In vitro transcription profiling of the σS subunit of bacterial RNA polymerase: re-definition of the σS regulon and identification of σS-specific promoter sequence elements

Specific promoter recognition by bacterial RNA polymerase is mediated by σ subunits, which assemble with RNA polymerase core enzyme (E) during transcription initiation. However, σ70 (the housekeeping σ subunit) and σS (an alternative σ subunit mostly active during slow growth) recognize almost identical promoter sequences, thus raising the question of how promoter selectivity is achieved in the bacterial cell. To identify novel sequence determinants for selective promoter recognition, we performed run-off/microarray (ROMA) experiments with RNA polymerase saturated either with σ70 (Eσ70) or with σS (EσS) using the whole Escherichia coli genome as DNA template. We found that Eσ70, in the absence of any additional transcription factor, preferentially transcribes genes associated with fast growth (e.g. ribosomal operons). In contrast, EσS efficiently transcribes genes involved in stress responses, secondary metabolism as well as RNAs from intergenic regions with yet-unknown function. Promoter sequence comparison suggests that, in addition to different conservation of the −35 sequence and of the UP element, selective promoter recognition by either form of RNA polymerase can be affected by the A/T content in the −10/+1 region. Indeed, site-directed mutagenesis experiments confirmed that an A/T bias in the −10/+1 region could improve promoter recognition by EσS

Nutritional Outcomes One Year after One Anastomosis Gastric Bypass Compared to Sleeve Gastrectomy

One Anastomosis Gastric Bypass (OAGB) and Sleeve Gastrectomy (SG) are the most common bariatric procedures performed worldwide. SG is a restrictive procedure whereas OAGB involves malabsorption as well, supposing a risk of deficiency development post OAGB. The aim of the study was to compare nutritional deficiencies and metabolic markers one year after the procedures, while adhering to the current protocols. Retrospective analysis was performed for data on 60 adults undergoing primary OAGB, compared to 60 undergoing primary SG. Mean pre-surgery BMI for SG was 42.7 kg/m2 and 43.3 kg/m2 for OAGB. A multidisciplinary team followed up with the patients at least 3 times during the first year. Mean weight loss was 39.0 kg for SG and 44.1 kg for OAGB. The OAGB group presented a significantly sharper decline in T.Chol and a trend for sharper LDL decrease; a higher increase in folate and a trend for a greater decrease in albumin and hemoglobin were observed in OAGB. For vitamin B12, D, iron and ferritin, no difference was observed between the treatment groups, although there were some in-group differences. Nutritional recommendations and adopted supplement plans minimize the risk of deficiencies and result in improvement in metabolic biomarkers one year after OAGB, which was comparable to SG

The influence of attractiveness and convenience cues on food appeal in adults with and without ADHD

Objective: previous research on adults with ADHD revealed high rates of overweight and obesity, as well as unhealthy diet habits. Other studies demonstrated that social-affective contexts can influence food choice. This study examines the sensitivity of adults with ADHD to cues of food attractiveness and convenience, for healthy and unhealthy foods. Method: one hundred and seventy-two university students with (n = 59) and without (n = 113) ADHD, aged 19–40, participated in the study. Participants rated the level of appeal of 32 pictures of healthy and unhealthy foods, which varied in the degree of attractiveness and convenience. Results: the findings reveal a higher level of appeal of attractive food items compared to non-attractive ones (p < .001), as well as of convenient compared to non-convenient food items (p = .005). Type of diagnostic group did not have an effect on the level of appeal. Conclusion: increasing the attractiveness and convenience of food items increased the level of appeal for both students with and without ADHD. These findings emphasize the importance of environmental health intervention to potentially reduce abnormal eating pattern in the ADHD adult population, which may contribute in preventing the reported higher risk of obesity in this population

Food perceptions in adults with and without ADHD

INTRODUCTION: Adults with attention-deficit/hyperactivity disorder (ADHD) have unhealthy eating habits, associated with overweight/obesity. We explored whether they present with different food-related benefit/risk perceptions, compared to those without ADHD.Methods: one hundred five university students with (n = 36) and without (n = 69) ADHD, aged 22-30, participated in the study. They rated the level of frequency and likelihood of food consumption, as well as the perceived attractiveness, convenience, and risk of 32 healthy and unhealthy food items.Results: the findings revealed significantly lower healthy/unhealthy food frequency consumption ratios for the ADHD group compared with the non-ADHD one but no differences in the ratios of estimated likelihood of food consumption and perceptions (attractiveness, convenience, and risk).Conclusions: the results of this study demonstrated a discrepancy between the eating behavior (more unhealthy eating patterns in adults with ADHD compared with controls) and their food-related perceptions (same perceptions regarding the benefit and risk of foods in both groups).</p

Advertising influences food choices of university students with ADHD

Objective: previous research in adults with ADHD showed high rates of obesity and unhealthy food choices. There is evidence that contextual cues, e.g., advertisements, influence food choices. This study assessed the sensitivity of university students with ADHD to advertised food.Method: university students (N = 457) with and without ADHD participated in a cafeteria field experiment. Food choices were examined in periods of advertising either healthy or unhealthy sandwiches. Results: the findings revealed that students with ADHD (1) chose less healthy food items; (2) were more influenced by advertising; (3) showed the same overall healthy food choices as controls when exposed to healthy advertising.Conclusion: university students with ADHD were more likely to opt for more unhealthy foods at the cafeteria but were also more influenced by advertising. Exposure to healthy food advertisements eliminated ADHD-related unhealthy food choices. As this population has strong association with unhealthy dietary patterns, it is important to continue the research of food cues and the influence on their eating habits.<br/

Insulin resistance: an independent risk factor for lung cancer?

Insulin resistance is closely associated with numerous metabolic disorders. Although studies have supported the importance of insulin resistance in carcinogenesis, the existing data have not established its relevance in the context of lung cancer. The aim of the present case-control study was to evaluate the association between insulin resistance and lung cancer after adjusting for possible confounders. Homeostasis model assessment of insulin resistance (HOMA-IR) and serum leptin and adiponectin levels were determined in 81 lung cancer cases and 162 age-and sex-matched controls; anthropometric and lifestyle variables were recorded. Mean HOMA-IR in the cases was more than 2-fold higher compared with the mean value of controls (P &lt; .001). Among controls, HOMA-IR correlated positively with serum leptin (r = 0.16; P = .04), body mass index (r = 0.43; 13 = .0001), and waist-to-hip ratio (r = 0.21; P = .01) but negatively with serum adiponectin (r = -0.29; P = .0002). As expected, smoking was associated with an approximately 10-fold increase in lung cancer risk in multiple logistic regression models. A positive association between HOMA-IR, treated as continuous variable, and lung cancer (odds ratio [OR] = 1.52, 95% confidence interval [CI]: 1.16-1.99, P = .002, model 1) was demonstrated, which persisted after adjustment for somatometric and lifestyle variables (OR = 2.36, 95% CI: 1.00-5.55, P =.05, model 2). When serum adiponectin was also taken into account, the association seemed fairly robust (OR = 2.58, 95% CI: 1.11-6.01, P = .03, model 3); on the contrary, when serum leptin was added, the association remained positive, but lost its statistical significance (OR = 1.76, 95% CI: 0.78-3.98, P = .17, model 4). In the fully adjusted model, HOMA-IR was still positively, but only marginally, associated with lung cancer risk (OR = 2.02, 95% CI: 0.88-4.65, P = .10, model 5). Insulin resistance may represent a meaningful risk factor for lung cancer. (C) 2011 Elsevier Inc. All rights reserved