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There is now considerable evidence suggesting that alterations in the DNA methylating machinery play an important role in tumorigenesis and tumour progression. For example, focal hypermethylation and generalised genomic demethylation are features of many different types of neoplasms. It is thought that tumorigenesis and tumour progression may be caused by hypermethylation induced mutational events and silencing of genes which control cellular proliferation and/or demethylation induced reactivation of genes which may only be required during embryological development. Consequently, we have begun to investigate the role of DNA methylation and developmental genes in malignant lymphoproliferative diseases. Previously, in all cases of non-Hodgkins lymphoma and leukemia studied, we have shown that the myogenic developmental gene Myf-3 is abnormally hypermethylated. In this review we discuss the possible significance of these findings since in vitro studies suggest that Myf-3 may play an important role in control of the cell cycle and therefore lymphomagenesis. In vitro and in vivo evidence suggests that PAX genes may also have oncogenic potential. The PAX family of developmental genes are involved in cellular differentiation, proliferation and cell migration. Expression of PAX3 in particular is associated with cellular mobility. Our previous studies have indicated that alternate regional expression of PAX genes may be controlled by DNA methylation. Therefore, we have proposed that abnormal methylation profiles of PAX3 may be associated with neoplastic transformation and/or metastatic potential. Results thus far reveal that the paired box of PAX3 is abnormally hypermethylated and the homeobox abnormally hypomethylated in lymphomas and leukemias. These new findings are consistent with our postulate and support the idea that inappropriate methylation induced activation or inactivation of developmental genes such as Myf-3 and PAX3 play an important role in lymphomagenesis and disease progression and that inspection of the methylation status of other developmental genes is warranted.  相似文献   
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An operator comparing the nonsteady output signals of a sensor to the characteristics of an external thermal perturbation is constructed.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 65, No. 6, pp. 718–724, December, 1993.  相似文献   
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Altogether 124 patients were followed up for disseminated breast cancer (82) and hematosarcoma (42). The patients were divided into two groups: the main group was given 500 ml of 20% protein or low-lactose enteral feeding in addition to the hospital diet; the control group received only the hospital diet. Chemotherapy lasted 3 weeks. The patients on chemotherapy received enteral feeding every day throughout the entire treatment period. In the course of treatment, the patients were examined for blood characteristics, size of the tumor and affected lymph nodes, body weight, major metabolism, protein metabolism, vitamin metabolism, osmotic and peroxide resistance of red cells, and liver function. The research program covered more than 150 characteristics. The data obtained were processed by computer. It has been disclosed that inclusion of protein and low-lactose enteral feeding into the diet of cancer patients improves the alimentary status, decreases the leukopenia and thrombocytopenia incidence. It is advisable that specialized milk concentrates (enteral feeding) should be included into the diet of cancer patients as a necessary component of a complex of therapeutic measures used during chemotherapy.  相似文献   
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