Background Previous studies suggest that l -arginine, an amino acid and a substrate of nitric oxide synthase, may have blood pressure (BP)-lowering effect. Because some studies were performed with ...limited number of patients with hypertension and therefore limited statistical power with sometimes inconsistent results, we aimed to examine the effect of oral l -arginine supplementation on BP by conducting a meta-analysis of randomized, double-blind, placebo-controlled trials. Methods PubMed, Cochrane Central Register of Controlled Trials, and the ClinicalTrials.gov databases were searched through June 2011 to identify randomized, double-blind, placebo-controlled trials of oral l -arginine supplementation on BP in humans. We also reviewed reference lists of obtained articles. Either a fixed-effects or, in the presence of heterogeneity, a random-effects model was used to calculate the combined treatment effect. Results We included 11 randomized, double-blind, placebo-controlled trials involving 387 participants with oral l -arginine intervention ranging from 4 to 24 g/d. Compared with placebo, l -arginine intervention significantly lowered systolic BP by 5.39 mm Hg (95% CI −8.54 to −2.25, P = .001) and diastolic BP by 2.66 mm Hg (95% CI −3.77 to −1.54, P < .001). Sensitivity analyses restricted to trials with a duration of 4 weeks or longer and to trials in which participants did not use antihypertensive medications yielded similar results. Meta-regression analysis suggested an inverse, though insignificant ( P = .13), relation between baseline systolic BP and net change in systolic BP. Conclusions This meta-analysis provides further evidence that oral l -arginine supplementation significantly lowers both systolic and diastolic BP.
Abstract
The prediction utility of Framingham Risk Score in populations with low conventional cardiovascular risk burden is limited, particularly among women. Gender-specific markers to predict ...cardiovascular risk in overtly healthy people are lacking. In this study we hypothesize that postprandial responses triggered by a high-calorie meal test differ by gender in their ability to triage asymptomatic subjects into those with and without subclinical atherosclerosis. A total of 101 healthy Chinese subjects (46 females, 55 males) at low risk of coronary heart disease completed the study. Subjects underwent cardiovascular imaging and postprandial blood phenotyping after consuming a standardized macronutrient meal. Prediction models were developed using logistic regression and subsequently subjected to cross-validation to obtain a de-optimized receiver operating characteristic (ROC) curve. Distinctive gender differences in postprandial trajectories of glucose, lipids and inflammatory markers were observed. We used gender-specific association with different combinations of postprandial predictors to develop 2 models for predicting risk of subclinical atherosclerosis in males (ROC AUC = 0.7867, 95% CI 0.6567, 0.9166) and females (ROC AUC = 0.9161, 95% CI 0.8340, 0.9982) respectively. We report novel postprandial models for predicting subclinical atherosclerosis in apparently healthy Asian subjects using a gender-specific approach, complementing the conventional Framingham Risk Score.
Clinical Trial Registration
: The trial was registered at clinicaltrials.gov as NCT03531879.
Bifidobacteria are Gram-positive prokaryotes that naturally colonize the human gastrointestinal tract (GIT) and vagina. Although not numerically dominant in the complex intestinal microflora, they ...are considered as key commensals that promote a healthy GIT. We determined the 2.26-Mb genome sequence of an infant-derived strain of Bifidobacterium longum, and identified 1,730 possible coding sequences organized in a 60%-GC circular chromosome. Bioinformatic analysis revealed several physiological traits that could partially explain the successful adaptation of this bacteria to the colon. An unexpectedly large number of the predicted proteins appeared to be specialized for catabolism of a variety of oligosaccharides, some possibly released by rare or novel glycosyl hydrolases acting on "nondigestible" plant polymers or host-derived glycoproteins and glycoconjugates. This ability to scavenge from a large variety of nutrients likely contributes to the competitiveness and persistence of bifidobacteria in the colon. Many genes for oligosaccharide metabolism were found in self-regulated modules that appear to have arisen in part from gene duplication or horizontal acquisition. Complete pathways for all amino acids, nucleotides, and some key vitamins were identified; however, routes for Asp and Cys were atypical. More importantly, genome analysis provided insights into the reciprocal interactions of bifidobacteria with their hosts. We identified polypeptides that showed homology to most major proteins needed for production of glycoprotein-binding fimbriae, structures that could possibly be important for adhesion and persistence in the GIT. We also found a eukaryotic-type serine protease inhibitor (serpin) possibly involved in the reported immunomodulatory activity of bifidobacteria.
Nutrition is closely related to the health of the elderly population. This study aimed to provide a comprehensive picture of the nutrition status of elderly Chinese and its related dietary, ...geographical, and socioeconomic factors.
A total of 13,987 ≥ 60-year-old persons from the 2010–2013 Chinese National Nutrition and Health Survey were included to evaluate various aspects of malnutrition, including underweight, overweight or obesity, and micronutrient inadequacy.
Overall, the prevalence of obesity, overweight, and underweight was 12.4%, 34.8%, and 5.7%, respectively, with disparities both geographically and socioeconomically. The prevalence of underweight was higher among the older old (≥ 75 years), rural residents and those with low income, with low education status, and residing in undeveloped West areas. More than 75% of the elderly do not meet the Dietary Reference Intakes for vitamins A, B1, B2, and E, folate, calcium, selenium, potassium, biotin, and choline, with the prevalence of inadequate intake increasing with age for most nutrients. At the population level, the mean intakes of numerous food groups did not meet the recommendations by the Chinese Dietary Guideline.
Obesity epidemic, inadequacy of micronutrient intake, and high prevalence of underweight and anemia in susceptible older people are the major nutrition challenges for the rapidly aging population in China.
Lactobacillus johnsonii NCC 533 is a member of the acidophilus group of intestinal lactobacilli that has been extensively studied for their "probiotic" activities that include, pathogen inhibition, ...epithelial cell attachment, and immunomodulation. To gain insight into its physiology and identify genes potentially involved in interactions with the host, we sequenced and analyzed the 1.99-Mb genome of L. johnsonii NCC 533. Strikingly, the organism completely lacked genes encoding biosynthetic pathways for amino acids, purine nucleotides, and most cofactors. In apparent compensation, a remarkable number of uncommon and often duplicated amino acid permeases, peptidases, and phosphotransferase-type transporters were discovered, suggesting a strong dependency of NCC 533 on the host or other intestinal microbes to provide simple monomeric nutrients. Genome analysis also predicted an abundance (>12) of large and unusual cell-surface proteins, including fimbrial subunits, which may be involved in adhesion to glycoproteins or other components of mucin, a characteristic expected to affect persistence in the gastrointestinal tract (GIT). Three bile salt hydrolases and two bile acid transporters, proteins apparently critical for GIT survival, were also detected. In silico genome comparisons with the >95% complete genome sequence of the closely related Lactobacillus gasseri revealed extensive synteny punctuated by clear-cut insertions or deletions of single genes or operons. Many of these regions of difference appear to encode metabolic or structural components that could affect the organisms competitiveness or interactions with the GIT ecosystem.
Serpins form a large class of protease inhibitors involved in regulation of a wide spectrum of physiological processes. Recently identified prokaryotic members of this protein family may provide a ...key to the evolutionary origins of the unique serpin fold and the associated inhibitory mechanism. We performed a biochemical characterization of a serpin from Bifidobacterium longum, an anaerobic Gram-positive bacterium that naturally colonizes human gastrointestinal tract. The B. longum serpin was shown to efficiently inhibit eukaryotic elastase-like proteases with a stoichiometry of inhibition close to 1. Porcine pancreatic elastase and human neutrophil elastase were inhibited with the second order association constants of 4.7 × 104m-1 s-1 and 2.1 × 104m-1 s-1, respectively. The B. longum serpin is expected to be active in the gastrointestinal tract, because incubation of the purified recombinant serpin with mouse feces produces a stable covalent serpin-protease adduct readily detectable by SDS-PAGE. Bifidobacteria may encounter both pancreatic elastase and neutrophil elastase in their natural habitat and protection against exogenous proteolysis may play an important role in the interaction between these commensal bacteria and their host.
Faced with global warming, the surface area of coffee cultivation regions is expected to diminish significantly in the near future. As a result, new varieties or agronomical practices improving ...drought tolerance need to be found. The aim of this work is to characterize drought tolerance of
Coffea canephora
genotypes and their reciprocal grafted plants with physiological tools and biochemical analyses. Under greenhouse conditions, control plants (sensitive or tolerant) and reciprocal grafted plants submitted to 14 days of water deprivation show variations of the monitored parameters, such as soil and leaf water potential, stomatal conductance, and osmoprotectant compounds (sugars, polyols, amino acids). The variations observed confirm the differences between the phenotypes defined as drought-tolerant and drought-sensitive. Reciprocal grafting shows enhanced and contrasting situations. A sensitive clone grafted onto tolerant rootstock presents higher tolerance to drought and physiological or biochemical parameters similar to a drought-tolerant clone. The opposite is observed for tolerant clones grafted onto a sensitive one. More contrasted results are obtained with glucose, fructose, proline, and mannitol content which could be used as indicators for drought tolerance. Our finding shows strong variability for drought tolerance in our Robusta clones and demonstrates the impact of grafting on physiological and biochemical parameters linked to drought tolerance. The use of drought-tolerant rootstock leads to better regulation of water management and biochemical composition of the scion in drought-sensitive clones. This could be an approach to improving drought tolerance of
Coffea canephora
genotypes and to limiting the impact of global warming on coffee farming.
By using cryo-scanning electron microscopy and quantification with lectin-conjugated probes, we have detected the production of exopolysaccharides (EPS) in Bifidobacterium animalis subsp. lactis in ...the presence of bile. In addition, the expression of gtf01207, which codifies a putative priming glycosyltransferase involved in EPS synthesis, was induced by bile.
PDF
