Neoplasms studies

It is clear from the studies reported in Table 1 (133-149) that there is no simple relation between treatment with hormonal oral contraceptives and the incidence of breast cancer. As in the case of other neoplasms, studies are confounded by the influence of many factors, including age, parity, age at first delivery, family history, pre-existent fibrocystic disease, geographical or... 

This is a very rare, possibly benign uterine tumor that is characterized by a cytologically bland and largely mitot-ically inactive proliferation of spindle cells in a myxoid matrix. The main differential diagnostic considerations include myxoid leiomyoma and leiomyosarcoma and endometrial stromal neoplasm with myxoid stroma. All inflammatory myofibroblastic tumors reported in the largest series were ALK-positive, which is similar to what has been described to occur in other sites. " All uterine mesenchymal neoplasms studied were ALK-negative, including smooth muscle and endometrial stromal tumors and carcinosarcomas. 

McKinnell RG, Carlson DL. Lucke renal adenocarcinoma, anuran neoplasm, studies at the interface of pathology, virology, and differentiation. J Cell Physiol. 1997 173 115-8. 

Mucopolysaccharide levels are increased in many cancer cells this increase is accompanied by a decreased vascular supply. Hyaluronidase [9001-54-17, obtained from bovine testis, dissolves the mucopolysaccharides surrounding a tumor, thereby allowing cytotoxic agents to penetrate the neoplasm with enhanced faciUty. In clinical studies hyaluronidase was given to patients with malignant tumors, alone or in combination with 5- uorouracil [51-21-8], significant decreases in tumormass were observed (55). 

Neoplasms of the liver have also been a prominent finding. In studies with beagles, hepatic neoplasms including hemangiosarcomas, fibrosarcomas, and fibromas were observed (Benjamin et al., 1973 1974 ... 

Tugnoli, V., Tosi, M. R., Barbarella, G. et al. Magnetic resonance spectroscopy study of low grade extra and intracerebral human neoplasms. Oncol. Rep. 5 1199-1203,1998. 

In utero exposure of mice to benzo(a)pyrene (B[a]P) resulted in suppression of the antibody response to SRBC, which persisted for up to 78 weeks in the offspring.102 In a follow up study, injection of B[a]P from gestation day 11 to 17 resulted in suppressed antibody responses to SRBC, MLR and graft versus host responses (GvH). It was suggested that lesions caused by B[a]P in the developing immune system may predispose the host to the growth of neoplasms.103... 

The antitumor alkaloid ellipticine (5,1 l-dimethyl-6//-pyrido[4,3-b]carbazole) has been isolated from many species of Ochrosia and Aspidosperma. Ellipticine and its derivatives are highly active versus several experimental neoplasms, and the compound has been widely subjected to studies devoted to its total synthesis, the preparation of derivatives, and metabolism. Metabolic transformation studies with ellipticines have been conducted, using microorganisms, in vivo and in vitro... 

Lungarella et al. 1984). In a chronic-duration study in B6C3F, mice where exposure was to commercial hexane (51.5% M-hexanc) for 6 hours/day, 5 days a week for 2 years, a statistically significant treatment-related increase in hepatocellular neoplasms (adenoma and carcinoma) was observed among females exposed at 9,018 ppm (Bio/Dynamics 1995b), but not at 900 or 3,000 ppm. No increases were observed in male mice or in Fischer 344 rats of either sex exposed similarly in a parallel experiment (Bio/Dynamics 1995a). 

Another approach to controlling the false positive rate in carcinogenicity studies was proposed by Haseman (1983). Under this rule, a compound would be declared a carcinogen if it produced an increase significant at the 1% level in a common tumor or an increase significant at the 5% level in a rear tumor. A rare neoplasm was defined as a neoplasm that occurred with a frequency of less than 1% in control animals. The overall false positive rate associated with this decision rule was found to be not more that 7-8%, based on control tumor incidences from NTP studies in rats and mice. This false positive rate compares favorably with the expected rate of 5%, which is the probability at which one would erroneously... 

Chu PG, Weiss LM (2002a) Expression of cytokeratin 5/6 in epithelial neoplasms an immuno histochemical study of 509 cases. Mod Pathol 15(1) 6 10 Chu PG, Weiss LM (2002b) Keratin expression in human tissues and neoplasms. Histopathology 40(5) 403 439... 

Demirkesen C, Hoede N, Moll R (1995) Epithelial markers and differentiation in adnexal neoplasms of the skin an immunohistochemical study including individual cytokeratins. JCutan Pathol 22(6) 518 535... 

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