Publications

TitleAbstractYear
Filter
PMID
Filter
localization of the site of adenylylation of glutamine synthetase by electron microscopy of an enzyme-antibody complex.antibodies to the nucleosidel,n(6)-ethenoadenosine have been used to localize the site of adenylylation of the glutamine synthetase [l-glutamate:ammonia ligase (adp-forming), ec 6.3.1.2] of escherichia coli. antibodies were induced in rabbits by injection of a bovine albumin-ethenoadenosine conjugate. the resulting antisera strongly bound ethenoadenosine, its 5'-nucleotide, or protein conjugates of the nucleoside; little or no crossreaction was seen to adenosine, amp, or the protein carrier. eth ...197832536
diastereoisomeric glucuronides of oxazepam. isolation and stereoselective enzymic hydrolysis.oxazepam glucuronide isolated from swine urine by previously published methods was separated into its diastereoisomers by ion-exchange chromatography on a preparative scale. quantitative high-performance liquid chromatography was used to monitor the separation. the two isomers were obtained in analytically pure form and then characterized by elemental analysis, oxazepam content, mass spectrometry, ultraviolet spectroscopy, optical rotation and optical rotatory dispersion-circular dichroism. the ...197935325
resistance of gram-negative bacteria to antibiotics in large calf agglomerations.the antibiotic resistance of e. coli, citrobacter, enterobacter-klebsiella and pseudomonas aeruginosa strains isolated from calves was tested. a high proportion of multiresistance was found even in e. coli strains isolated from newborn calves. gram-negative bacteria isolated from animals in three large calfhouses were almost 100% resistant to ampicillin, tetracyclines and sulphonamides. multiresistance was general and varied from 5 to 12 antibiotics among different strains. initial high sensitiv ...197941425
an attempt to identify the intestinal receptor for the k88 adhesin by means of a haemagglutination inhibition test using glycoproteins and fractions from sow colostrum.the k88 antigen of escherichia coli specifically adheres to the piglet intestinal cell; a solution of this antigen agglutinates guinea-pig red cells at 4 degrees c. the latter reaction was used as a model of the former, using inhibition of haemagglutination as an index of specific combination with the k88 adhesin. inhibition was found with mucous glycoproteins and chemical modification of their heterosaccharide residues by mild acid hydrolysis, periodate oxidation or the smith degradation proced ...197546271
mucosal adherence of human enteropathogenic escherichia coli.an in-vitro assay system has been developed to measure bacterial adhesion to the mucosa of human fetal small intestine. two strains of escherichia coli that are proven human enteropathogens (e.p.e.c.) have been shown to adhere in large numbers, compared with control organisms. the attachment mechanism is species specific and is not caused by common fimbriae. mucosal adhesion may be as important as enterotoxin production or invasiveness in determining the virulence of some strains of human e.p.e. ...197553431
new surface-associated heat-labile colonization factor antigen (cfa/ii) produced by enterotoxigenic escherichia coli of serogroups o6 and o8.enterotoxigenic escherichia coli (etec) belonging to serogroups o6 and o8 do not possess the h-10407-type colonization factor antigen (cfa/i). however, these frequently isolated etec were found to possess a second and distinct heat-labile surface-associated colonization factor antigen, termed cfa/ii. whereas cfa/i mediates mannose-resistant hemagglutination of human group a erythrocytes, cfa/ii does not. cfa/ii mediates mannose-resistant hemagglutination of bovine erythrocytes, and mannose-resis ...197880383
enzymic polyadenylation of 5s ribosomal ribonucleic acid and synthesis of a complementary deoxyribonucleic acid.the 5s ribosomal rna has been isolated, pure and intact, from rat liver (5 mg of 5s rna from 150g of liver). the 5s rna serves as a primer for calf thymus poly(a) polymerase with 20% of the efficiency of (ap)3a. bacterial 5s rna and transfer rna also serve as primers; rat liver 18s and 28s ribosomal rnas support poly(a) synthesis poorly. neither the 5s rna primer nor the appended poly(a) tract is nicked or degraded by poly(a) polymerase, and initiation of poly(a) tracts on 5s rna primers continu ...197988957
hygiene in the prevention of udder infections. iv. evaluation of teat dips with excised cows' teats.suspensions of staphylococcus aureus, streptococcus agalactiae, escherichia coli, and pseudomonas aeruginosa were used to contaminate teats excised from cows. commercially available teat dips were applied for evaluation of comparative germicidal activity. iodophors, sodium hypochlorite, and sodium dichloro-s-triazenetrione were highly effective against all four test organisms. quarternary ammonium, chlorhexidine, and cetylpyridinium chloride were effective against staphylococcus aureus, and stre ...1978100535
[microbiological studies on bacterial spectra of milk samples from healthy udder quarters and from those with increased cell counts and/or conductivity values].the germ levels of 2,182 milk samples obtained from udder quarters with subclinical mastitis were compared to milk sampled from 2,061 udder quarters with physiological cell counts or conductivity values. three cattle herds were involved in the test programme. no germ growth was established from 9.5 per cent of all samples taken from udder quarters with increased cell counts and conductivities and from 4.1 per cent of those samples taken from intact udder quarters. samples taken from udder quarte ...1978104694
incidence and relationship of group d streptococci with other indicator organisms in meats.raw and processed meats were analyzed for presumptive group d streptococci using kf streptococcus agar. counts were compared with coliform, presumptive escherichia coli, and enterobacteriaceae counts but no meaningful relationships were observed. results indicated that group d streptococci and e. coli type i were principally contaminants from the packing plant, rather than at retail level. the predominating group d streptococcus in both beef and pork cuts was streptococcus faecalis, while in pro ...1978106944
bacteriological quality of runoff water from pastureland.runoff from a cow-calf pasture in eastern nebraska was monitored for total coliforms (tc), fecal coliforms (fc), and fecal streptococci (fs) during 1976, 1977, and 1978. bacteriological counts in runoff from both grazed and ungrazed areas generally exceeded recommended water quality standards. the fc group was the best indicator group of the impact of grazing. rainfall runoff from the grazed area contained 5 to 10 times more fc than runoff from the fenced, ungrazed area. there was little differe ...1979114112
[aanalysis of resistance and its transferability in microflora from primary meat production].resistance spectra and their transferability were studied in g- strains isolated from the primary production of meat by the method after bohus (1974). out of the set of strains, 93% were resistant, and out of these, 65% were multiresistant. thirty-five per cent of the resistant strains were r plasmid donors. of the two recipients, the laboratory strain of e. coli ihe nx was significantly better. among the 21 determined resistance spectra, the following were the most frequent: tc, smtcsu, and tca ...1979117592
inhibition of e coli atpase activity by a troponin component, tn-i, and by mitochondrial atpase inhibitor.the enzymic activity of mg2+- or ca2+-stimulated atpase from escherichia coli was inhibited by one of the troponin components, tn-i, and by mitochondrial atpase inhibitor (f1-inhibitor). the inhibitory ability of component tn-i against mg2+-stimulated atpase activity was lost after digestion of component tn-i with trypsin. the mg2+-stimulated atpase activity inhibited by component tn-i was completely restored by the addition of another troponin component tn-c.1979160325
the interaction of bovine erythrocyte superoxide dismutase with hydrogen peroxide: chemiluminescence and peroxidation.reaction of bovine erythrocyte superoxide dismutase with h2o2 was accompanied by a luminescence whose intensity was a function of the concentration of h2o2 and whose duration was coincident with the inactivation of the enzyme by this reagent. oxygen, which protected against inactivation, also diminished the luminescence. several other compounds which prevented the inactivation by h2o2 also modified the luminescence. thus urate, formate, and triethylamine inhibited luminescence whereas imidazole ...1975172122
a study of the enzymic dephosphorylation of beta-casein and a derived phosphopeptide.beta-casein, and the phosphate containing peptide derived from it by tryptic digestion, have been dephosphorylated by the action of two phosphatases. escherichia coli alkaline phosphatase (ec 3.1.3.1) has been shown to remove the phosphates from these substrates in two distinct stages. substrate molecules retaining three of the original phosphoseryl residues accumulate during the reaction and are resistant to further dephosphorylation at low enzyme concentrations. in contrast bovine spleen phosp ...1976187232
changes in intestinal structure and function of neonatal calves infected with reovirus-like agent and eschericia coli.measurements of villus/crypt length ratio and mucosal beta-galactosidase activity were made on calves less than 3 weeks of age which had diarrhoea associated with reovirus-like agent and e. coli. in calves with diarrhoea, the villus/crypt length ratios at all sites examined along the small intestine were less than in normal calves of similar age. this was attributed to a reduction in length of vili in calves infected with the reovirus-like agent. the activity of mucosal beta-galactosidase in the ...1976189746
proposed calfhood immunization program for the commercial dairy herd.immunization programs never will usurp the central role of sound management practices and good nutrition in the disease prevention program of the commercial dairy operation. however, certain immunizations against diseases such as brucellosis, leptospirosis, and clostridial infections should be routine. other diseases such as infectious bovine rhinotracheitis, bovine virus diarrhea, parainfluenza-3, colibacillosis, and pasteurellosis should be considered if it can be determined that the herd is i ...1977190280
binding of phosphorylated histone h1 to dna.a chromatin associated protein kinase was used to add 3 moles of phosphate to seryl side chains of 1 mole of histone h1. the dna binding properties of this in vitro phosphorylated h1 were compared with those of unmodified h1. considerably more radioactive superhelical dna was retained on nitrocellulose filters at 20mm-40mm nacl by phosphorylated h1 than by unmodified h1. however, zone velocity sedimentation analysis of histone-dna complexes indicated that similar amounts of phosphorylated and un ...1978209406
glycoproteins of natural origin with an affinity for hepatitis b surface antigen.sera from certain animal species contain a substance(s) which binds hepatitis b surface antigen. the hepatitis b binding substance found in animals is not antibody, but appears to be a glycoprotein which reacted with antigen-coated beads and produced a "false positive" test for antibody. this glycoprotein could be selectively and quantitatively removed by reaction with purified hepatitis b surface antigen and centrifugation. pili fractions isolated from neisseria gonorrhoeae and escherichia coli ...1978213390
the radiometric assay of alkaline phosphatase activity with 125-i-labelled phenolphthalein monophosphate.the coupling of 125-i to phenolphthalein monophosphate is described. hydrolytic cleavage of the phosphate group by alkaline phosphatases (ec 3.1.-3.1) releases labelled phenolphthalein which is extracted into ethyl acetate at ph 10. this forms the basis of a sensitive assay for the enzyme with the advantages of sensitivity and rapidity from the use of a gamma-emitter. results with escherichia coli and calf intestine alkaline phosphatases are presented.1975237639
occurrence of k99 antigen on escherichia coli isolated from pigs and colonization of pig ileum by k99+ enterotoxigenic e. coli from calves and pigs.several strains of enterotoxigenic escherichia coli (etec) isolated from pigs were found to have an antigen (k99) previously reported only on strains of calf and lamb origin and which facilitates intestinal colonization in the latter two species. several human etec were also tested for k99; however, none were positive. each of four k99-positive etec strains of calf origin and one of pig origin produced k99 in pig ileum in vivo, adhered to villous epithelium in pig ileum, colonized pig ileum, and ...1977321356
inhibitory action of galactose on phagocytes from normal and hypergalactosemic chicks.the inhibitory effect of galactose on phagocyte function was investigated in normal and hypergalactosemic chicks by monitoring the in vitro killing of escherichia coli by leukocytes and the in vivo clearance of colloidal 125i-labeled bovine serum albumin ([125i]bsa) from the circulation. elevated levels of galactose (30 mm) significantly impaired the bactericidal activities of leukocytes from both control and hypergalactosemic chicks. however, the latter cells were more susceptible to the galact ...1977326668
blastogenic transformation by lipopolysaccharide of blood leukocytes from immunized but not normal cattle.escherichia coli lipopolysaccharide produced blastogenic transformation in whole-blood leukocytes from heifers that had been infected and immunized with campylobacter fetus, but not in cells from control animals. this suggests that lipopolysaccharide dose not function as a b-cell mitogen in cattle and that its stimulation of cells from immunized animals occurred through another mechanism.1977330414
mammary blood flow during experimental escherichia coli endotoxin induced mastitis in goats and cows.the effect of intramammary infusion of escherichia coli endotoxin upon mammary blood flow was studied in lactating goats and cows. blood flow was recorded by means of an electromagnetic flow probe chronically implanted around one mammary artery. endotoxin mastatis was always accompanied by a significant increase in mammary blood flow, characterized by 2 conspicuous peaks. the flow returned to control values by the thirteenth hour after infusion. other symptoms of acute mastitis were: fever, incr ...1977338650
studies on the immunity of the calf to colibacillosis--vii: the experimental reproduction of enteric colibacillosis in colostrum-fed calves.eight newborn calves were challenged orally with a known enteropathogenic strain of escherichia coli 0101 k?(a) and two to six hours later each calf was fed a minimum of three pints colostrum. all calves suffered from acute diarrhoea of varying severity within 24 to 48 hours of infection. immunofluorescent and histological examination of the small intestine demonstrated adherence of the challenge organism to the epithelium and the presence of pathological lesions similar to those seen in colostr ...1977339479
[dynamics of agglutinins following vaccination against coli-bacteriosis in calves].a bivalent vaccine, produced with strains escherichia coli 078 and 0117 to control colibacteriosis in calves, was used to vaccinate experimentally 20 cows following up the agglutinin dynamics in the serum of calves born later on. it was found that the agglutinin titers of the 0 antibodies were lower than those of ok, and varied within the range of from 1:10 to 1:320, the titers of 1:20-1:40 values being prevalent. highest level of titers was observed by the third day following birth. ok antibodi ...1977337649
[biochemical and serological studies of the e. coli strains isolated from cows with subclinical mastitis].studies were serologically and biochemically a total of 17 strains of escherichia coli isolated from mastitis-affected cows in the districts of sofia, varna, and plovidiv. demonstrated were the serogroups 0125, 0111, 086, 025, 026, 055, and 0128, which were pathogenic for humans too. via the milk they were shown to reach both newborn animals and children and to cause severely expressed colienteritis. all investigated strains attacked glucose and manite, reduced nitrates into nitrites, and gave a ...1977343354
in vitro adhesion of escherichia coli to porcine small intestinal epithelial cells: pili as adhesive factors.escherichia coli strains with pili (k99 or 987p) known to facilitate intestinal colonization adhered in vitro to porcine intestinal epithelial cells. these strains adhered equally to both ileal and jejunal epithelial cells. a laboratory e. coli strain that has type 1 pili also adhered to porcine intestinal epithelial cells. when nonpiliated cells derived from 987p+, k99+, or type 1 pilus+ strains were used for in vitro adhesion assays, they failed to adhere. the attachment of piliated bacteria t ...1978357285
biological evaluation of a methanol-soluble, heat-stable escherichia coli enterotoxin in infant mice, pigs, rabbits, and calves.escherichia coli p16 was shown to produce two heat-stable toxins (st) with differing biological activity. the toxins were separated by methanol extraction, and the first, sta, was methanol soluble, partially heat stable, active in neonatal piglets (1 to 3 days old) and infant mice, but inactive in weaned pigs (7 to 9 weeks old); the second, stb, was methanol insoluble, active in weaned pigs and rabbit ligated loops, but inactive in infant mice. it is therefore suggested that use of suckling mice ...1978357288
microscopic assay for the phagocytotic-collagenolytic performance (pcp index) of human gingival fibroblasts in vitro.using 16 human gingival fibroblasts cell lines from patients with periodontitis, dilantin hyperplasia, and nonpathological gingiva, a microscopic assay was developed to quantitate the cells' ability to lyse collagen substrates. the method employs tissue culture chambers with one cover slip partially coated with a thin layer of undenatured fibrillar bovine collagen. the assay measures the relative numbers and sizes of holes in the collagen within defined regions of the cover slips effected by the ...1978363754
incidence of colicinogenic escherichia coli in sheep, goats and cattle. 1978367012
acute undifferentiated neonatal diarrhea of beef calves: the prevalence of enterotoxigenic e. coli, reo-like (rota) virus and other enteropathogens in cow-calf herds. 1977326373
antibiotic resistance and transferable antibiotica resistance escherichia coli isolated from calves on a modern farm with therapeutic problems and unsatisfactory management conditions.on a farm with therapeutic problems and unsatisfactory management conditions, the occurrence of antibiotic resistance and transferable antibiotic resistance has been studied in e. coli isolated from calves which were 5 and 30 days old. strains with resistance to up to seven antibiotics as well as transferable resistance against up to five antibiotics were recorded. on an average, 4.2 strains with different patterns and 4.0 different strains with transferable resistance were isolated from each ca ...1979370760
elisa: enzyme-linked immunosorbent assay.similar in design to radioimmunoassay, comparable in sensitivity and specificity but easier, safer, and less expensive, this new diagnostic technique uses enzyme-labeled rather than isotope-labeled reagents. the end point is a color change that can be assessed by colorimetry or with the naked eye. various techniques of elisa are described, along with examples of current and potential clinical applications.1978215505
biochemical and topographical studies on escherichia coli cell surface. iv. giant spheroplast formation from a filamentous cell.long, nonseptate filamentous cells consisting of 5 to 40 single-cell unit lengths were formed from escherichia coli surface mutant ont-3 by treatment with a sublethal concentration of sodium dodecyl sylfate. as distinct from several other elongated cells (e.g., thymine-starved filaments), it was found here that stable giant spheroplasts, 5 to 10 micrometers in diameter, were produced by the action of lysozyme in the presence of bovine serum albumin via the gradual fusion of distinct spheroplasti ...1979374397
leucocytic changes in cows given intravenous injections of e coli endotoxin. 1979380122
thermal denaturation and template activities of reconstituted dna-histone complexes.reconstituted complexes of dna with histone were prepared by salt-and-urea step gradient dialysis. the dna was complexed with histone h1, with the combination of the other four histones h2a, h2b, h3 and h4, and with whole histones. these dna-histone complexes were purified by bio-gel column chromatography, and the weight ratio of histone-to-dna was determined in each complex. the thermal denaturation profile and nuclease digestion pattern of dna-histone h2a, h2b, h3 and h4 complex were compatibl ...1977146400
[interaction of oligophosphates of pyridoxal with certain enzymes of polynucleotide synthesis].the interaction of pyridoxal, pyridoxal-5'-mono-, di- and triphosphate with certain enzymes of polynucleotide synthesis (dna-dependent rna polymerase, dna-dependent dna polymerase i and polynucleotide phosphorylase from escherichia coli and terminal deoxyribonucleotide transferase from calf thymus) was studied. all compounds tested was found to be reversible and competitive inhibitors of these enzymes. the reduction of the enzyme-inhibitor complex with nabh4 gives rise to the complete irreversib ...1979381898
the transfer of bacterial biotin genes to escherichia coli k-12 cells by transfection with lambda bio phage dna.the transfection of biotin genes to biotin negative escherichia coli k-12 cells with donor dna isolated from transducing lambda bio phages was examined. the transfection of the cells was performed in the presence of bovine serum albumin and sucrose (osowiecki and skaliƄska, 1974).197770968
the pathogenesis of experimental escherichia coli mastitis in newly calved dairy cows.experimental infections of the mammary gland of newly calved cows with 500 serum resistant escherichia coli produced a very severe form of mastitis when compared with animals in mid-lactation. ten hours after infection the bacteria had multiplied in the milk to very high numbers (10(6)--10(7)/ml) and the animals showed signs of pyrexia, anorexia and diarrhoea. initially the gland and milk showed little or no clinical signs of mastitis, but later the secretion became a viscous, serous fluid with ...1979382318
some effects of the administration of endotoxin in mice. specific cleavage of serum albumin by an acid protease and the generation of amyloid serum component.endotoxin has been shown to induce amyloidosis in mice and to result in the appearance in serum of large amounts of amyloidrelated protein (saa). after injection of 300 mug lipopolysaccharide escherichia coli, saa behaves as an acute phase reactant with levels reaching a peak of >600 mug/ml at 18-22 h and returning to base line (<50 mug/ml) by 48 h in each of four strains tested; only the endotoxin-resistant c3h/hej strain showed a smaller response. lesser, though significant, elevations were al ...197934628
the origin of yolk-dna in xenopus laevis.xenopus laevis serum and plasma was found to contain an average of 25 microgram dna/ml. isolated x. laevis oocytes incubated in medium containing 25 microgram dna/ml labeled with either 125i, 32p or 14c and from three different sources (bovine, e. coli and x. laevis), incorporated the label at an average rate of 0.11 ng.mm-2.hr-1. sucrose gradient fractionation of oocytes revealed that 40-75% of the acid-precipitable label incorporated was associated with the yolk platelets. additional incubatio ...1979385804
the sources of "oh" serotypes of escherichia coli.the sources from which different "oh" serotypes of escherichia coli have been isolated are listed in a series of tables. it is considered that these tables should provide a basis for obtaining a greater understanding of the ecology of e. coli.1978340583
biochemical characteristics of enterotoxigenic and nonenterotoxigenic escherichia coli isolated from calves with diarrhea.eighteen isolates of enterotoxigenic escherichia coli (etec) and 15 isolates of nonenterotoxigenic e coli (netec) obtained from calves with diarrheal disease were characterized biochemically. of 64 biochemical tests employed, none allowed making differentiation of etec from netec. eleven tests were used to separate etec isolates into 1 of 5 biotypes, although the ability to ferment dulcitol, salicin, sucrose, and sorbose gave sufficient information to identify the 5 biotypes of etec. the biotype ...1977339791
the effect of an intramammary infusion of endotoxin on experimentally induced mycoplasmal mastitis.the infusion of 10 microgram of endotoxin lipopolysaccharide from escherichia coli into the mammary gland of four cows 16 h before inoculation with ureaplasmas did not prevent, or even diminish, the subsequent ureaplasmal mastitis. there was no reduction in the severity or duration of the inflammatory cell response in milk or in the clinical appearance of the resulting mastitis. also, the excretion of ureaplasmas was not reduced. a similar experiment with mycoplasma dispar in two cows demonstrat ...1979390046
recurrent coliform mastitis in the dairy cow.daily monitoring of milk over a 120-day period for bacteria and neutrophil counts revealed that following experimental e coli mastitis, five out of 28 infections resulted in the development of a long continued and recurring condition. intermittent periods of acute inflammation were observed in the gland, pyrexia was noted, and if bacteria were isolated they were always of the same serotype as the original infecting strain. failure to isolate bacteria and the lack of overt inflammation during per ...1979390847
the pathogenesis of enteric colibacillosis in neonatal unsuckled calves.the development of pathological lesions in the small intestine of neonatal calves is described. seven newborn calves were challenged orally with a known enteropathogenic strain of e coli 0101k?(a) and killed at varying times after inoculation. adhesion of bacteria to the mucosa of the small intestine was observed in all calves. a few organisms were seen in the distal small intestine at three hours after inoculation and thereafter adhesion progressed anteriorly along the intestine in calves kille ...1979390852
purification of 3-phosphoglycerate kinase from diverse sources by affinity elution chromatography.1. affinity elution chromatography was used to purify phosphoglycerate kinase from a variety of sources. the choice of buffer ph for the chromatography was made according to the relative electrophoretic mobility of the enzyme from the species concerned. 2. outlines of the methods used to isolate the enzyme from over 20 sources are presented. the enzyme was purified from the muscle tissue of a variety of mammals, fish and birds, from liver of several animals, from yeast, escherichia coli, and pla ...1978367367
use of polyvalent cow colostrum in the prevention of enteric infections in calves and piglets.colostrum of cows immunized with a polyvalent vaccine against enteropathogenic strains of escherichia coli gave good protection to piglets and calves against enteric coli infections. bovine immunoglobulin (igg1) and its precipitable fragments persisted in the small intestine of piglets for 6 hours after oral administration. the proteolytic breakdown of porcine colostral igg2, which occurs predominantly in the small intestine proceeded at a higher rate than that of heterologous bovine colostral i ...1978371506
methodology for recognition of invasive potential of escherichia coli.surveillance for dysentery-related invasive potential in bacteria using the sereny keratoconjunctivitis test is restricted by expense, time factor, and necessity for confirmation. primary screening of isolates in a standardized mammalian cell culture system is recommended. bacteria are grown 20 hr in veal infusion, washed, and resuspended in 20% heat-inactivated fetal bovine serum (fbs) supplemented with 0.12% brain heart infusion and 0.1% bile salts. the hela culture is grown 20 hr as a monolay ...1977323215
transcription of nucleosomal dna in sv40 minichromosomes by eukaryotic and prokaryotic rna polymerases.sv 40 minichromosomes can be transcribed by prokaryotic and eukaryotic rna polymerases. size analysis of transcripts indicated that dna in nucleosomes was accessible for transcription by both enzymes. sedimentation of the transcription complex showed that minichromosomes which were being transcribed had a full complement of nucleosomes. strand selection by e. coli rna polymerase was reduced by the presence of nucleosomes. no region of sv 40 dna was preferentially transcribed on minichromosomes b ...1979223131
inactivation by detergents of the proline transport system in membrane vesicles from escherichia coli and its reactivation by bovine serum albumin.the proline transport system of membrane vesicles from escherichia coli was inactivated by a low concentration of detergents such as deoxycholate, dodecyl sulfate and triton x-100. the addition of a large amount of bovine serum albumin to membrane vesicles which had been treated with one of these detergents resulted in the restoration of the proline transport activity. the restoration of the transport activity by bovine serum albumain was most remarkable with the deoxycholate-inactivated membran ...1976764873
early mitochondrial damage in the induction of haemorrhagic necrosis in the crocker sarcoma (s 180) by endotoxin.disturbances in the functional properties of tumor mitochondria have been studied during the course of induction of haemorrhage brought about by endotoxin in the murine crocker sarcoma (s 180). extensive impairment of function was already present in mitochondria isolated from control tumors, as shown by low respiratory control ratios. the existing mitochondrial damage intensified promptly in response to injection of endotoxin long before the onset of haemorrhage at 4 h. the nature of the additio ...1979381316
experimental neonatal colibacillosis in cows: serological studies.serological studies of passive immunity in experimentally induced bovine colibacillosis was studied in a 41-cow university herd. pregnant dams were antigenized prepartum with two injections administered by the subcutaneous and intrammamary routes with one of four vaccine preparations (killed bacteria, live bacteria, culture supernatant, or heart infusion broth [control]). the data indicate that 77% of the neonates born to vaccinated dams were strongly protected against oral challenge with escher ...1976765285
passive oral immunization with bovine immunoglobulins: enterpathogenic escherichia coli from infants and bovine anti-e. coli lactoserum assayed in the rabbit ileal loop model.the effect of immune bovine lactoserum (bls) antipolyvalent enteropathogenic escherichia coli on bacterial growth, viability and bacteria-induced fluid accumulation was examined in rabbit ileal loops. human enteropathogenic e. coli strains 0125:k70 (b15), 0111:k58 (b4) and 055:k59 (b5) (1-3 x 10(9) per inoculum) induced secretion of 4-6 ml fluid per 10 cm loop. this effect was inhibited effectively by bls (corresponding to 50 mg igg 1 per loop) while the viability of bacteria counts decreased 2- ...1975765710
[residues of antimicrobial materials in the effluents of livestock farms (author's transl)].forty water samples were taken from streams of three different regions of belgium, with intensive husbandry and examined for residual microbiological activity. in some samples, activity was detected against staphylococcus aureus; none of them were active against e. coli and c. albicans. the substances in the few positive samples were not identified. with this low activity and the small proportion of positive samples (12 out of 41) any influence on the water biosphere due to the methods of farmin ...1976766304
demonstation that thymine dimers are excised as oligonucleotides from specifically incised ultraviolet-irradiated deoxyribonucleic acid.the average size of the dimer-containing acid-soluble oligonucleotides after incubation of specifically incised dna with two dimer excising nuclease activities has been determined to be about 8 nucleotides.1975164436
replication of polyoma dna in isolated nuclei. v. complementation of in vitro dna replication.nuclei from polyoma-infected 3t6 fibroblasts elongate in vitro the progeny strands of the replicative intermediates of polyoma dna. when high concentrations of such nuclei were incubated, short dna fragments were formed and subsequently added onto growing progeny strands. when nuclei were repeatedly washed with buffer containing detergent and then incubated at low concentrations. dna synthesis was decreased. in particular, the joining process was reduced, resulting in an accumulation of short dn ...1975163354
the survival of serum resistant escherichia coli in the bovine mammary gland following experimental infection.serum resistant strains of escherichia coli were injected into one or two quarters of the udders of eight healthy dairy cows. animals receiving infection into two quarters showed variation in their ability to eliminate the bacteria. this variation extended from elimination from both glands to complete failure to remove the organisms from either gland. in most cases, the organisms were removed from one gland before the clinical signs of infection were observed, but persisted in the other gland fo ...1979382316
[the effect of dna isolated from different sources and different physico-chemical conditions on candida tropicalis strain d-2 his-].mutagenic effect of dna, isolated from escherichia coli, actinomyces olivaceus and calf thymus, on hystidine-deficient strain of candida tropicalis d-2 is demonstrated.1975773761
antibodies to the triplet codons aaa, aac, and aug: reactions with nucleic acids.antibodies specific for the trinucleotide codons aaa, aug, and aac were examined for their reactions with nucleic acids. anti-aug and anti-aac precipitated denatured dna. anti-aaa did not, and moreover, the binding of a tritiated aaa derivative to anti-aaa was not inhibited by denatured dna. radioligand-binding studies showed that anti-aaa was highly specific for the triplet sequence, some cross-reactions occurring with di-a and tetra-a but little with a and poly(a). the anti-codons did not prec ...1976774989
circular dichroism anisotrophy of dna with different modifications at n7 of guanine.the complexex dna-ag1+, dna-cu1+, protonated dna and dna methylated at n7 of guanine were oriented by pumping the solutions through a multicapillary cell in the direction of a light beam. the cd components along the dna axis, delta epsilon parallel, and normal to it, 2 delta epsilon perpendicular, were calculated from the cd spectra of the oriented samples by the method of chung and holzwarth, (1975) j. mol. biol. 92, 449--466. it was shown that in most cases, except that of the protonated dna, ...1979385054
resistance of neonatal calves given colostrum diet to oral challenge with a septicemia-producing escherichia coli.twenty holstein-friesian male calves were obtained within 4 hours after bith (colostrum deprived) and allotted to 1 of 4 groups, each given a different feeding: colostrum, milk replacer, polyvinylpyrrolidone (pvp), and saline solution (0.85% nacl). each calf was fed 2 l of the respective diets every 12 hours. rectal temperatures were recorded and blood samples were collected immediately before each feeding. at approximately 27 hours of age, all calves were inoculated orally with 1.5 x 10(10) via ...1977335927
[escherichia coli cell competence induced by calcium cations].escherichia coli k-12 cells grown to early and late exponential, and early and late stationary phases were treated with ca2+ and analysed for the ability of exogenous 14c-dna uptake and genetic transformation. dna-membrane complexes were detected detected by isopicnic centrifugation of cell lysates in sucrose density gradient. it is found that 1) during all the tested phases of the growth cycle, e. coli cells attain the ability of enhanced dna uptake after ca2+ treatment; 2) exogenous and host d ...1977334632
effect of tetracycline upon transfer of an r plasmid from calves to human beings.fecal specimens from human subjects in daily contact with calves shedding escherichia coli containing an r plasmid were analyzed for the presence of e coli and the plasmid. a low level of crossover was found to occur unrelated to whether or not the calves were receiving tetracycline.1977333999
[studies of immunity in mastitis in cows].studies were carried out to establish the specific antibodies in the milk and blood sera of cows recovered from a spontaneous infection of the udder caused by streptococci, staphylocci, corynebacteria, and some representatives of escherichia coli as well as of cows immunized with a polybacterial vaccine. followed up was likewise the resistance of the udder in vaccinated cows to bacterial infections. it was found that in both groups of animals the specific antibodies' titer ranged from 1:80 to 1: ...1977331658
vaccination of cows with an escherichia coli bacterin for the prevention of naturally occurring diarrheal disease in their calves.a formalin-killed escherichia coli bacterin composed of 6 enterotoxigenic strains of the organism prepared from calves with diarrheal disease with field tested for efficacy against naturally occurring diarrheal disease in young calves. the bacterin was tested in 23 privately owned beef herds in montana involving 3,508 cows and their calves. about half the cows in each herd were given 2 subcutaneous vaccinations before calving and the other half (controls) were injected twice with a placebo. almo ...1976779544
etiologic diagnosis of diarrheal disease of calves: frequency and methods for detecting enterotoxin and k99 antigen production by escherichia cola.escherichia coli isolated from calves in minnesota and montana were tested for enterotoxigenicity via bio-assay of cell-free broth culture fluid and for k99 antigen via a serum agglutination test. infant mice were used to assay for heat-stable enterotoxin (st), and adrenal cells in culture were used to assay for heat-labile enterotoxin (lt). forty-six of the 345 e coli isolates produced st enterotoxin, but none produced lt enterotoxin. thirty-five of the 46 enterotoxigenic isolates had k99 antig ...1976786085
in vitro packaging of uv radiation-damaged dna from bacteriophage t7.when dna from bacteriophage t7 is irradiated with uv light, the efficiency with which this dna can be packaged in vitro to form viable phage particles is reduced. a comparison between irradiated dna packaged in vitro and irradiated intact phage particles shows almost identical survival as a function of uv dose when escherichia coli wild type or pola or uvra mutants are used as the host. although uvra mutants perform less host cell reactivation, the pola strains are identical with wild type in th ...1977330877
lutropin stimulation of rna synthesis in corpus luteum chromatin.lutropin and human choriogonadotropin stimulated the endogenous chromatin-associated polymerase activity in purified chromatin prepared from nuclei of bovine corpus luteum. chromatin was incubated in two different buffer systems: one that mainly supports the activity of polymerase i, another that supports the activity of polymerase ii and is largely alpha-amanitin sensitive. the hormones lutropin and chorigonadotropin stimulated an increase in the rate of incorporation of [14c]atp or [14c]utp in ...1977329886
transcription of double-stranded rna by escherichia coli dna-dependent rna polymerase.double-stranded rna of some virus genomes can be used as template for the dna-dependent rna polymerase purified from escherichia coli. the rna synthesis requires all four nucleoside triphosphates and manganese ions and is dependent on the presence of sigma subunit. the reaction is inhibited by rifampicin, streptolydigin and ethidium bromide, but not by dnase and actinomycin d which does not bind to double-stranded rna. the template activity of double-stranded rna from various viruses is differen ...1977320006
pathogenesis and treatment of escherichia coli infections in calves.two clearly defined types of e. coli infection are recognised and the factors predisposing and giving rise to pathogenicity are discussed. the mode of action of enterotoxins in the secretary mechanism is thought to be through stimulation of adenyl cyclase activity. treatment and prevention of the disease is considered in relation to the pathogenesis of the infection.1976792447
studies on indoleamine 2,3-dioxygenase. i. superoxide anion as substrate.indoleamine 2,3-dioxygenase purified to apparent homogeneity from rabbit intestine was inhibited by scavengers for superoxide anion such as superoxide dismutase and 1,2-dihydroxybenzene-3,5-disulfonic acid (tiron). on the other hand, beta-carotene and 1,4-diazobicyclo-(2,2,2)-octane, scavengers for singlet oxygen, did not affect the enzyme activity significantly. the degree of inhibition of the dioxygenase by superoxide dismutase preparations from bovine erythrocytes, green peas, spinach leaves, ...1975238993
characterization of enterotoxigenic bovine escherichia coli.among 300 isolates of bovine escherichia coli, 56 which had been found enterotoxigenic in calf gut loops were characterized on the basis of o and k antigens, colonial morphology and resistance to seven antimicrobial drugs. the 56 isolates enterotoxigenic in the calf were compared with the nonenterotoxigenic ones. of the 56 enterotoxigenic e. coli the majority possessed the a type of k antigen and had ok groups, o9:k(ps274) or o101:k(rvc118). fourteen of these isolates had the k99 antigen. none o ...1976793694
specific limited cleavage of bihelical deoxyribonucleic acid by wheat seedling nuclease.wheat seedling nuclease catalyzes the hydrolysis of intact, bihelical viral dna or high molecular weight, native escherichia coli dna to produce limit polymers which are resistant to further hydrolysis by additional enzyme. these limit products are double-stranded polymers free of single strand interruptions and are terminated at their 5' ends with equal amounts of either deoxycytidylate or deoxyguanylate residues. the average size of the duplex limit products, as determined by (a) alkaline and ...1975236302
properties of a dna-adenylate complex formed in the reaction between mammalian dna ligase i and dna containing single-strand breaks.the major dna ligase from calf thymus (mammalian dna ligase i) forms a covalent enzyme-amp complex on incubation with atp [söderhäll & lindahl, j. biol. chem. 248, 672-675, (1973)]. the reaction of this complex with dna has now been studied. when the ligase-adenylate complex is incubated at 0 degrees c for short time periods with dna containing single-strand breaks, a dna-amp complex can be isolated from the reaction mixture by isopycnic centrifugation in cscl. incubation at ph 6.5 increased the ...1975235425
studies on the substrate specificity of the dna methylase activity from escherichia coli k-12.a partially purified extract of dna methylases from e. coli k-12 containing dna-adenine as well as dna-cytosine methylase activities has been examined with respect to different dna species as substrates. the results show that the natural content of 6-map) in the applied dna represses the dna-adenine methylase activity. on the other hand, 5-mc, already present in the substrate does not influence the activity of the dna-cytosine methylase. dna from micrococcus radiodurans, which is completely free ...1979232591
isolation and characterization of cytidine diphosphate diglyceride from beef liver.cytidine diphosphate diglyceride was isolated from beef liver by a combination of silicic acid column, deae-cellulose column, and this layer chromatography. the product (5.8 to 17.4 mumol/kg of liver) contained cytidine/phosphate/fatty acids in the molar proportions 1.05/2.0/2.05 (theoretical, 1.0/2.0/2.0) (average for three preparations). the liponucleotide was split quantitatively by a partially purified hydrolase from escherichia coli, specific for cdp-diglyceride, (raetz, c. r. h., hirschber ...1975169258
the effect of leukocyte hydrolases on bacteria. iii. bacteriolysis induced by extracts of different leukocyte populations and the inhibition of lysis by macromolecular substances.the lysis of 14c-labeled bacteria by hydrolases of human and rabbit leukocytes was studied in vitro. while staphylococcus albus, streptococcus faecalis, and streptococcus mutans were highly susceptible to lysis, staphylococcus auresus was intermediate in its susecptibility to lysis by the leukocyte enzymes. group a streptococcus, listeria monocytogenes, shigella flexneri, escherichia coli, and mycobacterium smegmatis were very resistant to degradation by these enzymes. the lytic activity of leuk ...1975804017
herd studies on coliform mastitis.escherichia coli, enterobacter aerogenes, and klebsiella pneumoniae were responsible for 63, 10, and 11 percent, respectively, of 158 coliform organisms recovered from mastitis cases in 8 california herds. the severity and nature of the coliform mastitis problem were found to vary greatly among herds but were characteristic for each of 4 herds studied in detail.1975804464
teat apex coliform populations and coliform mastitis--a herd study.a dairy herd having a high incidence of coliform mastitis was observed by means of pre- and post-milking samples and teat apex culture. infected quarters were the major source of teat apex contamination with coliform bacteria and therefore constituted a risk to unifected quarters and to other cows. coliform populations on the apex from environmental sources appeared to be transitory.1975806418
[effect of long-term freezing preservation on the level of bacterial contamination of the sperm].fourty-five ejaculates of breeding bulls were examined at a breeding station in order to study the contamination level of sperm after ejaculation, after thinning, after finished equilibration, after freezing, and after three months after placement in liquid nitrogen at -- 196 degrees c. the amount of germs in sperm was found to increase rapidly in the course of examination and thinning at laboratory temperature. the average number of 4,149 germs increased to 9,729. during equilibration the numbe ...1975808013
[false-positive results obtained on examining slaughtered animals for the presence of antibiotic residues (author's transl)].as part of the examination of emergency-slaughtered animals for the presence of antibiotic residues, studies were done to see whether false-positive results would be obtained when the sarcina lutea kidney test and bacillus subtilis bga test were performed. when the s. lutea kidney test was positive in cattle, calves and swine, penicillin was invariably found to be present in those animals, the histories of which showed that they had not been given antibiotics. a syringe and an injected fluid con ...1975809859
selective adhesion of microorganisms to the ductular epithelium of the bovine mammary gland.streptococcus agalactiae, streptococcus faecalis, staphylococcus aureus, escherichia coli, and corynebacterium bovis were examined for their ability to adhere to the ductular epithelial cells of the bovine udder. s. agalactiae and s. aureus adhered readily and in large numbers, whereas the other organisms adhered poorly or not at all. the organisms showing the ability to adhere are those which frequently cause mastitis. these data suggest that selective adherence to the ductular epithelium may b ...1975811566
[comparative study of some quaternary ammoniums neutralizing agents. influence of the nature of the bacterial strains used].the neutralising capacity of the anti-bacterial activity of a quaternary ammonium salt, depends on the nature of the bacterial strains used. consequently, the choice of a neutralising agent of the bactericidal activity can only be made following a preliminary study on several bacterial species. out of five products which we tested, we found the tween-lecithin fresh egg mixture alone had satisfactory activity.1975812041
clinical pharmacology of oxolinic acid in young dairy calves.the in vitro sensitivity to oxolinic acid shown by pathogenic gram-negative bacterial isolates from young calves with diarrhea, pneumonia, and septicemia was investigated by the bute dilution method. minimal bactericidal concentrations of the drug for 65.5% of the isolates were less than or equal to 1.56 mug/ml and for 90%, less than or equal to 6.25 mug/ml. cross resistance between oxolinic acid and chloramphenicol, streptomycin, neomycin, colistin, ampicillin, gentamicin, and oxytetracycline w ...1976776048
review: ethidium fluorescence assays. part 1. physicochemical studies.dna and rna can be assayed rapidly and very sensitively by exploiting the enhanced fluorescence of ethidium intercalated into duplex regions. by assaying at different phs and introducing a heating/cooling cycle, a great many physicochemical aspects of dna and rna can be studied avoiding the use of radiolabels, and often giving information not otherwise readily obtainable. studies are described on duplex dna which involve measurement of extinction coefficients, cross-linking by chemicals, cot cur ...197941222
bactericidal and haemolytic activity of complement in bovine colostrum and serum: effect of proteolytic enzymes and ethylene glycol tetraacetic acid (egta).bovine colostral whey (cw) possessed heat-labile bactericidal activity against an enteropathogenic serum-susceptible strain of escherichia coli. activity was readily destroyed by trypsin or rat pancreatic juice, and less readily by chymotrypsin. loss of activity due to trypsin, but not by chymotrypsin, could be prevented by addition of excess bovine colostral trypsin inhibitor. a second enteropathogenic strain of e. coli was killed by cw only if exogenous complement was added. this activity was ...1975813560
[etiology of mastitis in dairy cows in slovakia during 1972-1974].in the period from 1972 to 1974, veterinary institutes in slovakia performed bacteriological examinations in 178,853 milk samples coming from 72,454 dairy cows. on an annual average, the number of examined samples was higher by 61% than in 1967-1971. germs responsible for the inflammation of the mammary gland were found in the milk of 22.32% of the dairy cows. the following bacterial germs were represented: streptococcus agalactiae - 15.77%, staphylococcus aureus - 4.19%, other streptococci - 1. ...1975814671
]acute severe mastitis in cows of the dutch-friesian breed (author's transl)].one hundred cases of severe acute mastitis are reported. bacteriological examination of the milk was negative in 23% of the cases. e. coli was most frequently found to be the causative organism (23%), followed by st. aureus (19%), c. pyogenes (10%), str. dysgalactiae (9%), str. agalactiae (5%) and a number of other pathogenic agents such as atypical streptococci, str. uberis, haemolytic streptococci, aerobacter aerogenes, kl. pneumoniae, a clostridium and p. multocida. in several cases, a tentat ...1976818734
reversibility of partial denaturation of dna.the hypochromicity recovery of a partially denatured dna sample when salt concentration is suddenly increased at an intermediate stage of the transition, is studied. the results of csc1 gradient analysis, polyethylenglycol/dextran partition analysis, and the behaviour in a new thermal transition, support the view that the process is an intramolecular double chain renaturation as that induced by cooling. the degree of denaturation irreversibility is dependent on the size of dna segments between t ...1976825148
[infective situation in a cow barn contaminated with klebsiella mastitis].the infection situation in a four-row cow-house for 153 animals with a frequent occurrence of klebsiella mastitis was subject to a detailed analysis. the following results were obtained after two collections of blood and udder-quarter milk samples examined by the test-tube agglutination, gel precipitation, and bacteriological diagnosis methods: 1. streptococcus agalactiae was isolated from milk samples 28 and 31 times, pseudomonas aeruginosa 15 and 19 times, staphylococcus arueus 16 and 19 times ...1976828991
[etiology of mastitidos in dairy cows in slovakia during 1975].in 1975, in the veterinary institutes in slovakia bacteriological examinations of 54824 samples of milk coming from 28737 dairy cows were performed. bacterial germs responsible for the inflammation of the mammary gland were found in the milk of 18.91% of cows. these were: streptococcus agalactiae (in 13.93% of cows), staphylococcus aureus (2.86%), other streptococci (1.32%), e. coli (0.13%), klebsiella sp. (0.13%), corynebacterium pyogenes (0.15%), other bacterial germs (0.39%). streptococci and ...1976828997
secondary-structure predictions of calcium-binding proteins.the known tertiary structure of carp muscle parvalbumin is consistent with an "ef-hand" architecture (helix-loop-helix) for each calcium-ion binding site. primary-sequence alignments have indicated four ef hands in rabbit skeletal muscle troponin c and in rabbit myosin alkali light chains. five secondary-structure prediction methods, based on amino acid sequence only, have been fully computerized and used to calculate joint prediction histograms for several calcium-binding proteins. the joint hi ...1977836806
[methionyl-trna synthetase from wheat embryo: dissociation into subunits (author's transl)].wheat -embryo methionyl-trna synthetase is a dimeric protein of beta2 structure. when highly diluted, it loses the capacity to catalyze atp-[32p]ppi exchange and to aminoacylate trnamet: at low enzymatic concentrations the rates of formation of[32p]atp and [14c]methionyl-trnamet are lower than those predicatedby extrapolating the rates determined at higher enzyme concentrations. the difference between observed and expected rates becomes greater with decreasing enzyme concentration. filtration of ...1977849749
tissue distribution and residues of beta-lactam antibiotics in normal dairy cows.tissue residues and concentrations of benzylpenicillin, cloxacillin, ampicillin, amoxycillin, cephapirin, and cephacetrile were determined in normal dairy cows after parenteral administration of several forms of these drugs. assay methods included the sarcina lutea kidney test of van schothorst, the bacillus subtilis bga tests at ph 6.0 and 8.0, the escherichia coli test and a sarcina lutea test performed at ph 8.0 of the agar, and specific quantitative assay methods. the e. coli test method dem ...1977918925
bronchiectasis in yearling feedlot cattle.thoughout all of 1974, we surveyed, for illnesses and deaths, about 407,000 yearling feedlot cattle. from the 3,943 dead cattle, 1,988 necropsies were made; of the cattle necropsied, 32 (1.6%) had bronchiectasis. in this disease, the permanently dilated small bronchi and bronchioles, located in ventral parts of the lungs, were filled with accumulations of exudate and microorganisms, including pasteurella hemolytica, pasteurella multocida, corynebacterium pyogenes, escherichia coli, salmonella an ...1976956033
specific binding of a nonhistone chromosomal protein from lymphocyte to dna.the isolation of a nonhistone chromosomal protein, nh30 000, from bovine lymphocytes by affinity chromatography on a dna-agarose column is described. the procedure starts with nonhistone fraction nh4 obtained by hydroxyapatite chromatography as described previously [blüthmann, h., mrozek, s. & gierer, a. (1975) eur. j. biochem. 58, 315-326]. protein nh30 000 migrates as a single band with a molecular weight of 30 000 on sodium dodecylsulfate polyacrylamide gels. it contains, on a molar basis 25. ...19761009927
indirect consequences of low-level use of antimicrobial agents in animal feeds.antibiotics may be classified as "therapeutic" or "feed" depending on their use for treatment of disease or for promotion of growth in animals. the mechanism of growth promotion is largely unknown, but it has been shown that the specific feed additive causes defined lesions in the cell wall of escherichia coli. this effect may sensitize the bacteria to the action of therapeutic drugs. damage to the bacterial cell wall may also cause the bacteria to be more susceptible to the body defense mechani ...19751090454
a rhelogical separator for very large dna molecules.we present a rheological separation method for dna molecules in which their deformability is used to advantage. this is the "radial migration method"; here we present experimental verification of the principle, theory having been reported elsewhere. the main conclusions are: (1) the theory is reasonably good; (2) radial migration is highly sensitive to the molecular weight, as predicted, and (3) intact t2 dna (1.25 x 108 daltons) can be made to migrate about three centimeters in less than three ...1979388346
Displaying items 1 - 100 of 3459