Vitamin E family: Role in the pathogenesis and treatment of Alzheimer's disease

AbstractIntroductionVitamin E family, composed by tocopherols and tocotrienols, is a group of compounds with neuroprotective properties. The exact role in the pathogenesis and the benefit of vitamin E as treatment for Alzheimer's disease (AD) are still under debate.MethodsA literature search in PubMed, Medline, and Cochrane databases has been carried out. All types of studies, from bench and animal models to clinical, were included.ResultsHigh plasma vitamin E levels are associated with better cognitive performance, even if clear evidence of their ability to prevent or delay cognitive decline in AD is still lacking. Each vitamin E form is functionally unique and shows specific biological functions. Tocotrienols seem to have superior antioxidant and anti-inflammatory properties compared with tocopherols.DiscussionThe benefit of vitamin E as a treatment for AD is still under debate, mainly because of the inconsistent findings from observational studies and the methodological limitations of clinical trials

Sampling Molecular Conformers in Solution with Quantum Mechanical Accuracy at a Nearly Molecular-Mechanics Cost

We introduce a method to evaluate the relative populations of different conformers of molecular species in solution, aiming at quantum mechanical accuracy, while keeping the computational cost at a nearly molecular-mechanics level. This goal is achieved by combining long classical molecular-dynamics simulations to sample the free-energy landscape of the system, advanced clustering techniques to identify the most relevant conformers, and thermodynamic perturbation theory to correct the resulting populations, using quantum-mechanical energies from density functional theory. A quantitative criterion for assessing the accuracy thus achieved is proposed. The resulting methodology is demonstrated in the specific case of cyanin (cyanidin-3-glucoside) in water solution

Analysis of the Effects of Technological and Organizational Features on Intranet and Portal Usage

The paper’s purpose is to analyze the effects of technological and organizational features on intranet and portal usage. Technological features comprise common intranet functions such as collaboration, search engine, personalization, workflow and content management. Intranet organizational features were associated with intranet support team’s profile, existence of specific budget for the intranet project and relationship with users. The research model was based on TAM, TTF and on several checklists from intranet literature. A survey was conducted with intranet managers from 98 Brazilian and 70 Portuguese organizations. Factor analysis revealed intranet integration features as a separate construct from technological features. The results showed that many analyzed intranets were at the basic stages. There was evidence that intranet integration and organizational features had more impact on intranet quality and usage than technological features

unraveling the molecular mechanisms of color expression in anthocyanins

The complex behavior underlying color expression in this broad family of natural dyes is revealed through multi-scale simulations in excellent agreement with experimental spectra

Glycated hemoglobin for the diagnosis of diabetes and prediabetes: Diagnostic impact on obese and lean subjects, and phenotypic characterization

Aims/Introduction Measurement of glycated hemoglobin (HbA1c) has been recommended for the diagnosis of diabetes and prediabetes. However, epidemiological studies have shown significant discordance between HbA1c and glucose-based tests. Of the factors that could influence agreement between HbA1c and the oral glucose tolerance test (OGTT), bodyweight has not been fully evaluated. The aims of the present study were to evaluate the impact of HbA1c criteria to diagnose diabetes and prediabetes compared with OGTT, and to examine HbA1c in relation to body mass index. Materials and Methods Two cohorts were studied, one from an obesity clinic (n = 592) and one from subjects undergoing screening for diabetes (n = 462). All underwent OGTT and HbA1c measurement. Results In the obese cohort, HbA1c ≥6.5% (≥48 mmol/mol) showed a sensitivity of 69.3% for diabetes, whereas HbA1c 5.7–6.4% (39–46 mmol/mol) did not identify prediabetes well (sensitivity 39.1%). In the diabetes screening cohort, HbA1c h

Características geoquímicas de las cuñas de hielo en Puerto Deseado (Santa Cruz, Argentina): implicancias paleoambientales y cronológicas

Ground wedge structures of cryogenic origin are common in the Quaternary sediments along the coast of the Patagonia, and their formation is related to climatic cold events experienced by this area in the Late Quaternary. The infilling sediments of two wedges generations were analyzed in the area of Puerto Deseado. Bulk chemistry (major elements), X-ray diffraction (XRD), morphoscopic observations with Scanning Electronic Microscope (SEM) and chemical analyses of volcanic glass shards were undertaken to provide indications about infilling sediment provenience, along with chronological constraint for wedge formation. Bulk chemistry and XRD patterns indicate a significant SiO2- enriched composition of the sediment infilling compared to the most of the loess deposits of the North Argentina and the present day dust originated in Patagonia. This was interpreted as due to the nature of the bedrock present over the Deseado Massif. SEM morphoscopic characteristics of glass shards evidence typical aeolian reworking features, with impact structures and indented edges of the volcanic fragments. Chemical analyses of the glass shards indicate that they were probably generated by the H0 eruption (17,300-17,400 cal yr BP) of the Hudson volcano. Volcanological data indicate that H0 eruption dispersed toward NE, but volcanic glasses were available for reworking due to a WNW component in the western wind direction. Over the Deseado Massif structural high the glass shards mixed with sediments enriched in SiO2, and were eventually deflated further to SE reaching the present coastal area and infilling the frost cracks. The age of the glass shards (17,300-17,400 cal yr BP) and that of the sandy layer affected by cryogenic structures (14,670±750 yr BP) well constrain to the Late Glacial both wedge generations.Las cuñas de hielo son estructuras comunes en sedimentos cuaternarios a lo largo de la costa patagónica, y su formación está relacionada con eventos climáticos fríos experimentados en esta área en el Cuaternario Tardío. Se analizaron sedimentos que rellenan dos generaciones de cuñas de hielo en la zona de Puerto Deseado. Análisis químicos de elementos mayores, difractometría de rayos X (DRX), observaciones con microscopio electrónico de barrido (SEM) y análisis químico de fragmentos de vidrio volcánico contenidos en el sedimento que rellena las cuñas proporcionaron información sobre la precedencia del relleno, además de inferir antecedentes cronológicos sobre su formación. La composición química del sedimento y la difracción de rayos X indican una composición enriquecida en SiO2 en comparación con la mayoría de los depósitos de loess del norte de Argentina y el polvo actual originado en la Patagonia. Esto fue interpretado como producto de la influencia de las rocas que constituyen el macizo del Deseado. Las características morfológicas de los fragmentos de vidrio evidencian rasgos típicos de retrabajo eólico, con presencia de estructuras de impacto y bordes dentados. Los análisis químicos de los fragmentos de vidrio son compatibles con un origen en la erupción H0 (17.300-17.400 cal yr BP) del volcán Hudson. Datos volcanológicos indican que la erupción H0 originó una pluma de dispersión hacia el NE. El material volcánico dispersado por esta erupción quedó disponible para ser retrabajado por una componente WNW de los vientos del W dominantes en la zona. Sobre el macizo del Deseado, los fragmentos de vidrio se mezclaron con sedimentos ricos en SiO2 y fueron adicionalmente, enriquecidos en este elemento hasta alcanzar el área de costa actual, rellenando las cuñas de hielo. La edad de los fragmentos de vidrio (17.300-17.400 cal yr BP) y de la capa arenosa afectada por las estructuras criogénicas (14.670±750 años BP) limitan al glacial tardío la formación de ambas generaciones de cuñas.Centro de Estudios Integrales de la Dinámica Exógen

Aislamiento de Escherichia coli enteropatógeno O157:H16 de un caso de diarrea infantil y sus contactos familiares en La Pampa, Argentina

ResumenEscherichia coli enteropatógeno (EPEC) es uno de los principales agentes de diarrea infantil aguda en los países en desarrollo. Se clasifica en típico (tEPEC) y atípico (aEPEC) sobre la base de la presencia del factor bfp, asociado a la adherencia y codificado en el plásmido pEAF. Se describe el aislamiento de E. coli O157:H16, de la categoría aEPEC, en un caso de diarrea sanguinolenta infantil y en sus contactos familiares. De las muestras de materia fecal del niño, de la madre, del padre y de la hermana se aisló E. coli O157:H16 eae-ɛ-positivo, sorbitol-positivo, β-glucuronidasa-positivo, sensible a los antimicrobianos ensayados, y negativo para los factores stx1, stx2, ehxA y bfp. Por XbaI-PFGE, todos los aislamientos presentaron el patrón de macrorrestricción AREXHX01.1040, con 100% de similitud. Es importante la vigilancia epidemiológica de los casos de diarrea asociados a E. coli O157 y sus contactos familiares, y la incorporación de técnicas para detectar los distintos patotipos de E. coli.AbstractEnteropathogenic Escherichia coli (EPEC) is a major causative agent of acute diarrhea in children in developing countries. This pathotype is divided into typical EPEC (tEPEC) and atypical EPEC (aEPEC), based on the presence of the bfp virulence factor associated with adhesion, encoded in the pEAF plasmid. In the present study, the isolation of aEPEC O157:H16 from a bloody diarrhea case in a child and his household contacts (mother, father and sister) is described. The strain was characterized as E. coli O157:H16 eae-ɛ-positive, sorbitol fermenter with β-glucuronidase activity, susceptible to all antimicrobials tested, and negative for virulence factors stx1, stx2, ehxA and bfp. XbaI-PFGE performed on all isolates showed the AREXHX01.1040 macrorestriction pattern, with 100% similarity. These results highlight the importance of epidemiological surveillance of E. coli O157-associated diarrhea cases identified in children and their family contacts, as well as the incorporation of molecular techniques that allow the detection of the different E. coli pathotypes

Investigation on the Loss of Taste and Smell and Consequent Psychological Effects: A Cross-Sectional Study on Healthcare Workers Who Contracted the COVID-19 Infection

The aim of this study was to investigate the correlation between psychological distress and taste and sense of smell dysfunctions on healthcare workers (HCW) who contracted the COVID-19 infection in the midst of the disease outbreak. Reports of sudden loss of taste and smell which persist even after recovery from COVID-19 infection are increasingly recognized as critical symptoms for COVID-19 infections. Therefore, we conducted a cross-sectional study on COVID-19 HCW (N = 104) who adhered to respond to a phone semistructured interview addressing the virus symptoms and associated psychological distress. Data were collected from June to September 2020. Findings confirm the association between experienced taste/olfactory loss and emotional distress and suggest that dysfunctions of taste and smell correlate positively with anxiety and depression. Furthermore, their psychological impact tends to persist even after the recovery from the disease, suggesting the need for appropriate psychological interventions to prevent people from developing more serious or long-lasting psychological disorders and, as far as HCW, to reduce the risk of work-related distress