RESUMO
To investigate the biological function of p53 in colon carcinoma cells, a wild-type p53 expression plasmid under the control of the human cytomegalovirus promoter was stably transfected into the human colon adenocarcinoma cell line WiDr, which carries a mutation of the p53 gene at codon 273. Exogenous wild-type p53 transcripts were detected at various expression levels in 8 of 117 G418-resistant clones. The growth rates of the wild-type p53+ clones in culture did not change significantly. The efficiency of colony formation in soft agar, however, was completely suppressed in two wild-type p53+ clones. This is the first to demonstrate the feasibility of stable transfection of the wild-type p53 gene under the control of non-inducible promoter in human colon cancer cells. The major alteration found was that wild-type p53+ cells which were incubated with anti-Fas IgM showed marked cytolysis with preferential over-expression of wild-type p53 accompanied by overexpression of a cyclin-dependent kinase inhibitor, WAF1, whereas the endogenous mutant p53 retained its expression level. The findings suggest that a Fas-initiated pathway is incidentally linked to a p53-dependent apoptotic pathway through the reconstituted wild-type p53 gene in WiDr cells. This model should help elucidating the additional role of the p53 tumor suppressor gene and the mechanism of apoptosis in colon carcinoma cells.
Assuntos
Adenocarcinoma/genética , Apoptose/genética , Neoplasias do Colo/genética , Glicoproteínas de Membrana/fisiologia , Proteína Supressora de Tumor p53/fisiologia , Adenocarcinoma/patologia , Anticorpos/farmacologia , Apoptose/fisiologia , Sequência de Bases , Neoplasias do Colo/patologia , Inibidor de Quinase Dependente de Ciclina p21 , Ciclinas/metabolismo , Proteína Ligante Fas , Regulação Neoplásica da Expressão Gênica , Genes p53 , Humanos , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/imunologia , Dados de Sequência Molecular , Fenótipo , RNA Mensageiro/metabolismo , Transdução de Sinais/fisiologia , Transfecção , Células Tumorais Cultivadas , Proteína Supressora de Tumor p53/genéticaRESUMO
Early and delayed 201Tl SPECT studies were performed on 13 patients with intracranial meningiomas, which were classified in three groups according to their histological types: meningothelial (n = 7); transitional and fibroblastic (n = 3); and malignant types (n = 3). The early uptake indices (UI, ratios of average counts/pixel in the lesion to those of the contralateral area on early images) were relatively high in all types: meningothelial meningiomas, 5.75 +/- 2.16 (mean +/- s.d.); transitional and fibroblastic meningiomas, 4.69 +/- 0.54; and malignant meningiomas, 7.10 +/- 3.72. There were no statistical differences in relation to histological type. The delayed uptake indices were 2.65 +/- 0.89, 3.37 +/- 1.02, and 5.16 +/- 1.62, respectively. Statistically, the delayed UI of meningothelial meningiomas were lower than those of malignant types (p < 0.05). The retention indices (RI, ratios of delayed to early UI) were 0.48 +/- 0.08, 0.79 +/- 0.16, and 0.84 +/- 0.16, respectively. The RI of the meningothelial type were also statistically lower than those of the other two groups (p < 0.05). There were no statistically significant differences between transitional plus fibroblastic types and malignant meningiomas. We conclude that 201Tl exhibits early high accumulations in all types of meningiomas, but its retention rates probably differ according to histological types, and a high retention index is predictive of the malignant potential in a meningioma.
Assuntos
Neoplasias Meníngeas/diagnóstico por imagem , Meningioma/diagnóstico por imagem , Radioisótopos de Tálio , Tomografia Computadorizada de Emissão de Fóton Único , Adulto , Idoso , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Neoplasias Meníngeas/diagnóstico , Neoplasias Meníngeas/patologia , Meningioma/diagnóstico , Meningioma/patologia , Pessoa de Meia-IdadeRESUMO
UNLABELLED: The aim of this study was to review the etiology of CCD and study factors that affect the development and manifestation of CCD. METHODS: Three hundred and eleven patients with supratentorial lesions were evaluated for the presence of CCD with SPECT and 123I-IMP. In representative cases, continuous arterial blood sampling was done and rCBF was calculated using Kuhl's method. RESULTS: IMP-SPECT detected an abnormality in 206 patients, of whom 30 had CCD. Of CCD patients, 27 had more than single lobe involvement, 17 had motor impairment, 8 of 11 had rCBF of less than 29.1 +/- 10.9 ml/100 g/min. There was also a significant difference in rCBF between non-CCD and CCD cases. CONCLUSION: Although CCD can also occur with dementia (mixed or vascular type), it is more common with multilobar lesions. It is also associated with the presence of motor impairment but not related to its severity. It is more likely to develop, however, if rCBF is less than 29.1 +/- 10.9 ml/100 g/min regardless of etiology.
Assuntos
Anfetaminas , Doenças Cerebelares/diagnóstico por imagem , Radioisótopos do Iodo , Encéfalo/diagnóstico por imagem , Doenças Cerebelares/fisiopatologia , Circulação Cerebrovascular , Humanos , Iofetamina , Tomografia Computadorizada de Emissão de Fóton ÚnicoRESUMO
UNLABELLED: The purpose of this study is to clarify the changes of hippocampal perfusion in neuropsychiatric diseases, including dementia, compared with control subjects, and to correlate hippocampal perfusion with the dementia rating scale and the severity of memory disturbance in patients with these diseases. METHODS: A total of 45 right-handed patients were investigated (13 with dementia of Alzheimer type, 6 with multi-infarct dementia, 4 with progressive dementia with motor neuron disease (MND), 3 with transient global amnesia, 5 with other diseases and 14 control subjects). Regional cerebral blood flow (rCBF) in the parietal cortex and hippocampus was evaluated by high-resolution SPECT technique with HMPAO in all subjects. RESULTS: The rCBF measurements in the bilateral parietal cortices and hippocampus were lower in dementia of Alzheimer type and multi-infarct dementia patients than in controls. Hypoperfusion in the hippocampus was a more sensitive marker than hypoperfusion in the parietal cortex in diagnosing dementia of Alzheimer type. Hippocampal hypoperfusion was observed in demented patients regardless of etiology and in patients having memory disturbance without dementia, such as transient global amnesia. Finally, hippocampal hypoperfusion reflected the severity of dementia and memory disturbance regardless of etiology. CONCLUSION: The rCBF image with high-resolution SPECT system may be useful in assessing the extent of dementia and memory disturbance in patients with neuropsychiatric diseases.
Assuntos
Circulação Cerebrovascular , Hipocampo/diagnóstico por imagem , Transtornos Neurocognitivos/diagnóstico por imagem , Transtornos Neurocognitivos/fisiopatologia , Tomografia Computadorizada de Emissão de Fóton Único , Adulto , Idoso , Doença de Alzheimer/diagnóstico por imagem , Doença de Alzheimer/fisiopatologia , Demência/diagnóstico por imagem , Demência/etiologia , Demência por Múltiplos Infartos/diagnóstico por imagem , Demência por Múltiplos Infartos/fisiopatologia , Hipocampo/irrigação sanguínea , Humanos , Memória , Pessoa de Meia-Idade , Transtornos Neurocognitivos/psicologia , Lobo Parietal/irrigação sanguínea , Lobo Parietal/diagnóstico por imagemRESUMO
UNLABELLED: We studied the usefulness of IMP SPECT with acetazolamide in 16 patients with moyamoya disease. Cerebral angiography was performed for all patients who were classified in three grades according to their angiographic stages. METHODS: Techniques used included ring-type emission computed tomography with a minicomputer system. Patients received 111 MBq of 123I-IMP and SPECT images were obtained 20 min postinjection. Nine patients were studied using iodoamphetamine (IMP) SPECT with and without acetazolamide. IMP SPECT with acetazolamide was performed 20 min after each injection of 1 g of acetazolamide. RESULTS: Low perfusion areas in the upper and lower frontal, parietal and temporal regions in grades 2 and 3 using IMP SPECT were observed. The mean cerebral-to-cerebellar activity ratios (C/C ratio) of six regions (upper and lower frontal, temporal, parietal occipital and basal ganglia) in grades 1, 2 and 3 were 0.96 to 1.06, 0.91 to 0.96 and 0.76 to 0.88, respectively. CONCLUSION: Our results indicate that measurement of regional cerebral blood flow (rCBF) elucidates cerebral hemodynamic factors, including the reactivity of cerebral vessels which cannot be detected angiographically in patients with moyamoya disease, and that the acetazolamide test is useful for detecting cerebral blood flow reserve. The test can be used to detect disease progress prospectively.
Assuntos
Anfetaminas , Circulação Cerebrovascular , Doença de Moyamoya/diagnóstico por imagem , Tomografia Computadorizada de Emissão de Fóton Único , Acetazolamida , Adulto , Encéfalo/diagnóstico por imagem , Circulação Cerebrovascular/efeitos dos fármacos , Meios de Contraste , Feminino , Humanos , Radioisótopos do Iodo , Iofetamina , Masculino , Pessoa de Meia-Idade , Doença de Moyamoya/fisiopatologiaRESUMO
UNLABELLED: Technetium-99m methoxyisobutylisonitrile (MIBI) is a myocardial perfusion imaging agent that has been reported to effectively localize in various tumors (e.g., lung and thyroid carcinomas and osteogenic sarcoma). To determine its usefulness in thyroid tumors, we compared 99mTc-MIBI with 201TI imaging. METHOD: We evaluated 25 patients with thyroid tumors (papillary carcinoma in 11, follicular carcinoma in 2, follicular adenoma in 7, adenomatous goiter in 5). Fifteen metastatic lesions from differentiated thyroid carcinomas were also evaluated. Early (10 min after injection) and delayed images (120 min after injection) were obtained for both 99mTc-MIBI and 201TI scintigraphy. RESULTS: The early images showed very similar findings for both 99mTc-MIBI and 201TI. However, the delayed images showed that malignant tumors tended to retain more tracer agent than benign nodules. Marked retention was in 61.5% (8 of 13) of 201TI images and 53.8% (7 of 13) of 99mTc-MIBI images. For metastatic lesions from thyroid carcinomas, the findings for 99mTc-MIBI imaging were nearly identical to those for 201TI imaging. A slight difference in clarity was seen that may have been due to the effect of the 99mTc. CONCLUSION: Although 99mTc-MIBI scintigraphy does not have particularly good results in differentiating malignant from benign thyroid tumors, it may be useful in evaluating metastases or predicting recurrence because of its better imaging characteristics.
Assuntos
Tecnécio Tc 99m Sestamibi , Radioisótopos de Tálio , Neoplasias da Glândula Tireoide/diagnóstico por imagem , Adenocarcinoma Folicular/diagnóstico por imagem , Adenoma/diagnóstico por imagem , Adulto , Idoso , Carcinoma Papilar/diagnóstico por imagem , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , CintilografiaRESUMO
Unilateral Moyamoya disease presents as unilateral stenosis or obstruction of the supraclinoid internal carotid artery, which causes cerebral hypoperfusion resulting in seizures or TIA-like attacks. In severe cases, surgical treatment is performed with superficial temporal artery-middle cerebral artery anastomosis. In mild cases, conservative management is the treatment of choice. Flunarizine is a calcium ion anti-blocking agent, whose primary effect is that the cerebral vessels have been used for the treatment of postcerebrovascular disorders. Recently, it has been suggested that flunarizine could be used to treat Moyamoya disease. This report documents the efficacy of flunarizine to improve regional cerebral perfusion in Moyamoya disease.
Assuntos
Encéfalo/diagnóstico por imagem , Bloqueadores dos Canais de Cálcio/uso terapêutico , Flunarizina/uso terapêutico , Doença de Moyamoya/diagnóstico por imagem , Doença de Moyamoya/tratamento farmacológico , Compostos de Organotecnécio , Oximas , Tomografia Computadorizada de Emissão de Fóton Único , Criança , Quimioterapia Combinada , Humanos , Masculino , Doença de Moyamoya/diagnóstico , Tecnécio Tc 99m Exametazima , Ticlopidina/uso terapêuticoRESUMO
We studied the change in gap junctional intercellular communication (GJIC) on human umbilical vein endothelial cells (HUVEC) under hypoxia-reoxygenation (H-R) conditions by the fluorescence redistribution after photobleaching (FRAP) method. Confluent HUVEC monolayers were exposed to hypoxia (pO2<0.1%) for 12 hours, and then were returned to normal atmospheric conditions for reoxygenation. Contrast microscopic observation showed no significant changes in the morphology of the HUVEC at any times after H-R. Reoxygenation following hypoxia caused time-dependent decrease in GJIC, that is, GJIC reduction was induced after 2 hours and reached maximum at 4-6 hours which recovered to normal levels after 18 hours. Oxidant sensitive fluorescence dye assay revealed that the generation of intracellular free radicals increased during the first 2 hours after reoxygenation. Hydroxyl radical scavengers (MCI-186, DMSO) and an iron chelator (deferoxamine) abolished the reduction of GJIC due to H-R. However, SOD, catalase and probucol were essentially inactive on this reduction. These data suggest that ischemia-reperfusion injury may be caused by a functional defect of GJIC induced by reactive oxygen radicals.
Assuntos
Antipirina/análogos & derivados , Comunicação Celular , Endotélio Vascular/fisiologia , Junções Comunicantes/fisiologia , Oxigênio/fisiologia , Antipirina/farmacologia , Catalase/metabolismo , Hipóxia Celular , Células Cultivadas , Desferroxamina/farmacologia , Dimetil Sulfóxido/farmacologia , Edaravone , Endotélio Vascular/citologia , Junções Comunicantes/efeitos dos fármacos , Humanos , Citometria por Imagem/métodos , Lasers , Probucol/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Superóxido Dismutase/metabolismo , Fatores de Tempo , Veias Umbilicais/citologia , Veias Umbilicais/fisiologiaRESUMO
Accidental exposure to acute high-dose total body neutron radiation is rare. We report a 35-year-old man exposed to a total body dose of 5.4 Gy neutron- and 8.5-13 Gy gamma-radiation in a radiation criticality accident. He received a blood stem cell transplant from his HLA-identical sister. There was bone marrow recovery with complete donor chimerism. Random chromatid breaks were observed in donor cells suggesting a bystander effect of neutron exposure. The subject died 82 days after the accident (75 days post transplant) from multi-organ failure.
Assuntos
Nêutrons Rápidos/efeitos adversos , Raios gama/efeitos adversos , Transplante de Células-Tronco de Sangue Periférico/métodos , Liberação Nociva de Radioativos , Adulto , Medula Óssea , Cromátides/efeitos da radiação , Evolução Fatal , Sobrevivência de Enxerto , Humanos , Masculino , Centrais Elétricas , Doses de Radiação , Quimeras de TransplanteRESUMO
Regional cerebral blood flow was evaluated by single-photon emission CT (SPECT) with 123I-N-isopropyl-p-iodoamphetamine (123I-IMP) in 11 patients with dementia of the Alzheimer type, three patients with progressive dementia and motor neuron disease, and eight healthy control subjects. Regional blood flow measurements in the bilateral frontal, parietal association, and temporal cortices were lower in the Alzheimer dementia patients than in controls. Flow deficits in the parietal association cortex were demonstrated in all patients with Alzheimer-type dementia; these deficits were correlated with the severity of disease. Lateral hemispheric asymmetry was seen in nine of 11 patients with Alzheimer-type dementia. In all three patients with progressive dementia and motor neuron disease, flow deficits were demonstrated in the bilateral frontal and temporal cortices, but no flow deficits were seen in the parietal association cortex. Brain SPECT with 123I-IMP may be useful in the differential diagnosis and evaluation of the severity of degenerative dementia.
Assuntos
Anfetaminas , Circulação Cerebrovascular/fisiologia , Demência/diagnóstico por imagem , Tomografia Computadorizada de Emissão de Fóton Único , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/diagnóstico por imagem , Doença de Alzheimer/fisiopatologia , Demência/fisiopatologia , Feminino , Humanos , Radioisótopos do Iodo , Iofetamina , Masculino , Pessoa de Meia-Idade , Neurônios Motores/diagnóstico por imagem , Neurônios Motores/fisiologia , Doenças Neuromusculares/diagnóstico por imagem , Doenças Neuromusculares/fisiopatologiaRESUMO
PURPOSE: To compare MR with thallium-201 scintigraphy in the follow-up of patients who have undergone thyroidectomy and modified radical neck dissection for differentiated thyroid cancer. METHODS: Both MR imaging and 201Tl scintigraphy were performed in 39 patients after surgery for differentiated thyroid cancer. Ten patients did not have recurrence; 29 patients had 51 recurrent tumors in the neck and mediastinum. RESULTS: Among 51 tumor sites, 39 sites of recurrence were detected by MR and 24 were detected by 201Tl scintigraphy. The true-positive rate, false-negative rate, true-negative rate, and false-positive rate in detecting recurrent thyroid cancer were 76.5, 23.5, 100, and 0%, respectively, for MR and 47.1, 52.9, 100, and 0%, respectively, for 201Tl scintigraphy. MR was more sensitive than 201Tl scintigraphy in detecting recurrent tumors (especially small metastatic nodes). On T2-weighted MR images, recurrent tumor was characterized by high signal intensity. Scarring in the postoperative thyroid bed was characterized by low signal intensity on both T1- and T2-weighted images. Abnormal accumulation of 201Tl in the postoperative thyroid bed was not observed. CONCLUSIONS: Although both MR images and 201Tl scintigraphy were effective in distinguishing recurrent tumor from postoperative fibrous tissue, MR images were more sensitive than 201Tl scintigraphy in detecting recurrent tumors. These results suggest that MR imaging is more useful than 201Tl scintigraphy in the follow-up evaluation of patients after neck surgery for differentiated thyroid cancer.
Assuntos
Imageamento por Ressonância Magnética , Recidiva Local de Neoplasia/diagnóstico , Radioisótopos de Tálio , Neoplasias da Glândula Tireoide/diagnóstico , Adenocarcinoma Folicular/diagnóstico , Adenocarcinoma Folicular/diagnóstico por imagem , Adenocarcinoma Folicular/cirurgia , Adenocarcinoma Papilar/diagnóstico , Adenocarcinoma Papilar/diagnóstico por imagem , Adenocarcinoma Papilar/cirurgia , Carcinoma Medular/diagnóstico , Carcinoma Medular/diagnóstico por imagem , Carcinoma Medular/cirurgia , Diagnóstico Diferencial , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Esvaziamento Cervical , Recidiva Local de Neoplasia/diagnóstico por imagem , Complicações Pós-Operatórias/diagnóstico , Cintilografia , Sensibilidade e Especificidade , Neoplasias da Glândula Tireoide/diagnóstico por imagem , Neoplasias da Glândula Tireoide/cirurgia , TireoidectomiaRESUMO
The authors describe two patients with thyroid lymphoma and Hashimoto thyroiditis; T1- and T2-weighted MR sequences were used. In one patient, the region of lymphoma showed a different signal intensity on T2 images; in the other patient, the signal level was identical to the Hashimoto disease. In sum, the processes could not be significantly differentiated using MR.
Assuntos
Linfoma Folicular/diagnóstico , Linfoma não Hodgkin/diagnóstico , Imageamento por Ressonância Magnética , Neoplasias da Glândula Tireoide/diagnóstico , Tireoidite Autoimune/diagnóstico , Feminino , Humanos , Linfoma Folicular/complicações , Linfoma não Hodgkin/complicações , Pessoa de Meia-Idade , Neoplasias da Glândula Tireoide/complicações , Tireoidite Autoimune/complicaçõesRESUMO
Patient A who was exposed to a critical dose of radiation developed skin lesions throughout the body surface, gastrointestinal disorder with massive diarrhea and prominent bleeding, which caused severe loss in body fluids. Gastrointestinal bleeding due to the deteriorated intestinal mucosa was considered to be one of the major causes of death, although infection did not develop, possibly because of SDD and aseptic intensive care, until terminal stages. Patient A ultimately developed respiratory and renal failure in addition to skin exudate and gastrointestinal bleeding, and died of multiple organ failure on the 83rd day after exposure. The extreme unevenness of the dose distribution and the neutron versus y-ray component made the clinical manifestation very complicated. Initially, the mean absorbed dose was calculated as 16-20 GyEq for Patient A, mainly based on neutron-activated 24Na in the blood. However, a very recent calculation showed that the absorbed skin dose was highest at the upper-right abdomen reaching 61.8 Gy (27.0 as neutron plus 34.8 Gy as y-ray). The dorsal side was calculated to have received one eighth of the value of the abdominal side, and much smaller neutron component. His absorbed-dose distribution throughout the body was very inhomogeneous because of the closeness of the standing point to the mixing tank. Despite prolonged survival because of intensive care with massive fluids and blood transfusion, peripheral blood stem-cell transplantation, cultured skin-cell grafts, and the administration of cytokines for marrow, the patient was not saved. Restoration of the bone marrow function, prevention of skin fibrosis, radiation lung damage, and repair of gastrointestinal mucosa, and final recovery of the patient were elusive. Abundant personnel and resources were also a prerequisite to allow for the comprehensive and collective intensive care. A further understanding of the effects of high-dose radiation as well as the basic and clinical development of regeneration medicine are important issues for the future.
Assuntos
Doenças Profissionais/diagnóstico , Lesões por Radiação/diagnóstico , Liberação Nociva de Radioativos , Adulto , Sistema Cardiovascular/efeitos da radiação , Sistema Digestório/efeitos da radiação , Evolução Fatal , Hematopoese/efeitos da radiação , Humanos , Japão , Masculino , Doenças Profissionais/terapia , Exposição Ocupacional , Doses de Radiação , Lesões por Radiação/terapia , Sistema Respiratório/efeitos da radiação , Pele/efeitos da radiação , Fatores de TempoRESUMO
The aim of this study was to evaluate the efficacy of 99mTc-MIBI and 123I subtraction scintigraphy for the detection of abnormal parathyroid glands to be referred for surgical treatment. Thirty-nine consecutive patients, including 35 primary and four secondary cases of hyperparathyroidism, were evaluated. 99mTc-MIBI/123I subtraction scintigraphy (MIBI/I) was performed on all patients, and the results were compared with delayed images of 99mTc-MIBI (D-MIBI), magnetic resonance imaging (MRI) and ultrasonography (US). The overall sensitivity of MIBI/I, MRI, US and D-MIBI was 55.9%, 43.4%, 50.8% and 39.0%, respectively. In cases of single-gland disease, the sensitivity of MIBI/I, MRI, US and D-MIBI was 62.1%, 48.3%, 55.2% and 44.8%, respectively. In cases of multi-gland disease, the sensitivity of MIBI/I, MRI, US and D-MIBI was 50.0%, 37.5%, 46.7% and 36.7%, respectively. In cases of parathyroid adenoma, the sensitivity of MIBI/I, MRI, US and D-MIBI was 71.4%, 50.0%, 71.4% and 50.0%, respectively. In cases of parathyroid hyperplasia, the sensitivity of MIBI/I, MRI, US and D-MIBI was 55.2%, 42.3%, 50.0% and 39.7%, respectively. It is concluded that 99mTc-MIBI/123I subtraction is more useful than the delayed imaging of 99mTc-MIBI, MRI and US.
Assuntos
Hiperparatireoidismo/diagnóstico por imagem , Radioisótopos do Iodo , Glândulas Paratireoides/diagnóstico por imagem , Técnica de Subtração , Tecnécio Tc 99m Sestamibi , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Hiperparatireoidismo/diagnóstico , Hiperparatireoidismo Secundário/diagnóstico , Hiperparatireoidismo Secundário/diagnóstico por imagem , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Glândulas Paratireoides/patologia , Seleção de Pacientes , Cuidados Pré-Operatórios/métodos , Cintilografia , Compostos Radiofarmacêuticos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , UltrassonografiaRESUMO
The aim of the study was to evaluate the use of 201Tl single photon emission tomography (SPET) in differentiating histological types and lymph node sized of lung tumours based on the early uptake ratio (EUR), delayed uptake ratio (DUR) and retention index (RI). We also wished to compare the effectiveness of 201Tl SPET and computed tomography (CT) in detecting lymphadenopathy. We examined 41 subjects using both 201Tl SPET and CT. Fifty-seven lymph nodes were detected and were grouped according to size. The EUR, DUR and RI were determined and analysed using Student's t-test and a P-value < 0.05 was considered significant. Lymphadenopathy detected by both 201Tl SPET and CT correlated with the operative findings. There were no statistically differences in the EUR, DUR and RI between the various histological types. Statistically significant differences in EUR were noted between lymph nodes > 5 cm in size and those 3-5 cm in size, as well as between those < 3 cm and > 5 cm in size No significant differences were seen for the RI. The specificity, sensitivity and accuracy of 201Tl SPET were 81.3, 90.2 and 87.7% respectively, whereas for CT they were 81.3, 100 and 94.74% respectively. In conclusion, quantitative analysis with 201Tl SPET was unable to differentiate with accuracy between histological types but it could differentiate between nodes of varying sizes. However, CT had a better specificity and accuracy.
Assuntos
Neoplasias Pulmonares/diagnóstico por imagem , Radioisótopos de Tálio , Tomografia Computadorizada de Emissão , Tomografia Computadorizada por Raios X , Adenocarcinoma/diagnóstico por imagem , Carcinoma/diagnóstico por imagem , Carcinoma de Células Escamosas/diagnóstico por imagem , Humanos , Pneumopatias/diagnóstico por imagem , Neoplasias Pulmonares/cirurgia , Linfonodos/diagnóstico por imagem , Metástase Linfática , Sensibilidade e Especificidade , Radioisótopos de Tálio/farmacocinéticaRESUMO
We assessed the relationship between 99Tcm-HMDP extraosseous accumulation (EOA), the histopathology of primary lesions and various laboratory findings. In 155 of 4824 patients, 163 EOA were noted. Of these, 33.7% were in the abdomen, 27.6% in the chest, 22.7% in the extremities, 9.8% in the pelvic area and 6.1% in the head and neck area. We found that 72.4% of EOA were due to malignant processes and 27.6% to benign processes. In the abdomen, 36.6% of the EOA were due to hepatocellular carcinoma and intestinal carcinoma. In the chest, 46.7% of EOA were a result of breast carcinoma. In the extremities, 28.7% of the EOA were due to sarcoma. The mean white blood cell count was elevated (8.0 +/- 6.3 x 10(3)) in patients with malignant processes. The mean serum haemoglobin and haematocrit in benign and malignant processes, for both males and females, were below normal values. All other laboratory findings were within normal limits. Significant differences in serum haemoglobin and haematocrit were noted between male and female patients with benign processes (P = 0.04 and P = 0.04, respectively). No other significant differences between benign and malignant processes were noted. Therefore, EOA is more frequently associated with malignant processes of primary lesions and is often accompanied by leukocytosis and anaemia.
Assuntos
Osso e Ossos/diagnóstico por imagem , Compostos Radiofarmacêuticos/farmacocinética , Medronato de Tecnécio Tc 99m/análogos & derivados , Idoso , Envelhecimento/metabolismo , Neoplasias Ósseas/diagnóstico por imagem , Osso e Ossos/metabolismo , Osso e Ossos/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Cintilografia , Estudos Retrospectivos , Medronato de Tecnécio Tc 99m/farmacocinética , Ultrassonografia , Contagem Corporal TotalRESUMO
Regional cerebral blood flow (rCBF) was measured using N-isopropyl-123I-iodoamphetamine (123I-IMP) with single photon emission computed tomography (SPECT) in 27 patients with diabetes mellitus with an average age of 64.1 years and with an average fasting plasma glucose of 145 mg dl-1. Their data were compared with those of 12 non-diabetic subjects with an average age of 64.6 years. None had cerebral infarction on computed tomographic (CT) studies. There were no significant differences in the physiological or laboratory data between the diabetic and non-diabetic groups except for their fasting plasma glucose and HbA1c levels. A reference sampling method using continuous arterial blood sampling was employed to quantify the rCBF. The average rCBF in each region of the cerebrum and cerebellum was significantly lower in the diabetic group than in the non-diabetic group (P < 0.01). Although a definite cause was obscure, the rCBF of the diabetic patients was reduced even in the absence of findings indicative of cerebral infarction on a CT study.
Assuntos
Anfetaminas , Encéfalo/diagnóstico por imagem , Circulação Cerebrovascular/fisiologia , Diabetes Mellitus/fisiopatologia , Radioisótopos do Iodo , Tomografia Computadorizada de Emissão de Fóton Único , Glicemia/análise , Infarto Cerebral/diagnóstico por imagem , Diabetes Mellitus/diagnóstico por imagem , Feminino , Hemoglobinas Glicadas/análise , Humanos , Iofetamina , Masculino , Pessoa de Meia-IdadeRESUMO
The aim of this study was to investigate the relationship between autonomic nerve dysfunction and myocardial uptake of 123I-meta-iodobenzyl guanidine (MIBG) in patients with diabetes mellitus. Twenty-two non-insulin-dependent diabetic patients, 9 with autonomic neuropathy [ANP(+)] and 13 without autonomic neuropathy [ANP(-)], and 8 controls were included in the study. Both planar and single photon emission tomographic (SPET) images were obtained 30 min (early) and 3 h (delayed) after the 123I-MIBG injection. The heart-to-mediastinal uptake ratio (H/M) and the washout ratio of 123I-MIBG (%WR) were calculated from planar images. The uptake ratio of the inferior wall to the anterior wall (I/ A) and the %WR of both the inferior and anterior walls were calculated from the SPET images. On the early plantar images, the mean H/M ratio in the ANP(+) group was significantly lower than that of the control group. The mean %WR on the planar images in the ANP(-) group was significantly higher than that of the controls. The SPET images demonstrated a reduction in MIBG uptake and significantly increased clearance in the inferior wall of the ANP(-) patients. These findings extended to other areas of the heart in the ANP(+) patients. In the quantitative analysis of the SPET images, the ANP(+) group had significantly lower I/A values and significantly higher %WR values in the anterior wall. The ANP(+) group showed significantly increased clearance of 123I-MIBG in the inferior wall. We conclude that 123I-MIBG myocardial scintigraphy is a useful diagnostic tool both in the early detection and evaluation of the progression of myocardial sympathetic nerve dysfunction in patients with diabetes mellitus. Both the I/A and %WR calculated from SPET images are useful parameters.
Assuntos
Doenças do Sistema Nervoso Autônomo/diagnóstico por imagem , Diabetes Mellitus Tipo 2/diagnóstico por imagem , Neuropatias Diabéticas/diagnóstico por imagem , Coração/diagnóstico por imagem , Radioisótopos do Iodo , Iodobenzenos , 3-Iodobenzilguanidina , Idoso , Doenças do Sistema Nervoso Autônomo/complicações , Diabetes Mellitus Tipo 2/complicações , Neuropatias Diabéticas/complicações , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Tomografia Computadorizada de Emissão de Fóton ÚnicoRESUMO
Thallium-201 (201Tl) is widely used in the diagnosis of malignant tumours. However, its use in predicting the response to radiation therapy for head and neck cancer has not been established. Nineteen patients with histologically proven head and neck cancer were studied. 201Tl single photon emission tomographic (SPET) images were obtained 15 min (early) and 4 h (delayed) post-injection of the radionuclide. For a semi-quantitative assessment, regions of interest were drawn over the lesions and normal soft tissue. Lesion-to-normal tissue uptake ratios of 201Tl activity were measured from mean counts-per-voxel obtained on both the early and delayed scans, representing the early index (EI) and delayed index (DI) respectively. Subsequently, a retention index (RI) was calculated using the formula: RI = (DI - EI) x 100/(EI). The patients were classified into two groups according to the effect of radiotherapy: a partial response or complete response group (PR-CR group) and a no change group (NC group). In the analysis of primary lesions, both the delayed and retention indexes of the PR-CR group were significantly higher than those of the NC group. However, the early index was not significantly different between the two groups. In the metastatic lymph nodes, only the retention index was significantly different between the two groups. Our results demonstrate that 201Tl SPET and a 201Tl index can be used to predict the response to radiotherapy for primary head and neck cancer and lymph node metastases. The retention index is a useful parameter for estimating the effects of radiotherapy.
Assuntos
Neoplasias de Cabeça e Pescoço/diagnóstico por imagem , Neoplasias de Cabeça e Pescoço/radioterapia , Tomografia Computadorizada de Emissão de Fóton Único , Idoso , Feminino , Neoplasias Gengivais/diagnóstico por imagem , Neoplasias Gengivais/radioterapia , Neoplasias de Cabeça e Pescoço/patologia , Humanos , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Neoplasias Orofaríngeas/diagnóstico por imagem , Neoplasias Orofaríngeas/radioterapia , Valor Preditivo dos Testes , Radioisótopos de TálioRESUMO
The aims of this study were (1) to compare N-isopropyl-p-[I-123]-iodoamphetamine (123I-IMP) SPET with computed tomography (CT) in chronic-stage head trauma patients with neurological abnormalities and (2) to quantify regional cerebral blood flow (rCBF) in patients with chronic-stage head trauma. 123I-IMP SPET and CT were performed in 23 patients with chronic-stage head trauma and 12 normal controls. Both types of imaging were evaluated visually. In addition for the SPET images, the rCBF in 12 regions (bilateral frontal cortex, temporal cortex, parietal cortex, occipital cortex, perilolandic area, cerebellum: total 276 regions) was analysed quantitatively using a reference sampling method. In total, 39 focal lesions related to neurological abnormalities were detected. Although 22 (56.4%) lesions were observed using both CT and SPET, another 17 (43.6%) were detected by SPET only. The mean rCBF in the localized lesions of each lobe, which correspond to low-density areas (LDAs), were lower on CT than those of each lobe seen only on SPET. These rCBF values were lower than the mean rCBF values in the lobes of the controls. The mean rCBF values in each lobe with visually normal tracer uptakes were also significantly lower in the 23 patients than in the controls. 123I-IMP SPET is useful for demonstrating brain dysfunction in morphologically intact brain regions and for providing objective evidence to account for the clinical presentation of patients presenting with chronic traumatic brain injury.