95 resultados para 124-776
em Université de Lausanne, Switzerland
Resumo:
Mutations in kerato-epithelin are responsible for a group of hereditary cornea-specific deposition diseases, 5q31-linked corneal dystrophies. These conditions are characterized by progressive accumulation of protein deposits of different ultrastructure. Herein, we studied the corneas with mutations at kerato-epithelin residue Arg-124 resulting in amyloid (R124C), non-amyloid (R124L), and a mixed pattern of deposition (R124H). We found that aggregated kerato-epithelin comprised all types of pathological deposits. Each mutation was associated with characteristic changes of protein turnover in corneal tissue. Amyloidogenesis in R124C corneas was accompanied by the accumulation of N-terminal kerato-epithelin fragments, whereby species of 44 kDa were the major constituents of amyloid fibrils. R124H corneas with prevailing non-amyloid inclusions showed accumulation of a new 66-kDa species altogether with the full-size 68-kDa form. Finally, in R124L cornea with non amyloid deposits, we found only the accumulation of the 68-kDa form. Two-dimensional gels revealed mutation-specific changes in the processing of the full-size protein in all affected corneas. It appears that substitutions at the same residue (Arg-124) result in cornea-specific deposition of kerato-epithelin via distinct aggregation pathways each involving altered turnover of the protein in corneal tissue.
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Introduction: CD103 is a specific integrin present on some CD4+ lymphocytes of the mucosal immune system. It has been hypothesized that most CD4+ lymphocytes in pulmonary sarcoidosis do not originate from mucosal sites but from redistribution from the peripheral blood, and therefore do not bear the CD103 integrin. Several studies have suggested that a low CD103+ percentage among bronchoalveolar lavage (BAL) CD4+ lymphocytes discriminates between sarcoidosis and other causes of lymphocytic alveolitis, but contradictory data exist. Methods: We reviewed 1151 consecutive patients with BAL lymphocytosis >10% and flow cytometry performed between 2006 and 2014. 944 cases were excluded due to poor BAL quality (n= 97), unavailable clinical data (n= 760), or unclear diagnosis (n= 87). The remaining 207 patients were grouped into 9 diagnostic categories. To assess the discriminative value of the CD103+CD4+/CD4+ ratio to distinguish sarcoidosis from the other entities, area under ROC curves (AUC) were determined. Results: Sarcoidosis patients (n=53) had a lower CD103+CD4+/CD4+ ratio than the other diagnostic categories. AUC was 62% for sarcoidosis compared to all other patients and 69% for sarcoidosis compared to other interstitial lung diseases. When combining CD103+CD4+/CD4+ and CD4+/CD8+ ratios, AUC increased to 76% and 78% respectively. When applying published cut-offs from 4 previous studies to our population, AUC varied between 54 and 73%. Conclusions: The CD103+CD4+/CD4+ ratio does not accurately discriminate between sarcoidosis and other causes of lymphocytic alveolitis, neither alone nor in combination with CD4+/CD8+ ratio, and is not a relevant marker for the diagnosis of sarcoidosis.
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PURPOSE: To evaluate a diagnostic strategy for pulmonary embolism that combined clinical assessment, plasma D-dimer measurement, lower limb venous ultrasonography, and helical computed tomography (CT). METHODS: A cohort of 965 consecutive patients presenting to the emergency departments of three general and teaching hospitals with clinically suspected pulmonary embolism underwent sequential noninvasive testing. Clinical probability was assessed by a prediction rule combined with implicit judgment. All patients were followed for 3 months. RESULTS: A normal D-dimer level (<500 microg/L by a rapid enzyme-linked immunosorbent assay) ruled out venous thromboembolism in 280 patients (29%), and finding a deep vein thrombosis by ultrasonography established the diagnosis in 92 patients (9.5%). Helical CT was required in only 593 patients (61%) and showed pulmonary embolism in 124 patients (12.8%). Pulmonary embolism was considered ruled out in the 450 patients (46.6%) with a negative ultrasound and CT scan and a low-to-intermediate clinical probability. The 8 patients with a negative ultrasound and CT scan despite a high clinical probability proceeded to pulmonary angiography (positive: 2; negative: 6). Helical CT was inconclusive in 11 patients (pulmonary embolism: 4; no pulmonary embolism: 7). The overall prevalence of pulmonary embolism was 23%. Patients classified as not having pulmonary embolism were not anticoagulated during follow-up and had a 3-month thromboembolic risk of 1.0% (95% confidence interval: 0.5% to 2.1%). CONCLUSION: A noninvasive diagnostic strategy combining clinical assessment, D-dimer measurement, ultrasonography, and helical CT yielded a diagnosis in 99% of outpatients suspected of pulmonary embolism, and appeared to be safe, provided that CT was combined with ultrasonography to rule out the disease.
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Current explanatory models for binge eating in binge eating disorder (BED) mostly rely onmodels for bulimianervosa (BN), although research indicates different antecedents for binge eating in BED. This studyinvestigates antecedents and maintaining factors in terms of positive mood, negative mood and tension in asample of 22 women with BED using ecological momentary assessment over a 1-week. Values for negativemood were higher and those for positive mood lower during binge days compared with non-binge days.During binge days, negative mood and tension both strongly and significantly increased and positive moodstrongly and significantly decreased at the first binge episode, followed by a slight though significant, andlonger lasting decrease (negative mood, tension) or increase (positive mood) during a 4-h observation periodfollowing binge eating. Binge eating in BED seems to be triggered by an immediate breakdown of emotionregulation. There are no indications of an accumulation of negative mood triggering binge eating followed byimmediate reinforcing mechanisms in terms of substantial and stable improvement of mood as observed inBN. These differences implicate a further specification of etiological models and could serve as a basis fordeveloping new treatment approaches for BED.
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We reviewed our surgery registry, to identify predictive risk factors for operative results, and to analyse the long-term survival outcome in octogenarians operated for primary isolated aortic valve replacement (AVR). A total of 124 consecutive octogenarians underwent open AVR from January 1990 to December 2005. Combined procedures and redo surgery were excluded. Selected variables were studied as risk factors for hospital mortality and early neurological events. A follow-up (FU; mean FU time: 77 months) was obtained (90% complete), and Kaplan-Meier plots were used to determine survival rates. The mean age was 82+/-2.2 (range: 80-90 years; 63% females). Of the group, four patients (3%) required urgent procedures, 10 (8%) had a previous myocardial infarction, six (5%) had a previous coronary angioplasty and stenting, 13 patients (10%) suffered from angina and 59 (48%) were in the New York Heart Association (NYHA) class III-IV. We identified 114 (92%) degenerative stenosis, six (5%) post-rheumatic stenosis and four (3%) active endocarditis. The predicted mortality calculated by logistic European System for Cardiac Operative Risk Evaluation (EuroSCORE) was 12.6+/-5.7%, and the observed hospital mortality was 5.6%. Causes of death included severe cardiac failure (four patients), multi-organ failure (two) and sepsis (one). Complications were transitory neurological events in three patients (2%), short-term haemodialysis in three (2%), atrial fibrillation in 60 (48%) and six patients were re-operated for bleeding. Atrio-ventricular block, myocardial infarction or permanent stroke was not detected. The age at surgery and the postoperative renal failure were predictors for hospital mortality (p value <0.05), whereas we did not find predictors for neurological events. The mean FU time was 77 months (6.5 years) and the mean age of surviving patients was 87+/-4 years (81-95 years). The actuarial survival estimates at 5 and 10 years were 88% and 50%, respectively. Our experience shows good short-term results after primary isolated standard AVR in patients more than 80 years of age. The FU suggests that aortic valve surgery in octogenarians guarantees satisfactory long-term survival rates and a good quality of life, free from cardiac re-operations. In the era of catheter-based aortic valve implantation, open-heart surgery for AVR remains the standard of care for healthy octogenarians.
Resumo:
Schizophrenia has long been considered with pessimism, but the recent interest in the early phase of psychotic disorders has modified this often unjustified perception. Literature has demonstrated the benefit of the development of programs specialised in the treatment of early psychosis, which tend to be developed in many countries. It is however important to match them to local needs as well as to the structure of local health services. This paper reviews elements that justify such a development in Lausanne, Switzerland, and describe its various elements.
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Certaines dégénérescences rétiniennes sont engendrées par des mutations¦génétiques et conduisent à la perte des cellules photosensibles, les¦photorécepteurs (cônes et/ou bâtonnets), et donc à la cécité (Roy et al., 2010).¦La prévalence est de 1/3000 chez les Caucasiens. Les Rétinites Pigmentaires¦(RP) en composent la majorité des cas, suivent l'Amaurose congénitale de¦Leber et la maladie de Stargardt. Il n'y a pas une mutation type associés à une¦maladie mais diverses mutations peuvent aboutir à une dégénérescence de la¦rétine. Tout comme le reste du système nerveux central, la rétine lésée n'a pas¦les capacités de se régénérer. Un objectif du traitement est de ralentir la¦dégénérescence de la rétine dans le but de la stabiliser. La thérapie génique¦constitue actuellement la seule approche thérapeutique à même de traiter les¦dégénérescences rétiniennes d'origine génétique. Elle consiste à utiliser un virus¦modifié, qui n'a plus les capacités de se reproduire, appelé vecteur pour cibler¦certaines cellules afin d'ajouter un gène sain ou d'inhiber un gène malade. Les¦virus associés à l'adénovirus (AAV) et les Lentivirus (LV) sont les 2 principaux¦types de virus utilisés en thérapie génique en ophtalmologie. D'autres vecteurs¦existent, comme les adénovirus et le virus de l'anémie infectieuse équine. Des¦études de thérapie génique effectuées chez l'homme avec le vecteur AAV ont¦démontré une sensible amélioration des fonctions visuelles (acuité visuelle,¦champ visuel, pupillométrie et le déplacement dans un environnement avec une¦lumière tamisée) chez des patients atteints d'Amaurose congénitale de Leber¦(Maguire et al., Ali et al., Hauswirth et al., Bennett et al.). Le vecteur utilisé au¦cours de ce travail est un LV, qui a pour avantage de pouvoir transporter de¦grands gènes. Lorsque ce vecteur est pseudotypé avec une enveloppe VSVG, il¦transduit (transférer un gène qui sera fonctionnel dans la cellule cible) bien¦l'épithélium pigmentaire rétinien (nécessaire à la survie et à la fonction des¦photorécepteurs). Afin de changer le tropisme du vecteur, celui testé dans cette¦étude contient une enveloppe de type Mokola qui cible efficacement les cellules¦gliales du cerveau et donc probablement aussi les cellules de Müller de la rétine.¦Le but à court terme est de transformer génétiquement ces cellules pour leur¦faire sécréter des molécules favorisant la survie des photorécepteurs. Pour¦révéler la cellule ciblée par le vecteur, le gène qui sera exprimé dans les cellules¦transduites code pour la protéine fluorescente verte 2 (GFPII) et n'a pas de¦fonction thérapeutique. Après avoir produit le virus, deux types de souris ont été¦injectées : des souris dépourvues du gène de la rhodopsine appelées Rho -/- et¦des souris sauvages appelées C57BL6. Les souris Rho -/- ont été choisies en¦tant que modèle de dégénérescence rétinienne et les souris C57BL6 en tant que¦comparatif. Les souris Rho -/- et C57BL56 ont été injectées entre le 2ème et le¦3ème mois de vie et sacrifiées 7 jours après. Des coupes histologiques de la rétine¦ont permis de mesurer et comparer pour chaque oeil, les distances de¦transduction du RPE et de la neurorétine (= toute la rétine sauf le RPE). La¦distance sur laquelle le RPE est transduit détermine la taille de la bulle¦d'injection alors que la distance sur laquelle la neurorétine est transduite¦détermine la capacité du vecteur à diffuser dans la rétine. Les résultats montrent¦une expression plus importante de la GFPII dans le RPE que dans la neurorétine¦chez les souris Rho -/- et C57BL6. Les principales cellules transduites au¦niveau de la neurorétine sont, comme attendu, les cellules de Müller. Lorsque¦l'on compare les proportions de neurorétine et de RPE transduites, on constate¦qu'il y a globalement eu une meilleure transduction chez les souris Rho -/-¦que chez les souris C57BL6. Cela signifie que le vecteur est plus efficace pour¦transduire une rétine dégénérée qu'une rétine saine. Pour déterminer quels types¦de cellules exprimaient la GFPII, des anticorps spécifiques de certains types de¦cellules ont été utilisés. Ces résultats sont similaires à ceux d'autres études¦effectuées précédemment, dont celle de Calame et al. en 2011, et tendent à¦prouver que le vecteur lentiviral avec l'enveloppe Mokola et le promoteur EFs¦est idéal pour transduire avec un gène thérapeutique des cellules de Müller dans¦des rétines en dégénérescence.
Resumo:
Summary The best described physiological function of low-density lipoproteins (LDL) is to transport cholesterol to target tissues. LDL deliver their cholesterol cargo to cells following their interaction with the LDL receptor. LDL, when their vascular concentrations increase, have also been implicated in pathologies such as atherosclerosis. Among the cell types that are found in blood vessels, endothelial and smooth muscle cells have dominated cellular research on atherosclerotic mechanisms and LDL activation of signaling pathways, while very little is known about adventitial fibroblast activation caused by elevated lipoprotein levels. Since fibroblasts participate in wound repair and since it has recently been recognized that fibroblasts may play pivotal roles in vascular remodeling and repair of injury, we assessed whether lipoproteins affect fibroblast function. We have found that LDL specifically mediate the activation of a class of mitogen-activated protein kinases (MAPKs): the p38 MAPKs. The activation of this pathway in turn modulates cell shape by promoting lamellipodia formation and extensive cell spreading. This is of particular interest because it provides a mechanism by which LDL can promote wound healing or vessel wall remodeling as observed during the development of atherosclerosis. In order to understand the molecular mechanisms by which LDL induce p38 activation we searched for the component in the LDL particle responsible for the induction of this pathway. We found that cholesterol is the major component of lipoprotein particles that mediates their ability to stimulate the p38 MAPK pathway. Furthermore, we investigated the cellular mechanisms underlying the ability of LDL to induce cell shape changes and whether this could participate in wound repair. Our recent data demonstrates that the capacity of LDL to induce fibroblast spreading relies on their ability to stimulate IL-8 secretion, which in turn leads to accelerated wound healing. LDL-induced IL-8 production and subsequent wound closure are impaired upon inhibition of the p38 MAPK pathway indicating that the LDL-induced spreading and accelerated wound sealing rely on the ability of LDL to stimulate IL-8 secretion in a p38 MAPK-dependent manner. Therefore, regulation of fibroblast shape and migration by lipoproteins may be relevant to atherosclerosis that is characterized by increased LDL-cholesterol levels, IL-8 production and extensive remodeling of the vessel wall. Résumé: La fonction physiologique des lipoprotéines à faible densité (LDL) la mieux décrite est celle du transport du cholestérol aux tissus cibles. Les LDL livrent leur cargaison de cholestérol aux cellules après leur interaction avec le récepteur au LDL. Une concentration vasculaire des LDL augmenté est également impliquée dans le développement de l'athérosclérose. Parmi les types de cellule présents dans les vaisseaux sanguins, les cellules endothéliales et les cellules du muscle lisse ont dominé la recherche cellulaire sur les mécanismes athérosclérotiques et sur l'activation par les LDL des voies de signalisation intracellulaire. A l'inverse peu de choses sont connues sur l'activation des fibroblastes de l'adventice par les lipoprotéines. Puisqu'il a été récemment reconnu que les fibroblastes peuvent jouer un rôle central dans la remodélisation vasculaire et la réparation tissulaire, nous avons étudié si les lipoprotéines affectent la fonction des fibroblastes. Nous avons constaté que les LDL activent spécifiquement une classe de protéines kinases: les p38 MAPK (mitogen-activated protein kinases). L'activation de cette voie module à son tour la forme de la cellule en favorisant la formation de lamellipodes et l'agrandissement des cellules. Cela a un intérêt particulier car il fournit un mécanisme par lequel les LDL peuvent promouvoir la cicatrisation ou la remodélisation des parois vasculaires comme observés lors du développement de l'athérosclérose. Pour comprendre les mécanismes moléculaires par lesquels les LDL provoquent l'activation des p38 MAPK, nous avons cherché à identifier les composants dans la particule de LDL responsables de l'induction de cette voie. Nous avons constaté que le cholestérol est l'élément principal des particules de lipoprotéine qui contrôle leur capacité à stimuler la voie des p38 MAPK. En outre, nous avons examiné les mécanismes cellulaires responsables de la capacité des LDL à induire des changements dans la forme des cellules. Nos données récentes démontrent que la capacité des LDL à induire l'agrandissement des cellules, ainsi que leur aptitude à favoriser la cicatrisation, reposant sur leur capacité à stimuler la sécrétiond'IL-8. La production d'IL-8 induite par les LDL est bloquée par l'inhibition de la voie p38 MAPK, ce qui indique que l'étalement des cellules induit par les LDL ainsi que l'accélération de la cicatrisation sont liés à la capacité des LDL à stimuler la sécrétion d'IL8 via l'activation des p38 MAPK. La régulation de la forme et de la migration des fibroblastes par les lipoprotéines peuvent donc participer au développement de l'athérosclérose qui est caractérisée par l'augmentation des niveaux de production de LDL-cholestérol et d'IL-8 ainsi que par une remodélisation augmentée de la paroi du vaisseau.
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BACKGROUND: The presence of cognitive and structural deficits in euthymic elderly depressed patients remains a matter of debate. Integrative aetiological models assessing concomitantly these parameters as well as markers of psychological vulnerability such as persistent personality traits, are still lacking for this age group. METHODS: Cross-sectional comparisons of 38 elderly remitted patients with early-onset depression (EOD) and 62 healthy controls included detailed neuropsychological assessment, estimates of brain volumes in limbic areas and white matter hyperintensities, as well as evaluation of the Five-Factor personality dimensions. RESULTS: Both cognitive performances and brain volumes were preserved in euthymic EOD patients. No significant group differences were observed in white matter hyperintensity scores between the two groups. In contrast, EOD was associated with significant increase of Neuroticism and decrease of Extraversion facet scores. LIMITATIONS: Results concern the restricted portion of EOD patients without psychiatric and physical comorbidities. Future longitudinal studies are necessary to determine the temporal relationship between the occurrence of depression and personality dimensions. CONCLUSIONS: After remission from acute depressive symptoms, cognitive performances remain intact in elderly patients with EOD. In contrast to previous observations, these patients display neither significant brain volume loss in limbic areas nor increased vascular burden compared to healthy controls. Further clinical investigations on EOD patterns of vulnerability in old age will gain from focusing on psychological features such as personality traits rather than neurocognitive clues.