24 resultados para Amin, Samir
em BORIS: Bern Open Repository and Information System - Berna - Suiça
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Recent advances have revealed that during exogenous airway challenge, airway diameters can not be adequately predicted by their initial diameters. Furthermore, airway diameters can also vary greatly in time on scales shorter than a breath. In order to better understand these phenomena, we developed a multiscale model which allows us to simulate aerosol challenge in the airways during ventilation. The model incorporates agonist-receptor binding kinetics to govern the temporal response of airway smooth muscle (ASM) contraction on individual airway segments, which together with airway wall mechanics, determines local airway caliber. Global agonist transport and deposition is coupled with pressure-driven flow, linking local airway constrictions with global flow dynamics. During the course of challenge, airway constriction alters the flow pattern, redistributing agonist to less constricted regions. This results in a negative feedback which may be a protective property of the normal lung. As a consequence, repetitive challenge can cause spatial constriction patterns to evolve in time, resulting in a loss of predictability of airway diameters. Additionally, the model offers new insight into several phenomena including the intra- and inter-breath dynamics of airway constriction throughout the tree structure.
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ABSTRACT:
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We propose an innovative, integrated, cost-effective health system to combat major non-communicable diseases (NCDs), including cardiovascular, chronic respiratory, metabolic, rheumatologic and neurologic disorders and cancers, which together are the predominant health problem of the 21st century. This proposed holistic strategy involves comprehensive patient-centered integrated care and multi-scale, multi-modal and multi-level systems approaches to tackle NCDs as a common group of diseases. Rather than studying each disease individually, it will take into account their intertwined gene-environment, socio-economic interactions and co-morbidities that lead to individual-specific complex phenotypes. It will implement a road map for predictive, preventive, personalized and participatory (P4) medicine based on a robust and extensive knowledge management infrastructure that contains individual patient information. It will be supported by strategic partnerships involving all stakeholders, including general practitioners associated with patient-centered care. This systems medicine strategy, which will take a holistic approach to disease, is designed to allow the results to be used globally, taking into account the needs and specificities of local economies and health systems.
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Bladder urothelial carcinoma is typically a disease of older individuals and rarely occurs below the age of 40 years. There is debate and uncertainty in the literature regarding the clinicopathologic characteristics of bladder urothelial neoplasms in younger patients compared with older patients, although no consistent age criteria have been used to define "younger" age group categories. Use of the World Health Organization 2004/International Society of Urological Pathology 1998 grading nomenclature and recent molecular studies highlight certain unique features of bladder urothelial neoplasms in young patients, particularly in patients below 20 years of age. In this meta-analysis and review, the clinical, pathologic, and molecular features and risk factors of bladder urothelial neoplasms in patients 40 years or less are presented and analyzed according to decades of presentation. Similar to older patients, bladder urothelial neoplasms in patients 40 years or younger occur more common in male patients, present mainly with gross painless hematuria, and are more commonly located at bladder trigone/ureteral orifices, but in contrast have a greater chance for unifocality. Delay in diagnosis of bladder urothelial neoplasms seems not to be uncommon in younger patients probably because of its relative rarity and the predominance of benign causes of hematuria in this age group causing hesitancy for an aggressive work-up. Most tumors in patients younger than 40 years were low grade. The incidence of low-grade tumors was the lowest in the first 2 decades of life, with incremental increase of the percentage of high-grade tumors with increasing age decades. Classification according to the World Health Organization 2004/International Society of Urological Pathology grading system identified papillary urothelial neoplasms of low malignant potential to be relatively frequent among bladder tumors of young patients particularly in the teenage years. Similar to grade, there was marked predominance of low stage tumors in the first 2 decades of life with gradual inclusion of few higher stage and metastatic tumors in the 2 older decades. Bladder urothelial neoplasms occurring in patients <20 years of age lack or have a much lower incidence of aberrations in chromosome 9, FGFR3, p53, and microsatellite instability and have fewer epigenetic alterations. Tumor recurrence and deaths were infrequent in the first 2 decades and increased gradually in each successive decade, likely influenced by the increased proportion of higher grade and higher stage tumors. Our review of the literature shows that urothelial neoplasms of the bladder occurring in young patients exhibit unique pathologic and molecular features that translate to its more indolent behavior; this distinction is most pronounced in patients <20 years. Our overall inferences have potential implications for choosing appropriate noninvasive diagnostic and surveillance modalities, whenever feasible, and for selecting suitable treatment strategies that factor in quality of life issues vital to younger patients.
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Prediction of clinical outcome in cancer is usually achieved by histopathological evaluation of tissue samples obtained during surgical resection of the primary tumor. Traditional tumor staging (AJCC/UICC-TNM classification) summarizes data on tumor burden (T), presence of cancer cells in draining and regional lymph nodes (N) and evidence for metastases (M). However, it is now recognized that clinical outcome can significantly vary among patients within the same stage. The current classification provides limited prognostic information, and does not predict response to therapy. Recent literature has alluded to the importance of the host immune system in controlling tumor progression. Thus, evidence supports the notion to include immunological biomarkers, implemented as a tool for the prediction of prognosis and response to therapy. Accumulating data, collected from large cohorts of human cancers, has demonstrated the impact of immune-classification, which has a prognostic value that may add to the significance of the AJCC/UICC TNM-classification. It is therefore imperative to begin to incorporate the 'Immunoscore' into traditional classification, thus providing an essential prognostic and potentially predictive tool. Introduction of this parameter as a biomarker to classify cancers, as part of routine diagnostic and prognostic assessment of tumors, will facilitate clinical decision-making including rational stratification of patient treatment. Equally, the inherent complexity of quantitative immunohistochemistry, in conjunction with protocol variation across laboratories, analysis of different immune cell types, inconsistent region selection criteria, and variable ways to quantify immune infiltration, all underline the urgent requirement to reach assay harmonization. In an effort to promote the Immunoscore in routine clinical settings, an international task force was initiated. This review represents a follow-up of the announcement of this initiative, and of the J Transl Med. editorial from January 2012. Immunophenotyping of tumors may provide crucial novel prognostic information. The results of this international validation may result in the implementation of the Immunoscore as a new component for the classification of cancer, designated TNM-I (TNM-Immune).
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The CIAO Study ("Complicated Intra-Abdominal infection Observational" Study) is a multicenter investigation performed in 68 medical institutions throughout Europe over the course of a 6-month observational period (January-June 2012).Patients with either community-acquired or healthcare-associated complicated intra-abdominal infections (IAIs) were included in the study.2,152 patients with a mean age of 53.8 years (range: 4-98 years) were enrolled in the study. 46.3% of the patients were women and 53.7% were men. Intraperitoneal specimens were collected from 62.2% of the enrolled patients, and from these samples, a variety of microorganisms were collectively identified.The overall mortality rate was 7.5% (163/2.152).According to multivariate analysis of the compiled data, several criteria were found to be independent variables predictive of patient mortality, including patient age, the presence of an intestinal non-appendicular source of infection (colonic non-diverticular perforation, complicated diverticulitis, small bowel perforation), a delayed initial intervention (a delay exceeding 24 hours), sepsis and septic shock in the immediate post-operative period, and ICU admission.Given the sweeping geographical distribution of the participating medical centers, the CIAO Study gives an accurate description of the epidemiological, clinical, microbiological, and treatment profiles of complicated intra-abdominal infections (IAIs) throughout Europe.
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The CIAO Study is a multicenter observational study currently underway in 66 European medical institutions over the course of a six-month study period (January-June 2012).This preliminary report overviews the findings of the first half of the study, which includes all data from the first three months of the six-month study period.Patients with either community-acquired or healthcare-associated complicated intra-abdominal infections (IAIs) were included in the study.912 patients with a mean age of 54.4 years (range 4-98) were enrolled in the study during the first three-month period. 47.7% of the patients were women and 52.3% were men. Among these patients, 83.3% were affected by community-acquired IAIs while the remaining 16.7% presented with healthcare-associated infections. Intraperitoneal specimens were collected from 64.2% of the enrolled patients, and from these samples, 825 microorganisms were collectively identified.The overall mortality rate was 6.4% (58/912). According to univariate statistical analysis of the data, critical clinical condition of the patient upon hospital admission (defined by severe sepsis and septic shock) as well as healthcare-associated infections, non-appendicular origin, generalized peritonitis, and serious comorbidities such as malignancy and severe cardiovascular disease were all significant risk factors for patient mortality.White Blood Cell counts (WBCs) greater than 12,000 or less than 4,000 and core body temperatures exceeding 38°C or less than 36°C by the third post-operative day were statistically significant indicators of patient mortality.
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INTRODUCTION: The presence of an ectopic posterior pituitary gland (EPP) on magnetic resonance imaging (MRI) is associated with hypopituitarism with one or more hormone deficiencies. We aimed to identify risk factors for having multiple pituitary hormone deficiency (MPHD) compared to isolated growth hormone deficiency (IGHD) in patients with an EPP. METHODS: In 67 patients (45 male) with an EPP on MRI, the site (hypothalamic vs. stalk) and surface area (SA) [ x (maximum diameter/2) x (maximum height/2), mm(2)] of the EPP were recorded and compared in patients with IGHD and MPHD in relation to clinical characteristics. RESULTS: In MPHD (n = 32) compared to IGHD (n = 35) patients: age of presentation was younger (1.4 [0.1-10.7]vs. 4.0 [0.1-11.3] years, P = 0.005), major incidents during pregnancy were increased (47%vs. 20%, P = 0.02) as were admissions to a neonatal intensive care unit (NICU) (60%vs. 26%, P = 0.04), whilst EPP SA was lower (12.3 [2.4-34.6]vs. 25.7 [6.9-48.2] mm(2), P < 0.001). In patients with a hypothalamic (n = 56) compared to a stalk sited EPP (n = 11): prevalence of MPHD was greater (55%vs. 9%,P = 0.05) and EPP surface area was smaller (17.3 [2.4-48.2]vs. 25.3 [11.8-38.5] mm(2), P < 0.001). In regression analysis, after adjusting for age, presence of MPHD was associated with: major incidents during pregnancy (RR 6.8 [95%CI 1.2-37.7]), hypothalamic EPP site (RR 10.9 [1.0-123.9]) and small EPP SA (RR 2.5 [1.0-5.0] for tertiles of SA). CONCLUSION: In patients with an EPP, adverse antenatal events, size (small) and position (hypothalamic) of the posterior pituitary gland on MRI were associated with MPHD. These findings suggest that adverse factors during pregnancy may be important for the development of an EPP.
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Aim: We examined cellular uptake mechanisms of fluorescently labeled polymer-coated gold nanoparticles (NPs) under different biological conditions by two quantitative, microscopic approaches. Materials & methods: Uptake mechanisms were evaluated using endocytotic inhibitors that were tested for specificity and cytotoxicity. Cellular uptake of gold NPs was analyzed either by laser scanning microscopy or transmission electron microscopy, and quantified by means of stereology using cells from the same experiment. Results: Optimal inhibitor conditions were only achieved with chlorpromazine (clathrin-mediated endocytosis) and methyl-β-cyclodextrin (caveolin-mediated endocytosis). A significant methyl-β-cyclodextrin-mediated inhibition (63-69%) and chlorpromazine-mediated increase (43-98%) of intracellular NPs was demonstrated with both imaging techniques, suggesting a predominant uptake via caveolin-medicated endocytois. Transmission electron microscopy imaging revealed more than 95% of NPs localized in intracellular vesicles and approximately 150-times more NP events/cell were detected than by laser scanning microscopy. Conclusion: We emphasize the importance of studying NP-cell interactions under controlled experimental conditions and at adequate microscopic resolution in combination with stereology. Original submitted 10 July 2012; Revised submitted 23 January 2013.
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Background: Patients presenting to the emergency department (ED) currently face inacceptable delays in initial treatment, and long, costly hospital stays due to suboptimal initial triage and site-of-care decisions. Accurate ED triage should focus not only on initial treatment priority, but also on prediction of medical risk and nursing needs to improve site-of-care decisions and to simplify early discharge management. Different triage scores have been proposed, such as the Manchester triage system (MTS). Yet, these scores focus only on treatment priority, have suboptimal performance and lack validation in the Swiss health care system. Because the MTS will be introduced into clinical routine at the Kantonsspital Aarau, we propose a large prospective cohort study to optimize initial patient triage. Specifically, the aim of this trial is to derive a three-part triage algorithm to better predict (a) treatment priority; (b) medical risk and thus need for in-hospital treatment; (c) post-acute care needs of patients at the most proximal time point of ED admission. Methods/design: Prospective, observational, multicenter, multi-national cohort study. We will include all consecutive medical patients seeking ED care into this observational registry. There will be no exclusions except for non-adult and non-medical patients. Vital signs will be recorded and left over blood samples will be stored for later batch analysis of blood markers. Upon ED admission, the post-acute care discharge score (PACD) will be recorded. Attending ED physicians will adjudicate triage priority based on all available results at the time of ED discharge to the medical ward. Patients will be reassessed daily during the hospital course for medical stability and readiness for discharge from the nurses and if involved social workers perspective. To assess outcomes, data from electronic medical records will be used and all patients will be contacted 30 days after hospital admission to assess vital and functional status, re-hospitalization, satisfaction with care and quality of life measures. We aim to include between 5000 and 7000 patients over one year of recruitment to derive the three-part triage algorithm. The respective main endpoints were defined as (a) initial triage priority (high vs. low priority) adjudicated by the attending ED physician at ED discharge, (b) adverse 30 day outcome (death or intensive care unit admission) within 30 days following ED admission to assess patients risk and thus need for in-hospital treatment and (c) post acute care needs after hospital discharge, defined as transfer of patients to a post-acute care institution, for early recognition and planning of post-acute care needs. Other outcomes are time to first physician contact, time to initiation of adequate medical therapy, time to social worker involvement, length of hospital stay, reasons fordischarge delays, patient’s satisfaction with care, overall hospital costs and patients care needs after returning home. Discussion: Using a reliable initial triage system for estimating initial treatment priority, need for in-hospital treatment and post-acute care needs is an innovative and persuasive approach for a more targeted and efficient management of medical patients in the ED. The proposed interdisciplinary , multi-national project has unprecedented potential to improve initial triage decisions and optimize resource allocation to the sickest patients from admission to discharge. The algorithms derived in this study will be compared in a later randomized controlled trial against a usual care control group in terms of resource use, length of hospital stay, overall costs and patient’s outcomes in terms of mortality, re-hospitalization, quality of life and satisfaction with care.
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BACKGROUND The treatment and outcomes of patients with human immunodeficiency virus (HIV)-associated Hodgkin lymphoma (HL) continue to evolve. The International Prognostic Score (IPS) is used to predict the survival of patients with advanced-stage HL, but it has not been validated in patients with HIV infection. METHODS This was a multi-institutional, retrospective study of 229 patients with HIV-associated, advanced-stage, classical HL who received doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD) plus combination antiretroviral therapy. Their clinical characteristics were presented descriptively, and multivariate analyses were performed to identify the factors that were predictive of response and prognostic of progression-free survival (PFS) and overall survival (OS). RESULTS The overall and complete response rates to ABVD in patients with HIV-associated HL were 91% and 83%, respectively. After a median follow-up of 5 years, the 5-year PFS and OS rates were 69% and 78%, respectively. In multivariate analyses, there was a trend toward an IPS score >3 as an adverse factor for PFS (hazard ratio [HR], 1.49; P=.15) and OS (HR, 1.84; P=.06). A cluster of differentiation 4 (CD4)-positive (T-helper) cell count <200 cells/μL was associated independently with both PFS (HR, 2.60; P=.002) and OS (HR, 2.04; P=.04). The CD4-positive cell count was associated with an increased incidence of death from other causes (HR, 2.64; P=.04) but not with death from HL-related causes (HR, 1.55; P=.32). CONCLUSIONS The current results indicate excellent response and survival rates in patients with HIV-associated, advanced-stage, classical HL who receive ABVD and combination antiretroviral therapy as well as the prognostic value of the CD4-positive cell count at the time of lymphoma diagnosis for PFS and OS. Cancer 2014. © 2014 American Cancer Society.
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BACKGROUND Exposure to food allergens through a disrupted skin barrier has been recognized as a potential factor in the increasing prevalence of food allergy. OBJECTIVE We sought to test the immunologic mechanisms by which epicutaneous sensitization to food allergens predisposes to intestinal food allergy. METHODS Mice were epicutaneously sensitized with ovalbumin or peanut on an atopic dermatitis-like skin lesion, followed by intragastric antigen challenge. Antigen-specific serum IgE levels and T(H)2 cytokine responses were measured by ELISA. Expression of type 2 cytokines and mast cell proteases in the intestine were measured by using real-time PCR. Accumulation of basophils in the skin and mast cells in the intestine was examined by using flow cytometry. In vivo basophil depletion was achieved by using diphtheria toxin treatment of Baso-DTR mice. For cell-transfer studies, the basophil population was expanded in vivo by means of hydrodynamic tail vein injection of thymic stromal lymphopoietin (TSLP) cDNA plasmid. RESULTS Sensitization to food allergens through an atopic dermatitis-like skin lesion is associated with an expansion of TSLP-elicited basophils in the skin that promote antigen-specific T(H)2 cytokine responses, increased antigen-specific serum IgE levels, and accumulation of mast cells in the intestine, promoting the development of intestinal food allergy. Critically, disruption of TSLP responses or depletion of basophils reduced the susceptibility to intestinal food allergy, whereas transfer of TSLP-elicited basophils into intact skin promoted disease. CONCLUSION Epicutaneous sensitization on a disrupted skin barrier is associated with accumulation of TSLP-elicited basophils, which are necessary and sufficient to promote antigen-induced intestinal food allergy.
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Introduction In our program, simulated patients (SPs) give feedback to medical students in the course of communication skills training. To ensure effective training, quality control of the SPs’ feedback should be implemented. At other institutions, medical students evaluate the SPs’ feedback for quality control (Bouter et al., 2012). Thinking about implementing quality control for SPs’ feedback in our program, we wondered whether the evaluation by students would result in the same scores as evaluation by experts. Methods Consultations simulated by 4th-year medical students with SPs were video taped including the SP’s feedback to the students (n=85). At the end of the training sessions students rated the SPs’ performance using a rating instrument called Bernese Assessment for Role-play and Feedback (BARF) containing 11 items concerning feedback quality. Additionally the videos were evaluated by 3 trained experts using the BARF. Results The experts showed a high interrater agreement when rating identical feedbacks (ICCunjust=0.953). Comparing the rating of students and experts, high agreement was found with regard to the following items: 1. The SP invited the student to reflect on the consultation first, Amin (= minimal agreement) 97% 2. The SP asked the student what he/she liked about the consultation, Amin = 88%. 3. The SP started with positive feedback, Amin = 91%. 4. The SP was comparing the student with other students, Amin = 92%. In contrast the following items showed differences between the rating of experts and students: 1. The SP used precise situations for feedback, Amax (=maximal agreement) 55%, Students rated 67 of SPs’ feedbacks to be perfect with regard to this item (highest rating on a 5 point Likert scale), while only 29 feedbacks were rated this way by the experts. 2. The SP gave precise suggestions for improvement, Amax 75%, 62 of SPs’ feedbacks obtained the highest rating from students, while only 44 of SPs’ feedbacks achieved the highest rating in the view of the experts. 3. The SP speaks about his/her role in the third person, Amax 60%. Students rated 77 feedbacks with the highest score, while experts judged only 43 feedbacks this way. Conclusion Although evaluation by the students was in agreement with that of experts concerning some items, students rated the SPs’ feedback more often with the optimal score than experts did. Moreover it seems difficult for students to notice when SPs talk about the role in the first instead of the third person. Since precision and talking about the role in the third person are important quality criteria of feedback, this result should be taken into account when thinking about students’ evaluation of SPs’ feedback for quality control. Bouter, S., E. van Weel-Baumgarten, and S. Bolhuis. 2012. Construction and Validation of the Nijmegen Evaluation of the Simulated Patient (NESP): Assessing Simulated Patients’ Ability to Role-Play and Provide Feedback to Students. Academic Medicine: Journal of the Association of American Medical Colleges
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Antisense oligonucleotides (AONs) hold promise for therapeutic correction of many genetic diseases via exon skipping, and the first AON-based drugs have entered clinical trials for neuromuscular disorders1, 2. However, despite advances in AON chemistry and design, systemic use of AONs is limited because of poor tissue uptake, and recent clinical reports confirm that sufficient therapeutic efficacy has not yet been achieved. Here we present a new class of AONs made of tricyclo-DNA (tcDNA), which displays unique pharmacological properties and unprecedented uptake by many tissues after systemic administration. We demonstrate these properties in two mouse models of Duchenne muscular dystrophy (DMD), a neurogenetic disease typically caused by frame-shifting deletions or nonsense mutations in the gene encoding dystrophin3, 4 and characterized by progressive muscle weakness, cardiomyopathy, respiratory failure5 and neurocognitive impairment6. Although current naked AONs do not enter the heart or cross the blood-brain barrier to any substantial extent, we show that systemic delivery of tcDNA-AONs promotes a high degree of rescue of dystrophin expression in skeletal muscles, the heart and, to a lesser extent, the brain. Our results demonstrate for the first time a physiological improvement of cardio-respiratory functions and a correction of behavioral features in DMD model mice. This makes tcDNA-AON chemistry particularly attractive as a potential future therapy for patients with DMD and other neuromuscular disorders or with other diseases that are eligible for exon-skipping approaches requiring whole-body treatment.