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Biomedical subjects

M Villeneuve

Publications and source records attributed to M Villeneuve.

16 recordsLinked to original sources
PubMed2004

Evidence for an increased release of proteolytic activity by the eutopic endometrial tissue in women with endometriosis and for involvement of matrix metalloproteinase-9.

BACKGROUND: For the implantation of endometrium in ectopic locations, remodelling of the extracellular matrix (ECM) is necessary. Many studies have shown an increased expression of various proteases in the ectopic endometrium of women with endometriosis. Few, however, have addressed possible changes in protease expression in the eutopic endometrium. METHODS AND RESULTS: Herein, we reveal an increased release of proteolytic activity by the eutopic endometrium of women with endometriosis compared with normal women (P < 0.01). Using zymography and western blotting, we identified matrix metalloproteinase (MMP)-2 and MMP-9 in the culture medium, and further found that MMP-9 secretion, as assessed by zymography and enzyme-linked immunosorbent assay (ELISA), was elevated in women with endometriosis compared with normal women (P < 0.05). No statistically significant difference in MMP-2 secretion between women with and without endometriosis was noted. However, a significant difference in the levels of the tissue inhibitor of metalloproteinases (TIMP)-1, a known MMP-9 inhibitor, was found (P < 0.05). CONCLUSION: The endometriosis-associated increase in proteolysis and imbalance between the secretion of MMP-9 and that of its natural inhibitor, TIMP-1, revealed in the culture medium of endometrial tissue may reflect in vivo the enhanced capacity of this tissue to break down the ECM in host tissues, thereby favouring its ectopic implantation and development.

Adult↗
PubMed2001

Ectopic endometrial cells express high concentrations of interleukin (IL)-8 in vivo regardless of the menstrual cycle phase and respond to oestradiol by up-regulating IL-1-induced IL-8 expression in vitro.

Endometriosis, an oestrogen-dependent disorder affecting women of reproductive age, is associated with active angiogenesis and an increased recruitment of leukocyte into the peritoneal cavity where the implants often develop. The role of oestrogens in the development of endometriosis has been clearly established, but the biochemical mechanisms of their action are still not clearly elucidated. The present study shows that interleukin-1 (IL-1) induces interleukin-8 (IL-8) secretion by endometriotic cells and that oestradiol enhances endometriotic cell responsiveness to IL-1. In contrast, no significant cell responsiveness to progesterone either alone in the culture medium or in combination with oestradiol was noted. Positive immunostaining for IL-8 was observed throughout endometriotic tissue, and no perceptible difference in the intensity of staining regarding the menstrual cycle phase was observed. Together with the in-vitro data, this suggests that IL-8 expression in endometriotic tissue is not subject to cyclic variation. Furthermore, this study provides evidence that oestradiol indirectly up-regulates the expression by ectopic endometrial cells of IL-8, a cytokine endowed with neutrophil chemotactic and angiogenic properties. This may contribute to peritoneal leukocyte recruitment and to the growth of endometriotic implants, and may be a new mechanism for oestradiol action in endometriosis.

Adolescent↗
PubMed1998

Miscibility of Butanol and Cationic Surfactant in the Adsorbed Film and Micelle.

Mixed adsorbed films and micelles were investigated by measuring surface tension of the aqueous solutions for the following four mixtures: the n-butanol (NBA)-dodecylammonium chloride (DAC), t-butanol (TBA)-DAC, NBA-dodecyltrimethylammonium chloride (DTAC), and TBA-DTAC. Experimental results were analyzed thermodynamically. Phase diagrams of adsorption and micelle formation and that exhibiting the composition relation of micelle and adsorbed film at CMC were compared among the four systems. Excess Gibbs energy in the adsorbed film gH,E and activity coefficient in the micelle fM2+/- were calculated from the phase diagrams to estimate the miscibility of the butanol and cationic surfactant quantitatively. By comparing the results of the pairs of NBA-DAC and TBA-DAC systems with those of the NBA-DTAC and TBA-DTAC systems, it was shown that the substitution of the polar head group from ammonium to trimethylammonium changes the gH,E value from positive to negative and increases fM2+/-. Furthermore, by comparing the results of the pairs of NBA-DAC and NBA-DTAC systems with those of the TBA-DAC and TBA-DTAC systems, it was shown that the bulky hydrophobic group weakens the molecular interaction between the butanol and the cationic surfactant in the adsorbed film. Copyright 1998 Academic Press.

Journal Article↗
PubMed1998

Structure Effect on Miscibility of Butanol and Dodecyltrimethylammonium Chloride in Adsorbed Film.

Miscibility of components in the adsorbed film for the n-butanol (NBA)-dodecyltrimethylammonium chloride (DTAC) and tert-butyl alcohol (TBA)-DTAC mixtures were investigated by measuring surface tension of the aqueous solutions. The experimental results were analyzed thermodynamically. Diagrams of the excess Gibbs energy in the adsorbed film gH,E vs the composition in the adsorbed film XH 2 were obtained from the phase diagrams of adsorption. The gH,E values of the NBA-DTAC system are more negative than those of the TBA-DTAC system. It is concluded that the molecular interaction between NBA and DTAC is stronger than that between TBA and DTAC. With respect to the mean molar area in the adsorbed film A vs XH 2 curve at a fixed surface tension gamma, the criterion of ideal mixing is demonstrated to be a straight line connecting the pure values. The A vs XH 2 curves are convex downward in both systems and the deviation from the straight line is attributed to the dependence of gH,E on gamma. Copyright 1998 Academic Press.

Journal Article↗
PubMed1998

Measurement of endometrial thickness with transvaginal ultrasonography: is it reproducible?

To assess the intraobserver and interobserver variability of transvaginal ultrasonographic measurement of endometrial thickness, two investigators (M.V., M.-F. D.) independently evaluated two successive measurements in 55 patients with a 5.0 MHz transvaginal transducer. Each observer was blinded to his or her own and to the other's results. Measurements were taken at the maximal thickness in the longitudinal uterine axis. The intraclass coefficients evaluating the agreement between two measures of a same observer were 94% and 97%; the coefficient was 94% between the two investigators. Intraobserver kappa values (agreement on endometrium < or = 5 mm and > 5 mm) were 0.70 and 0.81, respectively; the interobserver kappa value was 0.74. Transvaginal sonographic measurement of endometrial thickness has excellent intraobserver and good interobserver agreement. However, in clinical practice, an endometrial thickness measuring +/- 1 mm of a cut-off value should be interpreted with caution, especially when this may modify the clinical management.

Endometrium↗
PubMed1997

Nonideal Mixing in Adsorbed Film and Micelle of Ionic-Nonionic Surfactant Mixtures

The surface tension of aqueous solutions of dodecylammonium chloride-octyl methyl sulfoxide (OMS) and dodecyltrimethylammonium bromide-OMS mixtures was measured as a function of the total molality of surfactants and the composition of OMS. The results were analyzed according to our thermodynamic procedure; the phase diagrams of adsorption and micelle formation and the diagram illustrating the composition relation between the micelle and the adsorbed film at the critical micelle concentration were drawn. The activity coefficient and excess Gibbs energy in the adsorbed film and the micelle were defined and then evaluated from the phase diagrams. They were found to give useful information on the deviation from ideal mixing and intermolecular interaction in the adsorbed film and micelle. Copyright 1997 Academic Press. Copyright 1997Academic Press

Journal Article↗
PubMed1997

Thermodynamic Study on the Surface Formation of the Mixture of Water and Ethanol

The formation of the water + ethanol mixture/air surface was studied by measuring the surface tension as a function of temperature and the mole fraction of ethanol in the mixture. The surface composition, the entropy Deltas , and energy Deltau of surface formation were evaluated by adopting the thermodynamic equations. It was shown that the surface was enriched in ethanol molecules compared with the bulk solution. The values of Deltas and Deltau were examined closely by estimating the contribution from the nonideal mixing in the bulk solution and that at the surface to Deltas and Deltau . It was concluded that the surface formation is driven by entropy at lower x 2 and by energy at higher x 2 , respectively, and that the surface formation becomes more energetically favorable with rising temperature.

Journal Article↗
PubMed1996

Human endometrial cells cultured in a type I collagen gel.

OBJECTIVE: To elaborate in vitro conditions that enable epithelial and stromal cells of human endometrium to grow within a gel of collagen. STUDY DESIGN: Primary cultures of epithelial cells derived from human endometrial biopsies were dissociated and mixed with a collagen solution, and the gel was allowed to form at physiologic pH. Control cultures were grown in plastic dishes. DNA replication was assessed by 3H-thymidine incorporation, morphology by histology and cell characterization by monoclonal antibodies to cytokeratins. RESULTS: Cells grown on plastic dishes exhibited a typical monolayer arrangement, and replication was increased 1.6-fold by the addition of stromal cell-conditioned medium (50% vol/vol). After a two- to three-week period of culture within the collagen gel in the presence of either stromal cells or stromal cell-conditioned medium, epithelial cells formed circular arrangements of cuboidal to columnar cells with open lumina resembling glands. These glandlike structures were cytokeratin positive as assessed by immunohistochemistry, thereby confirming their epithelial nature. CONCLUSION: The development of differentiated epithelial structures in a three-dimensional gel provides a promising method of studying various biochemical and cellular interactions of eutopic and ectopic endometrium.

Biopsy↗
PubMed1980

The relationship of 4-aminobutyric acid metabolism to ammoniagenesis in renal cortex.

Mitochondrial 4-aminobutyrate aminotransferase in rat kidney can utilize pyruvate as the acceptor for the amino group of 4-aminobutyrate. Renal 4-aminobutyrate aminotransferase activity at saturating equimolar concentration of 4-aminobutyrate and 5 mM pyruvate is 42.8 +/- 2.5 mumol/g protein per h (mean +/- S.E.M.) or 70% of 4-aminobutyrate aminotransferase activity with equimolar alpha-ketoglutarate. 4-Aminobutyrate aminotransferase in brain does not transaminate with pyruvate. Since pyruvate is an important mitochondrial metabolite in kidney, net disposal of glutamate via the 4-aminobutyrate pathway is possible. The renal 4-aminobutyrate pathway in the rat has other distinctive features when compared with the pathway in rat brain. Most inhibitors of rat neuronal glutamate decarboxylase were ineffective against the renal form of the enzyme, but 20 mM semicarbazide inhibited the latter form by 80% (P < 0.001) in vitro and reduced renal 4-aminobutyrate content by 75% (P < 0.001) in vivo. In the presence of 20 mM semicarbazide, ammoniagenesis by rat renal cortex slices incubated in 1 mM glutamine was inhibited 26% (P < 0.01). Semicarbazide was proportionately less effective (15% inhibition) when ammonia-genesis was stimulated (+243%) in slices prepared from chronically acidotic animals, and was no deterrant to ammoniagenesis when non-acidotic slices were incubated in supraphysiologic concentrations of 10 mM glutamine. We conclude that whereas integrity of the renal 4-aminobutyrate pathway may contribute to glutamate disposal and thus ammoniagenesis under physiologic conditions, the pathway is a passive participant in the overall process of ammoniagenesis.

4-Aminobutyrate Transaminase↗
PubMedDate not supplied

Professional education in a long-term-care facility: program development in diabetes.

To effect diabetes care in a 1000-bed chronic care institution, a program development approach to multidisciplinary staff education was implemented. Chart audit, staff interviews, and observations were used to evaluate care standards. Initial assessment revealed that none of the charts included a thorough evaluation of patients for skills, knowledge, and adherence related to care of diabetes. Additionally, it was found that the current diagnostic criteria for diabetes and urine testing procedures were not being used. An educational approach was implemented to teach current information about diabetes, to focus on multidisciplinary coordination of care, and to set goals for care on model care units. Postintervention assessments of the model care units were completed at 6 and 24 mo. There were substantial alterations in care, with more of the charts meeting the standard in each of the eight categories under investigation: diabetes diagnosis according to National Diabetes Data Group criteria, urine testing, capillary blood testing, rotation of insulin injection site, assessment of patients for adherence to regimen, assessment of patient skills and knowledge, and interdisciplinary coordination of care.

Cost-Benefit Analysis↗