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Biomedical subjects

A Masson

Publications and source records attributed to A Masson.

At least 37 records · Page 2Linked to original sources
PubMed1995

Biphasic transforming growth factor-beta production flanking the pro-inflammatory cytokine response in cerebral trauma.

We determined the time-course of the production of transforming growth factor-beta (TGF-beta) after fluid-percussion injury using a bioassay. Biophasic production of TGF-beta composed mainly of TGF-beta 2 was detected in the ipsilateral cortex, with a first peak 30 min and a second peak 48 h after the lesion, flanking the transient production of tumor necrosis factor-alpha and interleukin-6 occurring between 5 and 18 h after trauma. This temporal pattern suggested that TGF-beta plays alternatively a pro- and anti-inflammatory role in the regulation of the brain cytokine network in response to injury, providing an endogenous mechanism for the control of the inflammatory reaction in traumatic brain injury.

Animals↗
PubMed1995

Over-production, purification and properties of the uridine-diphosphate-N-acetylmuramate:L-alanine ligase from Escherichia coli.

The UDP-N-acetylmuramate:L-alanine ligase of Escherichia coli was over-produced in strains harbouring recombinant plasmids bearing the murC gene under the control of the lac or trc promoter. Plasmid pAM1005, in which the promoter and ribosome-binding site region of murC were removed and in which the gene was directly under the control of promoter trc, led to a 2000-fold amplification of the L-alanine-adding activity after induction by isopropyl-thio-beta-D-galactopyranoside. The murC gene product was visualized as a 50-kDa protein accounting for approximately 50% of the cell protein. A two-step purification led to 1 g of a homogeneous protein from an 18-1 culture. The N-terminal sequence of the purified protein correlated with the nucleotide sequence of the murC gene. The presence of 2-mercaptoethanol and glycerol was essential for the stability of the enzyme. The Km values for UDP-N-acetylmuramic acid, L-alanine and ATP/Mg2+ were estimated at 100, 20 and 450 microM, respectively. Under the optimal in vitro conditions a turnover number of 928 min-1 was calculated and a copy number/cell of 600 could be roughly estimated. The specificity of the enzyme for its substrates was investigated with various analogues. The enzyme also catalysed the reverse reaction.

Alanine↗
PubMed1993

[Neuroblastoma in the Auvergne region from 1986 to 1991: epidemiological data].

An epidemiological study of neuroblastoma in the Auvergne area of France (departments: Puy-de-Dôme, Allier, Cantal, Haute-Loire) was carried out over a 6 years period (1986-1991). Nineteen cases of neuroblastoma were registered during this period. The annual incidence rate is 1.2 among 100,000 children under the age of 15 years. Similar incidence rates from other studies have been reported in the literature. In the department of Rhône, France, a screening program for neuroblastoma was initiated in 1990. The Auvergne area may constitute a population-based control group.

Child↗
PubMed1992

Aptitude for physical exercise in a population of female hospital workers.

The aim of this study was to evaluate the level of physical capacity in a female hospital population of Paris and its suburbs. A total of 1505 women working in the selected departments filled in a questionnaire concerning their working conditions, life habits and health and also attended a medical examination. The effort test performed consisted in flexing the legs 20 times with the chest held straight, in 40 s. The heart rates were measured for the first, the second and the third minutes of recovery (first 15 s multiplied by 4). The blood pressure was measured just after the heart rate, for the first and the third minute. Recovery indices have been constituted from the results. The respective weights of anthropometric and sociodemographic risk factors for recovery indices were studied in multiple logistic regression models. The classification enables us to consider about 25%-30% of our population as having a satisfactory physical capacity, about 26%-27% as having an acceptable capacity, and about 24%-27% as having a weak capacity. About 21% of the population presented an excessive pressure reaction and 44% a questionable pressure reaction. Our results concerning the level of physical capacity of the female nursing staff should be taken into account especially in the future planning of work loads and architectural choices, which must avoid excessive physical burdens in relation to this level. An improvement in the level of physical capacity could be envisaged as well.

Adult↗
PubMed1992

Neuropsychological symptoms and occupational exposure to anaesthetics.

OBJECTIVE: To analyse the relation between symptoms regularly reported by hospital personnel and exposure to anaesthetics. SETTING: Personnel of 18 hospitals in Paris from 1987 to 1989. DESIGN: An exposed group that included all operating theatre members except for doctors, and which was divided into three subgroups depending on the degree of exposure--exposure was measured by the frequency of the use of the scavenging system--and a control group that included other hospital personnel matched by hospital, sex, occupation, age, and duration of service. SUBJECTS: 557 exposed workers and 566 unexposed workers. MAIN OUTCOME MEASURES: The groups were compared according to the crude rates of regular symptoms. Adjusted odds ratios were calculated to estimate the risks associated with exposure to anaesthetic gas. Liver transaminase activities (alanine aminotransferase, aspartate aminotransferase (s-ASAT, and gamma-glutamyl transpeptidase) were measured and compared between groups of exposure. RESULTS: After controlling for working conditions and matching factors, neuropsychological symptoms and tiredness were reported more by workers in less often scavenged theatres than by controls. No difference was found between workers of the well scavenged theatres and controls. Among the exposed workers, the members of paediatric surgical staffs reported a higher rate of neurological complaints (tingling, numbness, cramps) and tiredness than the members of the other surgical staffs. They had a high value of s-ASAT more frequently than the other exposed workers. CONCLUSION: These results strengthen the hypothesis of a causal relation between exposure to anaesthetics and neuropsychological symptoms, and show a dose-response effect. They suggest that the use of ventilating systems in operating rooms is an effective means of prevention.

Anesthetics↗
PubMed1991

Molecular characteristics of cytochrome b558 isolated from human granulocytes, monocytes and HL60 and U937 cells differentiated into monocyte/macrophages.

Enriched cytochrome b558 preparations were obtained from human mature monocytes (MN) and retinoic acid plus interferon gamma induced human myeloid leukemia cell lines HL-60 and U937, using an adaptation of the procedure described by A.W. Segal (Nature (1987) 326, 88-91) for purification of cytochrome b558 from human polymorphonuclear leukocytes (PMN). Spectral characteristics of cytochrome b558 were determined and found to be independent of cell type and specific heme b content of the preparation. To increase the sensitivity of the spectral assay, analysis in the gamma band were used and delta epsilon 427-413 was determined to be equal to 158 mM-1 cm-1. An alpha beta type heterodimeric cytochrome b558 was found for PMN and MN by the concordant elution of heme b spectral activity from heparin agarose and the detection of two polypeptide chains by SDS-PAGE. The expression of the lighter polypeptide alpha chain in the various human monocyte-like cell lines was assessed and its identity, as a component of cytochrome b, was confirmed by immunodetection using a rabbit polyclonal antibody reacting with the alpha subunit of PMN cytochrome b558. Immunoblotting studies detected the alpha subunit in monocyto-macrophagic differentiated HL-60 and U 937 cells and mature MN at 22 kDa, but not in uninduced cells which did not express the respiratory burst. Whatever the specific content or the cell origin of the cytochrome b558-enriched preparations, the heme b binding site was shown to be associated with the alpha subunit defined by a constant molecular mass of 22 kDa, as evidenced by the finding of a constant ratio between the silver stained band intensity and the corresponding heme b amount. The heavy polypeptide beta chain from MN cytochrome b was found to have a significantly higher molecular weight than the beta subunit from PMN at 94 +/- 5 kDa instead of 90 +/- 4 kDa. In contrast, in cytochrome b preparations from induced monocyto-macrophagic cells, isolated with a low heme specific content, the variability in the detection of the staining intensity of the beta band either in SDS-PAGE or immunodetection reactivities precludes accurate definition of its molecular mass and estimation of the stoichiometry between the alpha and beta subunits in the differentiated cells. However, wheat-germ agglutinin binding studies indicated the presence of N-glycosylated protein in the range of 85-110 kDa.

Cell Differentiation↗
PubMed1991

A monoclonal antibody against peripheral benzodiazepine receptor activities the human neutrophil NADPH-oxidase.

A murine monoclonal antibody, mAb 8523, raised against whole human pro-monocytic U937 cells recognizes an 18 kDa antigen in human neutrophils (PMN), as determined by immunoprecipitation and by immunodetection on Western blots of SDS-PAGE of PMN membrane fractions. That is 18 kDa antigen corresponds to the phagocyte peripheral benzodiazepine receptor (PBZDR) is evidenced by its co-migration with the 18 kDa covalently labeled PBZDR, detected by autoradiography, and their co-modulation upon phorbol-myristate-acetate activation of PMN. Purified mAb 8523 (IgG2b) is able to dose-dependently and specifically stimulate both the basal and the FMLP-induced oxidative burst of intact human PMN, assessed by luminol-amplified chemiluminescence. This property of the first described monoclonal antibody against PBZDR supports the implication of this receptor in NADPH-oxidase activation and consequently in phagocyte-dependent host defense mechanisms.

Antibodies, Monoclonal↗
PubMed1990

A double-blind comparative study of remoxipride and haloperidol in schizophrenic and schizophreniform disorders.

The antipsychotic effect of remoxipride was compared to that of haloperidol in a randomized double-blind study with parallel group design comprising 98 patients with schizophrenia or schizophreniform disorder according to DSM-III. After a 3-7 day placebo washout period, patients received either 150-600 mg of remoxipride or 5-20 mg of haloperidol daily for 6 weeks. No significant differences in efficacy were found between the two treatments. Treatment-emergent checklist symptoms such as hypokinesia, rigidity, and tremor occurred more frequently and were more severe during haloperidol than during remoxipride treatment despite a significantly higher concurrent use of anticholinergic drugs in the haloperidol group. Haloperidol-treated patients reported greater increases in sleep and salivation than remoxipride-treated patients. Shoulder shaking and tremor were reported as occurring more frequently in the haloperidol group according to the Simpson and Angus rating scale for extrapyramidal symptoms. In summary, the two drugs seemed to be equally efficacious, though the tolerability profile favoured remoxipride.

Adult↗
PubMed1989

[Epidemiology of cardiovascular risk factors in 1505 females working in hospitals].

One thousand and five women working in 26 wards of Paris hospitals were included in the study during their mandatory annual examination. The prevalence of arterial hypertension, calculated on this casual measurement (two readings) was 15.1 per cent; 6 per cent of the women were under medication for high blood pressure. In one fifth of the treated hypertensive women the blood pressure levels were not controlled by treatment. Two-thirds of the hypertensive women were untreated. Concerning the working conditions, psychic stress was associated with high blood pressure in women aged 30 to 39. The percentage of smokers was high (45 per cent below 30 years of age, 27 per cent between 30 and 40). The weight of 15 per cent of the women was at least 20 per cent over the "ideal" weight. The prevalence of cardiovascular risk factors is high among these female hospital workers. Prevention therefore must be developed in order to improve their health and to give the patients an opportunity to benefit from advice in this field during their stay in hospital.

Adult↗
PubMed1987

[Biological effects of SIN-1 in the vascular wall].

The biological effects of two vasodilatory drugs, SIN-1 (the active metabolite of molsidomine) and nitroglycerin were analysed in the arterial endothelium and vascular muscle. Both drugs induce the secretion of prostacyclin in endothelial cells in culture, but this secretion is short-lived and occurs for high doses of the two drugs (above 10(-5)M). These same drugs induce a dose-dependent relaxing effect on the smooth muscle contracted either by norepinephrine or 5-hydroxytryptamine with an ED50 of 5.10(-7)M. This relaxation is neither secondary to an endothelium-derived product nor to a cyclooxygenase or lipoxygenase-derived product.

Animals↗
PubMed1979

Evidence for non-random spatial distribution of meiotic exchanges in Podospora anserina: comparison between linkage groups 1 and 6.

In Podospora anserina, positive and very efficient chiasma interference is observed. However, its modalities are different for the two linkage groups 1 (LG1) and 6 (LG6) studied here. In the right arm of LG1, two zones exist in which always occurs only one crossing-over. They are formed independently each other. Moreover, the genetic map consists of clusters of genes located near the centromere and at the limit between the two interference zones. It is postulated that this structure of the map results from the localization of crossing-over in the middle of each zone. We suppose that the type of chiasma interference, in Podospora, is a typical one as it is in Drosophila. It seems that both these phenomena are under common genetical control. In the LG6, we observe a weaker positive chiasma interference without crossing-over localization.

Ascomycota↗