180 resultados para Primary Stability


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We have explored in vitro the mechanism by which human immunodeficiency virus, type 1 (HIV-1) induces cell death of primary CD4+ T cells in conditions of productive infection. Although HIV-1 infection primed phytohemagglutinin-activated CD4+ T cells for death induced by anti-CD95 antibody, T cell death was not prevented by a CD95-Fc decoy receptor, nor by decoy receptors of other members of the TNFR family (TNFR1/R2, TRAILR1/R2/OPG, TRAMP) or by various blocking antibodies, suggesting that triggering of death receptors by their cognate ligands is not involved in HIV-induced CD4 T cell death. HIV-1 induced CD4 T cell shrinkage, cell surface exposure of phosphatidylserine, loss of mitochondrial membrane potential (Deltapsim), and mitochondrial release of cytochrome c and apoptosis-inducing factor. A typical apoptotic phenotype (nuclear chromatin condensation and fragmentation) only occurred in around half of the dying cells. Treatment with benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone, a broad spectrum caspase inhibitor, prevented nuclear chromatin condensation and fragmentation in HIV-infected CD4+ T cells and in a cell-free system (in which nuclei were incubated with cytoplasmic extracts from the HIV-infected CD4+ T cells). Nevertheless, benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone did not prevent mitochondrial membrane potential loss and cell death, suggesting that caspases are dispensable for HIV-mediated cell death. Our findings suggest a major role of the mitochondria in the process of CD4 T cell death induced by HIV, in which targeting of Bax to the mitochondria may be involved.

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Fear of negative evaluation (FNE) is regarded as being the core feature of social anxiety. The present study examined how FNE is associated with physical activity (PA), body mass index (BMI) and perceived physical health (PPH) in children. Data were collected in a sample of 502 primary school children in first and fifth grades taking part in a randomized-controlled trial ("Kinder-Sportstudie KISS") aimed at increasing PA and health. PA was assessed by accelerometry over 7 days, PPH by the Child Health Questionnaire and FNE by the Social Anxiety Scale for Children--Revised. BMI z-scores were calculated based on Swiss norms. Cross-sectional analyses indicated that children high in FNE exercised less, reported lower levels of PPH and had higher BMI z-scores (P<0.01). Using mixed linear models, the school-based PA intervention did not manage to reduce FNE scores. Overweight children demonstrated a greater increase in FNE (P<0.05) indicating that enhanced weight may be a risk factor for FNE. In conclusion, the associations among high FNE, low PA and increased BMI should be considered when promoting an active lifestyle in children.

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Cet article a été réalisé dans le but d'évaluer la qualité des soins fournie à une population âgée de 50 à 80 ans suivie dans 4 policliniques médicales universitaires de Suisse, à savoir Bâle, Zurich, Genève et Lausanne. Nous avons sélectionné 37 indicateurs de qualité qui ont été développés et préalablement évalués au Etats-Unis. Ces indicateurs ont été divisés en 2 sous-groupes distincts : les indicateurs de prévention et les indicateurs concernant les facteurs de risque cardiovasculaires.¦L'étude a inclus des patients âgés de 50 à 80 ans avec un suivi d'un minimum de 1 an par un médecin dans l'une des policliniques de Suisse. Nous avons limité notre étude à ce groupe d'âge, afin d'avoir une prévalence élevée de facteur de risque cardiovasculaire et plus d'indications à des tests de dépistages. Les dossiers médicaux des patients ont été sélectionnés selon un mode aléatoire en prenant 250 dossiers par centre.¦L'enjeu principal de cette étude était de déterminer le niveau de soins fournis en Suisse dans les policliniques médicales universitaires. Il a été également possible de mettre en évidence les secteurs de prévention pour lesquels le taux d'application est encore insuffisant. Nous avons par la même occasion comparé nos résultats à ceux obtenus aux Etats-Unis, sachant que ce pays a un système d'évaluation de la qualité des soins qui fournit chaque années des statistiques à ce sujet.¦Les résultats de notre étude montrent qu'en Suisse les adultes reçoivent 69% des mesures de prévention recommandées mais que ces taux diffèrent d'un indicateur à l'autre. Les indicateurs à propos de la tension artérielle et de la mesure du poids (les 2 95%) ont plus souvent été réalisés durant les consultations que les indicateurs concernant l'arrêt du tabagisme (72%), les cancers du sein (40%), du colon (35%) et la vaccination annuelle contre la grippe (35.2% chez les patients de >65 ans et 29.3% chez les patient de <65 ans avec une maladie chronique). 83% des patients reçoivent les mesures préventives concernant les facteurs de risque cardiovasculaire, avec >75% pour l'hypertension, le diabète et la dyslipidémie. Cependant, l'examen des pieds est effectué chez seulement 50% des patients présentant un diabète.¦De même, nous avons pu démontrer que les femmes (65.3%) et les personnes âgées de plus de 65 ans (68.0%) reçoivent moins de mesures préventives que les hommes (72.2%) et les personnes plus jeunes (70.1%).¦Ce travail de recherche a donc permis de mettre en évidence les domaines de la prévention encore insuffisamment proposés aux patients et de rendre attentif le personnel médical sur le fait qu'il existe en Suisse des groupes de personnes qui reçoivent moins de prévention que d'autres groupes. Dans le futur, l'accent devrait être d'avantage mis durant les études de médecine et lors de la formation post-graduée sur les mesures préventives pas assez exploitées en Suisse en particulier le dépistage des cancers et la vaccination annuelle contre la grippe.

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Maintenance by the kidney of stable plasma K(+) values is crucial, as plasma K(+) controls muscle and nerve activity. Since renal K(+) excretion is regulated by the circadian clock, we aimed to identify the ion transporters involved in this process. In control mice, the renal mRNA expression of H,K-ATPase type 2 (HKA2) is 25% higher during rest compared to the activity period. Conversely, under dietary K(+) restriction, HKA2 expression is ∼40% higher during the activity period. This reversal suggests that HKA2 contributes to the circadian regulation of K(+) homeostasis. Compared to their wild-type (WT) littermates, HKA2-null mice fed a normal diet have 2-fold higher K(+) renal excretion during rest. Under K(+) restriction, their urinary K(+) loss is 40% higher during the activity period. This inability to excrete K(+) "on time" is reflected in plasma K(+) values, which vary by 12% between activity and rest periods in HKA2-null mice but remain stable in WT mice. Analysis of the circadian expression of HKA2 regulators suggests that Nrf2, but not progesterone, contributes to its rhythmicity. Therefore, HKA2 acts to maintain the circadian rhythm of urinary K(+) excretion and preserve stable plasma K(+) values throughout the day.

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BACKGROUND: The impact of preoperative impaired left ventricular ejection fraction (EF) in octogenarians following coronary bypass surgery on short-term survival was evaluated in this study. METHODS: A total of 147 octogenarians (mean age 82.1 ± 1.9 years) with coronary artery diseases underwent elective coronary artery bypass graft between January 2000 and December 2009. Patients were stratified into: Group I (n = 59) with EF >50%, Group II (n = 59) with 50% > EF >30% and in Group III (n = 29) with 30% > EF. RESULTS: There was no difference among the three groups regarding incidence of COPD, renal failure, congestive heart failure, diabetes, and preoperative cerebrovascular events. Postoperative atrial fibrillation was the sole independent predictive factor for in-hospital mortality (odds ratio (OR), 18.1); this was 8.5% in Group I, 15.3% in Group II and 10.3% in Group III. Independent predictive factors for mortality during follow up were: decrease of EF during follow-up for more that 5% (OR, 5.2), usage of left internal mammary artery as free graft (OR, 18.1), and EF in follow-up lower than 40% (OR, 4.8). CONCLUSIONS: The results herein suggest acceptable in-hospital as well short-term mortality in octogenarians with impaired EF following coronary artery bypass grafting (CABG) and are comparable to recent literature where the mortality of younger patients was up to 15% and short-term mortality up to 40%, respectively. Accordingly, we can also state that in an octogenarian cohort with impaired EF, CABG is a viable treatment with acceptable mortality.

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The public primary school system in the State of Geneva, Switzerland, is characterized by centrally evaluated pupil performance measured with the use of standardized tests. As a result, consistent data are collected among the system. The 2010-2011 dataset is used to develop a two-stage data envelopment analysis (DEA) of school efficiency. In the first stage, DEA is employed to calculate an individual efficiency score for each school. It shows that, on average, each school could reduce its inputs by 7% whilst maintaining the same quality of pupil performance. The cause of inefficiency lies in perfectible management. In the second stage, efficiency is regressed on school characteristics and environmental variables;external factors outside of the control of headteachers. The model is tested for multicollinearity, heteroskedasticity and endogeneity. Four variables are identified as statistically significant. School efficiency is negatively influenced by (1) the provision of special education, (2) the proportion of disadvantaged pupils enrolled at the school and (3) operations being held on multiple sites, but positively influenced by school size (captured by the number of pupils). The proportion of allophone pupils; schools located in urban areas and the provision of reception classes for immigrant pupils are not significant. Although the significant variables influencing school efficiency are outside of the control of headteachers, it is still possible to either boost the positive impact or curb the negative impact. Dans le canton de Genève (Suisse), les écoles publiques primaires sont caractérisées par un financement assuré par les collectivités publiques (canton et communes) et par une évaluation des élèves à l'aide d'épreuves standardisées à trois moments distincts de leur scolarité. Cela permet de réunir des informations statistiques consistantes. La base de données de l'année 2010-2011 est utilisée dans une analyse en deux étapes de l'efficience des écoles. Dans une première étape, la méthode d'analyse des données par enveloppement (DEA) est utilisée pour calculer un score d'efficience pour chaque école. Cette analyse démontre que l'efficience moyenne des écoles s'élève à 93%. Chaque école pourrait, en moyenne, réduire ses ressources de 7% tout en conservant constants les résultats des élèves aux épreuves standardisées. La source de l'inefficience réside dans un management des écoles perfectible. Dans une seconde étape, les scores d'efficience sont régressés sur les caractéristiques des écoles et sur des variables environnementales. Ces variables ne sont pas sous le contrôle (ou l'influence) des directeurs d'école. Le modèle est testé pour la multicolinéartié, l'hétéroscédasticité et l'endogénéité. Quatre variables sont statistiquement significatives. L'efficience des écoles est influencée négativement par (1) le fait d'offrir un enseignement spécialisé en classe séparée, (2) la proporition d'élèves défavorisés et (3) le fait d'opérer sur plusieurs sites différents. L'efficience des écoles est influencée positivement par la taille de l'école, mesurée par le nombre d'élèves. La proporition d'élèves allophones, le fait d'être situé dans une zone urbaine et d'offrir des classes d'accueil pour les élèves immigrants constituent autant de variables non significatives. Le fait que les variables qui influencent l'efficience des écoles ne soient pas sous le contrôle des directeurs ne signifie pas qu'il faille céder au fatalisme. Différentes pistes sont proposées pour permettre soit de réduire l'impact négatif soit de tirer parti de l'impact positif des variables significatives.

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Medication nonadherence is common and its determinants are diverse. Adherence is influenced by many parameters, such as patient's self-efficacy, knowledge of health risk, outcome expectations, benefits of change, and barriers and facilitators. The sociocognitive theory helps professionals to structure their approach and to support patients in managing their treatment. Professionals need skills and time, and benefit from coordination in care, in particular between physicians and pharmacists. This article presents the key elements of a medication adherence program as well as tools and some useful questions.

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Low-grade osteosarcoma is a rare malignancy that may be subdivided into two main subgroups on the basis of location in relation to the bone cortex, that is, parosteal osteosarcoma and low-grade central osteosarcoma. Their histological appearance is quite similar and characterized by spindle cell stroma with low-to-moderate cellularity and well-differentiated anastomosing bone trabeculae. Low-grade osteosarcomas have a simple genetic profile with supernumerary ring chromosomes comprising amplification of chromosome 12q13-15, including the cyclin-dependent kinase 4 (CDK4) and murine double-minute type 2 (MDM2) gene region. Low-grade osteosarcoma can be confused with fibrous and fibro-osseous lesions such as fibromatosis and fibrous dysplasia on radiological and histological findings. We investigated MDM2-CDK4 immunohistochemical expression in a series of 72 low-grade osteosarcomas and 107 fibrous or fibro-osseous lesions of the bone or paraosseous soft tissue. The MDM2-CDK4 amplification status of low-grade osteosarcoma was also evaluated by comparative genomic hybridization array in 18 cases, and the MDM2 amplification status was evaluated by fluorescence in situ hybridization or quantitative real-time polymerase chain reaction in 31 cases of benign fibrous and fibro-osseous lesions. MDM2-CDK4 immunostaining and MDM2 amplification by fluorescence in situ hybridization or quantitative real-time polymerase chain reaction were investigated in a control group of 23 cases of primary high-grade bone sarcoma, including 20 conventional high-grade osteosarcomas, two pleomorphic spindle cell sarcomas/malignant fibrous histiocytomas and one leiomyosarcoma. The results showed that MDM2 and/or CDK4 immunoreactivity was present in 89% of low-grade osteosarcoma specimens. All benign fibrous and fibro-osseous lesions and the tumors of the control group were negative for MDM2 and CDK4. These results were consistent with the MDM2 and CDK4 amplification results. In conclusion, immunohistochemical expression of MDM2 and CDK4 is specific and provides sensitive markers for the diagnosis of low-grade osteosarcomas, helping to differentiate them from benign fibrous and fibro-osseous lesions, particularly in cases with atypical radio-clinical presentation and/or limited biopsy samples.

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FANCM remodels branched DNA structures and plays essential roles in the cellular response to DNA replication stress. Here, we show that FANCM forms a conserved DNA-remodeling complex with a histone-fold heterodimer, MHF. We find that MHF stimulates DNA binding and replication fork remodeling by FANCM. In the cell, FANCM and MHF are rapidly recruited to forks stalled by DNA interstrand crosslinks, and both are required for cellular resistance to such lesions. In vertebrates, FANCM-MHF associates with the Fanconi anemia (FA) core complex, promotes FANCD2 monoubiquitination in response to DNA damage, and suppresses sister-chromatid exchanges. Yeast orthologs of these proteins function together to resist MMS-induced DNA damage and promote gene conversion at blocked replication forks. Thus, FANCM-MHF is an essential DNA-remodeling complex that protects replication forks from yeast to human.

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Stable gene silencing by RNA interference (RNAi) can be achieved by expression of small hairpin RNAs (shRNAs) from RNA polymerase III promoters. We have tested lentiviral vectors expressing shRNAs targetting CCR5 in primary CD4 T cells from donors representing various CCR5 and CCR2 genetic backgrounds covering the full spectrum of CCR5 expression levels and permissiveness for HIV-1 infection. A linear decrease in CCR5 expression resulted in a logarithmic decrease in cellular infection, giving up to three logs protection from HIV-1 infection in vitro. Protection was maintained at very high multiplicity of infection. This and other recent reports on RNAi should open a debate about the use of RNAi gene therapy for HIV infection.

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The peripheral projections of two distinct subpopulations of primary sensory neurons, expressing either calbindin D-28k or substance P, were studied in chick hindlimbs by immunodetecting calbindin D-28k with a rabbit antiserum and substance P with a mouse monoclonal antibody. Calbindin D-28k-immunoreactive axons provided an innervation restricted to specific mechanoreceptors such as muscle spindles, Herbst and Merkel corpuscles, or collars of feather follicles but were absent from Golgi tendon organs. In contrast, substance P-positive axons spread out diffusely in muscles and skin, formed loose plexuses, and extended free branches to the endomysium, arteries, superficial dermis, or dermal pulp of feather follicles. The present results show that calbindin D-28k- and substance P-immunoreactive primary sensory neurons provide distinct modes of innervation to selective targets in peripheral tissues. The results suggest a possible correlation between CaBP-expressing nerve endings and rapidly adapting mechanoreceptors.

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Lobectomy via video-assisted thoracoscopic surgery (VATS) is now considered as a valid alternative to conventional thoracotomy for early-stage primary lung cancer. Various studies have reported that VATS lobectomy is a safe technique associated with fewer postoperative complications and better post-operative recovery than open thoracotomy. Furthermore, studies suggest oncological equivalence between VATS and open lobectomy.

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Dystonia is associated with impaired somatosensory ability. The electrophysiological method of repetitive transcranial magnetic stimulation (rTMS) can be used for noninvasive stimulation of the human cortex and can alter cortical excitability and associated behavior. Among others, rTMS can alter/improve somatosensory discrimation abilities, as shown in healthy controls. We applied 5Hz-rTMS over the left primary somatosensory cortex (S1) in 5 patients with right-sided writer's dystonia and 5 controls. We studied rTMS effects on tactile discrimination accuracy and concomitant rTMS-induced changes in hemodynamic activity measured by functional magnetic resonance imaging (fMRI). Before rTMS, patients performed worse on the discrimination task than controls even though fMRI showed greater task-related activation bilaterally in the basal ganglia (BG). In controls, rTMS led to improved discrimination; fMRI revealed this was associated with increased activity of the stimulated S1, bilateral premotor cortex and BG. In dystonia patients, rTMS had no effect on discrimination; fMRI showed similar cortical effects to controls except for no effects in BG. Improved discrimination after rTMS in controls is linked to enhanced activation of S1 and BG. Failure of rTMS to increase BG activation in dystonia may be associated with the lack of effect on sensory discrimination in this group and may reflect impaired processing in BG-S1 connections. Alternatively, the increased BG activation seen in the baseline state without rTMS may reflect a compensatory strategy that saturates a BG contribution to this task.