Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0035412 (rhabdomyosarcoma)
 6,156 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

An assay for thymidine substitution by iododeoxyuridine (IdUrd) using reversed-phase high-performance liquid chromatography (HPLC) has been developed. Three principal steps in this procedure are: extraction of DNA from cell or tissues, hydrolysis of DNA into deoxynucleosides and separation using HPLC. Approximately 1 microgram of DNA was recovered from 10(5) cells by phenol extraction, and subjected to hydrolysis into deoxynucleosides which required a three-stage DNA digestion using enzymes DNAse I. phosphodiesterase I and alkaline phosphatase. The deoxynucleosides were separated on the Microsorb C18 column with isocratic elution; 90-100% of the DNA was recovered as deoxynucleosides on the column. The method was used to determine quantitatively the percent IdUrd substitution of thymidine in Chinese hamster lung cells in vitro and BA1112 rhabdomyosarcoma in WAG/Rij rats perfused with IdUrd. It was possible to determine the thymidine substitution by IdUrd as small as 1% using a few micrograms of DNA. The close correspondence between the percent substitutions determined by HPLC and those determined by radioactive assay using [125I]-labelled IdUrd, confirmed the accuracy of our HPLC method. The HPLC analysis is especially suitable for the determination of percent IdUrd substitution of thymidine in tissue biopsies from animals used in in vivo experiments or humans undergoing radiation treatment.
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PMID:A method for determination of iododeoxyuridine substitution of thymidine using reversed-phase high-performance liquid chromatography. 200 16

Four different methods of DNA extraction from formalin-fixed, paraffin-embedded tissues were compared for their ability to produce DNA suitable as a template for polymerase chain reaction (PCR). Seven paraffin-embedded rhabdomyosarcoma tissue blocks from the 1950s and one from 1960 were treated with the following extraction methods: 1. Proteinase K digestion and phenol/chloroform extraction; 2. Proteinase K digestion followed by boiling to inactivate the enzyme; 3. Proteinase K digestion, addition of Chelex-100, followed by boiling; and 4. Proteinase K digestion and Prep-A-Gene purification. DNA extracted by methods 1 and 2 was degraded, but DNA of high molecular weight was recovered in every sample extracted by methods 3 and 4 - even though some degradation was observed. Extracted DNA was used as a template for PCR amplification of exon 4 of the PAX-3 gene. PCR was successful in 7 out of 8 samples prepared using methods 3 and 4, producing levels of amplified product equivalent to those obtained with control DNA obtained from fresh lymphocytes. Only very weak products were found in samples prepared by methods 1 (2 out of 8) and 2 (4 out of 8). These results indicate that chelation of polyvalent ions (Chelex-100 method) or obviating the need for boiling (Prep-A-Gene) may protect DNA during extraction.
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PMID:PCR amplification of 40-year-old paraffin-embedded tumor-tissues - comparison of 4 different DNA extraction and purification methods. 2155 97