469 research outputs found
A case of primary renal angiosarcoma
A 78-year old man was diagnosed with a left bleeding renal cyst from CT scan results. Serial CT scans revealed the left kidney mass to be increasing in size and a new lesion in the liver. Renal cell carcinoma with liver metastasis was diagnosed and a radical nephrectomy performed. The initial pathological diagnosis was a benign chronic hematoma. However, the liver mass increased in size and multiplied, while another mass emerged in the twelfth thoracic vertebra with spinal paralysis and was immediately removed. Pathological findings for that specimen showed malignancy of stromal cell origin but low atypia. The renal specimen was re-evaluated using whole cross-section analysis and immunohistochemistry, and diagnosed as a primary renal angiosarcoma. Recombinant interleukin-2 therapy was started immediately; however, the patient died of metastatic disease 13 months after the initial operation. Although contrast imaging depicted the primary lesion as a non-specific hematoma with little focal pooling, and low-grade cytological atypia was shown pathologically, the angiosarcoma was extremely aggressive
Identification of disease-causing genes using microarray data mining and gene ontology
Background: One of the best and most accurate methods for identifying disease-causing genes is monitoring gene expression values in different samples using microarray technology. One of the shortcomings of microarray data is that they provide a small quantity of samples with respect to the number of genes. This problem reduces the classification accuracy of the methods, so gene selection is essential to improve the predictive accuracy and to identify potential marker genes for a disease. Among numerous existing methods for gene selection, support vector machine-based recursive feature elimination (SVMRFE) has become one of the leading methods, but its performance can be reduced because of the small sample size, noisy data and the fact that the method does not remove redundant genes.
Methods: We propose a novel framework for gene selection which uses the advantageous features of conventional methods and addresses their weaknesses. In fact, we have combined the Fisher method and SVMRFE to utilize the advantages of a filtering method as well as an embedded method. Furthermore, we have added a redundancy reduction stage to address the weakness of the Fisher method and SVMRFE. In addition to gene expression values, the proposed method uses Gene Ontology which is a reliable source of information on genes. The use of Gene Ontology can compensate, in part, for the limitations of microarrays, such as having a small number of samples and erroneous measurement results.
Results: The proposed method has been applied to colon, Diffuse Large B-Cell Lymphoma (DLBCL) and prostate cancer datasets. The empirical results show that our method has improved classification performance in terms of accuracy, sensitivity and specificity. In addition, the study of the molecular function of selected genes strengthened the hypothesis that these genes are involved in the process of cancer growth.
Conclusions: The proposed method addresses the weakness of conventional methods by adding a redundancy reduction stage and utilizing Gene Ontology information. It predicts marker genes for colon, DLBCL and prostate cancer with a high accuracy. The predictions made in this study can serve as a list of candidates for subsequent wet-lab verification and might help in the search for a cure for cancers
Use of antibiotic spacers for knee endoprosthesis infections treatment
OBJCTIVE: The aim of this study is to evaluate the use of cement spacers impregnated with antibiotics for the treatment of infections in the nonconventional endoprostheses of the knee. METHODOLOGY: We have treated seven patients since 2004 (of which six were submitted to surgery in our service and one patient had been submitted to a primary tumor surgery in another removal service) with deep infection in knee tumor prosthesis. All patients were submitted to endoprosthesis removal and reconstructed with antibiotic cement spacer. All patients were monitored both clinically and by lab tests as for monitoring the evolution, being considered able for reviews after 6 (six) months without infections signs. RESULTS: We have noted a small predominance of infectious processes on the prosthesis inserted on proximal tibia as compared with distal femur (57.1% x 42.9%). The mean follow-up time of patients was 68.2 months. During the follow up, one patient died as a result of the root disease. Six patients out of seven were regarded as cured and one persisted with infection signs and symptoms. CONCLUSION: The results obtained up to date have motivated us to continue using this method of treatment.OBJETIVO: O objetivo do estudo é avaliar a utilização dos espaçadores de cimento acrílico com antibiótico no tratamento das infecções em endopróteses não convencionais de joelho. MÉTODO: Desde de 2004 foram tratados sete pacientes (seis pacientes operados no nosso serviço e um paciente que havia sido submetido a cirurgia primária do tumor em outro serviço) com infecção peri-endoprótese não convencional de joelho. Todos pacientes foram submetidos a retirada da endoprótese e reconstrução com espaçador com cimento acrílico com antibiótico. Todos os pacientes foram monitorados clínica e laboratorialmente quanto ao controle da evolução, sendo considerados aptos para a revisão e recolocação de endoprótese após 06 (seis) meses sem sinais infecciosos RESULTADOS: Notamos um discreto predomínio do do processo infeccioso nas próteses realizadas na tíbia proximal em comparação com o fêmur distal (57,1% x 42,9%). O seguimento médio dos pacientes foi 68,2 meses. Durante o seguimento, um paciente faleceu devido a doença de base. Dos sete pacientes, 6 foram considerados curados e um persistiu com sinais e sintomas de infecção. CONCLUSÃO: Os resultados obtidos até o momento tem motivado a continuidade deste método de tratamento.Universidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Departamento de Ortopedia e TraumatologiaUNIFESP, EPM, Depto. de Ortopedia e TraumatologiaSciEL
Asteroseismology and Interferometry
Asteroseismology provides us with a unique opportunity to improve our
understanding of stellar structure and evolution. Recent developments,
including the first systematic studies of solar-like pulsators, have boosted
the impact of this field of research within Astrophysics and have led to a
significant increase in the size of the research community. In the present
paper we start by reviewing the basic observational and theoretical properties
of classical and solar-like pulsators and present results from some of the most
recent and outstanding studies of these stars. We centre our review on those
classes of pulsators for which interferometric studies are expected to provide
a significant input. We discuss current limitations to asteroseismic studies,
including difficulties in mode identification and in the accurate determination
of global parameters of pulsating stars, and, after a brief review of those
aspects of interferometry that are most relevant in this context, anticipate
how interferometric observations may contribute to overcome these limitations.
Moreover, we present results of recent pilot studies of pulsating stars
involving both asteroseismic and interferometric constraints and look into the
future, summarizing ongoing efforts concerning the development of future
instruments and satellite missions which are expected to have an impact in this
field of research.Comment: Version as published in The Astronomy and Astrophysics Review, Volume
14, Issue 3-4, pp. 217-36
Planning, Implementing, and Running a Multicentre Preterm Birth Study with Biobank Resources in Brazil: The Preterm SAMBA Study
Background. Our aim was to describe the steps in planning, implementing, and running a multicentre cohort study of maternal and perinatal health using a high-quality biobank comprised of maternal serum, plasma, and hair samples collected from five sites in Brazil. The Preterm SAMBA study, conducted by the Brazilian Network for Studies on Reproductive and Perinatal Health, was an innovative approach used to identify women at higher risk for preterm birth. It is also of great importance in the study of other maternal and perinatal complications in the context of Brazil, which is a middle-income country. Methods. We described phases of planning, implementing, and running the Preterm SAMBA study, a multicentre Brazilian cohort study of low-risk nulliparous pregnant women, to validate a set of metabolite biomarkers for preterm birth identified in an external cohort. Procedures and strategies used to plan, implement, and maintain this multicentre preterm birth study are described in detail. Barriers and experience cited in the current narrative are not usually discussed in the scientific literature or published study protocols. Results. Several barriers and strategies were identified in different phases of the Preterm SAMBA study at different levels of the study framework (steering committee; coordinating and local centres). Strategies implemented and resources used in the study are a legacy of the Brazilian Network, aimed at training collaborators in such complex settings. Conclusion. The Brazilian Network for Studies on Reproductive and Perinatal Health has gained some experience in conducting a multicentre cohort study using a resourceful biobank which may be helpful to other research groups and maternal/perinatal health networks that plan on employing a similar approach to a similar background.201
Burden and modifications in life from the perspective of caregivers for patients after stroke
OBJECTIVE: to analyze the impact that caring has on a member of the family caring for a patient after a cerebrovascular accident, correlating life modifications and mental suffering with the perceived burden. METHOD: a cross-sectional, quantitative study, undertaken in January-April 2010 in Fortaleza, Ceará, Brazil. RESULT: 61 individuals were investigated, monitored by three hospitals' Home Care Program. Data collection was through interviews for identifying life changes, and through the application of three scales for investigating perceived burden, mental state and mental suffering. Respectively these were the Caregiver Burden Scale (CBS), the Mini-Mental State Examination (MMSE) and the Self Reported Questionnaire (SRQ). The majority of the carers were female, married, and the children of the stroke patients. The average age was 48.2 years (±12.4). The most-cited life modifications referred to the daily routine, to leisure activities, and to exhaustion or tiredness. Regarding burden, the dimensions of General tension, Isolation and Disappointment stood out. It was ascertained that overload was more severe when the carer presented more symptoms of psychological distress, in the absence of a secondary carer, and when the principal carers reported perceiving changes in their bodies and health. CONCLUSION: an association between burden and the carer's mental state was not observed. Understanding the care, through analysis of the burden and of the knowledge of the biopsychosocial situation will provide support for the nurse's work in reducing the overload for family caregivers.OBJETIVO: analizar el impacto del cuidar para el cuidador familiar de paciente después de accidente vascular cerebral, correlacionando modificaciones de vida y sufrimiento psíquico con la sobrecarga percibida. MÉTODO: estudio transversal, cuantitativo, realizado de enero a abril de 2010, en Fortaleza, Ceará, Brasil. RESULTADO: se investigaron 61 individuos, acompañados por el Programa de Servicio Domiciliar de tres hospitales. La colecta de los datos ocurrió mediante entrevista para identificar modificaciones de vida, y con la aplicación de tres escalas para investigar la sobrecarga percibida, estado mental y sufrimiento psíquico. Son ellas, respectivamente: Caregiver Burden Scale (CBS), Mini Examen del Estado Mental (MEEM) y Self Reported Questionnaire (SRQ). Los cuidadores, en su mayoría, eran del sexo femenino, casados (as) e hijo (as) de los pacientes después del AVC. Edad Media de 48,2 años (±12,4). Las modificaciones de vida más citadas fueron referentes a la rutina diaria, a las actividades de ocio y agotamiento o cansancio. En cuanto a la sobrecarga, se destacaron las dimensiones Tensión general, Aislamiento y Decepción. Se verificó mayor sobrecarga cuanto más síntomas de sufrimiento psíquico el cuidador presentase, en la ausencia de cuidador secundario y cuando los cuidadores principales relataron percibir modificación en el cuerpo y en la salud. CONCLUSIÓN: no fue observada asociación de la sobrecarga con el estado mental del cuidador. Entender la coyuntura del cuidado, mediante análisis del recargo de trabajo, y del conocimiento de la situación biopsicosocial, suministrará subsidios para la actuación del enfermero para reducir la carga generada para los cuidadores familiares.OBJETIVO: analisar o impacto do cuidar para o cuidador familiar de paciente após acidente vascular cerebral (AVC), correlacionando modificações de vida e sofrimento psíquico com a sobrecarga percebida. MÉTODO: estudo transversal, quantitativo, realizado de janeiro a abril de 2010, em Fortaleza, Ceará, Brasil. RESULTADO: investigaram-se 61 indivíduos, acompanhados pelo Programa de Atendimento Domiciliar (PAD), de três hospitais. A coleta dos dados ocorreu mediante entrevista para identificar modificações de vida, e com a aplicação de três escalas para investigar sobrecarga percebida, estado mental e sofrimento psíquico. São elas, respectivamente: Caregiver Burden Scale (CBS), Miniexame do Estado Mental (MEEM) e Self Reported Questionnaire (SRQ). Os cuidadores, na sua maioria, eram do sexo feminino, casados(as) e filho(as) dos pacientes após AVC. A média de idade era de 48,2 anos (±12,4). As modificações de vida mais citadas foram referentes à rotina diária, às atividades de lazer e esgotamento ou cansaço. Quanto à sobrecarga, destacaram-se as dimensões tensão geral, isolamento e decepção. Verificou-se maior sobrecarga quanto mais sintomas de sofrimento psíquico o cuidador apresentasse, na ausência de cuidador secundário e quando os cuidadores principais relataram perceber modificação no corpo e na saúde. CONCLUSÃO: não foi observada associação da sobrecarga com o estado mental do cuidador. Entender a conjuntura do cuidado, mediante análise da sobrecarga de trabalho, e do conhecimento da situação biopsicossocial fornecerá subsídios para a atuação do enfermeiro para reduzir a carga gerada para os cuidadores familiares
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