172 research outputs found

    A Gamma Interferon Independent Mechanism of CD4 T Cell Mediated Control of M. tuberculosis Infection in vivo

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    CD4 T cell deficiency or defective IFNγ signaling render humans and mice highly susceptible to Mycobacterium tuberculosis (Mtb) infection. The prevailing model is that Th1 CD4 T cells produce IFNγ to activate bactericidal effector mechanisms of infected macrophages. Here we test this model by directly interrogating the effector functions of Th1 CD4 T cells required to control Mtb in vivo. While Th1 CD4 T cells specific for the Mtb antigen ESAT-6 restrict in vivo Mtb growth, this inhibition is independent of IFNγ or TNF and does not require the perforin or FAS effector pathways. Adoptive transfer of Th17 CD4 T cells specific for ESAT-6 partially inhibited Mtb growth while Th2 CD4 T cells were largely ineffective. These results imply a previously unrecognized IFNγ/TNF independent pathway that efficiently controls Mtb and suggest that optimization of this alternative effector function may provide new therapeutic avenues to combat Mtb through vaccination

    Evaluation of a range of mammalian and mosquito cell lines for use in Chikungunya virus research

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    Chikungunya virus (CHIKV) is becoming an increasing global health issue which has spread across the globe and as far north as southern Europe. There is currently no vaccine or anti-viral treatment available. Although there has been a recent increase in CHIKV research, many of these in vitro studies have used a wide range of cell lines which are not physiologically relevant to CHIKV infection in vivo. In this study, we aimed to evaluate a panel of cell lines to identify a subset that would be both representative of the infectious cycle of CHIKV in vivo, and amenable to in vitro applications such as transfection, luciferase assays, immunofluorescence, western blotting and virus infection. Based on these parameters we selected four mammalian and two mosquito cell lines, and further characterised these as potential tools in CHIKV research

    La adhesión de las enfermeras al Método Canguro: subvención para la administración del cuidado de enfermería

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    ;;OBJETIVO:;; construir um modelo teórico explicativo acerca da adesão das enfermeiras ao Método Canguru na Unidade de Terapia Intensiva Neonatal, a partir dos significados e interações para a gerência do cuidado.;;;;MÉTODO:;; pesquisa qualitativa, guiada pelo referencial da Grounded Theory. Foram entrevistadas oito enfermeiras de uma Unidade de Terapia Intensiva Neonatal da cidade do Rio de Janeiro. A análise comparativa dos dados percorreu as etapas de codificação aberta, axial e seletiva, sendo construído um modelo teórico do tipo condicional-causal.;;;;RESULTADOS:;; emergiram quatro categorias principais que compuseram o paradigma de análise: Vestindo a camisa do Método Canguru; Trabalhando com a complexidade do Método Canguru; Encontrando (des)motivação para aplicar o Método Canguru; e Deparando-se com os desafios para a adesão e aplicação do Método Canguru.;;;;CONCLUSÕES:;; o fenômeno central revelou que cada enfermeira e profissional da equipe possui um papel de multiplicador de valores e práticas que podem ou não ser construtivas, influenciando potencialmente na (des)continuidade do Método Canguru na Unidade de Terapia Intensiva Neonatal. Os achados podem ser utilizados para o delineamento de estratégias gerenciais que ultrapassem os cursos e treinamentos e garantam o fortalecimento do modelo assistencial.;;;;OBJECTIVE:;; construct an explanatory theoretical model about nurses' adherence to the Kangaroo Care Method at the Neonatal Intensive Care Unit, based on the meanings and interactions for care management.;;;;METHOD:;; qualitative research, based on the reference framework of the Grounded Theory. Eight nurses were interviewed at a Neonatal Intensive Care Unit in the city of Rio de Janeiro. The comparative analysis of the data comprised the phases of open, axial and selective coding. A theoretical conditional-causal model was constructed.;;;;RESULTS:;; four main categories emerged that composed the analytic paradigm: Giving one's best to the Kangaroo Method; Working with the complexity of the Kangaroo Method; Finding (de)motivation to apply the Kangaroo Method; and Facing the challenges for the adherence to and application of the Kangaroo Method.;;;;CONCLUSIONS:;; the central phenomenon revealed that each nurse and team professional has a role of multiplying values and practices that may or may not be constructive, potentially influencing the (dis)continuity of the Kangaroo Method at the Neonatal Intensive Care Unit. The findings can be used to outline management strategies that go beyond the courses and training and guarantee the strengthening of the care model.;;;;OBJETIVO:;; construir un modelo teórico explicativo acerca de la adhesión de las enfermeras al Método Canguro en la Unidad de Terapia Intensiva Neonatal, a partir de los significados e interacciones para la administración del cuidado.;;;;MÉTODO:;; investigación cualitativa, guiada por el referencial de la Grounded Theory. Fueron entrevistadas ocho enfermeras de una Unidad de Terapia Intensiva Neonatal de la ciudad de Rio de Janeiro. El análisis comparativo de los datos recorrió las etapas de codificación abierta, axial y selectiva, siendo construido un modelo teórico del tipo condicional-causal.;;;;RESULTADOS:;; surgieron cuatro categorías principales que compusieron los paradigmas del análisis: Vistiendo la camisa del Método Canguro; Trabajando con la complejidad del Método Canguro; Encontrando (des)motivación para aplicar el Método Canguro; y Encontrando los desafíos para la adhesión y aplicación del Método Canguro.;;;;CONCLUSIONES:;; el fenómeno central reveló que cada enfermera y profesional del equipo posee un papel de multiplicador de valores y prácticas que pueden o no ser constructivas, influenciando potencialmente en la (des)continuidad del Método Canguro en la Unidad de Terapia Intensiva Neonatal. Los hallazgos pueden ser utilizados para el delineamiento de estrategias de administración que sobrepasen los cursos y entrenamientos y garanticen el fortalecimiento del modelo asistencial.;

    Early Markers of Glycaemic Control in Children with Type 1 Diabetes Mellitus

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    Background: Type 1 diabetes mellitus (T1DM) may lead to severe long-term health consequences. In a longitudinal study, we aimed to identify factors present at diagnosis and 6 months later that were associated with glycosylated haemoglobin (HbA 1c) levels at 24 months after T1DM diagnosis, so that diabetic children at risk of poor glycaemic control may be identified. Methods: 229 children,15 years of age diagnosed with T1DM in the Auckland region were studied. Data collected at diagnosis were: age, sex, weight, height, ethnicity, family living arrangement, socio-economic status (SES), T1DM antibody titre, venous pH and bicarbonate. At 6 and 24 months after diagnosis we collected data on weight, height, HbA 1c level, and insulin dose. Results: Factors at diagnosis that were associated with higher HbA1c levels at 6 months: female sex (p,0.05), lower SES (p,0.01), non-European ethnicity (p,0.01) and younger age (p,0.05). At 24 months, higher HbA1c was associated with lower SES (p,0.001), Pacific Island ethnicity (p,0.001), not living with both biological parents (p,0.05), and greater BMI SDS (p,0.05). A regression equation to predict HbA1c at 24 months was consequently developed. Conclusions: Deterioration in glycaemic control shortly after diagnosis in diabetic children is particularly marked in Pacific Island children and in those not living with both biological parents. Clinicians need to be aware of factors associated wit

    Integration of Gene Dosage and Gene Expression in Non-Small Cell Lung Cancer, Identification of HSP90 as Potential Target

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    BACKGROUND: Lung cancer causes approximately 1.2 million deaths per year worldwide, and non-small cell lung cancer (NSCLC) represents 85% of all lung cancers. Understanding the molecular events in non-small cell lung cancer (NSCLC) is essential to improve early diagnosis and treatment for this disease. METHODOLOGY AND PRINCIPAL FINDINGS: In an attempt to identify novel NSCLC related genes, we performed a genome-wide screening of chromosomal copy number changes affecting gene expression using microarray based comparative genomic hybridization and gene expression arrays on 32 radically resected tumor samples from stage I and II NSCLC patients. An integrative analysis tool was applied to determine whether chromosomal copy number affects gene expression. We identified a deletion on 14q32.2-33 as a common alteration in NSCLC (44%), which significantly influenced gene expression for HSP90, residing on 14q32. This deletion was correlated with better overall survival (P = 0.008), survival was also longer in patients whose tumors had low expression levels of HSP90. We extended the analysis to three independent validation sets of NSCLC patients, and confirmed low HSP90 expression to be related with longer overall survival (P = 0.003, P = 0.07 and P = 0.04). Furthermore, in vitro treatment with an HSP90 inhibitor had potent antiproliferative activity in NSCLC cell lines. CONCLUSIONS: We suggest that targeting HSP90 will have clinical impact for NSCLC patients

    CHOP Mediates Endoplasmic Reticulum Stress-Induced Apoptosis in Gimap5-Deficient T Cells

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    Gimap5 (GTPase of the immunity-associated protein 5) has been linked to the regulation of T cell survival, and polymorphisms in the human GIMAP5 gene associate with autoimmune disorders. The BioBreeding diabetes-prone (BBDP) rat has a mutation in the Gimap5 gene that leads to spontaneous apoptosis of peripheral T cells by an unknown mechanism. Because Gimap5 localizes to the endoplasmic reticulum (ER), we hypothesized that absence of functional Gimap5 protein initiates T cell death through disruptions in ER homeostasis. We observed increases in ER stress-associated chaperones in T cells but not thymocytes or B cells from Gimap5−/− BBDP rats. We then discovered that ER stress-induced apoptotic signaling through C/EBP-homologous protein (CHOP) occurs in Gimap5−/− T cells. Knockdown of CHOP by siRNA protected Gimap5−/− T cells from ER stress-induced apoptosis, thereby identifying a role for this cellular pathway in the T cell lymphopenia of the BBDP rat. These findings indicate a direct relationship between Gimap5 and the maintenance of ER homeostasis in the survival of T cells

    Shiga Toxin Binding to Glycolipids and Glycans

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    Background: Immunologically distinct forms of Shiga toxin (Stx1 and Stx2) display different potencies and disease outcomes, likely due to differences in host cell binding. The glycolipid globotriaosylceramide (Gb3) has been reported to be the receptor for both toxins. While there is considerable data to suggest that Gb3 can bind Stx1, binding of Stx2 to Gb3 is variable. Methodology: We used isothermal titration calorimetry (ITC) and enzyme-linked immunosorbent assay (ELISA) to examine binding of Stx1 and Stx2 to various glycans, glycosphingolipids, and glycosphingolipid mixtures in the presence or absence of membrane components, phosphatidylcholine, and cholesterol. We have also assessed the ability of glycolipids mixtures to neutralize Stx-mediated inhibition of protein synthesis in Vero kidney cells. Results: By ITC, Stx1 bound both Pk (the trisaccharide on Gb3) and P (the tetrasaccharide on globotetraosylceramide, Gb4), while Stx2 did not bind to either glycan. Binding to neutral glycolipids individually and in combination was assessed by ELISA. Stx1 bound to glycolipids Gb3 and Gb4, and Gb3 mixed with other neural glycolipids, while Stx2 only bound to Gb3 mixtures. In the presence of phosphatidylcholine and cholesterol, both Stx1 and Stx2 bound well to Gb3 or Gb4 alone or mixed with other neutral glycolipids. Pre-incubation with Gb3 in the presence of phosphatidylcholine and cholesterol neutralized Stx1, but not Stx2 toxicity to Vero cells
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