8 resultados para multi-classification constrained-covariance regres
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BACKGROUND: Wireless capsule endoscopy has been introduced as an innovative, non-invasive diagnostic technique for evaluation of the gastrointestinal tract, reaching places where conventional endoscopy is unable to. However, the output of this technique is an 8 hours video, whose analysis by the expert physician is very time consuming. Thus, a computer assisted diagnosis tool to help the physicians to evaluate CE exams faster and more accurately is an important technical challenge and an excellent economical opportunity. METHOD: The set of features proposed in this paper to code textural information is based on statistical modeling of second order textural measures extracted from co-occurrence matrices. To cope with both joint and marginal non-Gaussianity of second order textural measures, higher order moments are used. These statistical moments are taken from the two-dimensional color-scale feature space, where two different scales are considered. Second and higher order moments of textural measures are computed from the co-occurrence matrices computed from images synthesized by the inverse wavelet transform of the wavelet transform containing only the selected scales for the three color channels. The dimensionality of the data is reduced by using Principal Component Analysis. RESULTS: The proposed textural features are then used as the input of a classifier based on artificial neural networks. Classification performances of 93.1% specificity and 93.9% sensitivity are achieved on real data. These promising results open the path towards a deeper study regarding the applicability of this algorithm in computer aided diagnosis systems to assist physicians in their clinical practice.
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OBJECTIVES: This study analyzes the results of the arterial switch operation for transposition of the great arteries in member institutions of the European Congenital Heart Surgeons Association. METHODS: The records of 613 patients who underwent primary arterial switch operations in each of 19 participating institutions in the period from January 1998 through December 2000 were reviewed retrospectively. RESULTS: A ventricular septal defect was present in 186 (30%) patients. Coronary anatomy was type A in 69% of the patients, and aortic arch pathology was present in 20% of patients with ventricular septal defect. Rashkind septostomy was performed in 75% of the patients, and 69% received prostaglandin. There were 37 hospital deaths (operative mortality, 6%), 13 (3%) for patients with an intact ventricular septum and 24 (13%) for those with a ventricular septal defect (P < .001). In 36% delayed sternal closure was performed, 8% required peritoneal dialysis, and 2% required mechanical circulatory support. Median ventilation time was 58 hours, and intensive care and hospital stay were 6 and 14 days, respectively. Although of various preoperative risk factors the presence of a ventricular septal defect, arch pathology, and coronary anomalies were univariate predictors of operative mortality, only the presence of a ventricular septal defect approached statistical significance (P = .06) on multivariable analysis. Of various operative parameters, aortic crossclamp time and delayed sternal closure were also univariate predictors; however, only the latter was an independent statistically significant predictor of death. CONCLUSIONS: Results of the procedure in European centers are compatible with those in the literature. The presence of a ventricular septal defect is the clinically most important preoperative risk factor for operative death, approaching statistical significance on multivariable analysis.
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AIMS: An epidemiological survey of diabetic foot infections (DFIs) in Lisbon, stratifying the bacterial profile based on patient demographical data, diabetic foot characteristics (PEDIS classification), ulcer duration and antibiotic therapy. METHODS: A transversal observational multicenter study, with clinical data collection using a structured questionnaire and microbiological products (aspirates, biopsies or swabs collected using the Levine method) of clinically infected foot ulcers of patients with diabetes mellitus (DM). RESULTS: Forty-nine hospitalized and ambulatory patients were enrolled in this study, and 147 microbial isolates were cultured. Staphylococcus was the main genus identified, and methicillin-resistant Staphylococcus aureus (MRSA) was present in 24.5% of total cases. In the clinical samples collected from patients undergoing antibiotic therapy, 93% of the antibiotic regimens were considered inadequate based on the antibiotic susceptibility test results. The average duration of an ulcer with any isolated multi-drug resistant (MDR) organism was 29 days, and previous treatment with fluoroquinolones was statistically associated with multi-drug resistance. CONCLUSIONS: Staphylococcus aureus was the most common cause of DFIs in our area. Prevalence and precocity of MDR organisms, namely MRSA, were high and were probably related to previous indiscriminate antibiotic use. Clinicians should avoid fluoroquinolones and more frequently consider the use of empirical anti-MRSA therapy.
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Acute renal failure (ARF) is common after orthotopic liver transplantation (OLT). The aim of this study was to evaluate the prognostic value of RIFLE classification in the development of CKD, hemodialysis requirement, and mortality. Patients were categorized as risk (R), injury (I) or failure (F) according to renal function at day 1, 7 and 21. Final renal function was classified according to K/DIGO guidelines. We studied 708 OLT recipients, transplanted between September 1992 and March 2007; mean age 44 +/- 12.6 yr, mean follow-up 3.6 yr (28.8% > or = 5 yr). Renal dysfunction before OLT was known in 21.6%. According to the RIFLE classification, ARF occurred in 33.2%: 16.8% were R class, 8.5% I class and 7.9% F class. CKD developed in 45.6%, with stages 4 or 5d in 11.3%. Mortality for R, I and F classes were, respectively, 10.9%, 13.3% and 39.3%. Severity of ARF correlated with development of CKD: stage 3 was associated with all classes of ARF, stages 4 and 5d only with severe ARF. Hemodialysis requirement (23%) and mortality were only correlated with the most severe form of ARF (F class). In conclusion, RIFLE classification is a useful tool to stratify the severity of early ARF providing a prognostic indicator for the risk of CKD occurrence and death.
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An increase in the number of new cases of tuberculosis (TB) combined with poor clinical outcome was identified among HIV-infected injecting drug users attending a large HIV unit in central Lisbon. A retrospective epidemiological and laboratory study was conducted to review all newly diagnosed cases of TB from 1995 to 1996 in the HIV unit. Results showed that from 1995 to 1996, 63% (109/173) of the Mycobacterium tuberculosis isolates from HIV-infected patients were resistant to one or more anti-tuberculosis drugs; 89% (95) of these were multidrug-resistant, i.e., resistant to at least isoniazid and rifampicin. Eighty percent of the multidrug-resistant strains (MDR) available for restriction fragment length polymorphism (RFLP) DNA fingerprinting clustered into one of two large clusters. Epidemiological data support the conclusion that the transmission of MDR-TB occurred among HIV-infected injecting drug users exposed to infectious TB cases on open wards in the HIV unit. Improved infection control measures on the HIV unit and the use of empirical therapy with six drugs once patients were suspected to have TB, reduced the incidence of MDR-TB from 42% of TB cases in 1996 to 11% in 1999.
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Existem diversos factores que podem influenciar o prognóstico funcional nos doentes com Acidente Vascular Cerebral (AVC), nomeadamente o hemisfério afectado, severidade do deficit neurológico inicial, presença de comorbilidades, etiologia, entre outros. A idade como factor preditivo na reabilitação destes doentes tem sido alvo de controvérsia. O objectivo deste trabalho foi avaliar a idade como variável preditiva de funcionalidade após AVC. Os autores recolheram retrospectivamente os dados dos processos clínicos dos doentes internados para reabilitação no Serviço de MFR do Hospital de Curry Cabral durante o ano de 2008, tendo como critério de inclusão diagnóstico de AVC. A funcionalidade foi avaliada à entrada e à saída do internamento, com a Medida de Independência Funcional (MIF) e o Índice de Barthel (IB). Os doentes com idade igual ou inferior a 45 anos foram considerados jovens adultos. Foi realizado o emparelhamento de doentes em casos-controlo. Para cada caso de AVC no adulto jovem os critérios de emparelhamento foram: idade> 45 anos, o mesmo tipo de AVC e hemisfério envolvido e igual MIF à entrada (mais ou menos três pontos). Para tratamento estatístico foi utilizado o programa SPSS 13.0. Foram recolhidos dados de 69 doentes com AVC, dos quais 12 foram considerados adultos jovens (38 +-5 anos). Quando comparados com os doentes mais velhos, os adultos jovens saíram com uma MIF maior (101 Vs 88 pontos; p=0,04), sem que se verificassem diferenças estatisticamente significativas em relação a: MIF à entrada, IB à entrada e saída, eficiência da MIF ou duração do internamento. A idade jovem associou-se com um melhor valor de MIF à saída (r=0,33, p=0,006), mesmo quando se controlou para a MIF à entrada (r=0,23, p=0,05). Em relação à análise dos nove pares caso-controlo, não se verificaram diferenças entre os grupos nas medidas de funcionalidade à entrada e à saída, nem na duração do internamento. A idade correlacionou-se com funcionalidade à saída, sendo que os doentes mais jovens saíram mais funcionais. No entanto, na análise caso-controlo, quando se controlou para outras variáveis (e.g. tipo de AVC), a variável perdeu o seu valor preditivo. Estes resultados podem dever-se ao facto de o AVC no jovem adulto ter diferentes características, como um maior número de eventos hemorrágicos. Nesta amostra, os jovens adultos tiveram igual número de AVC isquémicos e hemorrágicos (seis) e o grupo mais velho teve apenas 23% eventos hemorrágicos (p=0,07). É conhecido o melhor prognóstico funcional deste tipo de AVC, quando não associados a mortalidade precoce. Este estudo apresenta algumas limitações: o tamanho da amostra; o facto de a MIF e o IB não serem medidas de funcionalidade desenvolvidas especificamente para doentes com AVC; um viés de selecção, pois somente alguns doentes são incluídos em programa de reabilitação em internamento; o momento de avaliação da funcionalidade residual foi á saída do internamento, apenas algumas semanas pós-AVC. A idade jovem parece associar-se a um melhor prognóstico funcional. Este aspecto pode estar associado ao facto de o AVC nos doentes mais novos ter características diferentes (e.g. maior proporção de AVC hemorrágico), normalmente associadas a uma recuperação mais favorável.
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Infancy and early childhood are characterized by a dynamic and ever changing process. Since the beginning of their clinical work at the Infancy Unit, the authors were concerned with individual assessment and the questions about the role played by parents as well as by babies in pathology and intervention.In this article, the authors begin with a description of the path that led them to the selection of DC 0–3 as a diagnostic classification system and how this has been instrumental in helping them to better define infant psychopathology and guide them in treatment orientations. Next, they present the results of the applicationof Axis I and II of DC: 0–3 in their clinical population in the years 1997, 1998, and 1999. The objectives of this study were to learn more about the distribution of mental disorders in a clinical population up tofour years of age. The authors attempted to separate infants at risk for developing psychic disorders from those presenting current psychopathology as well as the possible influence of demographic features on this distribution, to define a target population and design adapted therapeutic measures. The identification of these objectives provides the rationale for the use of a diagnostic tool, like DC: 0–3, which is essential to plan clinical activity, to evaluate therapeutic efficacy, and to develop specific programs.