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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

Comparação entre testes químico (o-toluidina) e imunoquímico de pesquisa de sangue oculto nas fezes e correlação com os achados colonoscópicos / Comparison between chemical (toluidine) and immunochemical faecal occult blood tests and correlation with the colonoscopic findings

Borges, Luana Vilarinho 24 April 2013 (has links)
Introdução: O sangramento colorretal é considerado um sinal de alarme e não deve ser ignorado. A perda de sangue pode não ser identificada pelo paciente, o que caracteriza a presença de sangue oculto. Este diagnóstico pode ser confirmado por testes de Pesquisa de Sangue Oculto nas Fezes (PSOF), através de métodos químicos ou imunoquímicos de identificação da hemoglobina. O resultado positivo de um teste de PSOF requer investigação complementar com colonoscopia, exame invasivo, de alto custo e que exige preparo intestinal. Justifica-se, portanto, a aplicação de um teste diagnóstico mais sensível e específico. No presente estudo, foram avaliados quatro diferentes testes de PSOF em 176 pacientes submetidos à colonoscopia e seus resultados foram comparados. Objetivos: 1) avaliar o grau de concordância entre os testes de PSOF e a colonoscopia. 2) avaliar a sensibilidade, a especificidade e os valores de predição dos testes químico e imunoquímico de PSOF, em pacientes submetidos à colonoscopia. Métodos: Pacientes com indicação de realizar colonoscopia foram submetidos também à PSOF pelo método químico (o-toluidina) e pelo método imunoquímico, empregando três kits comerciais disponíveis no mercado. Os pacientes foram avaliados quanto à indicação do exame colonoscópico, resultado da colonoscopia e uso de alimentos e medicamentos que pudessem interferir no resultado dos testes fecais. Fundamentado nos achados endoscópicos, a colonoscopia foi categorizada em positiva ou negativa, de acordo com a possível fonte de sangramento colorretal. O grau de concordância entre os testes de PSOF foi avaliado pelo índice Kappa. Resultados: Dos 176 pacientes, houve predomínio do sexo feminino (64,8%), com média de idade de 55,5 anos. As indicações clínicas mais frequentes para realização de colonoscopia foram alteração do hábito intestinal, doença inflamatória intestinal, dor abdominal e anemia. Os principais achados foram pólipos < 1 cm, doença diverticular não complicada do cólon e exame normal. Quarenta e quatro (25%) colonoscopias foram categorizadas como positivas quanto à fonte de sangramento colorretal. Observou-se concordância (p<0,05) entre todos os testes avaliados e a colonoscopia. O teste da o-toluidina apresentou concordância pobre (Kappa 0,03), enquanto os demais testes apresentaram concordância moderada (Kappa entre 0,43-0,48). O teste da o-toluidina revelou menor sensibilidade, especificidade, valor preditivo positivo e valor preditivo negativo em comparação aos testes imunoquímicos. Conclusões: Os testes imunoquímicos apresentaram melhores índices de concordância com a colonoscopia, quando comparados ao teste da o-toluidina. Os testes imunoquímicos revelaram maior sensibilidade, especificidade e valores de predição na detecção de sangramento colorretal / Introduction: Colorectal bleeding is considered an alarm sign and should not be ignored. Blood loss can not be identified by the patient, which characterizes the presence of occult blood. This diagnosis can be confirmed by Faecal Occult Blood Testing (FOBT), through chemical or immunochemical methods. The positive outcome of a test requires complementary research FOBT with colonoscopy, an examination of invasive, costly and requires bowel preparation. It is justifiable, therefore, the application of diagnostic tests with better sensitivity and specificity. In the present study, we evaluated four different tests of PSOF in 176 patients undergoing colonoscopy and their results were compared. Objectives: 1) evaluate the degree of concordance between the PSOF tests and colonoscopy 2) assess the sensitivity, the specificity and the prediction values of the chemical and immunochemical FOBTs, in patients undergoing colonoscopy. Methods: Patients with indication of perform colonoscopy were subjected also to FOBT by the chemical method (toluidine test) and by the immunochemical method employing three commercial kits available in the market. Patients were evaluated regarding the indication of the colonoscopic examination, colonoscopy result, and use of foods and drugs that could interfere in the results of the faecal tests. Based on the endoscopic findings, the colonoscopy was rated as positive or negative, according to the possible colorectal bleeding source. The degree of accordance between FOBTs was evaluated by the Kappa index. Results: Among the 176 patients, there was a predominance of female gender (64.8%) with an average age of 55.5 years old. The most frequent clinical indication for colonoscopy were bowel habit changes, inflammatory bowel disease, abdominal pain and anemia. The main findings of colonoscopy were polyps <1 cm, uncomplicated colonic diverticular disease and normal exam. Forty-four (25%) colonoscopies were categorized as positive as to the possible source of colorectal bleeding. There was agreement (p<0.05) between all tests evaluated and the colonoscopy. The toluidine test presented poor accordance (Kappa 0.03), while the others showed moderate concordance (Kappa 0.43-0.48). The toluidine test showed less sensitivity, specificity, positive predictive value and negative predictive value compared to immunochemical tests. Conclusions: Immunochemical tests showed the best indexes of agreement with colonoscopy, when compared to the toluidine test. The immunochemical tests have shown greater sensitivity, specificity and predictive values in detecting colorectal bleeding
52

Impacto do uso de técnicas microbiológicas para o estreptococo beta hemolítico do grupo A no diagnóstico e tratamento das faringotonsilites / Impact of the use of microbiological techniques for Group A Streptococcus in the diagnosis and treatment of sore throats

Cardoso, Debora Morais 23 April 2015 (has links)
INTRODUÇÃO: A Faringotonsilite é doença comum nos consultórios e prontosocorros de pediatria. OBJETIVOS: Avaliar o impacto da realização rotineira da prova rápida para pesquisa de estreptococo do grupo A (PRE) no diagnóstico e tratamento da faringotonsilite aguda em crianças e adolescentes atendidos em um Hospital Geral. MÉTODOS: Trata-se de um estudo prospectivo, observacional, de protocolo de atendimento, instituído no Pronto-Socorro do Hospital Universitário da Universidade de São Paulo para o atendimento de crianças e adolescentes com diagnóstico de faringotonsilite aguda. RESULTADOS: Foram estudadas 1039 crianças e adolescentes. Com base no quadro clínico, antibiótico seria prescrito em 530 pacientes (51%), e com o uso da PRE e/ou cultura de orofaringe foi prescrito em 268 (25,8%) pacientes. Das 509 crianças que não receberiam antibiótico pelo quadro clínico, 157 tiveram PRE e/ou cultura de orofaringe positiva. O diagnóstico baseado no quadro clínico apresentou sensibilidade de 63,06% (IC-95%:62,95-63,17%); especificidade de 57,33% (IC-95%:57,25-57,41%); valor preditivo positivo de 50,57% (IC-95%:50,47-50,66%) e valor preditivo negativo de 69,16% (IC-95%: 50,47-50,66%). CONCLUSÕES: Neste estudo o diagnóstico clínico da faringotonsilite estreptocócica mostrou baixa sensibilidade e especificidade. O uso rotineiro da prova rápida para pesquisa de estreptococo permitiu uma redução do uso de antibiótico e a identificação de crianças e adolescentes com faringotonsilite estreptocócicas que não receberiam antibiótico e estariam sob o risco das complicações da infecção estreptocócica / BACKGROUND: Sore throat is a common disease in the pediatric emergency room. OBJECTIVES: The objective of this study was to evaluate the impact of routine performance of rapid antigen detection test (RADT) in the diagnosis and treatment of acute pharyngitis in children treated at an academic hospital. METHODS: This is a prospective, observational, protocol compliance, established at the Emergency of Hospital Universitário - Universidade de São Paulo for the care of children and adolescents diagnosed with acute pharyngitis. RESULTS: We studied 1039 children and adolescents. Based on clinical findings, antibiotic would be prescribed in 530 patients (51%) and using the RADT or sore throat culture was prescribed in 268 patients. Of the 509 children who did not receive antibiotics for the clinical, 157 had positive RADT or sore throat culture. The diagnosis based on clinical sensitivity was 63,06% (IC 95% 62,95- 63,17%), specificity 57,3% (IC 95% 57,25-57,41%), positive predictive value of 50,57% (IC 95% 50,47-50,66%) and negative predictive value of 69,16% (IC 95% 50,47-50,66%). CONCLUSIONS: In this study the clinical diagnosis of streptococcal pharyngitis had low sensitivity and specificity. The routine use of rapid test for streptococcal research led to a reduction of antibiotic use and the identification of a risk group for complication of streptococcal infection
53

Predição da restrição do crescimento fetal pela medida da altura uterina / Prediction of fetal growth restriction by uterine height

Silvio Martinelli 08 March 2004 (has links)
O objetivo deste estudo foi verificar o poder de predição da medida da altura uterina para a restrição do crescimento fetal (RCF), por meio da curva de MARTINELLI et al. (2001), tendo como limite o percentil 5 e 10 para a idade gestacional e comparar com a curva de BELIZÁN et al. (1978). Entre julho de 2000 e fevereiro de 2003, 238 gestantes de alto risco foram submetidas a medidas de altura uterina, da 20a à 42a semana de gestação. Todas possuíam idade gestacional confirmada por ultra-sonografia precoce. A confirmação do diagnóstico de RCF foi dada após o nascimento pela curva de RAMOS (1983). Entre as gestantes, 50 (21,0%) tiveram recém-nascidos pequenos para a idade gestacional. O mesmo observador realizou 1617 medidas de altura uterina, com fita métrica, da borda superior da sínfise púbica ao fundo uterino. Para a ocorrência de RCF, considerando um exame positivo se uma medida de altura uterina encontrava-se abaixo do percentil 10 para a idade gestacional na curva de MARTINELLI et al. (2001), a sensibilidade (S) foi de 78%, especificidade (E) de 77,1%, valor preditivo positivo (VPP) de 47,6% e valor preditivo negativo (VPN) de 92,9%. Utilizando como limite o percentil 5, foram obtidos S= 64%, E= 89,9%, VPP= 62,7% e VPN= 90,4%, para o diagnóstico da RCF. Utilizando-se a curva de BELIZÁN et al. (1978) e considerando positivo exame com um valor abaixo do percentil 10 para a idade gestacional, os resultados encontrados foram S= 54%, E= 97,3%, VPP= 84,4% e VPN= 88,8% para a identificação da RCF. Comparada à curva de BELIZÁN et al. (1978), a curva de altura uterina de MARTINELLI et al. (2001) apresentou maior sensibilidade e valor preditivo negativo, consistindo em método de triagem mais adequado para a RCF / The aim of this study was to correlate uterine height measurements below the 5th and 10th percentiles using MARTINELLI et al. (2001) curve to fetal growth restriction (FGR) and to compare with the BELIZÁN et al. (1978) curve. During the period of July 2000 and February 2003, 238 pregnant women of high risk were submitted to uterine height measurements between the 20th and 42nd weeks of gestation. The whole group had well-known gestational age, confirmed by early ultrasound. The diagnosis of FGR was confirmed after birth according to RAMOS (1983). Among these women, 50 (21,0%) gave birth to light for gestational age infants. The same observer, using tape measure, performed 1617 uterine height measurements, from the upper border of the symphysis pubis to the fundus uteri. For the diagnosis of FGR, being considered as positive the exam with measurements below the 10th percentile according to MARTINELLI et al. (2001) curve, the sensitivity (SE), specificity (SP), positive predictive value (PPV) and negative predictive value (NPV) were 78,0%, 77,1%, 47,6% and 92,9%, respectively. For the 5th percentile, this curve showed SE= 64,0%, SP= 89,9%, PPV= 62,7% and NPV= 90,4% for the detection of FGR. The BELIZÁN et al. (1978) curve, having the 10th percentile as the limit, yielded SE= 54,0%, SP= 97,3%, PPV= 84,4% and NPV= 88,8% for the identification of FGR. We conclude that, when used for screening FGR, the MARTINELLI et al. (2001) curve showed greater sensitivity and negative predictive value, and presents better results than that of Belizán et al. (1978)
54

Impacto do uso de técnicas microbiológicas para o estreptococo beta hemolítico do grupo A no diagnóstico e tratamento das faringotonsilites / Impact of the use of microbiological techniques for Group A Streptococcus in the diagnosis and treatment of sore throats

Debora Morais Cardoso 23 April 2015 (has links)
INTRODUÇÃO: A Faringotonsilite é doença comum nos consultórios e prontosocorros de pediatria. OBJETIVOS: Avaliar o impacto da realização rotineira da prova rápida para pesquisa de estreptococo do grupo A (PRE) no diagnóstico e tratamento da faringotonsilite aguda em crianças e adolescentes atendidos em um Hospital Geral. MÉTODOS: Trata-se de um estudo prospectivo, observacional, de protocolo de atendimento, instituído no Pronto-Socorro do Hospital Universitário da Universidade de São Paulo para o atendimento de crianças e adolescentes com diagnóstico de faringotonsilite aguda. RESULTADOS: Foram estudadas 1039 crianças e adolescentes. Com base no quadro clínico, antibiótico seria prescrito em 530 pacientes (51%), e com o uso da PRE e/ou cultura de orofaringe foi prescrito em 268 (25,8%) pacientes. Das 509 crianças que não receberiam antibiótico pelo quadro clínico, 157 tiveram PRE e/ou cultura de orofaringe positiva. O diagnóstico baseado no quadro clínico apresentou sensibilidade de 63,06% (IC-95%:62,95-63,17%); especificidade de 57,33% (IC-95%:57,25-57,41%); valor preditivo positivo de 50,57% (IC-95%:50,47-50,66%) e valor preditivo negativo de 69,16% (IC-95%: 50,47-50,66%). CONCLUSÕES: Neste estudo o diagnóstico clínico da faringotonsilite estreptocócica mostrou baixa sensibilidade e especificidade. O uso rotineiro da prova rápida para pesquisa de estreptococo permitiu uma redução do uso de antibiótico e a identificação de crianças e adolescentes com faringotonsilite estreptocócicas que não receberiam antibiótico e estariam sob o risco das complicações da infecção estreptocócica / BACKGROUND: Sore throat is a common disease in the pediatric emergency room. OBJECTIVES: The objective of this study was to evaluate the impact of routine performance of rapid antigen detection test (RADT) in the diagnosis and treatment of acute pharyngitis in children treated at an academic hospital. METHODS: This is a prospective, observational, protocol compliance, established at the Emergency of Hospital Universitário - Universidade de São Paulo for the care of children and adolescents diagnosed with acute pharyngitis. RESULTS: We studied 1039 children and adolescents. Based on clinical findings, antibiotic would be prescribed in 530 patients (51%) and using the RADT or sore throat culture was prescribed in 268 patients. Of the 509 children who did not receive antibiotics for the clinical, 157 had positive RADT or sore throat culture. The diagnosis based on clinical sensitivity was 63,06% (IC 95% 62,95- 63,17%), specificity 57,3% (IC 95% 57,25-57,41%), positive predictive value of 50,57% (IC 95% 50,47-50,66%) and negative predictive value of 69,16% (IC 95% 50,47-50,66%). CONCLUSIONS: In this study the clinical diagnosis of streptococcal pharyngitis had low sensitivity and specificity. The routine use of rapid test for streptococcal research led to a reduction of antibiotic use and the identification of a risk group for complication of streptococcal infection
55

Revis?o sistem?tica e meta-an?lise de tomografia por emiss?o de p?sitrons (PET) com ant?geno da membrana espec?fica da pr?stata (PSMA) marcado com 68GA, no c?ncer de pr?stata

Matushita, Cristina Sebasti?o 27 June 2018 (has links)
Submitted by PPG Medicina e Ci?ncias da Sa?de (medicina-pg@pucrs.br) on 2018-10-10T18:14:57Z No. of bitstreams: 1 Dissera??o CRIS rev_VFinal.pdf: 2998966 bytes, checksum: fef2ba937c2e3faa8a245d6da4b908ae (MD5) / Rejected by Caroline Xavier (caroline.xavier@pucrs.br), reason: Devolvido devido ? data de defesa cadastrada na publica??o (27/07/2018) estar diferente da data de defesa que consta na folha de aprova??o da banca (28/06/2018) no arquivo PDF. on 2018-10-16T17:23:19Z (GMT) / Submitted by PPG Medicina e Ci?ncias da Sa?de (medicina-pg@pucrs.br) on 2018-10-17T18:39:08Z No. of bitstreams: 1 Dissertac?a?o_Cristina_Sebastiao_Matushita rev_VFinal_corrigida.pdf: 2373644 bytes, checksum: 8a866e5c464e92b65ce80b925e027963 (MD5) / Approved for entry into archive by Sheila Dias (sheila.dias@pucrs.br) on 2018-10-19T11:20:18Z (GMT) No. of bitstreams: 1 Dissertac?a?o_Cristina_Sebastiao_Matushita rev_VFinal_corrigida.pdf: 2373644 bytes, checksum: 8a866e5c464e92b65ce80b925e027963 (MD5) / Made available in DSpace on 2018-10-19T11:26:52Z (GMT). No. of bitstreams: 1 Dissertac?a?o_Cristina_Sebastiao_Matushita rev_VFinal_corrigida.pdf: 2373644 bytes, checksum: 8a866e5c464e92b65ce80b925e027963 (MD5) Previous issue date: 2018-06-27 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / The purpose of this study was to assess the diagnostic performance of 68Ga?Prostate-specific Membrane Antigen (PSMA) Positron Emission Tomography (PET) for detection of prostate cancer and recurrent prostate cancer. Methods: A systematic search was performed in PubMed, Cochrane and Embase to identify relevant published studies reporting on the performance of 68Ga?Prostate-specific Membrane Antigen (PSMA) PET in patients with suspected, confirmed, untreated or recurrent Prostate Cancer. A composite standard included changing in PSA values, clinical follow?up and histopathological findings as reference standard. Results: Thirty-five studies including in total 3532 patients who underwent a 68Ga-PSMA PET met our inclusion criteria. We obtained a pooled positive likelihood ratio (LR) of 1.81 (0.75 to 4.36) with 0% heterogeneity. For patients with PSA <0.5ng/mL, the positive LR pooled estimate was 1.17 (0.37-3.73) and the sensitivity was 56% (0.42-0.68). Conclusion: This meta-analysis of available studies demonstrates that 68Ga-PSMA PET appears to provide good sensitivity and specificity. / O objetivo deste estudo foi avaliar o desempenho diagn?stico da tomografia por emiss?o de p?sitrons (PET) com ant?geno de membrana espec?fico da Pr?stata (PSMA) para detec??o de c?ncer de pr?stata e c?ncer de pr?stata recorrente. M?todos: uma pesquisa sistem?tica foi realizada em PubMed, Cochrane e Embase para identificar estudos relevantes publicados que relatam o desempenho do PSMA PET marcado com 68Ga em pacientes com c?ncer de pr?stata suspeito, confirmado, n?o tratado ou recorrente. Um composto padronizado incluiu altera??o nos valores de PSA, acompanhamento cl?nico e achados histopatol?gicos como padr?o de refer?ncia. Resultados: trinta e cinco estudos, que inclu?ram no total 3532 pacientes submetidos a um PET de 68Ga-PSMA, atendiam aos crit?rios de inclus?o. Obtivemos uma raz?o de verossimilhan?a positiva combinada (LR) de 1,81 (0,75 a 4,36) com 0% de heterogeneidade. Para pacientes com PSA <0,5ng/mL, a estimativa de LR combinada positiva foi de 1,17 (0,37-3,73) e a sensibilidade foi de 56% (0,42-0,68). Conclus?o: Esta meta-an?lise de estudos dispon?veis demonstra que o PET de 68Ga-PSMA parece fornecer boa sensibilidade e especificidade.
56

Modeling, Design, Fabrication, and Characterization of a Highly Sensitive Fluorescence-based Detection Platform for Point-of-Care Applications

January 2018 (has links)
abstract: Over the past several decades, there has been a growing interest in the use of fluorescent probes in low-cost diagnostic devices for resource-limited environments. This dissertation details the design, development, and deployment of an inexpensive, multiplexed, and quantitative, fluorescence-based lateral flow immunoassay platform, in light of the specific constraints associated with resource-limited settings. This effort grew out of the need to develop a highly sensitive, field-deployable platform to be used as a primary screening and early detection tool for serologic biomarkers for the high-risk human papillomavirus (hrHPV) infection. A hrHPV infection is a precursor for developing high-grade cervical intraepithelial neoplasia (CIN 2/3+). Early detection requires high sensitivity and a low limit-of-detection (LOD). To this end, the developed platform (DxArray) takes advantage of the specificity of immunoassays and the selectivity of fluorescence for early disease detection. The long term goal is to improve the quality of life for several hundred million women globally, at risk of being infected with hrHPV. The developed platform uses fluorescent labels over the gold-standard colorimetric labels in a compact, high-sensitivity lateral flow assay configuration. It is also compatible with POC settings as it substitutes expensive and bulky light sources for LEDs, low-light CMOS cameras, and photomultiplier tubes for photodiodes, in a transillumination architecture, and eliminates the need for expensive focusing/transfer optics. The platform uses high-quality interference filters at less than $1 each, enabling a rugged and robust design suitable for field use. The limit of detection (LOD) of the developed platform is within an order of magnitude of centralized laboratory diagnostic instruments. It enhances the LOD of absorbance or reflectometric and visual readout lateral flow assays by 2 - 3 orders of magnitude. This system could be applied toward any chemical or bioanalytical procedure that requires a high performance at low-cost. The knowledge and techniques developed in this effort is relevant to the community of researchers and industry developers looking to deploy inexpensive, quantitative, and highly sensitive diagnostic devices to resource-limited settings. / Dissertation/Thesis / Doctoral Dissertation Electrical Engineering 2018
57

Acurária do estudo dos jatos ureterais à ultra-sonografia do Doppler Colorido no diagnóstico das hidronefroses / Diagnostic accuracy of color Doppler sonographic study of the ureteric jets in evaluation of hydronephrosis

Bessa Junior, José de 10 August 2007 (has links)
Introdução e Objetivo: Hidronefrose e Obstrução são condições associadas, entretanto dilatações da via excretora podem ocorrer na ausência de obstruções clinicamente importantes. Ultra-sonografia convencional e Renograma com Diuréticos são os métodos diagnósticos complementares mais utilizados na avaliação das hidronefroses na infância. Recentes trabalhos têm demonstrado a possibilidade de observarmos os jatos ureterais com o Estudo Ultra-sonográfico com Doppler Colorido e sugerido a sua aplicação no diagnóstico diferencial das hidronefroses. O objetivo do presente trabalho foi avaliar a aplicabilidade do estudo dos jatos ureterais como método diagnóstico na identificação das hidronefroses obstrutivas e não obstrutivas na população pediátrica. Métodos: Foram estudadas 48 crianças (35 meninos e 13 meninas) com idade que variou de um mês a 14 anos (mediana de 4 anos), que se apresentaram com Hidronefroses Unilaterais, Graus III e IV, e com suspeita de obstrução da junção pieloureteral. Todos os sujeitos foram submetidos ao Estudo dos jatos ureterais e ao Renograma com Diuréticos num período de duas semanas. As unidades hidronefróticas foram consideradas obstruídas quando a Função Renal Diferencial era menor do que 40%, ou em indivíduos mais velhos que apresentavam dor lombar intermitente. Os jatos ureterais de cada meato foram contados por um período de 5 minutos e considerados separadamente. Freqüência Relativa dos Jatos (FRJ) foi definida como o numero de jatos ureterais no lado afetado dividido pela soma dos jatos ureterais observados bilateralmente. Resultados: Vinte e duas (45,8%) unidades hidronefróticas foram consideradas obstruídas.A média da FRJ diferiu significativamente entre as hidronefroses obstrutivas (0,09 ± 0,15) e não obstrutivas (0,41 ± 0,11). (p<0.001). Análise da Curva ROC revelou que FRJ < 0,25 é o melhor valor que distingue as hidronefroses obstrutivas e não obstrutivas e o faz corretamente em 91,2 % dos casos, com uma Sensibilidade de 86,4% (IC95%=78,6-98,2%) e Especificidade de of 96.15% (IC95%=87.8-99%). O Índice de Probabilidade Positivo foi de 22,45 e a Razão de Chances Diagnóstica de 158,3. A área sob a curva ROC foi de 0,91 (IC95%=0,86-0,98) indicando a excelente acurácia do método. Conclusões: FRJ < 25 % mostrou ser um bom indicador de obstrução nas hidronefroses unilaterais da infância. O estudo dos jatos ureterais a Ultrasonografia com Doppler Colorido é método simples, não invasivo e pode ser utilizado na abordagem inicial e no seguimento, na diferenciação das hidronefroses obstrutivas e não obstrutivas na população pediátrica / Introduction and Objective: Hydronephrosis (HN) and obstruction are closely associated, but upper urinary tract dilatation can occur without significant obstruction. Despite some pitfalls, conventional ultrasonography and diuretic renography (DR) are the main modalities in the evaluation of HN in children. Recent reports have demonstrated the usefulness of Color Doppler Ultrasonography (CDUS) as a reliable method to identify the ureteric jets (UJ) in the bladder. The aim of this study was to evaluate CDUS evaluation of the UJ in the bladder as a diagnostic tool to distinguish obstructive from non-obstructive dilatations of the upper tract in pediatric population. Methods: We evaluated 48 patients (35 boys and 13 girls), aged 1 month to 14 years (median = 4 ys.), who presented with unilateral grade III and IV hydronephrosis suspicious of pyeloureteral junction obstruction. All patients underwent DR and evaluation of UJ by transverse CDSG of the bladder within a maximum of 2 weeks. Obstruction was considered in the DR when the hydronephrotic unit showed Differential Renal Function of less than 40%, or when symptomatic intermittent renal colic was present in older children. The number of UJ was counted over a 5 min period and its frequency was calculated for each ureteral orifice. Relative Jet Frequency (RJF) was defined as the UJ frequency of hydronephrotic side divided by total UJ frequency. Receiver-Operating Characteristic (ROC) plots were constructed to determine the best cuttoff for RJF, in order to identify renal units with obstructive hydronephrosis. Results:Twenty-two(45.8%) hydronephrotic units were considered obstructed. The mean RJF differed significantly between obstructive (0.09 ± 0,15) and non-obstructive hydronephrosis (0.41± 0.11)(p<0.001). ROC analysis revealed that RJF< 0.25 was the best threshold and it correctly discriminates obstruction in 91.2% of the childrens with a sensitivity of 86.4% (95%CI=78.6-98.2%) and specificity of 96.15% (95%CI=87,8-99%). The Positive Likelihood Ratio was 22.45 and Diagnostic Odds Ratio was 158.3.The area under the ROC curve was 0.91 (95%CI=0.86-0.98), indicating excellent discrimination power. Conclusions: In this study RJF < 25% was found to be a good indicator of obstruction in children with unilateral hydronephrosis. CDUS evaluation of UJ is an easy and non-invasive method that can be used as an initial diagnostic tool and in follow-up cases, to differentiate obstructed from non-obstructed hydronephrosis in the pediatric population
58

Infrared Spectroscopy in Combination with Advanced Statistical Methods for Distinguishing Viral Infected Biological Cells

Tang, Tian 17 November 2008 (has links)
Fourier Transform Infrared (FTIR) microscopy is a sensitive method for detecting difference in the morphology of biological cells. In this study FTIR spectra were obtained for uninfected cells, and cells infected with two different viruses. The spectra obtained are difficult to discriminate visually. Here we apply advanced statistical methods to the analysis of the spectra, to test if such spectra are useful for diagnosing viral infections in cells. Logistic Regression (LR) and Partial Least Squares Regression (PLSR) were used to build models which allow us to diagnose if spectral differences are related to infection state of the cells. A three-fold, balanced cross-validation method was applied to estimate the shrinkages of the area under the receiving operator characteristic curve (AUC), and specificities at sensitivities of 95%, 90% and 80%. AUC, sensitivity and specificity were used to gauge the goodness of the discrimination methods. Our statistical results shows that the spectra associated with different cellular states are very effectively discriminated. We also find that the overall performance of PLSR is better than that of LR, especially for new data validation. Our analysis supports the idea that FTIR microscopy is a useful tool for detection of viral infections in biological cells.
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Incidence and interval breast cancers in retrospective assessment /

Moberg, Kerstin, January 2003 (has links)
Diss. (sammanfattning) Stockholm : Karol. inst., 2003. / Härtill 5 uppsatser.
60

Quantification of length-bias in screening trials with covariate-dependent test sensitivity /

Heltshe, Sonya Lenore. January 2007 (has links)
Thesis (Ph.D. in Biostatistics, Department of Preventive Medicine and Biometrics) -- University of Colorado Denver, 2007. / Typescript. Includes bibliographical references (leaves 89-93). Free to UCD affiliates. Online version available via ProQuest Digital Dissertations;

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