| inhibition of intercellular communication between liver cells by the liver tumor promoter 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane. | a dose dependent inhibition of intercellular communication (metabolic cooperation) between primary cultures of rat liver hepatocytes and an established adult rat liver epithelial cell 6-thioguanine resistant strain by the liver tumor promoter 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (ddt) is demonstrated. this in vitro assay is proposed to evaluate the tumor promoting activity of oncogenic agents shown to be non-genotoxic in the liver culture systems. | 1981 | 7296527 |
| biosynthesis of nanaomycin. ii. purification and properties of nanaomycin d reductase involved in the formation of nanaomycin a from nanaomycin d1. | nanaomycin d reductase, catalyzing the conversion of nanaomycin d to nanaomycin a, which is the first step in the biosynthetic sequence (d leads to a leads to e leads to b) in streptomyces rosa var. notoensis, was purified from the crude extract of the strain by ammonium sulfate fractionation and column chromatography on deae-cellulose, sephadex g-100 and hydroxyapatite to give an electrophoretically homogeneous preparation. the enzyme was found to be a flavoprotein which contains fad as a prost ... | 1981 | 7298593 |
| characterization of abnormalities in the visual system of the mutant mouse pearl. | mice of the mutant strain pearl (pe/pe) differ from the wild strain by a single gene mutation, which leads to a lightening of the coat color. we tested this strain to see if this mutant gene also expressed itself in one or more visual abnormalities. pearl mice were found to lack totally the optokinetic nystagmus reflex that was present in every normal mouse that we examined. this lack of optokinetic nystagmus was not due to oculomotor defects, since postrotatory nystagmus was normal. as describe ... | 1981 | 7310489 |
| rabies virus inactivation by binary ethylenimine: new method for inactivated vaccine production. | the inactivation dynamics of rabies virus (pv strain) by binary ethylenimine, and the immunogenic properites and the stability of the vaccines prepared using this agent, were studied. binary ethylenimine at a final concentration of 0.01 m was prepared wtih 2-bromoethylamine hydrobromide in alkaline solutions, either separately from or in suspensions of rabies virus propagated in bhk cells. the infectivity of virus suspensions containing more than 108 plaque-forming units per 0.1 ml was inactivat ... | 1980 | 7358836 |
| spontaneous variability of streptomyces glomeratus, a producer of the amthracycline antibiotics beromycins. | spontaneous variants of the beromycin-producing strain streptomyces glomeratus 3980 were divided into five groups (a-e) according to increasing antibiotic activity. the most active variants (group e) differed from the other types and the wild strain by a suppressed ability to produce aerial mycelium and melanoid piogment and by an increased production of propionic acid. strains with a 12-fold higher antibiotic production capacity (with respect to strain 3980) were obtained by selection of superi ... | 1980 | 7399371 |
| long-term torsional creep in compact bone. | bovine bone specimens loaded in torsion for periods of time exceeding one month exhibit pronounced time-dependent effects. the final strain exceeded the initial strain by a factor of more than four in some cases. creep failure was observed in two cases. the effects are not attributable to prolonged immersion in ringer's solution. | 1980 | 7412242 |
| experimental development of monensin resistance in eimeria meleagrimitis. | the discovery of monensin-resistant field isolates of eimeria meleagrimitis prompted an investigation of the ability of this parasite to develop monensin resistance in a laboratory selection experiment. a strain derived from a monensin-sensitive parent strain was intentionally selected for monensin resistance by propagation in monensin medicated turkeys in isolation, while the monensin-sensitive parent strain from which it was derived was cryogenically maintained as a genetic control. comparison ... | 1980 | 7413579 |
| biosynthesis of leupeptin. iii. isolation and properties of an enzyme synthesizing acetyl-l-leucine. | an enzyme which catalyzes acetylation of l-leucine with acetyl-coa was partially purified from a cell extract of streptomyces roseus ma839-a1, a leupeptin producer. the molecular weight of this enzyme is about 27,000 daltons. the enzyme has fairly broad specificity for acyl donors (i) and acceptors (ii): as for i, propionyl-coa was 1/10 as active as acetyl-coa with l-leucine as the acceptor; as for ii, l-leucyl-d-leucine, l-leucyl-l-leucine, l-arginine, l-leucyl-l-leucyl-l-leucine, l-phenylalani ... | 1980 | 7429989 |
| tumorigenic cell culture lines from a spontaneous vm/dk murine astrocytoma (sma). | one of the few spontaneous gliomas in inbred animals, the vm/dk spontaneous murine astrocytoma (sma), has seen limited use. previously restricted to an in vivo system, the sma was only transplantable intracerebrally (ic) using nonquantifiable suspensions of normal brain and tumor tissue. prior attempts at establishing permanent tumorigenic sma cell lines have not succeeded; tumorigenicity was lost during serial in vitro passage. we have established three different cell culture lines from a seria ... | 1980 | 7435141 |
| production of an attenuated influenza a (h3n2) strain "ko-1" by recombination with a/okuda/57 (h2n2) followed by selection of inhibitor-resistant virus. | a live attenuated influenza a (h3n2) strain "ko-1" was developed by recombination of wild influenza a/kumamoto/22/76 (h3n2) with attenuated a/okuda/57 (h2n2) followed by passage in developing chick eggs in the presence of horse serum inhibitor. the virus strain "ko-1" obtained is inhibitor-resistant, and has hemagglutinating (ha) and neuraminidase (na) antigenicity derived from the wild parent virus. rna analysis revealed that one rna segment (corresponding to m protein) was derived from the a/o ... | 1980 | 7437002 |
| in vitro differentiation of satellite cells isolated from normal and dystrophic mammalian muscles. a comparison with embryonic myogenic cells. | satellite cells were isolated from skeletal muscles of adult normal and dystrophic mice (c57/6j/dy strain) by sequential digestion of tissue fragments with collagenase, hyaluronidase and trypsin. these cells exhibit in culture similar behaviour to that of embryonic myoblasts, undergoing an initial duplicative period lasting about 2--3 days, followed by a shorter phase (1--2 days) of rapid cell fusion. during the duplicative phase most of the satellite cells appear round-shaped, whereas embryonic ... | 1980 | 7438216 |
| effect of immunization of guinea pigs on in vitro phagocytosis by polymorphonuclear leukocytes (pmnl). | it was found that the in vitro phagocytosis of 32p pulsed staphylococcus aureus 209 p strain by pmnl of immunized animals is inhibited in the presence of the antigens. the extent of inhibition depends on the antigen used. the release of acid phosphatase from phagocytizing pmnls decreased in the presence of antigens. | 1980 | 7447634 |
| comparison of mycoplasma synoviae hemagglutinating antigens by the hemagglutination-inhibition test. | mycoplasma synoviae (ms) strains were isolated from the trachea of hens from ms-positive broiler breeder flocks having progeny condemnations due to airsacculitis. hemagglutinating (ha) antigens were made from several strains. the ha antigen made from the 95th medium passage of ms fmt strain was compared with that of the standard ms wvu 1853 strain by the hemagglutination-inhibition (hi) test. sixty-six sera from 10 ms-positive flocks, 4 mycoplasma gallisepticum (mg)-positive sera, and 7 normal s ... | 1980 | 7447835 |
| x-linked dominant inheritance of partial phosphorylase kinase deficiency in mice. | a new mouse strain, the v strain, with a partial deficiency of phosphorylase kinase has been established. the deficiency is caused by an x-linked dominant gene (phkc). muscle extracts of homozygous and heterozygous females and hemizygous males have about 25% of the activity found in extracts of normal (c3h/hehan) mice. this dominant phosphorylase kinase deficiency of the new v strain is different from that of the i-strain mice with the x-linked recessive deficiency of skeletal muscle phosphoryla ... | 1980 | 7447922 |
| turkey breeder hen performance by strain during consecutive lay periods. | the results of this study provide information about reproductive performance among commercially available strains of large white turkey breeder hens, nicholas (n), british united (b), and hybrid (h). the hens were managed identically through two consecutive lay periods, summer-fall (1st-yr) followed by winter-spring (recycled). effects of the intensity (351 vs 24 lx) of supplemental light were evaluated during the 1st-yr lay period. data were collected for onset of oviposition, egg production, b ... | 1995 | 7479504 |
| [comparative study of the nucleotide sequence of the gene for the p/c wild strain or l-16 vaccine strain of measles virus]. | nucleotide sequences of p/c gene of measles virus il wild strain and l-16 vaccine strain were compared with the previously reported nucleotide sequence of edmonston vaccine strain p/c gene. the primary structure of il strain p/c gene was characterized by two substitutes in 395 (u-c) and 722 (g-a) positions in comparison with the primary structure of a similar edmonston strain. nucleotide sequence of l-16 vaccine strain p/c gene differed from the similar sequence of edmonston vaccine strain by 3 ... | 1995 | 7483563 |
| [induction of messenger rna of cytokines by herpes simplex virus infection in mice]. | the induction of the cytokine mrna after infection with herpes simplex virus (hsv) was studied using rt-pcr method capable of detecting low levels of mrna. total rna was prepared from spleen lymphocytes 3 h after infection with hsv-1 (+gc virulent variant and -gcr attenuated variant of miyama strain) by acid guanidinium thiocyanate-phenol-chloroform (agpc) method. cdna was synthesized by m-mlv reverse transcriptase, and amplified using the specific oligonucleotide primers for il-1, il-2, il-3, i ... | 1993 | 7517338 |
| cytokine sensitivity and methylation of lysine in rickettsia prowazekii evir and interferon-resistant r. prowazekii strains. | modified rickettsia prowazekii strains have been derived from the avirulent madrid e strain by passage in the lungs of white mice (strain evir) or by selection for resistance to gamma interferon (ifn-gamma) (strains 427-19 and 87-17) or alpha/beta interferon (ifn-alpha/beta) (strains 83-2p, 60p, 103-2p, and 110-1p). compared with the madrid e strain, strain evir has increased virulence (n. m. balayeva and v. n. nikolskaya, j. hyg. epidemiol. microbiol. immunol. 17:11-20, 1973) and a different ly ... | 1994 | 7518807 |
| antiatherosclerotic effects of the angiotensin-converting enzyme inhibitors captopril and fosinopril in hypercholesterolemic minipigs. | we evaluated the two angiotensin-converting enzyme (ace) inhibitors captopril and fosinopril with regard to possible antiatherosclerotic effects in minipigs. experimental hypercholesterolemia and atherosclerosis was produced in 33 minipigs of the göttingen strain by an egg yolk/cholesterol-enriched diet for 1 year. one group (n = 11) was fed the atherogenic diet alone and served as a control. a second group (n = 11) received captopril (80 mg/kg/day) added to the atherogenic diet, and a third gro ... | 1994 | 7528851 |
| analysis of reca mutants with altered sos functions. | the escherichia coli reca protein has at least three roles in sos mutagenesis: (1) derepression of the sos regulon by mediating lexa cleavage; (2) activation of the umud mutagenesis protein by mediating its cleavage; and (3) targeting the umu-like mutagenesis proteins to dna. using a combined approach of molecular and physiological assays, it is now possible to determine which of the three defined steps has been altered in any reca mutant. in this study, we have focused on the ability of six par ... | 1995 | 7528894 |
| occurrence and antigenic heterogeneity of l-2,4-diaminobutyrate decarboxylase in acinetobacter species. | we have previously reported that a novel enzyme, l-2,4-diaminobutyrate decarboxylase (daba dc), which is responsible for the formation of 1,3-diaminopropane, occurs in two acinetobacter species. the present study extends this observation to additional acinetobacter species and strains (6 reference strains and 30 clinical isolates). furthermore, the daba dc protein was detected in every strain by western blot analysis with the antiserum against the enzyme purified from a. baumannii atcc 19606. ho ... | 1995 | 7550102 |
| systemic infections in three infants due to a lactose-fermenting strain of salmonella virchow. | three previously healthy children developed gastroenteritis which led within a few days to systemic infections, two cases of bacteremia and one of meningitis. a lactose-fermenting salmonella virchow strain was isolated from cerebrospinal fluid and blood cultures. in one case, this strain was also isolated from stool cultures. all the children had been fed the same milk formula. there was no other relationship between them. the batch of dried-milk formula was confirmed as the source of the infect ... | 1995 | 7556238 |
| regulation of expression of the valine (branched-chain amino acid) dehydrogenase-encoding gene from streptomyces coelicolor. | expression of the streptomyces coelicolor (sc) valine (branched-chain amino acid) dehydrogenase-encoding gene (vdh) is regulated by valine, glucose and nh+4 at the transcriptional level. the results of assays for the level of accumulated vdh mrna in the sc j802 strain by primer extension experiments and for the level of catechol dioxygenase (xyle) activity in sc j802 (vdh::xyle) transformants show that transcription of the vdh gene is induced approx. 2.5-fold by valine, as compared to asparagine ... | 1995 | 7557420 |
| viral hazards to and from health care workers. | much attention has been directed towards nosocomial transmission of viruses as a result of clear evidence of patient-to-staff and staff-to-patient transmission of the blood-borne viruses hiv and hepatitis b virus. although the relatively long incubation periods of these viruses, together with the frequency of asymptomatic infections, renders problems for surveillance it has been possible to study modes of transmission and levels of risk over a number of years. information on trends of incidence ... | 1995 | 7560944 |
| a university outbreak of escherichia coli o157:h7 infections associated with roast beef and an unusually benign clinical course. | an outbreak of escherichia coli o157:h7 infections occurred after a graduation banquet at a university in wisconsin. sixty-one (32%) of 193 banquet attendees developed a gastrointestinal illness; 2 were hospitalized, none developed hemolytic-uremic syndrome or thrombotic thrombocytopenic purpura, and none died. the spectrum of illness was unusually mild, with 61% of ill persons reporting nonbloody diarrhea. a strain of e. coli o157:h7, indistinguishable from the outbreak strain by toxin type, pl ... | 1995 | 7561194 |
| peru-15, an improved live attenuated oral vaccine candidate for vibrio cholerae o1. | cholera vaccine candidate peru-15 was derived from a vibrio cholerae o1 el tor inaba strain by deleting the cholera toxin genetic element, introducing the gene encoding cholera toxin b subunit into reca, and screening for nonmotility. in a controlled study, peru-15 (2 x 10(8) cfu) was administered to 11 volunteers. no vaccinee developed diarrhea, and 10 of 11 had > 4-fold rises in vibriocidal antibody titers. one month later, 5 vaccinees and 5 control volunteers were challenged with wild type v. ... | 1995 | 7561195 |
| virulence of cryptococcus neoformans serotypes a, b, c and d for four mouse strains. | the relative virulence of cryptococcus neoformans serotypes a, b, c and d in four mouse strains was assessed by measuring their migration from the foot-pad of the animals to the spleen, lungs and brain in 6-week-old dba/2, balb/c, a/j and a hybrid mouse strain by re-isolating yeasts from the internal organs. comparable doses of each c. neoformans serotype were inoculated into the foot-pads of the mice. c. neoformans var neoformans strains a68, d52, a-(in) and d-(in) were more virulent than c. ne ... | 1995 | 7562991 |
| prevalence and genetic location of non-transferable trimethoprim resistant dihydrofolate reductase genes in south african commensal faecal isolates. | in a recent survey of trimethoprim resistance, 357 gram-negative aerobic organisms were isolated from healthy volunteers from rural and urban populations in south africa. trimethoprim resistance did not transfer to an escherichia coli j62-2 recipient strain by conjugation in a liquid mating in 161 (45.1%) of the isolates. these isolates which did not transfer their resistance were probed with intragenic oligonucleotide probes for the types ia, ib, iiia, v, vi, vii, viii, ix, x and xii dihydrofol ... | 1995 | 7589265 |
| amidepsines, inhibitors of diacylglycerol acyltransferase produced by humicola sp. fo-2942. i. production, isolation and biological properties. | humicola sp. fo-2942, a soil isolate, was found to produce a series of new inhibitors of diacylglycerol acyltransferase (dgat). three active compounds, designated amidepsines a, b and c, were isolated from the fermentation broth of the producing strain by solvent extraction, silica gel column chromatography, ods column chromatography and hplc. amidepsines inhibit dgat activity with ic50 values of 10.2 approximately 51.6 microm in an enzyme assay system using rat liver microsomes. amidepsines als ... | 1995 | 7592058 |
| study of neutralizing monoclonal antibodies to bovine herpes virus type-1 (cooper strain) by immunoperoxidase and immunoelectron microscopy. | three neutralizing monoclonal antibodies (mabs) that are specific against bovine herpes virus type-1 (bhv-1) were studied as to their viral specificity by immunoperoxidase and immunoelectron microscopy. microscopic examination of gbk bhv-1 infected cells revealed peroxidase activity represented by red-brown granular deposits in the nucleus and cytoplasm. no immunoperoxidase activity was observed in negative controls. for the ultrastructural observations, two approaches were used. firstly we test ... | 1995 | 7599599 |
| transketolase a of escherichia coli k12. purification and properties of the enzyme from recombinant strains. | transketolase a was purified to apparent homogeneity from recombinant escherichia coli k12 cells carrying the homologous cloned tkta gene on a puc19-derived plasmid. these recombinant cells exhibited a transketolase activity in crude extracts of up to 9.7 u/mg compared to < or = 0.1 u/mg in wild-type cells. transketolase a was purified from crude extracts of a recombinant strain by successive ammonium sulfate precipitations and two anion-exchange chromatography steps (q-sepharose ff, fractogel e ... | 1995 | 7607225 |
| incidence of prelay squatting behavior is not related to subsequent egg laying in turkey breeder hens. | sexual receptivity of turkey hens as indicated by squatting (sexual crouch) was evaluated in three strains of breeder hens, nicholas (n), hybrid (h), and british united (b). the incidence of squatting was compared among strains through 84 d of photostimulation and related to egg production characteristics. significant strain, time, and strain by time interaction effects occurred for the incidence of squatting. in all three strains, squatting started within the 1st wk of photostimulation, rapidly ... | 1995 | 7644415 |
| establishment of conditions for the detection of bovine herpesvirus-1 by polymerase chain reaction using primers in the thymidine kinase region. | polymerase chain reaction (pcr) for detection of bovine herpesvirus-1 (bhv-1) was developed and optimized using 22 bp sense and 20 bp antisense primers in the thymidine kinase (tk) coding region. the amplification product is 183 bp long. the pcr optimization was done using bhv-1 tissue culture supernate (bhv-1tcs), concentrated bhv-1 tissue culture supernate (cbhv-1tcs) and sucrose gradient purified bhv-1 (pbhv-1). the sensitivity of four methods of sample preparation which are standard dna extr ... | 1995 | 7648533 |
| comparison of four dna-based methods for strain delineation of candida lusitaniae. | four methods for the accurate delineation of epidemiologically related and unrelated strains of candida lusitaniae were compared. three pulsed-field electrophoretic methods, including two contour-clamped homogeneous field gel electrophoresis methods (ekp-1 and ekp-2) yielding electrophoretic karyotype patterns of intact chromosomal dna and a method in which the chromosomal dna was macrodigested with the endonuclease sfii prior to pulsed-field electrophoresis (mdp), and a random amplified polymor ... | 1995 | 7650168 |
| [changes in biogenesis and secretion of periplasmic alkaline phosphatase, coded by the phoa gene included in the escherichia coli dh1 plasmid]. | augmented synthesis of periplasmic alkaline phosphatase from e. coli dh1 coded by the phoa gene within the composition of plasmid phi-7 results in alterations in the enzyme biogenesis, such as accumulation of intermediate enzyme forms corresponding to various stages of its posttranslational modification, and alternative localization. the cell cytoplasm was found to contain a large proportion of alkaline phosphatase precursors in the form of insoluble aggregates. the mature enzyme was detected in ... | 1995 | 7662795 |
| isolation and sequencing of the replication region of mycobacterium avium plasmid plr7. | the mycobacterium avium plasmid plr7 is representative of a group of small plasmids that are common in isolates from aids patients with disseminated m. avium infections. determination of the functions of these and other plasmids has been hampered by the lack of methods for genetic manipulation of m. avium. in this study, the region of plr7 capable of replication was identified and sequenced. fragments of plr7 were cloned into a puc18 derivative carrying a kanamycin resistance marker and introduc ... | 1995 | 7665458 |
| cloning, sequencing, and characterization of the gene encoding the smallest subunit of the three-component membrane-bound alcohol dehydrogenase from acetobacter pasteurianus. | the membrane-bound alcohol dehydrogenase (adh) of acetobacter pasteurianus nci1452 consists of three different subunits, a 78-kda dehydrogenase subunit, a 48-kda cytochrome c subunit, and a 20-kda subunit of unknown function. for elucidation of the function of the smallest subunit, this gene was cloned from this strain by the oligonucleotide-probing method, and its nucleotide sequence was determined. comparison of the deduced amino acid sequence and the nh2-terminal sequence determined for the p ... | 1995 | 7665483 |
| stability of genomic dna fragment patterns in methicillin resistant staphylococcus aureus (mrsa) during the course of intra- and interhospital spread. | the analysis of genomic dna fragment patterns has revealed as a powerful tool for strain discrimination in staphylococcus aureus; for use as an epidemiological marker, stability during the course of an outbreak is an essential prerequisite. genomic dna fragment patterns (smai restriction, pulsed-field electrophoresis) of four different epidemic mrsa strains were compared along with intra- and interhospital and country-wide spread over more than 12 months in germany. strain i was isolated from in ... | 1994 | 7672057 |
| yeast seryl-trna synthetase expressed in escherichia coli recognizes bacterial serine-specific trnas in vivo. | the saccharomyces cerevisiae sers gene which encodes seryl-trna synthetase (serrs) was expressed in escherichia coli from the promoter and the ribosome binding sequences contained in its own 5'-flanking region. the low level of yeast serrs in the prokaryotic host was sufficient to permit in vivo complementation of two temperature-sensitive e. coli sers mutants at the nonpermissive temperature. thus, yeast serrs can aminoacylate e. coli trna(ser) species in vivo. yeast serrs, isolated from an ove ... | 1993 | 7686490 |
| functional properties of pro region of escherichia coli heat-stable enterotoxin. | escherichia coli heat-stable enterotoxin ip (stp) is synthesized as the 72-amino-acid residue precursor consisting of three regions: pre region (amino acid residues 1 to 19), pro region (amino acid residues 20 to 54), and mature st (mst) region (amino acid residues 55 to 72). we examined the role of the pro sequence of stp in enterotoxigenicity of a strain by deleting the gene fragment encoding amino acids 22 to 57. this deletion caused a remarkable reduction of its enterotoxic activity of cultu ... | 1993 | 7686611 |
| malignant transformation of a human fibroblast cell strain by transfection of a v-fes oncogene but not by transfection of a gag-human c-fes construct. | to determine whether the human c-fes gene, a homologue of the feline v-fes oncogene, can play a role in the malignant transformation of human fibroblasts, we transfected a near-diploid, infinite life span, growth factor-independent, human fibroblast cell strain, msu-1.2, with plasmids carrying a fes gene along with a selectable marker. the fes gene was either the v-fes oncogene from the gardner-arnstein strain of feline sarcoma virus or a chimeric construct in which 835 base pairs representing e ... | 1994 | 7696187 |
| early kinetics of toxoplasma gondii infection in mice infected orally with cysts of an avirulent strain. | we determined the early kinetics of toxoplasma gondii infection in swiss webster mice inoculated with the avirulent c strain by counting parasites in the blood, spleen, peyer's patches, liver, lungs, and brain. animals were orally inoculated with cysts on day zero (d0), and parasites were counted using a tissue culture method at 12, 24, and 36 hr and 2, 3, 7, 10, 14, 21, 30, 50, and 72 days postinfection. the spleen and peyer's patches were the first organs found parasitized, on d2 and d3, respe ... | 1995 | 7707221 |
| comparison of bovine coronavirus isolates associated with neonatal calf diarrhoea and winter dysentery in adult dairy cattle in québec. | cytopathic coronaviruses were isolated in hrt-18 cells from bloody faecal samples collected from cows in québec dairy herds having experienced typical outbreaks of winter dysentery (wd). the formation of polykaryons in the infected cell cultures was found to be dependent on the presence of trypsin in the medium. the wd isolates differed from the prototype mebus strain of bovine enteropathogenic coronavirus (bcv.meb) in respect to haemagglutination inhibition (hi), haemagglutination patterns at 4 ... | 1995 | 7730812 |
| construction of a food-grade host/vector system for lactococcus lactis based on the lactose operon. | a plasmid-based food-grade vector system was developed for lactococcus lactis by exploiting the genes for lactose metabolism. l. lactis mg5267 is a plasmid-free strain containing the entire lactose operon as a chromosomal insertion. the lacf gene was deleted from this strain by a double cross-over homologous recombination event. the lacf-deficient strain produced a lac- phenotype on indicator agar. a cloned copy of the lacf gene expressed on a plasmid was capable of complementing the lacf-defici ... | 1995 | 7737470 |
| strain differentiation of neisseria meningitidis by small-fragment restriction endonuclease analysis (sf-rea). | following an outbreak involving 3 cases of serogroup b meningococcal disease in a rural part of western norway, 2 clinical and 99 carrier isolates of neisseria meningitidis were examined by small-fragment restriction endonuclease analysis (sf-rea) using ecori, to determine its potential for strain differentiation. sf-rea characterized all isolates and provided reproducible results with acceptable inter-clonal differentiation. the results of sf-rea correlated well with those of serological typing ... | 1995 | 7748539 |
| phenotypic correction of hypercholesterolemia in apoe-deficient mice by adenovirus-mediated in vivo gene transfer. | to investigate the potential use of apoe in gene therapy of hyperlipidemias, an adenoviral vector was constructed that contained the human apoe3 cdna under the control of the rsv promoter (av1re). transduction of hepg2 cells resulted in the overexpression of human apoe secreted into the culture medium. intravenous injection of 5 x 10(11) av1re vector particles into apoe-deficient mice resulted in expression of human apoe3 in mouse plasma at levels of 1.2 +/- 0.4 micrograms/l (mean +/- sem, n = 5 ... | 1995 | 7749859 |
| the rpoe gene of escherichia coli, which encodes sigma e, is essential for bacterial growth at high temperature. | in vitro transcription analysis has shown that only rna polymerase containing an alternative sigma subunit, sigma e, activates transcription from one of the rpoh promoters and the htra promoter. the location of the rpoe gene encoding sigma e on the escherichia coli chromosome has recently been established, but no rpoe mutant has yet become available for phenotypic testing. we cloned the rpoe gene from the lambda-ordered clones of the e. coli genome and confirmed that the reconstituted rna polyme ... | 1995 | 7751307 |
| regulation of citrate-dependent iron transport of escherichia coli: fecr is required for transcription activation by feci. | citrate-dependent fe3+ transport into escherichia coli k-12 is induced by iron and citrate. the inducer is probably ferric dicitrate which does not have to be taken up into the cytoplasm to induce transcription of the fec transport genes. two regulatory genes, feci and fecr, located upstream of the fecabcde transport genes, are required for induction. we report that in vivo the chromosomally encoded feci protein activates transcription of the feca and fecb transport genes in response to ferric c ... | 1995 | 7752886 |
| evidence that surface fibrils expressed by haemophilus influenzae type b promote attachment to human epithelial cells. | haemophilus influenzae type b is a gram-negative bacillus that initiates infection by colonizing the upper respiratory tract. previous studies have established that h. influenzae haemagglutinating pili possess adhesive properties and influence the process of colonization. additional studies suggest the presence of a second h. influenzae adhesin distinct from haemagglutinating pili. in the present study, we examined a non-piliated h. influenzae type b strain by transmission electron microscopy an ... | 1995 | 7752898 |
| [immune bacteriolysis reaction in the assessment of immunological effectiveness of serogroup b meningococcal vaccine]. | the immunological efficacy of serogroup b meningococcal protein-polysaccharide vaccine was studied in newly developed immune bacteriolysis test. serogroup b meningococcus strains had different sensitivities to the bactericidal effects of immune sera. a single injection of the vaccine caused an induction of bactericidal antibodies to meningococcus vaccinal strain. three weeks after vaccination 77.7% of the vaccines developed an appreciable increase of the titers of bactericidal antibodies to the ... | 1995 | 7757362 |
| enhanced productivity through gratuitous induction in recombinant yeast fermentations. | the advantages of gratuitous induction for gal-regulated cloned gene (lacz) product synthesis were evaluated for the yeast saccharomyces cerevisiae. the growth, yield, and productivity of a gratuitous (gal1) strain were compared with those of an otherwise isogenic, nongratuitous (gal1) strain. batch studies clearly demonstrated the improvements possible in product synthesis when the inducer is not metabolized by the yeast cells; both beta-galactosidase specific and volumetric activities were sup ... | 1994 | 7764524 |
| role of bicarbonate/co2 in the inhibition of escherichia coli growth by cyanate. | cyanase is an inducible enzyme in escherichia coli that catalyzes the reaction of cyanate with bicarbonate to give two co2 molecules. the gene for cyanase is part of the cyn operon, which includes cynt and cyns, encoding carbonic anhydrase and cyanase, respectively. carbonic anhydrase functions to prevent depletion of cellular bicarbonate during cyanate decomposition (the product co2 can diffuse out of the cell faster than noncatalyzed hydration back to bicarbonate). addition of cyanate to the c ... | 1995 | 7768821 |
| crystalline surface protein of peptostreptococcus anaerobius. | the surface ultrastructure of three anaerobic gram-positive cocci frequently encountered in oral infections, peptostreptococcus micros, p. magnus and p. anaerobius, was studied. the type strains of p. micros (dsm 20468) and p. anaerobius (atcc 27337), several clinical isolates of both species and the type strain of p. magnus (dsm 20470) were included. thin-sectioned cells studied by electron microscopy revealed a homogeneous layer outside the peptidoglycan layer in p. anaerobius. in p. micros an ... | 1995 | 7773401 |
| directed genomic integration in actinobacillus actinomycetemcomitans: generation of defined leukotoxin-negative mutants. | to develop targeted gene integration in the periodontal pathogen actinobacillus actinomycetemcomitans, a cole1-based, spectinomycin-resistant plasmid containing a segment of the leukotoxin gene was electroporated into strain jp2. in all of the stable spectinomycin-resistant transformants that arose, the plasmid had recombined into the genomic leukotoxin locus since cole1-based vectors cannot replicate extrachromosomally in a. actinomycetemcomitans. directed genomic integration was then used to c ... | 1995 | 7790100 |
| [blood volume determination in female spf rats of wistar--imamichi strain by an extrapolation method with radioiodinated rat serum albumin]. | the total blood volume of spf female rats of wistar-imamichi strain, a strain that shows a 4-day estrous cycle at very high rates and is widely used in the study of reproductive biology in japan, was estimated from blood radioactivity after the intravenous administration of 125i-rat serum albumin. the radioactivity of blood showed a rapid decrease until 10 min after injection and a slow decay thereafter. radioactivity at time zero was estimated by extrapolation from this slow decay curve, and th ... | 1994 | 7805797 |
| an essential virulence protein of agrobacterium tumefaciens, virb4, requires an intact mononucleotide binding domain to function in transfer of t-dna. | the 11 gene products of the agrobacterium tumefaciens virb operon, together with the vird4 protein, are proposed to form a membrane complex which mediates the transfer of t-dna to plant cells. this study examined one putative component of that complex, virb4. a deletion of the virb4 gene on the ti plasmid ptia6nc was constructed by replacing the virb4 gene with the kanamycin resistance-conferring nptii gene. the virb4 gene was found to be necessary for virulence on plants and for the transfer of ... | 1994 | 7830718 |
| early detection of mouse wobbler mutation: a model of pathological motoneurone death. | the mouse recessive mutation wobbler, carried by the c57bl/6j strain, is a naturally occurring model of motoneurone death. the gene is unknown and in the absence of predictive markers, mutants have to be diagnosed by phenotypic criteria at 4 weeks after birth. we localized the wobbler gene to chromosome 11 at 0.98 +/- 1.1 cm from the glutamine synthetase (glns) gene. a polymorphic allele of the glns gene was then introduced into the congenic wobbler strain by intraspecific crossing. one-quarter ... | 1994 | 7841363 |
| source for influenza pandemics. | there are three ways how influenza a viruses can escape the immune response in the human population: (1) by antigenic drift. this means by mutation and selection of variants under the selection pressure of the immune system. these variants have amino acid replacements mainly in the epitopes of the hemagglutinin. (2) by antigenic shift. this means replacement of at least the hemagglutinin gene of the prevailing human strain by the allelic gene of an avian influenza virus by reassortment. (3) as a ... | 1994 | 7843354 |
| secretion of human interleukin 2 by recombinant mycobacterium bovis bcg. | the human interleukin 2 (huil-2) gene was introduced into mycobacterium bovis bcg by using the integrative vector pmv306. to express and secrete huil-2 from bcg, two different plasmids, ci and cii, were made. in ci, the huil-2-encoding region was under the control of the alpha-antigen promoter of bcg; in cii, the expression of huil-2 was regulated by the heat shock protein 60 promoter. a signal peptide sequence isolated from the naturally secreted alpha-antigen of bcg was inserted between the pr ... | 1995 | 7868249 |
| fudecalone, a new anticoccidial agent produced by penicillium sp. fo-2030. | penicillium sp. fo-2030, a soil isolate, was found to produce a new anticoccidial compound. the active compound, designated fudecalone, was isolated from the fermentation broth of the producing strain by solvent extraction, silica gel column chromatography and preparative hplc. the structure of fudecalone was elucidated to be 3,3a,6,6a,7,8,9,10-octahydro-1-hydroxy-4,7,7-trimethyl-1h-naphtho[1,8a- c]furan-6-one mainly by spectroscopic studies including various nmr measurements. the anticoccidial ... | 1995 | 7868390 |
| virulence determinants of uropathogenic escherichia coli and proteus mirabilis. | the urinary tract is among the most common sites of bacterial infection and e. coli is by far the most common infecting agent. in patients with urinary catheters in place or structural abnormalities of the urinary tract, proteus mirabilis is also a frequent isolate. to study virulence of these bacterial species, we have isolated the genes that encode putative virulence factors, constructed specific mutations within these genes, introduced the mutation back into the wild type strain by allelic ex ... | 1994 | 7869662 |
| the lps localization might explain the lack of protection of lps-specific antibodies in abortion-causing chlamydia psittaci infections. | four monoclonal antibodies against chlamydial lipopolysaccharide (lps) were used to study their localization and distribution in the chlamydia psittaci ab7 abortion-causing strain by immunoelectron microscopy. a non-embedding technique on whole chlamydiae, together with a post-embedding technique on mccoy cells infected with the strain, were performed. immunogold labelling was observed on the surface of reticular bodies (rb), but not on elementary bodies (eb). immunolabelling was observed in ult ... | 1994 | 7871240 |
| establishment of a microbiologically acceptable daily intake of antimicrobial drug residues. | a model is presented to calculate the microbiologically acceptable daily intake (adim) of antibiotic residues in food products. the adim calculation is based on mic values for indicator bacteria escherichia coli, bacteroides fragilis, bifidobacterium spp. and eubacterium spp., established under gut-like conditions in an in vitro simulation model. the maximum residue level (mrl) for residues in food products can be derived from the adim. four phases can be distinguished in this gastro-intestinal ... | 1994 | 7871699 |
| localization of cathepsin d in rat ocular tissues. an immunohistochemical study. | numerous studies have demonstrated that cathepsin d as a major lysosomal acid protease plays an important role in the degradation of protein in several tissues. an important function of the retinal pigment epithelium is to interact with the photoreceptor cells in the renewal process. during the renewal process, the rpe cell phagocytosis discarded photoreceptor discs which are then degraded in the rpe phagolysosomes. it is believed that cathepsin d plays a main role in the degradation of rod oute ... | 1995 | 7872492 |
| laboratory investigation of a multistate food-borne outbreak of escherichia coli o157:h7 by using pulsed-field gel electrophoresis and phage typing. | two hundred thirty-three isolates of escherichia coli o157:h7 were analyzed by both pulsed-field gel electrophoresis (pfge) and bacteriophage typing. all 26 isolates from persons whose illness was associated with a recent multistate outbreak of e. coli o157:h7 infections linked to the consumption of undercooked hamburgers and all 27 isolates from incriminated lots of hamburger meat had the same phage type and the same pfge pattern. twenty-five of 74 e. coli o157:h7 isolates from washington state ... | 1994 | 7883892 |
| replication and tropism of human immunodeficiency virus type 1 as predictors of disease outcome in infants with vertically acquired infection. | in a series of 97 infants born to mothers who were seropositive for human immunodeficiency virus type 1 (hiv-1), 18 were identified as infected within the first 60 days of life on the basis of viral culture and polymerase chain reaction findings. we studied viral burden in vivo by quantitative polymerase chain reaction and the in vitro replication pattern of the hiv-1 infecting strain by culturing patient cells with normal phytohemagglutinin-stimulated peripheral blood mononuclear cells. accordi ... | 1993 | 7901357 |
| nosocomial spread of staphylococcus aureus showing intermediate resistance to methicillin. | a nosocomial outbreak of infection and colonization involving six patients and caused by a strain of staphylococcus aureus showing intermediate resistance to methicillin (mic = 4-8 mg l-1) is described. the outbreak was associated with skin-carriage of the epidemic strain by a nurse suffering from severe eczema. the reduced susceptibility of the outbreak strain to methicillin was associated with beta-lactamase production. elimination or inhibition of beta-lactamase activity produced a two-fold d ... | 1993 | 7903092 |
| epizootiological study of hantavirus infection among rattus norvegicus in tokyo bay area, japan. | the prevalence of antibodies against hantavirus in 413 rats (rattus norvegicus) captured in eight regions of the tokyo bay area from 1983 to 1992 were examined by the indirect fluorescent antibody test. antibody-positive rats were found in tokyo port in 1983 (34.8%), 1984 (25.9%), 1985 (22.0%) and 1986 (15.6%), in kasai seaside park in 1989 (3.2%) and 1990 (4.2%) and in chiba port in 1990 (6.7%). in tokyo port, antibody-positive rats were found in any season in 1984 and 1985, and seroprevalences ... | 1993 | 7903711 |
| haemonchus contortus: the role of two beta-tubulin gene subfamilies in the resistance to benzimidazole anthelmintics. | the role of beta-tubulin genes in benzimidazole (bz) resistance was investigated using one susceptible (s) and two resistant (rt and rc) strains of haemonchus contortus. the rt strain was isolated from the field on the basis of thiabendazole resistance. the rc strain was derived from the s strain by treatment with cambendazole. cdnas, derived from the s strain, encoding two isoforms of beta-tubulin (beta 12-16 and beta 8-9), alpha-tubulin and phosphofructokinase (pfk) were used as probes for sou ... | 1994 | 7910461 |
| identification of brucella abortus b19 vaccine strain by the detection of dna polymorphism at the ery locus. | as sensitivity to erythritol is the main feature of the brucella abortus b19 vaccine strain, an attempt to define the genetic basis of this phenotypic trait was made in order to explore its usefulness as a means of molecular identification of strain b19. with this purpose, an erythritol-sensitive derivative of b. abortus strain 2308 was generated by tn5 transposition methods. restriction fragments from a cloned 13 kb tn5-containing ecori fragment from the ery locus of strain 2308 were used to pr ... | 1994 | 7912870 |
| construction of an mr/p fimbrial mutant of proteus mirabilis: role in virulence in a mouse model of ascending urinary tract infection. | proteus mirabilis, a cause of acute pyelonephritis, produces at least four types of fimbriae, including mr/p (mannose-resistant/proteus-like) fimbriae. to investigate the contribution of mr/p fimbriae to colonization of the urinary tract, we constructed an mr/p fimbrial mutant by allelic exchange. a 4.2-kb bamhi fragment carrying the mrpa gene was subcloned into a mobilizable plasmid, psup202. a 1.3-kb kanr cassette was inserted into the mrpa open reading frame, and the construct was transferred ... | 1994 | 7913698 |
| semliki forest virus infects mouse brain endothelial cells and causes blood-brain barrier damage. | induction of experimental allergic encephalomyelitis is facilitated in a genetically resistant balb/c mouse strain by a nonpathogenic strain of a neurotropic alphavirus, semliki forest virus (sfv-a7). one possible explanation for this enhancement is virus infection of endothelial cells (ec), causing increased permeability of the blood-brain barrier. we have now sought evidence for virus infection of ec in vivo by immunocytochemistry and in situ hybridization. sfv-a7 antigens and rna were detecte ... | 1994 | 7916058 |
| borrelia burgdorferi antigens that are targeted by antibody-dependent, complement-mediated killing in the rhesus monkey. | we identified surface antigens of borrelia burgdorferi that are targeted by antibody-dependent, complement-mediated killing (adck) in the rhesus monkey. for this purpose, we had available serum samples from three animals infected with b. burgdorferi jd1 by needle inoculation and from two monkeys that were infected with the same b. burgdorferi strain by ixodes scapularis tick bite. sera from monkeys from the first group contained antibodies to ospa and ospb detectable by western blot (immunoblot) ... | 1994 | 7927774 |
| [ onchocerciasis control program in west africa: socioeconomic development and risk of recrudescence of transmission. 1. experimental study of the transmission of onchocerca volvulus strains from southwestern sierra leone by simulium sirbanum]. | as part of the return of savanna migrants installed since a long time in forest regions, in the south of sierra leone, we carried out an experimental study about a cross-transmission between simulium sirbanum from missira (west-mali) and the forest strain of onchocerca volvulus in the south-west of sierra leone. this study will allow to know if there is a risk of onchocerciasis transmission recrudescence in relation to the reinstallation of these migrants in their native region. because of the v ... | 1994 | 7944648 |
| [use of a plasmid with integrative function of phage phic31 for transfer of cloned genes into streptomyces strains]. | opportunities for application of integrative vectors carrying the attp site and the int gene of the temperate actinophage phi c31 for cloning genes in streptomyces strains were demonstrated. the behavior of the integrative vectors pzat22 and pto1 in the model strain s. lividans tk64 and in the bialaphos-producing strain s. hygroscopicus, respectively, was characterized. restriction maps of the s. lividans and s. hygroscopicus chromosomal regions containing attb sites were constructed. the bar ge ... | 1994 | 7958803 |
| changing bacteriological profile of cholera in nagpur, 1991-93. | in nagpur (maharashtra) during the period 1991-93, vibrio cholerae serogroup 01 predominated in 1991 (94.7%) and 1992 (86.4%) but significantly declined in 1993 (10.7%). serogroups 02-0138 were infrequently encountered. a new strain v. cholerae serogroup 0139 emerged in 1993 and accounted for 89.3 per cent of the total vibrios isolated in the year. replacement of the endemic 01 strain by the new 0139 strain was observed. | 1994 | 7959972 |
| licochalcone a, a new antimalarial agent, inhibits in vitro growth of the human malaria parasite plasmodium falciparum and protects mice from p. yoelii infection. | licochalcone a, isolated from chinese licorice roots, inhibited the in vitro growth of both chloroquine-susceptible (3d7) and chloroquine-resistant (dd2) plasmodium falciparum strains in a [3h]hypoxanthine uptake assay. the growth inhibition of the chloroquine-resistant strain by licochalcone a was similar to that of the chloroquine-susceptible strain. to examine the activity of licochalcone a on the different asexual blood stages of the parasite, licochalcone a was added to highly synchronized ... | 1994 | 7979274 |
| [the use of a protoplast-generating method in selecting the lytic enzyme producer streptomyces recifensis subsp. lyticus]. | optimal conditions for the formation of stable protoplasts of s. recifensis subsp. lyticus 2435 were defined and the use of the protoplasting procedure to increase the activity of the synthesis of extracellular enzymes was shown in principle possible. the level of the synthesis of glycosidases and lytic endopeptidases by the isolated variant ii-29 was higher than that the initial strain by 40-45 per cent which was due to the enrichment of the population with more active variants. | 1994 | 7979802 |
| cytogenetic analysis of malignant skin tumors induced in chemically treated tg-ac transgenic mice. | tg.ac mice (which carry a v-ha-ras transgene) rapidly develop papillomas in response to 12-o-tetradecanoylphorbol-13-acetate (tpa). approximately 30% of the papillomas are associated with subsequent development of malignancies. early-passage spindle-shaped tumor cells arising from explant cultures of tpa-induced tumors in tg.ac mice were tumorigenic when transplanted to syngeneic recipients. the v-ha-ras transgene in the transplanted tumors was expressed at a high level. to identify possible gen ... | 1994 | 7999263 |
| genetic analysis and overexpression of lipolytic activity in bacillus subtilis. | the previously cloned bacillus subtilis lipase gene (lip) was mapped on the chromosome and used in the construction of a b. subtilis derivative totally devoid of any lip sequence. homologous overexpression was performed in this strain by subcloning the lip open reading frame on a multicopy plasmid under the control of a strong gram-positive promoter. a 100-fold overproducing strain was obtained, which should facilitate purification of the secreted protein. furthermore, the delta lip strain bcl10 ... | 1994 | 8017946 |
| the pacl gene of synechococcus sp. strain pcc 7942 encodes a ca(2+)-transporting atpase. | an atp-dependent ca2+ uptake activity was identified in plasma membrane vesicles prepared from synechococcus sp. strain pcc 7942. this activity was insensitive to agents which collapse ph gradients and membrane potentials but sensitive to vanadate, indicating that the activity is catalyzed by a p-type ca(2+)-atpase. a gene was cloned from synechococcus sp. strain pcc 7942 by using a degenerate oligonucleotide based on a sequence conserved among p-type atpases. this gene (pacl) encodes a product ... | 1994 | 8021228 |
| mechanisms of heteroresistance in methicillin-resistant staphylococcus aureus. | characteristic for methicillin-resistant (mcr) staphylococci is the heterogeneous expression of the intrinsic methicillin resistance. the majority of the cells express resistance to low concentrations of methicillin, and a minority of the cells express resistance to much higher concentrations. we show here (i) that the presence of the meca encoding region on plasmid pbbb79 was sufficient to render a methicillin-susceptible (mcs) staphylococcus aureus strain heteroresistant and (ii) that this mcr ... | 1994 | 8031036 |
| altered chemotaxis of bacillus sphaericus l-ethionine-resistant sporulation mutant. a probable link between chemotaxis and sporulation. | a uv irradiation-induced mutant of bacillus sphaericus 2362 whose sporulation was inhibited neither by natural amino acids nor by l-ethionine was selected. the mutant (a61) grew slowly in rich amino acid medium and contained increased concentrations of heat-resistant spores throughout the growth. slow growth of a61 was related to continuous presence of aging and sporulating cells even when the medium was rich in nutrients. ability of the mutant to sense nutrient presence in the environment and t ... | 1994 | 8034010 |
| double-stranded rna mycoviruses in section nigri of the aspergillus genus. | double-stranded rna bands were detected electrophoretically in about 7% of natural isolates and in 13 of 51 collection strains belonging in section nigri of the genus aspergillus. the identity of these bands was proved by s1 nuclease and rnase treatment. most of the virus-containing natural isolates came from indonesia. electron microscopic examination of the strains revealed the presence of virus-like particles in the mycelia of the strains examined. all of the virus-like particles were isometr ... | 1994 | 8039055 |
| vana-mediated vancomycin-resistant enterococcus spp. in sewage. | three high-level vancomycin-resistant enterococcus strains (two enterococcus faecium and one enterococcus durans) were recovered from three of eight sewage samples taken from the general sewage collector at logroño (northern spain). the strains were present in the sewage samples at estimated concentrations of ten resistant bacteria/ml, corresponding to about 0.4% of the enterococcal population. the vana protein was detected in each strain by immunoblotting of membrane extracts of the vancomycin- ... | 1994 | 8040119 |
| passive protection of mice against lethal francisella tularensis (live tularemia vaccine strain) infection by the sera of human recipients of the live tularemia vaccine. | the relative role that humoral immunity plays in protection against infection with the intracellular bacterium, francisella tularensis, remains controversial. cellular immunity is thought to play the major and perhaps only role. the authors, in this article, investigate the immunologic and protective properties of immune serum collected from human recipients of the live tularemia vaccine (lvs). sera of recipients of the vaccine demonstrated reactivity with the vaccine strain by enzyme-linked imm ... | 1994 | 8042659 |
| angiotensin converting enzyme inhibitors and atherosclerosis. | this study was designed to evaluate possible antiatherosclerotic effects of angiotensin converting enzyme inhibitors in mini-pigs. experimental hypercholesterolemia and atherosclerosis were produced in mini-pigs of the göttingen strain by adding 11% egg yolk and 1% cholesterol to the diet for 52 weeks. the animals were divided into three groups. one group was fed the atherogenic diet alone and served as control. the second group was treated with captopril in a dose of 80 mg/kg/day added to the a ... | 1994 | 8043902 |
| altered chemotaxis of a bacillus sphaericus l-ethionine-resistant sporulation mutant. a probable link between chemotaxis and sporulation. | a uv irradiation-induced mutant of b. sphaericus 2362 whose sporulation was inhibited neither by natural amino acids nor by l-ethionine was selected. the mutant (a61) grew slowly in rich amino acid medium and contained increased concentrations of heat-resistant spores throughout the growth. slow growth of a61 was related to continuous presence of aging and sporulating cells even when the medium was rich in nutrients. the ability of the mutant to sense nutrient presence in the environment and to ... | 1994 | 8050607 |
| overexpression, phosphorylation, and growth effects of orf162, a klebsiella pneumoniae protein that is encoded by a gene linked to rpon, the gene encoding sigma 54. | the product of a klebsiella pneumoniae gene, orf162, may regulate sigma 54-dependent transcription and has sequence similarity to proteins of the phosphoenolpyruvate-dependent phosphotransferase system (pts). we have overproduced the product of orf162 and demonstrated its pts-dependent phosphorylation in escherichia coli extracts. we have also observed moderate growth inhibition of a wild-type, but not a sigma 54-mutant, strain by overexpression of orf162. these results are consistent with the h ... | 1994 | 8050721 |
| induction of feline immunodeficiency virus-specific cytotoxic t cells in vivo with carrier-free synthetic peptide. | the role of cellular immunity in the establishment and progression of immunosuppressive lentivirus infection remains equivocal. to develop a model system with which these aspects of the host immune response can be studied experimentally, we examined the response of cats to a hybrid peptide containing predicted t-and b-cell epitopes from the gag and env genes of feline immunodeficiency virus (fiv). cats were immunized with an unmodified 17-residue peptide incorporating residues 196 to 208 (from g ... | 1994 | 8057464 |
| gene cloning in clostridium difficile using tn916 as a shuttle conjugative transposon. | a pbr322-based vector, pci195, containing a 4.2-kb region of the conjugative transposon tn919 was used as a vector for gene cloning in clostridium difficile. the plasmid was found to integrate into the chromosome of a bacillus subtilis strain that contained tn916 delta e. southern blot analysis of the recombinant demonstrated that pci195 had inserted into tn916 delta e by a recombination event. the transposon::plasmid structure could be transferred, by filter mating, from b. subtilis to c. diffi ... | 1994 | 8058827 |
| cytosaminomycins, new anticoccidial agents produced by streptomyces sp. ko-8119. i. taxonomy, production, isolation and physico-chemical and biological properties. | streptomyces amakusaensis ko-8119, a soil isolate, was found to produce a series of new anticoccidial compounds. four active compounds, designated as cytosaminomycins a, b, c and d, were isolated from the fermentation broth of the producing strain by solvent extraction, silica gel column chromatography and preparative hplc. cytosaminomycins inhibited the growth of eimeria tenella in an in vitro assay system using primary chicken embryonic cells as a host. no schizont in the cells was observed at ... | 1994 | 8071122 |
| [microbiological and clinical studies of infective endocarditis due to nutritionally variant streptococci]. | we report four cases of infective endocarditis due to nutritionally variant streptococci (nvs) that occurred between 1981 and 1991. three female and one male patients had underlying heart diseases. causative organisms showed satellitism to staphylococci. two strains were identified as s. adjacens and the other two were identified as s. defectivus by dna-dna hybridization. all strains had tolerance and one strain had resistance to benzylpenicillin (mic 4 micrograms/ml). this penicillin-resistant ... | 1994 | 8089548 |
| activities of roxithromycin used alone and in combination with ethambutol, rifampin, amikacin, ofloxacin, and clofazimine against mycobacterium avium complex. | preliminary studies showed that roxithromycin possessed significant in vitro activity against a variety of atypical mycobacteria such as the mycobacterium avium complex, m. scrofulaceum, m. szulgai, m. malmoense, m. xenopi, m. marinum, and m. kansasii and rare pathogens such as m. chelonae and m. fortuitum. in this investigation, radiometric mics of roxithromycin, ethambutol, rifampin, amikacin, ofloxacin, and clofazimine for 10 clinical isolates of the m. avium complex (5 each from human immuno ... | 1994 | 8092850 |
| evidence that the t cell repertoire of normal rats contains cells with the potential to cause diabetes. characterization of the cd4+ t cell subset that inhibits this autoimmune potential. | diabetes was induced in a normal nonautoimmune rat strain by rendering the animals relatively t cell deficient using a protocol of adult thymectomy and sublethal gamma irradiation. all male rats and 70% of females developed an acute syndrome with severe loss of weight and hyperglycemia. diabetes in these lymphopoenic rats was associated with extensive insulitis involving cd4+ and cd8+ t cells and macrophages. the cd8+ t cells were essential for the development of diabetes but not insulitis. the ... | 1993 | 8094734 |
| identification of plasmid and chromosomal copies of 987p pilus genes in enterotoxigenic escherichia coli 987. | a dna probe derived from the subunit gene of a cloned 987p determinant was used to characterize the locations of the 987p genes in several escherichia coli strains. we examined e. coli 987, a nonpiliated mutant of strain 987 (i36) that does not express 987p in vitro, and a variant of i36 that expressed 987p following growth in vivo. we found that plasmid and chromosomal copies of the 987p subunit gene could be differentiated in strain 987 by restriction endonuclease analysis and southern blot hy ... | 1993 | 8097495 |
| functional organization of the glnb-glna cluster of azospirillum brasilense. | the functional organization of the glnb-a cluster of azospirillum brasilense, which codes for the pii protein and glutamine synthetase, respectively, was studied with the aid of lacz fusions, deletion mapping, site-directed mutagenesis, and complementation. it was shown previously by mrna mapping that the cluster contains two tandemly organized promoters, glnbp1 and glnbp2, of the sigma 70 and sigma 54 types, respectively, upstream of glnb and a third unidentified promoter upstream of glna. data ... | 1993 | 8097514 |
| an epidemiological study of listeriosis complicating a bone marrow transplant. | following an unrelated-donor bone marrow transplant a six-year-old child with severe aplastic anaemia developed listeria monocytogenes septicaemia and meningitis. cook-chill foods consumed during his stay in hospital were found to contain strains of l. monocytogenes and other listeria species. whole cell protein sds-page was performed on all isolates. no food isolates were found that were identical to the patient's strain by this technique or by serotyping. the usefulness of whole cell protein s ... | 1993 | 8099929 |
| site-specific and compensatory mutations imply unexpected pathways for proton delivery to the qb binding site of the photosynthetic reaction center. | in photosynthetic reaction centers, a quinone molecule, qb, is the terminal acceptor in light-induced electron transfer. the protonatable residues glu-l212 and asp-l213 have been implicated in the binding of qb and in proton transfer to qb anions generated by electron transfer from the primary quinone qa. here we report the details of the construction of the ala-l212/ala-l213 double mutant strain by site-specific mutagenesis and show that its photosynthetic incompetence is due to an inability to ... | 1993 | 8105468 |
| bone marrow cell response following induction of acute inflammation in different strains of mice. | the magnitude of the macrophage inflammatory response differs among inbred mouse strains. mice of the a/j strain respond poorly to sterile inflammatory stimuli while those of the c57bl/6 strain show a strong response. inflammatory macrophages found at the site of inflammation are the product of bone marrow (bm) myeloid stem cells. mice of the a/j strain were found to have half the number of bm nucleated cells per femur than those of the c57bl/6 strain. the lower bm cellularity may be one reason ... | 1993 | 8112827 |