109 research outputs found

    The effect of anabolic-androgenic hormones on postprandial triglyceridaemia and lipoprotein profiles in man

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    It has been hypothesised that endogenous testosterone and AAS may predispose humans to premature CHD. However, there is no direct evidence to link these hormones with a greater prevalence of premature CHD. The aim of this thesis was to better describe atherosclerotic risk associated with these hormones by clarifying their effect on additional risk factors for premature atherosclerosis. Little is known about the effect of testosterone and AAS on 'atherogenic dyslipidaemia', a phenotype characterised by elevated postprandial triglyceridaemia, small dense LDL and a low HDLC concentration, which confers a high risk of CHD. Accordingly, the magnitude of postprandial triglyceridaemia, LDL and HDL particle size, and LDLC, HDLC and Lp(a) concentration were compared in male (n=9) and female (n=3) bodybuilders after self administration of AAS for 5-6 weeks (ON cycle) and again after a 4-6 week 'washout' period (OFF cycle), and in normal males (T) (n=10) before and during a reversible suppression of endogenous testosterone, induced using a GnRH agonist (triptorelin), and in a control group (C) (n=8). Lipoprotein size was assessed by gradient gel electrophoresis (GGE), lipoprotein concentrations by immuno and enzymatic assay, and postprandial triglyceridaemia by a standardised oral fat tolerance test (65g/m² ). HDLC decreased in male bodybuilders (0.94±0.30 vs 0.70±0.27 mmol/L, p=0.004; x ± SD) and female bodybuilders (1.3±0.5 vs 0.8±0.2 mmol/L) ON cycle. GGE studies suggested that mostly HDL₂ was reduced. There were no significant reductions in LDL particle size ON cycle. Two males had larger LDL species ON cycle. Lp(a) decreased in male bodybuilders (124.7±128.0 to 69.3±73.3 U/L, p=0.008). ON cycle postprandial triglyceride excursion was unchanged in female bodybuilders and reduced (11.6±10.0 vs 7.5±5.4 mmol/L.hr; p=0.027) in male bodybuilders. In the triptorelin study, HDLC was increased in T (1.07±0.18 vs 1.41±0.28 mmol/L, p=0.002) and not in C. GGE studies indicated an increase of HDL₂ in five T subjects and no increase in C. Total cholesterol increased in T (4.77±0.80 vs 5.24±1.04 mmol/L, p=0.039) but not in C. LDL size increased in four T subjects, and not in C. Lp(a) increased in T (277.9±149.l vs 376.5±222.2 U/L, p=0.004), but not in C. Postprandial triglyceridaemia was unchanged in both T and C. The results of these studies did not show any additional atherogenic effects of endogenous testosterone or AAS in humans. Rather, a suppression of Lp(a) may be an antiatherogenic effect of these hormones. A reduced postprandial triglyceridaemia and increased LDL size in individuals who are predisposed to 'atherogenic dyslipidaemia', may be further antiatherogenic effects of AAS use

    Combined immunodeficiency and Epstein-Barr virus-induced B cell malignancy in humans with inherited CD70 deficiency

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    In this study, we describe four patients from two unrelated families of different ethnicities with a primary immunodeficiency, predominantly manifesting as susceptibility to Epstein-Barr virus (EBV)–related diseases. Three patients presented with EBV-associated Hodgkin’s lymphoma and hypogammaglobulinemia; one also had severe varicella infection. The fourth had viral encephalitis during infancy. Homozygous frameshift or in-frame deletions in CD70 in these patients abolished either CD70 surface expression or binding to its cognate receptor CD27. Blood lymphocyte numbers were normal, but the proportions of memory B cells and EBV-specific effector memory CD8+ T cells were reduced. Furthermore, although T cell proliferation was normal, in vitro–generated EBV-specific cytotoxic T cell activity was reduced because of CD70 deficiency. This reflected impaired activation by, rather than effects during killing of, EBV-transformed B cells. Notably, expression of 2B4 and NKG2D, receptors implicated in controlling EBV infection, on memory CD8+ T cells from CD70-deficient individuals was reduced, consistent with their impaired killing of EBV-infected cells. Thus, autosomal recessive CD70 deficiency is a novel cause of combined immunodeficiency and EBV-associated diseases, reminiscent of inherited CD27 deficiency. Overall, human CD70–CD27 interactions therefore play a nonredundant role in T and B cell–mediated immunity, especially for protection against EBV and humoral immunity

    Practical consensus guidelines for the management of enuresis

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    Despite the high prevalence of enuresis, the professional training of doctors in the evaluation and management of this condition is often minimal and/or inconsistent. Therefore, patient care is neither optimal nor efficient, which can have a profound impact on affected children and their families. Once comprehensive history taking and evaluation has eliminated daytime symptoms or comorbidities, monosymptomatic enuresis can be managed efficaciously in the majority of patients. Non-monosymptomatic enuresis is often a more complex condition; these patients may benefit from referral to specialty care centers. We outline two alternative strategies to determine the most appropriate course of care. The first is a basic assessment covering only the essential components of diagnostic investigation which can be carried out in one office visit. The second strategy includes several additional evaluations including completion of a voiding diary, which requires extra time during the initial consultation and two office visits before treatment or specialty referral is provided. This should yield greater success than first-line treatment. Conclusion: This guideline, endorsed by major international pediatric urology and nephrology societies, aims to equip a general pediatric practice in both primary and secondary care with simple yet comprehensive guidelines and practical tools (i.e., checklists, diary templates, and quick-reference flowcharts) for complete evaluation and successful treatment of enuresis

    Body fatness during childhood and adolescence and incidence of breast cancer in premenopausal women: a prospective cohort study

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    INTRODUCTION: Body mass index (BMI) during adulthood is inversely related to the incidence of premenopausal breast cancer, but the role of body fatness earlier in life is less clear. We examined prospectively the relation between body fatness during childhood and adolescence and the incidence of breast cancer in premenopausal women. METHODS: Participants were 109,267 premenopausal women in the Nurses' Health Study II who recalled their body fatness at ages 5, 10 and 20 years using a validated 9-level figure drawing. Over 12 years of follow up, 1318 incident cases of breast cancer were identified. Cox proportional hazards regression was used to compute relative risks (RRs) and 95% confidence intervals (CIs) for body fatness at each age and for average childhood (ages 5–10 years) and adolescent (ages 10–20 years) fatness. RESULTS: Body fatness at each age was inversely associated with premenopausal breast cancer incidence; the multivariate RRs were 0.48 (95% CI 0.35–0.55) and 0.57 (95% CI 0.39–0.83) for the most overweight compared with the most lean in childhood and adolescence, respectively (P for trend < 0.0001). The association for childhood body fatness was only slightly attenuated after adjustment for later BMI, with a multivariate RR of 0.52 (95% CI 0.38–0.71) for the most overweight compared with the most lean (P for trend = 0.001). Adjustment for menstrual cycle characteristics had little impact on the association. CONCLUSION: Greater body fatness during childhood and adolescence is associated with reduced incidence of premenopausal breast cancer, independent of adult BMI and menstrual cycle characteristics

    Making subaltern shikaris: histories of the hunted in colonial central India

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    Academic histories of hunting or shikar in India have almost entirely focused on the sports hunting of British colonists and Indian royalty. This article attempts to balance this elite bias by focusing on the meaning of shikar in the construction of the Gond ‘tribal’ identity in late nineteenth and early twentieth-century colonial central India. Coining the term ‘subaltern shikaris’ to refer to the class of poor, rural hunters, typically ignored in this historiography, the article explores how the British managed to use hunting as a means of state penetration into central India’s forest interior, where they came to regard their Gond forest-dwelling subjects as essentially and eternally primitive hunting tribes. Subaltern shikaris were employed by elite sportsmen and were also paid to hunt in the colonial regime’s vermin eradication programme, which targeted tigers, wolves, bears and other species identified by the state as ‘dangerous beasts’. When offered economic incentives, forest dwellers usually willingly participated in new modes of hunting, even as impact on wildlife rapidly accelerated and became unsustainable. Yet as non-indigenous approaches to nature became normative, there was sometimes also resistance from Gond communities. As overkill accelerated, this led to exclusion of local peoples from natural resources, to their increasing incorporation into dominant political and economic systems, and to the eventual collapse of hunting as a livelihood. All of this raises the question: To what extent were subaltern subjects, like wildlife, ‘the hunted’ in colonial India

    Compartmentalization of total and virus-specific tissue-resident memory CD8+ T Cells in human lymphoid organs

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    Disruption of T cell memory during severe immune suppression results in reactivation of chronic viral infections, such as Epstein Barr virus (EBV) and Cytomegalovirus (CMV). How different subsets of memory T cells contribute to the protective immunity against these viruses remains poorly defined. In this study we examined the compartmentalization of virus-specific, tissue resident memory CD8+ T cells in human lymphoid organs. This revealed two distinct populations of memory CD8+ T cells, that were CD69+CD103+ and CD69+CD103-, and were retained within the spleen and tonsils in the absence of recent T cell stimulation. These two types of memory cells were distinct not only in their phenotype and transcriptional profile, but also in their anatomical localization within tonsils and spleen. The EBV-specific, but not CMV-specific, CD8+ memory T cells preferentially accumulated in the tonsils and acquired a phenotype that ensured their retention at the epithelial sites where EBV replicates. In vitro studies revealed that the cytokine IL-15 can potentiate the retention of circulating effector memory CD8+ T cells by down-regulating the expression of sphingosine-1-phosphate receptor, required for T cell exit from tissues, and its transcriptional activator, Kruppel-like factor 2 (KLF2). Within the tonsils the expression of IL-15 was detected in regions where CD8+ T cells localized, further supporting a role for this cytokine in T cell retention. Together this study provides evidence for the compartmentalization of distinct types of resident memory T cells that could contribute to the long-term protection against persisting viral infections

    Molecular Pathogenesis of EBV Susceptibility in XLP as Revealed by Analysis of Female Carriers with Heterozygous Expression of SAP

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    X-linked lymphoproliferative disease (XLP) is a primary immunodeficiency caused by mutations in SH2D1A which encodes SAP. SAP functions in signalling pathways elicited by the SLAM family of leukocyte receptors. A defining feature of XLP is exquisite sensitivity to infection with EBV, a B-lymphotropic virus, but not other viruses. Although previous studies have identified defects in lymphocytes from XLP patients, the unique role of SAP in controlling EBV infection remains unresolved. We describe a novel approach to this question using female XLP carriers who, due to random X-inactivation, contain both SAP+ and SAP− cells. This represents the human equivalent of a mixed bone marrow chimera in mice. While memory CD8+ T cells specific for CMV and influenza were distributed across SAP+ and SAP− populations, EBV-specific cells were exclusively SAP+. The preferential recruitment of SAP+ cells by EBV reflected the tropism of EBV for B cells, and the requirement for SAP expression in CD8+ T cells for them to respond to Ag-presentation by B cells, but not other cell types. The inability of SAP− clones to respond to Ag-presenting B cells was overcome by blocking the SLAM receptors NTB-A and 2B4, while ectopic expression of NTB-A on fibroblasts inhibited cytotoxicity of SAP− CD8+ T cells, thereby demonstrating that SLAM receptors acquire inhibitory function in the absence of SAP. The innovative XLP carrier model allowed us to unravel the mechanisms underlying the unique susceptibility of XLP patients to EBV infection in the absence of a relevant animal model. We found that this reflected the nature of the Ag-presenting cell, rather than EBV itself. Our data also identified a pathological signalling pathway that could be targeted to treat patients with severe EBV infection. This system may allow the study of other human diseases where heterozygous gene expression from random X-chromosome inactivation can be exploited

    Global wealth disparities drive adherence to COVID-safe pathways in head and neck cancer surgery

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