1,094 research outputs found
Peripheral blood leukocyte immune responses in sarcoidosis
Sarcoidosis is a multisystem granulomatous inflammatory disease of unknown aetiology with heterogeneous clinical manifestations. The disease is characterised by elevated Th1-like pro-inflammatory immune responses in tissue, whereas peripheral blood has been described as either having enhanced, diminished or similar responses in patients compared with healthy controls. The aim of this study was to characterise the immune responses from peripheral leukocytes in patients with sarcoidosis, focussing on inflammatory and regulatory features present in the disease.Immunophenotyping of peripheral blood mononuclear cells (PBMCs) by flow cytometry showed that 86% of patients with sarcoidosis displayed a T-cell lymphocytopenia, with over a 2 fold reduction in cell number compared to healthy controls, confirming the findings of other groups. The proportion of the more pro-inflammatory âIntermediateâ monocyte subset (CD14++ CD16+) was increased in patients with sarcoidosis, matched by a reduction in the âClassicalâ monocyte subset (CD14++ CD16-).High concentrations of phytohaemagglutinin (PHA) induced significantly increased IL-6 and TNF-α release from the blood of patients with sarcoidosis compared with controls in ex vivo whole blood assays. By contrast, IL-6 release in response to a high concentration of Staphylococcal enterotoxin A was significantly reduced in patients. There was no statistically significant difference in cytokine release from patients compared with controls when whole blood was treated with a range of other ligands and cytokines.The regulatory CD200 receptor (CD200R) expression was reduced on monocytes from patients with sarcoidosis, whereas there was no significant difference in IL-10 receptor or SIRP-α expression between patients and controls. The CD200Rlow phenotype on monocytes was associated with elevated PHA induced IL-6 and TNF-α release from whole blood.Patients with sarcoidosis are capable of robust peripheral blood leukocyte immune responses and display alterations in the regulatory CD200R/CD200L axis that may play a role in the immuopathogenesis of the disease
Salicylaldehyde hydrazones: buttressing of outer sphere hydrogen-bonding and copper-extraction properties
Salicylaldehyde hydrazones are weaker copper extractants than their oxime derivatives, which are used in hydrometallurgical processes to recover ~20â% of the worldâs copper. Their strength, based on the extraction equilibrium constant Ke, can be increased by nearly three orders of magnitude by incorporating electron-withdrawing or hydrogen-bond acceptor groups (X) ortho to the phenolic OH group of the salicylaldehyde unit. Density functional theory calculations suggest that the effects of the 3-X substituents arise from a combination of their influence on the acidity of the phenol in the pH-dependent equilibrium, Cu2+â+â2Lorgâââ[Cu(LâH)2]orgâ+â2H+, and on their ability to âbuttressâ interligand hydrogen bonding by interacting with the hydrazone NâH donor group. X-ray crystal structure determination and computed structures indicate that in both the solid state and the gas phase, coordinated hydrazone groups are less planar than coordinated oximes and this has an adverse effect on intramolecular hydrogen-bond formation to the neighbouring phenolate oxygen atoms
QT peak prolongation predicts cardiac death following stroke
Cardiac death has been linked in many populations to prolongation of the QT interval (QTe). However, basic science research suggested that the best estimate of the time point when repolarisation begins is near the T-wave peak. We found QT peak (QTp) was longer in hypertensive subjects with LVH. A prolonged âdepolarisationâ phase, rather than ârepolarisationâ (T peak to T end) might therefore account for the higher incidence of cardiac death linked to long QT. Hypothesis: We have tested the hypothesis that QT peak (QTp) prolongation predicts cardiac death in stroke survivors. Methods and Results: ECGs were recorded from 296 stroke survivors (152 male), mean age 67.2 (SD 11.6) approximately 1 year after the event. Their mean blood pressure was 152/88 mmHg (SD 29/15mmHg). These ECGs were digitised by one observer who was blinded to patient outcome. The patients were followed up for a median of 3.3 years. The primary endpoint was cardiac death. A prolonged heart rate corrected QT peak (QTpc) of lead I carried the highest relative risk of death from all cause as well as cardiac death, when compared with the other more conventional QT indices. In multivariate analyses, when adjusted for conventional risk factors of atherosclerosis, a prolonged QTpc of lead I was still associated with a 3-fold increased risk of cardiac death. (adjusted relative risk 3.0 [95% CI 1.1 - 8.5], p=0.037). Conclusion: QT peak prolongation in lead I predicts cardiac death after strok
Suboptimal blood pressure control in chronic kidney disease stage 3: baseline data from a cohort study in primary care
Background: poorly controlled hypertension is independently associated with mortality, cardiovascular risk and disease progression in chronic kidney disease (CKD). In the UK, CKD stage 3 is principally managed in primary care, including blood pressure (BP) management. Controlling BP is key to improving outcomes in CKD. This study aimed to investigate associations of BP control in people with CKD stage 3.Methods: 1,741 patients with CKD 3 recruited from 32 general practices for the Renal Risk in Derby Study underwent medical history, clinical assessment and biochemistry testing. BP control was assessed by three standards: National Institute for Health and Clinical Excellence (NICE), National Kidney Foundation Kidney Disease Outcome Quality Initiative (KDOQI) and Kidney Disease: Improving Global Outcomes (KDIGO) guidelines. Descriptive statistics were used to compare characteristics of people achieving and not achieving BP control. Univariate and multivariate logistic regression was used to identify factors associated with BP control.Results: the prevalence of hypertension was 88%. Among people with hypertension, 829/1426 (58.1%) achieved NICE BP targets, 512/1426 (35.9%) KDOQI targets and 859/1426 (60.2%) KDIGO targets. Smaller proportions of people with diabetes and/or albuminuria achieved hypertension targets. 615/1426 (43.1%) were only taking one antihypertensive agent. On multivariable analysis, BP control (NICE and KDIGO) was negatively associated with age (NICE odds ratio (OR) 0.27; 95% confidence interval (95% CI) 0.17-0.43) 70â79 compared to <60), diabetes (OR 0.32; 95% CI 0.25-0.43)), and albuminuria (OR 0.56; 95% CI 0.42-0.74)). For the KDOQI target, there was also association with males (OR 0.76; 95% CI 0.60-0.96)) but not diabetes (target not diabetes specific). Older people were less likely to achieve systolic targets (NICE target OR 0.17 (95% CI 0.09,0.32) p?<?0.001) and more likely to achieve diastolic targets (OR 2.35 (95% CI 1.11,4.96) p?<?0.001) for people >80 compared to?<?60).Conclusions: suboptimal BP control was common in CKD patients with hypertension in this study, particularly those at highest risk of adverse outcomes due to diabetes and or albuminuria. This study suggests there is scope for improving BP control in people with CKD by using more antihypertensive agents in combination while considering issues of adherence and potential side effects.<br/
Hypertensive Disorders of Pregnany and Offspring Cardiac Structure and Function in Adolescence
Background-Fetal exposure to preeclampsia is associated with higher blood pressure and later risk of stroke. We aimed to investigate the associations of maternal preeclampsia, gestational hypertension, and maternal blood pressure change in pregnancy with offspring cardiac structure and function in adolescence. Methods and Results-Using data from a prospective birth cohort study, we included offspring who underwent echocardiography (mean age, 17.7 years; SD, 0.3; N=1592). We examined whether hypertensive disorders of pregnancy were associated with offspring cardiac structure and systolic/diastolic function using linear regression. Using multilevel linear spline models (measurement occasions within women), we also investigated whether rate of maternal systolic/diastolic blood pressure change during pregnancy (weeks 8-18, 18-30, 30-36, and 36 or more) were associated with offspring outcomes. Main models were typically adjusted for maternal age, offspring age and sex, prepregnancy body mass index, parity, glycosuria/diabetes mellitus, education, and maternal smoking. Exposure to maternal preeclampsia (0.025; 95% CI, 0.008-0.043) and gestational hypertension (0.010; 0.002-0.017) were associated with greater relative wall thickness. Furthermore, preeclampsia was also associated with a smaller left ventricular end-diastolic volume (-9.0 mL; -15 to -3.1). No associations were found between hypertensive disorders of pregnancy and offspring cardiac function. Positive rate of maternal systolic blood pressure change during weeks 8 to 18 was associated with greater offspring left ventricular end-diastolic volume, left ventricular mass indexed to height2.7, and E/A. Conclusions-Adolescent offspring exposed to maternal preeclampsia had greater relative wall thickness and reduced left ventricular end-diastolic volume, which could be early signs of concentric remodeling and affect future cardiac function as well as risk of cardiovascular disease
Characterisation of a New Human Alveolar Macrophage-Like Cell Line (Daisy)
Purpose: There is currently no true macrophage cell line and in vitro experiments requiring these cells currently require mitogenic stimulation of a macrophage precursor cell line (THP-1) or ex vivo maturation of circulating primary monocytes. In this study, we characterise a human macrophage cell line, derived from THP-1 cells, and compare its phenotype to the THP-1 cells. Methods: THP-1 cells with and without mitogenic stimulation were compared to the newly derived macrophage-like cell line (Daisy) using microscopy, flow cytometry, phagocytosis assays, antigen binding assays and gene microarrays. Results: We show that the cell line grows predominantly in an adherent monolayer. A panel of antibodies were chosen to investigate the cell surface phenotype of these cells using flow cytometry. Daisy cells expressed more CD11c, CD80, CD163, CD169 and CD206, but less CD14 and CD11b compared with mitogen-stimulated THP-1 cells. Unlike stimulated THP-1 cells which were barely able to bind immune complexes, Daisy cells showed large amounts of immune complex binding. Finally, although not statistically significant, the phagocytic ability of Daisy cells was greater than mitogen-stimulated THP-1 cells, suggesting that the cell line is more similar to mature macrophages. Conclusions: The observed phenotype suggests that Daisy cells are a good model of human macrophages with a phenotype similar to human alveolar macrophages
Distinct immune regulatory receptor profiles linked to altered monocyte subsets in sarcoidosis
Background: In sarcoidosis, blood monocytes, circulating precursors of granuloma macrophages, display enhanced inflammatory cytokine production, reduced expression of the regulatory (inhibitory) receptor CD200R, and altered subsets defined by CD14 and CD16. Regulatory receptors serve to dampen monocyte and macrophage inflammatory responses. We investigated the relationship between monocyte subsets and regulatory receptor expression in sarcoidosis. Methods: Multiparameter flow cytometry was used to perform detailed analyses of cell surface regulatory molecules on freshly isolated blood immune cells from patients with chronic pulmonary sarcoidosis and age-matched healthy controls. Results: 25 patients with chronic pulmonary sarcoidosis (median duration of disease 22â
months) who were not taking oral corticosteroids or other immunomodulators were recruited. Nonclassical monocytes were expanded in sarcoidosis and exhibited significantly lower expression of regulatory receptors CD200R, signal regulatory protein-α and CD47 than classical or intermediate monocytes. In sarcoidosis, all three monocyte subsets had significantly reduced CD200R and CD47 expression compared with healthy controls. A dichotomous distribution of CD200R was seen on classical and intermediate monocytes in the sarcoidosis population, with 14 out of 25 (56%) sarcoidosis patients having a CD200Rlow phenotype and 11 out of 25 (44%) having a CD200Rhigh phenotype. These distinct sarcoidosis monocyte phenotypes remained consistent over time. Conclusions: Nonclassical monocytes, which are expanded in sarcoidosis, express very low levels of regulatory receptors. Two distinct and persistent phenotypes of CD200R expression in classical and intermediate monocytes could be evaluated as sarcoidosis biomarkers
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