137 research outputs found
Hyperinflammation in chronic granulomatous disease and anti-inflammatory role of the phagocyte NADPH oxidase
Chronic granulomatous disease (CGD) is an immunodeficiency caused by the lack of the superoxide-producing phagocyte nicotinamide adenine dinucleotide phosphate (NADPH) oxidase. However, CGD patients not only suffer from recurrent infections, but also present with inflammatory, non-infectious conditions. Among the latter, granulomas figure prominently, which gave the name to the disease, and colitis, which is frequent and leads to a substantial morbidity. In this paper, we systematically review the inflammatory lesions in different organs of CGD patients and compare them to observations in CGD mouse models. In addition to the more classical inflammatory lesions, CGD patients and their relatives have increased frequency of autoimmune diseases, and CGD mice are arthritis-prone. Possible mechanisms involved in CGD hyperinflammation include decreased degradation of phagocytosed material, redox-dependent termination of proinflammatory mediators and/or signaling, as well as redox-dependent cross-talk between phagocytes and lymphocytes (e.g. defective tryptophan catabolism). As a conclusion from this review, we propose the existence of ROShigh and ROSlow inflammatory responses, which are triggered as a function of the level of reactive oxygen species and have specific characteristics in terms of physiology and pathophysiolog
Chemotactic Factors in Bronchial Secretions of Cystic Fibrosis Patients
To understand chronic neutrophil attraction into cystic fibrosis airways, both global chemotactic activity and individual chemotactic factors were studied in bronchial secretions. Bronchial secretions of 8 cystic fibrosis patients, collected on the first day of admission for antibiotic treatment, showed a high chemotactic index (19.4 ± 5.7, n = 8). Fractionation by gel filtration of bronchial secretions resulted in three chemotactic fractions. The first factor corresponded to interleukin-8, and the second activated neutrophils via the FMLP receptor. The third factor, which was of lower molecular weight, did not activate FMLP or leukotriene B4 receptors, and its nature is still under investigation. Treating patients with antibiotics reduced global chemotactic activity, mainly by reducing the activity due to stimulation of the FMLP recepto
Left-sided lesions after anatomic repair of transposition of the great arteries, ventricular septal defect, and coarctation: Surgical factors
AbstractObjectiveThis study was undertaken to identify potential anatomic and surgical factors creating left-sided lesions, namely recoarctation of the aorta and neoaortic regurgitation, after anatomic repair of transposition of the great arteries with ventricular septal defect and aortic coarctation.MethodsFrom 1983 to September 2002, 109 survivors out of 120 patients were studied. Two-stage repair was performed in 42 patients (group A), and single-stage repair was performed in 67 (groups B and C). Before repair, the diameters of the ascending aorta and main pulmonary artery were measured. In the patients with single-stage repair, coarctation was repaired by extended end-to-end anastomosis in 35 patients (group B) and by pulmonary homograft patch augmentation in 32 patients (group C). The ventricular septal defect was closed through the pulmonary artery in 70 patients and through the right ventricle or atrium in 39 patients. The neoaorto-aortic discrepancy was treated by V-shaped resection of the posterior sinus of Valsalva in 7 cases, pulmonary homograft patch in 32 cases, and anterior splitting of the ascending aorta in all cases. Before discharge from the hospital, neoaortic root and ascending aorta diameters and aortic regurgitation grade were recorded. Neoaortic regurgitation progression and reintervention were the end points of follow-up (97.2 ± 61.2 months).ResultsEarly and late survivals were significantly better in group C (P < .001). Risk factors for neoaortic regurgitation at discharge by univariate analysis were single-stage repair (P < .05) and ventricular septal defect closure through the pulmonary artery (P = .0076). On multivariate analysis, the latter was the only risk factor for neoaortic regurgitation at discharge and at last follow-up. Multivariate analysis showed that higher neoaortic root/ascending aorta ratio and ventricular septal defect closure through the pulmonary artery were risk factors for neoaortic regurgitation evolution at last follow-up. There were 29 reinterventions, 19 for recoarctation of the aorta and 10 for neoaortic regurgitation with or without aortic root dilatation. Group B (P < .05), high neoaortic root/ascending aorta ratio (P < .01), and progressive neoaortic regurgitation (P < .05) were risk factors for recoarctation of the aorta. Group A was a risk factor for aortic valve replacement at 10 years (P < .05).ConclusionNeonatal single-stage repair with pulmonary homograft aortic augmentation remains the optimal approach to transposition of the great arteries with ventricular septal defect and aortic coarctation. It provides better early and late survivals and freedoms from left-sided lesions. Avoidance of late recoarctation of the aorta and progressive neoaortic regurgitation requires meticulous closure of the ventricular septal defect and evenly sized reconstruction of the aorta from root to distal arch
Caroli disease, bilateral diffuse cystic renal dysplasia, situs inversus, postaxial polydactyly, and preauricular fistulas: a ciliopathy caused by a homozygous NPHP3 mutation
We report the rare association of Caroli disease (intrahepatic bile duct ectasia associated with congenital hepatic fibrosis), bilateral cystic renal dysplasia, situs inversus, postaxial polydactyly, and preauricular fistulas in a female child. She presented with end-stage renal disease at the age of 1month, followed by a rapidly progressing hepatic fibrosis and dilatation of the intrahepatic bile ducts, leading to secondary biliary cirrhosis and portal hypertension. Combined liver-kidney transplantation was performed at the age of 4years, with excellent outcome. DNA analysis showed a NPHP3 (coding nephrocystin-3) homozygote mutation, confirming that this malformation complex is a ciliopathy. Conclusion: This rare association required an exceptional therapeutic approach: combined simultaneous orthotopic liver and kidney transplantation in a situs inversus recipient. The long-term follow-up was excellent with a very good evolution of the renal and hepatic grafts and normalization of growth and weight. This malformation complex has an autosomal recessive inheritance with a 25% recurrence risk in each pregnanc
Surgery for complications of trans-catheter closure of atrial septal defects: a multi-institutional study from the European Congenital Heart Surgeons Association
Objective: This study aims to analyse the collective experience of participating European Congenital Heart Surgeons Association centres in the surgical management of complications resulting from trans-catheter closure of atrial septal defects (ASDs). Methods: The records of all (n=56) patients, aged 3-70 years (median 18 years), who underwent surgery for complications of trans-catheter ASD closure in 19 participating institutions over a 10-year period (1997-2007) were retrospectively reviewed. Risk factors for surgical complications were sought. Surgical outcomes were compared with those reported for primary surgical ASD closure in the European Association of Cardio-thoracic Surgery Congenital Database. Results: A wide range of ASD sizes (5-34mm) and devices of various types and sizes (range 12-60mm) were involved, including 13 devices less than 20mm. Complications leading to surgery included embolisation (n=29), thrombosis/thrombo-embolism/cerebral ischaemia or stroke (n=12), significant residual shunt (n=12), aortic or atrial perforation or erosion (n=9), haemopericardium with tamponade (n=5), aortic or mitral valve injury (n=2) and endocarditis (n=1). Surgery (39 early emergent and 17 late operations) involved device removal, repair of damaged structures and ASD closure. Late operations were needed 12 days to 8 years (median 3 years) after device implantation. There were three hospital deaths (mortality 5.4%). During the same time period, mortality for all 4453 surgical ASD closures reported in the European Association of Cardio-Thoracic Surgery Congenital Database was 0.36% (p=0.001). Conclusions: Trans-catheter device closure of ASDs, even in cases when small devices are used, can lead to significant complications requiring surgical intervention. Once a complication leading to surgery occurs, mortality is significantly greater than that of primary surgical ASD closure. Major complications can occur late after device placement. Therefore, lifelong follow-up of patients in whom ASDs have been closed by devices is mandator
Molecular and biochemical characterisation of a novel mutation in POLG associated with Alpers syndrome
<p>Abstract</p> <p>Background</p> <p>DNA polymerase γ (<it>POLG</it>) is the only known mitochondrial DNA (mtDNA) polymerase. It mediates mtDNA replication and base excision repair. Mutations in the <it>POLG </it>gene lead to reduction of functional mtDNA (mtDNA depletion and/or deletions) and are therefore predicted to result in defective oxidative phosphorylation (OXPHOS). Many mutations map to the polymerase and exonuclease domains of the enzyme and produce a broad clinical spectrum. The most frequent mutation p.A467T is localised in the linker region between these domains. In compound heterozygote patients the p.A467T mutation has been described to be associated amongst others with fatal childhood encephalopathy. These patients have a poorer survival rate compared to homozygotes.</p> <p>Methods</p> <p>mtDNA content in various tissues (fibroblasts, muscle and liver) was quantified using quantitative PCR (qPCR). OXPHOS activities in the same tissues were assessed using spectrophotometric methods and catalytic stain of BN-PAGE.</p> <p>Results</p> <p>We characterise a novel splice site mutation in <it>POLG </it>found <it>in trans </it>with the p.A467T mutation in a 3.5 years old boy with valproic acid induced acute liver failure (Alpers-Huttenlocher syndrome). These mutations result in a tissue specific depletion of the mtDNA which correlates with the OXPHOS-activities.</p> <p>Conclusions</p> <p>mtDNA depletion can be expressed in a high tissue-specific manner and confirms the need to analyse primary tissue. Furthermore<it>, POLG </it>analysis optimises clinical management in the early stages of disease and reinforces the need for its evaluation before starting valproic acid treatment.</p
Machine learning algorithms performed no better than regression models for prognostication in traumatic brain injury
Objective: We aimed to explore the added value of common machine learning (ML) algorithms for prediction of outcome for moderate and severe traumatic brain injury. Study Design and Setting: We performed logistic regression (LR), lasso regression, and ridge regression with key baseline predictors in the IMPACT-II database (15 studies, n = 11,022). ML algorithms included support vector machines, random forests, gradient boosting machines, and artificial neural networks and were trained using the same predictors. To assess generalizability of predictions, we performed internal, internal-external, and external validation on the recent CENTER-TBI study (patients with Glasgow Coma Scale <13, n = 1,554). Both calibration (calibration slope/intercept) and discrimination (area under the curve) was quantified. Results: In the IMPACT-II database, 3,332/11,022 (30%) died and 5,233(48%) had unfavorable outcome (Glasgow Outcome Scale less than 4). In the CENTER-TBI study, 348/1,554(29%) died and 651(54%) had unfavorable outcome. Discrimination and calibration varied widely between the studies and less so between the studied algorithms. The mean area under the curve was 0.82 for mortality and 0.77 for unfavorable outcomes in the CENTER-TBI study. Conclusion: ML algorithms may not outperform traditional regression approaches in a low-dimensional setting for outcome prediction after moderate or severe traumatic brain injury. Similar to regression-based prediction models, ML algorithms should be rigorously validated to ensure applicability to new populations
Variation in Structure and Process of Care in Traumatic Brain Injury: Provider Profiles of European Neurotrauma Centers Participating in the CENTER-TBI Study.
INTRODUCTION: The strength of evidence underpinning care and treatment recommendations in traumatic brain injury (TBI) is low. Comparative effectiveness research (CER) has been proposed as a framework to provide evidence for optimal care for TBI patients. The first step in CER is to map the existing variation. The aim of current study is to quantify variation in general structural and process characteristics among centers participating in the Collaborative European NeuroTrauma Effectiveness Research in Traumatic Brain Injury (CENTER-TBI) study. METHODS: We designed a set of 11 provider profiling questionnaires with 321 questions about various aspects of TBI care, chosen based on literature and expert opinion. After pilot testing, questionnaires were disseminated to 71 centers from 20 countries participating in the CENTER-TBI study. Reliability of questionnaires was estimated by calculating a concordance rate among 5% duplicate questions. RESULTS: All 71 centers completed the questionnaires. Median concordance rate among duplicate questions was 0.85. The majority of centers were academic hospitals (n = 65, 92%), designated as a level I trauma center (n = 48, 68%) and situated in an urban location (n = 70, 99%). The availability of facilities for neuro-trauma care varied across centers; e.g. 40 (57%) had a dedicated neuro-intensive care unit (ICU), 36 (51%) had an in-hospital rehabilitation unit and the organization of the ICU was closed in 64% (n = 45) of the centers. In addition, we found wide variation in processes of care, such as the ICU admission policy and intracranial pressure monitoring policy among centers. CONCLUSION: Even among high-volume, specialized neurotrauma centers there is substantial variation in structures and processes of TBI care. This variation provides an opportunity to study effectiveness of specific aspects of TBI care and to identify best practices with CER approaches
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Primary versus early secondary referral to a specialized neurotrauma center in patients with moderate/severe traumatic brain injury: a CENTER TBI study
Funder: ZNS - Hannelore Kohl Stiftung; doi: http://dx.doi.org/10.13039/501100007731Funder: Integra LifeSciences CorporationFunder: OneMindAbstract: Background: Prehospital care for patients with traumatic brain injury (TBI) varies with some emergency medical systems recommending direct transport of patients with moderate to severe TBI to hospitals with specialist neurotrauma care (SNCs). The aim of this study is to assess variation in levels of early secondary referral within European SNCs and to compare the outcomes of directly admitted and secondarily transferred patients. Methods: Patients with moderate and severe TBI (Glasgow Coma Scale < 13) from the prospective European CENTER-TBI study were included in this study. All participating hospitals were specialist neuroscience centers. First, adjusted between-country differences were analysed using random effects logistic regression where early secondary referral was the dependent variable, and a random intercept for country was included. Second, the adjusted effect of early secondary referral on survival to hospital discharge and functional outcome [6 months Glasgow Outcome Scale Extended (GOSE)] was estimated using logistic and ordinal mixed effects models, respectively. Results: A total of 1347 moderate/severe TBI patients from 53 SNCs in 18 European countries were included. Of these 1347 patients, 195 (14.5%) were admitted after early secondary referral. Secondarily referred moderate/severe TBI patients presented more often with a CT abnormality: mass lesion (52% vs. 34%), midline shift (54% vs. 36%) and acute subdural hematoma (77% vs. 65%). After adjusting for case-mix, there was a large European variation in early secondary referral, with a median OR of 1.69 between countries. Early secondary referral was not associated with functional outcome (adjusted OR 1.07, 95% CI 0.78–1.69), nor with survival at discharge (1.05, 0.58–1.90). Conclusions: Across Europe, substantial practice variation exists in the proportion of secondarily referred TBI patients at SNCs that is not explained by case mix. Within SNCs early secondary referral does not seem to impact functional outcome and survival after stabilisation in a non-specialised hospital. Future research should identify which patients with TBI truly benefit from direct transportation
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How do 66 European institutional review boards approve one protocol for an international prospective observational study on traumatic brain injury? Experiences from the CENTER-TBI study
Abstract: Background: The European Union (EU) aims to optimize patient protection and efficiency of health-care research by harmonizing procedures across Member States. Nonetheless, further improvements are required to increase multicenter research efficiency. We investigated IRB procedures in a large prospective European multicenter study on traumatic brain injury (TBI), aiming to inform and stimulate initiatives to improve efficiency. Methods: We reviewed relevant documents regarding IRB submission and IRB approval from European neurotrauma centers participating in the Collaborative European NeuroTrauma Effectiveness Research in Traumatic Brain Injury (CENTER-TBI). Documents included detailed information on IRB procedures and the duration from IRB submission until approval(s). They were translated and analyzed to determine the level of harmonization of IRB procedures within Europe. Results: From 18 countries, 66 centers provided the requested documents. The primary IRB review was conducted centrally (N = 11, 61%) or locally (N = 7, 39%) and primary IRB approval was obtained after one (N = 8, 44%), two (N = 6, 33%) or three (N = 4, 23%) review rounds with a median duration of respectively 50 and 98 days until primary IRB approval. Additional IRB approval was required in 55% of countries and could increase duration to 535 days. Total duration from submission until required IRB approval was obtained was 114 days (IQR 75–224) and appeared to be shorter after submission to local IRBs compared to central IRBs (50 vs. 138 days, p = 0.0074). Conclusion: We found variation in IRB procedures between and within European countries. There were differences in submission and approval requirements, number of review rounds and total duration. Research collaborations could benefit from the implementation of more uniform legislation and regulation while acknowledging local cultural habits and moral values between countries
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