177 research outputs found
Differential gene network analysis for the identification of asthma-associated therapeutic targets in allergen-specific T-helper memory responses
Fifty most significant differentially expressed genes in HDM-stimulated versus resting CD4 T cells from HDM-sensitized atopics with asthmatics. Gene expression patterns were compared between HDM-stimulated and unstimulated CD4 T cells from HDM-sensitized atopics with asthma. Here we present the 50 most significant differentially expressed genes. (XLS 34Â kb
Identifying gene network patterns and associated cellular immune responses in children with or without nut allergy
Background: Although evidence suggests that the immune system plays a key role in the pathophysiology of nut allergy, the precise immunological mechanisms of nut allergy have not been systematically investigated. The aim of the present study was to identify gene network patterns and associated cellular immune responses in children with or without nut allergy. Methods: Transcriptome profiling of whole blood cells was compared between children with and without nut allergy. Three genes were selected to be validated on a larger cohort of samples (n = 86) by reverse transcription-polymerase chain reactions (RT-qPCR). The composition of immune cells was inferred from the transcriptomic data using the CIBERSORTx algorithm. A co-expression network was constructed employing weighted gene co-expression network analysis (WGCNA) on the top 5000 most variable transcripts. The modules were interrogated with pathway analysis tools (InnateDB) and correlated with clinical phenotypes and cellular immune responses. Results: Proportions of neutrophils were positively correlated and CD4+ T-cells and regulatory T-cells (Tregs) were negatively correlated with modules of nut allergy. We also identified 2 upregulated genes, namely Interferon Induced With Helicase C Domain 1 (IFIH1), DNA damage-regulated autophagy modulator 1 (DRAM1) and a downregulated gene Zinc Finger Protein 512B (ZNF512B) as hub genes for nut allergy. Further pathway analysis showed enrichment of type 1 interferon signalling in nut allergy. Conclusions: Our findings suggest that upregulation of type 1 interferon signalling and neutrophil responses and downregulation of CD4+ T-cells and Tregs are features of the pathogenesis of nut allergy
Predictors of 30-day and 90-day mortality among hemorrhagic and ischemic stroke patients in urban Uganda: a prospective hospital-based cohort study.
BACKGROUND: We report here on a prospective hospital-based cohort study that investigates predictors of 30-day and 90-day mortality and functional disability among Ugandan stroke patients. METHODS: Between December 2016 and March 2019, we enrolled consecutive hemorrhagic stroke and ischemic stroke patients at St Francis Hospital Nsambya, Kampala, Uganda. The primary outcome measure was mortality at 30 and 90 days. The modified Ranking Scale wasused to assess the level of disability and mortality after stroke. Stroke severity at admission was assessed using the National Institute of Health Stroke Scale (NIHSS) and Glasgow Coma Scale (GCS). Examination included clinical neurological evaluation, laboratory tests and brain computed tomography (CT) scan. Kaplan-Meier curves and multivariate Cox proportional hazard model were used for unadjusted and adjusted analysis to predict mortality. RESULTS: We enrolled 141 patients; 48 (34%) were male, mean age was 63.2 (+ 15.4) years old; 90 (64%) had ischemic and 51 (36%) had hemorrhagic stroke; 81 (57%) were elderly (≥ 60 years) patients. Overall mortality was 44 (31%); 31 (23%) patients died within the first 30 days post-stroke and, an additional 13 (14%) died within 90 days post-stroke. Mortality for hemorrhagic stroke was 19 (37.3%) and 25 (27.8%) for ischemic stroke. After adjusting for age and sex, a GCS score below < 9 (adjusted hazard ratio [aHR] =3.49, 95% CI: 1.39-8.75) was a significant predictor of 30-day mortality. GCS score < 9 (aHR =4.34 (95% CI: 1.85-10.2), stroke severity (NIHSS ≥21) (aHR = 2.63, 95% CI: (1.68-10.5) and haemorrhagic stroke type (aHR = 2.30, 95% CI: 1.13-4.66) were significant predictors of 90-day mortality. Shorter hospital stay of 7-13 days (aHR = 0.31, 95% CI: 0.11-0.93) and being married (aHR = 0.22 (95% CI: 0.06-0.84) had protective effects for 30 and 90-day mortality respectively. CONCLUSION: Mortality is high in the acute and sub-acute phase of stroke. Low levels of consciousness at admission, stroke severity, and hemorrhagic stroke were associated with increased higher mortality in this cohort of Ugandan stroke patients. Being married provided a protective effect for 90-day mortality. Given the high mortality during the acute phase, critically ill stroke patients would benefit from early interventions established as the post-stroke- standard of care in the country
Declining maternal mortality ratio in Uganda: priority interventions to achieve the Millennium Development Goal
Purpose: We conducted a survey to determine availability of emergency obstetric care (EmOC) and to provide data for advocating for improved maternal and newborn health in Uganda. Methods: The survey, covering 54 districts and 553 health facilities, assessed availability of EmOC signal functions, documented maternal deaths and the related causes. Three levels of health were covered. Findings: Few health units had running water; electricity or a functional operating theater. Yet having these items had a protective effect on maternal deaths as follows: theater (OR 0.56, P b 0.0001); electricity (OR 0.39, P b 0.0001); laboratory (OR 0.71, P b 0.0001) and staffing levels (midwives) OR 0.20, P b 0.0001. The availability of midwives had the highest protective effect on maternal deaths, reducing the case fatality rate by 80%. Further, most (97.2%) health facilities expected to offer basic EmOC, were not doing so. This is the likely explanation for the high health facility-based maternal death rate of 671/100,000 live births in Uganda. Conclusion: Addressing health system issues, especially human resources, and increasing access to EmOC could reduce maternal mortality in Uganda and enable the country to achieve the Millennium Development Goal (MDG)
Heterogeneous ketonic decarboxylation of dodecanoic acid: studying reaction parameters
Ketonic decarboxylation has gained significant attention in recent years as a pathway to reduce the oxygen content within biomass-derived oils, and to produce sustainable ketones. The reaction is base catalysed, with MgO an economic, accessible and highly basic heterogeneous catalyst. Here we use MgO to catalyse the ketonic decarboxylation of dodecanoic acid to form 12-tricosanone at moderate temperatures (250 °C, 280 °C and 300 °C) with low catalyst loads of 1% (w/w), 3% (w/w) and 5% (w/w) with respect to the dodecanoic acid, with a reaction time of 1 hour under batch conditions. Three different particle sizes for the MgO were tested (50 nm, 100 nm and 44 μm). Ketone yield was found to increase with increasing reaction temperature, reaching approximately 75% yield for all the samples tested. Temperature was found to be the main control on reaction yield, rather than surface area or particle size
Lipopolysaccharide-induced interferon response networks at birth are predictive of severe viral lower respiratory infections in the first year of life
Appropriate innate immune function is essential to limit pathogenesis and severity of severe lower respiratory infections (sLRI) during infancy, a leading cause of hospitalization and risk factor for subsequent asthma in this age group. Employing a systems biology approach to analysis of multi-omic profiles generated from a high-risk cohort (n = 50), we found that the intensity of activation of an LPS-induced interferon gene network at birth was predictive of sLRI risk in infancy (AUC = 0.724). Connectivity patterns within this network were stronger among susceptible individuals, and a systems biology approach identified IRF1 as a putative master regulator of this response. These findings were specific to the LPS-induced interferon response and were not observed following activation of viral nucleic acid sensing pathways. Comparison of responses at birth versus age 5 demonstrated that LPS-induced interferon responses but not responses triggered by viral nucleic acid sensing pathways may be subject to strong developmental regulation. These data suggest that the risk of sLRI in early life is in part already determined at birth, and additionally that the developmental status of LPS-induced interferon responses may be a key determinant of susceptibility. Our findings provide a rationale for the identification of at-risk infants for early intervention aimed at sLRI prevention and identifies targets which may be relevant for drug development
IRF7-Associated Immunophenotypes Have Dichotomous Responses to Virus/Allergen Coexposure and OM-85-Induced Reprogramming
High risk for virus-induced asthma exacerbations in children is associated with an IRF7lo immunophenotype, but the underlying mechanisms are unclear. Here, we applied a Systems Biology approach to an animal model comprising rat strains manifesting high (BN) versus low susceptibility (PVG) to experimental asthma, induced by virus/allergen coexposure, to elucidate the mechanism(s)-of-action of the high-risk asthma immunophenotype. We also investigated potential risk mitigation via pretreatment with the immune training agent OM-85. Virus/allergen coexposure in low-risk PVG rats resulted in rapid and transient airways inflammation alongside IRF7 gene network formation. In contrast, responses in high-risk BN rats were characterized by severe airways eosinophilia and exaggerated proinflammatory responses that failed to resolve, and complete absence of IRF7 gene networks. OM-85 had more profound effects in high-risk BN rats, inducing immune-related gene expression changes in lung at baseline and reducing exaggerated airway inflammatory responses to virus/allergen coexposure. In low-risk PVG rats, OM-85 boosted IRF7 gene networks in the lung but did not alter baseline gene expression or cellular influx. Distinct IRF7-associated asthma risk immunophenotypes have dichotomous responses to virus/allergen coexposure and respond differentially to OM-85 pretreatment. Extrapolating to humans, our findings suggest that the beneficial effects OM-85 pretreatment may preferentially target those in high-risk subgroups
Searching for a technology-driven acute rheumatic fever test: The START study protocol
Introduction: The absence of a diagnostic test for acute rheumatic fever (ARF) is a major impediment in managing this serious childhood condition. ARF is an autoimmune condition triggered by infection with group A Streptococcus. It is the precursor to rheumatic heart disease (RHD), a leading cause of health inequity and premature mortality for Indigenous peoples of Australia, New Zealand and internationally. Methods and analysis: Searching for a Technology-Driven Acute Rheumatic Fever Test\u27 (START) is a biomarker discovery study that aims to detect and test a biomarker signature that distinguishes ARF cases from non-ARF, and use systems biology and serology to better understand ARF pathogenesis. Eligible participants with ARF diagnosed by an expert clinical panel according to the 2015 Revised Jones Criteria, aged 5-30 years, will be recruited from three hospitals in Australia and New Zealand. Age, sex and ethnicity-matched individuals who are healthy or have non-ARF acute diagnoses or RHD, will be recruited as controls. In the discovery cohort, blood samples collected at baseline, and during convalescence in a subset, will be interrogated by comprehensive profiling to generate possible diagnostic biomarker signatures. A biomarker validation cohort will subsequently be used to test promising combinations of biomarkers. By defining the first biomarker signatures able to discriminate between ARF and other clinical conditions, the START study has the potential to transform the approach to ARF diagnosis and RHD prevention. Ethics and dissemination: The study has approval from the Northern Territory Department of Health and Menzies School of Health Research ethics committee and the New Zealand Health and Disability Ethics Committee. It will be conducted according to ethical standards for research involving Indigenous Australians and New Zealand Mā ori and Pacific Peoples. Indigenous investigators and governance groups will provide oversight of study processes and advise on cultural matters
Progressive increase of FcεRI expression across several PBMC subsets is associated with atopy and atopic asthma within school-aged children
Background: Antigen-specific IgE binds the Fcε receptor I (FcεRI) expressed on several types of immune cells, including dendritic cells (DCs). Activation of FcεRI on DCs in atopics has been shown to modulate immune responses that potentially contribute to asthma development. However, the extent to which DC subsets differ in FcεRI expression between atopic children with or without asthma is currently not clear. This study aimed to analyse the expression of FcεRI on peripheral blood mononuclear cells (PBMCs) from atopic children with and without asthma, and non-atopic/non-asthmatic age-matched healthy controls. Methods: We performed multiparameter flow cytometry on PBMC from 391 children across three community cohorts and one clinical cohort based in Western Australia. Results: We confirmed expression of FcεRI on basophils, monocytes, plasmacytoid and conventional DCs, with higher proportions of all cell populations expressing FcεRI in atopic compared to non-atopic children. Further, we observed that levels of FcεRI expression were elevated across plasmacytoid and conventional DC as well as basophils in atopic asthmatic compared to atopic non-asthmatic children also after adjusting for serum IgE levels. Conclusion: Our data suggest that the expression pattern of FcεRI on DC and basophils differentiates asthmatic from non-asthmatic atopic children. Given the significant immune modulatory effects observed as a consequence of FcεRI expression, this altered expression pattern is likely to contribute to asthma pathology in children
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