RESUMO
To establish the tolerance of liver tissue to single high-dose intraoperative irradiation, the histopathological changes in the canine liver after single high-dose intraoperative irradiation were investigated by means of radionuclide imaging and light microscopy. Intraoperative irradiation at doses of 0, 10, 20, 25 or 30 Gy was applied to a part of the liver of 25 beagles. Radionuclide imaging using (99m)Tc-sulfur colloid was performed at several times during follow-up. Elective humane killing was done 3 months and 1, 2, 3 and 5 years after irradiation. Light microscopy was used to identify histopathological alterations. There was no morbidity or mortality during a maximal follow-up of 5 years. In 40% of the animals, a region of diminished uptake was observed at the irradiation site. The regions of diminished uptake of the radiopharmaceutical agent became smaller with time. Light microscopic examination revealed severe parenchymal fibrosis, liver cell atrophy, and bile duct proliferation at the irradiated area 1 to 2 years after irradiation. At 3 and 5 years, vascular changes with endothelial proliferation and focal arteriolar hyalinosis were observed. This study demonstrates that intraoperative irradiation of a part of the liver in the canine model can be applied safely. Light microscopy confirmed that histological damage was not always accompanied by diminished uptake of the radiopharmaceutical agent at the irradiation site.
Assuntos
Fígado/efeitos da radiação , Animais , Cães , Relação Dose-Resposta à Radiação , Fígado/diagnóstico por imagem , Fígado/patologia , Microscopia , Doses de Radiação , Cintilografia , Fatores de TempoAssuntos
Hematoma/diagnóstico por imagem , Doenças do Mediastino/diagnóstico por imagem , Glândula Tireoide/irrigação sanguínea , Artérias , Feminino , Hematoma/etiologia , Humanos , Hipertireoidismo/radioterapia , Radioisótopos do Iodo/uso terapêutico , Doenças do Mediastino/etiologia , Pessoa de Meia-Idade , RadiografiaRESUMO
To evaluate the necessity of an objective cardiopulmonary exercise test in the selection procedure of patients for heart failure studies, 50 patients with congestive heart failure New York Heart Association (NYHA) class II and III and a left ventricular ejection fraction less than 40% were subjected to a cardiopulmonary exercise test. The results of the exercise test were compared with the independent clinical estimation of NYHA class and data of measurements obtained at rest. The NYHA classification separated the patients with a mild to moderate impairment of aerobic capacity from patients with a moderate to severe impairment of aerobic capacity very well, but 32% of the NYHA class II patients had a near normal aerobic capacity, and 29% of the NYHA class III patients had a very severe impairment of aerobic capacity, more compatible with NYHA class IV. Only data from exercise measurements showed differences between groups. The determination of maximal aerobic capacity for an objective assessment of patients' performance at exercise is necessary for a proper selection procedure of patients for heart failure studies.
Assuntos
Ensaios Clínicos como Assunto/métodos , Insuficiência Cardíaca/diagnóstico , Adulto , Idoso , Estudos de Avaliação como Assunto , Teste de Esforço , Feminino , Insuficiência Cardíaca/classificação , Insuficiência Cardíaca/diagnóstico por imagem , Humanos , Masculino , Pessoa de Meia-Idade , Cintilografia , Pertecnetato Tc 99m de SódioRESUMO
Radionuclide renography showed an obstructed pattern in 6 patients with meningomyelocele without dilatation of the upper urinary tract or reflux when the bladder was filled to the volume that during previous urodynamic testing had resulted in an intravesical pressure of 40 cm. water but not when these patients were studied with an empty bladder. Therefore, this study indicates that treatment should be directed at avoiding long-standing intravesical pressure exceeding 40 cm. water in patients with meningomyelocele.