439 research outputs found

    Genetic Control of Susceptibility to Infection with Candida albicans in Mice

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    Candida albicans is an opportunistic pathogen that causes acute disseminated infections in immunocompromised hosts, representing an important cause of morbidity and mortality in these patients. To study the genetic control of susceptibility to disseminated C. albicans in mice, we phenotyped a group of 23 phylogenetically distant inbred strains for susceptibility to infection as measured by extent of fungal replication in the kidney 48 hours following infection. Susceptibility was strongly associated with the loss-of-function mutant complement component 5 (C5/Hc) allele, which is known to be inherited by approximately 40% of inbred strains. Our survey identified 2 discordant strains, AKR/J (C5-deficient, resistant) and SM/J (C5-sufficient, susceptible), suggesting that additional genetic effects may control response to systemic candidiasis in these strains. Haplotype association mapping in the 23 strains using high density SNP maps revealed several putative loci regulating the extent of C. albicans replication, amongst which the most significant were C5 (P value = 2.43×10−11) and a novel effect on distal chromosome 11 (P value = 7.63×10−9). Compared to other C5-deficient strains, infected AKR/J strain displays a reduced fungal burden in the brain, heart and kidney, and increased survival, concomitant with uniquely high levels of serum IFNγ. C5-independent genetic effects were further investigated by linkage analysis in an [A/JxAKR/J]F2 cross (n = 158) where the mutant Hc allele is fixed. These studies identified a chromosome 11 locus (Carg4, Candida albicans resistance gene 4; LOD = 4.59), and a chromosome 8 locus (Carg3; LOD = 3.95), both initially detected by haplotype association mapping. Alleles at both loci were inherited in a co-dominant manner. Our results verify the important effect of C5-deficiency in inbred mouse strains, and further identify two novel loci, Carg3 and Carg4, which regulate resistance to C. albicans infection in a C5-independent manner

    An exploratory study of Muslim adolescents' views on sexuality: Implications for sex education and prevention

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    <p>Abstract</p> <p>Background</p> <p>This paper describes the results of an exploratory qualitative study on Muslim adolescents' views on sexuality in the Netherlands.</p> <p>Methods</p> <p>Data were gathered from an Internet forum on which 44 Muslim and 33 non-Muslim adolescents discussed sexuality as it relates to Islam. These discussions were subsequently analyzed for content using Nvivo 2.0.</p> <p>Results</p> <p>Our analysis revealed several issues that are relevant for the design of future sex education programs targeting Muslim youth. Apart from some expected outcomes regarding, for example, taboos on sexuality, sex outside marriage, abortion, homosexuality and conservative gender roles, our analyses showed that in cases of disputes 1) discussions were polarized, 2) opponents used the same Qur'anic passages to support their views, and 3) the authority of an Imam was questioned when his interpretation of Qur'anic passages was not in line with the views of participants.</p> <p>Conclusions</p> <p>Our findings show that current approaches to sex education among Muslim youth are likely to be unsuccessful given the rigidity of sexual norms in Muslim society. In addition, we also identified new barriers to sex education among Muslim youth (e.g. lack of respect for an Imam who opposes a youth's views on sexuality).</p

    ILK Induces Cardiomyogenesis in the Human Heart

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    Integrin-linked kinase (ILK) is a widely conserved serine/threonine kinase that regulates diverse signal transduction pathways implicated in cardiac hypertrophy and contractility. In this study we explored whether experimental overexpression of ILK would up-regulate morphogenesis in the human fetal heart.Primary cultures of human fetal myocardial cells (19-22 weeks gestation) yielded scattered aggregates of cardioblasts positive for the early cardiac lineage marker nk × 2.5 and containing nascent sarcomeres. Cardiac cells in colonies uniformly expressed the gap junction protein connexin 43 (C × 43) and displayed a spectrum of differentiation with only a subset of cells exhibiting the late cardiomyogenic marker troponin T (cTnT) and evidence of electrical excitability. Adenovirus-mediated overexpression of ILK potently increased the number of new aggregates of primitive cardioblasts (p<0.001). The number of cardioblast colonies was significantly decreased (p<0.05) when ILK expression was knocked down with ILK targeted siRNA. Interestingly, overexpression of the activation resistant ILK mutant (ILK(R211A)) resulted in much greater increase in the number of new cell aggregates as compared to overexpression of wild-type ILK (ILK(WT)). The cardiomyogenic effects of ILK(R211A) and ILK(WT) were accompanied by concurrent activation of β-catenin (p<0.001) and increase expression of progenitor cell marker islet-1, which was also observed in lysates of transgenic mice with cardiac-specific over-expression of ILK(R211A) and ILK(WT). Finally, endogenous ILK expression was shown to increase in concert with those of cardiomyogenic markers during directed cardiomyogenic differentiation in human embryonic stem cells (hESCs).In the human fetal heart ILK activation is instructive to the specification of mesodermal precursor cells towards a cardiomyogenic lineage. Induction of cardiomyogenesis by ILK overexpression bypasses the requirement of proximal PI3K activation for transduction of growth factor- and β1-integrin-mediated differentiation signals. Altogether, our data indicate that ILK represents a novel regulatory checkpoint during human cardiomyogenesis

    Thinking outside the curve, part I: modeling birthweight distribution

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    <p>Abstract</p> <p>Background</p> <p>Greater epidemiologic understanding of the relationships among fetal-infant mortality and its prognostic factors, including birthweight, could have vast public health implications. A key step toward that understanding is a realistic and tractable framework for analyzing birthweight distributions and fetal-infant mortality. The present paper is the first of a two-part series that introduces such a framework.</p> <p>Methods</p> <p>We propose describing a birthweight distribution via a normal mixture model in which the number of components is determined from the data using a model selection criterion rather than fixed <it>a priori</it>.</p> <p>Results</p> <p>We address a number of methodological issues, including how the number of components selected depends on the sample size, how the choice of model selection criterion influences the results, and how estimates of mixture model parameters based on multiple samples from the same population can be combined to produce confidence intervals. As an illustration, we find that a 4-component normal mixture model reasonably describes the birthweight distribution for a population of white singleton infants born to heavily smoking mothers. We also compare this 4-component normal mixture model to two competitors from the existing literature: a contaminated normal model and a 2-component normal mixture model. In a second illustration, we discover that a 6-component normal mixture model may be more appropriate than a 4-component normal mixture model for a general population of black singletons.</p> <p>Conclusions</p> <p>The framework developed in this paper avoids assuming the existence of an interval of birthweights over which there are no compromised pregnancies and does not constrain birthweights within compromised pregnancies to be normally distributed. Thus, the present framework can reveal heterogeneity in birthweight that is undetectable via a contaminated normal model or a 2-component normal mixture model.</p

    Biochemical, physiological, and performance response of a functional watermelon juice enriched in L-citrulline during a half-marathon race

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    Background: Watermelon is a rich natural source of l-citrulline. This non-essential amino acid increases exercise performance. Objective: Evaluate the effect of Fashion watermelon juice enriched in l-citrulline (CWJ) (3.45 g per 500 mL) in physical performance and biochemical markers after a half-marathon race. Design: A randomised, double blind, crossover design where 2 h after drinking 500 mL of CWJ or placebo (PLA, beverage without l-citrulline) amateur male runners performed two half-marathon races. Jump height, heart rate and rating of perceived exertion were evaluated before and after the races. Moreover, muscle soreness and plasma markers of muscle damage and metabolism were evaluated for 72 h after the races. Results: Muscle soreness perception was significantly lower from 24 to 72 h after the race with CWJ beverage. Immediately after the races, runners under CWJ condition showed plasma lactate and glucose concentrations significantly lower and higher lactate dehydrogenase and l-arginine concentration than runners under PLA. A maintenance of jump heights after the races under CWJ supplementation was found, decreasing significantly with PLA. Conclusion: A single Fashion watermelon juice enriched in l-citrulline dose diminished muscle soreness perception from 24 to 72 h after the race and maintained lower concentrations of plasma lactate after an exhausting exercise.Actividad Física y Deport

    The reliability of postural balance measures in single and dual tasking in elderly fallers and non-fallers

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    BACKGROUND: The purpose of this study was to determine the reliability of a forceplate postural balance protocol in a group of elderly fallers and non-fallers. The measurements were tested in single and dual-task conditions, with and without vision. METHODS: 37 elderly (mean age 73 +/- 6 years) community-dwellers were included in this study. All were tested in a single (two-legged stance) and in a dual-task (two-legged stance while counting backwards aloud in steps of 7's) condition, with and without vision. A forceplate was used for registering postural variables: the maximal and the root-mean-square amplitude in medio-lateral (Max-ML, RMS-ML) and antero-posterior (Max-AP, RMS-AP) direction, mean velocity (MV), and the area of the 95% confidence ellipse (AoE). Reliability of the test protocol was expressed with intraclass correlation coefficients (ICC), with 95% limits of agreement (LoA), and with the smallest detectable difference (SDD). RESULTS: The ICCs for inter-rater reliability and test-retest reliability of the balance variables were r = 0.70-0.89. For the variables Max-AP and RMS-AP the ICCs were r = 0.52-0.74. The SDD values were for variable Max-ML and Max-AP between 0.37 cm and 0.83 cm, for MV between 0.48 cm/s and 1.2 cm/s and for AoE between 1.48 cm2 and 3.75 cm2. The LoA analysis by Bland-Altman plots showed no systematic differences between test-retest measurements. CONCLUSION: The study showed good reliability results for group assessment and no systematic errors of the measurement protocol in measuring postural balance in the elderly in a single-task and dual-task condition

    Serum antibodies against genitourinary infectious agents in prostate cancer and benign prostate hyperplasia patients: a case-control study

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    <p>Abstract</p> <p>Background</p> <p>Infection plays a role in the pathogenesis of many human malignancies. Whether prostate cancer (PCa) - an important health issue in the aging male population in the Western world - belongs to these conditions has been a matter of research since the 1970 s. Persistent serum antibodies are a proof of present or past infection. The aim of this study was to compare serum antibodies against genitourinary infectious agents between PCa patients and controls with benign prostate hyperplasia (BPH). We hypothesized that elevated serum antibody levels or higher seroprevalence in PCa patients would suggest an association of genitourinary infection in patient history and elevated PCa risk.</p> <p>Methods</p> <p>A total of 434 males who had undergone open prostate surgery in a single institution were included in the study: 329 PCa patients and 105 controls with BPH. The subjects' serum samples were analysed by means of enzyme-linked immunosorbent assay, complement fixation test and indirect immunofluorescence for the presence of antibodies against common genitourinary infectious agents: human papillomavirus (HPV) 6, 11, 16, 18, 31 and 33, herpes simplex virus (HSV) 1 and 2, human cytomegalovirus (CMV), Chlamydia trachomatis, Mycoplasma hominis, Ureaplasma urealyticum, Neisseria gonorrhoeae and Treponema pallidum. Antibody seroprevalence and mean serum antibody levels were compared between cases and controls. Tumour grade and stage were correlated with serological findings.</p> <p>Results</p> <p>PCa patients were more likely to harbour antibodies against Ureaplasma urealyticum (odds ratio (OR) 2.06; 95% confidence interval (CI) 1.08-4.28). Men with BPH were more often seropositive for HPV 18 and Chlamydia trachomatis (OR 0.23; 95% CI 0.09-0.61 and OR 0.45; 95% CI 0.21-0.99, respectively) and had higher mean serum CMV antibody levels than PCa patients (p = 0.0004). Among PCa patients, antibodies against HPV 6 were associated with a higher Gleason score (p = 0.0305).</p> <p>Conclusions</p> <p>Antibody seropositivity against the analyzed pathogens with the exception of Ureaplasma does not seem to be a risk factor for PCa pathogenesis. The presence or higher levels of serum antibodies against the genitourinary pathogens studied were not consistently associated with PCa. Serostatus was not a predictor of disease stage in the studied population.</p

    The development of compassionate engagement and action scales for self and others

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    Background Studies of the value of compassion on physical and mental health and social relationships have proliferated in the last 25 years. Although, there are several conceptualisations and measures of compassion, this study develops three new measures of compassion competencies derived from an evolutionary, motivational approach. The scales assess 1. the compassion we experience for others, 2. the compassion we experience from others, and 3. self-compassion based on a standard definition of compassion as a ‘sensitivity to suffering in self and others with a commitment to try to alleviate and prevent it’. We explored these in relationship to other compassion scales, self-criticism, depression, anxiety, stress and well-being. Methods Participants from three different countries (UK, Portugal and USA) completed a range of scales including compassion for others, self-compassion, self-criticism, shame, depression, anxiety and stress with the newly developed ‘The Compassionate Engagement and Actions’ scale. Results All three scales have good validity. Interestingly, we found that the three orientations of compassion are only moderately correlated to one another (r < .5). We also found that some elements of self-compassion (e.g., being sensitive to, and moved by one’s suffering) have a complex relationship with other attributes of compassion (e.g., empathy), and with depression, anxiety and stress. A path-analysis showed that self-compassion is a significant mediator of the association between self-reassurance and well-being, while self-criticism has a direct effect on depressive symptoms, not mediated by self-compassion. Discussion Compassion evolved from caring motivation and in humans is associated with a range of different socially intelligent competencies. Understanding how these competencies can be inhibited and facilitated is an important research endeavour. These new scales were designed to assess these competencies. Conclusions This is the first study to measure the three orientations of compassion derived from an evolutionary model of caring motivation with specified competencies. Our three new measures of compassion further indicate important complex relationships between different potentiation’s of compassion, well-being, and vulnerability to psychopathologies.N/
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