| btcd, a mouse protein that binds to curved dna, can substitute in escherichia coli for h-ns, a bacterial nucleoid protein. | in an escherichia coli mutant devoid of h-ns, a bacterial nucleoid protein, mouse protein btcd was able to substitute for h-ns in two tested functions. it restored cell motility and repression of the expression of the bgl operon. btcd1, a mutant btcd protein deleted of its zinc finger and thus having reduced dna binding, failed to substitute for h-ns. mouse protein btcd was shown to repress the bgl operon at the level of transcription initiation and to bind preferentially to a curved dna fragmen ... | 1996 | 8670903 |
| targeted disruption of the rad51 gene leads to lethality in embryonic mice. | the mouse rad51 gene is a mammalian homologue of the escherichia coli reca and yeast rad51 genes, both of which are involved in homologous recombination and dna repair. to elucidate the physiological role of rad51 protein, the gene was targeted in embryonic stem (es) cells. mice heterozygous for the rad51 null mutation were intercrossed and their offspring were genotyped. there were no homozygous (rad51-/-) pups among 148 neonates examined but a few rad51-/- embryos were identified when examined ... | 1996 | 8692798 |
| molecular cloning of a rat chromosome putative recombinogenic sequence homologous to the hepatitis b virus encapsidation signal. | previously, we reported that a 61-bp subgenomic hbv dna sequence (designated as 15ab, nt 1855-1915) is a hot spot for genomic recombination and that a cellular protein binding to 15ab may be the putative recombinogenic protein. in the present study, we established the existence of a 15ab-like sequence in human and rat chromosomal dna by southern blot analysis. the 15ab-like sequence isolated from the rat chromosome demonstrated a 80.9% identity with 5'-ccaagctgtgccttgggtggc-3', at 1872-1892 of t ... | 1996 | 8692987 |
| construction of recombinant extended single-chain antibody peptide conjugates for use in the diagnosis of hiv-1 and hiv-2. | the construction, expression and evaluation of recombinant scfv based hiv diagnostic reagents are described. in a whole-blood, erythrocyte agglutination assay format, recombinant scfv antibodies (expressed in escherichia coli), linked to a spacer domain and hiv-gp36 or -gp41 peptides, were shown to be able to detect efficiently natural antibodies against hiv in human serum. performance in trials suggests that these single chain reagents have potential as alternatives to existing fab-peptide chem ... | 1996 | 8699008 |
| recombinant toxoplasma gondii surface antigen 1 (p30) expressed in escherichia coli is recognized by human toxoplasma-specific immunoglobulin m (igm) and igg antibodies. | the immunodominant surface antigen of toxoplasma gondii, surface antigen 1 (sag1), was expressed in escherichia coli as a fusion protein containing a majority of the sag1 protein supplied with six histidyl residues in the n-terminal end. the recombinant protein was purified on a ni-chelate column and then on a fast-performance liquid chromatography column and was in a nonreduced condition. it was recognized by t. gondii-specific human immunoglobulin g (igg) and igm antibodies as well as by a mou ... | 1996 | 8705683 |
| expression of senescence-induced protein ws3-10 in vivo and in vitro. | in our efforts to characterize cellular senescence we have shown that the mrna encoding ws3-10 protein is overexpressed in senescent human diploid fibroblasts (hdf) when compared with their younger counterparts, and that forced expression of the ws3-10 cdna in young hdf results in suppression of calcium-dependent membrane currents, presumably due in part to the presence of a calcium binding domain within the ws3-10 protein. we have now expressed this protein in e. coli and have obtained affinity ... | 1996 | 8706785 |
| hybrid hepatitis b virus core antigen as a vaccine carrier moiety: i. presentation of foreign epitopes. | hepatitis b virus (hbv) core antigen (hbcag) is a highly immunogenic subviral particle. here, we review recent progress in the use of hbcag as a carrier moiety for heterologous epitopes. to define surface exposed and immunogenic insertion sites for foreign epitopes in hbcag, peptidic epitopes representing binding sites for virus neutralizing antibodies on the hbv surface antigens were inserted at different positions within hbcag using genetic engineering in an escherichia coli expression system ... | 1996 | 8717391 |
| outer membrane proteins of pseudomonas aeruginosa as vaccine candidates. | we tested the ability of the recombinant outer membrane proteins of pseudomonas aeruginosa to serve as a protective vaccine against this gram-negative pathogen in the presence of two main pathophysiological events leading to p. aeruginosa sepsis: (i) systemic infection during immunosuppression; and (ii) bacterial translocation. a hybrid vaccine was cloned which combined the protective epitopes of outer membrane protein f (oprf) and outer membrane protein i (opri). this vaccine proved to be highl ... | 1996 | 8717398 |
| similar binding properties for a neutralizing anti-tetanus toxoid human monoclonal antibody and its bacterially expressed fab. | a high-affinity anti-tenanus toxoid (tt) human monoclonal antibody showing neutralizing activity was isolated from a fusion between mouse myeloma and human splenic cells. fab fragments from this antibody were obtained using a recombinant phage surface-display expression system. the parental antibody and the corresponding fab had identical immunological activities, including specificity and affinity. these results confirm the feasibility of developing escherichia coli expression of monoclonal hum ... | 1995 | 8719661 |
| heterologous expression and characterisation of mouse brain fatty acid binding protein. | a novel brain-type member of the fatty acid binding protein family (b-fabp) was heterologously expressed in escherichia coli, either as inclusion bodies at 37 degrees c or in soluble form at 22 degrees c. both b-fabp renatured from inclusion bodies and the solubly expressed protein could be purified to homogeneity by anion exchange chromatography and gel filtration in a functional conformation as they bound oleic acid with high affinity. none of the five cysteines of b-fabp was involved in disul ... | 1996 | 8722323 |
| lipopolysaccharide stimulates differential expression of myristoylated protein kinase c substrates in murine microglia. | microglia rapidly respond to lipoplysaccharide (lps) by transformation from resting to active states and secretion of several neuro- and immuno-regulators including tumour necrosis factor alpha (tnf-alpha), interleukin 1 beta (il-1 beta), and interleukin 6 (il-6). with longer lps treatment, microglia are converted to reactive or phagocytic states with characteristics similar to macrophages in inflammation and injury processes. we have investigated lps-mediated changes in two myristoylated substr ... | 1996 | 8723762 |
| in vivo activities of u-100592 and u-100766, novel oxazolidinone antimicrobial agents, against experimental bacterial infections. | the upjohn oxazolidinones, u-100592 and u-100766, are orally bioavailable synthetic antimicrobial agents with spectra of activity against antibiotic-susceptible and -resistant gram-positive pathogens. in several mouse models of methicillin-resistant staphylococcus aureus infection, u-100592 and u-100766 yielded oral 50% effective doses (ed50) ranging from 1.9 to 8.0 mg/kg of body weight, which compared favorably with vancomycin subcutaneous ed50 values of 1.1 to 4.4 mg/kg. similarly, both compou ... | 1996 | 8726028 |
| a biological method for the quantitative measurement of tetrodotoxin (ttx): tissue culture bioassay in combination with a water-soluble tetrazolium salt. | a tissue culture bioassay, using the mouse neuroblastoma cell line (neuro2a), was improved to provide a simple and sensitive bioassay for ttx or sodium channel-blocking toxins (scb). the water-soluble tetrazolium salt, 2-(4-iodophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2h-tetraz olium, monosodium salt (wst-1), was applied to replace the time-consuming and subjective cell-counting procedure of the cells with automatic measurement, using a microplate reader. it was also confirmed that this m ... | 1996 | 8735249 |
| human interleukin-2 (il-2) expressed by transfected mammalian cells. | cdna for human interleukin-2 (il-2) was cloned into the prc/rsv vector for expression in animal cells. baby hamster kidney (bhk-21) cells and chinese hamster ovary (cho) cells were transfected several times using calcium phosphate and electroporation methods with the construct prc/rsv sigil2. different transfection efficiencies were obtained. the biological test on ctll-2 (mouse cytotoxic lymphocytes) showed that the kinetics of cell proliferation were different from those of ril-2 (recombinant ... | 1996 | 8739347 |
| searching for new tnf-alpha analogs having potential application in cancer therapy. | two new tnf-alpha analogs were prepared and tested for their anti-tumor activity on fibrosarcoma sa-1 tumor model in vivo. in analog lk-801 two histidines (his107his108) were introduced into the surface loop thus enabling efficient purification by metal-affinity chromatography. this analog showed less side effects and can serve as a lead compound to look for other useful mutations. another analog lk-802 was designed by introduction of additional pair of mutations (cys95cys148) into lk-801 in ord ... | 1996 | 8739350 |
| analysis of regulatory regions of the ciliary neutrophic factor gene in transgenic mice. | in order to study the regulatory regions of the human ciliary neurotrophic factor (cntf) gene we made constructs containing sequences upstream and downstream of cntf coding regions and the lacz gene and analysed their expression in transgenic mice. we show that 240 bp upstream of the translation start codon are sufficient for the transcription of the lacz gene. a further 4 kb upstream sequence is required for the expression of the transgene in schwann cells. these two upstream regions together w ... | 1995 | 8742416 |
| variation in repeat number within the alpha c protein of group b streptococci alters antigenicity and protective epitopes. | variable expression of repeating units of the protective alpha c proteins among clinical isolates of group b streptococci (gbs) may have implications for vaccine development. in this study, alpha c protein genes containing various numbers of repeats (1,2,9, and 16) were cloned in a t7 overexpression vector in escherichia coli. expression was induced by isopropyl-beta-d-thiogalactopyranoside, and proteins were purified by anion-exchange, gel filtration, or affinity chromatography or by isoelectri ... | 1996 | 8751902 |
| [localization of reca-like proteins in preparations of spread nuclei of mouse spermatocytes at meiotic prophase i]. | earlier, polyclonal antibodies to escherichia coli reca protein were used to identify immunologically related proteins in meiotic spermatocytes of different eukaryotes. at least one such protein proved to be a component of the synaptonemal complex (sc) [1]. subsequent experiments on localization of reca-like antigens in scs of spermatocytes were performed by indirect immunocytochemical methods and electron microscopy, which showed that reca-like protein(s) at early leptotene are largely associat ... | 1996 | 8754067 |
| mouse and rat cystatin c: escherichia coli production, characterization and tissue distribution. | recombinant mouse (mus musculus) and rat (rattus norvegicus) cystatin c were produced by expression in escherichia coli, isolated and functionally characterized. the mouse and rat inhibitors were both fully active in titrations of papain. determination of equilibrium constants for dissociation (ki) for their complexes with the target proteinase, cathepsin b, produced values not largely different from that for human cystatin c (ki 0.07-0.13 nm). rabbit antisera against mouse and rat cystatin c we ... | 1996 | 8761177 |
| hypothalamic and pituitary leukemia inhibitory factor gene expression in vivo: a novel endotoxin-inducible neuro-endocrine interface. | we have recently shown expression of leukemia inhibitory factor (lif) in human fetal pituitary tissue and its in vitro induction of pomc transcription. we now use qualitative and semiquantitative rt-pcr to demonstrate that lif and lif-receptor (lif-r) are constitutively expressed in the normal mouse hypothalamus and pituitary. hypothalamic and pituitary lif and lif-r are significantly induced (up to 6- and 4-fold, respectively) in vivo in response to lipopolysaccharide endotoxin (lps) administer ... | 1996 | 8770918 |
| bi-directional dideoxy fingerprinting (bi-ddf): rapid and efficient screening for mutations in the big blue transgenic mouse mutation detection system. | | 1996 | 8780870 |
| eotaxin triggers eosinophil-selective chemotaxis and calcium flux via a distinct receptor and induces pulmonary eosinophilia in the presence of interleukin 5 in mice. | understanding the processes that control selective eosinophilia is of fundamental importance in a variety of human diseases (e.g., allergies, parasitic infections, malignancy). interleukin 5, an eosinophil-specific growth and activating factor, and eotaxin appear to collaborate in this process. eotaxin is a recently described chemotactic factor that belongs to the c-c (or beta) chemokine family and has been implicated in animal and human eosinophilic inflammatory states. we have recently reporte ... | 1996 | 8784786 |
| in vitro binding of type 1-fimbriated escherichia coli to uroplakins ia and ib: relation to urinary tract infections. | urinary tract infections, caused mainly by escherichia coli, are among the most common infectious diseases. most isolates of the uropathogenic e.coli can express type 1 and p fimbriae containing adhesins that recognize cell receptors. while p fimbriae recognize kidney glycolipid receptors and are involved in peyelonephritis, the urothelial for type 1 fimbriae were not identified. we show that type 1-fimbriated e. coli recognize uroplakins ia and ib, two major glycoproteins of urothelial apical p ... | 1996 | 8790381 |
| type 1 fimbrial expression enhances escherichia coli virulence for the urinary tract. | type 1 fimbriae are adhesion organelles expressed by many gram-negative bacteria. they facilitate adherence to mucosal surfaces and inflammatory cells in vitro, but their contribution to virulence has not been defined. this study presents evidence that type 1 fimbriae increase the virulence of escherichia coli for the urinary tract by promoting bacterial persistence and enhancing the inflammatory response to infection. in a clinical study, we observed that disease severity was greater in childre ... | 1996 | 8790416 |
| high field epr studies of mouse ribonucleotide reductase indicate hydrogen bonding of the tyrosyl radical. | ribonucleotide reductase catalyzes by free radical chemistry the reduction of ribonucleotides to deoxyribonucleotides. the r2 protein of a class 1 ribonucleotide reductase contains a stable tyrosyl radical of neutral phenoxy character, which is necessary for normal enzymatic activity. here we present the epr spectra from the tyrosyl free radical in the r2 protein from mouse at 9.62, 115, and 245 ghz. we show that the g-value anisotropy of the mouse r2 radical, when precisely determined from high ... | 1996 | 8798575 |
| localization of the effector-specifying regions of gi2alpha and gqalpha. | heterotrimeric g proteins transmit hormonal and sensory signals received by cell surface receptors to effector proteins that regulate cellular processes. members of the highly conserved family of alpha subunits specifically modulate the activities of a diverse array of effector proteins. to investigate the determinants of alpha subunit-effector specificity, we localized the effector-specifying regions of alphai2, which inhibits adenylyl cyclase, and alphaq, which stimulates phosphoinositide phos ... | 1996 | 8798740 |
| identification of histone h2a.x as a growth factor secreted by an androgen-independent subline of mouse mammary carcinoma cells. | shionogi carcinoma 115 (sc 115) cells and chiba subline 2 (cs 2) cells are clones of an androgen-responsive mouse tumor cell line and its autonomous subline, respectively. we have shown previously that cs 2 cells produce a heparin-binding growth factor that stimulates the growth of sc 115 cells as well as the growth of themselves. in this study, a growth factor was purified from serum-free conditioned media of cs 2 cells cultured without testosterone. a heparin-binding fraction showed growth- pr ... | 1996 | 8810267 |
| induction by chronic autoimmune arthritis in dba/1 mice by oral administration of type ii collagen and escherichia coli lipopolysaccharide. | we have developed a new model of autoimmune arthritis in dba/1 mice by feeding chick type ii collagen (cii) for 2-3 week intervals over a 15 week period. clinically evident arthritis occurred in 8/10 mice receiving native cii (ncii; 100 micrograms/mouse) alone at 9-13 weeks. arthritis was aggravated by the further ingestion of cii, while remission occurred after withdrawal of the cii. heat-denatured cii (dcii; 200 micrograms/mouse) was also arthritogenic if co-administered with ovoinhibitor (ovi ... | 1996 | 8810665 |
| comparison of plasmid dna preparation methods for direct gene transfer and genetic immunization. | plasmid dna is widely used for direct gene transfer in animals to study gene therapy, gene regulation, drug delivery and genetic immunization. here we compare cesium chloride and anion-exchange purified plasmid dna for direct gene transfer in mouse muscle and show no differences in efficiency of transfection with reporter genes or in humoral response to dna-based immunization. | 1996 | 8816242 |
| transdominant inhibition of moloney murine leukemia virus proliferation by defective mutants of reverse transcriptase. | to investigate the dominant-negative inhibition of moloney murine leukemia virus (mo-mulv) proliferation by polymerization-defective mutants of reverse transcriptase (rt), we constructed several plasmids harboring the mo-mulv rt gene in which the yvdd sequence, one of the conserved sequences in rna-dependent polymerases, was altered, and then transformed mouse nih3t3 cells and escherichia coli with the mutant plasmids. mouse nih3t3 cells expressing these mutant rt genes were highly resistant to ... | 1996 | 8827439 |
| characterization of the leader papain-like protease of mhv-a59. | sequence analysis of the mouse hepatitis virus, strain a59 (mhv-a59) genome predicts the presence of two papain-like proteases encoded within the first open reading frame of the replicase gene. the more 5' of these domains, the leader papain-like protease, is responsible for the cleavage of the amino terminal protein, p28. we have defined the core of this protease to between amino acids 1075 and 1344 from the beginning of orf 1a. deletion analysis coupled with in vitro expression, was used to st ... | 1995 | 8830518 |
| separable cis-regulatory elements that contribute to tissue- and site-specific alpha 2(xi) collagen gene expression in the embryonic mouse cartilage. | type xi collagen is a structural component of the cartilage extracellular matrix and plays an important role in skeletal morphogenesis. as a step toward defining the molecular mechanisms responsible for the regulation of type xi collagen expression, we characterized the promoter region of the mouse alpha 2(xi) collagen gene (coll1a2). we also generated transgenic mice harboring various fragments of the promoter and the first intron of coll1a2 linked to the escherichia coli beta-galactosidase gen ... | 1996 | 8830784 |
| survival rate of mice after transient colonization with escherichia coli clones carrying variant shiga-like toxin type ii operons. | we have previously employed a streptomycin-treated mouse model to demonstrate that escherichia coli clones expressing particular variant shiga-like toxin type ii operons differ in oral virulence, as judged by median survival time. differences in virulence were not seen between all toxin variants, including two which differed significantly in cytotoxicity for vero cells. in the present study, we have modified the animal model by withdrawing antibiotic selection and reintroducing normal mouse inte ... | 1996 | 8831832 |
| toxicological evaluation of 1,1,1,2,2-pentafluoroethane (hfc-125). | acute, subacute, and subchronic inhalation toxicity studies, developmental toxicity studies, a cardiac sensitization evaluation, and mutagenicity assays were conducted with pentafluoroethane (hfc-125). in the acute study, rats were exposed to a single concentration of 800,000 ppm for 4 hr. ataxic gait and abnormal respiration were observed during exposure but not after exposure. there was no mortality or other signs of toxicity. repeated exposures of rats to 50,000 ppm, 6 hr/day, 5 days/week for ... | 1995 | 8835232 |
| engineering, expression and renaturation of targeted tgf-beta fusion proteins. | this study reports the expression, purification, and renaturation of biologically active transforming growth factor-beta 1 (tgf-beta 1) fusion proteins from escherichia coli (e. coli). a prokaryotic expression vector was engineered to produce tripartite fusion proteins consisting of (i) a purification tag, (ii) a protease-sensitive linker/collagen binding domain, and (iii) a cdna sequence encoding the active fragment of human tgf-beta 1. the expressed fusion proteins tgf-b1-f1 and tgf-b1-f2, loc ... | 1996 | 8835843 |
| identification and neuron specific expression of the s182/presenilin i protein in human and rodent brains. | many individuals with familial alzheimer disease (fad) have mutations in a gene termed s182 or presenilin i (ps-i). currently, the ps-i gene product has not been identified and its function remains unknown. here we report that affinity purified antibodies against the predicted amino acid sequence of the ps-i gene product detected in homogenates of human, mouse, and rat brains a single antigen of approximately 48 kda. this antigen was also present in immortalized human and mouse neuronal cell cul ... | 1996 | 8841992 |
| internalization and translocation of a new chimeric protein composed of pseudomonas aeruginosa exotoxin a and mouse dihydrofolate reductase as a model system. | in an attempt to introduce a large peptide that is not normally translocated across membranes into the cytosol of eukaryotic cells, we created a new chimeric protein termed cedh between pseudomonas aeruginosa exotoxin a (eta) and a variant enzyme of mus musculus dihydrofolate reductase (dhfr) with reduced affinity for antifolates, eta(1-413).dhfr(1-187).eta(609-613). we have defined, genetically constructed and expressed the chimeric protein in escherichia coli. we showed that the cedh chimeric ... | 1996 | 8844833 |
| molecular cloning of the cdna of mouse mitochondrial nadp-dependent isocitrate dehydrogenase and the expression of the gene during lymphocyte activation. | the current report documents the molecular cloning of the mouse mitochondrial nadp-dependent isocitrate dehydrogenase (mnadp-idh) cdna. the cdna was 1,863 bp in length and contained one open reading frame encoding a 523-residue polypeptide with a predicted molecular weight of 58 kda. the cdna and the deduced amino acid (aa) sequence of the mouse mnadp-idh had a high degree of homology with those of porcine, bovine, alfalfa, and yeast. the recombinant mnadp-idh expressed in escherichia coli had a ... | 1996 | 8867815 |
| selective response of ternary complex factor sap1a to different mitogen-activated protein kinase subgroups. | mitogenic and stres signals results in the activation of extracellular signal-regulated kinases (erks) and stress-activated protein kinase/c-jun n-terminal kinases (sapk/jnks), respectively, which are two subgroups of the mitogen-activated protein kinases. a nuclear target of mitogen-activated protein (map) kinases is the ternary complex factor elk-1, which underlies its involvement in the regulation of c-fos gene expression by mitogenic and stress signals. a second ternary complex factor, sap1a ... | 1996 | 8876175 |
| involvement of two basic residues (lys-17 and arg-39) of mouse lung carbonyl reductase in nadp(h)-binding and fatty acid activation: site-directed mutagenesis and kinetic analyses. | mouse lung carbonyl reductase, a member of the short-chain dehydrogenase/reductase (sdr) family, shows a strong coenzyme preference for nadp(h) over nad(h), and is uniquely activated by fatty acids. previous chemical modification and x-ray crystallography studies show that interactions responsible for the coenzyme specificity include salt linkages between the 2'-phosphate of nadph and side-chains of lys-17 and arg-39 of the enzyme. although arg-39 is highly conserved in nadp(h)-dependent enzymes ... | 1996 | 8889808 |
| control by h-2 genes of the th1 response induced against a foreign antigen expressed by attenuated salmonella typhimurium. | attenuated salmonellae represent an attractive vehicle for the delivery of heterologous protective antigens to the immune system. here, we have investigated the influence of the genetic background of the host which regulates the growth and elimination of salmonella cells on the cellular response induced against a foreign antigen delivered by an aroa salmonella strain. we have tested cd4+ t-cell responses (cell proliferation and cytokine production) in various mouse strains following immunization ... | 1996 | 8890187 |
| the amino acids of escherichia coli enterotoxin b subunit involved in binding to bio-gel a-5m or to the glycoprotein from mouse intestinal epithelial cells. | we determined whether arg13, met31, and ser95 of the heat-labile enterotoxin b subunit (lt-b) might be involved in lt-b binding to oligosaccharides, which did not bind to the b subunit of the cholera toxin (ct-b). three lt-b mutants, r13h, m31l, and s95a were prepared by substituting three amino acid residues that differ in ct-b. these mutants formed a pentamer and exhibited the same binding ability to the gm1 ganglioside as native lt-b. although these mutants did not bind to bio-gel a-5m, they ... | 1996 | 8890479 |
| synthesis, processing, and oligomerization of bovine herpesvirus 1 ge and gi membrane proteins. | this study reports the identification and initial characterization of the precursors, modified forms, and oligomers of bovine herpesvirus 1 (bhv-1) gi and ge proteins with polyvalent rabbit serum specific for gi or ge. our experiments used the colorado strain of bhv-1 and mutant viruses with insertions of the escherichia coli lacz gene into the predicted ge and gi reading frames. we also translated the ge and gi open reading frames in vitro and expressed them in uninfected cells using eukaryotic ... | 1996 | 8892910 |
| interleukin-1beta and ibuprofen effects on cd4/cd8 cells after endotoxic challenge. | multiple-organ failure is considered a consequence of autodestructive inflammatory response during which a state of immunosuppression is produced. alterations in cd4 and cd8 lymphocytes after experimental endotoxic challenge and their correlation with the protective effects of interleukin-1beta (il-1beta) and ibuprofen pretreatment were investigated. cba/h mice were injected with lipopolysaccharide (lps) of escherichia coli (125 mg/kg); 40 mice were pretreated with il-1beta (80 ng/mouse, 24 hr p ... | 1996 | 8895611 |
| overcoming the crypticity of a viral t cell determinant by insertion into a chimeric bacterial protein. | among the potential t cell determinants contained in a protein antigen, the t cell response only focuses on a few immunodominant t cell determinants, whereas cryptic epitopes remain hidden to the immune system. in the present work, we have studied the antigen processing and presentation of the c3:93-115 sequences of mahoney poliovirus vp1 protein, which is immunodominant in h-2d but cryptic in h-2s and h-2q mouse mhc haplotypes. for this purpose, we genetically inserted the c3 determinant into f ... | 1996 | 8918694 |
| cloning and expression of the cdna for mouse nad(+)-dependent 15-hydroxyprostaglandin dehydrogenase. | the cdna for mouse nad+ dependent 15-hydroxyprostaglandin dehydrogenase (15-pgdh) was isolated from a lung cdna library. the cdna contains a 798 bp open reading frame that codes for a protein of 266 amino acids (m(r) 28775) which shares 87% identity with the human 15-pgdh protein. the regions that are believed to form the nad+ binding site and the active site are conserved in the mouse and human enzymes. the authenticity of the mouse cdna was confirmed by expression of an active 15-pgdh in esche ... | 1996 | 8950170 |
| adrenocortical-specific transgene expression directed by steroid hydroxylase gene promoters. | the 5'-flanking regions of genes for three mouse adrenal steroid hydroxylases were analyzed for their ability to direct adrenal cortex-specific beta-galactosidase (beta-gal) reporter expression both in cell culture and transgenic mice. the 5'-flanking regions chosen were from the genes for steroid 21-hydroxylase (21-ohase), expressed throughout the adrenal cortex and mediating both glucocorticoid and mineralocorticoid synthesis, and aldosterone synthetase (as) and steroid 11 beta-hydroxylase (11 ... | 1996 | 8969922 |
| removal of an intron with unique 3' branch site creates an amino-terminal protein sequence directing the scerv1 gene product to mitochondria. | the yeast scerv1 gene is of special interest because it has a dual function in mitochondrial biogenesis and in the regulation of the cell cycle. the recent discovery that the yeast scerv1 gene has a structural and functional human homologue initiated a detailed comparison of the genes and their structures. in addition the homologous alr (augmenter of liver regeneration) genes from rat and mouse have just been identified and it has been found that the mammalian proteins have a specific function i ... | 1996 | 8972573 |
| identification and characterization of a novel prfa-regulated gene in listeria monocytogenes whose product, irpa, is highly homologous to internalin proteins, which contain leucine-rich repeats. | the expression of all virulence factors in listeria monocytogenes characterized to date is controlled by the virulence regulator protein, prfa. to identify further prfa-regulated proteins, we examined supernatants of l. monocytogenes egd harboring additional copies of the prfa regulator for the presence of novel proteins. this led to the identification and biochemical purification of a hitherto uncharacterized prfa-dependent 30-kda protein (a. lingnau, t. chakraborty, k. niebuhr, e. domann, and ... | 1997 | 8975898 |
| parameters affecting the use of the lac repressor system in eukaryotic cells and transgenic animals. | elements of the lactose operon were used to study parameters affecting gene expression in cultured cells and transgenic animals. a lac repressor protein containing a nuclear transport signal was shown to inhibit expression of a reporter gene by interacting with lac operator sequences. in cultured cells, operator sequence, operator placement and induction parameters were all shown to be important for obtaining tight repression of a reporter gene followed by high level expression upon induction. i ... | 1996 | 8991077 |
| dna repair functions in heterologous cells. | our genetic information is constantly challenged by exposure to endogenous and exogenous dna-damaging agents, by dna polymerase errors, and thereby inherent instability of the dna molecule itself. the integrity of our genetic information is maintained by numerous dna repair pathways, and the importance of these pathways is underscored by their remarkable structural and functional conservation across the evolutionary spectrum. because of the highly conserved nature of dna repair, the enzymes invo ... | 1996 | 8994804 |
| inducible retroviral vectors regulated by lac repressor in mammalian cells. | we have developed lac repressor-regulated retroviral expression vectors that are induced by beta-galactosides upon stable transduction in mammalian cells. these vectors, derived from a moloney-virus-based vector lncx, contain an internal rous sarcoma virus (rsv) or cytomegalovirus (cmv) promoter, coupled with 2 to 4 lac operator sequences and placed in anti orientation relative to the retroviral long terminal repeat (ltr). three different vectors were tested in stably infected mass populations o ... | 1996 | 8996098 |
| the dutpases from herpes simplex virus type 1 and mouse mammary tumour virus are less specific than the escherichia coli enzyme. | the enzyme dutpase catalyses the hydrolysis of dutp to dump and pyrophosphate, thereby suppressing incorporation of uracil into dna and providing a pool of dump, the precursor of dttp. hydrolysis of other nucleotides similar in structure to dutp would conceivably be physiologically detrimental and high specificity of the reaction seems to be necessary. in this work, we characterize the substrate specificity of the dutpases from herpes simplex virus type 1 (hsv-1) and mouse mammary tumour virus ( ... | 1996 | 9000104 |
| [expression of functionally active hyman cytochrome p-450c21 (cypxxia2) in escherichia coli and single-stage purification of it using metal-affinity chromatography]. | active human cytochrome p-450c21 was expressed in escherichia coli and purified to homogeneity. to increase expression, cdna encoding for the n-terminal fragment of cytochrome p-450c21 was modified. four histidine codons were added to cdna encoding for the c-terminus of the protein; thus, recombinant protein could have been rapidly and effectively purified by metal-affinity chromatography. modified human cytochrome p-450c21 was expressed (40-50 nmoles/l of culture according to spectrophotometry) ... | 1996 | 9011227 |
| fetal mouse selenophosphate synthetase 2 (sps2): characterization of the cysteine mutant form overproduced in a baculovirus-insect cell system. | a novel gene detected in mouse embryonic sites of hematopoiesis was cloned and shown to be a eukaryotic analog of the escherichia coli selenophosphate synthetase gene. unlike the e. coli enzyme, which is not a selenoprotein, the presence of selenocysteine in the mouse enzyme is indicated by a tga codon in the open reading frame of the gene in a position corresponding to the essential cysteine of the e. coli enzyme. an ionized selenol group in place of a cysteine sulfhydryl group could render thi ... | 1997 | 9012797 |
| cocirculation of multiple hantaviruses in texas, with characterization of the small (s) genome of a previously undescribed virus of cotton rats (sigmodon hispidus). | an environmental and laboratory investigation was conducted after a fatal childhood case of hantavirus pulmonary syndrome occurred in deaf smith county, texas in may 1995. a trapping campaign was conducted to identify possible rodent carriers. six species of murid and heteromyid rodents were collected, and at least one hantavirus-seropositive specimen was found in each of the five murid species. tissues from a selection of 11 seropositive specimens were examined by the polymerase chain reaction ... | 1996 | 9025697 |
| carbonic anhydrase ii and carbonic anhydrase-related protein in the cerebellar cortex of normal and lurcher mice. | the developmental profiles of carbonic anhydrase ii (ca-ii) and a carbonic anhydrase related protein (carp) were studied in rat and mouse cerebella. enzyme histochemistry, immunohistochemistry, in situ hybridisation and western blotting were used to study the synthesis and expression of these enzymes in cerebellar sections from age matched control, ca-ii deficient and lurcher mice, the latter being characterised by purkinje cell degeneration. both ca-ii and carp were first found to be expressed ... | 1997 | 9027408 |
| generation and pcr screening of bacteriophage gamma sublibraries enriched for rare clones (the "sublibrary method"). | | 1997 | 9031159 |
| nerve growth factor somatic mosaicism produced by herpes virus-directed expression of cre recombinase. | focal molecular genetic alteration of the intact mammalian brain will be required to elucidate gene product function in cells comprising synaptic networks. to this end, a somatic mosaic approach has been developed for the mouse whereby a dormant germline transgene is activated by the somatic delivery and expression of cre recombinase. transgenic mice harboring a recombinational substrate, the germline-transmitted nerve growth factor excision activation transgene (ngf-xat) were generated. somatic ... | 1997 | 9035107 |
| endothelial structural integrity is maintained during endotoxic shock in an interleukin-1 type 1 receptor knockout mouse. | the derangement of arterial endothelial cell morphology is a good indicator of a severe shock state. because interleukin (il)-1 has been implicated in this process, we examined the structural integrity of aortic endothelial cells in conjunction with serum il-6 concentrations and nitric oxide levels, which are known to increase during endotoxemia in animals genetically devoid of the type 1 il-1 receptor. endotoxin (10 mg/kg escherichia coli, injected intraperitoneally) (ld100) or saline vehicle w ... | 1997 | 9035286 |
| the role of lipopolysaccharide and shiga-like toxin in a mouse model of escherichia coli o157:h7 infection. | the role of lipopolysaccharide (lps) and shiga-like toxin (slt) in the pathogenesis of hemolytic uremic syndrome (hus) was studied in a mouse model. mice inoculated intragastrically with escherichia coli o157:h7 developed gastrointestinal, neurologic, and systemic symptoms, necrotic foci in the colon, glomerular and tubular histopathology, and fragmented erythrocytes. lps-responder (c3h/hen) mice developed a combination of neurologic and systemic symptoms, whereas lps-nonresponder (c3h/hej) mice ... | 1997 | 9041333 |
| [the dna-binding activity of the membrane protein annexin ii and its interaction with antibodies to the chromatin nuclear ribonucleoprotein (alpha-rnp)]. | by screening with labeled alu dna, a clone was isolated from cdna expression library, which appeared identical in sequence to the well-known ca-phospholipid-binding protein annexin ii. to evidence the dna-binding activity of recombinant annexin ii and its presence in the cell nucleus, we have expressed full-length mouse annexin ii cdna in bacteria with pgemex vector. the expressed protein was studied with electrophoretic mobility shift assay and for its reaction with polyclonal antibody to chrom ... | 1996 | 9045426 |
| "peptabody": a new type of high avidity binding protein. | a new type of high avidity binding molecule, termed "peptabody" was created by harnessing the effect of multivalent interaction. a short peptide ligand was fused via a semi-rigid hinge region with the coiled-coil assembly domain of the cartilage oligomeric matrix protein, resulting in a pentameric multivalent binding molecule. in the first peptabody (pab-s) described here, a peptide (s) specific for the mouse b-cell lymphoma bcl1 surface ig idiotype, was selected from a phage display library. a ... | 1997 | 9050835 |
| mutations induced in male germ cells after treatment of transgenic mice with ethylnitrosourea. | the present study was undertaken to clarify whether the transgenic mouse mutagenesis assay system can be used instead of dominant lethals or specific locus test after treatment of male germ cells in mouse with ethylnitrosourea (enu). male big blue transgenic mice (bb) carrying a laci target gene were given a single intraperitoneal injection of 150 mg/kg enu. vasa deferential sperm, caudal epididymal sperm or whole testes were assayed for mutation at 3, 14, 22 and 93 days after treatment with enu ... | 1997 | 9057885 |
| cross protective immunity conferred by a marker-free aroa mutant of pasteurella multocida. | the aroa gene from pasteurella multocida serotype a:1 (x-73) was cloned by complementation of the escherichia coli aroa mutant ab2829 with a dna library constructed in puc18. the cloned aroa gene was inactivated by deletion of a 300 bp internal sequence and reintroduced by homologous recombination into the chromosome of x-73 and p-1059 (serotype a:3) using a pasteurella-e. coli shuttle vector ppba1100. by subjecting the transformed cells to repeated subculturing in the presence of antibiotic sel ... | 1997 | 9066039 |
| a murine model of pulmonary damage induced by lipopolysaccharide via intranasal instillation. | this study examines the intranasal instillation of lipopolysaccharide (lps) into balb/c mice causing acute pulmonary damage, due to neutrophil infiltration and sepsis. a dose response with lps showed that an intranasal instillation of 167 microg/ml (10 microg/mouse) caused acute lung injury within 2-4 h and reached maximal damage at 24-48 h. we found the method of lps administration for induction of acute pulmonary damage to be crucial. after 24 h post-lps injection, a comparison showed a substa ... | 1997 | 9075771 |
| cloning and characterization of an mn-containing superoxide dismutase (soda) of bordetella pertussis. | the fur titration assay (furta) recently developed by i. stojiljkovic and coworkers (j. mol. biol. 236:531-545, 1994) was applied to clone iron-regulated genes of bordetella pertussis. after sequence analysis, one of the clones obtained by this selection procedure was shown to contain an open reading frame with significant sequence similarities to mn-containing superoxide dismutases (soda). the open reading frame was preceded by a fur consensus binding site, which according to primer extension a ... | 1997 | 9079904 |
| cytotoxic necrotizing factor 1 from escherichia coli and dermonecrotic toxin from bordetella bronchiseptica induce p21(rho)-dependent tyrosine phosphorylation of focal adhesion kinase and paxillin in swiss 3t3 cells. | treatment of swiss 3t3 cells with cytotoxic necrotizing factor 1 (cnf1) from escherichia coli and dermonecrotic toxin (dnt) from bordetella bronchiseptica, which directly target and activate p21(rho), stimulated tyrosine phosphorylation of focal adhesion kinase (p125(fak)) and paxillin. tyrosine phosphorylation induced by cnf1 and dnt occurred after a pronounced lag period (2 h), and was blocked by either lysosomotrophic agents or incubation at 22 degrees c. cnf1 and dnt stimulated tyrosine phos ... | 1997 | 9083104 |
| 2.1 kb 5'-flanking region of the brain type dystrophin gene directs the expression of lacz in the cerebral cortex, but not in the hippocampus. | duchenne muscular dystrophy is a muscle-wasting disease accompanied by a variable, but often significant degree of mental retardation, possibly due to the absence of dystrophin. however, the function of brain type dystrophin remains insufficiently clear. with this background, in order to study the cell-specific regulation of brain type dystrophin expression in mice, we generated transgenic mice carrying the 2.1 kb 5'-fragment of the mouse brain type dystrophin gene, fused to the coding region of ... | 1997 | 9094055 |
| cloning and expression of cdna encoding heart-type isoform of amp deaminase. | mouse cdna for the heart-type (h) isoform of amp deaminase (ec 3.5.4.6., ampd) has been isolated and characterized. the cdna for the ampd gene expressed in heart is predicted to encode a peptide of 766 amino acids with a molecular mass of 88 kda. the coding region of this cdna was quite homologous to the human ampd3 gene which encodes the erythrocyte-type (e) isoform of ampd, although the h-isoform of rodent ampd was reported to be immunologically distinct from the e-isoform of human ampd. the n ... | 1997 | 9133604 |
| contribution of tnf/tnf receptor and of fas ligand to toxicity in murine models of endotoxemia and bacterial peritonitis. | fas/fas ligand and tnf/tnf receptors are involved in apoptosis. whether both systems are involved in septic shock has not been determined so far. we investigated the role of tnf/tnfr and fas/fas ligand in models of endotoxemia and of speticemia in mice. upon lps challenge, tnf and tnfr p55 were involved in the process inducing lethality. fasl did not contribute to enhance lethality, as evidenced in gld mice, lacing fasl. following an intraperitoneal injection of live e. coli, tnf and tnfr p55 we ... | 1995 | 9144074 |
| identification of cramp, a cathelin-related antimicrobial peptide expressed in the embryonic and adult mouse. | cathelicidins are the precursors of potent antimicrobial peptides that have been identified in several mammalian species. prior work has suggested that members of this gene family can participate in host defense through their antimicrobial effects and activate mesenchymal cells during wound repair. to permit further study of these proteins a reverse transcriptase-polymerase chain reaction approach was used to identify potential mouse homologs. a full-length 562-base pair cdna clone was obtained ... | 1997 | 9148921 |
| down-regulation of the filamentous actin cross-linking activity of cortactin by src-mediated tyrosine phosphorylation. | cortactin, a prominent substrate for pp60(c-src), is a filamentous actin (f-actin) binding protein. we show here that cortactin can promote sedimentation of f-actin at centrifugation forces under which f-actin is otherwise not able to be precipitated. electron microscopic analysis after negative staining further revealed that actin filaments in the presence of cortactin are cross-linked into bundles of various degrees of thickness. hence, cortactin is also an f-actin cross-linking protein. we al ... | 1997 | 9153252 |
| cloning and characterization of two immunophilin-like genes, ilpa and fkpa, on a single 3.9-kilobase fragment of aeromonas hydrophila genomic dna. | antiserum to aeromonas hydrophila a6 cell envelopes was shown in a previous study (c. y. f. wong, g. mayrhofer, m. w. heuzenroeder, h. m. atkinson, d. m. quinn, and r. l. p. flower, fems immunol. med. microbiol. 15:233-241, 1996) to protect mice against lethal infection by this organism. in this study, colony blot analysis of an a. hydrophila genomic library using antiserum to a. hydrophila a6 cell envelopes revealed a cosmid clone expressing a 30-kda protein which has not been described previou ... | 1997 | 9171380 |
| cloning and characterization of the r1 and r2 subunits of ribonucleotide reductase from trypanosoma brucei. | ribonucleotide reductase (rnr) catalyzes the rate limiting step in the de novo synthesis of deoxyribonucleotides by directly reducing ribonucleotides to the corresponding deoxyribonucleotides. to keep balanced pools of deoxyribonucleotides, all nonviral rnrs studied so far are allosterically regulated. most eukaryotes contain a class i rnr, which is a heterodimer of two nonidentical subunits called proteins r1 and r2. we have isolated cdnas encoding the r1 and r2 proteins from trypanosoma brucei ... | 1997 | 9192674 |
| high expression of human amelogenin in e. coli. | a human cdna, encoding for the 175-amino-acid human amelogenin, was prepared by rt pcr from tooth bud mrna and sub-cloned into pgex-kg expression plasmid for over-expression in e. coli. the expressed protein was characterized by sds-page western blotting, and n-terminal amino acid sequencing. | 1996 | 9206336 |
| the n-terminal region of alpha-dystroglycan is an autonomous globular domain. | the structure of the n-terminal region of mouse alpha-dystroglycan (dgn) was investigated by expression of two protein fragments (residues 30-180 and 30-438) in escherichia coli cells. trypsin susceptibility experiments show the presence of a stable alpha-dystroglycan n-terminal region (approximately from residue 30 to 315). in addition, guanidinium hydrochloride (gdn/hcl) denaturation of dgn-(30-438)-peptide, monitored by means of tryptophan fluorescence, produces a cooperative transition typic ... | 1997 | 9210479 |
| an upstream, dnase i hypersensitive region of the hematopoietic-expressed transcription factor gata-1 gene confers developmental specificity in transgenic mice. | the transcription factor gata-1, which is expressed in several hematopoietic lineages and multipotential progenitors, is required for the development of red blood cells and platelets. to identify control elements of the mouse gata-1 gene, we analyzed dnase i hypersensitivity of the locus in erythroid chromatin and the expression of gata-1/escherichia coli beta-galactosidase (lacz) transgenes in mice. transgenes with 2.7 kb of promoter sequences are expressed infrequently and only within adult (d ... | 1997 | 9223298 |
| involvement of diacylglycerol production in activation of nuclear factor kappab by a cd14-mediated lipopolysaccharide stimulus. | exposure of chinese hamster cho-k1 transfectant cells expressing mouse cd14 (cho/cd14 cells) to lipopolysaccharide (lps) induced rapid elevation of the cellular diacylglycerol (dag) and choline/phosphocholine levels and nuclear translocation of nuclear factor kappab (nfkappab). when cells were incubated with short-chain dag analogues or bacterial phospholipase c, nfkappab activation occurred even without the lps stimulus. treatment of cho/cd14 cells with tricyclo[5.2.1.0(2.6)]decyl-(9[8])xanthog ... | 1997 | 9224650 |
| elongation factor ts of chlamydia trachomatis: structure of the gene and properties of the protein. | a putative structural gene cluster containing four open reading frames (orfs) located downstream of the omp1 gene of chlamydia trachomatis mouse pneumonitis (mopn) was cloned and sequenced. a genbank survey indicated that the identified cluster is similar to the rpsb-tsf-pyrh(smba)-frr region of escherichia coli. the second orf was 846 bp encoding a 282-amino-acid polypeptide with a calculated m(r) 30,824. alignment of this deduced protein sequence and e. coli elongation factor ts (ef-ts, produc ... | 1997 | 9244380 |
| analysis of mammalian cdc37, a protein kinase targeting subunit of heat shock protein 90. | | 1997 | 9251022 |
| heparin binding protein-44 (hbp-44)/receptor-associated protein (rap)mediates cell-substratum adhesion of mouse nih/3t3 cells through its binding to low density lipoprotein (ldl) receptor-related protein (lrp). | the low density lipoprotein receptor-related protein (lrp) is a multifunctional endocytic receptor with the ability to bind and endocytose several structurally and functionally distinct ligands. the 39 kda receptor-associated protein (rap) is an endoplasmic reticulum (er) resident protein, which is believed to function intracellularly as a molecular chaperone for lrp and to regulate its ligand binding activity along the secretory pathway. mouse heparin binding protein-44 (hbp-44) is a homologue ... | 1997 | 9253767 |
| the 58 kda mouse selenoprotein is a bcnu-sensitive thioredoxin reductase. | the flavoprotein thioredoxin reductase [ec 1.6.4.5] (nadph + h+ + thioredoxin-s2 --> nadp+ + thioredoxin-(sh)2) was isolated from mouse ehrlich ascites tumour (eat) cells. like the counterpart from human placenta but unlike the known thioredoxin reductases from non-vertebrate organisms, the mouse enzyme was found to contain 1 equivalent of selenium per subunit of 58 kda. the k(m) values were 4.5 microm for nadph, 480 microm for dtnb and 36 microm for escherichia coli thioredoxin, the turnover nu ... | 1997 | 9256243 |
| a 6-kb promoter fragment mimics in transgenic mice the prostate-specific and androgen-regulated expression of the endogenous prostate-specific antigen gene in humans. | prostate-specific antigen (psa) is a kallikrein-like serine protease, which is almost exclusively synthesized in the luminal epithelial cells of the human prostate. psa expression is androgen regulated. previously, we characterized in vitro the proximal promoter, and a strong enhancer region, approximately 4 kb upstream of the psa gene. both regions are needed for high, androgen-regulated activity of the psa promoter in lncap cells. the goal of the present study is the in vivo characterization o ... | 1997 | 9259317 |
| dissection of pathways implicated in integrin-mediated actin cytoskeleton assembly. involvement of protein kinase c, rho gtpase, and tyrosine phosphorylation. | a panel of antibodies to the alphaiibbeta3 integrin was used to promote adhesion of chinese hamster ovary cells transfected with the alphaiibbeta3 fibrinogen receptor. while some alphaiibbeta3 antibodies were not able to induce p125 focal adhesion kinase (p125fak) tyrosine phosphorylation, all the antibodies equally support cell adhesion but not spreading and assembly of actin stress fibers. absence of stress fibers was also obtained by plating on antibodies directed to the hamster beta1 integri ... | 1997 | 9268301 |
| localization of a domain in the fimh adhesin of escherichia coli type 1 fimbriae capable of receptor recognition and use of a domain-specific antibody to confer protection against experimental urinary tract infection. | the fimh subunit of type 1-fimbriated escherichia coli has been implicated as an important determinant of bacterial adherence and colonization of the urinary tract. here, we sought to localize the functionally important domain(s) within the fimh molecule and to determine if antibodies against this domain would block adherence of type 1-fimbriated e. coli to the bladder mucosa in situ and in vivo in an established mouse model of cystitis. we generated translational fusion proteins of disparate re ... | 1997 | 9276729 |
| novel approaches to control of bacterial infections in animals. | bacterial infections of poultry remain of great importance world-wide in terms of economic effects and public health. they include infections caused by salmonella, escherichia coli, campylobacter and pasteurella. through the introduction of rigid hygienic measures it is possible to breed and rear poultry free of these pathogens. however, the cost to the industry would be prohibitive and economically disastrous. biological measures have been introduced albeit in a relatively empirical way. antibi ... | 1997 | 9276992 |
| complete cdna sequence and tissue localization of n-rap, a novel nebulin-related protein of striated muscle. | we have cloned and sequenced the full-length cdna of n-rap, a novel nebulin-related protein, from mouse skeletal muscle. the n-rap message is specifically expressed in skeletal and cardiac muscle, but is not detected by northern blot in non-muscle tissues. the full-length n-rap cdna contains an open reading frame of 3,525 base pairs which is predicted to encode a protein of 133 kda. a 587 amino acid region near the c-terminus is 45% identical to the actin binding region of human nebulin, contain ... | 1997 | 9295142 |
| tetracycline regulated expression of vimentin in fibroblasts derived from vimentin null mice. | fibroblast cell lines were derived from vim-/- mice that express a mouse vimentin transgene in a tetracycline regulatable manner. vimentin null mouse primary embryo fibroblasts were transformed with sv-40 early genes and vim- cell lines were isolated. a vim- cell line was then serially transfected with an expression plasmid encoding the tetracycline regulatable transactivator (tta) and a mouse vimentin cdna expression plasmid under the regulation of escherichia coli tet operator and minimal cmv ... | 1997 | 9296393 |
| spontaneous mutation frequencies and spectra in p53 (+/+) and p53 (-/-) mice: a test of the 'guardian of the genome' hypothesis in the big blue transgenic mouse mutation detection system. | tsg-p53/big blue double transgenic mice offer a powerful tool for examining the effect of a p53 germline mutation on spontaneous somatic mutation in vivo. after sequencing the dna-binding domain of the laci gene, we previously reported no differences in mutant frequency between p53 nullizygous (-/-) and p53 wild-type (+/+) mice in liver, spleen and brain. however, jackpot mutations elsewhere in the gene may have obscured a real difference in mutation frequency and the small sample size of mutati ... | 1997 | 9330618 |
| in vitro and in vivo antibacterial efficacies of cfc-222, a new fluoroquinolone. | cfc-222 is a novel fluoroquinolone containing a c-7 bicyclic amine moiety with potent antibacterial activities against gram-positive, gram-negative, and anaerobic organisms. we compared the in vitro and in vivo activities of cfc-222 with those of ciprofloxacin, ofloxacin, and lomefloxacin. cfc-222 was more active than the other fluoroquinolones tested against gram-positive bacteria. cfc-222 was particularly active against streptococcus pneumoniae (mic at which 90% of isolates are inhibited [mic9 ... | 1997 | 9333049 |
| molecular cloning, sequencing, and expression in escherichia coli of mouse flavin-containing monooxygenase 3 (fmo3): comparison with the human isoform. | the sequence of mouse flavin-containing monooxygenase 3 (fmo3) was obtained from several clones isolated from a mouse liver cdna library. the nucleotide sequence of mouse fmo3 was 2020 bases in length containing 37 bases in the 5' flanking region, 1602 in the coding region, and 381 in the 3' flanking region. the derived protein sequence consisted of 534 amino acids including the putative flavin adenine dinucleotide and nadp+ pyrophosphate binding sites (characteristic of mammalian fmos) starting ... | 1997 | 9344459 |
| involvement of nitric oxide in the in vivo effects of lipopolysaccharide on the contractile and electrical properties of mouse diaphragm. | the contractile and electrical properties of the mouse diaphragm during endotoxemia were studied, and the possible role of nitric oxide (no) on these changes was investigated. the mice were injected intraperitoneally with e. coli. lipopolysaccharide (endotoxin, lps) at various times before isolation of the diaphragm to induce endotoxemia. it was observed that direct twitch tension was slightly increased, and that there was a significant increase in tetanic tension when compared with controls. th ... | 1997 | 9349638 |
| genes coding for enterotoxins and verotoxins in porcine escherichia coli strains belonging to different o:k:h serotypes: relationship with toxic phenotypes. | seventy-four e. coli strains isolated from piglets with diarrhea or edema disease in spain were serotyped and examined for production of heat-labile (lt) and heat-stable (st) enterotoxins (lt-i, lt-ii, stah, stap, and stb) and verotoxins (vt1, vt2, and vt2v = vte) by phenotypic (vero cell assay and infant mouse test) and genotypic (colony hybridization and pcr) methods. in general, an excellent correlation was found between the results obtained with a pcr approach and those determined with biolo ... | 1997 | 9350767 |
| nucleotide sequence of the porphyromonas gingivalis w83 reca homolog and construction of a reca-deficient mutant. | degenerate oligonucleotide primers were used in pcr to amplify a region of the reca homolog from porphyromonas gingivalis w83. the resulting pcr fragment was used as a probe to identify a recombinant lambda dash phage (l10) carrying the p. gingivalis reca homolog. the reca homolog was localized to a 2.1-kb bamhi fragment. the nucleotide sequence of this 2.1-kb fragment was determined, and a 1.02-kb open reading frame (341 amino acids) was detected. the predicted amino acid sequence was strikingl ... | 1997 | 9353038 |
| contribution of the mn-cofactored superoxide dismutase (soda) to the virulence of yersinia enterocolitica serotype o8. | enteric pathogens harbor a set of enzymes (e.g., superoxide dismutases [sod]) for detoxification of endogenous and exogenous reactive oxygen species which are encountered during infection. to analyze the role of the mn-cofactored sod (soda) in the pathogenicity of yersiniae, we cloned the soda gene of yersinia enterocolitica serotype o8 by complementation of an escherichia coli soda sodb mutant and subsequently constructed an isogenic mutant by allelic exchange. sequence analysis revealed an ope ... | 1997 | 9353054 |
| study of the role of the htrb gene in salmonella typhimurium virulence. | we have undertaken a study to investigate the contribution of the htrb gene to the virulence of pathogenic salmonella typhimurium. an htrb::mini-tn10 mutation from escherichia coli was transferred by transduction to the mouse-virulent strain s. typhimurium sl1344 to create an htrb mutant. the s. typhimurium htrb mutant was inoculated into mice and found to be severely limited in its ability to colonize organs of the lymphatic system and to cause systemic disease in mice. a variety of experiments ... | 1997 | 9353064 |
| purification and characteristics of recombinant mouse metallothionein-i from escherichia coli. | the mouse metallothionein-i (mmt-i) cdna was amplified by polymerase chain reaction (pcr), inserted into vector pgex-4t-1, and expressed in escherichia coli as a carboxyl terminal extension of the 26-kda glutathione-s-transferase (gst). analyzed by sds-page, the amount of the expressed fusion protein gst-mt was over 50% of total cellular proteins. after the fusion protein had been digested with thrombin on a glutathione-sepharose 4b affinity chromatography column, recombinant mmt-i was purified ... | 1997 | 9354383 |
| the design of a new mutation model for active genes: expression of the escherichia coli lac operon in mammalian cells. | the design of a novel transgenic mouse model is described that should allow analysis of mutations at a single cell level in all tissues of a model animal. the model is based on the correct regulation of the escherichia coli lac operon in mammalian cells. induction of a mutation in the laci gene will result in the loss of transcriptional repression of the lacz gene in mutated cells. expression of beta-galactosidase can subsequently be detected at the single cell level. the model was first tested ... | 1997 | 9360635 |
| [development of genetically engineered chimeric and single chain antibodies against human brain glioma: a preliminary report]. | in order to improve the clinical usefulness of mab of mouse origin in targeting diagnosis and therapy for human brain glioma, it is necessary to humanize it and reduce its molecular size. by means of rt-pcr technique, a 348 bp heavy chain variable domain (vh), and a 318 bp light chain variable domains (vl) cdna fragments were cloned from mouse hybridoma cell line sz39 secreting mab against human brain glioma. by recombinant dna technique, the two cdna fragments were linked to human igg1 heavy ch ... | 1996 | 9387315 |