2,300 research outputs found

    Ablation of GalNAc-4-sulfotransferase-1 enhances reproduction by altering the carbohydrate structures of luteinizing hormone in mice

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    Luteinizing hormone (LH), produced in the anterior lobe of the pituitary, is a member of the hypothalamic-pituitary-gonad axis that is required for production of the sex hormones estradiol, progesterone, and testosterone. Perturbations in levels of hormones associated with this axis can result in defects in sexual development and maturity. LH bears unique N-linked carbohydrate units that terminate with a sulfated N-acetylgalactosamine structure (GalNAc-4-SO(4)) that mediates its clearance from the blood. To determine the significance of this terminal structure, we ablated the gene encoding the sulfotransferase responsible for sulfate addition to GalNAc on LH, GalNAc-4-sulfotransferase-1 (GalNAc-4-ST1) in mice. Mice lacking GalNAc-4-ST1 exhibited increased levels of circulating LH. In male mice, this resulted in elevated levels of testosterone and precocious maturation of testis and seminal vesicles. Female mice lacking GalNAc-4-ST1 demonstrated elevated estrogen levels and exhibited precocious sexual maturation and increased fecundity. Female mice remained in estrus for prolonged periods and produced almost 50% more litters per mouse than wild-type mice over the same period of time. Thus, sulfate modification of the terminal glycosylation of LH plays a central role in regulating the hypothalamic-pituitary-gonad axis in vivo

    Cliophysics: Socio-political Reliability Theory, Polity Duration and African Political (In)stabilities

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    Quantification of historical sociological processes have recently gained attention among theoreticians in the effort of providing a solid theoretical understanding of the behaviors and regularities present in sociopolitical dynamics. Here we present a reliability theory of polity processes with emphases on individual political dynamics of African countries. We found that the structural properties of polity failure rates successfully capture the risk of political vulnerability and instabilities in which 87.50%, 75%, 71.43%, and 0% of the countries with monotonically increasing, unimodal, U-shaped and monotonically decreasing polity failure rates, respectively, have high level of state fragility indices. The quasi-U-shape relationship between average polity duration and regime types corroborates historical precedents and explains the stability of the autocracies and democracies.Comment: 4 pages, 3 figures, 1 tabl

    Black Hairy Tongue Associated with Erlotinib Treatment in a Patient with Advanced Lung Cancer

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    Erlotinib is a tyrosine kinase inhibitor that acts on the epidermal growth factor receptor (EGFR). There have been many reports of the mucocutaneous side effects related to several EGFR inhibitors (EGFRIs). However, no case of black hairy tongue (BHT) associated with EGFRI has been reported. Herein, we report the first case of erlotinib-induced BHT in a 61-year-old man with advanced lung cancer. Considering recent use of EGFRIs worldwide, dermatologists should recognize the possible occurrence of BHT associated with EGFRIs such as erlotinib

    Comparison of Hospital Charge Prediction Models for Colorectal Cancer Patients: Neural Network vs. Decision Tree Models

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    Analysis and prediction of the care charges related to colorectal cancer in Korea are important for the allocation of medical resources and the establishment of medical policies because the incidence and the hospital charges for colorectal cancer are rapidly increasing. But the previous studies based on statistical analysis to predictthe hospital charges for patients did not show satisfactory results. Recently, data mining emerges as a new technique to extract knowledge from the huge and diverse medical data. Thus, we built models using data mining techniques to predict hospital charge for the patients. A total of 1,022 admission records with 154 variables of 492 patients were used to build prediction models who had been treated from 1999 to 2002 in the Kyung Hee University Hospital. We built an artificial neural network (ANN) model and a classification and regression tree (CART) model, and compared their prediction accuracy. Linear correlation coefficients were high in both models and the mean absolute errors were similar. But ANN models showed a better linear correlation than CART model (0.813 vs. 0.713 for the hospital charge paid by insurance and 0.746 vs. 0.720 for the hospital charge paid by patients). We suggest that ANN model has a better performance to predict charges of colorectal cancer patients

    Leadership and decision-making practices in public versus private universities in Pakistan

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    The goal of this study is to examine differences in leadership and decision-making practices in public and private universities in Pakistan, with a focus on transformational leadership (TL) and participative decision-making (PDM). We conducted semi-structured interviews with 46 deans and heads of department from two public and two private universities in Pakistan. Our findings indicate that leadership and decision-making practices are different in public and private universities. While differences were observed in all six types of TL-behaviour, the following three approaches emerged to be crucial in both public and private universities: (1) articulating a vision, (2) fostering the acceptance of group goals, and (3) high-performance expectations. In terms of PDM, deans and heads of department in public and private universities adopt a collaborative approach. However, on a practical level this approach is limited to teacher- and student-related matters. Overall, our findings suggest that the leadership and decision-making practices in Pakistani public and private universities are transformational and participative in nature

    Behaviourally Mediated Phenotypic Selection in a Disturbed Coral Reef Environment

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    Natural and anthropogenic disturbances are leading to changes in the nature of many habitats globally, and the magnitude and frequency of these perturbations are predicted to increase under climate change. Globally coral reefs are one of the most vulnerable ecosystems to climate change. Fishes often show relatively rapid declines in abundance when corals become stressed and die, but the processes responsible are largely unknown. This study explored the mechanism by which coral bleaching may influence the levels and selective nature of mortality on a juvenile damselfish, Pomacentrus amboinensis, which associates with hard coral. Recently settled fish had a low propensity to migrate small distances (40 cm) between habitat patches, even when densities were elevated to their natural maximum. Intraspecific interactions and space use differ among three habitats: live hard coral, bleached coral and dead algal-covered coral. Large fish pushed smaller fish further from the shelter of bleached and dead coral thereby exposing smaller fish to higher mortality than experienced on healthy coral. Small recruits suffered higher mortality than large recruits on bleached and dead coral. Mortality was not size selective on live coral. Survival was 3 times as high on live coral as on either bleached or dead coral. Subtle behavioural interactions between fish and their habitats influence the fundamental link between life history stages, the distribution of phenotypic traits in the local population and potentially the evolution of life history strategies

    Effects of Gonadotropin-Releasing Hormone Agonist Therapy on Body Mass Index and Height in Girls with Central Precocious Puberty

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    Treatment with gonadotropin-releasing hormone (GnRH) agonist is the treatment of choice for central precocious puberty (CPP). Many of the previous studies concerning the auxological effects of treatment with GnRH agonist in CPP have focused on final height. Much less attention has been paid to changes in body weight. However, concerns have been expressed that CPP may be associated with increased body mass index (BMI) both at initial presentation and during GnRH agonist treatment. We retrospectively reviewed the height and BMI of 38 girls with CPP. All patients were treated with GnRH agonist over 18 months. The height standard deviation score (SDS) for chronological age was significantly decreased during GnRH agonist treatment, whereas the height SDS for bone age was significantly increased. The predicted adult height was increased from 157.78±6.45 cm before treatment to 161.41±8.97 cm at 12 months after treatment. The BMI SDS for chronological age was significantly increased during treatment. The BMI SDS of normal-weight girls increased more than did the BMI SDS of overweight girls, but the increase was not significant. Preventive measures, such as increased physical activity, can be introduced to minimize possible alterations in body weight, and a long-term follow-up study is required to elucidate whether GnRH agonist treatment in Korean girls with CPP affects adult obesity

    Longitudinal seroepidemiologic study of the 2009 pandemic influenza A (H1N1) infection among health care workers in a children's hospital

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    <p>Abstract</p> <p>Background</p> <p>To probe seroepidemiology of the 2009 pandemic influenza A (H1N1) among health care workers (HCWs) in a children's hospital.</p> <p>Methods</p> <p>From August 2009 to March 2010, serum samples were drawn from 150 HCWs in a children's hospital in Taipei before the 2009 influenza A (H1N1) pandemic, before H1N1 vaccination, and after the pandemic. HCWs who had come into direct contact with 2009 influenza A (H1N1) patients or their clinical respiratory samples during their daily work were designated as a high-risk group. Antibody levels were determined by hemagglutination inhibition (HAI) assay. A four-fold or greater increase in HAI titers between any successive paired sera was defined as seroconversion, and factors associated with seroconversion were analyzed.</p> <p>Results</p> <p>Among the 150 HCWs, 18 (12.0%) showed either virological or serological evidence of 2009 pandemic influenza A (H1N1) infection. Of the 90 unvaccinated HCWs, baseline and post-pandemic seroprotective rates were 5.6% and 20.0%. Seroconversion rates among unvaccinated HCWs were 14.4% (13/90), 22.5% (9/40), and 8.0% (4/50) for total, high-risk group, and low-risk group, respectively. Multivariate analysis revealed being in the high-risk group is an independent risk factor associated with seroconversion.</p> <p>Conclusion</p> <p>The infection rate of 2009 pandemic influenza A (H1N1) in HCWs was moderate and not higher than that for the general population. The majority of unvaccinated HCWs remained susceptible. Direct contact of influenza patients and their respiratory samples increased the risk of infection.</p

    The therapeutic potential of the filarial nematode-derived immunodulator, ES-62 in inflammatory disease

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    The dramatic recent rise in the incidence of allergic or autoimmune inflammatory diseases in the West has been proposed to reflect the lack of appropriate priming of the immune response by infectious agents such as parasitic worms during childhood. Consistent with this, there is increasing evidence supporting an inverse relationship between worm infection and T helper type 1/17 (Th1/17)-based inflammatory disorders such as rheumatoid arthritis, inflammatory bowel disease, type 1 diabetes and multiple sclerosis. Perhaps more surprisingly, given that such worms often induce strong Th2-type immune responses, there also appears to be an inverse correlation between parasite load and atopy. These findings therefore suggest that the co-evolution of helminths with hosts, which has resulted in the ability of worms to modulate inflammatory responses to promote parasite survival, has also produced the benefit of protecting the host from pathological lesions arising from aggressive proinflammatory responses to infection or, indeed, aberrant inflammatory responses underlying autoimmune and allergic disorders. By focusing upon the properties of the filarial nematode-derived immunomodulatory molecule, ES-62, in this review we shall discuss the potential of exploiting the immunomodulatory products of parasitic worms to identify and develop novel therapeutics for inflammation
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