Cancer, exogenous

Thyroid cancer Exogenous thyroid hormone may produce regression of metastases from follicular and papillary carcinoma of the thyroid and is used as ancillary therapy of these conditions with radioactive iodine. Larger doses than those used for replacement therapy are required. 

Umemura, T., Sai, K., Takagi, A., Hasegawa, R. and Kurokawa, Y. (1991). The effects of exogenous glutathione and cysteine on oxidative stress induced by ferric nitrilo-triacetate. Cancer Lett. 58, 49-56. 

Ovarian cancer is associated with certain dietary and environmental factors as well. A diet that is high in galactose and animal fat and meat increases the risk of ovarian cancer, whereas a vegetable-rich diet is suggested to decrease risk.4,8 Although controversial, exogenous factors such as asbestos and talcum powder use on the perineal area also have been suggested to increase the risk of ovarian cancer.4,8... 

Melatonin secretion is synchronized to the light/dark (LD) cycle, with a nocturnal maximum (in young humans, about 200 pg/ml plasma) and low diurnal baseline levels (about 10 pg/ml plasma). Studies have supported the value of the exogenous administration of melatonin in circadian rhythm sleep disorders, insomnia, cancer, neurodegenerative diseases, disorders of the immune function, and oxidative damage (Karasek et al. 2002 Pandi-Perumal et al. 2005, 2006 Srinivasan et al. 2005a,b, 2006 Hardeland et al. 2006). 

A low RAIU indicates the excess thyroid hormone is not a consequence of thyroid gland hyperfunction. This may be seen in painful subacute thyroiditis, painless thyroiditis, struma ovarii, follicular cancer, and factitious ingestion of exogenous thyroid hormone. 

Bums, C. P., and Wagner, B. A, 1993, Effects of exogenous Upids on cancer and cancer chemotherapy. Implications for treatment, Drug 8 57-68. 

The molecular interactions between PTEN and FAK were studied in glioblastoma and breast cancer cells lacking PTEN. The PTEN trapping mutant bound wild-type FAK, requiring FAK autophosphorylation site Tyr397. In PTEN-mutated cancer cells, FAK phosphorylation was retained even in suspension after detachment from extracellular matrix, accompanied by enhanced PI3-K association with FAK and sustained PI3-K activity. PTEN-mutated cells were resistant to apoptosis in suspension, but most of the cells entered apoptosis after expression of exogenous PTEN or... 

Cancer. Studies found no relationship between endogenous p-cresol levels in the urine and the occurrence of large bowel cancer (Bone et al. 1976) or bladder cancer (Renwick et al. 1988) in humans. There are no data available regarding the carcinogenicity of exogenous cresols in humans. No cancer bioassays have been conducted in animals, but the results of a promotion study in mice suggested that cresols can be cancer promoters. Cresols have some ability to interact with mammalian DNA in vitro, but it is impossible to assess the potential hazard to humans without more information. 

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