Functional consequences of microbial shifts in the human gastrointestinal tract linked to antibiotic treatment and obesity

The microbiomes in the gastrointestinal tract (GIT) of individuals receiving antibiotics and those in obese subjects undergo compositional shifts, the metabolic effects and linkages of which are not clearly understood. Herein, we set to gain insight into these effects, particularly with regard to carbohydrate metabolism, and to contribute to unravel the underlying mechanisms and consequences for health conditions. We measured the activity level of GIT carbohydrate-active enzymes toward 23 distinct sugars in adults patients (n = 2) receiving 14-d β-lactam therapy and in obese (n = 7) and lean (n = 5) adolescents. We observed that both 14 d antibiotic-treated and obese subjects showed higher and less balanced sugar anabolic capacities, with 40% carbohydrates being preferentially processed as compared with non-treated and lean patients. Metaproteome-wide metabolic reconstructions confirmed that the impaired utilization of sugars propagated throughout the pentose phosphate metabolism, which had adverse consequences for the metabolic status of the GIT microbiota. The results point to an age-independent positive association between GIT glycosidase activity and the body mass index, fasting blood glucose and insulin resistance (r2 ≥ 0.95). Moreover, antibiotics altered the active fraction of enzymes controlling the thickness, composition and consistency of the mucin glycans. Our data and analyses provide biochemical insights into the effects of antibiotic usage on the dynamics of the GIT microbiota and pin-point presumptive links to obesity. The knowledge and the hypotheses generated herein lay a foundation for subsequent, systematic research that will be paramount for the design of “smart” dietary and therapeutic interventions to modulate host-microbe metabolic co-regulation in intestinal homeostasis

Differential Effects of Antibiotic Therapy on the Structure and Function of Human Gut Microbiota

The human intestinal microbiota performs many essential functions for the host. Antimicrobial agents, such as antibiotics (AB), are also known to disturb microbial community equilibrium, thereby having an impact on human physiology. While an increasing number of studies investigate the effects of AB usage on changes in human gut microbiota biodiversity, its functional effects are still poorly understood. We performed a follow-up study to explore the effect of ABs with different modes of action on human gut microbiota composition and function. Four individuals were treated with different antibiotics and samples were taken before, during and after the AB course for all of them. Changes in the total and in the active (growing) microbiota as well as the functional changes were addressed by 16S rRNA gene and metagenomic 454-based pyrosequencing approaches. We have found that the class of antibiotic, particularly its antimicrobial effect and mode of action, played an important role in modulating the gut microbiota composition and function. Furthermore, analysis of the resistome suggested that oscillatory dynamics are not only due to antibiotic-target resistance, but also to fluctuations in the surviving bacterial community. Our results indicated that the effect of AB on the human gut microbiota relates to the interaction of several factors, principally the properties of the antimicrobial agent, and the structure, functions and resistance genes of the microbial community

Allergen sensitization linked to climate and age, not to intermittent-persistent rhinitis in a cross-sectional cohort study in the (sub)tropics

Background: Allergen exposure leads to allergen sensitization in susceptible individuals and this might influence allergic rhinitis (AR) phenotype expression. We investigated whether sensitization patterns vary in a country with subtropical and tropical regions and if sensitization patterns relate to AR phenotypes or age. Methods: In a national, cross-sectional study AR patients (2-70 y) seen by allergists underwent blinded skin prick testing with a panel of 18 allergens and completed a validated questionnaire on AR phenotypes. Results: 628 patients were recruited. The major sensitizing allergen was house dust mite (HDM) (56%), followed by Bermuda grass (26%), ash (24%), oak (23%) and mesquite (21%) pollen, cat (22%) and cockroach (21%). Patients living in the tropical region were almost exclusively sensitized to HDM (87%). In the central agricultural zones sensitization is primarily to grass and tree pollen. Nationwide, most study subjects had perennial (82.2%), intermittent (56.5%) and moderate-severe (84.7%) AR. Sensitization was not related to the intermittent-persistent AR classification or to AR severity; seasonal AR was associated with tree (p < 0.05) and grass pollen sensitization (p < 0.01). HDM sensitization was more frequent in children (0-11 y) and adolescents (12-17 y) (subtropical region: p < 0.0005; tropical region p < 0.05), but pollen sensitization becomes more important in the adult patients visiting allergists (Adults vs children + adolescents for tree pollen: p < 0.0001, weeds: p < 0.0005). Conclusions: In a country with (sub)tropical climate zones SPT sensitization patterns varied according to climatological zones; they were different from those found in Europe, HDM sensitization far outweighing pollen allergies and Bermuda grass and Ash pollen being the main grass and tree allergens, respectively. Pollen sensitization was related to SAR, but no relation between sensitization and intermittent-persistent AR or AR severity could be detected. Sensitization patterns vary with age (child HDM, adult pollen). Clinical implications of our findings are dual: only a few allergens –some region specific- cover the majority of sensitizations in (sub)tropical climate zones. This is of major importance for allergen manufacturers and immunotherapy planning. Secondly, patient selection in clinical trials should be based on the intermittent-persistent and severity classifications, rather than on the seasonal-perennial AR subtypes, especially when conducted in (sub)tropical countries

Assimilation or Consciousness: Perceptions of U.S. Society Among Recent Latin American Immigrants to the United States

Two competing views of determinants of immigrants' perceptions of U.S. society and perceptions of discrimination against their own group are examined. Assimilation theory suggests a process leading to lesser discrimination and a more favorable evaluation of the host society as immigrants' economic position, and their knowledge of the culture and language improve. More recent conflict theories indicate a possible reversal in this causal sequence: greater familiarity with the culture and language and some economic advancement can lead to greater consciousness of the reality of discrimination and a more critical appraisal of the host society. These competing perspectives are examined on samples of Cuban and Mexican immigrants interviewed at the moment of arrival in the U.S. and reinterviewed three years after. Bivariate and multivariate regression results are mixed, but lean definitely in the direction of the conflictlconsciousness hypothesis. A LISREL model of immigrants' perceptions of society and discrimination confirms the basic similarity of causal effects across the two immigrant groups and the general agreement of those effects with conflict theory predictions. Implications of these findings are discussed

Alteraciones cardiovasculares en pacientes en hemodiálisis

En la insuficiencia renal crónica (IRC) y en los pacientes en diálisis hay múltiples factores que alteran la función cardíaca y son las complicaciones cardiovasculares la principal causa de muerte en estos pacientes. Se realizó un estudio cardiovascular a los 20 pacientes que se encuentran en hemodiálisis en el servicio de Nefrología del Hospital de Centro Habana que consistía en examen físico cardiovascular, electrocardiograma, telecardiograma, ecocardiograma, además de hemograma y lipidograma. Los resultados indican una alta presencia de soplos e hipertensión arterial en el examen físico. El 50 % presenta hipertrofia ventricular izquierda en el electrocardiograma y confirmada con el ecocardiograma; no hubo diferencia importante en la relación entre triglicéridos elevados con la presencia de alteraciones cardiovasculares, pero sí con el colesterol alto y hemoglobina inferior a 70 g/L. Alta incidencia de alteraciones cardiovasculares en pacientes que llevan más de un año en hemodiálisis.<br>In chronic kidney failure (CKF) and in dialysis patients there are multiple factors altering the heart function. The cardiovascular complications are the main cause of death among these patients. A cardiovascular study was conducted in 20 hemodialysis patients at the Nephrology Service of the Centro Habana Hospital. The study consisted in cardiovascular physical examination, electrocardiogram, telecardiogram, echocardiogram, hemogram and lipids count. The results showed a high presence of murmurs and arterial hypertension on the physical examination. 50 % presented left ventricular hypertrophia on the EKG that was confirmed by the echocardiogram. There were no significant differences in the relation between elevated triglycerides and the presence of cardiovascular alterations, but important differences were found between high colesterol and haemoglobin lower then 70 g/l. It was observed a high incidence of cardiovascular alterations among patients that had been on hemodialysis for more than a year

Oportunidades de negocio en la apertura de emprendimientos en la zona sierra de la Provincia de Bolívar

El emprendimiento se ha convertido en un elemento de la cotidianeidad posibilitando la mejora de la calidad de vida de las personas, realizándose en el Ecuador estudios al respecto. Sin embargo, en la Zona Sierra de la provincia de Bolívar no se reportan análisis sobre el tema. El objetivo de la investigación es la determinación de la incidencia de las oportunidades de negocio (los factores externos), o necesidades sociales (motivaciones personales) en la apertura de emprendimientos en la Zona Sierra de la provincia Bolívar. El estudio desarrollado ha sido de tipo descriptivo, con un diseño no experimental. Se consideró una muestra estratificada de 747 personas, utilizando como instrumento el cuestionario, con una escala ordinal del tipo multivariado y de opciones múltiples. Los resultados permiten concluir que en los tres cantones de la Zona Sierra de la provincia Bolívar predominan las necesidades sociales por encima de las oportunidades de negocios para iniciar un emprendimiento, lo que constituye una regularidad de aquellas regiones donde imperan carencias de tipo económica social.

Efficient cycloaddition of arynes to carbon nanotubes under microwave irradiation

The functionalization of single-wall carbon nanotubes (SWCNT) by cycloaddition reactions with arynes under microwave irradiation has been studied. The efficiency of the functionalization was monitored by XPS, FTIR and Raman spectroscopies, TGA and HR-TEM. All experimental results point to the formation of SWCNT with a high degree of functionalization, with mass increases ranging from 6.4% to 15.1% depending on the aryne substitution.This work was supported by the Ministry of Economy and Innovation of Spain, (MICINN, CTQ2010-17498, CTQ2010- 18208 and CTQ2010-11423-E, PLE2009-0038 and ConsoliderIngenio Projects HOPE CSD2007-00007), Xunta de Galicia (10PXIB2200222PR) and FEDER. A. C. thanks the MEC for the award of an FPU fellowshipPeer Reviewe