The loss of pancreatic islet NADPH oxidase (NOX)2 improves islet transplantation

Islet transplantation is a promising treatment strategy for type 1 diabetes mellitus (T1DM) patients. However, oxidative stress-induced graft failure due to an insufficient revascularization is a major problem of this therapeutic approach. NADPH oxidase (NOX)2 is an important producer of reactive oxygen species (ROS) and several studies have already reported that this enzyme plays a crucial role in the endocrine function and viability of β-cells. Therefore, we hypothesized that targeting islet NOX2 improves the outcome of islet transplantation. To test this, we analyzed the cellular composition and viability of isolated wild-type (WT) and Nox2-/- islets by immunohistochemistry as well as different viability assays. Ex vivo, the effect of Nox2 deficiency on superoxide production, endocrine function and anti-oxidant protein expression was studied under hypoxic conditions. In vivo, we transplanted WT and Nox2-/- islets into mouse dorsal skinfold chambers and under the kidney capsule of diabetic mice to assess their revascularization and endocrine function, respectively. We found that the loss of NOX2 does not affect the cellular composition and viability of isolated islets. However, decreased superoxide production, higher glucose-stimulated insulin secretion as well as expression of nuclear factor erythroid 2-related factor (Nrf)2, heme oxygenase (HO)-1 and superoxide dismutase 1 (SOD1) was detected in hypoxic Nox2-/- islets when compared to WT islets. Moreover, we detected an early revascularization, a higher take rate and restoration of normoglycemia in diabetic mice transplanted with Nox2-/- islets. These findings indicate that the suppression of NOX2 activity represents a promising therapeutic strategy to improve engraftment and function of isolated islets.

Predictors of adherence to tuberculosis treatment in a supervised therapy programme for prisoners before and after release. Study Group of Adherence to Tuberculosis Treatment of Prisoners

The prison population is a high-risk group for tuberculosis (TB). This investigation aimed to study predictive factors of treatment adherence among prisoners involved in a pilot programme of supervised treatment. The study included TB patients from the Men's Penitentiary Center of Barcelona (MPCB) in 1995. Directly observed therapy (DOT) was carried out in the infirmary or in a methadone programme. Released prisoners were referred to the municipal maintenance methadone programmes (MMP) and other social resources. Incentives and enablers were used to improve compliance (economic aid for nutritional and housing needs, methadone programmes and admittance to a sociosanitary centre). The outcome of the patients' adherence was classified as follows: completed, defaulted, dead or transferred out. Factors associated with adherence were investigated through logistic regression. The programme included 62 patients, 43 of whom were intravenous drug users (IVDU) and 46 were infected with the human immunodeficiency virus (HIV). Nineteen had previously had TB and 32 were released from prison during TB treatment. Overall adherence was 89%; 97% among those who completed treatment in prison, and 79% among those who completed treatment outside prison (p=0.05). Ninety-five per cent of IVDU in an MMP completed treatment. Homeless or alcoholic exprisoners completed treatment only if they were admitted to sociosanitary centres. DOT throughout treatment resulted in better adherence (odds ratio (OR)= 16.80; confidence interval (CI): 2.42-116.2)). Those who were incarcerated throughout treatment also showed better adherence (OR= 7.36; CI: 0.79-48.16). Antituberculosis treatment adherence in prisoners was high even after release with adequate co-ordination among intrapenitentiary and extrapenitentiary programmes. Maintenance methadone programmes proved very useful in intravenous drug users, as did admittance to sociosanitary centres for indigent or alcoholic exprisoners undergoing treatment.