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Biomedical subjects

Y Tenjin

Publications and source records attributed to Y Tenjin.

46 records · Page 3Linked to original sources

Possible mechanisms of resistance to cis-diamminedichloroplatinum (II) of human ovarian cancer cells.

The mechanism of cis-diamminedichloroplatinum (II) (CDDP) resistance was examined by using a CDDP-resistant (KFr) cell line established by continuous exposure of KF cells (derived from serous cystadenocarcinoma of the ovary) to escalating doses of CDDP. When KFr cells were incubated with 66.7 microM CDDP, the uptake of CDDP was significantly inhibited and the cellular content in the KFr cells was about a half of that in KF cells after incubation for 4 h. When the KF or KFr cells were incubated for 4 h with 100 microM CDDP, the release pattern of CDDP from KFr cells was similar to that from KF cells. In addition, the DNA histogram of both KF and KFr cells revealed that KF cells seemed to contain two clones of cell population and the KFr cells may have been selected by exposure to CDDP. At 3 h after intraperitoneal administration of 0.5 mg of CDDP per mouse to nude mice with KF or KFr tumor, the CDDP content in the KFr tumor was significantly lower than that in the KF tumor. In contrast, at 6 or 9 h after CDDP administration the CDDP content in the KFr tumor was significantly higher than that in the KF tumor. Furthermore, the KFr cells had cross-resistance to various CDDP analogues including carboplatin. It was shown that cellular uptakes of two CDDP analogues into KFr cells were significantly lower than those into KF cells.

Animals↗

Telomerase activity in gynecological tumors.

The aim of this study was to define the clinical implications of semi-quantitative telomerase activity in gynecological tumors by comparing the telomerase activity of cancerous lesion and the adjacent non-cancerous lesion. In 118 cases of gynecologic tumors, including 41 uterine cervical tumors, 43 uterine body tumors and 34 ovarian tumors, telomerase activities were determined using TRAPeze telomerase detection kit for the extension reaction of the telomere sequence and the PCR reaction for amplification of the sequence, and using fluorecence-based telomere repeat amplification protocol (F-TRAP) method for the detection. In all gynecologic cancers examined, telomerase activity of the cancerous lesion was significantly higher than that of the non-cancerous lesion. Telomerase activity in the uterine cervix increased in the following order of the normal uterine cervix, cervical dysplasia and cervical cancer. Regarding the endometrial cancer, telomerase activity at the primary lesion in patients with lymph node metastases was significantly higher than that in patients without lymph node metastases. When telomerase activity was compared by histologic subtypes of the ovarian cancer, clear cell adenocarcinoma showed significantly lower telomerase activity than the other subtypes, especially endometrioid adenocarcinoma. In all gynecologic cancers examined, there was no clear correlation between the telomerase activity and age at diagnosis or age of menopause. Although all tumors with 100 units or more telomerase activity were cancerous, the sensitivity was 39% in cervical cancer, 41% in endometrial cancer and 21% in ovarian cancer, respectively. Cervical intraepithelial neoplasia (CIN) had already increased telomerase activity and endometrial cancer with lymph node metastases had also greater activity than that without lymph node metastases. Although telomerase activity in ovarian cancer tended to increase as stage advances, it is noteworthy that clear cell adenocarcinoma showed significantly lower telomerase activity than endometrioid adenocarcinoma.

Cervix Uteri↗

Automated cytoscreening system using 16mm roll film.

1. Cell preparations are fixed to a transport film by our coating. 2. No special cover for the preparation is required. 3. Our system allows efficient cytological identification. 4. By attaching an automatic cancer cell scanning system, checked cells can be projected on a large screen immediately and be rechecked by cytologists.

Cytodiagnosis↗

Basic studies on repair, especially histology, cytology and microspectrophotometry of DNA contents.

We studied epithelial regeneration from its cytologic, histologic and microspectrophotometric aspects. In the squamous region of the uterine cervix, repair cells which have characteristic atypia appear approximately seven days after injury. Thereafter, these repair cells resemble normal squamous cells or metaplastic cells. In the vaginal region, the reparative processes are no different from those in the squamous region of the uterine cervix. Repair cells in the cervical columnar region are most prominent and atypical two weeks after cryosurgery. From the standpoint of clinical cytology, the differential diagnosis of repair cells from malignant cells is possible through follow-up of repeated smears.

Biopsy, Needle↗