163 research outputs found
Pediatric neurosurgical-oncology scope and management paradigms in Sub-Saharan Africa: a collaboration among 7 referral hospitals on the subcontinent
BackgroundUnderstanding of the epidemiology and biology of pediatric CNS tumors has advanced dramatically over the last decade; however there remains a discrepancy in the understanding of epidemiologic data and clinical capacity between high- and lower-income countries.ObjectiveWe collected and analyzed hospital-level burden and capacity-oriented data from pediatric neurosurgical oncology units at 7 referral hospitals in Sub-Saharan Africa (SSA).MethodsA cross sectional epidemiological survey was conducted using REDCap at the 7 SSA sites, capturing 3-month aggregate data for patients managed over a total of 9 months. Descriptive statistical analyses for the aggregate data were performed.ResultsAcross the neurosurgical spectrum, 15% of neurosurgery outpatient and 16% of neurosurgery operative volume was represented by pediatric neuro-oncology across the 7 study sites. Eighty-six percent and 87% of patients who received surgery underwent preoperative CT scan and/or MRI respectively. Among 312 patients evaluated with a CNS tumor, 211 (68%) underwent surgery. Mean surgery wait time was 26.6 ± 36.3 days after initial presentation at the clinic. The most common tumor location was posterior fossa (n=94, 30%), followed by sellar/suprasellar region (n=56, 18%). Histopathologic analysis was performed for 189 patients (89%). The most common pathologic diagnosis was low grade glioma (n=43, 23%), followed by medulloblastoma (n=37, 20%), and craniopharyngioma (n=31, 17%). Among patients for whom adjuvant therapy was indicated, only 26% received chemotherapy and 15% received radiotherapy.ConclusionThe histopathologic variety of pediatric brain and spinal tumors managed across 7 SSA referral hospitals was similar to published accounts from other parts of the world. About two-thirds of patients received a tumor-directed surgery with significant inter-institutional variability. Less than a third of patients received adjuvant therapy when indicated. Multi-dimensional capacity building efforts in neuro-oncology are necessary to approach parity in the management of children with brain and spinal tumors in SSA
The prevalence and importance of frailty in heart failure with reduced ejection fraction – an analysis of PARADIGM-HF and ATMOSPHERE
Aims:
Frailty, characterized by loss of homeostatic reserves and increased vulnerability to physiological decompensation, results from an aggregation of insults across multiple organ systems. Frailty can be quantified by counting the number of ‘health deficits’ across a range of domains. We assessed the frequency of, and outcomes related to, frailty in patients with heart failure and reduced ejection fraction (HFrEF).
Methods and results:
Using a cumulative deficits approach, we constructed a 42‐item frailty index (FI) and applied it to identify frail patients enrolled in two HFrEF trials (PARADIGM‐HF and ATMOSPHERE). In keeping with previous studies, patients with FI ≤0.210 were classified as non‐frail and those with higher scores were divided into two categories using score increments of 0.100. Clinical outcomes were examined, adjusting for prognostic variables. Among 13 625 participants, mean (± standard deviation) FI was 0.250 (0.10) and 8383 patients (63%) were frail (FI >0.210). The frailest patients were older and had more symptoms and signs of heart failure. Women were frailer than men. All outcomes were worse in the frailest, with high rates of all‐cause death or all‐cause hospitalization: 40.7 (39.1–42.4) vs. 22.1 (21.2–23.0) per 100 person‐years in the non‐frail; adjusted hazard ratio 1.63 (1.53–1.75) (P < 0.001). The rate of all‐cause hospitalizations, taking account of recurrences, was 61.5 (59.8–63.1) vs. 31.2 (30.3–32.2) per 100 person‐years (incidence rate ratio 1.76; 1.62–1.90; P < 0.001).
Conclusion:
Frailty is highly prevalent in HFrEF and associated with greater deterioration in quality of life and higher risk of hospitalization and death. Strategies to prevent and treat frailty are needed in HFrEF
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Disrupting Bordetella Immunosuppression Reveals a Role for Eosinophils in Coordinating the Adaptive Immune Response in the Respiratory Tract.
Recent findings revealed pivotal roles for eosinophils in protection against parasitic and viral infections, as well as modulation of adaptive immune responses in the gastric mucosa. However, the known effects of eosinophils within the respiratory tract remain predominantly pathological, associated with allergy and asthma. Simulating natural respiratory infections in mice, we examined how efficient and well-adapted pathogens can block eosinophil functions that contribute to the immune response. Bordetella bronchiseptica, a natural pathogen of the mouse, uses the sigma factor btrS to regulate expression of mechanisms that interfere with eosinophil recruitment and function. When btrS is disrupted, immunomodulators are dysregulated, and eosinophils are recruited to the lungs, suggesting they may contribute to much more efficient generation of adaptive immunity induced by this mutant. Eosinophil-deficient mice failed to produce pro-inflammatory cytokines, to recruit lymphocytes, to organize lymphoid aggregates that resemble Bronchus Associated Lymphoid Tissue (BALT), to generate an effective antibody response, and to clear bacterial infection from the respiratory tract. Importantly, the failure of eosinophil-deficient mice to produce these lymphoid aggregates indicates that eosinophils can mediate the generation of an effective lymphoid response in the lungs. These data demonstrate that efficient respiratory pathogens can block eosinophil recruitment, to inhibit the generation of robust adaptive immune responses. They also suggest that some post-infection sequelae involving eosinophils, such as allergy and asthma, might be a consequence of bacterial mechanisms that manipulate their accumulation and/or function within the respiratory tract
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Protein-coding variants implicate novel genes related to lipid homeostasis contributing to body-fat distribution.
Body-fat distribution is a risk factor for adverse cardiovascular health consequences. We analyzed the association of body-fat distribution, assessed by waist-to-hip ratio adjusted for body mass index, with 228,985 predicted coding and splice site variants available on exome arrays in up to 344,369 individuals from five major ancestries (discovery) and 132,177 European-ancestry individuals (validation). We identified 15 common (minor allele frequency, MAF ≥5%) and nine low-frequency or rare (MAF <5%) coding novel variants. Pathway/gene set enrichment analyses identified lipid particle, adiponectin, abnormal white adipose tissue physiology and bone development and morphology as important contributors to fat distribution, while cross-trait associations highlight cardiometabolic traits. In functional follow-up analyses, specifically in Drosophila RNAi-knockdowns, we observed a significant increase in the total body triglyceride levels for two genes (DNAH10 and PLXND1). We implicate novel genes in fat distribution, stressing the importance of interrogating low-frequency and protein-coding variants
Assessing mechanical integrity of spinal fusion by in situ endochondral osteoinduction in the murine model
<p>Abstract</p> <p>Background</p> <p>Historically, radiographs, micro-computed tomography (micro-CT) exams, palpation and histology have been used to assess fusions in a mouse spine. The objective of this study was to develop a faster, cheaper, reproducible test to directly quantify the mechanical integrity of spinal fusions in mice.</p> <p>Methods</p> <p>Fusions were induced in ten mice spine using a previously described technique of in situ endochondral ossification, harvested with soft tissue, and cast in radiolucent alginate material for handling. Using a validated software package and a customized mechanical apparatus that flexed and extended the spinal column, the amount of intervertebral motion between adjacent vertebral discs was determined with static flexed and extended lateral spine radiographs. Micro-CT images of the same were also blindly reviewed for fusion.</p> <p>Results</p> <p>Mean intervertebral motion between control, non-fused, spinal vertebral discs was 6.1 ± 0.2° during spine flexion/extension. In fusion samples, adjacent vertebrae with less than 3.5° intervertebral motion had fusions documented by micro-CT inspection.</p> <p>Conclusions</p> <p>Measuring the amount of intervertebral rotation between vertebrae during spine flexion/extension is a relatively simple, cheap (<$100), clinically relevant, and fast test for assessing the mechanical success of spinal fusion in mice that compared favorably to the standard, micro-CT.</p
Clinical characteristics and outcomes of patients with heart failure with reduced ejection fraction and chronic obstructive pulmonary disease: insights from PARADIGM-HF
Background:
Chronic obstructive pulmonary disease (COPD) is a common comorbidity in heart failure with reduced ejection fraction, associated with undertreatment and worse outcomes. New treatments for heart failure with reduced ejection fraction may be particularly important in patients with concomitant COPD.
Methods and Results:
We examined outcomes in 8399 patients with heart failure with reduced ejection fraction, according to COPD status, in the PARADIGM‐HF (Prospective Comparison of Angiotensin Receptor Blocker–Neprilysin Inhibitor With Angiotensin‐Converting Enzyme Inhibitor to Determine Impact on Global Mortality and Morbidity in Heart Failure) trial. Cox regression models were used to compare COPD versus non‐COPD subgroups and the effects of sacubitril/valsartan versus enalapril. Patients with COPD (n=1080, 12.9%) were older than patients without COPD (mean 67 versus 63 years; P<0.001), with similar left ventricular ejection fraction (29.9% versus 29.4%), but higher NT‐proBNP (N‐terminal pro‐B‐type natriuretic peptide; median, 1741 pg/mL versus 1591 pg/mL; P=0.01), worse functional class (New York Heart Association III/IV 37% versus 23%; P<0.001) and Kansas City Cardiomyopathy Questionnaire–Clinical Summary Score (73 versus 81; P<0.001), and more congestion and comorbidity. Medical therapy was similar in patients with and without COPD except for beta‐blockade (87% versus 94%; P<0.001) and diuretics (85% versus 80%; P<0.001). After multivariable adjustment, COPD was associated with higher risks of heart failure hospitalization (hazard ratio [HR], 1.32; 95% CI, 1.13–1.54), and the composite of cardiovascular death or heart failure hospitalization (HR, 1.18; 95% CI, 1.05–1.34), but not cardiovascular death (HR, 1.10; 95% CI, 0.94–1.30), or all‐cause mortality (HR, 1.14; 95% CI, 0.99–1.31). COPD was also associated with higher risk of all cardiovascular hospitalization (HR, 1.17; 95% CI, 1.05–1.31) and noncardiovascular hospitalization (HR, 1.45; 95% CI, 1.29–1.64). The benefit of sacubitril/valsartan over enalapril was consistent in patients with and without COPD for all end points.
Conclusions:
In PARADIGM‐HF, COPD was associated with lower use of beta‐blockers and worse health status and was an independent predictor of cardiovascular and noncardiovascular hospitalization. Sacubitril/valsartan was beneficial in this high‐risk subgroup.
Registration:
URL: https://www.clinicaltrials.gov; Unique identifier: NCT01035255
Feasibility of achieving the 2025 WHO global tuberculosis targets in South Africa, China, and India: a combined analysis of 11 mathematical models.
BACKGROUND: The post-2015 End TB Strategy proposes targets of 50% reduction in tuberculosis incidence and 75% reduction in mortality from tuberculosis by 2025. We aimed to assess whether these targets are feasible in three high-burden countries with contrasting epidemiology and previous programmatic achievements. METHODS: 11 independently developed mathematical models of tuberculosis transmission projected the epidemiological impact of currently available tuberculosis interventions for prevention, diagnosis, and treatment in China, India, and South Africa. Models were calibrated with data on tuberculosis incidence and mortality in 2012. Representatives from national tuberculosis programmes and the advocacy community provided distinct country-specific intervention scenarios, which included screening for symptoms, active case finding, and preventive therapy. FINDINGS: Aggressive scale-up of any single intervention scenario could not achieve the post-2015 End TB Strategy targets in any country. However, the models projected that, in the South Africa national tuberculosis programme scenario, a combination of continuous isoniazid preventive therapy for individuals on antiretroviral therapy, expanded facility-based screening for symptoms of tuberculosis at health centres, and improved tuberculosis care could achieve a 55% reduction in incidence (range 31-62%) and a 72% reduction in mortality (range 64-82%) compared with 2015 levels. For India, and particularly for China, full scale-up of all interventions in tuberculosis-programme performance fell short of the 2025 targets, despite preventing a cumulative 3·4 million cases. The advocacy scenarios illustrated the high impact of detecting and treating latent tuberculosis. INTERPRETATION: Major reductions in tuberculosis burden seem possible with current interventions. However, additional interventions, adapted to country-specific tuberculosis epidemiology and health systems, are needed to reach the post-2015 End TB Strategy targets at country level. FUNDING: Bill and Melinda Gates Foundation
The ERCC6 Gene and Age-Related Macular Degeneration
Background: Age-related macular degeneration (AMD) is the leading cause of irreversible visual loss in the developed countries and is caused by both environmental and genetic factors. A recent study (Tuo et al., PNAS) reported an association between AMD and a single nucleotide polymorphism (SNP) (rs3793784) in the ERCC6 (NM_000124) gene. The risk allele also increased ERCC6 expression. ERCC6 is involved in DNA repair and mutations in ERCC6 cause Cockayne syndrome (CS). Amongst others, photosensitivity and pigmentary retinopathy are hallmarks of CS. Methodology/Principal Findings: Separate and combined data from three large AMD case-control studies and a prospective population-based study (The Rotterdam Study) were used to analyse the genetic association between ERCC6 and AMD (2682 AMD cases and 3152 controls). We also measured ERCC6 mRNA levels in retinal pigment epithelium (RPE) cells of healthy and early AMD affected human donor eyes. Rs3793784 conferred a small increase in risk for late AMD in the Dutch population (The Rotterdam and AMRO-NL study), but this was not replicated in two non-European studies (AREDS, Columbia University). In addition, the AMRO-NL study revealed no significant association for 9 other variants spanning ERCC6. Finally, we determined that ERCC6 expression in the human RPE did not depend on rs3793784 genotype, but, interestingly, on AMD status: Early AMD-affected donor eyes had a 50% lower ERCC6 expression than healthy donor eyes (P = 0.018). Conclusions/Significance: Our meta analysis of four Caucasian cohorts does not replicate the reported association between SNPs in ERCC6 and AMD. Nevertheless, our findings on ERCC6 expression in the RPE suggest that ERCC6 may be functionally involved in AMD. Combining our data with those of the literature, we hypothesize that the AMD-related reduced transcriptional activity of ERCC6 may be caused by diverse, small and heterogeneous genetic and/or environmental determinants
Cost-effectiveness and resource implications of aggressive action on tuberculosis in China, India, and South Africa: a combined analysis of nine models.
BACKGROUND: The post-2015 End TB Strategy sets global targets of reducing tuberculosis incidence by 50% and mortality by 75% by 2025. We aimed to assess resource requirements and cost-effectiveness of strategies to achieve these targets in China, India, and South Africa. METHODS: We examined intervention scenarios developed in consultation with country stakeholders, which scaled up existing interventions to high but feasible coverage by 2025. Nine independent modelling groups collaborated to estimate policy outcomes, and we estimated the cost of each scenario by synthesising service use estimates, empirical cost data, and expert opinion on implementation strategies. We estimated health effects (ie, disability-adjusted life-years averted) and resource implications for 2016-35, including patient-incurred costs. To assess resource requirements and cost-effectiveness, we compared scenarios with a base case representing continued current practice. FINDINGS: Incremental tuberculosis service costs differed by scenario and country, and in some cases they more than doubled existing funding needs. In general, expansion of tuberculosis services substantially reduced patient-incurred costs and, in India and China, produced net cost savings for most interventions under a societal perspective. In all three countries, expansion of access to care produced substantial health gains. Compared with current practice and conventional cost-effectiveness thresholds, most intervention approaches seemed highly cost-effective. INTERPRETATION: Expansion of tuberculosis services seems cost-effective for high-burden countries and could generate substantial health and economic benefits for patients, although substantial new funding would be required. Further work to determine the optimal intervention mix for each country is necessary. FUNDING: Bill & Melinda Gates Foundation
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