RESUMO
Additional strategies are needed to prevent and treat tuberculosis (TB). Although vitamin D may have antimycobacterial effects, it is unknown whether low vitamin D status confers a risk for active TB in African children. This case-control study assessed serum 25-hydroxyvitamin D (25(OH)D) concentration in children with and without active TB in Gaborone, Botswana. A total of 80 children under 2 years old with and without active TB, seen at hospitals and clinics in the greater Gaborone area between September 2010 and November 2012, were enrolled. Of these, 39 cases did not differ from the 41 controls in median 25(OH)D levels (P = 0.84). The 25(OH)D was < 20 ng/mL in 8/39 (21%) cases and 7/41 (17%) controls (P = 0.69, χ(2)). Univariate analyses of subject clinical characteristics (other than 25(OH)D levels) showed that any degree of weight loss was associated with a diagnosis of TB (P = 0.047). Other clinical characteristics, including age (P = 0.08) or weight below third percentile (P = 0.58), showed no association with TB. There was no significant difference in vitamin D status between children under 2 years old with and without active TB. Lower vitamin D status did not appear to be a risk factor for TB in this small Gaborone cohort.
Assuntos
Tuberculose/complicações , Tuberculose/epidemiologia , Deficiência de Vitamina D/complicações , Deficiência de Vitamina D/epidemiologia , Vitamina D/análogos & derivados , Botsuana/epidemiologia , Estudos de Casos e Controles , Feminino , Infecções por HIV/complicações , Infecções por HIV/epidemiologia , Humanos , Lactente , Masculino , Tuberculose/sangue , Vitamina D/sangue , Deficiência de Vitamina D/sangueRESUMO
Nitroxyl (HNO) donated by Angeli's salt activates uptake of Ca(2+) by the cardiac SR Ca(2+) pump (SERCA2a). To determine whether HNO achieves this by a direct interaction with SERCA2a or its regulatory protein, phospholamban (PLN), we measured its effects on SERCA2a activation (as reflected in dephosphorylation) using insect cell microsomes expressing SERCA2a with or without PLN (wild-type and Cys --> Ala mutant). The results show that activation of SERCA2a dephosphorylation by HNO is PLN-dependent and that PLN thiols are targets for HNO. We conclude that HNO produces a disulfide bond that alters the conformation of PLN, relieving inhibition of the Ca(2+) pump.