Plos One
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β-site amyloid precursor protein (APP) cleaving enzyme 1 (BACE1) initiates the production of β-amyloid (Aβ), the major constituent of amyloid plaques in Alzheimer's disease (AD). BACE1 is elevated ∼2-3 fold in AD brain and is concentrated in dystrophic neurites near plaques, suggesting BACE1 elevation is Aβ-dependent. Previously, we showed that phosphorylation of the translation initiation factor eIF2α de-represses translation of BACE1 mRNA following stress such as energy deprivation. ⋯ We conclude that amyloid-associated BACE1 elevation is not caused by translational de-repression via eIF2α phosphorylation, but instead appears to involve a post-translational mechanism. These definitive genetic results exclude a role for eIF2α phosphorylation in Aβ-dependent BACE1 and APP elevation. We suggest a vicious pathogenic cycle wherein Aβ42 toxicity induces peri-plaque BACE1 and APP accumulation in dystrophic neurites leading to exacerbated Aβ production and plaque progression.
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Protein-Protein Interaction (PPI) extraction is an important task in the biomedical information extraction. Presently, many machine learning methods for PPI extraction have achieved promising results. However, the performance is still not satisfactory. ⋯ Particularly, we extend the shortest path-enclosed tree kernel (SPT) by a dynamic extended strategy to retrieve the richer syntactic information. Our semantic kernel calculates the protein-protein pair similarity and the context similarity based on two semantic resources: WordNet and Medical Subject Heading (MeSH). We evaluate our method with Support Vector Machine (SVM) and achieve an F-score of 69.40% and an AUC of 92.00%, which show that our method outperforms most of the state-of-the-art systems by integrating semantic information.
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Coral reef ecosystems are based on coral-zooxanthellae symbiosis. During the initiation of symbiosis, majority of corals acquire their own zooxanthellae (specifically from the dinoflagellate genus Symbiodinium) from surrounding environments. The mechanisms underlying the initial establishment of symbiosis have attracted much interest, and numerous field and laboratory experiments have been conducted to elucidate this establishment. ⋯ Subsequent attraction tests revealed that three Symbiodinium strains were attracted toward Acropora larvae, and within them, only A1 and D1-4 strains were acquired by the larvae. Another three strains did not intrinsically approach to the larvae. These findings suggest the initial establishment of corals-Symbiodinium symbiosis is not random, and the infection mechanism appeared to comprise two steps: initial attraction step and subsequent selective uptake by the coral.
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Little information is known about factors that influence perioperative and anesthesia-related cardiac arrest (CA) in older patients. This study evaluated the incidence, causes and outcome of intraoperative and anesthesia-related CA in older patients in a Brazilian teaching hospital between 1996 and 2010. ⋯ The study identified high incidence of intraoperative CAs with high mortality in older patients. The large majority of CAs were caused by factors not anesthesia-related. Anesthesia-related CA and mortality rates were 3.26 and 1.63 per 10,000 anesthetics, with no anesthesia-related CA in the last five years of the study. Major predictors of intraoperative CAs were poorer ASA physical status and emergency surgery. All anesthesia-related CAs were medication-related or airway-related, which is important for prevention strategies.
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To identify the current clinical, socio-demographic and obstetric factors associated with the various types of delivery strategies in Mexico. ⋯ The existence of different socio-demographic and obstetric profiles among women who receive care for vaginal or cesarean delivery, are supported by the findings of the present study. The frequency of vaginal delivery is higher in indigenous women, when the care provider is public and, in women with two or more children at time of the most recent child birth. Planned cesarean deliveries are positively associated with years of schooling, a higher socioeconomic level, and higher age. The occurrence of emergency cesarean sections is elevated in women with a diagnosis of a health issue during pregnancy or delivery, and it is reduced in highly marginalized settings.