10 resultados para Feature discretization
Resumo:
Myasthenia Gravis is an autoimmune disorder that generally presents with ocular symptoms, specially diplopia and ptosis. Dysphagia may be a manifestation of the generalised type of the disease, but rarely is its presenting feature. The authors describe a case of Myasthenia Gravis in an old patient complaining of dysphagia and dysarthria. Because Myasthenia Gravis is a potentially serious but treatable disease, we emphasize the need to consider it in the differential diagnosis of dysphagia, namely in the elderly. In fact, the disorder is probably underdiagnosed in this population group, because clinicians tend to accept other more frequent diagnosis to explain these symptoms.
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BACKGROUND: The major causes of renal transplant loss are death and chronic allograft dysfunction (CAD). The aims of this study were to determine the incidence of CAD in our population and the relation between allograft survival and immunosuppressive regimens. METHODS: We studied retrospectively 473 patients who received deceased donor kidney transplants with at least 1 allograft biopsy between January 1990 and May 2007. Clinical data included age, gender, biopsy data, and immunosuppression before and after kidney biopsy. Mean age was 45.4 +/- 12.7 years including 65% males with a mean follow-up of 6.7 +/- 4.5 years. CAD was observed in 177 of 473 biopsies: 48 patients showed interstitial fibrosis (IF); 101 chronic rejection (CR); 16 transplant glomerulopathy (TG); and 12, CR and TG. Mean follow-up since the discovery of the histologic feature was 60.5 +/- 50.5 months for IF; 38.3 +/- 40.8 for CR, and 18.2 +/- 19.2 for TG. RESULTS: CAD, which was more common in younger patients (P = .03), correlated upon univariate and multivariate analysis with CKD stage 5d development (P < .001). Deposition of C4d in peritubular capillaries was more frequent among CAD patients (P = .004), an association with particular relevance to recipients with CR (P = .02) and TG (P < .001). When we analyzed CAD subpopulation, we observed a positive correlation between allograft survival and immunosuppression modification after biopsy. Substitution of sirolimus (40/177) was shown in univariate, multivariate and Cox regression analyses to be a renal protector (P < .002). Allograft survival was also correlated with initial mycophenolate mofetil versus azathioprine, (62/177) immunosuppression (P < .001). CONCLUSION: CAD, a frequent histologic feature, may benefit from sirolimus conversion.
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Neurotransmitter diseases are a group of inherited disorders attributable to a disturbance of neurotransmitter metabolism. Biogenic amines are neurotransmitters with multiple roles including psychomotor function, hormone secretion, cardiovascular, respiratory and gastrointestinal control, sleep mechanisms, body temperature and pain. Given the multiple functions of monoamines, disorders of their metabolism comprise a wide spectrum of manifestations, with motor dysfunction being the most prominent clinical feature. Methods: Case review of 12 patients from 4 families, with primary disorders of biogenic amine metabolism. Results: Aromatic L-amino acid decarboxylase deficiency (4 patients from 2 families), and GTP-cyclohydrolase (8 patients from 2 families) were the two diseases identified. Age at first symptoms varied between 2 months and 6 years. Developmental delay was present in all cases except 2 patients with GTP cyclohydrolase deficiency. The combination of axial hypotonia and limb dystonia was also frequent. Children with aromatic L-amino acid decarboxylase deficiency exhibited temperature instability, oculogyric crisis and disturbances of sleep. The index case of one family with GTP cyclohydrolase deficiency presented with Parkinsonism (bradykinesia, rigidity and hypomimia). Analysis of neurotransmitters and their metabolites in CSF was crucial for the identification of index cases. Response to therapy was variable but in general unsatisfactory except in a family with GTP cyclohydrolase deficiency. Conclusions: These disorders should be considered in the differential diagnosis of paediatric neurodegenerative diseases, in order to allow an adequate therapeutic trial that can favor prognosis.
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Recurrence of cardiac myxoma is a rare condition, observed in about 3% of patients in sporadic cases, although it is more frequent in familial ones. Several mechanisms have been proposed to explain such recurrence, and the importance of increased vascularization as a facilitating feature is the subject of debate. The authors report the case of a non-familial right atrial myxoma, unusual for both its histopathology and recurrence.
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Individuals with mosaic trisomy 18, only approximately 5% of all trisomy 18 cases, carry both a trisomy 18 and an euploid cell line. Their clinical findings are highly variable, from the absence of dysmorphic features to the complete trisomy 18 syndrome. A five month old daughter of a 38-year-old mother, with vomiting and feeding problems, was referred to our department. She was undernourished and had axial hypotony and developmental delay, an irregular pattern of hypopigmentation on the right side of the abdomen, and moderate sagittal body asymmetry with left-side muscular hemihypotrophy.Mild craniofacial dysmorphy included dolichocephaly, frontal bossing, prominent occiput, long downslanting palpebral fissures, hypertelorism, and retrognathia. A complex heart defect with atrial and ventricular septal defects, pulmonary artery stenosis, and bicuspid aortic valve was identified. Cytogenetic analysis revealedmosaic trisomy 18with trisomy in 90%of peripheral lymphocytes and 17%of skin fibroblasts.This case adds to our knowledge of the phenotypic spectrum and the natural history of mosaic trisomy 18 by adding a dysmorphic feature and a cardiac abnormality that, to the best of our knowledge, had not been previously described.
Resumo:
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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OBJECTIVE: Despite the apparent familial tendency toward abdominal aortic aneurysm (AAA) formation, the genetic causes and underlying molecular mechanisms are still undefined. In this study, we investigated the association between familial AAA (fAAA) and atherosclerosis. METHODS: Data were collected from a prospective database including AAA patients between 2004 and 2012 in the Erasmus University Medical Center, Rotterdam, The Netherlands. Family history was obtained by written questionnaire (93.1% response rate). Patients were classified as fAAA when at least one affected first-degree relative with an aortic aneurysm was reported. Patients without an affected first-degree relative were classified as sporadic AAA (spAAA). A standardized ultrasound measurement of the common carotid intima-media thickness (CIMT), a marker for generalized atherosclerosis, was routinely performed and patients' clinical characteristics (demographics, aneurysm characteristics, cardiovascular comorbidities and risk factors, and medication use) were recorded. Multivariable linear regression analyses were used to assess the mean adjusted difference in CIMT and multivariable logistic regression analysis was used to calculate associations of increased CIMT and clinical characteristics between fAAA and spAAA. RESULTS: A total of 461 AAA patients (85% men, mean age, 70 years) were included in the study; 103 patients (22.3%) were classified as fAAA and 358 patients (77.7%) as spAAA. The mean (standard deviation) CIMT in patients with fAAA was 0.89 (0.24) mm and 1.00 (0.29) mm in patients with spAAA (P = .001). Adjustment for clinical characteristics showed a mean difference in CIMT of 0.09 mm (95% confidence interval, 0.02-0.15; P = .011) between both groups. Increased CIMT, smoking, hypertension, and diabetes mellitus were all less associated with fAAA compared with spAAA. CONCLUSIONS: The current study shows a lower atherosclerotic burden, as reflected by a lower CIMT, in patients with fAAA compared with patients with spAAA, independent of common atherosclerotic risk factors. These results support the hypothesis that although atherosclerosis is a common underlying feature in patients with aneurysms, atherosclerosis is not the primary driving factor in the development of fAAA.
Resumo:
The correct interpretation of chest film on cardiac patients is very important. The most important feature is the radiographic appearance of the pulmonary vascularity. Four different patterns of pulmonary vascularity are considered: normal, decreased, increased and uneven. The different diseases associated with each type are mentioned. From the pulmonary vascular pattern one can deduct hemodynamic data which are important for the diagnosis, grade of severity and follow-up.
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OBJECTIVES: To investigate if the shading sign is an exclusive MRI feature of endometriomas or endometrioid tumors, and to analyze its different patterns. METHODS: Three hundred and fourty six women with adnexal masses who underwent 1.5/3-T MRI were included in this retrospective, board-approved study. The shading sign was found in 56 patients, but five cases were excluded due to lack of imaging follow-up or histological correlation. The final sample included 51 women. The type of tumor and the pattern of shading were recorded for each case. RESULTS: Thirty endometriomas and five endometrioid carcinomas were found. The remaining 16 cases corresponded to other benign and malignant tumors. The overall sensitivity, specificity, positive predictive value, and negative predictive value were 73%, 93%, 59%, and 96%, respectively. Restricting the analysis to cystic lesions without solid or fat component, sensitivity, specificity, positive predictive value, and negative predictive value were 73%, 96%, 94%, and 80%. Five shading patterns were identified: layering (15.7%), liquid-liquid level (11.8%), homogenous (45.1%), heterogeneous (11.8%), and focal/multifocal shading within a complex mass (19.6%). No significant correlation was found between these patterns and the type of tumor. CONCLUSIONS: The shading sign is not exclusive of endometriomas or endometrioid tumors. Homogenous shading was the most prevalent pattern in endometriomas and half of the cases with focal/multifocal shading within a complex mass were endometrioid carcinomas.
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Acute otitis media (AOM) is the most common infection in childhood, resulting from both anatomic and immunologic specificities of this age group. Recurrent AOM has been defined as one of the warning signs for primary immunodeficiencies (PID), In this study we evaluated the strength of recurrent AOM as clinical predictor of PID. Methods: Retrospective study (August 2010 - December 2013) which included all patients referred to PID appointment because of recurrent AOM (= 8 AOM episodes/year). Syndromic patients or those presenting with another warning sign for PID were excluded. Clinical, demographic and laboratory results were analized and statistical analysis was made using SPSS 20. Results: Seventy-five patients were included (median age 37,8 months; 62,7% male gender), corresponding to 15% of all first appointments. Other comorbidities were present in 20% of the patients and 17% had ORL surgery prior to PID referral. In most patients, the immunologic screening consisted on the evaluation of humoral function, but in selected cases other studies were performed (namely complement and lymphocyte immunophenotyping). A PID was identified in 12 children (16,0%) and the majority of these patients had other distinctive feature (personal or familiar antecedent of infection or auto-immunity, 66,7%, p<0,05). Nine children (12,0%) underwent prophylactic cotrimoxazole. The average length of follow-up was 11,2 months. Conclusion: Despite being a very frequent cause of immunologic screening, in this study recurrent AOM was not found to be a good predictor of underlying PID, unless the patients presents other significant personal or family history.