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Biomedical subjects

Y Furuhashi

Publications and source records attributed to Y Furuhashi.

47 records · Page 3Linked to original sources

[Multidisciplinary treatment of choriocarcinoma].

The remarkable improvement has been recently made in the treatment of choriocarcinoma, about 80% of survival rate has been achieved. This improvement was acquired according to appearance and betterment on administration method of MTX and ACTG, surgical treatment for pulmonary and cerebral metastases and irradiation for cerebral metastases. Recent died cases were analysed and divided into two groups; one group consisted of recurrent cases and the other consisted of those who, at first showed good response to therapy resulted in drop of hCG value and reduction of tumor, however, then showed gradual reincrease of hCG and expired at latt. Therefore for achieving the 0% of mortality rate, it is a important subject to exterminate the death from recurrence and clarify more aggressive treatment method at the time when reduction of the tumor is obtained.

Antineoplastic Combined Chemotherapy Protocols↗

[Specific in vitro effects of methotrexate entrapped into liposomes bearing antibody fragments against human chorionic gonadotropin on cell growth of cultured human choriocarcinoma cells].

Methotrexate (MTX) was entrapped into liposomes, to which rabbit antibody fragments (Fab') against human chorionic gonadotropin (hCG) had been coupled covalently, using N-[4-(p-maleimidophenyl) butyryl] phosphatidyl ethanolamine. By this system, The resulting molar ratio in the prepared liposomes was 15 MTX per Fab', and the activities of both MTX and the antibody were well preserved. The inhibitory effects of MTX entrapped in liposomes bearing anti-hCG Fab' (Lip[MTX, anti-hCG]) on the growth of choriocarcinoma cells (BeWo) in vitro were examined. The 50% inhibitory concentration of Lip[MTX, anti-hCG] was found to be 1 X 10(-3) micrograms MTX/ml, which was significantly lower than the concentrations of control groups, free MTX (2.5 X 10(-3) micrograms/ml) or MTX entrapped in liposomes bearing no antibody (Lip [MTX], 1.3 X 10(-2) micrograms/ml). The effect of the coupling of the specific antibody was more clearly demonstrated by a short-time incubation (60 min) experiment. Lip [MTX, anti-hCG] exhibited marked inhibition on cell growth, compared to MTX entrapped in liposomes bearing non-immunized Fab' (Lip[MTX, non-immunized Fab']). On the other hand, free MTX showed no effect in this experiment. We may conclude that Lip [MTX, anti-hCG] has a specific inhibitory effect on the growth of choriocarcinoma cells in vitro, which suggests the possibility of a specific immunochemotherapy for this disease, using the specific antibody to this tumor coupled to liposomes.

Antibodies↗

Monoclonal antibodies to human chorionic gonadotropin and its beta-subunit.

Using the technique of somatic cell fusion, monoclonal antibodies to human chorionic gonadotropin (hCG) and its beta-subunit were produced. Spleen cells from immunized mice were fused with the myeloma line NS-1 using 50% polyethylene glycol and cultured in a selection medium. A sensitive enzyme immunoassay was performed for antibody screening using immobilized solid-phase antigen and anti-mouse IgG Fab' (rabbit)-beta-D-galactosidase complex. Three double-cloned hybridomas (named 4H10, 4G2 and 1D12) were obtained. Anti-hCG 4H10 antibody reacted with hCG, the alpha-subunit of hCG (alpha-hCG) and human luteinizing hormone (hLH); and anti-hCG 4G2 antibody reacted with hCG and the beta-subunit of hCG (beta-hCG). It was interesting that anti-beta-hCG 1D12 antibody had the capacity to bind with free beta-hCG but not with intact hCG, which suggests that the 1D12 antibody can recognize a determinant site that is unique to beta-hCG. This unique epitope in beta-hCG might be expressed in or near a part which is hidden in the intact hCG molecule which is composed of alpha- and beta-subunits.

Animals↗

[Specific effects of methotrexate bound to the antibodies against hCG and placental alkaline phosphatase to the cultured human choriocarcinoma cells].

Methotrexate (MTX) was covalently bound to rabbit antibodies (IgG) against hCG and placental alkaline phosphatase (PLALP) by two different methods. By carbodiimide method, 16.9 mols of MTX could be coupled to one mol of IgG, but the antibody activity was completely lost. Whereas, 2.6-3.4 mols of MTX were bound to one mol of IgG and a quarter of original antibody activity was preserved by dextran bridge method. Choriocarcinoma cells BeWo and SCH were exposed to the IgG-MTX conjugates prepared by the latter method for 30 minutes, and the cell growth was investigated. To BeWo, which produces much hCG and less PLALP, anti hCG-IgG-MTX showed a considerable growth inhibition compared to the control groups (p less than 0.05). No effect was observed with anti PLALP-IgG-MTX, nonimmunized IgG-MTX, free MTX and anti hCG-IgG. In contrast, to SCH, which produces much PLALP and less hCG, anti PLALP-IgG-MTX exhibited considerable inhibition (p less than 0.05), whereas anti hCG-IgG-MTX showed no inhibition. Neither anti hCG-IgG-MTX nor anti PLALP-IgG-MTX showed any effect to the endometrial carcinoma cell HEC50B. We concluded that MTX bound to anti hCG-IgG and anti PLALP-IgG have specific growth inhibition effects to the choriocarcinoma cells in vitro, and suggested the possibility of specific immunochemotherapy of this disease.

Alkaline Phosphatase↗

Specific enzyme immunoassay for human chorionic gonadotropin using antibody to the synthetic peptide corresponding to the carboxyl-terminal region of the beta-subunit of hCG.

A sandwich-type enzyme immunoassay for human chorionic gonadotropin (hCG) was developed with anti hCG-beta antibody-enzyme complex and the immobilized solid-phase antibody which was prepared from the antiserum to the synthetic peptide corresponding to the carboxyl-terminal region of the beta-subunit of hCG (hCG-beta). This assay system showed a high sensitivity equal to the radioimmunoassay and did not cross-react with human luteinizing hormone (hLH), human follicle stimulating hormone (hFSH) or alpha-subunit of hCG (hCG-alpha). The coefficients of variation in within-run and between-run were less than 10% and there was a good correlation between the enzyme immunoassay and the radioimmunoassay of serum sample with a regression equation of y = 1.038 x -0.647 and a correlation coefficient of r = 0.953.

Chemical Phenomena↗

Specific enzyme immunoassay for human chorionic gonadotrophin.

A sandwich-type enzyme immunoassay system specific for human chorionic gonadotrophin (hCG) was prepared with the antibody Fab'-beta-D-galactosidase complex and the antibody F(ab')2-immobilized silicone rubber solid phase by using a purified antibody to beta subunit of hCG (hCG beta). The assay system cross-reacted less than 4% with human luteinizing hormone (hLH) and human follicular stimulating hormone (hFSH), and proved to be highly sensitive with hCG measurable at levels as low as 0.3 mIU per assay tube. Using 50 microliter of serum sample, 6-600 mIU/ml of hCG in serum could be determined specifically with the same degree of precision as in radioimmunoassay but without sample interference with the assay. The coefficients of variation within-run and between-run were 8.6-8.9%, and 4.9-10.7%, respectively. Values obtained with the enzyme immunoassay correlated well with those of radioimmunoassay (r = 0.98, slope = 0.94, y-intercept = 10.2 mIU/ml for 75 serum samples). Results of the immunoassay of hCG levels in serial samples of serum from healthy women and patients with choriocarcinoma show that this method is useful in the clinical diagnosis of trophoblastic disease.

Chorionic Gonadotropin↗

Sandwich-type enzyme immunoassay for human chorionic gonadotropin.

We have developed a sandwich-type enzyme immunoassay for human chorionic gonadotropin (hCG), in which antibody Fab'-beta-D-galactosidase complex and an antibody-immobilized silicone rubber solid phase were used. Despite the fact this assay system crossreacted about 40% with human luteinizing hormone (LH) that contains an immunologically very similar subunit to that of hCG, it proved to be highly sensitive with hCG measurable at levels as low as 0.3 mIU per assay tube. Using 25 microliter of urine sample, hCG levels in serum (10-1000 mlU/ml) or in urine (3-300 mlU/ml) could be determine with the same degree of precision as in radioimmunoassay without sample interference with the assay. The coefficients of variation in within-run, and between-run were 9.2-13.3%, and 4.2-18.8%, respectively. Values obtained with enzyme immunoassay correlate well with those of radioimmunoassay (r = 0.961, slope = 1.129, y-intercept = 3.7 mlU/ml for 35 serum samples) and hemagglutination assay (r = 0.954, slope = 0.951, y-intercept = 1.8 mlU/ml for 88 urine samples).

Chorionic Gonadotropin↗

Mucinous carcinoma of the ovary. Clinicopathologic analysis.

Since the incidence of mucinous carcinoma of the ovary is relatively low, with only small numbers of cases at any institution, detailed clinicopathologic studies on the prognosis and the care of patients with mucinous carcinoma are missing. Forty-four patients with mucinous carcinoma were histopathologically subclassified into endocervical (n = 8) and intestinal types (n = 36), and studied for clinical manifestations. All tumors of the endocervical type were stage I, whereas 14 intestinal-type tumors were stage II or higher (p < 0.05). Stromal invasion was not observed in 14 of 44 tumors, 13 of which were stage I. Analysis of prognostic factors disclosed that the clinical stage, maximum residual tumor diameter, volume of ascites, stromal invasion, and preoperative CA125 and CA19-9 levels significantly affected prognosis. However, multivariate analysis (stepwise regression) showed that the only significant factor was clinical stage (p < 0.004). In conclusion it is believed that, pathologically, the endocervical-type mucinous carcinoma is not as aggressive as the intestinal-type cancer. The clinical stage was found to be a significant prognostic factor even by multivariate analysis, and the prognosis at stages III and IV was unfavorable compared to stages I and II.

Adenocarcinoma, Mucinous↗

A randomized trial of cisplatin, vinblastine, and bleomycin versus cyclophosphamide, aclacinomycin, and cisplatin in epithelial ovarian cancer.

After primary cytoreductive surgery, a randomized clinical trial was conducted in women with epithelial ovarian cancer to compare the impact on survival between PVB chemotherapy, consisting of cisplatin, vinblastine and bleomycin, and CAP chemotherapy, consisting of cyclophosphamide, aclacinomycin and cisplatin. There were 148 evaluable patients. One hundred and five patients with stage II, III and IV were analyzed in this study, 49 of them received PVB chemotherapy while the remaining 56 patients received CAP chemotherapy. Sixty-four patients fulfilled the criteria for clinical remission set by the Tokai Ovarian Tumor Study Group [Gynecol Oncol 1993;48:342-348]. The remission rate was 73 and 50% in the PVB and CAP groups, respectively, and showed a significant advantage for the PVB group (p = 0.0139). Moreover, the recurrence rate was 44% in the PVB group and 61% in the CAP group after clinical remission, although there was no significant difference between the two groups. The final survival rate was 32% in the PVB group and 24% in the CAP group. There was a significant difference of survival rate between both groups at 24 months (p = 0.0378) and 48 months (p = 0.0450), but finally no significant difference was found at 96 months (p = 0.0660). Compared to the CAP regimen, the PVB combination has a significantly higher efficacy in remission, but there was no significant difference in the long-term survival rate. Furthermore, multivariate analysis demonstrated that the PVB chemotherapy improved the survival, but it was not significant. The authors conclude that PVB chemotherapy may be more effective than CAP chemotherapy for epithelial ovarian cancer.

Aclarubicin↗

Modulation of multidrug resistance by immunosuppressive agents: cyclosporin analogues, FK506 and mizoribine.

It has recently been reported that an immunosuppressive agent, cyclosporin A, shows a potent overcoming effect on multidrug resistance (MDR). We studied the presence of such a modulating effect of cyclosporin analogues and other immunosuppressive agents, FK506 and mizoribine, in human multidrug-resistant ovarian cancer cells (TAOV/A0.2). The intensity of the overcoming effect of cyclosporin analogues against adriamycin resistance was found to be in the other of cyclosporin D greater than A greater than C greater than H. It was found that cyclosporin D, which has relatively weak immunosuppressive activity, overcame adriamycin resistance in the multidrug-resistant ovarian cancer cells to a remarkable degree. On the other hand, it was found that FK506, a new potent immunosuppressant, could also distinctly modulate adriamycin-resistance. It was found that FK506 conferred chemosensitization upon adriamycin with reincreasing intracellular adriamycin accumulation in MDR cells which was far less than the parent strain. However, in the case of mizoribine, no modulation of drug resistance existed. Such modulation was not necessarily accompanied by immunosuppressive activity and the two functions were thought to be based on different mechanisms.

ATP Binding Cassette Transporter, Subfamily B, Mem↗