Proton leak induced by reactive oxygen species produced during in vitro anoxia/reoxygenation in rat skeletal muscle mitochondria.

in Journal of Bioenergetics & Biomembranes (2006), 38

Superoxide anion generation and the impairment of oxidative phosphorylation yield were studied in rat skeletal muscle mitochondria submitted to anoxia/reoxygenation in vitro. Production of superoxide ... [more ▼]

Superoxide anion generation and the impairment of oxidative phosphorylation yield were studied in rat skeletal muscle mitochondria submitted to anoxia/reoxygenation in vitro. Production of superoxide anion was detected after several cycles of anoxia/reoxygenation. Concomitantly, a decrease of state 3 respiration and phosphorylation yield (ADP/O) were observed. The latter resulted from a proton leak. The presence of palmitic acid during anoxia/reoxygenation cycles led to a dose-dependent inhibition of superoxide anion production together with a partial protection of the ADP/O ratio measured after anoxia/reoxygenation. The ADP/O decrease was shown to be due to a permeability transition pore-sustained proton leak, as it was suppressed by cyclosporine A. The permeability transition pore activation was induced during anoxia/reoxygenation by superoxide anion, as it was cancelled by the spin trap (POBN), which scavenges superoxide anion and by palmitic acid, which induces mitochondrial uncoupling. It can be proposed that the palmitic acid-induced proton leak cancels the production of superoxide anion by mitochondria during anoxia/reoxygenation and therefore prevents the occurrence of the superoxide anion-induced permeability transition pore-mediated proton leak after anoxia/reoxygenation [less ▲]

A proton nuclear resonance study of the inclusion complex of miconazole with b-cyclodextrin in an acidic medium

Poster (1998)

Proton precipitation during substorm growth observed by IMAGE-FUV: a case study

Poster (2006, March)

Proton precipitation during transpolar auroral events: Observations with the IMAGE-FUV imagers

in Journal of Geophysical Research. Space Physics (2004), 109

Several transpolar auroras have been observed with the IMAGE-Far Ultraviolet (FUV) imagers. The unique capability of the IMAGE-FUV experiment to image the proton and electron aurora simultaneously on a ... [more ▼]

Several transpolar auroras have been observed with the IMAGE-Far Ultraviolet (FUV) imagers. The unique capability of the IMAGE-FUV experiment to image the proton and electron aurora simultaneously on a global scale is used to study this phenomenon. A set of 12 transpolar aurora observed with IMAGE-FUV is studied. We find that the dynamics of the transpolar aurora in relation with the IMF is consistent with previously published studies. The proton energy flux in the transpolar structure is determined and compared with the electron contribution. The contribution of the proton aurora inside the transpolar arc is also considered at the global scale. On the average, transpolar structure contributes ~10% of the total precipitation. We find that the proton precipitation carries ~5% of the energy flux of the transpolar arc. In 11 of the 12 cases of transpolar events studied, a local brightening of the auroral Lyman-alpha emission is detected concurrently with the appearance of the transpolar structure. The intensification takes place at the nightside base of the transpolar arc, in the auroral oval. The duration of the intensification is variable but shorter than the lifetime of the transpolar arc. This study also suggests that the localized intensification is mainly due to an increase of the proton precipitation. [less ▲]

Protoplast Fusion Technology For Somatic Hybridisation In Phaseolus

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2008), 12(1), 41-46

Prototype de banque de données pour la cartographie urbaine

in Merenne-Schoumaker, Bernadette (Ed.) Recherches de Géographie urbaine, Hommage au Prof. J.A. Sporck (1987)

A Prototype System for 3D Color Fusion and Mining of Multisensor/Spectral Imagery

Conference (2001, August)

Protracted Herpes Zoster and severe postherpetic neuralgia after inadvertant infliximab administration

in European Journal of Dermatology (2011), 21/5

Provasopressin expression by breast cancer cells: implications for growth and novel treatment strategies

in Breast Cancer Research and Treatment (2006), 95(3), 265-277

The arginine vasopressin (AVP) gene is expressed in certain cancers such as breast cancer, where it is believed to act as an autocrine growth factor. However, little is known about the regulation of the ... [more ▼]

The arginine vasopressin (AVP) gene is expressed in certain cancers such as breast cancer, where it is believed to act as an autocrine growth factor. However, little is known about the regulation of the AVP protein precursor (proAVP) or AVP-mediated signaling in breast cancer and this study was undertaken to address some of the basic issues. The cultured cell lines examined (Mcf7, Skbr3, BT474, ZR75, Mcf10a) and human breast cancer tissue extract were found to express proAVP mRNA. Western analysis revealed multiple forms of proAVP protein were present in cell lysates, corresponding to those detected in human hypothalamus extracts. Monoclonal antibodies directed against different regions of proAVP bound to intact live Mcf7 and Skbr3 cells. Dexamethasone increased the amount of proAVP-associated glycopeptide (VAG) secreted by Skbr3 cells and a combination of dexamethasone, IBMX and 8br-cAMP increased cellular levels of VAG. Exogenous AVP (1, 10, and 100 nM) elevated phospho-ERK1/2 levels, and increased cell proliferation was observed in the presence of 10 nM AVP. Concurrent treatment with the V1a receptor antagonist SR49059 reduced the effects of AVP on proliferation in Mcf7 cells, and abolished it in Skbr3 cells. Results here show that proAVP components are found at the surface of Skbr3 and Mcf7 cells and are also secreted from these cells. In addition, they show that AVP promotes cancer cell growth, apparently through a V1-type receptor-mediated pathway and subsequent ERK1/2 activation. Thus, strategies for targeting proAVP should be examined for their effectiveness in diagnosing and treating breast cancer. [less ▲]

Provider continuity in family medicine: does it make a difference for total health care costs?

in Annals of Family Medicine (2003), 1(3), 144-8

BACKGROUND: International comparisons of health care systems have shown a relationship at the macro level between a well-structured primary health care plan and lower total health care costs. The ... [more ▼]

BACKGROUND: International comparisons of health care systems have shown a relationship at the macro level between a well-structured primary health care plan and lower total health care costs. The objective of this study was to assess whether provider continuity with a family physician is related to lower health care costs using the individual patient as the unit of analysis. METHODS: We undertook a study of a stratified sample of patients (age, sex, region, insurance company) for which 2 cohorts were constructed based on the patients' utilization pattern of family medicine (provider continuity or not). Patient utilization patterns were observed for 2 years. The setting was the Belgian health care system. The participants were 4,134 members of the 2 largest health insurance companies in 2 regions (Aalst and Liege). The main outcome measures were the total health care costs of patients with and without provider continuity with a family physician, controlling for variables known to influence health care utilization (need factors, predisposing factors, enabling factors). RESULTS: Bivariate analyses showed that patients who were visiting the same family physician had a lower total cost for medical care. A multivariate linear regression showed that provider continuity with a family physician was one of the most important explanatory variables related to the total health care cost. CONCLUSIONS: Provider continuity with a family physician is related to lower total health care costs. This finding brings evidence to the debate on the importance of structured primary health care (with high continuity for family practice) for a cost-effective health policy. [less ▲]