TAKAHASHI Shigeru Hokkaido Univ., Grad. School of Den., Lec., 大学院・歯学研究科, 助手 (70241338)
IIZUKA Tadashi Hokkaido Univ., Grad. School of Den., Lec., 大学院・歯学研究科, 助手 (80168062)
SHINDOH Masanobu Hokkaido Univ., Grad. School of Den., Asso. Pro., 大学院・歯学研究科, 助教授 (20162802)
|Budget Amount *help
¥10,200,000 (Direct Cost: ¥10,200,000)
Fiscal Year 2001: ¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 2000: ¥8,400,000 (Direct Cost: ¥8,400,000)
1) Apoptosis and proliferation of parenchymal cells during atrophy of rat submandibular gland induced by double duct ligation were investigated. At 2 and 3 days after ligation, increased PCNA positive cells and mitoses were seen in ducts; thereafter PCNA positive cells decreased in number. At After 7 days, most acinar cells had disappeared; a few acinar cells remained, especially at the lobule periphery. Marked depletion of acinar cell by apoptosis and a concurrent short-lived cycle of duct cell proliferation were seen. Both apoptosis and proliferation of myoepithelial cells occurred, especially in the early phase of atrophy.
2) We investigated a sex differences and the effects of ovariectomy on the histology of 9,10-dimethyl-1,2-benzanthracene (DMBA)-induced adenocarcinomas in the submandibular gland of rats. Wistar rats were divided four groups : (1) non ovariectomy, (2) ovariectomy(OV), (3) anti-estrogen Tamoxifen application after development of DMBA-induced adenocarcinoma (4) male
rats. In Ov rats, induction of adenocarcinoma was significantly reduced but the incidence of squamous cell carcinomas significantly increased. Moreover, the results of anti-estrogen tamoxifen application showed similar changes as those seen in Ov rats. As a ovarian function, estrogen seemed to play an important role in the tumorigenesis and transformation of adenocarcinoma in female rat.
3) Clinicopathologically, mucoepidermoid carcinomas were investigated. The sections were immunostained with ER, progesterone receptor (PgR), MIB-1, and cytokeratin (CK) 6,7,8,13, and 19 antibodies. The rate of ER positivity was larger in epidermoid cells than in intermediate cells. The percentage of ER positivity was higher in the low-grade tumors than in the high-grade ones. The MIB-1 positivity was significantly higher in high-grade than in low-grade tumors. ER expression was associated with lymph node metastasis in male mucoepidermoid carcinomas.
The expression of different types of CKs and ER suggests that ER is related to cellular differentiation in mucoepidermoid carcinomas. Less