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The epidemiology and histopathology of human cancers and studies of animal models of tumorigenesis have led to a widely-accepted notion that multiple genetic and epigenetic changes have to accrue for the successful development of a malignant phenotype. Tumor growth and expansion requires an ability not only to proliferate, but also to down-modulate cell death (apoptosis) and activate angiogenesis to produce a tumor neovasculature. This review will describe the interplay between apoptosis and proliferation, as well as the characteristics of the angiogenic phenotype in two transgenic mouse models of multi-step tumorigenesis, namely, pancreatic islet cell carcinomas and squamous cell carcinomas of the skin.  相似文献   
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BACKGROUND: Although expression of the HER-2/neu oncogene may be of some prognostic importance in advanced ovarian cancer, its role in early-stage disease has not been established. The current study examined the prevalence and significance of HER-2/neu expression in early epithelial ovarian cancer. METHODS: The authors analyzed the expression of HER-2/neu on frozen tumor specimens from 40 patients with early epithelial ovarian cancer using the indirect immunoperoxidase technique with monoclonal antibodies that detect epitopes on the extracellular domain of the HER-2/neu protein. All patients underwent comprehensive surgical staging. HER-2/neu expression was graded as negative, weak, moderate (1+ to 2+), or strong (3+). Complete clinical data and long-term follow up were available for all patients. RESULTS: The distribution of patients by stage was as follows: Stage IA, 6; IB, 0; IC, 14; IIA, 4; IIB, 6; IIC, 10. The mean patient age was 53 years. Fourteen patients had serous tumors; nine, endometrioid; eight, clear cell; eight, mucinous; and one, undifferentiated. Intratumoral heterogeneity of HER-2/neu expression was observed with most specimens. In eight specimens (20%), some areas of the tumor showed strong (3+) expression, beyond the level that can be seen in normal ovarian epithelium. Twenty-eight specimens (70%) showed moderate (1+ to 2+) staining, whereas four specimens (10%) showed negative or weak staining. At a mean follow-up time among surviving patients of 32 months, 15 patients (37%) have had cancer recurrence. No statistically significant relationship was found between HER-2/neu expression and survival, disease-free survival, stage, or grade. A significant increase was found in 3+ expression of HER-2/neu in clear cell tumors. CONCLUSION: Consistent HER-2/neu overexpression occurs infrequently in early ovarian cancer, making it unlikely that such overexpression is a general early event in ovarian carcinogenesis. HER-2/neu expression does not appear to be a strong prognostic marker in early epithelial ovarian cancer.  相似文献   
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Short-rib polydactyly dysplasia (SRP) is an autosomal recessive, lethal skeletal dysplasia. Sonographic assessment of subsequent pregnancies is, therefore, recommended. This case indicates that this diagnosis can be made in the latter part of the first trimester. A 30-year-old multigravid woman presented at 13 weeks' gestation for an ultrasound examination. She had had a termination of pregnancy for a fetus with pathologically confirmed short-rib polydactyly dysplasia, type I (Saldino-Noonan). On transvaginal sonography, a narrow chest, symmetrical micromelia, polydactyly and anasarca were present. An autopsy confirmed recurrent SRP. Short-rib polydactyly dysplasia may be diagnosed with transvaginal sonography in the first trimester.  相似文献   
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Sturge-Weber syndrome is characterized by the presence of a port-wine nevus, epilepsy, stroke-like episodes, headache, and developmental delay. We studied 20 cases to test the hypothesis that decreased cerebral blood flow alters neurologic function by affecting cellular glucose metabolism. Group A consisted of 10 patients with a mean age of 1.75 years and early seizure onset (6.8 months), whereas group B was composed of older patients (mean age, 15.3 years) with later onset of seizures (3.7 years). Neurologic disease was more severe in group A, but group B had more widespread structural brain defects - shown on computed tomographic scans and magnetic resonance imaging - and metabolic brain defects shown on hexamethylpropyleneamine oxime and [18F] fluorodeoxyglucose single photon emission computed tomographic scans. Six group A cases had hypoperfusion at baseline and five of nine had worsening of perfusion and glucose metabolism 1 year later. A total of 119 stroke-like episodes occurred in six group A cases and eight group B cases; there were 65% fewer strokes in children treated with aspirin. The data suggest that progressive hypoperfusion and glucose hypometabolism are associated with neurologic deterioration in Sturge-Weber syndrome. Longitudinal studies are needed to better define the natural history of disease and to evaluate the safety and efficacy of aspirin therapy.  相似文献   
127.
The study of the origin and pathogenetic relevance of the oligoclonal antibodies present in the cerebrospinal fluid (CSF) of multiple sclerosis (MS) patients has been hampered by a lack of specific ligands. We recently reported a general strategy, based on phage-displayed random peptide libraries, to identify ligands for disease-specific antibodies even in the absence of any information on the nature of the pathologic antigen. With this procedure, we identified several peptides specifically recognized by antibodies present in the CSF of MS patients. Using these peptides as reagents, we demonstrated that they mimic different natural epitopes and react with antibodies enriched in the CSF of MS patients. Antibodies recognizing the selected peptides are commonly found with equal frequency in the sera of MS patients and of normal individuals. In contrast, the repertoire of CSF antibodies appears to be individual-specific and is probably the result of a nonspecific immunodysregulation rather than a stereotyped response to a single antigen/agent.  相似文献   
128.
BACKGROUND: Many studies have reported the increased expression of epidermal growth factor receptor (EGFR) in various human malignancies and its association with the biologic behavior of the tumors. METHODS: We performed an immunohistochemical analysis of the EGFR in 217 cases of human esophageal squamous cell carcinoma, 161 lymph node metastases and 23 foci of squamous dysplasias. The findings were correlated with clinicopathologic features, including the clinical outcome. Southern blot analysis was performed in 42 cases for the detection of DNA amplification of the EGFR gene and subsequently was correlated with EGFR immunoreactivity. RESULTS: Epidermal growth factor receptor overexpression was detected in 71% of primary tumors and 88% of lymph node metastases, as compared to nonpathologic adjacent esophageal epithelium. Statistically significant correlations were observed between EGFR overexpression and sex, age, histologic type, and the presence of invasion. Tumor staining was classified into two patterns, homogeneous and heterogeneous, based on the distribution of EGFR-positive cells. The immunostaining patterns of primary tumors had a statistically significant correlation with histologic type, the presence of adventitial invasion, histologic stage and lymph node metastasis. There was a tendency toward a worse prognosis for those patients with EGFR overexpression in the primary tumor. Greater than 90% of the foci of squamous dysplasia demonstrated homogeneous EGFR overexpression. DNA amplification of the EGFR was observed in 21% of primary tumors, and all demonstrated immunohistochemical overexpression. CONCLUSIONS: Immunohistochemical overexpression of the EGFR, which was more frequent than EGFR DNA amplification, appears to play an important role in biologic behavior of human esophageal squamous cell carcinomas.  相似文献   
129.
We report on a 4-year-old girl with obesity and hyperphagia whose peripheral blood cytogenetic analysis showed mosaicism for a deletion of band 1p36.33. Terminal 1p deletions are rarely reported and this patient represents the first identified case of mosaicism. Given the subtlety of the cytogenetic abnormality and the possibility of mosaicism, the incidence of such deletions has probably been underestimated. While a characteristic phenotype associated with this karyotypic abnormality was described recently, the present report highlights the additional clinical findings of obesity and hyperphagia and the overlap of manifestations with Prader-Willi syndrome.  相似文献   
130.
Clinically apparent prostate cancer occurs more commonly among Caucasians living in Western countries than in Chinese in the Far East. Prior studies demonstrated diminished facial and body hair and lower levels of plasma 3 alpha-androstanediol glucuronide and androsterone glucuronide in Chinese than in Caucasian men. Based upon these findings, investigators postulated that Chinese men could have diminished 5 alpha-reductase activity with a resultant decrease in prostate tissue dihydrotestosterone levels and clinically apparent prostate cancer. An alternative hypothesis suggests that decreased 3 alpha-androstanediol glucuronide and androsterone glucuronide levels might reflect reduced production of androgenic ketosteroid precursors as a result of genetic or environmental factors. The present study examined 5 alpha-reductase activity, androgenic ketosteroid precursors, and the influence of genetic and environmental/dietary factors in groups of Chinese and Caucasian men. We found no significant differences in the ratios of 5 beta-:5 alpha-reduced urinary steroids (a marker of 5 alpha-reductase activity) between Chinese subjects living in Beijing, China, and Caucasians living in Pennsylvania. To enhance the sensitivity of detection, we used an isotopic kinetic method to directly measure 5 alpha-reductase activity and found no difference in testosterone to dihydrotestosterone conversion ratios between groups. Then, addressing the alternative hypothesis, we found that the Caucasian subjects excreted significantly higher levels of individual and total androgenic ketosteroids than did their Chinese counterparts. To distinguish genetic from environmental/dietary factors as a cause of these differences, we compared Chinese men living in Pennsylvania and a similar group living in Beijing, China. We detected a reduction in testosterone production rates and total plasma testosterone and sex hormone-binding levels, but not in testosterone MCRs in Beijing Chinese as a opposed to those living in Pennsylvania. Comparing Pennsylvania Chinese with their Caucasian counterparts, we detected no significant differences in total testosterone, free and weakly bound testosterone, sex hormone-binding globulin levels, and testosterone production rates. Taken together, these studies suggest that environmental/dietary, but not genetic, factors influence androgen production and explain the differences between Caucasian and Chinese men.  相似文献   
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