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H Barrière

Publications and source records attributed to H Barrière.

At least 19 recordsLinked to original sources
PubMed2003

Swelling-activated chloride and potassium conductance in primary cultures of mouse proximal tubules. Implication of KCNE1 protein.

Volume-sensitive chloride and potassium currents were studied, using the whole-cell clamp technique, in cultured wild-type mouse proximal convoluted tubule (PCT) epithelial cells and compared with those measured in PCT cells from null mutant kcne1 -/- mice. In wild-type PCT cells in primary culture, a Cl- conductance activated by cell swelling was identified. The initial current exhibited an outwardly rectifying current-voltage (I-V) relationship, whereas steady-state current showed decay at depolarized membrane potentials. The ion selectivity was I- > Br- > Cl- > > gluconate. This conductance was sensitive to 1 mM 4,4'-Diisothiocyanostilbene-2,2'-disulfonic acid (DIDS), 0.1 mM 5-nitro-2-(3-phenylpropylamino)benzoic acid (NPPB) and 1 mM diphenylamine-2-carboxylate (DPC). Osmotic stress also activated K+ currents. These currents are time-independent, activated at depolarized potentials, and inhibited by 0.5 mM quinidine, 5 mM barium, and 10 microM clofilium but are insensitive to 1 mM tetraethylammonium (TEA), 10 nM charybdotoxin (CTX), and 10 microM 293B. In contrast, the null mutation of kcne1 completely impaired volume-sensitive chloride and potassium currents in PCT. The transitory transfection of kcne1 restores both Cl- and K+ swelling-activated currents, confirming the implication of KCNE1 protein in the cell-volume regulation in PCT cells in primary cultures.

Animals↗
PubMed2001

CFTR modulates programmed cell death by decreasing intracellular pH in Chinese hamster lung fibroblasts.

To study the potential influence of cystic fibrosis conductance regulator (CFTR) on intracellular pH regulation during apoptosis induction, we used PS120 Chinese hamster lung fibroblasts devoid of the Na(+)/H(+) exchanger (NHE1 isoform) transfected with constructs, allowing the expression of CFTR and/or NHE1. Kinetics of lovastatin-induced apoptosis were measured by orcein staining, double staining with Hoechst-33258, propidium iodide, DNA fragmentation, and annexin V labeling. In PS120 control cells, the percentage of apoptotic cells after 40 h of lovastatin treatment was 23 +/- 3%, whereas in PS120 CFTR-transfected cells, this percentage was 40 +/- 4%. In PS120 NHE1 cells, the transfection with CFTR did not modify the percentage of apoptotic cells after 40 h (control: 19 +/- 3%, n = 8; CFTR: 17 +/- 1%, n = 8), indicating that blocking intracellular acidification by overexpressing the Na(+)/H(+) exchanger inhibited the enhancement of apoptosis induced by CFTR. In all cell lines, the initial pH values were identical (pH = 7.46 +/- 0.04, n = 9), and treatment with lovastatin led to intracellular acidification. However, the pH value after 40 h was lower in PS120 CFTR-transfected cells (pH = 6.85 +/- 0.02, n = 10) than in PS120 cells (pH = 7.15 +/- 0.03, n = 10). To further investigate the origin of this increased intracellular acidification observed in CFTR-transfected cells, the activity of the DIDS-inhibitable Cl(-)/HCO exchanger was studied. 8-Bromoadenosine 3',5'-cyclic monophosphate incubation resulted in Cl(-)/HCO exchanger activation in PS120 CFTR-transfected cells but had no effect on PS120 cells. Together, our results suggest that CFTR can enhance apoptosis in Chinese hamster lung fibroblasts, probably due to the modulation of the Cl(-)/HCO exchanger, resulting in a more efficient intracellular acidification.

8-Bromo Cyclic Adenosine Monophosphate↗
PubMed2001

Extracellular adenosine modulates a volume-sensitive-like chloride conductance in immortalized rabbit DC1 cells.

Cl(-) currents induced by cell swelling were characterized in an immortalized cell line (DC1) derived from rabbit distal bright convoluted tubule by the whole cell patch-clamp techniques and by (125)I(-) efflux experiments. Exposure of cells to a hypotonic shock induced outwardly rectifying Cl(-) currents that could be blocked by 0.1 mM 5-nitro-2-(3-phenylpropyl-amino)benzoic acid, 1 mM DIDS, and by 1 mM diphenylamine-2-carboxylate. (125)I(-) efflux experiments showed that exposure of the monolayer to a hypotonic medium increased (125)I(-) loss. Preincubation of cells with LaCl(3) or GdCl(3) prevented the development of the response. The addition of 10 microM adenosine to the bath medium activated outwardly rectifying whole cell currents similar to those recorded after hypotonic shock. This conductance was inhibited by the A(1)-receptor antagonist 8-cyclopentyl-1,3-diproxylxanthine (DPCPX), LaCl(3), or GdCl(3) and was activated by GTPgammaS. The selective A(1)-receptor agonist N(6)-cyclopentyladenosine (CPA) mimicked the effect of hypotonicity on (125)I(-) efflux. The CPA-induced increase of (125)I(-) efflux was inhibited by DPCPX and external application of LaCl(3) or GdCl(3). Adenosine also enhanced Mn(2+) influx across the apical membrane. Overall, the data show that DC1 cells possess swelling- and adenosine-activated Cl(-) conductances that share identical characteristics. The activation of both conductances involved Ca(2+) entry into the cell, probably via mechanosensitive Ca(2+) channels. The effects of adenosine are mediated via A(1) receptors that could mediate the purinergic regulation of the volume-sensitive Cl(-) conductance.

Adenosine↗
PubMed1990

Absence of fodrin (spectrin-like protein) under the pseudopod membrane in stimulated thyroid cells.

A fodrin-like protein purified from porcine thyroid cells and characterized by its properties identical to those of pig brain spectrin (F. Regnouf et al., Eur. J. Biochem. 153, 313-319 (1985)) has been localized by immunofluorescence and electron immunocytochemistry in porcine and rat thyroid. Fodrin-like polypeptides were detected in subplasmalemmal meshworks of microfilaments attached to isolated or in situ plasma membranes. In resting cells, fodrin was found under apical and basolateral membrane domains, whereas it was always absent under the pseudopod membrane domain induced by acute TSH stimulation in vitro, using monolayers of porcine cultured cells attached to collagen permeable substrates, as well as in vivo, using rats intravenously treated with TSH. Thyroid fodrin could be involved in exocytosis and membrane stabilization which occurs during the formation of pseudopods induced by TSH stimulation.

Animals↗
PubMed1988

Cholesterol-rich microdomains in rat and porcine thyroid membranes involved in TSH-induced endocytotic processes.

Filipin, a polyene antibiotic, was used to detect cholesterol in thyroid membranes in vivo and in culture during TSH stimulation. We found that apical and basolateral plasma membranes were heterogeneously modified by filipin which induced abundant lesions in apical membranes, whereas Golgi apparatus, endoplasmic reticulum, nuclear membranes were unmodified. Small apical vesicles and colloid droplets were generally highly enriched in these complexes, suggesting a high cholesterol concentration in their membranes. Pseudopod membranes, known to be highly specialized domains in the apical plasma membrane, appeared enriched in cholesterol. Consequently, we suggest that an increased cholesterol content may be involved in the stabilization of thyroid membranes during endocytotic processes.

Animals↗
PubMed1987

Roxithromycin in skin and soft tissue infections.

In a double blind randomised investigation in 76 patients, roxithromycin (150 mg bd) and doxycycline (200 mg once daily) were compared in two groups of patients who were well-matched for age, sex, body weight, diagnosis, duration and severity of disease and associated pathological conditions, with infected skin conditions. Clinical effectiveness was 92% for roxithromycin and 82% for doxycycline, and bacteriological effectiveness also 92% and 82% respectively, the differences not being statistically significant.

Aged↗
PubMed1986

[Prognosis of generalized scleroderma. A retrospective study of 78 cases].

From 1960 to 1984, 78 new patients with progressive systemic sclerosis were followed up: 60 women and 18 men whose ages ranged from 20 to 83 years, with a mean age of 58 years. Twenty nine are known to be dead and 3 were lost of follow-up. Forty six have been followed up to the present time for a mean period of 5 years. The cumulative survival rates were 88 +/- 7 p. 100 at one year, 62,5 +/- 11,5 p. 100 at five years and 50,5 +/- 15 p. 100 at ten years. These figures are significantly different from those found in a matched group from the French general population. Nine features at the time of diagnosis which might influence prognosis were studied. Seven factors apparently have not affected prognosis: sex, age, time elapsed between initial symptom and definitive diagnosis, location of scleroderma, blood pressure, erythrocyte sedimentation rate and creatinine clearance. On the other hand, survival declined significantly faster in the 28 patients with anemia than in the 50 patients without anemia (P less than 0,001). Similarly, the 47 patients with radiological pulmonary involvement or pulmonary function abnormalities were at significantly higher risk for death than the 31 patients without interstitial pulmonary fibrosis. Anemia and pulmonary involvement are predictors of mortality and important prognostic tools in the management of the different drugs that have been recommended for the treatment of patients with systemic sclerosis.

Adult↗
PubMed1986

Plasma zinc is decreased only in generalized pustular psoriasis.

Plasma and cutaneous zinc were studied in 22 psoriatic patients and 14 controls. The psoriatics were divided into three groups: 10 extensive psoriasis vulgaris, 5 palmoplantar psoriasis and 7 extensive pustular psoriasis. Low plasma zinc and decreased in vitro chemotaxis of polymorphonuclear leukocytes were found only in extensive pustular psoriasis, whereas zinc was not decreased but rather elevated in skin. This explains why conflicting results on plasma zinc have been previously reported in psoriasis and confirms that cutaneous zinc depletion is not a feature of psoriasis.

Adult↗
PubMed1985

The benefit of chilling in argon-laser treatment of port-wine stains.

The authors compare results obtained in argon laser treatment of port-wine stains with and without preliminary chilling, noting that the success rate is considerably greater with the former procedure (68.6 percent) than with the latter (37.5 percent) (X2 = 4.37 p less than 0.05). The effect of chilling has been studied with special reference to the vitropressure test. Different hypotheses are presented to account for the difference and possible complications of the treatment are considered.

Adolescent↗
PubMed1985

A study of intermediate filaments (cytokeratin, vimentin, neurofilament) in two cases of Merkel cell tumor.

In two cases of Merkel cell tumor, the study of intermediate filaments, using monoclonal antibodies (vimentin, cytokeratin, neurofilaments), confirmed the double differentiation (neuroendocrine and epithelial) of this tumor as previously observed in histological, electron microscopical and histochemical analyses. Labelling of the tumor cells was positive with monoclonal antibodies against neurofilament proteins and cytokeratin.

Adenocarcinoma↗