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C Hermier

Publications and source records attributed to C Hermier.

89 records · Page 5Linked to original sources
PubMedDate not supplied

Lack of short-term modulation of in vitro placental progesterone secretion in sheep.

Experiments were performed in order to determine whether progesterone secretion in the ovine placenta can be short-term regulated. There was an increase in progesterone content per unit weight in ovine fetal cotyledons as gestation progressed: 17.0 +/- 4.7 ng/100 mg of wet tissue in ewes between 40 and 54 days of pregnancy (n = 7) and 70.7 +/- 18.8 (n = 9) between 100 and 118 days. At all stages of pregnancy, neither progesterone nor 20 alpha-dihydroprogesterone synthesis were significantly affected when fetal cotyledons were incubated for 3 h in the presence of LH, 8-Br-cAMP, GnRH agonist or GnRH antagonist. Addition of pregnenolone to the incubation medium increased progesterone secretion in a dose-dependent manner while addition of 25-hydroxycholesterol did not. These results suggest that the existent (basal) synthesis of progesterone reflects the maximal capacity of steroidogenesis through the cholesterol side-chain-cleavage system. In the presence of these precursors, LH, 8-Br-cAMP, the phorbol ester derivative PMA and calcium ionophore A23187 were not able to modify progesterone or 20 alpha-dihydroprogesterone synthesis. These results also suggest that LH or GnRH and the two signal mechanisms involved in their action, i.e. cAMP and Ca2+ sensitive-inositol phospholipid-dependent mechanisms are not implicated in the short-term regulation of progesterone synthesis in the ovine placenta.

8-Bromo Cyclic Adenosine Monophosphate↗
PubMedDate not supplied

Evidence for modulation of progesterone secretion by calcium and protein kinase C activators in ovine chorionic cells.

The hypothesis that calcium-dependent mechanisms may be involved in regulating ovine placental steroidogenesis was investigated using chorionic cells isolated by enzymatic digestion. Treatment of the cells with the calmodulin antagonist trifluoperazine (TFP) or pimozide caused a dose-related inhibition of progesterone (P4) production by 80 percent (P less than 0.001) at 40 microM TFP and 56 per cent (P less than 0.001) at 10 microM pimozide. Moreover, the conversion of 25 hydroxycholesterol (25 OH Chol.) to P4 was impaired in the presence of these compounds. These experiments suggest the involvement of a calcium-calmodulin system in the regulation of ovine placental P4 synthesis. Interestingly, calcium ionophore A23187 caused a gradual decline in P4 secretion and completely blocked it at 1 microM (P less than 0.001) and remains absent even in the presence of 25 OH Chol. In contrast, EGTA increased P4 secretion (P less than 0.01). Further, in the presence of 3 mM EGTA the inhibitory effect of 1 microM A23187 was fully reversed. Taken together these results suggest that extracellular calcium could play a role of negative modulation of P4 secretion in these cells. The possible involvement of protein kinase C (PKC) was tested using tumor-promoting phorbol ester (PMA) or permeant diacylglycerols (OAG or DOG). These compounds were unable to modify basal P4 secretion but reduced 25 OH Chol stimulated secretion to basal level. The phorbol ester that was unable to activate PKC had no effect on the metabolism of 25 OH chol. Thus, PMA and diacylglycerol effects are probably mediated by PKC. These data support the hypothesis that PKC activation plays a role in the modulation of cholesterol side-chain cleavage activity in ovine chorionic cells. These results show that calcium-dependent processes are involved in both positive and negative control of P4 secretion by ovine placenta. Our results also suggest a role for calmodulin and PKC pathways in modulating this secretion.

Animals↗
PubMedDate not supplied

[Systemic urticaria associated with autoimmune thyroiditis].

A case of chronic urticaria associated with thyroiditis is described. The diagnosis of autoimmune thyroid disease (Hashimoto's disease) rested on the presence of nodular goiter, thyroid dysfunction and significantly elevated thyroid microsomal antibodies (greater than 6,400). Skin biopsy showed changes suggestive of leucocytoclastic vasculitis. Immunological studies showed few abnormalities (low titers of antinuclear antibodies and rheumatoid factor) but a search for circulating immune complexes was negative, and serum complement levels were within normal range. The patient complained of severe pruritus and polyarthralgia but no systemic involvement occurred. Urticaria vasculitis has never previously been described in association with thyroid autoimmunity. This suggests the possibility of an autoimmune cause of urticaria. The urticaria improved and disappeared after treatment with levothyroxine. The frequent clinical latency of thyroiditis warrants systematic testing for circulating anti-microsome antibodies in women presenting with an apparently idiopathic chronic urticaria.

Antibodies↗
PubMedDate not supplied

Neuron-specific enolase is a marker of cutaneous Langerhans' cell histiocytosis ("X")-a comparative study with S100 protein.

The immunohistochemical expression of neuron-specific enolase (gamma/gamma) (NSE) was studied comparatively with S100 protein in a group of Langerhans-cell-type ("X") (n = 8) and non-Langerhans-cell-type ("non X") (n = 24) cutaneous histiocytoses. NSE was expressed by the majority (70-90%) of histiocytic cells in all cases of Langerhans-cell histiocytoses, whereas it was absent from non-Langerhans-cell histiocytoses. S100 protein was expressed by the majority of Langerhans-cell histiocytosis cells but also by a small percentage (1-5%) of cells in non Langerhans-cell histiocytoses. These results show that NSE is almost as sensitive as, but more specific than, S100 protein in discriminating Langerhans-cell from non-Langerhans cell cutaneous histiocytoses, and that it consequently represents a useful adjunct in the immunohistochemical diagnosis of histiocytic skin diseases.

Biomarkers↗
PubMedDate not supplied

[Acute generalized exanthematic pustulosis in children. Apropos of a case].

A seven year old girl without any personal or familial history of psoriasis presented with a maculo-papular then pustular, uniformly generalized eruption. She also had fever, neutrophilic granulocytosis, conjunctivitis and vulvitis. There was no evidence for bacterial or viral aetiology. Skin biopsy showed spongiform multilocular pustules and a vasculitis. The child recovered spontaneously within one week without further relapse.

Acute Disease↗