| stenotrophomonas africana sp. nov., an opportunistic human pathogen in africa. | a gram-negative bacterium was isolated from a cerebrospinal fluid sample from an hiv-seropositive rwandan refugee with primary meningoencephalitis. this marseille-goma sample b isolate, strain mgbt (t = type strain), was found to exhibit evolutionary homology with stenotrophomonas maltophilia, as determined by a 16s rrna gene sequence analysis, and this finding was reflected by similar phenotypic traits. mgbt could, however, be distinguished from the s. maltophilia type strain by using a number ... | 1997 | 8995819 |
| tagging a vibrio cholerae el tor candidate vaccine strain by disruption of its hemagglutinin/protease gene using a novel reporter enzyme: clostridium thermocellum endoglucanase a. | the cela gene encoding clostridium thermocellum endoglucanase a was expressed in vibrio cholerae on its own promoter and used to tag a candidate el tor biotype cholera vaccine strain. colonies of the tagged strain could be unequivocally distinguished by overlaying them with cm-cellulose indicator agar and congo red staining. expression of cela did not affect growth of v. cholerae in vitro and in vivo. the cela gene was inserted in the chromosomal hap locus encoding v. cholerae hemagglutinin/prot ... | 1996 | 9014293 |
| gazelle herpesvirus 1: a new neurotropic herpesvirus immunologically related to equine herpesvirus 1. | a herpesvirus was isolated from thomson's gazelle (gazella thomsoni) kept at a zoological garden in japan during an outbreak of epizootic acute encephalitis. the virus, gazelle herpesvirus 1 (ghv-1), was serologically related to equine herpesvirus 1 (ehv-1). however, dna fingerprints of ghv-1 were different from those of ehv-1 and other equine herpesviruses. southern hybridization with probes of cloned bamhi fragments derived from ul and us segments of ehv-1 revealed differences in the dna restr ... | 1997 | 9015181 |
| aut1, a gene essential for autophagocytosis in the yeast saccharomyces cerevisiae. | autophagocytosis is a starvation-induced process responsible for transport of cytoplasmic proteins to the vacuole. in saccharomyces cerevisiae, autophagy is characterized by the phenotypic appearance of autophagic vesicles inside the vacuole of strains deficient in proteinase yscb. the aut1 gene, essential for autophagy, was isolated by complementation of the sporulation deficiency of a diploid aut1-1 mutant strain by a yeast genomic library and characterized. aut1 is located on the right arm of ... | 1997 | 9023185 |
| reconstitution of stretch-activated cation channels by expression of the alpha-subunit of the epithelial sodium channel cloned from osteoblasts. | osteoblasts respond to repetitive strain by activating stretch-activated, nonselective cation channels (sa-cat) and increasing matrix protein production. sa-cat channels are thought to be responsible for mechano-transduction in osteoblasts, although the molecular identity of the sa-cat channel has previously been unknown. we have demonstrated that both the umr-106 osteoblast-like cell line and human osteoblasts in primary culture express the alpha-subunit of the epithelial sodium channel (alpha- ... | 1997 | 9023374 |
| characterization of flagella genes of agrobacterium tumefaciens, and the effect of a bald strain on virulence. | agrobacterium tumefaciens produces flagella that are arranged circumthecally near one end of the bacilliform cell. the flagella are required for motility to facilitate reaching the root surface, and possibly aid in orientating the bacterial cells at various sites for infection. we have identified three flagella genes designated flaa, flab, and flac. mutations in flaa, flab and flac result in abberant swimming behaviour. electron microscopic examination of these mutants revealed the defective fla ... | 1997 | 9044291 |
| cloning and expression of the gene for a protein disulfide oxidoreductase from azotobacter vinelandii: complementation of an escherichia coli dsba mutant strain. | the gene for a disulfide oxidoreductase was cloned and sequenced from azotobacter vinelandii and termed the dsba locus. the deduced amino acid sequence contains 214 residues with a potential 17-residue signaling sequence on the n-terminal end. this gives the mature protein a calculated molecular mass of 21 799 da. the a. vinelandii dsba protein contains the well-conserved motif of c-p-h-c, which is found in the catalytic site of other bacterial dsba enzymes. the a. vinelandii dsba gene was expre ... | 1997 | 9099867 |
| [protective effect of a tetracycline-sensitive strain of escherichia coli on the growth of a tetracyclic-resistant strain in the presence of tetracycline in a coculture]. | the addition of tetracycline to a culture of a tetracycline-sensitive strain of escherichia coli leads to the appearance in the medium of a chemical compound (or compounds) that in part relieve the inhibition of growth of a tetracycline-resistant strain by a high concentration of the antibiotic. an increase in the growth rate can be as high as 50%. | 1996 | 9102551 |
| the influence of protein level in the diet on cannibalism and quality of plumage of layers. | a factorial experiment, with seven levels of protein and seven strains of layers, was conducted to determine the effect of protein level on plumage condition and mortality due to cannibalism. the experiment was carried out with a total of 3,136 layers. the protein content of the feed varied from 11.1 to 19.3%. the experiment revealed that protein levels had an effect (p < 0.0001) on plumage condition, and that the plumage condition also varies (p < 0.01) with strain of layers. a strain by protei ... | 1997 | 9106882 |
| cyclic strain induces an oxidative stress in endothelial cells. | hypertension imposes an oxidant stress on the aorta and also causes mechanical deformation of the aortic wall. to assess whether deformation causes an oxidative stress, isolated porcine aortic endothelial cells (paec) were subjected to cyclic strain, and the cumulative amount of thiobarbituric acid reactive substances (tbars, an index of lipid peroxidation) and h2o2 (a reactive oxygen species) was measured in the eluent at 2, 6, and 24 h. tbars were increased by 40.5 +/- 9.2% after 24 h in cells ... | 1997 | 9124284 |
| mechanical forces alter growth factor release by pleural mesothelial cells. | the mesothelial cells that form the visceral pleura of the lung are subjected to physical forces such as stretch due to lung expansion and fluid shear stress due to the sliding motion of the lung against the chest wall. in this study, the effect of mechanical forces on the production of growth factors by mesothelial cells was investigated. rat visceral pleura mesothelial (rvpm) cells were exposed to fluid shear stress by perfusing a column of cell-covered beads. rvpm cells grown on a silicone el ... | 1997 | 9124613 |
| stenotrophomonas maltophilia: emergence of multidrug-resistant strains during therapy and in an in vitro pharmacodynamic chamber model. | emergence of stenotrophomonas maltophilia as a nosocomial pathogen is becoming increasingly apparent. pleiotropic resistance characterizes s. maltophilia. furthermore, a slow growth rate and an increased mutation rate generate discordance between in vitro susceptibility testing and clinical outcome. despite original susceptibility, drug-resistant strains of s. maltophilia are often recovered from patients receiving beta-lactams, quinolones, or aminoglycosides. given the disparity among various i ... | 1996 | 9124855 |
| karyotype variability in yeast caused by nonallelic recombination in haploid meiosis. | chromosomes of altered size were found in the meiotic products of a haploid saccharomyces cerevisiae strain by pulsed field gel electrophoretic separation of whole chromosomes. about 7% of haploid meioses produced chromosomes that differed by > or = 10 kb from their wild-type counterparts. chromosomes most often became enlarged or shortened due to recombination events between sister chromatids at nonallelic sequences. by this mechanism chromosome iii acquired tandem arrays of up to eight extra c ... | 1997 | 9136002 |
| directed introduction of dna cleavage sites to produce a high-resolution genetic and physical map of the acinetobacter sp. strain adp1 (bd413ue) chromosome. | the natural transformability of the soil bacterium acinetobacter sp. adp1 (bd413ue), formerly classified as a. calcoaceticus, has facilitated previous physiological and biochemical investigations. in the present studies, the natural transformation system was exploited to generated a physical and genetic map of this strain's 3780 +/- 191 kbp circular chromosome. previously isolated acinetobacter genes were modified in vitro to incorporate a recognition sequence for the restriction endonuclease no ... | 1997 | 9141698 |
| distribution, cloning, characterisation and mutagenesis of sodc, the gene encoding copper/zinc superoxide dismutase, a potential determinant of virulence, in haemophilus ducreyi. | the sodc gene encoding the periplasmic enzyme copper/zinc superoxide dismutase (cuznsod) has been cloned from haemophilus ducreyi, the causative agent of the genital ulcer disease, chancroid. examination of a collection of diverse strains indicates that it is present throughout the species. cloned sodc has been expressed in e. coli and shown to encode active enzyme. insertional mutagenesis was used to construct a non-functional version of the gene. this has been transferred into the chromosome o ... | 1997 | 9143881 |
| deletion of the herpes simplex 1 internal repeat sequences affects pathogenicity in the mouse. | we have isolated three different herpes simplex virus 1 (hsv-1) recombinant viruses, each frozen in either the p (prototype), is (inversion of s component), or ils (inversion of both components) genome arrangement. common to all three recombinant viruses is the deletion of approximately 14 kilobases (kb) of viral dna sequences representing greater than 95% of the internal repeat sequences and the insertion of a 9.6 kb mini-mu genome containing a functional thymidine kinase gene. no unique dna se ... | 1996 | 9159195 |
| comparisons of genetic variability and genome structure among mosquito strains selected for refractoriness to a malaria parasite. | restriction fragment length polymorphism (rflp) markers were used to evaluate aedes aegypti genome structure and genetic variability within and between substrains selected for different levels of refractoriness to the malaria parasite, plasmodium gallinaceum. the moyo-r substrain was previously selected for complete refractoriness and the moyo-is substrain for intermediate susceptibility from the moyo-in-dry (moyo) strain by selective inbreeding (f = 0.5). eighteen mapped rflp markers were used ... | 1997 | 9183846 |
| [intervention of campylobacter jejuni subsp. jejuni flagella in the adhesion to cellular cultures: bacteriological and immunological evidence]. | the participation of the flagella of a virulent strain (o52) of campylobacter jejuni subsp. jejuni in the adhesion to hep-2 cells and their inhibition by means of homologous polyclonal antibodies, monoclonal anti-flagella antibodies and colostral natural antibodies (iga) was studied. an aflagellated strain (t1) was used as negative control. adhesion was observed in higher rates with o52 strain (72%) than with t1 strain (27.5%). polyclonal, monoclonal and colostral antibodies inhibited o52 strain ... | 1996 | 9197015 |
| effect of strain and age of the broiler breeder female on incubation time and chick weight. | two experiments were conducted to evaluate effects of strain [five in experiment (exp.) 1 and six in exp. 2)] and age (29, 47, and 57 wk in exp. 1 and 29, 41, and 52 wk in exp. 2) of commercial broiler breeders on incubation time and chick weight. highly significant differences in egg weight were found among strains in both exp. after adjusting for effects of egg weight, significant effects of strain, age, and their interactions were found on incubation time, egg weight at transfer, and chick we ... | 1997 | 9200240 |
| human papillomavirus type 16 virus-like particles expressed in attenuated salmonella typhimurium elicit mucosal and systemic neutralizing antibodies in mice. | attenuated strains of salmonella are attractive live vaccine candidates for eliciting mucosal as well as systemic immune responses. the ability to induce immune responses in the reproductive tract may be critical for the effectiveness of a prophylactic vaccine against genital human papillomaviruses (hpv), which are important etiologic agents in the development of cervical cancer. to examine the potential of a live salmonella-based vaccine to prevent genital hpv infection, the l1 major capsid pro ... | 1997 | 9234794 |
| thermal-death times of opaque and translucent morphotypes of vibrio vulnificus. | thermal-death times were determined for vibrio vulnificus strains with different morphotypes. opaque strains showed higher d values (times required to reduce the viable population of a given strain by 90%) than translucent strains. z values (absolute values of the temperature required to reduce 1 log scale of d values) were also significantly higher in opaque morphotypes (2.4 to 2.5 degrees c) than in translucent ones (1.7 to 2.1 degrees c). these results indicate that the morphotype is related ... | 1997 | 9251221 |
| restored expression of transforming growth factor beta type ii receptor in k-ras-transformed thyroid cells, tgf beta-resistant, reverts their malignant phenotype. | transforming growth factor beta 1 (tgf beta 1) inhibits the growth of normal rat epithelial thyroid cells (frtl-5 strain) by counteracting thyrotropin (tsh)-stimulated dna synthesis and by slowing the cells in the g1 phase of the cell cycle. here, we have studied two clones of frtl-5 thyroid cell line transformed by the wild type (wt) v-k-ras oncogene (k.m.a1, k.m.a2) and one clone (a6) transformed by a temperature-sensitive (ts) v-k-ras mutant. anchorage-dependent as well as anchorage-independe ... | 1997 | 9258341 |
| infections with roseomonas gilardii and review of characteristics used for biochemical identification and molecular typing. | roseomonas is a recently described genus of gram-negative coccobacilli formerly designated as "pink-coccoid" groups i through iv by the centers for disease control and prevention (atlanta, ga) because of the organism's characteristic pink colonies. since 1991 we have isolated roseomonas from eight patients; in seven from blood cultures and in one from a skin lesion. the seven blood isolates were from patients with clinically significant underlying diseases who had central venous catheters in pla ... | 1997 | 9260763 |
| mutation of the htrb gene in a virulent salmonella typhimurium strain by intergeneric transduction: strain construction and phenotypic characterization. | the htrb gene product of haemophilus influenzae contributes to the toxicity of the lipooligosaccharide. the htrb gene encodes a 2-keto-3-deoxyoctulosonic acid-dependent acyltransferase which is responsible for myristic acid substitutions at the hydroxy moiety of lipid a beta-hydroxymyristic acid. mass spectroscopic analysis has demonstrated that lipid a from an h. influenzae htrb mutant is predominantly tetraacyl and similar in structure to lipid iv(a), which has been shown to be nontoxic in ani ... | 1997 | 9287009 |
| extracellular 37-kda antigenic protein from actinobacillus actinomycetemcomitans induces tnf-alpha, il-1 beta, and il-6 in murine macrophages. | the extracellular antigens of actinobacillus actinomycetemcomitans y4 (serotype b) contain a 37-kda protein which is a major target for iggs from patients suffering from severe alveolar bone loss. since the 37-kda protein has not been studied sufficiently, our investigation focused on its characteristics, e.g., its localization, specificity, and whether it directly stimulates macrophages to produce cytokines. the 37-kda protein was purified from the culture supernatant of the y4 strain by means ... | 1997 | 9294487 |
| homologous recombination based modification in escherichia coli and germline transmission in transgenic mice of a bacterial artificial chromosome. | escherichia coli-based artificial chromosomes have become important tools for physical mapping and sequencing in various genome projects. the lack of a general method to modify these large bacterial clones, however, has limited their utility in functional studies. we developed a simple method to modify bacterial artificial chromosomes directly in the recombination-deficient e. coli host strain by homologous recombination for in vivo studies. the ires-lacz marker gene was introduced into a 131 kb ... | 1997 | 9306400 |
| isolation of aspergillus niger crea mutants and effects of the mutations on expression of arabinases and l-arabinose catabolic enzymes. | aspergillus niger mutants relieved of carbon repression were isolated from an area parental strain by selection of colonies that exhibited improved growth on a combination of 4-aminobutanoic acid (gaba) and d-glucose. in addition to derepression of the utilization of gaba as a nitrogen source in the presence of d-glucose, three of the four mutants also showed derepression of l-alanine and l-proline utilization. transformation of the mutants with the a. niger crea gene, encoding the repressor pro ... | 1997 | 9308182 |
| [cdnas encoding the antigenic proteins in pathogenic strain of entamoeba histolytica]. | the differential display reverse transcription polymerase chain reaction (ddrt-pcr) analysis was performed to identify the pathogenic strain specific amplicons. mrnas were purified from the trophozoites of the pathogenic strain ys-27 and the non-pathogenic strain s 16, respectively. three kinds of first stranded cdnas were reverse transcribed from the mrnas by one base anchored oligo-dt11m (m: a, c, or g) primers. each cdna template was used for ddrt-pcr analysis. a total of 144 pathogenic strai ... | 1997 | 9335186 |
| a conjugative linear plasmid in streptomyces laurentii atcc31255. | plasmid psll of streptomyces laurentii atcc31255 (wild-type strain p0) is a 93-kilobase linear dna plasmid that carries a protein bound to each 5' end of the dna. it was self-transmitted to the psll-cured strain by conjugation in solid culture. the psll-cured strain carried a circular plasmid, psls, and showed a marked decrease in spore formation and thiostrepton productivity, owing to the psls. however, by retransmission of psll, these things reverted to levels seen in strain p0. thus, plasmid ... | 1997 | 9339547 |
| prp43: an rna helicase-like factor involved in spliceosome disassembly. | the saccharomyces cerevisiae genes prp2, prp16, and prp22 encode pre-mrna splicing factors that belong to the highly conserved "deah" family of putative rna helicases. we previously identified two additional members of this family, ja1 and ja2. to investigate its biological function, we cloned the ja1 gene and generated alleles carrying mutations identical to those found in highly conserved regions of other members of the deah family. a ja1 allele carrying a mutation identical to that in the tem ... | 1997 | 9342317 |
| strains of glycopeptide-resistant enterococcus faecium can alter their van genotypes during an outbreak. | two isolates of enterococcus faecium with vana glycopeptide resistance were isolated during a hospital outbreak of e. faecium with plasmid-mediated vanb resistance. both were found to be identical to the vanb outbreak strain by pulsed-field gel electrophoresis. the genotype of this strain changed from vanb to vana through an intermediate isolate that contained both the vana and vanb gene clusters on distinct plasmids. | 1997 | 9350769 |
| investigation of an outbreak of multidrug resistant tuberculosis among renal patients using rpo b gene sequencing and is6110 inverse pcr. | a cluster of cases of tuberculosis among five patients receiving treatment for renal failure was investigated. insertion sequence (is6110) fingerprinting and antibiotic resistance profiling of the mycobacterium tuberculosis isolates from four of the patients (a-d), who had been on the same ward, showed that three of these cases (a-c) were related, but that the fourth (d) was distinct. an isolate from the fifth patient (e), who had been on a separate ward, was indistinguishable from the outbreak ... | 1997 | 9354346 |
| reduction in plate strain by addition of an intramedullary pin. | the purpose of this study was to determine the strain sparing effect of a bone plate and rod system compared with a bone plate alone. | 1997 | 9387208 |
| a defect in gtp synthesis affects mannose outer chain elongation in saccharomyces cerevisiae. | we have found that yeast mutants that are defective in mannose outer chain elongation of n-linked glycoproteins show higher cell wall porosity than normal cells, and are hypersensitive to antibiotics with a large molecular weight; such as neomycin and geneticin. wild-type yeast cells also showed enhanced sensitivity to neomycin in the presence of tunicamycin, an inhibitor of n-glycosylation, suggesting that the extent of n-glycosylation may affect the sensitivity of yeast cells to drugs and that ... | 1997 | 9413430 |
| an avirulent mutant of rabies virus is unable to infect motoneurons in vivo and in vitro. | an antigenic double mutant of rabies virus (challenge virus standard [cvs] strain) was selected by successive use of two neutralizing antiglycoprotein monoclonal antibodies, both specific for antigenic site iii. this mutant differed from the original virus strain by two amino acid substitutions in the ectodomain of the glycoprotein. the lysine in position 330 and the arginine in position 333 were replaced by asparagine and methionine, respectively. this double mutant was not pathogenic for adult ... | 1998 | 9420224 |
| interpretation of trailing endpoints in antifungal susceptibility testing by the national committee for clinical laboratory standards method. | trailing endpoints remain a problem in antifungal susceptibility testing using the national committee for clinical laboratory standards (nccls) method. for isolates for which trailing endpoints are found, mics of < or = 1 microg/ml at 24 h and of > 64 microg/ml at 48 h are usually observed. in a study of human immunodeficiency virus (hiv)-infected patients with oropharyngeal candidiasis, we identified three patients with multiple serial isolates for which trailing endpoints were observed with fl ... | 1998 | 9431939 |
| control of herpetic stromal keratitis using ctla4ig fusion protein. | herpetic stromal keratitis (hsk) is an immunoinflammatory lesion in the cornea of the eye set off by infection with herpes simplex virus (hsv). the disease appears to be orchestrated by cd4+ t cells of the th1 phenotype but the identity of target antigens involved in hsk remains unknown. in this proposal, we investigated if the inhibition of t cell activation with the fusion protein ctla4ig would abrogate the disease process when administered systemically. balb/c mice infected with hsv-1 (re str ... | 1998 | 9434800 |
| residue-specific bioincorporation of non-natural, biologically active amino acids into proteins as possible drug carriers: structure and stability of the per-thiaproline mutant of annexin v. | residue-specific bioincorporation of 1,3-thiazolidine-4-carboxylic acid [thiaproline, pro(s)], a non-natural amino acid analog of proline, into human recombinant annexin v was achieved with a proline-auxotrophic escherichia coli strain by fermentation procedures in minimal medium. quantitative replacement of proline with thiaproline was confirmed by mass-spectrometric, amino acid, and x-ray crystallographic analyses. the wild-type protein and its per-pro(s) mutant were found to crystallize isomo ... | 1998 | 9435213 |
| expression cloning of a pseudomonas gene encoding a hydroxydecanoyl-acyl carrier protein-dependent udp-glcnac acyltransferase. | udp-n-acetylglucosamine-3-o-acyltransferase (udp-glcnac acyltransferase) catalyzes the first step of lipid a biosynthesis (m. s. anderson and c. r. h. raetz, j. biol. chem. 262:5159-5169, 1987). we here report the isolation of the lpxa gene of pseudomonas aeruginosa from a library of pseudomonas strain pao1 expressed in escherichia coli le392 (j. lightfoot and j. s. lam, j. bacteriol. 173:5624-5630, 1991). pseudomonas lpxa encodes a 10-carbon-specific udp-glcnac acyltransferase, whereas the e. c ... | 1998 | 9440522 |
| involvement of a 70-kb plasmid of the epidemic shigella dysenteriae type 1 (dt66) strain in drug-resistance, lipopolysaccharide synthesis, and virulence. | the present work characterizes a 70 kb plasmid of the indian epidemic isolate shigella dysenteriae type 1 strain dt66 in relation to virulence and drug-resistance characters. curing of the plasmids of dt66 strain by acriflavine (af) yielded seven groups of af-cured derivatives. one group of derivatives containing 5 plasmids (70-2.5 kb) as against 6 (120-2.5 kb) in the wild type showed resistance to chloramphenicol, pivmecillinam, streptomycin, and tetracycline (cmrpivrsmrtcr) but sensitivity for ... | 1997 | 9442487 |
| transduction of antibiotic resistance markers among actinobacillus actinomycetemcomitans strains by temperate bacteriophages aa phi 23. | actinobacillus actinomycetemcomitans (aa) strain st1 carries the tetracycline (tc) resistance transposon tn916 and the aa phi st1 prophage, which is closely related to temperate bacteriophage aa phi 23. high titre phage preparations were obtained from this strain by mitomycin c induction and were used to transduce the tcr determinant to the tcs recipient strains zib1001 and zib1015 (mic 2 micrograms tc/ml). tcr transductants (mic > or = 32 micrograms tc/ml) were detected at frequencies of 3 x 10 ... | 1997 | 9447241 |
| a novel extended-spectrum tem-type beta-lactamase (tem-52) associated with decreased susceptibility to moxalactam in klebsiella pneumoniae. | klebsiella pneumoniae nem865 was isolated from the culture of a stool sample from a patient previously treated with ceftazidime (caz). analysis of this strain by the disk diffusion test revealed synergies between amoxicillin-clavulanate (amx-ca) and caz, amx-ca and cefotaxime (ctx), amx-ca and aztreonam (atm), and more surprisingly, amx-ca and moxalactam (mox). clavulanic acid (ca) decreased the mics of caz, ctx, and mox, which suggested that nem865 produced a novel extended-spectrum beta-lactam ... | 1998 | 9449269 |
| engineering of quasi-natural pseudomonas putida strains for toluene metabolism through an ortho-cleavage degradation pathway. | to construct a bacterial catalyst for bioconversion of toluene and several alkyl and chloro- and nitro-substituted derivatives into the corresponding benzoates, the upper tol operon of plasmid pww0 of pseudomonas putida was fully reassembled as a single gene cassette along with its cognate regulatory gene, xylr. the corresponding dna segment was then targeted to the chromosome of a p. putida strain by using a genetic technique that allows deletion of all recombinant tags inherited from previous ... | 1998 | 9464417 |
| rapid, low-technology mic determination with clinical mycobacterium tuberculosis isolates by using the microplate alamar blue assay. | a colorimetric, microplate-based alamar blue assay (maba) method was used to determine the mics of isoniazid (inh), rifampin, streptomycin (sm), and ethambutol (emb) for 34 peruvian mycobacterium tuberculosis isolates (including both pansensitive and multidrug-resistant strains) and the h37rv strain by using bacterial suspensions prepared directly from solid media. results for all isolates were available within 8 days. discordant results were observed on initial tests for 3 of 16 inh-susceptible ... | 1998 | 9466742 |
| importance of calcium to the regulation of polymorphism in wangiella (exophiala) dermatitidis. | critical steps implicated in the polymorphism of wangiella dermatitidis were found to be sensitive to calcium ion availability. when grown in a defined, synthetic medium under various ph and temperature conditions, two thresholds of calcium ion concentrations were identified: a lower concentration favouring non-polarized growth leading to multicellular form development and a higher concentration promoting polarized growth characterized by yeast budding or pseudo/true hyphal growth. the phenotypi ... | 1997 | 9467104 |
| pathogenesis of ovine lentiviral encephalitis: derivation of a neurovirulent strain by in vivo passage. | the lentiviruses of sheep replicate almost exclusively in macrophages and cause chronic interstitial pneumonia, arthritis, and mastitis, but only rarely encephalitis. this study was undertaken to determine whether a non-neurovirulent field strain of ovine lentivirus isolated from joint fluid that replicated productively in lung and joint macrophages could be adapted to enter and replicate in the brain and cause encephalitis. the field isolate was passed seven times sequentially by intracerebral ... | 1997 | 9475113 |
| periplasmic copper-zinc superoxide dismutase protects haemophilus ducreyi from exogenous superoxide. | haemophilus ducreyi causes chancroid, a sexually transmitted genital ulcer disease implicated in increased heterosexual transmission of hiv. as part of an effort to identify h. ducreyi gene products involved in virulence and pathogenesis, we created random tnphoa insertion mutations in an h. ducreyi 35000 library cloned in escherichia coli. inserts encoding exported or secreted phoa fusion proteins were characterized by dna sequencing. one such clone encoded a cu-zn superoxide dismutase (sod) en ... | 1998 | 9484894 |
| construction of a reca mutant of burkholderia (formerly pseudomonas), cepacia. | a reca mutant was constructed of a soil isolate of burkholderia cepacia, strain atcc 17616. prior to mutagenesis, the reca gene was cloned from this strain by its ability to complement the methyl methanesulfonate sensitivity of an escherichia coli reca mutant. sequence analysis of the strain showed high sequence similarity (94% nucleic acid and 99% amino acid identity) with the reca gene previously cloned from a clinical isolate of b. cepacia, strain jn25. the subcloned reca gene from b. cepacia ... | 1998 | 9487711 |
| elasticity reconstructive imaging by means of stimulated echo mri. | a method is introduced to measure internal mechanical displacement and strain by means of mri. such measurements are needed to reconstruct an image of the elastic young's modulus. a stimulated echo acquisition sequence with additional gradient pulses encodes internal displacements in response to an externally applied differential deformation. the sequence provides an accurate measure of static displacement by limiting the mechanical transitions to the mixing period of the simulated echo. elastic ... | 1998 | 9498605 |
| lung function and bacterial proliferation in experimental neonatal pneumonia in ventilated rabbits exposed to monoclonal antibody to surfactant protein a. | surfactant protein a (sp-a) increases the resistance of surfactant to inhibition by plasma and other proteins. in a previous study we found that a monoclonal anti-sp-a antibody (r 5) increased the sensitivity of surfactant to inhibition by fibrinogen in vivo and in vitro. sp-a has been shown to stimulate microbial phagocytosis and killing by alveolar macrophages. we hypothesized that using r 5 to inactivate sp-a in an animal model mimicking congenital group b streptococcal (gbs) pneumonia might ... | 1998 | 9500297 |
| rnase iii deficient salmonella typhimurium lt2 contains intervening sequences (ivss) in its 23s rrna. | salmonella typhimurium lt2 contains intervening sequences (ivss) of 90-110 nt within all its 23s rrna that are cleaved out by rnase iii, resulting in rrna fragmentation. in order to determine the functionality of 23s rrna that contains unexcised ivss, we constructed an s. typhimurium rnase iii (rnc) deficient strain by transducing a mini-tn10 (rnc-14::tn10) from escherichia coli k-12. the resulting strain of s. typhimurium was viable, contained ivss within all of its 23s rrna, and showed a growt ... | 1998 | 9503611 |
| [study of coxsackievirus group a. i. serological variation of coxsackieviruses group a isolated in gifu prefecture]. | forty four isolated strains of coxsackievirus group a were tested for antigenic variation with antiserum against each prototype strain by neutralization test. isolates of type 2, type 4, type 5, type 8 and type 10 of coxsackievirus group a, were not confirmed antigenic variation by neutralization test with immune sera to the prototype virus strain. however, 57.1% of type 9 isolates of coxsackievirus a group were confirmed as variants. in isolates of coxsackievirus group a type 16, the isolate in ... | 1998 | 9503781 |
| expression of multiple pili by legionella pneumophila: identification and characterization of a type iv pilin gene and its role in adherence to mammalian and protozoan cells. | legionella pneumophila expresses pili of variable lengths, either long (0.8 to 1.5 microm) or short (0.1 to 0.6 microm), that can be observed by transmission electron microscopy. we have identified a gene in l. pneumophila with homology to the type iv pilin genes (pilel). an insertion mutation was constructed in pilel and introduced into the l. pneumophila wild-type strain by allelic exchange. the pilin mutant is defective for expression of long pili. reintroduction of the pilin locus on a cosmi ... | 1998 | 9529112 |
| cloning and disruption of the beta-isopropylmalate dehydrogenase gene (leu2) of pichia stipitis with ura3 and recovery of the double auxotroph. | transformation of pichia stipitis is required to advance genetic studies and development of xylose metabolism in this yeast. to this end, we used p. stipitis ura3 (psura3) to disrupt p. stipitis leu2 in a p. stipitis ura3 mutant. a highly fermentative p. stipitis mutant (fpl-dx26) was selected for resistance to 5'-fluoroorotic acid to obtain p. stipitis fpl-uc7 (ura3-3). a ura3:lacz "pop-out" cassette was constructed containing psura3 flanked by direct repeats from segments of the lacz reading f ... | 1998 | 9534253 |
| the desulfuromonas acetoxidans triheme cytochrome c7 produced in desulfovibrio desulfuricans retains its metal reductase activity. | multiheme cytochrome c proteins that belong to class iii have been recently shown to exhibit a metal reductase activity, which could be of great environmental interest, especially in metal bioremediation. to get a better understanding of these activities, the gene encoding cytochrome c7 from the sulfur-reducing bacterium desulfuromonas acetoxidans was cloned from genomic dna by pcr and expressed in desulfovibrio desulfuricans g201. the expression system was based on the cyc transcription unit fr ... | 1998 | 9546165 |
| decreased physical performance of congenic mice with mismatch between the nuclear and the mitochondrial genome. | maternal transmission of mitochondrial dna (mtdna) allows us to generate mtdna congenic strain by repeating backcrosses of female mice to male mice of an inbred strain, which carries different mtdna haplotype from that of the female progenitor. since genetic backgrounds of inbred strains commonly used (e.g., c57bl/6j [b6] and balb/c) are mainly derived from an european subspecies of mus musculus domesticus, congenic strains, in which mtdna originated from an asian subspecies m. musculus musculus ... | 1998 | 9546205 |
| generation and properties of a streptococcus pneumoniae mutant which does not require choline or analogs for growth. | a mutant (jy2190) of streptococcus pneumoniae rx1 which had acquired the ability to grow in the absence of choline and analogs was isolated. lipoteichoic acid (lta) and wall teichoic acid (ta) isolated from the mutant were free of phosphocholine and other phosphorylated amino alcohols. both polymers showed an unaltered chain structure and, in the case of lta, an unchanged glycolipid anchor. the cell wall composition was also not altered except that, due to the lack of phosphocholine, the phospha ... | 1998 | 9555891 |
| clinical, cellular, and molecular factors that contribute to antifungal drug resistance. | in the past decade, the frequency of diagnosed fungal infections has risen sharply due to several factors, including the increase in the number of immunosuppressed patients resulting from the aids epidemic and treatments during and after organ and bone marrow transplants. linked with the increase in fungal infections is a recent increase in the frequency with which these infections are recalcitrant to standard antifungal therapy. this review summarizes the factors that contribute to antifungal d ... | 1998 | 9564569 |
| mechanical strain suppresses inducible nitric-oxide synthase in cardiac myocytes. | we investigated the effects of precisely controlled mechanical strain on nitric-oxide synthase activity in cultured neonatal rat cardiac myocytes. incubation of cardiac myocytes for 24 h with 4 ng/ml interleukin-1beta and 100 units/ml interferon-gamma stimulated an increase in nitric oxide production, inducible nitric-oxide synthase (inos) mrna, and inos protein. mechanical strain suppressed nitric oxide production, inos mrna, and inos protein stimulated by cytokines in an amplitude-dependent ma ... | 1998 | 9565611 |
| smith/birnstiel mapping of genome rearrangements in pseudomonas aeruginosa. | a novel application of the smith/birnstiel technique is presented for the analysis of intraspecies genomic diversity in small genomes. rare-cutter total/n frequent-cutter partial restriction digestions are separated in n separate lanes by pulsed-field gel electrophoresis, blotted and hybridized with rare-cutter fragment ends as probes. the evaluation of the autoradiogram results in high-resolution restriction maps of 10-200 kbp regions. the technique was applied to the analysis of genome rearran ... | 1998 | 9588793 |
| isolation of a trichoderma reesei cdna encoding gtp: a-d-mannose-1-phosphate guanyltransferase involved in early steps of protein glycosylation. | a cdna coding for gtp: alpha-d-mannose-1-phosphate guanyltransferase (mpg1 transferase) (ec 2.7.7.13) was isolated from a cdna library of the trichoderma reesei rutc-30 strain by suppression of the yeast saccharomyces cerevisiae mutation in the dpm1gene encoding mannosylphosphodolichol (mpd) synthase. the nucleotide sequence of the 1.6 kb-long cdna revealed an orf which encodes a protein of 364 amino acids. sequence comparisons demonstrate 70% identity with the s. cerevisiae guanyl transferase g ... | 1998 | 9644208 |
| potential for transmission of the finch strain of mycoplasma gallisepticum between house finches and chickens. | although mycoplasma gallisepticum (mg) is established in house finch (carpodacus mexicanus) populations in at least 33 states, the potential risk of mg introduction to domestic poultry by infected finches currently is unknown. the objectives of this study were to determine if chickens could be infected with the finch strain of mg via direct, across-wire, and proximity (across-room) contact with naturally infected house finches and to determine if house finches could be infected through direct co ... | 1998 | 9645326 |
| a phylogenetic analysis of the trypanosoma cruzi genome project cl brener reference strain by multilocus enzyme electrophoresis and multiprimer random amplified polymorphic dna fingerprinting. | we have assessed the phylogenetic status of the trypanosoma cruzi genome project cl brener reference strain by multilocus enzyme electrophoresis (mlee) and multiprimer random amplified polymorphic dna (rapd) including a set of cloned stocks representative of the whole genetic diversity of t. cruzi. mlee and rapd data gave congruent phylogenetic results. the cl brener reference strain fell into the second major phylogenetic subdivision of t. cruzi, and was genetically very close to the tulahuen r ... | 1998 | 9657330 |
| flow-function relations during graded coronary occlusions in the dog: effects of transmural location and segment orientation. | the sensitive relationship between regional myocardial perfusion and local systolic deformation during acute myocardial ischemia is not independent of the transmural location or segment orientation. the aim of this study was to determine the effects of fiber orientation and transmural location on the relationships between regional myocardial flow and three-dimensional systolic wall strain during graded coronary artery occlusions. | 1998 | 9659447 |
| genetic relationship between central beta-endorphin and novelty-induced locomotor activity. | the goal of research presented in this report was to investigate the possibility that differences in beta-ed levels could account for some portion of genetically mediated variation in locomotor activity. subjects representing six of the lsxss ri mouse strains were activity tested in a novel environment. significant effects of strain and time as well as a significant strain by time interaction were detected. beta-ed levels were estimated from several brain regions and the pituitary of naive and a ... | 1998 | 9678655 |
| expression of smooth muscle myosin heavy chain b in cardiac vessels of normotensive and hypertensive rats. | we investigated expression of the 5'-spliced isoform of smooth muscle myosin heavy chain (sm-mhc-b) in smooth muscle cells of cardiac vessels of the left ventricle of normotensive (wistar-kyoto) and spontaneously hypertensive rats of the stroke-prone strain by immunofluorescence microscopy. in parallel, liver and bladder were studied for characterization of the nature of vessels expressing sm-mhc-b and for semiquantitative evaluation of its abundance. smooth muscle cells were detected by stainin ... | 1998 | 9686760 |
| gene sequence and transcription differences in 70 kda heat shock protein correlate with murine virulence of toxoplasma gondii. | this study compared the genes encoding cytoplasmic 70 kda heat shock protein in virulent and avirulent strains of toxoplasma gondii, to determine whether differences may contribute to the variation in protein expression levels previously reported for this protozoan parasite. a t. gondii pcr probe with homology to eimeria acervulina cytoplasmic 70 kda heat shock protein was used to screen a genomic dna mini-library and isolate the gene from the virulent rh strain. the entire coding region was sub ... | 1998 | 9724875 |
| erabulenols, inhibitors of cholesteryl ester transfer protein produced by penicillium sp. fo-5637. i.production, isolation and biological properties. | penicillium sp. fo-5637, a soil isolate, was found to produce a series of inhibitors of cholesteryl ester transfer protein (cetp). novel active compounds, designated erabulenols a and b, were isolated from the fermentation broth of the producing strain by solvent extraction, ods column chromatography and hplc. erabulenols a and b inhibit human cetp activity with ic50 values of 47.7 and 58.2 microm in an in vitro assay system containing 200 microm bsa, respectively. | 1998 | 9727386 |
| prolonged replication of a type 1 vaccine-derived poliovirus in an immunodeficient patient. | vp1 sequences were determined for poliovirus type 1 isolates obtained over a 189-day period from a poliomyelitis patient with common variable immunodeficiency syndrome (a defect in antibody formation). the isolate from the first sample, taken 11 days after onset of paralysis, contained two poliovirus populations, differing from the sabin 1 vaccine strain by approximately 10%, differing from diverse type 1 wild polioviruses by 19 to 24%, and differing from each other by 5.5% of nucleotides. speci ... | 1998 | 9738040 |
| ndt80 and the meiotic recombination checkpoint regulate expression of middle sporulation-specific genes in saccharomyces cerevisiae. | distinct classes of sporulation-specific genes are sequentially expressed during the process of spore formation in saccharomyces cerevisiae. the transition from expression of early meiotic genes to expression of middle sporulation-specific genes occurs at about the time that cells exit from pachytene and form the meiosis i spindle. to identify genes encoding potential regulators of middle sporulation-specific gene expression, we screened for mutants that expressed early meiotic genes but failed ... | 1998 | 9742092 |
| a hospital outbreak of extended-spectrum beta-lactamase-producing klebsiella pneumoniae investigated by rapd typing and analysis of the genetics and mechanisms of resistance. | between july and september 1997 a ceftazidime- and aminoglycoside-resistant strain of klebsiella pneumoniae infected or colonized seven patients on three paediatric wards at guy's hospital in london. the patients were mostly neonates or infants recovering from cardiac surgery for congenital defects. the organism was probably introduced by an asymptomatic patient from greece and the subsequent outbreak could largely be explained by person-to-person spread on individual wards and frequent transfer ... | 1998 | 9749400 |
| hepatitis c virus e1 protein induces modification of membrane permeability in e. coli cells. | the e1 gene of hepatitis c virus (hcv) has been cloned and expressed in bl21(de3)plys escherichia coli strain by pet3a vector to analyze changes in membrane permeability produced by this protein. we showed that the expression of e1 (aa 192-383), as well as of two c-terminal fragments (aa 331-383 and aa 341-383) corresponding to the transmembrane (tm) region of this protein, induced a rapid lysis of cells. on the contrary, the expression of a mutant of e1 (aa 192-340), lacking the last 40 amino a ... | 1998 | 9770414 |
| [studies on the susceptibility of two northern taiwan strains of aedes albopictus mosquitoes to japanese encephalitis virus]. | aedes albopictus is a dominant mosquito species in northern taiwan. in laboratory, the vector competence of 2 geographical strains of aedes albopictus mosquitoes to nt 113 strain of japanese encephalitis virus was examined. the mosquito infection dose50 (mi-d50) of sanhsia (sh) strain by intrathoracic (i.t.) inoculation was shown to be -1.1 log wmicld50 (weanling mice intracerebrum lethal dose), while that of yungho (yh) strain was -2.0 log wmicld50. the infection dose for 50% mosquitoes transmi ... | 1995 | 9774983 |
| identification of the schistosoma japonicum 22.6-kda antigen as a major target of the human ige response: similarity of ige-binding epitopes to allergen peptides. | human resistance to reinfection with schistosoma mansoni and schistosoma haematobium correlates with elevated ige titers against worm antigens (soluble worm antigen preparation, swap). in s. mansoni infection, low levels of reinfection following chemotherapy are associated with the recognition of a cloned tegumental protein sm22.6. because of potential species-specific differences in resistance to schistosomes, we attempted to identify schistosoma japonicum antigens recognized by human ige. foll ... | 1998 | 9784652 |
| nitazoxanide, a potential drug for eradication of helicobacter pylori with no cross-resistance to metronidazole. | nitazoxanide, a thiazolide compound, and its desacetyl derivative, tizoxanide, have antimicrobial properties against anaerobic bacteria, as well as against helminths and protozoa. because the treatment of helicobacter pylori infection may be jeopardized by metronidazole resistance, nitazoxanide and tizoxanide were tested in vitro against these bacteria. the mics of these two compounds were determined by agar dilution and were compared to those of metronidazole. exposure to subinhibitory concentr ... | 1998 | 9797212 |
| targeted mutagenesis of sigma54 activator proteins in myxococcus xanthus. | myxococcus xanthus dna segments related to the highly conserved central sequence of sigma54 activator proteins have been investigated. a genetic technique designed to inactivate a gene that encodes such an activator by inserting a plasmid-borne internal fragment of the putative gene has been tested. when the internal fragment inserted by homologous recombination into the corresponding chromosomal locus, the expected duplication of the gene was observed by southern hybridization. the single restr ... | 1998 | 9811647 |
| reactivity of human sera to different strains of granulocytic ehrlichiae in immunodiagnostic assays. | sera from 35 patients diagnosed with human granulocytic ehrlichiosis in connecticut were tested by indirect ifa staining methods with 5 strains of ehrlichia equi or the human granulocytic ehrlichiosis agent to assess the suitability of different strains in laboratory analyses. antigens included horse-derived infected neutrophils (mrk and bds strains) and human isolates cultured in human promyelocytic leukemia cells (nch-1, rch, and webster). of 35 sera, 23 (65.7%) reacted to all 5 strains. serop ... | 1998 | 9815246 |
| enhancement of mycinamicin production by dotriacolide in micromonospora griseorubida. | production of macrolide antibiotic mycinamicin was greatly increased by addition of sulfate ion into the culture medium of micromonospora griseorubida. an o-sulfate ester compound, also produced by the strain, was shown to be dotriacolide. in an m. griseorubida dotriacolide non-producing strain, the production level of mycinamicin remained low, but increased to the level of dotriacolide producing strain by the addition of dotriacolide. dotriacolide enhanced mycinamicin production in m. griseorub ... | 1998 | 9841223 |
| genotypes of helicobacter pylori in lithuanian families. | infection by helicobacter pylori is very common in eastern europe, but the genotypes of predominant strains and prevalence of single vs. multiple infection in this geographic region have not been much studied. | 1998 | 9844072 |
| decorin, biglycan and their endocytosis receptor in rat renal cortex. | among the small proteoglycans, biglycan and decorin have been proposed to be potent modulators of tgf-beta-mediated inflammatory kidney diseases. they were considered to become induced during glomerulonephritis and to subsequently inactivate the cytokine. | 1998 | 9844129 |
| eliminating arterial pulsatile strain by external banding induces medial but not neointimal atrophy and apoptosis in the rabbit. | we have examined the role of vessel pulsation and wall tension on remodeling and intimal proliferation in the rabbit infrarenal abdominal aorta. a rigid perivascular polyethylene cuff was used to reduce vessel systolic diameter by 25%, producing a region of reduced circumferential strain. at 6 weeks postoperatively, reduced circumferential strain caused medial atrophy, with 45% reduction of medial area and 30% loss of medial smooth muscle cells. apoptotic cell death was indicated by dna fragment ... | 1998 | 9846963 |
| quantitative analysis of yeast gene function using competition experiments in continuous culture. | one possible route to the evaluation of gene function is a quantitative approach based on the concepts of metabolic control analysis (mca). an important first step in such an analysis is to determine the effect of deleting individual genes on the growth rate (or fitness) of s. cerevisiae. since the specific growth-rate effects of most genes are likely to be small, we employed competition experiments in chemostat culture to measure the proportion of deletion mutants relative to that of a standard ... | 1998 | 9848233 |
| preoperative diagnosis of mycobacterium avium lymphadenitis in two immunocompetent children by polymerase chain reaction of gastric aspirates. | analysis of gastric aspirates is a routine procedure for detection of mycobacterium tuberculosis in pediatric pulmonary tuberculosis. however, identification of nontuberculous mycobacteria in gastric aspirates of immunocompetent children is not thought to be clinically significant. | 1998 | 9849985 |
| isolation and characterisation of disodium (4-amino-4-deoxy-beta-l- arabinopyranosyl)-(1-->8)-(d-glycero-alpha-d-talo-oct-2-ulopyranosylona te)- (2-->4)-(methyl 3-deoxy-d-manno-oct-2-ulopyranosid)onate from the lipopolysaccharide of burkholderia cepacia. | a trisaccharide was isolated from the core oligosaccharide in the lipopolysaccharide (lps) of burkholderia cepacia gifu 645 (atcc 25416, type strain) by methanolysis followed by hplc and saponification. it was identified by ms, methylation analysis and 1h and 13c nmr spectroscopy as disodium (4-amino-4-deoxy-beta-l-arabinopyranosyl)-(1-->8)-(d-glycero- alpha-d-talo-oct-2-ulopyranosylonate)-(2-->4)-(methyl 3-deoxy-d-manno-oct-2-ulopyranosid)onate. in addition to the trisaccharide derivative, meth ... | 1998 | 9861699 |
| psa causes oncogenic suppression of agrobacterium by inhibiting vire2 protein export. | when coresident with the ti (tumor-inducing) plasmid, the 21-kda product of the osa gene of the plasmid psa can suppress crown gall tumorigenesis incited by agrobacterium tumefaciens. neither t-dna processing nor vir (virulence) gene induction is affected by the presence of osa in the bacterium. we used arabidopsis thaliana root segments and tobacco leaf discs to demonstrate that osa inhibits a. tumefaciens from transforming these plants to the stable phenotypes of tumorigenesis, kanamycin resis ... | 1999 | 9864329 |
| cell integrity and morphogenesis in a budding yeast septin mutant. | the non-sporulating diploid strain v327 of saccharomyces cerevisiae was previously isolated in a search for thermosensitive autolytic mutants. this strain is very efficient at releasing intracellular proteins into the medium when incubated at high temperatures. the expression of this lytic phenotype depends on a morphogenetic defect, consisting of the appearance of elongated chains of cells. transmission electron microscopy revealed a mislocalization of septa at semi-permissive temperatures and ... | 1998 | 9884239 |
| isotype-specific immune responses in murine experimental anisakiasis. | a murine experimental model of anisakiasis has been developed in balb/c and c57bl/10 mice orally inoculated with an anisakis simplex living third stage larva (l3) in order to investigate isotype-specific immune responses against excretory-secretory (es) products and crude extracts (ce) from l3. specific antibody production showed similar patterns against both es and ce antigens with higher levels against the latter. the dynamics of the production showed the earliest responses in balb/c, in which ... | 1998 | 9916551 |
| transduction of multiple drug resistance of salmonella enterica serovar typhimurium dt104. | epidemic strain salmonella typhimurium dt104 is characterized by various multiresistance patterns. at least some of the resistance genes are organized as integrons. resistance genes of dt104 isolates can be efficiently transduced by p22-like phage es18 and by phage pdt17 which is released by all dt104 isolates so far analyzed. cotransduction tests demonstrate that the resistance genes, although not organized in a unique integron, are tightly clustered on the salmonella chromosome. the spread of ... | 1999 | 9919675 |
| alterations in adhesion, transport, and membrane characteristics in an adhesion-deficient pseudomonad. | a stable adhesion-deficient mutant of burkholderia cepacia g4, a soil pseudomonad, was selected in a sand column assay. this mutant (env435) was compared to the wild-type strain by examining the adhesion of the organisms to silica sand and their transport through two aquifer sediments that differed in their sand, silt, and clay contents. we compared the longitudinal transport of the wild type and the adhesion mutant to the transport of a conservative chloride tracer in 25-cm-long glass columns. ... | 1999 | 9925613 |
| the influence of alveolar structures on the torsional strain field in a gorilla corporeal cross-section. | anthropologists have often used mandibular torsional properties to make inferences about primate dietary adaptations. most of the methods employed are based on assumptions related to periodontal and alveolar properties. this study uses the finite element method to evaluate some of these assumptions with a cross-section through the third molar of a gorilla. results indicate that the properties of alveolar bone play an important role in determining the strain field. in comparison, the exact stiffn ... | 1998 | 9929172 |
| identification and characterization of a two-component sensor-kinase and response-regulator system (dcus-dcur) controlling gene expression in response to c4-dicarboxylates in escherichia coli. | the dcub gene of escherichia coli encodes an anaerobic c4-dicarboxylate transporter that is induced anaerobically by fnr, activated by the cyclic amp receptor protein, and repressed in the presence of nitrate by narl. in addition, dcub expression is strongly induced by c4-dicarboxylates, suggesting the presence of a novel c4-dicarboxylate-responsive regulator in e. coli. this paper describes the isolation of a tn10 mutant in which the 160-fold induction of dcub expression by c4-dicarboxylates is ... | 1999 | 9973351 |
| lectin-like protein fractions in lactic acid bacteria isolated from chickens. | agglutination of fifty bacterial strains isolated from gastric-intestinal tract of chickens with yeasts treated with glutaraldehyde and glycine was assayed to study possible adhesion mechanisms to epithelia. it was found that lactobacillus fermentum, lactobacillus fermentum subsp. cellobiosus and lactobacillus animalis agglutinated yeasts massively and this agglutination was inhibited in each strain by different representative sugars: agglutination was inhibited in three selected strains with 0. ... | 1999 | 9989654 |
| molecular relationships of helicobacter pylori strains in a family with gastroduodenal disease. | few studies have examined the genetic relationships of helicobacter pylori strains affecting family members. our aim was to do so. | 1999 | 10022630 |
| disruption of the toxoplasma gondii bradyzoite-specific gene bag1 decreases in vivo cyst formation. | the bradyzoite stage of the apicomplexan protozoan parasite toxoplasma gondii plays a critical role in maintenance of latent infection. we reported previously the cloning of a bradyzoite-specific gene bag1/hsp30 (previously referred to as bag5) encoding a cytoplasmic antigen related to small heat shock proteins. we have now disrupted bag1 in the t. gondii plk strain by homologous recombination. h7, a cloned null mutant, and y8, a control positive for both cat and bag1, were chosen for further ch ... | 1999 | 10027984 |
| different effects of fibronectin on the phagocytosis of staphylococcus aureus and coagulase-negative staphylococci by murine peritoneal macrophages. | fibronectin is known to be an important factor in colonization by staphylococcus aureus of host tissues as well as other extracellular matrix proteins such as collagen and laminin. we investigated the effect of fibronectin on the phagocytosis of the s. aureus cowan i strain by macrophages and of coagulase-negative staphylococci (cns) strains for comparison. fibronectin-reduced serum in place of normal serum lowered the phagocytic activity of the macrophages on the cowan i strain. purified fibron ... | 1998 | 10037220 |
| modulation of estrogen action in the rat pituitary and mammary glands by dietary energy consumption. | we are investigating the mechanisms through which estrogens induce development of prolactin (prl)-producing pituitary tumors and mammary carcinomas in rats and how these mechanisms are affected by dietary energy consumption. the hypothesis under examination is that dietary energy restriction inhibits tumorigenesis in estrogen-responsive tissues by altering cellular responsiveness to estrogenic hormones. in the fischer 344 (f344) rat strain, a 40% restriction of energy consumption virtually aboli ... | 1999 | 10064338 |
| dna banding pattern polymorphism in vancomycin-resistant enterococcus faecium and criteria for defining strains. | the degree of dna banding pattern polymorphism exhibited by vancomycin-resistant enterococcus faecium (vrem) strains isolated on a renal unit over an 11-month period was investigated. thirty vrem strains from different patients were analyzed by pulsed-field gel electrophoresis (pfge; with extended run and optimal pulse times), ribotyping, plasmid profile analysis, biotyping, pyrolysis mass spectrometry, and antibiogram analysis. pfge resolved 17 banding patterns which formed four distinct cluste ... | 1999 | 10074530 |
| induction of tolerance to an "untolerizable" strain by double-strain intrathymic inoculation in experimental rat cardiac transplantation. | | 1999 | 10083364 |
| beauveriolides, specific inhibitors of lipid droplet formation in mouse macrophages, produced by beauveria sp. fo-6979. | beauveria sp. fo-6979, a soil isolate, was found to produce inhibitors of lipid droplet formation in mouse peritoneal macrophages. a new compound beauveriolide iii was isolated along with a known compound beauveriolide i from the fermentation broth of the producing strain by solvent extraction, ods column chromatography, silica gel column chromatography and preparative hplc. beauveriolides i and iii caused a reduction in the number and size of cytosolic lipid droplets in macrophages at 10 microm ... | 1999 | 10092189 |
| the cyclic structure of microcin j25, a 21-residue peptide antibiotic from escherichia coli. | microcin j25 (mccj25) is the single representative of the immunity group j of the microcin group of peptide antibiotics produced by enterobacteriaceae. it induces bacterial filamentation in susceptible cells in a non-sos-dependent pathway [r. a. salomon and r. farias (1992) j. bacteriol. 174, 7428-7435]. mccj25 was purified to homogeneity from the growth medium of a microcin-overproducing escherichia coli strain by reverse-phase hplc. based on amino acid composition and absolute configuration de ... | 1999 | 10092860 |