958 research outputs found

    Molecular diagnosis of multiple endocrine neoplasia type 2A

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    Objective. To identify by means of genetic analyses individuals who are at risk of developing medullary thyroid cancer that is a component of multiple endocrine neoplasia.Subjects. A three-generation kindred with clinically and biochemically diagnosed medUllary thyroid cancer.Method. Identification of a heterozygote mutation by nucleic acid sequencing and restriction analyses.Results. A heterozygote T → C (Cys → Arg) mutation at codon 618 in exon 10 of the RET proto-oncogene was identified in 4 family members who had previously been diagnosed with medullary thyroid cancer. The same mutation was also found in one of the proband's presymptomatic children who subsequently underwent a preemptive thyroidectomy. The genetic diagnosis was confirmed by histology. No mutations were detected in any other family members.Conclusion. Identification of heterozygote germline mutations in multiple endocrine neoplasia is direct, highly accurate and cost-effective. This study demonstrates that, appropriately used, molecular diagnosis can supersede conventional biochemical methods in the management of patients with inherited cancers

    C/EBPβ-Thr217 Phosphorylation Signaling Contributes to the Development of Lung Injury and Fibrosis in Mice

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    mice are refractory to Bleomycin-induced lung fibrosis the molecular mechanisms remain unknown. Here we show that blocking the ribosomal S-6 kinase (RSK) phosphorylation of the CCAAT/Enhancer Binding Protein (C/EBP)-β on Thr217 (a RSK phosphoacceptor) with either a single point mutation (Ala217), dominant negative transgene or a blocking peptide containing the mutated phosphoacceptor ameliorates the progression of lung injury and fibrosis induced by Bleomycin in mice. mice with a cell permeant, C/EBPβ peptide that inhibits phosphorylation of C/EBPβ on Thr217 (40 µg instilled intracheally on day-2 and day-6 after the single Bleomycin dose) also blocked the progression of lung injury and fibrosis induced by Bleomycin. Phosphorylation of human C/EBPβ on Thr266 (human homologue phosphoacceptor) was induced in collagen-activated human lung fibroblasts in culture as well as in activated lung fibroblasts in situ in lungs of patients with severe lung fibrosis but not in control lungs, suggesting that this signaling pathway may be also relevant in human lung injury and fibrosis.These data suggest that the RSK-C/EBPβ phosphorylation pathway may contribute to the development of lung injury and fibrosis

    Melaena with Peutz-Jeghers syndrome: a case report

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    Introduction: Peutz-Jeghers syndrome (PJS) is a rare familial disorder characterised by mucocutaneous pigmentation, gastrointestinal and extragastrointestinal hamartomatous polyps and an increased risk of malignancy. Peutz-Jeghers polyps in the bowel may result in intussusception. This complication usually manifests with abdominal pain and signs of intestinal obstruction. Case Presentation: We report the case of a 24-year-old Caucasian male who presented with melaena. Pigmentation of the buccal mucosa was noted but he was pain-free and examination of the abdomen was unremarkable. Upper gastrointestinal endoscopy revealed multiple polyps. An urgent abdominal computed tomography (CT) scan revealed multiple small bowel intussusceptions. Laparotomy was undertaken on our patient, reducing the intussusceptions and removing the polyps by enterotomies. Bowel resection was not needed. Conclusion: Melaena in PJS needs to be urgently investigated through a CT scan even in the absence of abdominal pain and when clinical examination of the abdomen shows normal findings. Although rare, the underlying cause could be intussusception, which if missed could result in grave consequences

    Genome-Wide Studies of Histone Demethylation Catalysed by the Fission Yeast Homologues of Mammalian LSD1

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    In order to gain a more global view of the activity of histone demethylases, we report here genome-wide studies of the fission yeast SWIRM and polyamine oxidase (PAO) domain homologues of mammalian LSD1. Consistent with previous work we find that the two S. pombe proteins, which we name Swm1 and Swm2 (after SWIRM1 and SWIRM2), associate together in a complex. However, we find that this complex specifically demethylates lysine 9 in histone H3 (H3K9) and both up- and down-regulates expression of different groups of genes. Using chromatin-immunoprecipitation, to isolate fragments of chromatin containing either H3K4me2 or H3K9me2, and DNA microarray analysis (ChIP-chip), we have studied genome-wide changes in patterns of histone methylation, and their correlation with gene expression, upon deletion of the swm1+ gene. Using hyper-geometric probability comparisons we uncover genetic links between lysine-specific demethylases, the histone deacetylase Clr6, and the chromatin remodeller Hrp1. The data presented here demonstrate that in fission yeast the SWIRM/PAO domain proteins Swm1 and Swm2 are associated in complexes that can remove methyl groups from lysine 9 methylated histone H3. In vitro, we show that bacterially expressed Swm1 also possesses lysine 9 demethylase activity. In vivo, loss of Swm1 increases the global levels of both H3K9me2 and H3K4me2. A significant accumulation of H3K4me2 is observed at genes that are up-regulated in a swm1 deletion strain. In addition, H3K9me2 accumulates at some genes known to be direct Swm1/2 targets that are down-regulated in the swm1¿ strain. The in vivo data indicate that Swm1 acts in concert with the HDAC Clr6 and the chromatin remodeller Hrp1 to repress gene expression. In addition, our in vitro analyses suggest that the H3K9 demethylase activity requires an unidentified post-translational modification to allow it to act. Thus, our results highlight complex interactions between histone demethylase, deacetylase and chromatin remodelling activities in the regulation of gene expression

    The role of partner support for health behaviours in people living with and beyond cancer: A qualitative study

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    Objective This study aimed to qualitatively explore how partner support for health behaviours is perceived, received, and utilised in people living with and beyond cancer (LWBC). Methods Semi-structured audio interviews were conducted with 24 participants, 15 men and nine women, living with and beyond breast, prostate, and colorectal cancer. Inductive and deductive Thematic Analysis was used to analyse the data. Results Three key themes with six subthemes were identified relating to partner support for health behaviours: (1) Interdependence (Reciprocity, Overt Control, Influence & Motivation) (2) Concordance (Shared Attitudes & Health Beliefs, Shared Health Behaviour) and (3) Communal Coping (Communal Orientation towards Health and Decision Making, Co-operative Action in Health Behaviour). Conclusions Partner support plays a unique and significant role in the health behaviours of people LWBC. Partners play a collaborative role in managing health and facilitating health behaviours, while the high level of concordance in couples may represent a potential barrier to change via the reinforcement of maladaptive health beliefs and behaviours. Implications for Cancer Survivors Overall, findings demonstrate that partners should be considered and included where possible when designing future behaviour change interventions for people LWBC

    Effects of pesticide mixtures on host-pathogen dynamics of the amphibian chytrid fungus

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    Anthropogenic and natural stressors often interact to affect organisms. Amphibian populations are undergoing unprecedented declines and extinctions with pesticides and emerging infectious diseases implicated as causal factors. Although these factors often cooccur, their effects on amphibians are usually examined in isolation. We hypothesized that exposure of larval and metamorphic amphibians to ecologically relevant concentrations of pesticide mixtures would increase their post-metamorphic susceptibility to the fungus Batra-chochytrium dendrobatidis (Bd), a pathogen that has contributed to amphibian population declines worldwide. We exposed five anuran species (Pacific treefrog, Pseudacris regilla; spring peeper, Pseudacris crucifer; Cascades frog, Rana cascadae; northern leopard frog, Lithobates pipiens; and western toad, Anaxyrus boreas) from three families to mixtures of four common insecticides (chlorpyrifos, carbaryl, permethrin, and endosulfan) or herbicides (glyphosate, acetochlor, atrazine, and 2,4-D) or a control treatment, either as tadpoles or as newly metamorphic individuals (metamorphs). Subsequently, we exposed animals to Bd or a control inoculate after metamorphosis and compared survival and Bd load. Bd exposure significantly increased mortality in Pacific treefrogs, spring peepers, and western toads, but not in Cascades frogs or northern leopard frogs. However, the effects of pesticide exposure on mortality were negligible, regardless of the timing of exposure. Bd load varied considerably across species; Pacific treefrogs, spring peepers, and western toads had the highest loads, whereas Cascades frogs and northern leopard frogs had the lowest loads. The influence of pesticide exposure on Bd load depended on the amphibian species, timing of pesticide exposure, and the particular pesticide treatment. Our results suggest that exposure to realistic pesticide concentrations has minimal effects on Bd-induced mortality, but can alter Bd load. This result could have broad implications for risk assessment of amphibians; the outcome of exposure to multiple stressors may be unpredictable and can differ between species and life stages

    The Effects of Sodium Phosphate Supplementation on Physiological Responses to Submaximal Exercise and 20 km Cycling Time-Trial Performance

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    The aim of this study was to examine the effects of sodium phosphate (SP) supplementation on 26 physiological responses to submaximal exercise and 20 km cycling time-trial performance. Using a 27 randomised, double-blind, crossover design, 20 endurance-trained male cyclists (age: 31 ± 6 years; 28 height: 1.82 ± 0.07 m; body mass: 76.3 ± 7.0 kg; maximal oxygen uptake [V̇O2max]: 57.9 ± 5.5 mL·kg-29 1·min-1) completed two supplementation trials separated by a 14-day washout period. The trials 30 consisted of 10 minutes of cycling at 65% V̇O2max followed by a 20 km time-trial. Expired air was 31 monitored throughout each trial for the evaluation of V̇O2, minute ventilation (V̇E), and respiratory 32 exchange ratio (RER). Heart rate was monitored during each trial along with ratings of perceived 33 exertion (RPE) and blood lactate concentration. For four days before each trial, participants ingested 50 34 mg∙kg fat-free-mass-1·day-1 of either SP or placebo. There were no effects (p ≥ 0.05) of supplementation 35 on physiological responses during cycling at 65% V̇O2max. There were also no effects of 36 supplementation on time-trial performance (placebo: 32.8 ± 2.2 mins; SP: 32.8 ± 2.3 mins). 37 Nevertheless, relative to placebo, SP increased V̇E (mean difference: 3.81 L·min-1; 95% likely range: 38 0.16-7.46 L·min-1), RER (mean difference: 0.020; 95% likely range: 0.004-0.036), and RPE (mean 39 difference: 0.39; 95% likely range: 0.04-0.73) during time-trials; as well as post time-trial blood lactate 40 concentration (mean difference: 1.06 mmol·L-1; 95% likely range: 0.31-1.80 mmol·L-1). In conclusion, 41 SP supplementation has no significant effects on submaximal physiological responses or 20 km time-42 trial performance

    Percentile reference values for anthropometric body composition indices in European children from the IDEFICS study

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    INTRODUCTION: To characterise the nutritional status in children with obesity or wasting conditions, European anthropometric reference values for body composition measures beyond the body mass index (BMI) are needed. Differentiated assessment of body composition in children has long been hampered by the lack of appropriate references. OBJECTIVES: The aim of our study is to provide percentiles for body composition indices in normal weight European children, based on the IDEFICS cohort (Identification and prevention of Dietary-and lifestyle-induced health Effects in Children and infantS). METHODS: Overall 18 745 2.0-10.9-year-old children from eight countries participated in the study. Children classified as overweight/obese or underweight according to IOTF (N = 5915) were excluded from the analysis. Anthropometric measurements (BMI (N = 12 830); triceps, subscapular, fat mass and fat mass index (N = 11 845-11 901); biceps, suprailiac skinfolds, sum of skinfolds calculated from skinfold thicknesses (N = 8129-8205), neck circumference (N = 12 241); waist circumference and waist-to-height ratio (N = 12 381)) were analysed stratified by sex and smoothed 1st, 3rd, 10th, 25th, 50th, 75th, 90th, 97th and 99th percentile curves were calculated using GAMLSS. RESULTS: Percentile values of the most important anthropometric measures related to the degree of adiposity are depicted for European girls and boys. Age-and sex-specific differences were investigated for all measures. As an example, the 50th and 99th percentile values of waist circumference ranged from 50.7-59.2 cm and from 51.3-58.7 cm in 4.5-to < 5.0-year-old girls and boys, respectively, to 60.6-74.5 cm in girls and to 59.9-76.7 cm in boys at the age of 10.5-10.9 years. CONCLUSION: The presented percentile curves may aid a differentiated assessment of total and abdominal adiposity in European children

    Emergent global patterns of ecosystem structure and function from a mechanistic general ecosystem model

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    Anthropogenic activities are causing widespread degradation of ecosystems worldwide, threatening the ecosystem services upon which all human life depends. Improved understanding of this degradation is urgently needed to improve avoidance and mitigation measures. One tool to assist these efforts is predictive models of ecosystem structure and function that are mechanistic: based on fundamental ecological principles. Here we present the first mechanistic General Ecosystem Model (GEM) of ecosystem structure and function that is both global and applies in all terrestrial and marine environments. Functional forms and parameter values were derived from the theoretical and empirical literature where possible. Simulations of the fate of all organisms with body masses between 10 µg and 150,000 kg (a range of 14 orders of magnitude) across the globe led to emergent properties at individual (e.g., growth rate), community (e.g., biomass turnover rates), ecosystem (e.g., trophic pyramids), and macroecological scales (e.g., global patterns of trophic structure) that are in general agreement with current data and theory. These properties emerged from our encoding of the biology of, and interactions among, individual organisms without any direct constraints on the properties themselves. Our results indicate that ecologists have gathered sufficient information to begin to build realistic, global, and mechanistic models of ecosystems, capable of predicting a diverse range of ecosystem properties and their response to human pressures
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