Promoter Methylation of LEP and LEPR before and after Bariatric Surgery: A Cross-Sectional Study

IntroductionDNA methylation constitutes one important epigenetic mechanism that regulates gene expression in human cells. With regard to obesity, bariatric surgery-induced weight loss has been associated with promoter methylation changes in several genes. Hyperleptinemia is a characteristic feature of obesity. The underlying regulating mechanisms have not yet been completely elucidated.MethodsWe investigated the methylation of the promoters of the leptin gene (LEP) and the leptin receptor gene (LEPR) as well as leptin expression in pre- and postbariatric surgery patients using a comparative cross-sectional design.ResultsOur results revealed significantly higher LEP promoter methylation patterns in prebariatric surgery patients compared to postoperatively. DNA methylation of the LEPR promoter was significantly higher in the postoperative group. Moreover, we found significantly higher leptin serum levels in patients before the bariatric surgery than afterwards.DiscussionThese findings strengthen the suggestion that there is an association between LEP expression and LEP methylation in obesity. We suggest that the epigenetic profile of LEP might be influenced by leptin serum levels in the form of a regulating feedback mechanism.     

Drug-Resistant Tuberculosis in HIV-Infected Persons: Italy 1999–2000

Abstract Background: Patients with HIV infection may be a valuable target for assessing the impact of drug-resistant tuberculosis (TB). Patients and Methods: An observational, prospective study was conducted in 96 infectious disease hospital units in Italy during 1999–2000. A total of 140 HIV-infected patients with diagnosis of TB and with an isolate tested for drug susceptibility entered the analysis. Drug resistance (DR) was defined as resistance to either isoniazid (INH) or rifampin (RIF), while multidrug resistance (MDR) was defined as resistance to INH and RIF. Results: A total of 117 (83.6%) episodes of TB were classified as new cases and 23 (16.4%) as previously treated cases. Prevalence of resistance to INH or RIF was 12.8% and 4.3% among new cases, and 17.4% and 26.1% among previously treated cases, respectively. Prevalence rates of DR and MDR were 14.5% and 2.6% among new cases and 30.4% and 12.5% among previously treated cases, respectively. No statistically significant risk factors associated with DR or MDR TB emerged in this analysis. Conclusion: High prevalence rates of DR and MDR are present among HIV-infected TB patients in Italy, in particular among previously treated cases.*Members of the GISTA–SIMIT Study Group and participating institutions are listed at the end of the paper.