209 resultados para High-through put screening
em Université de Lausanne, Switzerland
Resumo:
Mutations in the isocitrate dehydrogenase family genes 1 or 2 (IDH1/2) have been discovered by high through put sequencing approaches inglioma and acute myeloid leukemia (AML) and related myeloproliferativeneoplasms. In both diseases, the discovery of IDH mutations has identifieda prognostically new subtype with distinct pathogenetic evolution. Ingliomas mutations are mostly found in IDH1 (>90%). They are infrequent inprimary glioblastoma (GBM) (<10%), but common in secondary GBM thatevolve from lower grade glioma (60−90%). Mutations in IDH1 precede p53mutations or 1p/19q co-deletions in sporadic low grade glioma, hence arean early evant. Co-deletions of 1p/19q, characteristic for oligodenroglioma,are highly associated with IDH1/2 mutations, while they are mutuallyexclusive with EGFR amplifications, a hall mark of primary GBM. IDH1 or 2mutations are associated with younger patient age, but absent in childhoodgliomas, and have a better prognosis that seems to be consistent in gradeII through IV gliomas. In myeloid malignancies mutations are more likelyin IDH2 and are found in de novo and secondary AML (12−18%) andpre-leukemic clonal malignancies (5% chronic; 20% transformed). IDH1/2mutations are strongly associated with NPM1 mutations that are found in30% of novo cytogenetically normal AML. In CN-AML with mutated NPM1,without FLT3 internal tandem duplication (ITD) IDH mutations constitutean adverse prognostic factor. Mutations in the metabolic enzymes IDH1 or2 result in a neomorphic reaction, generating high levels of the metabolite2-hydroxyglutarate (2-HG). IDH mutations are mutually exclusive with TET2mutations in myeloid malignancies that led to the discovery that high levelsof 2-HG inhibit the a-KG dependent dioxygenase TET2. TET2 is involved inepigenetic regulation and mediates demethylation of DNA. This mechanismis in accordance with the association of a methylator phenotype with loss offunction of TET2 by mutation or indirectly by mutation of IDH1/2 in myeloidmalignancies and gliomas, respectively.Metabolism meets Epigenetics. These discoveries will have importantclinical implications: IDH1/2 mutants may serve as unique targets fortherapy. Further, the high concentrations of the onco-metabolite 2-HGgenerated by IDH1/2 mutants, may serve as biomarker in the serum ofpatients with myeloid malignancies and may be amenable by magneticresonance spectroscopy in glioma patients.
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BACKGROUND: Migration is one of the major causes of tuberculosis in developed countries. Undocumented patients are usually not screened at the border and are not covered by a health insurance increasing their risk of developing the disease unnoticed. Urban health centres could help identify this population at risk. The objective of this study is to assess the prevalence of latent tuberculosis infection (LTBI) and adherence to preventive treatment in a population of undocumented immigrant patients. METHODS: All consecutive undocumented patients that visited two urban healthcare centres for vulnerable populations in Lausanne, Switzerland for the first time were offered tuberculosis screening with an interferon-gamma assay. Preventive treatment was offered if indicated. Adherence to treatment was evaluated monthly over a nine month period. RESULTS: Of the 161 participants, 131 (81.4%) agreed to screening and 125 had complete examinations. Twenty-four of the 125 patients (19.2%; CI95% 12.7;27.2) had positive interferon-gamma assay results, two of which had active tuberculosis. Only five patients with LTBI completed full preventive treatments. Five others initiated the treatment but did not follow through. CONCLUSION: Screening for tuberculosis infection in this hard-to-reach population is feasible in dedicated urban clinics, and the prevalence of LTBI is high in this vulnerable population. However, the low adherence to treatment is an important public health concern, and new strategies are needed to address this problem.
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Scanty information, limited to selected areas of the country, is available on cancer mortality in Brazil. Age-standardized (world population) mortality rates between 1980 and 2004, derived from the WHO database, were computed for all cancers and 24 major cancer sites in Brazil. Joinpoint regression analyses were used to identify the significant changes in trends and estimate annual percent change (APC) in rates. Total cancer mortality rates increased over the last decade in men (APC = 0.5) to reach 101.2/100 000, and in women (APC = 0.3) to reach 71.3/100 000. In men, upward trends were observed for cancers of the oral cavity and pharynx with a rate of 5.9/100 000 in 2000-2004, intestines (whose rate, however was low, i.e. 7.6), prostate (12.2), and leukemias (3.4). Male lung cancer increased until 1993 (APC = 1.39) and decreased thereafter (APC = -0.29), with a relatively low rate of 16.2/100 000 in 2000-2004. In women, there were steady upward trends for cancers of the lung (APC = 2.3), reaching 6.2/100 000 in 2000-2004, and leukemias (2.5). Breast cancer mortality leveled off at around 10/100 000 in the last decade, whereas declines were observed for cancers of the uterus, whose rate (8.3) however, remained comparatively high. Declines were observed for stomach cancer in both sexes, with rates of 11.1 in men and 4.6 in women. In conclusion, the key issues of cancer mortality in Brazil are the high rates of head and neck cancers in men and (cervix) uterine cancer in women, that is, in principle cancers that are largely avoidable through prevention, screening, and early diagnosis.
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OBJECTIVE: Because of its high prevalence, early screening for occupational asthma (OA) is crucial. We aimed to evaluate the screening performance of the Occupational Asthma Screening Questionnaire-11 items (OASQ-11) in a clinical setting. METHODS: Between January 2009 and December 2011, 169 workers referred for potential OA to our hospital completed the OASQ-11 and underwent workups to determine the final diagnosis. The discriminative abilities of the OASQ-11 as a whole and in relation to demographic and exposure parameters were determined by the area under the receiving operator characteristic curve (AUC). RESULTS: Model 1, consisting of the OASQ's items, showed fair discrimination (AUC, 0.69; 95% confidence interval, 0.58 to 0.80). Addition of age and exposure duration to model 1 improved discrimination (AUC, 0.80; confidence interval, 0.72 to 0.88). CONCLUSION: A simple model consisting of the OASQ-11's items, age, and exposure duration could well discriminate subjects with OA in a clinical setting.
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OBJECTIVE: As universal screening of hypertension performs poorly in childhood, targeted screening to children at higher risk of hypertension has been proposed. Our goal was to assess the performance of combined parental history of hypertension and overweight/obesity to identify children with hypertension. We estimated the sensitivity, specificity, negative and positive predictive values of overweight/obesity and parental history of hypertension for the identification of hypertension in children. DESIGN AND METHOD: We analyzed data from a school-based cross-sectional study including 5207 children aged 10 to 14 years from all public 6th grade classes in the canton of Vaud, Switzerland. Blood pressure was measured with a clinically validated oscillometric automated device over up to three visits separated by one week. Children had hypertension if they had sustained elevated blood pressure over the three visits. Parents were interviewed about their history of hypertension. RESULTS: The prevalence of hypertension was 2.2%. 14% of children were overweight or obese and 20% had a positive history of hypertension in either or both parents. 30% of children had either or both conditions. After accounting for several potential confounding factors, parental history of hypertension (odds ratio (OR): 2.6; 95% confidence interval (CI): 1.8-4.0), overweight excluding obesity (OR: 2.5; 95% CI: 1.5-4.2) and obesity (OR: 10.1; 95% CI: 6.0-17.0) were associated with hypertension in children. Considered in isolation, the sensitivity and positive predictive values of parental history of hypertension (respectively 41% and 5%) or overweight/obesity (respectively 43% and 7%) were relatively low. Nevertheless, considered together, the sensitivity of targeted screening in children with either overweight/obesity or paternal history of hypertension was higher (65%) but the positive predictive value remained low (5%). The negative predictive value was systematically high. CONCLUSIONS: Restricting screening of hypertension to children with either overweight/obesity or with hypertensive parents would substantially limit the proportion of children to screen (30%) and allow the identification of a relatively large proportion (65%) of hypertensive cases. That could be a valuable alternative to universal screening.
Resumo:
In natural conditions, basidiomycete ectomycorrhizal fungi such as Laccaria bicolor are typically in the dikaryotic state when forming symbioses with trees, meaning that two genetically different individuals have to fuse or 'mate'. Nevertheless, nothing is known about the molecular mechanisms of mating in these ecologically important fungi. Here, advantage was taken of the first sequenced genome of the ectomycorrhizal fungus, Laccaria bicolor, to determine the genes that govern the establishment of cell-type identity and orchestrate mating. The L. bicolor mating type loci were identified through genomic screening. The evolutionary history of the genomic regions that contained them was determined by genome-wide comparison of L. bicolor sequences with those of known tetrapolar and bipolar basidiomycete species, and by phylogenetic reconstruction of gene family history. It is shown that the genes of the two mating type loci, A and B, are conserved across the Agaricales, but they are contained in regions of the genome with different evolutionary histories. The A locus is in a region where the gene order is under strong selection across the Agaricales. By contrast, the B locus is in a region where the gene order is likely under a low selection pressure but where gene duplication, translocation and transposon insertion are frequent.
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Morphogens of the Wnt protein family are the secreted lipoglycoprotein ligands which initiate several pathways heavily involved in the coordination of various developmental stages of organisms in the majority of animal species. Deregulation of these pathways in the adult leads to formation and sustaining of multiple types of cancer. The latter notion is reinforced by the fact that the very discovery of the first Wnt ligand was due to its role as the causative factor of carcinogenic transformation (Nusse and Varmus, 1982). Nowadays our knowledge on Wnt signaling has "moved with the times" and these pathways were identified to be often crucial for tumor formation, its interactions with the microenvironment, and promotion of the metastases (Huang and Du, 2008; Zerlin et al., 2008; Jessen, 2009). Thus the relevance of the pathway as the target for drug development has further increased in the light of modern paradigms of the complex cancer treatments which target also spreading and growth- promoting factors of tumors by specific and highly efficient substances (Pavet et al., 2010). Presently the field of the Wnt-targeting drug research is almost solely dominated by assays based on transcriptional activation induced by the signaling. This approach resulted in development of a number of promising substances (Lee et al., 2011). Despite its effectiveness, the method nevertheless suffers from several drawbacks. Among the major ones is the fact that this approach is prone to identify compounds targeting rather downstream effectors of the pathway, which are indiscriminately used by all the subtypes of the Wnt signaling. Additionally, proteins which are involved in several signaling cascades and not just the Wnt pathway turn out as targets of the new compounds. These issues increase risks of side effects due to off-target interactions and blockade of the pathway in healthy cells. In the present work we put forward a novel biochemical approach for drug development on the Wnt pathway. It targets Frizzleds (Fzs) - a family of 7-transmbembrane proteins which serve as receptors for Wnt ligands. They offer unique properties for the development of highly specific and effective drugs as they control all branches of the Wnt signaling. Recent advances in the understanding of the roles of heterotrimeric G proteins downstream from Fzs (Katanaev et al., 2005; Liu et al., 2005; Jernigan et al., 2010) suggest application of enzymatic properties of these effectors to monitor the receptor-mediated events. We have applied this knowledge in practice and established a specific and efficient method based on utilization of a novel high-throughput format of the GTP-binding assay to follow the activation of Fzs. This type of assay is a robust and well-established technology for the research and screenings on the GPCRs (Harrison and Traynor, 2003). The conventional method of detection involves the radioactively labeled non-hydrolysable GTP analog [35S]GTPyS. Its application in the large-scale screenings is however problematic which promoted development of the novel non-radioactive GTP analog GTP-Eu. The new molecule employs phenomenon of the time-resolved fluorescence to provide sensitivity comparable to the conventional radioactive substance. Initially GTP-Eu was tested only in one of many possible types of GTP-binding assays (Frang et al., 2003). In the present work we expand these limits by demonstrating the general comparability of the novel label with the radioactive method in various types of assays. We provide a biochemical characterization of GTP-Eu interactions with heterotrimeric and small GTPases and a comparative analysis of the behavior of the new label in the assays involving heterotrimeric G protein effectors. These developments in the GTP-binding assay were then applied to monitor G protein activation by the Fz receptors. The data obtained in mammalian cultured cell lines provides for the first time an unambiguous biochemical proof for direct coupling of Fzs with G proteins. The specificity of this interaction has been confirmed by the experiments with the antagonists of Fz and by the pertussis toxin-mediated deactivation. Additionally we have identified the specificity of Wnt3a towards several members of the Fz family and analyzed the properties of human Fz-1 which was found to be the receptor coupled to the Gi/o family of G proteins. Another process playing significant role in the functioning of every GPCR is endocytosis. This phenomenon can also be employed for drug screenings on GPCRs (Bickle, 2010). In the present work we have demonstrated that Drosophila Fz receptors are involved in an unusual for many GPCRs manifestation of the receptor-mediated internalization. Through combination of biochemical approaches and studies on Drosophila as the model organism we have shown that direct interactions of the Fzs and the α-subunit of the heterotrimeric G protein Go with the small GTPase Rab5 regulate internalization of the receptor in early endosomes. We provide data uncovering the decisive role of this self-promoted endocytosis in formation of a proper signaling output in the canonical as well as planar cell polarity (PCP) pathways regulated by Fz. The results of this work thus establish a platform for the high-throughput screening to identify substances active in the cancer-related Wnt pathways. This methodology has been adjusted and applied to provide the important insights in Fz functioning and will be instrumental for further investigations on the Wnt-mediated pathways.
High prevalence of osteoporosis in Swiss women aged 60 and older: a 2-year pilot screening campaign.
Resumo:
Background: Osteoporosis (OP) is frequent in postmenopausal women, but remains underdiagnosed and undertreated. In Switzerland, DXA is not reimbursed by the insurances for screening, even if it is recommended to test women's Bone Mineral Density (BMD) at the age of 65. Methods: To assess the feasibility of a screening program for OP, the Bone diseases center of Lausanne has been mandated to perform a 2-year information and screening campaign (3 days per months) for women age 60 and older through the state of Vaud using a mobile unit for bone assessment. This project is still ongoing. Women are informed by media for dates and screening locations. Appointments are taken by phone. Women known for osteoporosis or already treated are excluded. During the evaluation every women is assessed by a questionnaire for risk factors, by a DXA measurement (Discovery C, Hololgic), and by Vertebral Fracture Assessment (VFA) for Genant's grades 2 and 3 prevalent vertebral fractures (VF). Women are considered at high risk of fracture if they have a hip fracture, a VF, another fragility fracture with a BMD T-score ≤-2 or a BMD T-score ≤-2.5. Results: After 17 months (50 days of screening), 752 women were assessed, mean age 66±6 yrs, mean BMI 26±5 kg/m2, mean lowest T-score -1.6±1.0 SD. 215 women (29%) were considered at high risk, 92 of them (12%) having established OP and 50 (7%) having one or more fragility VF. VF were unknown for 83% of the women and discovered by VFA. The number needed to screen (NNS) were 3.5 for high risk women, 8.2 for established OP and 15 for VF. Conclusions: After near ¾ of the project, prevalence of women at high risk of fracture was high, with a NNS below 4. Knowing the global cost of OP and that current treatment have a high efficacy for fracture risk reduction, such a screening program could have a positive economic impact. VFA allowed discovering many women with unknown VF, who were at very high risk of further fractures. A systematic screening for VF should be added to BMD measurements after the age of 60.
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Indoleamine 2,3-dioxygenase 1 (IDO1) is a key regulator of immune responses and therefore an important therapeutic target for the treatment of diseases that involve pathological immune escape, such as cancer. Here, we describe a robust and sensitive high-throughput screen (HTS) for IDO1 inhibitors using the Prestwick Chemical Library of 1200 FDA-approved drugs and the Maybridge HitFinder Collection of 14,000 small molecules. Of the 60 hits selected for follow-up studies, 14 displayed IC50 values below 20 μM under the secondary assay conditions, and 4 showed an activity in cellular tests. In view of the high attrition rate we used both experimental and computational techniques to identify and to characterize compounds inhibiting IDO1 through unspecific inhibition mechanisms such as chemical reactivity, redox cycling, or aggregation. One specific IDO1 inhibitor scaffold, the imidazole antifungal agents, was chosen for rational structure-based lead optimization, which led to more soluble and smaller compounds with micromolar activity.
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The potential and applicability of UHPSFC-MS/MS for anti-doping screening in urine samples were tested for the first time. For this purpose, a group of 110 doping agents with diverse physicochemical properties was analyzed using two separation techniques, namely UHPLC-MS/MS and UHPSFC-MS/MS in both ESI+ and ESI- modes. The two approaches were compared in terms of selectivity, sensitivity, linearity and matrix effects. As expected, very diverse retentions and selectivities were obtained in UHPLC and UHPSFC, proving a good complementarity of these analytical strategies. In both conditions, acceptable peak shapes and MS detection capabilities were obtained within 7min analysis time, enabling the application of these two methods for screening purposes. Method sensitivity was found comparable for 46% of tested compounds, while higher sensitivity was observed for 21% of tested compounds in UHPLC-MS/MS and for 32% in UHPSFC-MS/MS. The latter demonstrated a lower susceptibility to matrix effects, which were mostly observed as signal suppression. In the case of UHPLC-MS/MS, more serious matrix effects were observed, leading typically to signal enhancement and the matrix effect was also concentration dependent, i.e., more significant matrix effects occurred at the lowest concentrations.
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ABSTRACT The drug discovery process has been profoundly changed recently by the adoption of computational methods helping the design of new drug candidates more rapidly and at lower costs. In silico drug design consists of a collection of tools helping to make rational decisions at the different steps of the drug discovery process, such as the identification of a biomolecular target of therapeutical interest, the selection or the design of new lead compounds and their modification to obtain better affinities, as well as pharmacokinetic and pharmacodynamic properties. Among the different tools available, a particular emphasis is placed in this review on molecular docking, virtual high throughput screening and fragment-based ligand design.
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The introduction of Next Generation Sequencing (NGS) facilitated the task of localizing DNA variation and identifying the genetic cause of yet unsolved Mendelian disorders. Using Whole Exome Capture method and NGS, we identified the causative genetic aberration responsible for a number of monogenic disorders previously undetermined. Due to the novelty of the NGS method we benchmarked different algorithms to assess their merits and defects. This allowed us to establish a pipeline that we successfully used to pinpoint genes responsible for a form of West's syndrome, a Complex Intellectual Disability syndrome associated with patellar dislocation and celiac disease, and correcting some erroneous molecular diagnosis of Alport's syndrome in a Saudi Arabian family.
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When subjects studied at school are close to societal discourses and to the students' social identities, when they have high emotional resonance, is it possible to enable the students to distance themselves from their emotions and personal experience, and to conceptualise them? Examining the relation between emotion and learning through the lens of socio-cultural psychology, the aim of our study was to shed light on "secondarisation" processes, that is, processes that transform personal experience and emotions into conceptualised forms of thinking. We analysed 85 video-recorded lessons in education for cultural diversity involving 12 teachers (of primary and secondary schools). Having identified episodes in which emotions were put into words or personal experience was reported, we analysed the use of pronouns (taken as indicators of secondarisation processes) and found a recurrent pattern: "the unicity-genericity routine". We illustrate the functioning of this routine with various excerpts taken from lessons in education for diversity taught in the classes of two teachers in primary school. The results show that the interplay between unicity and genericity works as a discursive resource for the development of secondarisation processes.
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Mothers' general anxiety, anxiety about the well-being of the child and psychological stress before prenatal testing was studied by comparing women who conceived through in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) with women who conceived naturally. Before the first trimester screening test for Down's syndrome, a group of 51 women who conceived through IVF/ICSI and a group of 54 women who conceived spontaneously completed the State Scale of the State-Trait Anxiety Inventory (S-Anxiety; Spielberger, 1983), the Fear of Bearing a Physically or Mentally Handicapped Child Subscale of the Pregnancy-related Anxiety Questionnaire (PRAQ-R; Huizink et al., 2004), the Psychological Stress Measure (PSM; Lemyre & Tessier, 1988), and the Prenatal Psychosocial Profile (PPP; Curry, Campbell, & Christian, 1994). Women who conceived through IVF/ICSI had more elevated levels of general anxiety and psychological stress than the women who conceived naturally; however, no difference was observed between the two groups for anxiety specifically related to the health of the child. These results underline the need to monitor women's emotional state after conception via IVF/ICSI-when counseling usually ends-and around the time of the first trimester screening. Counseling might thus be extended.
Resumo:
BACKGROUND: Community-based diabetes screening programs can help sensitize the population and identify new cases. However, the impact of such programs is rarely assessed in high-income countries, where concurrent health information and screening opportunities are common place. INTERVENTION AND METHODS: A 2-week screening and awareness campaign was organized as part of a new diabetes program in the canton of Vaud (population of 697,000) in Switzerland. Screening was performed without appointment in 190 out of 244 pharmacies in the canton at the subsidized cost of 10 Swiss Francs per participant. Screening included questions on risk behaviors, measurement of body mass index, blood pressure, blood cholesterol, random blood glucose (RBG), and A1c if RBG was >/=7.0 mmol/L. A mass media campaign promoting physical activity and a healthy diet was channeled through several media, eg, 165 spots on radio, billboards in 250 public places, flyers in 360 public transport vehicles, and a dozen articles in several newspapers. A telephone survey in a representative sample of the population of the canton was performed after the campaign to evaluate the program. RESULTS: A total of 4222 participants (0.76% of all persons aged >/=18 years) underwent the screening program (median age: 53 years, 63% females). Among participants not treated for diabetes, 3.7% had RBG >/= 7.8 mmol/L and 1.8% had both RBG >/= 7.0 mmol/L and A1c >/= 6.5. Untreated blood pressure >/=140/90 mmHg and/or untreated cholesterol >/=5.2 mmol/L were found in 50.5% of participants. One or several treated or untreated modifiable risk factors were found in 78% of participants. The telephone survey showed that 53% of all adults in the canton were sensitized by the campaign. Excluding fees paid by the participants, the program incurred a cost of CHF 330,600. CONCLUSION: A community-based screening program had low efficiency for detecting new cases of diabetes, but it identified large numbers of persons with elevated other cardiovascular risk factors. Our findings suggest the convenience of A1c for mass screening of diabetes, the usefulness of extending diabetes screening to other cardiovascular risk factors, and the importance of a robust background communication campaign.