The association of transcription factor Pit 1/GHF-1 with Pit and Oct binding elements.
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Animals↗
Biomedical subjects
F Martin
Publications and source records attributed to F Martin.
Comparison of the effectiveness of various antibiotics in the treatment of methicillin-susceptible Staphylococcus aureus experimental infective endocarditis.
The effectiveness of various antibiotics was tested in the eradication of a strain of methicillin-susceptible Staphylococcus aureus (MSSA) of cardiac vegetations, in an experimental model of endocarditis in rabbits. Twelve animals comprised the control group and 48 the treated ones. After inducing the experimental endocarditis, the animals were treated for three days; then mortality, blood cultures at 48 and 72 hours and the title of the colony forming units per gram of vegetation (CFU/g) were evaluated. Imipenem and the cloxacillin-gentamicin association were found to be as effective as cloxacillin in eradicating the microorganisms of the vegetation. Clindamycin in high doses was shown to be a valid alternative. Vancomycin, teicoplanin, rifampin and ciprofloxacin were less effective than cloxacillin. The experimental model seems to be an effective method for evaluating antimicrobial treatments in staphylococcal endocarditis.
Animals↗
Attachment of boar sperm to mucosal explants of oviduct in vitro: possible role in formation of a sperm reservoir.
Ejaculated boar sperm were incubated with explants of porcine oviductal mucosa that had been dissected from the isthmic and ampullar regions of gilts. Sperm bound within minutes to the epithelial surfaces of the explants. Binding was not affected by region (isthmus or ampulla) nor day of estrous cycle (Day 0 or Day 10), but was increased by addition of 70 pg/ml 17 beta-estradiol to the medium. Scanning electron micrographs indicated that sperm bound, via the acrosomal region, to ciliated cells. After 24 h, the numbers of bound sperm dropped significantly, but the motility of the bound sperm did not. A mucous material that entrapped sperm was observed on the epithelial surfaces of 23/32 isthmic and only 4/32 ampullar explants. These results indicate that sperm sticking to ciliated cells and mucus can create a sperm reservoir in the isthmus, but the means by which sperm are released remain unknown.
Animals↗
Ectomycorrhizin Synthesis and Polypeptide Changes during the Early Stage of Eucalypt Mycorrhiza Development.
In functioning eucalypt ectomycorrhizas, biochemical alterations are accompanied by a differential accumulation of polypeptides including the synthesis of symbiosis-related proteins (JL Hilbert, Martin FM [1988] New Phytol 110: 339-346). In the present study, protein biosynthesis in the early stages of ectomycorrhiza formation on Eucalyptus globulus subsp. bicostata Kirkp. was examined using compatible and incompatible isolates of the basidiomycete Pisolithus tinctorius (Coker & Couch). Changes in polypeptide composition were observed within hours following contact of the compatible mycelium with the roots, well before the differentiation of typical symbiotic tissues. At this stage, at least seven symbiosis-related proteins (ectomycorrhizins) accumulated in root tissues. In vivo incorporation of [(35)S]methionine by ectomycorrhizas followed by electrophoresis of the labeled proteins revealed that most of these differences in polypeptide concentrations, including the ectomycorrhizin accumulation, are the result of differential protein biosynthesis rather than posttranslational modifications of the polypeptides. The initial development of eucalypt ectomycorrhizas, therefore, coincides with the synthesis of symbiosis-related proteins and the data presented here provide essential evidence to ascribe a functional developmental role to these proteins.
Journal Article↗
Apolipoprotein B polymorphism and altered apolipoprotein B concentrations in Congolese blacks.
The immunoreactivity of apolipoprotein B (apo B) in plasma obtained from 238 unrelated black African male subjects from the People's Republic of Congo was analysed by non-competitive Enzyme Linked-Immunosorbent Assay (ELISA) with monoclonal BIP 45 anti-LDL antibody. The polymorphism detected by BIP 45 monoclonal antibody is identical to the Ag(c,g) polymorphism. Antibody BIP 45 distinguishes three apo B allotypes (immunophenotypes) encoded by the two allelic genes apo B Ag(c) and apo B Ag(g). Because of co-dominant transmission, genotypes may be inferred from allotypes, and it has been shown that BIP 45 binds strongly to the Ag(c) factor and only weakly to the allelic Ag(g) factor. Analysis of the Congolese plasma samples indicated that 67.65% of them bound BIP 45 with low affinity (Ag(c-,g+) genotype), 28.15% with intermediate affinity (Ag(c+,g+) genotype) and 4.20% with high affinity (Ag(c+,g-) genotype). According to the Hardy-Weinberg equilibrium, this corresponds to gene frequencies of 0.817 and 0.183 for the type Ag(g)/Ag(c) alleles, respectively. After adjustment for age and body-mass index, it was found that the Ag(c) allele decreases the apo B level by 9.62 mg/dl and that the Ag(g) allele increases apo B by 0.43 mg/dl. Therefore, as much as 4.30% of the genetic variance for apo B level could be accounted for by the Ag(c,g) gene locus.
Alleles↗
Differential effects of pinealectomy on amygdala and hippocampus serotonin metabolism.
The purpose of the present study was to determine the effects of long-term pinealectomy on serotonin metabolism in the amygdala and the hippocampus of male rats. Pinealectomy did not significantly alter either tryptophan or serotonin concentrations in the amygdala or the hippocampus. However, statistically significant decreases in 5-hydroxyindole-3-acetic acid levels and tryptophan hydroxylase activity were found in the amygdala. Monoamine oxidase activity was unchanged in both regions. These results support the involvement of the amygdaloid serotoninergic system in mediating the functions of the pineal gland.
Amygdala↗
A cytogenetic study of men occupationally exposed to uranium.
Blood lymphocyte cultures from two groups of workers occupationally exposed to uranium were examined for asymmetrical chromosome aberrations and sister chromatid exchanges (SCEs). Significant increases in both cytogenetic endpoints were seen. For dicentrics this appeared to be particularly associated with exposure to soluble uranium. The external radiation exposure experienced by these men was insufficient to explain the increase in dicentrics, and irradiation of lymphocytes by internally deposited uranium would have been minimal. As the SCEs were also raised, the genotoxic effect is likely to be due to the chemical nature of the compound. The increase in frequency of dicentrics associated with smoking was greatest in the group with exposure to soluble uranium suggesting some interaction between the two clastogens. No such interactive effect was seen for SCE frequencies, in which increases attributable to smoking were similar in the worker and control groups.
Adult↗
A cross-sectional study of pulmonary function in autobody repair workers.
This study evaluated pulmonary function in workers from 39 autobody repair shops. Based on 152 White male workers with known smoking status, the mean percent predicted FEV1, FVC, and FEV1/FVC were 93.6, 96.8, and 96.6, respectively. Twenty-three percent of workers had a FEV1/FVC ratio less than the fifth percentile. Isocyanate levels ranged from nondetectable to 0.06 parts per million (STEL = 0.02 ppm). No shop had an adequate respiratory protection program. We concluded that there was an increase in abnormal pulmonary function in autobody workers. Three recommendations were made to shop owners: functional paint booths should be maintained, respiratory protection programs should be developed, and isocyanate-free paints should be used.
Adult↗
Characterisation of functional inhibition of the glucocorticoid receptor by Fos/Jun.
We have studied the effects of Fos and Fos/Jun on glucocorticoid induction of hormone-sensitive gene expression. In NIH3T3 cells overexpression of Fos or Fos/Jun by transfection of pSV2-fos and pSV2-jun inhibited glucocorticoid-dependent expression of MMTV LTR-CAT. Expression of p39v-mos had a similar effect on glucocorticoid-dependent reporter gene expression which is most likely mediated by simulation of endogenous Fos. In both cases, this inhibition could be overcome by overexpression of the glucocorticoid receptor (GR) from a transiently transfected expression vector. In receptor deficient CV-1 cells glucocorticoid-dependent reporter gene expression was induced by a range of functional GR truncation mutants. It was established that the C/D domain of the receptor was a sufficient target for inhibition by Fos and Fos/Jun. The C/D domain encompasses the DNA-binding domain, a dimerisation domain and a weak transactivational domain of the GR. When present simultaneously in the cell nucleus Fos and Jun were shown to form a specific and stable protein/protein complex with the glucocorticoid receptor. Finally, it was demonstrated that the GR interacts physically with both Fos and Jun when cotranslated simultaneously in vitro. We propose that this interaction may be the mechanism by which Fos or Fos/Jun bring about inhibition of GR function.
Animals↗
Gene regulation in megakaryocyte.
Analysis of the mechanisms which control the differentiation of the megakaryocytic lineage is a major commitment to understand the production of circulating blood platelets. One way to approach this question is to examine the promoter domain of a marker gene which is expressed exclusively in the megakaryocytic lineage and at an early stage of the differentiation process. For this purpose the gene coding for the platelet specific glycoprotein IIb was isolated and its promoter was analysed. This promoter contains positive and negative DNA responsive elements that are responsible for the cell specific expression of the gene. With this promoter region it is now possible to direct the expression of heterologous genes in vivo using the transgenic approach.
Biomarkers↗
[Underestimation of cases of occupational asthma in Provence-Alpes-Côte d'Azur and Corse region].
To evaluate a possible underestimation of disability claims for occupational asthma in the Provence-Alpes-Côte d'Azur-Corse area, we compared the actual figures collected from 1986 to 1988 to the predicted figures. The latter were computed from the number of exposed subjects in at-risk industries and the prevalence of occupational asthma reported in the literature for each exposure category. From 1986 to 1988, only 44 disability claims were submitted and 25 of them were accepted. These disability claims represent about 2% of the occupational asthma cases which would be expected. The reasons for such a large discrepancy could be a selection bias leading disabled subjects to leave the occupation at risk, a failure by the patient and/or the physician to identify the disease, or a poor compensation system which is not an incentive for performing a disability claim.
Asthma↗
mos-induced inhibition of glucocorticoid receptor function is mediated by Fos.
Activation of glucocorticoid hormone-dependent transcription involves the binding of the glucocorticoid hormone to its receptor followed by a specific interaction of the hormone/receptor complex with glucocorticoid responsive elements in the promoter region of hormone-inducible genes. In stably transfected NIH3T3 cells expressing the oncogene product of v-mos or fos, the expression from two glucocorticoid responsive promoters, MMTV LTR and metallothionein IIA (MtIIA), was shown to be impaired and was only transient. Cadmium-dependent MtIIA gene expression was not affected by the expression of v-mos in the cells. In transiently transfected NIH3T3 cells constitutive fos expression also inhibited glucocorticoid hormone-induced expression from the MMTV LTR. However, co-expression of antisense fos (here referred to as sof) inhibited the down-regulatory effect of Fos on glucocorticoid induced gene expression. v-mos expression in NIH3T3 cells induces fos mRNA and functional fos product (Fos) as reflected by its ability to induce expression of a transiently transfected AP-1 dependent reporter plasmid. We show that sof expression inhibits the down-regulatory effect of mos on expression of a transiently transfected pMMTV LTR-CAT. Our findings, thus, strongly suggest that the inhibition of glucocorticoid receptor function in cells expressing the v-mos oncogene is mediated by Fos.
Animals↗
[Gastric acidity inhibition. Consequences on N-nitrosocompounds-induced gastric carcinogenesis].
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Gastric Acid↗
Influence of the injection site on the tumorigenicity of a cloned colon tumor cell line in the rat.
The cloned DHD/K12/TSb line obtained from a chemically-induced rat colon carcinoma, presents tumors which always regress when injected subcutaneously to the syngeneic animal. This study reports that an intraperitoneal injection of the DHD/K12/TSb cells induces a progressive carcinomatosis in a high proportion of the syngeneic rats. This result underlines the effect that the local environment has on tumorigenicity.
Animals↗
[A rare cause of non-nosocomial pneumonia in a healthy adult: Morganella morganii].
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Adult↗
F11C antigen: a membrane marker able to distinguish two regressive and progressive variants from a rat colon adenocarcinoma.
Cell variants that differ in their tumorigenicity and immunogenicity have been isolated from a BDIX rat colon adenocarcinoma cell line, DHD/K12. One variant, PRO, and the clones derived from it, are poorly immunogenic and induce progressive and metastatic tumors; the other one, REG, and its clones, are highly immunogenic and induce regressive tumors. When looking for a membrane marker distinguishing between PRO and REG lines, we obtained monoclonal hybridomas by immunizing BALB/c mice with PROb or REGb cell clones. Hybridoma F11C, producing an IgM monoclonal antibody (MAb) was able to distinguish between the cell variants on membrane immunofluorescence. All REGb cells strongly express F11C membrane antigen. On PROb cells, F11C antigen expression is weak, as demonstrated by cytofluorimetric analysis, and limited to a fraction of the cell population. The F11C membrane antigen is highly specific for the DHD/K12 cell line and the variants derived from it, but is not expressed on cells dissociated from the DHD transplanted tumor, from which DHD/K12 was established, suggesting that F11C antigen emerged during cell culture. Fluorescence absorption on synthetic oligosaccharides demonstrated that F11C antibody cross-reacts with A type 3, A type 4 and A type 5 chain blood group tetrasaccharides.
Adenocarcinoma↗
Mechanisms of resistance of confluent human and rat colon cancer cells to anthracyclines: alteration of drug passive diffusion.
Two colon cancer cell lines, HT-29 (human) and DHD/K12/TRb (rat), were grown as monolayer cultures to various confluence degrees. The cytotoxic efficacies of doxorubicin and 4'-deoxydoxorubicin, evaluated by a survival assay, and the nuclear drug concentrations, measured by microspectrofluorometry, were shown to progressively decrease with the augmentation of confluence. This confluence dependent resistance (CDR) to anthracyclines was demonstrated independent of the multidrug resistance drug efflux mechanism. The cellular uptake of three compounds (sodium [51Cr]chromate, D-[14C]alanine, L-[14C]glucose) known to passively diffuse across the cell membrane as anthracyclines do was also reduced in confluent cells. After trypsin cell detachment, the kinetics of reversion of the sodium [51Cr]chromate uptake decrease and that of CDR were similar. Therefore, CDR may be attributed to a reduction of anthracycline cell intake due to a general alteration of passive diffusion across the cell membrane. However, CDR is only partly explained by this phenomenon since a reduced sensitivity of confluent cells was observed compared with nonconfluent cells for a similar amount of drug in their nuclei. CDR could explain the high resistance to anthracyclines of some solid tumors, such as colon tumors, in which cancer cells are tightly aggregated.
Animals↗
Characterisation of tissue-specific trans-acting factor binding to a proximal element in the rat growth hormone gene promoter.
Using an exonuclease III protection assay, tissue-specific binding of rat pituitary tumour cell (GH3 cell) nuclear factors to a proximal region (-68 to -138) of the rat growth hormone gene promoter has been detected. The binding is particularly strong between the borders -68 to -102. The binding is eliminated in the presence of excess unlabelled rat growth hormone gene promoter sequences but also by proximal (-423 to +38) or distal (-1960 to -1260) rat prolactin gene promoter sequences and simian virus 40 enhancer/promoter sequences. Extracts of rat pituitaries showed identical binding characteristics. Methylation interference analysis indicated that the contact points between the pituitary-specific factor and the proximal rat growth hormone gene promoter-binding element (-65 to -95) are over a conserved sequence which occurs twice in the rat growth hormone gene promoter and at least eight times in the rat prolactin gene 5'-flanking sequences. This sequence has previously been proposed to constitute the binding site for the somatotroph/lactotroph tissue-specific transcription factor. Gel-retardation and exonuclease III competition analysis showed that three of the rat prolactin gene promoter elements (-46 to -71, -156 to -180 and -174 to -204) share the ability to bind the pituitary-specific factor. The binding to the most proximal rat prolactin gene promoter element (-46 to -71) was clearly more avid than to the rat growth hormone gene promoter (-65 to -95) proximal element. However, both these elements displayed the formation of two gel-retarded complexes while the more distal rat prolactin gene binding elements (-156 to -180 and -174 to -204) formed only the smaller of the two complexes. Finally, we demonstrated by co-transfection competition analysis that plasmids containing the most proximal rat prolactin gene promoter binding element completely inhibited transcription from the rat growth hormone gene promoter while rat growth hormone gene promoter sequences only partially inhibited transcription from the rat prolactin gene promoter. This suggests that the higher affinity for factor binding displayed by the proximal rat prolactin gene promoter binding site in vitro is reflected in factor binding activity in vivo.
Animals↗