| purification and characterization of s-adenosyl-l-methionine: uroporphyrinogen iii methyltransferase from pseudomonas denitrificans. | s-adenosyl-l-methionine:uroporphyrinogen iii methyltransferase (sumt), the enzyme of the cobalamin biosynthetic pathway which catalyzes c methylation of uroporphyrinogen iii, was purified about 150-fold to homogeneity from extracts of a recombinant strain of pseudomonas denitrificans derived from a cobalamin-overproducing strain by ammonium sulfate fractionation, anion-exchange chromatography, and hydroxyapatite chromatography. the purified protein has an isoelectric point of 6.4 and molecular w ... | 1989 | 2546914 |
| characterization of a canine rotavirus strain by neutralization and molecular hybridization assays. | a canine rotavirus, rs-15, previously isolated in japan was determined to be subgroup i and serotype 3. when compared with prototype human and animal rotavirus strains by rna-rna hybridization assay, the rs-15 strain showed a high degree of homology only with the canine cu-1 strain isolated in the united states of america, suggesting that canine rotaviruses constitute a distinct gene family, which we have elsewhere proposed to term "genogroup". | 1989 | 2548456 |
| siderophore production by aeromonas salmonicida. | growth under conditions of iron-restriction and the production of siderophores was examined in 21 typical and 14 atypical strains of aeromonas salmonicida. with the exception of one atypical strain, all strains grew and multiplied in the presence of the high-affinity iron chelators ethylenediamine di(o-hydroxyphenylacetic acid), alpha, alpha'-dipyridyl or transferrin. chrome azurol s agar was used to screen bacterial strains growing under these conditions for the production of siderophores. side ... | 1991 | 1830896 |
| nucleotide sequence of a neurovirulent variant of the type 2 oral poliovirus vaccine. | infectious cdnas of the sabin type 2 poliovirus vaccine virus and a vaccine-derived neurovirulent type 2 strain (p2/117) have been cloned in escherichia coli. nucleotide sequence analysis revealed that p2/117 differs from the vaccine strain by just 23 point mutations. three occur in the 5' noncoding region. the remainder result in a total of 5 coding changes located in vp1, vp4, 2b, and 3d. the likely role of these mutations in the evolution to neurovirulence is discussed. | 1989 | 2552175 |
| genetic heterogeneity within echinococcus granulosus: isolates from different hosts and geographical areas characterized with dna probes. | a segment of the ribosomal rna gene of schistosoma mansoni and a dna fragment specific to echinococcus granulosus, cloned in plasmids, have been used as dna probes to assess the extent of genetic variability within e. granulosus and some distinct strains have been identified. the dna analysis, involving restriction endonuclease digestion and southern blot hybridization with the probes, did not demonstrate any significant genetic variation within the u.k. horse/dog or sheep/dog strains but confir ... | 1989 | 2552377 |
| dideoxycytidine metabolism in wild type and mutant cem cells deficient in nucleoside transport or deoxycytidine kinase. | the growth inhibitory effects and metabolism of 2',3'-dideoxycytidine (ddc) were examined in wild type human cem t lymphoblasts and in mutant populations of cem cells that were genetically deficient in either nucleoside transport or deoxycytidine kinase activity. whereas ddc at a concentration of 4 um inhibited growth of the wild type cem parental strain by 50%, two nucleoside transport-deficient clones were four-fold resistant to the pyrimidine analog. the deoxycytidine kinase-deficient cell li ... | 1989 | 2558543 |
| the influence of cold or isolation stress on neuroinvasiveness and virulence of an attenuated variant of west nile virus. | the effect of cold or isolation stress on neuroinvasiveness and virulence was investigated in mice inoculated with an attenuated wnv (wn-25) strain. the wn-25 variant differed from the parent strain by its inability to kill mice after i.p. injection though it was able to immunize even after injection with low doses of virus. exposure of inoculated mice for 5 minutes a day to cold water (1 +/- 0.5 degrees c) for 8 days resulted in 60% mortality, while in nonstressed infected mice no death was obs ... | 1989 | 2558625 |
| [rapid serologic diagnosis of argentinian hemorrhagic fever in whole blood]. | the usefulness of a method for detection of antibodies against junin virus in whole blood was tested. n: nih adult mice were inoculated with 10(3) pfu of attenuated xj-clon 3 junin virus strain by intraperitoneal route and blood was obtained by retro-orbital puncture at 21 days post-infection. one blood aliquot (50 microliters) was collected in tubes containing a stabilizer solution for whole blood and another was processed for serum obtention. immunofluorescent antibodies were tested on spot sl ... | 1989 | 2559426 |
| inbred rat strain comparisons indicate different sites of action for cocaine and amphetamine locomotor stimulant effects. | cocaine and amphetamine produce several behavioral effects, most notably locomotor stimulation. biochemically, evidence suggests specific involvement of dopaminergic systems, although not necessarily identical sites, in mediating cocaine- and amphetamine-induced locomotor stimulation. this study examined the effects of cocaine or amphetamine on locomotor activity in rats from the aci, f344, lew and nbr inbred strains. dose-dependent increases in locomotor activity were found for both drugs in al ... | 1991 | 1838200 |
| the complete sequence (22 kilobases) of murine coronavirus gene 1 encoding the putative proteases and rna polymerase. | the 5'-most gene, gene 1, of the genome of murine coronavirus, mouse hepatitis virus (mhv), is presumed to encode the viral rna-dependent rna polymerase. we have determined the complete sequence of this gene of the jhm strain by cdna cloning and sequencing. the total length of this gene is 21,798 nucleotides long, which includes two overlapping, large open reading frames. the first open reading frame, orf 1a, is 4488 amino acids long. the second open reading frame, orf 1b, overlaps orf 1a for 75 ... | 1991 | 1846489 |
| [the clinical effectiveness of oflx in the treatment of chlamydial pneumonia]. | we treated three patients of chlamydial pneumonia with oflx, two patients were diagnosed as psittacosis and one as pneumonia associated with twar strain by serologic test. three hundred mg of oflx was orally administered three times per day and the duration of treatment was from seven to fourteen days, and we compared the clinical effectiveness of oflx in three cases (mild: 1, moderate: 2) with that of mino in eleven cases (mild: 3, moderate: 8), who were administered two hundred mg of mino two ... | 1989 | 2614088 |
| pif1: a dna helicase in yeast mitochondria. | the pif1 gene is involved in repair and recombination of mitochondrial dna (mtdna). in this study, the pif1 gene product, which cannot be identified in normal yeast cells, has been overproduced from the gali promoter to detectable protein levels. location of pif1 in mitochondria has been shown by immunoelectron microscopy and in vivo import experiments using ts mas1 mutants deficient in the mitochondrial matrix-localized processing protease. overproduction of pif1 protein in pif1 mutants restore ... | 1991 | 1849081 |
| isolation, characterization, and complementation of a paralyzed flagellar mutant of rhodobacter sphaeroides ws8. | a paralyzed rhodobacter sphaeroides mutant strain (para1) was isolated by a motility screening procedure following mutagenesis of wild-type r. sphaeroides ws8-n with the transposable element tnphoa (tn5 is50l::phoa). para1 synthesized a wild-type level of flagellin, as detected by western immunoblotting with antiflagellar antiserum. flagellar staining showed that flagellin was assembled into apparently normal external flagellar filaments. electron micrographs of basal body structures from para1 ... | 1991 | 1850401 |
| purification and some properties of pseudomonas fluorescens lipase. | lipase (triacylglycerol lipase, ec 3.1.1.3) has been purified from pseudomonas fluorescens wild strain by chromatography on deae-cellulose and octyl-sepharose cl-4b. the yield was 21% and the specific activity of the purified enzyme 4780 u/mg protein. it showed a mr of about 45 x 10(4) by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. the enzyme is active over a wide ph range and at 50-55 degrees c. | 1991 | 1905137 |
| engineering a poliovirus type 2 antigenic site on a type 1 capsid results in a chimaeric virus which is neurovirulent for mice. | poliovirus type 2 (pv-2) lansing strain produces a fatal paralytic disease in mice after intracerebral injection, whereas poliovirus type 1 (pv-1) mahoney strain causes disease only in primates. atomic models derived from the three-dimensional crystal structure of the pv-1 mahoney strain have been used to locate three antigenic sites on the surface of the virion. we report here the construction of type 1-type 2 chimaeric polioviruses in which antigenic site 1 from the pv-1 mahoney strain was sub ... | 1988 | 2460345 |
| immunochemical identification and biological characterization of cytotoxic necrotizing factor from escherichia coli. | the aim of this study was to identify escherichia coli cytotoxic necrotizing factor (cnf) by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (sds-page) analysis and to investigate the possible dissociation of cnf from hemolysin (hly), which is often produced by cnf-producing strains. cnf was purified from cell lysates of a cnf-producing strain by using ammonium sulfate precipitation, ion-exchange chromatography, gel filtration, and preparative nondenaturing page. all eluates from succe ... | 1989 | 2663921 |
| [pharmacodynamics of dihydroartemisinine against plasmodium berghei in mice]. | dihydroartemisinine (dha) is a derivative of qinghaosu(artemisine), which is an antimalarial drug. dha was given to mice inoculated with plasmodium berhgei anka strain by intramuscular injection. within proper dose range, the dose-effect and time-effect curves of dha against the malaria can be described by y = 4.9960 + 2.9536 x and y = 7.2654 - 0.3414 t, respectively, where y is the estimated value of parasitemia suppressing rate in probit; x is log dose; t is the period since drug administratio ... | 1989 | 2694757 |
| [serratia marcescens infections in a hospital: typing of isolated strains]. | ninety six strains of serratia marcescens were isolated from one hospital. strains originated from various sources: pressure transducer head (14), arterial catheter tip (4), blood (33), sputum (12), bronchial aspirate (10), urine (10), wound (8), miscellaneous (5). most of the blood strains were isolated on the intensive care unit (icu). contaminated pressure transducer heads seemed to be involved in a nosocomial epidemic. all strains were characterized by serotyping, antibiotic resistance patte ... | 1989 | 2700064 |
| effect of different methods of maintenance on the pathogenicity and infectivity of babesia bigemina for the vector boophilus microplus. | observations were made on the effects of five different methods of laboratory maintenance on the infectivity and virulence of babesia bigemina for the tick boophilus microplus. the original isolate was highly infective and virulent, causing premature death of engorged female ticks and reduced egg production. maintenance of the strain by syringe passage in unsplenectomised calves at six to 10 week intervals reduced both its infectivity and virulence for ticks. when slow passages were preceded by ... | 1989 | 2704879 |
| phagocytosis and intracellular killing of staphylococcus aureus by bovine blood polymorphonuclear leukocytes after migration in vitro. | phagocytic activity and intracellular killing of opsonized staphylococci (smith strain) by bovine blood polymorphonuclear leukocytes (pmnl) was studied after their migration in vitro in blind well chambers. the results indicate that migration of pmnl to rpmi-1640 medium without chemotactic factor significantly (p less than 0.01) increased the percentage of rosette-forming pmnl (from 11 +/- 2 to 49 +/- 4%), as well as phagocytic activity mediated through fc receptors (fcrs) (from 25 +/- 3 to 81 + ... | 1989 | 2750362 |
| the detection of natural opal suppressor seryl-trna in escherichia coli by the dot blot hybridization and phosphorylation by a trna kinase [corrected] . | it was believed that there was no natural suppressor trna in escherichia coli, however, it has been suggested that selc, relating to the synthesis of formate dehydrogenase of a selenoprotein [(1988) nature 331, 723-725], codes for trna, even though the presence of trna has not yet been demonstrated. we detected the product of selc in the trna preparation of the e. coli mc 4100 strain by the dot blot hybridization method with a dna probe (accgctggcggc) corresponding to the extra arm of selc trna. ... | 1989 | 2469600 |
| genetic transfer systems for delivery of plasmid deoxyribonucleic acid to lactobacillus acidophilus adh: conjugation, electroporation, and transduction. | lactobacillus acidophilus adh is a bacteriocin-producing human isolate that adheres to human fetal intestinal cells and human ileal cells. we have employed both electroporation and conjugation methodologies to transfer various plasmids to l. acidophilus adh. furthermore, we have demonstrated transduction of plasmid dna within this strain by a temperate bacteriophage (phi adh) harbored by l. acidophilus adh. plasmid pgk12 was introduced into strain adh by electroporation at frequencies as high as ... | 1989 | 2503549 |
| isolation of the structural genes for the rieske fe-s protein, cytochrome b and cytochrome c1 all components of the ubiquinol: cytochrome c2 oxidoreductase complex of rhodopseudomonas capsulata. | the structural genes for the rieske fe-s protein (peta), cytochrome b (petb) and cytochrome c1 (petc) subunits of the ubiquinol:cytochrome c2 oxidoreductase (bc1 complex) of rhodopseudomonas capsulata have been cloned by complementation, using a mutant defective in this complex. the location of these genes on the obtained plasmid, pr14a, was determined using synthetic mixed oligonucleotide probes corresponding to highly conserved amino acid sequences of these proteins from various organisms. the ... | 1987 | 2821266 |
| characterization of high-level expression and sequencing of the escherichia coli k-12 cyns gene encoding cyanase. | restriction fragments containing the gene encoding cyanase, cyns, without its transcriptional regulatory sequences were placed downstream of lac and tac promoters in various puc derivatives to maximize production of cyanase. plasmid psj105, which contains the cyns gene and an upstream open reading frame, gave the highest expression of cyanase. approximately 50% of the total soluble protein in stationary-phase cultures of a lac-deleted strain containing plasmid psj105 was cyanase. the inserted dn ... | 1987 | 2822670 |
| urban trypanosoma (schizotrypanum) cruzi: pathology in white mice of isolates from panstrongylus geniculatus. | the histopathological alterations produced in white mice (nmri strain) by isolates of trypanosoma (schizotrypanum) cruzi from panstrongylus geniculatus captured in dwellings of the city of caracas, venezuela are reported. the heart, skeletal muscle, liver, spleen, duodenum, colon, lung, and brain were parasitized by all the isolates. all showed strong myotropism, with elevated virulence and severe histopathological alterations in the cardiac and skeletal muscle, and in the smooth muscle of the d ... | 1989 | 2517002 |
| prolonged excretion of an identical cytomegalovirus strain by two siblings and the intermittent isolation of an adenovirus from the urine of one of them. | restriction endonucleases were used to show the excretion of an identical strain of cytomegalovirus (cmv) by two brothers over a 2 1/2-yr period. the same enzymes were used to show that the younger brother, case report, excreted an adenovirus over at least a 3-mo period. we are unable to determine the contribution of each virus to this child's clinical picture; however, this is the first report of a prolonged excretion of an adenovirus associated with cmv excretion in an immunocompetent host. | 1987 | 2828524 |
| [association of the infection of the thymus and bone marrow with the establishment of persistent infection with junin virus in 2 genera of rodents]. | junin virus infection of immune system organs was correlated with persistence establishment in the mouse and rat. rockland mice under 24 or at 72 and 120 h of age received 10(4) pfu of junin virus xj strain by ic route. separately, two groups of mice under 24 h old were infected with the same dose of xj or xjcl3 strain by the same route respectively. results showed that higher thymus virus titer correlated with greater survival. in turn, the former also seemed to correlate with decreasing age at ... | 1985 | 2829274 |
| identification of the structural proteins of turkey enteric coronavirus. | coronaviruses in the intestinal contents of turkey poults from quebec flocks with outbreaks of enteritis were detected by electron microscopy. five isolates were serially propagated in embryonic turkey eggs by inoculation of clarified intestinal contents into the amniotic cavity. viral particles contained in the intestinal contents of infected embryos were purified by differential and isopycnic centrifugation in sucrose gradients. intact virions present in fractions of densities 1.18 to 1.20 g/m ... | 1988 | 2835946 |
| molecular cloning and mechanism of trimethoprim resistance in haemophilus influenzae. | we studied 10 trimethoprim-resistant (tmpr) haemophilus influenzae isolates for which agar dilution mics were 10 to greater than 200 micrograms/ml. trimethoprim resistance was transferred from two tmpr h. influenzae isolates to a tmps strain by conjugation or transformation. wild-type tmpr strains and tmpr transcipients did not contain detectable plasmid dna. the trimethoprim resistance gene was cloned into a cosmid vector, and recombinant plasmids were transduced into escherichia coli. a 0.50-k ... | 1988 | 2837138 |
| genetic resistance in experimental autoimmune encephalomyelitis. i. analysis of the mechanism of ler resistance using radiation chimeras. | experimental autoimmune encephalomyelitis (eae) is a cell-mediated autoimmune disease of the central nervous system that has been extensively studied in the rat. the lewis rat is highly susceptible to the induction of eae, while the lewis resistant (ler) rat is known to be resistant. in this paper, we demonstrate that the ler rat, which was derived from the lewis strain by inbreeding of fully resistant animals, is histocompatible with the lewis strain. radiation chimeras, a tool for distinguishi ... | 1989 | 2527617 |
| mutations in three of the putative transmembrane helices of subunit a of the escherichia coli f1f0-atpase disrupt atp-driven proton translocation. | three missense mutants in subunit a of the escherichia coli f1f0-atpase were isolated and characterized after hydroxylamine mutagenesis of a plasmid carrying the uncb (subunit a) gene. the mutations resulted in asp119----his, ser152----phe, or gly197----arg substitutions in subunit a. function was not completely abolished by any of the mutations. the f0 membrane sector was assembled in all three cases as judged by restoration of dicyclohexylcarbodiimide sensitivity to the f1f0-atpase. the h+ tra ... | 1989 | 2528329 |
| overproduction of glycolytic enzymes in yeast. | eight different enzymes for glycolysis and alcoholic fermentation were overproduced in a common saccharomyces cerevisiae strain by placing their genes on multicopy vectors. the specific enzyme activities were increased between 3.7- and 13.9-fold above the wild-type level. the overproduction of the different glycolytic enzymes had no effect on the rate of ethanol formation, even with those enzymes that catalyse irreversible steps: hexokinase, phosphofructokinase and pyruvate kinase. also the simu ... | 1989 | 2528863 |
| an enzyme-linked immunosorbent assay for the detection of avian encephalomyelitis virus antigens. | an enzyme-linked immunosorbent assay for detection of the antigens of avian encephalomyelitis viruses (aevs) was developed, using an antigen capture method with affinity-purified anti-aev immunoglobulins prepared in rabbits. both the van roekel strain and a field strain of aev could be detected at concentrations of 4 x 10(3) ng/g tissue in the presence or absence of an uninfected chicken embryo extract. the procedure was used to determine the distribution of antigens to the van roekel strain aft ... | 1988 | 2840879 |
| differentiation of junin virus and antigenic variants isolated in vivo by kinetic neutralization assays. | the major natural reservoir of junin virus, the aetiological agent of argentine haemorrhagic fever, is the cricetid calomys musculinus. neonatal animals experimentally infected with junin virus (xjcl3 strain) developed typical disease and approximately 80% of them died. most survivors become persistently infected. antigenically variant viruses were isolated from the blood and brain of infected cricetids during the acute and chronic stages of the disease. these variants could be distinguished fro ... | 1988 | 2841418 |
| construction of delta aroa his delta pur strains of salmonella typhi. | salmonella typhi strains with two deletion mutations, each causing an attenuating auxotrophy, have been constructed from strains ty2 and cdc 10-80 for possible use as oral-route live vaccines. an aroa(serc)::tn10 transposon insertion was first transduced from a salmonella typhimurium donor into each wild-type s. typhi strain. transductants of the aro- serc- phenotype were treated with transducing phage grown on an s. typhimurium strain with an extensive deletion at aroa; selection for serc+ yiel ... | 1988 | 2842296 |
| molecular cloning of glts and gltp, which encode glutamate carriers of escherichia coli b. | two genes encoding distinct glutamate carrier proteins of escherichia coli b were cloned into an e. coli k-12 strain by using a cosmid vector, phc79. one of them was the glts gene coding for a glutamate carrier of an na+-dependent, binding protein-independent, and glutamate-specific transport system. the content of the glutamate carrier was amplified about 25-fold in the cytoplasmic membranes from a glts-amplified strain. the glts gene was located in a 3.2-kilobase ecori-mlui fragment, and the g ... | 1989 | 2537813 |
| seca protein is required for secretory protein translocation into e. coli membrane vesicles. | the soluble and membrane components of an e. coli in vitro protein translocation system prepared from a seca amber mutant, seca13[am], contain reduced levels of seca and are markedly defective in both the cotranslational and posttranslational translocation of ompa and alkaline phosphatase into membrane vesicles. moreover, the removal of seca from soluble components prepared from a wild-type strain by passage through an anti-seca antibody column similarly abolishes protein translocation. transloc ... | 1988 | 2846186 |
| [monoclonal antibodies to flavivirus antigens induced by a vaccinal strain of yellow fever]. | monoclonal antibodies (mabs) yel-2 induced by the vaccine fns dakar yellow fever (yf) virus were characterized for their capacity to enter into serological reactions and to react with heterologous flaviviruses. yel-2 mabs belong to the igg2a class of immunoglobulins, possess the antihemagglutination properties, are active in indirect if test but do not activate complement and have no neutralizing properties. the inability to enter into cft in the presence of antihemagglutinating properties sugge ... | 1988 | 2848367 |
| purification of a dna methyltransferase from bacillus natto b3364. | an s-adenosyl-l-methionine:dna-methyltransferase, termed m.bnai, was purified from bacillus natto b3364 strain by successive column chromatography. the molecular weight determined by gel filtration was 37 kda for m.bnai. analysis of methyltransferase by sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed correspondence of the m.bnai activity with one protein band at a molecular weight of 35 kda. sequencing of puc19 dna methylated with m.bnai showed the cytosine-5 methylation in the ... | 1989 | 2551737 |
| non-neurovirulent, genetically stable clone of poliovirus (sabin type iii vaccine strain). | a clone of poliovirus type iii (tru-3) was derived from the sabin-3 vaccine strain by the cdna:rna hybrid molecular cloning method. the virus recovered was found to be considerably less neurovirulent for primates than its progenitor sabin iii vaccine strain. upon serial passages in humans, tru-3 did not increase its neurovirulence (unlike the sabin strain) and maintained the base sequence of the attenuated strain in a critical part of the 5' region of the genome (unlike the sabin strain). the su ... | 1988 | 2854337 |
| [study of the regulation of crp gene expression in escherichia coli k12]. | the regulation of crp gene expression by crp-camp complex was studied in e. coli strain by the crp-lac operon fusion. f'141 crp+ episome decreased 5-7 fold the high level of crp-lac expression in crp strains while f'141 crp episome had no effect. the hybrid plasmid pcap2 crp+ with the intact crp gene did not affect the crp gene expression level in crp mutants, though they had acquired the crp+ phenotype just as they did in f'141 crp+ presence. the f'141 crp+ and pcap2 crp+ combination in crp mut ... | 1990 | 2163492 |
| antimicrobial susceptibility of salmonella typhimurium carrying the outer membrane permeability mutation ss-b. | the antibiotic susceptibility profile of salmonella typhimurium ss-b, a mutant susceptible to some antimicrobial agents, was studied in detail. twenty-eight agents were tested, and eleven of these had mics significantly lower (32- to greater than 250-fold) for the ss-b strain than for its parent. the drugs were generally hydrophobic or amphiphilic. polymyxin b nonapeptide, which has a known outer membrane permeabilizing action, further reduced the mic of several of these agents for the ss-b stra ... | 1990 | 2193622 |
| comparison of edmonston-zagreb and schwarz strains of measles vaccine given by aerosol or subcutaneous injection. | the serological response to measles vaccine was tested in bangladesh in groups of infants aged 4-6 months who received equal doses of edmonston-zagreb or schwarz vaccine by subcutaneous injection or by aerosol. seroconversion (as measured by the haemagglutination test) occurred in 62% of infants receiving edmonston-zagreb strain by injection compared with only 37% of those receiving schwarz strain. seroconversion occurred in 35% of those given edmonston-zagreb and 34% of those given schwarz vacc ... | 1987 | 2879981 |
| studies on influenza-virus virulence in recombinants between epidemic and vaccine strains. | influenza virus recombinants between epidemic strains a/brazil/11/78 (h1n1), a/ussr/382/78 (h3n2) and vaccine strains a/leningrad/9/46 (h1n1), a/victoria/35/72/50 (h3n2) have been tested for virulence for humans and albino mice; their genome structure has also been determined. it has been shown that after the replacement of surface antigens of a/leningrad/9/46 (h1n1) strain by surface antigens of a/brazil/11/78 (h1n1) or a/ussr/382/78 (h3n2), strains, the virus becomes totally nonpathogenic for ... | 1987 | 2891277 |
| further characterization of japanese acellular pertussis vaccine prepared in 1988 by 6 japanese manufacturers. | in 1974, we published a paper entitled "leukocytosis-promoting factor of bordetella pertussis. its identity with protective antigen". a preparation which was purified from the culture supernatant of bordetella pertussis phase i, tohama strain by consecutive steps of ammonium sulfate fractionation and sucrose density gradient centrifugation showed leukocytosis-promoting, histamine-sensitizing and hemagglutinating activities. the preparation consisted of two proteins: pertussis toxin (pt) and fila ... | 1988 | 2908530 |
| malignant transformation of an infinite life span human fibroblast cell strain by transfection with v-ki-ras. | to determine if human fibroblasts can be transformed into malignant cells by transfection of a k-ras oncogene, we transfected the provirus of kirsten murine sarcoma virus (v-ki-ras) into an infinite life span human cell strain, msu-1.1, which has a normal morphology, is not anchorage independent, and has a stable, near-diploid karyotype. the transfected populations gave rise to distinct foci composed of morphologically-altered cells. the cells from several independent foci were isolated, propaga ... | 1990 | 2216465 |
| characterization of a legionella pneumophila extracellular protease exhibiting hemolytic and cytotoxic activities. | a preliminary screening of selected legionella species for proteolytic and hemolytic phenotypes suggested a correlation between these activities. to investigate the relationship of these phenotypes, a mutant strain of legionella pneumophila deficient in the expression of a 38-kilodalton (kda) exoprotease was isolated and characterized. this strain, designated prt8, was also found to be nonhemolytic when screened on blood agar composed of 5% canine or guinea pig erythrocytes. strain prt8 was sero ... | 1989 | 2917785 |
| nosocomial clonal dissemination of methicillin-resistant staphylococcus aureus. elucidation by plasmid analysis. | an outbreak of methicillin sodium-resistant staphylococcus aureus (mrsa) infection and colonization, mainly centered in the vascular surgery service, occurred in a 1000-bed tertiary care center between december 1983 and december 1984. methicillin-resistant s aureus isolated before and during the outbreak was studied by both bacteriophage typing and by restriction endonuclease digestion of bacterial plasmid dna. bacteriophage typing was discrepant in nine (56%) of the 17 repeated analyses compare ... | 1987 | 2950835 |
| in vivo assessment of antimicrobial agents against toxoplasma gondii by quantification of parasites in the blood, lungs, and brain of infected mice. | the in vivo effects of antimicrobial agents against toxoplasma gondii were evaluated in mice that were infected intraperitoneally with 10(4) tachyzoites of the rh strain by determination of survival rates and study of the kinetics of growth of t. gondii in infected mice. at various intervals after infection, subcultures of serial dilutions of blood, lung, and brain homogenates were performed in fibroblast tissue cultures for determination of parasitic loads. pyrimethamine (18.5 mg/kg per day), s ... | 1990 | 2221854 |
| transduction of virulence in herpes simplex virus type 1 from a pathogenic to an apathogenic strain by a cloned viral dna fragment. | herpes simplex virus (hsv) type 1 strain hfem, the genome of which contains a deletion of about 4 kilobasepairs (kbp) between 0.7 and 0.8 viral map units, is apathogenic in the tree shrew when the animals are inoculated intravenously, intraperitoneally and/or subcutaneously. similar results were obtained using balb/c mice. studies of the state of viral latency in animals infected with hsv-1 strain hfem revealed that this strain was unable to colonize the ganglia of tree shrews. infectious virus ... | 1985 | 2982083 |
| [modification of the modification-restriction system in staphylococci]. | a new system of host specificity of dna, called sau67 according to the available nomenclature, was identified in staphylococcus aureus 6782 strain by means of cross titration with staphylophage 729 considering that the phage exhibited the highly effective absorption properties. a total preparation of sau67 methylases was isolated using ammonium sulfate fractionation. the enzyme preparation contained methylases of cytosine and adenine, where the activity of adenine methylases constituted only for ... | 1985 | 2984842 |
| cyclic biaxial strain of pulmonary artery endothelial cells causes an increase in cell layer-associated fibronectin. | bovine pulmonary artery endothelial (pae) cells were cultured on an artificial compliant substrate (mitrathane) and were strained biaxially at a frequency of 1/s for 2, 4, 6, 7, or 24 h. total protein synthesis, determined by estimating the incorporation of radiolabeled precursors into nondialyzable protein, was increased in cultures that had been biaxially strained for 6, 7, or 24 h, with differences more apparent in the cell layer fraction than in the medium fraction. medium and cell layer-ass ... | 1990 | 2223099 |
| molecular cloning of the delta-endotoxin gene of bacillus thuringiensis var. israelensis. | a transformant of bacillus megaterium, vb131, was isolated which carries a 6.3-kb xbai segment of the crystal toxin gene of bacillus thuringiensis var. israelensis (bti) cloned in a vector plasmid pbc16 to yield pvb131. the chimeric plasmid dna from vb131 was introduced into a transformable bacillus subtilis strain by competence transformation. both the b. megaterium vb131 strain and the b. subtilis strain harboring the chimeric plasmid produced irregular, parasporal, phase-refractile, crystalli ... | 1985 | 2987085 |
| inhibition of herpes simplex virus type 1 penetration by cytochalasins b and d. | internalization of herpes simplex virus type 1 (hsv) kos strain by hep-2 cells was reversibly inhibited by pretreatment of cells with cytochalasins b and d. internalization of virus following preincubation at 4 degrees c and temperature shift to 37 degrees c was normally preceded by a 5 to 8 min lag period and was complete within 20 to 30 min. a similar lag period followed hsv addition at 37 degrees c. cytochalasin d was fivefold more active on hsv entry than cytochalasin b, with 50% inhibition ... | 1985 | 2991432 |
| direct and indirect gene replacements in aspergillus nidulans. | we performed three sets of experiments to determine whether cloned dna fragments can be substituted for homologous regions of the aspergillus nidulans genome by dna-mediated transformation. a linear dna fragment containing a heteromorphic trpc+ allele was used to transform a trpc- strain to trpc+. blot analysis of dna from the transformants showed that the heteromorphic allele had replaced the trpc- allele in a minority of the strains. an a. nidulans trpc+ gene was inserted into the argb+ gene, ... | 1985 | 2991748 |
| ectopic peptides released by a human melanoma cell line that modulate the transformed phenotype. | cells derived from a human melanoma strain by low-serum selection in monolayer were found to be capable of growth in semisolid medium, forming colonies ranging from tight to loose or dispersed. these phenotypes were found to be stable after cloning and retesting. examination of the biological activities of ectopic peptides produced by a clone that gives rise to loose dispersed colonies revealed the presence of a transforming growth factor beta (tgf-beta; apparent mr 14,700) and a single tgf-alph ... | 1985 | 2991904 |
| [metabolic characteristics of polyphosphates and other macroergic phosphorus compounds in relation to the degree of penicillin production and growth conditions of penicillium chrysogenum]. | metabolism of macroergic phosphorus compounds was studied in high- and low-productive isogenic strains of penicillium chrysogenum. it was shown that the levels of the high-polymer polyphosphates (fractions pp1, pp2 and pp3) in the strain intensively producing penicillin were 2-3 times higher than those in the low-productive strain by the 2nd day of the fermentation process (the period of penicillin production). the levels of pyrophosphate and atp in the mycelium during the fermentation process d ... | 1985 | 2998269 |
| in vitro protective effect of bacteria-derived bovine alpha interferon i1 against selected bovine viruses. | we used bacteria-derived bovine alpha-interferon i1 (bo ifn-alpha i1) to study its antiviral effect in a bovine turbinate cell line on bovine diarrhea virus, infectious bovine rhinotracheitis virus, parainfluenza 3 virus, and pseudorabies virus. we based our study upon replicate tests for each strain by using a block titration system with various concentrations of bo ifn-alpha i1 against various concentrations of virus. the data were compiled in two-axis tables (replicate x concentration) and we ... | 1985 | 2999188 |
| characterization of iron superoxide dismutase cdnas from plants obtained by genetic complementation in escherichia coli. | the inability of superoxide dismutase (sod; superoxide:superoxide oxidoreductase, ec 1.15.1.1)-deficient mutants of escherichia coli to grow aerobically on minimal medium can be restored by functional complementation with a heterologous sod-encoding sequence. based upon this property, a phenotypic selection system has been developed for the isolation of clones containing eukaryotic sod cdnas. cdna expression libraries from both nicotiana plumbaginifolia and arabidopsis thaliana were transformed ... | 1990 | 2263641 |
| biochemical characterization of a foot-and-mouth disease virus strain attenuated for cattle. brief report. | wild-type, virulent (a-24 cruzeiro subtype) foot-and-mouth disease virus (fmdv), a related attenuated strain and revertants of the attenuated strain were examined by titration on primary bovine kidney (pbk) and baby hamster kidney (bhk-21) cells, as well as, by infection of unweaned mice. wild type virus grew equally well in all three systems, whereas the attenuated strain had a titer 2-3 log lower in pbk cells than in the other 2 assays. within 9 successive passages in bhk-21 cells the attenuat ... | 1986 | 3006639 |
| [studies on new adenovirus types of subgenus d causing conjunctivitis--antigenic and restriction endonuclease analysis of adenovirus types 19 and 37]. | neutralization test and dna restriction endonuclease analysis were performed in strains of adenovirus types 19 (ad-19) and 37 (ad-37) isolated from patients with acute conjunctivitis in sapporo, kao-hsiung (taiwan) and pusan (korea) in the period of 1979 and 1984. although ad-19 and ad-37 were differentiated, they were related to each other in neutralization test. there was no difference between prototype strain and isolates in ad-19 and ad-37 strains. by dna restriction endonuclease analysis ad ... | 1986 | 3017830 |
| polyomavirus mutation that confers a cell-specific cis advantage for viral dna replication. | the structural and biological properties of a polyomavirus mutant selected in friend erythroleukemic cells were investigated. the growth efficiency of this mutant (pyfl78) was compared with that of the parental pya2 strain by a growth competition assay in friend erythroleukemic and 3t3 (or 3t6) cell lines. the results reveal that pyfl78 displays a cis-acting growth advantage over the pya2 parental strain in friend erythroleukemic cells but not in 3t3 or 3t6 cells. this cell-specific cis advantag ... | 1985 | 3018552 |
| anastomotic healing after resection of left-colon stenosis: effect on collagen metabolism and anastomotic strength. an experimental study in the rat. | anastomotic breaking strength and collagen metabolism in the colonic wall were studied after resection of a standardized left-colon stenosis in the rat. an increased complication rate was found in the stenosis group compared with the control group (27 percent vs. 2 percent) and the complications arise soon after surgery. the collagen turnover in the anastomotic area, as well as the changes of breaking strength, were equal between the groups in the early healing course, implying that the stenosis ... | 1990 | 2311466 |
| response of four broiler strains to dietary phosphorus above and below the requirement when brooded at two temperatures. | four strains of broilers (1,200 birds) were fed diets containing .14, .51, and .88% available phosphorus. the birds were raised for 3 wk at two brooding temperatures, 29.4 c and 35 c, with each being reduced 2.8 degrees per week. feed consumption, feed conversion, body weight, bone weight (tibia), strength and percentage ash, and mortality were measured in order to assess broiler response. an increase or improvement in each measurement was observed from feeding diets containing .51% rather than ... | 1990 | 2345726 |
| differentiation of field isolates of pasteurella multocida serotype 3,4 from live vaccine strain by genotypic characterization. | fifty-five serotype 3,4 isolates of pasteurella multocida, isolated from turkeys dead from fowl cholera, were characterized (fingerprinted) genotypically for comparison with the serotype 3,4 live fowl cholera vaccine principally used in turkeys in california. twenty-three isolates were obtained from turkeys vaccinated with the m9 live vaccine, and 32 additional isolates were from turkeys not vaccinated for fowl cholera. methods of characterization included restriction endonuclease analysis of ch ... | 1990 | 2369381 |
| established mouse liver cell lines as a model system for studying epithelio-mesenchymal interactions in morphogenesis. | four cell lines were established from both fetal and adult livers of mice (ddy strain) by colony isolation methods, and these were characterized by morphological, immunological and biochemical examination. an epithelial cell line from a fetus (ee1-10) was identified to be derived from the biliary tract epithelium. another epithelial cell line from an adult (ae3) reconstructed bile canaliculi-like structures in aggregates and secreted several serum proteins, indicating that it was derived from th ... | 1990 | 2386886 |
| genomic variation among avian rotavirus-like viruses detected by polyacrylamide gel electrophoresis. | the genomes of five turkey and two chicken rotavirus-like virus (rvlv) strains were compared with the genome of a reference turkey rvlv strain by co-electrophoresis in polyacrylamide gels. the genomes of these avian rvlv strains could be distinguished from the reference strain genome by differences in the mobilities of from three to 10 segments. | 1986 | 3028359 |
| immediate strain shielding after femoral reaming and nailing. an in vivo study in rat femora. | following intramedullary reaming and nailing of rat femora, in vivo changes in dynamic strain were correlated with in vitro measurements of the bones. reaming and nailing procedures were performed 2 days after implantation of unidirectional strain gauges at the anterior, mid-diaphyseal level of the femur. structural stiffness of polyacetal nails were three times as stiff as intact bone. reaming only decreased the median strain value by 26 percent, and this value was not reduced by insertion of p ... | 1989 | 2750512 |
| use of microplate cell culture and enzyme immunoassay in titration of serum neutralizing antibody against hochi strain of serotype 4 human rotavirus. | the tube neutralization test read by enzyme immunoassay developed by wyatt et al. (1983) for serotype determination of human rotavirus was modified so as to use stationary cultures of ma104 cells in a microtiter plate instead of roller tube cultures. sera obtained from different age groups were titrated for neutralizing antibody against serotype 4 human rotavirus hochi strain by this test and the results were compared with those obtained by the plaque neutralization test. there was a good correl ... | 1986 | 3035256 |
| differentiation of poliovirus type i isolates in the 1982 epidemic from sabin-i strain by antigenic and temperature markers. | poliovirus type 1 strains recovered from patients with poliomyelitis during the epidemic of 1982, were distinct antigenically from sabin-1 strain by comparing homologous and heterologous neutralization rate constants of sabin-1 specific antiserum. with the reproductive capacity at 40 degrees c, these isolates could be easily differentiated from vaccine strain. it was suggested that the epidemic of poliomyelitis in 1982 was not caused by vaccine strain. the 24 isolates reacted with lsc and/or sab ... | 1987 | 3036431 |
| antibody to the outer membrane proteins is the dominant opsonic antibody in normal human serum against h. influenzae type b. | we hypothesized that the predominant opsonic antibody of normal serum is directed against outer membrane proteins (omp). sera from 10 normal adults were tested for their opsonic capacity against haemophilus influenzae b (eagan strain) by the luminol-enhanced neutrophil chemiluminescence elicited on incubation with serum-opsonized bacteria, and the ability to deposit c3 on the bacterial surface. peak chemiluminescence correlated with the amount of c3 on the bacterial surface (r = 0.71, p less tha ... | 1989 | 2786843 |
| clustering of mutations blocking synthesis of xanthan gum by xanthomonas campestris. | mutations that block the synthesis of xanthan gum by xanthomonas campestris b1459s-4l-ii were isolated as nonmucoid colonies after treatment with ethyl methanesulfonate. complete libraries of dna fragments from wild-type x. campestris were cloned into escherichia coli by using a broad-host-range cosmid vector and then transferred into each mutant strain by conjugal mating. cloned fragments that restored xanthan gum synthesis (xgs+; mucoidy) were compared according to restriction pattern, dna seq ... | 1987 | 3038845 |
| size variation in group a streptococcal m protein is generated by homologous recombination between intragenic repeats. | m protein, a major surface protein and virulence factor for the group a streptococcus, exhibits extraordinary size variation in strains of the same serotype (fischetti et al. 1985). rna sequence analysis of spontaneous m protein size variants shows that deletion mutations arise in a single strain by homologous recombination events between intragenic tandem repeats. similar deletion and duplication events also occur in serial streptococcal isolates from a single patient and among related strains ... | 1987 | 3039291 |
| isolation and characterization of a penicillinase from pseudomonas cepacia 249. | pseudomonas cepacia has an inducible beta-lactamase which is responsible for its novel ability to catabolize beta-lactam compounds. the gene encoding this enzyme, pena, was cloned from a genomic library of p. cepacia 249 on the broad-host-range cosmid plafr. this separated the pena gene from the gene encoding a second beta-lactamase in p. cepacia 249. expression of pena was inducible in an escherichia coli host strain by low levels of penicillin. the 33,500-molecular-weight enzyme had penicillin ... | 1988 | 3046483 |
| rna processing by rnase iii is involved in the synthesis of escherichia coli polynucleotide phosphorylase. | the synthesis of escherichia coli polynucleotide phosphorylase (pnpase) was examined in a mutant strain defective in the rna processing enzyme rnase iii (rnc-). we found that the specific activity and the synthesis rate of pnpase were increased in the rnc- strain by more than three times that in an rnc+ strain. such increased synthesis of pnpase was not observed in a mutant strain transformed with a plasmid carrying the rnc+ gene. quantitative analysis of rna showed that the transcripts from the ... | 1987 | 2823071 |
| plasma membrane associated antigens of trophozoites of axenic giardia lamblia. | plasma membrane isolated from axenically grown giardia lamblia (portland 1 strain) by treatment with a membrane stabilizing agent followed by osmotic stress and manual sheer showed a significant enrichment of the membrane bound marker enzymes ca++atpase/mg++atpase. crossed immunoelectrophoresis (cie) was used to identify membrane antigens. 11 major peaks were detected in cie profiles of the whole trophozoites. 6 major peaks were detected in cie profiles of the membrane preparation. 2 surface mem ... | 1988 | 3068858 |
| fecal bile acids and neutral sterols in rats with spontaneous colon cancer. | fecal bile acids and neutral sterols of spontaneous colon cancer-bearing wistar-furth strain rats were examined and compared with those of control rats of the same strain by gas chromatography and gas chromatography-mass spectrometry. the amount of total fecal bile acids and the percentage of fecal lithocholic acid were almost similar in both groups, but the percentage of fecal deoxycholic acid was significantly higher in the colon cancer group than in the controls. the amount of total fecal neu ... | 1986 | 3082773 |
| an epidemic spread of multiresistant pseudomonas aeruginosa in a cystic fibrosis centre. | early in 1983 an epidemic of a pseudomonas aeruginosa resistant to aminoglycosides, carbenicillin, ureidopenicillins, ceftazidime, cefsulodin and imipenem occurred in a cystic fibrosis centre. most of the epidemic could be attributed to a specific nosocomial strain by means of o-grouping and phage-typing. this strain was present in the centre at a low frequency in 1973 and developed resistance during courses of chemotherapy. the epidemic was stopped by isolating patients with the resistant strai ... | 1986 | 3086274 |
| genetic analysis of myxococcus xanthus and isolation of gene replacements after transduction under conditions of limited homology. | genetic analysis of myxococcus xanthus is greatly facilitated by the ability to introduce cloned dna into m. xanthus to generate gene replacement and merodiploid strains. however, gene replacement strains are difficult to obtain when the region(s) of homology between the cloned dna and the m. xanthus chromosome is limited (less than 1 kilobase). we found that gene replacements can be obtained at an increased frequency by a two-step procedure involving the use of bacteriophage p1 to isolate merod ... | 1986 | 3090023 |
| relationship between sporulation and synthesis of mycobacillin and dipicolinic acid under condition of catabolite repression in bacillus subtilis. | sporulation was repressed in the parent strain by various carbon sources whereas glucose-resistant mutants were resistant to them but not to glycerol 2-phosphate. both mycobacillin and dipicolinic acid synthesis were repressed in the parent by some of the compounds tested, viz. glucose, pyruvate and glycerol 2-phosphate. however, these syntheses in the glucose-resistant mutants were not repressed by glucose and pyruvate but were repressed by glycerol 2-phosphate. the possible interrelationship b ... | 1986 | 3093340 |
| construction of a dihydrofolate reductase-deficient mutant of escherichia coli by gene replacement. | the dihydrofolate reductase (fol) gene in escherichia coli has been deleted and replaced by a selectable marker. verification of the delta fol::kan strain has been accomplished using genetic and biochemical criteria, including southern analysis of the chromosomal dna. the delta fol::kan mutation is stable in e. coli k549 [thya pola12 (ts)] and can be successfully transduced to other e. coli strains providing they have mutations in their thymidylate synthetase (thya) genes. a preliminary investig ... | 1988 | 2838456 |
| translational autoregulation of ermc 23s rrna methyltransferase expression in bacillus subtilis. | ermc specifies an rrna methyltransferase that confers resistance to erythromycin. the expression of this determinant is induced by the addition of erythromycin. the induction mechanism has been shown to operate posttranscriptionally, and its mechanism has been elucidated. we now show that synthesis of the ermc gene product in bacillus subtilis is also autoregulated by a mechanism operating on the level of translation. the synthesis of methyltransferase was shown to be gene dosage compensated by ... | 1986 | 3096970 |
| abnormalities in hypothalamic and neurohypophysial vasopressin content are not a consequence of hypertension in the spontaneously hypertensive rat. | in order to determine if the decreased hypothalamic and increased posterior pituitary content of vasopressin (vp) observed previously in spontaneously hypertensive rats (shr) were a secondary consequence of the hypertension, the effect of preventing the development of hypertension on vp content of the hypothalamoneurohypophyseal system was evaluated. two methods for preventing the hypertension were used: (1) chronic angiotensin-converting enzyme inhibition (oral captopril, 100 mg/kg/day at 4-12 ... | 1988 | 3130152 |
| stage and strain specific expression of the tandemly repeated 90 kda surface antigen gene family in trypanosoma cruzi. | a recombinant cdna library constructed in the expression vector lambda gtll using mrna from the trypomastigote stage of trypanosoma cruzi was screened with two monoclonal antibodies that have been shown to react with a 105 kda and a 90 kda surface antigen in trypomastigotes of the peru and y strains of t. cruzi. one recombinant lambda phage, designated tcc-20, was reactive to both monoclonals. the beta-galactosidase/t. cruzi hybrid protein encoded in tcc-20 is recognized by the monoclonal antibo ... | 1988 | 2838752 |
| isolation of colonial variants of bacteroides gingivalis w50 with a reduced virulence. | the spontaneous appearance of unusual colony forms was observed during prolonged growth of bacteroides gingivalis w50 in a chemostat. two variants were selected for further study which could be distinguished from the parent strain by the rate and intensity of pigmentation of their colonies. for example, after anaerobic incubation for 14 days, variant w50/br1 produced brown colonies whereas those of the parent strain were black; in contrast, variant w50/be1 did not show signs of pigmentation unti ... | 1988 | 3172171 |
| atpenins, new antifungal antibiotics produced by penicillium sp. production, isolation, physico-chemical and biological properties. | penicillium sp. fo-125, a soil isolate, was found to produce a new antifungal antibiotic complex named atpenin. three components a4, a5 and b were isolated from the fermentation broth of the producing strain by solvent extraction, silica gel column chromatography and hplc. the molecular formula of atpenins a4, a5 and b were determined to be c15h22no5cl, c15h21no5cl2 and c15h23no5, respectively, on the basis of high resolution electron impact mass spectrometry and elemental analysis. they are act ... | 1988 | 3209470 |
| poliovirus host range is determined by a short amino acid sequence in neutralization antigenic site i. | the mouse-adapted strain of poliovirus type 2 (lansing) induces fatal poliomyelitis in mice after intracerebral inoculation, whereas mice inoculated with poliovirus type 1 (mahoney) show no signs of disease. previous work indicated that the adaptation to mouse virulence is associated with the viral capsid proteins and that mutations in neutralization antigenic site i of poliovirus reduce neurovirulence of the lansing strain in mice. the role of antigenic site i in mouse neurovirulence was furthe ... | 1988 | 2838906 |
| [changes in the host-dependent characteristics of the tick-borne encephalitis virus during its adaptation to ticks and its readaptation to white mice]. | features of multiplication in pig embryo kidney (pek) cells of a variant of tick-borne encephalitis (tbe) virus previously selected by passages in h. plumbeum ticks and changes in the properties of the variant upon its repassages in white mouse brains were studied. the tick-adapted tbe variant differed from the original strain in the following characteristics: a lower yield of infectious virus and physical virus particles, altered time-course of infectious virus release from the cell, the lack o ... | 1988 | 3218215 |
| genetic analysis of 2',3'-dideoxycytidine incorporation into cultured human t lymphoblasts. | in order to analyze the cellular determinants that mediate the action of 2',3'-dideoxycytidine, the growth inhibitory and cytotoxic effects and the metabolism of the dideoxynucleoside were examined in wild type human cem t lymphoblasts and in mutant populations of cem cells that were genetically deficient in either nucleoside transport or deoxycytidine kinase activity. whereas 2',3'-dideoxycytidine at a concentration of 5 microm inhibited growth of the wild type cem parental strain by 50%, two n ... | 1988 | 2842332 |
| requirement of the escherichia coli dnaa gene function for integrative suppression of dnaa mutations by plasmid r 100-1. | the phenotype of escherichia coli dnaa missense and nonsense mutations was integratively suppressed by plasmid r100-1. the suppressed strains, however, could not survive when the dnaa function was totally inactivated. this was demonstrated by the inability of replacing the dnaa allele in the suppressed strain by a dnaa::tn10 insertion using phage p1-mediated transduction. when the intact dnaa+ allele was additionally supplied by a specialized transducing phage, lambda imm21 dnaa+, which integrat ... | 1988 | 2851703 |
| cloning of chromosomal dna encoding the f41 adhesin of enterotoxigenic escherichia coli and genetic homology between adhesins f41 and k88. | the genetic determinant for production of the adhesive antigen f41 was isolated from a porcine enterotoxigenic escherichia coli strain by cosmid cloning. the cloned dna included sequences homologous to those of hybridization probes prepared from the k88 adhesive antigen operon. transposon insertions which inactivated f41 production mapped to the same region of dna showing homology with the k88 genes, demonstrating the genetic relatedness of f41 and k88. hybridization of a k88 gene probe to plasm ... | 1986 | 2875061 |
| stabilization of the attenuated poliovirus type 3 vaccine strain by sucrose. | highly temperature-sensitive and attenuated poliovirus type 3, strain leon 12a1b, was stabilized at 37 degrees c by 15% sucrose without 1 mol/1 mgcl2. the finding will contribute to poliovaccination in tropical countries. | 1989 | 2569817 |
| legionella cincinnatiensis sp. nov. isolated from a patient with pneumonia. | a legionella-like organism (strain 72-oh-h [= atcc 43753]) was isolated from an open-lung biopsy specimen from a hemodialysis patient with end-stage renal disease and bronchopneumonia. growth characteristics and gas-liquid chromatographic profiles of the isolate were consistent with those for legionella spp. the isolate was presumptively identified as a legionella longbeachae serogroup 1 strain by direct immunofluorescence staining. however, the organism was serologically distinct in the slide a ... | 1988 | 3281971 |
| genetic and phenotypic analyses indicating occurrence of the recn262 and radb101 mutations at the same locus in escherichia coli. | the radb101 and recn262 mutations showed essentially identical phenotypes when compared in isogenic escherichia coli strains for their effects on gamma and uv radiation survival and on conjugal recombination in a uvra recb recc sbcb sbcc strain. complementation tests involving attempts to reconstitute a radb+ recn+ strain by transductions between radb101 and recn262 donors and recipients, and tests involving plasmids carrying recn+ and recn::tn1000 inserts, indicated that the radb and recn genes ... | 1988 | 3283110 |
| non-h-2 histocompatibility antigens encoded by moloney-murine leukemia virus in mov mouse strains are detectable by skin grafting and cytolytic t lymphocytes. | the integration and expression of moloney-murine leukemia virus (m-mulv) into the germ line of mov mouse strains on the c57bl/6 background results in the expression of a cell-surface ag with characteristics expected from non-h-2 histocompatibility ag: the ability to stimulate graft rejection and generation of ctl. however, both the previously studied mov-3 and mov-14 strains differ from the coisogenic c57bl/6 strain by different length segments of chromosome derived from the icr strain in additi ... | 1988 | 3286772 |
| [aminoside sensitivity of bacteria isolated in 1984 at the military hospital complex in the paris region]. | the minimal inhibiting concentrations (mic) of 5 aminosids have been determined by the microdilution method in liquid medium of 4,582 bacterial strains isolated from various pathological samples: 1,039 staphylococcus, 2,629 enterobacteria, 759 pseudomonas and 155 acinetobacter. the phenotype of resistance has been defined for each strain by listing the antibiotics for which a resistance was observed. the frequencies of the bacterial resistances varied according to the aminosid (gentamicin, sisom ... | 1987 | 3302847 |
| a genomic change associated with the development of resistance to hycanthone in schistosoma mansoni. | ribosomal gene probes were used to investigate the genetic basis of drug resistance in schistosomes in a model where resistance to the anthelmintic hycanthone (hc) is generated by exposing immature worms to the drug. two strains of schistosoma mansoni, jhu and nmri, were used. drug resistance could be produced in the jhu strain by treatment with hc, but was also found to occur spontaneously. in contrast, it was not possible to detect or produce resistance to hc in the nmri strain. a genomic alte ... | 1989 | 2571929 |
| a simplified method for purification of an antitumor acidic glycoprotein from streptococcus pyogenes (su strain) by immunoadsorbent chromatography. | a simplified method for purification of an antitumor acidic glycoprotein (sagp) from streptococcus pyogenes (su strain) by immunoaffinity chromatography is described. a cell-free crude extract prepared from the cocci was applied to the anti-sagp igg coupled sepharose column, and elution was conducted with an alkaline buffer. the material eluted was confirmed to be homogeneous and identical with sagp as demonstrated by both relative mobility on the sds-polyacrylamide gel column and the antigenici ... | 1989 | 2651374 |
| a gale via (vi antigen-negative) mutant of salmonella typhi ty2 retains virulence in humans. | we have recently described the construction of a gale derivative of salmonella typhi ty2 (ty2h1) which had a 0.4-kilobase deletion in the gale gene and was sensitive to galactose-induced lysis when cultured with greater than or equal to 0.06 mm galactose (d. m. hone, r. morona, s. attridge, and j. hackett, j. infect. dis. 156:167-174, 1987). we now report the selection of a rifampin-resistant, via derivative of ty2h1, ex462. compared with the ty2 parent strain, ex462 was serum sensitive and high ... | 1988 | 3356467 |
| characterization of resistance phenotype and cephalosporin activity in oxacillin-resistant staphylococcus aureus. | forty isolates of methicillin-resistant staphylococcus aureus were tested versus oxacillin at 30 and 35 degrees c with and without 2% nacl supplementation of mueller-hinton broth and classified as having resistance that was low (mic, less than or equal to 16 micrograms/ml) or high (mic, greater than or equal to 32 micrograms/ml) and temperature or nacl dependent. only three isolates had low-grade resistance at both 30 and 35 degrees c; for two isolates the mics at 35 degrees c were greater than ... | 1988 | 3364941 |