Examining the Interaction of the Gut Microbiome with Host Metabolism and Cardiometabolic Health in Metabolic Syndrome

(1) Background: The microbiota-host cross-talk has been previously investigated, while its role in health is not yet clear. This study aimed to unravel the network of microbial-host interactions and correlate it with cardiometabolic risk factors. (2) Methods: A total of 47 adults with overweight/obesity and metabolic syndrome from the METADIET study were included in this cross-sectional analysis. Microbiota composition (151 genera) was assessed by 16S rRNA sequencing, fecal (m = 203) and plasma (m = 373) metabolites were profiled. An unsupervised sparse generalized canonical correlation analysis was used to construct a network of microbiota-metabolite interactions. A multi-omics score was derived for each cluster of the network and associated with cardiometabolic risk factors. (3) Results: Five multi-omics clusters were identified. Thirty-one fecal metabolites formed these clusters and were correlated with plasma sphingomyelins, lysophospholipids and medium to long-chain acylcarnitines. Seven genera from Ruminococcaceae and a member from the Desulfovibrionaceae family were correlated with fecal and plasma metabolites. Positive correlations were found between the multi-omics scores from two clusters with cholesterol and triglycerides levels. (4) Conclusions: We identified a correlated network between specific microbial genera and fecal/plasma metabolites in an adult population with metabolic syndrome, suggesting an interplay between gut microbiota and host lipid metabolism on cardiometabolic health.     

Factors associated with unprotected sexual intercourse with steady male, casual male, and female partners among men who have sex with men in Barcelona, Spain.

To increase understanding of the HIV epidemic among MSM in Barcelona, anonymous questionnaires were completed by 640 MSM recruited in the city in 2002. The prevalence of unprotected anal intercourse (UAI) with casual male partners in the prior 12 months was higher among self-reported HIV-positive men (confirmed through saliva testing) than among men who were HIV-negative or of unknown serostatus (35% vs. 20%, p < .01). The prevalence of UAI with steady male partners was substantially lower among HIV-positive men than other men (28% vs. 60%, p < .01). In multivariate analyses, UAI with casual partners was more likely among HIV-positive individuals; those who used drugs before sex; perceived less acceptance of their sexual orientation by family, friends, or coworkers; and were less concerned about HIV prevention because of antiretroviral therapy (ART). UAI with steady partners was more likely among HIV-negative men with seroconcordant partners, those living with a partner, and men less concerned about HIV prevention because of ART. Findings indicate a need for prevention programs targeting HIV-positive MSM in Barcelona. Attention to substance use and attitudes about HIV prevention are needed for MSM in general.     

Inhibition of hepatic cell nuclear DNA fragmentation by zinc in carbon tetrachloride-treated rats.

BACKGROUND/AIMS: The aims of this study were to ascertain: 1) whether hepatic cell DNA fragmentation is increased in rats with early stages of liver disease induced by carbon tetrachloride; 2) whether the inhibition of DNA cleavage is involved in the hepatoprotective effects of zinc; and 3) if relationships exist between DNA fragmentation and the onset of fibrosis in this experimental model. METHODS: Twenty-one treated rats and 23 controls were divided into two groups to receive either a standard diet or one supplemented with zinc. All the animals were sacrificed 1 week later for histological and biochemical assessments, which included a DNA fragmentation index, hepatic zinc and metallothionein concentrations, fibrosis measured by hepatic hydroxyproline concentration and plasma alanine aminotransferase activity. RESULTS: Hepatic cell DNA fragmentation was increased in rats with early hepatic fibrosis and the increase was independent of hepatocytolysis, as measured by alanine aminotransferase activity. Oral zinc administration inhibited hepatic cell DNA fragmentation in the treated rats and was proportional to the hepatic concentration of the metal. The mechanism of the zinc-mediated decrease in DNA cleavage was related to an increase in the hepatic metallothionein concentration. Hepatic cell DNA fragmentation was related to hydroxyproline concentration. CONCLUSIONS: Our results suggest that apoptosis may be involved in the early transformations occurring in the liver and which can lead to the initiation of cirrhosis. As such, the potential therapeutic use of zinc supplementation would warrant further investigation.     

Stacks of Microfabricated Structures as Scaffolds for Cell Culture and Tissue Engineering

The fabrication of microscopic 3-dimensional structures for directing and inducing cell proliferation, migration and differentiation is a prevailing goal in tissue engineering. We have developed microfluidic molding methods to generate proof-of-principle polyurethane microstructures containing holes as models of synthetic tissue scaffolds. Molding is achieved by injecting sub-milliliter quantities of polyurethane precursor into a network of capped polydimethylsiloxane microchannels. After curing of the polyurethane, the microchannels can be opened to release a solid polyurethane structure which replicates the structure of the microchannel network. The microchannels can be reused to generate many exact replicas which can be stacked. We were able to design stacks that mimic various bone architectures. 3-dimensional microtomographic images were used for the first time for visualization and quality control of the stacked microfabricated structures. The polyurethane structures are amenable to cell culture. This technology could potentially be applied to microfabricate implanTable 3-dimensional scaffolds of specified architecture and composition for tissue growth and regeneration.     

Prevalence of human immunodeficiency virus, Chlamydia trachomatis, and Neisseria gonorrhoeae and risk factors for sexually transmitted infections among immigrant female sex workers in Catalonia, Spain

OBJECTIVES: To determine the prevalence of human immunodeficiency virus (HIV), Chlamydia trachomatis (CT), and Neisseria gonorrhoeae (NG) among immigrant female sex workers (FSW) according to their geographic area of origin and identify possible risk factors independently associated with current infection with CT and/or NG. STUDY DESIGN: Cross-sectional study of 357 FSW in Catalonia in 2005. Information on sociodemographic and sex work characteristics, use of alcohol and drugs, sexual practices, and the use of social and health care services was collected. Oral fluid and urine samples were collected to determine the prevalence of HIV and CT/NG, respectively. Factors independently associated with CT/NG were assessed using multivariate logistic regression models. RESULTS: A total of 36.4% of women were from Eastern Europe, 34.5% from Latin America, and 29.1% from Africa. Overall CT and NG prevalence were 5.9% [95% confidence interval (CI): 3.7-8.9] and 0.6% (95% CI: 0.1-2.0), respectively. No differences were observed by geographic origin. Three African women were HIV positive (overall HIV prevalence was 0.8%, 95% CI: 0.2-2.4). In multivariate analysis, younger age and unprotected sex with clients were associated with the presence of CT/NG. CONCLUSIONS: The prevalence of sexually transmitted infections among FSW in Catalonia was lower than in other European countries. Even though the prevalence of HIV was only 0.8%, it could increase in the future given the high vulnerability of these women and their wide geographic mobility. It is necessary to continue with the work carried out by nongovernmental organizations (harm reduction programs, outreach programs, and safe sex workshops) as well as to facilitate the access to health centers, especially for the youngest women.     

A flow-cytometric method to study DNA fragmentation in lymphocytes.

A method to measure DNA fragmentation cell by cell in a cell population was implemented based on acridine orange procedure to determine DNA content of single cells by flow cytometry. Using this method it can be observed that the fragmentation process induced by irradiation in thymic cells occurs in a fraction of the population, thus indicating that this process is not evenly distributed over the total population, and that it corresponds to a fast phenomenon in which the cells suddenly lose DNA material.     

Évaluation d''une batterie de tests pour la sélection des jointeurs d''une firme hydroélectrique

The purpose of this study was to evaluate the specificity, the reliability and the discriminative power of 12 tests that could be used to select electrical utility workers-splicers. The work of electrical utility workers-splicers consists of building, repair and modification of the underground power grid or lines. The first requirement to retain a test was its reliability (standard error of the estimate arbitrarily set to or lower than 12%). With 13 unexperienced subjects, only four tests met that criterion. The remaining original tests, although specific to the task, show very high test-retest variability (SEE = 15.7 to 107.7%) and were thus rejected on that basis alone. The test-retest data also showed a learning process for many of the tests. Theoretically, that would have to be considered when choosing a pass or fail criterion. From a practical point of view, however, the learning process was observed mostly in the agility tests, which were the same as those rejected due to their low reliability. In the second phase of this study, the discriminative power of the tests was established in comparing inexperienced male subjects (n = 13) to experienced male workers (n = 16). Again, significant differences were found for agility tests that were already rejected. For the four reliability tests, with high physical requirements regarding strength or muscular endurance, there was a significant difference for only one test, indicating a lack of discrimination for the other three. As a result, a logical decision would be to reject those tests. However, considering that these tests were “physical” rather than involving “motor abilities”, the experience of the workers did not make any difference. It is important to underline that inexperienced subjects were physically fit physical education students, which may explain why they scored as high as the workers in these tests. In other words, the unexperienced subjects barely passed these tests. Ideally, it would have been preferable to compare poor and good workers but that was not possible due to adminitrative problems. The correlations among test items was determined in order to eliminate tests having high levels of covariance. None of the retained reliability tests were highly correlated but all were retained as valid tests. In general however, this study has shown the difficulties in constructing task-specific tests. Too many of the original tests, mostly “motor abilities” tests, had to be rejected due to low reliability. Other tests would need to be designed and tested again in order to have a complete battery to mimic the essential aspects of this task.