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To understand the influence of hormonal and environmental factors on the risk of ovarian cancer, it is important to remember the established risk factors and postulated mechanisms that lead to the development of ovarian cancer. Several risk factors have been identified as increasing the risk of epithelial ovarian cancer, including low pariety, infertility, early age of menarche, and late age of menopause. This article discusses the different hypotheses and focuses on hormonal and environmental risk factors, as well the chemoprevention of epithelial ovarian cancer.  相似文献   
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Hypoxia and transforming growth factor-β1 (TGF-β1) increase vascular endothelial growth factor A (VEGFA) expression in a number of malignancies. This effect of hypoxia and TGF-β1 might be responsible for tumor progression and metastasis of advanced prostate cancer. In the present study, TGF-β1 was shown to induce VEGFA165 secretion from both normal cell lines (HPV7 and RWPE1) and prostate cancer cell lines (DU145 and PC3). Conversely, hypoxia-stimulated VEGFA165 secretion was observed only in prostate cancer cell lines. Hypoxia induced TGF-β1 expression in PC3 prostate cancer cells, and the TGF-β type I receptor (ALK5) kinase inhibitor partially blocked hypoxia-mediated VEGFA165 secretion. This effect of hypoxia provides a novel mechanism to increase VEGFA expression in prostate cancer cells. Although autocrine signaling of VEGFA has been implicated in prostate cancer progression and metastasis, the associated mechanism is poorly characterized. VEGFA activity is mediated via VEGF receptor (VEGFR) 1 (Flt-1) and 2 (Flk-1/KDR). Whereas VEGFR-1 mRNA was detected in normal prostate epithelial cells, VEGFR-2 mRNA and VEGFR protein were expressed only in PC3 cells. VEGFA165 treatment induced phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2) in PC3 cells but not in HPV7 cells, suggesting that the autocrine function of VEGFA may be uniquely associated with prostate cancer. Activation of VEGFR-2 by VEGFA165 was shown to enhance migration of PC3 cells. A similar effect was also observed with endogenous VEGFA induced by TGF-β1 and hypoxia. These findings illustrate that an autocrine loop of VEGFA via VEGFR-2 is critical for the tumorigenic effects of TGF-β1 and hypoxia on metastatic prostate cancers.  相似文献   
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BACKGROUND: Although full-thickness burns present no difficulty to clinical judgment, accurate assessment of burn depth immediately after injury in partial thickness burns has always been difficult. METHODS: Thermal burns (applied by a 3-mm-diameter brass rod heated to 50 degrees--80 degrees C for 20 seconds) were induced on the skin of anesthetized hairless mice. Anesthesia was maintained throughout all experiments. Both burns and normal skin were investigated noninvasively in vivo using fiber-optic confocal imaging (FOCI) microscopy (excitation, 488 nm; detection, 505 nm). RESULTS: Autofluorescence was detected in burned skin, and the depth of the autofluorescent region was found to correlate with the intensity of heat applied. Cool water treatment (for 20 minutes immediately after burn induction) significantly reduced the progressive increase in autofluorescence in deeper layers of the skin over the 4-hour postburn observation period. Histology showed burn-associated changes at a lower temperature than that at which autofluorescence was first detected in vivo by FOCI. However, there was a good correlation (r = 0.78) between depth of damage revealed by FOCI compared with that by histology. CONCLUSION: These results suggest that FOCI may be used to provide an index of burn depth.  相似文献   
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BACKGROUND: Mucinous, medullary, and tubular carcinomas are uncommon types of breast cancer whose rarity does not permit large single-institution studies or randomized trials to define optimal treatments. In this study, we evaluated the long-term outcomes of breast-conserving therapy (BCT) for these subtypes of breast cancer and compared them with those for invasive ductal carcinoma. METHODS: In our institutional database of patients who received BCT from 1965 to 1999, 1,643 patients with stage I to II mucinous (61), medullary (37), tubular (60), and invasive ductal (1,485) histologies were identified. The clinical and pathologic features of the 4 groups were evaluated and compared with respect to local-regional recurrence rates, disease-free survival, and overall survival (OS). RESULTS: No statistically significant differences were found in the local-regional failure rate among the 4 groups (10.6-year median follow-up). Only patients with tubular carcinoma had better 5- and 10-year OS rates (P = .013). In multivariable analysis, factors associated with improved OS included age at or below 50 years, negative nodal status, use of chemotherapy or hormonal therapy, and tubular histology. CONCLUSIONS: BCT for mucinous, medullary, or tubular carcinoma resulted in similar local-regional failure rates to that for invasive ductal carcinoma. Tubular carcinoma patients had the most favorable OS. BCT is an appropriate treatment strategy for early-stage mucinous, medullary, and tubular carcinomas.  相似文献   
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