a mammalian dna polymerase alpha holoenzyme functioning on defined in vivo-like analogy to the escherichia coli replicative dna polymerase iii we define two forms of dna polymerase alpha: the core enzyme and the holoenzyme. the core enzyme is not able to elongate efficiently primed single-stranded dna templates, in contrast to the holoenzyme which functions well on in vivo-like template. using these criteria, we have identified and partially purified dna polymerase alpha holoenzyme from calf thymus and have compared it to the corresponding homogeneous dna polymerase alph ...19826765199
synthesis of alpha- and beta-glycosides containing spin labels, as probes for studies of carbohydrate-protein interaction.nitroxide spin-labeled alpha-d-glycopyranosides were synthesized in good yield and in a highly stereoselective manner by reaction of per-o-benzyl-alpha-d-glycopyranosyl bromides with 2,2,6,6-tetramethyl-4-piperidinol under the bromide ion-catalyzed conditions devised by lemieux et al. after hydrogenolysis, the deblocked intermediates were oxidized to give the desired, spin-labeled alpha-d-glycopyranosides. nitroxide spin-labeled beta-d-glycopyranosides, as well as a beta-maltoside, were synthesi ...19816786748
identification of a class of lysines within the non-specific dna-binding site of rna polymerase core enzyme from escherichia coli.the imido ester, methyl acetimidate, which specifically amidinates lysine residues, modifies rna polymerase core enzyme, leading to rapid loss of activity. calf thymus dna partially protects the enzyme against this inactivation, an effect which disappears at high salt concentration. dna protects 17 +/- 6 lysines from amidination at low salt concentration. the dependence of amidination on methyl acetimidate concentration is examined in the presence of dna at high and low salt concentration. analy ...19806804229
nucleotide sequence of calf prorennin cdna cloned in escherichia coli.the nucleotide sequence of prorennin (prochymosin) cdna cloned in e. coli was determined by the technique of maxam and gilbert. the longest prorennin cdna insert in ptacr1 contained the putative signal sequence and the coding sequence for the peptide from the 1st amino acid, ala (nh2 terminal), to the 296th, ser, and the other clone ptacr9 contained the coding sequence from the 258th, asp, to the 365th, ile (cooh terminal), and the tga termination codon followed by the 3'-untranslated region. th ...19826804449
antimicrobial characteristic of insoluble alkylpyridinium iodide.insoluble and soluble alkylpyridinium iodides (c8 to c18) were synthesized. the insoluble agents were quaternized 4-vinylpyridine-divinylbenzene copolymers. the insoluble agent [c12(50)] that contained 50% divinylbenzene and had a c12 alkyl chain was selected as the most suitable insoluble agent. c12(50) showed poor durability of the antibacterial activity, but c12(50), which had lost the activity, was refreshed by washing with ethanol. this washing became ineffective after a few cycles of antib ...19826808918
fidelity in transcription assessed by dna-dependent rna polymerases.the use of in vitro transcription of polynucleotides by prokaryotic and eukaryotic dna-dependent rna polymerases has proven of great usefulness in detecting mutagenic base modifications. quite similar results are obtained with ribo- and deoxyribopolymers as templates, and with mg2+ and mn2+ at optimal concentrations. recent studies have centered on polymers containing etheno c, as well as its hydrated form. these modifications are of particular interest, since they are the consequence of metabol ...19826814508
chemotactic factors for bovine agarose method was used to determine the nature of chemotaxins for bovine leukocytes as related to coliform mastitis. freshly collected bovine serum or plasma was frequently chemotactic, probably due to spontaneous complement activation. fresh serum was always rendered chemotactic when activated with zymosan or when heat-killed or viable coliform bacteria were incubated in the serum. the bacteria did not contribute to preexisting activity in the serum. escherichia coli grown in synthetic medi ...19826816108
lipopolysaccharide-mediated bovine endothelial cell injury in vitro.lipopolysaccharide (lps) produced time- and dose-dependent bovine endothelial cell injury in vitro that was manifested initially by cell detachment from culture substrate with subsequent cell lysis. bovine endothelial cell injury was observed with lps derived from salmonella minnesota r595, a lps comprised only of lipid a and a trisaccharide core, as well as intact lps preparations derived escherichia coli and s. typhosa. lps-mediated bovine endothelial cell detachment was prevented by incubatio ...19836827807
why are two different types of pyridine nucleotide transhydrogenase found in living organisms?two types of pyridine nucleotide transhydrogenases have been reported in living organisms. the energy-linked transhydrogenase is found in mitochondria and in certain heterotrophic and photosynthesizing bacteria, while the non-energy-linked transhydrogenase is found in certain heterotrophic bacteria. the presence of a structurally similar non-energy-linked transhydrogenase in azotobacter vinelandii, pseudomonas aeruginosa and pseudomonas fluorescens is readily shown in extracts from these bacteri ...19836840064
cross-reactivity of haemophilus somnus antibody in agglutination and complement fixation tests and in the enzyme-linked immunosorbent assay.the specificity and sensitivity of agglutination, complement fixation, and enzyme-linked immunosorbent assay (elisa) procedures in the detection of antibodies to haemophilus somnus was investigated. h. somnus rabbit immune sera were found to agglutinate pasteurella multocida, staphylococcus aureus, and haemophilus agni and, in some instances, also pasteurella haemolytica, salmonella dublin, streptococcus agalactiae, and corynebacterium pyogenes. in complement fixation tests with saline extracts ...19836841584
concentrations of methicillin in blood, normal milk and mastitic milk of cows after intramuscular injection of methicillin and tamethicillin.tamethicillin (tam) is a basic ester pro-drug of methicillin (met) which is converted in the body by non-specific esterases to met. equal doses of met and tam were administered intramuscularly in a crossover trial involving four dairy cows. acute mastitis was induced in each cow by infusing two quarters of the udder with escherichia coli endotoxin 3 h before antibiotic administration. peak serum met concentrations after met injection were significantly (p less than 0.001) higher than peak serum ...19836854731
[intrauterine bacterial and mycotic infections in cows].bacteriologic, mycologic, and serologic investigations of cows and calves and three experiments with rabbits were carried out to shed light on the bacteriology and mycology of the intrauterine infections in cows. the following organisms were isolated from the investigated cows that exhibited disturbances in their reproduction, and had abortions, or gave birth to calves that were affected with diseases or died: escherichia coli (17.84%), association of bacteria (7.64%); vibrio genitalis (3.86%); ...19836880018
structurally unique basic protein coextracted with histones from calf thymus chromatin.a histone-like protein that is rich in alanine and lysine (protein ak) has been obtained in homogeneous form by high-resolution gel filtration of h2so4 extracts of calf thymus chromatin. protein ak: (i) migrates as a single band in polyacrylamide gel electrophoresis in both acetic acid/urea and sodium dodecyl sulfate; (ii) is a basic protein; (iii) lacks tryptophan; (iv) is not extracted from chromatin with 0.35 m nacl; and (v) is not soluble in 0.75 m hclo4. protein ak is distinguished from the ...19806929493
responses of b-cells to mitogens and antigen in mice receiving isogenic splenocytes from animals treated with trichinella extract.splenocytes of c57bl/6j mice injected with a trichinella spiralis larval extract for 7 consecutive days were transferred in two doses into isogenic, immunocompetent mice. on the 3rd day, some recipients were immunized with 10(9) sheep red blood cells and others were killed to investigate blastogenic response of their splenocytes to concanavalin a (con a), escherichia coli lipopolysaccharide (lps), and mycobacterium's purified protein derivative (ppd). on the 8th day of immunization, the correspo ...19806970260
vaccination of cows with a k99 extract to protect newborn calves against experimental enterotoxic colibacillosis.pregnant cows and heifers were vaccinated with a crude k99 extract prepared from an escherichia coli k-12, k99 strain. a similar group, injected with an extract prepared from the k-12 parent strain, served as a control. eleven calves were born to both groups and challenged orally with a mean of 1.6 x 10(11) bacteria of enterotoxic e. coli b41 (o101:k99+, st+) at the time of first colostrum uptake (1 to 7 h after birth). as a result of challenge, no death occurred in the vaccine group, but four c ...19806987168
the antibiotic activity of the lactoperoxidase-thiocyanate-hydrogen peroxide system in the calf abomasum.the lactoperoxidase system which had been previously shown to kill gram-negative organisms (eg, coliforms, salmonellae, pseudomonads) in vitro, was found to be activated in vivo. the lactoperoxidase was provided by the milk and the thiocyanate either by the milk or by its secretion in the abomasum. the third factor was provided either by a h2o2 generating system (glucose oxidase and glucose) or by h2o2 producing lactobacilli. the latter occur naturally in large numbers in the abomasum of the cal ...19806990446
fibrin in peritonitis. i. beneficial and adverse effects of fibrin in experimental e. coli peritonitis.fibrin has classically been considered a defense mechanism of the peritoneal cavity. we have studied the role of purified fibrin in the pathogenesis of intraperitoneal infection. implantation of 0.5% bovine fibrin clots containing 2 x 10(8) e. coli into the rat peritoneal cavity reduces the 24-hour mortality rate from 100% to 0% compared to bacteria in a similar volume of saline solution. however, the 10-day mortality rate with fibrin is 90%; 100% develop intraperitoneal abscesses. animals recei ...19806992321
the distribution of prostaglandins in afferent and efferent lymph from inflammatory sites.arachidonic acid labeled with (14)c was injected directly into lymph nodes that had been stimulated at various times with escherichia coli. the efferent lymph was collected, and labeled catabolites were extracted and analyzed chromatographically. the pimary conversion product recovered was prostaglandin e(2) (pge(2)), with the lesser products thromboxane, prostacyclin and prostaglandin f(2alpha) (pgf(2alpha)) also detected. when the efferent lymph was analyzed by radioimmunoassay after subcutane ...19806992593
cloning of dna complementary to bovine prolactin mrna.we have cloned dna complementary to mrna coding for bovine prolactin (bprl). double-stranded cdna prepared from bovine pituitary mrna was inserted into the pst i site of plasmid bpr322 by the dc x dg tailing technique and amplified in e. coli chi 1776. a recombinant plasmid containing bprl cdna was identified by hybridization to cloned rat prl cdna. it contains cdna corresponding to the region of the mrna coding for the carboxy terminal 101 amino acids of bprl, as well as 42 nucleotides in the 3 ...19806995103
identification of a carbohydrate receptor recognized by uropathogenic escherichia coli.earlier investigations have shown that pyelonephritic escherichia coli specifically recognize and bind to carbohydrate structures correlated to the p blood group antigens. these findings are confirmed and extended in this study. twenty-two of 23 nonselected e. coli strains from children with acute febrile pyelonephritis failed to agglutinate human erythrocytes lacking the antigens within the p blood group system. only one of 32 faecal isolates exhibited this specific agglutinating property. the ...19806997213
cephamycin c treatment of induced enterotoxigenic colibacillosis (scours) in calves and piglets.cephamycin c is a beta-lactam antibiotic that has broad gram-negative activity and is resistant to degradation by beta-lactamases and safe for use in animals. in colostrum-fed calves infected with escherichia coli strain b44, cephamycin c administered by gavage at 31.3 to 1,000 mg per calf (0.75 to 24 mg/kg) twice a day for 6 days starting at 20 h post-inoculation eliminated the diarrhea and reduced the mortality from 90% in infected, nonmedicated calves to 14% in infected, medicated calves (p < ...19806999985
the binding of a fluorescent activator 2-(n-decyl)aminonaphthalene-6-sulfonic acid to pyruvate oxidase.e. coli pyruvate oxidase (pyruvate:ferricytochrome b1 oxidoreductase, ec is a peripheral membrane flavoenzyme which has been purified to homogeneity. in vivo the oxidase resides on the inner surface of the cytoplasmic membrane and is coupled to the bacterial electron transport chain. in vitro, the purified oxidase requires lipids for full enzymatic activity. previous studies have characterized the conformational and energetic coupling between the lipid-binding site(s) and the catalytic ...19807000189
construction and characterization of a cdna clone containing a portion of the bovine prolactin sequence.poly(a)-containing rna from the bovine anterior pituitary has been used as a template for the enzymatic synthesis of double-stranded cdna. the resulting double-stranded cdna was inserted into the pst i site of pbr322 with the oligo(dg)-oligo(dc) tailing technique and subsequently cloned in e. coli chi 1776. clones containing sequences complementary to prolactin mrna were identified by colony hybridization with partially purified prolactin cdna. a 250 base pair sequence from one prolactin positiv ...19807001369
novel histone h2a-like protein of escherichia coli.a histone-like protein (h) from escherichia coli has been purified to more than 98% homogeneity by using its capacity to inhibit dna functions. h protein behaves as a dimer of 28,000-dalton subunits. the histone h2a-like properties of h protein are: (i) binding to dna at a stoichiometry of 1 h protein dimer per 75 bases; (ii) abundance of about 30,000 molecules per cell, sufficient to bind about 20% of the chromosome; (iii) limiting digestion of double-stranded dna by micrococcal nuclease; (iv) ...19807001471
intramammary coliform infection after heavy external contamination of teats.teats of lactating dairy cows were exposed to massive, repeated external contamination by application of a freshly prepared broth culture of escherichia coli that was maintained in wet contact with the teat ends during 14 or 21 successive entire intermilking periods. when contamination was restricted to the intermilking periods by dipping teats in an iodophor germicide before each milking, 18 new intramammary infections occurred among the 93 mammary quarters at risk. the rate of infection achiev ...19807004280
[blood bactericidal activity in calves].methodical aspects relating to determination of serum-bactericidal capacities were studied, with the view to using them to test the bearing of abiotic environmental factors on defence mechanisms against infections. communicated are methodical experience by which to enhance the methods used to higher accuracy as well as experience regarding biological variance in calf and results obtained from follow-up checks in which antigens were systematically used. reference is made also to other methodical ...19807006553
variation in the susceptibility of bovine mycoplasmas to killing by the alternative complement pathway in bovine serum.all but one of nine acholeplasma strains were susceptible to killing by gnotobiotic-calf serum while all but one of fifteen mycoplasma strains were resistant. the mechanism of killing was examined using inhibitors of complement, viz. edta. mgegta. epsilon-amino caproic acid, and also by desalting serum and adding mgcl2 and cacl2. the results indicated that, when strains were killed by serum from gnotobiotic calves it was by the alternative complement pathway. however, experiments with mycoplasma ...19807007210
differences in inhibition of the growth of commensal and enteropathogenic strains of escherichia coli by lactotransferrin and secretory immunoglobulin a isolated from human milk.immunoglobulins from bovine and human colostrum and milk and lactotransferrin (ltf) from human milk were investigated for bacteriostatic activity against escherichia coli growing in a tissue culture medium. when tested separately, ltf or secretory immunoglobulin a (siga) from pooled human milk showed only slight bacteriostatic activity against human commensal or enteropathogenic strains of e. coli. together, they had a considerable bacteriostatic effect, but only against strains of enteropathoge ...19807007213
comparison between milk deprivation and oral rehydration with a glucose-glycine-electrolyte formulation in diarrhoeic and transported calves.treatment of diarrhoeic calves by oral administration of a glucose-glycine-electrolyte solution (gges) was compared with milk deprivation (water given instead) and with no treatment (milk-fed controls). the diarrhoea followed challenge with enteropathogenic escherichia coli. the gges group showed a significantly lower mortality (5 per cent) in comparison with the controls (37 per cent). the milk-deprived group had a slightly lower mortality (30 per cent) in comparison with the controls. the milk ...19807008333
[infant mouse model of "escherichia coli" infectious diarrhoea (author's transl)].three enteropathogenic bovine strains of escherichia coli (b41, b44 and 17c), carrying k99 antigen (k99+) and producing heat-stable enterotoxin (ent+), caused infectious diarrhoea when administered orally to swiss of1 and cd-1 infant mice. a mortality rate of 40 t0 60% was obtained after administration of 10 e. coli b41 to mice which were less than 48 h old. a mortality rate of 80 to 100% was obtained with 10(3) e. coli b41, selected as reference inoculum. inoculation of mice older than 48 h wit ...19807008674
role of platelet serotonin in the canine pulmonary response to endotoxin.there is evidence suggesting a role for platelet serotonin (5-ht) in the immediate pulmonary response to endotoxin in the dog (j. appl. physiol. 23: 47, 1967). to further define this role, autologous canine platelets were labeled with 5-[14c]ht in vitro and then reinfused. subsequently escherichia coli endotoxin (0.55:b-5, difco), 2.5 mg/kg, was injected. within 5 min dynamic compliance (cl) fell by more than 50%, and nonelastic resistance (rl) increased by more than 200%. despite a 95% decrease ...19817009524
spontaneous emergence of an hfr strain with a cit plasmid from natural isolates of citrate-positive escherichia coli bovine origin.from citrate-utilizing (cit+) escherichia coli strain c53 of bovine origin, strains c53a and c53b were obtained. upon mating with reca+ but not with reca mutant recipients of k-12, c53a produced chromosomal recombinants at quite high frequencies, leading to the following conclusions: (i) c53a is an hfr strain; (ii) the site of integration of the cit plasmid (inch1) is between meta (89 min) and ara (1 min); (iii) the direction of chromosome transfer is clockwise; and (iv) the plasmid-associated d ...19807009550
[demonstration of enteropathogenic e. coli by the ligated intestinal segment technic].through the implementation of the technique of ligated intestinal segments with established the enteropathogenic character of strains e. coli, isolated from calves by means of enteritis. the enteropathogenic e. coli provoked dilatation of the ligated intestinal segments on the basis of the enterotoxin produced by them, whereas in the case of the non-enteropathogenic ones such a reaction was not observed. the dilated intestinal segments were filled with an exudate of watery consistency under pres ...19807010769
sensitivities of escherichia coli isolated from bovine and porcine enteric infections to antimicrobial antibiotics.the antibiotic sensitivities of escherichia coli isolated from 91 diarrheal pigs and 98 diarrheal calves were determined to 19 different microbials by the kirby-bauer method. virtually all e coli isolated from pigs and calves were sensitive to amikacin, colistin, gentamicin, and polymyxin b. in vitro minimum inhibitory concentrations for these 4 antibiotics were determined for isolates from both pigs and calves.19807011124
evidence of cytocidal effects of pasteurella haemolytica on bovine peripheral blood mononuclear leukocytes.pasteurella haemolytica had a pronounced cytocidal effect on bovine mononuclear leukocytes. mononuclear leukocytes separated from venous blood on ficoll-diatrizoate and incubated with either p haemolytica or escherichia coli showed a significantly greater percentage cell death than did cells incubated with staphylococcus epidermidis or controls. neither heat-killed nor x-irradiated p haemolytica caused a significant percentage cell death. the cytotoxic potential of p haemolytica was dose related ...19807013577
membrane filter contact technique for bacteriological sampling of moist surfaces.we used a membrane filter contact technique to pick up and grow bacteria from artificially contaminated surfaces. we were able to recover individual colony-forming units (cfu) of staphylococcus aureus from a moist agar surface more efficiently with 3- and 5- micron membrane filters than with rodac plates, velvet pads, velveteen pads, or smaller-pore membrane filters. the effective transfer of bacteria with the 3- and 5-micron membrane filters was 0.96 +/- 0.04 (standard error of the mean) and 0. ...19807014608
[enteropathogenicity of e. coli strains isolated from calves].by applying the technique of ligated intestinal segments, comparative studies were carried out on the enteropathogenic character of e. coli eliminated from calves. in was proved that the anatomic-topographic position of ligated intestinal segments, as well as the quantity of the innoculated bacterial suspension, exercise an influence on the intensity of intestinal reaction. the first 2.5 m and the last 4 m of the thin intestines are inappropriate for the investigation because of the spurious rea ...19807015684
the isolation of antibiotic resistant coliforms from meat and sewage.beef and pig carcases, meat products, frozen chickens, and sewage were examined in 3 separate surveys for antibiotic resistant coliforms. escherichia coli was isolated from 18 of 50 beef carcases; the numbers were low and resistance was found only to tetracycline. e. coli was isolated from 45 to 50 pig carcases; the numbers were high and showed a range of patterns of multiple antibiotic resistance. in meat products, the proportion of e. coli in contaminating organisms was low, and most resistanc ...19817016108
the efficacy of teat dips of differing persistence on teat skin in preventing intramammary infection by streptococcus uberis and escherichia coli in dry cows. 19807016251
a survey of antibiotic resistance of escherichia coli isolated from farm animals in great britain from 1971 to 1977.a total of 94,827 escherichia coli strains isolated from cattle, sheep, pigs and poultry during the years 1971 to 1977 were tested for resistance to six antibiotics using a disc diffusion technique. the percentage of strains resistant to chloramphenicol (10 microgram), streptomycin (10 microgram), tetracycline (10 microgram), neomycin (10 microgram) and furazolidone (15) were 16.8, 53.9, 42.7, 18 and 10.9 per cent, respectively; 52.2 per cent of strains (1971 and 1972) were resistant to 2 microg ...19817020230
experimental intramammary infection of the dairy cow with escherichia coli during the nonlactating period.the nonlactating mammary gland was experimentally inoculated with escherichia coli. during the first half of the nonlactating period, 32% of 34 inoculated glands were temporarily infected. all intramammary infections were eradicated by the cow without therapy and no signs of mastitis were observed. during the 30 days before parturition occurred, 88% of 42 inoculated glands in the cows became infected. twenty-three intramammary infections were eradicated by the cow and infection in 14 glands pers ...19817020495
development of a radioimmunoassay for escherichia coli heat-stable enterotoxin: comparison with the suckling mouse bioassay.escherichia coli strains which produce heat-stable enterotoxin (st) are usually identified by demonstrating the production of st. at present, st can be detected only by bioassay methods. recently, we purified e. coli st, which enabled us to develop a radioimmunoassay for st. radioiodination of st was performed by the lactoperoxidase method, which resulted in a high specific activity and retained the biological activity of st. anti-st antisera were raised in goats by injecting the goats with pure ...19817021423
the association of the o18, k1 and h7 antigens and the co1v plasmid of a strain of escherichia coli with its virulence and immunogenicity.from an o18ac:k1:h7 colv+ strain of escherichia coli (designated mw) that had caused meningitis in a human baby, mutant forms were isolated that lacked different combinations of its o, k and h antigens and its colv plasmid. these characters were also transmitted by conjugation to e. coli k12 and the virulence, immunogenicity and other properties of the different forms of both strains were studied. all the forms of the mw strain that lacked either the o18 or k1 antigens or the colv plasmid, but n ...19807021764
antagonistic reactions of the moulds from cattle-feeds in relation of staphylococcus aureus and escherichia coli, pathogenic to cattle. 19817024798
[ca antibodies (enterobacteriaceae common antigen) in the sera of domestic animals].using the indirect hemagglutination test, antibodies against enterobacteriaceae common antigen (ca) were tested in the sera of 123 horses, 142 cows, 108 sheep, 142 mature pigs and 60 piglets (3-4 weeks of age). anti ca antibody level and antibody titers for somatic antigens (phenol-water extracts) various serogroups of e. coli (0149, 0138, 0115, 078, 09) and s. typhimurium were compared. ca antibodies in titer equal or higher than 1:15 were found to occur in 100% of the examined horses and cows, ...19817029490
factors influencing the outcome of escherichia coli mastitis in the dairy cow.eight dairy cows at various stages of lactation were infected in a single mammary quarter with approximately 5 x 10(2) colony-forming units of serum-resistant escherichia coli. the severity of the mastitis which followed depended on the speed at which neutrophils were mobilised in the gland and the opsonic activity of the whey within the gland. newly calved cows tended to be refractory to the presence of irritants in the udder and hence were slow to mobilise defence mechanisms following infectio ...19817031811
[pathomorphology of gastroenteritis in newborn calves].the morphologic changes were studied in the parenchymal and digestive organs of a total of 39 calves with gastroenteritis from which pathogenic escherichia coli organisms were isolated. a correlation was established between the age of calves and the forms of gastroenteritis manifestation. in 1 to 3-day-old calves 63.6 per cent of the cases presented histologic changes of enteritis, and 36.3 per cent presented the septic form of the disease, while in 4 to 7 day-old calves these forms were present ...19817032052
intramolecular coupling of active sites in the pyruvate dehydrogenase multienzyme complexes from bacterial and mammalian sources.a simple method was developed for assessing the intramolecular coupling of active sites in the lipoate acetyltransferase (e2) component of the pyruvate dehydrogenase multienzyme complexes from escherichia coli, bacillus stearothermophilus and ox heart and pig heart mitochondria. samples of enzyme complex were prepared in which the pyruvate decarboxylase (e1) component was selectively and partly inhibited by treatment with increasing amounts of a transition-state analogue, thiamin thio-thiazolone ...19817032507
enzyme-linked immunosorbent assay for the quantitation of immunoglobulin g bound to escherichia coli.two strains of escherichia coli were opsonized by incubation in heat-inactivated bovine blood serum and in whey. the opsonized bacteria were then immobilized by complexing with anti-bovine antibodies previously coated to walls of polystyrene tubes. the amount of bovine immunoglobulin (ig) g in the immobilized complex was then determined by a direct enzyme-linked immunosorbent assay, using peroxidase as enzyme. thus, a direct measurement of one class of opsonic substances on the surface of the or ...19817034599
role of lymphatic vessels in bacterial clearance from early soft-tissue infection.a popular concept regarding the pathophysiologic characteristics of infection is that early bacterial clearance from tissue is an important host defense mechanism. staphylococcus aureus, s epidermidis, escherichia coli, enterococcus, and klebsiella pneumoniae were radiolabeled with tritiated thymidine and injected subcutaneously into rabbit ears. negligible clearance occurred at five hours, and less than 30% of injected bacteria cleared in 24 hours. lymphatic function measured by clearance with ...19827034674
bovine mastitis: antimicrobial resistance patterns.resistance to 15 antimicrobials was determined for klebsiella spp, escherichia coli, and staphylococcus aureus in 302, 370, and 344 samples. respectively, from cases of bovine mastitis, the degree of association of resistance for all 2-way combinations of antimicrobials was calculated for each organism. significantly high and low associations were reported. an association greater than 1 indicated an increased probability of resistance to the 2nd antimicrobial of a 2-way combination, whereas an a ...19827037719
somatic and capsular factors of coliforms which affect resistance to bovine serum bactericidal activity.killing of bacteria which cause acute coliform mastitis was studied in vitro, using serum without exogenous complement. using 10% freshly collected whole serum, it was found that some strains were killed rapidly and could be classified as serum sensitive and others were killed less rapidly and could be classified as intermediate serum sensitive. with other strains, fewer were killed, and then the survivors multiplied; these could be classified as serum resistant. a 50-percentage kill of serum-re ...19817039431
assay of penetrability of bovine papillary duct implanted with escherichia coli endotoxin.a method has been developed to assay the relative penetrability to a solute of the papillary duct (streak canal) of the bovine teat. escherichia coli lipopolysaccharide endotoxin (1.0 microgram in 2.5 microliter of sterile distilled water) was implanted at a depth of 3 mm from the distal end (papillary orifice) of the papillary duct. if penetration by the irritant occurred after any one of 5 successive daily implantations, the inflammatory response of the mammary gland was detected by a precipit ...19817039434
production and evaluation of antibody to the heat-stable enterotoxin from a human strain of enterotoxigenic escherichia coli.escherichia coli heat-stable enterotoxin was coupled to bovine serum albumin by a carbodiimide reagent. antibody to the conjugate was produced by immunization of rabbits. data from radioimmunoassay and infant mouse tests indicate the presence of antibody to the enterotoxin. the antisera can be used in a radioimmunoassay to measure enterotoxin in various fluids.19817039508
inhibition of dna polymerase by captan.captan inhibits dna polymerases of both eukaryotic and prokaryotic sources. when polymerases were employed in assays with various nucleotides as template-primer, no specificity in the base sequence of polynucleotide was required for inhibition. sucrose gradient centrifugation and preincubation studies showed the inhibition was caused by an irreversible alteration of the polymerase. captan and dna compete for the same site on the polymerase, thus dna can serve a protective role in the elimination ...19827039680
plasma zinc and iron concentrations as measurements for evaluating the influence of endotoxin-neutralizing agents in escherichia coli endotoxin-induced mastitis.the influence of bacterial lipopolysaccharides on plasma zn and fe concentrations and the endotoxin-neutralizing capacity of polymyxin b was studied in 3 dairy cows. also, the feasibility of using plasma zn and fe concentrations as measurements for evaluating the influence of endotoxin-neutralizing agents in escherichia coli endotoxin-induced mastitis was studied. a positive relationship was ascertained between the dose of endotoxin given intramammarily (imm) and the effect on mean values of pla ...19827041717
inhibition of k99 antigen synthesis by l-alanine enterotoxigenic escherichia coli.the effect of various culture media on k99 antigen production by enterotoxigenic escherichia coli strains of bovine origin was investigated by slide agglutination tests, enzyme-linked immunosorbent assays and in vitro attachment to intestinal villi. a-alanine at concentrations higher than 0.7 g 1(-1) was responsible for the inhibition of k99 synthesis observed on media rich in amino acids. the increased inhibitory activity of l-alanine in glucose-rich media after autoclaving suggested the format ...19827042906
glutaredoxin from calf thymus. purification to homogeneity.the protein glutaredoxin, required for gsh-dependent ribonucleotide reduction, has been purified to homogeneity from calf thymus. the preparative method consisted of ammonium sulfate precipitation and three chromatography steps on deae-cellulose, sephadex g-50, and cm-sepharose. calf thymus glutaredoxin was assayed on the basis of its inherent gsh-disulfide transhydrogenase activity. glutaredoxin, purified 3000-fold was demonstrated to be homogeneous by polyacrylamide gel electrophoresis and hig ...19827045093
the biotyping of escherichia coli isolated from healthy farm animals.a total of 2973 escherichia coli, isolated from six different groups of animals, were examined for their ability to ferment adonitol, dulcitol, raffinose, rhamnose and sorbose in solid media. twenty-nine fermentation patterns were recorded although 2443 (82%) of the e. coli belonged to seven of the 32 possible biotypes. ninety-six o-serotypes were identified within the 2973 e. coli. the number of o-serotypes represented in the 15 most common biotypes ranged from three to 15. serotypes o8 and o9 ...19827045219
scanning and transmission electron microscopic study of the small intestine of colostrum-fed calves infected with selected strains of escherichia coli.colostrum-fed calves were fed milk replacer containing 10(11) enteropathogenic escherichia coli (eec) or nonenteropathogenic e coli (neec). the neec failed to colonize the small intestine or to be associated with the intestinal wall. the eec colonized the middle and caudal portions of the small intestine, and in these areas, 80% of the organisms were associated with the intestinal wall. light, immunofluorescence, scanning, and transmission electron microscopic studies demonstrated a layer of eec ...19827046530
electrical conductivity of milk for detection of mastitis.the potential value of electrical conductivity of milk as a screening test for subclinical mastitis was evaluated. conductivity of foremilk and of postmilking strippings from 368 quarters of 92 cows was measured. infection status of quarters was determined by bacteriological analysis of strict foremilk samples. infections were classified as by primary or secondary pathogens, depending on the importance of the isolated organism as a mastitis pathogen. somatic cells were counted on foremilk sample ...19827047600
effects of dietary milk fat (whole milk) and propionic acid on intestinal coliforms and lactobacilli in calves.calves fed whole milk had 2,000-fold fewer (p less than 0.001) coliforms in the cranial part of the small intestine than did calves fed skim milk (fat removed). calves fed milk with 32 mm added propionic acid had nearly 1,000-fold lower (p less than 0.001) counts of lactobacilli in the entire gastrointestinal tract than did calves fed milk without added propionic acid.19827049020
alkaline opening of imidazole ring of 7-methylguanosine. 1. analysis of the resulting pyrimidine derivatives.column chromatography and spectroscopy have been employed in analyzing pyrimidine derivatives obtained from alkaline-treated 7-methylguanosine (7-meguo). high performance liquid chromatography (hplc) revealed that the alkaline generated products consist predominantly of two forms of ring opened 7-methylguanine (rom7gua) in equal amounts. material from both dowex 50 and sephadex lh-20 columns was readily resolvable into two hplc peaks. the species in one peak appears to be composed of formylated ...19827049418
interactions of lipopolysaccharides, glycolipid, lipid a with acid soluble basement membrane collagen during thermal aggregation.lipopolysaccharides derived from a number of escherichia coli and salmonella species were incorporated into thermal aggregates acid soluble basement membrane collagens. although most of these endotoxins were noted to inhibit basement membrane collagen aggregation, some lipopolysaccharides possessed little or no inhibitory properties. however, the lipid a derived from all of the latter lipopolysaccharides and the glycolipid from salmonella minnesota r595 were noted to be significant inhibitors of ...19817049550
bovine mammary involution following intramammary infusion on colchicine and endotoxin at drying off.effects of intramammary infusion of colchicine, endotoxin, and colchicine in combination with endotoxin on mammary involution were studied on 25 dairy cows in late lactation. both quarters of right udder halves were infused at or near drying off while left udder halves received no infusion. samples of mammary secretion were obtained 1 day prior to drying off, at drying off, and .5, 1, 2, 3, and 7 days post drying off. mammary secretion obtained during the early dry period from udder halves infus ...19827050191
infectious agents associated with neonatal calf disease in southwestern idaho and eastern oregon.over a 2-year period, 296 episodes of disease involving 226 1-to-60-day-old calves were referred to the caldwell veterinary teaching center. infectious disease agents were found in 96% of the cases. salmonella spp were the most frequently isolated agents from dairy calves, whereas coronavirus was the agent most commonly associated with diarrhea in beef calves. multiple agents were found in 20% of the dairy calves and in 12% of the beef calves. salmonella dublin, which is associated with severe d ...19827085442
the immunosuppressive effects of trichothecenes and cyclochlorotine on the antibody responses in guinea pigs.immunosuppressive effects of trichothecenes of fusarium solani and fusarium nivale, t-2 toxin and fusarenon-x, and also of a mycotoxin of penicillium islandicum, cyclochlorotine, were studied by measuring the anti-2,4-dinitrophenyl (dnp) antibody responses in guinea pigs immunized with dnp-bovine serum albumin. among these mycotoxins, t-2 toxin alone suppressed strongly the anti-dnp antibody responses at a certain sublethal dose. with other mycotoxins, no effect was observed at any sublethal dos ...19827120038
kinetics of cytochrome b oxidation in antimycin-treated submitochondrial has been shown that in bovine heart submitochondrial particles, antimycin and 2-heptyl-4-hydroxyquinoline n-oxide (hqno) inhibit the oxidation of nadh, succinate, and reduced ubiquinone incompletely, the uninhibited rate being about 20-40 nmol of substrate oxidized min-1 (mg of protein)-1. by contrast, rotenone, cyanide, bal (2,3-dimercaptopropanol), and 5-n-undecyl-6-hydroxy-4,7-dioxobenzothiazole [trumpower, b. l., & haggerty, j. g. (1980) j. bioenerg. biomembr. 12, 151-164] caused essentia ...19827150580
occurrence of proteins immunoreactive with anti-coupling factor b in phosphorylating membrane preparations.coupling factor b has been isolated from beef heart mitochondria, apparently in multiple forms which differ in molecular weight and specific activity. since it has no known intrinsic catalytic activity, detection and quantitation have been based upon the factor b-dependent stimulation of atp-linked activities in factor b-deficient sub-mitochondrial particles. this communication reports the development of a reliable and more universally applicable enzyme-linked immunosorbent assay (elisa) for det ...19817284357
control of electron transfer in the cytochrome system of mitochondria by ph, transmembrane ph gradient and electrical potential. the cytochromes b-c segment.1. a study is presented of the effects of ph, transmembrane ph gradient and electrical potential on oxidoreductions of b and c cytochromes in ox heart mitochondria and 'inside-out' submitochondrial particles. 2. kinetic analysis shows that, in mitochondria at neutral ph, there is a restraint on the aerobic oxidation of cytochrome b566 with respect to cytochrome b562. valinomycin plus k+ accelerates cytochrome b566 oxidation and retards net oxidation of cytochrome b562. at alkaline ph the rate of ...19817305997
fluorescence-determined preferential binding of quinacrine to dna.quinacrine complexes with native dna (calf thymus, micrococcus lysodeikticus, escherichia coli, bacillus subtilis, and colstridium perfringens) and synthetic polynucleotides (poly(da) . poly(dt), poly[d(a-t)] . poly[d(a-t)], poly(dg) . poly(dc) and poly[d(g-c)] . poly[d(g-c)]) has been investigated in solution at 0.1 m nacl, 0.05 m tris hcl, 0.001 m edta, ph 7.5, at 20 degrees c. fluorescence excitation spectra of complexes with dye concentration d = 5-30 microm and dna phosphate concentration p ...19817326321
purification of a low molecular weight non-histone chromosomal protein.a non-histone chromosomal proteins was extracted from rat liver chromatin with 0.35 m nacl and purified more than 2758 times to near homogeneity by hydroxyapatite, gel filtration, and phosphocellulose chromatography. the final fraction was greater than 95% pure as judged by non-denaturing gel electrophoresis. the protein, designated loosely bound non-histone chromosomal protein 1, had an observed molecular weight of 15 700. this protein was demonstrated to increase the amount of rna synthesized ...19807353013
infectious bovine keratoconjunctivitis: effects of vaccination on moraxella bovis carrier state in cattle.a study was conducted to determine whether vaccination of cattle while they were undergoing an acute episode of infectious bovine keratoconjunctivitis (ibk), would cause vaccinated cattle to abort moraxella bovis infection sooner than nonvaccinated cattle. fourteen calves were allotted into two groups of seven calves each, and the eyes of each calf were exposed to a virulent culture of m bovis. twenty days after calves were infected and showing signs of ibk, seven calves were vaccinated with m b ...19807369598
superoxide dismutase from bacillus stearothermophilus. complete amino acid sequence of a manganese enzyme.superoxide dismutase from the thermophilic bacterium bacillus stearothermophilus is dimeric with a molecular weight of 45 487. it contains one atom manganese(iii) per dimeric molecule [brock, c. j., harris, j. i., & sato, s. (1976) j. mol. biol. 107, 175-178]. the subunits are identical, and the following primary structure comprising 203 amino acids has been determined: (formula: see text) the enzyme is identical in 60% of its residues with the escherichia coli b manganese enzyme [steinman, h. m ...19807397109
evidence of species specificity in the cytocidal effects of pasteurella haemolytica.pasteurella haemolytica was found to have a cytotoxic effect on the peripheral blood mononuclear leukocytes of cattle, sheep, and goats, but no effect on the mononuclear leukocytes of swine, horses, or humans. in contrast, escherichia coli caused marked cell death among mononuclear leukocytes of all species tested.19807439998
diffusion-in-gel enzyme-linked immunosorbent assay (dig-elisa): optimal conditions for quantitation of the diffusion-in-gel enzyme-linked immunosorbent assay (dig-elisa) the quantitation of antibodies is based on their ability to form a diffusion gradient over an antigen-coated polystyrene surface. the antigen-antibody reaction is then visualized by an enzyme-conjugated anti-immunoglobulin. the enzyme-substrate reaction is finally performed by pouring a substrate-containing gel over the polystyrene surface. in this study with bovine serum albumin as antigen and a corresponding rabbit antiserum ...19807462651
the role of tau phosphorylation in transfected cos-1 cells.tau cdnas from each of the six human isoforms were transfected into cos-1 cells and, in every case, more than one peptide was observed. the diversity of expressed isoforms was due to different levels of tau phosphorylation. tau phosphorylation results in a decrease of the protein electrophoretic mobility. the major contribution to this mobility shift is due to the phosphorylation at the at the c-terminus of the molecule, as inferred from the expression of tau fragments. phosphorylation takes pla ...19957476937
isolation of genomic and cdna clones encoding bovine poly(a) binding protein ii.cdna clones for bovine poly(a) binding protein ii (pab ii) were isolated. their sequence predicts a protein of 32.8 kda, revising earlier estimates of molecular mass. the protein contains one putative rna-binding domain of the rnp type, an acidic n-terminal and a basic c-terminal domain. analyses of authentic pab ii were in good agreement with all predictions from the cdna sequence except that a number of arginine residues appeared to be post-translationally modified. poly(a) binding protein ii ...19957479061
[determination of escherichia coli shiga-like toxins by means of the mtt bioassay].tissue culture cells' metabolism and viability are measured by the mitochondrial reduction rate of a yellow tetrazolium salt (mtt) to blue formazan crystals in the mtt-bioassay. thus the mtt-bioassay is a standardizable and reproducible bioassay for measuring cytotoxicity or cytostimulation. it is shown that the mtt-bioassay is also very suitable for determining bacterial cytotoxins using escherichia coli's shiga-like toxins as example. 177 strains of e. coli, isolated from carcasses and organs ...19957483864
effects of staphylococcus aureus mastitis after endotoxin application on milk yield and composition during subsequent lactation of guinea-pigs.the effects of staphylococcus aureus mastitis on milk yield and composition throughout subsequent lactation in lactating guinea-pigs and the role of endotoxin pretreatment on these phenomena were investigated. primiparous lactating guinea-pigs were intramammarily inoculated with sterile saline (group 1), s. aureus strain uc 6097 (group 2), or with s. aureus uc 6097 after endotoxin pretreatment (group 3). clinical signs and survival rate were monitored. during the second lactation, daily milk yie ...19957483905
effect of phenylbutazone and flunixin meglumine on acute toxic mastitis in dairy cows.a double-blinded randomized prospective clinical trial was designed to evaluate the effectiveness of flunixin meglumine and phenylbutazone for treatment of acute toxic mastitis in dairy cows. all cows were treated 4 times at 12-hour intervals by intramammary infusion of gentamicin (150 mg). a total of 45 dairy cows with toxic mastitis were randomly assigned to 1 of 3 treatment groups: group 1 (control), saline solution, iv; group 2, 1 g of flunixin meglumine, iv; or group 3, 4 g of phenylbutazon ...19957486401
recombinant human dihydroorotate dehydrogenase: expression, purification, and characterization of a catalytically functional truncated n-terminally truncated cdna for human dihydroorotate dehydrogenase (dhodase) was placed under the control of the inducible t7 lac promoter in a pyrimidine auxotrophic strain of escherichia coli lacking the endogenous enzyme. induction of gene expression rescued growth in media lacking exogenous pyrimidines. the recombinant enzyme was purified to homogeneity from detergent extracts of bacterial membranes by two chromatographic steps. the purity of the resulting enzyme was judged to be > 95% ba ...19957487077
recombinant human pancreatic ribonuclease produced in e. coli: importance of the amino-terminal sequence.human pancreatic ribonuclease 1 (hrnase 1) in the mature form has been produced in e. coli using t7 expression system. the recombinant hrnase 1 protein was solubilized from the inclusion bodies, refolded in glutathione redox system, and purified through chromatographic procedures by utilizing cation-exchange and reversed-phase columns. the ribonucleolytic activity of recombinant hrnase 1 was examined on yeast rna and cytidylyl-3',5'-adenosine revealing the distinctive ribonucleolytic activity. t ...19957488119
molecular basis of antigenic variation between the glycoproteins c of respiratory bovine herpesvirus 1 (bhv-1) and neurovirulent bhv-5.herpesvirus glycoprotein c (gc) functions as a major virus attachment protein. the gc sequence of the neurovirulent bovine herpesvirus type 5 (bhv-5) virus was determined and compared with the gc sequence of the nonneurovirulent bhv-1. alignment of the predicted amino acid sequences of bhv-1 and bhv-5 gc orfs showed that the amino-terminal third of the protein differed between the two viruses. whole or subgenomic fragments of gc coding regions from both viruses were expressed as trpe-gc fusion p ...19957491780
molecular characterization of a hamster oviduct-specific glycoprotein.there is growing evidence that the oviduct is not a passive conduit for gamete and embryo transport but serves a function for the gametes and/or embryos. the oviductal epithelium secretes one or more specific glycoproteins that associate with the egg after ovulation. several published reports including our preliminary studies have suggested that the egg-associating glycoprotein(s) from the oviduct exists in several mammalian species including golden hamster. however, little or almost no biochemi ...19957492686
proton-translocating nicotinamide nucleotide transhydrogenase. reconstitution of the extramembranous nucleotide-binding domains.the nicotinamide nucleotide transhydrogenase of bovine mitochondria is a homodimer of monomer m(r) = 109,065. the monomer is composed of three domains, an nh2-terminal 430-residue-long hydrophilic domain i that binds nad(h), a central 400-residue-long hydrophobic domain ii that is largely membrane intercalated and carries the enzyme's proton channel, and a cooh-terminal 200-residue-long hydrophilic domain iii that binds nadp(h). domains i and iii protrude into the mitochondrial matrix, where the ...19957499307
lipopolysaccharide (lps)-binding protein and soluble cd14 function as accessory molecules for lps-induced changes in endothelial barrier function, in vitro.bacterial lps induces endothelial cell (ec) injury both in vivo and in vitro. we studied the effect of escherichia coli 0111:b4 lps on movement of 14c-bsa across bovine pulmonary artery ec monolayers. in the presence of serum, a 6-h lps exposure augmented (p < 0.001) transendothelial 14c-bsa flux compared with the media control at concentrations > or = 0.5 ng/ml, and lps (10 ng/ml) exposures of > or = 2-h increased (p < 0.005) the flux. in the absence of serum, lps concentrations of up to 10 mic ...19947509346
[antibodies against escherichia coli reca protein reveal two nuclear proteins in bovine spermatocytes which interact with synaptonemal complex structures of meiotic chromosomes of various eukaryotic organisms].three reca-like proteins were detected in bovine meiotic cells using antibodies against escherichia coli reca protein. after isolation and purification of these reca-like proteins their molecular weights appeared to be equal to 37, 70 and 130 kd. the 37 kd protein accompanies all the stages of spermatogenesis up to the stage of mature spermatozoa. the 70 kd protein is detectable only in nuclei of cells at the stage of prophase i of meiotic division. these reca-like proteins are involved in the f ...19937509766
molecular characterization of dog albumin as a cross-reactive allergen.indoor allergens comprise a group of allergenic proteins that are commonly derived from house dust mite and cat and dog dander. in addition to the two major dog allergens (molecular weights: 19 and 23 kd), dog albumin represents an important allergen for up to 35% of patients who are allergic to dogs. in ige immunoblot inhibition studies and histamine release tests it has been demonstrated that patients who react to dog albumin exhibit ige reactivity with purified albumins from cat, mouse, chick ...19947512102
characterization of a linear epitope on chlamydia trachomatis serovar l2 dnak-like protein.a cytoplasmic 75-kda immunogen from chlamydia trachomatis serovar l2 has previously been characterized as being similar to the escherichia coli heat shock protein dnak. we have localized a linear epitope for one monoclonal antibody specific for c. trachomatis dnak. by use of a recombinant dna technique, the epitope was limited to 14 amino acids. with synthetic peptides, the epitope was further limited to eight amino acids. six of these amino acids are conserved in bovine hsp70, which has a known ...19947513310
effects of dsba on the disulfide folding of bovine pancreatic trypsin inhibitor and alpha-lactalbumin.dsba is a protein found in the periplasm of escherichia coli that is required for the formation of disulfide bonds in secreted proteins. it contains only two cysteine residues, which can form reversibly a very unstable disulfide bond that has been proposed to be the oxidant that introduces disulfide bonds into secreted proteins. the present study investigates the effect of dsba on the well-characterized disulfide-coupled refolding processes of bpti and of alpha-lactalbumin. disulfide-bonded dsba ...19947513556
cs31a capsule-like antigen as an exposure vector for heterologous antigenic determinants.cs31a is a multimeric surface protein surrounding certain enterotoxigenic and septicemic bovine escherichia coli strains. the possibility of using cs31a as a carrier of foreign antigenic determinants was investigated. introduction of heterologous viral epitopes into the cs31a major subunit, clpg, was successfully performed in the v3 region of the molecule which encodes for an immunodominant linear epitope. e. coli k-12 strains producing the hybrid cs31a molecules or the purified chimeric protein ...19947514578
interactions between fluoroquinolones, mg2+, dna and dna gyrase, studied by phase partitioning in an aqueous two-phase system and by affinity chromatography.the primary target of fluoroquinolones has been identified as the enzyme dna gyrase, but the mechanism of action of these antibacterial agents is still a matter of controversy. using partitioning in aqueous polyethylene glycol (peg)-dextran systems, the affinities of several fluoroquinolones for dna were determined with accuracy and at equilibrium. it was proved that the binding was strongly dependent on the ability of the drugs to bind mg2+, with ka values of about 40 000 l mol-1, but was poorl ...19947516247
three distinct human thymopoietins are derived from alternatively spliced mrnas.thymopoietin (tp) was originally isolated as a 5-kda 49-aa protein from bovine thymus in studies of the effects of thymic extracts on neuromuscular transmission and was subsequently observed to affect t-cell differentiation and function. we now report the isolation of cdna clones for three alternatively spliced mrnas that encode three distinct human t-cell tps. proteins encoded by these mrnas, which we have named tp alpha (75 kda), tp beta (51 kda), and tp gamma (39 kda), contain identical n-ter ...19947517549
interaction of immobilized recombinant mouse c-type macrophage lectin with glycopeptides and oligosaccharides.inflammatory and tumoricidal macrophages express galactose- and n-acetylgalactosamine-specific ca(2+)-dependent lectins on their surfaces. this lectin is a family member of membrane-bound c-type animal lectins and consists of 304 amino acid residues (molecular weight 34,595). in the present study, expression vectors containing a nucleotide sequence corresponding to the carbohydrate-binding domain of mouse macrophage lectin cdna have been prepared. the carbohydrate-binding specificity of the reco ...19947517698
conjugation of recombinant reverse transcriptase of hiv-1 to beta-d-galactosidase from escherichia coli for ultrasensitive enzyme immunoassay (immune complex transfer enzyme immunoassay) of anti-hiv-1 igg.recombinant reverse transcriptase (rt) of hiv-1 was conjugated to beta-d-galactosidase from escherichia coli in three different ways. maleimide groups were introduced into beta-d-galactosidase molecules using n,n'-o-phenylenedimaleimide in the absence (method i) or presence (method ii) of n-ethylmaleimide or into beta-d-galactosidase molecules, which had been treated with excess of 4,4'-dithiodipyridine to block thiol groups, using n-succinimidyl-6-maleimidohexanoate (method iii). subsequently, ...19947518483
[study of the transmembrane organization of the c-terminal domain of the alpha subunit of na+,k+-atpase using polyclonal antibodies to its perimembrane fragments].the fragments 825-842, 868-886, 928-945, 946-967, 962-978 of the alpha-subunit of the porcine na+,k(+)-atpase were expressed in e. coli as fusion proteins with human tumour necrosis factor. polyclonal antibodies were obtained to these fragments. the location of the chosen fragments according to the plasma membrane was determined with the polyclonal antibodies by elisa on intact, lysed or solubilized pig kidney embryo cells. the fragments 825-842, 928-945, and 962-978 contained intracellular epit ...19947530006
src-homology 2 (sh2) domain ligation as an allosteric regulator: modulation of phosphoinositide-specific phospholipase c gamma 1 structure and activity.phosphoinositide-specific phospholipase c gamma 1 (pi-plc gamma 1) catalyses the hydrolysis of ptdins(4,5)p2 to generate the second messengers diacylglycerol and ins(1,4,5)p3. pi-plc gamma 1, an src-homology 2/3 (sh2/sh3)-domain-containing enzyme, is activated in response to growth-factor-induced tyrosine phosphorylation, and, in vivo, is translocated from the cytosol to the particulate cell fraction. here we report the bacterial expression of rat brain pi-plc gamma 1 under the control of the t7 ...19957531435
characterization of gangliosides of epithelial cells of calf small intestine, with special reference to receptor-active sequences for enteropathogenic escherichia coli k99.glycolipids were prepared from epithelial cells of the small intestine of a newborn calf and assayed for escherichia coli k99 binding activity on thin-layer chromatograms and in microtiter wells. the bacteria did not bind to any of the non-acid glycolipids, while in the acid fraction several binding-positive glycolipids were detected. the acid glycolipids were isolated and characterized by mass spectrometry, proton nmr spectroscopy and other methods. the following gangliosides were identified, m ...19947531686
virulence markers of shiga-like toxin-producing escherichia coli strains originating from healthy domestic animals of different species.shiga-like toxin (verotoxin)-producing strains of escherichia coli (sltec) originating from healthy cattle, sheep, goats, pigs, cats, and dogs were investigated for properties which are related to virulence of e. coli for humans. the slt-ii (shiga-like toxin ii) and slt-iic genes were frequent in sltec from healthy cattle and dogs but were rarely found in sltec from other animals. the slt-iie gene was detected only in porcine sltec. sltec from goats and sltec from sheep were found to carry diffe ...19957538509
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