strains of serogroup o101, o9, o8, or o20 and of variants bearing or not bearing antigens k99 and f41. k99 and f41 expressions were checked by slide agglutination with k99 and f41 ... | 1988 | 2895746 |
| incidence and some characteristics of fimbriae fy and 31a of escherichia coli isolates from calves with diarrhea in japan. | escherichia coli isolates from calves with diarrhea (1 day to 8 weeks old, 140 individuals) were surveyed for the three immunologically distinct fimbrial adhesins fy, 31a, and k99. of a total of 1,370 strains isolated, 96 (7.0%), 34 (2.5%), 75 (5.5%), and 13 (0.9%) were identified as fy+, 31a+, fy+.31a+, and k99+, respectively. the k99+ strains also manifested heat-stable enterotoxin production (st+), while fy+, 31a+, and fy+.31a+ strains were st-. expression of fy and 31a was repressed at lower ... | 1987 | 2889130 |
| cattle as reservoir of verotoxin-producing escherichia coli o157:h7. | 1987 | 2886741 | |
| receptor-specific agglutination tests for detection of bacteria that bind globoseries glycolipids. | specific binding to the globoseries of glycolipid receptors explains the adherence of uropathogenic escherichia coli to host cells. the minimal receptor disaccharide gal alpha 1----4gal beta [galactose alpha (1----4)galactose beta] is recognized by most attaching clinical isolates. however, wild-type isolates can express adhesins with several different receptor specificities. bioassays do not permit separate analysis of each receptor specificity, since the target cells contain multiple potential ... | 1987 | 2880867 |
| monoclonal antibody passive hemagglutination and capture enzyme-linked immunosorbent assays for direct detection and quantitation of f41 and k99 fimbrial antigens in enterotoxigenic escherichia coli. | production of diarrhea in neonatal calves by enterotoxigenic escherichia coli depends on its ability to attach to the epithelial cells of the intestine via surface adhesins called pili or fimbriae and to secrete enterotoxins. the most important of these fimbriae are designated k99 and f41. we produced and characterized a murine monoclonal antibody specific to f41. this monoclonal antibody and a k99-specific monoclonal antibody were used to develop sensitive and specific passive hemagglutination ... | 1987 | 2880866 |
| f41 pili as protective antigens of enterotoxigenic escherichia coli that produce f41, k99, or both pilus antigens. | pigs suckling dams that have been vaccinated with pilus antigen are protected against challenge with enterotoxigenic escherichia coli (etec) strains that express the same pilus antigen. however, some etec strains express more than one pilus antigen. pregnant swine were vaccinated either with e. coli hb101 that harbored a recombinant plasmid coding for f41 expression (f41+) or with the hb101 parent strain that carries the phc79 vector (f41-). suckling pigs born to vaccinated dams were challenged ... | 1987 | 2880807 |
| stimulation of human polymorphonuclear leukocyte oxidative metabolism by type 1 pili from escherichia coli. | we compared the degree to which escherichia coli phase variants which do (t1p+ e. coli) or do not (t1p- e. coli) express type 1 pili (t1p) stimulate human polymorphonuclear leukocyte (pmn) oxidative activity. unopsonized t1p+ e. coli stimulated the release of 0.20 to 0.24 nmol of h2o2 per 10(6) pmn per min and the consumption of 1.4 to 4.0 nmol of o2 per 10(6) pmn per min; no measurable pmn oxidative activity was stimulated by unopsonized t1p- e. coli. in the presence of serum opsonins, t1p+ e. ... | 1987 | 2880806 |
| isolation of escherichia coli o157:h7 from dairy cattle associated with two cases of haemolytic uraemic syndrome. | 1986 | 2877210 | |
| additive protective effects of colostral antipili antibodies in calves experimentally infected with enterotoxigenic escherichia coli. | with oral infection of calves by an enterotoxigenic escherichia coli strain carrying k99, f41, and fy adhesins, colostrums from cows vaccinated against either k99+f41 or fy did not provide protection, but a mixture of the two colostrums did. the association of antibodies directed against the different adhesins is more effective than antibodies directed against one adhesin alone for colostral protection against enterotoxigenic e. coli carrying several adhesins. | 1985 | 2866162 |
| high performance liquid chromatography purification and amino terminal sequence analysis of the subunits of bovine heart mitochondrial f1-atpase. | all five subunits of bovine heart mitochondrial f1-atpase have been isolated by reverse-phase hplc and nh2-terminal sequences determined by gas phase edman degradations. bovine gamma exhibits 16 identities in the first 30 residues compared with the nh2-terminus of gamma from e.coli f1. bovine delta exhibit about 27% identity with residues 28-59 of precursor delta from n.crassa and in the first six residues is identical with delta from s.cerevisiae. approximately half of bovine epsilon has been s ... | 1985 | 2864928 |
| expression of human terminal deoxynucleotidyl transferase in escherichia coli. | a cloned dna fragment related to pt17 containing a partial cdna sequence of human terminal deoxynucleotidyl transferase was used as a probe to screen for the full length cdna sequence of the enzyme in a lambda gt11 library constructed from human lymphoblastoid km-3 cdna. a recombinant containing a 2068-base pair insert was isolated and recloned into the ecori site of the sequencing plasmic puc-8 as two subclones, pt711 and pt106. dna sequencing and hybridization studies showed that pt711 contain ... | 1985 | 2863268 |
| the use of [3h]aniline to identify the essential carboxyl group in the bovine mitochondrial f1-atpase that reacts with 1-(ethoxycarbonyl)-2-ethoxy-1,2-dihydroquinoline. | the inactivation of the bovine heart mitochondrial f1-atpase with 1-(ethoxycarbonyl)-2-ethoxy-1,2-dihydroquinoline (eedq) in the presence of [3h]aniline at ph 7.0 led to the covalent incorporation of 3h into the enzyme. when the atpase was inactivated by 94% with 0.9 mm eedq in the presence of 3.6 mm [3h]aniline in a large-scale experiment in which the protein concentration was 21 mg/ml, 4.2 mol [3h]anilide were formed per mol enzyme, of which 0.35 mol was incorporated per mol of the alpha subun ... | 1985 | 2862844 |
| [anti-k99 vaccination and colostric protection of calves infected experimentally with escherichia coli k99]. | colostral antibodies of cows vaccinated with e. coli b41 (o101: k99, f41) protect completely b41 experimentally infected calves. in order to know more precisely the role of k99, f41 antibodies in protection, calves receiving the colostrum of b41 vaccinated cows are infected with e. coli b44 (o9: k30: h-k99, f41). vaccination multiplies k99 antibodies in colostrum by seven. in b44 infected calves, specific k99, f41 antibodies protect only 3 out of 6 calves completely. additive effect of antibodie ... | 1985 | 2861786 |
| [frequency of fy and k99 pili in strains of escherichia coli isolated from diarrheal calves in france]. | epidemiological study of bovine e. coli shows that the fy e. coli pilus which has previously been described and is also known as att25, can be found in 30 of 415 fecal samples of diarrheic calves, eight of them carrying both fy and k99 pili. the k99 e. coli pilus is present in 86 fecal samples. strains carrying both fy and k99 pili account for 9% of k99 enterotoxigenic e. coli. k99-, fy+ e. coli do not produce the thermostable enterotoxin (tsa). k99+, fy- or k99+, fy+ e. coli are present mainly ... | 1985 | 2861785 |
| inactivation of escherichia coli glutamine synthetase by xanthine oxidase, nicotinate hydroxylase, horseradish peroxidase, or glucose oxidase: effects of ferredoxin, putidaredoxin, and menadione. | previous studies have shown that several mixed-function oxidation (mfo) systems are capable of catalyzing the inactivation of glutamine synthetase (gs) [r.l. levine, c. n. oliver, r. m. fulks, and e. r. stadtman (1978) proc. natl. acad. sci. usa 78, 2120-2124] and a number of the other enzymes [l. fucci, c. n. oliver, m. j. coon, and e. r. stadtman (1983) proc. natl. acad. sci. usa 80, 1521-1525]. it has now been found that in the presence of fe(iii), o2, and an appropriate electron donor (hypox ... | 1985 | 2860872 |
| arylsulphatase a and acid phosphatase activities in plasma and leucocytes during lps fever in the ox (bos taurus). | intravenous injection of e. coli lps (0.5 micrograms/kg) produced the biphasic elevation of rectal temperature (tr) in conscious oxen. the fever was accompanied by a significant increase of the arylsulphatase a (asa) activities in plasma and in mononuclear leucocytes. in polymorphonuclear cells a substantial decrease of the asa activity after 1 hr fever was observed. after 3.5 hr of fever the polymorphonuclear activity of asa restored to normal found before lps administration. in contrast with a ... | 1985 | 2859950 |
| [synthesis and cloning of dna complementary to mrna of the bovine mammary gland]. | poly(a+)mrna from bovine mammary glands was used to synthesize double-stranded cdnas that were subsequently inserted into the plasmid vector pbr322 at the pst1 site by means of oligo(dg)-oligo(dc) tailing. after transfection of escherichia coli jc5183, recombinant plasmid library containing 5400 clones was screened by serial rounds of colony hybridization in situ to total [23p] poly(a+)mrna and electrophoretically homogenious [32p]16smrna of mammary glands. then hybrid selection of mrna and subs ... | 1985 | 2859232 |
| the action of alpha-ketoglutarate dehydrogenase on 4-chloronitrosobenzene: evidence for species-dependent differences in active site properties. | the reaction of bovine (bos taurus) and porcine (sus scrufa) cardiac alpha-ketoglutarate dehydrogenase complex (alpha-kgd) with 4-chloronitrosobenzene (i) was shown to produce a hydroxamic acid (iv) and a product due to a bamberger rearrangement as previously shown for escherichia coli alpha-kgd. the conversion of i into an active site-bound electrophile was general among the three alpha-kgd enzymes tested, but quantitative differences in products and kinetics were shown. the reaction of i was s ... | 1985 | 2858339 |
| a model of acute infectious neonatal diarrhoea. | oral inoculation of neonatal mfi mice with enterotoxigenic strains of escherichia coli that possessed the k99 or f41 antigen or both resulted in severe diarrhoea with high mortality. the diarrhoea was associated with increased fluid in the gut, greatly increased numbers of e. coli in gut homogenates and reduced weight gain compared to control animals. further studies with strain b44 demonstrated greatly increased numbers of e. coli on the surface of the intestinal mucosa and haemo-concentration. ... | 1987 | 2856846 |
| diphosphonates are potent inhibitors of mammalian inorganic pyrophosphatase. | methanediphosphonate and 12 analogs thereof with different substituents at the carbon atom are potent competitive inhibitors of highly purified rat liver and bovine heart inorganic pyrophosphatases. the inhibition constants for the most effective diphosphonates, which contain an nh2 or oh group at the bridge carbon atom, are in the micromolar range. yeast and escherichia coli pyrophosphatases are markedly less sensitive to the diphosphonates. pyrophosphatase inhibition may be related to the nume ... | 1988 | 2848451 |
| polymorphonuclear leucocyte dysfunction during short term metabolic changes from normo- to hyperglycemia in type 1 (insulin dependent) diabetic patients. | polymorphonuclear leucocyte (pmn) ingestion of particles coated with lipopolysaccharide (lps) from escherichia coli was compared to other pmn functions in seven patients with insulin dependent diabetes mellitus (iddm) during short-term controlled metabolic changes from normo- to hyperglycemia without ketoacidosis. factors known to interfere with pmn functions were excluded. pmn ingestion of particles coated with both lps and bovine serum albumin became reduced from normo- to hyperglycemia. pmn m ... | 1988 | 2846445 |
| activation of ada protein as a transcriptional regulator by direct alkylation with methylating agents. | the adaptive response is a cellular process to induce dna repair enzymes in response to a challenge of alkylating agents. in this process ada protein, the product of the ada gene, plays a major role; it accepts the methyl groups of the methylated dna at the cysteine residues of its own molecule, and the methylated form of ada protein promotes transcription of its own gene, thereby triggering induction of the whole process. in addition to this dna-mediated activation of ada protein, we have propo ... | 1988 | 2843522 |
| electron-transfer complexes of ascaris suum muscle mitochondria. iii. composition and fumarate reductase activity of complex ii. | complex ii of the anaerobic respiratory chain in ascaris muscle mitochondria showed a high fumarate reductase activity when reduced methyl viologen was used as the electron donor. the maximum activity was 49 mumol/min per mg protein, which is much higher than that of the mammalian counterpart. the mitochondria of ascaris-fertilized eggs, which require oxygen for its development, also showed fumarate reductase activity with a specific activity intermediate between those of adult ascaris and mamma ... | 1988 | 2843227 |
| comparison of the bovine herpesvirus 1 gi gene and the herpes simplex virus type 1 gb gene. | in a previous report, we localized the gene for a 130-kilodalton envelope glycoprotein (gi) of bovine herpesvirus 1 (bhv-1) to a 3.6-kilobase hpai-kpni restriction endonuclease fragment from the long unique region of the bhv-1 genome (map position 0.405 to 0.432) and showed that a herpes simplex virus 1 (hsv-1) glycoprotein b (gb) probe uniquely hybridized to this bhv-1 restriction fragment. here we present the complete nucleotide sequence of the bhv-1 gi gene and the predicted 932-amino-acid se ... | 1988 | 2841484 |
| site-specific dna recombination in mammalian cells by the cre recombinase of bacteriophage p1. | the cre protein encoded by the coliphage p1 is a 38-kda protein that efficiently promotes both intra- and intermolecular synapsis and recombination of dna both in escherichia coli and in vitro. recombination occurs at a specific site, called lox, and does not require any other protein factors. the cre protein is shown here also to be able to cause synapsis of dna and site-specific recombination in a mammalian cell line. a stable mouse cell line was established that expresses the cre protein unde ... | 1988 | 2839833 |
| nonradioactive labeling of synthetic oligonucleotide probes with terminal deoxynucleotidyl transferase. | synthetic oligonucleotides were tailed at the 3' end using terminal deoxynucleotidyl transferase. nucleotide triphosphates with free primary amines at the end of side chains were compared for their tailing efficiency and/or detection sensitivity, using biotin-11-dutp as a reference. free primary amines were tagged with activated biotin or fluorescein isothiocyanate. the probes were then detected with either streptavidin-alkaline phosphatase complex or anti-fluorescein antibodies and alkaline pho ... | 1988 | 2837921 |
| conservation of primary structure in the lipoyl-bearing and dihydrolipoyl dehydrogenase binding domains of mammalian branched-chain alpha-keto acid dehydrogenase complex: molecular cloning of human and bovine transacylase (e2) cdnas. | the subunit structures and conservation of the dihydrolipoyl transacylase (e2) components of bovine and human branched-chain alpha-keto acid dehydrogenase complexes were investigated by western blotting, peptide sequencing, and cdna cloning methods. rabbit antiserum prepared against the sodium dodecyl sulfate (sds) denaturated bovine e2 subunit recognized the inner e2 core, and the first hinge region of the e2 chain, but failed to react with the lipoyl-bearing domain as determined by western blo ... | 1988 | 2837277 |
| bovine seminalplasmin [corrected] is a dna unwinding protein. | the duplex dna unwinding ability of seminalplasmin [corrected] from bovine semen was examined by treatment of plasmid-protein complexes with calf thymus topoisomerase i and resolution of the topoisomer distributions by agarose gel electrophoresis. binding of seminalplasmin [corrected] results in a moderate degree of unwinding of supercoiled plasmid. the elongation of the rna chain by e. coli rna polymerase over promoter containing template is not inhibited by seminalplasmin [corrected]. however, ... | 1988 | 2834234 |
| colonization of the streptomycin-treated mouse large intestine by a human fecal escherichia coli strain: role of adhesion to mucosal receptors. | escherichia coli f-18, a normal fecal isolate, was previously shown to be an excellent colonizer of the streptomycin-treated cd-1 mouse large intestine, whereas e. coli f-18col-, a derivative of e. coli f-18 that no longer makes the e. coli f-18 colicin, was shown to be a poor mouse colonizer. it was also shown that e. coli f-18 bound two to three times more soluble colonic mucus protein than did e. coli f-18col- and that a major receptor in cd-1 mouse colonic mucus was a 50.5-kilodalton glycopr ... | 1988 | 2833441 |
| functional mapping of the human papillomavirus type 11 transcriptional enhancer and its interaction with the trans-acting e2 proteins. | the transcriptional enhancer sequences of the papillomaviruses are regulated by trans-acting factors encoded by the viral e2 open reading frame. we have performed detailed functional and physical analyses of the enhancer of the human papillomavirus type 11 (hpv-11). using the chloramphenicol acetyltransferase (cat) assay in transiently transfected monkey cv-1 cells, the enhancer region has been localized to a 270-bp tract immediately preceding the e6 open reading frame, and it consists of two fu ... | 1988 | 2833426 |
| illegitimate recombination mediated by calf thymus dna topoisomerase ii in vitro. | we have found that purified calf thymus dna topoisomerase ii mediates recombination between two phage lambda dna molecules in an in vitro system. the enzyme mainly produced a linear monomer recombinant dna that can be packaged in vitro. novobiocin and anti-calf thymus dna topoisomerase ii antibody inhibit this atp-dependent recombination. the recombinant molecules contain duplications or deletions, and most crossovers take place between nonhomologous sequences of lambda dna, as judged by the seq ... | 1988 | 2832845 |
| enteric infections in veal calves: a longitudinal study on four veal calf units. | forty-five calves on four veal calf units were monitored during the first four weeks after their arrival. faecal samples were collected on alternate days and screened for the presence of rotaviruses, bovine coronavirus, cryptosporidium oocysts, k99 positive strains of e. coli and salmonella spp. rotaviruses and cryptosporidium were the most commonly detected agents (78% and 60% respectively of the calves). bovine coronavirus was detected in the faeces of 18% of the calves, whilst k99 positive e. ... | 1987 | 2827367 |
| expression and accurate processing of yeast penta-ubiquitin in escherichia coli. | an expression vector (psjyub-5) was constructed which contained five repeats of the "yeast ubiquitin gene" regulated by a heat-inducible lambda pl promoter. the vector, when expressed in escherichia coli, produced a penta-ubiquitin of approximately 42 kda. purified penta-ubiquitin was found to be as active as the human mono-ubiquitin in the in vitro atp/ubiquitin-dependent proteolytic assay of the reticulocyte lysate, indicating that the expressed gene product was recognized by the enzymes invol ... | 1987 | 2826431 |
| nucleotide sequence and expression in escherichia coli of the gene encoding the nonstructural protein ncvp2 of bovine rotavirus. | cloned dna copy of rotavirus genome segment 5 from bovine rotavirus rf strain has been used to determine the nucleotide sequence of the gene that encodes for the nonstructural viral protein ncvp2. the sequence data indicated that segment 5 consists of 1581 base pairs and is a + t rich (66%). the positive strand of segment 5 contains a single open reading frame that extends 491 codons and possesses 5'- and 3'-terminal untranslated regions of 32 and 73 base pairs, respectively. the first aug confo ... | 1987 | 2823457 |
| non-oxidative antibacterial activity of bovine neutrophil granule proteins towards mastitis pathogens. | acid extracts of bovine neutrophil granules displayed potent antibacterial activity towards a number of mastitis pathogens in vitro. killing of pathogens by acid extractable granule protein was dependent on incubation time, protein concentration, bacterial cell load, ph and ionic strength. gram-negative and gram-positive organisms showed variable sensitivity to granule extract. strains of staphylococcus aureus were the most resistant of tested organisms to granule extract. gram-negative organism ... | 1989 | 2816175 |
| high levels of circulating neutralizing antibody in normal animals to recombinant mouse interferon-beta produced in yeast. | plasma from normal outbred swiss mice not previously given interferon (ifn) neutralized a glycosylated (high-mannose) recombinant murine ifn-beta made in yeast (rmuifn-beta y). the neutralization antibody titers were as high as 1:6,000 versus rmuifn-beta y, whereas the titers obtained with native murine ifn-beta (muifn-beta) were 100-fold less; a recombinant murine ifn-beta make in escherichia coli (rmuifn-beta ec) was not neutralized at 1:10 dilution of plasma. an elisa using rmuifn-beta y demo ... | 1989 | 2809279 |
| bovine mitochondrial protein synthesis elongation factors. identification and initial characterization of an elongation factor tu-elongation factor ts complex. | animal mitochondrial protein synthesis factors elongation factor (ef) tu and ef-ts have been purified as an ef-tu.ts complex from crude extracts of bovine liver mitochondria. the mitochondrial complex has been purified 10,000-fold to near homogeneity by a combination of chromatographic procedures including high performance liquid chromatography. the mitochondrial ef-tu.ts complex is very stable and cannot be dissociated even in the presence of high concentrations of guanine nucleotides. no guani ... | 1989 | 2808417 |
| purification, composition, and activity of two bactenecins, antibacterial peptides of bovine neutrophils. | extracts of granules of bovine neutrophils are known to exhibit a marked antibacterial activity in vitro. by a simple, two-step chromatographic procedure, we have resolved two peptide components of the antibacterial system. they were named bac-5 and bac-7 from the general term bactenecin and had molecular masses of about 5 and 7 kilodaltons, respectively. over 45 and 20% of the amino acid residues in the two bactenecins are proline and arginine, respectively. the remaining amino acids are mainly ... | 1989 | 2777377 |
| combined immunodeficiency in a calf. | combined immunodeficiency was documented in a 6-week-old angus calf. the calf had lymphopenia, undetectable serum igm or iga, and low concentrations of serum igg (420 mg/dl). the calf was treated for diarrhea, pneumonia, and shock, and was given antimicrobial drugs, fluids, and plasma. the calf died of systemic candidiasis and escherichia coli bacteremia. aggregated lymphatic folliculi (peyer patches), lymph nodes, and thymic and splenic lymphoid tissue could not be identified at necropsy. | 1989 | 2768060 |
| a covalent angiogenin/ribonuclease hybrid with a fourth disulfide bond generated by regional mutagenesis. | human angiogenin is a blood vessel inducing protein whose primary structure displays 33% identity to that of bovine pancreatic ribonuclease a (rnase a). angiogenin catalyzes limited cleavage of 18s and 28s ribosomal rna and is several orders of magnitude less potent than rnase a toward conventional substrates. a striking structural difference between angiogenin and rnase is the virtual absence of sequence similarity within the region of rnase that contains the cys-65--cys-72 disulfide bond. inde ... | 1989 | 2719939 |
| production of monoclonal antibodies toward bovine interferons-alpha suitable for immunopurification. | five murine hybridoma clones, producing monoclonal antibodies (mabs) to bovine interferon-alpha (boifn-alpha) were established. one of these, f12, secreted mabs giving high titers, in elisa tests, neutralizing both boifn-alpha, -alpha c, and boifn-alpha d activities, belonging to the mouse igg1 class, and having a binding affinity constant of 10(8) m-1. f12 mabs were used for immunoaffinity purification of boifn-alpha, and recombinant boifn-alpha c from escherichia coli extracts was purified to ... | 1989 | 2715671 |
| hemagglutination, hydrophobicity, enterotoxigenicity, and drug-resistance characteristics of avian escherichia coli. | a total of 35 escherichia coli isolates obtained from necropsy materials of hens with septicemia in the konya region of turkey were examined for hemagglutination (ha), cell-surface hydrophobicity, enterotoxigenicity, and drug resistance. ha tests were performed on live cultures with human (group a), bovine, avian (chicken), and guinea pig erythrocytes with and without mannose. nine ha patterns were observed. of the 35 isolates, 62.8% exhibited mannose sensitive hemagglutination (msha), 8.6% exhi ... | 1989 | 2695047 |