| differential expression of cloned mouse metallothionein sequences in escherichia coli. | a cdna for mouse hepatic metallothionein i has been cloned into pbr322 (mbikay et al., 1981). although this recombinant plasmid (m135) possesses the metallothionein sequence in the same reading frame as that of beta-lactamase, it fails to direct the synthesis of a fused beta-lactamase-metallothionein protein in escherichia coli. another plasmid (m244) was derived from m135 by deleting an internal 390-bp segment made of the 5' noncoding region of metallothionein, the dg-dc tail, and some beta-lac ... | 1983 | 6343048 |
| failure to detect conventional enterotoxins in classical enteropathogenic (serotyped) escherichia coli strains of proven pathogenicity. | ammonium sulfate-precipitated supernatants of classical enteropathogenic escherichia coli strains were negative when investigated for enterotoxin production in rabbit ligated ileal loops, rabbit skin vascular permeability factor tests, suckling mice, and y-1 adrenal cells. they also failed to stimulate guanylate cyclase activity in homogenates of rabbit, rat, and infant mouse intestines. furthermore, dna from enteropathogenic e. coli lacked sequences that encode heat-labile and heat-stable enter ... | 1982 | 6754624 |
| inhibition of calf thymus dna polymerase alpha and of normal and cancer cell growth by butylanilinouracil and butylphenylguanine. | 6-(p-n-butylanilino)uracil and n2-(p-butylphenyl)guanine inhibited the activity of dna polymerase alpha from calf thymus but had no effect on other eukaryotic polymerases (dna polymerases beta and gamma) or escherichia coli dna polymerase i. inhibition was competitive with deoxyguanosine 5'-triphosphate and did not occur in the reaction of dna polymerase alpha with a template that did not contain cytosine residues. the results support a mechanism which involves hydrogen bonding of inhibitors wit ... | 1982 | 6756479 |
| cloning of mouse mitochondrial dna in e. coli affects bacterial viability. | | 1980 | 6265318 |
| immunosuppressive factors from mastocytoma cells cultured in serum-free medium. | immunosuppressive factors were isolated from culture fluids of dba/2 mouse mastocytoma cells grown in serum-free rpmi-1640 medium by measurement of inhibitory activity on tritiated thymidine uptake of dba/2 spleen cells responding to escherichia coli lipopolisaccharide (lps) and concanavalin a (cona) and by comparison of the number of hemolytic antibody-forming cells in vitro after simultaneous addition of the factors with sheep red blood cells (srbc). the culture fluids were separated into four ... | 1980 | 6775120 |
| characterization of the free radical of mammalian ribonucleotide reductase. | mouse fibroblast 3t6 cells, selected for resistance to hydroxyurea, were shown to overproduce protein m2, one of the two nonidentical subunits of mammalian ribonucleotide reductase. packed resistant cells gave an epr signal at 77 k very much resembling the signal given by the tyrosine-free radical of the b2 subunit of escherichia coli ribonucleotide reductase. also, the m2-specific free radical was shown to be located at a tyrosine residue. of the known tyrosine-free radicals of ribonucleotide r ... | 1982 | 6279610 |
| induction of indoleamine 2,3-dioxygenase in alveolar interstitial cells of mouse lung by bacterial lipopolysaccharide. | the cellular localization of indoleamine 2,3-dioxygenase was studied in the mouse lung after induction by lipopolysaccharide treatment. no significant indoleamine 2,3-dioxygenase activity was detected in alveolar macrophages and type ii epithelial cells, which were recovered by alveolar lavages and trypsin-treatment, respectively. to determine this enzyme activity in other types of lung cells, we prepared monodispersed lung cells (6.5 x 10(7) cells/lung) by incubation with 0.1% collagenase and 0 ... | 1983 | 6343379 |
| isolation and characterization of monoclonal antibodies directed against the dna repair enzyme uracil dna glycosylase from human placenta. | a series of monoclonal antibodies has been prepared against the base excision repair enzyme uracil dna glycosylase isolated from human placenta. spleen cells from balb/c mice immunized with purified human placental uracil dna glycosylase were fused with either p3x63 ag8.653 or sp2/0 myeloma cells. hybridomas producing antibodies directed against the placental glycosylase were identified in an enzyme-linked immunosorbent assay. each positive hybridoma was cloned twice by limit dilution and tested ... | 1983 | 6577457 |
| stimulation of peritoneal cell arginase by bacterial lipopolysaccharides. | the conditions under which bacterial endotoxins stimulate arginase production in mouse peritoneal macrophages have been defined. both lipid-a and lipid-a-associated protein are potent activators. fetal calf serum and normal mouse serum enhance macrophage arginase levels in the presence and absence of lipopolysaccharide (lps). lps in the amount of 10(-1) microgram/ml represents a maximal stimulus for macrophage arginase production and release. thioglycollate-elicited peritoneal cells have increas ... | 1980 | 6990772 |
| endotoxin-induced appearance of peroxidase-positive cells in the white pulp of the mouse spleen. | endotoxin (1-10 microgram intravenously) increased the number of strongly peroxidase-positive cells in the white pulp of the mouse spleen, demonstrable by the graham-karnovsky technique. the increase was greatest after 10 h, the cells being found most frequently around the central vessels of the white pulp. the appearance of such cells at this critical immunological site may relate to the known adjuvant activity of endotoxin in promoting immune responses against protein antigens. | 1980 | 6991399 |
| infant mouse model of e. coli diarrhoea: clinical protection induced by vaccination of the mothers. | protection of infant mice against experimental e. coli b41 diarrhoea by immunization of the mothers with homologous e. coli strain was studied. the influence of the number, dose, route and moment of vaccination(s) on protection, measured by the reduced mortality rate of infant mice during the 15 days following oral challenge, was tested. the highest dose of vaccine, namely 10(8) formalin-killed e. coli by parenteral routes or 3 x 10(9) live e. coli by peroral (p.o.) route resulted in the best ef ... | 1983 | 6362544 |
| [infant mouse test for the assay of thermostable (st) enterotoxin from escherichia coli. histological studies and influence of mice age (author's transl)]. | mices with different ages ranging 1 to 60 days old were inoculated with thermostable (st) enterotoxin of escherichia coli, either by intragastric injection through the abdominal wall or by intubation. doses were proportional to body weight and values obtained for intestines/carcass weight ratios (ri/c) of inoculated mice showed that mice remained susceptible to the enterotoxin up to 16 days old, with ri/c values equal or greater than 0.085. older mice were completely resistant to st activity as ... | 1980 | 6997937 |
| association of human enteric pathogenicity and mouse lung toxicity of escherichia coli. | mouse lung toxicity of 439 strains (431 escherichia coli, 1 shigella dysenteriae 1, 1 enterobacter cloacae, 5 vibrio sp., 1 klebsiella) was compared to other pathogenicity tests (mouse virulence, enterotoxicity, guinea pig eye test), to serogroup distribution, loss of virulence on storage, origin and haemolytic activity. mouse lethality was highest in serogroup o4 (p < 0.001), o18a,c (p < 0.001); serogroups o6, o20, o75, o115, o147 were next in order. e. coli serogroups o19, o26, o28a,b, o32, o5 ... | 1980 | 6998258 |
| degradation of non-opsonized 32p-labelled e. coli by unstimulated mouse peritoneal macrophages. evaluation of a method. | five hours after the ingestion of non-opsonized e. coli by mouse peritoneal macrophages in vitro, 60-70 per cent of the bacteria were killed, estimated as decrease in colony forming units. when employing 32p-labelled e. coli, 50-60 per cent of the radioactivity was released to the medium by the macrophages during the same period of time. the mean number of visually-counted bacteria per macrophage was constant in the post-ingestive period. the macrophages killed the bacteria without early destruc ... | 1980 | 7004082 |
| induction of histidine decarboxylase in mouse tissues by mitogens in vivo. | various types of mitogenic substances, such as a escherichia coli lipopolysaccharide (lps), concanavalin a (con a), pokeweed mitogen, polyi:polyc (a synthetic double-stranded rna) and 12-o-tetradecanoylphorbol-13-acetate (a component of croton oil), induced histidine decarboxylase (hdc) in the liver, spleen and lung of mice at 4.5 hr after injection. other inflammatory agents without mitogenic activity, such as zymosan, carrageenan, glycogen, d-galactosamine and n-acetyl-muramyl-l-alanyl-d-isogl ... | 1983 | 6661256 |
| toxin a of clostridium difficile: production, purification and effect in mouse intestine. | clostridium difficile produces one diarrhoeogenic toxin designed a, and one cytopathogenic toxin designed b. toxin a was purified in a four-step-fractionation procedure. in the last purification step the toxin was separated by elution with galactose from an agarose gel. the purified toxin a induced a clear and watery hypersecretion in intestinal loops of mouse, while mixtures of toxin a and b induced a haemorrhagic secretion. at an ed50 value for the purified toxin a of 0.5 microgram there was a ... | 1983 | 6673499 |
| [infant mouse model of "escherichia coli" infectious diarrhoea (author's transl)]. | three enteropathogenic bovine strains of escherichia coli (b41, b44 and 17c), carrying k99 antigen (k99+) and producing heat-stable enterotoxin (ent+), caused infectious diarrhoea when administered orally to swiss of1 and cd-1 infant mice. a mortality rate of 40 t0 60% was obtained after administration of 10 e. coli b41 to mice which were less than 48 h old. a mortality rate of 80 to 100% was obtained with 10(3) e. coli b41, selected as reference inoculum. inoculation of mice older than 48 h wit ... | 1980 | 7008674 |
| possible ideal lac operator: escherichia coli lac operator-like sequences from eukaryotic genomes lack the central g x c pair. | five dna fragments have been cloned from yeast, chicken, and mouse dna that titrate lac repressor in an escherichia coli lac+ i+z+ wild-type strain when on a multi-copy plasmid. the five repressor-binding sequences have been identified by dna sequence determinations and dnase cleavage-inhibition patterns. they share the 14-base-pair symmetrical consensus sequence 5' t-g-t-g-a-g-c:g-c-t-c-a-c-a 3' (the colon represents the center of symmetry), which is an inverted repeat of 7 base pairs of the le ... | 1984 | 6369330 |
| identification of a cdna clone encoding a mature blood stage antigen of plasmodium falciparum by immunization of mice with bacterial lysates. | a cdna library was constructed in pbr322 using mrna from blood stages of a papua new guinean isolate of plasmodium falciparum. expression of parasite antigens was not directly detectable by conventional immunological assays. to circumvent this, mice were immunized with lysates of cdna clones, and the antisera raised were assayed for anti-parasite reactivity. one cdna clone was identified which reliably elicited antibodies to p. falciparum. the mouse antisera were used to characterize the native ... | 1984 | 6370681 |
| phagocytosis and killing of escherichia coli x43 by individual resident mouse peritoneal macrophages assessed by an autoradiographic technique. | an autoradiographic technique for the determination of viable bacteria in individual cells is described, based on the incorporation of [3h]thymidine into the dna of viable escherichia coli x43, following phagocytosis by resident mouse peritoneal macrophages. the results of the autoradiographic technique were in overall agreement with viable colony counts. investigation of the killing of e. coli x43 with the autoradiographic technique showed that the percentage viable bacteria tended to be the sa ... | 1984 | 6371139 |
| development of a radioimmunoassay for escherichia coli heat-stable enterotoxin: comparison with the suckling mouse bioassay. | escherichia coli strains which produce heat-stable enterotoxin (st) are usually identified by demonstrating the production of st. at present, st can be detected only by bioassay methods. recently, we purified e. coli st, which enabled us to develop a radioimmunoassay for st. radioiodination of st was performed by the lactoperoxidase method, which resulted in a high specific activity and retained the biological activity of st. anti-st antisera were raised in goats by injecting the goats with pure ... | 1981 | 7021423 |
| haemolysis by urinary escherichia coli and virulence in mice. | the influence of haemolysin production on virulence was studied in an experimental mouse model. urinary strains of escherichia coli can be divided into three virulence groups by determining their kinetics in the mouse kidney after intravenous injection. virulent strains of groups ii and iii were more often haemolytic than avirulent group-i strains. haemolytic virulent strains often caused haemoglobinuria in the mice, and killed the mice more rapidly than did non-haemolytic virulent strains. no r ... | 1981 | 7021838 |
| [preliminary results on the effects of pretreatment with thymic extract on experimental endotoxin hepatitis in the mouse]. | the authors wish to examine the protective effects which a period of pre-treatment with thymostimulin, would have on endotoxin hepatitis, induced in thymectomized and non-thymectomized animals. the test showed that the histological picture and the degree of endotoxinemia, measured with the lymulus test, benefited from treatment with a thymic extract. this therapy was effect (and was statistically significant) in obtaining an immunorestoring effect (in the thymectomized mouse) and in inducing an ... | 1981 | 7023499 |
| structure and distribution of alu family sequences or their analogs within heterogeneous nuclear rna of hela, kb, and l cells. | we studied the distribution of repetitive sequence elements capable of forming double-stranded regions in nuclear rna of hela, kb, and l cells. in human rna populations, we called these regions duplex alu family rna (dafrna) because they represent transcripts of the highly reiterated family of dna regions known as "alu family dna" (rubin et al., nature (london) 284:372-374, 1980). although the dafrna populations of both human cell lines (hela and kb) have low sequence complexity, they represent ... | 1984 | 6700593 |
| isolation of short interspersed repetitive dna sequences present in the regions of initiation of mammalian dna replication. | nascent dna chains containing the putative replication origins were isolated from cells of human embryonic lung fibroblasts, hela, ehrlich ascites tumour and guerin ascites tumour as described earlier [ russev , g., and vassilev , l. (1982) j. mol. biol. 161, 77-87]. it was demonstrated that the synthesis of these nascent chains correlated with the ability of cells to initiate semiconservative dna replication. reassociation and electrophoretic analysis showed that the nascent chains from all fou ... | 1984 | 6723654 |
| studies on differentiation inducing substances of animal cells. i. differenol a, a differentiation inducing substance against mouse leukemia cells. | | 1981 | 7026524 |
| escherichia coli antibodies in opsonisation and protection against infection. | the opsonic and protective capacities of rabbit antisera against escherichia coli o, k and core-glycolipid cell-wall antigens were compared with specific antibody titres as measured by agglutination and enzyme-linked immunosorbent assay. anti-o antisera were opsonic and protective against two noncapsulate strains. only anti-k antisera were opsonic and protective against a k-antigen-containing strain. in a mouse model anti-core-glycolipid antiserum was not protective against challenge even by a s ... | 1981 | 7031250 |
| secondary structure model for 23s ribosomal rna. | a secondary structure model for 23s ribosomal rna has been constructed on the basis of comparative sequence data, including the complete sequences from e. coli. bacillus stearothermophilis, human and mouse mitochondria and several partial sequences. the model has been tested extensively with single strand-specific chemical and enzymatic probes. long range base-paired interactions organize the molecule into six major structural domains containing over 100 individual helices in all. regions contai ... | 1981 | 7031608 |
| renin synthesis and gene cloning. | 1. the present study describes the biosynthesis and gene cloning of mouse submandibular gland renin. 2. after translation of mrna coding for renin a mr 46 000 protein is produced (preprorenin). however, rapid removal of the 'pre' segment from the nascent chain would account for the fact that in pulse-chase and continuous labelling experiments the largest renin-immunoreactive protein seen was of mr 44 500, pi 6.4 (determined by 2-dimensional gel electrophoresis). this 'prorenin' was rapidly conve ... | 1982 | 6754188 |
| dna polymerase i and dna primase complex in yeast. | chromatographic analysis of poly(dt) replication activity in fresh yeast extracts showed that the activities required co-fractionate with the yeast dna polymerase i. since poly(dt) replication requires both a primase and a dna polymerase, the results of the fractionation studies suggest that these two enzymes might exist as a complex in the yeast extract. sucrose gradient analysis of concentrated purified yeast dna polymerase i preparations demonstrates that the yeast dna polymerase i does sedim ... | 1984 | 6376490 |
| [an oral enteritis-vaccine composed of twelve heat-inactivated enterobacteriaceae 3. communication: studies on efficacy tests in mice protection tests (author's transl)]. | the polyvalent vaccine consists of twelve heat-inactivated species of enterobacteriaceae (six strains of salmonellae, two strains of shigellae, four strains of dyspepsia coli). the above vaccine is administered orally (6) to man for prophylactic purposes against local infections. the present communication describes the efficacy results of the vaccine obtained for different parameters by the mouse protection test. for this purpose, seven different infection models were used: oral infection with a ... | 1981 | 7036591 |
| production and evaluation of antibody to the heat-stable enterotoxin from a human strain of enterotoxigenic escherichia coli. | escherichia coli heat-stable enterotoxin was coupled to bovine serum albumin by a carbodiimide reagent. antibody to the conjugate was produced by immunization of rabbits. data from radioimmunoassay and infant mouse tests indicate the presence of antibody to the enterotoxin. the antisera can be used in a radioimmunoassay to measure enterotoxin in various fluids. | 1981 | 7039508 |
| endotoxin-induced antitumor activity in the mouse is highly potentiated by muramyl dipeptide. | the ability of aqueous solutions of various endotoxin preparations, muramyl dipeptide (mdp) and combinations of endotoxin and mdp, to induce necrosis and regression of subcutaneous meth a transplants in mice and their toxicity were studied. while intravenously injected toxic endotoxins, in contrast to a detoxified preparation and to mdp, induced considerable necrosis and regression of their own, addition of mdp potentiated the antitumor potential of both toxic and detoxified endotoxins to the sa ... | 1984 | 6378362 |
| chemical synthesis of an octadecapeptide with the biological and immunological properties of human heat-stable escherichia coli enterotoxin. | an eighteen-amino-acid peptide having the linear amino acid sequence of human heat-stable enterotoxin (st) has been synthesized by solid phase peptide synthesis. the purified peptide could be obtained in yields approaching 25% after purification by size, charge, and high-performance ligand chromatography. this material was pure and identical to native st by analytical high-performance ligand chromatography, amino acid analysis, paper electrophoresis and thin-layer chromatography. the formation o ... | 1984 | 6386477 |
| structure of moloney murine leukemia viral dna: nucleotide sequence of the 5' long terminal repeat and adjacent cellular sequences. | some unintegrated and all integrated forms of murine leukemia viral dna contain long terminal repeats (ltrs). the entire nucleotide sequence of the ltr and adjacent cellular sequences at the 5' end of a cloned integrated proviral dna obtained from balb/mo mouse has been determined. it was compared to the nucleotide sequence of the ltr at the 3' end. the results indicate: (i) a direct 517-nucleotide repeat at the 5' and 3' termini; (ii) 145 nucleotides out of 517 nucleotides represent sequences b ... | 1980 | 6251455 |
| does enteropathogenic escherichia coli produce heat-labile enterotoxin, heat-stable enterotoxins a or b, or cholera toxin a subunits? | although most enteropathogenic escherichia coli strains do not produce recognized enterotoxins, we wished to examine whether they produce any factors like heat-stable enterotoxin b or cholera toxin active subunits that might be missed by conventional assay methods. e. coli strains e851 (o142) and e2348 (o127) that had caused diarrhea in volunteers were negative for heat-labile enterotoxin and heat-stable enterotoxin a in chinese hamster ovary cell and suckling mouse assays, failed to cause secre ... | 1984 | 6389354 |
| morphologic and functional effects of clostridium difficile enterotoxin in tissue culture. | the effects of the clostridium difficile toxin were examined in hela and mouse adrenal tumor (mat) cells. cytotoxicity was evaluated by vital dye exclusion and 51cr release. in both hela and mat cells, c. difficile toxin caused rounding of virtually 100% of cells. this rounding was distinguishable from rounding produced by the escherichia coli heat-labile enterotoxin (lt): (1) lt was inactive in hela cells; (2) in mat cells, c. difficile toxin produced uniformly rounded cells, while lt-rounded c ... | 1982 | 7066760 |
| high-affinity microtubule protein-higher organism dna complexes. many-fold enrichment in repetitive mouse dna sequences comprised of satellite dnas. | we have examined aspects of the interaction of cycled microtubule protein preparations with 35s-labeled mouse dna tracer in a competition system with unlabelled competitor e. coli or mouse dna. the nitrocellulose filter binding assay was used to measure interaction by scintillation counting. dna molecular weight affected the levels of filter retained 35s-labelled mouse tracer dna. filter retention levels increased if 35s-labelled mouse dna tracer size was increased, and the filter binding level ... | 1984 | 6391551 |
| mercury-resistant plasmids in bacteria from a mercury and antimony deposit area. | most bacterial cells (pseudomonas, acinetobacter) obtained from the soil at the khaidarkan mercury and antimony mine (kirghiz ussr) contain r plasmids with mercury (hgcl2) resistance determinants. the plasmids have a large molecular mass (about 100 md, though smaller ones also occur), and at least some of them are transmissive. many of the hgr bacteria also display an elevated antimony (sbcl3) resistance, though this trait was not shown to be plasmid-dependent. there are practically no hgr plasm ... | 1984 | 6394954 |
| cloning of mouse beta-casein gene sequences. | casein messenger rnas (mrnacsn) were purified from lactating mammary glands of balb/c mice and used as a starting material for cloning of casein gene sequences. double-stranded casein cdna (ds-cdnacsn) was prepared and blunt-end ligated to hindiii-specific dna linker molecules. after digestion with hindiii, the dsdnacsn was inserted into the hindiii site of plasmid pbr322, using t4 dna ligase. escherichia coli strain rh202 was transformed with the hybrid plasmids, and transformants were selected ... | 1981 | 7297856 |
| bone solubilization by mononuclear cells. | mononuclear cells derived from chicken peripheral blood or from thioglycollate-induced mouse peritoneal exudates were found to cause calcium release from devitalized homologous bone in vitro. these mononuclear cells with osteolytic activity were adherent to plastic surfaces and were identified as being macrophages by cell surface markers and histochemical staining. other mononuclear cells such as chicken thymocytes, nonadherent peripheral blood mononuclear cells, and chick embryo fibroblasts did ... | 1980 | 7374109 |
| quantification of large c3 fragments as an index of complement activation in mice. ii. in vivo studies. | a method which enables to evaluate the mouse c3 activation has been used to study the activation of the complement system in c57bl/6 mice injected with cobra venom factor, with escherichia coli, and with bacterial lipopolysaccharide. it was found that this method was able to detect the complement activation early, at a time when total levels of c3-reacting molecules had not yet decreased. | 1984 | 6399880 |
| relative colonizing abilities of human fecal and k 12 strains of escherichia coli in the large intestines of streptomycin-treated mice. | male cd-1 mice, fed streptomycin in their drinking water, were used to study colonization of the mouse intestine by both fecal escherichia coli strains isolated from healthy humans and escherichia coli k12 strains which are routinely used as hosts for recombinant dna. prior to use in mice, all the strains were made resistant to streptomycin. several facts emerged from these studies: (a) strains isolated from different healthy humans colonized the mouse intestine with equal ability (approximately ... | 1982 | 6756909 |
| cloned mouse interferon-gamma inhibits the growth of rickettsia prowazekii in cultured mouse fibroblasts. | the effect of treating cultured mouse fibroblasts (l929 cells) with cloned mouse interferon-gamma on the growth of rickettsia prowazekii within the fibroblasts was studied. within 48 h after infection, rickettsiae were cleared from a substantial proportion of the initially infected cells and rickettsial growth was inhibited in those cells that remained infected, when l929 cells were treated with cloned mouse interferon-gamma both before and after infection. when l929 cells were treated with clon ... | 1983 | 6417262 |
| therapeutic efficacy of a new cephamycin, mt-141, in compromised mice. | the antibacterial activity of mt-141 against escherichia coli and proteus morganii in compromised mice was investigated and compared with that of latamoxef, cefmetazole and cefoxitin. the bactericidal activity of mt-141 in short-term contact with e. coli and p. morganii was markedly enhanced when combined with mouse serum, and the activity of mt-141 was greater than the activities of the three reference drugs. the antibacterial activities of mt-141 in the liver, spleen and kidney of neutropenic ... | 1984 | 6441793 |
| in vivo and in vitro association of hsc70 with polyomavirus capsid proteins. | members of the 70-kda family of cellular stress proteins assit in protein folding by preventing inappropriate intra- and intermolecular interactions during normal protein synthesis and transport and when cells are exposed to a variety of environmental stresses. during infection of a31 mouse fibroblasts with polyomavirus, the constitutive form of hsp70, hsc70, coimmunoprecipitated with all three viral capsid proteins (vp1, vp2, and vp3). in addition, the subcellular location of hsc70 changed from ... | 1995 | 7494292 |
| salmonella-specific monoclonal antibodies against recombinant salmonella typhi 36-kilodalton porin. | mouse monoclonal antibodies were raised against recombinant salmonella typhi 36-kda porin monomer. specificities of 16 monoclonal antibodies were analyzed as reactivity patterns in dot immunobinding and western blot (immunoblot) assays using isolated outer membrane proteins of gram-negative bacteria and cloned purified s. typhi porin monomers and trimers. four monoclonal antibodies were specific for salmonella spp. | 1994 | 7496957 |
| lipopolysaccharide-induced activation of suppressor cells: reversal by an agent which alters cyclic nucleotide metabolism. | the effects of bacterial lipopolysaccharides (lps) on the suppressor activity of mouse spleen cells were examined. pretreatment with lps was shown to induce suppressor activity in vivo and in vitro. concurrent treatment of spleen cells with lps and imidazole, an agent which increases the activity of cyclic nucleotide phosphodiesterases and hastens the degradation of cyclic amp, reversed the suppressor-inducing effects of lps. in vitro treatment of spleen cells with aminophylline, an agent which ... | 1982 | 6459992 |
| the role of formaldehyde and s-chloromethylglutathione in the bacterial mutagenicity of methylene chloride. | methylene chloride was less mutagenic in salmonella typhimurium ta100/ng-11 (glutathione-deficient) compared to ta100, indicating that glutathione is involved in the activation of methylene chloride to a mutagen in bacteria. in rodents, the pathway of methylene chloride metabolism utilizing glutathione produces formaldehyde via a postulated s-chloromethylglutathione conjugate (gsch2cl). formaldehyde is known to cause dna-protein cross-links, and gsch2cl may act as a monofunctional dna alkylator ... | 1994 | 7508089 |
| heat-stable enterotoxins from escherichia coli p16. | escherichia coli p16 infant mouse active heat-stable enterotoxin may be fractionated into two distinct active moieties by ion-exchange chromatography, sephadex g-25 chromatography, and isoelectric focusing. | 1980 | 6995318 |
| molecular characterization of dog albumin as a cross-reactive allergen. | indoor allergens comprise a group of allergenic proteins that are commonly derived from house dust mite and cat and dog dander. in addition to the two major dog allergens (molecular weights: 19 and 23 kd), dog albumin represents an important allergen for up to 35% of patients who are allergic to dogs. in ige immunoblot inhibition studies and histamine release tests it has been demonstrated that patients who react to dog albumin exhibit ige reactivity with purified albumins from cat, mouse, chick ... | 1994 | 7512102 |
| toxin detection after storage or cultivation of enterotoxigenic with colicinogenic escherichia coli: a possible mechanism for toxin-negative pools. | of 100 non-enterotoxigenic escherichia coli isolated from children with diarrhea in bangkok, thailand, 24 were found to produce colicin(s). of these, 87% were active against one or more enterotoxigenic e. coli isolated from the same population. storage of nine enterotoxigenic e. coli with known inhibitory colicin-producing e. coli in different proportions caused 51 of 96 pools to become negative in the suckling mouse assay (heat-stable toxin) and 17 of 52 to become negative in the y-1 adrenal ce ... | 1981 | 7007422 |
| reduction in immunogenicity and clearance rate of escherichia coli l-asparaginase by modification with monomethoxypolyethylene glycol. | escherichia coli l-asparaginase was modified with monomethoxypolyethylene glycol using cyanuric chloride as a coupler. the modified enzyme did not cross-react with anti-l-asparaginase antibody in precipitin reaction, but retained some catalytic activity (8% of the original activity). it has the same km value for l-asparagine and the same optimal ph as the native enzyme. the immunogenicity of the modified enzyme was substantially reduced because mouse antiserum to it showed no significant increas ... | 1981 | 7007618 |
| interaction of immobilized recombinant mouse c-type macrophage lectin with glycopeptides and oligosaccharides. | inflammatory and tumoricidal macrophages express galactose- and n-acetylgalactosamine-specific ca(2+)-dependent lectins on their surfaces. this lectin is a family member of membrane-bound c-type animal lectins and consists of 304 amino acid residues (molecular weight 34,595). in the present study, expression vectors containing a nucleotide sequence corresponding to the carbohydrate-binding domain of mouse macrophage lectin cdna have been prepared. the carbohydrate-binding specificity of the reco ... | 1994 | 7517698 |
| assembly of tobacco mosaic virus and tmv-like pseudovirus particles in escherichia coli. | high-level expression of plant viral proteins, including coat protein (cp), is possible in escherichia coli. native tobacco mosaic virus (tmv) cp expressed in e. coli remains soluble but has a non-acetylated n-terminal ser residue and following extraction, is unable to package tmv rna in vitro under standard assembly conditions. changing the ser to ala or pro by pcr-mutagenesis did not confer assembly competence in vitro, despite these being non-acetylated n-termini present in two natural strain ... | 1994 | 7518274 |
| mannose-binding activity of escherichia coli: a determinant of attachment and ingestion of the bacteria by macrophages. | recently, it was suggested that a mannose-specific lectin on the bacterial cell surface is responsible for the recognition by phagocytic cells of certain nonopsonized escherichia coli strains. in this study we assessed the interaction of two strains of e. coli at different phases of growth with a monolayer of mouse peritoneal macrophages and developed a direct method with [(14)c]mannan to quantitate the bacterial mannose-binding activity. normal-sized bacteria were obtained from logarithmic and ... | 1980 | 7011977 |
| borrelia burgdorferi upregulates the adhesion molecules e-selectin, p-selectin, icam-1 and vcam-1 on mouse endothelioma cells in vitro. | in order to obtain more information on processes leading to borrelia burgdorferi-induced inflammation in the host, we have developed an in vitro model to study the upregulation of cell surface expression of adhesion molecules on endothelial cells by spirochetes. a mouse endothelioma cell line, derived from brain capillaries, bend3, was used as indicator population. bend3 cells were incubated with preparations of viable, inactivated or sonicated spirochetes and the expression of e-selectin, p-sel ... | 1994 | 7521760 |
| cell growth and antimicrobial activity of mouse peritoneal macrophages in response to glucocorticoids, choleragen and lipopolysaccharide. | normal, thioglycollate-stimulated and bcg-activated mouse peritoneal macrophages were cultivated in vitro with the conditioned medium of mouse l-929 cells. the thioglycollate- and bcg-macrophages rapidly proliferated, whereas normal macrophages grew more slowly. a clear morphological difference between the three types of macrophages in the culture was observed. glucocorticoids inhibited the growth of the macrophages at pharmacological concentrations. other steroids, progesterone, diethylstilbest ... | 1980 | 7012550 |
| selection for animal cells that express the escherichia coli gene coding for xanthine-guanine phosphoribosyltransferase. | cultured monkey (tc7) and mouse (3t6) cells synthesize an excherichia coli enzyme, xanthine-guanine phosphoribosyltransferase (xgprt; 5-phospho-alpha-d-ribose-1-diphosphate:xanthine phosphoribosyltransferase, ec 2.4.2.22), after transfection with dna vectors carrying the corresponding bacterial gene, ecogpt. in contrast to mammalian cells, which do not efficiently use xanthine for purine nucleotide synthesis, cells that produce e. coli xgprt can synthesize gmp from xanthine via xmp. after transf ... | 1981 | 7017722 |
| nucleotide sequence analysis of the m genomic segment of el moro canyon hantavirus: antigenic distinction from four corners hantavirus. | el moro canyon hantavirus (elmc, previously known as hmv-1) is associated with the western harvest mouse reithrodontomys megalotis. the interpretation that elmc is a novel hantavirus was based upon comparisons of the nucleotide sequence of the s genomic segment with those of other hantaviruses. we now show that the elmc m genome, like the s genome, is genetically similar to but distinct from that of four corners hantavirus (fc). the elmc m genome is 3801 nt in length and encodes a glycoprotein p ... | 1995 | 7544047 |
| secondary structure of the large subunit ribosomal rna from escherichia coli, zea mays chloroplast, and human and mouse mitochondrial ribosomes. | short base-paired rna fragments, and fragments containing intra-rna cross-links, were isolated from e. coli 23s rrna or 50s ribosomal subunits by two-dimensional gel electrophoresis. the interactions thus found were used as a first basis for constructing a secondary structure model of the 23s rrna. sequence comparison with the 23s rdna from z. mays chloroplasts, as well as with the 16s (large subunit) rdna from human and mouse mitochondria, enabled the experimental model to be improved and extra ... | 1981 | 7024913 |
| sequence, molecular properties, and chromosomal mapping of mouse lumican. | lumican is a major proteoglycan of vertebrate cornea. this study characterizes mouse lumican, its molecular form, cdna sequence, and chromosomal localization. | 1995 | 7558724 |
| in-vivo induction of apoptosis in murine lymphocytes by bacterial lipopolysaccharides. | the effect of bacterial lipopolysaccharide (lps) on the lymphoid organs in c3h/hen and c3h/hej mice was investigated. in c3h/hen mice, lps induced apoptosis, characterised by morphological nuclear condensation and dna fragmentation resulting in thymic atrophy. similar but less severe changes were also observed in the spleen and lymph nodes. in c3h/hej mice, only a slight depletion of lymphocyte numbers was observed in the lymphoid organs. the plasma endotoxin levels were dependent on the lps dos ... | 1995 | 7562985 |
| secondary structure comparisons between small subunit ribosomal rna molecules from six different species. | secondary structure models are presented for three pairs of small subunit ribosomal rna molecules. these are the 16s rrna from e. coli cytoplasmic and z. mays chloroplast ribosomes, the 18s rrna from s. cerevisiae and x. laevis cytoplasmic ribosomes, and the 12s rrna from human and mouse mitochondrial ribosomes. using the experimentally-established secondary structure of the e. coli 16s rrna as a basis, the models were derived both by searching for primary structural homology between the three c ... | 1981 | 7024918 |
| selection of mouse virulent non-motile strains of escherichia coli by the soft agar technique. | using strain sme-12 of escherichia coli and its variants a and b showing large round, diffuse and compact-type colonial morphology, respectively, in soft-agar medium, their capsule showed that although these strains were similar in toxicity, the parent strain exhibited a large capsule, a large cell volume and a high mouse virulence. variant a had no capsule, its cell volume was remarkably lower than that of the original strain, and was avirulent; variant b had no capsule and displayed the lowest ... | 1981 | 7032235 |
| failure of bacterial lipopolysaccharide to elicit a cytostatic effect on plasmodium vinckei petteri in c3h/hej mice. | malarial parasites, plasmodium vinckei petteri, taken from lipopolysaccharide (lps) high-responder (c3h/hejgifwehi) mice which had been injected 7 to 8 h previously with either escherichia coli lps b or lps w incorporated the purine nucleotide precursor hypoxanthine more slowly in an in vitro assay than parasites taken from saline-injected controls. in contrast, malarial parasites taken from lps low-responder c3h/hej mice after injection of either lps b or lps w did not show reduced levels of hy ... | 1982 | 7033142 |
| the role of interleukin 1 in acute phase serum amyloid a (saa) and serum amyloid p (sap) biosynthesis. | the acute phase saa and sap profiles have been compared for localized and endotoxin induced inflammation in lps responder and nonresponder strains of mice. the sap profile can reflect a delay with respect to the start of the increase. its maximum is on the order of ten times the nonacute phase concentration and elevated concentrations are sustained 24 to 48 hours after saa concentration is rapidly decreasing to normal. the role of interleukin 1, known to have an essential role in saa production, ... | 1982 | 6807177 |
| synthesis by the dna primase of drosophila melanogaster of a primer with a unique chain length. | the primase associated with the dna polymerase alpha from embryos of drosophila melanogaster catalyzes the synthesis of ribo-oligonucleotide primers on single-stranded m13 dna or polydeoxythymidylate templates, which can be elongated by dna polymerase action [conaway, r. c. & lehman, i. r. (1982) proc, natl. acad. sci, usa 79, 2523--2527]. the primers synthesized in a coupled primase-dna polymerase alpha reaction with an m13 dna template are of a unique size (15 residues); those synthesized with ... | 1982 | 6812052 |
| stimulation of human and mouse lymphocytes by ribosomal proteins. | ribosomal 30s and 50s subunits as well as total proteins from the large subunit of e. coli ribosomes were found to be potent mitogens for both human adult and cord blood lymphocytes. on the other hand, the rna fraction of the 50s subunit had only a weak stimulatory capacity suggesting that the protein moiety contains the stimulatory component. experiments with lymphocyte subpopulations obtained by nylon wool filtration of e-rosette separation have shown that, in human, the main target cells are ... | 1980 | 6989750 |
| identification of enterotoxigenic escherichia coli by colony hybridization using three enterotoxin gene probes. | the applicability of examining clinical specimens with a dna hybridization technique for genes encoding enterotoxins was examined using enterotoxigenic escherichia coli (etec) that produced both heat-labile toxin (lt) and heat-stable toxin (st) (24 isolates), etec that produced lt only (17 isolates), and etec that produced st only (22 isolates) from thailand. etec was identified with y-l adrenal cell and suckling mouse assays. all were homologous with radiolabeled fragments of dna encoding lt or ... | 1982 | 7045250 |
| de novo dna synthesis by a novel mouse dna polymerase associated with primase activity. | | 1982 | 7045691 |
| release of endotoxic lipopolysaccharide by sensitive strains of escherichia coli submitted to the bactericidal action of human serum. | free endotoxin was assayed in filtered samples of e. coli suspensions submitted to the bactericidal and bacteriolytic action of 10% human serum. the limulus amoebocyte lysate test, a passive hemolysis inhibition assay based on o antigenic specificity and the determination of 3-oh-myristic acid by mass spectrometry were used as assay methods differing from one another with regard to the part of the endotoxin macromolecule involved in the reaction. the biological activity of endotoxin was assessed ... | 1982 | 7048047 |
| chemical modifications of escherichia coli l-asparaginase and their effect on plasma clearance rate and other properties. | escherichia coli asparaginase (l-asparagine amidohydrolase, ec 3.5.1.1) has been modified by succinylation, acetylation and the attachment of n,n-dimethyl-1,3-propanediamine and glucuronic acid. the effect of these modifications on plasma clearance rates in mice and on other properties is compared to the effects of modification with lactose and n-acetylneuraminyl lactose studied previously. the t 1/2 values for the acylated enzyme samples (lower pi) were reduced, succinylated asparaginase sharpl ... | 1982 | 7049249 |
| methods for the detection of single-strand breaks in dna under neutral conditions and their application in a study on the mechanism of repair of n-methylated purines in mouse cells. | considering enzymatic activities found in bacteria and in animal cells, there are two possible mechanisms for repair of n-methylated purines produced by methylating agents such as the mutagen and carcinogen n-methyl-n'-nitro-n-nitrosoguanidine. both mechanisms involve first an enzymatic removal of the methylated bases by glycosylases. the resulting apurinic sites could then be repaired by (a) direct insertion of the correct bases purine insertases or (b) opening of the polynucleotide chain by ap ... | 1982 | 7106118 |
| antibodies to ornithine decarboxylase. immunochemical cross-reactivity. | l-ornithine decarboxylase was purified to apparent homogeneity from the kidneys of testosterone-treated mice. antibodies to ornithine decarboxylase were raised in a rabbit using the purified enzyme. ouchterlony double diffusion technique revealed a single precipitin line between the antiserum and purified mouse kidney ornithine decarboxylase. the antibodies inhibited ornithine decarboxylase from various tissues of mice and rats to the same extent, indicating a close immunological relationship. s ... | 1982 | 7164704 |
| effects of fmlp and lps on [ca2+]i of peritoneal exudate polymorphonuclear leukocytes following onset of inflammation. | because a general study of activated neutrophils may have relevance to periodontal diseases and accompanying inflammation, we studied a function of mouse polymorphonuclear leukocytes (pmns) that exude into the peritoneal cavity in response to inflammation caused by i.p. injection of 2% casein. the effects of e. coli-lipopolysaccharide (e-lps) and a chemotactic factor, n-formyl-n-methionyl-n-leucyl-l-phenylalanine (fmlp), on the level of intracellular calcium ([ca2+]i) in these pmns were examined ... | 1995 | 7472996 |
| interaction of ect2 and dbl with rho-related gtpases. | | 1995 | 7476459 |
| early increase in choline kinase activity upon induction of the h-ras oncogene in mouse fibroblast cell lines. | the effects of expression of the h-ras oncogene on phosphatidylcholine metabolism were examined in c3h10t1/2 and nih3t3 cells expressing ras constitutively or under the control of inducible promoters. cell lines expressing ras under the control of the mouse metallothionein promoter and the escherichia coli lac operator/repressor system and an nih3t3 cell line stably transfected with the ras oncogene were studied. phosphocholine levels were elevated in the cells constitutively expressing ras and ... | 1995 | 7487093 |
| induction of t-cell immunity against ras oncoproteins by soluble protein or ras-expressing escherichia coli. | point mutations in the ras proto-oncogene that activate its oncogenic potential occur in approximately 30% of human cancers. previous studies have demonstrated that t-cell immunity against some forms of mutant ras proteins could be elicited, and some effectiveness against tumors expressing activated ras has been reported. | 1995 | 7494229 |
| embryonic expression of human keratin 18 and k18-beta-galactosidase fusion genes in transgenic mice. | during embryogenesis, endob, the mouse form of human keratin 18 (k18), is expressed in a complex spatial and temporal pattern in various embryonic epithelia. we have compared the expression of transgenic human k18 to the endogenous mouse homolog and to the coexpressed, complementary keratin 8 homolog, endoa, during postimplantation mouse embryogenesis and fetal development in order to determine the developmental expression pattern of the human gene in a mouse environment. the tissue distribution ... | 1993 | 7504637 |
| dual mechanism for the control of inducible-type no synthase gene expression in macrophages during activation by interferon-gamma and bacterial lipopolysaccharide. transcriptional and post-transcriptional regulation. | production of nitric oxide (no) by macrophages is enhanced upon activation by bacterial endotoxins and cytokines mainly via an increase of the intracellular content of the inducible isoform of nitric oxide synthase (i-nos). we have studied in detail the effect of several modulators of macrophage activity on steady state levels of i-nos mrna in the mouse macrophage-like cell line raw 264.7. bacterial lipopolysaccharide (lps) and interferon-gamma (ifn-gamma) were found to be effective inducers of ... | 1994 | 7510685 |
| mechanisms of the dna breaking activity of mutagenic 5-diazouracil. | 5-diazouracil in monohydrated form showed mutagenicity and cytotoxicity on salmonella typhimurium ta98 and ta100 strains without metabolic activation, and induced mouse micronucleated peripheral reticulocytes. incubation of a plasmid supercoiled dna with the compound caused dna single-strand breaking: the supercoiled form was transformed into an open circular relaxed form and then into a linear form. the breaking was similarly caused in the absence of molecular oxygen. the breaking was not inhib ... | 1994 | 7512214 |
| response of the muta mouse lacz/gale- transgenic mutation assay to dmn: comparisons with the corresponding big blue (laci) responses. | the lacz muta mouse transgenic mutation assay was recently adapted into a selective assay based on use of e. coli gale(-) bacteria and phenyl galactoside (p-gal). a preliminary assessment of this selective assay was undertaken using a single oral dose of 10 mg/kg of dimethyl nitrosamine (dmn). the livers of treated male mice were assessed for uds 2 h after dosing, and for lacz- mutations 7, 11 and 20 days after dosing. a strong uds response was recorded and a clear mutagenic response was observe ... | 1994 | 7513794 |
| the beta 1 integrin distal promoter is developmentally regulated in transgenic mice. | transgenic mice harbouring 5' flanking sequences of the human beta 1 integrin gene linked to the escherichia coli lacz gene have been generated to examine spatial and temporal distribution of the promoter activity during development. our previous data showed that this regulatory region is composed by two promoters, called distal and proximal, located closely on the human genome. to determine the role of each promoter region during development we generated transgenic mice using these two sequence ... | 1993 | 7521754 |
| purification of e. coli-synthesized pan proteins and development of a pan-specific monoclonal antibody. | the helix-loop-helix (hlh) transcription factors, pan-1 (e47) and pan-2 (e12), are produced by the mechanism of alternative transcript splicing. pan-1 and pan-2 were expressed in escherichia coli, and a purification scheme was developed. purified pan-2 was used to immunize smith-webster mice and a hybridoma was generated that produced a monoclonal antibody (yae) that specifically recognized both native and denatured pan-1 and pan-2. deletion mapping and sequence transfer studies have localized t ... | 1994 | 7523277 |
| [detection of the generation of nitric oxide from l-arginine in the murine brain in vivo using epr]. | nitric oxide (no) was shown by epr method to be generated via l-arginine-dependent way in brain of mice in vivo. the complexes of diethyldithiocarbamate (detc) or pirrolidinedithiocarbamate (pdtc) with endogenous or exogenous fe2+ were used as a traps of no, which are capable to bind no resulted in the formation of mononitrosyl iron complexes with detc or pdtc (mnic-detc or pdtc) recovered by epr method. these complexes were detected in mouse brain in concentration of 2.5 nmole/g of wet tissue f ... | 1994 | 7529563 |
| molecular cloning of the cdna and gene for an elastinolytic aspartic proteinase from aspergillus fumigatus and evidence of its secretion by the fungus during invasion of the host lung. | hydrolysis of structural proteins in the lung by extracellular proteinases secreted by aspergillus fumigatus is thought to play a significant role in invasive aspergillosis. this fungus was found previously to secrete an elastinolytic serine proteinase and a metalloproteinase. we report that a. fumigatus also secretes an aspartic proteinase (aspergillopepsin f) that can catalyze hydrolysis of the major structural proteins of basement membrane, elastin, collagen, and laminin. the ph optimum for t ... | 1995 | 7558282 |
| genetic studies reveal that myristoylcoa:protein n-myristoyltransferase is an essential enzyme in candida albicans. | myristoylcoa:protein n-myristoyltransferase (nmt) catalyses the co-translational, covalent attachment of myristate (c14:0) to the amino-terminal glycine residue of a number of eukaryotic proteins involved in cellular growth and signal transduction. the nmt1 gene is essential for vegetative growth of saccharomyces cerevisiae. studies were carried out to determine if nmt is also essential for vegetative growth of the pathogenic fungus candida albicans. a strain of c. albicans was constructed in wh ... | 1995 | 7565086 |
| the role of neuropeptide y in the antiobesity action of the obese gene product. | recently zhang et al. cloned a gene that is expressed only in adipose tissue of the mouse. the obese phenotype of the ob/ob mouse is linked to a mutation in the obese gene that results in expression of a truncated inactive protein. human and rat homologues for this gene are known. previous experiments predict such a hormone to have a hypothalamic target. hypothalamic neuropeptide y stimulates food intake, decreases thermogenesis, and increases plasma insulin and corticosterone levels making it a ... | 1995 | 7566151 |
| molecular engineering of microsomal p450 2a-4 to a stable, water-soluble enzyme. | peptitergented p450 2a-4 (pepti-p450), a water-soluble form of the mouse microsomal p450 2a-4, was genetically engineered and expressed in escherichia coli. the nh2-terminal hydrophobic sequence (positions 2 to 19) of pepti-p450 was replaced by a peptitergent pd1, amphipathic peptide consisting of 24 residues (c. e. schafmeister, l. j. miercke, and r. m. stroud (1993) science 262, 734-738). the expression level of pepti-p450 (90,000 molecules/cell) was at least four times greater than that of wi ... | 1995 | 7574685 |
| domain organization and a protease-sensitive loop in eukaryotic ornithine decarboxylase. | trypanosoma brucei ornithine decarboxylase was reconstituted by coexpression of two polypeptides corresponding to residues 1-305 and residues 306-425 in escherichia coli. the two peptides were coexpressed, at wild-type levels, from a single transcriptional unit that was separated by a 15-nucleotide untranslated region containing a ribosome binding site. the fragmented enzyme was purified and analyzed. the n- and c-terminal peptides are tightly associated into a fully active tetramer which has th ... | 1995 | 7577930 |
| the influence of antioxidants and cycloheximide on the level of nitric oxide in the livers of mice in vivo. | when injected into mice prior to the no generation increase induced with lipopolysaccharide (lps) from escherichia coli, exogenous antioxidants diethyldithiocarbamate (detc) or phenazan (sodium 3.5-di-tert-butyl-4-oxiphenylpropionate) as well as the inhibitor of protein biosynthesis, cycloheximide (chi) attenuated the no production in mouse liver in vivo. these data demonstrated the key role of free radicals, which were likely, active oxygen species, in the synthesis of inducible no-synthase (in ... | 1995 | 7578266 |
| reduction of the tyrosyl radical and the iron center in protein r2 of ribonucleotide reductase from mouse, herpes simplex virus and e. coli by p-alkoxyphenols. | the rate of reduction of the tyrosyl radical in the small subunit of ribonucleotide reductase (protein r2) from e. coli, mouse, and herpes simplex virus (hsv-2) by a series of p-alkoxyphenols with different alkyl chains, have been studied by stopped-flow uv-vis and stopped-flow epr spectroscopy. the reduction and release of iron in r2 by the inhibitors was followed using bathophenanthroline as chelator of fe2+. p-alkoxyphenols reduce the mouse r2 tyrosyl radical 1-2 orders of magnitude faster th ... | 1995 | 7589521 |
| molecular analysis of a metalloprotease from proteus mirabilis. | proteus mirabilis is known for its ability to differentiate from swimmer to swarmer cells, a process crucial for the pathogenesis of these bacteria during urinary tract infections. among the many virulence factors produced during swarmer cell differentiation is an extracellular metalloprotease. a cosmid containing a large fragment of p. mirabilis chromosomal dna was obtained by measuring protease expression in recombinant escherichia coli. the recombinant and native enzymes were purified to over ... | 1995 | 7592325 |
| mouse mth1 protein with 8-oxo-7,8-dihydro-2'-deoxyguanosine 5'-triphosphatase activity that prevents transversion mutation. cdna cloning and tissue distribution. | 8-oxo-7,8-dihydro-2'-deoxyguanosine 5'-triphosphate (8-oxo-dgtp) is formed in the nucleotide pool of a cell during normal cellular metabolism, and when it is incorporated into dna causes mutation. organisms possess 8-oxo-dgtpase, an enzyme that specifically degrades 8-oxo-dgtp to 8-oxo-dgmp. we isolated cdna for mouse 8-oxo-dgtpase, using as a probe human mth1 (escherichia coli mutt homolog) cdna. the nucleotide sequence of the cdna revealed that the mouse mth1 protein (molecular weight of 17,89 ... | 1995 | 7592783 |
| biochemical, structural, and transglutaminase substrate properties of human loricrin, the major epidermal cornified cell envelope protein. | loricrin is the major protein of the cornified cell envelope of terminally differentiated epidermal keratinocytes which functions as a physical barrier. in order to understand its properties and role in cornified cell envelope, we have expressed human loricrin from a full-length cdna clone in bacteria and purified it to homogeneity. we have also isolated loricrin from newborn mouse epidermis. by circular dichroism and fluorescence spectroscopy, the in vivo mouse and bacterially expressed human l ... | 1995 | 7592852 |
| mouse chick chimera: a new model to study the in ovo developmental potentialities of mammalian somites. | chimeras were prepared by transplanting somites from 9-day post-coïtum mouse embryos or somitic dermomyotomes from 10-day post-coïtum mouse embryos into 2-day-old chick embryos at different axial levels. mouse somitic cells then differentiated in ovo in dermis, cartilage and skeletal muscle as they normally do in the course of development and were able to migrate into chick host limb. to trace the behavior of somitic myogenic stem cells more closely, somites arising from mice bearing a transgene ... | 1995 | 7600987 |
| isolation of cdna clones encoding the mouse protein v-1. | the amino acid (aa) sequence of rat v-1, a developmentally regulated brain protein, was used to isolate clones encoding mouse v-1, a protein of 118 aa, from an embryoid body cdna library. the aa sequences of rat and mouse v-1 are identical. v-1 shares several properties (including a 23 of 24 aa match of a tryptic peptide) with myotrophin, a protein that induces cardiac myocyte hypertrophy. attempts to show that v-1 produced in escherichia coli could induce the cardiac myocyte hypertrophy ascribe ... | 1995 | 7607560 |
| influence of endogenous biotin on the biodistribution of labelled biotin derivatives in mice. | previously, this laboratory reported that in mice pre-targeted with unlabelled streptavidin, the biodistribution of 111in administered on one biotin derivative (eb1) was superior to that of another derivative (db2). in addition, a scatchard analysis showed that the affinity constant of 111in-eb1 is lower by seven orders of magnitude from that of 111in-db2. therefore, this paper considers the role that endogenous biotin may play in these observations. both 111in-labelled eb1 and db2 were bound to ... | 1995 | 7609933 |
| mouse methyltransferase for repair of o6-methylguanine and o4-methylthymine in dna. | cdna for mouse o6-methylguanine-dna methyltransferase was expressed in methyltransferase-deficient escherichia coli mutant cells, and the overproduced mouse enzyme was purified to a homogeneous state. using this purified product, polyclonal antibodies were prepared and used to estimate amounts of the methyltransferase protein in cells. a single cell of nih3t3 contained 1.8 x 10(4) molecules of the methyltransferase protein. when mouse fibroblasts were immunostained, it was shown that most of the ... | 1995 | 7614694 |