930 resultados para Potential methods
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BACKGROUND AND AIM OF THE STUDY: Transapical transcatheter aortic valve replacement (TAVR) is a new minimally invasive technique with a known risk of unexpected intra-procedural complications. Nevertheless, the clinical results are good and the limited amount of procedural adverse events confirms the usefulness of a synergistic surgical/anesthesiological management in case of unexpected emergencies. METHODS: A review was made of the authors' four-year database and other available literature to identify major and minor intra-procedural complications occurring during transapical TAVR procedures. All implants were performed under general anesthesia with a balloon-expandable Edwards Sapien stent-valve, and followed international guidelines on indications and techniques. RESULTS: Procedural success rates ranged between 94% and 100%. Life-threatening apical bleeding occurred very rarely (0-5%), and its incidence decreased after the first series of implants. Stent-valve embolization was also rare, with a global incidence ranging from 0-2%, with evidence of improvement after the learning curve. Rates of valve malpositioning ranged from 0% to < 3%, whereas the risk of coronary obstruction ranged from 0% to 3.5%. Aortic root rupture and dissection were dramatic events reported in 0-2% of transapical cases. Stent-valve malfunction was rarely reported (1-2%), whereas the valve-in-valve bailout procedure for malpositioning, malfunctioning or severe paravalvular leak was reported in about 1.0-3.5% of cases. Sudden hemodynamic management and bailout procedures such as valve-in-valve rescue or cannulation for cardiopulmonary bypass were more effective when planned during the preoperative phase. CONCLUSION: Despite attempts to avoid pitfalls, complications during transapical aortic valve procedures still occur. Preoperative strategic planning, including hemodynamic status management, alternative cannulation sites and bailout procedures, are highly recommended, particularly during the learning curve of this technique.
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BACKGROUND: The proportion of surgery performed as a day case varies greatly between countries. Low rates suggest a large growth potential in many countries. Measuring the potential development of one day surgery should be grounded on a comprehensive list of eligible procedures, based on a priori criteria, independent of local practices. We propose an algorithmic method, using only routinely available hospital data to identify surgical hospitalizations that could have been performed as one day treatment. METHODS: Moving inpatient surgery to one day surgery was considered feasible if at least one surgical intervention was eligible for one day surgery and if none of the following criteria were present: intervention or affection requiring an inpatient stay, patient transferred or died, and length of stay greater than four days. The eligibility of a procedure to be treated as a day case was mainly established on three a priori criteria: surgical access (endoscopic or not), the invasiveness of the procedure and the size of the operated organ. Few overrides of these criteria occurred when procedures were associated with risk of immediate complications, slow physiological recovery or pain treatment requiring hospital infrastructure. The algorithm was applied to a random sample of one million inpatient US stays and more than 600 thousand Swiss inpatient stays, in the year 2002. RESULTS: The validity of our method was demonstrated by the few discrepancies between the a priori criteria based list of eligible procedures, and a state list used for reimbursement purposes, the low proportion of hospitalizations eligible for one day care found in the US sample (4.9 versus 19.4% in the Swiss sample), and the distribution of the elective procedures found eligible in Swiss hospitals, well supported by the literature. There were large variations of the proportion of candidates for one day surgery among elective surgical hospitalizations between Swiss hospitals (3 to 45.3%). CONCLUSION: The proposed approach allows the monitoring of the proportion of inpatient stay candidates for one day surgery. It could be used for infrastructure planning, resources negotiation and the surveillance of appropriate resource utilization.
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BACKGROUND: Peroxisome proliferator activated receptors (PPARs) are nuclear hormone receptors involved in genetic control of many cellular processes. PPAR and PPAR have been implicated in colonic malignancy. Here we provide three lines of evidence suggesting an inhibitory role for PPAR in colorectal cancer development. METHODS: Levels of PPAR mRNA and protein in human colorectal cancers were compared with matched non-malignant mucosa using RNAse protection and western blotting. APC(Min)/+ mice were randomised to receive the PPAR activator methylclofenapate 25 mg/kg or vehicle for up to 16 weeks, and small and large intestinal polyps were quantified by image analysis. The effect of methylclofenapate on serum stimulated mitogenesis (thymidine incorporation), linear cell growth, and annexin V and propidium iodide staining were assessed in human colonic epithelial cells. RESULTS: PPAR (mRNA and protein) expression levels were significantly depressed in colorectal cancer compared with matched non-malignant tissue. Methylclofenapate reduced polyp area in the small intestine from 18.7 mm(2) (median (interquartile range 11.1, 26.8)) to 9.90 (4.88, 13.21) mm(2) (p=0.003) and in the colon from 9.15 (6.31, 10.5) mm(2) to 3.71 (2.71, 5.99) mm(2) (p=0.009). Methylclofenapate significantly reduced thymidine incorporation and linear cell growth with no effect on annexin V or propidium iodide staining. CONCLUSIONS: PPAR may inhibit colorectal tumour progression, possibly via inhibition of proliferation, and may be an important therapeutic target.
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The implementation of new techniques of imaging in the daily practice of the radiation oncologist is a major advance in these last 10 years. This allows optimizing the therapeutic intervals and locoregional control of the disease while limiting side effects. Among them, positron emission tomography (PET) offers an opportunity to the clinician to obtain data relative to the tumoral biological mechanisms, while benefiting from the morphological images of the computed tomography (CT) scan. Recently hybrid PET/CT has been developed and numerous studies aimed at optimizing its use in the planning, the evaluation of the treatment response and the prognostic value. The choice of the radiotracer (according to the type of cancer and to the studied biological mechanism) and the various methods of tumoral delineation, require a regular update to optimize the practices. We propose throughout this article, an exhaustive review of the published researches (and in process of publication) until December 2011, as user guide of PET/CT in all the aspects of the modern radiotherapy (from the diagnosis to the follow-up): biopsy guiding, optimization of treatment planning and dosimetry, evaluation of tumor response and prognostic value, follow-up and early detection of recurrence versus tumoral necrosis. In a didactic purpose, each of these aspects is approached by primary tumoral location, and illustrated with representative iconographic examples. The current contribution of PET/CT and its perspectives of development are described to offer to the radiation oncologist a clear and up to date reading in this expanding domain.
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Objective: Despite progress during recent decades, long-term outcome¦of patients with pancreatic cancer remains dismal. Since positive resection¦margins and metastatic lymph nodes are known risk factors for early tumor¦recurrence, patients at risk should be identified and could potentially benefit¦from preoperative radio-chemotherapy. This study aimed to assess whether the¦presence of lymph node metastasis could be used to predict positive resection¦margins in patients with pancreatic cancer.¦Methods: A series of 146 patients (82 male, 64 female, median age 68 years)¦underwent pancreatic head resection for various malignant diseases (pancreatic¦ductal adenocarcinoma, biliary cancer, periampullary cancer) at our institution¦from 2000 to 2011. Patients were identified from our prospective database¦that collects more than 60 single items of all patients undergoing pancreatic¦resection. Lymph node metastasis and positive resection margins were all¦confirmed by histological evaluation. Positive predictive value (PPV), negative¦predictive value (NPV), sensitivity and specificity were calculated to assess¦the predictive value of metastatic lymph nodes regarding tumor-free (R0) and¦tumor-involved (R1) resection margins.¦Results: There were 110 specimens (76%) with tumor-positive lymph nodes¦and 36 specimens with tumor-negative lymph nodes. Resection margins were¦positive in 47 specimens (32%) and negative in 99 specimens. Sensitivity of¦tumor-positive lymph nodes to detect positive resection margins was 96%, and¦the NPV was 94%. In contrast, specificity was 34% and the PPV was 41%.¦Conclusion: Patients with resectable pancreatic cancer, who have no lymph¦node metastasis, are at very low risk to have positive resection margins (2 of¦36 patients, NPV 94%). In contrast, more than one third of patients with¦metastatic lymph nodes are at increased risk for an incomplete tumor resection¦(sensitivity 96%). If lymph nodesmetastases are highly suspected at preoperative¦staging, a neoadjuvant treatment strategy should be considered to increase the¦R0 resection rate.
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Superheater corrosion causes vast annual losses for the power companies. With a reliable corrosion prediction method, the plants can be designed accordingly, and knowledge of fuel selection and determination of process conditions may be utilized to minimize superheater corrosion. Growing interest to use recycled fuels creates additional demands for the prediction of corrosion potential. Models depending on corrosion theories will fail, if relations between the inputs and the output are poorly known. A prediction model based on fuzzy logic and an artificial neural network is able to improve its performance as the amount of data increases. The corrosion rate of a superheater material can most reliably be detected with a test done in a test combustor or in a commercial boiler. The steel samples can be located in a special, temperature-controlled probe, and exposed to the corrosive environment for a desired time. These tests give information about the average corrosion potential in that environment. Samples may also be cut from superheaters during shutdowns. The analysis ofsamples taken from probes or superheaters after exposure to corrosive environment is a demanding task: if the corrosive contaminants can be reliably analyzed, the corrosion chemistry can be determined, and an estimate of the material lifetime can be given. In cases where the reason for corrosion is not clear, the determination of the corrosion chemistry and the lifetime estimation is more demanding. In order to provide a laboratory tool for the analysis and prediction, a newapproach was chosen. During this study, the following tools were generated: · Amodel for the prediction of superheater fireside corrosion, based on fuzzy logic and an artificial neural network, build upon a corrosion database developed offuel and bed material analyses, and measured corrosion data. The developed model predicts superheater corrosion with high accuracy at the early stages of a project. · An adaptive corrosion analysis tool based on image analysis, constructedas an expert system. This system utilizes implementation of user-defined algorithms, which allows the development of an artificially intelligent system for thetask. According to the results of the analyses, several new rules were developed for the determination of the degree and type of corrosion. By combining these two tools, a user-friendly expert system for the prediction and analyses of superheater fireside corrosion was developed. This tool may also be used for the minimization of corrosion risks by the design of fluidized bed boilers.
Establishing intercompany relationships: Motives and methods for successful collaborative engagement
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This study explores the early phases of intercompany relationship building, which is a very important topic for purchasing and business development practitioners as well as for companies' upper management. There is a lot ofevidence that a proper engagement with markets increases a company's potential for achieving business success. Taking full advantage of the market possibilities requires, however, a holistic view of managing related decision-making chain. Most literature as well as the business processes of companies are lacking this holism. Typically they observe the process from the perspective of individual stages and thus lead to discontinuity and sub-optimization. This study contains a comprehensive introduction to and evaluation of literature related to various steps of the decision-making process. It is studied from a holistic perspective ofdetermining a company's vertical integration position within its demand/ supplynetwork context; translating the vertical integration objectives to feasible strategies and objectives; and operationalizing the decisions made through engagement with collaborative intercompany relationships. The empirical part of the research has been conducted in two sections. First the phenomenon of intercompany engagement is studied using two complementary case studies. Secondly a survey hasbeen conducted among the purchasing and business development managers of several electronics manufacturing companies, to analyze the processes, decision-makingcriteria and success factors of engagement for collaboration. The aim has been to identify the reasons why companies and their management act the way they do. As a combination of theoretical and empirical research an analysis has been produced of what would be an ideal way of engaging with markets. Based on the respective findings the study concludes by proposing a holistic framework for successful engagement. The evidence presented throughout the study demonstrates clear gaps, discontinuities and limitations in both current research and in practical purchasing decision-making chains. The most significant discontinuity is the identified disconnection between the supplier selection process and related criteria and the relationship success factors.
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Current diagnostic methods in differentiating septic from non-septic arthritis are time-consuming (culture) or have limited sensitivity (Gram stain). Microcalorimetry is a novel method that can rapidly detect microorganisms by their heat production. We investigated the accuracy and time to detection of septic arthritis by using microcalorimetry. Patients older than 18 years of age with acute arthritis of native joints were prospectively included. Synovial fluid was aspirated and investigated by Gram stain, culture and microcalorimetry. The diagnosis of septic arthritis and non-septic arthritis were made by experienced rheumatologists or orthopaedic surgeons. Septic arthritis was diagnosed by considering the finding of acute arthritis together with findings such as positive Gram stain or positive culture of synovial fluid or positive blood culture. The sensitivity and specificity for diagnosing septic arthritis and the time to positivity of microcalorimetry were determined. Of 90 patients (mean age 64 years), nine had septic arthritis, of whom four (44 %) had positive Gram stain, six (67 %) positive synovial fluid culture and four (44 %) had positive blood culture. The sensitivity of microcalorimetry was 89 %, the specificity was 99 % and the mean detection time was 5.0 h (range, 2.2-8.0 h). Microcalorimetry is an accurate and rapid method for the diagnosis of septic arthritis. It has potential to be used in clinical practice in diagnosing septic arthritis.
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BACKGROUND: In most of the emergency departments (ED) in developed countries, a subset of patients visits the ED frequently. Despite their small numbers, these patients are the source of a disproportionally high number of all ED visits, and use a significant proportion of healthcare resources. They place a heavy economic burden on hospital and healthcare systems budgets overall. Several interventions have been carried out to improve the management of these ED frequent users. Case management has been shown in some North American studies to reduce ED utilization and costs. In these studies, cost analyses have been carried out from the hospital perspective without examining the costs induced by healthcare consumed in the community. However, case management might reduce ED visits and costs from the hospital's perspective, but induce substitution effects, and increase health service utilization outside the hospital. This study examined if an interdisciplinary case-management intervention-compared to standard ED care -reduced costs generated by frequent ED users not only from the hospital perspective, but also from the healthcare system perspective-that is, from a broader perspective taking into account the costs of healthcare services used outside the hospital. METHODS: In this randomized controlled trial, 250 adult frequent emergency department users (5 or more visits during the previous 12 months) who visited the ED of the University Hospital of Lausanne, Switzerland, between May 2012 and July 2013 were allocated to one of two groups: case management intervention (CM) or standard ED care (SC), and followed up for 12 months. Depending on the perspective of the analysis, costs were evaluated differently. For the analysis from the hospital's perspective, the true value of resources used to provide services was used as a cost estimate. These data were obtained from the hospital's analytical accounting system. For the analysis from the health-care system perspective, all health-care services consumed by users and charged were used as an estimate of costs. These data were obtained from health insurance providers for a subsample of participants. To allow comparisons in a same time period, individual monthly average costs were calculated. Multivariate linear models including a fixed effect "group" were run using socio-demographic characteristics and health-related variables as controlling variables (age, gender, educational level, citizenship, marital status, somatic and mental health problems, and risk behaviors).
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Gene turnover rates and the evolution of gene family sizes are important aspects of genome evolution. Here, we use curated sequence data of the major chemosensory gene families from Drosophila-the gustatory receptor, odorant receptor, ionotropic receptor, and odorant-binding protein families-to conduct a comparative analysis among families, exploring different methods to estimate gene birth and death rates, including an ad hoc simulation study. Remarkably, we found that the state-of-the-art methods may produce very different rate estimates, which may lead to disparate conclusions regarding the evolution of chemosensory gene family sizes in Drosophila. Among biological factors, we found that a peculiarity of D. sechellia's gene turnover rates was a major source of bias in global estimates, whereas gene conversion had negligible effects for the families analyzed herein. Turnover rates vary considerably among families, subfamilies, and ortholog groups although all analyzed families were quite dynamic in terms of gene turnover. Computer simulations showed that the methods that use ortholog group information appear to be the most accurate for the Drosophila chemosensory families. Most importantly, these results reveal the potential of rate heterogeneity among lineages to severely bias some turnover rate estimation methods and the need of further evaluating the performance of these methods in a more diverse sampling of gene families and phylogenetic contexts. Using branch-specific codon substitution models, we find further evidence of positive selection in recently duplicated genes, which attests to a nonneutral aspect of the gene birth-and-death process.
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INTRODUCTION: Congenital hypogonadotropic hypogonadism (CHH) is a rare, genetic, reproductive endocrine disorder characterized by absent puberty and infertility. Limited information is available on the psychosocial impact of CHH and psychosexual development in these patients. AIM: The aim of this study was to determine the impact of CHH on psychosexual development in men on long-term treatment. METHODS: A sequential mixed methods explanatory design was used. First, an online survey (quantitative) was used to quantify the frequency of psychosexual problems among CHH men. Second, patient focus groups (qualitative) were conducted to explore survey findings in detail and develop a working model to guide potential nursing and interdisciplinary interventions. MAIN OUTCOME MEASURES: Patient characteristics, frequency of body shame, difficulty with intimate relationships, and never having been sexually active were assessed. Additionally, we collected subjective patient-reported outcomes regarding the impact of CHH on psychological/emotional well-being, intimate relationships, and sexual activity. RESULTS: A total of 101 CHH men on long-term treatment (>1 year) were included for the analysis of the online survey (mean age 37 ± 11 years, range 19-66, median 36). Half (52/101, 51%) of the men had been seen at a specialized academic center and 37/101 (37%) reported having had fertility-inducing treatment. A high percentage of CHH men experience psychosexual problems including difficulty with intimate relationships (70%) and body image concerns/body shame (94/101, 93%), and the percentage of men never having been sexually active is five times the rate in a reference group (26% vs. 5.4%, P < 0.001). Focus groups revealed persisting body shame and low self-esteem despite long-term treatment that has lasting impact on psychosexual functioning. CONCLUSIONS: CHH men frequently experience psychosexual problems that pose barriers to intimate relationships and initiating sexual activity. These lingering effects cause significant distress and are not ameliorated by long-term treatment. Psychosexual assessment in CHH men with appropriate psychological support and treatment should be warranted in these patients. Dwyer AA, Quinton R, Pitteloud N, and Morin D. Psychosexual development in men with congenital hypogonadotropic hypogonadism on long-term treatment: A mixed methods study. Sex Med 2015;3:32-41.
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Tissue engineering is a popular topic in peripheral nerve repair. Combining a nerve conduit with supporting adipose-derived cells could offer an opportunity to prevent time-consuming Schwann cell culture or the use of an autograft with its donor site morbidity and eventually improve clinical outcome. The aim of this study was to provide a broad overview over promising transplantable cells under equal experimental conditions over a long-term period. A 10-mm gap in the sciatic nerve of female Sprague-Dawley rats (7 groups of 7 animals, 8 weeks old) was bridged through a biodegradable fibrin conduit filled with rat adipose-derived stem cells (rASCs), differentiated rASCs (drASCs), human (h)ASCs from the superficial and deep abdominal layer, human stromal vascular fraction (SVF), or rat Schwann cells, respectively. As a control, we resutured a nerve segment as an autograft. Long-term evaluation was carried out after 12 weeks comprising walking track, morphometric, and MRI analyses. The sciatic functional index was calculated. Cross sections of the nerve, proximal, distal, and in between the two sutures, were analyzed for re-/myelination and axon count. Gastrocnemius muscle weights were compared. MRI proved biodegradation of the conduit. Differentiated rat ASCs performed significantly better than undifferentiated rASCs with less muscle atrophy and superior functional results. Superficial hASCs supported regeneration better than deep hASCs, in line with published in vitro data. The best regeneration potential was achieved by the drASC group when compared with other adipose tissue-derived cells. Considering the ease of procedure from harvesting to transplanting, we conclude that comparison of promising cells for nerve regeneration revealed that particularly differentiated ASCs could be a clinically translatable route toward new methods to enhance peripheral nerve repair.
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During different forms of neurodegenerative diseases, including the retinal degeneration, several cell cycle proteins are expressed in the dying neurons from Drosophila to human revealing that these proteins are a hallmark of neuronal degeneration. This is true for animal models of Alzheimer's, and Parkinson's diseases, Amyotrophic Lateral Sclerosis and for Retinitis Pigmentosa as well as for acute injuries such as stroke and light damage. Longitudinal investigation and loss-of-function studies attest that cell cycle proteins participate to the process of cell death although with different impacts, depending on the disease. In the retina, inhibition of cell cycle protein action can result to massive protection. Nonetheless, the dissection of the molecular mechanisms of neuronal cell death is necessary to develop adapted therapeutic tools to efficiently protect photoreceptors as well as other neuron types.
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Background: Information about the composition of regulatory regions is of great value for designing experiments to functionally characterize gene expression. The multiplicity of available applications to predict transcription factor binding sites in a particular locus contrasts with the substantial computational expertise that is demanded to manipulate them, which may constitute a potential barrier for the experimental community. Results: CBS (Conserved regulatory Binding Sites, http://compfly.bio.ub.es/CBS) is a public platform of evolutionarily conserved binding sites and enhancers predicted in multiple Drosophila genomes that is furnished with published chromatin signatures associated to transcriptionally active regions and other experimental sources of information. The rapid access to this novel body of knowledge through a user-friendly web interface enables non-expert users to identify the binding sequences available for any particular gene, transcription factor, or genome region. Conclusions: The CBS platform is a powerful resource that provides tools for data mining individual sequences and groups of co-expressed genes with epigenomics information to conduct regulatory screenings in Drosophila.
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BACKGROUND: Dysferlin is reduced in patients with limb girdle muscular dystrophy type 2B, Miyoshi myopathy, distal anterior compartment myopathy, and in certain Ethnic clusters. METHODS: We evaluated clinical and genetic patient data from three different Swiss Neuromuscular Centers. RESULTS: Thirteen patients from 6 non-related families were included. Age of onset was 18.8 ± 4.3 years. In all patients, diallelic disease-causing mutations were identified in the DYSF gene. Nine patients from 3 non-related families from Central Switzerland carried the identical homozygous mutation, c.3031 + 2T>C. A possible founder effect was confirmed by haplotype analysis. Three patients from two different families carried the heterozygous mutation, c.1064_1065delAA. Two novel mutations were identified (c.2869C>T (p.Gln957Stop), c.5928G>A (p.Trp1976Stop)). CONCLUSIONS: Our study confirms the phenotypic heterogeneity associated with DYSF mutations. Two mutations (c.3031 + 2T>C, c.1064_1065delAA) appear common in Switzerland. Haplotype analysis performed on one case (c. 3031 + 2T>C) suggested a possible founder effect.