In vitro determination of tritiated thymidine labeling index (LI). Evaluation of a method utilizing hyperbaric oxygen and observations on the li of human mammary carcinoma
✍ Scribed by John S. Meyer; Walter C. Bauer
- Publisher
- John Wiley and Sons
- Year
- 1975
- Tongue
- English
- Weight
- 656 KB
- Volume
- 36
- Category
- Article
- ISSN
- 0008-543X
No coin nor oath required. For personal study only.
✦ Synopsis
A simple method for incubation of tissue specimens with tritiated thymidine under 3 atm oxygen tension gave an in vitro labeling index (LI) that corresponded closely with LI's determined by injection of vitiated thymidine in vivo. T h e LI of tumors was not affected by storage at room temperature for u p to 135 minutes. The mean LI for 39 h u m a n mammary carcinomas was 3.8, but the distribution was skewed to the right, and the most frequently observed LI's were between 2 a n d 3. Larger carcinomas had significantly larger LI's than smaller tumors, which suggests that the larger tumora were faster-growing a t the time of observation than the smaller tumors. The capacity of the larger tumors to maintain a relatively rapid growth rate may account for their large size. The data suggested, but did not prove, that a high LI was associated with more frequent metastasis to axillary lymph nodes.