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Dehydration reduces stroke volume and cardiac output during exercise because of impaired cardiac filling and venous return, not left ventricular function
Dehydration accrued during intense prolonged wholeâbody exercise in the heat compromises peripheral blood flow and cardiac output (urn:x-wiley:2051817X:media:phy214433:phy214433-math-0001). A markedly reduced stroke volume (SV) is a key feature of the dehydrationâinduced cardiovascular strain, but whether the lower output of the heart is mediated by peripheral or cardiac factors remains unknown. Therefore, we repeatedly quantified left ventricular (LV) volumes, LV mechanics (LV twist, a marker of systolic muscle function, and LV untwisting rate, an independent marker of LV muscle relaxation), left intraâventricular pressure gradients, blood volume and peripheral blood flow during 2 hr of cycling in the heat with and without dehydration (DEH: 4.0 ± 0.2% body mass loss and EUH: euhydration control, respectively) in eight participants (three females and five males). While brachial and carotid blood flow, blood volume, SV, LV endâdiastolic volume (LVEDV), cardiac filling time, systemic vascular conductance and urn:x-wiley:2051817X:media:phy214433:phy214433-math-0002 were reduced in DEH compared to EUH after 2 hr, LV twist and untwisting rate tended to be higher (p = .09 and .06, respectively) and intraâventricular pressure gradients were not different between the two conditions (p = .22). Furthermore, LVEDV in DEH correlated strongly with blood volume (r = .995, p < .01), head and forearms beat volume (r = .98, p < .05), and diastolic LV filling time (r = .98, p < .05). These findings suggest that the decline in SV underpinning the blunted urn:x-wiley:2051817X:media:phy214433:phy214433-math-0003 with exerciseâinduced dehydration is caused by compromised LV filling and venous return, but not intrinsic systolic or diastolic LV function
The Cochrane Skin Group: a vanguard for developing and promoting evidence-based dermatology
Aim
The Cochrane Skin Group (CSG) is part of the international Cochrane Collaboration (http://www.cochrane.org/). The CSG prepares, maintains and disseminates high quality evidence-based summaries on the prevention, diagnosis and treatment of skin diseases. We present a synopsis of the history, scope and priorities of the CSG. In addition, we report outcomes of CSG reviews and critically assess clinical value.
Methods
Descriptive analysis of systematic reviews published by the CSG since its inception including output, impact factor, associated methodological studies, and influence in clinical guidelines, promoting patient and public engagement and in triggering new primary research.
Results
The CSG started in 1997, and has published 61 reviews, 34 protocols and 31 registered titles by August 2013. The CSG scope includes 1000 skin diseases; 80% of reviews cover the top ten diagnoses and 40% of reviews provide clear guidance for clinical practice. CSG reviews had an impact factor of 6.1 in 2011 which places it alongside top dermatology journals. CSG reviews are typically broad in focus and have been shown to be of better quality than non-Cochrane reviews. They are highly cited in clinical guidelines. Several reviews have identified evidence gaps that have led to better primary research.
Conclusions
The CSG has emerged as a vanguard of evidence-based dermatology by growing a community interested in applying best external evidence to the care of skin patients and by identifying topics for research. CSG reviews are high impact, clinically relevant and have tangibly influenced international dermatology clinical practice guidelines and new research
The Antioxidant Potential of the Mediterranean Diet in Patients at High Cardiovascular Risk: An In-Depth Review of the PREDIMED
Cardiovascular disease (CVD) is the leading global cause of death. Diet is known to be important in the prevention of CVD. The PREDIMED trial tested a relatively low-fat diet versus a high-fat Mediterranean diet (MedDiet) for the primary prevention of CVD. The resulting reduction of the CV composite outcome resulted in a paradigm shift in CV nutrition. Though many dietary factors likely contributed to this effect, this review focuses on the influence of the MedDiet on endogenous antioxidant systems and the effect of dietary polyphenols. Subgroup analysis of the PREDIMED trial revealed increased endogenous antioxidant and decreased pro-oxidant activity in the MedDiet groups. Moreover, higher polyphenol intake was associated with lower incidence of the primary outcome, overall mortality, blood pressure, inflammatory biomarkers, onset of new-onset type 2 diabetes mellitus (T2DM), and obesity. This suggests that polyphenols likely contributed to the lower incidence of the primary event in the MedDiet groups. In this article, we summarize the potential benefits of polyphenols found in the MedDiet, specifically the PREDIMED cohort. We also discuss the need for further research to confirm and expand the findings of the PREDIMED in a non-Mediterranean population and to determine the exact mechanisms of action of polyphenols
Randomized clinical trial to evaluate the effect of fecal microbiota transplant for initial Clostridium difficile infection in intestinal microbiome
Objective The aim of this study was to evaluate the impact of fecal donor-unrelated donor mix (FMT-FURM) transplantation as first-line therapy for C. difficile infection (CDI) in intestinal microbiome. Methods We designed an open, two-arm pilot study with oral vancomycin (250mg every 6 h for 10â14 days) or FMT-FURM as treatments for the first CDI episode in hospitalized adult patients in Hospital Universitario âDr. Jose Eleuterio Gonzalezâ. Patients were randomized by a closed envelope method in a 1: 1 ratio to either oral vancomycin or FMT-FURM. CDI resolution was considered when there was a reduction on the Bristol scale of at least 2 points, a reduction of at least 50% in the number of bowel movements, absence of fever, and resolution of abdominal pain (at least two criteria). From each patient, a fecal sample was obtained at days 0, 3, and 7 after treatment. Specimens were cultured to isolate C. difficile, and isolates were characterized by PCR. Susceptibility testing of isolates was performed using the agar dilution method. Fecal samples and FMT-FURM were analyzed by 16S rRNA sequencing. Results We included 19 patients; 10 in the vancomycin arm and 9 in the FMT-FURM arm. However, one of the patients in the vancomycin arm and two patients in the FMT-FURM arm were eliminated. Symptoms resolved in 8/9 patients (88.9%) in the vancomycin group, while symptoms resolved in 4/7 patients (57.1%) after the first FMT-FURM dose (P = 0.26) and in 5/7 patients (71.4%) after the second dose (P = 0.55). During the study, no adverse effects attributable to FMT-FURM were observed in patients. Twelve isolates were recovered, most isolates carried tcdB, tcdA, cdtA, and cdtB, with an 18-bp deletion in tcdC. All isolates were resistant to ciprofloxacin and moxifloxacin but susceptible to metronidazole, linezolid, fidaxomicin, and tetracycline. In the FMT-FURM group, the bacterial composition was dominated by Firmicutes, Bacteroidetes, and Proteobacteria at all-time points and the microbiota were remarkably stable over time. The vancomycin group showed a very different pattern of the microbial composition when comparing to the FMT-FURM group over time. Conclusion The results of this preliminary study showed that FMT-FURM for initial CDI is associated with specific bacterial communities that do not resemble the donorsâ sample.Peer reviewedFinal Published versio
Effect of Biodiversity Changes in Disease Risk: Exploring Disease Emergence in a Plant-Virus System
The effect of biodiversity on the ability of parasites to infect their host and cause disease (i.e. disease risk) is a major question in pathology, which is central to understand the emergence of infectious diseases, and to develop strategies for their management. Two hypotheses, which can be considered as extremes of a continuum, relate biodiversity to disease risk: One states that biodiversity is positively correlated with disease risk (Amplification Effect), and the second predicts a negative correlation between biodiversity and disease risk (Dilution Effect). Which of them applies better to different host-parasite systems is still a source of debate, due to limited experimental or empirical data. This is especially the case for viral diseases of plants. To address this subject, we have monitored for three years the prevalence of several viruses, and virus-associated symptoms, in populations of wild pepper (chiltepin) under different levels of human management. For each population, we also measured the habitat species diversity, host plant genetic diversity and host plant density. Results indicate that disease and infection risk increased with the level of human management, which was associated with decreased species diversity and host genetic diversity, and with increased host plant density. Importantly, species diversity of the habitat was the primary predictor of disease risk for wild chiltepin populations. This changed in managed populations where host genetic diversity was the primary predictor. Host density was generally a poorer predictor of disease and infection risk. These results support the dilution effect hypothesis, and underline the relevance of different ecological factors in determining disease/infection risk in host plant populations under different levels of anthropic influence. These results are relevant for managing plant diseases and for establishing conservation policies for endangered plant species
Incidencia de la personalidad y resiliencia en la aparición del burnout en una muestra de deportistas españoles
The aim of this research was to know the level of burnout in athletes and the relation between this syndrome and personality from Costa and McCraeâs five factors model, adding also the resilience. The sample consisted of 141 athletes (M = 21.20; SD = 3.64). IBD-R, NEO-FFI, Resilience Scale, and IPAQ were used to record and measure the variables previously mentioned. Results indicated that the participants had moderated levels in all dimensions of burnout. Also, being a man was associated to higher burnout levels, as well as being federated, participating in an individual sport and spending a higher quantity of hours training. Age didnât turn out to be an influential variable in the suffering of this syndrome. Moreover, results indicated a vulnerable personality pattern from Five Factors Model, consisting on high levels of neuroticism and low levels of responsibility, kindness, openness and extraversion. Lastly, resilience was also a protective variable for burnout.El objetivo principal de esta investigaciĂłn fue conocer los niveles de burnout en deportistas y la relaciĂłn de este sĂndrome con la personalidad desde el Modelo de los Cinco Factores de Costa y McCrae, añadiendo asimismo la resiliencia. La muestra estuvo constituida por 141 hombres y mujeres. Se utilizaron el IBD-R, NEO-FFI, Escala de Resistencia, e IPAQ para registrar y medir las variables anteriormente mencionadas. Los resultados apuntaron a que los participantes presentaban niveles moderados en todas las dimensiones del burnout. AdemĂĄs, ser hombre estaba asociado a mayores niveles de burnout, asĂ como estar federado, participar en un deporte individual y pasar un mayor nĂșmero de horas de entrenamiento. La edad no resultĂł ser una variable influyente en el padecimiento de este sĂndrome. Asimismo, los resultados indicaron un patrĂłn de personalidad vulnerable del Modelo de los Cinco Factores, consistente en altos niveles de neuroticismo y bajos niveles de responsabilidad, amabilidad, apertura y extraversiĂłn. Por Ășltimo, la resiliencia tambiĂ©n fue una variable protectora del burnout
The young open cluster NGC 7067 using Strömgren photometry
© 2016 The Authors. NGC 7067 is a young open cluster located in the direction between the first and the second Galactic quadrants and close to the Perseus spiral arm. This makes it useful for studies of the nature of the MilkyWay spiral arms. Strömgren photometry taken with theWide Field Camera at the Isaac Newton Telescope allowed us to compute individual physical parameters for the observed stars and hence to derive the cluster's physical parameters. Spectra from the 1.93-m telescope at the Observatoire de Haute-Provence helped to check and improve the results. We obtained photometry for 1233 stars, individual physical parameters for 515 and spectra for 9 of them. The 139 selected cluster members lead to a cluster distance of 4.4 ±0.4 kpc, with an age below log10(t(yr)) = 7.3 and a present mass of 1260 ± 160 Mâ. The morphology of the data reveals that the centre of the cluster is at (α, ÎŽ) = (21: 24: 13.69, +48: 00: 39.2) J2000, with a radius of 6.1 arcmin. Strömgren and spectroscopic data allowed us to improve the previous parameters available for the cluster in the literature
Anaerobic Carbon Monoxide Dehydrogenase Diversity in the Homoacetogenic Hindgut Microbial Communities of Lower Termites and the Wood Roach
Anaerobic carbon monoxide dehydrogenase (CODH) is a key enzyme in the Wood-Ljungdahl (acetyl-CoA) pathway for acetogenesis performed by homoacetogenic bacteria. Acetate generated by gut bacteria via the acetyl-CoA pathway provides considerable nutrition to wood-feeding dictyopteran insects making CODH important to the obligate mutualism occurring between termites and their hindgut microbiota. To investigate CODH diversity in insect gut communities, we developed the first degenerate primers designed to amplify cooS genes, which encode the catalytic (ÎČ) subunit of anaerobic CODH enzyme complexes. These primers target over 68 million combinations of potential forward and reverse cooS primer-binding sequences. We used the primers to identify cooS genes in bacterial isolates from the hindgut of a phylogenetically lower termite and to sample cooS diversity present in a variety of insect hindgut microbial communities including those of three phylogenetically-lower termites, Zootermopsis nevadensis, Reticulitermes hesperus, and Incisitermes minor, a wood-feeding cockroach, Cryptocercus punctulatus, and an omnivorous cockroach, Periplaneta americana. In total, we sequenced and analyzed 151 different cooS genes. These genes encode proteins that group within one of three highly divergent CODH phylogenetic clades. Each insect gut community contained CODH variants from all three of these clades. The patterns of CODH diversity in these communities likely reflect differences in enzyme or physiological function, and suggest that a diversity of microbial species participate in homoacetogenesis in these communities
Ears of the Armadillo: Global Health Research and Neglected Diseases in Texas
Neglected tropical diseases (NTDs) have\ud
been recently identified as significant public\ud
health problems in Texas and elsewhere in\ud
the American South. A one-day forum on the\ud
landscape of research and development and\ud
the hidden burden of NTDs in Texas\ud
explored the next steps to coordinate advocacy,\ud
public health, and research into a\ud
cogent health policy framework for the\ud
American NTDs. It also highlighted how\ud
U.S.-funded global health research can serve\ud
to combat these health disparities in the\ud
United States, in addition to benefiting\ud
communities abroad
The HIV/AIDS epidemic in Cuba: description and tentative explanation of its low HIV prevalence
<p>Abstract</p> <p>Background</p> <p>The Cuban HIV/AIDS epidemic has the lowest prevalence rate of the Caribbean region. The objective of this paper is to give an overview of the HIV/AIDS epidemic in Cuba and to explore the reasons for this low prevalence.</p> <p>Methods</p> <p>Data were obtained from the Cuban HIV/AIDS programme established in 1983. This programme has an extensive adult HIV testing policy, including testing of all pregnant women. HIV and AIDS cases have been recorded since 1986. Persons found to be HIV-positive are interviewed on their sexual behaviour and partners. Tracing and voluntary testing of these partners are organised. Epidemiological description of this epidemic was obtained from analysis of this data set. Using elementary mathematical analyses, we estimated the coverage of the detection system (percentage of HIV-positive adults detected) and the average period between HIV infection and detection. Estimated HIV prevalence rates were corrected to account for the coverage.</p> <p>Results</p> <p>HIV prevalence has increased since 1996. In 2005, the prevalence among pregnant women was 1.2 per 10,000 (16/137000). Estimated HIV prevalence among 15- to 49-year-olds was 8.1 per 10,000 (4913/6065000; 95%CI: 7.9 per 10,000 â 8.3 per 10,000). Most (77%) of the HIV-positive adults were men, most (85.1%) of the detected HIV-positive men were reported as having sex with men (MSM), and most of the HIV-positive women reported having had sex with MSM. The average period between HIV infection and detection was estimated to be 2.1 years (IQR = 1.7 â 2.2 years). We estimated that, for the year 2005, 79.6% (IQR: 77.3 â 81.4%) of the HIV-positive persons were detected.</p> <p>Conclusion</p> <p>MSM drive the HIV epidemic in Cuba. The extensive HIV testing policy may be an important factor in explaining the low HIV prevalence. To reduce the HIV epidemic in Cuba, the epidemic among MSM should be addressed. To understand this epidemic further, data on sexual behaviour should be collected. Now that antiretroviral therapy is more widely available, the Cuban policy, based on intensive HIV testing and tracing of partners, may be considered as a possible policy to control HIV/AIDS epidemics in other countries.</p
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