486 resultados para Bayesian diagnostic measure


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Because the diagnostic tools for predicting whether an early cleavage stage embryo can lead to a viable pregnancy are still elusive, transfer of more than one embryo remains quite common. However, the only way to reduce multiple pregnancies, considered as the main adverse effect of assisted reproductive technology, is to transfer a single embryo. In countries such as Switzerland and Germany, the law allows cryopreservation only at the 2-pronuclear stage. This restricts considerably the possibility of selecting the embryos to be transferred. Therefore, a good cryopreservation program at the 2-pronuclear stage is an essential tool to optimize the efficiency of in vitro fertilization (IVF). We therefore recommend the Cumulated Singleton Delivery Rate (CUSIDERA) as a measure of standard IVF efficiency. This rate averages approximately 23.5% when calculated over the last 10 years in our unit and reaches a value above 35% for patients with more than 10 zygotes. Elective single-embryo transfers and the decrease of iatrogenic multiple pregnancies in IVF remain dependent on better prognostic tools for the appropriate selection of patients, gametes, and zygotes.

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The diagnosis of multiple myeloma is often suggested by disturbances found in routine laboratory tests such as sedimentation rate, electrophoresis of serum proteins and search for proteinuria. In light chain myeloma these tests are nonspecific and therefore misleading. We present 8 cases of light chain myeloma and discuss the diagnosis of multiple myeloma with its associated pitfalls.

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Introduction: Residual pulmonary artery (PA) anomalies are a major concern after surgery for cono-truncal malformations. This study sought to assess residual PA anomalies using MRI/MRA. Methods: 43 MRI/MRA studies were performed in 37 patients after corrective surgery for cono-truncal malformations. MRI/MRA studies comprised spin-echo, cine, velocity-encoded and 3D Gadolinium-enhanced MRA sequences. Residual PA anomalies were searched in ail patients; angiographie data were available in 13 patients and a comparison with MRI/MRA was made. Results: 32/37 patients had postoperative anomalies of the pulmonary arterial tree. Left pulmonary artery stenosis was the most common finding (14/32), followed by stenosis at multiple sites (11/32). Isolated right pulmonary artery stenosis was rare (2/32). The median time interval between MRI/MRA and angiography in the 13 patients undergoing both types of studies was 54 days. The findings between the two examinations were identical regarding stenoses and collateral vessels. In 4 patients, the MRI/MRA study allowed to plan interventional catheterization with balloon dilatation and/or stenting of the obstructed arteries or co il-occlusion of systemic collaterals. Eleven patients had additional surgery based on MRI/MRA findings. Conclusions: Post-operative anomalies of the PA in cono-truncal malformations can reliably be detected with MRI/MRA. This technique allows planning of the intervention al or surgical procedure to correct the residual anomalies and may th us replace or precede catheterization during the follow-up of surgically corrected cono-truncal malformations.

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The 2012 Swiss consensus paper on diagnosis and management of patients suffering from dementia resulted from the work of an expert panel who met on March 23d to 25th in Luzem. Based on a literature review, panel members wrote a first draft that was subsequently circulated among multiple dementia experts in Switzerland. After adaptation and revisions according to comments, all consulted dementia specialists and panel members fully endorse the consensus content. The conference was financed by the Swiss Alzheimer Forum.

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Background The 'database search problem', that is, the strengthening of a case - in terms of probative value - against an individual who is found as a result of a database search, has been approached during the last two decades with substantial mathematical analyses, accompanied by lively debate and centrally opposing conclusions. This represents a challenging obstacle in teaching but also hinders a balanced and coherent discussion of the topic within the wider scientific and legal community. This paper revisits and tracks the associated mathematical analyses in terms of Bayesian networks. Their derivation and discussion for capturing probabilistic arguments that explain the database search problem are outlined in detail. The resulting Bayesian networks offer a distinct view on the main debated issues, along with further clarity. Methods As a general framework for representing and analyzing formal arguments in probabilistic reasoning about uncertain target propositions (that is, whether or not a given individual is the source of a crime stain), this paper relies on graphical probability models, in particular, Bayesian networks. This graphical probability modeling approach is used to capture, within a single model, a series of key variables, such as the number of individuals in a database, the size of the population of potential crime stain sources, and the rarity of the corresponding analytical characteristics in a relevant population. Results This paper demonstrates the feasibility of deriving Bayesian network structures for analyzing, representing, and tracking the database search problem. The output of the proposed models can be shown to agree with existing but exclusively formulaic approaches. Conclusions The proposed Bayesian networks allow one to capture and analyze the currently most well-supported but reputedly counter-intuitive and difficult solution to the database search problem in a way that goes beyond the traditional, purely formulaic expressions. The method's graphical environment, along with its computational and probabilistic architectures, represents a rich package that offers analysts and discussants with additional modes of interaction, concise representation, and coherent communication.

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There are no validated criteria for the diagnosis of sensory neuronopathy (SNN) yet. In a preliminary monocenter study a set of criteria relying on clinical and electrophysiological data showed good sensitivity and specificity for a diagnosis of probable SNN. The aim of this study was to test these criteria on a French multicenter study. 210 patients with sensory neuropathies from 15 francophone reference centers for neuromuscular diseases were included in the study with an expert diagnosis of non-SNN, SNN or suspected SNN according to the investigations performed in these centers. Diagnosis was obtained independently from the set of criteria to be tested. The expert diagnosis was taken as the reference against which the proposed SNN criteria were tested. The set relied on clinical and electrophysiological data easily obtainable with routine investigations. 9/61 (16.4 %) of non-SNN patients, 23/36 (63.9 %) of suspected SNN, and 102/113 (90.3 %) of SNN patients according to the expert diagnosis were classified as SNN by the criteria. The SNN criteria tested against the expert diagnosis in the SNN and non-SNN groups had 90.3 % (102/113) sensitivity, 85.2 % (52/61) specificity, 91.9 % (102/111) positive predictive value, and 82.5 % (52/63) negative predictive value. Discordance between the expert diagnosis and the SNN criteria occurred in 20 cases. After analysis of these cases, 11 could be reallocated to a correct diagnosis in accordance with the SNN criteria. The proposed criteria may be useful for the diagnosis of probable SNN in patients with sensory neuropathy. They can be reached with simple clinical and paraclinical investigations.

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La thrombocytopénie immune primaire (ITP) est une affection auto-immune acquise avec diminution de la survie des plaquettes et perturbation de la production plaquettaire. Il n'existe aucun test clinique simple permettant de prouver la nature auto-immune de l'affection. Pour cette raison, il s'agit presque toujours d'un diagnostic par exclusion d'autres causes. Bien que les plaquettes soient souvent inférieures à 10 x 109/l lors de la présentation initiale, la tendance hémorragique est étonnamment modérée chez la majorité des patients. Le traitement initial fait toujours appel aux corticostéroïdes, combinés à des immunoglobulines intraveineuses et à des transfusions de plaquettes dans les formes compliquées avec hémorragies significatives. Chez l'enfant, la maladie est souvent induite par des infections virales et son évolution est bénigne et spontanément régressive dans la majorité des cas. Chez l'adulte, la maladie est plus souvent persistante ou chroniquement récidivante, et le taux de plaquettes se situe souvent à un taux suffisant pour prévenir des hémorragies spontanées. Seule une faible proportion de patients souffre d'une thrombocytopénie sévère prolongée accompagnée de saignements réguliers avec risque d'hémorragies potentiellement fatales. C'est probablement ce groupe de patients restreint qui tirera surtout profit des nouvelles options thérapeutiques telles que les agonistes du récepteur de la thrombopoïétine. A la lumière de ces nouvelles possibilités, un groupe d'hématologues suisses s'est réuni pour élaborer des directives concernant la prise en charge de l'ITP conformément aux besoins et aux habitudes de notre pays.

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Background: Chest pain (CP) represents about 5% of admissions to emergency departments (ED), even in young people. Acute coronary syndrome (ACS) and myocarditis are among the most important diagnoses to rule out. Clinical and ECG findings are not specific for either condition and separating both diagnoses is a challenge. Aim of the study: To evaluate the prevalence of ACS and myocarditis in young patients presenting with CP and elevated cardiac biomarkers to the ED and to determinate the differences in their clinical presentation. Methods: Retrospective study of all consecutive patients < 40 years old admitted to our ED from January 2009 to June 2011 for CP with elevated serum troponin concentration. All clinical, angiographic and cardiac magnetic resonance (CMR) data from the local database was reviewed. Clinical follow-up was obtained to assess all cause mortality, myocardial infarction and re-hospitalisation for CP. Results: 1588 patients < 40 years old were admitted to the ED with chest pain. 49 (3%) patients presenting with an elevated troponin I (> 0.09ug/l) were included in the study. 32.7% (16/49) were diagnosed with ACS (11 STEMI and 5 NSTEMI) and 59.2% (29/49) with myocarditis. Among the 29 patients with myocarditis, 17 presented with typical subepicardial late enhancement on CMR and 12 were diagnosed based on clinical presentation (6 had no complementary workup, 3 normal coronary angiogram and 3 inconclusive CMR). 8.1% (4/49) of patients had other diagnoses. Compared to patients with myocarditis, ACS patients were older (34.1±3.9 vs 26.9±6.4, p=0.0002) with significantly more cardiovascular risk factors (mean 2.06 vs 0.69, p<0.0001). Diabetes (18.8% vs 0%, p=0.004), dyslipidemia (56.3% vs 3.4%, p=0.0001) and family history of coronary artery disease (CAD) (37.5% vs 10.3%, p=0.050) were significantly associated with ACS. No significant association was found for smoking, hypertension and obesity. Fever (>38°C) or recent viral illness were present in 75.9% (22/29) of patients with myocarditis, and in 0% of ACS patients. During follow-up (mean 19.9 months ± 8.6), only 2 patients with myocarditis were re-admitted for chest pain. Conclusions: In this study, 32.7% of patients < 40 year old admitted to an ED with CP and elevated troponin had an ACS. Key clinical factors include diabetes, dyslipidemia, family history of CAD, fever or recent viral illness, and may help to differentiate ACS from myocarditis.

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Chlamydia are obligate intracellular bacteria. Three species are considered human pathogens. Chlamydophila pneumoniae is one of the most common agents of atypical community-acquired pneumonia. Chlamydophila psittaci causes psittacosis, a severe zoonotic pneumonia transmitted by birds. Finally, Chlamydia trachomatis is the etiologic agent of trachoma and urogenital infections. The latter are commonly asymptomatic or paucisymptomatic. Thus, they may remain undiagnosed for years, leading to serious late complications such as salpingitis, ectopic pregnancy and infertility. Currently, the diagnosis of chlamydial infections is essentially based on molecular methods. Treatment should use an antibiotic with good intracellular bioavailability such as tetracycline, macrolides and new generation fluoroquinolones.

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Originally invented for topographic imaging, atomic force microscopy (AFM) has evolved into a multifunctional biological toolkit, enabling to measure structural and functional details of cells and molecules. Its versatility and the large scope of information it can yield make it an invaluable tool in any biologically oriented laboratory, where researchers need to perform characterizations of living samples as well as single molecules in quasi-physiological conditions and with nanoscale resolution. In the last 20 years, AFM has revolutionized the characterization of microbial cells by allowing a better understanding of their cell wall and of the mechanism of action of drugs and by becoming itself a powerful diagnostic tool to study bacteria. Indeed, AFM is much more than a high-resolution microscopy technique. It can reconstruct force maps that can be used to explore the nanomechanical properties of microorganisms and probe at the same time the morphological and mechanical modifications induced by external stimuli. Furthermore it can be used to map chemical species or specific receptors with nanometric resolution directly on the membranes of living organisms. In summary, AFM offers new capabilities and a more in-depth insight in the structure and mechanics of biological specimens with an unrivaled spatial and force resolution. Its application to the study of bacteria is extremely significant since it has already delivered important information on the metabolism of these small microorganisms and, through new and exciting technical developments, will shed more light on the real-time interaction of antimicrobial agents and bacteria.