3,012 research outputs found

    Bariatric Surgery in Hypothalamic Obesity

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    Craniopharyngiomas (CP) are epithelial neoplasms generally found in the area of the pituitary and hypothalamus. Despite benign histology, these tumors and/or their treatment often result in significant, debilitating disorders of endocrine, neurological, behavioral, and metabolic systems. Severe obesity is observed in a high percentage of patients with CP resulting in significant comorbidities and negatively impacting quality of life. Obesity occurs as a result of hypothalamic damage and disruption of normal homeostatic mechanisms regulating energy balance. Such pathological weight gain, termed hypothalamic obesity (HyOb), is often severe and refractory to therapy. Unfortunately, neither lifestyle intervention nor pharmacotherapy has proven effective in the treatment of HyOb. Given the limited choices and poor results of these treatments, several groups have examined bariatric surgery as a treatment alternative for patients with CP–HyOb. While a large body of evidence exists supporting the use of bariatric surgery in the treatment of exogenous obesity and its comorbidities, its role in the treatment of HyOb has yet to be defined. To date, the existing literature on bariatric surgery in CP–HyOb is largely limited to case reports and series with short term follow-up. Here we review the current reports on the use of bariatric surgery in the treatment of CP–HyOb. We also compare these results to those reported for other populations of HyOb, including Prader–Willi Syndrome, Bardet–Biedl syndrome, and hypothalamic melanocortin signaling defects. While initial reports of bariatric surgery in CP–HyOb are promising, their limited scope makes it difficult to draw any substantial conclusions as to the long term safety and efficacy of bariatric surgery in CP–HyOb. There continues to be a need for more robust, controlled, prospective studies with long term follow-up in order to better define the role of bariatric surgery in the treatment of HyOb

    Nasal administration of cardiac myosin suppresses autoimmune myocarditis in mice

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    AbstractOBJECTIVESThis study was designed to examine whether myocarditis induced in a mouse model can be effectively suppressed by nasal administration of cardiac myosin (CM).BACKGROUNDMyocarditis in humans often follows viral infection and is accompanied by evidence of an autoimmune response to CM. Treatment has been hampered by the fact that measures undertaken to reduce the autoimmune response often enhance the viral infection. Delivery of antigen via nasal route has been shown to induce antigen-specific tolerance and suppress certain autoimmune diseases in animal models.METHODSMyocarditis was induced in A/J mice by two subcutaneous injections of CM emulsified in complete Freund’s adjuvant. Nasal instillation of CM (200 μg/mouse) or vehicle buffer was carried out three days before the first subcutaneous injection (day −3). The effect of nasal instillation of CM on cardiac histopathology, cytokine production by splenocytes, and antibody response was examined three weeks after the first subcutaneous injection (day 21).RESULTSNasal administration of CM effectively reduced the severity of myocarditis. Consistent with the histological findings, the levels of interleukin-2 (IL-2), tumor necrosis factor-α, and IL-1β produced by splenocytes in response to CM were significantly decreased. In addition, the serum levels of IgE and IgG1 anti-myosin antibodies were suppressed. However, the levels of transforming growth factor-β (TGF-β) and CM-specific IgA antibodies were not affected.CONCLUSIONSTaken together, our results do not support active suppression through upregulation of TGF-β, IL-4, and IL-10 as a mechanism of tolerance, but favor anergy or deletion of both Th1 and Th2 autoreactive T cells

    Exploiting parallels between livestock and wildlife: Predicting the impact of climate change on gastrointestinal nematodes in ruminants.

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    Global change, including climate, policy, land use and other associated environmental changes, is likely to have a major impact on parasitic disease in wildlife, altering the spatio-temporal patterns of transmission, with wide-ranging implications for wildlife, domestic animals, humans and ecosystem health. Predicting the potential impact of climate change on parasites infecting wildlife will become increasingly important in the management of species of conservation concern and control of disease at the wildlife-livestock and wildlife-human interface, but is confounded by incomplete knowledge of host-parasite interactions, logistical difficulties, small sample sizes and limited opportunities to manipulate the system. By exploiting parallels between livestock and wildlife, existing theoretical frameworks and research on livestock and their gastrointestinal nematodes can be adapted to wildlife systems. Similarities in the gastrointestinal nematodes and the life-histories of wild and domestic ruminants, coupled with a detailed knowledge of the ecology and life-cycle of the parasites, render the ruminant-GIN host-parasite system particularly amenable to a cross-disciplinary approach

    Response to GH Treatment After Radiation Therapy Depends on Location of Irradiation

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    OBJECTIVES: Cancer survivors with GH deficiency (GHD) receive GH therapy (GHT) after 1+ year observation to ensure stable tumor status/resolution. HYPOTHESIS: Radiation therapy (RT) to brain, spine, or extremities alters growth response to GHT. AIM: Identify differences in growth response to GHT according to type/location of RT. METHODS: The Pfizer International Growth Database was searched for cancer survivors on GHT for ≥5 years. Patient data, grouped by tumor type, were analyzed for therapy (surgery, chemotherapy, RT of the focal central nervous system, cranial, craniospinal, or total body irradiation [TBI] as part of bone marrow transplantation), sex, peak stimulated GH, age at GHT start, and duration from RT to GHT start. Kruskal-Wallis test and quantile regression modeling were performed. RESULTS: Of 1149 GHD survivors on GHT for ≥5 years (male 733; median age 8.4 years; GH peak 2.8 ng/mL), 431 had craniopharyngioma (251, cranial RT), 224 medulloblastoma (craniospinal RT), 134 leukemia (72 TBI), and 360 other tumors. Median age differed by tumor group (P < 0.001). Five-year delta height SD score (SDS) (5-year ∆HtSDS; median [10th-90th percentile]) was greatest for craniopharyngioma, 1.6 (0.3-3.0); for medulloblastoma, 5-year ∆HtSDS 0.9 (0.0-1.9); for leukemia 5-year ∆HtSDS, after TBI (0.3, 0-0.7) versus without RT (0.5, 0-0.9), direct comparison P < 0.001. Adverse events included 40 treatment-related, but none unexpected. CONCLUSIONS: TBI for leukemia had significant impact on growth response to GHT. Medulloblastoma survivors had intermediate GHT response, whereas craniopharyngioma cranial RT did not alter GHT response. Both craniospinal and epiphyseal irradiation negatively affect growth response to GH therapy compared with only cranial RT or no RT

    Natural Resistance-Associated Macrophage Protein Is a Cellular Receptor for Sindbis Virus in Both Insect and Mammalian Hosts

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    SummaryAlphaviruses, including several emerging human pathogens, are a large family of mosquito-borne viruses with Sindbis virus being a prototypical member of the genus. The host factor requirements and receptors for entry of this class of viruses remain obscure. Using a Drosophila system, we identified the divalent metal ion transporter natural resistance-associated macrophage protein (NRAMP) as a host cell surface molecule required for Sindbis virus binding and entry into Drosophila cells. Consequently, flies mutant for dNRAMP were protected from virus infection. NRAMP2, the ubiquitously expressed vertebrate homolog, mediated binding and infection of Sindbis virus into mammalian cells, and murine cells deficient for NRAMP2 were nonpermissive to infection. Alphavirus glycoprotein chimeras demonstrated that the requirement for NRAMP2 is at the level of Sindbis virus entry. Given the conserved structure of alphavirus glycoproteins, and the widespread use of transporters for viral entry, other alphaviruses may use conserved multipass membrane proteins for infection

    Molecular mechanisms and phenotypic variation in RYR1-related congenital myopathies

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    Dominant mutations in the skeletal muscle ryanodine receptor (RYR1) gene are well-recognized causes of both malignant hyperthermia susceptibility (MHS) and central core disease (CCD). More recently, recessive RYR1 mutations have been described in few congenital myopathy patients with variable pathology, including multi-minicores. Although a clinical overlap between patients with dominant and recessive RYR1 mutations exists, in most cases with recessive mutations the pattern of muscle weakness is remarkably different from that observed in dominant CCD. In order to characterize the spectrum of congenital myopathies associated with RYR1 mutations, we have investigated a cohort of 44 patients from 28 families with clinical and/or histopathological features suggestive of RYR1 involvement. We have identified 25 RYR1 mutations, 9 of them novel, including 12 dominant and 13 recessive mutations. With only one exception, dominant mutations were associated with a CCD phenotype, prominent cores and predominantly occurred in the RYR1 C-terminal exons 101 and 102. In contrast, the 13 recessive RYR1 mutations were distributed evenly along the entire RYR1 gene and were associated with a wide range of clinico-pathological phenotypes. Protein expression studies in nine cases suggested a correlation between specific mutations, RyR1 protein levels and resulting phenotype: in particular, whilst patients with dominant or recessive mutations associated with typical CCD phenotypes appeared to have normal RyR1 expression, individuals with more generalized weakness, multi-minicores and external ophthalmoplegia had a pronounced depletion of the RyR1 protein. The phenomenon of protein depletion was observed in some patients compound heterozygous for recessive mutations at the genomic level and silenced another allele in skeletal muscle, providing additional information on the mechanism of disease in these patients. Our data represent the most extensive study of RYR1-related myopathies and indicate complex genotype-phenotype correlations associated with mutations differentially affecting assembly and function of the RyR1 calcium release channe

    Associations of HDL metrics with coronary artery calcium score and density among women traversing menopause

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    The cardioprotective association of high-density lipoprotein cholesterol (HDL-C) may vary by menopause stage or estradiol level. We tested whether associations of comprehensive HDL metrics (HDL subclasses, phospholipid and triglyceride content, and HDL cholesterol efflux capacity [HDL-CEC]) with coronary artery calcium (CAC) score and density vary by menopause stage or estradiol level in women transitioning through menopause. Participants (N = 294; mean age [SD]: 51.3 [2.9]) had data on HDL metrics and CAC measures at one or two time points during the menopause transition. Generalized estimating equations were used for analyses. Effect modifications by menopause stage or estradiol level were tested in multivariable models. In adjusted models, menopause stage modified the associations of specific HDL metrics with CAC measures. Higher small HDL particles (HDL-P) concentrations (p-interaction = 0.008) and smaller HDL size (p-interaction = 0.02) were associated with greater odds of CAC presence in late perimenopause than in pre/early perimenopause stage. Women in the highest estradiol tertile, but not the lower tertiles, showed a protective association of small HDL-P with CAC presence (p-interaction = 0.007). Lower large HDL-P concentrations (p-interaction = 0.03) and smaller HDL size (p-interaction = 0.03) were associated with lower CAC density in late perimenopause than in postmenopause stage. Associations of HDL phospholipid and triglyceride content and HDL-CEC with CAC measures did not vary by menopause stage or estradiol level. We concluded that HDL subclasses may impact the likelihood of CAC presence and the stability of coronary plaque differently over the menopause transition. Endogenous estradiol levels may contribute to this observation
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