Publications
| Title | Abstract | Year Filter | PMID(sorted descending) Filter |
|---|
| 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 ... | 1979 | 374397 |
| 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 ... | 1978 | 371506 |
| 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 ... | 1979 | 370760 |
| 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 ... | 1978 | 367367 |
| incidence of colicinogenic escherichia coli in sheep, goats and cattle. | 1978 | 367012 | |
| 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 ... | 1978 | 363754 |
| 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 ... | 1978 | 357288 |
| 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 ... | 1978 | 357285 |
| [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 ... | 1977 | 343354 |
| 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. | 1978 | 340583 |
| 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 ... | 1977 | 339791 |
| 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 ... | 1977 | 339479 |
| 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 ... | 1977 | 338650 |
| [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 ... | 1977 | 337649 |
| 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 ... | 1977 | 335927 |
| [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 ... | 1977 | 334632 |
| 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. | 1977 | 333999 |
| [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: ... | 1977 | 331658 |
| 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 ... | 1977 | 330877 |
| 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. | 1977 | 330414 |
| 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 ... | 1977 | 329886 |
| 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 ... | 1977 | 326668 |
| acute undifferentiated neonatal diarrhea of beef calves: the prevalence of enterotoxigenic e. coli, reo-like (rota) virus and other enteropathogens in cow-calf herds. | 1977 | 326373 | |
| 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 ... | 1977 | 323215 |
| 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 ... | 1977 | 321356 |
| 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 ... | 1977 | 320006 |
| 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, ... | 1975 | 238993 |
| 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. | 1975 | 237639 |
| 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 ... | 1975 | 236302 |
| 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 ... | 1975 | 235425 |
| 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 ... | 1979 | 232591 |
| 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 ... | 1979 | 223131 |
| 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. | 1978 | 215505 |
| 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 ... | 1978 | 213390 |
| 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 ... | 1978 | 209406 |
| 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 ... | 1977 | 190280 |
| 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 ... | 1976 | 189746 |
| 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 ... | 1976 | 187232 |
| 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 ... | 1975 | 172122 |
| 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 ... | 1975 | 169258 |
| 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. | 1975 | 164436 |
| 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 ... | 1975 | 163354 |
| 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. | 1979 | 160325 |
| 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 ... | 1977 | 146400 |
| [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 ... | 1979 | 117592 |
| 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 ... | 1979 | 114112 |
| 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 ... | 1978 | 106944 |
| [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 ... | 1978 | 104694 |
| 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 ... | 1978 | 100535 |
| 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 ... | 1979 | 88957 |
| 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 ... | 1978 | 80383 |
| 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 skalińska, 1974). | 1977 | 70968 |
| 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. ... | 1975 | 53431 |
| 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 ... | 1975 | 46271 |
| 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 ... | 1979 | 41425 |
| 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 ... | 1979 | 41222 |
| 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 ... | 1979 | 35325 |
| 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 ... | 1979 | 34628 |
| 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 ... | 1978 | 32536 |