High-affinity DNA binding sites for H-NS provide a molecular basis for selective silencing within proteobacterial genomes

The global transcriptional regulator H-NS selectively silences bacterial genes associated with pathogenicity and responses to environmental insults. Although there is ample evidence that H-NS binds preferentially to DNA containing curved regions, we show here that a major basis for this selectivity is the presence of a conserved sequence motif in H-NS target transcriptons. We further show that there is a strong tendency for the H-NS binding sites to be clustered, both within operons and in genes contained in the pathogenicity-associated islands. In accordance with previously published findings, we show that these motifs occur in AT-rich regions of DNA. On the basis of these observations, we propose that H-NS silences extensive regions of the bacterial chromosome by binding first to nucleating high-affinity sites and then spreading along AT-rich DNA. This spreading would be reinforced by the frequent occurrence of the motif in such regions. Our findings suggest that such an organization enables the silencing of extensive regions of the genetic material, thereby providing a coherent framework that unifies studies on the H-NS protein and a concrete molecular basis for the genetic control of H-NS transcriptional silencing

Voluntarily induced vomiting – A yoga technique to enhance pulmonary functions in healthy humans

Vomiting is a complex autonomic reflex orchestrated by several neurological centres in the brain. Vagus, the cranial nerve plays a key role in regulation of vomiting. Kunjal Kriya (Voluntarily Induced Vomiting), is a yogic cleansing technique which involves voluntarily inducing vomiting after drinking saline water (5%) on empty stomach. This study was designed with an objective to understand the effect of voluntary induced vomiting (ViV) on pulmonary functions in experienced practitioners and novices and derive its possible therapeutic applications. Eighteen healthy individuals volunteered for the study of which nine had prior experience of ViV while nine did not. Pulmonary function tests were performed before and after 10 min of rest following ViV. Analysis of Covariance was performed adjusted for gender and baseline values. No significant changes were observed across genders. The results of the present study suggest a significant increase in Slow Vital Capacity [F(1,13) = 5.699; p = 0.03] and Forced Inspiratory Volume in 1st Second [p = 0.02] and reduction in Expiratory Reserve Volume [F(1,13) = 5.029; p = 0.04] and Respiratory Rate [F(1,13) = 3.244, p = 0.09]. These changes suggest the possible role of ViV in enhancing the endurance of the respiratory muscles, decreased airway resistance, better emptying of lungs and vagal predominance respectively. We conclude that ViV when practiced regularly enhances the endurance of the respiratory muscles and decreases airway resistance. These findings also indicate need for scientific understanding of ViV in the management of motion sickness and restrictive pulmonary disorders like bronchitis and bronchial asthma. Keywords: Kunjala Kriya, Voluntarily induced vomiting, Pulmonary functions, Yoga, Kriy

Effect of yoga on adipokine levels among overweight and obese people: A systematic review

Background: Adipokines have an important role in the pathophysiology of overweight and obesity and associated inflammatory diseases. Objective: The present review aims to evaluate the role of Yoga on adipokines among people with overweight and obesity. Methods: Authors performed a systematic search for relevant research studies as per the PRISMA guidelines in Google Scholar, Medline/Pubmed, Scopus, Web of Science, PsychInfo electronic databases.Two independent authors conducted the selection of articles, data extraction, assessment of the risk of bias for individual studies. Any disagreements were resolved by discussion with the third author. Results: Eight randomized trials and four uncontrolled trials involving a total of 1054 participants were included. Yoga with varying frequencies was administered for different durations. The studied adipokines among overweight and obese were leptin, adiponectin, interleukin-6 (IL-6), Tumor necrosis factor-alpha (TNF-α), chemerin, visfatin, plasminogen activator inhibitor-1 (PAI-1), and transforming growth factor-beta (TGF-β). The methodological quality of the included studies was low to moderate on the Cochrane risk of bias tool and Newcastle-Ottawa Quality Assessment Scale. The higher the frequency and duration of Yoga practice, the more significant changes in the adipokine levels were seen. Conclusion: The present review indicates that Yoga practices positively impacts adipokines among people with overweight and obesity. However, the present study precludes the generalizability of results due to the methodological heterogeneity, the type of Yoga intervention, and settings

Homeostatic regulation of supercoiling sensitivity coordinates transcription of the bacterial genome

Regulation of cellular growth implies spatiotemporally coordinated programmes of gene transcription. A central question, therefore, is how global transcription is coordinated in the genome. The growth of the unicellular organism Escherichia coli is associated with changes in both the global superhelicity modulated by cellular topoisomerase activity and the relative proportions of the abundant DNA-architectural chromatin proteins. Using a DNA-microarray-based approach that combines mutations in the genes of two important chromatin proteins with induced changes of DNA superhelicity, we demonstrate that genomic transcription is tightly associated with the spatial distribution of supercoiling sensitivity, which in turn depends on chromatin proteins. We further demonstrate that essential metabolic pathways involved in the maintenance of growth respond distinctly to changes of superhelicity. We infer that a homeostatic mechanism organizing the supercoiling sensitivity is coordinating the growth-phase-dependent transcription of the genome