Spatial distribution of metals in sediments of the Ribeira Bay, Angra dos Reis, Rio de Janeiro, Brazil.

This study aims to analyze the spatial distributions of several metals in sediments from five sites in Ribeira Bay, Brazil. Ribeira Bay is a very important area to the local community, due to its artisan fishery, and it also has a biological relevance for many marine species that use mangroves as nursery and feeding sites. According to the results, the area was not considered a metal polluted area. Despite not having a significant source of metals inside the Bay nowadays, Ilha Grande Bay harbors a shipyard, an oil terminal, and a commercial port, as well as two thermonuclear power plants (Angra I e II), all of which indirectly influence the study area.

Human chorionic gonadotropin in human placentas from normal and preeclamptic pregnancies.

OBJECTIVE: The aim of this study was to examine the distribution of human chorionic gonadotropin (hCG) in the human placenta of normotensive and preeclamptic pregnancies and to determine by computer image analysis, whether differences in hCG immunoreactivity occurred in preeclamptic as apposed to normotensive pregnancies. We discuss how far elevated maternal serum levels of hCG normally observed in preeclamptic patients reflect an increased secretory activity of the syncytiotrophoblast. METHODS: We used the immunoperoxidase technique to locate hCG. Quantification of immunostaining intensity was done by computer image analysis. RESULTS: In normotensive placentas from all the gestational ages human chorionic gonadotrophin immunoreactivity was specifically detected in the syncytiotrophoblast. There is an apparent decrease in the intensity of the hCG immunostaining in the syncytiotrophoblast from the 29th to 36th week of gestation in normotensive placentas. No hCG immunostaining was observed in the villous or extravillous cytotrophoblast of all placentas. In preeclamptic placentas the expression of hCG was homogeneous with a moderate to intense immunoreactivity in the syncytiotrophoblast. Microdensitometric analysis of the section from normotensive and preeclamptic placentas indicated that there is a statistically significant preeclampsia-induced increase in immunohistochemical reaction intensity for hCG (p < 0.05). CONCLUSION: This study seems to demonstrate that increased production of hCG by preeclamptic placentas is associated with strong hCG immunostaining of the syncytiotrophoblast.

Immunocytochemical localization of endothelin-1 in human placenta from normal and preeclamptic pregnancies.

OBJECTIVE: The aim of this study was to examine the distribution of endothelin-1 (ET-1) in the human placenta at different gestational ages and to determine whether differences in ET-1 immunoreactivity occurred in preeclamptic compared with uncomplicated pregnancies. METHODS: Localization of ET-1 was investigated by the immunoperoxidase technique in first-trimester, second-trimester, and term human placentas from normal pregnancies and in placentas from preeclamptic pregnancies. RESULTS: In normal placentas from all gestational ages studied, endothelin-1 immunoreactivity (ET-1 IR) was specifically detected in the endothelium of the fetal vessels and in the syncytiotrophoblast. ET-1 IR was also expressed by the villous cytotrophoblast of first- and second-trimester normal placentas. The extravillous cytotrophoblast of the basal and chorionic plates also exhibited ET-1 IR, but with varying degrees of intensity. In preeclamptic placentas, the expression of ET-1 IR was uneven with a negative staining in all placentas from pregnancies between the 29th and 32nd weeks of gestation. The expression of ET-1 IR was most intense in some syncytiotrophoblast tissue in the terminal villi after the 33rd week of gestation. In placentas from preeclamptic pregnancies between the 35th and the 36th weeks of gestation, strong ET-1 IR expression was evident in the endothelium of fetal vessels and in the syncytiotrophoblast. Regardless of gestational age, ET-1 IR was also observed in the extravillous cytotrophoblast of the basal and chorionic plates of preeclamptic placentas. CONCLUSION: This study demonstrates that ET-1 IR is widely distributed in the human placenta and provides further evidence to support the concept that ET-1 plays an important role as a modulator of vascular tone in the uteroplacental and fetoplacental units and may participate in the pathogenesis of preeclampsia.