Publications

the susceptibility of gram-negative rods and their adaptive forms resistant to colistine to the bactericidal action of sera.	the susceptibility of escherichia coli k1, salmonella enteritidis, salmonella typhimurium strains and their adaptative forms resistant to colistine (colr forms) was compared with respect to their sensitivity to the bactericidal action of normal cord serum and normal bovine serum. it has been shown that the colr forms are more susceptible to sera as compared to initial strains. the increase of sensitivity of the colr forms is connected with structural changes within bacterial cell wall which is t ...	1998	9990711
mechanisms of dna damage by chromium(v) carcinogens.	reactions of bis(2-ethyl-2-hydroxy-butanato)oxochromate(v) with puc19 dna, single-stranded calf thymus dna (ss-ctdna), a synthetic oligonucleotide, 5'-gatctatggacttacttcaaggccgggtaatgcta-3' (35mer), deoxyguanosine and guanine were carried out in bis-tris buffer at ph 7.0. the plasmid dna was only nicked, whereas the single-stranded dna suffered extensive damage due to oxidation of the ribose moiety. the primary oxidation product was characterized as 5-methylene-2-furanone. although all four base ...	1998	9512527
evaluation of an enzyme-linked immunosorbent assay using recombinant major surface protein 5 for serological diagnosis of bovine anaplasmosis in venezuela.	an indirect enzyme-linked immunosorbent assay (elisa) was developed for the serological diagnosis of bovine anaplasmosis with purified recombinant major surface protein 5 (msp5) of anaplasma marginale produced in escherichia coli. serum antibody responses against msp5 were detected in calves experimentally infected with a. marginale as early as 21 days postinfection and reached maximum titers at 28 days postinfection. the msp5 elisa performed with serum samples taken from field cattle from diffe ...	1998	9521155
one-headed kinesin derivatives move by a nonprocessive, low-duty ratio mechanism unlike that of two-headed kinesin.	a single molecule of the "two-headed" motor enzyme kinesin can move along a microtubule continuously for many enzymatic turnovers (processive movement), and the velocity produced by one kinesin molecule is the same as that produced by many kinesin molecules (high duty ratio). we studied the microtubule movement driven at 1 mm atp by biotinated n-terminal fragments of drosophila kinesin heavy chain attached to streptavidin-coated coverslips at various surface densities. k448-bio has velocity at a ...	1998	9521668
risk factors for clinical mastitis in a random sample of dairy herds from the southern part of the netherlands.	the incidence of clinical mastitis in dairy cows was estimated in 171 randomly selected dairy herds from the southern part of the netherlands. a total of 1103 quarter cases was reported. the mean annual incidence rate was 12.7 quarter cases/yr per 100 cows. the modeling incidence rate of clinical mastitis at the herd level indicated that a number of risk factors were associated with a higher rate of clinical mastitis: one or more cows that were leaking milk, one or more cows with trampled teats, ...	1998	9532495
alteration in immune responsiveness during the peripartum period and its ramification on dairy cow and calf health.	substantial evidence indicates that innate and acquired defense mechanisms are lowest from 3 wk precalving to 3 wk postcalving. this lowered responsiveness includes aspects of systemic and mammary gland immunity that may account, at least in part, for the increased incidence of peripartum disease. the physical and metabolic stresses of pregnancy, calving, and lactation may contribute to this decrease in host resistance and the subsequent increase in disease incidence. however, variation among co ...	1998	9532513
reduction of carriage of enterohemorrhagic escherichia coli o157:h7 in cattle by inoculation with probiotic bacteria.	bacteria inhibitory to escherichia coli o157:h7 were isolated from cattle and evaluated for their potential for reducing carriage of e. coli o157:h7 in calves. eighteen of 1,200 bacterial isolates from cattle feces and intestinal tissue samples were screened and determined to inhibit the growth of e. coli o157:h7 in vitro. seventeen of the isolates were e. coli and one was proteus mirabilis. none produced shiga toxin. genomic dna fingerprinting by pulsed-field gel electrophoresis revealed 13 dis ...	1998	9508288
intergenic suppression of the gammam23k uncoupling mutation in f0f1 atp synthase by betaglu-381 substitutions: the role of the beta380delseed386 segment in energy coupling.	we previously demonstrated that the escherichia coli f0f1-atp synthase mutation, gammam23k, caused increased energy of interaction between gamma- and beta-subunits which was correlated to inefficient coupling between catalysis and transport [al-shawi, ketchum and nakamoto (1997) j. biol. chem. 272, 2300-2306]. based on these results and the x-ray crystallographic structure of bovine f1-atpase [abrahams, leslie, lutter and walker (1994) nature (london) 370, 621-628] gammam23k is believed to form ...	1998	9480879
sequence and context dependence of ef-hand loop dynamics. an 15n relaxation study of a calcium-binding site mutant of calbindin d9k.	the influence of amino acid sequence and structural context on the backbone dynamics of ef-hand calcium-binding loops was investigated using 15n spin relaxation measurements on the calcium-free state of the calbindin d9k mutant (a14d+a15delta+p20delta+n21g+p43m), in which the n-terminal pseudo-ef-hand loop, characteristic of s100 proteins, was engineered so as to conform with the c-terminal consensus ef-hand loop. the results were compared to a previous study of the apo state of the wild-type-li ...	1998	9485409
purification and characterization of the hnda subunit of nadp-reducing hydrogenase from desulfovibrio fructosovorans overproduced in escherichia coli.	based on the dna sequence of its structural genes, clustered in the hnd operon, the nadp-reducing hydrogenase of desulfovibrio fructosovorans is thought to be a heterotetrameric complex in which hnda and hndc constitute the nadp-reducing unit and hndd constitutes the hydrogenase unit, respectively. the weak representativity of the enzyme among cell proteins has prevented its purification. this paper discusses the purification and characterization of the hnda subunit of this unique tetrameric iro ...	1998	9485416
isolation from an ant myrmecia gulosa of two inducible o-glycosylated proline-rich antibacterial peptides.	reported here is the isolation and characterization of two antibacterial peptides synthesized in an ant myrmecia gulosa in response to bacterial challenge. the peptides were purified by reversed-phase high performance liquid chromatography and characterized by peptide sequencing and mass spectrometry. both peptides were formed from 16 amino acids, were rich in proline ( approximately 30%), and had n-acetylgalactosamine o-linked to a conserved threonine. the activity of a synthetic non-glycosylat ...	1998	9497332
infectious agents associated with diarrhoea of calves in the canton of tilarán, costa rica.	a case-control study of calves under 3 months of age was carried out by weekly visits to 15 farms in the canton of tilarán, costa rica. most farms were dedicated to beef or dual-purpose (dp) production. faecal samples were collected over a 6-month period from a total of 194 calves with clinical signs and from 186 animals without clinical signs of diarrhoea as assessed by a scoring system. the samples were investigated for the presence of viruses, bacteria and parasites. torovirus was detected fo ...	1998	9500174
recurrent clinical mastitis caused by escherichia coli in dairy cows.	in this study, the occurrence of persistent intramammary infections caused by escherichia coli with recurrent episodes of clinical mastitis caused by e. coli are described for a cohort of 300 dutch dairy herds. calculations on the recurrent episodes were based on data collected by dairy farmers. the genotype of the e. coli strains was determined by means of a polymerase chain reaction using enterobacterial repetitive intergenic consensus (eric) primers, resulting in a dna fingerprint. quarters i ...	1999	10022009
influence of oxygen availability on physiology, verocytotoxin expression and adherence of escherichia coli o157.	a strain of escherichia coli serotype o157 was grown in steady state chemostat culture under aerobic, oxygen-limited and anaerobic conditions. the growth and metabolic efficiency of oxygen-limited and anaerobic cultures was impaired, with biomass yield and the molar growth yield for glucose, yglucose, reduced markedly in comparison with aerobic cultures. steady state cells were typically short rods 2-3 microns long, and were encapsulated by a layer of extracellular material. the majority of cell ...	1999	10030015
escherichia coli o157:h7 in retail ground beef in seattle: results of a one-year prospective study.	escherichia coli o157:h7 was sought systematically in 1,400 samples of retail ground beef in seattle in a 1-year prospective study. sorbitol-nonfermenting, lactose-fermenting, indole-positive colonies isolated after enrichment culture were probed for the presence of shiga toxin genes. totals of 67,040 sorbitol-nonfermenting and 66,705 sorbitol-fermenting colonies were characterized, but e. coli o157:h7 was not identified. the sensitivity of this technique was usually sufficient to detect e. coli ...	1999	10030631
cytochrome p450c17-expressing escherichia coli as a first-step screening system for 17alpha-hydroxylase-c17,20-lyase inhibitors.	we have designed and synthesized a number of cytochrome p450 17alpha-hydroxylase-c17,20-lyase (p450c17) inhibitors with the aim of inhibiting androgen synthesis. to select the most potent inhibitors, we initially used human testicular microsomes, which have a high level of expression of this enzyme. however, due to lack of availability of human tissue and variability among the samples, we utilized recombinant human enzyme expressed in escherichia coli. we designed a simple and economical protoco ...	1999	10036137
assessment of the adequacy of cleaning of equipment used for breaking beef carcasses.	enumeration of bacteria on product entering or leaving a beef carcass breaking process showed that the meat was being contaminated with escherichia coli during the process. the equipment used in the process appeared to be well cleaned, and few bacteria were recovered from meat-contacting surfaces of cleaned equipment. however, careful inspection of the cleaned equipment revealed obscured locations in the equipment which harboured detritus that carried large numbers of aerobic bacteria including ...	1999	10050680
collaborative evaluation of detection methods for escherichia coli o157:h7 from radish sprouts and ground beef.	for the evaluation of plating and immunological methods applicable to the detection of escherichia coli o157:h7 from ground beef and radish sprouts, a collaborative study was conducted. it focused on a comparison of the efficiency of the plating and immunological methods using various plating agars and immuno-kits in combination with enrichment in modified e. coli broth supplemented with novobiocin (mec + n), and using immunomagnetic separation. the plating media tested were sorbitol macconkey a ...	1999	10050682
characterization of rpos alleles in escherichia coli o157:h7 and in other e. coli serotypes.	the rpos nucleotide and predicted amino acid sequences from three escherichia coli o157:h7 isolates were compared with those from three other e. coli isolates, including the likely o157:h7 progenitor, e. coli o55:h7. these clinical and environmental isolates all had identical sigma s amino acid sequences, while laboratory strains k12 and dh1 had three and one amino acid alterations, respectively, in comparison with the majority sequence. to extend the analysis of sigma s sequence conservation to ...	1999	10063629
characterization of the cardiac holotroponin complex reconstituted from native cardiac troponin t and recombinant i and c.	cardiac troponin i (ctni), the inhibitory subunit of cardiac troponin (ctn), is phosphorylated by the camp-dependent protein kinase a at two adjacently located serine residues within the heart-specific n-terminal elongation. four different phosphorylation states can be formed. to investigate each monophosphorylated form ctni mutants, in which each of the two serine residues is replaced by an alanine, were generated. these mutants, as well as the wild-type cardiac troponin i (ctni-wt) have been e ...	1999	10103031
real-time monitoring of escherichia coli o157:h7 adherence to beef carcass surface tissues with a bioluminescent reporter.	a method for studying bacteria that are attached to carcass surfaces would eliminate the need for exogenous sampling and would facilitate understanding the interaction of potential human food-borne pathogens with food animal tissue surfaces. we describe such a method in which we used a bioluminescent reporter strain of escherichia coli o157:h7 that was constructed by transformation with plasmid pcgls1, an expression vector that contains a complete bacterial luciferase (lux) operon. beef carcass ...	1999	10103275
catalase hpii from escherichia coli exhibits enhanced resistance to denaturation.	catalase hpii from escherichia coli is a homotetramer of 753 residue subunits. the multimer displays a number of unusual structural features, including interwoven subunits and a covalent bond between tyr415 and his392, that would contribute to its rigidity and stability. as the temperature of a solution of hpii in 50 mm potassium phosphate buffer (ph 7) is raised from 50 to 92 degrees c, the enzyme begins to lose activity at 78 degrees c and 50% inactivation has occurred at 83 degrees c. the ina ...	1999	10194300
a mutation in the heterotrimeric stimulatory guanine nucleotide binding protein alpha-subunit with impaired receptor-mediated activation because of elevated gtpase activity.	it has been reported that substitution of arg258, a residue within the gtpase domain of the heterotrimeric guanine nucleotide binding protein (g protein) alpha-subunit (alphas), to alanine (alphas-r258a) results in decreased activation by receptor or aluminum fluoride (alf4-) and increased basal gdp release. arg258 interacts with gln170 in the helical domain, and, presumably, loss of this interaction between the gtpase and helical domain leads to more rapid gdp release, resulting in decreased ac ...	1999	10200251
chloroplast nadh dehydrogenase from pisum sativum: characterization of its activity and cloning of ndhk gene.	the pea chloroplast ndhk gene coding for a component of a nadh-plastoquinone oxidoreductase has been cloned and sequenced. this gene codes for a polypeptide of 227 amino acids and a predicted molecular mass of 25,495 da which belongs to the family of the 20 kda psst subunit of the bovine mitochondrial complex i. a fragment of this gene has been overexpressed in escherichia coli, and antibodies against the expressed polypeptide recognize a protein of the predicted molecular mass from pea thylakoi ...	1999	10202810
detection of multidrug-resistant salmonella enterica serotype typhimurium dt104 based on a gene which confers cross-resistance to florfenicol and chloramphenicol.	salmonella enterica serotype typhimurium (s. typhimurium) dt104 (dt104) first emerged as a major pathogen in europe and is characterized by its pentadrug-resistant pattern. it has also been associated with outbreaks in the united states. the organism typically carries resistance to ampicillin, chloramphenicol, streptomycin, sulfonamides, and tetracycline. the mechanism of chloramphenicol resistance in dt104 was determined by producing antibiotic-resistant escherichia coli host strain clones from ...	1999	10203484
effect of antibiotic induced bacterial clearance in the udder on l-selectin shedding of blood neutrophils in cows with escherichia coli mastitis.	bacterial clearance, l-selectin adhesion receptor expression and neutrophil recruitment during experimentally induced escherichia coli mastitis were investigated. acute mastitis was induced by injection of 10(4) cfu e. coli into both left quarters of 12 clinically healthy lactating cows, 2-6 weeks after parturition. half the cows were treated intravenously 10 h after infection, and subcutaneously 30 h after infection with enrofloxacin. in both groups, bacterial count, milk serum albumin, milk so ...	1999	10206204
antibacterial activity of gentamicin and ciprofloxacin against gram-negative bacteria: interactions with pig and calf sera.	the antibacterial activity of pig and calf serum and its ability to interact with gentamicin and ciprofloxacin were studied in vitro using escherichia coli k-12, proteus rettgeri (sanelli) and klebsiella pneumoniae atcc 10031. the antimicrobial activity of the above drugs, alone or in combination with serum, was investigated by the checkerboard method and expressed as the minimal inhibitory concentration (microg ml-1). pig serum (25%) with gentamicin had a synergistic antibacterial effect agains ...	1999	10208763
unusual sites of arginine methylation in poly(a)-binding protein ii and in vitro methylation by protein arginine methyltransferases prmt1 and prmt3.	arginine methylation is a post-translational modification found mostly in rna-binding proteins. poly(a)-binding protein ii from calf thymus was shown by mass spectrometry and sequencing to contain ng, ng-dimethylarginine at 13 positions in its amino acid sequence. two additional arginine residues were partially methylated. almost all of the modified residues were found in arg-xaa-arg clusters in the c terminus of the protein. these motifs are distinct from arg-gly-gly motifs that have been previ ...	1999	10224081
molecular cloning of a novel human collectin from liver (cl-l1).	collectins are a c-lectin family with collagen-like sequences and carbohydrate recognition domains. these proteins can bind to carbohydrate antigens of microorganisms and inhibit their infection by direct neutralization and agglutination, the activation of complement through the lectin pathway, and opsonization by collectin receptors. here we report the cloning of a cdna encoding human collectin from liver (cl-l1 (collectin liver 1)) that has typical collectin structural characteristics, consist ...	1999	10224141
shiga toxin 1 from escherichia coli blocks activation and proliferation of bovine lymphocyte subpopulations in vitro.	shiga toxin-producing escherichia coli (stec) is widespread in the cattle population, but the clinical significance of shiga toxins (stx's) for the bovine species remains obscure. since stx's exert immunomodulating effects in other species, we examined the effect of purified stx1 on a bovine b lymphoma cell line (bl-3) and peripheral blood mononuclear cells (pbmc) isolated from adult bovine blood by viability assays and flow cytometry analysis. stx1 markedly induced apoptosis in stimulated bl-3 ...	1999	10225876
detection of escherichia coli o157:h7 from musca domestica (diptera: muscidae) at a cattle farm in japan.	enterohemorrhagic escherichia coli (ehec) o157:h7 was isolated for the first time from musca domestica l. a total of 310 fly samples was collected from 4 different farms in obihiro-city, hokkaido, in the summer and autumn of 1997;5 samples carried e. coli serotype o157:h7. using elisa and vero cell cytotoxicity assay, 3 isolates from 1 cattle farm produced both active shiga-toxin type 1 (stx1) and 2 (stx2). these isolates also carried hemolysin and eaea genes and harbored the 90-kb virulence pla ...	1999	10071501
modulation of the remote heme site geometry of recombinant mouse neuronal nitric-oxide synthase by the n-terminal hook region.	the role of two essential residues at the n-terminal hook region of neuronal nitric-oxide synthase (nnos) in nitric-oxide synthase activity was investigated. full-length mouse nnos proteins containing single-point mutations of thr-315 and asp-314 to alanine were produced in the escherichia coli and baculovirus-insect cell expression systems. the molecular properties of the mutant proteins were analyzed in detail by biochemical, optical, and electron paramagnetic resonance spectroscopic technique ...	1999	10075660
pattern of diarrhoea in newborn beef calves in south-west france.	a prospective study was carried out on 94 randomly selected beef herds in the midi-pyrénées region in france. the objective was to describe diarrhoea and mortality in beef calves from birth to 30 days of age. calves (3,080) were followed from december 1995 to april 1996, and a total of 700 visits allowed records of herd management practices, individual data and environmental conditions to be collected. the incidence rate for diarrhoea during the neonatal period was 14.6%, and varied markedly bet ...	1999	10081113
expression of bovine cytokines in escherichia coli.	glutathione s-transferase fusion proteins of bovine interleukin-2 (il-2), il-4, il-6 and interferon-gamma (ifn-gamma) were expressed in escherichia coli. complementary dna (cdna) for open reading frame of each cytokine without signal peptide encoding region was amplified by reverse transcriptional polymerase chain reaction method and was subcloned into pgex-5x-1. in result, il-6 and ifn-gamma fusion proteins in bacteria were soluble, but il-2 and il-4 fusion proteins were insoluble. the insolubl ...	1999	10081758
lipopolysaccharide enhances the production of vascular endothelial growth factor by human pulp cells in culture.	we investigated whether vascular endothelial growth factor (vegf) production by human pulp cells (hpc) is regulated by lipopolysaccharide (lps) in relation to the pathogenesis of pulpitis. although hpc incubated with medium alone only marginally expressed vegf mrna and produced a low level of vegf as detected by enzyme-linked immunosorbent assay, the vegf mrna expression and vegf production were markedly enhanced upon stimulation with lps from escherichia coli. prevotella intermedia lps, phorbol ...	1999	10084996
rapid and sensitive detection of escherichia coli o157:h7 in bovine faeces by a multiplex pcr.	cattle are considered the major reservoir for escherichia coli o157:h7, one of the newly emerged foodborne human pathogens of animal origin and a leading cause of haemorrhagic colitis in humans. a sensitive test that can accurately and rapidly detect the organism in the food animal production environment is critically needed to monitor the emergence, transmission, and colonization of this pathogen in the animal reservoir. in this study, a novel multiplex polymerase chain reaction (pcr) assay was ...	1999	10664910
purification and characterization of chitin-binding proteins from the hemolymph of sweet potato hornworm, agrius convolvuli.	three chitin-binding proteins (cbps: cbp9, cbp15, cbp66) were identified from the larval hemolymph of sweet potato hornworm, agrius convolvuli. two (cbp9 and cbp15) of them have been isolated and purified by gel filtration (superdex hr 75), cation-exchange chromatography (mono s), and reverse-phase chromatography (murpc pc 2.1/3). in experiments to detect cbps in hemolymph, we examined whether ionic strength and existence of bovine serum albumin in the incubation solution influenced binding affi ...	1999	10665375
effects of ph and acid resistance on the radiation resistance of enterohemorrhagic escherichia coli.	the effects of ph and the induction of ph-dependent stationary-phase acid resistance on the radiation resistance of escherichia coli were determined for seven enterohemorrhagic strains and one nonenterohemorrhagic strain. the isolates were grown in acidogenic or nonacidogenic media to ph levels of approximately 4.7 and 7.2, respectively. the cells were then transferred to brain heart infusion (bhi) broth adjusted to ph 4.0, 4.5, 5.0, and 5.5 (with hcl) that was preequilibrated to 2 degrees c, an ...	1999	10090239
a recombinant bovine gallbladder mucin polypeptide binds biliary lipids and accelerates cholesterol crystal appearance time.	mucin has a central role in the pathogenesis of cholesterol gallstones, in part because of its ability to bind biliary lipids and accelerate cholesterol crystal appearance time. previous studies have localized these properties to nonglycosylated mucin domains, and we have recently shown that these domains contain a series of 127-amino acid, cysteine-rich repeats. the aim of this study was to express a recombinant mucin polypeptide containing these repeats and investigate its lipid-binding and pr ...	1999	10092316
the effects of the surface charge and hydrophobicity of escherichia coli on its adhesion to beef muscle.	the surface characteristics of escherichia coli strains were studied to evaluate the effect upon bacterial adhesion to beef muscle. the influence of suspension conditions upon the surface charge of a pathogenic strain, e. coli o157:h7 (ec01), and a saprophytic laboratory strain, e. coli jm109 (ec22) were investigated and compared. the cellular surface charge of most e. coli o157:h7 strains were much less affected by changes in the ph, ionic strength or concentration of surfactants in the suspend ...	1999	10634709
phosphoserine aminotransferase, the second step-catalyzing enzyme for serine biosynthesis.	as a step toward analyzing the serine biosynthetic pathway in mammals, we have studied the properties of phosphoserine aminotransferase, the second step-catalyzing enzyme. the k(m) values for 3-phosphohydroxypyruvate and l-phosphoserine are 5 and 35 microm, respectively, and those for glutamate and alpha-ketoglutarate are 1.2 and 0.8 mm, respectively. the product inhibition studies strengthened the support for a ping-pong mechanism and allowed evaluation of ki values for the four substrates. the ...	1999	10637769
some emerging food and water borne pathogens.	emerging pathogens are those infective organisms whose incidence has recently increased or is likely to increase during the next two decades due to changes in demography, food habits, food technology, commerce, water sources and environmental factors. some important emerging food and water borne bacterial pathogens include listeria monocytogenes, campylobacter jejuni, yersinia enterocolitica, salmonella enteritidis, escherichia coli o157: h7, vibrio cholerae biotype e1 tor serotype 0139, vibrio ...	1999	10810592
expression and characterization of e. coli-produced soluble, functional human dihydroorotate dehydrogenase: a potential target for immunosuppression.	human dihydroorotate dehydrogenase (hudhodh) is essential for de novo biosynthesis of pyrimidines and the target of two immunosuppressive drugs, brequinar and the leflunomide metabolite a77-1726 (chen et al., 1992; davis et al., 1996). using a t7 rna polymerase expression system, we produced hudhodh as a fusion protein containing an amino-terminal decahistidine tag. escherichia coli growth and expression conditions were optimized to enhance hudhodh solubility and to permit purification of the en ...	1999	10941801
interactions of the papovavirus dna replication initiator proteins, bovine papillomavirus type 1 e1 and simian virus 40 large t antigen, with human replication protein a.	papovaviruses utilize predominantly cellular dna replication proteins to replicate their own viral genomes. to appropriate the cellular dna replication machinery, simian virus 40 (sv40) large t antigen (tag) binds to three different cellular replication proteins, the dna polymerase alpha-primase complex, the replication protein a (rpa) complex, and topoisomerase i. the functionally similar papillomavirus e1 protein has also been shown to bind to the dna polymerase alpha-primase complex. enzyme-l ...	1999	10233951
patterning cells and their environments using multiple laminar fluid flows in capillary networks.	this paper describes the use of laminar flow of liquids in capillary systems to pattern the cell culture substrate, to perform patterned cell deposition, and to pattern the cell culture media. we demonstrate the patterning of the cell culture substrate with different proteins, the patterning of different types of cells adjacent to each other, the patterned delivery of chemicals to adhered cells, and performing enzymatic reactions over select cells or over a portion of a cell. this method offers ...	1999	10318920
evaluation of the role of endotoxin and cortisol on modulation of cd18 adhesion receptors in cows with mastitis caused by escherichia coli.	to determine the effect of mastitis caused by escherichia coli on expression of cd18 cell surface receptors and to evaluate the involvement and regulation of receptors by lipopolysaccharide (lps) and cortisol.	1999	10328420
expression of recombinant bovine l-selectin in escherichia coli and insect cells.	bovine l-selectin was expressed in bacteria using pgex vector and in insect cells infected with recombinant baculovirus in order to obtain recombinant protein for preparation of specific antiserum and its functional studies. in bacterial expression, l-selectin fusion protein with glutathione s-transferase was detected in the insoluble fraction with the expected molecular weight of 60 kda by sds-page and reacted with anti-bovine cd62l monoclonal antibody in immunoblot analysis. in insect cells in ...	1999	10331197
activation of toxin adp-ribosyltransferases by eukaryotic adp-ribosylation factors.	adp-ribosylation factors (arfs) are members of a multigene family of 20-kda guanine nucleotide-binding proteins that are regulatory components in several pathways of intracellular vesicular trafficking. the relatively small (approximately 180-amino acids) arf proteins interact with a variety of molecules (in addition to gtp/gdp, of course). cholera toxin was the first to be recognized, hence the name. later it was shown that arf also activates phospholipase d. different parts of the molecule are ...	1999	10331652
recombinant chicken ifn-gamma expressed in escherichia coli: analysis of c-terminal truncation and effect on biologic activity.	interferon-gamma (ifn-gamma) possesses potent immunostimulatory properties, and it has recently been shown to have potential therapeutic properties. recombinant protein technology is frequently used for commercial production of therapeutics, such as ifn. biologically active recombinant chicken ifn-gamma (rchifn-gamma) constructs bearing an n-terminal poly-his tag were expressed in escherichia coli. preparations of rchifn-gamma contained varying ratios of a full-length and a truncated protein spe ...	1999	10334390
genomic dna restriction site heterogeneity in bovine pasteurella multocida serogroup a isolates detected with an rrna probe.	a total of 81 pasteurella multocida isolates from healthy and diseased dairy and beef cattle originating from various geographical locations was examined by rrna gene restriction site polymorphism analysis (ribotyping), restriction endonuclease analysis (rea), sds-page analysis of whole-cell (wcp) and outer-membrane (omp) proteins, and capsule and somatic serotyping. bacterial strains were isolated from nose, lung and in one case testicle, of holstein and cross-bred beef cattle. the isolates rep ...	1999	10334595
new general approach for determining the solution structure of a ligand bound weakly to a receptor: structure of a fibrinogen aalpha-like peptide bound to thrombin (s195a) obtained using noe distance constraints and an ecepp/3 flexible docking program.	a new approach incorporating flexible docking simulations and nmr data is presented for calculating the bound conformation of a ligand that interacts weakly with an enzyme. this approach consists of sampling directly the conformation of a flexible ligand inside a receptor active site containing surrounding flexible loops. to make this sampling efficient, a ligand-growing procedure has been adopted. optimization of the ecepp/3-plus-noe constraint function is carried out by using a collective vari ...	1999	10336381
[detection of pas gene in shiga toxin producing escherichia coli (stec)].	results of detection of the pas gene in 10 shigatoxin-producing escherichia coli strains (stec) isolated from foods (raw milk, certified milk, and beef) and in 18 enterohaemorrhagic escherichia coli strains (ehec) isolated from stool samples of patients suffering from hus, diarrhea or from carriers without symptoms are given. all isolates showed the eae gene coding for intimin. we could make sure by using pcr that all isolates showed the pas gene, too. this gene is a factor mainly responsible fo ...	1999	10337054
the use of non-immune plasma powder in the prophylaxis of neonatal escherichia coli diarrhoea in calves.	the protective use of plasma powder from cattle and swine against experimentally induced neonatal e. coli diarrhoea in colostrum-deprived calves was examined. diarrhoea was induced with a strain expressing f5+ fimbriae and a strain expressing f17+ fimbriae. in all groups supplemented with bovine plasma powder, diarrhoea and fever were less severe than in the control groups. for the groups infected with the f5+ e. coli strain, a reduction in excretion of the challenge strain by 2-4 orders of magn ...	1999	10337234
growth of starved escherichia coli o157 cells in selective and non-selective media.	escherichia coli o157 strains starved in sterile deionized water (sdw) and filter-sterilized natural river water (srw) were investigated with specific reference to their culturability in selective and non-selective media. growth of the strains starved in both sdw and srw were markedly suppressed with time in selective liquid media such as modified trypticase soy broth supplemented with novobiocin (mtsb+n) and modified e. coli broth supplemented with novobiocin (mec+n). this suppression was more ...	1999	10338190
incidence of salmonella on beef carcasses relating to the u.s. meat and poultry inspection regulations.	this article is part of a major study designed to collect baseline contamination data by sampling beef carcasses in seven slaughtering plants (four steer-heifer and three cow-bull plants) during both a dry season (november to january) and a wet season (may to june). samples (n = 30) were excised from each of three carcass anatomical sites (brisket, flank, and rump) at each of three points in the slaughtering chain (pre-evisceration, following final carcass washing, after 24-h carcass chilling). ...	1999	10340666
infection of gnotobiotic calves with escherichia coli o157:h7 strain a84.	six colostrum-deprived, hysterotomy-derived calves were maintained under sterile conditions and fed a milk replacer diet. at five days of age, five of the calves were dosed orally with 10(9) cfu of escherichia coli o157:h7 strain a84. they were killed after, one, two, six, 12 and 24 days, and samples were taken for bacteriological and pathological examination. the sixth uninfected control calf was killed at seven days of age and matched samples were taken for pathological comparison. the animals ...	1999	10358875
identification of the rna-binding, dimerization, and eif4gi-binding domains of rotavirus nonstructural protein nsp3.	the rotavirus nonstructural protein nsp3 is a sequence-specific rna binding protein that binds the nonpolyadenylated 3' end of the rotavirus mrnas. nsp3 also interacts with the translation initiation factor eif4gi and competes with the poly(a) binding protein. deletion mutations and point mutations of nsp3 from group a rotavirus (nsp3a), expressed in escherichia coli, indicate that the rna binding domain lies between amino acids 4 and 149. similar results were obtained with nsp3 from group c rot ...	1999	10364288
afa and f17 adhesins produced by pathogenic escherichia coli strains in domestic animals.	afa and f17 are afimbrial and fimbrial adhesins, respectively, produced by pathogenic escherichia coli strains in domestic animals. f17-related fimbriae are mainly detected on bovine and ovine e. coli associated with diarrhoea or septicaemia. the f17-g adhesin subunits recognize n-acetyl-d-glucosamine (glcnac) receptors present on bovine intestinal cells. some f17 subtypes also bind to glcnac receptors present on human uroepithelial and intestinal caco-2 cells or to the laminin contained in the ...	1999	10367361
[udder health on dairy farms. 1. results of a longitudinal study on 300 dutch farms].	udder health was studied in 300 dairy herds grouped in three categories according to the bulk milk somatic cell count. in all herds, lactating cows were housed in a free-stall barn during the winter. all herds participated in a three or four-weekly milk recording system, had annual production quota between 300,000 and 900,000 kg, and were stocked with cows of the holstein-friesian or dutch friesian breeds. the incidence of clinical mastitis was not different among herds with a low (< or = 150,00 ...	1999	10372420
role of lactosyl glycan sequences in inhibiting enteropathogenic escherichia coli attachment.	previously, we found that asialo-lactosamine sequences served as receptors for enteropathogenic escherichia coli (epec) binding to chinese hamster ovary (cho) cells. in the present report, we have extended these earlier results by examining the ability of lactosamine- or fucosylated lactosamine-bovine serum albumin (bsa) glycoconjugates to inhibit epec, strain e2348/69, binding to hep-2 cells. we found that, consistent with our previous findings with cho cells, n-acetyllactosamine-bsa was the mo ...	1999	10377105
assessment of the microbiological conditions of tails, tongues, and head meats at two beef-packing plants.	newly skinned tails of beef carcasses at two packing plants were similarly contaminated with total aerobes and with coliforms that were largely escherichia coli at log mean numbers about 3.5/cm2 and 4.5/100 cm2, respectively. the log mean numbers of aerobes and coliforms on the skinned tails after washing at plant a were, respectively, 1 and 2 log units less than the numbers on the newly skinned tails. at plant b, the log mean numbers of aerobes on skinned and on washed tails were similar while ...	1999	10382660
[prevalence and serotypes of verocytotoxin-producing escherichia coli (vtec) isolates from dairy cattle].	to clarify the source of infection and route of transmission of verocytotoxin-producing escherichia coli (vtec) in humans, we collected fresh feces from healthy dairy cattle reared in hokkaido, fukushima, kanagawa and okinawa prefectures between june 1996 and march 1997, and attempted to isolate vtec. the results are described below. 1) vtec was isolated from 68 (27.1%) of 251 fecal samples tested. vtec was isolated from 14 (28.0%) of 50 in hokkaido, 13 (26.0%) of 50 in fukushima, 20 (39.2%) of ...	1999	10386024
effect of cattle diet on escherichia coli o157:h7 acid resistance.	the duration of shedding of escherichia coli o157 isolates by hay-fed and grain-fed steers experimentally inoculated with e. coli o157:h7 was compared, as well as the acid resistance of the bacteria. the hay-fed animals shed e. coli o157 longer than the grain-fed animals, and irrespective of diet, these bacteria were equally acid resistant. feeding cattle hay may increase human infections with e. coli o157:h7.	1999	10388727
shiga toxin-producing escherichia coli o157 in feedlot cattle and norwegian rats from a large-scale farm.	a total of 365 faecal samples from different categories of cattle, 12 samples of untreated slurry, 50 samples of fresh droppings of feral domestic pigeons, 20 samples of fresh droppings of domestic sparrows and stool samples of 19 synanthropic rodents were examined for the presence of escherichia coli by broth enrichment culture and a subsequent immunomagnetic separation. escherichia coli o157 was found in 72 (20%) bovine samples, six (50%) samples of untreated slurry and four (40%) of 10 rats ( ...	1999	10389259
peroxynitrite-mediated modification of proteins at physiological carbon dioxide concentration: ph dependence of carbonyl formation, tyrosine nitration, and methionine oxidation.	the ability of peroxynitrite to modify amino acid residues in glutamine synthetase (gs) and bsa is greatly influenced by ph and co2. at physiological concentrations of co2 (1.3 mm), the generation of carbonyl groups (0.2-0.4 equivalents/subunit) is little affected by ph over the range of 7.2-9.0, but, in the absence of co2, carbonyl formation increases (from 0.1- 1.2 equivalents/subunit) as the ph is raised from 7.2 to 10.5. this increase is attributable, in part but not entirely, to the increas ...	1999	10393903
decay-accelerating factor and cytoskeleton redistribution pattern in hela cells infected with recombinant escherichia coli strains expressing dr family of adhesins.	escherichia coli strains expressing dr fimbriae are able to enter epithelial cells by interacting with a complement-regulatory protein, decay-accelerating factor. this model of bacterial internalization, with a well-characterized bacterial ligand and host receptor, provides a unique opportunity to investigate the early stages of invasion. we used immunofluorescence staining techniques to examine the distribution of receptor and cytoskeletal proteins in hela cells infected with e. coli recombinan ...	1999	10417165
purification and properties of proline-rich antimicrobial peptides from sheep and goat leukocytes.	we purified three proline-rich antimicrobial peptides from elastase-treated extracts of sheep and goat leukocytes and subjected two of them, oabac5alpha and chbac5, to detailed analysis. oabac5alpha and chbac5 were homologous to each other and to bovine bac5. both exhibited potent, broad-spectrum antimicrobial activity under low-concentration salt conditions. while the peptides remained active against escherichia coli, pseudomonas aeruginosa, bacillus subtilis, and listeria monocytogenes in 100 ...	1999	10417180
acute phase response in dairy cows with experimentally induced escherichia coli mastitis.	six finnish ayrshire cows were challenged intramammarily with 1500 cfu of escherichia coli (e. coli) into single udder quarters, and the challenge was repeated into contralateral quarters 3 weeks later. all cows received flunixine meglumine once, and 3 of them were also treated with enrofloxacin. at the 2nd challenge, treatments were changed vice versa. the development of mastitis was followed by monitoring of systemic and local clinical signs, and with serial milk and serum samples. intramammar ...	1999	10418194
isolation of verocytotoxin-producing escherichia coli o157:h7 from cattle at slaughter in italy.	cattle arriving for slaughter at a large abattoir in northern italy between april 1997 and january 1998 were examined for intestinal carriage of verocytotoxin-producing escherichia coli (vtec) o157 using an immunomagnetic separation technique. sixty sorbitol non-fermenting vtec o157 strains were isolated from 59 (13.1%) of the 450 cattle examined. in particular, vtec o157 was found in 37 (16.6%) of 223 feedlot cattle and in 22 (16.1%) of 137 dairy cull cows, but not in the 90 veal calves sampled ...	1999	10418874
factors associated with fecal shedding of verotoxin-producing escherichia coli o157 on dairy farms.	fecal samples were collected from 4,361 dairy cows on 91 dairy operations between 26 february and 8 july 1996. fecal samples were cultured for escherichia coli o157, and positive isolates were probed for verotoxin-producing genes. a total of 52 (1.2%) fecal samples on 22 (24.2%) operations were positive for verotoxin-producing e. coli o157. herds in which samples were collected on or after 1 may 1996 were significantly more likely to test positive than herds sampled before that date (odds ratio ...	1999	10419200
antibacterial effect of lactoferricin b on escherichia coli o157:h7 in ground beef.	the antibacterial activity of lactoferricin b on enterohemorrhagic escherichia coli o157:h7 in 1% peptone medium and ground beef was studied at 4 and 10 degrees c. in 1% peptone medium, 50 and 100 microg of lactoferricin b per ml reduced e. coli o157:h7 populations by approximately 0.7 and 2.0 log cfu/ml, respectively. studies comparing the antibacterial effect of lactoferricin b on e. coli o157:h7 in 1% peptone at ph 5.5 and 7.2 did not reveal any significant difference (p > 0.5) at the two ph ...	1999	10419266
excretion of vtec o157 by cattle.		1999	10420488
a chromogenic plating medium for isolating escherichia coli o157:h7 from beef.	there was no significant difference (p > 0.05) in the percentages of escherichia coli o157:h7 cells recovered on bcm o157:h7 (+) agar (69.7%) and macconkey sorbitol agar containing 5-bromo-4-chloro-3-indoxyl-beta-d-glucuronic acid (msa-bcig) (76.8%) vs tryptic soy agar. three e. coli o157:h7 strains (atcc 35150, 43890 and 43894) were separately inoculated into raw ground beef at low (mean 0.32 cfu g-1) and high (mean 3.12 cfu g-1) levels. using the united states department of agriculture (usda) ...	1999	10432628
antibodies produced by mice immunized with recombinant vaccinia viruses expressing two different types of a major theileria sergenti surface antigen (p32) react with the native surface antigen.	a 32 kda major surface antigen, p32, of theileria sergenti at the piroplasm stage is the main target of the host immune response. the immunogenic property of the p32 varies in some strains among the population of theileria sergenti in japan where the chitose type and the ikeda type are the most common varieties. we have constructed vaccinia virus recombinants vv/p32c and vv/p32i which harbor the chitose and ikeda types of p32 gene, respectively. it was found that vv/p32c and vv/p32i produced typ ...	1999	10435791
stability, activity and flexibility in alpha-lactalbumin.	alpha-lactalbumins and the type-c lysozymes are homologues with similar folds that differ in function and stability. to determine if the lower stability of alpha-lactalbumin results from specific substitutions required for its adaptation to a new function, the effects of lysozyme-based and other substitutions on thermal stability were determined. unblocking the upper cleft in alpha-lactalbumin by replacing tyr103 with ala, perturbs stability and structure but pro, which also generates an open cl ...	1999	10436084
the metal function in the reactions of bovine serum amine oxidase with substrates and hydrazine inhibitors.	bovine serum amine oxidase (bsao) reacts with 2-hydrazinopyridine, which binds the organic co-factor 2,4,5-trihydroxyphenylalanine quinone, forming a band at 435 nm. the band shifts to 526 nm around 60 degrees c, to 415 nm upon denaturation, but only shifts to 429 nm upon cu2+ depletion. its wavelength and intensity suggest that the adduct has the azo conformation, whilst the same adduct of crystalline escherichia coli amine oxidase (ecao) shows the hydrazone conformation in the x-ray structure. ...	1999	10439080
semi-automated fluorogenic pcr assays (taqman) forrapid detection of escherichia coli o157:h7 and other shiga toxigenic e. coli.	semi-automated detection of enterohaemorrhagic escherichia coli (ehec) o157:h7 and non-o157:h7 shiga toxin-producing e. coli (stec) was achieved using fluorogenic polymerase chain reaction (pcr). these pcr assays were designed to amplify 80, 120 and 150 bp regions of virulence genes stx1, stx2 and eaea, respectively, using specific primers. the fluorogenic probes were used for specific detection of amplified products of the stx1 and stx2 genes of stec, and the eaea gene of ehec o157:h7. for mult ...	1999	10441202
antibacterial effects of lactoferricin b.	the antimicrobial peptide, lactoferricin, can be generated upon gastric pepsin cleavage of lactoferrin. we have examined the inhibitory efficacy of lactoferricin of bovine origin (lf-cin b) on escherichia coli, proteus mirabilis and staphylococcus aureus with or without a cell wall. we found that spheroplasts and protoplasts had a lower mic than their counterparts with a cell wall. we also compared the efficacies of lf-cin b (17-31) made of all l-amino acids and all d-amino acids. the peptide ma ...	1999	10447329
the role of the amino-terminal beta-barrel domain of the alpha and beta subunits in the yeast f1-atpase.	the crystal structure of mitochondrial f1-atpase indicates that the alpha and beta subunits fold into a structure defined by three domains: the top beta-barrel domain, the middle nucleotide-binding domain, and the c-terminal alpha-helix bundle domain (abrahams et al., 1994); bianchet et al., 1998). the beta-barrel domains of the alpha and beta subunits form a crown structure at the top of f1, which was suggested to stabilize it (abrahams et al. 1994). in this study, the role of the beta-barrel d ...	1999	10449236
genetic subtyping of escherichia coli o157 isolates from 41 pacific northwest usa cattle farms.	escherichia coli o157 (n = 376) from 41 cattle farms were subtyped using pulsed field gel electrophoresis of endonuclease cleaved chromosomal dna. cleavage with xbai resulted in 81 subtypes. fifty-one isolates from subtypes found in more than one herd, or in herds on multiple sample collection dates were compared using the endonuclease noti, resulting in 23 additional subtypes. up to 11 xbai subtypes were found per farm with up to 7 subtypes/farm identified from a single date. indistinguishable ...	1999	10459653
hydrochloric acid treatment for rapid recovery of shiga toxin-producing escherichia coli o26, o111 and o157 from faeces, food and environmental samples.	we developed a hydrochloric acid treatment for the isolation of shiga toxin-producing escherichia coli (stec) o26:h11, o111:h- and o157:h7 strains from a variety of samples. after exposure to an equal volume of 1/8n hcl solution for 30 sec, the fecal suspensions and enrichment cultures were spread onto cefixime-tellurite-sorbitol-macconkey (ct-smac) agar. this hcl treatment increased the sensitivity for detection of stec o26:h11, o111:h- and o157:h7 strains and decreased the growth of other micr ...	1999	10467660
a reverse-sandwich enzyme-linked immunosorbent assay for verocytotoxin 1 and 2 antibodies in human and bovine sera.	a reverse-sandwich enzyme-linked immunosorbent assay (elisa), in which an antibody is sandwiched by antigens, was established for the titration of antibodies to verocytotoxins (vt) in human and animal sera. this assay has two advantages over a conventional indirect elisa: (i) higher specificity and sensitivity and (ii) the ability to comparably titrate antibodies from different species. the vt1 (shiga-like toxin 1) antibody-positive rates were 5% in 202 normal adult humans and 99% in 93 normal c ...	1999	10473521
molecular definition and characterization of recombinant bovine cb8 and cb10: immunogenicity and arthritogenicity.	theoretically, the ability to produce recombinant type ii collagen (cii) peptide fragments in a prokaryotic expression system would be extremely useful for preparing adequate amounts of cii peptides suitable for therapeutic uses. bacteria do not contain the enzymes involved in the extensive posttranslational modifications that occur during the biosynthesis of cii, such as the hydroxylation of prolyl and lysyl residues and glycosylation of hydroxylysyl residues. as these posttranslational modific ...	1999	10479530
prevalence of verotoxin-producing escherichia coli (vtec) in bovine coli mastitis and their antibiotic resistance patterns.	between december 1996 and october 1997, milk samples from a total of 145 cows with coli mastitis were screened for the presence of verotoxin-producing e. coli (vtec). vtec were found in four (2.8%) out of the 145 samples. the four isolated strains proved to be verotoxin (vt) 1-, vt2- or vt1- and vt2-positive. however, no strain contained all three virulence factors tested. further strain characterization was carried out by serotyping as well as by resistance pattern analysis.	1999	10481626
paua: a novel plasminogen activator from streptococcus uberis.	chromosomal dna from two geographically distinct isolates of streptococcus uberis was used to clone the plasminogen activator in an active form in escherichia coli. the cloned fragments from each strain contained four potential open reading frames (orfs). that for the plasminogen activator encoded a protein of 286 amino acids (33.4 kda) which is cleaved between residues 25 and 26 during secretion by s. uberis. the amino acid sequence of the mature protein showed only weak homology (23.5-28%) to ...	1999	10483719
role of cryptosporidium parvum as a pathogen in neonatal diarrhoea complex in suckling and dairy calves in france.	this study was carried out to find the importance of cryptosporidium parvum in diarrhoea of neonatal calves in two types of breeding - suckling and dairy calves - in france. different agents causing neonatal diarrhoea, e. coli, rotavirus, coronavirus, salmonella and cryptosporidium were systematically researched in faeces. 1. suckling calves: in 40 livestock farms selected for diarrhoea, 311 calves 4 to 10 days old which had diarrhoea for less than 24h or no diarrhoea, were included in the study ...	1999	10488727
expression of inducible nitric oxide synthase in spontaneous bovine bronchopneumonia.	the expression of inducible nitric oxide synthase (inos), major histocompatibility class ii molecules (mhc-ii), cd68, and the calcium-binding proteins s100a8 and s100a9 (also called mrp8 and mrp14, respectively) was assessed in lung tissues from cattle that succumbed to pneumonia. expression patterns of these markers were related to the types of lung lesion. inos expression was only observed in lungs infected with arcanobacterium pyogenes or pasteurella haemolytica but not in lungs from cattle w ...	1999	10490207
activation of the cdc42 effector n-wasp by the shigella flexneri icsa protein promotes actin nucleation by arp2/3 complex and bacterial actin-based motility.	to propel itself in infected cells, the pathogen shigella flexneri subverts the cdc42-controlled machinery responsible for actin assembly during filopodia formation. using a combination of bacterial motility assays in platelet extracts with escherichia coli expressing the shigella icsa protein and in vitro analysis of reconstituted systems from purified proteins, we show here that the bacterial protein icsa binds n-wasp and activates it in a cdc42-like fashion. dramatic stimulation of actin asse ...	1999	10491394
expression, purification, and crystal structure determination of recombinant human epidermal-type fatty acid binding protein.	we describe the crystal structure of human epidermal-type fatty acid binding protein (e-fabp) that was recently found to be highly upregulated in human psoriatic keratinocytes. to characterize e-fabp with respect to ligand-binding properties and tertiary structure, we cloned the respective cdna, overexpressed the protein in escherichia coli and purified it to homogeneity by a combination of ion-exchange and size-exclusion chromatographic steps with a yield of 30 mg/l broth. the purified protein ...	1999	10493790
prevalence of escherichia coli o157:h7 in white-tailed deer sharing rangeland with cattle.	to determine the prevalence of fecal shedding of escherichia coli o157:h7 in white-tailed deer (odocoileus virginianus) with access to cattle pastures.	1999	10496130
production of engineered human pancreatic ribonucleases, solving expression and purification problems, and enhancing thermostability.	human pancreatic ribonuclease, the homolog of bovine pancreatic ribonuclease, has a significant therapeutic potential. its study has been hindered by the difficulty of obtaining the enzyme in a pure and homogeneous form, either from human source or using heterologous expression. engineering of different variants of human pancreatic ribonuclease has allowed us to study and overcome some problems encountered during its heterologous production in an escherichia coli system and its purification from ...	1999	10497083
use of heme-protein complexes by the yersinia enterocolitica hemr receptor: histidine residues are essential for receptor function.	the abilities of two bacterial active heme transporters, hmbr of neisseria meningitidis and hemr of yersinia enterocolitica, to use different heme sources were compared. while hmbr-expressing cells used only hemoglobin (hb) and heme, hemr-expressing bacteria were able to grow on hb, heme, myoglobin, hemopexin, catalase, human and bovine serum albumin-heme, and haptoglobin-hemoglobin complexes as sources of iron. expression of functional hemr allowed escherichia coli cells to respond to heme-cont ...	1999	10498719
micellar electrokinetic chromatography as a complementary method to sodium dodecyl sulfate-polyacrylamide gel electrophoresis for studying limited proteolysis of proteins.	micellar electrokinetic chromatography (mekc) has been utilized as an analytical method to perform investigations on limited proteolysis of proteins. to this purpose partial proteolysis experiments with a series of proteinases were performed, utilizing as model protein pyruvate kinase (pk) from escherichia coli, an enzyme that is regulated allosterically by fructose 1,6-bisphosphate (fbp). data obtained with sodium dodecyl sulfate-polyacrylamide gel electrophoresis (sds-page) and mekc were compa ...	1999	10499331
serological evidence of an australian bovine lentivirus.	recombinant 26 kda capsid (ca) proteins of bovine lentiviruses, bovine immunodeficiency virus (biv) and jembrana disease virus (jdv), were expressed in escherichia coli and utilised as antigens for an enzyme-linked immunosorbent assay (elisa) and a western immunoblot (wib) procedure for the detection of antibody in dairy cattle in western australia. a total of 690 serum samples, 30 from each of 23 farms, were tested by elisa with a jdv ca protein antigen, and antibody was detected in 3.8% (p<0.0 ...	1999	10501174
1,25-dihydroxyvitamin d3 enhances milk antibody titers to escherichia coli j5 vaccine.	recent evidence in cattle and mice has suggested that 1,25-dihydroxyvitamin d3 may stimulate t-lymphocyte differentiation pathways responsible for humoral immunity. the use of 1,25-dihydroxyvitamin d3 as an adjuvant for an escherichia coli j5 vaccine was tested. ten midlactation cows received j5 vaccine and were revaccinated 6 wk after the first vaccine administration. five of these cows were given 200 micrograms of 1,25-dihydroxyvitamin d3, in addition to the primary vaccination, and they recei ...	1999	10509248
detection of low dose radiation induced dna damage using temperature differential fluorescence assay.	a rapid and sensitive fluorescence assay for radiation-induced dna damage is reported. changes in temperature-induced strand separation in both calf thymus dna and plasmid dna (puc 19 plasmid from escherichia coli) were measured after exposure to low doses of radiation. exposures of between 0.004 and 1 gy were measured with doses as low as 0.008 gy yielding significant responses. the double-strand, sensitive dye picogreen was used as an indicator of dna denaturation. calibration plots indicate t ...	1999	10517153
reduction of escherichia coli o157:h7 by stimulated pediococcus acidilactici.	this study was conducted to determine if stimulating the growth of meat starter culture (pediococcus acidilactici) in a laboratory medium (brain heart infusion broth +2.3% nacl + 1.5% sucrose; lbhi) and during meat fermentation would control escherichia coli o157:h7. in lbhi medium without p. acidilactici, the numbers of e. coli o157:h7 increased from 4.00 to 8.34 log10 cfu ml-1, whereas in the presence of p. acidilactici (approximately 6.0 log10 cfu ml-1) in lbhi, lbhim (lbhi + 0.005% mnso4), l ...	1999	10530043
prevalence and infection risks of zoonotic enteropathogenic bacteria in swiss cow-calf farms.	a longitudinal study was performed in 67 larger swiss cow-calf farms from september 1996 through november 1997. the objectives of the study were to estimate prevalence and risk factors for colonization with potentially zoonotic enteropathogenic bacteria in younger calves and in calves at weaning age. the study included data from 395 calves with three to four fecal samples each. fecal samples were analyzed for campylobacter spp., verotoxin producing e. coli (vtec), yersinia spp. and salmonella sp ...	1999	10535771
e. coli expressed proteins as diagnostic reagents for typing of foot-and-mouth disease virus.	truncated proteins corresponding to the c-terminal half of vp1 of four vaccine strains and two field variants of foot-and-mouth disease virus (fmdv) were expressed in e. coli. the expressed proteins were affinity purified and their type specific reactivity was confirmed by immunoprecipitation with anti-virus antibodies. antibodies were raised against the purified proteins in guinea pigs and the type specificity of the anti peptide antibodies was confirmed by antigen capture reverse transcription ...	1999	10542020
polycitone a, a novel and potent general inhibitor of retroviral reverse transcriptases and cellular dna polymerases.	polycitone a, an aromatic alkaloid isolated from the ascidian polycitor sp. exhibits potent inhibitory capacity of both rna- and dna-directed dna polymerases. the drug inhibits retroviral reverse transcriptase (rt) [i.e. of human immunodeficiency virus type 1 (hiv), murine leukaemia virus (mlv) and mouse mammary tumour virus (mmtv)] as efficiently as cellular dna polymerases (i.e. of both dna polymerases alpha and beta and escherichia coli dna polymerase i). the mode and mechanism of inhibition ...	1999	10548537