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111.
Epstein-Barr virus (EBV) is associated with the development of several B cell malignancies including Burkitt's lymphoma (BL), post-transplant lymphoproliferative disease (PTLD), and AIDS-related lymphomas. The latter two diseases result from EBV-driven B cell proliferation in the absence of normal immunosurveillance and as such, represent a heterogenous family of lymphoproliferative disorders. This article reviews studies on EBV gene expression and antibody development in PTLD and introduces recent information on the levels of EBV+ peripheral blood lymphocytes to discuss possible mechanisms of pathogenesis under varying conditions of immunosuppression.  相似文献   
112.
During the period from 1969 through 1977, 124 patients with advanced Hodgkin's disease underwent treatment with combination chemotherapy and radiotherapy. Sixty-three cases were previously untreated, and 61 were relapses following radical radiotherapy for localized Hodgkin's disease. No patient in this series had received prior chemotherapy. Of 102 patients (84%) who have entered complete remission, 92 remain in complete remission with a median follow up time of five years, 10 patients having relapsed, and acute leukemia having developed in 2. The cumulative survival rate for all 124 patients is 80% at five years; the relapse-free survival rate is 74%. In many, if not most cases, the Hodgkin's disease appears to be cured. We have also identified two subgroups of patients for whom the prognosis is worse than for patients with advanced-stage disease as a whole. Patients over the age of 40 years have a five-year survival rate of only 45%, compared with 89% for all other patients. Those Stage IV patients with multiple extranodal sites of involvement have a five-year survival rate of 48%, compared with 81% for other Stage IV patients with only a single extranodal site involved.  相似文献   
113.
Patients with unstable angina, refractory to intensive medical therapy, are at high risk for developing thrombotic complications, such as recurrent ischemia, myocardial infarction and coronary occlusion during coronary angioplasty. As both platelet aggregation and/or thrombus formation play an important role in this ongoing ischemic process, a monoclonal platelet GPIIb/IIIa receptor antibody (c7E3) or thrombolytic therapy (alteplase) might be able to modify the clinical course and underlying coronary lesion morphology. To evaluate whether alteplase or c7E3 could influence the incidence of complications, we randomized 36 and 60 patients, respectively to alteplase or placebo, or c7E3 or placebo. All patients exhibited dynamic ECG changes and recurrent pain attacks, despite maximal tolerated medical therapy. Patients were randomized in both studies after initial angiography had demonstrated a culprit lesion amenable for angioplasty. After study drug infusion quantitative angiography was repeated and angioplasty performed. Recurrent ischemia during study drug infusion occurred in 5, 6, 9 and 16 patients from the alteplase, placebo, c7E3 and placebo group, respectively. Major events defined as death, myocardial infarction or urgent intervention occurred in 7, 3, 1 and 7 patients, respectively. Two patients died: one in the alteplase group and one in the placebo group from the c7E3 study. The first patient due to retroperitoneal hemorrhage, the second as a result of recurrent infarction. Qualitative angiography showed resolution of clots in the c7E3 group only, while the same group of patients showed in 20% an improvement in TIMI flow grade, without deterioration in any patient from this group.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
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The prognostic value of p53 protein in tumor extracts as measured by ELISA was studied retrospectively in 228 non-small cell lung cancer (NSCLC) patients. The assay measures both wild-type and mutated p53. The specimens on which this study was performed have been used earlier to analyze the prognostic impact of components of the plasminogen activation system, which enabled an analysis of relationships between these components and p53 protein. The median of the p53 protein values in the 228 patients was 0.10 (range, 0-0.70) ng/mg protein. Survival analysis comparing patients with p53 levels below versus above the median showed no significant difference (P = 0.67). When analyzing the histological types, adenocarcinoma (n = 106), squamous cell carcinoma (n = 84), and large cell carcinoma of the lung (n = 38) separately, similarly, no significant differences in survival between patients having low versus high tumor p53 levels were found. When comparing levels of p53 protein in the three histological types, a significant difference (P < 0.0001) was found, with adenocarcinomas having the lowest levels. There was a weak positive correlation (r = 0.22) between p53 protein and plasminogen activator inhibitor type 1 (PAI-1). Multivariate analysis proved no impact of p53 on survival; tumor size, PAI-1, and lymph node involvement were the only variables with significant influence on survival. These data indicate that p53 protein quantitated with a sandwich ELISA in tumor extracts from NSCLC has no prognostic value, but the observed statistically significant difference of p53 protein content between histological subgroups may be related to differences in etiology and biology in different NSCLC subtypes. In addition, the weak association found between p53 protein and the independent prognostic marker PAI-1 could suggest yet undefined interactions in lung cancer.  相似文献   
117.
A neostriatal habit learning system in humans   总被引:1,自引:0,他引:1  
Amnesic patients and nondemented patients with Parkinson's disease were given a probabilistic classification task in which they learned which of two outcomes would occur on each trial, given the particular combination of cues that appeared. Amnesic patients exhibited normal learning of the task but had severely impaired declarative memory for the training episode. In contrast, patients with Parkinson's disease failed to learn the probabilistic classification task, despite having intact memory for the training episode. This double dissociation shows that the limbic-diencephalic regions damaged in amnesia and the neostriatum damaged in Parkinson's disease support separate and parallel learning systems. In humans, the neostriatum (caudate nucleus and putamen) is essential for the gradual, incremental learning of associations that is characteristic of habit learning. The neostriatum is important not just for motor behavior and motor learning but also for acquiring nonmotor dispositions and tendencies that depend on new associations.  相似文献   
118.
Severe birth asphyxia leads to a transient organic aciduria and increased hypoxanthine excretion. To investigate its origin and timing, we analyzed urine from 12 late gestation fetal sheep in utero subjected to moderately severe isocapnic hypoxia for 1 h. In six fetuses the carotid sinus nerves were cut to determine whether reflex peripheral vasoconstriction contributed to the changes in excretion. After a control period of 1 h, maternal inspired oxygen was reduced for 1 h so that fetal arterial oxygen tension fell significantly from 2.86 +/- 0.12 kPa (mean +/- SEM) to 1.55 +/- 0.04 kPa. The ewes were returned to normoxia, and monitoring was continued for 1 h. Fetal heart rate, arterial blood pressure, and femoral arterial blood flow (intact fetuses only) were recorded, and arterial pH, blood gases, and lactate were measured. Urine collected via a bladder catheter was analyzed for organic acids and hypoxanthine with gas chromatography-mass spectrometry. In intact fetuses, hypoxia increased excretion of hypoxanthine and several organic acids, notably lactic acid and intermediates of valine catabolism. Changes were apparent by 15 min, significant by 45 min, and maximal after reoxygenation. In denervated fetuses, there were small, significant, increases in organic acids and hypoxanthine by 45 min of hypoxia, but there was no surge in excretion posthypoxia. Hypoxia caused a large, significant, fall in femoral arterial blood flow in intact fetuses. We conclude that the extent of the reflex peripheral vasoconstriction, particularly in skeletal muscle, determines the amount of organic acid and hypoxanthine excretion and may explain similar biochemical disturbances after birth asphyxia. Urinary lactic acid measurement has a potential value for grading birth asphyxia.  相似文献   
119.
The expression of nitric oxide synthase (NOS) in the mucosa of the canine colon was investigated with in situ hybridzation, immunohistochemistry (using isoform specific antibodies), western analysis, and NADPH diaphorase (NADPH-d) histochemistry. In situ hybridization using a common probe for known isoforms of NOS showed that NOS mRNA was strongly expressed in mucosal cells. A gradient in the degree of hybridization was noted from the base of the crypts to the luminal surface. This gradient was also apparent using an endothelial NOS (eNOS)-specific probe. Neural NOS-like immunoreactivity (nNOS-LI) was observed in columnar epithelial cells, and the same population of cells was stained with NADPH-d. Endothelial NOS-like immunoreactivity (eNOS-LI) was also found in mucosal cells; however, this eNOS-LI was confined to mucous cells. These cells were not stained with NADPH-d. The existence of eNOS in mucosal cells was confirmed by in situ hybridization using the probe which specifically hybridized with mRNA of eNOS and by western blots which demonstrated the expression of a 135-kDa protein in mucosal homogenates. The differential expression of NOS isoforms and the gradient in expression along the length of the crypts suggest complex roles for NO in the development of colonic epithelial cells and in secretion and transport functions of the colonic mucosa.  相似文献   
120.
The effect of the host system on the pathogenicity, immunogenicity, and antigenicity of infectious bursal disease virus (IBDV) was investigated. One classic (SAL) and one variant strain (IN) of IBDV were passaged separately six times in three host systems, namely BGM-70 continuous cell line, primary chicken embryo fibroblast (CEF) cells, or embryonating chicken eggs (embryos) or one time in the bursa of Fabricius (BF) of specific-pathogen-free (SPF) chickens. Passage in BGM-70 cells or CEF cells resulted in loss of pathogenicity, but viruses passaged in embryos or BF maintained their pathogenicity. For the immunogenicity study, the viruses described above were used to prepare live and inactivated vaccines, containing 10(3) mean embryo infectious doses (EID50s) and 10(5) EID50s respectively. These vaccines induced different levels of protection. It was concluded that the antigen titration methodology employing embryonating chicken eggs was not suitable for titration of viruses propagated in other host systems because of varying degrees of adaptation and/or pathogenicity of the viruses resulting in variability in antigen mass of the tested vaccines. To test this assumption, an antigen-capture enzyme-linked immunosorbent assay was used as a titration system to compare the antigenicity of viruses propagated in BGM-70 cells or BF. Preparations containing similar antigen masses were inactivated then inoculated into two age groups of SPF chickens and antibody titers were monitored. During the experimental period, the geometric mean virus-neutralizing (VN) antibody titers of the vaccinated groups did not differ significantly (P > 0.05).  相似文献   
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