234 resultados para heat value


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Rapport de synthèse : Les tumeurs de la paroi thoracique sont des pathologies graves dont le traitement principal consiste en une résection chirurgicale. L'enjeu majeur de cette intervention ontologique est de réséquer la totalité de la tumeur, ce qui nécessite une planification préopératoire minutieuse. Classiquement, l'identification et la localisation de la tumeur se fait à l'aide de la tomodensitométrie (computed tomography, CT) ou de l'imagerie par résonnance magnétique (1RM). Actuellement, l'imagerie nucléaire fonctionnelle par tomographie par émission de positons (positron emission tomography, PET) qui peut être couplée au CT (PET/CT) est de plus en plus appliquée aux patients présentant une tumeur maligne. Son efficacité a fréquemment été démontrée. Le but de la présente étude est d'évaluer la valeur du PET dans la planification de la résection des tumeurs de la paroi thoracique. Une analyse rétrospective de dix-huit patients opérés entre 2004 et 2006 a été réalisée; Dans ce groupe de patient, la taille de la tumeur mesurée sur la pièce opératoire réséquée a été comparée à la taille de la tumeur mesurée sur le CT et le PET. Les résultats démontrent que le CT surestimait de manière consistante la taille réelle de la tumeur par rapport au PET (+64% par rapport à +1%, P<0.001). De plus, le PET s'est avéré particulièrement performant pour prédire la taille des tumeurs de plus de 5.5 cm de diamètre par rapport au CT (valeur prédictive positive 80% par rapport à 44% et spécificité 93% par apport à 64%, respectivement). Cette étude démontre que le PET permettrait de mesurer la taille des tumeurs de la paroi thoracique de manière plus précise que le CT. Cette nouvelle modalité diagnostique s'avèrerait donc utile pour planifier les résections chirurgicales de telles tumeurs. A notre connaissance, aucune publication ne décrit la valeur du PET dans ce domaine. Les performances accrues du PET permettraient une meilleure délimitation des tumeurs ce qui améliorerait la précision de la résection chirurgicale. En conclusion, cette étude préliminaire rétrospective démontre la faisabilité du PET pour les tumeurs de la paroi thoracique. Ces résultats devraient être confirmés par une étude prospective incluant un plus grand nombre de patients avec la perspective de juger l'impact clinique réel du PET sur la prise en charge thérapeutique des patients.

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Glioblastoma (GBM) is a morphologically heterogeneous tumor type with a median survival of only 15 months in clinical trial populations. However, survival varies greatly among patients. As part of a central pathology review, we addressed the question if patients with GBM displaying distinct morphologic features respond differently to combined chemo-radiotherapy with temozolomide. Morphologic features were systematically recorded for 360 cases with particular focus on the presence of an oligodendroglioma-like component and respective correlations with outcome and relevant molecular markers. GBM with an oligodendroglioma-like component (GBM-O) represented 15% of all confirmed GBM (52/339) and was not associated with a more favorable outcome. GBM-O encompassed a pathogenetically heterogeneous group, significantly enriched for IDH1 mutations (19 vs. 3%, p = 0.003) and EGFR amplifications (71 vs. 48%, p = 0.04) compared with other GBM, while co-deletion of 1p/19q was found in only one case and the MGMT methylation frequency was alike (47 vs. 46%). Expression profiles classified most of the GBM-O into two subtypes, 36% (5/14 evaluable) as proneural and 43% as classical GBM. The detection of pseudo-palisading necrosis (PPN) was associated with benefit from chemotherapy (p = 0.0002), while no such effect was present in the absence of PPN (p = 0.86). In the adjusted interaction model including clinical prognostic factors and MGMT status, PPN was borderline nonsignificant (p = 0.063). Taken together, recognition of an oligodendroglioma-like component in an otherwise classic GBM identifies a pathogenetically mixed group without prognostic significance. However, the presence of PPN may indicate biological features of clinical relevance for further improvement of therapy.

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AIM: To determine the long-term prognostic value of SPECT myocardial perfusion imaging (MPI) for the occurrence of cardiovascular events in diabetic patients. PATIENTS, METHODS: SPECT MPI of 210 consecutive Caucasian diabetic patients were analysed using Kaplan-Meier event-free survival curves and independent predictors were determined by Cox multivariate analyses. RESULTS: Follow-up was complete in 200 (95%) patients with a median period of 3.0 years (0.8-5.0). The population was composed of 114 (57%) men, age 65 +/- 10 years, 181 (90.5%) type 2 diabetes mellitus, 50 (25%) with a history of coronary artery disease (CAD) and 98 (49%) presenting chest pain prior to MPI. The prevalence of abnormal MPI was 58%. Patients with a normal MPI had neither cardiac death, nor myocardial infarction, independently of a history of coronary artery disease or chest pain. Among the independent predictors of cardiac death and myocardial infarction, the strongest was abnormal MPI (p < 0.0001), followed by history of CAD (Hazard Ratio (HR) = 15.9; p = 0.0001), diabetic retinopathy (HR = 10.0; p = 0.001) and inability to exercise (HR = 7.7; p = 0.02). Patients with normal MPI had a low revascularisation rate of 2.4% during the follow-up period. Compared to normal MPI, cardiovascular events increased 5.2 fold for reversible defects, 8.5 fold for fixed defects and 20.1 fold for the association of both defects. CONCLUSION: Diabetic patients with normal MPI had an excellent prognosis independently of history of CAD. On the opposite, an abnormal MPI led to a >5-fold increase in cardiovascular events. This emphasizes the value of SPECT MPI in predicting and risk-stratifying cardiovascular events in diabetic patients.

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Her2/neu is a tyrosine kinase receptor which stimulates cell growth. The receptor is overexpressed in about 20% of breast cancers. Her2/neu expression is an indicator of poor prognosis but also the target of the treatment of breast cancer using humanised anti-Her2/ neu antibodies. Only cancers overexpressing the protein will respond to this therapy, but which has significant (cardiac) side effects and is expensive. It is therefore important to test for the overexpression of the protein on breast cancer cells. This paper discusses how this can be done and ongoing research into new therapeutic options targeting the involved signaling pathways.

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BACKGROUND: Early diagnosis of postoperative orthopaedic infections is important in order to rapidly initiate adequate antimicrobial therapy. There are currently no reliable diagnostic markers to differentiate infectious from noninfectious causes of postoperative fever. We investigated the value of the serum procalcitonin level in febrile patients after orthopaedic surgery. METHODS: We prospectively evaluated 103 consecutive patients with new onset of fever within ten days after orthopaedic surgery. Fever episodes were classified by two independent investigators who were blinded to procalcitonin results as infectious or noninfectious origin. White blood-cell count, C-reactive protein level, and procalcitonin level were assessed on days 0, 1, and 3 of the postoperative fever. RESULTS: Infection was diagnosed in forty-five (44%) of 103 patients and involved the respiratory tract (eighteen patients), urinary tract (eighteen), joints (four), surgical site (two), bloodstream (two), and soft tissues (one). Unlike C-reactive protein levels and white blood-cell counts, procalcitonin values were significantly higher in patients with infection compared with patients without infection on the day of fever onset (p = 0.04), day 1 (p = 0.07), and day 3 (p = 0.003). Receiver-operating characteristics demonstrated that procalcitonin had the highest diagnostic accuracy, with a value of 0.62, 0.62, and 0.71 on days 0, 1, and 3, respectively. In a multivariate logistic regression analysis, procalcitonin was a significant predictor for postoperative infection on days 0, 1, and 3 of fever with an odds ratio of 2.3 (95% confidence interval, 1.1 to 4.4), 2.3 (95% confidence interval, 1.1 to 5.2), and 3.3 (95% confidence interval, 1.2 to 9.0), respectively. CONCLUSIONS: Serum procalcitonin is a helpful diagnostic marker supporting clinical and microbiological findings for more reliable differentiation of infectious from noninfectious causes of fever after orthopaedic surgery.

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OBJECTIVE: The goal of our study was to compare Doppler sonography and renal scintigraphy as tools for predicting the therapeutic response in patients after undergoing renal angioplasty. SUBJECTS AND METHODS. Seventy-four hypertensive patients underwent clinical examination, Doppler sonography, and renal scintigraphy before and after receiving captopril in preparation for renal revascularization. The patients were evaluated for the status of hypertension 3 months after the procedure. The predictive values of the findings of clinical examination, Doppler sonography, renal scintigraphy, and angiography were assessed. RESULTS: For prediction of a favorable therapeutic outcome, abnormal results from renal scintigraphy before and after captopril administration had a sensitivity of 58% and specificity of 57%. Findings of Doppler sonography had a sensitivity of 68% and specificity of 50% before captopril administration and a sensitivity of 81% and specificity of 32% after captopril administration. Significant predictors of a cure or reduction of hypertension after revascularization were low unilateral (p = 0.014) and bilateral resistive (p = 0.016) indexes on Doppler sonography before (p = 0.009) and after (p = 0.028) captopril administration. On multivariate analysis, the best predictors were a unilateral resistive index of less than 0.65 (odds ratio [OR] = 3.7) after captopril administration and a kidney longer than 93 mm (OR = 7.8). The two best combined criteria to predict the favorable therapeutic outcome were a bilateral resistive index of less than 0.75 before captopril administration combined with a unilateral resistive index of less than 0.70 after captopril administration (sensitivity, 76%; specificity, 58%) or a bilateral resistive index of less than 0.75 before captopril administration and a kidney measuring longer than 90 mm (sensitivity, 81%; specificity, 50%). CONCLUSION: Measurements of kidney length and unilateral and bilateral resistive indexes before and after captopril administration were useful in predicting the outcome after renal angioplasty. Renal scintigraphy had no significant predictive value.

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Heat shock protein 90 (Hsp90) is an essential chaperone involved in the fungal stress response that can be harnessed as a novel antifungal target for the treatment of invasive aspergillosis. We previously showed that genetic repression of Hsp90 reduced Aspergillus fumigatus virulence and potentiated the effect of the echinocandin caspofungin. In this study, we sought to identify sites of posttranslational modifications (phosphorylation or acetylation) that are important for Hsp90 function in A. fumigatus. Phosphopeptide enrichment and tandem mass spectrometry revealed phosphorylation of three residues in Hsp90 (S49, S288, and T681), but their mutation did not compromise Hsp90 function. Acetylation of lysine residues of Hsp90 was recovered after treatment with deacetylase inhibitors, and acetylation-mimetic mutations (K27A and K271A) resulted in reduced virulence in a murine model of invasive aspergillosis, supporting their role in Hsp90 function. A single deletion of lysine K27 or an acetylation-mimetic mutation (K27A) resulted in increased susceptibility to voriconazole and caspofungin. This effect was attenuated following a deacetylation-mimetic mutation (K27R), suggesting that this site is crucial and should be deacetylated for proper Hsp90 function in antifungal resistance pathways. In contrast to previous reports in Candida albicans, the lysine deacetylase inhibitor trichostatin A (TSA) was active alone against A. fumigatus and potentiated the effect of caspofungin against both the wild type and an echinocandin-resistant strain. Our results indicate that the Hsp90 K27 residue is required for azole and echinocandin resistance in A. fumigatus and that deacetylase inhibition may represent an adjunctive anti-Aspergillus strategy.

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Accurate estimates of water losses by evaporation from shallow water tables are important for hydrological, agricultural, and climatic purposes. An experiment was conducted in a weighing lysimeter to characterize the diurnal dynamics of evaporation under natural conditions. Sampling revealed a completely dry surface sand layer after 5 days of evaporation. Its thickness was <1 cm early in the morning, increasing to reach 4?5 cm in the evening. This evidence points out fundamental limitations of the approaches that assume hydraulic connectivity from the water table up to the surface, as well as those that suppose monotonic drying when unsteady conditions prevail. The computed vapor phase diffusion rates from the apparent drying front based on Fick's law failed to reproduce the measured cumulative evaporation during the sampling day. We propose that two processes rule natural evaporation resulting from daily fluctuations of climatic variables: (i) evaporation of water, stored during nighttime due to redistribution and vapor condensation, directly into the atmosphere from the soil surface during the early morning hours, that could be simulated using a mass transfer approach and (ii) subsurface evaporation limited by Fickian diffusion, afterward. For the conditions prevailing during the sampling day, the amount of water stored at the vicinity of the soil surface was 0.3 mm and was depleted before 11:00. Combining evaporation from the surface before 11:00 and subsurface evaporation limited by Fickian diffusion after that time, the agreement between the estimated and measured cumulative evaporation was significantly improved.

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BACKGROUND: Reactive oxygen species production increases during aging, whereas protective mechanisms such as heat shock proteins (HSPs) or antioxidant capacity are depressed. Physical activity has been hypothesized to provide protection against oxidative damage during aging, but results remain controversial. This study aimed to investigate the effect of different levels of physical activity during aging on Hsp72 expression and systemic oxidative stress at rest and in response to maximal exercise. METHODS: Plasma antioxidant capacity (Trolox equivalent antioxidant capacity, TEAC), thiobarbituric acid-reactive species (TBARS), advanced oxidized proteins products (AOPP), and Hsp72 expression in leukocytes were measured before and after maximal exercise testing in 32 elderly persons (aged 73.2 years), who were assigned to two different groups depending on their level of physical activity during the past 12 months (OLow = moderate to low level; OHigh = higher level). RESULTS: The OHigh group showed higher aerobic fitness and TEAC (both representing 120% of OLow values) as well as lower oxidative damage (50% of OLow values) and Hsp72 expression. Exercise led to a lower increase in oxidative damage in the OHigh group. Aerobic fitness was positively correlated with TEAC and negatively with lipid peroxidation (TBARS). Hsp72 expression was negatively correlated with TEAC but positively correlated with TBARS levels. CONCLUSIONS: The key finding of this study is that, in people aged 60 to 90 years, long-term high level of physical activity preserved antioxidant capacity and limited oxidative damage accumulation. It also downregulated Hsp72 expression, an adaptation potentially resulting from lower levels of oxidative damage.

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The subject "Value and prices in Russian economic thought (1890--1920)" should evoke several names and debates in the reader's mind. For a long time, Western scholars have been aware that the Russian economists Tugan-Baranovsky and Bortkiewicz were active participants to the Marxian transformation problem, that the mathematical models of Dmitriev prefigured forthcoming neoricardian based models, and that many Russian economists were either supporting the Marxian labour theory of value or being revisionists. Moreover, these ideas were preparing the ground for Soviet planning. Russian scholars additionally knew that this period was the time of introduction of marginalism in Russia, and that, during this period, economists were active in thinking the relation of ethics with economic theory. All these issues are well covered in the existing literature. But there is a big gap that this dissertation intends to fill. The existing literature handles these pieces separately, although they are part of a single, more general, history. All these issues (the labour theory of value, marginalism, the Marxian transformation problem, planning, ethics, mathematical economics) were part of what this dissertation calls here "The Russian synthesis". The Russian synthesis (in the singular) designates here all the attempts at synthesis between classical political economy and marginalism, between labour theory of value and marginal utility, and between value and prices that occurred in Russian economic thought between 1890 and 1920, and that embraces the whole set of issues evoked above. This dissertation has the ambition of being the first comprehensive history of that Russian synthesis. In this, this contribution is unique. It has always surprised the author of the present dissertation that such a book has not yet been written. Several good reasons, both in terms of scarce availability of sources and of ideological restrictions, may accounted for a reasonable delay of several decades. But it is now urgent to remedy the situation before the protagonists of the Russian synthesis are definitely classified under the wrong labels in the pantheon of economic thought. To accomplish this task, it has seldom be sufficient to gather together the various existing studies on aspects of this story. It as been necessary to return to the primary sources in the Russian language. The most important part of the primary literature has never been translated, and in the last years only some of them have been republished in Russian. Therefore, most translations from the Russian have been made by the author of the present dissertation. The secondary literature has been surveyed in the languages that are familiar (Russian, English and French) or almost familiar (German) to the present author, and which are hopefully the most pertinent to the present investigation. Besides, and in order to increase the acquaintance with the text, which was the objective of all this, some archival sources were used. The analysis consists of careful chronological studies of the authors' writings and their evolution in their historical and intellectual context. As a consequence, the dissertation brings new authors to the foreground - Shaposhnikov and Yurovsky - who were traditionally confined to the substitutes' bench, because they only superficially touched the domains quoted above. In the Russian synthesis however, they played an important part of the story. As a side effect, some authors that used to play in the foreground - Dmitriev and Bortkiewicz - are relegated to the background, but are not forgotten. Besides, the dissertation refreshes the views on authors already known, such as Ziber and, especially, Tugan-Baranovsky. The ultimate objective of this dissertation is to change the opinion that one could have on "value and prices in Russian economic thought", by setting the Russian synthesis at the centre of the debates.

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BACKGROUND: Replicative phenotypic HIV resistance testing (rPRT) uses recombinant infectious virus to measure viral replication in the presence of antiretroviral drugs. Due to its high sensitivity of detection of viral minorities and its dissecting power for complex viral resistance patterns and mixed virus populations rPRT might help to improve HIV resistance diagnostics, particularly for patients with multiple drug failures. The aim was to investigate whether the addition of rPRT to genotypic resistance testing (GRT) compared to GRT alone is beneficial for obtaining a virological response in heavily pre-treated HIV-infected patients. METHODS: Patients with resistance tests between 2002 and 2006 were followed within the Swiss HIV Cohort Study (SHCS). We assessed patients' virological success after their antiretroviral therapy was switched following resistance testing. Multilevel logistic regression models with SHCS centre as a random effect were used to investigate the association between the type of resistance test and virological response (HIV-1 RNA <50 copies/mL or ≥1.5 log reduction). RESULTS: Of 1158 individuals with resistance tests 221 with GRT+rPRT and 937 with GRT were eligible for analysis. Overall virological response rates were 85.1% for GRT+rPRT and 81.4% for GRT. In the subgroup of patients with >2 previous failures, the odds ratio (OR) for virological response of GRT+rPRT compared to GRT was 1.45 (95% CI 1.00-2.09). Multivariate analyses indicate a significant improvement with GRT+rPRT compared to GRT alone (OR 1.68, 95% CI 1.31-2.15). CONCLUSIONS: In heavily pre-treated patients rPRT-based resistance information adds benefit, contributing to a higher rate of treatment success.

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Research on achievement goal promotion at University has shown that performance-approach goals are perceived as a means to succeed at University (high social utility) but are not appreciated (low social desirability). We argue that such a paradox could explain why research has detected that performance-approach goals consistently predict academic grades. First-year psychology students answered a performance-approach goal scale with standard, social desirability and social utility instructions. Participants' grades were recorded at the end of the semester. Results showed that the relationship between performance-approach goals and grades was inhibited by the increase of these goals' social desirability and facilitated by the increase of their social utility, revealing that the predictive validity of performance-approach goals depend on social value.