| bacterial ribosomal immunostimulants prime alveolar macrophages in vivo to produce interleukin 1 in vitro. | alveolar macrophages (ams) may play a key role in human respiratory immune defenses, partially by synthesizing and releasing interleukin 1 (il = 1). d53 (ribomunyl), a composite bacterial ribosomal immunostimulant, has been recognized as an efficient prevention of respiratory tract infections. in vitro, d53 enhances the il-1 production by mouse spleen adherent cells. a thymocyte proliferative response assay was used to evaluate the in vitro il-1 production by ams in healthy subjects who received ... | 1991 | 1889248 |
| identification of phosphorylation sites in the repetitive carboxyl-terminal domain of the mouse rna polymerase ii largest subunit. | the largest subunit of eukaryotic rna polymerase ii contains a carboxyl-terminal domain (ctd) which is comprised of repetitive heptapeptides with a consensus sequence tyr1-ser2-pro3-thr4-ser5-pro6-ser7. we demonstrate here that the mouse ctd expressed in and purified from escherichia coli can be phosphorylated in vitro by a p34cdc2/cdc28-containing ctd kinase from mouse ascites tumor cells. the product of this reaction, a phosphorylated form of the ctd, contains phosphoserine and phosphothreonin ... | 1991 | 1899239 |
| reduction of ribonucleotides by the obligate intracytoplasmic bacterium rickettsia prowazekii. | rickettsia prowazekii, an obligate intracellular parasitic bacterium, was shown to have a ribonucleotide reductase that would allow the rickettsiae to obtain the deoxyribonucleotides needed for dna synthesis from rickettsial ribonucleotides rather than from transport. in the presence of hydroxyurea, r. prowazekii failed to grow in mouse l929 cells or sc2 cells (a hydroxyurea-resistant cell line), which suggested that r. prowazekii contains a functional ribonucleotide reductase. this enzymatic ac ... | 1991 | 1899861 |
| mouse hepatocytes migrate to liver parenchyma and function indefinitely after intrasplenic transplantation. | one approach to gene therapy for hepatic diseases is to remove hepatocytes from an affected individual, genetically alter them in vitro, and reimplant them into a receptive locus. although returning hepatocytes to the liver itself would be advantageous, the feasibility of this approach has never been evaluated due to the inability to distinguish donor from host hepatocytes. to unambiguously identify transplanted hepatocytes after transplantation, and to better quantitate their number and degree ... | 1991 | 1899924 |
| expression of the vibrio cholerae gene encoding aldehyde dehydrogenase is under control of toxr, the cholera toxin transcriptional activator. | the toxr gene of vibrio cholerae encodes a transcriptional activator required for the expression of the cholera toxin genes (ctxab) and more than 15 other genes encoding secreted or membrane proteins. the latter group includes virulence genes involved in the biogenesis of the tcp pilus, the accessory colonization factor, and such toxr-activated genes as taga, mutations in which cause no detectable virulence defect in the suckling mouse model. to analyze the regulation of expression and the struc ... | 1991 | 1902210 |
| immunogenicity and protective efficacy of pertussis toxin subunit s1 produced by bacillus subtilis. | pertussis toxin (pt) subunit s1 was produced in bacillus subtilis as a secretory protein designated bacs1. bacs1 was partially purified and used to immunize mice. the sera were tested for pt-neutralizing antibodies and for protective capacity in a mouse model. unlike previous findings with recombinant s1 from escherichia coli, the recombinant bacs1 protein induced antibodies that were both neutralizing and protective. an adjuvant was necessary for efficient immunization with bacs1 but not with p ... | 1991 | 1909767 |
| role of bacterial hemolysin production in induction of macrophage ia expression during infection with listeria monocytogenes. | the production of a hemolytic exotoxin (hly) termed listeriolysin o (llo) is a major determinant of the virulence of the gram-positive bacterium listeria monocytogenes. as determined by lethal inoculum size, llo- strains of l. monocytogenes generally are several orders of magnitude less virulent than their llo+ counterparts. the generation of protective anti-listeria t cell immunity also has been shown to depend on the llo phenotype of the bacteria present during primary infection, although the ... | 1991 | 1918964 |
| identification and expression of the cdna of kin17, a zinc-finger gene located on mouse chromosome 2, encoding a new dna-binding protein. | we report the cloning of kin17 cdna, 1414 bp long with an orf of 391 residues showing a zinc finger and nuclear localization signals. by recloning the cdna into an appropriate vector, we produced kin17 protein in e. coli, purified it partially and shown that kin17 protein binds to double-stranded dna. the kin17 gene was localized by cytogenetic mapping in mouse chromosome 2, band a. genomic sequences homologous to kin17 cdna were detected also in rat and human dnas. kin17 mrna is highly expresse ... | 1991 | 1923796 |
| cdna and deduced amino acid sequence of a mouse dna repair enzyme (apex nuclease) with significant homology to escherichia coli exonuclease iii. | we purified a mouse dna repair enzyme having apurinic/apyrimidinic endonuclease, dna 3'-phosphatase, 3'-5'-exonuclease and dna 3' repair diesterase activities, and designated the enzyme as apex nuclease. a cdna clone for the enzyme was isolated from a mouse spleen cdna library using probes of degenerate oligonucleotides deduced from the n-terminal amino acid sequence of the enzyme. the complete nucleotide sequence of the cdna (1.3 kilobases) was determined. northern hybridization using this cdna ... | 1991 | 1939131 |
| molecular cloning and expression of a mouse muscle cdna encoding adenylosuccinate synthetase. | adenylosuccinate synthetase (ec 6.3.4.4) catalyzes the first step in formation of amp from imp. at least two isozymes exist in vertebrate tissue. an acidic form, present in most tissues, has been suggested to be involved in de novo biosynthesis while a basic isozyme, which predominates in muscle, appears to function in the purine nucleotide cycle. antibodies specific for the basic isozyme detect a single protein in mouse tissues with highest levels in skeletal muscle, tongue, esophagus, and hear ... | 1991 | 1939273 |
| gene expression of the a- and b-chain of mouse c1q in different tissues and the characterization of the recombinant a-chain. | immunoscreening of a mouse macrophage cdna library with an anti-mouse c1q-antibody resulted in the isolation of cdna clones. the deduced amino acid sequence was homologous to the a-chain of human c1q. homology on the dna level was found to be 76% and on the protein level 72% thus it appeared the clones coded for the mouse c1q a-chain. an immunoblot of murine serum c1q separated by sds-page was detected with an a-chain specific antibody that had been affinity purified on recombinant mouse c1q a-c ... | 1991 | 1940381 |
| characteristics of alpha-hemolytic strains of escherichia coli isolated from dogs with gastroenteritis. | twenty-four hemolysin producing (hly+) strains of escherichia coli isolated from dogs with gastroenteritis were investigated for their virulence markers and their phenotypic properties. the strains were distributed over eleven known e. coli o-serogroups and most of them were heterogeneous for their phenotypes. all strains were found to produce alpha-hemolysin which was detected by southern hybridization and colony immunoblotting using a specific gene probe and a monoclonal antibody. eight strain ... | 1991 | 1949555 |
| integration of pharmacokinetics and pharmacodynamics of imipenem in a human-adapted mouse model. | the relationship between the pharmacokinetics and bactericidal activity of imipenem against pseudomonas aeruginosa and escherichia coli was investigated in a neutropenic mouse thigh infection model. to circumvent the problem of short elimination time in small animals, imipenem was administered in fractionized, decreasing doses such that the pharmacokinetic profiles as observed in humans after intravenous and intramuscular injections were approximated in mice. the human-simulated kinetic profile ... | 1991 | 1952865 |
| catalytic antibodies: contributions from engineering and expression in escherichia coli. | antibodies have been raised against the transition state of many reactions and shown to catalyse the relevant reaction. their moderate catalytic efficiencies can be increased by protein engineering, if ways can be found to express the engineered antibody. we have developed a system by which fully functional fv and fab fragments can be expressed in escherichia coli. the fv fragment dissociates at low concentrations; we therefore devised methods to stabilize the fragment. we showed that the fv fra ... | 1991 | 1959443 |
| functional analysis of an oxygen-regulated transcriptional enhancer lying 3' to the mouse erythropoietin gene. | erythropoietin, the major hormone controlling red-cell production, is regulated in part through oxygen-dependent changes in the rate of transcription of its gene. using transient transfection in hepg2 cells, we have defined a dna sequence, located 120 base pairs 3' to the poly(a)-addition site of the mouse erythropoietin gene, that confers oxygen-regulated expression on a variety of heterologous promoters. the sequence has the typical features of a eukaryotic enhancer. approximately 70 base pair ... | 1991 | 1961720 |
| systemic delivery of human growth hormone by injection of genetically engineered myoblasts. | a recombinant gene encoding human growth hormone (hgh) was stably introduced into cultured myoblasts with a retroviral vector. after injection of genetically engineered myoblasts into mouse muscle, hgh could be detected in serum for 3 months. the fate of injected myoblasts was assessed by coinfecting the cells with two retroviral vectors, one encoding hgh and the other encoding beta-galactosidase from escherichia coli. these results provide evidence that myoblasts, which can fuse into preexistin ... | 1991 | 1962213 |
| cloning and expression of a pili gene of corynebacterium renale in escherichia coli. | a plasmid gene library of corynebacterium renale piliated strain no. 109p+ was prepared in escherichia coli in order to study the chemical structure of the pili of c. renale. of 3,000 recombinant clones tested, 5 reacted with anti-pili anti-serum. the gene products of these clones reacted with anti-pili monoclonal antibodies 8/4, 5/2 and b20/3 but lacked the reactivity with 13/4. sds-page analysis revealed that the expressed protein had a molecular mass of 48 kilodalton and deletion analysis sho ... | 1990 | 1968989 |
| identification of plasmid-encoded mannose-resistant hemagglutinin and hep-2 and hela cell adherence factors of two diarrheagenic escherichia coli strains belonging to an enteropathogenic serogroup. | two escherichia coli strains (b/m 369 and c-35) belonging to enteropathogenic serogroup o86 were isolated from patients with infantile diarrhea and studied with respect to their cellular adherence properties. both strains exhibited adherence (ad+) to hep-2 and hela cell monolayers in vitro and expressed mannose-resistant hemagglutinating (mrha+) activity towards human, chicken, and sheep (but not mouse, rabbit, or guinea pig) erythrocytes. cellular adherence properties of both strains could be s ... | 1990 | 1969390 |
| evidence for positive and negative regulation of the hox-3.1 gene. | the region-specific patterns of expression of mouse homeobox genes are considered important for establishing the embryonic body plan. a 5-kilobase (kb) dna fragment from the hox-3.1 locus that is sufficient to confer region-specific expression to a beta-galactosidase reporter gene in transgenic mouse embryos has been defined. the observed reporter gene expression pattern closely parallels endogenous hox-3.1 expression in 8- to 9.5-day postcoitum (p.c.) embryos. at 10.5 days p.c. and later, the p ... | 1990 | 1978325 |
| nucleotide sequence of mouse hsp60 (chaperonin, groel homolog) cdna. | the cdna sequence of the 60 kda heat-shock protein from mouse 3t3 cells has been determined. the deduced amino acid sequence of mouse hsp60 protein differs from the corresponding proteins from chinese hamster and human cells in 7 and 13 residues, respectively, most of which are conservative replacements. | 1990 | 1979012 |
| structure, localization and function of fanf, a minor component of k99 fibrillae of enterotoxigenic escherichia coli. | the dna sequence of the k99 fanf gene, encoding fanf, was determined. an open reading frame of 999 bp was found. the primary structure of fanf was deduced and analysis revealed the presence of a signal sequence of 22 amino acid residues. the mature protein contains 311 amino acid residues (mr 33,905 d). the amino acid sequence of fanf showed similarity with the k88ab major subunit faeg. a specific mouse antiserum against fanf was prepared by constructing and purifying a hybrid cro-lacz-fanf prot ... | 1990 | 1982454 |
| disulfide assignments in recombinant mouse and human interleukin 4. | the disulfide pairings of mouse and human interleukin 4 (il-4) proteins have been determined. the purified proteins, synthesized by recombinant dna technology, are fully active as judged by their ability to stimulate an appropriate biological response in a variety of functional assays. peptide maps were produced by digesting the proteins with pepsin and separating the resulting fragments by reverse-phase hplc using linear acetonitrile-tfa gradients. cystine-containing peptides were identified by ... | 1991 | 1993171 |
| the presence of sialidase-sensitive sialosylgangliotetraosyl ceramide (gm1b) in stimulated murine macrophages. deficiency of gm1b in escherichia coli-activated macrophages from the c3h/hej mouse. | the stimulated murine macrophage was found to contain 11 major gangliosides of which 8 were determined to be monosialylated. the thin-layer chromatographic patterns were complicated by the presence of both sialic acid and ceramide fatty acid heterogeneity. n-glycolyl and n-acetylneuraminic acid-containing species were present for each ganglioside characterized. although c18 sphingosine was the only long chain base detected, ceramide fatty acid ranged from c16 to c24 carbon moieties. based on gas ... | 1991 | 2005385 |
| the c terminus of mouse ornithine decarboxylase confers rapid degradation on dihydrofolate reductase. support for the pest hypothesis. | several years ago, we proposed that polypeptide regions rich in proline (p), glutamic acid (e), serine (s), and threonine (t) (pest) target intracellular proteins for destruction (rogers, s., wells, r., and rechsteiner, m. (1986) science 234, 364-368). to test the pest hypothesis, we have produced chimeric proteins in which the n or c terminus of mouse dihydrofolate reductase is extended by the pest-containing c terminus of mouse ornithine decarboxylase. oligonucleotides encoding the 37 c-termin ... | 1991 | 2040628 |
| comparative efficacies of ticarcillin, ticarcillin/clavulanic acid, piperacillin and cefoxitin against polymicrobial infections in mice caused by escherichia coli and bacteroides fragilis. | a model of localised abscess formation was used to establish mixed infections caused by escherichia coli and bacteroides fragilis. the beta-lactamase producing, ticarcillin-resistant strains e. coli e96 and b. fragilis vpi 8708 were used to produce one infection, and in another infection, a beta-lactamase hyperproducing strain e. coli 41548 was combined with a ticarcillin-susceptible strain, b. fragilis b3. treatment, at doses producing clinically achievable concentrations in mouse serum, began ... | 1991 | 2050417 |
| a chimeric mammalian transactivator based on the lac repressor that is regulated by temperature and isopropyl beta-d-thiogalactopyranoside. | lap267 is a laci activator protein (lap) containing an insertion of the transcriptional activation domain of the herpes simplex virus virion protein 16 within the inducer-binding and dimerization domain of the lac repressor protein. lap267 strongly induces expression in a conditional manner from a minimal simian virus 40 early promoter linked to lac operator sequences. lap267 is temperature-sensitive, activating expression at 32 degrees c but not at 39.5 degrees c. it is allosterically regulated ... | 1991 | 2052587 |
| influence of the oral administration of excess copper on the immune response. | we have studied the influence of the oral administration of excess copper (cu) on the immune response. with this aim, mice maintained on standard laboratory diet received 50, 100, 200, or 300 ppm of cu as copper sulfate in the drinking water during 3 to 10 weeks. inhibition of the proliferative response to concanavalin a was observed in mice exposed to 100 ppm of cu for 8 weeks and to 200 ppm of cu for either 3 or 8 weeks. conversely, a significant increase in the proliferative response to esche ... | 1991 | 2055356 |
| comparison of biologic activities of synthetic lipopentapeptide analogs of bacterial lipoprotein in mice. | mitogenicity, lethal toxicity, induction of tumor necrotizing factor (tnf), and antitumor activity against meth a fibrosarcoma of four chemically synthesized lipopentapeptide analogs, s-[2,3-bis(palmitoyloxy)-2r (designated as kab-1), -2s(kab-3)-propyl]-n-palmitoyl-(r)-cysteinyl-(s)-seryl- (s)-seryl-(s)-asparaginyl-(s)-alanine, s-[2,3-bis(palmitoyloxy)-2r(kab-2), and -2s(kab-4)-propyl]-n-[(2,2,2)-trichloroethoxycarbonyl]-(r)- cysteinyl-(s)-seryl-(s)-seryl-(s)-asparaginyl-(s)-alanine, of bacteria ... | 1991 | 2069759 |
| [flow cytometric analysis of oxidative burst of phagocytes with small amount of peripheral blood]. | we have developed a simple method for assessing the oxidative metabolic burst of peripheral blood leukocytes with a minute amount of whole peripheral blood by flow cytometry according to the method of bass et al. with some modification. by this method, we can measure the h2o2 production by both granulocytes and monocytes in the same blood sample. the oxidative product formation by peripheral blood neutrophils can be monitored sequentially in the same mouse infected with e. coli. the mice infecte ... | 1990 | 2082028 |
| isolation, characterization and expression of the complementary dna for human tumor necrosis factor (tnf-alpha). | a cdna for human tnf-alpha (615bp) was isolated by means of polymerase chain reaction (pcr) using first strand cdna from pma-induced hl-60 cells as template. the result from sequencing the 615 bp cdna fragment indicated that it corresponded to the entire sequence of mature human tnf coding region. direct expression of mature human tnf was achieved using a plasmid pht-1 constructed by ligation of the cdna and a synthetic dna. the iptg-induced bacterial product (htnf) showed cytotoxicity to mouse ... | 1990 | 2085391 |
| expression of the envelope antigen of dengue virus in vaccine strains of salmonella. | the envelope gene of dengue 4 virus (den) was cloned in a plasmid under the control of escherichia coli expression signals. a clone that expressed 93% of the gene was found to be detrimental to the bacterial host. another clone which carried only 76% of the e gene was found to be quite stable in vitro as well as in vivo. the killed recombinant bacteria induced antibodies in mice which recognized native den virus. attenuated salmonella typhimurium (sal) strains carrying the den-e plasmid were tes ... | 1990 | 2101475 |
| cell lineage analyses of epithelia and blood vessels in chimeric mouse embryos by use of an embryonic stem cell line expressing the beta-galactosidase gene. | we have established an embryonic stem (es) cell line, ms1-el4, which has the potential to make various tissues in chimeric embryos and, at the same time, expresses the beta-galactosidase gene which was introduced as a good cell marker. to examine cell behavior and lineage during embryogenesis, we injected ms1-el4 cells into host blastocysts and recovered chimeric embryos at various developmental stages. we examined the distribution of the ms1-el4 cell derivatives by staining whole embryos with x ... | 1990 | 2112420 |
| genomic analysis of sequence variation in tandemly repeated dna. evidence for localized homogeneous sequence domains within arrays of alpha-satellite dna. | as a model to examine the local distribution of sequence variation within large arrays of tandemly repeated dna in complex genomes, the long-range organization of alpha-satellite dna from human chromosome 17 was investigated. three individual chromosomes, representing different alpha-satellite haplotypes, were segregated into mouse and human somatic cell hybrids and their arrays sized by pulse-field gel electrophoresis. an inventory of the higher-order repeat units found in multiple separate reg ... | 1990 | 2122000 |
| anti-il-6 monoclonal antibodies protect against lethal escherichia coli infection and lethal tumor necrosis factor-alpha challenge in mice. | potentially fatal physiologic and metabolic derangements can occur in response to bacterial infection in animals and man. recently it has been shown that alterations in the levels of circulating cytokines such as il-6 and tnf-alpha occur shortly after bacterial challenge. to understand better the role of il-6 in inflammation, we investigated the effects of in vivo anti-mouse il-6 antibody treatment in a mouse model of septic shock. rat anti-mouse il-6 neutralizing mab was produced from splenocyt ... | 1990 | 2124237 |
| effects of bacterial lipopolysaccharide and calmodulin on ca2(+)-atpase and calcium in human natural killer cells, studied by a combined technique of immunoelectron microscopy and ultracytochemistry. | our previous studies indicate that bacterial lipopolysaccharide (lps) enhances natural killer (nk) cell-mediated cytotoxicity and increases intracellular calcium (ca2+) in hepatocytes. calmodulin (cam) regulates ca2(+)-atpase activity, intracellular ca2+, and is also implicated in nk cell-mediated cytolysis. in the present work, the effects of lps and cam on ca2(+)-atpase and intracellular ca2+ in human nk cells were studied by a combined technique of immunogold electron microscopy and ultracyto ... | 1990 | 2137483 |
| transport of the yeast atp synthase beta-subunit into mitochondria. effects of amino acid substitutions on targeting. | we have isolated the yeast atp2 gene encoding the beta-subunit of mitochondrial atp synthase and determined its nucleotide sequence. a fusion between the n-terminal 15 amino acid residues of beta-subunit and the mouse cytosolic protein dihydrofolate reductase (dhfr) was transcribed and translated in vitro and found to be transported into isolated yeast mitochondria. a fusion with the first 35 amino acid residues of beta-subunit attached to dhfr was not only transported but also proteolytically p ... | 1990 | 2138017 |
| the use of transgenic mice for short-term, in vivo mutagenicity testing. | in order to develop a short-term, in vivo assay to study the mutagenic effects of chemical exposure, transgenic mice were generated using a lambda shuttle vector containing a lacz target gene. following exposure to mutagens, this target can be rescued efficiently from genomic dna prepared from tissues of the treated mice using restriction minus, in vitro lambda phage packaging extract and restriction minus escherichia coli plating cultures. mutations in the target gene appear as colorless plaque ... | 1990 | 2151115 |
| comparison of methods in the detection of enterotoxigenic escherichia coli in a malaysian laboratory. | the prevalence of enterotoxigenic escherichia coli (etec) in 433 stool samples from diarrhoeal cases of all ages was studied using two commercially available test kits for the detection of heat labile toxin (lt) and the infant mouse assay for the heat stable toxin (st). 16 samples (3.7%) were positive for etec, of which nine were producing st alone, six lt alone and only one was producing both lt and st. although the percentage of isolation rate was low, its occurrence was almost as common as th ... | 1990 | 2152068 |
| cloning and sequence analyses of cdnas for interferon- and virus-induced human mx proteins reveal that they contain putative guanine nucleotide-binding sites: functional study of the corresponding gene promoter. | the human protein p78 is induced and accumulated in cells treated with type i interferon or with some viruses. it is the human homolog of the mouse mx protein involved in resistance to influenza virus. a full-length cdna clone encoding the human p78 protein was cloned and sequenced. it contained an open reading frame of 662 amino acids, corresponding to a polypeptide with a predicted molecular weight of 75,500, in good agreement with the mr of 78,000 determined on sodium dodecyl sulfate gels for ... | 1990 | 2154602 |
| proton-linked sugar transport systems in bacteria. | the cell membranes of various bacteria contain proton-linked transport systems for d-xylose, l-arabinose, d-galactose, d-glucose, l-rhamnose, l-fucose, lactose, and melibiose. the melibiose transporter of e. coli is linked to both na+ and h+ translocation. the substrate and inhibitor specificities of the monosaccharide transporters are described. by locating, cloning, and sequencing the genes encoding the sugar/h+ transporters in e. coli, the primary sequences of the transport proteins have been ... | 1990 | 2172229 |
| homologous recombination in a mammalian plasmid. | bovine papillomavirus (bpv) shuttle vectors replicate as a circular plasmid in mouse cell nuclei without impairing host cell viability. we used these vectors to analyze homologous recombination in mammalian cells. when several bpv-based plasmids carrying direct repeats were introduced into c127 cells, we detected many recombinant plasmid molecules that have lost the sequence between the repeats. many recombinant type molecules as well as parental type molecules were detected in all the cell clon ... | 1990 | 2177135 |
| differences in susceptibility of inbred and outbred infant mice to enterotoxigenic escherichia coli of bovine, porcine and human origin. | infant mice from outbred swiss of1 and from inbred dba/2, c57bl/6, balb/cby and cba strains were screened for usefulness in the diarrhoea model with enterotoxigenic escherichia coli (etec) strains of bovine, porcine and human origin. mouse strains were either weakly susceptible or not susceptible to etec strains of porcine or human origin bearing antigen k88, 987p, cfa/i or cfa/ii. in contrast, some mouse strains were highly susceptible to bovine and porcine etec strains bearing k99 or f41 or bo ... | 1990 | 2179554 |
| specific interaction of the murine transcription termination factor ttf i with class-i rna polymerases. | the 18-base-pair sequence element aggtcgaccagtactccg (the sal box) signals termination of mouse ribosomal gene transcription. this sequence is recognized by a sequence-specific dna-binding protein, ttf i, which mediates the termination of transcription by rna polymerase i (pol i). subsequently, the ends of the primary transcripts are trimmed by 10 nucleotides in a sequence-dependent 3'-terminal processing reaction. we have now investigated whether ttf i bound to its target sequence will block el ... | 1990 | 2181320 |
| analysis of gpt activity in mammalian cells with a chromosomally integrated shuttle vector containing altered gpt genes. | the molecular mechanisms of reversion in mammalian cells were studied utilizing the pzipgptneo shuttle vector, with the bacterial gpt gene in the vector integrated into the chromosomal dna of mouse cells. from mutant cell lines containing gpt genes with single base changes, revertants were selected for the reappearance of gpt activity. the copy number and expression of the gpt genes in such revertants were analyzed, and the gpt activity encoded by revertant genes in both mammalian cells and bact ... | 1990 | 2181699 |
| escherichia coli f-18 makes a streptomycin-treated mouse large intestine colonization factor when grown in nutrient broth containing glucose. | escherichia coli f-18 fima-, a type 1 fimbria-less derivative of a normal human fecal isolate, e. coli f-18, has previously been shown to be as good a colonizer of streptomycin-treated mouse large intestine as its parent, suggesting that type 1 fimbriae are not necessary in this process. in this study it was found that when e. coli f-18 fima- was grown standing overnight at 37 degrees c in nutrient broth, it remained uniformly suspended; however, when grown in nutrient broth containing 1% (wt/wt ... | 1990 | 2182545 |
| retropseudogenes constitute the major part of the human elongation factor 1 alpha gene family. | the elongation factor 1 alpha (ef-1 alpha) is a protein which promotes the gtp-dependent binding of aminoacyl-trna to ribosomes in the protein synthesis process. a human gene coding for ef-1 alpha has previously been cloned and sequenced along with a pseudo-gene. here, we have further analyzed the family of human ef-1 alpha genes. using an ef-1 alpha cdna as probe twelve genomic ef-1 alpha-like clones were isolated and analyzed. four of these were sequenced and found to contain ef-1 alpha retrop ... | 1990 | 2183196 |
| cloning and sequencing of mammalian glutathione reductase cdna. | the molecular cloning of a partial cdna to mouse glutathione reductase mrna and of a full-length cdna to the mrna of the human enzyme is described. an initial cdna clone designated lambda grm-b11 was isolated by plaque-screening of an induced mouse cdna expression library in the lambda gt11 vector with a rabbit antibody probe to human glutathione reductase. 125iodine-labelled whole anti-rabbit immunoglobulin was used as second antibody. ecori digestion of the lambda grm-b11 clone released a 720- ... | 1990 | 2185014 |
| evidence for two types of cytotoxic necrotizing factor in human and animal clinical isolates of escherichia coli. | we have characterized the in vitro and in vivo toxic properties of cell sonic extracts from 22 animal and human clinical isolates of escherichia coli that caused both necrosis in the rabbit skin and multinucleation in tissue cultures, two toxic properties previously reported as being specific for e. coli cytotoxic necrotizing factor (cnf). two distinct toxic phenotypes were observed. type 1, which was displayed by originally described cnf strains, was characterized by extensive multinucleation a ... | 1990 | 2185259 |
| escherichia coli and klebsiella vaccines and immunotherapy. | a polyvalent vaccine has been prepared from the capsular polysaccharide of 24 different serotypes of klebsiella spp. nearly 200 volunteers have received this vaccine. it is very well tolerated and elicits both binding (elisa) and functional antibody to 21 of 24 antigens. antibodies were also detected against 10 serotypes not included in the vaccine. an immunoglobulin for intravenous use (ivig) was more protective in mouse lethality assays and enhanced opsonophagocytic killing of bacteria more th ... | 1990 | 2189000 |
| mutagenicity evaluation of hc blue no. 1 and hc blue no. 2. iii. effects in the salmonella typhimurium/escherichia coli reversion assay and the mouse lymphoma l5178y tk+/- forward mutation assay. | the hair-dye ingredients, hc blue no. 1 (hcb1) and hc blue no. 2 (hcb2), were tested for the induction of bacterial mutation using salmonella typhimurium strains ta1535, ta1537, ta98 and ta100; and escherichia coli strains wp2uvra-. in addition, both dyes were evaluated in the mouse lymphoma l5178y tk+/- assay (mla) for the potential to induce forward mutation. a liver homogenate (s9) prepared from aroclor 1254-induced male fischer 344 rats was used to provide a means for metabolic activation. h ... | 1990 | 2189067 |
| expression and biochemical characterization of human immunodeficiency virus type 1 nef gene product. | nef genes from human immunodeficiency virus type 1 isolates bh10 and lav1 (lymphadenopathy-associated virus type 1) were expressed in escherichia coli under the deo operon promoter. the two proteins found in the soluble compartment of the bacterial lysate were purified by ion-exchange column chromatography to apparent homogeneity. determination of the amino-terminal sequence revealed glycine as the first amino acid in the nef protein, indicating removal of the initiator methionine during express ... | 1990 | 2191151 |
| [the selective isolation of cosmid clones by homologous recombination in escherichia coli--a cosmid clone containing t complex linkage dna sequence of mouse was isolated]. | a procedure for the selective isolation of specific cosmid clones by homologous recombination between cosmid clones of genomic library and a probe dna sequence cloned in a plasmid in vivo has been developed. the cosmid library was constructed in a rec- host cell strain and packaged into phage particles in vivo. the rec+ host cells containing a dna sequence used as selection probe cloned in the puc plasmid were infected by packaged cosmid phage particles. there is no homology between cosmid and t ... | 1990 | 2196913 |
| effects of endothelin on the lethality induced by platelet-activating factor or endotoxin in the mouse. | platelet-activating factor (paf) is a mediator that decreases cardiac output and total peripheral resistances leading to profound hypotension. it seems to be involved in shock states and in the deleterious effects of endotoxin. as the natural peptide endothelin (et) shows potent vasoconstrictor properties, we evaluate its activity towards paf and endotoxin-induced lethality in mice. et, at doses which per se did not exert any effects on mice vitality, produced a dose-dependent decrease in the pa ... | 1990 | 2208608 |
| reverse guanine phosphoribosyltransferase selection of recombinant vaccinia viruses. | we have developed a procedure for the selection of recombinant vaccinia viruses with applicability to poxvirus mutagenesis studies and to the use of vaccinia virus as an expression vector. the method depends on the specific inability of a recombinant vaccinia virus expressing the escherichia coli guanine phosphoriboxyltransferase gene (gpt) to form plaques on a hypoxanthine-guanine phosphoribosyltransferase-negative line of mouse fibroblasts in the presence of 6-thioguanine. recombinant viruses ... | 1990 | 2219714 |
| embryonic neural cell adhesion molecule in cerebrospinal fluid of younger children: age-dependent decrease during the first year. | poly-alpha-2,8-n-acetylneuraminic acid (poly-alpha-2,8-neuac) is developmentally expressed in neural tissue of higher animals, where it is covalently attached to the neural cell adhesion molecule (ncam), a large integral membrane glycoprotein mediating cell-cell adhesion during neuronal development. ncam exists in several molecular forms, of which only embryonic ncam carries lengthy chains (n greater than 5) of poly-alpha-2,8-neuac. chemically identical poly-alpha-2,8-neuac of bacterial origin i ... | 1990 | 2230809 |
| molecular cloning, sequencing, and expression of mouse ferrochelatase. | the cdna encoding mouse ferrochelatase (protoheme ferrolyase, ec 4.99.1.1) was isolated from a mouse erythroleukemia (mel) cell cdna library in lambda gt11 expression vector, by immunoscreening with a polyclonal antibody. two full-length clones containing cdna inserts of 2.2 and 2.90 kilobases were obtained. these clones have the same entire enzyme coding region, but alternative putative polyadenylation sites in the 3'-noncoding regions. from the deduced primary structure, a putative leader sequ ... | 1990 | 2246229 |
| interactions of escherichia coli and proteus mirabilis with mouse mononuclear phagocytes. | five strains of enterobacteria (three of escherichia coli and two of proteus mirabilis) were studied to assess and compare their phagocytic uptake and intracellular killing by mouse macrophages. each strain was injected intraperitoneally into separate groups of mice and peritoneal exudate cells were harvested after 3 min for phagocytosis to occur in vivo. acridine orange staining showed that there were approximately 10-fold fewer intracellular p. mirabilis than e. coli cells. the average numbers ... | 1990 | 2250285 |
| hepatotoxic activity of campylobacter jejuni. | hepatotoxic factor(s) were isolated from whole-cell lysates of campylobacter jejuni gifu 8734 and purified by chromatography. a single intravenous injection of 10 micrograms of this factor reproducibly produced hepatitis in mice, as determined by histology and liver function tests. the hepatic lesions were very similar to those evoked by c. jejuni infection. tissue-culture studies with mouse hepatocytes demonstrated that low concentrations of the factor caused release of hepatic enzymes into the ... | 1990 | 2250287 |
| heat shock response of murine chlamydia trachomatis. | we have investigated the heat shock response in the mouse pneumonitis strain of chlamydia trachomatis. the kinetics of the chlamydial heat shock response resembled that of other procaryotes: the induction was rapid, occurring over a 5- to 10-min time period, and was regulated at the level of transcription. immunoblot analysis and immunoprecipitations with heterologous antisera to the heat shock proteins dnak and groel demonstrated that the rate of synthesis, but not the absolute amount of these ... | 1990 | 2254267 |
| detection of the aerolysin gene in aeromonas hydrophila by the polymerase chain reaction. | synthetic oligonucleotide primers were used in a polymerase chain reaction (pcr) technique to detect the gene for aerolysin in strains of aeromonas hydrophila and to screen for identical genes in a. caviae, a. sobria, and a. veronii isolated from patients with diarrheal disease. primers targeted a 209-bp fragment of the aer gene coding for the beta-hemolysin and detected template dna only in the pcr using nucleic acid (na) from hemolytic strains of a. hydrophila which were also cytotoxic to vero ... | 1990 | 2254423 |
| association of virulence markers with animal pathogenicity of escherichia coli in different models. | employing chicken and several strains of mice, different routes (intraperitoneal, subcutaneous) of infections and isogenic pairs of strains, association of virulence markers with animal pathogenicity was studied in escherichia coli. mouse virulence of avian strains was less significant than the lethality for chicks of human strains. ld50 in various animals did not differ significantly. strains with antigen k1 were more virulent for mice than their k1- derivatives. loss of haemolysin (hly), manno ... | 1990 | 2270740 |
| thrombopoietic activity of human interleukin-6. | thrombopoietin (tpo), a regulatory factor in platelet production, was purified from the conditioned medium of tnk-01 cells cultured in the presence of human interleukin-1. the n-terminal sequence of purified tpo was determined to be vppgedskdvaaphrqplt, identical to that of the n-terminal region of human interleukin-6 (il-6). two forms of tpo with molecular masses of 24 and 27 kda were identified as il-6 by western analysis using an anti-il-6 antibody. commercial recombinant human il-6 produced ... | 1990 | 2298297 |
| expression and secretion of aequorin as a chimeric antibody by means of a mammalian expression vector. | a fusion protein has been expressed from the relevant genes in mammalian cells consisting of the photoprotein aequorin and an anti-4-hydroxy-3-nitrophenacetyl antibody gene. this chimeric antibody has allowed the development of a sensitive luminescent immunoassay. initially the cdna of the photoprotein aequorin from aequorea victoria was cloned and expressed in escherichia coli. the gene was expressed as apoaequorin and, by using luciferin isolated from renilla reniformis, its activity was found ... | 1990 | 2315301 |
| glucose phosphorylation in tumor cells. cloning, sequencing, and overexpression in active form of a full-length cdna encoding a mitochondrial bindable form of hexokinase. | in rapidly growing tumor cells exhibiting high glucose catabolic rates, the enzyme hexokinase is markedly elevated and bound in large amounts (50-80% of the total cell activity) to the outer mitochondrial membrane (arora, k.k., and pedersen, p.l. (1988) j. biol. chem. 263, 17422-17428; parry, d.m., and pedersen, p.l. (1983) j. biol. chem. 258, 10904-10912). in extending these studies, we have isolated a cdna clone of hexokinase from a lambda gt11 library of the highly glycolytic, c37 mouse hepat ... | 1990 | 2318862 |
| the primary structure of rat ribosomal protein s16. | the amino acid sequence of rat ribosomal protein s16 was deduced from the sequence of nucleotides in a recombinant cdna and confirmed from the nh2-terminal amino acid sequence of the protein. s16 contains 145 amino acids (the nh2-terminal methionine is removed after translation of the mrna) and has a molecular mass of 16,304. hybridization of the cdna to digests of nuclear dna suggests that there are 11-13 copies of the s16 gene. the mrna for the protein is about 700 nucleotides in length. rat s ... | 1990 | 2332055 |
| the gene sequence and some properties of protein h. a novel igg-binding protein. | the gene for protein h, a novel bacterial cell wall protein with specific affinity for human igg fc, was cloned from a group a streptococcus and expressed in escherichia coli. recombinant e. coli cells produced two forms of a human igg fc-binding protein, one with an apparent mr of 42 kda in a periplasmic fraction and the other with an apparent mr of 45 kda in a mixed fraction of cytoplasms and membranes. both 42-kda and 45-kda protein preparations similarly bound to human igg1 to igg4, human ig ... | 1990 | 2332638 |
| interleukin 6 perfusion stimulates reconstitution of the immune and hematopoietic systems after 5-fluorouracil treatment. | effects of interleukin 6 (il-6) on the functional capacity of the immune and hematopoietic systems in 5-fluorouracil (5-fu)-treated mice were determined. il-6 (5 x 10(4) units/mouse/day) was administered s.c. for 7 days by implantation of an osmotic pump, since it was demonstrated that a much higher increase in the primary response to sheep rbc was observed by administration of slowly released rather than daily s.c. injection of il-6. il-6 perfusion significantly augmented anti-sheep rbc antibod ... | 1990 | 2334892 |
| detection of dna strand breaks in hela cells in vitro and in mouse sarcoma 180 cells in vivo induced by an alkylating agent, carboquone, using in situ nick translation. | we determined the correlation between dna strand breaks and the toxicity of carboquone (cq) in hela cells in vitro and in mouse sarcoma 180 (s-180) cells in vivo, using in situ nick translation. the break sites in the dna were translated artificially in the presence of escherichia coli dna polymerase i and [3-h]-labelled dttp, and sites in the dna were visualized by autoradiographic observation of grains in the nuclei. these breaks appeared as early as 5 min in the cq-treated hela cells and incr ... | 1990 | 2342771 |
| 27 amino acid residues can be deleted from the n-terminus of human lymphotoxin without impairment of its cytotoxic activity. | in order to study the relationship between activity and structure of human lymphotoxin (hlt, 171 aa), we synthesized the gene (519 bp) for hlt and expressed it in escherichia coli. purification of the recombinant hlt from crude extracts was difficult because of the low level of expression of the gene. to improve the yield of the recombinant protein, we prepared five truncated genes for mutant proteins in which 25, 26, 27, 28 and 37 amino acid residues, respectively, were missing from the n-termi ... | 1990 | 2361063 |
| isolation and structural characterization of a cdna clone encoding the human dna repair protein for o6-alkylguanine. | o6-methylguanine-dna methyltransferase (mgmt; dna-o6-methylguanine:protein-l-cysteine s-methyltransferase, ec 2.1.1.63), a unique dna repair protein present in most organisms, removes the carcinogenic and mutagenic adduct o6-alkylguanine from dna by stoichiometrically accepting the alkyl group on a cysteine residue in a suicide reaction. the mammalian protein is highly regulated in both somatic and germ-line cells. in addition, the toxicity of certain alkylating drugs in tumor and normal cells i ... | 1990 | 2405387 |
| comparison of biological and immunological activities of human monocyte-derived interleukin 1 beta and human recombinant interleukin 1 beta. | recombinant human interleukin 1 beta (rhil-1 beta) and supernatants of escherichia coli lipopolysaccharides-stimulated human monocyte (mo) cultures, containing native human il-1 beta (nhil-1 beta), demonstrate significant differences when tested in the mouse co-stimulatory thymocyte (lymphocyte activating factor [laf]) assay. the aims of the present study were to investigate this characteristic difference between rhil-1 beta and mo culture supernatants (mo supernatants), and to compare the biolo ... | 1990 | 2408138 |
| slo4, a new interferon inducer isolated from klebsiella pneumoniae and escherichia coli. | a product isolated from klebsiella pneumoniae and escherichia coli, coded slo4, has been shown to be effective in endogenous interferon induction in vivo in mouse when administered ip or iv, and in vitro with human leukocyte cultures. in these two systems induced interferon was defined. the inducer has not yet been characterized but seems not to belong to any components known to be interferon inducers such as viral particles, nucleic acids or endotoxins. an analytical study will be carried out t ... | 1985 | 2409177 |
| insertion of the bacterial gpt gene into the germ line of mice by retroviral infection. | mouse substrains genetically transmitting the exogenous moloney murine leukemia virus (mo-mulv) at a single locus have been derived previously by infection of preimplantation embryos. here we explore the potential of retroviral vectors for transferring nonviral genes into the germ line of mice. preimplantation mouse embryos were cocultivated with a cell line that produces a recombinant retrovirus whose genome carries the escherichia coli gene gpt. we show that the vector sequence was inserted in ... | 1985 | 2413448 |
| the human 18s ribosomal rna gene: evolution and stability. | we report the 1,870-base-pair primary sequence of a human 18s rrna gene and propose a secondary structure based on this sequence and the general mammalian structure. a basic secondary structure for the small subunit rrna has been preserved throughout evolution by compensatory and neutral base changes in double-stranded regions. the molecule contains eight regions that can vary in structure and that comprise 432 bases, while 1,438 bases belong to regions of conserved structure among all species t ... | 1986 | 2422931 |
| [new data on the biological action of normal immunoglobulins]. | experiments on 2,520 cba mice (cba x x c57bl) f1 nice have shown that the injection of homologous serum immunoglobulins (obtained from intact and blood-stimulated animals), made 2 hours after gamma irradiation from a 60co source, prevents the development of intestinal dysbacteriosis and endogenous infection. the injection of mouse and human immunoglobulins to nonirradiated mice improved their resistance to experimental infection with escherichia coli live culture, increased the expression of rec ... | 1986 | 2425516 |
| monoclonal antibodies against escherichia coli heat-stable toxin (sta) and their use in a diagnostic st ganglioside gm1-enzyme-linked immunosorbent assay. | seven monoclonal antibodies (mabs) against heat-stable enterotoxin (st) from a human escherichia coli isolate were prepared and evaluated for their usefulness in an st immunodetection assay, the st ganglioside gm1-enzyme-linked immunosorbent assay (elisa). this assay is based on the ability of sta, as present in, for example, culture filtrates from st-producing e. coli, to inhibit specific anti-st antibody from binding to solid-phase-bound st ganglioside (gm1-bound st-cholera b subunit). four of ... | 1986 | 2429984 |
| endothelial plasminogen activator inhibitor (pai): a new member of the serpin gene family. | a human endothelial cdna expression library, based on the escherichia coli plasmid puc9, was screened with a heterologous antibody raised against purified bovine aortic endothelial plasminogen activator inhibitor (pai). a synthetic oligonucleotide, derived from a partial pai cdna expression clone, was used to select a full-length pai cdna, the size of which coincides with the length of pai mrna (approximately 2350 nucleotides) as determined by northern blot analysis. the authenticity of full-len ... | 1986 | 2430793 |
| in vitro methylation of bovine papillomavirus alters its ability to transform mouse cells. | bovine papillomavirus (bpv) was methylated in vitro at either the 29 hpaii sites, the 27 hhai sites, or both. methylation of the hpaii sites reduced transformation by the virus two- to sixfold, while methylation at hhai sites increased transformation two- to fourfold. dna methylated at both hpaii and hhai sites did not differ detectably from unmethylated dna in its efficiency of transformation. these results indicate that specific methylation sites, rather than the absolute level of methylated c ... | 1986 | 2431294 |
| t gamma protein is expressed on murine fetal thymocytes as a disulphide-linked heterodimer. | during the search for genes coding for the mouse alpha and beta subunits of the antigen-specific receptor of mouse t cells we encountered a third gene, subsequently designated gamma. this gene has many properties in common with the alpha and beta genes, somatic assembly from gene segments that resemble the gene segments for immunoglobulin variable (v), joining (j) and constant (c) regions; rearrangement and expression in t cells and not in b cells; low but distinct sequence homology to immunoglo ... | 1987 | 2434855 |
| fine mapping of epitopes by intradomain kd/dd recombinants. | 11 intradomain recombinants between h-2kd and h-2dd were produced using an original technique based on in vivo recombination in escherichia coli. after transfection into mouse l cells, all these recombinants were expressed at high levels on the cell surface. the specificities of 77 mabs were examined on these cell lines. mabs could be organized in 12 groups. in each group, a small number of amino acids participating in the recognized epitope(s) were identified. in a few instances, noncontinuous ... | 1987 | 2439641 |
| [combined effects of astromicin and human gamma-globulin prepared for intravenous use]. | combination therapy of antibiotics and human intravenous gamma immunoglobulin (igg) prepared for intravenous use is widely applied to control severe infectious diseases. to evaluate the antimicrobial activity of astromicin (astm, fortimicin), the combination effect of astm with igg was investigated in vitro and in mice with experimental infection (i.p.) with pseudomonas aeruginosa bmh no. 1. sulfonated igg (venilon, vl), and plasmin-treated igg (venoglobulin, vg) were administered (i.v., 42 mg/k ... | 1987 | 2439721 |
| serological characterisation of a mouse monoclonal anti-p-like antibody. | an igm mouse monoclonal antibody, lm 147/328, raised against an escherichia coli immunogen, was found to possess anti-p-like specificity. it is proposed that this antibody recognises an epitope on a gal beta 1-3galnac disaccharide structure (galnac = n-acetyl-d-galactosamine). the haemagglutinating activity of this antibody was consistently strong with adult erythrocytes, but gave significantly weak reactions with about 7% of cord erythrocyte samples. | 1987 | 2440182 |
| functional activities of monoclonal antibodies to the o side chain of escherichia coli lipopolysaccharides in vitro and in vivo. | mouse hybridoma antibodies (igg and igm) to o side chain determinants of escherichia coli strain bort (o18ac:k1:h7) were evaluated for their in vitro and in vivo activities against e. coli strains. both igg and igm were opsonic in vitro and protected newborn rats challenged with a k1 e. coli strain, but their activities were strain specific. the antibodies protected against a k1 strain possessing a homologous o serotype but not against one possessing a heterologous o serotype. these antibodies w ... | 1988 | 2447199 |
| immune response to escherichia coli alpha-hemolysin in patients. | the serum antibody response of patients infected with alpha-hemolysin (ah)-producing escherichia coli was measured by three immunoassays: tube neutralization, microneutralization, and enzyme-linked immunosorbent assay. all three assay results showed good correlation with each other. the mean anti-ah titer in patients with e. coli infection was higher than the mean titer in noninfected patients. the hemolysin-neutralizing activity was immunoglobulin g. the amount of lipopolysaccharide (lps) antib ... | 1988 | 2454938 |
| virulence factors in escherichia coli strains isolated from swedish piglets with diarrhea. | parenteral vaccination of sows against escherichia coli diarrhea in their newborn piglets has become more common during the last decade in sweden, and the vaccination has generally had positive effects. for more than 20 years we have investigated e. coli strains isolated from piglets and weaned pigs with enteric disorders, noting the presence of o groups, enterotoxins, and adhesins. there has been a continuous change in the frequency of these virulence factors. the present study was performed du ... | 1988 | 2454939 |
| candida albicans- and candida stellatoidea-specific dna fragment. | dna was isolated from whole cells of candida albicans and digested with mspi restriction enzyme. in addition to the expected large number of low-molecular-weight dna pieces resulting from the digestion, multiple high-molecular-weight (greater than 3.0 kilobase pairs) fragments were generated by this enzyme, which cleaves dna at ccgg sequences. some of these fragments appeared highly repeated. an mspi fragment which was similar in size to one of the repeat elements (2.9 kilobase pairs) was cloned ... | 1988 | 2460494 |
| an eif-4a-like protein is a suppressor of an escherichia coli mutant defective in 50s ribosomal subunit assembly. | the assembly of ribosomes in bacterial cells is a complex process that remains poorly characterized. the in vitro assembly of active ribosomal subunits from purified rna and protein components indicates that all of the information for proper assembly resides in the primary sequences of these macromolecules. on the other hand, the in vitro requirement of unphysiological heating steps suggests that this pathway may not accurately reflect the in vivo pathway, and that other proteins may be required ... | 1988 | 2461520 |
| genomic cloning and heterologous expression of human differentiation-stimulating factor. | differentiation-stimulating factor (d-factor) purified from mouse ehrlich ascites cells was sequenced partially and found to be almost identical to leukemia inhibitory factor (lif) from mouse krebs ii ascites cells. in comparison to lif, d-factor had an additional amino-terminal serine residue. using synthetic oligonucleotide probes designed from the murine d-factor sequence, we cloned the human gene encoding d-factor. a partial d-factor cdna was cloned from cos-1 cells transfected with the huma ... | 1989 | 2475312 |
| effects of interferons, interferon inducers and growth factors on phagocytosis measured by quantitative determination of synthetic compound ingested by mouse bone marrow-derived macrophages. | sodium salt of 9-oxo-10-acridineacetohydroxamic acid (hca), a new synthetic compound, forms small crystals in aqueous solution. these crystals were easily phagocytized by the mouse bone marrow-derived macrophages. the ingested hca crystals were visible under light microscope as dark granules. the degree of phagocytosis was estimated by the spectroscopic measurements of absorption of ingested hca. about 10 day-old cultures of mouse bone marrow-derived macrophages were found to be suitable for a s ... | 1988 | 2478100 |
| production and characterisation of monoclonal antibodies to verotoxins 1 and 2 from escherichia coli of serotype o 157:h7. | fourteen hybridoma cell lines were isolated that produced monoclonal antibodies (mabs) to purified verotoxins 1 and 2 (vt1, vt2) of escherichia coli of serotype o157:h7. of these mabs, eight were obtained by immunisation of balb/c mice with purified vt1, and six were obtained from balb/c mice immunised with purified vt2. with the exception of mab 1c5, with a heavy chain of igg2b class, antibodies produced from mice immunised with heat-treated toxin were of igm class. mabs produced from mice immu ... | 1989 | 2479749 |
| construction of an ebv-derived shuttle vector for studying the influence of transcription on mutagenesis. | we have constructed an ebv-derived shuttle vector, pf1-ebv, which replicates in human cells as an extrachromosomal element. the structural sequences of the gene encoding the bacterial xanthine-guanine-phosphoribosyltransferase (gpt) were fused to the promoter and presumptive control region of the mouse metallothionein i (mt-i) gene. human 293 cells transformed with the recombinant plasmid synthesized gpt mrna and the expression of the gene was inducible by zinc. the gpt gene offers a convenient ... | 1989 | 2480810 |
| an in situ transgenic enzyme marker for the midgestation mouse embryo and the visualization of inner cell mass clones during early organogenesis. | in order to study the deployment of cells during gastrulation and early organogenesis, it is necessary to have an in situ cell marker which can be used to follow cell fate. to create such a marker a transgenic mouse strain, designated tg(act-lac z)-1, which carries 6 copies of the escherichia coli lac z gene under the control of the rat beta-actin promoter, was made by pronuclear injection of dna. staining early postimplantation hemizygous mouse conceptuses, during gastrulation and early organog ... | 1989 | 2483370 |
| pseudomonas aeruginosa cytotoxin: periplasmic localization and inhibition of macrophages. | pseudomonas aeruginosa cytotoxin has been isolated previously from cell autolysates. both purified cytotoxin and periplasmic contents (osmotic shock fluid) cross-reacted on western immunoblots with antibodies specific for cytotoxin. in addition, both preparations caused a significant reduction in antibody-mediated phagocytosis of p. aeruginosa m2 by mouse macrophage cell line p388d1. phagocytosis was restored in each case on preincubation of cytotoxin or periplasmic contents with anti-cytotoxin ... | 1989 | 2492976 |
| coumamidines, new broad spectrum antibiotics of the cinodine type. iii. microbiologic activity of coumamidine gamma 1. | the coumamidines are novel antibiotics with activity against a wide spectrum of aerobic gram-positive and gram-negative bacteria. all microbiological studies were performed on coumamidine gamma 1. the mic90s (micrograms/ml) of coumamidine are as follows: staphylococcus aureus 1.0, streptococcus pyogenes 8, enterobacteriaceae 2.0, pseudomonas aeruginosa 8, campylobacter jejuni and campylobacter coli 1, legionella pneumophila 8, haemophilus influenzae 0.5, neisseria gonorrhoeae 0.5. coumamidine ha ... | 1989 | 2498268 |
| pseudomonas aeruginosa outer membrane lipoprotein i gene: molecular cloning, sequence, and expression in escherichia coli. | lipoprotein i (opri) is one of the major proteins of the outer membrane of pseudomonas aeruginosa. like porin protein f (oprf), it is a vaccine candidate because it antigenically cross-reacts with all serotype strains of the international antigenic typing scheme. since lipoprotein i was expressed in escherichia coli under the control of its own promoter, we were able to isolate the gene by screening a lambda embl3 phage library with a mouse monoclonal antibody directed against lipoprotein i. the ... | 1989 | 2502533 |
| phage particle-mediated gene transfer of recombinant cosmids to cultured mammalian cells. | an efficient procedure for the introduction of recombinant cosmids into cultured mammalian cells consists of the following steps. cosmids were packaged, in vitro, into lambda phage particles and transduced into escherichia coli hosts lysogenized with thermo-inducible lambda c its phage. the introduced cosmids were repackaged into phage particles in the thermo-induced hosts. the efficiency of such in vivo cosmid packaging was further improved by construction of ptc vectors that carried three cohe ... | 1989 | 2531106 |
| generation of a large combinatorial library of the immunoglobulin repertoire in phage lambda. | a novel bacteriophage lambda vector system was used to express in escherichia coli a combinatorial library of fab fragments of the mouse antibody repertoire. the system allows rapid and easy identification of monoclonal fab fragments in a form suitable for genetic manipulation. it was possible to generate, in 2 weeks, large numbers of monoclonal fab fragments against a transition state analog hapten. the methods described may supersede present-day hybridoma technology and facilitate the producti ... | 1989 | 2531466 |
| bacterial expression of the p24 gag protein of the bovine leukaemia virus. | the possibility of expression of the gag gene of bovine leukaemia virus (blv) in the bacterial system was investigated. the dna fragment coding for the gag core 24 kda protein of blv was inserted into the porf1 expression vector. the polypeptides expressed in e. coli were analysed by western blotting. the bacterially synthesized antigens were detected by the serum of a blv-infected cow and by mouse monoclonal antibodies against the native p24 gag protein. | 1989 | 2541030 |
| a long-acting heat-stable enterotoxin analog of enterotoxigenic escherichia coli with a single d-amino acid. | a heat-stable enterotoxin (stp) consisting of 18 amino acid residues including 6 half-cystine residues is produced by a porcine strain of enterotoxigenic escherichia coli. analogs of stp with replacements of single residues at each from positions 5 to 17 by the corresponding d-amino acid residue were synthesized by a solid-phase method. of these analogs, [d-cys5]-stp[5-17] showed the same biological properties as stp[5-17]. moreover, its activity to cause fluid accumulation in suckling mouse las ... | 1989 | 2543409 |
| cloning and expression of plasmid dna sequences involved in salmonella serotype typhimurium virulence. | a 22kb region of the 90kb virulence-associated plasmid, pip1350, of typhimurium strain c52 was cloned into the mobilizable vector psup202, yielding plasmid pip1352. this recombinant plasmid restored full virulence to plasmidless strain c53 in a mouse model. transposon tn5 insertion mutagenesis demonstrated the existence of two dna sequences in pip1352 designated vira and virb, both of which are essential for the expression of virulence. a recombinant plasmid containing only the vira and virb reg ... | 1989 | 2546008 |