1,776 research outputs found

    Proteoforms of transthyretin - candidate biomarkers in diagnosis of obstructive sleep

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    Obstructive sleep apnea (OSA) is a common sleep-related breathing disorder which is characterized by recurrent occurrence of partial or complete closure of the upper airway during sleep, despite ongoing efforts to breathe. The majority of patients with OSA remain undiagnosed since most of them only come to the attention of a clinician when they complain of daytime sleepiness or when their bed partners report loud snoring or witnessed apnea episodes.Epidemiological studies have indicated that OSA affects 6–13% of the adult population. OSA is multifactorial disease, also considered as metabolic syndrome, which diagnosis in early stages is challenging thus often remain undiagnosed. Recently was found connection between transthyretin (TTR) protein modifications present in human plasma samples and appearance of sleep apnea syndrome1,2 . Mass Spectrometric Immunoassay (MSIA) was successfully applied previously on identification of and quantification of TTR variants present in human serum3. We took advantage on this powerful method to investigate possible modifications of TTR proteoforms in patients with OSAS.N/

    Awareness, treatment and control of hypertension: Trend from population-based surveys conducted in a low-middle income country

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    Aim: To estimate and determine temporal trends for awareness, treatment and control of hypertension in adults from the urban area in Colombia. Methods: We conducted two population-based surveys (years 2010 and 2015) in the Metropolitan Area of Bucaramanga-Santander, Colombia, using the WHO STEPwise approach. Participants were asked to provide demographic, socioeconomic and cardiovascular risk factors data. Blood pressure (BP) was measured twice using an automated device. Hypertension was defined as a systolic BP≥140 mmHg, a diastolic BP≥90 mmHg or self-reported antihypertensive treatment. We estimated age, sex, and socioeconomic status (SES) adjusted prevalence ratios (PR), with 2010 as the reference survey, using poisson regression and correcting standard errors by clustering. Results: We evaluated 1,136 (mean age: 35.7 years; 43% male) and 872 (mean age:37.7 years; 41% male) adults from the 2010 and 2015 surveys, respectively. There were a larger proportion of individuals sampled from low SES in the 2015 as compared to the 2010 survey (93.6% vs. 70.9%). Overall, prevalence of hypertension was 16.4% (95%CI: 14.8 – 17.9): It increased significantly with age (from 2.4% among individuals 15-19 years old to 41.1% among individuals 50 years and older; p-trend<0.001) but did not differed by sex (17.8% in men vs. 15.4% in women) or year (16.1% vs. 16.6% in 2010 and 2015, respectively). Overall, prevalence of awareness, treatment and control of hypertension were 65.0%, 84.1%, and 62.2%, respectively. Although awareness and control increased from 2010 to 2015 (PR=1.05 and PR=1.12, respectively), only the prevalence of treatment showed a statistically significant increment of 11% (PR=1.11; 95%IC: 1.01 – 1.24). Implication: The STEPwise is a suitable surveillance strategy to estimate the burden of cardiovascular risk factors in low-middle income countries. Our results are consistent with national data from urban areas and show for the first time a short-time improvement in antihypertensive coverage

    Performance of yam microtubers from temporary immersion system in field conditions

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    The yam clones ´Pacala Duclos´ and ´Belep´ of Dioscorea alata were used to evaluate the performance of microtubers formed in temporary immersion systems (TIS) in field conditions. Previously sprouted microtubers with a fresh weight higher than 3.0 gFW were used while in vitro plants and tuber crowns from conventional propagation methods served as control. In both clones there were no significant differences in qualitative morphological characters between plants from microtubers and in vitro plants for all traits but both differed significantly from plants obtained from tuber crowns. The same trend was observed for number, length, diameter and fresh weight of tubers produced 36 weeks after field planting. The number of tubers formed per plant raised from microtubers doubled that raised from tuber crowns in both clones. Microtubers from temporary immersion systems can be grown on the field and used in original seed production programs.Key words: Microtuber, yam, field, temporary immersion system

    Predicting the onset and persistence of episodes of depression in primary health care. The predictD-Spain study: Methodology

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    Background: The effects of putative risk factors on the onset and/or persistence of depression remain unclear. We aim to develop comprehensive models to predict the onset and persistence of episodes of depression in primary care. Here we explain the general methodology of the predictD-Spain study and evaluate the reliability of the questionnaires used. Methods: This is a prospective cohort study. A systematic random sample of general practice attendees aged 18 to 75 has been recruited in seven Spanish provinces. Depression is being measured with the CIDI at baseline, and at 6, 12, 24 and 36 months. A set of individual, environmental, genetic, professional and organizational risk factors are to be assessed at each follow-up point. In a separate reliability study, a proportional random sample of 401 participants completed the test-retest (251 researcher-administered and 150 self-administered) between October 2005 and February 2006. We have also checked 118,398 items for data entry from a random sample of 480 patients stratified by province. Results: All items and questionnaires had good test-retest reliability for both methods of administration, except for the use of recreational drugs over the previous six months. Cronbach's alphas were good and their factorial analyses coherent for the three scales evaluated (social support from family and friends, dissatisfaction with paid work, and dissatisfaction with unpaid work). There were 191 (0.16%) data entry errors. Conclusion: The items and questionnaires were reliable and data quality control was excellent. When we eventually obtain our risk index for the onset and persistence of depression, we will be able to determine the individual risk of each patient evaluated in primary health car

    Brain Performance versus Phase Transitions

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    We here illustrate how a well-founded study of the brain may originate in assuming analogies with phase-transition phenomena. Analyzing to what extent a weak signal endures in noisy environments, we identify the underlying mechanisms, and it results a description of how the excitability associated to (non-equilibrium) phase changes and criticality optimizes the processing of the signal. Our setting is a network of integrate-and-fire nodes in which connections are heterogeneous with rapid time-varying intensities mimicking fatigue and potentiation. Emergence then becomes quite robust against wiring topology modification—in fact, we considered from a fully connected network to the Homo sapiens connectome—showing the essential role of synaptic flickering on computations. We also suggest how to experimentally disclose significant changes during actual brain operation.The authors acknowledge support from the Spanish Ministry of Economy and Competitiveness under the project FIS2013-43201-P

    Multifrequency Strategies for the Identification of Gamma-Ray Sources

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    More than half the sources in the Third EGRET (3EG) catalog have no firmly established counterparts at other wavelengths and are unidentified. Some of these unidentified sources have remained a mystery since the first surveys of the gamma-ray sky with the COS-B satellite. The unidentified sources generally have large error circles, and finding counterparts has often been a challenging job. A multiwavelength approach, using X-ray, optical, and radio data, is often needed to understand the nature of these sources. This chapter reviews the technique of identification of EGRET sources using multiwavelength studies of the gamma-ray fields.Comment: 35 pages, 22 figures. Chapter prepared for the book "Cosmic Gamma-ray Sources", edited by K.S. Cheng and G.E. Romero, to be published by Kluwer Academic Press, 2004. For complete article and higher resolution figures, go to: http://www.astro.columbia.edu/~muk/mukherjee_multiwave.pd

    A cross-sectional study on attitudes toward gender equality, sexual behavior, positive sexual experiences, and communication about sex among sexually active and non-sexually active adolescents in Bolivia and Ecuador

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    Background: It is widely agreed upon that gender is a key aspect of sexuality however, questions remain on how gender exactly influences adolescents’ sexual health. Objective: The aim of this research was to study correlations between gender equality attitudes and sexual behavior, sexual experiences and communication about sex among sexually active and non-sexually active adolescents in 2 Latin American countries. Design: In 2011, a cross-sectional study was carried out among 5,913 adolescents aged 14–18 in 20 secondary schools in Cochabamba (Bolivia) and 6 secondary schools in Cuenca (Ecuador). Models were built using logistic regressions to assess the predictive value of attitudes toward gender equality on adolescents’ sexual behavior, on experiences and on communication. Results: The analysis shows that sexually active adolescents who consider gender equality as important report higher current use of contraceptives within the couple. They are more likely to describe their last sexual intercourse as a positive experience and consider it easier to talk with their partner about sexuality than sexually experienced adolescents who are less positively inclined toward gender equality. These correlations remained consistent whether the respondent was a boy or a girl. Non-sexually active adolescents, who consider gender equality to be important, are more likely to think that sexual intercourse is a positive experience. They consider it less necessary to have sexual intercourse to maintain a relationship and find it easier to communicate with their girlfriend or boyfriend than sexually non-active adolescents who consider gender equality to be less important. Comparable results were found for boys and girls. Conclusions: Our results suggest that gender equality attitudes have a positive impact on adolescents’ sexual and reproductive health (SRH) and wellbeing. Further research is necessary to better understand the relationship between gender attitudes and specific SRH outcomes such as unwanted teenage pregnancies and sexual pleasure among adolescents worldwide

    Gamma Ray Pulsars: Multiwavelength Observations

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    High-energy gamma rays are a valuable tool for studying particle acceleration and radiation in the magnetospheres of energetic pulsars. The seven or more pulsars seen by instruments on the Compton Gamma Ray Observatory (CGRO) show that: the light curves usually have double-peak structures (suggesting a broad cone of emission); gamma rays are frequently the dominant component of the radiated power; and all the spectra show evidence of a high-energy turnover. For all the known gamma-ray pulsars, multiwavelength observations and theoretical models based on such observations offer the prospect of gaining a broad understanding of these rotating neutron stars. The Gamma-ray Large Area Space Telescope (GLAST), now in planning for a launch in 2007, will provide a major advance in sensitivity, energy range, and sky coverage.Comment: To appear in Cosmic Gamma Ray Sources, Kluwer ASSL Series, Edited by K.S. Cheng and G.E. Romer

    Comparison of the effect of lps and pam3 on ventilated lungs

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    <p>Abstract</p> <p>Background</p> <p>While lipopolysaccharide (LPS) from Gram-negative bacteria has been shown to augment inflammation in ventilated lungs information on the effect of Gram-positive bacteria is lacking. Therefore the effect of LPS and a lipopetide from Gram-positive bacteria, PAM3, on ventilated lungs were investigated.</p> <p>Methods</p> <p>C57/Bl6 mice were mechanically ventilated. Sterile saline (sham) and different concentrations of LPS (1 μg and 5 μg) and PAM3 (50 nM and 200 nM) were applied intratracheally. Lung function parameters and expression of MIP-2 and TNFα as well as influx of neutrophils were measured.</p> <p>Results</p> <p>Mechanical ventilation increased resistance and decreased compliance over time. PAM3 but not LPS significantly increased resistance compared to sham challenge (P < 0.05). Both LPS and PAM3 significantly increased MIP-2 and TNFα mRNA expression compared to sham challenge (P < 0.05). The numbers of neutrophils were significantly increased after LPS at a concentration of 5 μg compared to sham (P < 0.05). PAM3 significantly increased the numbers of neutrophils at both concentrations compared to sham (P < 0.05).</p> <p>Conclusions</p> <p>These data suggest that PAM3 similar to LPS enhances ventilator-induced inflammation. Moreover, PAM3 but not LPS increases pulmonary resistance in ventilated lungs. Further studies are warranted to define the role of lipopetides in ventilator-associated lung injury.</p

    Substrate specificity of a peptidyl-aminoacyl-l/d-isomerase from frog skin

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    In the skin of fire-bellied toads (Bombina species), an aminoacyl-l/d-isomerase activity is present which catalyses the post-translational isomerization of the l- to the d-form of the second residue of its substrate peptides. Previously, this new type of enzyme was studied in some detail and genes potentially coding for similar polypeptides were found to exist in several vertebrate species including man. Here, we present our studies to the substrate specificity of this isomerase using fluorescence-labeled variants of the natural substrate bombinin H with different amino acids at positions 1, 2 or 3. Surprisingly, this enzyme has a rather low selectivity for residues at position 2 where the change of chirality at the alpha-carbon takes place. In contrast, a hydrophobic amino acid at position 1 and a small one at position 3 of the substrate are essential. Interestingly, some peptides containing a Phe at position 3 also were substrates. Furthermore, we investigated the role of the amino-terminus for substrate recognition. In view of the rather broad specificity of the frog isomerase, we made a databank search for potential substrates of such an enzyme. Indeed, numerous peptides of amphibia and mammals were found which fulfill the requirements determined in this study. Expression of isomerases with similar characteristics in other species can therefore be expected to catalyze the formation of peptides containing d-amino acids
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