107 resultados para Cross reaction
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Despite the long tradition for asking about the negative social and health consequences of alcohol consumption in surveys, little is known about the dimensionality of these consequences. Analysing cross-sectional and longitudinal data from the Nordic Taxation Study collected for Sweden, Finland, and Denmark in two waves in 2003 and 2004 by means of an explorative principal component analysis for categorical data (CATPCA), it is tested whether consequences have a single underlying dimension across cultures. It further tests the reliability, replicability, concurrent and predictive validity of the consequence scales. A one-dimensional solution was commonly preferable. Whereas the two-dimensional solution was unable to distinguish clearly between different concepts of consequences, the one-dimensional solution resulted in interpretable, generally very stable scales within countries across different samples and time.
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BACKGROUND: The debate about a possible relationship between aerobic fitness and motor skills with cognitive development in children has recently re-emerged, because of the decrease in children's aerobic fitness and the concomitant pressure of schools to enhance cognitive performance. As the literature in young children is scarce, we examined the cross-sectional and longitudinal relationship of aerobic fitness and motor skills with spatial working memory and attention in preschool children. METHODS: Data from 245 ethnically diverse preschool children (mean age: 5.2 (0.6) years, girls: 49.4%) analyzed at baseline and 9 months later. Assessments included aerobic fitness (20 m shuttle run) and motor skills with agility (obstacle course) and dynamic balance (balance beam). Cognitive parameters included spatial working memory (IDS) and attention (KHV-VK). All analyses were adjusted for age, sex, BMI, migration status, parental education, native language and linguistic region. Longitudinal analyses were additionally adjusted for the respective baseline value. RESULTS: In the cross-sectional analysis, aerobic fitness was associated with better attention (r=0.16, p=0.03). A shorter time in the agility test was independently associated with a better performance both in working memory (r=-0.17, p=0.01) and in attention (r=-0.20, p=0.01). In the longitudinal analyses, baseline aerobic fitness was independently related to improvements in attention (r=0.16, p=0.03), while baseline dynamic balance was associated with improvements in working memory (r=0.15, p=0.04). CONCLUSIONS: In young children, higher baseline aerobic fitness and motor skills were related to a better spatial working memory and/or attention at baseline, and to some extent also to their future improvements over the following 9 months. TRIAL REGISTRATION: clinicaltrials.gov NCT00674544.
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The geometry and kinematics of the map scale Maggia cross-fold structure has been studied by several generations of geologists over seventy years and different models have been proposed for its formation. New observations indicate that the Maggia structure is a SW-verging cross-fold created after earlier NW-directed overthrusting of the Maggia nappe onto the deeper Simano and Antigorio recumbent fold nappes. The nappe emplacement and later cross-folding occurred under amphibolite facies conditions by detachment of the upper European crust during its SE-directed underthrusting below the Adriatic plate.
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BACKGROUND: The value of adenovirus plasma DNA detection as an indicator for adenovirus disease is unknown in the context of T cell-replete hematopoietic cell transplantation, of which adenovirus disease is an uncommon but serious complication. METHODS: Three groups of 62 T cell-replete hematopoietic cell transplant recipients were selected and tested for adenovirus in plasma by polymerase chain reaction. RESULTS: Adenovirus was detected in 21 (87.5%) of 24 patients with proven adenovirus disease (group 1), in 4 (21%) of 19 patients who shed adenovirus (group 2), and in 1 (10.5%) of 19 uninfected control patients. The maximum viral load was significantly higher in group 1 (median maximum viral load, 6.3x10(6) copies/mL; range, 0 to 1.0x10(9) copies/mL) than in group 2 (median maximum viral load, 0 copies/mL; range, 0 to 1.7x10(8) copies/mL; P<.001) and in group 3 (median maximum viral load, 0 copies/mL; range 0-40 copies/mL; P<.001). All patients in group 2 who developed adenoviremia had symptoms compatible with adenovirus disease (i.e., possible disease). A minimal plasma viral load of 10(3) copies/mL was detected in all patients with proven or possible disease. Adenoviremia was detectable at a median of 19.5 days (range, 8-48 days) and 24 days (range, 9-41 days) before death for patients with proven and possible adenovirus disease, respectively. CONCLUSION: Sustained or high-level adenoviremia appears to be a specific and sensitive indicator of adenovirus disease after T cell-replete hematopoietic cell transplantation. In the context of low prevalence of adenovirus disease, the use of polymerase chain reaction of plasma specimens to detect virus might be a valuable tool to identify and treat patients at risk for viral invasive disease.
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Abstract: Background: Amoebae are phagocytic protists where genetic exchanges might take place between amoeba-resistant bacteria. These amoebal pathogens are able to escape the phagocytic behaviour of their host. They belong to different bacterial phyla and often show a larger genome size than human-infecting pathogens. This characteristic is proposed to be the result of frequent gene exchanges with other bacteria that share a sympatric lifestyle and contrasts with the genome reduction observed among strict human pathogens.Results: We sequenced the genome of a new amoebal pathogen, Legionella drancourtii, and compared its gene content to that of a Chlamydia-related bacterium, Parachlamydia acanthamoebae. Phylogenetic reconstructions identified seven potential horizontal gene transfers (HGTs) between the two amoeba-resistant bacteria, including a complete operon of four genes that encodes an ABC-type transporter. These comparisons pinpointed potential cases of gene exchange between P. acanthamoebae and Legionella pneumophila, as well as gene exchanges between other members of the Legionellales and Chlamydiales orders. Moreover, nine cases represent possible HGTs between representatives from the Legionellales or Chlamydiales and members of the Rickettsiales order.Conclusions: This study identifies numerous gene exchanges between intracellular Legionellales and Chlamydiales bacteria, which could preferentially occur within common inclusions in their amoebal hosts. Therefore it contributes to improve our knowledge on the intra-amoebal gene properties associated to their specific lifestyle.
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Astrocytes play a central role in the brain by regulating glutamate and extracellular potassium concentrations ([K+]0), both released by neurons into the extracellular space during neuronal activity. Glutamate uptake is driven by the inwardly directed sodium gradient across the astrocyte membrane and involves the influx of three sodium ions and one proton and the efflux of one K+ ion per glutamate molecule. The glutamate transport induced rise in intracellular sodium stimulates the Na+/K+-ATPase which leads to significant energetic costs in astrocytes. To evaluate how these two fundamental functions of astrocytes, namely glutamate transport and K+ buffering, which are directly associated with neuronal activity, coexist and if they influence each other, in this thesis work we examined different cellular parameters of astrocytes. We therefore investigated the impact of altered [K+]0 on glutamate transporter activity. To assess this question we measured intracellular sodium fluctuations in mouse primary cultured astrocytes using dynamic fluorescence imaging. We found that glutamate uptake was tightly modulated both in amplitude and kinetics by [K+]0. Elevated [K+]0 strongly decreased glutamate transporter activity, with significant consequences on the cells energy metabolism. To ultimately evaluate potential effects of [K+]0 and glutamate on the astrocyte mitochondrial energy production we extended these studies by investigating their impact on the cytosolic and mitochondrial pH. We found that both [K+],, and glutamate strongly influenced cytosolic and mitochondrial pH, but in opposite directions. The effect of a simultaneous application of K+ and glutamate, however, did not fit with the arithmetical sum of each individual effects, suggesting that an additional non¬linear process is involved. We also investigated the impact of [K+]0 and glutamate transport, respectively, on intracellular potassium concentrations ([K+]0 in cultured astrocytes by characterizing and applying a newly developed Insensitive fluorescent dye. We observed that [K+]i followed [K+]0 changes in a nearly proportional way and that glutamate superfusion caused a reversible, glutamate-concentration dependent drop of [K+],, Our study shows the powerful influence of [K+]u on glutamate capture. These findings have strong implications for our understanding of the tightly regulated interplay between astrocytes and neurons in situations where [K+]0 undergoes large activity-dependent fluctuations. However, depending on the extent of K+ versus glutamate extracellular rise, energy metabolism in astrocytes will be differently regulated. Moreover, the novel insights obtained during this thesis work help understanding some of the underlying processes that prevail in certain pathologies of central nervous system, such as epilepsy and stroke. These results will possibly provide a basis for the development of novel therapeutic strategies. -- Les astrocytes jouent un rôle central dans le cerveau en régulant les concentrations de potassium (K+) et de glutamate, qui sont relâchés par les neurones dans l'espace extracellulaire lorsque ceux- ci sont actifs. La capture par les astrocytes du glutamate est un processus secondairement actif qui implique l'influx d'ions sodium (Na+) et d'un proton, ainsi que l'efflux d'ions K+, ce processus entraîne un coût métabolique important. Nous avons évalué comment ces fonctions fondamentales des astrocytes, la régulation du glutamate et du K+ extracellulaire, qui sont directement associés à l'activité neuronale, coexistent et si elles interagissent, en examinant différents paramètres cellulaires. Dans ce projet de thèse nous avons évalué l'impact des modifications de la concentration de potassium extracellulaire ([K+],,) sur le transport du glutamate. Nous avons mesuré le transport du glutamate par le biais des fluctuations internes de Na+ grâce à un colorant fluorescent en utilisant de l'imagerie à fluorescence dynamique sur des cultures primaires d'astrocytes. Nous avons trouvé que la capture du glutamate était étroitement régulée par [K+]0 aussi bien dans son amplitude que dans sa cinétique. Par la suite, nous avons porté notre attention sur l'impact de [K+]0 et du glutamate sur le pH cytosolique et mitochondrial de l'astrocyte dans le but, in fine, d'évaluer les effets potentiels sur la production d'énergie par la mitochondrie. Nous avons trouvé qu'autant le K+ que le glutamate, de manière individuelle, influençaient fortement le pH, cependant dans des directions opposées. Leurs effets individuels, ne peuvent toutefois pas être additionnés ce qui suggère qu'un processus additionnel non-linéaire est impliqué. En appliquant une nouvelle approche pour suivre et quantifier la concentration intracellulaire de potassium ([K+]0 par imagerie à fluorescence, nous avons observé que [K+]i suivait les changements de [K+]0 de manière quasiment proportionnelle et que la superfusion de glutamate induisait un décroissement rapide et réversible de [K+]i, qui dépend de la concentration de glutamate. Notre étude démontre l'influence de [K+]0 sur la capture du glutamate. Ces résultats permettent d'améliorer notre compréhension de l'interaction entre astrocytes et neurones dans des situations où [K+]0 fluctue en fonction de l'activité neuronale. Cependant, en fonction de l'importance de l'augmentation extracellulaire du K+ versus le glutamate, le métabolisme énergétique des astrocytes va être régulé de manière différente. De plus, les informations nouvelles que nous avons obtenues durant ce travail de thèse nous aident à comprendre quelques- uns des processus sous-jacents qui prévalent dans certaines pathologies du système nerveux central, comme par exemple l'épilepsie ou l'accident vasculaire cérébral. Ces informations pourront être importantes à intégrer dans la cadre du développement de nouvelles stratégies thérapeutiques.
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Twelve patients with a catastrophic reaction (CR) (an outburst of frustration, depression, and anger when confronted with a task) were identified in a prospective cohort population (n = 326) with first-ever stroke admitted within 48 hours from onset. The authors' findings suggest that CR is a rare though not exceptional phenomenon in acute stroke and is associated with nonfluent aphasias and left opercular lesions. CR, poststroke depression, and emotionalism are distinct but related disorders.
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BACKGROUND: Fat redistribution, increased inflammation and insulin resistance are prevalent in non-diabetic subjects treated with maintenance dialysis. The aim of this study was to test whether pioglitazone, a powerful insulin sensitizer, alters body fat distribution and adipokine secretion in these subjects and whether it is associated with improved insulin sensitivity. TRIAL DESIGN: This was a double blind cross-over study with 16 weeks of pioglitazone 45 mg vs placebo involving 12 subjects. METHODS: At the end of each phase, body composition (anthropometric measurements, dual energy X-ray absorptometry (DEXA), abdominal CT), hepatic and muscle insulin sensitivity (2-step hyperinsulinemic euglycemic clamp with 2H2-glucose) were measured and fasting blood adipokines and cardiometabolic risk markers were monitored. RESULTS: Four months treatment with pioglitazone had no effect on total body weight or total fat but decreased the visceral/sub-cutaneous adipose tissue ratio by 16% and decreased the leptin/adiponectin (L/A) ratio from 3.63×10-3 to 0.76×10-3. This was associated with a 20% increase in hepatic insulin sensitivity without changes in muscle insulin sensitivity, a 12% increase in HDL cholesterol and a 50% decrease in CRP. CONCLUSIONS/LIMITATIONS: Pioglitazone significantly changes the visceral-subcutaneous fat distribution and plasma L/A ratio in non diabetic subjects on maintenance dialysis. This was associated with improved hepatic insulin sensitivity and a reduction of cardio-metabolic risk markers. Whether these effects may improve the outcome of non diabetic end-stage renal disease subjects on maintenance dialysis still needs further evaluation. TRIAL REGISTRATION: ClinicalTrial.gov NCT01253928.
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The optimal size-to-age at maturity depends on growth and mortality rates, which vary with environment. Therefore, organisms in spatially or temporaly changing environments should develop adaptative phenotypic plasticity for this trait. Experimental work by Alm (1959) on several fish species shows a dome-shape norm of reaction for size-to-age at maturity: size at maturity is smaller in both fast-growing and slow-growing fishes, than it is in fish with a medium growth rate. Using computer simulations, we show that such a dome-shaped norm of reaction is optimal when assuming a finite life span and a negative relationship between production and survival rates. This latter assumption is supported by empirical data, as well as by physiological and emographic arguments.
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OBJECTIVES: To examine the association between socioeconomic status (SES) and several cardiovascular disease risk factors (CVRFs) and to assess whether this association has changed over a 15-year observation period. METHODS: Three independent population-based surveys of CVRFs were conducted in representative samples of all adults aged 25-64 years in the Seychelles, a small island state located east to Kenya, in 1989 (N=1081), 1994 (N=1067) and 2004 (N=1255). RESULTS: Among men, current smoking and heavy drinking were more prevalent in the low versus the high SES group, and obesity was less prevalent. The socioeconomic gradient in diabetes reversed over the study period from lower prevalence in the low versus the high SES group to higher prevalence in the low SES group. Hypercholesterolemia was less prevalent in the low versus the high SES group in 1989 but the prevalence was similar in the two groups in 2004. Hypertension showed no consistent socioeconomic pattern. Among women, the SES gradient in smoking tended to reverse over time from lower prevalence in the low SES group to lower prevalence in the high SES group. Obesity and diabetes were more common in the low versus the high SES group over the study period. Heavy drinking, hypertension and hypercholesterolemia were not socially patterned among women. CONCLUSION: The prevalence of several CVRFs was higher in low versus high SES groups in a rapidly developing country in the African region, and an increase of the burden of these CVRFs in the most disadvantaged groups of the population was observed over the 15 years study period.
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Most studies about the higher-order dimensions to be considered in order to parsimoniously describe Personality Disorders (PDs) have identified between two and four factors but there is still no consensus about their exact number. In this context, the cultural stability of these structures might be a criterion to be considered. The aim of this study was to identify stable higher-order structures of PD traits in a French-speaking African and Swiss sample (N = 2,711). All subject completed the IPDE screening questionnaire. Using Everett's criterion and conducting a series of principal component analyses, a cross-culturally stable two- and four-factor structure were identified, associated with a total congruence coefficient of respectively .98 and .94 after Procrustes rotation. Moreover, these two structures were also highly replicable across the four African regions considered, North Africa, West Africa, Central Africa, and Mauritius, with a mean total congruence coefficient of respectively .97 and .87. The four-factor structure presented the advantage of being similar to Livesely's four components and of describing the ten PDs more accurately.