RESUMEN

The ventricular-subventricular zone (V-SVZ) is located in the walls of the lateral ventricles and produces new neurons in the postnatal brain of mammals, including humans. Immature new neurons called "neuroblasts" generated by neural stem cells in the V-SVZ migrate toward their final destinations and contribute to brain development and plasticity. In this review, we describe recent progress in understanding the similarities and dissimilarities in postnatal neurogenesis and neuronal migration between rodents and primates. In rodents, most new V-SVZ-derived neurons migrate along the rostral migratory stream towards the olfactory bulb, where they differentiate into interneurons. In contrast, in humans, the extensive migration of new neurons towards the neocortex continues for several months after birth and might be involved in the development of the expanded neocortex. The mode of migration and the fate of neuroblasts seem to change depending on their environment, destination, and roles in the brain. A better understanding of these similarities and differences between rodents and primates will help translate important findings from animal models and may contribute to the development of clinical strategies for brain repair.

Asunto(s)

RESUMEN

Even after birth, neuronal production continues in the ventricular-subventricular zone (V-SVZ) and hippocampus in many mammals. The immature new neurons ("neuroblasts") migrate and then mature at their final destination. In humans, neuroblast production and migration toward the neocortex and the olfactory bulb (OB) occur actively only for a few months after birth and then sharply decline with age. However, the precise spatiotemporal profiles and fates of postnatally born neurons remain unclear due to methodological limitations. We previously found that common marmosets, small nonhuman primates, share many features of V-SVZ organization with humans. Here, using marmosets injected with thymidine analogue(s) during various postnatal periods, we demonstrated spatiotemporal changes in neurogenesis during development. V-SVZ progenitor proliferation and neuroblast migration toward the OB and neocortex sharply decreased by 4 months, most strikingly in a V-SVZ subregion from which neuroblasts migrated toward the neocortex. Postnatally born neurons matured within a few months in the OB and hippocampus but remained immature until 6 months in the neocortex. While neurogenic activity was sustained for a month after birth, the distribution and/or differentiation diversity was more restricted in 1-month-born cells than in the neonatal-born population. These findings shed light on distinctive features of postnatal neurogenesis in primates.

Asunto(s)

RESUMEN

BACKGROUND: Diabetes is associated with oxidative stress and considered as a major risk factor for cardiac disease. We attempted to investigate the role of oral antidiabetic (OAD) agents gliclazide and metformin in lowering the lipid peroxidation and managing the risk for cardiovascular (CV) complications in diabetic patients in comparison with nondiabetic healthy individuals. MATERIALS AND METHODS: This cross-sectional study was comprised of 150 individuals grouped in three, namely, Group A (n = 60) healthy volunteers, Group B (n = 30) newly diagnosed diabetes, and Group C (n = 60) diabetes treated with OAD. Serum malondialdehyde (MDA), nitric oxide (NO), and Vitamin C were assessed for studying lipid peroxidation status, whereas serum triglyceride (TG) and total cholesterol were monitored as predictors for CV risk. RESULTS: We found significantly higher concentrations of MDA and NO levels (P < 0.001) in both groups of patients (Group B and C) in comparison to control group (Group A). Regarding antioxidants, significantly lower concentrations of Vitamin C (P = 0.046) were found in Group B and C compared to Group A. Moreover, there was significant difference exhibited in concentration level of MDA (P = 0.001) and NO (P = 0.015) between Group B and C, whereas difference of Vitamin C (P = 0.147) was not statistically significant. CONCLUSION: Our data confirmed that treatment with gliclazide and metformin significantly reduced the lipid peroxidation accompanied with attenuated levels of serum TGs and cholesterol and suggested that oral hypoglycemic agents have great impact to reduce the oxidative stress and increase the antioxidant status in diabetes.

RESUMEN

OBJECTIVES: Preeclampsia is a hypertensive disorder of pregnancy which is one of the leading causes of maternal and perinatal mortality and pre-term delivery, especially in low and middle income countries. Selenium is an important constituent of selenoproteins that act as antioxidant and have several metabolic functions. The present study was conducted to determine serum selenium concentration in preeclampsia patients in order to find out the role of selenium in preeclampsia. METHODS: This study was conducted as case-control study with 74 preeclampsia patients as cases whose gestation were ≥20 weeks (52 mild and 22 severe patients) and 118 normotensive pregnant women as controls from same gestational period. Detailed patient history was recorded during routine hospital visits. Serum selenium concentration was determined by using atomic absorption spectroscopy. Independent sample t-test and Pearson's correlation test were done for the statistical analysis using the statistical software package SPSS, version 16. RESULTS: Our study found that mean serum concentration of selenium in preeclampsia patients was significantly lower than that of healthy pregnant women (p<0.05). Further analysis for selenium concentration with disease severity explored that selenium concentration was significantly lower in severe preeclampsia in comparison to mild preeclampsia (p<0.05). We found no significant difference for selenium concentration between rural and urban preeclampsia patients (p>0.05). Pearson's correlation analysis reveals significant negative correlation of selenium with systolic blood pressure (r=-0.419, p=0.001), diastolic blood pressure (r=-0.392, p=0.001), and gestational period (r=-0.218, p=0.001). CONCLUSION: Our study found that preeclampsia patients have decreased serum selenium concentration than the healthy pregnant women.

Asunto(s)