Publications

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
investigating site-specific effects of the -x glutamate in a parvalbumin cd site model peptide.	the -x glutamate in a 33-residue model peptide comprising the cd site of carp parvalbumin 4.25 (parvcd) was replaced with aspartate (parvcd-xd) and the effect on calcium-dependent dimerization and calcium affinity assessed. the peptide parvcd demonstrates a 10(5)-fold lower calcium affinity than the same site in the native protein. both the parvcd and parvcd-xd model peptides fail to bind magnesium. the low calcium affinity and failure of the model parvcd site to bind magnesium may be due to hig ...	1999	10562419
experimental infection of calves with escherichia coli o157:h7.	three 3-month-old japanese black calves were experimentally infected with escherichia coli o157:h7 to define the magnitude (cfu/g) and duration of fecal shedding of the organism. in two of the three calves, fecal shedding of e. coli o157:h7 ceased in 5 and 9 weeks. the remaining calf continued shedding e. coli o157:h7 for more than 31 weeks, and the magnitude of the shedding ranged from 10(1) to 10(4) cfu/g of feces. the possibility is suggested that a percentage of animals naturally infected wi ...	1999	10563303
comparative sensitivity of immunoassays for haptens using monomeric and dimeric antibody fragments.	a single-chain anti-atrazine antibody fragment, scab (single-chain fv with a ck domain), was expressed in escherichia coli, and monomeric and dimeric species were preferentially purified from periplasmic extracts by chromatography upon nickel chelate immunosorbent columns or by immunoaffinity purification using a constant domain (ck) tag. recombinant monomeric and dimeric antibody fragments, fab, and intact monoclonal antibodies were compared in assays by competition between free atrazine in sol ...	1999	10563896
[fecal shedding and serum antibody responses of cattle experimentally infected with enterohaemorrhagic escherichia coli o157:h7].		1999	10565127
genotoxic effects of benzyl isothiocyanate, a natural chemopreventive agent.	benzyl isothiocyanate (bitc) is contained in cruciferous plants which are part of the human diet. numerous reports indicate that bitc prevents chemically induced cancer in laboratory animals and it has been postulated that bitc might also be chemoprotective in humans. on the other hand, evidence is accumulating that this compound is a potent genotoxin in mammalian cells by itself. to further elucidate the potential hazards of bitc, we investigated its genotoxic effects in different in vitro geno ...	1999	10567035
autoantibodies to brain components and antibodies to acinetobacter calcoaceticus are present in bovine spongiform encephalopathy.	bovine spongiform encephalopathy (bse) is a neurological disorder, predominantly of british cattle, which belongs to the group of transmissible spongiform encephalopathies together with creutzfeldt-jakob disease (cjd), kuru, and scrapie. autoantibodies to brain neurofilaments have been previously described in patients with cjd and kuru and in sheep affected by scrapie. spongiform-like changes have also been observed in chronic experimental allergic encephalomyelitis, at least in rabbits and guin ...	1999	10569779
occurrence of escherichia coli o157:h7 in hamburgers produced in brazil.	the occurrence of escherichia coli o157:h7 was evaluated in 886 samples of hamburgers produced by eight manufacturers in the south and southeast of brazil from january to september of 1997. the pathogen was not detected in any of the samples analyzed, although 17 (1.9%) showed the presence of e. coli strains, which presented agglutination with o157 antiserum. these strains were not confirmed, since a subsequent identification indicated that they were fermentation positive for sorbitol, incapable ...	1999	10571325
the effect of alpha-lactalbumin and beta-lactoglobulin hydrolysates on the metabolic activity of escherichia coli jm103.	bovine milk proteins alpha-lactalbumin (alpha-la) and beta-lactoglobulin (beta-lg) were hydrolysed with seven different proteolytic enzymes, and the effect of various hydrolysates on a genetically modified luminous escherichia coli jm103 was tested in vitro with a bioluminescence assay for bacterial growth and metabolism. undigested proteins did not inhibit the activity of tested e. coli jm103 at a concentration as high as 0.1 g ml-1. at the same concentrations, alpha-la hydrolysed with pepsin o ...	1999	10583682
agar underlay method for recovery of sublethally heat-injured bacteria.	a method of recovering sublethally heat-injured bacteria was developed. the procedure (termed the agar underlay method) uses a nonselective agar underlaid with a selective medium. in a two-chambered petri dish, the lutri plate (lp), a nonselective agar is inoculated with a population of sublethally heat-injured bacteria. after a 2-h repair incubation period, selective agar is added to the bottom chamber of the lp and incubated. by diffusing through the nonselective top agar, selective agents fro ...	1999	10583985
unusual amino acid usage in the variable regions of mercury-binding antibodies.	monoclonal antibodies (mab) specific for mercuric ions were isolated from balb/c mice injected with a mercury-containing, hapten-carrier complex. the antibodies reacted by enzyme-linked immunosorbent assay with bovine serum albumin-glutathione-mercuric chloride (bsa-gsh-hgcl) but not with bsa-gsh without mercury. nucleotide sequences from polymerase chain reaction products encoding six of the antibody heavy-chain variable regions and seven light-chain variable regions revealed that all the antib ...	1999	10591102
high occurrence of shiga toxin-producing escherichia coli (stec) in healthy cattle in rio de janeiro state, brazil.	in order to evaluate the prevalence of shiga toxin-producing escherichia coli (stec) strains, 197 fecal samples of healthy cattle from 10 dairy farms, four beef farms and one slaughterhouse at rio de janeiro state, brazil, were examined for shiga toxin (stx) gene sequences by polymerase chain reaction (pcr). for presumptive isolation of o157:h7 e. coli, the cefixime-potassium tellurite-sorbitol macconkey agar (ct-smac) was used. a high occurrence (71%) of stx was detected, and was more frequentl ...	1999	10591502
characterization of two fungal-elicitor-induced rice cdnas encoding functional homologues of the rab-specific gdp-dissociation inhibitor.	by using the mrna differential display approach to isolate defense signaling genes active at the early stage of fungal infection two cdna fragments with high sequence homology to rab-specific gdp-dissociation inhibitors (gdis) were identified in rice (oryza sativa l.) suspension cells. using polymerase-chain-reaction products as probes, two full-length cdna clones were isolated from a cdna library of fungal-elicitor-treated rice, and designated as osgdi1 and osgdi2. the deduced amino acid sequen ...	1999	10592042
mammalian mitochondrial ribosomal proteins (2). amino acid sequencing, characterization, and identification of corresponding gene sequences.	four different classes of mammalian mitochondrial ribosomal proteins were identified and characterized. mature proteins were purified from bovine liver and subjected to n-terminal or matrix-assisted laser-desorption mass spectroscopic amino acid sequencing after tryptic in-gel digestion and high pressure liquid chromatography separation of the resulting peptides. peptide sequences obtained were used to virtually screen expressed sequence tag data bases from human, mouse, and rat. consensus cdnas ...	1999	10593885
lactoferrin concentration in milk of bovine clinical mastitis.	the lactoferrin (lf) concentration in the milk from dairy cows with clinical mastitis was determined to evaluate the relationship between the lf concentration (lfc) in milk and the non-specific defensive capability of the udder. the mean lfc in 368 milk samples from 319 cows with clinical mastitis was significantly higher (p < 0.01) than that of normal cows. the mean lfc in milk from quarters infected with mycoplasma bovis or staphylococcus aureus was significantly higher (p < 0.05) than that of ...	1999	10598071
characterization of monoclonal antibodies against bovine herpesvirus 1 gd fusion protein expressed in e. coli.	a total of 20 hybridoma cell lines secreting monoclonal antibodies (mabs) against e. coli expressed bovine herpesvirus-1 (bhv-1) gd fusion protein were produced following the fusion of sp2/0 myeloma cells with splenocytes from balb/c mice immunized previously with immunoaffinity purified bhv-1 gd fusion protein. an indirect fluorescent antibody test (ifat) using bhv-1 infected mdbk cells was used for the selection of positive hybridomas secreting specific antibody. the monoclonal antibody isotyp ...	1999	10598086
protective cultures inhibit growth of listeria monocytogenes and escherichia coli o157:h7 in cooked, sliced, vacuum- and gas-packaged meat.	contamination of cooked meat products with listeria monocytogenes poses a constant threat to the meat industry. the aim of this study was therefore to investigate the use of indigenous lactic acid bacteria (lab) as protective cultures in cooked meat products. cooked, sliced, vacuum- or gas-packaged ham and servelat sausage from nine meat factories in norway were inoculated with 10(3) cfu/g of a mixture of three rifampicin resistant (rif-mutant) strains of l. monocytogenes and stored at 8 degrees ...	1999	10598113
crystal structure of the purine nucleoside phosphorylase (pnp) from cellulomonas sp. and its implication for the mechanism of trimeric pnps.	the three-dimensional structure of the trimeric purine nucleoside phosphorylase (pnp) from cellulomonas sp. has been determined by x-ray crystallography. the binary complex of the enzyme with orthophosphate was crystallized in the orthorhombic space group p212121 with unit cell dimensions a=64.1 a, b=108.9 a, c=119.3 a and an enzymatically active trimer in the asymmetric unit. x-ray data were collected at 4 degrees c using synchrotron radiation (embl/desy, hamburg). the structure was solved by m ...	1999	10600382
virulence factors of avian escherichia coli associated with swollen head syndrome.	virulence characteristics of 50 strains of escherichia coli isolated from chickens with swollen head syndrome were examined. the results were the following: in the absence of d-mannose, 74% of strains agglutinated guinea pig erythrocytes, but in the presence of d-mannose 32% agglutinated guinea-pig erythrocytes and 62% agglutinated human erythrocytes. when slide agglutination assays were carried out with antisera to adhesin of bovine and swine origin (k88, k99, f41, f42 987p and 2134p), only 14% ...	1998	18483979
ribotyping of fusobacterium necrophorum strains isolated from bovine and ovine hepatic abscesses.	a microbiological study was made of 100 strains of fusobacterium necrophorum isolated from hepatic abscesses in bovine and ovine herds. differences between the biological activity and ribotypes within the two f. necrophorum subspecies were studied. conventional methods identified 89 isolates as f. necrophorum subsp. necrophorum and 11 as f. necrophorum subsp. funduliforme. for ribotyping, 50 strains (35 f.n. subsp. necrophorum, 11 f.n. subsp. funduliforme and 4 reference strains) were digested w ...	1998	16887645
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
cloning, sequencing and expression of a cdna encoding bovine pancreatic deoxyribonuclease i in escherichia coli: purification and characterization of the recombinant enzyme.	the bovine pancreatic (bp-) dnase i gene has been cloned from bp-cdna and expressed in e. coli. a polynucleotide sequence of 1295 base pairs was deduced from clones of the cdna. the sequence showed an open reading frame which can be translated as a 282-amino acid polypeptide, including a hydrophobic signal peptide and the polypeptide of bp-dnase i. an expression plasmid was constructed by inserting into the vector pet-15b, a cdna fragment coding for bp-dnase i ligated with a hexanucleotide codin ...	1998	9469931
efficacy of parenteral administration of three antimicrobial agents in treatment of clinical mastitis in lactating cows: 487 cases (1989-1995).	to evaluate the efficacy of parenteral administration of procaine penicillin g, spiramycin, or enrofloxacin in the treatment of clinical mastitis in lactating cows.	1998	9470054
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
isolation and characterization of verocytotoxin-producing escherichia coli o157 strains from dutch cattle and sheep.	in the periods from july to november 1995 and 1996, fecal samples from dutch cattle and sheep were collected at the main slaughterhouses of the netherlands, located at different geographic sites. the samples were examined for the presence of verocytotoxin (vt)-producing escherichia coli (vtec) of serogroup 0157. e. coli o157 strains could be isolated from 57 (10.6%) of 540 adult cattle, 2 (0.5%) of 397 veal calves, 2 (3.8%) of 52 ewes, and 2 (4.1%) of 49 lambs. immunomagnetic separation with o15 ...	1998	9542902
a case-control study of verocytotoxigenic escherichia coli infection in cats with diarrhea.	the objectives of this study were to determine the prevalence of enteric verocytotoxigenic e. coli (vtec) infection in a population of cats in ontario, and to determine whether an association exists between the presence of vtec and feline diarrhea. fecal samples from 179 cats, representing 113 cats with diarrhea and 66 cats with normal feces, were cultured for e. coli. the fecal cultures were screened for verocytotoxin activity with a vero cell assay. confirmation of the presence of verocytotoxi ...	1998	9553706
phenotypic expression of k88 adhesion alone or simultaneously with k99 and/or f41 adhesins in the bovine enterotoxigenic escherichia coli strain b41.	f41-positive and f41-negative derivatives of bovine enterotoxigenic escherichia coli strain b41 carrying k88 or k88 and k99 plasmids were investigated for stability and expression of genes for their fimbrial antigens. either k88 plasmid alone or both k88 and k99 plasmids could be maintained in these strains though stability could depend on culture medium. k99 antigen could be detected in each strain bearing k99 plasmid. clones that produced k88 antigen or clones that did not produce this antigen ...	1998	9556859
nadph-flavodoxin reductase and flavodoxin from escherichia coli: characteristics as a soluble microsomal p450 reductase.	in addition to their endogenous roles as an activation system for various escherichia coli metabolic pathways, the soluble flavoproteins flavodoxin (fld) and nadph-flavodoxin (ferredoxin) reductase (fpr) can serve as an electron-transfer system for microsomal cytochrome p450s. furthermore, since fld and fpr are structurally similar to the functional domains (fmn binding and nadph/fad binding domains, respectively) of nadph-cytochrome p450 reductases (p450 reductases), these bacterial proteins re ...	1998	9558349
combined effect of ampicillin, colistin and dexamethasone administered intramuscularly to dairy cows on the clinico-pathological course of e. coli-endotoxin mastitis.	the effects of a single intramuscular injection of a drug product containing ampicillin, colistin and dexamethasone, as a suspension in a diester of propylene glycol of medium-chain fatty acids, on the clinico-pathological course of experimental escherichia coli-endotoxin mastitis was examined in 30 dairy cows. cows were divided into five groups, six cows per group, and 24 of them were infused with e. coli endotoxin into two quarters of their udders. the drug product was injected at 25,000 iu co ...	1998	9559523
type specific and genotype cross reactive b epitopes of the l1 protein of hpv16 defined by a panel of monoclonal antibodies.	mouse monoclonal antibodies (mabs) were raised against the major capsid protein, l1, of human papillomavirus type 16 (hpv16), produced in escherichia coli with the expression plasmid ptrcl1. epitope specificity could be assigned to 11 of these 12 antibodies using a series of linear peptides and fusion proteins from hpv16. one mab (mc53) recognized a novel linear epitope that appears to be unique to the hpv16 genotype. a further 11 mabs were characterized as recognizing novel and previously defin ...	1998	9568027
crystallization and preliminary x-ray analysis of a 1:1 complex between a designed monomeric interferon-gamma and its soluble receptor.	a variant of human interferon-gamma (ifn-gamma) has been created in which the two chains of the homodimeric cytokine were linked n- to c-terminus by an eight residue polypeptide linker. the sequence of this linker was derived from a loop in bira bifunctional protein, and was determined from a structural database search. this "single-chain" variant was used to create an ifn-gamma molecule that binds only a single copy of the alpha-chain receptor, rather than the 2 alpha-chain receptor: 1 ifn-gamm ...	1998	9568913
cattle and verotoxigenic escherichia coli (vtec), an old relationship?		1998	9569484
effects of temperature and novobiocin on the expression of calf prochymosin gene and on plasmid copy number in recombinant escherichia coli.	escherichia coli strain hb101 harboring an expression plasmid bearing calf prochymosin gene under the control of the tac promoter was grown in the presence of iptg with or without novobiocin at 28 and 40 degrees c, respectively. the differential rates of synthesis of prochymosin inclusions, and, for comparison, of beta-lactamase and beta-galactosidase, as well as plasmid copy number, were determined during the first hours of steady state growth. at 28 degrees c the induced expression of prochymo ...	1998	9569630
delta subunit of rat liver mitochondrial atp synthase: molecular description and novel insights into the nature of its association with the f1-moiety.	the f1 moiety of atp synthase complexes consists of five subunit types in the stoichiometric ratio alpha 3, beta 3, gamma, delta epsilon. of these, the delta subunit has received very little attention in the study of f1 preparations from eukaryotic cells. although recently shown to associate tightly with the beta subunit [pedersen, p. l., hullihen, j., bianchet, m., amzel, l. m., and lebowitz, m. s. (1995) j. biol. chem. 270, 1775-1784], the delta subunit is not resolved in the x-ray structure o ...	1998	9578578
expression of catalytically active human cytochrome p450scc in escherichia coli and mutagenesis of isoleucine-462.	cytochrome p450scc (p450scc) catalyzes the first step in steroid hormone synthesis, the conversion of cholesterol to pregnenolone. human p450scc has been poorly studied due to the difficulty of purifying reasonable quantities of enzyme from human tissue. to provide a more convenient source of the human enzyme and to enable structure-function studies to be done using site-directed mutagenesis, we expressed the mature form of human p450scc in escherichia coli. the expression system enabled us to p ...	1998	9578606
endotoxin impairs agonist-induced calcium mobilization in bovine aortic myocytes by a nitric oxide-independent mechanism.	we hypothesized that endotoxin (lps) would impair vasoconstrictor-agonist-induced calcium (ca2+) mobilization by a nitric oxide (no)-dependent mechanism. we incubated bovine aortic myocytes (passages 16 to 23) for 22 to 24 hours with 0 to 1.0 mg/ml escherichia coli lipopolysaccharide (lps). medium (dulbecco's modified eagle's medium (dmem) + 10% fetal bovine serum (fbs)) was assayed for nitrite (chemiluminescence), and myocytes were loaded with fura-2 acetoxymethyl ester (fura-2am), after which ...	1998	9579387
mammalian mitochondrial methionyl-trna transformylase from bovine liver. purification, characterization, and gene structure.	the mammalian mitochondrial methionyl-trna transformylase (mtfmt) was partially purified 2,200-fold from bovine liver mitochondria using column chromatography. the polypeptide responsible for mtfmt activity was excised from a sodium dodecyl sulfate-polyacrylamide gel and the amino acid sequences of several peptides were determined. the cdna encoding bovine mtfmt was obtained and its nucleotide sequence was determined. the deduced amino acid sequence of the mature form of mtfmt consists of 357 am ...	1998	9614118
lipofection of cultured mouse muscle cells: a direct comparison of lipofectamine and dosper.	cationic lipid-dna complexes (lipoplexes) have been widely used as gene transfer vectors which avoid the adverse immunogenicity and potential for viraemia of viral vectors. with the long-term aim of gene transfer into skeletal muscle in vivo, we describe a direct in vitro comparison of two commercially available cationic lipid formulations, lipofectamine and dosper. optimisation of transfection was performed in the c2c12 mouse muscle cell line, before further studies in primary mouse myoblasts a ...	1998	9614580
the flavoprotein component of the escherichia coli sulfite reductase can act as a cytochrome p450c17 reductase.	the flavoprotein component (sir-fp) of the e. coli sulfite reductase was found to support 17 alpha-hydroxylation of pregnenolone in the presence of cytochrome p450c17. half maximum activity is obtained for a 1:1 ratio of sir-fp, expressed as monomer concentration, to p450c17. when compared to bovine nadph-cytochrome p450 reductase, sir-fp is about 12-15 times less efficient. p450c17 was demonstrated to interact specifically with the fmn-binding domain of the protein and the n-terminal part of si ...	1998	9618257
the dinuclear center of cytochrome bo3 from escherichia coli.	for the study of the dinuclear center of heme-copper oxidases cytochrome bo3 from escherichia coli offers several advantages over the extensively characterized bovine cytochrome c oxidase. the availability of strains with enhanced levels of expression allows purification of the significant amounts of enzyme required for detailed spectroscopic studies. cytochrome bo3 is readily prepared as the fast form, with a homogeneous dinuclear center which gives rise to characteristic broad epr signals not ...	1998	9623806
association of genes encoding p fimbriae, cs31a antigen and east 1 toxin among cnf1-producing escherichia coli strains from cattle with septicemia and diarrhea.	fifty-six cnf1-producing escherichia coli strains isolated from cattle with diarrhea or septicemia were screened by pcr for the detection of pap, sfa, afa, clpg, or f17 adherence factor and east 1 toxin genes. all the isolates were pap-positive, in accordance with the close association of pap, cnf1 and alpha-hemolysin genes observed on human and porcine e. coli. only the gene encoding the p adhesin of class iii (prsg) was detected. genes encoding cs31a antigen (71%) and s fimbriae (34%) (but not ...	1998	9627958
research notes: prevalence of selected microbial pathogens in processed poultry waste used as dairy cattle feed.	processed poultry litter intended for dairy cattle feed was collected on 13 dairy ranches in the san joaquin valley of california and analyzed for the presence of significant bacterial pathogens associated with clinical disease in cattle or foodborne disease in humans. litter samples were collected from the surface and interior of the litter piles upon arrival on the dairies and 2 to 4 wk later. litter samples were cultured for salmonella, escherichia coli, campylobacter, and other bacteria. the ...	1998	9628527
adhesion of some probiotic and dairy lactobacillus strains to caco-2 cell cultures.	the adhesion of 12 different lactobacillus strains was studied using caco-2 cell line as an in vitro model for intestinal epithelium. some of the strains tested have been used as probiotics, and most of them are used in the dairy and food industry. human and bovine enterotoxigenic escherichia coli strains were used as positive and negative control, respectively. bacterial adhesion to caco-2 cell cultures was quantitated using radiolabelled bacteria. the adherence of bacteria was also observed mi ...	1998	9631336
novel recombinant analogues of bovine placental lactogen. g133k and g133r provide a tool to understand the difference between the action of prolactin and growth hormone receptors.	two new analogues of bovine placental lactogen (bpl), bpl(g133k) and bpl(g133r), were expressed in escherichia coli, refolded, and purified to a native form. binding experiments, which are likely to represent the binding to site 1 only, to intact fdc-p1 cells transfected with rabbit (rb) growth hormone receptor (ghr) or with human (h) ghr, to nb2 rat lymphoma cells, or to rabbit mammary gland membranes prolactin receptor (prlr), revealed only small or no reduction in binding capacity. the comple ...	1998	9632658
factors affecting the heat resistance of escherichia coli o157:h7.	escherichia coli o157:h7 has been reported as being not particularly heat resistant. however, several factors which might increase its heat resistance have been investigated in this study using five strains. increase in growth temperature to 40 degrees c, as found in the cow gut, heat-shock at sub-lethal temperatures of 42, 45, 48 and 50 degrees c, and variable heating rate (1 degree c min-1 to 23 degrees c min-1) had no dramatic effect on heat resistance. growth phase had a marked impact on hea ...	1998	9633099
compensation of preliminary blood phagocyte immaturity in the newborn calf.	to estimate the functional maturity of the phagocytic defence in neonatal calves, we analyzed the characteristics of blood phagocytes from calves (n = 10) 1 h post partum (p.p.) and 4 h p.p. at 1 h p.p., all calves were colostrum-deprived, while 5 calves had received colostrum before the 4 h p.p. sampling. the results were compared to those obtained from 3-9-week-old calves (n = 10). phagocytic and oxidative burst activity of polymorphonuclear leukocytes (pmnl) and monocytes were determined in w ...	1998	9646436
endocytosis and mhc class ii expression by human oviductal epithelium according to stage of the menstrual cycle.	the epithelium is the first barrier against pathogens invading the lumen of the human oviduct. its expression of class ii major histocompatibility complex (mhc class ii) proteins suggests that it might play a role in antigen presentation during the local immune response. to study the role of the oviductal epithelium in antigen processing, its endocytic properties and mhc class ii expression were examined. for assay of endocytosis, fluorescein isothiocyanate-labelled bovine serum albumin (bsa-fit ...	1998	9647540
potent enzyme inhibitors derived from dromedary heavy-chain antibodies.	evidence is provided that dromedary heavy-chain antibodies, in vivo-matured in the absence of light chains, are a unique source of inhibitory antibodies. after immunization of a dromedary with bovine erythrocyte carbonic anhydrase and porcine pancreatic alpha-amylase, it was demonstrated that a considerable amount of heavy-chain antibodies, acting as true competitive inhibitors, circulate in the bloodstream. in contrast, the conventional antibodies apparently do not interact with the enzyme's ac ...	1998	9649422
detection of verotoxin-producing escherichia coli o157:h7 by multiplex polymerase chain reaction.	we constructed primers for multiplex polymerase chain reaction (pcr) to detect verotoxin-producing escherichia coli (vtec) o157:h7. the multiplex pcr primers were designed from the sequence of the flagellin structural gene of escherichia coli flagellar type h7 (genbank under accession number l07388), and from the sequence of the rfbe gene of escherichia coli o157:h7 (genbank under accession number s83460). in addition to these primers, we used a primer pair reported by karch and meyer (j. clin. ...	1998	9654369
u1 snrnp inhibits pre-mrna polyadenylation through a direct interaction between u1 70k and poly(a) polymerase.	it has previously been shown in vivo that bovine papillomavirus represses its late gene expression via a 5' splice site sequence located upstream of the late polyadenylation signal. here, the mechanism of repression is determined by in vitro analysis. u1 snrnp binding to the 5' splice site results in inhibition of polyadenylation via a direct interaction with poly(a) polymerase (pap). although the inhibitory mechanism is similar to that used in u1a autoregulation, u1a within the u1 snrnp does no ...	1998	9659922
virulence determinants of escherichia coli isolated from milk of sows with coliform mastitis.	escherichia coli isolates recovered from the milk of sows with coliform mastitis were examined to determine their biochemical and serologic characteristics, serum resistance and ability to adhere to fibronectin and bovine fetal fibroblasts. no common biotype was identified, and a variety of serovars were detected. ninety-five per cent of the investigated strains were serum resistant in swine serum. binding to fibronectin was demonstrated in most of the strains. at a binding level above 13% of th ...	1998	9673580
differentiation and quantification of theileria sergenti piroplasm types using type-specific monoclonal antibodies.	antigenic properties of two representative allelic products of the major piroplasm surface protein (mpsp) of theileria sergenti were studied. sera from cattle infected with either of ikeda and chitose types of the parasite reacted strongly with homologous but weakly with heterologous recombinant antigens in immunoblotting. monoclonal antibodies (moabs) produced against the both allelic products of mpsp parasites reacted only to the immunizing antigen. these results suggested that crossreactivity ...	1998	9673935
association of herd management factors with colonization of dairy cattle by shiga toxin-positive escherichia coli o157.	management factors in 36 pacific northwest dairy herds were evaluated for their association with the prevalence of shiga toxin-positive escherichia coli o157 (e. coli o157) in dairy cattle. the within-herd prevalence of e. coli o157 was estimated by bacteriological culture of fecal pat samples, collected monthly for 6 months (approximately 60 per visit), from heifer cattle. during the first visit to each farm, a management questionnaire was administered that covered a broad range of animal husba ...	1998	9678159
enhancement by copper, zinc superoxide dismutase of dna damage and mutagenicity with hydrogen peroxide.	oxidative dna damage caused by hydrogen peroxide was enhanced by copper, zinc superoxide dismutase (cuznsod) in a concentration-dependent manner, as reflected by the formation of 8-hydroxy-2'-deoxyguanosine (8-oh-dg) and strand breaks. hydroxyl radical scavengers such as sodium azide, mannitol and 5,5-dimethyl-1-pyrroline n-oxide (dmpo), a metal chelator, diethylenetriamine-pentaacetic acid, and catalase decreased strand breaks and 8-oh-dg formation in dna. the deoxyribose assay showed that hydr ...	1998	9679665
the region of alpha-lactalbumin recognized by groel.	the binding constants between disulfide-intact or various disulfide-reduced bovine alpha-lactalbumins and an escherichia coli chaperonin, groel, were determined by using the equilibrium dialysis method. the disulfide-intact and one-disulfide (cys6-cys120)-reduced alpha-lactalbumins were shown not to bind with groel both in the presence and absence of ca2+. the two-disulfide (cys6-cys120 and cys28-cys111)-reduced alpha-lactalbumin, which has the native-like tertiary structure in its beta-domain r ...	1998	9685721
role of phe120 in the activity and structure of bovine pancreatic ribonuclease a.	phenylalanine120 is a candidate residue juxtaposing catalytic his12 and his119 in ribonuclease a (rnase a). to clarify its role in construction of the catalytic center, phe120 was replaced by alanine, tryptophan, leucine, or glutamic acid by site-directed mutagenesis. the transphosphorylation and hydrolysis activities of the mutant rnase as, respectively, toward cytidinyl 3',5' adenosine (cpa) and cytidine 2',3' cyclic monophosphate (c>p) were compared with those of the wild type enzyme. the km ...	1998	9685734
expression and equilibrium denaturation of cardiac troponin i: stabilization of a folding intermediate during denaturation by urea.	human cardiac troponin i has been expressed at high level in escherichia coli as a fusion protein by using the expression vector ptac114. the expressed protein forms primarily intracellular inclusion bodies that are solubilized in the presence of 8 m urea. the purified troponin i is recognized by anti-(human cardiac troponin i) monoclonal antibodies. equilibrium denaturation of recombinant human troponin i and bovine troponin i is compared by monitoring changes in the protein's fluorescence and ...	1998	9693083
actin enhances the haemolytic activity of escherichia coli.	actin is a major cytoskeletal protein of mammalian muscle and non-muscle cells. exposure of cells to soluble factors that damage cell membranes results in the release of actin into the extracellular spaces. the alpha-haemolysin (hlya) of escherichia coli is the prototype rtx (repeat in toxin) toxin and is thought to be important in virulence because of its ability to lyse cells by formation of pores in the cell membrane. these studies were conducted to determine if actin influences growth and ha ...	1998	9695917
influence of escherichia coli endotoxin induced fever on the pharmacokinetics and dosage regimen of oxytetracycline in cross-bred calves.	the pharmacokinetics and dosage regimen of oxytetracycline were determined in healthy and febrile cross-bred calves following its single intravenous administration (10 mg kg-1). fever was induced by a single intravenous injection of e. coli endotoxin (1 microgram kg-1 i.v.). the elimination half-life (t1/2 beta) and the apparent volume of distribution [vd(area)] were slightly increased in febrile calves, as compared to healthy animals. the values of t1/2 beta and vd(area) were 3.22 +/- 0.20 h an ...	1998	9704514
use of hot water for beef carcass decontamination.	hot water treatment of beef carcass surfaces for reduction of escherichia coli o157:h7, salmonella typhimurium, and various indicator organisms was studied using a model carcass spray cabinet. paired hot carcass surface regions with different external fat characteristics (inside round, outside round, brisket, flank, and clod) were removed from carcasses immediately after the slaughter and dressing process. all cuts were inoculated with bovine feces containing 10(6)/g each of rifampicin-resistant ...	1998	9708247
a representative microbial sampling method for large commercial containers of raw beef based on purge.	the purge from beef combos ( a boxed collection of beef trimmings) was tested as a means of representatively sampling the microbial content of this raw product. in the first experiment, purge was sampled from model beef combos that had been inoculated with bovine feces.. data from this experiment indicated a strong correlation (r = 0.94) between the total aerobic bacteria counts derived from the purge samples of a model beef combo and the total aerobic bacteria present in a rinse sample of the e ...	1998	9708274
thermal inactivation of escherichia coli o157:h7 isolated from ground beef and bovine feces, and suitability of media for enumeration.	rates of thermal inactivation of five strains of escherichia coli o157:h7 isolated from ground beef implicated in outbreaks of hemorrhagic colitis and five strains isolated from bovine feces were determined. ground beef (22% fat, 10 g), inoculated with individual test strains at populations ranging from 6.85 to 7.40 log10 cfu g-1 of beef, was formed into patties (0.3 cm thick and 8.0 cm in diameter) and sealed in polyethylene bags. for each strain and treatment temperature (54.4, 58.9, 62.8, 65. ...	1998	9708297
long-term effect of alkaline, organic acid, or hot water washes on the microbial profile of refrigerated beef contaminated with bacterial pathogens after washing.	the effect of 2% (vol/vol) lactic acid, 2% (vol/vol) acetic acid, 12% (wt/vol) trisodium phosphate, water at 72 degrees c and water at 32 degrees c washes on bacterial populations introduced onto beef carcass surfaces after treatment was determined for up to 21 days at 4 degrees c storage in vacuum packaging. beef carcass short plates were collected from cattle immediately after slaughter and subjected to the above treatments or left untreated (c). short plates were then inoculated with low leve ...	1998	9708300