A common African variant of human connexin 37 is associated with Caucasian primary ovarian insufficiency and has a deleterious effect in vitro.

Folliculogenesis requires communication between granulosa cells and oocytes, mediated by connexin-based gap junctions. Connexin 37 (Cx37)-deficient female mice are infertile. The present study assessed Cx37 deficiency in patients with primary ovarian insufficiency (POI).

The type III effector IpgD recodes Ca signals during invasion of epithelial cells.

The role of second messengers in the diversion of cellular processes by pathogens remains poorly studied despite their importance. Among these, Ca virtually regulates all known cell processes, including cytoskeletal reorganization, inflammation, or cell death pathways. Under physiological conditions, cytosolic Ca increases are transient and oscillatory, defining the so-called Ca code that links cell responses to specific Ca oscillatory patterns.

[The benefit of systematic hearing screening of school-age children].

The hearing is routinely tested in all newborns in most European countries. Thereafter, no hearing test is performed in a systematic way, despite the many conditions that can cause hearing loss in the first years of life. If language acquisition is possible with only one ear, even a unilateral hearing loss can be the cause of learning difficulties at school.

Cadmium disorganises the scaffolding of gap and tight junction proteins in the hepatic cell line WIF B9.

Background Information: Hepatocytes, which perform the main functions of the liver, are particularly vulnerable to toxic agents such as cadmium, an environmental pollutant. To identify the molecular targets for cadmium in hepatocytes, we have studied the effects of CdCl2 on the hybrid cell line WIF-B9 that exhibits stable structural and functional hepatocytic polarity.

Results: We showed that the toxicity of CdCl2 (1 µM, 24 h) resulted in a reduction in direct intercellular communication (via gap junctions) and in an increase in paracellular permeability (decrease in the sealing of tight junctions).

Rat hepatocytes express functional P2X receptors.

Extracellular ATP regulates many hepatic functions by stimulating purinergic receptors. Only the G protein-coupled P2Y receptors have been studied in hepatocytes. We investigated the functional expression of P2X receptors, the ATP-gated channels in rat hepatocytes.

Effects of the prostaglandins PGF2alpha and PGE2 on calcium signaling in rat hepatocyte doublets.

Coordination of intercellular Ca2+ signals is important for certain hepatic functions including biliary flow and glucose output. Prostaglandins, such as PGF2alpha and PGE2, may modify these hepatocyte functions by inducing Ca2+ increase, but very little is known about the organization of the Ca2+ signals induced by these agonists. We studied Ca2+ signals induced by PGF2alpha and PGE2 in fura-2 AM-loaded hepatocyte doublets.

Cholestatic bile acids inhibit gap junction permeability in rat hepatocyte couplets and normal rat cholangiocytes.

Background/aims: The aim of this work was to study the effects of different bile acids on the permeability of gap junction channels (PGJC). We also looked at the effects of some bile acids on the coordination of intercellular calcium oscillations.

Methods: The permeability of gap junctions was assessed by fluorescent dye transfer and calcium signalling on fluorescent microscopy.

Hypothalamic vasopressin release and hepatocyte Ca2+ signaling during liver regeneration: an interplay stimulating liver growth and bile flow.

Liver regeneration after partial hepatectomy is a plastic process during which the mechanisms that coordinate liver mass restoration compensate one another through a complex regulatory network of cytokines, growth factors, and hormones. Vasopressin, an agonist that triggers highly organized Ca2+ signals in the liver, may be one of these factors, although little in vivo evidence is available in support of this hypothesis. We provide evidence that hypothalamic vasopressin secretion is stimulated early after partial hepatectomy.

Hormone receptor gradients supporting directional Ca2+ signals: direct evidence in rat hepatocytes.

Background/aims: In the liver, InsP(3)-dependent agonists such as vasopressin and noradrenaline induce tightly coordinated sequences of intracellular Ca(2+) increases, leading to apparent unidirectional Ca(2+) waves. In previous works, we have postulated that cell-to-cell differences in hormone receptor density create a cellular sensitivity gradient that determines which cell initiates the intercellular Ca(2+) wave and the direction of propagation of the Ca(2+) signal. The aim of this study was to test directly this hypothesis.

Inducible nitric-oxide synthase attenuates vasopressin-dependent Ca2+ signaling in rat hepatocytes.

Increases in both Ca(2+) and nitric oxide levels are vital for a variety of cellular processes; however, the interaction between these two crucial messengers is not fully understood. Here, we demonstrate that expression of inducible nitric-oxide synthase in hepatocytes, in response to inflammatory mediators, dramatically attenuates Ca(2+) signaling by the inositol 1,4,5-trisphosphate-forming hormone, vasopressin. The inhibitory effects of induction were reversed by nitric oxide inhibitors and mimicked by prolonged cyclic GMP elevation.

Tissue levels of histamine, PAF-acether and lysopaf-acether in carrageenan-induced granuloma in rats.

The tissue concentrations of several inflammatory mediators were determined from day 0 to day 60 in granuloma induced in rats (n = 105) by injection of carrageenan in the fascia of the latissimus dorsi muscle. Noncollagen proteins (NCP) and the number of polymorphonuclear leukocytes (PMN) and mast cells were also assessed. In comparison with the tissue at time 0, we noted in the inflamed tissue (at 4 h) an increase in total proteins (4.

Effects of long-term treatment with D-penicillamine on antigen-induced arthritis in rabbits: studies on in vivo articular chondrocyte damage and in vitro collagen biosynthesis by cultured chondrocytes.

The effects of a long-term (120 days) treatment with D-penicillamine (DP) (50 mg/kg/day; i.v.) on antigen-induced arthritis were studied in rabbit.

Comparison of effects of D. Penicillamine and dexamethasone on the articular and non articular lesions in immune connective tissue disease induced in rabbits.

The effect of D. Penicillamine (DP) at the dose of 50 mg/kg/day, on an immune induced connective tissue disease in rabbit, is compared to that of dexamethasone (Dexa) at the doses of 0.15 and 0.

[N1-substituted 1H-indazole-3-ethyl carboxylates and 1H-indazole-3-hydroxamic acids].

Sixty five new derivatives of ethyl-1H-indazole-3-carboxylate are described; they contain in N1 various aliphatic or aromatic acyl radicals. Moreover halogens or methyl groups are present as substituents at the 5 position or methyl groups at 5,6. The synthesis of seven 1H-indazole-3-hydroxamic acids, substituted at 6 and/or 5 as above, is also described.