Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 56
Filtrar
1.
Ecol Appl ; 18(7): 1718-27, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18839766

RESUMO

The striped bass (Morone saxatilis) is an economically and ecologically important finfish species along the Atlantic seaboard of the United States. Recent stock assessments in Chesapeake Bay (U.S.A.) indicate that non-fishing mortality in striped bass has increased since 1999, concomitant with very high (>50%) prevalence of visceral and dermal disease caused by Mycobacterium spp. Current fishery assessment models do not differentiate between disease and other components of non-fishing mortality (e.g., senescence, predation); therefore, disease impact on the striped bass population has not been established. Specific measurement of mortality associated with mycobacteriosis in wild striped bass is complicated because the disease is chronic and mortality is cryptic. Epidemiological models have been developed to estimate disease-associated mortality from cross-sectional prevalence data and have recently been generalized to represent disease processes more realistically. Here, we used this generalized approach to demonstrate disease-associated mortality in striped bass from Chesapeake Bay. To our knowledge this is the first demonstration of cryptic mortality associated with a chronic infectious disease in a wild finfish. This finding has direct implications for management and stock assessment of striped bass, as it demonstrates population-level negative impacts of a chronic disease. Additionally, this research provides a framework by which disease-associated mortality may be specifically addressed within fisheries models for resource management.


Assuntos
Doenças dos Peixes/mortalidade , Infecções por Mycobacterium não Tuberculosas/veterinária , Distribuição por Idade , Animais , Bass , Feminino , Doenças dos Peixes/microbiologia , Masculino , Mycobacterium , Infecções por Mycobacterium não Tuberculosas/microbiologia , Oceanos e Mares , Estados Unidos
2.
Transplantation ; 66(9): 1167-74, 1998 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-9825813

RESUMO

BACKGROUND: The role of bone marrow-derived "passenger" leukocytes in the outcome of solid organ transplantation remains controversial. This study tested the relationship between high levels of donor-derived leukocytes within the transplanted organ and clinical outcome after lung transplantation. METHODS: Sequential bronchoalveolar lavage samples were obtained from human lung allograft recipients. Leukocytes of donor origin in the bronchoalveolar lavage fluid were detected using two-color immunofluorescence, and the results were correlated with multiple clinical parameters. RESULTS: Mean donor leukocyte levels for the first 200 days after transplantation were higher in patients with a good transplantation outcome compared with those patients who lost their grafts due to acute rejection (AR) or developed bronchiolitis obliterans syndrome. The presence of low numbers of donor-derived leukocytes for the first 200 days after transplantation was found to be a significant risk factor for graft loss due to either acute or chronic rejection (P=0.032). Nearly all patients (85%) experienced AR episodes. However, the time to onset of severe AR episodes was significantly longer (P=0.049), and the incidence of these episodes reduced, in patients who maintained high numbers of donor-derived leukocytes for the first 200 days after transplantation. CONCLUSIONS: The presence of high numbers of donor-derived leukocytes, particularly macrophages, in the transplanted lung in the first 200 days after transplantation was associated with stable graft function. Donor-derived leukocytes were reduced or absent in patients with a poor transplantation outcome. These findings rule out a negative influence of persisting donor leukocytes and are consistent with the emerging two-way models of transplant tolerance.


Assuntos
Leucócitos/citologia , Transplante de Pulmão/patologia , Doadores de Tecidos , Líquido da Lavagem Broncoalveolar/citologia , Movimento Celular , Infecções por Citomegalovirus/epidemiologia , Feminino , Sobrevivência de Enxerto/fisiologia , Humanos , Incidência , Pneumopatias/cirurgia , Masculino , Infecção da Ferida Cirúrgica/epidemiologia , Transplante Homólogo/imunologia , Resultado do Tratamento
3.
Transplantation ; 64(12): 1716-20, 1997 Dec 27.
Artigo em Inglês | MEDLINE | ID: mdl-9422408

RESUMO

BACKGROUND: Diastolic hypertension after renal transplantation leads to significant chronic morbidity and mortality. Recently, calcineurin phosphatase inhibition by cyclosporine or tacrolimus has been postulated to lead to diastolic hypertension through the induction of transforming growth factor-beta (TGF-beta) and resultant endothelin-mediated renal arteriolar vasospasm. METHODS: To investigate this hypothesis in humans, the allografts of 40 stable renal allograft recipients were biopsied 2 to 3 years after transplantation. Both cyclosporine and tacrolimus patients were included. Biopsies were divided and processed for histology and RNA extraction. RNA was then converted to cDNA and evaluated by semiquantitative polymerase chain reaction (actin-standardized, high-performance liquid chromatography-quantitated) for TGF-beta, endothelin, and renin transcription. Inflammatory cytokine gene transcription was also evaluated. Blood pressure was measured during the clinic check-in before biopsy. Variables were evaluated by Spearman rank correlation coefficient (rs) analysis. RESULTS: Diastolic hypertension was prevalent in the study population, with 40% of individuals having diastolic pressure >90 mmHg. TGF-beta and endothelin transcription were detected in 88% of biopsies studied, and renin transcription was detected in 91%. Intragraft transcription of TGF-beta (rs=0.61, P=0.0003) and endothelin (rs=0.43, P=0.0188) was strongly correlated with increasing transcription intragraft renin. In turn, renin transcription was strongly correlated with increasing diastolic blood pressure (rs=0.55, P=0.0015). Histological correlation of fibrosis score did not predict the degree of hypertension, nor did it correlate with TGF-beta transcription. Inflammatory cytokine transcription was not related to renin transcription or diastolic hypertension but was correlated with histological evidence of immune graft injury. CONCLUSIONS: These data support the hypothesis that posttransplant diastolic hypertension is a result of TGF-beta-induced, endothelin-mediated arteriolar vasoconstriction and subsequent activation of the renin-angiotensin pathway. These effects are independent of immune-mediated graft injury.


Assuntos
Endotelinas/genética , Hipertensão/etiologia , Transplante de Rim/efeitos adversos , Renina/genética , Fator de Crescimento Transformador beta/genética , Adulto , Biópsia , Pressão Sanguínea , Citocinas/genética , Diástole , Expressão Gênica , Humanos , Reação em Cadeia da Polimerase , RNA Mensageiro/genética , Transcrição Gênica
4.
Transplantation ; 68(10): 1578-82, 1999 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-10589958

RESUMO

BACKGROUND: Chronic rejection (CR) remains idiopathic, difficult to prospectively identify, and once detected, unresponsive to increased immunosuppression. We hypothesized that clinically stable human renal allografts have ongoing evidence of injury and immune activity, and that this correlates with the worsening of allograft function characteristic of CR. METHODS: The allografts of 40 stable renal allograft recipients were biopsied 2-3 years after transplantation. Biopsies were processed for histology and RNA extraction. RNA was evaluated by semi-quantitative RT-polymerase chain reaction for CD3y mRNA (a marker of T cell receptor turnover), and mRNA from cytokine genes previously shown to be transcribed during acute rejection: tumor necrosis factor-alpha, interferon-gamma, interleukin- (IL) 1beta, IL-2, IL-4, IL-6, and IL-8. Clinical parameters including urine protein and glomerular filtration rate were measured the day of biopsy. Findings were then compared with clinical outcome to establish associations between subclinical inflammation and graft dysfunction. Allograft function was measured again 2 years after biopsy and correlated with findings at the time of biopsy. RESULTS: Cytokine transcripts and histological evidence of injury were detected in more than two-thirds of stable grafts. The degree of the lymphocytic infiltrate correlated with the degree of proteinuria (P=0.034) and histological fibrosis (P=0.005). Similarly, the degree of intragraft CD3y transcription correlated with increasing proteinuria (P=0.043). IL-6 and IL-8 transcripts were also correlated with evidence of graft injury. After 2 years, those biopsies originally found to have evidence of fibrosis, tubular atrophy, or CD3gamma transcription had worsening graft function as determined by creatinine and glomerular filtration rate. CONCLUSIONS: These data demonstrate that significant injury and immune activity can be detected in patients who are stable on clinical grounds. Undetected subclinical graft injury may be a cause of chronic allograft rejection.


Assuntos
Imunossupressores/uso terapêutico , Transplante de Rim/patologia , Transplante de Rim/fisiologia , RNA Mensageiro/análise , Biomarcadores , Biópsia por Agulha , Citocinas/genética , Quimioterapia Combinada , Taxa de Filtração Glomerular , Humanos , Transplante de Rim/imunologia , RNA Mensageiro/genética , Complexo Receptor-CD3 de Antígeno de Linfócitos T/genética , Reprodutibilidade dos Testes , Transplante Homólogo
5.
Transplantation ; 62(12): 1758-62, 1996 Dec 27.
Artigo em Inglês | MEDLINE | ID: mdl-8990357

RESUMO

BACKGROUND: Exposure to hepatitis C virus (HCV) and subsequent infection after renal transplantation lead to significant clinical hepatitis in approximately 50% of graft recipients. METHODS: One hundred thirty-two consecutive renal allotransplant patients, who underwent transplantation of kidneys from HCV-positive cadaveric donors, were studied to investigate the relationship between donor and recipient HLA type and the risk of developing clinical hepatitis. Specific attention was directed toward the DR3 and DR4 alleles, as these had previously been associated with worse prognoses in autoimmune and viral hepatitis. RESULTS: Overall, 42% of patients receiving kidneys from donors seropositive for HCV developed clinical hepatitis. This was unrelated to preoperative recipient HCV serum reactivity (P=0.65). Patients receiving kidneys from seropositive donors with HCV RNA as detected by PCR were more likely to develop hepatitis than those receiving kidneys from PCR-negative donors (56% vs. 11%; P=0.005). The presence of the DR3 allele was associated with a significant risk of clinical hepatitis (P=0.025); 80% of DR3-positive recipients (n=34) progressed to hepatitis compared with 42% of DR3-negative patients. No other recipient HLA type was significantly related to prognosis. All patients receiving a donated kidney that expressed the B41 allele developed hepatitis, compared with 55% of recipients of non-B41 grafts (P=0.039). No association between the development of clinical hepatitis and HLA compatibility was found. CONCLUSIONS: These results suggest that both HLA type and viral presence as assayed by polymerase chain reaction, influence the risk of disease progression after transplantation of HCV-positive kidneys. Application of these associations may decrease the relative risk of a recipient contracting HCV hepatitis after cadaveric renal transplantation.


Assuntos
Hepatite C/sangue , Hepatite/etiologia , Transplante de Rim/efeitos adversos , Transplante de Rim/imunologia , Rim/microbiologia , Alelos , Antígeno HLA-DR3/análise , Antígeno HLA-DR4/análise , Antígeno HLA-DR5/análise , Antígeno HLA-DR5/genética , Hepacivirus/isolamento & purificação , Hepatite C/epidemiologia , Humanos , Fatores de Risco
6.
Transplantation ; 68(1): 72-5, 1999 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-10428270

RESUMO

BACKGROUND: Hypoalbuminemia is associated with poorer outcomes in renal transplantation. Diabetes can compound hypoalbuminemia's detrimental effects. Kidney-pancreas transplantation alters the diabetic milieu; yet, some patients continue to be hypoalbuminemic. METHODS: We retrospectively analyzed 232 patients who underwent simultaneous kidney-pancreas transplantation (SPK) between 1993 and 1997 to determine the incidence and clinical correlates of hypoalbuminemia in SPK recipients. Post-SPK hypoalbuminemia was defined as a serum albumin level < or =3.5 g/dl. Univariate analyses were performed to determine whether post-SPK hypoalbuminemia was associated with pre-SPK variables. The effect of albumin level and hypoalbuminemia on the risk of post-SPK events (cardiac events, cytomegalovirus [CMV] infection, rejection, readmission, kidney and pancreas graft failure, and death) was examined with a Cox proportional hazards model. RESULTS: The study population consisted of 149 men and 83 women. Average follow-up was 2.0+/-1.3 years. Hypoalbuminemia (serum albumin level < or =3.5 g/dL) was most common early after SPK (3 months: 44% of evaluable patients were hypoalbuminemic; 12 months: 15.3%; 36 months: 8.3%). Acute rejection episodes and readmission were the most common adverse events after SPK transplantation. There were 24 episodes of renal allograft loss and only 5 cardiac events. Ten SPK recipients died during the study time period. SPK-related hypoalbuminemia was associated with an increased risk for CMV infection (risk ratio [RR] 2.5; P<0.02), renal graft failure (RR 2.41; P=0.05), pancreas graft failure (RR 3.66; P=0.01), and a trend toward an increased risk for death (RR 2.8; P=0.19). CONCLUSIONS: Post-SPK hypoalbuminemia resolves over time in many patients. Persistent post-SPK hypoalbuminemia is associated with an increased risk for CMV infection, graft loss, and a trend toward decreased survival. Efforts to improve nutrition, as it may affect hypoalbuminemia in SPK recipients, may be one strategy for improving SPK outcomes.


Assuntos
Transplante de Rim , Transplante de Pâncreas , Albumina Sérica/deficiência , Idoso , Infecções por Citomegalovirus/epidemiologia , Infecções por Citomegalovirus/etiologia , Diabetes Mellitus Tipo 1/fisiopatologia , Diabetes Mellitus Tipo 1/cirurgia , Feminino , Sobrevivência de Enxerto/fisiologia , Humanos , Transplante de Rim/efeitos adversos , Masculino , Pessoa de Meia-Idade , Transplante de Pâncreas/efeitos adversos , Fatores de Risco
7.
Transplantation ; 69(7): 1485-91, 2000 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-10798775

RESUMO

BACKGROUND: Registry analyses and single-center studies have demonstrated that hypertension significantly increases the risk for chronic graft loss. The graft itself may contribute to posttransplant hypertension, and intragraft vasoactive hormones therefore, may be dysregulated in posttransplant hypertension. METHODS: We used the reverse-transcription polymerase chain reaction to assess the intragraft regulation of renin-angiotensin system transcripts in biopsy samples from 42 stable renal transplant patients with posttransplant hypertension. We also examined mRNA expression of inducible nitric oxide synthase, transforming growth factor-beta (TGF-beta), select cytokines, and metalloproteinase transcripts in biopsy tissue. Polymerase chain reaction products were quantitated using high performance liquid chromatography and normalized to beta-actin mRNA expression. Serum creatinine, glomerular filtration rate or creatinine clearance and tubular atrophy on biopsy were concurrently assessed. RESULTS: Renin and select Thl cytokine mRNA expression correlated with blood pressure. Type 1 angiotensin II receptor mRNA expression significantly correlated with glomerular filtration rate or creatinine clearance (P = 0.034) and inversely correlated with Th1 cytokines, inducible nitric oxide synthase, and cyclooxygenase-1 mRNA expression (P< or =0.013 for each). Type 1 angiotensin II receptor mRNA also approached a significant inverse correlation with TGF-beta mRNA expression (P = 0.09). Conversely, angiotensin-converting enzyme mRNA expression directly correlated with Thl cytokine (P< or =0.008 for each) and TGF-beta mRNA expression (P = 0.006). Type 1 angiotensin II receptor mRNA expression also correlated with matrix metalloproteinase-1 promoter region, tissue inhibitor of matrix metalloproteinase-2 (TIMP-2) and tissue inhibitor of matrix metalloproteinase-3 mRNA expression. Notably, matrix metalloproteinase-1 promoter region, tissue inhibitor of matrix metalloproteinase-2, and tissue inhibitor of matrix metalloproteinase-3 inversely correlated with TGF-beta mRNA expression (P< or =0.0027 for each). Type 1 angiotensin II receptor mRNA expression at biopsy directly correlated with glomerular filtration rate at 2 year's follow-up. However, angiotensin-converting enzyme mRNA expression at biopsy inversely correlated with glomerular filtration rate at 2 year's follow-up. CONCLUSIONS: These data suggest that allograft-level RAS gene expression may be predictive of future graft function in the setting of diastolic hypertension.


Assuntos
Expressão Gênica , Hipertensão/genética , Transplante de Rim , Rim/fisiopatologia , Sistema Renina-Angiotensina/genética , Adulto , Citocinas/genética , Feminino , Humanos , Masculino , Metaloendopeptidases/genética , Pessoa de Meia-Idade , Complicações Pós-Operatórias , Valor Preditivo dos Testes , Prognóstico , Receptor Tipo 1 de Angiotensina , Receptor Tipo 2 de Angiotensina , Receptores de Angiotensina/genética , Renina/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transplante Homólogo
8.
Hum Immunol ; 52(2): 95-108, 1997 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9077558

RESUMO

We hypothesized that the small amounts of donor HLA-A and HLA-B proteins detected in the serum during organ allograft rejection are indicative of higher local releases within the graft itself. We determined the concentrations of total HLA class I (HLA-I) and, in selected cases, specific donor and host HLA-A and HLA-B proteins, in the epithelial lining fluid (ELF) sampled by bronchoalveolar lavage (BAL) of lung transplant recipients (n = 37) and of normal controls (n = 25). We found that 1) HLA-I proteins were enriched in the lung ELF relative to other proteins; 2) the concentration of HLA-I in the ELF of well-functioning transplants was similar to that in normal lungs; 3) HLA-I proteins and total proteins were elevated in the ELF of patients who developed chronic rejection or refractory acute rejection; 4) the concentration of HLA-I was correlated with the percentage of neutrophils but not with the percentage of lymphocytes in the ELF of transplanted lungs; and 5) only the percentage of lymphocytes was elevated in the ELF of transplant patients with active CMV infections. Total HLA-I from the ELF was found to contain a mixture of both donor- and recipient-type HLA-A and HLA-B proteins and the donor-type HLA-A2 was found to be highly enriched in the ELF relative to serum.


Assuntos
Antígenos de Histocompatibilidade Classe I/metabolismo , Transplante de Pulmão/imunologia , Doença Aguda , Líquidos Corporais/citologia , Líquidos Corporais/imunologia , Líquido da Lavagem Broncoalveolar/imunologia , Infecções por Citomegalovirus/etiologia , Infecções por Citomegalovirus/imunologia , Infecções por Citomegalovirus/patologia , Epitélio/imunologia , Rejeição de Enxerto/etiologia , Rejeição de Enxerto/imunologia , Rejeição de Enxerto/patologia , Humanos , Contagem de Leucócitos , Transplante de Pulmão/efeitos adversos , Transplante de Pulmão/patologia , Neutrófilos , Prognóstico , Solubilidade
9.
Hum Pathol ; 26(7): 792-6, 1995 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-7628853

RESUMO

This article describes the use of computer-based analytical techniques to define nuclear size, shape, and texture features. These features are then used to distinguish between benign and malignant breast cytology. The benign and malignant cell samples used in this study were obtained by fine needle aspiration (FNA) from a consecutive series of 569 patients: 212 with cancer and 357 with fibrocystic breast masses. Regions of FNA preparations to be analyzed were converted by a video camera to computer files that were displayed on a computer monitor. Nuclei to be analyzed were roughly outlined by an operator using a mouse. Next, the computer generated a "snake" that precisely enclosed each designated nucleus. The computer calculated 10 features for each nucleus. The ability to correctly classify samples as benign or malignant on the basis of these features was determined by inductive machine learning and logistic regression. Cross-validation was used to test the validity of the predicted diagnosis. The logistic regression cross validated classification accuracy was 96.2% and the inductive machine learning cross-validated classification accuracy was 97.5%. Our computerized system provides a probability that a sample is malignant. Should this probability fall between 30% and 70%, the sample is considered "suspicious," in the same way a visually graded FNA may be termed suspicious. All of the 128 consecutive cases obtained since the introduction of this system were correctly diagnosed, but nine benign aspirates fell into the suspicious category.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Doenças Mamárias/patologia , Neoplasias da Mama/patologia , Diagnóstico por Computador , Mama/citologia , Humanos
10.
Surgery ; 120(4): 719-24, 1996 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8862383

RESUMO

BACKGROUND: Since the advent of cyclosporine-based immunosuppression for cadaveric kidney transplants in 1983, several changes have been made in immunosuppressive management at the University of Wisconsin. Since 1986, OKT3 has been available to treat steroid-resistant rejection; since 1992, OKT3 has been used as an induction agent replacing antilymphocyte globulin; and since 1993, mycophenolate mofetil has been used in 104 patients. METHODS: The impact of different immunosuppressive strategies on overall and immunologic graft survival (defined as graft loss caused by rejection) was evaluated in 1210 primary cadaveric renal transplants at the University of Wisconsin. Covariables, including degree of human leukocyte antigen matching, age, gender, cause of kidney failure, and early graft dysfunction, were evaluated. The series was subdivided into four eras according to immunosuppressive regimen, and the results were analyzed by era. RESULTS: Our principal findings are that immunologic graft survival has improved significantly during this series whereas overall graft survival has not. Mycophenolate was associated with a significant decrease in acute rejection. For a given patient, graft loss from rejection becomes less likely over time. Late rejection poses a greater risk than early rejection for graft loss. CONCLUSIONS: Improving outcomes may be related to improving immunosuppressive treatment, increasing degree of human leukocyte antigen matching, and better early graft function.


Assuntos
Ciclosporina/uso terapêutico , Sobrevivência de Enxerto/efeitos dos fármacos , Imunossupressores/uso terapêutico , Transplante de Rim , Adulto , Fatores Etários , Soro Antilinfocitário/uso terapêutico , Cadáver , Estudos de Coortes , Demografia , Estudos de Avaliação como Assunto , Feminino , Rejeição de Enxerto/prevenção & controle , Teste de Histocompatibilidade , Humanos , Masculino , Pessoa de Meia-Idade , Muromonab-CD3/uso terapêutico , Ácido Micofenólico/análogos & derivados , Ácido Micofenólico/uso terapêutico , Doadores de Tecidos , Transplante Homólogo
11.
Surgery ; 116(4): 649-56; discussion 656-7, 1994 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-7940162

RESUMO

BACKGROUND: A controversy has evolved as to which therapy, thrombolysis or thromboembolectomy, represents the optimal initial treatment for acute native artery occlusion. METHODS: Forty-eight cases of acute class I or II limb ischemia caused by native artery occlusion were retrospectively analyzed between 1988 and 1993. Nineteen of the patients were initially treated with thrombolysis (group 1), and 29 underwent thromboembolectomy (group 2). RESULTS: Initial clinical improvement was seen in 11 (57.9%) of 19 extremities in group 1, with complete clot resolution in 21%, partial lysis in 47.4%, and no angiographic improvement in 31.6%. Significantly superior results were achieved in group 2; 28 (97%) of 29 limbs showed clinical improvement after initial surgical therapy (p = 0.001). Limb salvage was 88.2% in group 1 and 96.6% in group 2 (p = 0.5). Adjunctive procedures for limb salvage were necessary in 10 (52.6%) of 19 limbs in group 1 compared with only five (17.2%) of 29 limbs in group 2 (p = 0.013). Perioperative mortality was 10.5% and 10.3% (p = 1.0), whereas major postoperative complications occurred in 63.2% and 37% of patients in groups 1 and 2, respectively (p = 0.14). Hospital and professional patient charges were analyzed for the 12 most recent patients from each group. Total mean charges per patient were higher in group 1 ($45,171) than in group 2 ($24,898) (p = 0.046). CONCLUSIONS: Patients initially treated surgically achieved better immediate clinical results with significant cost savings and without significant differences in morbidity, mortality, or limb salvage compared with patients treated initially by thrombolysis.


Assuntos
Arteriopatias Oclusivas/terapia , Embolectomia , Trombectomia , Terapia Trombolítica , Doença Aguda , Adulto , Idoso , Idoso de 80 Anos ou mais , Embolectomia/efeitos adversos , Embolectomia/economia , Extremidades/irrigação sanguínea , Feminino , Custos de Cuidados de Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Trombectomia/efeitos adversos , Trombectomia/economia , Terapia Trombolítica/efeitos adversos , Terapia Trombolítica/economia
12.
Arch Surg ; 130(5): 511-6, 1995 May.
Artigo em Inglês | MEDLINE | ID: mdl-7748089

RESUMO

OBJECTIVE: To use digital image analysis and machine learning to (1) improve breast mass diagnosis based on fine-needle aspirates and (2) improve breast cancer prognostic estimations. DESIGN: An interactive computer system evaluates, diagnoses, and determines prognosis based on cytologic features derived from a digital scan of fine-needle aspirate slides. SETTING: The University of Wisconsin (Madison) Departments of Computer Science and Surgery and the University of Wisconsin Hospital and Clinics. PATIENTS: Five hundred sixty-nine consecutive patients (212 with cancer and 357 with benign masses) provided the data for the diagnostic algorithm, and an additional 118 (31 with malignant masses and 87 with benign masses) consecutive, new patients tested the algorithm. One hundred ninety of these patients with invasive cancer and without distant metastases were used for prognosis. INTERVENTIONS: Surgical biopsy specimens were taken from all cancers and some benign masses. The remaining cytologically benign masses were followed up for a year and surgical biopsy specimens were taken if they changed in size or character. Patients with cancer received standard treatment. OUTCOME MEASURES: Cross validation was used to project the accuracy of the diagnostic algorithm and to determine the importance of prognostic features. In addition, the mean errors were calculated between the actual times of distant disease occurrence and the times predicted using various prognostic features. Statistical analyses were also done. RESULTS: The predicted diagnostic accuracy was 97% and the actual diagnostic accuracy on 118 new samples was 100%. Tumor size and lymph node status were weak prognosticators compared with nuclear features, in particular those measuring nuclear size. Compared with the actual time for recurrence, the mean error of predicted times for recurrence with the nuclear features was 17.9 months and was 20.1 months with tumor size and lymph node status (P = .11). CONCLUSION: Computer technology will improve breast fine-needle aspirate accuracy and prognostic estimations.


Assuntos
Biópsia por Agulha , Neoplasias da Mama/patologia , Diagnóstico por Computador , Núcleo Celular/patologia , Humanos , Recidiva Local de Neoplasia , Valor Preditivo dos Testes , Prognóstico
13.
Ann Thorac Surg ; 62(4): 1123-7, 1996 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8823100

RESUMO

BACKGROUND: Despite the steady increase in the number of elderly patients undergoing coronary artery bypass grafting (CABG), skepticism still exists as to whether this operation is justified in older people with a reduced life expectancy. The purpose of this study was to examine the effects of increasing age on outcome after CABG. METHODS: A retrospective chart review was performed on 1,689 consecutive veterans of the United States Armed Forces undergoing isolated primary CABG from January 1972 through December 1994. For better comparison, they were arbitrarily divided by age into three groups: group I, 50 years of age or less (n = 213), group II, between 51 and 70 years of age (n = 1,258), and group III, more than 70 years of age (n = 218). Long-term survival for each group was compared to that of their age-matched population derived from Wisconsin life tables. RESULTS: The preoperative ejection fraction was comparable in all three groups (p = 0.114). The patients older than 70 years of age had received more grafts per operation than the patients 50 years of age and younger (3.7 versus 3.3) (p = 0.0001). Although the aortic cross-clamp time was prolonged with advanced age (p = 0.0002), the cardiopulmonary perfusion time was shortest in elderly patients (p = 0.0001). The early (30-day) mortality for the entire study population was 1.3%. There was a linear correlation between increasing age and early (30-day) mortality: group I, 0.5% (1/213); group II, 1.0% (13/1,258); and group III, 3.2% (7/218). The overall 10-year actuarial survival for all patients was 67%. The 10-year survival was diminished with increasing age (p = 0.0001): 74% for group I, 68% for group II, and 47% for group III. Comparative analysis of the three groups with their age-matched counterparts demonstrated an age-related survival after CABG. In group I, reduced survival was evident 4 years after the CABG: the 10-year survival in group I was 74.2%, and the survival of their age-matched population was 93.4% (confidence interval, 67% to 81.9%). In group II a survival difference was obvious 8 years after CABG: 10-year survival of 67.5% versus 75.1% in their age-matched population (confidence interval, 64.8% to 71.6%). In the elderly group of patients, no survival difference was noted: 10-year survival of 42.7% versus 45.9% of the age-matched population (confidence interval, 29.8% to 64.6%). CONCLUSIONS: An acceptable early mortality and long-term survival equal to those seen for an age-matched elderly population are sound outcome measures that support the justification of CABG in older patients irrespective of age.


Assuntos
Ponte de Artéria Coronária/mortalidade , Adulto , Fatores Etários , Idoso , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Taxa de Sobrevida , Fatores de Tempo
14.
Urology ; 50(5): 700-3, 1997 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9372878

RESUMO

OBJECTIVES: We surveyed a "population" of younger men (20 to 49 years old) for lower urinary tract symptomatology and for symptomatology associated with prostatitis. METHODS: A National Guard unit was surveyed by mail with a 58-question urinary symptom questionnaire. Surveys were returned anonymously by mail. RESULTS: International Prostate Symptom Score (IPSS) of 8 or greater was seen in 5% of men in their 20s and rose to 15% of those in their 40s. Approximately 5% (0% to 7%) reported a history of prostatitis. Caffeine caused symptoms in 2% to 13%, while exercise and smoking were not associated with symptoms. Individual prostatitis symptoms were only seen occasionally across this age group. CONCLUSIONS: As measured by the IPSS, urinary symptoms increased during the 20 to 49-year age period. A history of prostatitis in much less common than most nonpopulation studies suggest.


Assuntos
Prostatite/complicações , Adulto , Fatores Etários , Humanos , Masculino , Pessoa de Meia-Idade , Prostatite/diagnóstico , Índice de Gravidade de Doença , Inquéritos e Questionários
15.
Urology ; 50(4): 525-8, 1997 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-9338726

RESUMO

OBJECTIVES: To determine if there is an increased rate of occurrence of bladder cancer in renal transplant recipients. METHODS: We reviewed the records of 3130 consecutive renal transplant recipients at the University of Wisconsin Hospital from 1980 to 1994. We then compared the rate of occurrence of bladder cancer in this population with that of the general population of Wisconsin. Using an age-specific hazard model based on the rate of bladder cancer in the general population of Wisconsin, we predicted the expected number of bladder cancer cases in this renal transplant population. RESULTS: Using this model, one would expect 1.81 cases of bladder cancer in the renal transplant data set, as opposed to the observed 6, resulting in a relative risk of 3.31 of developing bladder cancer as a result of renal transplantation. CONCLUSIONS: There is a higher incidence of bladder cancer in renal transplant recipients. Therefore, despite a higher incidence of hematuria in this population, each noninfected patient with microscopic (or gross) hematuria should undergo a careful urologic evaluation.


Assuntos
Transplante de Rim , Complicações Pós-Operatórias/epidemiologia , Neoplasias da Bexiga Urinária/epidemiologia , Adulto , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais
16.
Urology ; 51(3): 404-7, 1998 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9510343

RESUMO

OBJECTIVES: To identify the incidence and the success of endourologic therapy for symptomatic bladder-related calculi in simultaneous kidney-pancreas (SPK) transplant patients with bladder drainage. METHODS: A retrospective review of 300 SPK transplant patients with bladder drainage, treated at the University of Wisconsin, Madison from December 1985 to November 1995, is presented. A 3% incidence of bladder calculi was identified. All patients underwent cystolitholapaxy using electrohydraulic lithotripsy and endoscopic suture removal. Follow-up ranged from 15 to 86 months. RESULTS: A 100% stone-free rate was achieved after cystolitholapaxy and endoscopic suture removal. Two patients (22%) developed postprocedural urinary tract infections. No pancreaticoduodenocystotomy leaks or further complications were identified. CONCLUSIONS: SPK transplant patients with nonabsorbable sutures used for the duodenocystotomy anastomosis are at an increased risk for bladder calculi. Cystolitholapaxy with electrohydraulic lithotripsy is a safe and effective treatment for these suture-related stones.


Assuntos
Transplante de Rim , Litotripsia , Transplante de Pâncreas , Cálculos da Bexiga Urinária/terapia , Adulto , Feminino , Seguimentos , Humanos , Período Intraoperatório , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
17.
J Gastrointest Surg ; 5(6): 594-601; discussion 601-2, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-12086897

RESUMO

The use of orthotopic liver transplantation (OLTX) for the treatment of hepatocellular carcinoma (HCC) has generally become restricted to carefully selected cases of small oligocentric tumors. However, it is not uncommon to find previously undetected HCC within recipient cirrhotic livers at the time of hepatectomy. The impact of unsuspected HCC on patient outcomes remains unclear. A retrospective analysis of our institutional experience with adult primary OLTX was performed comparing recipients with incidental HCC (group 1), recipients with known or suspected HCC (group 2), and recipients confirmed by pathologic examination to be tumor free (group 3). Between 1984 and 2000, 27 patients in group 1, 12 patients in group 2, and 612 patients in group 3 underwent primary OLTX. Tumors were smaller (P = 0.0172) in group 1 than in group 2; however, the number of tumors and the histologic findings were similar in the groups. Incidence of bilobar involvement, vascular invasion, portal vein tumor thrombus, lymphatic involvement, and distant metastasis at the time of OLTX did not differ significantly between these groups. Four-year patient survival appeared to be lower in group 1 (70.0%) than in group 3 (79.0%) (P = 0.0546); 4-year patient survival was significantly worse in group 2 (31.0%) compared to group 3 (P = 0.0106). Thus, in our experience, incidentally diagnosed cases of HCC possess many of the same features of malignancy as preoperatively diagnosed HCC. Indeed, patient survival after OLTX appears to be adversely affected by the presence of incidental HCC.


Assuntos
Carcinoma Hepatocelular/mortalidade , Carcinoma Hepatocelular/patologia , Cirrose Hepática/mortalidade , Cirrose Hepática/patologia , Neoplasias Hepáticas/mortalidade , Neoplasias Hepáticas/patologia , Transplante de Fígado/métodos , Adulto , Biópsia por Agulha , Carcinoma Hepatocelular/cirurgia , Comorbidade , Feminino , Rejeição de Enxerto , Sobrevivência de Enxerto , Humanos , Cirrose Hepática/cirurgia , Neoplasias Hepáticas/cirurgia , Transplante de Fígado/mortalidade , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Probabilidade , Prognóstico , Modelos de Riscos Proporcionais , Sistema de Registros , Estudos Retrospectivos , Análise de Sobrevida , Transplante Homólogo , Resultado do Tratamento
18.
Am J Surg ; 180(1): 6-12, 2000 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11036131

RESUMO

BACKGROUND: Four different techniques for aorto-iliac magnetic resonance angiography (MRA) were assessed for accuracy using a digital subtraction angiography (DSA) gold standard. Surgeons' confidence in their ability to generate treatment plans with MRA and DSA was assessed, in consultation with a radiologist. METHODS: Two different two-dimensional (2D) time-of-flight (TOF) sequences, a phase-contrast sequence, and a contrast-enhanced (CE) MRA sequence were used. Receiver operating characteristic (ROC) curves were plotted and areas (A(z)) calculated from radiologists' readings. Surgeons' confidence in their ability to utilize the images for treatment planning was assessed with a 5-point Likert scale. Thirty-six patients were evaluated. RESULTS: CE MRA had a sensitivity, specificity, and A(z) of.92,.93, and.96, respectively, for stenoses 50% or greater. CE MRA performed better than other sequences, but the improvement compared with gated 2D TOF was not statistically significant. Interobserver agreement for CE MRA and DSA yielded identical Kappa values. Surgeons were most confident in DSA, followed by CE MRA, which was significantly preferred to other techniques. CONCLUSIONS: CE MRA closely approximates DSA in terms of diagnostic accuracy. Surgeons considering treatment plans are confident in the CE MRA technique, relative to other MRA methods.


Assuntos
Doenças da Aorta/diagnóstico , Arteriopatias Oclusivas/diagnóstico , Artéria Ilíaca/patologia , Angiografia por Ressonância Magnética , Adulto , Idoso , Angiografia Digital , Doenças da Aorta/cirurgia , Arteriopatias Oclusivas/cirurgia , Meios de Contraste , Feminino , Cirurgia Geral , Humanos , Artéria Ilíaca/cirurgia , Aumento da Imagem/métodos , Processamento de Imagem Assistida por Computador/métodos , Relações Interprofissionais , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Planejamento de Assistência ao Paciente , Curva ROC , Radiologia , Sensibilidade e Especificidade , Método Simples-Cego , Estatística como Assunto
19.
Am J Surg ; 178(2): 166-72, 1999 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10487272

RESUMO

BACKGROUND: The purpose of the study was to determine whether preoperative treatment plans for patients with lower extremity ischemia can be made with electrocardiography (EKG)-triggered two-dimensional (2D) time-of-flight (TOF) magnetic resonance angiography (MRA) as accurately as digital subtraction angiography (DSA). METHODS: Forty patients were prospectively evaluated with the combination of EKG-triggered 2D TOF MRA, DSA, and pulse volume recordings. Blinded reviewers graded arterial segments for disease severity. Accuracy of separate MRA- and DSA-based treatment plans was compared with the procedures performed based on all available information. RESULTS: There was an 86% exact match between MRA- and DSA-based plans (92% MRA and 94% DSA accuracy). The MRA-based plan accurately predicted 90% of suprainguinal and 95% of infrainguinal procedures, whereas the DSA-based plan accurately predicted 100% of suprainguinal and 85% of infrainguinal procedures. Two-year primary patency was 83% for all procedures. Radiologists' review of disease severity resulted in a mean exact correlation between studies of 81% (kappa = 0.64). The agreement between radiologists interpreting the MRA was 84% (kappa = 0.7) compared with 82% (kappa = 0.66) for the DSA. CONCLUSIONS: MRA- and DSA-based preoperative management plans were of comparable efficacy. Significant interobserver variability was seen with the interpretations of both preoperative studies. EKG-triggered 2D TOF MRA can be used to plan arterial reconstructions; however, all patients require arterial pressure measurements prior to suprainguinal repair and confirmatory intraoperative angiography during infrainguinal revascularization.


Assuntos
Angiografia Digital , Arteriopatias Oclusivas/diagnóstico , Eletrocardiografia , Perna (Membro)/irrigação sanguínea , Angiografia por Ressonância Magnética/métodos , Planejamento de Assistência ao Paciente , Idoso , Arteriopatias Oclusivas/classificação , Arteriopatias Oclusivas/diagnóstico por imagem , Arteriopatias Oclusivas/cirurgia , Pressão Sanguínea/fisiologia , Seguimentos , Previsões , Humanos , Processamento de Imagem Assistida por Computador/métodos , Canal Inguinal/irrigação sanguínea , Cuidados Intraoperatórios , Isquemia/classificação , Isquemia/diagnóstico , Isquemia/diagnóstico por imagem , Isquemia/cirurgia , Masculino , Variações Dependentes do Observador , Estudos Prospectivos , Pulso Arterial , Radiografia Intervencionista , Sensibilidade e Especificidade , Método Simples-Cego , Grau de Desobstrução Vascular
20.
Med Decis Making ; 20(1): 79-88, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-10638540

RESUMO

PURPOSE: The wait tradeoff (WTO) is a simple time-tradeoff method designed for temporary health states that uses a realistic and intuitive interface for the patient/subject. This method was tested by assessing patients' preferences for magnetic resonance angiography (MRA) versus x-ray angiography (XRA). MATERIALS AND METHODS: The WTO was tested by telephone interview in 38 patients with atherosclerotic peripheral vascular disease, all having previously undergone both MRA and XRA. At indifference point, patients were ambivalent about having MRA or XRA and immediate treatment, versus having a waiting period for test results and treatment after a hypothetical "ideal test" that entailed no pain or risk. RESULTS: The patients were willing to wait a mean of 42.1 days after the ideal test for results and treatment, as opposed to XRA. They were willing to wait only 16.1 days as opposed to MRA. This difference in waiting times was significant (p = 0.0001) and indicates a clear preference for MRA, in agreement with known literature. CONCLUSION: The WTO method assesses preferences for these radiologic tests in an intuitive fashion that does not invoke artificial or irrelevant health states. This approach may also prove useful for other testing situations or short-term treatments being evaluated for cost-effectiveness.


Assuntos
Satisfação do Paciente , Doenças Vasculares Periféricas/diagnóstico por imagem , Doenças Vasculares Periféricas/diagnóstico , Anos de Vida Ajustados por Qualidade de Vida , Listas de Espera , Adulto , Idoso , Idoso de 80 Anos ou mais , Angiografia/economia , Análise Custo-Benefício , Feminino , Humanos , Angiografia por Ressonância Magnética/economia , Masculino , Pessoa de Meia-Idade , Modelos Econométricos , Fatores de Tempo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA