32 research outputs found
Low fruit consumption and folate deficiency are associated with LINE-1 hypomethylation in women of a cancer-free population
Characterization of the early steps of human parvovirus B19 infection
The early steps of human parvovirus B19 (B19V) infection were investigated in UT7/Epo cells. B19V and its receptor globoside (Gb4Cer) associate with lipid rafts, predominantly of the noncaveolar type. Pharmacological disruption of the lipid rafts inhibited infection when the drug was added prior to virus attachment but not after virus uptake. B19V is internalized by clathrin-dependent endocytosis and spreads rapidly throughout the endocytic pathway, reaching the lysosomal compartment within minutes, where a substantial proportion is degraded. B19V did not permeabilize the endocytic vesicles, indicating a mechanism of endosomal escape without apparent membrane damage. Bafilomycin A(1) (BafA1) and NH(4)Cl, which raise endosomal pH, blocked the infection by preventing endosomal escape, resulting in a massive accumulation of capsids in the lysosomes. In contrast, in the presence of chloroquine (CQ), the transfer of incoming viruses from late endosomes to lysosomes was prevented; the viral DNA was not degraded; and the infection was boosted. In contrast to the findings for untreated or BafA1-treated cells, the viral DNA was progressively associated with the nucleus in CQ-treated cells, reaching a plateau by 3 h postinternalization, a time coinciding with the initiation of viral transcription. At this time, more than half of the total intracellular viral DNA was associated with the nucleus; however, the capsids remained extranuclear. Our studies provide the first insight into the early steps of B19V infection and reveal mechanisms involved in virus uptake, endocytic trafficking, and nuclear penetration
Method for the validation and uncertainty estimation of tocopherol analysis applied to soybean oil with addition of spices and TBHQ
The tocopherol contents of refined soybean oil with the addition of rosemary, oregano, garlic, annatto seeds and TBHQ was evaluated during storage at 25 °C and 35 °C for twelve months, in comparison with a control soybean oil without the antioxidant addition. The method proposed to assess the tocopherol content was validated and the uncertainty estimation was determined. The method presented adequate linearity and precision, accuracy between 93% and 103% and expanded uncertainty of 2%. The contents of α-, Îł- and ÎŽ-tocopherols of all the tested soybean oils remained constant during the storage at 25 °C and 35 °C regardless of antioxidant addition, while ÎČ-tocopherol content decreased. The addition of a mixture of rosemary, oregano, garlic and annatto seeds increased the concentration of Îł- and ÎŽ-tocopherol. The oil with spices presented a similar behavior to that of the oil with the addition of TBHQ.<br><br>La concentraciĂłn de tocoferoles en aceite de soja refinado (muestra control), aceite de soja adicionado de romero, orĂ©gano, ajo, semilla de achiote y TBHQ fueron cuantificados durante el almacenamiento durante 12 meses a 25°C y 35°C. El mĂ©todo propuesto para medir tocoferoles fue validado y determinada la incertidumbre. Este mĂ©todo presentĂł linealidad y precisiĂłn adecuadas, exactitud entre 93% y 103% ademĂĄs de una incertidumbre expandida de 2%. Las cantidades de α-, Îł- y ÎŽ-tocoferol en el aceite de soja refinado, aceite de soja adicionado de condimentos y aceite de soja adicionado con TBHQ se mantuvieron constantes durante el almacenamiento a 25°C y 35°C con excepciĂłn del ÎČ-tocoferol el cual disminuyĂł. El aceite de soja adicionado de condimentos (romero, orĂ©gano, ajo, y semilla de achiote) presentĂł mayores concentraciones de Îł- y ÎŽ-tocoferol en comparaciĂłn con el aceite de soja refinado utilizado como control. El aceite de soja adicionado de condimentos presentĂł un comportamiento semejante al aceite de soja adicionado de TBHQ
Sclerostin regulation, microarchitecture, and advanced glycation end-products in the bone of elderly women with type 2 diabetes
Increased circulating sclerostin and accumulation of advanced glycation endâproducts (AGEs) are two potential mechanisms underlying low bone turnover and increased fracture risk in type 2 diabetes (T2D). Whether the expression of the sclerostinâencoding SOST gene is altered in T2D, and whether it is associated with AGEs accumulation or regulation of other bone formationârelated genes is unknown. We hypothesized that AGEs accumulate and SOST gene expression is upregulated in bones from subjects with T2D, leading to downregulation of bone forming genes (RUNX2 and osteocalcin) and impaired bone microarchitecture and strength. We obtained bone tissue from femoral heads of 19 T2D postmenopausal women (mean HbA1c 6.5%) and 73 ageâ and BMIâcomparable nonâdiabetic women undergoing hip replacement surgery. Despite similar bone mineral density (BMD) and biomechanical properties, we found a significantly higher SOST (p=0.006) and a parallel lower RUNX2 (p=0.025) expression in T2D compared with nonâdiabetic subjects. Osteocalcin gene expression did not differ between T2D and nonâdiabetic subjects, as well as circulating osteocalcin and sclerostin levels. We found a 1.5âfold increase in total bone AGEs content in T2D compared with nonâdiabetic women (364.8±78.2 vs. 209.9±34.4 ÎŒg quinine/g collagen, respectively; p<0.001). AGEs bone content correlated with worse bone microarchitecture, including lower volumetric BMD (r=â0.633; p=0.02), BV/TV (r=â0.59; p=0.033) and increased trabecular separation/spacing (r=â0.624; p=0.023). In conclusion, our data show that even in patients with good glycemic control, T2D affects the expression of genes controlling bone formation (SOST and RUNX2). We also found that accumulation of AGEs is associated with impaired bone microarchitecture. We provide novel insights that may help understand the mechanisms underlying bone fragility in T2D