997 resultados para Trehalase essential groups


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Although increasing our knowledge of the properties of networks of cities is essential, these properties can be measured at the city level, and must be assessed by analyzing actor networks. The present volume focuses less on individual characteristics and more on the interactions of actors and institutions that create functional territories in which the structure of existing links constrains emerging links. Rather than basing explanations on external factors, the goal is to determine the extent to which network properties reflect spatial distributions and create local synergies at the meso level that are incorporated into global networks at the macro level where different geographical scales occur. The paper introduces the way to use the graphs structure to identify empirically relevant groups and levels that explain dynamics. It defines what could be called âeurooemulti-levelâeuro, âeurooemulti-scaleâeuro, or âeurooemultidimensionalâeuro networks in the context of urban geography. It explains how the convergence of the network multi-territoriality paradigm collaboratively formulated, and manipulated by geographers and computer scientists produced the SPANGEO project, which is exposed in this volume.

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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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OBJECTIVE: Nandrolone is an anabolic steroid widely used in several sports. The numerous nandrolone positive cases in the recent years (International Olympic Committee statistics) led to several studies in the antidoping field. Nevertheless, essential questions pertaining to nandrolone endogenous production, the effects of physical exercise on the excretion of nandrolone metabolites, and contamination from nutritional supplements must still be addressed. The purpose of this study was to evaluate the influence of exhaustive exercises on 19-norandrosterone (19-NA) and 19-noretiocholanolone (19-NE) urinary excretion rates after administration of labeled nandrolone. SETTING AND PARTICIPANTS: A total of 34 healthy male Caucasian volunteers from the Institute of Sports Sciences and Physical Education (University of Lausanne) applied to participate in the study. All subjects were free from any physical drug addiction and were instructed strictly to avoid any nutritional supplement or steroid before and during the study. The participants were randomly dispatched in 2 groups in a double-blind way: a placebo group and a group treated with C-labeled nandrolone. MAIN OUTCOME MEASUREMENTS: The urinary concentrations of the 2 main nandrolone metabolites, 19-NA and 19-NE, were measured using gas chromatography coupled with mass spectrometry. In addition, clinical parameters such as creatinine, total protein, and beta2-microglobuline levels were determined using immunologic assays. RESULTS: After an oral ingestion of a 25 mg 3,4-C2-nandrolone dose, followed by a second identical dose 24 hours later, 19-NA and 19-NE could be detected in the urine for a period of 6 days after the initial intake. Despite several interesting observations, the measurements were very scattered and did not appear to be significantly influenced by exercise sessions in the athlete population. CONCLUSIONS: The results of this study suggest that physical exercise cannot be considered as a reliable parameter that systematically affects nandrolone metabolite concentrations in the urine.

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The GTPases Rab3a and Rab27a and their effectors Granuphilin/Slp4 and Noc2 are essential regulators of neuroendocrine secretion. Chronic exposure of pancreatic beta-cells to supraphysiological glucose levels decreased selectively the expression of these proteins. This glucotoxic effect was mimicked by cAMP-raising agents and blocked by PKA inhibitors. We demonstrate that the transcriptional repressor ICER, which is induced in a PKA-dependent manner by chronic hyperglycemia and cAMP-raising agents, is responsible for the decline of the four genes. ICER overexpression diminished the level of Granuphilin, Noc2, Rab3a and Rab27a by binding to cAMP responsive elements located in the promoters of these genes and inhibited exocytosis of beta-cells in response to secretagogues. Moreover, the loss in the expression of the genes of the secretory machinery caused by glucose and cAMP-raising agents was prevented by an antisense construct that reduces ICER levels. We propose that induction of inappropriate ICER levels lead to defects in the secretory process of pancreatic beta-cells possibly contributing, in conjunction with other known deleterious effects of hyperglycemia, to defective insulin release in type 2 diabetes.

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RESUME Peu d'informations sont disponibles concernant la prévalence et les motifs de refus de la vaccination contre la grippe dans la population âgée. Le but de notre recherche était d'investiguer les vrais motifs de refus de la vaccination (c'est-à-dire pas uniquement les raisons de non-vaccination parfois indépendantes du patient lui- même) chez les personnes âgées. Tous les patients ambulatoires de plus de 65 ans consultant la Policlinique Médicale Universitaire (PMU) de Lausanne ou leur médecin traitant durant les périodes de vaccination contre la grippe 1999-2000 et 2000-2001 ont été inclus. Chaque patient recevait une information sur la grippe et ses complications, de même que sur la nécessité de la vaccination, son efficacité et ses effets seconda ires éventuels. En l'absence de contre-indication, la vaccination était proposée. En cas de refus, les motifs étaient investigués par une question ouverte. Sur 1398 sujets inclus, 148 (12%) ont refusé la vaccination. Les raisons principales de refus étaient la perception d'être en bonne santé (16%), de ne pas être susceptible à la grippe (15%) ou le fait de ne jamais avoir été vacciné contre la grippe dans le passé (15%). On retrouvait également la mauvaise expérience personnelle ou d'un proche lors d'une vaccination (15%) et l'impression d'inutilité du vaccin (10%). 17% des personnes interrogées ont donné des motifs autres et 12% n'ont pas explicité leur non-acceptation. Les refus de vaccination contre la grippe dans la population âgée sont essentiellement liés aux convictions intimes du patient quant à son état de santé et à sa susceptibilité à la grippe, de même qu'à l'efficacité supposée de la vaccination. La résistance au changement semble être un obstacle majeur à l'introduction de la vaccination chez les personnes de plus de 65 ans. SUMMARY More knowledge on the reasons for refusal of the influenza vaccine in elderly patients is essential to target groups for additional information, and hence improve coverage rate. The objective of the present study was to describe precisely the true motives for refusal. All patients aged over 64 who attended the Medical Outpatient Clinic, University of Lausanne, or their private practitioner's office during the 1999 and 2000 vaccination periods were included. Each patient was informed on influenza and its complications, as well as on the need for vaccination, its efficacy and adverse events. The vaccination was then proposed. In case of refusal, the reasons were investigated with an open question. Out of 1398 patients, 148 (12%) refused the vaccination. The main reasons for refusal were the perception of being in good health (16%), of not being susceptible to influenza (15%), of not having had the influenza vaccine in the past (15%), of having had a bad experience either personally or a relative (15%), and the uselessness of the vaccine (10%). Seventeen percent gave miscellaneous reasons and 12% no reason at all for refusal. Little epidemiological knowledge and resistance to change appear to be the major obstacles for wide acceptance of the vaccine by the elderly.

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The CD8alphabeta heterodimer is integral to the selection of the class I-restricted lineage in the thymus; however, the contribution of the CD8beta chain to coreceptor function is poorly understood. To understand whether the CD8beta membrane proximal stalk region played a role in coreceptor function, we substituted it with the corresponding sequence from the CD8alpha polypeptide and expressed the hybrid molecule in transgenic mice in place of endogenous CD8beta. Although the stalk-swapped CD8beta was expressed on the cell surface as a disulfide-bonded heterodimer at equivalent levels of expression to an endogenous CD8beta molecule, it failed to restore selection of CD8(+) class I MHC-restricted T cells and it altered the response of peripheral T cells. Thus, the stalk region of the CD8beta polypeptide has an essential role in ensuring functionality of the CD8alphabeta heterodimer and its replacement compromises the interaction of CD8 with peptide-MHC complexes.

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Purpose: The accurate estimation of total energy expenditure (TEE) is essential to allow the provision of nutritional requirements in patients treated by maintenance hemodialysis (MHD). The measurement of TEE and resting energy expenditure (REE) by direct or indirect calorimetry and doubly labeled water are complicated, timeconsuming and cumbersome in this population. Recently, a new system called SenseWear® armband (SWA) was developed to assess TEE, physical activity and REE. This device works by measurements of body acceleration in two axes, heat production and steps counts. REE measured by indirect calorimetry and SWA are well correlated. The aim of this study was to determine TEE, physical activity and REE on patients on MHD using this new device. Methods and materials: Daily TEE, REE, step count, activity time, intensity of activity and lying time were determined for 7 consecutive days in unselected stable patients on MHD and sex, age and weightmatched healthy controls (HC). Patients with malnutrition, cancer, use of immunosuppressive drugs, hypoalbumemia <35 g/L and those hospitalized in the last 3 months, were excluded. For MHD patients, separate analyses were conducted in dialysis and non-dialysis days. Relevant parameters known to affect REE, such as BMI, albumin, pre-albumin, hemoglobin, Kt/V, CRP, bicarbonate, PTH, TSH, were recorded. Results: Thirty patients on MHD and 30 HC were included. In MHD patients, there were 20 men and 10 women. Age was 60,13 years ± 14.97 (mean ± SD), BMI was 25.77 kg/m² ± 4.73 and body weight was 74.65 kg ± 16.16. There were no significant differences between the two groups. TEE was lower in MHD patients compared to HC (28.79 ± 5.51 SD versus 32.91 ± 5.75 SD kcal/kg/day; p <0.01). Activity time was significantly lower in patients on MHD (101.3 ± 12.6SD versus 50.7 ± 9.4 SD min; p = 0.0021). Energy expenditure during the time of activity was significantly lower in MHD patients. MHD patients walked 4543 ± 643 SD vs 8537 ± 744 SD steps per day (p <0.0001). Age was negatively correlated with TEE (r = -0.70) and intensity of activity (r = -0.61) in HC, but not in patients on MHD. TEE showed no difference between dialysis and non-dialysis days (29.92 ± 2.03 SD versus 28.44 ± 1.90 SD kcal/kg/day; p = NS), reflecting a lack of difference in activity (number of steps, time of physical activity) and REE. This finding was observed in MHD patients both older and younger than 60 years. However, age stratification appeared to have an influence on TEE, regardless of dialysis day, (29.92 ± 2.07 SD kcal/kg/day for <60 years-old versus 27.41 ± 1.04 SD kcal/kg/day for ≥60 years old), although failing to reach statistical significance. Conclusion: Using SWA, we have shown that stable patients on MHD have a lower TEE than matched HC. On average, a TEE of 28.79 kcal/kg/day, partially affected by age, was measured. This finding gives support to the clinical impression that it is difficult and probably unnecessary to provide an energy amount of 30-35 kcal/kg/day, as proposed by international guidelines for this population. In addition, we documented for the first time that MHD patients exert a reduced physical activity as compared to HC. There were surprisingly no differences in TEE, REE and physical activity parameters between dialysis and non-dialysis days. This observation might be due to the fact that patients on MHD produce a physical effort to reach the dialysis centre. Age per se did not influence physical activity in MHD patients, contrary to HC, reflecting the impact of co-morbidities on physical activity in this group of patients.

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EMBnet is a consortium of collaborating bioinformatics groups located mainly within Europe (http://www.embnet.org). Each member country is represented by a 'node', a group responsible for the maintenance of local services for their users (e.g. education, training, software, database distribution, technical support, helpdesk). Among these services a web portal with links and access to locally developed and maintained software is essential and different for each node. Our web portal targets biomedical scientists in Switzerland and elsewhere, offering them access to a collection of important sequence analysis tools mirrored from other sites or developed locally. We describe here the Swiss EMBnet node web site (http://www.ch.embnet.org), which presents a number of original services not available anywhere else.

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(from the journal abstract) Scientific interest for the concept of alliance has been maintained and stimulated by repeated findings that a strong alliance is associated with facilitative treatment process and favourable treatment outcome. However, because the alliance is not in itself a therapeutic technique, these findings were unsuccessful in bringing about significant improvements in clinical practice. An essential issue in modern psychotherapeutic research concerns the relation between common factors which are known to explain great variance in empirical results and the specific therapeutic techniques which are the primary basis of clinical training and practice. This pilot study explored sequences in therapist interventions over four sessions of brief psychodynamic investigation. It aims at determining if patterns of interventions can be found during brief psychodynamic investigation and if these patterns can be associated with differences in the therapeutic alliance. Therapist interventions where coded using the Psychodynamic Intervention Rating Scale (PIRS) which enables the classification of each therapist utterance into one of 9 categories of interpretive interventions (defence interpretation, transference interpretation), supportive interventions (question, clarification, association, reflection, supportive strategy) or interventions about the therapeutic frame (work-enhancing statement, contractual arrangement). Data analysis was done using lag sequential analysis, a statistical procedure which identifies contingent relationships in time among a large number of behaviours. The sample includes N = 20 therapist-patient dyads assigned to three groups with: (1) a high and stable alliance profile, (2) a low and stable alliance profile and (3) an improving alliance profile. Results suggest that therapists most often have one single intention when interacting with patients. Large sequences of questions, associations and clarifications were found, which indicate that if a therapist asks a question, clarifies or associates, there is a significant probability that he will continue doing so. A single theme sequence involving frame interventions was also observed. These sequences were found in all three alliance groups. One exception was found for mixed sequences of interpretations and supportive interventions. The simultaneous use of these two interventions was associated with a high or an improving alliance over the course of treatment, but not with a low and stable alliance where only single theme sequences of interpretations were found. In other words, in this last group, therapists were either supportive or interpretative, whereas with high or improving alliance, interpretations were always given along with supportive interventions. This finding provides evidence that examining therapist interpretation individually can only yield incomplete findings. How interpretations were given is important for alliance building. It also suggests that therapists should carefully dose their interpretations and be supportive when necessary in order to build a strong therapeutic alliance. And from a research point of view, to study technical interventions, we must look into dynamic variables such as dosage, the supportive quality of an intervention, and timing. (PsycINFO Database Record (c) 2005 APA, all rights reserved)

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The treatment of advanced prostate cancer (PCa) remains a challenge. Identification of new molecular mechanisms that regulate PCa initiation and progression would provide targets for the development of new cancer treatments. The Foxm1 transcription factor is highly up-regulated in tumor cells, inflammatory cells, and cells of tumor microenvironment. However, its functions in different cell populations of PCa lesions are unknown. To determine the role of Foxm1 in tumor cells during PCa development, we generated two novel transgenic mouse models, one exhibiting Foxm1 gain-of-function and one exhibiting Foxm1 loss-of-function under control of the prostate epithelial-specific Probasin promoter. In the transgenic adenocarcinoma mouse prostate (TRAMP) model of PCa that uses SV40 large T antigen to induce PCa, loss of Foxm1 decreased tumor growth and metastasis. Decreased prostate tumorigenesis was associated with a decrease in tumor cell proliferation and the down-regulation of genes critical for cell proliferation and tumor metastasis, including Cdc25b, Cyclin B1, Plk-1, Lox, and Versican. In addition, tumor-associated angiogenesis was decreased, coinciding with reduced Vegf-A expression. The mRNA and protein levels of 11β-Hsd2, an enzyme playing an important role in tumor cell proliferation, were down-regulated in Foxm1-deficient PCa tumors in vivo and in Foxm1-depleted TRAMP C2 cells in vitro. Foxm1 bound to, and increased transcriptional activity of, the mouse 11β-Hsd2 promoter through the -892/-879 region, indicating that 11β-Hsd2 was a direct transcriptional target of Foxm1. Without TRAMP, overexpression of Foxm1 either alone or in combination with inhibition of a p19(ARF) tumor suppressor caused a robust epithelial hyperplasia, but was insufficient to induce progression from hyperplasia to PCa. Foxm1 expression in prostate epithelial cells is critical for prostate carcinogenesis, suggesting that inhibition of Foxm1 is a promising therapeutic approach for prostate cancer chemotherapy.

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We present an agent-based model with the aim of studying how macro-level dynamics of spatial distances among interacting individuals in a closed space emerge from micro-level dyadic and local interactions. Our agents moved on a lattice (referred to as a room) using a model implemented in a computer program called P-Space in order to minimize their dissatisfaction, defined as a function of the discrepancy between the real distance and the ideal, or desired, distance between agents. Ideal distances evolved in accordance with the agent's personal and social space, which changed throughout the dynamics of the interactions among the agents. In the first set of simulations we studied the effects of the parameters of the function that generated ideal distances, and in a second set we explored how group macrolevel behavior depended on model parameters and other variables. We learned that certain parameter values yielded consistent patterns in the agents' personal and social spaces, which in turn led to avoidance and approaching behaviors in the agents. We also found that the spatial behavior of the group of agents as a whole was influenced by the values of the model parameters, as well as by other variables such as the number of agents. Our work demonstrates that the bottom-up approach is a useful way of explaining macro-level spatial behavior. The proposed model is also shown to be a powerful tool for simulating the spatial behavior of groups of interacting individuals.

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Little is known about the mechanisms that establish the position of the division plane in eukaryotic cells. Wild-type fission yeast cells divide by forming a septum in the middle of the cell at the end of mitosis. Dmf1 mutants complete mitosis and initiate septum formation, but the septa that form are positioned at random locations and angles in the cell, rather than in the middle. We have cloned the dmf1 gene as a suppressor of the cdc7-24 mutant. The dmf1 mutant is allelic with mid1. The gene encodes a novel protein containing a putative nuclear localization signal, and a carboxy-terminal PH domain. In wild-type cells, Dmf1p is nuclear during interphase, and relocates to form a medial ring at the cell cortex coincident with the onset of mitosis. This relocalization occurs before formation of the actin ring and is associated with increased phosphorylation of Dmf1p. The Dmf1p ring can be formed in the absence of an actin ring, but depends on some of the genes required for actin ring formation. When the septum is completed and the cells separate, Dmf1p staining is once again nuclear. These data implicate Dmf1p as an important element in assuring correct placement of the division septum in Schizosaccharomyces pombe cells.

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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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Wound healing proceeds by the concerted action of a variety of signals that have been well identified. However, the mechanisms integrating them and coordinating their effects are poorly known. Herein, we reveal how PPARbeta/delta (PPAR: peroxisome proliferator-activated receptor) follows a balanced pattern of expression controlled by a crosstalk between inflammatory cytokines and TGF-beta1. Whereas conditions that mimic the initial inflammatory events stimulate PPARbeta/delta expression, TGF-beta1/Smad3 suppresses this inflammation-induced PPARbeta/delta transcription, as seen in the late re-epithelialization/remodeling events. This TGF-beta1/Smad3 action involves an inhibitory effect on AP-1 activity and DNA binding that results in an inhibition of the AP-1-driven induction of the PPARbeta/delta promoter. As expected from these observations, wound biopsies from Smad3-null mice showed sustained PPARbeta expression as compared to those of their wild-type littermates. Together, these findings suggest a mechanism for setting the necessary balance between inflammatory signals, which trigger PPARbeta/delta expression, and TGF-beta1/Smad3 that governs the timely decrease of this expression as wound healing proceeds to completion.