Myocardial Protective Effect of Cardioxane for the Myocardial Damage due to Doxorubicin

PURPOSE: To find out the myocardial protective effect of cardioxane for the myocardial damage by doxorubicin. METHODS: Using Eighteen rabbits(2.0-3.2 kg), doxorubicin(30 mg/m2) was injected intravenously once a week in group I(12 rabbits) and cardioxane(600 mg/m2) was injected at 20-30 minutes before doxorubicin administration in group II(6 rabbits). After this, we operated on the rabbits when the total cumulative dose of doxorubicin was reached at 210, 240, 270 and 300 mg/m2 and observed the degree of myocardial damage with light and electronic microscope. RESULTS: In group I, rabbits with less than 210 mg/m2 of total cumulative dose of doxorubicin, there was no definite myocardial damage but with 240 mg/m2, focal degenerative change was observed and with 300 mg/m2, severe degenerative change was detected with light microscopic examination. With electronic microscope, rabbits with less than 180 mg/m2 of total cumulative dose of doxorubicin in group I, there was no evidence of myocardial damage. In 210 mg/m2, focal degenerative change was detected. With 240 mg/m2, degenerative change was much more advanced and with 300 mg/m2, severe degenerative change was detected. In group II, no definite myocardial damage was observed even though the total cumulative dose of doxorubicin reached 300 mg/m2, but with 360 mg/m2, there was a focal area where myocardial fibers were somewhat decreased, but it's difficult to say whether these decrement were due to adriamycin in the electronic microscopic examination. CONCLUSION: Cardioxane have a good protective effect for the doxorubicin induced cardiomyopathy and it will be used safely in pediatric cancer patients.

A Study on the Tyrosinase Related to the Albinism / 체질인류학회지

The gene for tyrosinase has been mapped to the long arm of chromosome 11 at 11q14-21. The gene is at least 50Kb in length and its coding region is divided into five exons. Until now several mutations of the tyrosinase gene have been identifed in patient with typical oculocutaneous albinism (OCA) who are responsible for tyrosinase negative OCA. It may be possible to determine the types of OCA by measuring the hairbulb tyrosinase activity. Hairbulb tyrosinase activity was examined in a Korean albino to determine the type of OCA. And also tyrosinase assay was carried out in normally pigmented individuals and all members of a Korean albino's family to examine the tyrosinase activities. Five exons of tyrosinase gene from a Korean albino were amplified by polymerase chain reaction. Each amplified exon segments were independently subcloned and DNA sequences of clones were determined. The results obtained were as follows : 1. A Korean albino had no measurable hairbulb tyrosinase activity and was identified as type IA (tyrosinase negative) oculocutaneous albinism. 2. Normally pigmented individuals had different ranges of hairbulb tyrosinase activity. 3. A Korean albino had two single base insertions within exon V (between 337bp and 338bp, 353bp and 354bp) of tyrosinase gene. These insertional mutations might disrupt tyrosinase function and were associated with a total lack of melanin biosynthesis.