Programme Hospitalier Recherche Clinique, Institut Pasteur, Inserm, French Public Health Agency.

Neuropathological conditions might affect adult granulogenesis in the adult human dentate gyrus. However, radial glial cells (RGCs) have not been well characterized during human development and aging. We have previously described progenitor and neuronal layer establishment in the hippocampal pyramidal layer and dentate gyrus from embryonic life until mid-gestation. Here, we describe RGC subtypes in the hippocampus from 13 gestational weeks (GW) to mid-gestation and characterize their evolution and the dynamics of neurogenesis from mid-gestation to adulthood in normal and Alzheimer's disease (AD) subjects. In the pyramidal ventricular zone (VZ), RGC density declined with neurogenesis from mid-gestation until the perinatal period. In the dentate area, morphologic and antigenic differences among RGCs were observed from early ages of development to adulthood. Density and proliferative capacity of dentate RGCs as well as neurogenesis were strongly reduced during childhood until 5 years, few DCX+ cells are seen in adults. The dentate gyrus of both control and AD individuals showed Nestin+ and/or GFAPδ+ cells displaying different morphologies. In conclusion, pools of morphologically, antigenically, and topographically diverse neural progenitor cells are present in the human hippocampus from early developmental stages until adulthood, including in AD patients, while their neurogenic potential seems negligible in the adult.

Integrins play a pivotal role in organogenesis, by mediating the interactions between differentiating cells and the extracellular matrix. We analyzed the expression of integrins and their ligands during human liver organogenesis. The expression of ␤1, ␤3, and ␤4 integrins and the distribution of several extracellular matrix proteins were studied by immunoperoxidase in fetal liver samples from 5 to 40 weeks' gestation. Hepatoblasts expressed only the ␤1, ␣1, ␣5, ␣6, and ␣9 integrin chains. Fetal hepatocytes, emerging at the 8th week of gestation, initially retained the same combination of integrins, but presented a progressive decrease in their expression levels. After 15 weeks' gestation, the expression levels of ␤1, ␣1, ␣5, and ␣9 reached levels comparable to those observed in the adult state. ␣6 expression became undetectable after 30 weeks' gestation. As compared to hepatoblasts, intrahepatic biliary epithelial cells, differentiating at the 8th week of gestation in the ductal plate, were characterized by the progressive loss of ␣1, the marked induction of ␣6, and the de novo acquisition of the ␤4, ␣2, and ␣3 integrin chains. The disappearance of integrin receptors for laminin on hepatocytes was associated with the rarefaction of laminin in the perisinusoidal matrix, whereas their induction on biliary epithelial cells was associated with laminin deposition at the point of contact with the ductal plate. In conclusion, integrins likely play an important role in the differentiation of the epithelial and endothelial cell populations of the liver. (HEPATOLOGY 1998;26:839-847.)Integrins are membrane receptors for extracellular matrix proteins, which play an essential role in mediating the structural and functional interactions between cells and the extracellular matrix. 1 Previous studies have shown that markedly different combinations of integrins are expressed by the two populations of epithelial cells present in the adult liver, hepatocytes and biliary epithelial cells. [2][3][4] Like other simple epithelial cells, intrahepatic biliary epithelial cells express a large combination of integrin receptors, including the ␣2␤1, ␣3␤1, ␣5␤1, ␣6␤1, ␣9␤1, ␣V␤1, and ␣6␤4 dimers. 2,5 In striking contrast, the integrin repertoire of hepatocytes is restricted to the ␣1␤1, ␣5␤1, and ␣9␤1 dimers. This combination is highly distinctive. 3 The expression of ␣1␤1 integrin, a receptor for collagens and laminin, 6 is very unusual for an epithelial cell, since this integrin receptor is characteristically expressed by fibroblasts, muscle cells, and endothelial cells. Moreover, the absence of ␣6␤4, a characteristic component of hemidesmosomes, 7,8 is unique among the epithelial cells tested so far.It is likely that the differences in the combinations of integrins expressed, respectively, by hepatocytes and biliary epithelial cells are related to the differences in the constitution of their pericellular environments. Like all other lining epithelial cells, intrahepatic biliary epithelial cells are surrounded by a typical basement membran...

ObjectiveDesign Retrospective study. SettingPopulation A consecutive series of 956 terminations of pregnancy performed for fetal anomalies in singleton pregnancies, 305 of which were in the third trimester and 651 in the second. Main outcome measuresIndications for termination of pregnancy; process leading to late termination of pregnancy; maternal morbidity. ResultsOne hundred and thirteen (37%) third trimester terminations of pregnancy were associated with false negative resulted from the results of earlier screening tests. In 15 terminations (5%), the decision was postponed, although the poor fetal prognosis was established earlier. In 55 (1 8%) the diagnosis was not possible earlier than the third trimester, and in 122 (40%) the diagnosis was possible earlier but the poor prognosis for the fetus was not established until the third trimester. Maternal morbidity due to termination of pregnancy was similar in the second and third trimester.Conclusion One-third of late terminations of pregnancy could have been avoided by more efficient screening in the second trimester. However, because fetal prognosis is not always clear when a malformation is diagnosed, postponing the decision until fetal development allows more thorough evaluation and may avoid unnecessary termination of pregnancy in the second trimester. This could be the main beneficial aspect of not setting a limit to the gestational age for performing termination of pregnancy.To analyse the process in making decisions leading to termination of pregnancy in the third trimester and to evaluate the maternal morbidity associated with this procedure.

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Objective To evaluate the efficacy and tolerance of mifepristone in women undergoing induction of labour at term after previous caesarean section. Design A prospective double blind placebo controlled trial. Subjects Thirty‐two women at term (after 37.5 weeks' amenorrhea) who had had a previous caesarean delivery with a low transverse uterine incision. All women had a clear clinical indication for induction of labour with unfavourable cervical conditions (Bishop's score < 4). They were randomised to receive either 200 mg of mifepristone or placebo on days one and two of a four‐day observation period. Results Thirteen women entered spontaneous labour: 11 were treated with mifepristone and two were in the control group (P < 0.01). Thirteen women, still with an unfavourable cervix on day four needed cervical ripening with vaginal tablets of prostaglandins. Of these, four had received mifepristone and nine the placebo. Mean oxytocin requirements were lower in the mifepristone group (P < 0.01) and the mean time interval between day one and start of labour was also significantly shorter in this group. Mode of delivery and neonatal outcome were similar in both groups. Conclusions Induction of labour is facilitated in term women with prior caesarean section by the use of mifepristone. This induction agent appears safe and useful with no adverse events on the fetus or mother.

Our results suggest that stress urinary incontinence after pregnancy arises from a multifactorial condition. The main risk factors are: age, previous incontinence (before or during the first pregnancy), prolonged labor and vaginal delivery.

Our results suggest recommendations for preserving fertility whenever possible without compromising the oncological prognosis. In particular, OSS should be reserved for patients who meet all criteria for localized mature teratoma. Long-term follow-up is crucial.