Biomedical subjects

M Mathieu

Publications and source records attributed to M Mathieu.

At least 19 recordsLinked to original sources

PubMed2006

Immunohistochemical localization of serotonin (5-hydroxytryptamine) in the gonad and digestive gland of Mya arenaria (Mollusca: Bivalvia).

Serotonin (5-hydroxytryptamine or 5-HT) C(10)H(12)N(2)O plays a central role in several physiological processes in marine molluscs, especially in reproduction. 5-HT acts as a neurohormone to modulate spawning, parturition and meiosis by reinitiating prophase in arrested oocytes. Preliminary experiments using 10(-5)M 5-HT dissolved in aquarium water showed that 5-HT induced spawning movements in ripe clams and in both sexes of Mya arenaria while only a few males released sperm. The occurrence of serotoninergic fibers was demonstrated by PAP immunohistochemical reaction in the gonad of both sexes during gametogenesis. In an organism infected by the trematode parasite Prosorhynchus squamatus, we showed that serotoninergic innervation completely disappeared around the gonad's follicles. Although the gonad and digestive gland are intertwined, no serotoninergic innervations were found in the digestive gland. These findings suggest, for the first time to our knowledge in the soft shell clam, that serotonin might be involved in the regulation of gametogenesis.

Animals↗

PubMed2006

Cryopreservation of Crassostrea gigas vesicular cells: viability and metabolic activity.

Cryopreservation is widely used for long-term conservation of various tissues, embryos or gametes. However, few studies have described cryopreservation of invertebrate primary cell cultures and more particularly of marine invertebrate somatic cells. This technique would however be of great interest to facilitate the study of various metabolic processes which vary seasonally. The aim of the present study was to develop a protocol for cryopreservation of Crassostrea gigas vesicular cells. Different parameters were adjusted to improve recovery of cells after freezing. The most efficient cryoprotectant agent was a mix of Me(2)SO, glycerol, and ethylene glycol (4% each). The optimal cooling rate was -1 degrees Cmin(-1) down to -70 degrees C before transfer into liquid nitrogen. In these conditions the percentage of viable cells reached 70% of the control. The glucose metabolism of thawed cells was evaluated using radioactive glucose as a tracer. Immediately after thawing, glucose uptake involving membrane transporters was greatly reduced (24% of control) whereas glucose incorporation into glycogen was less affected (68% of control).

Animals↗

PubMed2006

Germin-like genes are expressed during somatic embryogenesis and early development of conifers.

Germins and germin-like proteins (GLPs) are members of a superfamily of proteins widely distributed in plants. Their localization within the extracellular matrix and in some cases their hydrogen peroxide-producing activity suggests that these proteins are involved in cell wall metabolism during stress responses and developmental processes. Several very highly conserved conifer GLPs have been identified in somatic embryo tissues. In order to gain more knowledge on their potential involvement in the development of this particular tissue, we have characterized a new GLP gene, LmGER1 in hybrid larch. Anti-GLP immunserum and in-gel activity analyses suggested the presence of superoxide dismutase activity in apoplastic proteins from larch somatic embryos. These results could indicate a possible role for LmGER1 in this physiological process. The expression of LmGER1 has been followed during the maturation of somatic embryos and in different organs of young plantlets by homologous transformation with a promoter-gus construct. This promoter was activated in the root cap of young embryos and, later on, in the cotyledons and in the vascular procambium and xylem. Furthermore, the importance of this gene in embryo development was evaluated by transforming embryonal masses with a gene construct encoding a hairpin RNA leading to gene silencing. The potential role of LmGER1 in cross-linking of cell wall components is discussed.

Amino Acid Sequence↗

PubMed2006

[Epidemiology and delays in the management of 355 patients with lung cancer].

BACKGROUND: The epidemiology of patients with lung cancer in a Seine-Saint-Denis hospital are reported, as well as causes of diagnostic and therapeutic delays in their management. MATERIAL AND METHODS: Retrospective analysis of cases diagnosed from January 1, 1997 to December 31, 2003. RESULTS: Of 355 cases, 15.8% were women; the average age was 62 +/- 11. Mean smoking history was 50 +/- 24 pack years. Women were more likely to be non-smokers than men (16% and 1% respectively, p < 0.01) and were more likely to present at a young age (under the age of 50: 26.8% and 13.7% respectively, p < 0.05). Among women, adenocarcinoma was more frequent (41% vs. 25%, p < 0.05), and often presented with stage IV disease (74%). Squamous cell carcinoma occurred more frequently with increasing age (18.7% vs. 32.2% before and after the age of 60, p < 0.01). The median pre hospital, diagnostic and treatment delays were respectively 30, 10 and 9 days, the global delay from first symptom to treatment was 62 days. Surgery increased therapeutic delay by 20 days. CONCLUSION: Our results are complementary to those found in KBP-2000-CPHG study. Young women are diagnosed at a late stage. Influence of delays on prognosis is not proved and require others studies.

Aged↗

PubMed2006

Is obesity an aggravating factor in chronic venous disease? Results of a French epidemiological study in male patients.

AIM: In a recent epidemiological study on chronic venous disease (CVD) in French male patients, a correlation was found between obesity and disease severity. The objective of this study was to further analyze the relationship between age and/or obesity, and CVD severity as assessed by the CEAP C-class. METHODS: Each physician taking part in this cross-sectional study included the first 3 adult male patients consulting for the first time and presenting at least one sign and one symptom of CVD. Patients' socio-demographic and clinical data were collected, and findings for obese (body mass index BMI: >30 kg/m(2)), overweight (25 60 years experienced trophic disorders, i.e., CEAP classes C4, C5, and C6). CONCLUSIONS: This study does not show any relationship between the CEAP C-class and obesity in male patients. Obesity was thus probably not an aggravating factor in CVD but a simple reflection of ageing.

Adult↗

PubMed2004

[Glucocorticoids and their receptor: mechanisms of action and clinical implications].

BACKGROUND: Glucocorticoids are used as anti-inflammatory, immuno-modulatory, anti-proliferative and cytotoxic drugs, but they also trigger important side-effects. These hormones bind to glucocorticoid receptor alpha (GRalpha), an intracellular protein, which acts essentially in the nucleus. MAIN POINTS: GRalpha is a ligand-activated transcription factor that positively or negatively regulates gene expression by distinct mechanisms. Stimulation of gene transcription occurs after direct binding of the receptor to specific responsive DNA elements. Gene activation by glucocorticoids is mainly responsible for certain adverse effects. In contrast, the therapeutic effects of glucocorticoids are predominantly mediated through repression of genes encoding inflammatory mediators. Inhibitory protein-protein interaction between the hormone-activated receptor and the transcription factors NF-kappaB and AP-1 was found to be the underlying mechanism. However, inhibition of other transcription factors may account for deleterious effects of glucocorticoids, such as adrenal suppression and osteoporosis. GRalpha also mediates rapid non-genomic effects of glucocorticoids. Side-effects are reduced by using topical glucocorticoids which have a low systemic bioavailability. Moreover, it is important to determine the lowest effective maintenance dose of systemic and topical glucocorticoids to further decrease the risk of adverse effects. This is particularly justified because inhibition of AP-1 and NF-kappaB activities, that is the anti-inflammatory effect, occurs at much lower hormone concentrations than transactivation. PERSPECTIVES: Clinical use of glucocorticoids is limited by occurrence of severe adverse effects. Therefore, the current aim is to design GRalpha ligands that retain only the anti-inflammatory activities of GC.

Administration, Topical↗

PubMed2004

Design and applications of a home-built in situ FT-Raman spectroscopic cell.

In the field of heterogeneous catalysis, in situ spectroscopy is one of the topics with growing interest. The characterization of a catalyst under working conditions is essential to identify the catalytic active site and to study the relation between the surface structure of a catalyst and its catalytic performance. For the first time, the design of an in situ spectroscopic cell for FT-Raman is presented and its performance is demonstrated by monitoring the thermal conversion of as synthesized mesoporous titanium and by characterizing the molecular surface structure of the vanadium oxides grafted on MCM-48 after exposure to a probe molecule. The results in both cases indicate that the in situ FT-Raman cell is a promising technique for characterizing the molecular surface structure of catalyst materials.

Catalysis↗

PubMed2004

Jun localization in cytosolic and nuclear compartments in brain-pituitary system of the frog, Rana esculenta: an analysis carried out in parallel with GnRH molecular forms during the annual reproductive cycle.

The presence of c-jun like mRNA was assessed in the brain of the frog, Rana esculenta, during the annual sexual cycle. In parallel, Jun protein and GnRH molecular form (mammalian and chicken II also indicated as GnRH1 and GnRH2, respectively) activity was studied in order to establish possible relationships. Northern blot analysis of total RNA reveals the presence of a 2.7 kb c-jun-like mRNA. Western blots, carried out on cytoplasmic and nuclear protein extracts, show the presence of Jun immunoreactive band of 39 kDa in brain and pituitary. Fluctuations of c-jun-like mRNA and Jun immunoreactive protein (cytoplasmic and nuclear) levels in brains during the year indicate relationships among transcription, translation, and nuclear activity. In particular, mRNA levels increase gradually from September until November when Jun protein concentration peaks in cytosolic extracts. Conversely, the nuclear protein reaches highest concentration in July when the cytosolic level shows low values. Immunocytochemical studies confirm the presence of Jun immunoreactivity in both cytoplasmic and nuclear compartments of several brain areas, including those primarily involved in gonadotropin discharge (e.g., anterior preoptic area and preoptic nucleus). GnRH molecular forms and Jun are colocalized in anterior preoptic area and preoptic nucleus. Moreover, during the period characterized by GnRH release, Jun levels strongly decrease in nuclei. Finally, we show that treatments with a GnRH analog (buserelin, Hoechst, Frankfurt) increase Jun levels in brain nuclear extracts.

Animals↗

PubMed2004

[Pulmonary nocardiosis and broncho-oesophageal fistula in a patient infected with HIV].

INTRODUCTION: We report a case of extensive pulmonary nocardiosis in a patient infected with HIV. CASE REPORT: It presented as bilateral cavitated masses and bulky necrotic mediastinal lymphadenopathy causing broncho-oesophageal fistulae. There was associated infection with Mycobacterium Avium. There was satisfactory progress following bipolar oesophageal isolation, nutrition via a jejunostomy and antibiotic therapy with co-amoxiclav. Healing of the fistulae after 11 months allowed surgical restoration of oesophago-gastric continuity. CONCLUSION: As with other bacteria, HIV can modify the clinical spectrum of nocardiosis.

Adult↗

PubMed2004

Chronic venous disease in the male. An epidemiological survey.

AIM: Chronic venous disease affects large numbers of men but there are fewer references to them than to women in the literature. The aim of our study was to determine the time lapse between the first symptom(s) and/or clinical signs of venous disease in the male and the first consultation with an angiologist to define the status of the veins within this population, and to demonstrate any possible links between the characteristics of the disorder in accordance with the CEAP international classification. METHODS: The design was a cross-sectional descriptive survey. Each physician had to include the first 3 patients examined for the first time. Each male patient had to present at least 1 sign and 1 symptom of chronic venous disease. After randomization, 192 physicians included 561 patients: 494 have been analyzed. RESULTS: The examined patients had a mean age of 49.3+/-13.7 years, mean height of 1.76+/-0.07 m, mean weight of 78.2+/-11.2 kg and a BMI of 25.3+/-3.3. The disorder had been developing for a mean 76.8+/-90.3 months prior to the specialist consultation. The longer the time span between the onset of the condition and the first consultation with a specialist, the more advanced was the condition as was also true with the increasing age of the patients. The following associations were observed: the incidence of trophic disorders increased with age (odds-ratio 1.47). The severity of the disease increased the greater the extent of obesity (odds-ratio 3.5). CONCLUSION: The risk of trophic disorders was higher in shop workers, craftsmen (odds-ratio 3.7) and workers (odds-ratio 2.68) than in executives, in those working in a standing position (odds-ratio 1.5), in those whose father had the condition (odds-ratio 1.9), in the event of a popliteal reflux (odds-ratio 3.2) rather than affecting a saphenous trunk (small saphenous vein odds-ratio 2.5, great saphenous vein odds-ratio 1.9). Thirty-two percent of patients with trophic disorders had already worn elastic compression prior to the specialist consultation. After this consultation, the numbers for whom this was prescribed rose to 87%.

Adolescent↗

PubMed2003

Insulin-like system and growth regulation in the Pacific oyster Crassostrea gigas: hrIGF-1 effect on protein synthesis of mantle edge cells and expression of an homologous insulin receptor-related receptor.

The involvement of molecules belonging to the insulin/IGF family in regulation of growth has been investigated in the Pacific oyster Crassostrea gigas. In vitro biological effects of human recombinant IGF-1 (hrIGF-1) on mantle edge cells, involved in oyster shell and soft body growth, were studied over an annual cycle. In mantle edge cells hrIGF-1 stimulates protein synthesis of 56+/-5.1% over basal for 10(-10) M in September with in addition a clear dose-effect corresponding to the highest shell growth period, and 57.5+/-3.45% over basal for 10(-11) M in March and 51+/-5.4% over basal for 10(-10) M in April corresponding to the period of mantle growth. These insulin-like effects were associated with the expression of a recently identified C. gigas insulin receptor-related receptor (CIR) in mantle edge cells as demonstrated by RT-PCR. Moreover, in situ hybridisation (ISH) confirmed this expression at the level of the inner and outer epithelia involved in mantle growth and shell formation.

Analysis of Variance↗

PubMed2003

[Value of karyotyping women patients of couples referred for sterility].

It has been known for some 25 years that there is a causal relation between chromosomal aberrations and male infertility and that the major indication for karyotyping an infertile man is still usually an abnormal sperm analysis. The value of karyotyping women in the routine work-up of couples referred for sterility has long been debated. A French recent cytogenetic study found an overall increased frequency of chromosomal aberrations in the female and confirmed that in some cases of poor reproductive outcome there may be a contribution of maternal chromosome aberrations. Indeed, the existence of a chromosome abnormality in the female partner was associated with the group of infertile men in which there was no apparent cause of infertility. These results emphasise the need for thorough genetic work-up in couples referred for sterility. This work-up should include karyotyping of the female for some indications explained in this work.

Chromosome Aberrations↗

PubMed2003

[Compliance with hormone replacement therapy in menopausal women: results of a two-year prospective French study comparing transdermal treatment with fixed oral combination therapy].

OBJECTIVES: To evaluate rates of continuation with hormone replacement therapy (HRT) at 2 years in 2 cohorts of female patients, one of which was treated with a set combination of oral oestradiol valerate and medroxyprogesterone acetate and the other with percutaneous 17 beta-oestradiol gel combined with an oral progestogen selected by the prescribing doctor. PATIENTS AND METHODS: A prospective, randomised, open study, including 885 patients followed for 2 years whose 477 were in the oral HRT cohort and 408 were in the dermal cohort. Randomisation was done by group with prescription of the selected HRT for the cohort. The 2 treatment groups were compared using chi(2) tests and Fisher's exact test for qualitative variables, Student's t test or Wilcoxon's test for qualitative variables and Kaplan-Meier survival curves for continuation of HRT, with comparisons using the log-rank test. The prognostic value of baseline parameters on subsequent continuation of HRT was studied using the Cox model (Wald test, odds ratio). RESULTS; Among the 885 treated patients, 711 received the HRT assigned to their cohort (382 in the oral HRT cohort, 329 in the dermal HRT cohort). After 2 years, 77.9% of the patients in the oral HRT cohort and 73.4% of the patients in the dermal HRT cohort were continuing to take their prescribed HRT (P = 0. 076): 37.9% of patients in the oral HRT cohort and 20.2% of patients in the dermal HRT cohort (P < 0.001) continued taking their treatment without any modification. CONCLUSION: Although there was no significant difference in the level of compliance in the 2 groups, it is nonetheless worth noting that the HRT compliance with a sequential fixed estroprogestogen combination was, in this trial, at least equal to that with the free combination of a transdermal estrogen and a progestogen whose nature, dosage and sequence duration are selected by the prescriber. On the other hand, treatment modifications occurred more frequently in the cutaneous HRT group, which is logical as free combination affords to adapt the treatment to each patient.

Administration, Cutaneous↗

PubMed2003

Fluticasone propionate and mometasone furoate have equivalent transcriptional potencies.

BACKGROUND: Glucocorticoids exert their anti-inflammatory effects mainly through transrepression of the transcription factors activator protein-1 (AP-1) and nuclear factor-kappa B (NF-kappaB). Certain adverse effects of glucocorticoids are mediated through gene transactivation. Fluticasone propionate (FP) and mometasone furoate (MF) are the most recently developed topical glucocorticoids for the treatment of airway disorders. Their relative capacities to repress AP-1 and NF-kappaB activities are not known and comparison of their transactivation potencies has given unclear results. OBJECTIVE: To determine the relative transactivation and transrepression potencies of FP and MF. METHODS: Transactivation assays were performed in HeLa cells carrying a glucocorticoid-inducible luciferase gene. To measure transrepressive potencies of FP and MF, A549 lung epithelial cells were transiently transfected with an AP-1- or NF-kappaB-dependent luciferase gene. Using an immunoassay, we also evaluated the ability of MF and FP to inhibit the production of Regulated upon Activation, Normal T-cell Expressed and Secreted (RANTES), a pro-inflammatory cytokine, whose gene is controlled by AP-1 and NF-kappaB. Areas under the dose-response curve were calculated to determine relative potencies. RESULTS: FP and MF are equipotent for transactivation. Both molecules show globally the same potency to inhibit AP-1 and NF-kappaB activities and RANTES production. MF and FP have very significant transcriptional effects at 2x10(-10) M, which is the peak concentration reached in the plasma after inhalation of high dosages. Indeed, they produce a 17-fold induction of luciferase in the transactivation assay, and inhibit AP-1 activity, NF-kappaB activity and RANTES release by approximately 40%. CONCLUSION: FP and MF have the same ability to trigger gene activation and also the same potency to inhibit AP-1 and NF-kappaB activities. Their strong transcriptional effects at 2x10(-10) M suggest that these compounds act not only topically but also systemically, with the risk of provoking concomitant adverse effects at high dosages.

Androstadienes↗

PubMed2003

[Home chemotherapy for lung cancer: a five year retrospective study].

INTRODUCTION: We present the results of a five year retrospective study of chemotherapy delivered at home for patients suffering from non-small cell lung cancer. METHODS: In partnership with "hospital at home" we have developed mechanisms to improve safety: secured prescriptions, treatments confirmations transmitted by fax, designed specific chemotherapy file and approval of family doctor prior to administration. RESULTS: We treated 74 patients and administered 401 injections of which 72% were for Vinorelbine and 28% for Gemcitabine. These protocols corresponded to day 8 injections for Cisplatin-based double drug therapies in 47% of cases and to weekly single drug chemotherapies in 53%. CONCLUSIONS: Constraints regarding medical staff availability were exceeded by many advantages: better hospital bed management, guaranteed treatment, improvements in patients' quality of life and strengthening of links between hospital and community.

Aged↗

PubMed2002

Immunocytochemical demonstration of glucagon-like peptides in Mytilus edulis cerebral ganglia and an in vitro effect of vertebrate glucagon on glycogen metabolism.

Immunological detection of glucagon-like peptides was performed in the cerebral ganglia of the mussel Mytilus edulis using an anti-vertebrate glucagon antibody. Two clusters of positive neurosecretory cells were observed, as well as stained nervous fibers. The effect of vertebrate glucagon on glucose incorporation into glycogen of reserve cells was tested using an in vitro microplate bioassay. Optimal incubation conditions were previously defined and an inhibitory effect of porcine glucagon was obtained for concentrations ranging from 10(-6) to 10(-9)M. It is postulated that the glucagon-like peptide may be implicated in the regulation of glucose metabolism in bivalves.

Animals↗

PubMed2002

Heterologous expression of the Aspergillus nidulans alcR-alcA system in Aspergillus niger.

The inducible and strongly expressed alcA gene encoding alcohol dehydrogenase I from Aspergillus nidulans was transferred together with the activator gene alcR, in the industrial fungus Aspergillus niger. This latter organism does not possess an inducible alc system but has an endogenously constitutive lowly expressed alcohol dehydrogenase activity. The overall induced expression of the alcA gene was of the same order in both fungi, as monitored by alcA transcription, alcohol dehydrogenase activity and heterologous expression of the reporter enzyme, beta-glucuronidase. However, important differences in the pattern of alcA regulation were observed between the two fungi. A high basal level of alcA transcription was observed in A. niger resulting in a lower ratio of alcA inducibility. This may be due to higher levels of the physiological inducer of the alc regulon, acetaldehyde, from general metabolism in A. niger which differs from that of A. nidulans.

Alcohol Dehydrogenase↗

PubMed2001

Immunohistochemical localization of 3 beta-hydroxysteroid dehydrogenase and 5 alpha-reductase in the brain of the African lungfish Protopterus annectens.

The localization of the enzymes responsible for the biosynthesis of neurosteroids in the brain of dipnoans has not yet been determined. In the present study, we investigated the immunohistochemical distribution of 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD) and 5 alpha-reductase (5 alpha-R) in the brain and pituitary of the African lungfish Protopterus annectens by using antibodies raised against type I human 3 beta-HSD and type I human 5 alpha-R. The 3 beta-HSD and 5 alpha-R immunoreactivities were detected in cell bodies and fibers located in the same areas of the lungfish brain, namely, in the pallium, thalamus, hypothalamus, tectum, and periaqueductal gray. Identification of astrocytes, oligodendrocytes, and neurons with antisera against glial fibrillary acidic protein, galactocerebroside and neurofilaments revealed that, in the lungfish brain, 3 beta-HSD immunolabeling is expressed exclusively by neurons, whereas the 5 alpha-R-immunoreactive material is contained in both neurons and glial cells. In the pituitary gland, 3 beta-HSD- and 5 alpha-R-like immunoreactivity was localized in both the pars distalis and the pars intermedia. The present study provides the first immunocytochemical mapping of two key steroidogenic enzymes in the brain and pituitary of a lungfish. These data strongly suggest that neurosteroid biosynthesis occurs in the brain of fishes, as previously shown for amphibians, birds, and mammals.

3-Hydroxysteroid Dehydrogenases↗