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Biomedical subjects

H Iwasawa

Publications and source records attributed to H Iwasawa.

At least 55 records · Page 3Linked to original sources
PubMed1984

Effect of cytochalasin B on growth, Multinucleation and human chorionic gonadotropin secretion in a human choriocarcinoma cell line.

Treatment of human choriocarcinoma cells with cytochalasin B at the doses of inhibiting cell division but not inhibiting nuclear division led to in vitro formation of the multinucleated syncytiotrophoblast-like ( STL ) cells. A concomitant increase in human chorionic gonadotropin (hCG) secretion per cell was noted. Immunocytochemical staining demonstrated the predominant localization of hCG in the STL cells. These results indicate that multinucleation stimulates hCG synthesis and secretion in the choriocarcinoma cells.

Cell Division↗
PubMed1984

[Clinical studies on malignant ovarian tumor--with special reference to therapy and prognosis of epithelial ovarian tumor].

Two hundred and ninety-two (75%) patients with common "epithelial" tumors of 391 patients with various kinds of malignant ovarian tumors treated at our hospital and other 14 hospitals between 1971 and 1981 were evaluated particularly to determine 1) the prognostic value of the disease stage and 2) results of therapy. Of the 292 patients, 49.8% were classified in Stage I, 12.8% in Stage II, 27.2% in Stage III and 10.1% in Stage IV. The 5-year survival rates for the various stages were: Stage I, 70.2%; Stage II, 50. 0%; Stage III, 3.4%; and Stage IV, 0%. Postoperative chemotherapy was given to 56.9% of the patients. The prognosis of patients with Stage Ia or Ic who received adjuvant chemotherapy improved, as compared to those who were treated with surgery alone. However, the role of chemotherapy in advanced stages (Stage III and IV) remains unclear.

Adenocarcinoma, Mucinous↗
PubMed1984

[Pathological study of endometrial carcinogenesis in androgen-sterilized-rats].

As reported previously, squamous metaplasias, endometrial hyperplasias and cancers of the uterus occurred more frequently in androgen-sterilized-rats (ASR) than in normal rats (NR). This time we pathologically examined the endometrium of ASP in detail and obtained the following results: 1) In NR, aged from 70 to 750 days, no abnormal findings were found. In 61 ASR, aged more than 500 days, were found 8 simple endometrial hyperplasias, 2 atypical endometrial hyperplasias, 15 simple squamous metaplasias, 1 atypical squamous metaplasia, 2 adenocarcinomas, 1 adenosquamous carcinoma and 1 squamous carcinoma. 2) In ASR, proliferative and metaplastic changes coexisted in the endometrium. Two adenocarcinomas were accompanied by metaplasias and atypical hyperplasias, and one squamous carcinoma was accompanied by simple hyperplasias. 3) The endometrial carcinogenesis of ASR was thought to be as follows. In ASR, the endometrial epithelium loses its secretory function, becoming low columnar epithelium. A part of the non-secretory endometrium gains proliferative activity and progresses to metaplastic epithelium or to glandular hyperplasia. The former may develop to atypical metaplasia and squamous carcinoma, the latter to atypical hyperplasia and adenocarcinoma.

Adenocarcinoma↗
PubMed1984

Malignant change of dermoid cysts of the ovary. Report on an adenosquamous cell carcinoma and a clear cell carcinoma.

Five cases of malignant change of ovarian dermoid cyst are presented. Two of these cases were of special interest due to the unusual nature of the malignancy. One case (an adenosquamous cell carcinoma) was apparently a malignant change of the columnar epithelium and its squamous metaplasia. The other case (a clear cell carcinoma) appeared to represent coincidental development of two tumors.

Adenocarcinoma↗
PubMed1983

Effect of methotrexate on the growth and human chorionic gonadotropin secretion of human choriocarcinoma cell lines in vitro.

The effect of methotrexate (MTX) on the growth and human chorionic gonadotropin (hCG) secretion of five gestational and two nongestational human choriocarcinoma cell lines was studied in vitro. A striking heterogeneity in hCG secretion was noted among the cell lines. The growth of cells which secreted large quantities of hCG, such as HCCM-5, BeWo, and IMa, was inhibited by continuous exposure to 2 X 10(-8)M MTX. In contrast, cells which secreted little hCG, such as SCH, ENAMI-1, and GCH-1, showed no response to the growth inhibitory action of 2 X 10(-8)M MTX and the 3H-thymidine uptake was not reduced by treatment with MTX at doses of up to 10(-4)M for 48 hours. The common morphologic alterations observed in the cells which responded to MTX were an increase in the number of multinucleated giant cells, the appearance of vacuoles and granules in the cytoplasm, and enlargement of the nuclei. Increased hCG secretion was observed in accordance with the appearance of such morphologically altered cells. Part of the mechanisms of resistance to MTX appeared to involve both impairment of MTX uptake by the cells and an increase in the level of intracellular dihydrofolate reductase.

Cell Line↗
PubMed1983

Establishment and properties of a human choriocarcinoma cell line of ovarian origin.

A human nongestational choriocarcinoma cell line of ovarian origin (IMa) was established in vitro. This cell line had been subcultured serially more than 22 times over 18 months. Small polygonal cells with a prominent nucleus were dominant and a sparsity of cytoplasmic organelles was an ultrastructural characteristic of the IMa cells. The production and secretion of human chorionic gonadotropin and its subunits were identified by radioimmunoassay. The IMa cells were transplantable in the hamster cheek pouch and the histological diagnosis was choriocarcinoma. A newly established ovarian choriocarcinoma cell line can be considered useful for clarifying the biological differences between nongestational and gestational choriocarcinoma cells.

Animals↗
PubMed1983

In vivo studies on the antitumor effect of cis-dichlorodiammineplatinum(II) against transplantable ovarian adenocarcinoma cells of the rat.

Both prolongation of survival and inhibition of tumor growth were observed in rats inoculated with 5 X 10(5) cloned ovarian adenocarcinoma (ROT68/C1) cells when they were administered intraperitoneally with cis-dichlorodiammineplatinum(II) (Cisplatin) at doses of from 1 to 4 mg/kg body wt every 3 weeks or one-third of the dose every week. However, the effects were not dose-schedule dependent and administration of 2 mg/kg every 3 weeks appeared to be the most effective. In contrast to nontreated controls, rats treated with Cisplatin developed both degeneration and necrosis particularly in tumor cells located around the capillaries, and thrombus formation was detected on the inside of many capillaries. Severe nephro- and hepatotoxicities were demonstrated after four courses of Cisplatin administration at doses of 2 mg/kg or more every 3 weeks.

Adenocarcinoma↗
PubMed1983

A newly established human gestational choriocarcinoma cell line and its characterization.

The cell biological characteristics of a newly established human gestational choriocarcinoma cell line, HM, were examined and compared with four other gestational and two nongestational choriocarcinoma cell lines. Striking heterogeneity in the production and secretion of hCG and its subunits was observed among the cell lines. The HM cell line consisted mainly of cytotrophoblast-like cells, and the hCG and its subunit values in both the cells and culture fluid were extremely low. The syncytiotrophoblast-like multinucleated giant cells which were occasionally seen in other cell lines were scarce in the HM cell line in vitro. On the other hand, deviation of the LDH isozyme pattern to the heart-type (LDH1) was characteristic of the HM cells in contrast to the other cell lines in which LDH3 was dominant. The HM cell line represents useful material for investigating the cell biological heterogeneity of human choriocarcinomas.

Adult↗
PubMed1983

Characterization of human choriocarcinoma cell lines secreting high and low amounts of chorionic gonadotropin.

The secretory potential of human chorionic gonadotropin (hCG) in eight strains of human choriocarcinoma cell lines was examined in vitro and the correlation between the secretory potential and certain cell biological characteristics was studied. Multinucleated giant cells (syncytiotrophoblast-like cells) were occasionally observed only in high hCG-secreting cell lines in accordance with inhibition of growth. Appearance of abundant dilated rough endoplasmic reticulum and aggregated glycogen particles in the cytoplasm seemed to represent ultrastructural characteristics of high hCG-secreting cell lines. A shift of nuclear DNA to hyperploidy, its wide distribution, and S phase accumulation of cells by flow cytometry were also characteristic of them. However, no correlation was noted between the hCG secretory potential and population doubling time of the cell lines in vitro.

Cell Line↗
PubMed1982

Synthesis of (-)-15-deoxyspergualin and (-)-spergualin-15-phosphate.

The method for chemical modification of spergualin with retention of the configuration at the C-11 has been achieved by the use of tetrahydropyranyl group for protection of the 11-hydroxyl group. (-)-15-Deoxyspergualin (2), which shows about eight times stronger inhibition against mouse leukemia L-1210 than the natural (-)-spergualin(1), and (-)-spergualin-15-phosphate(3) possessing a good antitumor activity have been synthesized starting from 1.

Animals↗
PubMed1982

[In vitro studies on the antitumor effect of cis-diamminedichloroplatinum II (cisplatin) against ovarian adenocarcinoma cell line of the rat].

The survival of asynchronous rat ovarian adenocarcinoma cells (ROT68/C1) treated for 1 hr with more than 0.5 microgram/ml of cis-diamminedichloroplatinum (II) (Cisplatin) revealed a marked decrease in a dose-dependent manner, as estimated by the vitro colonyforming method. Although the ROT68/C1 cells showed no significant sensitivity to 0.1 microgram/ml of Cisplatin for 1 hr, more than 50% of the cells were killed when the exposure interval was prolonged for 16 hr. The decrease in percent survival of cells with increasing Cisplatin concentration was parallel to that of the uptake of 3H-thymidine, whereas the uptake of 3H-uridine was not inhibited in a dose-dependent manner. The DNA histogram pattern of nontreated asynchronous ROT68/C1 cells was distributed widely and a peak of accumulation was observed near 6C. When the cells were exposed to more than 0.5 microgram/ml of Cisplatin for 1 hr, the accumulation of cells near 2C was observed to occur more rapidly with increasing concentration. The cells distributed near 2C appeared to be cells with karyorrhexis and damaged irreversibly.

Adenocarcinoma↗
PubMed1982

[Antitumor effect of cis-diamminedichloroplatinum (II) against transplantable ovarian adenocarcinoma cells of the rat].

We studied on the antitumor effect of cis-diamminedichloroplatinum (II) (CDDP) with different dose schedules against a transplantable ovarian adenocarcinoma cell line of Sprague-Dawley rat. CDDP was administered intraperitoneally in the rats at doses of 2 to 4 mg/kg body weight every 3 weeks or one third of the doses every week. Administration of 2 mg/kg every 3 weeks seemed to be the most effective. In contrast to non-treated tumor tissues, in rats administered with CDDP thrombus formations were detected in many areas of the tumor tissues and obstruction of blood supply seemed to be a cause of cell damage. Severe nephro- and hepatotoxicities were observed after 4 courses of CDDP administration. Histologically vacuolated degeneration of cytoplasm and disappearance of nuclei were observed in renal proximal tubules.

Adenocarcinoma↗