Vitamin D, menopause, and aging: quo vadis?

Menopause and aging are associated with changes in circulating gonadal steroid hormones, insulin sensitivity, body composition, and also lifestyle and social coordinates. Vitamin D status influences different metabolic adjustments, aside from calcium-phosphorus and bone metabolism. The main blood marker used to measure endogenous vitamin D status is 25-hydroxyvitamin D. Aging is associated with increases in serum parathyroid hormone and alkaline phosphatase, and a decrease of serum calcium, phosphorus, and vitamin D metabolites. 25-Hydroxyvitamin D status is also influenced by the circannual rhythm of sun irradiation. Results of clinical association studies have not correlated with intervention trials, experimental studies, and/or meta-analyses regarding the role of vitamin D on different outcomes in women during their second half of life and the vitamin D supplementation dose needed to improve clinical endpoints. Discordant results have been related to the method used to measure vitamin D, the studied population (i.e., sociodemographics and ethnicity), study designs, and biases of analyses. Vitamin D supplementation with cholecalciferol or calcifediol may improve some metabolic variables and clinical outcomes in young postmenopausal and older women. Studies seem to suggest that calcifediol may have some advantages over other forms of vitamin D supplementation. Further studies are needed to define interventions with supplements and effective food fortification.

Síndrome constitucional con impotencia funcional de miembro inferior izquierdo en varón de 76 años / Constitutional syndrome with loss of functional capacity of the lower left limb in a 76-year old male

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Molecular characterization of a novel endo-beta-1,4-xylanase gene from the vascular wilt fungus Fusarium oxysporum.

A gene, xyl5, was identified from the tomato vascular wilt fungus Fusarium oxysporum f.sp. lycopersici, whose predicted amino acid sequence shows significant homology with family 11 xylanases. Expression of xyl5 was detected during growth both on xylan and cellulose substrates as carbon sources and on tomato vascular tissue. RT-PCR analysis revealed the presence of two different transcript sizes, resulting from differential splicing of the third intron. The 3'-untranslated region of the xyl5 transcript contained a region of homology to cellulose-binding domains, suggesting that such a domain may have been part of an ancestral XYL5 version. As shown by RT-PCR, xyl5 is expressed by F. oxysporum exclusively during the initial stages of infection in tomato roots. Targeted inactivation of xyl5 had no detectable effect on virulence.