| Autor: |
Robert W. Zumwalt, John E. McEntire, Charles W. Gehrke, Ben W. Papermaster, Jack W. Richens, Mark E. Smith, Kenneth C. Kuo, David L. Stalling |
| Rok vydání: |
1990 |
| Předmět: |
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| Popis: |
Publisher Summary This chapter describes serum nucleoside chromatography for classification of lung cancer patients and controls. Modified ribonucleosides derived predominantly from transfer RNA and ribosomal RNA, are known to be excreted in abnormal amounts in the urine of cancer patients. The molecular mechanisms of elevated excretion are unclear. Extract of neoplastic tissues have aberrant tRNA methyltransferases, and it has been suggested that the high turnover of tRNA is because of the rapid degradation of aberrantly modified tRNAs. Experimental evidence indicates that methylation of tRNA occurs only after-synthesis of the intact macro-molecule. No kinases have been found that will re-incorporate these compounds into tRNA, and consequently, they are excreted following metabolic degradation of tRNA. A characteristic of small cell carcinoma (SCC) is its tendency toward early and distant metastases estimated to occur in 70% of patients at the time of diagnosis. This very typical behavior of SCC creates problems in accurately defining tumor burden, and in estimating extent of disease despite technical advances in modern radiological techniques for demonstrating the presence of tumor in organs or tissues. As a consequence, difficulties are frequently encountered not only at initial staging but in correctly quantifying response and assessing sites of recurrent or metastatic disease. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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