996 resultados para Chronic Hypobaric Hypoxia


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This study aimed to evaluate well-documented diagnostic antigens, named B13, 1F8 and JL7 recombinant proteins, as potential markers of seroconversion in treated chagasic patients. Prospective study, involving 203 patients treated with benznidazole, was conducted from endemic areas of northern Argentina. Follow-up was possible in 107 out of them and blood samples were taken for serology and PCR assays before and 2, 3, 6, 12, 24 and 36 months after treatment initiation. Reactivity against Trypanosoma cruzi lysate and recombinant antigens was measured by ELISA. The rate of decrease of antibody titers showed nonlinear kinetics with an abrupt drop within the first three months after initiation of treatment for all studied antigens, followed by a plateau displaying a low decay until the end of follow-up. At this point, anti-B13, anti-1F8 and anti-JL7 titers were relatively close to the cut-off line, while anti-T. cruzi antibodies still remained positive. At baseline, 60.8% (45/74) of analysed patients tested positive for parasite DNA by PCR and during the follow-up period in 34 out of 45 positive samples (75.5%) could not be detected T. cruzi DNA. Our results suggest that these antigens might be useful as early markers for monitoring antiparasitic treatment in chronic Chagas disease.

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Objectives: To evaluate outcome of patients treated "off-label" by bosentan and/or sildenafil for chronic thromboembolic pulmonary hypertension (CTEPH). Patients and methods: Since 2003, 18 patients (mean age 69 ± 11 years) have been treated with bosentan and/or sildenafil for CTEPH (mean pulmonary arterial resistance 8.1 ± 3.7 U Wood) in Lausanne University Hospital, with a follow-up of at least 12 months. Sixteen of them were inoperable because of distal disease and/or age or significant co-morbidities and 2 had persistent or recurrent pulmonary hypertension despite surgery. Efficacy of treatment was evaluated by comparison of New York Heart Association functional class (NYHA), six-minute walk test (6-MWT) and serum levels of N-terminal-pro brain natriuretic peptide (NT pro-BNP) at baseline (T0) and at 12 months (T12). Wilcoxon rank test was used for statistics. Results: At T0, median NYHA class was III (range II-IV), 6-MWT was 348 meters (5 and 95 centiles:0, 539) and NT pro-BNP was 387 mmol/l (58, 3508). At T12, 11 patients were treated with bosentan, 5 with sildenafil, 1 with inhaled Iloprost (because of failure of the two other treatments) and 1 with a combination of sildenafil and Iloprost. NYHA had improved in 10 patients, remained stable in 7 and worsened in 1 (median decrease 0.5 (-2; 0.2) p = 0.013). Six-MWT improved by a median of 15 meters (-142, +270) (p = 0.047) and NT pro-BNP decreased by a median of 65 mmol/l (-2988, +187) (p = n.s.). Among the 10 patients with a follow-up of 2 years or longer, two thirds remained stable and one third had worsened at 24 month. Treatments were well tolerated and only one patient had significant side effects (cutaneous reaction to bosentan) necessitating a switch to another treatment. Conclusion: In agreement with published data, bosentan and sildenafil improved functional status (NYHA, 6-MWT) and haemodynamics (NT pro BNP) in our patients with inoperable CTEPH. However these medications should not be used as substitute for surgery when the latter is applicable.

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On the basis of MRI examinations in 88 neonates and infants with perinatal asphyxia, we defined 6 different patterns on T2-weighted images: pattern A--scattered hyperintensity of both hemispheres of the telencephalon with blurred border zones between cortex and white matter, indicating diffuse brain injury; pattern B--parasagittal hyperintensity extending into the corona radiata, corresponding to the watershed zones; pattern C--hyper- and hypointense lesions in thalamus and basal ganglia, which relate to haemorrhagic necrosis or iron deposition in these areas; pattern D--periventricular hyperintensity, mainly along the lateral ventricles, i.e. periventricular leukomalacia (PVL), originating from the matrix zone; pattern E--small multifocal lesions varying from hyper--to hypointense, interpreted as necrosis and haemorrhage; pattern F--periventricular centrifugal hypointense stripes in the centrum semiovale and deep white matter of the frontal and occipital lobes. Contrast was effectively inverted on T1-weighted images. Patterns A, B and C were found in 17%, 25% and 37% of patients, and patterns D, E and F in 19%, 17% and 35%, respectively. In 49 patients a combination of patterns was observed, but 30% of the initial images were normal. At follow-up, persistent abnormalities were seen in all children with patterns A and D, but in only 52% of those with pattern C. Myelination was retarded most often in patients with diffuse brain injury and PVL (patterns A and D).

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BACKGROUND/AIMS: While several risk factors for the histological progression of chronic hepatitis C have been identified, the contribution of HCV genotypes to liver fibrosis evolution remains controversial. The aim of this study was to assess independent predictors for fibrosis progression. METHODS: We identified 1189 patients from the Swiss Hepatitis C Cohort database with at least one biopsy prior to antiviral treatment and assessable date of infection. Stage-constant fibrosis progression rate was assessed using the ratio of fibrosis Metavir score to duration of infection. Stage-specific fibrosis progression rates were obtained using a Markov model. Risk factors were assessed by univariate and multivariate regression models. RESULTS: Independent risk factors for accelerated stage-constant fibrosis progression (>0.083 fibrosis units/year) included male sex (OR=1.60, [95% CI 1.21-2.12], P<0.001), age at infection (OR=1.08, [1.06-1.09], P<0.001), histological activity (OR=2.03, [1.54-2.68], P<0.001) and genotype 3 (OR=1.89, [1.37-2.61], P<0.001). Slower progression rates were observed in patients infected by blood transfusion (P=0.02) and invasive procedures or needle stick (P=0.03), compared to those infected by intravenous drug use. Maximum likelihood estimates (95% CI) of stage-specific progression rates (fibrosis units/year) for genotype 3 versus the other genotypes were: F0-->F1: 0.126 (0.106-0.145) versus 0.091 (0.083-0.100), F1-->F2: 0.099 (0.080-0.117) versus 0.065 (0.058-0.073), F2-->F3: 0.077 (0.058-0.096) versus 0.068 (0.057-0.080) and F3-->F4: 0.171 (0.106-0.236) versus 0.112 (0.083-0.142, overall P<0.001). CONCLUSIONS: This study shows a significant association of genotype 3 with accelerated fibrosis using both stage-constant and stage-specific estimates of fibrosis progression rates. This observation may have important consequences for the management of patients infected with this genotype.

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Chronic periaortitis (CP) is an uncommon inflammatory disease which primarily involves the infrarenal portion of the abdominal aorta. However, CP should be regarded as a generalized disease with three different pathophysiological entities, namely idiopathic retroperitoneal fibrosis (RPF), inflammatory abdominal aortic aneurysm and perianeurysmal RPF. These entities share similar histopathological characteristics and finally will lead to fibrosis of the retroperitoneal space. Beside fibrosis, an infiltrate with variable chronic inflammatory cell is present. The majority of these cells are lymphocytes and macrophages as well as vascular endothelial cells, most of which are HLA-DR-positive. B and T cells are present with a majority of T cells of the T-helper phenotype. Cytokine gene expression analysis shows the presence of interleukin (IL)-1alpha, IL-2, IL-4, interferon-gamma and IL-2 receptors. Adhesion molecules such as E-selectin, intercellular adhesion molecule-1 and the vascular cell adhesion molecule-1 were also found in aortic tissue, and may play a significant role in CP pathophysiology. Although CP pathogenesis remains unknown, an exaggerated inflammatory response to advanced atherosclerosis (ATS) has been postulated to be the main process. Autoimmunity has also been proposed as a contributing factor based on immunohistochemical studies. The suspected allergen may be a component of ceroid, which is elaborated within the atheroma. We review the pathogenesis and the pathophysiology of CP, and its potential links with ATS. Clinically relevant issues are summarized in each section with regard to the current working hypothesis of this complex inflammatory disease.

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Résumé Alors que le système nerveux sympathique a un rôle bien établi dans la régulation de la pression artérielle, l'influence de la fonction ou dysfonction du système parasympathique sur la pression artérielle n'est pas évidente, en particulier à long terme. Nous avons testé l'hypothèse que l'inhibition chronique du système parasympathique a un effet persistant sur la pression artérielle (PA), la fréquence cardiaque (FC) et la variabilité de la pression artérielle (VPA). Des rats de type Sprague Dawley ont été instrumentés pour monitoring de la pression artérielle 22h par jour par télémétrie et abrités dans des cages métaboliques. Après guérison de l'intervention et après une période contrôle de référence, de la scopolamine methyl bromide (SMB), un antagoniste muscarinique périphérique, a été perfusé i.v. pendant 12 jours. Le tout fut suivi d'une période de récupération de 10 jours. La SMB a entraîné une augmentation rapide de la PA de 98±2 mmHg à un maximum de 108±2 mmHg le deuxième jour de perfusion de la SMB puis la PA s'est stabilisée à une valeur plateau de +3±1 mmHg au dessus de la valeur contrôle (P < 0.05). Après l'arrêt de la perfusion de SMB, la PA moyenne a diminué de 6±1 mmHg. La FC a augmenté immédiatement et est restée significativement au dessus de la valeur contrôle le dernier jour de 1a perfusion de SMB. La SMB a également induit une diminution de la variabilité à court terme de la FC (au sein d'intervalles de 30 minutes et une augmentation de la variabilité à court terme et à long terme (entre intervalles de 30 minutes) de la PA. Ces données suggèrent que l'inhibition muscarinique périphérique chronique conduit à une augmentation modeste mais persistante de la PA, FC et VPA, qui sont des facteurs de risque cardiovasculaires connus.

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OBJECTIVE: Vitamin D deficiency is frequent in the general population and might be even more prevalent among populations with kidney failure. We compared serum vitamin D levels, vitamin D insufficiency/deficiency status, and vitamin D level determinants in populations without chronic kidney disease (CKD) and with CKD not requiring renal dialysis. DESIGN AND METHODS: This was a cross-sectional, multicenter, population-based study conducted from 2010 to 2011. Participants were from 10 centers that represent the geographical and cultural diversity of the Swiss adult population (≥15 years old). INTERVENTION: CKD was defined using estimated glomerular filtration rate and 24-hour albuminuria. Serum vitamin D was measured by liquid chromatography-tandem mass spectrometry. Statistical procedures adapted for survey data were used. MAIN OUTCOME MEASURE: We compared 25-hydroxy-vitamin D (25(OH)D) levels and the prevalence of vitamin D insufficiency/deficiency (serum 25(OH)D < 30 ng/mL) in participants with and without CKD. We tested the interaction of CKD status with 6 a priori defined attributes (age, sex, body mass index, walking activity, serum albumin-corrected calcium, and altitude) on serum vitamin D level or insufficiency/deficiency status taking into account potential confounders. RESULTS: Overall, 11.8% (135 of 1,145) participants had CKD. The 25(OH)D adjusted means (95% confidence interval [CI]) were 23.1 (22.6-23.7) and 23.5 (21.7-25.3) ng/mL in participants without and with CKD, respectively (P = .70). Vitamin D insufficiency or deficiency was frequent among participants without and with CKD (75.3% [95% CI 69.3-81.5] and 69.1 [95% CI 53.9-86.1], P = .054). CKD status did not interact with major determinants of vitamin D, including age, sex, BMI, walking minutes, serum albumin-corrected calcium, or altitude for its effect on vitamin D status or levels. CONCLUSION: Vitamin D concentration and insufficiency/deficiency status are similar in people with or without CKD not requiring renal dialysis.

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Background & Aims: Single nucleotide polymorphisms (SNPs) associated with IL28B influence the outcome of peginterferon-alpha/ribavirin therapy of chronic hepatitis C virus (HCV) infection. We analyzed the kinetics of HCV RNA during therapy as a function of IL28B SNPs.Methods: IL28B SNPs rs8099917, rs12979860, and rs12980275 were genotyped in 242 HCV treatment-naive Caucasian patients (67% genotype 1, 28% genotype 2 or 3) receiving peginterferon-alpha 2a (180 mu g weekly) and ribavirin (1000-1200 mg daily) with serial HCV-RNA quantifications. Associations between IL28B polymorphisms and early viral kinetics were assessed, accounting for relevant covariates.Results: In the multivariate analyses for genotype 1 patients, the T allele of rs12979860 (T(rs12979860)) was an independent risk factor for a less pronounced first phase HCV RNA decline (log(10) 0.89 IU/ml among T carriers vs. 2.06 among others, adjusted p <0.001) and lower rapid (15% vs. 38%, adjusted p = 0.007) and sustained viral response rates (48% vs. 66%, adjusted p <0.001). In univariate analyses, Trs12979860 was also associated with a reduced second phase decline (p = 0.002), but this association was no longer significant after adjustment for the first phase decline (adjusted p = 0.8). In genotype 2/3 patients, Trs12979860 was associated with a reduced first phase decline (adjusted p = 0.04), but not with a second phase decline.Conclusions: Polymorphisms in IL28B are strongly associated with the first phase viral decline during peginterferon-alpha/ribavirin therapy of chronic HCV infection, irrespective of HCV genotype. (C) 2011 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

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While one of the main objectives of adolescence is to achieve autonomy, for the specific population of adolescents with a chronic illness (CI), the struggle for autonomy is accentuated by the limits implied by their illness. However, little is known concerning the way their parents manage and cope with their children's autonomy acquisition. Our aim was to identify the needs and preoccupations of parents of adolescents with CI in coping with their children's autonomy acquisition and to determine whether mothers and fathers coped differently. Using a qualitative approach, 30 parents of adolescents with CI participated in five focus groups. Recruitment took place in five specialized pediatric clinics from our university hospital. Thematic analysis was conducted. Transcript analyses suggested four major categories of preoccupations, those regarding autonomy acquisition, giving or taking on autonomy, shared management of treatment and child's future. Some aspects implied differences between mothers' and fathers' viewpoints and ways of experiencing this period of life. Letting go can be hard for the father, mother, adolescent or all three. Helping one or the other can in turn improve family functioning as a whole. Reported findings may help health professionals better assist parents in managing their child's acquisition of autonomy.

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Using genome-wide association, we identify common variants at 2p12-p13, 6q26, 17q23 and 19q13 associated with serum creatinine, a marker of kidney function (P = 10(-10) to 10(-15)). Of these, rs10206899 (near NAT8, 2p12-p13) and rs4805834 (near SLC7A9, 19q13) were also associated with chronic kidney disease (P = 5.0 x 10(-5) and P = 3.6 x 10(-4), respectively). Our findings provide insight into metabolic, solute and drug-transport pathways underlying susceptibility to chronic kidney disease.

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Specific CD8(+) T cells (CTLs) play an important role in resolving protracted infection with hepatitis B and C virus in humans and lymphocytic choriomeningitis virus (LCMV) in mice. The contribution of individual CTL specificities to chronic virus control, as well as epitope-specific patterns in timing and persistence of antiviral selection pressure, remain, however, incompletely defined. To monitor and characterize the antiviral efficacy of individual CTL specificities throughout the course of chronic infection, we coinoculated mice with a mixture of wild-type LCMV and genetically engineered CTL epitope-deficient mutant virus. A quantitative longitudinal assessment of viral competition revealed that mice continuously exerted CTL selection pressure on the persisting virus population. The timing of selection pressure characterized individual epitope specificities, and its magnitude varied considerably between individual mice. This longitudinal assessment of "antiviral efficacy" provides a novel parameter to characterize CTL responses in chronic viral infection. It demonstrates remarkable perseverance of all antiviral CTL specificities studied, thus raising hope for therapeutic vaccination in the treatment of persistent viral diseases.

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Modern dietary habits are characterized by high-sodium and low-potassium intakes, each of which was correlated with a higher risk for hypertension. In this study, we examined whether long-term variations in the intake of sodium and potassium induce lasting changes in the plasma concentration of circulating steroids by developing a mathematical model of steroidogenesis in mice. One finding of this model was that mice increase their plasma progesterone levels specifically in response to potassium depletion. This prediction was confirmed by measurements in both male mice and men. Further investigation showed that progesterone regulates renal potassium handling both in males and females under potassium restriction, independent of its role in reproduction. The increase in progesterone production by male mice was time dependent and correlated with decreased urinary potassium content. The progesterone-dependent ability to efficiently retain potassium was because of an RU486 (a progesterone receptor antagonist)-sensitive stimulation of the colonic hydrogen, potassium-ATPase (known as the non-gastric or hydrogen, potassium-ATPase type 2) in the kidney. Thus, in males, a specific progesterone concentration profile induced by chronic potassium restriction regulates potassium balance.

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AIM: Sclerotherapy is the targeted chemical ablation of varicose veins by intravenous injection of a liquid or foamed sclerosing drug. The treated veins may be intradermal, subcutaneous, and/or transfascial as well as superficial and deep in venous malformations. The aim of this guideline is to give evidence-based recommendations for liquid and foam sclerotherapy. METHODS: This guideline was drafted on behalf of 23 European Phlebological Societies during a Guideline Conference on 7-10 May 2012 in Mainz. The conference was organized by the German Society of Phlebology. These guidelines review the present state of knowledge as reflected in published medical literature. The regulatory situation of sclerosant drugs differs from country to country but this has not been considered in this document. The recommendations of this guideline are graded according to the American College of Chest Physicians Task Force recommendations on Grading Strength of Recommendations and Quality of Evidence in Clinical Guidelines. RESULTS: This guideline focuses on the two sclerosing drugs which are licensed in the majority of the European countries, polidocanol and sodium tetradecyl sulphate. Other sclerosants are not discussed in detail. The guideline gives recommendations concerning indications, contraindications, side-effects, concentrations, volumes, technique and efficacy of liquid and foam sclerotherapy of varicose veins and venous malformations.