175 resultados para Factors (Algebra)
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OBJECTIVES: To compare the prevalence and management of cardiovascular risk factors (CVRFs) between immigrant groups and Swiss nationals. METHODS: The Swiss Health Surveys (SHS, N = 49,245) and CoLaus study (N = 6,710) were used. Immigrant groups from France, Germany, Italy, Portugal, Spain, former Yugoslavia, other European and other countries were defined. RESULTS: Immigrants from Italy, France, Portugal, Spain and former Yugoslavia presented a higher prevalence of smoking than Swiss nationals. Immigrants reported less hypertension than Swiss nationals, but the differences were reduced when blood pressure measurements were used. The prevalence of dyslipidaemia was similar between immigrants and Swiss nationals in the SHS. When eligibility for statin treatment was assessed, immigrants from Italy were more frequently eligible than Swiss nationals. Immigrants from former Yugoslavia presented a lower prevalence of diabetes in the SHS, but a higher prevalence in the CoLaus study. Most differences between immigrant groups and Swiss nationals disappeared after adjusting for age, leisure-time physical activity, being overweight/obesity and education. CONCLUSIONS: Most CVRFs are unevenly distributed among immigrant groups in Switzerland, but these differences are due to disparities in age, leisure-time physical activity, being overweight/obesity and education.
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PURPOSE: Obesity represents a growing public health concern worldwide. The latest data in Switzerland rely on self-reported body mass index (BMI), leading to underestimation of prevalence. We reassessed the prevalence of obesity and overweight in a sample of the Swiss population using measured BMI and waist circumference (WC) and explored the association with nutritional factors and living in different linguistic-cultural regions. METHODS: Data of 1,505 participants of a cross-sectional population-based survey in the three linguistic regions of Switzerland were analyzed. BMI and WC were measured, and a 24-h urine collection was performed to evaluate dietary sodium, potassium and protein intake. RESULTS: The prevalence of overweight, obesity and abdominal obesity was 32.2, 14.2 and 33.6 %, respectively. Significant differences were observed in the regional distribution, with a lower prevalence in the Italian-speaking population. Low educational level, current smoking, scarce physical activity and being migrant were associated with an higher prevalence of obesity. Sodium, potassium and protein intake increased significantly across BMI categories. CONCLUSIONS: Obesity and overweight affect almost half of the Swiss adolescents and adults, and the prevalence appears to increase. Using BMI and WC to define obesity led to different prevalences. Differences were furthermore observed across Swiss linguistic-cultural regions, despite a common socio-economic and governmental framework. We found a positive association between obesity and salt intake, with a potential deleterious synergistic effect on cardiovascular risk.
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Evidence of a sport-specific hierarchy of protective factors against doping would thus be a powerful aid in adapting information and prevention campaigns to target the characteristics of specific athlete groups, and especially those athletes most vulnerable for doping control. The contents of phone calls to a free and anonymous national anti-doping service called 'ecoute dopage' were analysed (192 bodybuilders, 124 cyclists and 44 footballers). The results showed that the protective factors that emerged from analysis could be categorised into two groups. The first comprised 'Health concerns', 'Respect for the law' and 'Doping controls from the environment' and the second comprised 'Doubts about the effectiveness of illicit products, 'Thinking skills' and 'Doubts about doctors'. The ranking of the factors for the cyclists differed from that of the other athletes. The ordering of factors was 1) respect for the law, 2) doping controls from the environment, 3) health concerns 4) doubts about doctors, and 5) doubts about the effectiveness illicit products. The results are analysed in terms of the ranking in each athlete group and the consequences on the athletes' experience and relationship to doping. Specific prevention campaigns are proposed to limit doping behaviour in general and for each sport.
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BACKGROUND: Adrenal insufficiency is a rare and potentially lethal disease if untreated. Several clinical signs and biological markers are associated with glucocorticoid failure but the importance of these factors for diagnosing adrenal insufficiency is not known. In this study, we aimed to assess the prevalence of and the factors associated with adrenal insufficiency among patients admitted to an acute internal medicine ward. METHODS: Retrospective, case-control study including all patients with high-dose (250 μg) ACTH-stimulation tests for suspected adrenal insufficiency performed between 2008 and 2010 in an acute internal medicine ward (n = 281). Cortisol values <550 nmol/l upon ACTH-stimulation test were considered diagnostic for adrenal insufficiency. Area under the ROC curve (AROC), sensitivity, specificity, negative and positive predictive values for adrenal insufficiency were assessed for thirteen symptoms, signs and biological variables. RESULTS: 32 patients (11.4%) presented adrenal insufficiency; the others served as controls. Among all clinical and biological parameters studied, history of glucocorticoid withdrawal was the only independent factor significantly associated with patients with adrenal insufficiency (Odds Ratio: 6.71, 95% CI: 3.08 -14.62). Using a logistic regression, a model with four significant and independent variable was obtained, regrouping history of glucocorticoid withdrawal (OR 7.38, 95% CI [3.18 ; 17.11], p-value <0.001), nausea (OR 3.37, 95% CI [1.03 ; 11.00], p-value 0.044), eosinophilia (OR 17.6, 95% CI [1.02; 302.3], p-value 0.048) and hyperkalemia (OR 2.41, 95% CI [0.87; 6.69], p-value 0.092). The AROC (95% CI) was 0.75 (0.70; 0.80) for this model, with 6.3 (0.8 - 20.8) for sensitivity and 99.2 (97.1 - 99.9) for specificity. CONCLUSIONS: 11.4% of patients with suspected adrenal insufficient admitted to acute medical ward actually do present with adrenal insufficiency, defined by an abnormal response to high-dose (250 μg) ACTH-stimulation test. A history of glucocorticoid withdrawal was the strongest factor predicting the potential adrenal failure. The combination of a history of glucocorticoid withdrawal, nausea, eosinophilia and hyperkaliemia might be of interest to suspect adrenal insufficiency.
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Abstract: The improvement in antiretroviral drug therapy has transformed HIV infection into a chronic disease. However, treatment failure and drug toxicity are frequent. Inadequate response to treatment is clearly multifactorial and, therefore, dosage individualisation based on demographic factors, genetic markers and measurement of cellular and plasma drug level may enhance both drug efficacy and tolerability. At present, antiretroviral drugs levels are monitored in plasma, whereas only drugs penetrating into cells are able to exert an antiviral activity, suggesting that cellular drug determination may more confidently reflect drug exposure at the site of pharmacological action. The overall objective of this thesis is to provide a better understanding of the Pharmacokinetic and pharmacogenetic factors influencing the plasma and cellular disposition of antiretroviral drugs. To that endeavour, analytical methods for the measurements of plasma and cellular drug levels have been developed and validated using liquid chromatography methods coupled with ultraviolet and tandem mass spectrometry detection, respectively. Correlations between plasma and cellular exposures were assessed during observational and experimental studies. Cytochrome (CYP) 2B6, efflux transporters (ABCB1, ABCC1, ABCC2 and ABCG2) and orosomucoid (ORM) polymorphisms were determined and were related to plasma and cellular exposures, as well as toxicity of antiretroviral drugs. A Pharmacokinetic population model was developed to characterise inter- and intra-patient variability of atazanavir pharmacokinetics, and to identify covariates influencing drug disposition. In that context, a Pharmacokinetic interaction study between atazanavir and lopinavir, both boosted with ritonavir, has beén conducted to assess the safety and pharmacokinetics of this boosted double-protease inhibitors regimen. Well to moderately-correlated cellular and plasma drug levels are .observed or protease inhibitors, whereas for efavirenz and nevirapine these correlations are weak. Cellular exposure, and CYP2B6 genotype (516G>T) are predictors of efavirenz neuropsychological toxicity. Nevirapine plasma exposure is also influenced by CYPZB6 polymorphism. Nelfinavir cellular exposure appears to be significantly associated only with ABCB1 genotype (3435C>T and intron 26 + 80T>C). Indinavir and lopinavir clearance and lopinavir cellular/plasma exposure ratio are influenced by the concentration of the variant S of ORM, suggesting-a specific binding of these drugs to this variant. Nelfinavir and efavirenz are not influenced by ORM concentration and phenotype. The Pharmacokinetic parameters of atazanavir are adequately described by our population model. The atazanavir-lopinavir interaction study indicates no influence on plasma and cellular atazanavir pharmacokinetics, while limited decrease in lopinavir concentrations was observed after atazanavir addition. The residual variability unexplained by the considered variables suggests that other covariates either uncontrolled at present or remaining to be identified, such as genetic and environmental factors influence antiretroviral drug pharmacokinetics, with substantial impact on treatment efficacy and tolerability. In that context, a comprehensive approach taking into account drug pharmacokinetics and patient genetic background is expected to contribute to increase treatment success, and to reduce the occurrence of adverse drug reactions by stratifying patients in an individualised antiretroviral therapy approach. Résumé Facteurs pharmacocinétiques et pharmacogénétiques influençant l'exposition plasmatique et cellulaire des antirétroviraux Les progrès de la thérapie antirétrovirale ont transformé l'infection par le VIH d'une affection mortelle à une maladie chronique. En dépit de ce succès, l'échec thérapeutique et la toxicité médicamenteuse restent fréquents. Une réponse inadéquate au traitement est clairement multifactorielle et une individualisation de la posologie des médicaments qui se baserait sur les facteurs démographiques et génétiques des patients et sur les taux sanguins des médicaments pourrait améliorer à la fois l'efficacité et la tolérance de la thérapie. Par ailleurs, seules les concentrations plasmatiques sont actuellement considérées pour le suivi thérapeutique des médicaments, alors que les taux cellulaires pourraient mieux refléter l'activité de ses médicaments qui agissent au niveau intracellulaire. L'objectif global de cette thèse était de mieux comprendre les facteurs pharmacocinétiques et pharmacocénétiques influençant l'exposition plasmatique et cellulaire des médicaments antirétroviraux. A cet effet, des méthodes pour quantifier les concentrations plasmatiques et cellulaires des antirétroviraux ont été développées et validées en utilisant la chromatographie liquide couplée à la détection ultraviolette et la spectrométrie de masse en tandem, respectivement. La corrélation entre l'exposition cellulaire et plasmatique de ces médicaments a été étudiée lors d'études observationnelles et expérimentales. Les polymorphismes du cytochrome (CYP) 2B6, ainsi que des transporteurs d'efflux (ABCB1, ABCC1, ABCC2 et ABCG2) et de l'orosomucoïde (ORM) ont été déterminés et corrélés avec l'exposition plasmatique et cellulaire des antirétroviraux, ainsi qu'à leur toxicité. Un modèle de pharmacocinétique de population a été établi afin de caractériser la variabilité inter- et intra-individuelle de l'atazanavir, et d'identifier les covariables pouvant influencer le devenir de ce médicament. Dans ce contexte, une étude d'interaction entre l'atazanavir et le lopinavir a été effectuée afin de déterminer la sécurité et le profil pharmacocinétique de ce régime thérapeutique. Des corrélations modérées à bonnes ont été observées entre les taux cellulaires et plasmatiques des inhibiteurs de protéase, alors que pour l'efavirenz et la névirapine ces corrélations sont faibles. L'exposition cellulaire, ainsi que le génotype du CYP2B6 (516G>T) sont des indices de la toxicité neuropsychologique de l'efavirenz. L'exposition plasmatique de la névirapine est également influencée par le polymorphisme du CYPZB6. L'exposition cellulaire du nelfinavir est significativement associée au génotype du ABCB1 (3435C>T et intron 26 + 80T>C). La clairance de l'indinavir et du lopinavir, ainsi que le rapport entre exposition cellulaire et plasmatique du lopinavir sont influencés par la concentration du variant S de l'ORM, suggérant une liaison spécifique de ces médicaments à ce variant. La clairance du nelfinavir et de l'efavirenz n'est pas influencée ni par la concentration ni par le phénotype de l'ORM. Les paramètres pharmacocinétiques de l'atazanavir ont été décrits de façon adéquate par le modèle de population proposé. De plus, le lopinavir n'influence pas les concentrations plasmatiques et cellulaires de l'atazanavir; alors que celui-ci conduit à une baisse limitée des taux de lopinavir. L'importante variabilité pharmacocinétique des antirétroviraux suggère que d'autres facteurs génétiques et environnementaux -qui restent encore à découvrir- influencent également leur disponibilité. Dans un proche futur, une prise en charge qui tienne. compte de la pharmacocinétique des médicaments et des caractéristiques génétiques du patient devrait permettre d'individualiser le traitement, contribuant certainement à une amélioration de la réponse thérapeutique et à une diminution de la toxicité. Résumé grand public Facteurs pharmacocinétiques et pharmacogénétiques influençant l'exposition plasmatique et cellulaire des antirétroviraux Les progrès effectués dans le traitement de l'infection par le virus de l'immunodéficience humaine acquise (VIH), ont permis de transformer une maladie avec un pronostic sombre, en une maladie chronique traitable avec des médicaments de plus en plus efficaces. Malgré ce succès, de nombreux patients ne répondent pas de façon optimale à leur traitement et/ou souffrent d'effets indésirables médicamenteux entraînant fréquemment une modification de leur thérapie. Actuellement, le suivi de la réponse au traitement s'effectue par la mesure chez les patients de la quantité de virus et du nombre des cellules immunitaires dans le sang, ainsi que par la concentration sanguine des médicaments administrés. Cependant, comme le virus se réplique à l'intérieur de la cellule, la mesure des concentrations médicamenteuses au niveau intracellulaire pourrait mieux refléter l'activité pharmacologique au site d'action. De plus, il a été possible de mettre en évidence la grande variabilité des concentrations plasmatiques de médicaments chez des patients prenant pourtant la même dose de médicament. Comme cette variabilité est notamment due à des facteurs génétiques qui sont susceptibles d'influencer la réponse au traitement antirétroviral, des analyses génétiques ont été également effectuées chez ces patients. Cette thèse a eu pour objectif de mieux comprendre les facteurs pharmacologiques et génétiques influençant l'activité et la toxicité des médicaments antirétroviraux afin de réduire la variabilité de la réponse thérapeutique. A cet effet, une méthode de dosage permettant la quantification des médicaments anti-HIV au niveau intracellulaire a été développée. Par ailleurs, nos études ont également porté .sur les variations génétiques influençant la quantité et l'activité des protéines impliquées dans le métabolisme et dans le transport des médicaments antirétroviraux. Enfin, les conséquences de ces variations sur la réponse clinique et la toxicité du traitement ont été évaluées. Nos études ont mis en évidence des associations significatives entre les variations génétiques considérées et la concentration sanguine, cellulaire et la toxicité de quelques médicaments antirétroviraux. La complémentarité des connaissances pharmacologiques, génétiques et virales pourrait aboutir à une stratégie globale permettant d'individualiser le traitement et la dose administrée, en fonction des caractéristiques propres de chaque patient. Cette approche pourrait contribuer à une optimisation du traitement antirétroviral dans la perspective d'une meilleure- efficacité thérapeutique à long terme et d'une diminution des effets indésirables rencontrés.
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Background Working in a teaching hospital is a highly stressful occupation, which can lead to burnout. The consequences of burnout in health professionals can be very serious, both for themselves and patients. The aim of this cross-sectional study was to assess the extent of burnout and associated factors in hospital employees. Methods In the Fall of 2007, all employees of a Swiss teaching hospital were invited to complete a job satisfaction survey. It included the work-related burnout scale (scored 0-100) of the Copenhagen Burnout Inventory (CBI-French version), measuring the degree of physical and psychological fatigue and exhaustion perceived as related to the person's work; a high degree of burnout was defined as a score _50. Logistic regression analyses were used to determine factors associated with a high degree of burnout. Results A total of 4575 individuals returned the questionnaire (response rate 54%). Of them, 1503 (33%) had a high degree of burnout. The rate of burnout was higher among women (34.3% versus 30.5%, P = 0.012) and respondents younger than 40 years (37.7% versus 28.6%, P < 0.001). Executives were less prone to burnout than employees (27.1% versus 33.9%, P < 0.0019). Rates of burnout differed by profession: nurses and physicians had higher rates than administrative and logistic staff (42.8% and 37.4% versus 25.6% and 20.9%, respectively P < 0.001). Burnout was inversely associated with job satisfaction. In multivariate analysis, factors associated with burnout were overall dissatisfaction (OR 3.23; 95% CI 2.66-3.91), dissatisfaction with workload (OR 2.09; 95% CI 1.74-2.51) and work-life balance (OR 2.25; 95% CI 1.83-2.77), being a woman (OR 1.56; 95% CI 1.28-1.90), working fulltime (OR 1.41; 95% CI 1.08-1.85) and working as a nurse, a physician or in the psychosocial sector. Conclusions One-third of respondents, mostly nurses and physicians, experienced burnout and had lower levels of job satisfaction. The factors associated with burnout may help to tailor programmes aiming at reducing burnout at both the individual and organizational level within the hospital.
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AIMS/HYPOTHESIS: The metabolic syndrome comprises a clustering of cardiovascular risk factors but the underlying mechanism is not known. Mice with targeted disruption of endothelial nitric oxide synthase (eNOS) are hypertensive and insulin resistant. We wondered, whether eNOS deficiency in mice is associated with a phenotype mimicking the human metabolic syndrome. METHODS AND RESULTS: In addition to arterial pressure and insulin sensitivity (euglycaemic hyperinsulinaemic clamp), we measured the plasma concentration of leptin, insulin, cholesterol, triglycerides, free fatty acids, fibrinogen and uric acid in 10 to 12 week old eNOS-/- and wild type mice. We also assessed glucose tolerance under basal conditions and following a metabolic stress with a high fat diet. As expected eNOS-/- mice were hypertensive and insulin resistant, as evidenced by fasting hyperinsulinaemia and a roughly 30 percent lower steady state glucose infusion rate during the clamp. eNOS-/- mice had a 1.5 to 2-fold elevation of the cholesterol, triglyceride and free fatty acid plasma concentration. Even though body weight was comparable, the leptin plasma level was 30% higher in eNOS-/- than in wild type mice. Finally, uric acid and fibrinogen were elevated in the eNOS-/- mice. Whereas under basal conditions, glucose tolerance was comparable in knock out and control mice, on a high fat diet, knock out mice became significantly more glucose intolerant than control mice. CONCLUSIONS: A single gene defect, eNOS deficiency, causes a clustering of cardiovascular risk factors in young mice. We speculate that defective nitric oxide synthesis could trigger many of the abnormalities making up the metabolic syndrome in humans.
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Although hemoglobin (Hb) is mainly present in the cytoplasm of erythrocytes (red blood cells), lower concentrations of pure, cell-free Hb are released permanently into the circulation due to an inherent intravascular hemolytic disruption of erythrocytes. Previously it was shown that the interaction of Hb with bacterial endotoxins (lipopolysaccharides, LPS) results in a significant increase of the biological activity of LPS. There is clear evidence that the enhancement of the biological activity of LPS by Hb is connected with a disaggregation of LPS. From these findings one questions whether the property to enhance the biological activity of endotoxin, in most cases proven by the ability to increase the cytokine (tumor-necrosis-factor-alpha, interleukins) production in human mononuclear cells, is restricted to bacterial endotoxin or is a more general principle in nature. To elucidate this question, we investigated the interaction of various synthetic and natural virulence (pathogenicity) factors with hemoglobin of human or sheep origin. In addition to enterobacterial R-type LPS a synthetic bacterial lipopeptide and synthetic phospholipid-like structures mimicking the lipid A portion of LPS were analysed. Furthermore, we also tested endotoxically inactive LPS and lipid A compounds such as those from Chlamydia trachomatis. We found that the observations made for endotoxically active form of LPS can be generalized for the other synthetic and natural virulence factors: In every case, the cytokine-production induced by them is increased by the addition of Hb. This biological property of Hb is connected with its physical property to convert the aggregate structures of the virulence factors into one with cubic symmetry, accompanied with a considerable reduction of the size and number of the original aggregates.
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BACKGROUND: Smokeless tobacco is of increasing interest to public health researchers and policy makers. This study aims to measure prevalence of smokeless tobacco use (nasal dry snuff, snus and chewing tobacco) among young Swiss men, and to describe its correlates. METHODS: We invited 13 245 young men to participate in this survey on socio-economic and substance use data. Response rate was 45.2%. We included 5720 participants. Descriptive statistics and multivariable-adjusted logistic regression were performed. RESULTS: Mean age of participants was 19.5 years. Self-reported use once a month or more often was 8% for nasal dry snuff, 3% for snus and negligible for chewing tobacco. In multivariable-adjusted logistic regression, the odds for nasal dry snuff use increased in non daily smokers [odds ratio (OR) 2.41, 95% confidence interval (CI) 1.90-3.05], compared with non smokers, participants reporting risky weekly drinking volume (OR 3.93, 95% CI 1.86-8.32), compared with abstinents, and binge drinking once a month or more often (OR 7.41, 95% CI 4.11-13.38), compared with never binge drinking. Nasal dry snuff use was positively associated with higher BMI, average or above family income and German language, compared with French, and negatively associated with academic higher education, compared with non higher education, and occasional cannabis use, compared with no cannabis use. Correlates of snus were similar to those of nasal dry snuff. CONCLUSION: One in 12 young Swiss men use nasal dry snuff and 3% use snus. Consumption of smokeless tobacco is associated with a cluster of other risky behaviours, especially binge drinking.
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Background The prognostic potential of individual clinical and molecular parameters in stage II/III colon cancer has been investigated, but a thorough multivariable assessment of their relative impact is missing. Methods Tumors from patients (N = 1404) in the PETACC3 adjuvant chemotherapy trial were examined for BRAF and KRAS mutations, microsatellite instability (MSI), chromosome 18q loss of heterozygosity (18qLOH), and SMAD4 expression. Their importance in predicting relapse-free survival (RFS) and overall survival (OS) was assessed by Kaplan-Meier analyses, Cox regression models, and recursive partitioning trees. All statistical tests were two-sided. Results MSI-high status and SMAD4 focal loss of expression were identified as independent prognostic factors with better RFS (hazard ratio [HR] of recurrence = 0.54, 95% CI = 0.37 to 0.81, P = .003) and OS (HR of death = 0.43, 95% CI = 0.27 to 0.70, P = .001) for MSI-high status and worse RFS (HR = 1.47, 95% CI = 1.19 to 1.81, P < .001) and OS (HR = 1.58, 95% CI = 1.23 to 2.01, P < .001) for SMAD4 loss. 18qLOH did not have any prognostic value in RFS or OS. Recursive partitioning identified refinements of TNM into new clinically interesting prognostic subgroups. Notably, T3N1 tumors with MSI-high status and retained SMAD4 expression had outcomes similar to stage II disease. Conclusions Concomitant assessment of molecular and clinical markers in multivariable analysis is essential to confirm or refute their independent prognostic value. Including molecular markers with independent prognostic value might allow more accurate prediction of prognosis than TNM staging alone.
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ABSTRACT Poor outcome for glioblastoma patients is largely due to resistance to chemoradiation therapy. While epigenetic inactivation of MGMT mediated DNA repair is highly predictive for benefit from the alkylating agent therapy Temozolomide, additional mechanisms for resistance associated with molecular alterations exist. Furthermore, new concepts in cancer suggest that resistance to treatment may be linked to cancer stem cells that escape therapy and act as source for tumour recurrence. We determined gene expression signatures associated with outcome in glioblastoma patients enrolled in a phase II and phase III clinical trial establishing the new combination therapy of radiation plus concomitant and adjuvant Temozolomide. Correlating stable gene clusters emerging from unsupervised analysis with survival of 42 treated patients identified a number of biological processes associated with outcome. Most prominent, a gene cluster dominated by HOX genes and comprising PROM1, was associated with resistance. PROM1 encodes CD133, a marker for a subpopulation of tumour cells enriched for glioblastoma stem- like cells. The core of this correlated HOX cluster was comprised in the top genes of a "self-renewal signature" defined in a mouse model for MLL-AF9 initiated leukaemia. The association of the HOX gene cluster with tumour resistance was confirmed in two external data sets of 146 malignant glioma As additional resistance factors we identified over-expression of the epidermal growth factor receptor gene, EGFR, while increased gene expression related to biological features of tumour host interaction, including markers for tumour vascular and cell adhesion, and innate immune response, were associated with better outcome. The "self-renewal" signature associated with resistance to the new combination chemoradiation therapy provides first clinical evidence that glioma stem like cells may implicated in resistance in a uniformly treated cohort of glioblastoma patients. This study underlines the need to target the tumour stem cell compartment, and provides some testable hypothesis for biological mechanisms relevant for malignant behaviour of glioblastoma that may be targeted in new treatment approaches. Résumé Le glioblastome, tumeur cérébrale primaire maligne la plus fréquente, est connue pour son mauvais pronostique. Des avancées chimiothérapeutiques récentes avec des agents alkylants comme le témozolomide (TMZ), ont permis une amélioration notable dans la survie de certains patients. Les bénéficiaires ont la caractéristique commune de présenter une particularité génétique, la methylation du MGMT (methylguanine methyltransferase). Néanmoins, d'autres mécanismes de résistance en fonction des aberrations moléculaires existent. Nous avons établi les profils d'expressions génétiques des patients traités par irradiation et TMZ dans des études cliniques de phase II et III. En combinant des méthodes non-supervisées et supervisées, de l'étude de la cohorte des patients traités nous avons découvert des groupes de gènes associés à la survie. Un ensemble de gènes contenant les gènes Hox semble lié au mécanisme de résistance au traitement. Récemment, les gènes Hox ont été décrits comme faisant partie d"une signature d'autorenouvellement (self-renewal) des cellules souches cancéreuses de la leucémie. L'autorenouvellement est un processus grâce auquel les cellules souches se maintiennent tout au long de la vie. Cette association à la résistance est confirmée dans deux autres études indépendantes. Un autre facteur de résistance au traitement est la surexpression du gène EGFR. D'autre part, deux groupes de gènes associés à la relation entre hôte-tumeur tels que les marqueurs des vaisseaux tumoraux et de la réponse immunitaire innée s'avèrent avoir un effet positif sur la survie des patients traités. La découverte de la signature d'autorenouvellement comme facteur de résistance à la nouvelle chimio-radiothérapie offre une preuve clinique que les cellules souches cancéreuses sont impliquées dans la résistance au traitement. If est donc logique de penser que le traitement ciblé contre des cellules souches cancéreuses va dans l'avenir permettre des thérapies anticancéreuses plus performantes.
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Delirium presents clinically with differing subtypes ranging from hyperactive to hypoactive. The clinical presentation is not clearly linked to specific pathophysiological mechanisms. Nevertheless, there seem to be different mechanisms that lead to delirium; for example the mechanisms leading to alcohol-withdrawal delirium are different from those responsible for postoperative delirium. In many forms of delirium, the brain's reaction to a peripheral inflammatory process is considered to be a pathophysiological key element and the aged brain seems to react more markedly to a peripheral inflammatory stimulus than a younger brain. The effects of inflammatory mediators on the brain include changes in neurotransmission and apoptosis. On a neurotransmitter level, impaired cholinergic transmission and disturbances of the intricate interactions between dopamine, serotonin and acetylcholine seem to play an important role in the development of delirium. The risk factors for delirium are categorised as predisposing or precipitating factors. In the presence of many predisposing factors, even trivial precipitating factors may trigger delirium, whereas in patients without or with only a few predisposing factors, a major precipitating insult is necessary to trigger delirium. Well documented predisposing factors are age, medical comorbidities, cognitive, functional, visual and hearing impairment and institutional residence. Important precipitating factors apart from surgery are admission to an ICU, anticholinergic drugs, alcohol or drug withdrawal, infections, iatrogenic complications, metabolic derangements and pain. Scores to predict the risk of delirium based on four or five risk factors have been validated in surgical patients.
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Rapport de synthèse : Les maladies cardio-vasculaires constituent les causes principales causes de morbidité et de mortalité dans les pays industrialisés. Des études épidémiologiques ont démontré l'implication de facteurs de risques comme l'hypertension, l'hypercholestérolémie, l'obésité abdominale, le diabète et le tabagisme dans le développement des affections cardiovasculaires comme l'infarctus du myocarde ou l'accident vasculaire cérébral. De larges études génétiques cas-contrôle ont contribué modestement à l'identification de gènes de susceptibilité au développement de ces FRCV. Une étude populationnelle offre par contre l'avantage d'effectuer des études associatives pour des traits phénotypiques continus correctement mesurés et aussi pour des traits de catégories utilisant des protocoles d'étude cas-contrôle très discordants. ~ Elle permet l'exploration des déterminants génétiques comme par exemple le syndrome métabolique. Cette approche permet également de procéder à des analyses de séquençage sur l'ADN des participants chez qui un trait phénotypique spécifique est étudié mais distribué de manière opposée. A titre d'exemple, le séquençage de l'ADN de participants à taux très élevé d'HDL-cholestérol versus très bas de ce marqueur lipidique permet d'identifier des variants génétiques rares localisés sur les parties codantes de gènes spécifiques associés aux dyslipidémies. Pour ce faire, nous avons recruté 6'188 personnes âgées de 35 à 75 ans, d'origine caucasienne et résidant en ville de Lausanne (3251 femmes et 2937 hommes). L'obtention d'un tel collectif a nécessité l'échantillonnage aléatoire de quelque 19'830 personnes de cette tranche d'âge. Les participants ont fait l'objet d'une anamnèse approfondie et d'un examen clinique. Le bilan était complété par une prise de sang pour le dosage de paramètres biologiques ainsi qu'une analyse .génétique. Cette dernière a été effectuée après extraction d'ADN au moyen d'une puce Affimetrix qui évalue la présence de quelques 500'000 SNPs. Les données récoltées lors de cette étude dévoilent que l'obésité (index de masse corporelle > 30 kg/m2), le tabagisme, l'hypertension (pression artérielle >_ 140/90 mmHg et/ou hypertension traitée), une dyslipidémie (LDL cholestérol élevé et/ou HDL cholestérol bas et/ou triglycéride élevé) et le diabète (glucose à jeun >_ 7 mmol/l et/ou traitement) affectent respectivement 947 (15,7%), 1673 (27%), 2268 (36,7%), 2113 (34,2%) et 407 (6,6%) participants. La prévalence de ces FRCV est plus marquée chez les hommes que chez les femmes. Dans les deux genres les prévalences de l'obésité, de l'hypertension et du diabète augmentent drastiquement avec l'âge. En conclusion la prévalence des FRCV est élevée au sein d'une population représentative de Lausanne âgée de 35 à 75 ans. A l'avenir, l'étude CoLaus constituera par la richesse de ses données phénotypiques et génétiques, une source unique pour investiguer l'épidémiologie et l'identification de gènes associés à ces FRCV.
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OBJECTIVE: Assess outcome of patients with descending thoracic aortic aneurysms complicated by aortobronchial and aortoesophageal fistulae in comparison to patients undergoing repair of aortic aneurysms without fistulae. METHODS: In a consecutive series of 145 patients (age 60 +/- 12 years) with repair of descending thoracic and thoracoabdominal aortic aneurysms, 11 patients (8%; age 63 +/- 9; NS) primarily presented for hematemesis and/or hemoptysis. In 8/11 patients (73%) an aortobronchial fistula was identified, and 3/11 patients (27%) suffered from an aortoesophageal fistula. Five of 11 patients (45%) had undergone previous aortic surgery in the same region. RESULTS: Extent of aortic segments (range 1-8) replaced was 3.1 +/- 1.4 for all versus 2.6 +/- 0.9 for fistulae (NS). Aortic cross clamp time was 38 +/- 22 min for all versus 45 +/- 15 min for fistulae (NS). Mortality at 30 days was 18/145 (12%) for all versus 16/134 (12%) without fistulae versus 2/11 (18%) with fistulae (NS). Paraparesis and or paraplegia was observed in 11/145 (8%) for all versus 10/134 (7%) without fistulae versus 1/11 (9%) for cases with fistulae (NS). Nine additional patients died after hospital discharge, seven without fistulae and two with fistulae (days 80, and 120) bringing the 1-year mortality up to 23/134 (17%) without fistulae versus 4/11 (36%) with fistulae (NS). Further analysis shows that the 1-year mortality accounts for 1/8 patients (13%) with aorto-bronchial fistulae versus to 3/3 patients (100%) with aorto-esophageal fistulae (esophageal versus bronchial fistula: P = 0.018; esophageal versus no fistula: P = 0.006). CONCLUSIONS: Outcome of patients suffering from descending thoracic aortic aneurysms complicated by aorto-bronchial fistulae can be similar to that without fistulae, whereas for cases complicated by aorto-esophageal fistulae the prognosis seems to remain poor even after successful hospital discharge.
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BACKGROUND: Hypertension, hypercholesterolemia, obesity and smoking are highly prevalent among patients with familial premature coronary artery disease (FP-CAD). Whether these risk factors equally affect other family members remains unknown. METHODS: We examined 222 FP-CAD patients, 158 unaffected sibs, 197 offspring and 94 spouses in 108 FP-CAD families (> or = 2 sibs having survived CAD diagnosed before age 51 (M)/56 (F)), and compared them to population controls. RESULTS: Unaffected sibs had a higher prevalence of hypertension (49% versus 24%, p<0.001), hypercholesterolemia (47% versus 34%, p=0.002), abdominal obesity (35% versus 24%, p=0.006) and smoking (39% versus 24%, p=0.001) than population controls. Offspring had a higher prevalence of hypertension (females), hypercholesterolemia and abdominal obesity than population controls. No difference was observed between spouses and controls. Compared to unaffected sibs, FP-CAD affected sibs had a similar risk factor profile, except for smoking, which was more prevalent (76% versus 39%, p=0.008). CONCLUSIONS: Hypertension, obesity and hypercholesterolemia are highly prevalent among first-degree relatives, but not spouses, of patients with FP-CAD. These persons deserve special medical attention due to their familial/genetic susceptibility to atherogenic metabolic abnormalities. In these families, smoking may be the trigger for FP-CAD.