| a possible effect of heme on the fate of dna ligase activity extracted from differentiating mouse erythroleukemia cells. | when mouse erythroleukemia (mel) cells were induced to differentiate by growth in the presence of dimethyl sulfoxide, hexamethylene bisacetamide (hmba), or hemin, the apparent activity of dna ligase extractable from inducer-treated cells decreased 70 to 80% when compared to untreated cells. earlier work had indicated that these changes did not occur in a differentiation-resistant mel cell variant and suggested that the decrease in the level of dna ligase activity might be related to the differen ... | 1988 | 3180046 |
| interleukin 1 administration in mice produces hypoferremia despite neutropenia. | to determine whether the hypoferremic response to inflammation requires neutrophils, we administered human recombinant il-1 to mice made neutropenic with cyclophosphamide. with single intraperitoneal injections of il-1 the plasma iron concentrations decreased significantly in mice with either normal neutrophil counts or neutropenia. after single injections transferrin concentrations were not significantly changed, but the decrease in serum iron lowered mean transferrin saturations from a baselin ... | 1988 | 3264289 |
| kinetics of phagocytosis and killing of e. coli by murine macrophages in presence of different serum preparations. | in this study we evaluated the kinetics of phagocytosis and killing of e. coli by thioglycollate-elicited murine peritoneal macrophages and the role of specific antibodies and complement present in different serum preparations in modulating these processes. in our system phagocytosis of e. coli by macrophage monolayer was exponential for 180 min. the killing activity was high in the first 30-60 min and then virtually ceased. the least phagocytosis and killing occurred in presence of heat-inactiv ... | 1988 | 3280948 |
| expression of the mouse lactate dehydrogenase-a promoter fused with the bacterial gpt gene in chinese hamster ovary cells. | the promoter region of the cloned mouse lactate dehydrogenase-a gene was fused with the gpt gene of escherichia coli, and this fusion gene was shown to express in chinese hamster ovary cells. this result demonstrates that the cloned ldh-a promoter is indeed functional. | 1988 | 3284773 |
| genotoxicity studies on selected organosilicon compounds: in vitro assays. | a series of 12 organosilicon compounds representing potential intermediates in the synthesis and degradation of polydimethylsiloxanes were evaluated for genotoxic potential with a battery of in vitro assays. microbial assays included the ames bacterial reverse mutation in salmonella, mitotic gene conversion in saccharomyces cerevisiae d4 and dna repair in e. coli pol a +/-. these assays were conducted with and without a metabolic activation system containing aroclor 1254-induced rat-liver homoge ... | 1988 | 3284798 |
| escherichia coli secretion of an active chimeric antibody fragment. | a chimeric mouse-human fab protein that binds specifically to the human carcinoma cell line c3347 has been expressed and secreted from escherichia coli. this molecule, which contains functionally assembled kappa and fd proteins, binds as effectively to sites on the surface of c3347 cells as fab fragments prepared proteolytically from whole chimeric or mouse antibody. the production in escherichia coli of foreign heterodimeric protein reagents, such as fab, should prove useful in the management o ... | 1988 | 3285471 |
| myogenic lineage determination and differentiation: evidence for a regulatory gene pathway. | stable myogenic cell lines have been derived at a high frequency by transfection of a cloned multipotential mouse embryo cell line, c3h 10t1/2, with cloned human dna linked to a selectable neomycin resistance gene. the myogenic phenotype remains linked to neomycin resistance during secondary transfections. although proliferative in growth conditions, these cell lines maintain the ability to differentiate and express muscle-specific proteins. we conclude that there is a simple genetic basis for m ... | 1988 | 3286015 |
| studies on inflammation in mice: dynamics of inflammatory response induced by extract from escherichia coli and influence of antiinflammatory drugs. | the intraperitoneal injection of e. coli extract in the mouse resulted in a biphasic accumulation of leukocytes. the first phase of leukocyte accumulation was based on neutrophil influx in the peritoneal cavity, which occurred 1-2 days after e. coli extract administration. the second phase was based on macrophage influx, which occurred 12 days after e. coli extract administration. preceding the influx of neutrophils in the first phase, the exudation of plasma proteins in the peritoneal fluid occ ... | 1988 | 3294207 |
| differential elaboration of prostaglandin e2 by cells of the hemopoietic microenvironment in response to endotoxin. | eight daily intraperitoneal injections of endotoxin (lps) induced hematologic abnormalities in mice like those previously observed with chronic inflammation, sterile abscess, and tumor bearing. by the ninth day, anemia, leukocytosis, hypocellularity of the bone marrow, and compensatory hemopoietic hyperplasia of the spleen had occurred. the suppressed hemopoietic recovery and impaired survival of mice with these abnormalities, after receiving an ordinarily sublethal dose of total body irradiatio ... | 1987 | 3295086 |
| degradation of a camp-binding protein is inhibited by human c-ha-ras gene products. | incubation of the particulate fraction of cell extract prepared from nih3t3 mouse fibroblasts resulted in preferential proteolytic degradation of a camp-binding protein. the proteolysis was inhibited by human c-ha-ras gene products produced by escherichia coli. the proteolysis was observed at ph 6 to 7, and inhibited by antipain and leupeptin. these results suggest that camp-binding proteins might be cleaved by thiol proteinases. in fact, c-ha-ras gene products were proved to inhibit the catheps ... | 1987 | 3304283 |
| effects of endotoxins from bacteroides intermedius and escherichia coli on cytotoxic and lysosomal activity in peritoneal macrophages from endotoxin responder and low responder mouse strains. | peritoneal macrophages from normal mice strains (c3h/tif and c57bl/6j) and from the endotoxin (lipopolysaccharide, lps) low responder strain (c3h/hej were exposed to two structurally different endotoxins from bacteroides intermedius and escherichia coli in vitro. intracellular activity of a lysosomal enzyme (acid phosphatase) and macrophage mediated cytotoxic activity against a tumor cell line (l929) were tested. both endotoxins caused increased levels of acid phosphatase activity in normal mice ... | 1987 | 3307300 |
| characterization of human and mouse granulocyte-macrophage-colony-stimulating factors derived from escherichia coli. | human and mouse granulocyte-macrophage-colony-stimulating factors (hgm-csf and mgm-csf, respectively), isolated from escherichia coli cells expressing the corresponding human and mouse genes, have been characterized. the observed properties of the proteins have been compared with those properties which can be deduced from the dna sequence alone and the published properties of natural gm-csfs. the purified e. coli-derived proteins were found to have the expected molecular masses, amino acid compo ... | 1987 | 3318813 |
| microdissection and microcloning from the proximal region of mouse chromosome 7: isolation of clones genetically linked to the pudgy locus. | microdissection and microcloning have been utilized in order to create a bank of clones from the proximal region of mouse chromosome 7. several important loci map to this area, including the albino locus (c), pink-eye dilution (p), and the developmental mutant, pudgy (pu). by use of interspecific crosses between mus musculus domesticus and mus spretus, we have generated backcross progeny segregating for the mutations chinchilla (cch) and pink-eye dilution (p). exploiting the evolutionary diverge ... | 1987 | 3319884 |
| alternative procedure for the purification of the heat-stable enterotoxin of enterotoxigenic escherichia coli pathogenic for calves. | a method for purification of the heat-stable enterotoxin (st) of enterotoxigenic escherichia coli (etec) strains (c1444 and b41) pathogenic for calves and some physiochemical properties of the st are described. the method involved ultrafiltration on pm-10 and um-2 diaflo membranes, acetone fractionation, ion-exchange chromatography on ag 1-x2, chromatofocusing and a combination of hydrophobic interaction chromatography on octyl-sepharose cl-4b and gel-permeation on bio-gel p-2. polyacrylamide ge ... | 1987 | 3320075 |
| interaction of escherichia coli and macrophages: alteration by treatment of bacteria with beta-lactam antibiotics. | antibiotics are known to exert an influence on the host-parasite relationship either by impairment of immunocompetent cells or by alteration of the bacterium, such as changes of surface properties or the production of toxins. the main problem in investigating the effect of antibiotics on the surface properties of bacteria consists in morphological changes of bacteria (round cell or filament formation) after treatment e.g. with beta-lactam antibiotics. these changes of morphology lead to problems ... | 1987 | 3321761 |
| selection against expression of the escherichia coli gene gpt in hprt+ mouse teratocarcinoma and hybrid cells. | thioxanthine is toxic for mammalian cells transformed by the dominant selectable marker gpt. it allowed us to select, in the presence of the endogenous hypoxanthine-guanine phosphoribosyltransferase gene, mutants that did not express gpt any more and also hybrid cells that had lost the chromosome carrying it. the gpt marker is thus dominant in negative as well as in positive selection, which makes it potentially very useful for genetic studies of mammalian cells. | 1987 | 3323888 |
| direct effects of endotoxin on hepatocytes. synthesis of a specific secretory protein. | the synthesis of acute-phase proteins by the liver during sepsis has been thought to be induced primarily by monokines released from activated macrophages, although glucocorticoid hormones may also stimulate this process to a lesser degree. according to this concept, synthesis of these proteins following administration of bacterial endotoxins would be an indirect effect and would not reflect a direct interaction of the endotoxin molecule with the hepatic parenchymal cell. we observed, however, t ... | 1988 | 3341913 |
| quantitative assays for uracil-dna glycosylase of high sensitivity. | we have developed a sensitive fluorometric assay using bisulfite deaminated (c----u), covalently-closed circular pm2 dna as the substrate. we describe a reliable way to prepare this substrate without nicking the pm2 dna. methods, which depend on toluenization of the cells, are described for reproducibly and quantitatively assaying uracil-dna glycosylase. the sensitivity is such that only 200 el4 mouse thymoma cells or 30,000 escherichia coli cells are needed for each point in a kinetic assay. | 1988 | 3370147 |
| abilities of human oligodendroglial cells and mouse schwann cells to phagocytose mycobacterium leprae and other mycobacteria. | human oligodendroglial kg-1-c cells derived from human cerebral mixed glioma and mouse schwann cells derived from dorsal root ganglion were studied with respect to their abilities to phagocytose various mycobacteria, especially mycobacterium leprae, and other microorganisms. kg-1-c cells phagocytosed m. leprae at a markedly higher rate than balb/3t3, bhk 21, hela s3, mks-a tu-7, xc, tsv-5, n-18, and schwann cells but at a lower rate than peritoneal macrophages. schwann cells also exhibited subst ... | 1986 | 3510165 |
| the reproductive effects assessment group's review of the mutagenicity of vinylidene chloride. | a large number of studies indicate that vinylidene chloride is mutagenic to bacteria and that this activity is largely dependent on microsomal activation. vinylidene chloride gave positive results for gene reversion and conversion in yeast that was also dependent on metabolic activation, and was positive in tradescantia. in mammalian systems, vinylidene chloride failed to induce gene mutations in v79 cells at two separate loci, failed to induce chromosomal aberrations in mouse bone marrow in viv ... | 1986 | 3510861 |
| microscopic alterations in jejunal epithelium of 3-week-old pigs induced by pig-specific, mouse-negative, heat-stable escherichia coli enterotoxin. | the objective of this study was to determine whether exposure of swine jejunum to crude culture filtrates containing escherichia coli pig-specific, mouse-negative, heat-stable enterotoxin (stb) induces structural alterations in the jejunal mucosa of pigs. two ligated intestinal loops in each of twelve 3-week-old pigs were exposed for 2 hours to sterile e coli culture filtrates from each of the following strains: 431 (sta-producing), 1261 (sta and stb-producing), and 1790 (stb-producing); recombi ... | 1986 | 3516028 |
| interaction of a pyelonephritogenic escherichia coli strain with the tissue components of the mouse urinary tract. | immediately following the introduction of cells of a pyelonephritogenic strain of escherichia coli (expressing both gs and ms adhesins) into the mouse bladder, these cells were found to be randomly distributed on the mucosal surfaces of both the bladder and the kidney. after 24 hr. these adherent bacterial cells had proliferated to form nonrandomly distributed adherent microcolonies on both mucosal surfaces and large masses within the renal ducts. large amounts of amorphous material, which we pr ... | 1986 | 3520025 |
| wounding a fibroblast monolayer results in the rapid induction of the c-fos proto-oncogene. | the c-fos gene has previously been shown to be transiently induced within minutes after the stimulation of mouse fibroblasts with growth factors. induction of c-fos was observed specifically with competence factors (e.g., platelet-derived growth factor), not with progression factors (e.g., platelet-poor plasma), suggesting a role for c-fos in conferring competence on fibroblasts. to test this hypothesis we have analyzed c-fos expression in nih 3t3 cells that were made competent in a different wa ... | 1986 | 3522222 |
| expression of reovirus p14 in bacteria and identification in the cytoplasm of infected mouse l cells. | reovirus genome segment s1 is transcribed by the virion-associated polymerase to form a single mrna species that codes for two polypeptides: the 49-kda cell-attachment protein, sigma 1, starting from the first a-u-g in the s1 transcript, and a 14-kda nonstructural, basic protein initiated from the second a-u-g in a different reading frame (ernst and shatkin, 1985; jacobs et al., 1985; shatkin, 1985). to confirm that p14 is made in reovirus-infected cells, determine its intracellular location, an ... | 1986 | 3526708 |
| simultaneous synthesis of human-, mouse- and chimeric epidermal growth factor genes via 'hybrid gene synthesis' approach. | simultaneous synthesis of two dna duplexes encoding human and mouse epidermal growth factors (egf) was accomplished in a single step. a 174 b.p. dna heteroduplex, with 16 single and double base pair mismatches, was designed. one strand encoded the human egf, and the opposite strand indirectly encoded the mouse egf. the heteroduplex dna was synthesized by ligation of seven overlapping oligodeoxyribonucleotides with a linearized plasmid. after transformation in e. coli hb101 (reca 13), the resulti ... | 1986 | 3529034 |
| nucleotide sequence and characteristics of the gene for l-lactate dehydrogenase of thermus caldophilus gk24 and the deduced amino-acid sequence of the enzyme. | the gene for l-lactate dehydrogenase (ldh) (ec 1.1.1.27) of thermus caldophilus gk24 was cloned in escherichia coli using synthetic oligonucleotides as hybridization probes. the nucleotide sequence of the cloned dna was determined. the primary structure of the ldh was deduced from the nucleotide sequence. the deduced amino acid sequence agreed with the nh2-terminal and cooh-terminal sequences previously reported and the determined amino acid sequences of the peptides obtained from trypsin-digest ... | 1986 | 3533539 |
| blinded, two-laboratory comparative analysis of escherichia coli heat-stable enterotoxin production by using monoclonal antibody enzyme-linked immunosorbent assay, radioimmunoassay, suckling mouse assay, and gene probes. | heat-stable enterotoxin (st)-producing enterotoxigenic escherichia coli (etec) can be identified by a variety of assays, including the suckling mouse assay (sma), radioimmunoassay (ria), polyclonal or monoclonal antibody enzyme-linked immunosorbent assay (elisa), and dna hybridization with sth and stp gene probes. to compare the sensitivity and reliability of these assays, 100 coded etec and non-etec isolates were blindly tested in two independent laboratories. sma, ria, and monoclonal elisa wer ... | 1986 | 3533986 |
| assessment of in vivo revival, growth, and pathogenicity of escherichia coli strains after copper- and chlorine-induced injury. | cells of one enteroinvasive and three enterotoxigenic strains of escherichia coli were exposed to sublethal concentrations of copper and chlorine to produce 85 to 94% injury. injured cells were intraluminally inoculated into ligated ileal loops of anesthetized mice, and injury was assessed at timed intervals. substantial recovery (72-84%) of copper- and chlorine-injured cells was observed in the inoculated loops at 4 and 3 h, respectively. no appreciable increase in total numbers was observed du ... | 1986 | 3535675 |
| two-site column enzyme immunoassay for neuron-specific enolase (nse) in human serum using monoclonal antibodies. | a new method for the rapid determination of neuron-specific gamma-enolase (nse), gamma-subunit of alpha gamma- and gamma gamma-enolase in human serum was developed by employing monoclonal antibodies for the separation method. the assay system consists of 0.1 ml sepharose 4b column with immobilized rabbit anti-mouse igg antibodies for the separation of bound label, fab' fragments of rabbit anti-bovine gamma gamma-enolase igg labeled with beta-d-galactosidase from escherichia coli, and f(ab')2 fra ... | 1986 | 3537135 |
| comparative study of synthetic oligonucleotide and cloned polynucleotide enterotoxin gene probes to identify enterotoxigenic escherichia coli. | escherichia coli isolated from 2,126 children in thailand and the philippines was examined for enterotoxin production and for dna hybridization with synthetic oligonucleotide and cloned polynucleotide enterotoxin gene probes. a total of 233 infections with e. coli that were detected by one or more of these assays were identified. of the infections, 75% (164/233) were identified by all three methods. an additional 18% (43/233) were identified by two of three methods. isolates from 10% (19/183) of ... | 1987 | 3539983 |
| establishment of four mouse hybridoma cell lines producing monoclonal antibodies reactive with ras oncogene product p21. | with the use of proteins derived from escherichia coli cells expressing the v-h-ras gene product as immunogens and an enzyme-linked immunosorbent assay with whole cells for a screening method, 4 balb/c mouse hybridoma cell lines (rp-12, rp-28, rp-35, and rp-38) were isolated that produced monoclonal antibodies (moabs) showing higher reactivity with murine ras gene-activated cell lines than with normal cell lines. all the moabs complexed p21ras from the ras gene-activated cell lines in western im ... | 1986 | 3540418 |
| use of mucin and hemoglobin in experimental murine gram-negative bacteremia enhances the immunoprotective action of antibodies reactive with the lipopolysaccharide core region. | an antiserum with a high content of antibodies, binding to the gram-negative lipopolysaccharide core region, was prepared by immunizing rabbits with the rough escherichia coli mutant j5. this antiserum was capable of protecting mice against lethal challenge doses of e. coli 0 111:b4 in a mouse model where the animals were compromised by means of mucin plus hemoglobin (ld 50 = 10(3) bacteria). however, no protection was observed in a non-compromised mouse model (ld 50 = 10(7) bacteria). this obse ... | 1986 | 3545072 |
| prophylactic administration of interleukin-2 protects mice from lethal challenge with gram-negative bacteria. | prophylactic administration of recombinant human interleukin-2 (il-2) in mice enhanced survival and produced complete recovery from an otherwise lethal acute bacterial infection. il-2 was administered as a single intraperitoneal or intravenous bolus dose to cdi mice 18 h before challenge with a lethal dose of a clinical isolate of escherichia coli type o2 (minimal 100% lethal dose, 6 x 10(7) cfu per mouse). at il-2 dosages of 7 x 10(6) u/kg, 90% of treated cdi mice survived as compared to 0% for ... | 1987 | 3546134 |
| structure of human tumor necrosis factor alpha derived from recombinant dna. | recombinant dna derived tumor necrosis factor alpha, when expressed at a high level in escherichia coli, appeared in the pellet and soluble fractions of disrupted cells. the protein was purified from the pellet fraction by solubilizing it in urea and reducing agent and was refolded into a buffer without these additives. the structure of the protein was identical with that purified from the soluble fraction without exposure to both reducing and denaturing agents, as demonstrated by circular dichr ... | 1987 | 3552045 |
| comparative anatomy of the human aprt gene and enzyme: nucleotide sequence divergence and conservation of a nonrandom cpg dinucleotide arrangement. | the functional human adenine phosphoribosyltransferase (aprt) gene is less than 2.6 kilobases in length and contains five exons. the amino acid sequences of aprts have been highly conserved throughout evolution. the human enzyme is 82%, 90%, and 40% identical to the mouse, hamster, and escherichia coli enzymes, respectively. the promoter region of the human aprt gene, like that of several other "housekeeping" genes, lacks "tata" and "ccaat" boxes but contains five gc boxes that are potential bin ... | 1987 | 3554238 |
| sequence analysis of spontaneous mutations in a shuttle vector gene integrated into mammalian chromosomal dna. | we have studied the molecular mechanisms of spontaneous mutations in mouse cells carrying a selectable bacterial gene. the mouse cells carry the escherichia coli xanthine (guanine) phosphoribosyltransferase (gpt) gene in a retroviral shuttle vector integrated into chromosomal dna in a proviral form. cells with spontaneous mutations in the gpt gene were selected as resistant to 6-thioguanine and then were fused with cos cells for recovery of the mutant genes. out of a total of 77 independent 6-th ... | 1987 | 3554239 |
| effects of toxic shock syndrome staphylococcus aureus, endotoxin and tampons in a mouse model. | synthetic tampons and toxic shock syndrome toxin-one (tsst-1)-producing strains of staphylococcus aureus have been linked to an increased incidence of toxic shock syndrome (tss). while recent reports attempt to define the tampon connection as the creation of an optimal environment for the production of tsst-1, the role of other factors in disease expression in an animal model remain under investigation. to understand the role of tampons and bacteria, pools of swiss mice were inoculated with perm ... | 1987 | 3581548 |
| immunological responsiveness of mouse spleen cells after in vivo or in vitro exposure to 3-acetyldeoxynivalenol. | the effects of 3-acetyldeoxynivalenol (3-acdon) on mitogen-induced lymphocyte proliferation and antibody production were studied in male cd-1 mice exposed to 0, 2.5, 5 or 10 ppm 3-acdon in the diet for 35 days. mitogen-induced lymphocyte proliferation and t-cell-independent antibody responses to dinitrophenyl-ficoll or escherichia coli were not altered by dietary exposure to 3-acdon. the t-cell-dependent antibody response to sheep red blood cells was increased in the group fed 10 ppm 3-acdon. in ... | 1987 | 3609979 |
| analysis of functional domains on reovirus cell attachment protein sigma 1 using cloned s1 gene deletion mutants. | previously a reovirus (serotype 3) s1 gene cdna was inserted into the lac cloning site of puc13 and expressed in escherichia coli to yield a sigma 1 fusion protein (f-sigma 1) capable of binding to mouse l fibroblasts and of agglutinating human red blood cells (s.a. masri, l. nagata, d. c. w. mah, and p. w. k. lee, 1986, virology 149, 83-90). to probe the functional domains on the sigma 1 protein, restriction enzymes which divide the s1 gene into four segments (5'-i-ii-iii-iv-3') of similar size ... | 1987 | 3629973 |
| transcriptional control of rat heme oxygenase by heat shock. | a heat shock element is located in the 5'-flanking region of the rat heme oxygenase gene (ho gene). the incubation of rat glioma cells at 42 degrees c or with hemin at 37 degrees c increased the levels of heme oxygenase mrna within 1 h and produced a maximum at 3 h (at least a 20-fold increase). in both treatments, the heme oxygenase activity started to increase after a lag period of about 1 h and reached a maximum value at 5 h. there was an apparent additive effect of both treatments on the hem ... | 1987 | 3654594 |
| expression of a pseudogene for interferon-alpha l. | the human leukocyte interferon-alpha l (ifn-alpha l) appears to be a pseudogene because it contains a termination codon in the dna coding for the precursor peptide (signal peptide), but the remainder of the gene codes for an interferon protein of normal length. to determine if this gene codes for an active interferon molecule, an expression plasmid was constructed for ifn-alpha l that was produced in escherichia coli. the ifn-alpha l is active on human and bovine cells, and exhibits a trace of a ... | 1987 | 3681016 |
| production and characterization of monoclonal antibodies against recombinant human tumor necrosis factor/cachectin. | tumor necrosis factor is a monokine, which causes cytolysis of many transformed cells. in this study we have found that in addition to cytotoxicity recombinant escherichia coli-derived human tumor necrosis factor, like cachectin, inhibited the lipoprotein lipase of 3t3-l1 preadipocytes. both effects were inhibited by monoclonal anti-tumor necrosis factor antibodies. monoclonal antibodies against recombinant human tumor necrosis factor were produced by fusing splenocytes of immune mice with p3x63 ... | 1986 | 3729942 |
| cloning and sequence analysis of mrna for mouse aspartate aminotransferase isoenzymes. | the nucleotide sequences of mrnas for the mouse mitochondrial and cytosolic aspartate aminotransferase isoenzymes (maspat and caspat) (ec 2.6.1.1) were determined from complementary dnas. the maspat mrna comprises minimally 2460 nucleotides and codes for a polypeptide of 430 amino acid residues corresponding to the precursor form of the maspat (pre-maspat). the caspat mrna comprises minimally 2086 nucleotides and codes for a polypeptide of 413 amino acid residues. the region coding for the matur ... | 1986 | 3782150 |
| purification and characterization of clostridium sordellii lethal toxin and cross-reactivity with clostridium difficile cytotoxin. | lethal toxin (lt) was purified from clostridium sordellii ip82 by deae-trisacryl, ultrogel aca3-4 gel filtration, and hydroxyapatite column chromatography. the molecular weight of purified lt was estimated to be 240,000 to 250,000, and the pi was at ph 4.55. lt was lethal for mice by intraperitoneal injection (3.4 x 10(5) mouse lethal doses per mg of protein), cytotoxic for vero cells (6.1 x 10(4) cytotoxic units per mg of protein), erythematous and edematous by intradermal injection in guinea p ... | 1987 | 3793234 |
| evaluation of bw942c, a novel antidiarrheal agent, against enterotoxins of escherichia coli and vibrio cholerae. | bw942c, an enkephalin-like pentapeptide with anti-diarrheal activity, was tested against crude toxins of escherichia coli and vibrio cholerae in the y-1 adrenal cell assay, rabbit ileal loop assay, and suckling mouse assay. the effects of bw942c on in vitro ion transport were measured in rabbit ileum mounted in ussing chambers. in vitro, bw942c decreased basal short-circuit current (2.26 and 3.15 mueq cm-2 h-1 in experimental samples and controls, respectively; n = 7, p less than 0.05) and incre ... | 1985 | 3838969 |
| production of neutralizing monoclonal antibodies to escherichia coli heat-stable enterotoxin. | in an effort to develop new approaches to the study and control of infectious diarrhea, we prepared murine monoclonal antibodies to the escherichia coli heat-stable enterotoxin (sta). the toxin was purified from e. coli culture media and conjugated to bovine serum albumin. the sta-bovine serum albumin conjugate was used to immunize balb/c mice, and the immune spleen cells from these mice were fused with sp2/0 myeloma cells. resultant hybridomas were screened in an enzyme-linked immunosorbent ass ... | 1985 | 3880723 |
| identification by dna hybridization of enterotoxigenic escherichia coli in a longitudinal study of villages in thailand. | radioactively labeled enterotoxin genes were used to study the epidemiology of enterotoxigenic escherichia coli infections in two thai villages. when e. coli that were isolated from 674 specimens were fixed on nitrocellulose paper and examined for hybridization with e. coli enterotoxin gene probes in bangkok, the technique had a sensitivity of 94% (31 of 33) and a specificity of 100% (641 of 641), when compared with tests of e. coli for enterotoxin production in the y-1-adrenal cell and suckling ... | 1985 | 3880798 |
| evaluation of the dna-repair host-mediated assay. i. induction of repairable dna damage in e. coli cells recovered from liver, spleen, lungs, kidneys, and the blood stream of mice treated with methylating carcinogens. | the dna-repair host-mediated assay was further calibrated by determining the genotoxic activities of 4 methylating carcinogens, namely, dimethylnitrosamine (dmna), 1,2-dimethylhydrazine (sdmh), methyl nitrosourea (mnu) and methyl methanesulphonate (mms) in various organs of treated mice. the ranking of the animal-mediated genotoxic activities of the compounds was compared with that obtained in dna repair assays performed in vitro. the differential survival of strain e. coli k-12/343/113 and of i ... | 1985 | 3881659 |
| macrophage activation by monosaccharide precursors of escherichia coli lipid a. | certain escherichia coli mutants defective in phosphatidylglycerol biosynthesis accumulate two novel glycolipids, designated x and y. lipid x is a diacylglucosamine 1-phosphate bearing beta-hydroxymyristoyl groups at positions 2 and 3, and lipid y has the same structure as x, except for the additional presence of a palmitoyl moiety on the n-linked beta-hydroxymyristate. we have examined the activities of x, y, and several related compounds as activators of macrophages. both x and y induce morpho ... | 1985 | 3881760 |
| integration of a dominant selectable marker into human chromosomes and transfer of marked chromosomes to mouse cells by microcell fusion. | a method for the production of stable mouse-human cell hybrids containing a single human chromosome is described. as a first step in this method, a cloned selectable marker, the e. coli xanthine-guanine phosphoribosyltransferase (ecogpt) gene, was transferred to human cells to generate cell lines each carrying ecogpt integrated into a different site. human chromosomes marked with ecogpt were transferred further into mouse cells by microcell fusion. monochromosomal hybrids, in which the human chr ... | 1985 | 3885417 |
| expression of plasmodium falciparum surface antigens in escherichia coli. | the asexual blood stages of the human malarial parasite plasmodium falciparum produce many antigens, only some of which are important for protective immunity. most of the putative protective antigens are believed to be expressed in schizonts and merozoites, the late stages of the asexual cycle. with the aim of cloning and characterizing genes for important parasite antigens, we used late-stage p. falciparum mrna to construct a library of cdna sequences inserted in the escherichia coli expression ... | 1985 | 3887406 |
| linkage of genes for heat-stable enterotoxin, drug resistance, k99 antigen, and colicin in bovine and porcine strains of enterotoxigenic escherichia coli. | linkages among genes for production of escherichia coli heat-stable enterotoxin (st), drug resistance, k99 antigen, and colicin were investigated in 2 bovine and 3 porcine strains of enterotoxigenic e coli. in conjugation experiments, all 5 isolates transferred enterotoxigenicity and the ability to produce k99; 4 of the 5 isolates also transferred antibiotic resistance markers, and 3 colicinogenic strains transmitted the ability to produce colicin. in 2 of the 3 colicin-producing strains, the ge ... | 1985 | 3888010 |
| cross-reactive immunoprotective antibodies to escherichia coli o111 rough mutant j5. | the potential immunoprotective role of antiserum to an escherichia coli j5 mutant derived from e. coli o111:b4 was demonstrated in an experimental mouse model. overwhelming bacterial inocula masked the effects of cross-reactive immunoprotection due to antiserum to strain j5. enhanced bacterial clearance was observed in mice receiving antiserum to strain j5 in sublethal infections but not from lethal doses. incorporation of hemoglobin with the bacterial inocula decreased the 50% lethal dose of ch ... | 1985 | 3889175 |
| efficient expression in escherichia coli of two species of human interferon-alpha and their hybrid molecules. | a new type of interferon (ifn)-alpha cdna (ifn-alpha i') was identified in a cdna library constructed from namalva cells infected with sendai virus. the nucleotide sequence of this cdna showed homology, with the exception of two nucleotides in the coding region, with the previously identified ifn-alpha i gene (lawn et al., 1981). an expression plasmid which directs the synthesis of the mature ifn-alpha i' peptide was constructed using vectors carrying the lpp/lac promoter and "runaway" replicon. ... | 1985 | 3891272 |
| pathogenic synergy between escherichia coli and bacteroides fragilis: studies in an experimental mouse model. | an animal model is described for quantitative evaluation of pathogenic synergy between escherichia coli and bacteroides fragilis in which adjuvants were not required for abscess formation. two sets of strains of e. coli and b. fragilis isolated from human wound infections were tested. pathogenic synergy was observed in only one of the two combinations and was dependent on properties of e. coli. | 1985 | 3892009 |
| factors affecting the efficiency of introducing foreign dna into mice by microinjecting eggs. | microinjection of foreign dna into fertilized mammalian eggs is a convenient means of introducing genes into the germ line. some of the more important parameters that influence successful integration of foreign dna into mouse chromosomes are described. the effects of dna concentration, size, and form (supercoiled vs. linear with a variety of different ends) are considered as well as the site of injection (male pronucleus, female pronucleus, or cytoplasm) and buffer composition. the optimal condi ... | 1985 | 3892534 |
| evaluation of the in-vivo efficacy of sch 34343. | sch 34343 showed a linear dose response (with respect to aucs) in mice following both intravenous and subcutaneous administration. it was 100% bioavailable following subcutaneous administration. peak serum levels, aucs, beta-phase half-life and recovery of sch 34343 from the urine of mice indicated that it was similar to cephalothin and cefamandole. in experimental mouse infections, against gram-negative strains, sch 34343 was more active than cephalothin, equal to or more active than cefamandol ... | 1985 | 3897173 |
| colonization of human wounds by escherichia vulneris and escherichia hermannii. | in this report we present clinical descriptions of 12 hawaiian patients from whom escherichia vulneris or e. hermannii strains were isolated. all but two patients had soft-tissue infections with multiple bacteria, particularly staphylococcus aureus. the other two had purulent conjunctivitis associated with s. aureus and infected malignant peritonitis with multiple organisms, respectively. in none of the cases were the escherichia spp. found in abundant quantities or considered pathogenic. in pre ... | 1985 | 3897270 |
| quantitation of s-adenosylmethionine decarboxylase protein. | a method for the specific labeling of the active site of s-adenosylmethionine decarboxylase was developed. the method consisted of incubating cell extracts with 3h-decarboxylated s-adenosylmethionine and sodium cyanoborohydride in the presence of a spermidine synthase inhibitor. under these conditions, s-adenosylmethionine decarboxylase was labeled specifically and stoichiometrically. this procedure was used (a) to establish that the subunit molecular weight of s-adenosylmethionine decarboxylase ... | 1985 | 3902085 |
| acquisition of genes from an o18:k1:h7 colv+ strain of escherichia coli renders intracranially-inoculated e. coli k12 highly virulent for chickens, ducks and guinea-pigs but not mice. | the virulence of intracranially-inoculated mutant forms of an o18ac:k1:h7 colv+ strain of escherichia coli (designated mw) that lacked different combinations of its o and k antigens and colv, and of an e. coli k12 strain to which these characters had been transmitted was studied in mice, chickens, ducks and guinea-pigs. the o18+k1+colv+ form of mw was highly virulent for chickens and mice but the corresponding form of k12 was only highly virulent for chickens; the o18-k1-colv- forms of both stra ... | 1985 | 3905956 |
| effects of vp-16 on cell growth and metabolism of nucleic acids in mouse leukemia l-1210 cells and on the activity of dna polymerase i of e. coli. | | 1985 | 3911717 |
| [characterization of strains of escherichia coli isolated from calves with neonatal diarrhea]. | thirty fecal samples of diarrheic calves from a beef herd with previous history of neonatal diarrhea were cultured for isolation of escherichia coli k99 (+) and for enterotoxigenic tests. the age distribution of sampled calves was: 1 animal less than 6 days old, 21 between 7-15 days old and 8 between 16-30 days old. although most strains were classified as isaacson et al (16) biotype four, they were negative for detection of k99 antigen by slide agglutination test. the assay for heat-stable (st) ... | 1985 | 3916646 |
| expression in mammalian cells of the diaminopimelic acid decarboxylase of escherichia coli permits cell growth in lysine-free medium. | the lysa gene of escherichia coli encodes for a diaminopimelic acid decarboxylase (ec 4.1.1.20) which allows the conversion of diaminopimelic acid into lysine in bacteria. it has been cloned in an eukaryotic expression vector containing upstream the sv40 early promoting sequence, and downstream mouse alpha-globin maturating sequences. the recombinant plasmid psb99 (4800 base pairs) has been introduced into several mammalian cell lines by cotransfection with a second selectable marker i.e. the po ... | 1985 | 3917917 |
| an ex vivo method for evaluating prostaglandin synthetase activity in cortical slices of mouse brain. | the release of prostaglandin e2 (pge2) from cortical slices of mice into incubation medium is followed for 3 h and compared to pge2 levels in the corresponding slice. immediately after decapitation, the rate of pge2 released into the incubation medium is elevated and a steady low rate of spontaneous release is gained within 1-2 h of incubation. pge2 synthesis and release is blocked in a dose-dependent manner by either indomethacin (3 x 10(-6) -3 x 10(-4) m) or flufenamic acid (2.6 x 10(-6) m) ei ... | 1985 | 3923156 |
| faithful cell-cycle regulation of a recombinant mouse histone h4 gene is controlled by sequences in the 3'-terminal part of the gene. | we have analyzed the expression of endogenous histone h4 genes and of a newly introduced h4 gene in 21-tb cells, a mouse mastocytoma cell-cycle mutant. endogenous h4 mrnas were less abundant by a factor of 120-180 in g1-arrested than in exponentially multiplying cells. however, h4 transcription rates were only decreased by a factor of 3 under these conditions, as determined by in vitro elongation of nascent transcripts. this indicates that post-transcriptional control of histone mrna levels is i ... | 1985 | 3925455 |
| effect of chemotactins released by staphylococcus aureus and pseudomonas aeruginosa on the murine respiratory tract. | staphylococcus aureus, the pseudomonas aeruginosa temperature-sensitive (ts) mutant a/10/25, and the p. aeruginosa parental wild type were aerosolized to c5-deficient mice, and the total number of polymorphonuclear leukocytes (pmn) recovered by lung lavage was determined 4 h after aerosol exposure. s. aureus induced a slight but significant recruitment of pmn, as compared with the effect of a saline aerosol. both wild-type p. aeruginosa and the ts mutant induced a significant pmn recruitment of ... | 1985 | 3926643 |
| molecular cloning and expression of human tumor necrosis factor and comparison with mouse tumor necrosis factor. | u-937 cells, a monocytic line derived from a human histiocytic lymphoma, were induced for human tumor necrosis factor (tnf) secretion into the medium and were used for the preparation of tnf mrna. biological activity of the latter was quantified in a xenopus laevis oocyte injection system. tnf mrna was enriched by gradient centrifugation and this size-fractionated mrna was used for synthesis of cdna and inserted into the unique psti site of pat153. a recombinant plasmid containing human tnf cdna ... | 1985 | 3932069 |
| purification, characterization, and immunological properties of fumarase from euglena gracilis var. bacillaris. | a rapid three-step procedure utilizing heat treatment, ammonium sulfate fractionation, and affinity chromatography on matrex gel orange a purified fumarase (ec 4.2.1.2) 632-fold with an 18% yield from crude extracts of euglena gracilis var. bacillaris. the apparent molecular weight of the native enzyme was 120,000 as determined by gel filtration on sephacryl s-300. the preparation was over 95% pure, and the subunit molecular weight was 60,000 as determined by sodium dodecyl sulfate-polyacrylamid ... | 1985 | 3932328 |
| production of epidermal growth factor in escherichia coli from a synthetic gene. | mouse epidermal growth factor (egf) is under investigation as a deflecting agent for sheep. substantial quantities of the pure protein are required for these studies and to supply this need a gene for the protein was synthesized and inserted into plasmid vectors to direct the expression of egf polypeptide, or fusion proteins containing the egf peptide sequence, in transformed escherichia coli. mature egf was released by lysine specific proteolysis of a fusion protein consisting of part of the e. ... | 1985 | 3938982 |
| purification and characterization of hypoxanthine-guanine phosphoribosyltransferase from schistosoma mansoni. a potential target for chemotherapy. | hypoxanthine phosphoribosyltransferase and guanine phosphoribosyltransferase activities are essential for the supply of guanine nucleotides in schistosoma mansoni schistosomules. in crude extracts of adult s. mansoni, these two activities co-elute in size exclusion, ion exchange, and chromatofocusing chromatography and exhibit similar stabilities to heat treatment, suggesting that they are associated in one enzyme protein hypoxanthine-guanine phosphoribosyltransferase. this enzyme has been purif ... | 1986 | 3941107 |
| immunotherapy of gram-negative bacterial sepsis. a single murine monoclonal antibody provides cross-genera protection. | previous experimental and clinical studies have demonstrated the ability of polyclonal antibody directed against the core lipopolysaccharide (lps)-lipid a component of endotoxin to reduce mortality. we sought to characterize the ability of a single murine monoclonal igg1 antibody (8a1 mab) to react to a variety of gram-negative microorganisms, to promote phagocytosis, and to provide protection during experimental murine sepsis. the 8a1 mab reacted to various gram-negative bacterial whole cell an ... | 1986 | 3942500 |
| hemolytic-uremic syndrome--an outbreak in sacramento, california. | between july and november 1982, 14 cases of the hemolytic-uremic syndrome occurred in the sacramento, california, metropolitan area; 9 of the 14 patients lived within a 7.5-mile radius in northeast sacramento, 10 were female, 12 were white non-hispanic and 13 were children with a mean age of 3.6 years. of the 14 patients, 13 were admitted to hospital; 7 required peritoneal dialysis. the 14th child, a 3-month-old white female infant, was found dead in her crib and had renal histopathologic findin ... | 1986 | 3953085 |
| selective transfer of individual human chromosomes to recipient cells. | two hypoxanthine phosphoribosyltransferase-deficient human cell lines, d98/ah-2 and ht1080-6tg, were stably transfected with psv2 gpt, a plasmid containing the selectable marker escherichia coli xanthine-guanine phosphoribosyl transferase (eco gpt). hypoxanthine-aminopterin-thymidine-resistant transformants arose with a frequency of ca. 10(-6) and contained mostly single, but occasionally multiple, copies of the plasmid sequences. these transformants actively express the eco gpt marker. single c ... | 1985 | 3982414 |
| the influence of murine macrophage-conditioned medium on cloning efficiency, antibody synthesis, and growth rate of hybridomas. | murine b-cell hybridomas made with the p3x63-ag8.653 myeloma showed increases in cloning efficiency and efficiency of growth in hypoxanthine-aminopterin-thymidine (hat) medium of 50-100-fold in the presence of medium conditioned by primary mouse peritoneal macrophages (mcm). similar effects were elicited by mcm from 3 continuous macrophage lines. the j774a.1 line conditioned the medium as efficiently as primary macrophages without induction. conditioning by the p388d1 line was several-fold less ... | 1985 | 3998479 |
| cathepsin b activity in human blood monocytes during differentiation in vitro. | the activity of cathepsin b was assayed in human blood monocytes during differentiation into macrophages in vitro. freshly isolated monocytes showed negligible cathepsin b activity. on day 3 in culture the enzyme activity was still very low, but it was markedly increased on day 7, concomitant with the monocytes' morphological differentiation into tissue macrophage-like cells. a further rise in enzyme activity was seen on day 10 in culture. acid phosphatase activity showed similar, but less marke ... | 1985 | 4023633 |
| [study of mouse or rat livers perfused "in vitro" with blood containing bacterial dna]. | | 1970 | 4098015 |
| antigenic relationships in mammalian dna polymerase. | rabbit antibody was prepared against a high-molecular-weight dna polymerase purified from the soluble fraction of calf thymus gland. this antibody does not inhibit terminal deoxynucleotidyl transferase isolated from that source, but does inhibit both low-molecular-weight and high-molecular-weight dna polymerases isolated from cytoplasmic and nuclear fractions of a number of mammalian tissues (mouse l cells, calf thymus, phytohemagglutinin-stimulated human lymphocytes, rat liver, and rabbit bone ... | 1972 | 4110484 |
| evidence for single copies of globin genes in the mouse genome. | | 1972 | 4117010 |
| hybridization characteristics of enzymatically synthesised dna complementary to mouse immunoglobulin messenger rna. | | 1974 | 4136787 |
| [persistance of morphologic differences between thymodependent and thymo-independant lymphocytes in the mouse after selective antigenic sollicitation of one or the other population]. | | 1973 | 4214368 |
| skin reaction produced by endotoxins and lactobacillus in mouse. | | 1974 | 4215912 |
| techniques used in the establishment and maintenance of a barrier mouse breeding colony. | | 1968 | 4247420 |
| effect of normal mouse serum on mouse lymphocyte transformation in vitro. | | 1974 | 4277456 |
| attempts to detect an integrated polyoma genome by nucleic acid hybridization ii. complementarity between polyoma virus dna and normal mouse synthetic rna. | | 1965 | 4285375 |
| studies on the influence of host defence mechanisms on the antimicrobial effect of chemotherapeutic agents. effect of antibiotics on phagocytosis of mouse-peritoneal-macrophages in vitro. | | 1971 | 4326907 |
| the distribution and binding of tritiated polymyxin b in the mouse. | | 1972 | 4343416 |
| the production of vesicular stomatitis virus by antigen- or mitogen-stimulated lymphocytes and continuous lymphoblastoid lines. | a variety of lymphoid cell populations were examined in terms of their ability to replicate vesicular stomatitis virus (vsv), a lytic, rna-containing virus maturing at the cell surface. the number of cells capable of producing vsv was estimated in terms of infectious centers by the virus plaque assay (vpa), and morphologically by electron microscopy (em). the lymphoid cells examined in this study included: (a) lymph node cells from delayed hypersensitive guinea pigs stimulated by specific antige ... | 1973 | 4348276 |
| comparison of the acceptance activity of the ribosome-bound and the total cellular transfer ribonucleic acids from sv40-transformed mouse fibroblasts. | | 1973 | 4360078 |
| selective activation of mouse t and b lymphocytes by periodate, galactose oxidase and soybean agglutinin. | | 1974 | 4372060 |
| the reversible inhibition of catalase activity by nucleotides and its possible relationship to mouse liver catalase depression induced by biological substances. | | 1971 | 4399192 |
| failure of poly (i-c) to enhance killing of escherichia coli by mouse peritoneal macrophages. | | 1972 | 4561487 |
| characterization of a mouse ascites cell-free system. | | 1972 | 4565029 |
| characteristics and products of a cell-free polypeptide synthesizing system from neonatal and adult mouse brain. | | 1972 | 4569109 |
| transfer ribonucleic acids from mouse plasmacytoma tumors producing kappa and immunoglobulin chains. | | 1973 | 4569775 |
| age-dependent changes in sensitivity to antigen in the mouse. | | 1973 | 4576505 |
| common enterobacterial antigen. ii. effect of immunization on challenge with heterologous bacilli. | studies were carried out evaluating the protective activity of immunization with common enterobacterial antigen (ca) against challenge with heterologous gram-negative bacilli. active immunization of mice with escherichia coli 0:14 elicited titers of antibody to ca of 1:640 or greater but completely failed to enhance resistance to challenge by mouse virulent strains of klebsiella pneumoniae or e. coli. similarly, two lots, 324 and 422, of rabbit antisera to ca failed to afford passive protection ... | 1973 | 4576679 |
| regulation of immunoglobulin synthesis by dextran. | dextran, of the variety commonly used as plasma expander, markedly altered antibody synthesis to an unrelated antigenic stimulus, srbc, in two animal species, guinea pig and mouse. the time at which dextran was administered relative to antigen was found to be most critical for increasing or decreasing the number of igm and igg pfc. furthermore, these times differed for the two species studied. typically, when given to guinea pigs 6 h before srbc, dextran caused a 20-fold rise in igm-producing ce ... | 1973 | 4577618 |
| protein synthesis initiation in eukaryotes. characterization of ribosomal factors from mouse fibroblasts. | | 1973 | 4581104 |
| susceptibility of the mouse intestine to heat-stable enterotoxin produced by enteropathogenic escherichia coli of porcine origin. | ligated intestinal loops of mice were found suitable for the assay of heat-stable enterotoxin produced by enteropathogenic escherichia coli strains of porcine origin; loops inoculated with heat-labile enterotoxin failed to react. | 1973 | 4584587 |
| effect of 5-bromodeoxyuridine on chromatin transcription in confluent fibroblasts. | 3t6 mouse fibroblasts were grown in 5-bromodeoxyuridine (brdu) so that approximately 20% of the thymine residues in dna were replaced by brdu. brdu replacement caused an alteration in the relative incorporation of labeled nucleotide precursors into rna. the rna synthesized by cells grown in brdu has a lower proportion of adenine and a higher guanine complement. this was shown for (a) nascent rna made in vivo by confluent monolayers of cells in culture; (b) rna synthesized in vitro on a chromatin ... | 1974 | 4592691 |