About 99% of neonatal deaths occur in low- and middle-income countries. There is a paucity of information on the exact timing of neonatal deaths in these settings. The objective of this review was to determine the timing of overall and cause-specific neonatal deaths in developing country settings. We searched MEDLINE via PubMed, Cochrane CENTRAL, WHOLIS and CABI using sensitive search strategies. Searches were limited to studies involving humans published in the last 10 years. A total of 22 studies were included in the review. Pooled results indicate that about 62% of the total neonatal deaths occurred during the first 3 days of life; the first day alone accounted for two-thirds. Almost all asphyxia-related and the majority of prematurity- and malformation-related deaths occurred in the first week of life (98%, 83% and 78%, respectively). Only one-half of sepsis-related deaths occurred in the first week while one-quarter occurred in each of the second and third to fourth weeks of life. The distribution of both overall and cause-specific mortality did not differ greatly between Asia and Africa. The first 3 days after birth account for about 30% of under-five child deaths. The first week of life accounts for most of asphyxia-, prematurity- and malformation-related mortality and one-half of sepsis-related deaths.
Background: Alzheimer's disease is associated with the accumulation of intracellular Tau tangles within neurons and extracellular amyloid-β plaques in the brain parenchyma, which altogether results in synaptic loss and neurodegeneration. Extracellular concentrations of oligomers and aggregated proteins initiate microglial activation and convert their state of synaptic surveillance into a destructive inflammatory state. Although Tau oligomers have fleeting nature, they were shown to mediate neurotoxicity and microglial pro-inflammation. Due to the instability of oligomers, in vitro experiments become challenging, and hence, the stability of the full-length Tau oligomers is a major concern. Methods: In this study, we have prepared and stabilized hTau40 WT oligomers, which were purified by size-exclusion chromatography. The formation of the oligomers was confirmed by western blot, thioflavin-S, 8-anilinonaphthaalene-1sulfonic acid fluorescence, and circular dichroism spectroscopy, which determine the intermolecular cross-β sheet structure and hydrophobicity. The efficiency of N9 microglial cells to phagocytose hTau40 WT oligomer and subsequent microglial activation was studied by immunofluorescence microscopy with apotome. The one-way ANOVA was performed for the statistical analysis of fluorometric assay and microscopic analysis. Results: Full-length Tau oligomers were detected in heterogeneous globular structures ranging from 5 to 50 nm as observed by high-resolution transmission electron microscopy, which was further characterized by oligomer-specific A11 antibody. Immunocytochemistry studies for oligomer treatment were evidenced with A11 + Iba1 high microglia, suggesting that the phagocytosis of extracellular Tau oligomers leads to microglial activation. Also, the microglia were observed with remodeled filopodia-like actin structures upon the exposure of oligomers and aggregated Tau. Conclusion: The peri-membrane polymerization of actin filament and co-localization of Iba1 relate to the microglial movements for phagocytosis. Here, these findings suggest that microglia modified actin cytoskeleton for phagocytosis and rapid clearance of Tau oligomers in Alzheimer's disease condition.
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