Publications
| Title | Abstract | Year Filter | PMID(sorted descending) Filter |
|---|
| detection and characterization of enterohaemorrhagic escherichia coli in slaughtered cattle. | fecal samples from slaughtered cattle were studied for enterohaemorrhagic escherichia coli (ehec) by dna hybridization with biotin-labelled dna probes specific for the ehec virulence plasmid, shiga-like toxin i (slt i), shiga-like toxin ii (slt ii) and eae gene. among 136 animals analysed, 47 (34.5%) were found to carry ehec. the cytotoxic genotypes observed for ehec strains were: 60.4% slt i, 12.5% slt ii and 10.4% slt i + slt ii; 16.7% resulted slt i and slt ii negative. a total of 14 out of 4 ... | 1997 | 9270349 |
| recombinant uracil phosphoribosyltransferase from the thermophile bacillus caldolyticus: expression, purification, and partial characterization. | the upp gene encoding the major uracil phosphoribosyltransferase (uprt) of the thermophile bacillus caldolyticus was cloned by complementation of an escherichia coli upp mutation. the nucleotide sequence of the cloned dna revealed an open reading frame of 630 bp encoding a polypeptide of 209 amino acids (m(r) 22,817) with 84% amino acid sequence identity to the deduced upp gene product of bacillus subtilis. primer extension analysis indicated that the transcriptional start site of the cloned gen ... | 1997 | 9268683 |
| role of domains in escherichia coli and mammalian mitochondrial elongation factor ts in the interaction with elongation factor tu. | bovine mitochondrial elongation factor ts (ef-tsmt) stimulates the activity of escherichia coli elongation factor tu (ef-tu). in contrast, e. coli ef-ts is unable to stimulate mitochondrial ef-tu. ef-tsmt forms a tight complex with e. coli ef-tu governed by an association constant of 8.6 x 10(10). this value is 100-fold stronger than the binding constant for the formation of the e. coli ef-tu.ts complex. to test which domain of ef-tsmt is important for its strong binding with ef-tu, chimeras wer ... | 1997 | 9268331 |
| the crystal structure of the nucleotide-free alpha 3 beta 3 subcomplex of f1-atpase from the thermophilic bacillus ps3 is a symmetric trimer. | f1-atpase, an oligomeric assembly with subunit stoichiometry alpha 3 beta 3 gamma delta epsilon, is the catalytic component of the atp synthase complex, which plays a central role in energy transduction in bacteria, chloroplasts and mitochondria. the crystal structure of bovine mitochondrial f1-atpase displays a marked asymmetry in the conformation and nucleotide content of the catalytic beta subunits. the alpha 3 beta 3 subcomplex of f1-atpase has been assembled from subunits of the moderately ... | 1997 | 9261073 |
| immunolocalization of the pseudorabies virus immediate-early protein ie180 by immunoperoxidase staining. | the immediate-early (1e) gene of pseudorabies virus (prv) expresses immediately upon infection, a phosphorylated protein (immediate-early protein, ie180) that can transactivate viral other genes and plays an essential role in regulating viral gene expression. in order to detect and localize ie180 in infected cells early on, this gene was cloned for overexpression, and the expressed products were applied to generate specific antibodies against ie180 protein. two recombinant expression plasmids pn ... | 1997 | 9255733 |
| outbreak of clinical mastitis in dairy cows following 'blitz' therapy. | 1997 | 9253837 | |
| endotoxin induces endothelial barrier dysfunction through protein tyrosine phosphorylation. | bacterial lipopolysaccharide (lps) induces actin reorganization, intercellular gap formation, and endothelial barrier dysfunction in vitro. we studied whether lps-induced increments in 14c-labeled bovine serum albumin (bsa) flux across bovine pulmonary artery endothelial cell (ec) monolayers and actin depolymerization are mediated through protein tyrosine phosphorylation. lysates from ec exposed to lps derived from escherichia coli 0111:b4 (100 ng/ml, 1 h) demonstrated increased tyrosine phospho ... | 1997 | 9252559 |
| microbiological composition of raw milk from selected farms in the camembert region of normandy. | raw milk from 27 farms was sampled over 6 months for listerias, salmonellas, yersinia enterocolitica and campylobacters. total bacterial counts and somatic cell counts were measured. lactococci, lactobacilli, dextran-producing leuconostocs, brevibacterium linens, yeasts and moulds, staphylococcus aureus and other micrococcaceae, pseudomonas, coliforms, escherichia coli, enterococci, clostridium perfringens and spores of anaerobic lactate-fermenting bacteria were also counted. pseudomonas (2000 c ... | 1997 | 9246770 |
| synthesis and characterization of selenolipoylated h-protein of the glycine cleavage system. | h-protein of the glycine cleavage system has a lipoic acid prosthetic group. selenolipoic acid is a lipoic acid analog in which both sulfur atoms are replaced by selenium atoms. two isoforms of bovine lipoyltransferase that are responsible for the attachment of lipoic acid to h-protein had an affinity for selenolipoyl-amp and transferred the selenolipoyl moiety to bovine apoh-protein comparable to lipoyl-amp. selenolipoylated h-protein was overexpressed in escherichia coli and purified. selenoli ... | 1997 | 9242652 |
| complement fragment c5a and inflammatory cytokines in neutrophil recruitment during intramammary infection with escherichia coli. | generation of inflammatory mediators and leukocyte recruitment to infection at an epithelial surface were studied during escherichia coli-induced mastitis. one uninfected gland of each of eight midlactation cows was challenged with only 30 cfu of e. coli mcdonald strain 487, a serum-resistant isolate from a cow with mastitis. bacteria grew logarithmically during the first 10 to 12 h after challenge, reaching concentrations of more than 10(5) cfu/ml with no detectable host response during this ti ... | 1997 | 9234788 |
| evaluation of blood acid-base balance after experimental administration of endotoxin in adult cow. | esherichia coli endotoxin was administered intravenously to 7 holstein adult cows, to evaluate the effect of endotoxin on acid-base balance. endotoxin shock was observed immediately after the administration of endotoxin. a loss of appetite and depression of digestive tract motility continued for about 120 hr after the challenge. metabolic alkalosis following hypochloremia and hypokalemia were particularly pronounced at 12 to 72 hr after the administration of endotoxin. | 1997 | 9234228 |
| endotoxaemia in dairy cattle: mechanism of reticulorumen stasis. | the objective of this study was to determine whether blockade of alpha(-2) adrenergic receptors would restore reticulorumen motility during toxaemia in cows. reticulorumen contractions were measured via a water-filled balloon connected to a pressure transducer. intravenous infusion of endotoxin (100 ng kg-1 over 30 min) significantly decreased the number of reticulorumen contractions. intravenous infusion of yohimbine (125 micrograms kg-1 over 30 min) alone did not affect reticulorumen contracti ... | 1997 | 9232121 |
| expression of p, s, and f1c adhesins by cytotoxic necrotizing factor 1-producing escherichia coli from septicemic and diarrheic pigs. | nineteen papc-positive cytotoxic necrotizing factor 1 (cnf1)-producing escherichia coli isolates from pigs with septicemia or diarrhea were tested for the presence of pap-, sfa-, and afa-related sequences encoding p/prs, s/f1c, and dr/afa adhesins respectively. production of adhesins by isolates was tested by mannose-resistant hemagglutination (mrha), sialidase treatment of erythrocytes and particle agglutination tests. production of p, s, and f1c fimbriae by isolates was also examined by immuno ... | 1997 | 9231424 |
| the effect of discontinuation of postmilking teat disinfection in low somatic cell count herds. ii. dynamics of intramammary infections. | results of a 20 month split-udder trial on the effect of discontinuation of postmilking teat disinfection on intramammary infections (imi) with major and minor pathogens in seven dairy herds with a low somatic cell count are described. the incidence of escherichia coli imi was found to be significantly lower, whereas the incidence of imi with staphylococcus aureus and minor pathogens was significantly higher in quarters for which postmilking teat disinfection was discontinued than in disinfected ... | 1997 | 9225431 |
| thermal activation of the bovine hsc70 molecular chaperone at physiological temperatures: physical evidence of a molecular thermometer. | differential scanning calorimetry was used to monitor the thermal transitions of the 70 kda heat shock cognate protein (hsc70). hsc70 had endothermic transitions with midpoints (tm) at 59 degrees c and 63 degrees c in the absence and presence of atp, respectively, and a similar increase in tm was observed using intrinsic fluorescence of tryptophan. combined with increased exposure at 60 degrees c of non-polar residues of hsc70 to which the hydrophobic, fluorescent probe ans bound, these data ind ... | 1996 | 9222592 |
| expression of ovine interleukin-2 cdna in escherichia coli. | the expression plasmids pgex-2t and pt7-7 were used to express ovine (ov) il-2 cdna in escherichia coli. the pgex-2t vector contained glutathione-s-transferase (gst) as the affinity handle and resulted in high level expression of the gst-il-2 fusion protein. however, only a small proportion of this fusion protein was present in the soluble fraction. the insoluble fraction was extracted with a detergent, sarkosyl, and even though a large amount of fusion product was obtained, it would not bind to ... | 1997 | 9220585 |
| selective modification at the n-terminal region of human growth hormone that shows antagonistic activity. | a new analogue of recombinant human growth hormone (hgh), hgh des(1-6,14) was expressed in escherichia coli, refolded and purified to homogeneity. the mutation decreased the hormone's ability to bind lactogenic and somatogenic receptors through its site 1, and almost completely abolished its ability to bind these receptors through site 2, as evidenced by both binding and gel-filtration experiments. more specifically, the binding to prolactin receptors (prlrs) from various species or their solubl ... | 1997 | 9220030 |
| sensitization of the bovine mammary gland to escherichia coli endotoxin. | the effect of repeated infusions of escherichia coli endotoxin on the acute phase response in the bovine mammary gland was assessed through the concentrations of tumor necrosis factor alpha (tnf-alpha) in milk. four clinically normal lactating cows received two intramammary infusions of e coli endotoxin (33 micrograms) 24 h apart in the same mammary quarter. along with the second infusion, the cows received one dose of endotoxin in the contralateral quarter. milk was collected at varying interva ... | 1997 | 9208443 |
| global aspects of emerging and potential zoonoses: a who perspective. | many new human pathogens that have emerged or reemerged worldwide originated from animals or from products of animal origin. many animal species as well as categories of agents have been involved in the emergence of diseases. wild (e.g., bats, rodents) as well as draught animals (e.g., horses) and food animals (e.g., poultry, cattle) were implicated in the epidemiologic cycles of these diseases. many of the agents responsible for new infections and diseases in humans were viruses (e.g., hantavir ... | 1997 | 9204308 |
| [federal investigations on the distribution and in vitro resistance of udder pathogenic bacteria in the milk of cows with subclinical mastitis]. | 1644 quarter milk samples of 948 dairy cows with subclinical mastitis, collected from 63 veterinary practices all over germany origined by 262 livestocks with problems in udder health were examined semiquantitatively by "aulendorfer mastitistest" for cell count and additionally bacteriologically. potentially udder pathogenic bacteria were tested for in vitro-sensitivity to penicillin g, ampicillin, oxacillin, cefacetril, tylosin, neomycin, gentamicin, polymyxin b and enrofloxacin. 24.5% of all t ... | 1997 | 9198960 |
| characterization of a specific mycobacterium paratuberculosis recombinant clone expressing 35,000-molecular-weight antigen and reactivity with sera from animals with clinical and subclinical johne's disease. | johne's disease is a chronic enteritis of ruminants associated with enormous worldwide economic losses for the dairy cow- and goat-rearing industries. management limitations and eradication programs for this disease have been hampered by the lack of a simple and specific diagnostic test for the detection of subclinical cases. we used a recombinant clone expressing a 35,000-molecular-weight mycobacterium paratuberculosis antigen (p35 antigen) from a previously constructed expression library of m. ... | 1997 | 9196196 |
| a novel developmental process of intestinal epithelial lesions in a calf infected with attaching and effacing escherichia coli. | a comparative study on the adhesion of attaching and effacing escherichia coli (aeec) to the enterocytes between the colon of a calf and the jejunum of a piglet showed differences in the developmental process of attaching and effacing (ae) lesions. in the calf, pedestals consisted of fused microvilli, while in the piglet they developed from the apical epithelial cell membranes after effacing microvilli. microvilli adjacent to the aeec attachment site were atrophic in the calf, whereas they were ... | 1997 | 9192365 |
| hemolysin phenotypes and genotypes of eaea-positive and eaea-negative bovine verotoxigenic escherichia coli. | intimin or eaea protein has been implicated in the attaching/effacing lesion caused by entero-hemorrhagic escherichia coli (ehec) in the intestine but it is not produced by all ehec and is therefore not adequate as a marker for ehec. hemolysins are produced by a high percentage of verotoxigenic e. coli (vtec) and could be a marker for ehec, but their distribution and relation to virulence are not known. we used pcr amplification to determine the presence or absence of eaea sequences in 281 vtec ... | 1997 | 9192033 |
| verotoxigenic escherichia coli in slaughter cattle and ground beef in south dakota. | 1997 | 9191996 | |
| variation in virulence in the gnotobiotic pig model of o157:h7 escherichia coli strains of bovine and human origin. | escherichia coli strains of serotype o157:h7 have been incriminated in outbreaks and sporadic cases of food-borne illness, including diarrhea, hemorrhagic colitis, hemolytic uremic syndrome and thrombotic thrombocytopenic purpura. food-producing animals, particularly cattle, are believed to be reservoirs of the organism. whether all strains of bovine origin pose human health risk is unknown and was the impetus for this investigation. we compared the virulence of ten slt-i, slt-ii, and eae dna pr ... | 1997 | 9191990 |
| serine protease of pestiviruses: determination of cleavage sites. | the single-stranded genomic rna of pestiviruses is of positive polarity and encompasses one large open reading frame of about 4,000 codons. the resulting polyprotein is processed co- and posttranslationally by virus-encoded and host cell proteases to give rise to the mature viral proteins. a serine protease residing in the nonstructural (ns) protein ns3 (p80) has been shown to be essential for the release of the ns proteins located downstream of ns3. in this report the ns3 serine protease-depend ... | 1997 | 9188613 |
| chaperone properties of the bacterial periplasmic substrate-binding proteins. | bacterial periplasmic substrate-binding proteins are initial receptors in the process of active transport across cell membranes and/or chemotaxis. each of them binds a specific substrate (e.g. sugar, amino acid, or ion) with high affinity. for transport, each binding protein interacts with a cognate membrane complex consisting of two hydrophobic proteins and two subunits of a hydrophilic atpase. for chemotaxis, binding proteins interact with specific membrane chemotaxis receptors. we report, her ... | 1997 | 9188448 |
| resazurin reduction as a function of respiratory burst in bovine neutrophils. | to determine whether the respiratory burst of neutrophils from bovine blood and milk can be analyzed by use of a fluorometric resazurin reduction assay. | 1997 | 9185965 |
| cdna cloning, expression, and rapid purification of a kunitz-type winged bean chymotrypsin inhibitor. | a 183-residue kunitz-type winged bean chymotrypsin inhibitor (wbci), inhibits its cognate protease at a molar ratio of 1:2, instead of the usual ratio of 1:1 common to other members of the family. from the cdna pool obtained by reverse transcription of the poly(a)+ rna of the developing winged bean seeds, the structural gene of wbci has been amplified by pcr using primers designed to delete the 24-residue signal peptide and introduce ecori and sali sites at the ends of the amplified dna. the lat ... | 1997 | 9179296 |
| a 5-h screening and 24-h confirmation procedure for detecting escherichia coli o157:h7 in beef using direct epifluorescent microscopy and immunomagnetic separation. | an antibody-direct epifluorescent filter technique (ab-deft) detected 100% of the raw ground beef samples inoculated with escherichia coli o157:h7 cells (0.15 cells g-1) and incubated in a prewarmed, modified buffered peptone water (mbpw) non-selective enrichment broth for 5 h at 42 degrees c in an orbital shaking water bath (200 rev min-1). over 50% of the microscopic fields viewed were positive (1-10 fluorescent cells field-1) in the ab-deft. all positive screening results were confirmed withi ... | 1997 | 9172447 |
| survival of escherichia coli o157:h7 in yoghurt during preparation and storage at 4 degrees c. | cow's milk was inoculated with ca 10(3) and 10(7) cfu ml-1 escherichia coli o157:h7. after fermentation at 42 degrees c for 0-5 h, the yoghurt was stored at 4 degrees c. two kinds of yoghurt were used: traditional yoghurt (ty), made with streptococcus thermophilus and lactobacillus bulgaricus starter cultures, and 'bifido' yoghurt (by), made with the two starter cultures plus bifidobacterium bifidum. after 7 d e. coli o157:h7 decreased from 3.52 to 2.72 log10 cfu ml-1 and from 7.08 to 5.32 log10 ... | 1997 | 9172440 |
| epidemiological relatedness and clonal types of natural populations of escherichia coli strains producing shiga toxins in separate populations of cattle and sheep. | two separate animal populations consisting of a herd of cattle (19 animals) and a flock of sheep (25 animals) were investigated for strains of escherichia coli producing shiga toxins (stec) over a time period of 6 months. thirty-three stec were isolated from 63.2% of cattle and grouped into 11 serotypes and eight electrophoretic types (ets) by multilocus enzyme analysis. in sheep, 88% of the animals excreted stec (n = 67 isolates) belonging to 17 different serotypes and 12 different ets. stec fr ... | 1997 | 9172336 |
| membrane binding and enzymatic activation of a dbl homology domain require the neighboring pleckstrin homology domain. | dbl-homology (dh) domains are invariably located immediately n-terminal to a pleckstrin homology (ph) domain. to understand the functional relationship between these two domains we expressed the dh domain alone, the ph domain alone, and the dh-ph combination of the invasion inducing protein tiam-1 fused to glutathione-s-transferase (gst) or green fluorescent protein (gfp). we found that the gst-dh-ph and the gst-ph constructs bind to preparations of brain membranes and to the beta gamma subunits ... | 1997 | 9168986 |
| structure of a truncated human surfactant protein d is less effective in agglutinating bacteria than the native structure and fails to inhibit haemagglutination by influenza a virus. | surfactant protein d (sp-d) is a lung-specific protein that is synthesized and secreted by lung epithelial cells and is believed to play an important role in lung host defence. this protein belongs to the c-type lectin family, which is characterized by an n-terminal cysteine-rich domain, a collagen-like domain, a neck domain and a carbohydrate recognition domain (crd). to elucidate the biological actions of this animal lectin against such pathogens as micro-organisms, the biological activities o ... | 1997 | 9163329 |
| monitoring the microbiology of high quality milk by monthly sampling over 2 years. | the concentrations of seven types of microorganism in the milk produced by farms using high quality milking procedures were monitored monthly. the most commonly encountered bacterium was pseudomonas, whose concentration varied greatly between samples, but lactococci, lactobacilli and yeasts were also present at more stable concentrations. staphylococcus aureus and beta-glucuronidase-positive escherichia coli were occasionally detected. listeria monocytogenes was found in the samples from only on ... | 1997 | 9161919 |
| "designing out" disulfide bonds: thermodynamic properties of 30-51 cystine substitution mutants of bovine pancreatic trypsin inhibitor. | we have used a combination of spectroscopic and calorimetric techniques to assess the thermodynamic and extrathermodynamic consequences of paired amino acid substitutions at positions 30 and 51 in bovine pancreatic trypsin inhibitor (bpti). correctly folded, wild type bpti contains a disulfide at the 30-51 positions, with the nonbackbone atoms of this cystine being relatively solvent inaccessible. mutants missing this buried 30-51 disulfide adopt a conformation very similar to that of the native ... | 1997 | 9154914 |
| ard-1 cdna from human cells encodes a site-specific single-strand endoribonuclease that functionally resembles escherichia coli rnase e. | the human ard-1 (activator of rna decay) cdna sequence can rescue mutations in the escherichia coli rne gene, which specifies the essential endoribonuclease rnase e, resulting in rnase e-like cleavages in vivo in rne-defective bacteria and in vitro in extracts isolated from these cells (wang, m., and cohen, s. n. (1994) proc. natl. acad. sci. u. s. a. 91, 10591-10595). recent studies indicate that the 13.3-kda protein encoded by ard-1 cdna is almost identical to the carboxyl-terminal end of the ... | 1997 | 9153239 |
| antibacterial peptides of bovine lactoferrin: purification and characterization. | three peptides with antibacterial activity toward enterotoxigenic escherichia coli have been purified from a pepsin digest of bovine lactoferrin. all peptides were cationic and originated from the n-terminus of the molecule in a region where a bactericidal peptide, lactoferricin b, had been previously identified. the most potent peptide, peptide i, was almost identical to lactoferricin b; the sequence corresponded to residues 17 to 42, and the molecular mass was 3195 as determined by mass spectr ... | 1997 | 9149961 |
| influence of ozone on the susceptibility of escherichia coli k1 to the bactericidal action of serum. | the susceptibility to the bactericidal action of normal bovine serum of twenty two escherichia coli k1 strains, isolated from the urine of patients with urinary tract infections, was determined. only four strains were resistant. ozonization of bacterial suspensions enhanced the sensitivity of the strains to the action of both normal serum and a serum in which the alternative pathway of complement activation was thermally blocked. | 1996 | 9131796 |
| evaluation of hematological, serum biochemical and cerebrospinal fluid parameters in experimental bacterial meningitis in the calf. | to evaluate the effects of bacterial meningitis on blood and csf parameters, an experiment was conducted with five iranian crossbred male calves. blood and csf samples were collected 3 times within a 5-day interval before the administration of bacteria for obtaining control values. following the injection of e. coli, k12 into the cerebrospinal fluid from the lumbosacral space, samples were collected and clinical signs of meningitis were observed. blood and csf samples were obtained from the meni ... | 1997 | 9123983 |
| preinfection in vitro chemotaxis, phagocytosis, oxidative burst, and expression of cd11/cd18 receptors and their predictive capacity on the outcome of mastitis induced in dairy cows with escherichia coli. | four to 6 wk after parturition, 12 cows in second, fourth, or fifth lactation were experimentally infected in one gland with escherichia coli. the capacity of chemotaxis, phagocytosis, oxidative burst, and expression of cd11/cd18 receptors to predict the severity of imi was measured. bacterial counts in the infected quarter, expressed as area under the curve, and residual milk production in the uninfected quarters were compared to determine severity of the infection. although these two outcome p ... | 1997 | 9120097 |
| nonaldehyde sterilization of biologic tissue for use in implantable medical devices. | biologic tissue stabilized by dye-mediated photooxidation has found application in implantable devices. the desire to avoid aldehydes in the processing of photooxidized tissues led to the development of a nonaldehyde, iodine based sterilant. the interaction of tissue with iodine was indicated by a change in tissue shrinkage temperature, dependent upon solution and incubation parameters. the amino acid tyrosine also was altered, presumably because of aromatic ring iodination. transmission electro ... | 1997 | 9116349 |
| isolation and characterization of the cdna encoding bovine poly(adp-ribose) glycohydrolase. | the synthesis and rapid turnover of adp-ribose polymers is an immediate cellular response to dna damage. we report here the isolation and characterization of cdna encoding poly(adp-ribose) glycohydrolase (parg), the enzyme responsible for polymer turnover. parg was isolated from bovine thymus, yielding a protein of approximately 59 kda. based on the sequence of oligopeptides derived from the enzyme, polymerase chain reaction products and partial cdna clones were isolated and used to construct a ... | 1997 | 9115250 |
| thermal destruction of escherichia coli o157:h7 in beef and chicken: determination of d- and z-values. | thermal inactivation of a four-strain mixture of e. coli o157:h7 was determined in 90% lean ground beef, and lean ground chicken. inoculated meat was packaged in bags which were completely immersed in a circulating water bath and held at 55, 57.5, 60, 62.5, and 65 degrees c for predetermined lengths of time. d-values, determined by linear regression, in beef were 21.13, 4.95, 3.17, 0.93 and 0.39 min, respectively (z = 6.0 degrees c). using a survival model for non-linear survival curves, d-value ... | 1997 | 9105932 |
| effect of inclusion body contaminants on the oxidative renaturation of hen egg white lysozyme. | the effect of typical contaminants in inclusion body preparations such as dna, ribosomal rna, phospholipids, lipopolysaccharides, and other proteins on renaturation rate and yield of hen egg white lysozyme was investigated. separate experiments were conducted in which known amounts of individual contaminants were added to test their effect on renaturation kinetics. on the basis of a simplified model for the kinetic competition between folding and aggregation, it was found that none of the above ... | 1997 | 9104038 |
| hamburger-associated escherichia coli o157:h7 infection in las vegas: a hidden epidemic. | this study sought to determine whether a multistate fast food hamburger-associated outbreak of escherichia coli o157:h7 infection involved las vegas residents as well and, if so, why public health officials had not detected it. | 1997 | 9103093 |
| distribution and characterization of faecal verotoxin-producing escherichia coli (vtec) isolated from healthy cattle. | faecal swabs obtained from a random sample of 268 cows and 90 calves on 19 lugo farms were examined for verotoxin-producing escherichia coli (vtec). we found vtec on 95% of the farms. the prevalence rates of vtec infection in asymptomatic cows and calves were estimated to be 35 and 37%, respectively. the proportion of animals infected on each farm ranged from 0 to 100%. vtec strains isolated from healthy cattle belonged to 27 o serogroups; however, 57% (85 of 149) were of one of 8 serogroups (o2 ... | 1997 | 9100331 |
| binding of transducin to light-activated rhodopsin prevents transducin interaction with the rod cgmp phosphodiesterase gamma-subunit. | in photoreceptor cells of vertebrates, the gtp-bound alpha-subunit of rod g-protein, transducin (g(t alpha)), interacts with the cgmp phosphodiesterase inhibitory gamma-subunit (pgamma) to activate the effector enzyme. the gdp-bound g(t alpha) can also bind the pgamma subunit, albeit with a lower affinity than g(t alpha)gtp. in this work, interactions between g(t alpha)gdp and pgamma or pgamma-24-45cys labeled with the fluorescent probe 3-(bromoacetyl)-7-(diethylamino)coumarin (pgammabc, pgamma- ... | 1997 | 9100013 |
| the reversible antiport-uniport conversion of the phosphate carrier from yeast mitochondria depends on the presence of a single cysteine. | wild type and mutant phosphate carriers (pic) from saccharomyces cerevisiae mitochondria were expressed in escherichia coli as inclusion bodies, solubilized, purified, and optimally reconstituted into liposomal membranes. this pic can function as coupled antiport (pi-/pi- antiport and pi- net transport, i.e. pi-/oh- antiport) and uncoupled uniport (mercuric chloride-induced pi- efflux). the basic kinetic properties of these three transport modes were analyzed. the kinetic properties closely rese ... | 1997 | 9099701 |
| improved activity of a synthetic indolicidin analog. | a novel cationic peptide, cp-11, based on the structure of the bovine neutrophil peptide indolicidin, was designed to increase the number of positively charged residues, maintain the short length (13 amino acids), and enhance the amphipathicity relative to those of indolicidin. cp-11, and especially its carboxymethylated derivative, cp-11c, demonstrated improved activity against gram-negative bacteria and candida albicans, while it maintained the activity of indolicidin against staphylococci and ... | 1997 | 9087487 |
| characterization of human p33/41 (annexin iv), a ca2+ dependent carbohydrate-binding protein with monoclonal anti-annexin iv antibodies, as11 and as17. | p33/41 (annexin iv) is a member of the family of ca(2+)-dependent phospholipid binding proteins known as annexins. we previously described that bovine kidney p33/41 (annexin iv) has ca(2+)-dependent carbohydrate binding activity. in this study, we purified human p33/41 (annexin iv) from the ht29, human colon adenocarcinoma cell line, as well as the bovine kidney annexin by affinity chromatography. then, we prepared recombinant human p33/41 (annexin iv) expressed in escherichia coli. the apparent ... | 1997 | 9084877 |
| a gene cluster closely related to type ii secretion pathway operons of gram-negative bacteria is located on the large plasmid of enterohemorrhagic escherichia coli o157 strains. | analysis of 14.162 kb of dna derived from plasmid po157 of enterohemorrhagic escherichia coli (ehec) o157:h7 strain edl933, extending in the 5' direction of the recently described ehec-hly operon, revealed 13 open reading frames (orf) which showed great similarities to genes of members of the type ii pathway secretion systems of gram-negative bacteria. we named the orfs etpc to etpo for ehec type ii secretion pathway. in addition, an is911-like insertion element was found to separate the etp gen ... | 1997 | 9084155 |
| nucleotide occupancy of f1-atpase catalytic sites under crystallization conditions. | using site-directed tryptophan fluorescence we studied nucleotide occupancy of the catalytic sites of escherichia coli f1-atpase, under conditions used previously for crystallization and x-ray structure analysis of the bovine mitochondrial enzyme [abrahams et al. (1994) nature 370, 621-628]. we found that only two of the three catalytic sites were filled in the e. coli enzyme under these conditions (250 microm mgamppnp plus 5 microm mgadp), consistent with what was reported in the bovine f1 x-ra ... | 1997 | 9074628 |
| large-scale preparation and characterization of recombinant ovine placental lactogen. | to clone ovine placental lactogen (opl) cdna, total rna from sheep placental cotyledon was reverse transcribed and the single-stranded cdna was pcr-amplified with 5' and 3' primers containing, respectively, ncoi and psti sites. the opl cdna fragment amplified between these two primers extended from a(-1) to the natural stop codon. the pcr product was gel-purified and subcloned into a puc vector and the insert was sequenced on both strands, revealing several differences relative to the published ... | 1997 | 9071989 |
| role of polyethyleneimine in the purification of recombinant human tumour necrosis factor beta. | the chromatographic behaviour of recombinant human tumour necrosis factor beta (rhtnf-beta) (pi approximately 9.0) during cation-exchange chromatography at ph 7.5 is investigated. without prior treatment of the escherichia coli cell extract with polyethyleneimine (pei), very little rhtnf-beta was bound to the column. however, upon addition of 5% pei (100 microliters ml-1) to the cell lysate, rhtnf-beta was shown to bind to cation-exchange columns normally. tnf-beta was readily precipitated from ... | 1997 | 9062987 |
| cloning and expression of cdna for a newly identified isozyme of bovine liver 3-hydroxyacyl-coa dehydrogenase and its import into mitochondria. | cdna for a heretofore undescribed mitochondrial 3-hydroxyacyl-coa dehydrogenase, designated as the type ii enzyme with different molecular and catalytic properties, compared to those of the classical mitochondrial beta-oxidation enzyme (type i enzyme), was cloned from a bovine liver cdna library. nucleotide sequence of the cdna encoded 261 amino acids with a subunit molecular weight of 27,140. the deduced primary structure of the type ii enzyme showed no significant homology to the reported amin ... | 1997 | 9061028 |
| efficacy of cefquinome for treatment of cows with mastitis experimentally induced using escherichia coli. | the efficacy of intramuscularly and intramammarily administered cefquinome was evaluated in experimental escherichia coli mastitis in dairy cows. forty-seven multiparous, israeli holstein cows in early lactation that produced at least 25 l/d of milk were used, and 400 to 750 cfu of e. coli were infused into two healthy quarters of each cow. cows were randomly assigned to one of the following treatment groups: 1) 75 mg of cefquinome administered intramammarily three times at 12-h intervals, 2) 75 ... | 1997 | 9058274 |
| reticuloendothelial system uptake of infused 125i-trypsin in newborn and adult rats. | previous studies have demonstrated enhanced intestinal trypsin uptake and decreased liver clearance of trypsin in newborn rats compared to adults. in order to examine the effectiveness of the reticuloendothelial system (res) in clearing trypsin, bovine trypsin (1.25 mg/100 g body weight) plus trace 125i-trypsin were injected into the portal vein of 2-week-old (n = 57) and adult (n = 44) control rats or following res stimulation using intraperitoneally injected lipopolysaccharide or res suppressi ... | 1997 | 9057994 |
| the function of recombinant cytochrome p450s in intact escherichia coli cells: the 17 alpha-hydroxylation of progesterone and pregnenolone by p450c17. | studies are reported showing that recombinant p450c17, coexpressed with rat nadph-p450 reductase or expressed as a fusion protein containing the domain of the p450 linked to the domain of nadph-p450 reductase, function effectively in intact escherichia coli cells. progesterone is rapidly hydroxylated by transformed e. coli cells at rates as rapid as 50 nmol of steroid hydroxylated/min/nmol of p450 at 37 degrees c. this rate measured in vivo equals or exceeds the best rates we have measured when ... | 1997 | 9056252 |
| [low molecular weight gtpase of the rac family from the bovine retina. structure of cdna and its expression in a prokaryotic system]. | cdna with a high degree of homology to the rac1 gene of the ras-like protein from the hl-60 cell line was isolated from a bovine retina cdna library. the homologies of the nucleotide and deduced amino acid sequences were 90 and 98%, respectively. the product of cdna expression in e. coli cells purified by chromatography displayed gtp-binding and gtpase activities. the data suggest that the rac1 protein is one of the low-molecular gtp-binding proteins in photoreceptor membranes of vertebrates. | 1996 | 9054337 |
| fimbriae extracts from enterotoxigenic escherichia coli strains of bovine and porcine origin with k99 and/or f41 antigens. | fimbriae extracts obtained using the thermal shock method, from bovine and porcine enterotoxigenic escherichia coli strains with k99 and/ or f41 antigens, were analyzed by sds-page, immunoblotting and haemagglutinating activity. three major protein bands with molecular weights 17 kda, 29.3 kda and 30.9 kda were detected depending on the strain assayed. a 17 kda band was identified as the fimbrial subunit for k99 fimbriae and was detected in strains of bovine and porcine origin. the 30.9 kda band ... | 1996 | 9054120 |
| expression and function of recombinant endothelial nitric oxide synthase gene in canine basilar artery. | endothelial no synthase (enos) is an enzyme responsible for the production of a potent vasodilator and a key regulator of vascular tone, no. in peripheral arteries, expression of a recombinant enos gene increases production of no in the blood vessel wall. this approach appears to be a promising strategy for gene therapy of cerebrovascular disease. the major objective of the present study was to determine whether a recombinant enos gene (adcmvnos) can be functionally expressed in cerebral arterie ... | 1997 | 9048652 |
| expression, purification and immunochemical characterization of recombinant bovine beta-lactoglobulin, a major cow milk allergen. | the immunological characteristics of a recombinant beta-lactoglobulin were studied using monoclonal antibodies, polyclonal antiserum and sera from allergic patients. recombinant beta-lactoglobulin (rblg) was expressed in escherichia coli strain dh5alpha and purified as described previously [cho et al. (1994) j. biol. chem. 269, 11 102-11 107]. the method has been modified by adding an immunoaffinity purification step. a quantity of 5-10mg of purified rblg per liter of medium culture can be produ ... | 1996 | 9047377 |
| studies on the development and use of a monoclonal sandwich elisa for the detection of verotoxic escherichia coli in animal faeces. | a sandwich elisa using monoclonal antibodies to escherichia coli verocytotoxins 1 and 2 for capture and detection was developed for detection of verocytotoxin-producing escherichia coli (vtec) in animal faeces. for optimal toxin detection, the faeces were cultured in macconkey broth before subculture on to trypticase soy agar containing mitomycin c. it was possible to detect between 10 and 10(3) vti-producing and 1 to 10 vt2-producing e coli/g faeces, and overall the sensitivity and specificity ... | 1997 | 9042694 |
| comparison of the recombinant and authentic forms of the pasteurella haemolytica a1 glycoprotease. | the o-sialoglycoprotein endopeptidase (glycoprotease, gcp) is secreted by pasteurella haemolytica a1, a gram-negative pathogen associated with bovine pneumonic pasteurellosis. when the cloned gcp gene is expressed in escherichia coli, the recombinant glycoprotease (rgcp) is exported to the periplasm but does not exhibit enzymatic activity. polyclonal calf sera and murine monoclonal antibodies to rgcp were used for the further immunological and biochemical characterization of the authentic and re ... | 1997 | 9037761 |
| interconversion of red opsin isoforms by the cyclophilin-related chaperone protein ran-binding protein 2. | ran-binding protein 2 (ranbp2) (type ii) is a retinal cyclophilin-related protein that binds ran-gtpase. type i cyclophilin is a shorter, alternatively spliced isoform of ranbp2. recently, we showed that the ran-binding domain 4 (rbd4)/cyclophilin (cy) supradomain of ranbp2 acts both in vitro and in vivo as a specific chaperone for bovine red/green opsin (r/g opsin). r/g opsin undergoes a stable modification of its electrophoretic mobility upon binding to ranbp2. this modification is likely due ... | 1997 | 9037092 |
| effects of minor and major groove-binding drugs and intercalators on the dna association of minor groove-binding proteins reca and deoxyribonuclease i detected by flow linear dichroism. | linear and circular dichroic spectroscopies have been employed to investigate the effects of small dna ligands on the interactions of two proteins which bind to the minor groove of dna, viz. reca protein from escherichia coli and deoxyribonuclease i (bovine pancreas). ligands representing three specific non-covalent binding modes were investigated: 4',6-diamidino-2-phenylindole and distamycin a (minor groove binders), methyl green (major groove binder), and methylene blue, ethidium bromide and e ... | 1997 | 9030776 |
| bacteriological culture of blood from critically ill neonatal calves. | the objectives of this study were to estimate the prevalence of bacteremia in critically ill, neonatal calves with severe diarrhea or depression, and to describe the variety of bacteria involved. two studies were conducted in the summers of 1991 and 1993 involving 190 neonatal calves, 1-day to 19-days-old. bacteremia was detected by blood culture in 31% (28/90) of calves in study 1, and in 24% (19/79) of ill calves and 0% (0/21) of control calves in study 2. bacteria cultured from blood included ... | 1997 | 9028592 |
| ultrastructural and immunocytochemical study of the pulmonary intravascular macrophages of escherichia coli lipopolysaccharide-treated sheep. | pulmonary intravascular macrophages (pims) of sheep, cattle, goats, and horses have a novel heparin-sensitive chain of globules, called a surface coat, on their plasma membrane. the globules are arranged at a distance of 32-39 nm from the plasma membrane of pims. intravascular nonbiological tracer particles complex with these globules prior to their endocytosis by the pims. | 1997 | 9026001 |
| the recombinant alpha isoform of protein kinase ck1 from xenopus laevis can phosphorylate tyrosine in synthetic substrates. | the cdna coding for protein kinase ck1 alpha has been cloned from a xenopus laevis cdna library. the derived amino acid sequence of the protein contains 337 amino acids and has a calculated molecular mass of 38874 da. the sequence is identical to that of the human ck1 alpha and to the bovine ck1 alpha, except that it is 12 amino acids longer than the latter protein. southern blotting with a 264-bp probe demonstrates that four or more fragments are obtained upon digestion of genomic dna with ecor ... | 1996 | 9022677 |
| the proton-translocating nadh-quinone oxidoreductase (ndh-1) of thermophilic bacterium thermus thermophilus hb-8. complete dna sequence of the gene cluster and thermostable properties of the expressed nqo2 subunit. | the genes encoding the proton-translocating nadh-quinone oxidoreductase (ndh-1) of a thermophilic bacterium thermus thermophilus hb-8 were cloned and sequenced. they constitute a cluster that is composed of 14 structural genes and contains no unidentified reading frames. all of the 14 structural genes, which are designated nqo1-14, encode subunits homologous to those of paracoccus denitrificans ndh-1, respectively, and are arranged in the same order as other bacterial ndh-1 genes. t. thermophilu ... | 1997 | 9020134 |
| kinetics of excision of purine lesions from dna by escherichia coli fpg protein. | the kinetics of excision of damaged purine bases from oxidatively damaged dna by escherichia coli fpg protein were investigated. dna substrates, prepared by treatment with h2o2/fe(iii)-edta or by gamma-irradiation under n2o or air, were incubated with fpg protein, followed by precipitation of dna. precipitated dna and supernatant fractions were analyzed by gas chromatography/isotope-dilution mass spectrometry. kinetic studies revealed efficient excision of 8-hydroxyguanine (8-oh-gua), 2,6-diamin ... | 1997 | 9016584 |
| identification of a c-terminal binding site for g-protein betagamma-subunits in phosducin-like protein. | phosducin-like protein (phlp) has recently been identified as a ubiquitous inhibitor of g-protein betagamma-subunit (g betagamma)-mediated signaling, with an affinity about 5-fold lower than that of phosducin. the g betagamma binding site of phosducin has been suggested to be contained in its n-terminus. a region corresponding to this n-terminus is lacking in phlp, suggesting that phlp must utilize a different mode of g betagamma binding. to map the g betagamma binding site in phlp, a series of ... | 1997 | 9013896 |
| expression of the colh gene encoding clostridium histolyticum collagenase in bacillus subtilis and its application to enzyme purification. | the colh gene encoding 116-kda collagenase of clostridium histolyticum (ccolh) was cloned into an escherichia coli-bacillus subtilis shuttle vector to develop a method for purification of recombinant collagenase (rcolh). when plasmid pjcm310 containing the colh gene was introduced into b. subtilis db104 and the transformant was grown in lb broth at 37 c, stability of the plasmid was not maintained. however, stability was partly improved by growing the transformant in a modified lb broth containi ... | 1996 | 9013490 |
| casein kinase ii phosphorylates bovine papillomavirus type 1 e1 in vitro at a conserved motif. | the e1 protein of bovine papillomavirus type 1 (bpv-1) is a phosphoprotein which specifically binds and unwinds the virus replication origin by atp-dependent helicase activity. the el protein has been shown to be multiply phosphorylated in vivo, although the sites of modification are incompletely mapped. examination of the predicted amino acid sequence of all available e1 proteins revealed strong conservation between amino acids 25 and 60 of a motif consisting of a serine residue followed by a s ... | 1997 | 9010301 |
| structure-function studies of the adenylate cyclase toxin of bordetella pertussis and the leukotoxin of pasteurella haemolytica by heterologous c protein activation and construction of hybrid proteins. | the adenylate cyclase toxin (cyaa) from bordetella pertussis and the leukotoxin (lkta) from pasteurella haemolytica are members of the rtx (stands for repeats in toxin) family of cytolytic toxins. they have pore-forming activity and share significant amino acid homology but show marked differences in biological activity. cyaa is an invasive adenylate cyclase and a weak hemolysin which is active on a wide range of mammalian cells. lkta is a cytolytic protein with a high target cell specificity an ... | 1997 | 9006045 |
| [utilization of nylon membranes for specific isolation and characterization of verotoxin-producing escherichia coli using dna probes]. | a method for specific isolation of vt(+)-strains in raw milk is given. dna-hybridization technique with dig-labeled pcr-amplificates as probes are the basis. no background is seen by using "dig easy hyb" solution and nylon membranes for colony- and plaque-hybridization (boehringer mannheim gmbh). marked colonies are visible on the membranes after detection. so it is possible to select these colonies from a masterplate. the results are available within one day (without enrichment and membrane pre ... | 1996 | 8999776 |
| intrauterine bacterial findings and hormonal profiles in post-partum cows with normal puerperium. | the post-partum intrauterine bacterial flora, prostaglandin release, uterine involution and resumption of ovarian activity were studied in 9 swedish dairy cows during the first 8-week period. uterine involution was monitored by transrectal examinations of the reproductive tract 3 times weekly. bacteriological examination was performed from twice weekly uterine biopsies. the main pgf2 alpha metabolite (15-ketodihydro-pgf2 alpha) was monitored from twice daily blood plasma samples, while morning s ... | 1996 | 8996871 |
| effect of natural infection with minor pathogens on susceptibility to natural infection with major pathogens in the bovine mammary gland. | to evaluate the effect of natural udder infection with minor pathogens on subsequent natural infection with major pathogens. | 1997 | 8989490 |
| evaluation of a nutritive oral rehydration solution for the treatment of calf diarrhoea. | the essential constituents of a conventional oral rehydration solution (ors) are sodium, glucose and a bicarbonate precursor. the glucose promotes sodium uptake but because these solutions are isotonic, it is insufficient to sustain calorie requirements. this paper examines the performance of a novel ors with over three times the conventional glucose concentration, by comparing it with two leading commercial orss in calves with induced escherichia coli diarrhoea. this solution showed greater abi ... | 1996 | 8979427 |
| experimental escherichia coli o157:h7 carriage in calves. | nine weaned calves (6 to 8 weeks of age) were given 10(10) cfu of a five-strain mixture of enterohemorrhagic escherichia coli o157:h7 by oral-gastric intubation. after an initial brief period of pyrexia in three calves and transient mild diarrhea in five calves, calves were clinically normal throughout the 13- to 27-day study. the population of e. coli o157:h7 in the faces decreased dramatically in all calves during the first 2 weeks after inoculation. thereafter, small populations of e. coli o1 ... | 1997 | 8979335 |
| human insulin-like growth factor i (igf-i) produced in the mammary glands of transgenic rabbits: yield, receptor binding, mitogenic activity, and effects on igf-binding proteins. | insulin-like growth factor i (igf-i) has acute insulin-like metabolic effects and long-term anabolic actions offering a range of important therapeutic applications. to evaluate a system for large-scale production of this peptide in the mammary glands of transgenic livestock, we generated transgenic rabbits carrying fusion genes in which a synthetic dna coding for human igf-i (higf-i) was placed under the transcriptional control of regulatory elements isolated from the bovine alpha s1-casein (alp ... | 1997 | 8977418 |
| anaplasma marginale major surface protein 3 is encoded by a polymorphic, multigene family. | the immunodominant surface protein, msp3, is structurally and antigenically polymorphic among strains of anaplasma marginale. in this study we show that a polymorphic multigene family is at least partially responsible for the variation seen in msp3. the a. marginale msp3 gene msp3-12 was cloned and expressed in escherichia coli. with msp3-12 as a probe, multiple, partially homologous gene copies were identified in the genomes of three a. marginale strains. these copies were widely distributed th ... | 1997 | 8975906 |
| site-directed mutagenesis and spectroscopic characterization of human ferrochelatase: identification of residues coordinating the [2fe-2s] cluster. | the five cysteines closest to the carboxyl terminus of human ferrochelatase have been individually mutated to serine, histidine, or aspartate residues in an attempt to identify the protein ligands to the [2fe-2s] cluster. mutations of cysteines at positions 403, 406, and 411 (c403d, c403h, c406d, c406h, c406s, c411h, and c411s mutants) all resulted in inactive enzyme that failed to assemble the [2fe-2s] cluster as judged by whole-cell epr studies. in contrast, mutation of the cysteines at positi ... | 1996 | 8973195 |
| the use of selective and differential agars in the isolation of escherichia coli o157 from dairy herds. | the use of selective and differential agars for the isolation of escherichia coli o157 from the faeces of dairy herds was investigated. out of the 614 isolates which were positive for one or more of the selective criteria employed in the media only four proved to be e. coli o157. ninety-nine per cent of the isolates were false positives. the procedure which resulted in the isolation of e. coli o157 from faecal samples was enrichment in modified tryptone soya broth supplemented with novobiocin an ... | 1996 | 8972093 |
| the use of electrochemistry for the synthesis of 17 alpha-hydroxyprogesterone by a fusion protein containing p450c17. | a method has been developed for the commercial application of the unique oxygen chemistry catalyzed by various cytochrome p450s. this is illustrated here for the synthesis of hydroxylated steroids. this method requires the preparation of large amounts of enzymatically functional p450 proteins that can serve as catalysts and a technique for providing electrons at an economically acceptable cost. to generate large amounts of enzymatically active recombinant p450s we have engineered the cdnas for v ... | 1996 | 8969926 |
| [synthesis in escherichia coli and certain properties of hybrid protein consisting of a modified precursor of adrenodoxin reductase and shortened precursor of adrenodoxin]. | some aspects of formation and functioning of the cholesterol hydroxylase system were studied. a hybrid protein was synthesized in e. coli composed of the modified form of the (nadph)adrenodoxin reductase precursor (n-terminal domain) and the shortened adrenodoxin precursor (c-terminal domain). the modified reductase precursor contained 12 extra amino acid residues at the n-terminus and the n-terminally shortened adrenodoxin precursor had 17 c-terminal amino acids of its targeting presequence. th ... | 1996 | 8962919 |
| the atpase inhibitor protein from bovine heart mitochondria: the minimal inhibitory sequence. | the mitochondrial atpase inhibitor subunit is a basic protein of 84 amino acids that helps to regulate the activity of f1f0-atpase. in order to obtain structural information on the mechanism of inhibition, the bovine inhibitor subunit has been expressed in escherichia coli and purified in high yield. the recombinant protein has a similar inhibitory activity to the inhibitor subunit isolated from bovine mitochondria. progressive n-terminal and c-terminal deletion mutants of the inhibitor subunit ... | 1996 | 8961923 |
| rnas mediating cotranslational insertion of selenocysteine in eukaryotic selenoproteins. | selenocysteine, a selenium-containing analog of cysteine, is found in the prokaryotic and eukaryotic kingdoms in active sites of enzymes involved in oxidation-reduction reactions. its biosynthesis and cotranslational insertion into selenoproteins is performed by an outstanding mechanism, implying the participation of several gene products. the trna(sec) is one of these. in eukaryotes, its transcription mode by rna polymerase iii differs from that of classical trna genes, both at the level of the ... | 1996 | 8955902 |
| interpretive criteria for antimicrobial susceptibility testing of ceftiofur against bacteria associated with swine respiratory disease. | ceftiofur, an extended-spectrum cephalosporin, is active against a variety of animal pathogens, including organisms associated with swine respiratory disease. however, minimum inhibitory concentration (mic) breakpoint and disk diffusion interpretive criteria have not been established for swine pathogens. susceptibility tests were performed by broth microdilution mic and disk diffusion methods on 246 bacterial species that cause swine respiratory disease. ceftiofur was active against salmonella s ... | 1996 | 8953533 |
| human endothelial nitric oxide synthase: expression in escherichia coli, coexpression with calmodulin, and characterization. | human endothelial nitric oxide synthase (enos) has been cloned and expressed in escherichia coli. the spectroscopic properties and specific activity (100-130 nmol x min(-1) x mg(-1) at 37 degrees c) of the recombinant protein are similar to those of the bovine enzyme. fplc and low-temperature sds-page indicate that the protein is mostly dimeric in both the absence and presence of tetrahydrobiopterin. human enos thus has a higher tendency to dimerize than the bovine enzyme. a chloramphenicol-resi ... | 1996 | 8951046 |
| replication protein-a mediates the association of calf thymus dna polymerase alpha-dna primase complex with guanine-rich dna sequence. | we have shown that calf thymus dna polymerase alpha-dna primase complex (pol alpha-primase) preferentially binds to pyrimidine-rich sequences and initiates rna primer synthesis [suzuki, m. et al. (1993) biochemistry 32, 12782-12792]. here we tested the association of pol alpha-primase with a guanine-rich dna fragment (svg, 30-mer) containing in vivo initiation sites of simian virus 40 dna replication. while pyrimidine-rich fragment (ctpps 1, 30-mer), that is a preferred sequence for calf thymus ... | 1996 | 8947839 |
| rapid and specific detection of f17-related pilin and adhesin genes in diarrheic and septicemic escherichia coli strains by multiplex pcr. | the f17-related adhesins are prevalent in escherichia coli strains isolated from calves with diarrhea or septicemia and from lambs with nephropathy. the f17 family includes the f17a, f17b, f17c, and f111 fimbriae produced by bovine e. coli strains and the g agglutinin produced by human uropathogenic e. coli strains. an easy and inexpensive multiplex pcr method was developed to detect all the f17-related fimbriae and to identify four subtypes of structural subunit genes and two distinct subfamili ... | 1996 | 8940423 |
| binding of an n-terminal rhodanese peptide to dnaj and to ribosomes. | a peptide corresponding to the n-terminal 17 amino acids of bovine rhodanese was fluorescently labeled with a coumarin derivative at its primary amino group(s) and then purified by high performance liquid chromatography. this peptide interacted with the molecular chaperone dnaj in the absence of other chaperones and atp. in the presence of atp, the molecular chaperone dnak bound to the dnaj-peptide complex, but not to the peptide alone. the chaperone grpe appeared to cause the release of the pep ... | 1996 | 8940114 |
| cholesterol 7alpha-hydroxylase activities from human and rat liver are modulated in vitro posttranslationally by phosphorylation/dephosphorylation. | purified cholesterol 7alpha-hydroxylases (c7alphah) from human and rat liver microsomes, and from transformed escherichia coli expression systems, were incubated with 0.3 mmol/l [gamma-32p] adenosine triphosphate (atp) in the presence and absence of bacterial alkaline phosphatase (ap) or rabbit muscle adenosine 3',5'-cyclic monophosphate (camp)-dependent protein kinase. the amounts of 32p incorporation after separation of human and rat c7alphah proteins by sodium dodecyl sulfate-polyacrylamide g ... | 1996 | 8938182 |
| equilibrium constants for nonspecific binding of proteins to dna may be obtained by quantitative zonal dna affinity chromatography. | quantitative zonal dna affinity chromatography may be used to determine accurate equilibrium constants for the binding of proteins nonspecifically to dna. zonal quantitative affinity chromatography has not previously been applied to the determination of binding constants of proteins to dna, although its use is quite commonplace for determination of affinity constants for protein-protein or protein-small ligand interactions. equilibrium constants were measured for the nonspecific binding of bovin ... | 1996 | 8937566 |
| the restriction-modification system of pasteurella haemolytica is a member of a new family of type i enzymes. | genes encoding the type i restriction-modification (r-m) system of the bovine pathogen, pasteurella haemolytica, have been identified immediately downstream of a locus that encodes a transcriptional activator of p. haemolytica leukotoxin expression. type i enzymes are encoded by three genes called hsdm, hsds and hsdr, and have fallen into three groups, called ia, ib and ic. hsds provides a sequence recognition function which in concert with hsdm forms an active methyltransferase (mtase). inclusi ... | 1996 | 8921897 |
| a pcr-based assay for the detection of escherichia coli shiga-like toxin genes in ground beef. | a detection system based on the pcr has been developed for escherichia coli strains which harbor the shiga-like toxin genes. this quantitative detection system involves the 5'-->3' nuclease activity of thermus aquaticus dna polymerase, which cleaves an internal oligonucleotide probe that has been labeled with both a fluorescent reporter dye (6-carboxy-fluorescein [fam]) and a quencher dye (6-carboxytetramethyl-rhodamine [tamra]). parameters which affected the performance of the assay included pr ... | 1996 | 8919796 |
| structure-biological activity relationships of 11-residue highly basic peptide segment of bovine lactoferrin. | the antimicrobial peptide, lactoferricin, is generated upon the gastric pepsin cleavage of lactoferrin and has many basic and hydrophobic amino acid residues essential for its biological activity. to investigate the structure-antimicrobial activity relationships, the basic amino acid-rich region of bovine lactoferricin (blfc), rrwqwrmkklg, was selected. using chemically synthesized blfc and its substituted peptides, the antimicrobial activities of the peptides were tested by determining the mini ... | 1996 | 8919056 |
| bacterial growth, inflammatory cytokine production, and neutrophil recruitment during coliform mastitis in cows within ten days after calving, compared with cows at midlactation. | to define causes of increased susceptibility to coliform mastitis after parturition. | 1996 | 8915431 |