90 resultados para Indicator Groups
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The toxicity of yew (Taxus spp) is well known from ancient times and is mainly due to taxins acting as inhibitors of calcium and sodium transport across the cell membrane of cardiac myocytes. The confirmation of yew taxins in body fluids can be carried out by liquid chromatography-tandem mass spectrometry (LC-MS/MS). However, before selecting this precise but expensive technique, an orientation test should be done to ascertain yew presence as toxic agent in the organism. As the 3,5-dimethoxyphenol (3,5-DMP), myrtenol and 1-octen-3-ol appear as glycosidically bound volatile compounds and are very yew specific, the detection of 3,5-DMP and the measurement of 1-octen-3-ol / myrtenol concentration ratio constitute reliable indicators of yew presence in forensic cases. The detection of these compounds is easily performed by gas chromatography-mass spectrometry (GC-MS) (SIM) after an enzymatic hydrolysis (β-glucosidase) allowing the release of volatile compounds from yew glycosides. Copyright © 2012 John Wiley & Sons, Ltd.
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Six gases (N((CH3)3), NH2OH, CF3COOH, HCl, NO2, O3) were selected to probe the surface of seven combustion aerosol (amorphous carbon, flame soot) and three types of TiO2 nanoparticles using heterogeneous, that is gas-surface reactions. The gas uptake to saturation of the probes was measured under molecular flow conditions in a Knudsen flow reactor and expressed as a density of surface functional groups on a particular aerosol, namely acidic (carboxylic) and basic (conjugated oxides such as pyrones, N-heterocycles) sites, carbonyl (R1-C(O)-R2) and oxidizable (olefinic, -OH) groups. The limit of detection was generally well below 1% of a formal monolayer of adsorbed probe gas. With few exceptions most investigated aerosol samples interacted with all probe gases which points to the coexistence of different functional groups on the same aerosol surface such as acidic and basic groups. Generally, the carbonaceous particles displayed significant differences in surface group density: Printex 60 amorphous carbon had the lowest density of surface functional groups throughout, whereas Diesel soot recovered from a Diesel particulate filter had the largest. The presence of basic oxides on carbonaceous aerosol particles was inferred from the ratio of uptakes of CF3COOH and HCl owing to the larger stability of the acetate compared to the chloride counterion in the resulting pyrylium salt. Both soots generated from a rich and a lean hexane diffusion flame had a large density of oxidizable groups similar to amorphous carbon FS 101. TiO2 15 had the lowest density of functional groups among the three studied TiO2 nanoparticles for all probe gases despite the smallest size of its primary particles. The used technique enabled the measurement of the uptake probability of the probe gases on the various supported aerosol samples. The initial uptake probability, g0, of the probe gas onto the supported nanoparticles differed significantly among the various investigated aerosol samples but was roughly correlated with the density of surface groups, as expected. [Authors]
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Purpose: The aim of this study was to evaluate the oxygen saturation in patients with inherited diseases of the retina. Methods: Fundus oximetry images were taken using a retinal vessel analyser (IMEDOS Systems UG, Jena, Germany). Retinal vessel oximetry was performed in 53 eyes of 27 patients suffering from inherited retinal diseases and compared to 22 eyes of 11 healthy controls. The oxygen saturation in all four major retinal arterioles (A-SO2) and venules (V-SO2) were measured and their difference (A - V SO2) was calculated. The data were compared within groups and to controls. Results: Based on V-SO2 values, the rod-cone dystrophy group (66.46 %; SD, ± 5.09) could well be differentiated from controls 54.02 % (SD, ± 3.04), from cone-rod dystrophies 57.56 % (SD, ± 5.66), as well as from inherited maculopathies 58.42% (SD, ± 4.74). The mean A-SO2 in the rod-cone dystrophy group was increased to 98.96 % (SD, ± 6.06, p < 0.014), while in the cone-rod group and in the maculopathy group it was 92.75 % (SD, ± 3.75), respectively 94.44 % (SD ± 4.85), closer to the normal values (92.68 %; SD, ± 3.53, p > 0.05). The A - V SO2 difference, as an indirect indicator for retinal oxygen use, was reduced in the rod-cone patients, however only when the controls were taken into account (p = 0.01). Conclusion: This is to our knowledge the first study which proposes the retinal vessel oximetry to be a sensitive measure for differentiating rod-cone dystrophy patients not only from controls, but also from patients with other inherited retinal dystrophies.
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This study explores the impact of relative size on the intra- and intergroup attitudes of groups who either share a language or have a different language. For that purpose, we examined international attitudes, comparing a small nation, Switzerland, and two larger nations, Germany and France. We found support for the assumption that large neighbouring nations pose a threat to the smaller nation's identity, especially when they are linguistically similar. Consequently, in line with Tajfel's Social Identity Theory (1978), the smaller nation's inhabitants evaluate those of the larger nation less positively, liking them less and perceiving them to be more arrogant than vice versa. By investigating the special case of the French-speaking and the German-speaking Swiss as linguistic groups within their own nation we were able to demonstrate that these groups seek support with the larger-linguistically-similar nation to defend themselves against the more direct in-country threat to their identity. They acknowledge the similarity with the larger nation, yet keep defending their social identity by expressing a dislike for this perceived similarity.
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BACKGROUND: Microalbuminuria (MA) has been shown to be an early biomarker of renal damage. It is postulated that MA is the early result of hyperfiltration, which could evolve into glomerular sclerosis and renal failure if hyperfiltration is left untreated. We hypothesized that MA is a good indicator of hyperfiltration in children with kidney disorders, obviating the need to calculate the filtration fraction (FF). METHODS: A total of 155 children or young adults were prospectively included [42 single kidney (SK), 61 vesico-ureteral reflux, 23 obstructive uropathies, 29 other kidney diseases]. We measured inulin, para-aminohippuric acid clearances, FF and MA. Prediction of hyperfiltration was explored by studying the association between the FF and other variables such as urinary albumin (Alb), urinary albumin-creatinine ratio (ACR) and creatinine clearance. RESULTS: A significant but weak association between urinary Alb or ACR and FF was found in subjects with an SK (Spearman correlation coefficients 0.32 and 0.19, respectively). Multivariate analysis also showed that urinary Alb and ACR significantly predict FF only in subjects with an SK (r(2) = 0.17, P = 0.01 and r(2) = 0.13, P = 0.02, respectively). This holds true only in subjects with an SK and inulin clearance >90 mL/min/1.73 m(2) (r(2) = 0.41, P < 0.001). There was no association between creatinine clearance and FF. CONCLUSIONS: MA is not associated with FF in our subjects with nephro-urological disorders, except in those with an SK, where the association is weak, indicating that MA is due to other mechanisms than high FF and cannot predict hyperfiltration in such groups.
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BACKGROUND: The purpose of this study was to explore the potential use of image analysis on tissue sections preparation as a predictive marker of early malignant changes during squamous cell (SC) carcinogenesis in the esophagus. Results of DNA ploidy quantification on formalin-fixed, paraffin-embedded tissue using two different techniques were compared: imprint-cytospin and 6 microm thick tissue sections preparation. METHODS: This retrospective study included 26 surgical specimens of squamous cell carcinoma (SCC) from patients who underwent surgery alone at the Department of Surgery in CHUV Hospital in Lausanne between January 1993 and December 2000. We analyzed 53 samples of healthy tissue, 43 tumors and 7 lymph node metastases. RESULTS: Diploid DNA histogram patterns were observed in all histologically healthy tissues, either distant or proximal to the lesion. Aneuploidy was observed in 34 (79%) of 43 carcinomas, namely 24 (75%) of 32 early squamous cell carcinomas and 10 (91%) of 11 advanced carcinomas. DNA content was similar in the different tumor stages, whether patients presented with single or multiple synchronous tumors. All lymph node metastases had similar DNA content as their primary tumor. CONCLUSIONS: Early malignant changes in the esophagus are associated with alteration in DNA content, and aneuploidy tends to correlate with progression of invasive SCC. A very good correlation between imprint-cytospin and tissue section analysis was observed. Although each method used here showed advantages and disadvantages; tissue sections preparation provided useful information on aberrant cell-cycle regulation and helped select the optimal treatment for the individual patient along with consideration of other clinical parameters.
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The objectives of this study were to develop a computerized method to screen for potentially avoidable hospital readmissions using routinely collected data and a prediction model to adjust rates for case mix. We studied hospital information system data of a random sample of 3,474 inpatients discharged alive in 1997 from a university hospital and medical records of those (1,115) readmitted within 1 year. The gold standard was set on the basis of the hospital data and medical records: all readmissions were classified as foreseen readmissions, unforeseen readmissions for a new affection, or unforeseen readmissions for a previously known affection. The latter category was submitted to a systematic medical record review to identify the main cause of readmission. Potentially avoidable readmissions were defined as a subgroup of unforeseen readmissions for a previously known affection occurring within an appropriate interval, set to maximize the chance of detecting avoidable readmissions. The computerized screening algorithm was strictly based on routine statistics: diagnosis and procedures coding and admission mode. The prediction was based on a Poisson regression model. There were 454 (13.1%) unforeseen readmissions for a previously known affection within 1 year. Fifty-nine readmissions (1.7%) were judged avoidable, most of them occurring within 1 month, which was the interval used to define potentially avoidable readmissions (n = 174, 5.0%). The intra-sample sensitivity and specificity of the screening algorithm both reached approximately 96%. Higher risk for potentially avoidable readmission was associated with previous hospitalizations, high comorbidity index, and long length of stay; lower risk was associated with surgery and delivery. The model offers satisfactory predictive performance and a good medical plausibility. The proposed measure could be used as an indicator of inpatient care outcome. However, the instrument should be validated using other sets of data from various hospitals.
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A multicomponent indicator displacement assay ( MIDA) based on an organometallic receptor and three dyes can be used for the identification and quantification of nucleotides in aqueous solution at neutral pH.
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Rapport de synthèse Objectifs : Évaluer l'impact clinique de femmes infectées par de multiples papillomavirus human (HPV) à haut risque dont le HPV 16 en comparaison de l'évolution de femmes infectées par du HPV 16 seul. Méthode : 169 femmes ont été classifiées en trois groupes, dépendant de leur profile HPV: HPV-16 seul, HPV-16 et un HPV de type bas risque, HPV-16 et un autre HPV à haut risque. Le HPV-DNA des frottis cervicaux a été analysé par polymerase chain reaction (PCR) et reverse line blot hybridization (RLBH). Toutes les femmes ont été suivies à la consultation de colposcopie pour une durée de 24 mois ou plus. La prise en charge s'est faite selon les recommandations de Bethesda. Résultats : Les femmes infectées par du HPV 16 et un autre HPV à haut risque n'ont présenté aucun changement voire une progression de leur dysplasie en comparaison des femmes des autres groupes (RR: 1.39; 95%CI: 1.07 à 1.82; p value: 0.02 à 6 mois; RR: 2.10; 95%CI: 1.46 à 3.02; p value: <0.001 à 12 mois; RR: 1.82; 95%CI: 1.21 à 2.72; p value: 0.004 à 24 mois). Conclusions : Les femmes présentant une co-infection par du HPV 16 ainsi qu'un autre HPV de haut risque voient leur risque d'évolution défavorable augmenter.
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Data collected by the Cancer Registry of the Canton of Vaud, Switzerland, were used to estimate proportional mortality ratios (PMR) and mortality odds ratios (MOR) for various neoplasms according to social class and sector of occupation (agriculture versus others). Mortality ratios were elevated in lower social classes for cancers of the lung (MOR = 1.18 for social class IV or V vs I or II) and other sites strictly related to tobacco (mouth or pharynx, oesophagus and larynx; MOR = 1.70), and (though not significantly) for cancers of the stomach (MOR = 1.16) and uterus (MOR = 1.30 for cervix and 1.47 for corpus uteri). Furthermore, there was a strong negative social class gradient for thyroid cancer (a neoplasm with particularly elevated incidence and mortality in Switzerland), probably attributable to higher prevalence of iodine deficiency in lower social classes (MOR = 3.17). Positive social class gradients emerged for cancers of the intestines (MOR = 0.77 for social class IV or V), skin (MOR = 0.74) and prostate (MOR = 0.87). Agricultural workers showed decreased ratios for cancers of the lung (MOR = 0.75), cervix uteri (MOR = 0.72) and prostate (MOR = 0.80), and excess mortality from cancers of the upper digestive and respiratory sites (MOR = 1.22), stomach (MOR = 1.18), testis (MOR = 2.05) and lympho-haematopoietic neoplasms, particularly myeloma (MOR = 2.14).
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We present a new indicator taxa approach to the prediction of climate change effects on biodiversity at the national level in Switzerland. As indicators, we select a set of the most widely distributed species that account for 95% of geographical variation in sampled species richness of birds, butterflies, and vascular plants. Species data come from a national program designed to monitor spatial and temporal trends in species richness. We examine some opportunities and limitations in using these data. We develop ecological niche models for the species as functions of both climate and land cover variables. We project these models to the future using climate predictions that correspond to two IPCC 3rd assessment scenarios for the development of 'greenhouse' gas emissions. We find that models that are calibrated with Swiss national monitoring data perform well in 10-fold cross-validation, but can fail to capture the hot-dry end of environmental gradients that constrain some species distributions. Models for indicator species in all three higher taxa predict that climate change will result in turnover in species composition even where there is little net change in predicted species richness. Indicator species from high elevations lose most areas of suitable climate even under the relatively mild B2 scenario. We project some areas to increase in the number of species for which climate conditions are suitable early in the current century, but these areas become less suitable for a majority of species by the end of the century. Selection of indicator species based on rank prevalence results in a set of models that predict observed species richness better than a similar set of species selected based on high rank of model AUC values. An indicator species approach based on selected species that are relatively common may facilitate the use of national monitoring data for predicting climate change effects on the distribution of biodiversity.
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The representation of age groups is becoming an increasingly discussed topic in Swiss politics. In this study, we explore inequalities in the descriptive and substantive representation of various age groups and find that despite important disparities in descriptive representation, the policy preferences of various age groups are relatively equally represented in the lower house of the Swiss parliament. Our analysis thus suggests that even if it is gaining visibility, the age cleavage is not central for parliamentary representation in Switzerland.
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Travaux effectués dans le cadre de l'étude "Case Mix" menée par l'Institut universitaire de médecine sociale et préventive de Lausanne et le Service de la santé publique et de la planification sanitaire du canton de Vaud, en collaboration avec les cantons de Berne, Fribourg, Genève, Jura, Neuchâtel, Soleure, Tessin et Valais
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Introduction: THC-COOH has been proposed as a criterion to help to distinguish between occasional from regular cannabis users. However, to date this indicator has not been adequately assessed under experimental and real-life conditions. Methods: We carried out a controlled administration study of smoked cannabis with a placebo. Twenty-three heavy smokers and 25 occasional smokers, between 18 and 30 years of age, participated in this study [Battistella G et al., PloS one. 2013;8(1):e52545]. We collected data from a second real case study performed with 146 traffic offenders' cases in which the whole blood cannabinoid concentrations and the frequency of cannabis use were known. Cannabinoid levels were determined in whole blood using tandem mass spectrometry methods. Results: Significantly high differences in THC-COOH concentrations were found between the two groups when measured during the screening visit, prior to the smoking session, and throughout the day of the experiment. Receiver operating characteristic (ROC) curves were determined and two threshold criteria were proposed in order to distinguish between these groups: a free THC-COOH concentration below 3 μg/L suggested an occasional consumption (≤ 1 joint/week) while a concentration higher than 40 μg/L corresponded to a heavy use (≥ 10 joints/month). These thresholds were successfully tested with the second real case study. The two thresholds were not challenged by the presence of ethanol (40% of cases) and of other therapeutic and illegal drugs (24%). These thresholds were also found to be consistent with previously published experimental data. Conclusion: We propose the following procedure that can be very useful in the Swiss context but also in other countries with similar traffic policies: If the whole blood THC-COOH concentration is higher than 40 μg/L, traffic offenders must be directed first and foremost toward medical assessment of their fitness to drive. This evaluation is not recommended if the THC-COOH concentration is lower than 3 μg/L. A THC-COOH level between these two thresholds can't be reliably interpreted. In such a case, further medical assessment and follow up of the fitness to drive are also suggested, but with lower priority.