165 resultados para 240
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Beside the several growth factors which play a crucial role in the development and regeneration of the nervous system, thyroid hormones also contribute to the normal development of the central and peripheral nervous system. In our previous work, we demonstrated that triiodothyronine (T3) in physiological concentration enhances neurite outgrowth of primary sensory neurons in cultures. Neurite outgrowth requires microtubules and microtubule associated proteins (MAPs). Therefore the effects of exogenous T3 or/and nerve growth factors (NGF) were tested on the expression of cytoskeletal proteins in primary sensory neurons. Dorsal root ganglia (DRG) from 19 day old rat embryos were cultured under four conditions: (1) control cultures in which explants were grown in the absence of T3 and NGF, (2) cultures grown in the presence of NGF alone, (3) in the presence of T3 alone or (4) in the presence of NGF and T3 together. Analysis of proteins by SDS-polyacrylamide gel electrophoresis revealed the presence of several proteins in the molecular weight region around 240 kDa. NGF and T3 together induced the expression of one protein, in particular, with a molecular weight above 240 kDa, which was identified by an antibody against MAP1c, a protein also known as cytoplasmic dynein. The immunocytochemical detection confirmed that this protein was expressed only in DRG explants grown in the presence of NGF and T3 together. Neither control explants nor explants treated with either NGF or T3 alone expressed dynein. In conclusion, a combination of nerve growth factor and thyroid hormone is necessary to regulate the expression of cytoplasmic dynein, a protein that is involved in retrograde axonal transport.
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On three occasions, unusually high trough plasma concentrations of venlafaxine were measured in a patient phenotyped and genotyped as being an extensive CYP2D6 metabolizer and receiving 450 mg/day of venlafaxine and multiple comedications. Values of 1.54 and of 0.60 mg/l of venlafaxine and O-desmethylvenlafaxine, respectively, were determined in the first blood sample, giving an unusually high venlafaxine to O-desmethylvenlafaxine ratio. This suggests an impaired metabolism of venlafaxine to O-desmethylvenlafaxine, and is most likely due to metabolic interactions with mianserin (240 mg/day) and propranolol (40 mg/day). Concentration of (S)-venlafaxine measured in this blood sample was almost twice as high as (R)-venlafaxine ((S)/(R) ratio: 1.94). At the second blood sampling, after addition of thioridazine (260 mg/day), which is a strong CYP2D6 inhibitor, concentrations of venlafaxine were further increased (2.76 mg/l), and concentrations of O-desmethylvenlafaxine decreased (0.22 mg/l). A decrease of the (S)/(R)-venlafaxine ratio (-20%) suggests a possible stereoselectivity towards the (R)-enantiomer of the enzyme(s) involved in venlafaxine O-demethylation at these high venlafaxine concentrations. At the third blood sampling, after interruption of thioridazine, concentrations of venlafaxine and O-desmethylvenlafaxine were similar to those measured in the first blood sample. This case report shows the importance of performing studies on the effects of either genetically determined or acquired deficiency of metabolism on the kinetics of venlafaxine.
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A procedure was developed for determining Pu-241 activity in environmental samples. This beta emitter isotope of plutonium was measured by ultra low level liquid scintillation, after several separation and purification steps that involved the use of a highly selective extraction chromatographic resin (Eichrom-TEVA). Due to the lack of reference material for Pu-241, the method was nevertheless validated using four IAEA reference sediments with information values for Pu-241. Next, the method was used to determine the Pu-241 activity in alpine soils of Switzerland and France. The Pu-241/Pu-239,Pu-240 and Pu-238/Pu-239,Pu-240 activity ratios confirmed that Pu contamination in the tested alpine soils originated mainly from global fallout from nuclear weapon tests conducted in the fifties and sixties. Estimation of the date of the contamination, using the Pu-241/Am-241 age-dating method, further confirmed this origin. However, the Pu-241/Am-241 dating method was limited to samples where Pu-Am fractionation was insignificant. If any, the contribution of the Chernobyl accident is negligible.
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PURPOSE: The aim of this study was to develop models based on kernel regression and probability estimation in order to predict and map IRC in Switzerland by taking into account all of the following: architectural factors, spatial relationships between the measurements, as well as geological information. METHODS: We looked at about 240,000 IRC measurements carried out in about 150,000 houses. As predictor variables we included: building type, foundation type, year of construction, detector type, geographical coordinates, altitude, temperature and lithology into the kernel estimation models. We developed predictive maps as well as a map of the local probability to exceed 300 Bq/m(3). Additionally, we developed a map of a confidence index in order to estimate the reliability of the probability map. RESULTS: Our models were able to explain 28% of the variations of IRC data. All variables added information to the model. The model estimation revealed a bandwidth for each variable, making it possible to characterize the influence of each variable on the IRC estimation. Furthermore, we assessed the mapping characteristics of kernel estimation overall as well as by municipality. Overall, our model reproduces spatial IRC patterns which were already obtained earlier. On the municipal level, we could show that our model accounts well for IRC trends within municipal boundaries. Finally, we found that different building characteristics result in different IRC maps. Maps corresponding to detached houses with concrete foundations indicate systematically smaller IRC than maps corresponding to farms with earth foundation. CONCLUSIONS: IRC mapping based on kernel estimation is a powerful tool to predict and analyze IRC on a large-scale as well as on a local level. This approach enables to develop tailor-made maps for different architectural elements and measurement conditions and to account at the same time for geological information and spatial relations between IRC measurements.
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OBJECTIVE: Palliative sedation is a last resort medical act aimed at relieving intolerable suffering induced by intractable symptoms in patients at the end-of-life. This act is generally accepted as being medically indicated under certain circumstances. A controversy remains in the literature as to its ethical validity. There is a certain vagueness in the literature regarding the legitimacy of palliative sedation in cases of non-physical refractory symptoms, especially "existential suffering." This pilot study aims to measure the influence of two independent variables (short/long prognosis and physical/existential suffering) on the physicians' attitudes toward palliative sedation (dependent variable). METHODS: We used a 2 × 2 experimental design as described by Blondeau et al. Four clinical vignettes were developed (vignette 1: short prognosis/existential suffering; vignette 2: long prognosis/existential suffering; vignette 3: short prognosis/physical suffering; vignette 4: long prognosis/physical suffering). Each vignette presented a terminally ill patient with a summary description of his physical and psychological condition, medication, and family situation. The respondents' attitude towards sedation was assessed with a six-point Likert scale. A total of 240 vignettes were sent to selected Swiss physicians. RESULTS: 74 vignettes were completed (36%). The means scores for attitudes were 2.62 ± 2.06 (v1), 1.88 ± 1.54 (v2), 4.54 ± 1.67 (v3), and 4.75 ± 1.71 (v4). General linear model analyses indicated that only the type of suffering had a significant impact on the attitude towards sedation (F = 33.92, df = 1, p = 0.000). Significance of the results: The French Swiss physicians' attitude toward palliative sedation is more favorable in case of physical suffering than in existential suffering. These results are in line with those found in the study of Blondeau et al. with Canadian physicians and will be discussed in light of the arguments given by physicians to explain their decisions.
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In the realm of forensic pathology, β-tryptase measurement for diagnostic purposes is performed in postmortem serum obtained from femoral blood. This may be partially or completely unavailable in some specific cases, such as infant autopsies and severely damaged bodies. The aim of this study was to investigate the usefulness of determining β-tryptase levels for diagnostic purposes in alternative biological samples. Urine, vitreous humor and pericardial fluid were selected and measured in 94 subjects including: fatal anaphylaxis following contrast material administration (6 cases), hypothermia (10 cases), diabetic ketoacidosis (10 cases), gunshot suicide (10 cases), heroin injection-related deaths (18 cases), trauma (10 cases), sudden death with minimal coronary atherosclerosis (10 cases), severe coronary atherosclerosis without myocardial infarction (10 cases) and severe coronary atherosclerosis with myocardial infarction (10 cases). Postmortem serum and pericardial fluid β-tryptase levels higher than the clinical reference value (11.4ng/ml) were systematically identified in fatal anaphylaxis following contrast material administration and 6 cases unrelated to anaphylaxis. β-tryptase concentrations in urine and vitreous humor were lower than the clinical reference value in all cases included in this study. Determination of β-tryptase in pericardial fluid appears to be a possible alternative to postmortem serum in the early postmortem period when femoral blood cannot be collected during autopsy and biochemical investigations are required to objectify increased β-tryptase levels.
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The purpose of this study was to evaluate the association of the T309G MDM2 gene polymorphism with renal cell carcinoma (RCC) risk, pathology, and cancer-specific survival (CSS). T309G MDM2 was genotyped in 449 Caucasians, including 240 with RCC and 209 cancer-free controls. The T309G MDM2 genotype was TT in 174 (38.8%), GT in 214 (47.7%), and GG in 61 (13.6%) subjects, without any significant differences between cases and controls on both univariable (p=0.58) and multivariable logistic regression (each p>0.25). Furthermore, T309G MDM2 was not linked with T stage (p=0.75), N stage (p=0.37), M stage (p=0.94), grade (p=0.21), and subtype (p=0.55). There was, however, a statistically significant association of T309G MDM2 with CSS (p=0.022): patients with TT had significantly worse survival than GG/GT (p=0.009), while those with GT and GG had similar outcomes (p=0.92). The 5-year survival rate for patients with TT, GT, and GG was 69.5%, 84.5%, and 89.7%, respectively. On the multivariable analysis, T309G was identified as an independent prognostic factor. The T309G MDM2 polymorphism is an independent prognostic factor for patients with RCC, with the TT genotype being associated with worse prognosis. In this study, there were no significant associations with RCC risk and pathology.
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Résumé Ce travail de thèse étudie des moyens de formalisation permettant d'assister l'expert forensique dans la gestion des facteurs influençant l'évaluation des indices scientifiques, tout en respectant des procédures d'inférence établies et acceptables. Selon une vue préconisée par une partie majoritaire de la littérature forensique et juridique - adoptée ici sans réserve comme point de départ - la conceptualisation d'une procédure évaluative est dite 'cohérente' lors qu'elle repose sur une implémentation systématique de la théorie des probabilités. Souvent, par contre, la mise en oeuvre du raisonnement probabiliste ne découle pas de manière automatique et peut se heurter à des problèmes de complexité, dus, par exemple, à des connaissances limitées du domaine en question ou encore au nombre important de facteurs pouvant entrer en ligne de compte. En vue de gérer ce genre de complications, le présent travail propose d'investiguer une formalisation de la théorie des probabilités au moyen d'un environment graphique, connu sous le nom de Réseaux bayesiens (Bayesian networks). L'hypothèse principale que cette recherche envisage d'examiner considère que les Réseaux bayesiens, en concert avec certains concepts accessoires (tels que des analyses qualitatives et de sensitivité), constituent une ressource clé dont dispose l'expert forensique pour approcher des problèmes d'inférence de manière cohérente, tant sur un plan conceptuel que pratique. De cette hypothèse de travail, des problèmes individuels ont été extraits, articulés et abordés dans une série de recherches distinctes, mais interconnectées, et dont les résultats - publiés dans des revues à comité de lecture - sont présentés sous forme d'annexes. D'un point de vue général, ce travail apporte trois catégories de résultats. Un premier groupe de résultats met en évidence, sur la base de nombreux exemples touchant à des domaines forensiques divers, l'adéquation en termes de compatibilité et complémentarité entre des modèles de Réseaux bayesiens et des procédures d'évaluation probabilistes existantes. Sur la base de ces indications, les deux autres catégories de résultats montrent, respectivement, que les Réseaux bayesiens permettent également d'aborder des domaines auparavant largement inexplorés d'un point de vue probabiliste et que la disponibilité de données numériques dites 'dures' n'est pas une condition indispensable pour permettre l'implémentation des approches proposées dans ce travail. Le présent ouvrage discute ces résultats par rapport à la littérature actuelle et conclut en proposant les Réseaux bayesiens comme moyen d'explorer des nouvelles voies de recherche, telles que l'étude de diverses formes de combinaison d'indices ainsi que l'analyse de la prise de décision. Pour ce dernier aspect, l'évaluation des probabilités constitue, dans la façon dont elle est préconisée dans ce travail, une étape préliminaire fondamentale de même qu'un moyen opérationnel.
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Aim: The obesity epidemic has increased the number of obese patients admitted to the ICU. In vitro studies suggest that adipose tissue response to inflammation is enhanced: in vivo data are not conclusive yet. The aim of this study was to test the physiologic response of healthy obese subjects to a standardized intravenous LPS challenge.Methods: Prospective single-blind, randomized, cross-over study in eight subjects (four men, four women), aged 34 +/- 7 years, BMI 34.7 +/- 4.2, without glucose intolerance and lipid abnormalities, testing the impact of intravenous LPS (2 ng kg(-1) of actual body weight) versus placebo.Results: Temperature, hemodynamic variables, indirect calorimetry and blood samples (TNF-alpha, IL-6, stress hormones, hs-CRP) were collected. After LPS temperature, heart rate. TNF-alpha and IL-6 concentrations and stress hormones (cortisol and glucagon) increased significantly, with maximal responses between 120 and 240 min after the injection. The pattern, the timing and the magnitude of change were similar to those observed in lean subjects.Conclusion: This study shows that healthy obese subjects have a similar response pattern to intravenous LPS as described in lean subjects.
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OBJECTIVE: Cuff inflation at the arm is known to cause an instantaneous rise in blood pressure, which might be due to the discomfort of the procedure and might interfere with the precision of the blood pressure measurement. In this study, we compared the reactive rise in blood pressure induced by cuff inflation when the cuff was placed at the upper arm level and at the wrist. PARTICIPANTS AND METHODS: The reactive rise in systolic and diastolic blood pressure to cuff inflation was measured in 34 normotensive participants and 34 hypertensive patients. Each participant was equipped with two cuffs, one around the right upper arm (OMRON HEM-CR19, 22-32 cm) and one around the right wrist (OMRON HEM-CS 19, 17-22 cm; Omron Health Care Europe BV, Hoofddorp, The Netherlands). The cuffs were inflated in a double random order (maximal cuff pressure and position of the cuff) with two maximal cuff pressures: 180 and 240 mmHg. The cuffs were linked to an oscillometric device (OMRON HEM 907; Omron Health Care). Simultaneously, blood pressure was measured continuously at the middle finger of the left hand using photoplethysmography. Three measurements were made at each level of blood pressure at the arm and at the wrist, and the sequence of measurements was randomized. RESULTS: In normotensive participants, no significant difference was observed in the reactive rise in blood pressure when the cuff was inflated either at the arm or at the wrist irrespective of the level of cuff inflation. Inflating a cuff at the arm, however, induced a significantly greater rise in blood pressure than inflating it at the wrist in hypertensive participants for both systolic and diastolic pressures (P<0.01), and at both levels of cuff inflation. The blood pressure response to cuff inflation was independent of baseline blood pressure. CONCLUSIONS: The results show that in hypertensive patients, cuff inflation at the wrist produces a smaller reactive rise in blood pressure. The difference between the arm and the wrist is independent of the patient's level of blood pressure.
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A conditional heat-sensitive mutation in the cdc14 gene of the fission yeast Schizosaccharomyces pombe results in failure to form a septum. Cells become highly elongated and multinucleate as growth and nuclear division continue in the absence of cell division. This article describes the cloning of the cdc14 gene and the identification of its product, a protein of 240 amino acids, p28cdc14. A null allele of the cdc14 gene shows that the gene is essential for septum formation and completion of the cell-division cycle. Overexpression of the gene product, p28cdc14, causes cell-cycle arrest in late G2 before mitosis. Cells leaking past the block activate p34cdc2 kinase and show condensed chromosomes, but the normal rearrangements of the microtubules and microfilaments that are associated with the transition from interphase to mitosis do not occur. Overexpression of p28cdc14 in mutants, in which the timing of mitosis is altered, suggests that these effects may be mediated upstream of the mitotic inhibitor wee1. These data are consistent with the idea that p28cdc14 may play a role in both the initiation of mitosis and septum formation and, by doing so, be part of the mechanism that coordinates these two cell-cycle events.
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Objectif Le présent travail a consisté à identifier et comparer, au moyen d'un questionnaire auto-administré, les conditions ergonomiques, les nuisances environnementales et les facteurs de stress rencontrés par le personnel soignant (n = 35) et le personnel pénitentiaire (n = 240) travaillant dans les mêmes prisons. Quatre ans ont séparé la remise du questionnaire auprès des surveillants et des soignants, ce qui limite la portée des résultats. Malgré cela, la comparaison des données fournies montre des tendances intéressantes. Résultats Sur un plan ergonomique, les soignants rencontrent une plus faible pénibilité que les surveillants. Sur un plan environnemental, les soignants sont gênés par un nombre moins important de nuisances que les surveillants, ces derniers étant exposés à des conditions très diverses de travail (divisions de haute sécurité, ateliers de production, domaines agricoles). Par contre, concernant les facteurs de stress, les soignants éprouvent des tensions dans des proportions presque identiques aux surveillants, suite aux interventions d'urgences, à la surcharge de travail, aux relations avec les détenus et à la mauvaise ambiance au travail. En outre, les soignants et surveillants paraissent souffrir différemment d'éléments d'organisation tels que le sentiment de travailler sous pression, le manque d'écoute et le manque de considération. Enfin les soignants signalent un risque de violence plus élevé ainsi qu'un manque de reconnaissance plus important que les surveillants. Conclusion Les surveillants doivent continuer à faire l'objet d'un suivi attentif des services de santé au travail. En ce qui concerne les soignants, l'accent doit être mis sur l'amélioration de leur organisation interne de travail en approfondissant, entre autres, la question du manque de reconnaissance, le sentiment de travail sous pression, ainsi qu'en poursuivant les efforts sur la formation à la lutte contre la violence. [Auteurs]
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How communication systems emerge and remain stable is an important question in both cognitive science and evolutionary biology. For communication to arise, not only must individuals cooperate by signaling reliable information, but they must also coordinate and perpetuate signals. Most studies on the emergence of communication in humans typically consider scenarios where individuals implicitly share the same interests. Likewise, most studies on human cooperation consider scenarios where shared conventions of signals and meanings cannot be developed de novo. Here, we combined both approaches with an economic experiment where participants could develop a common language, but under different conditions fostering or hindering cooperation. Participants endeavored to acquire a resource through a learning task in a computer-based environment. After this task, participants had the option to transmit a signal (a color) to a fellow group member, who would subsequently play the same learning task. We varied the way participants competed with each other (either global scale or local scale) and the cost of transmitting a signal (either costly or noncostly) and tracked the way in which signals were used as communication among players. Under global competition, players signaled more often and more consistently, scored higher individual payoffs, and established shared associations of signals and meanings. In addition, costly signals were also more likely to be used under global competition; whereas under local competition, fewer signals were sent and no effective communication system was developed. Our results demonstrate that communication involves both a coordination and a cooperative dilemma and show the importance of studying language evolution under different conditions influencing human cooperation.
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Background: Medical and pharmacological direct costs of cigarette smoking cessation programmes are not covered by health insurance in several countries despite documented cost-effectiveness. Design: prospective cost identification study of a 9-week programme in Switzerland. Methods: A total of 481 smokers were followed-up for 9 weeks. Socio-demographic characteristics, number of outpatient visits, dosage and frequency of use of nicotine replacement therapy (NRT) as well as date of relapse were prospectively collected. Individual cost of care until relapse or programme end as well as cost per week of follow-up were computed. Comparisons were carried out between the groups with or without relapse at the end of the programme. Results: Of the 209 men and 272 women included, 347 patients (72%) finished the programme. Among them, 240 patients (70%) succeeded in quitting and 107 patients (30%) relapsed. As compared with the group relapsing by the end of the programme, the group succeeding in quitting was more often living in a couple (68% vs. 55%, p = 0.029). Their mean weekly costs of visits were higher (CHF 81.2 ± 6.1 vs. 78.4 ± 7.6, p = 0.001), while their mean weekly costs for NRT were similar (CHF 24.2 ± 12.6 vs. 25.4 ± 15.9, p = 0.711). Mean total costs per week were similar (CHF 105.4 ± 15.4 vs. 103.8 ± 19.4, p = 0.252). More intensive NRT at week 4 increased the probability not to relapse at the end of the programme. Conclusions: Over 9 weeks, medical and pharmacological costs of stopping smoking are low. Good medical and social support as well as adequate NRT seem to play a role in successful quitting.