Biomedical subjects

S Todo

Publications and source records attributed to S Todo.

654 records · Page 37Linked to original sources

PubMedDate not supplied

Effect of preoperative thoracic duct drainage on canine kidney transplantation.

Chronic drainage of the thoracic duct to the esophagus was developed in dogs, and its efficacy in immunomodulation was tested using kidney transplantation. Compared to 9.7 days in the control, the mean animal survival was prolonged to 9.9 days, 17.8 days, and 18.5 days when TDD was applied preoperatively for 3 weeks, 6 weeks, and 9 weeks, respectively. Prolongation was significant after 6 weeks. Patency of the fistula was 93.5, 80.4, and 76.1% at respective weeks. Number of peripheral T-lymphocytes determined by a new monoclonal antibody diminished after 3 weeks. All animals were in normal health, requiring no special care for fluid, electrolyte, or protein replacement.

Animals↗

PubMedDate not supplied

Combined treatment with TNP-470 and 5-fluorouracil effectively inhibits growth of murine colon cancer cells in vitro and liver metastasis in vivo.

The combined effects of TNP-470 (TNP), a semisynthetic analogue of fumagillin, and 5-fluorouracil (5FU), a representative chemotherapeutic agent for colorectal cancer, were investigated using murine colon 26 adenocarcinoma (CT 26) cells. In a cell-proliferation study in vitro, 50% inhibitory concentrations (IC50) were determined to be 5.2 microg/ml and 240 ng/ml for TNP and 5FU, respectively. When CT 26 cells were treated with TNP and 5FU in combination, a remarkable cytotoxic effect was obtained. Isobologram analysis revealed synergism of these two agents in inhibition of the cell growth. In vivo, using a dorsal air sac assay, we found that TNP significantly inhibited the CT 26-induced angiogenesis. In addition, the combination of TNP and 5FU exerted a synergistic anti-tumor effect in a model of hepatic metastasis by portal injection of CT 26 cells. Since TNP is known to exert inhibitory effects on tumor cell growth through suppression of cell cycle progress from the G1 to S phases as well as neovascularization, it is speculated that the treatment with TNP enhanced the anti-tumor effect of 5FU through suppression of the cell cycle and tumor-derived angiogenesis. Taken together, these results suggest that combined treatment with TNP and 5FU is potentially useful for inhibition of tumor cell growth and liver metastasis of colorectal cancer.

Adenocarcinoma↗

PubMedDate not supplied

Initial studies with FK506 in renal transplantation.

FK506 is a novel immunosuppressive agent which is approximately 100 times as potent as cyclosporine in vitro. In this initial trial, 65 renal transplant patients of high complexity received primary FK506 immunosuppression. Overall, graft and patient survival rates are 80% and 98.5%, respectively. A major advantage of FK506 is its potency with relatively few side effects, which has permitted elimination of steroids in 31 (60%) of these patients. Because of these encouraging results, a randomized trial comparing the therapeutic efficacy and toxicity of FK506 and cyclosporine is currently underway at our institution.

Follow-Up Studies↗

PubMedDate not supplied

Effects of polyunsaturated fatty acids on vincristine-resistance in human neuroblastoma cells.

PUFAs such as GLA (n-6) or DHA (n-3) were shown to exert antitumor activity on a human neuroblastoma cell line (NCG) and its VCR-resistant subline (NCG/VCR1, 8.6-fold resistant to VCR) in vitro. The NCG/VCR1 line had markedly decreased intracellular accumulation of [3H]-VCR and an accelerated drug efflux, compared to the NCG. The cytotoxic activity of PUFAs was correlated with the generation of MDA-like products in these cells. When VCR was added simultaneously with GLA or DHA to culture medium, the cytotoxic effect of VCR was about 2-fold enhanced, accompanied by about 1.5-2.0-fold increase of intracellular [3H]-VCR in both cell lines. Fatty acid analysis of membrane phospholipids of the NCG and the NCG/VCR1 cells treated with GLA or DHA showed an increased total PUFAs and SFAs, associated with markedly decreased total MUFAs and an inverted PUFAs/MUFAs ratio. Such phospholipid modification may have altered the membrane physical properties and enhanced the VCR cytotoxicity by increasing intracellular VCR accumulation; however, these PUFAs did not affect the drug efflux sufficiently enough to overcome completely the VCR resistance in the NCG/VCR1 cells. These results indicate that PUFAs partially alleviate the VCR-resistance in human neuroblastoma cells, not directly acting on VCR-resistance mechanism(s).

Cell Division↗

PubMedDate not supplied

Gamma linolenic acid alters the cytotoxic activity of anticancer drugs on cultured human neuroblastoma cells.

Gamma linolenic acid (GLA) by itself shows anti-tumor activity on various neoplastic cells in culture. We investigated the combined effect of GLA and anticancer drugs on two human neuroblastoma cell lines. The cytotoxic effect of Vinca alkaloids such as vincristine (VCR), vindesine (VDS) and vinblastine (VBL) was about 2-fold enhanced when GLA was added simultaneously to the growth medium. On the other hand, that of platinating agents such as cisplatin (CDDP) and carboplatin (CBDCA) was inhibited by GLA supplementation. The cytotoxic activity of other anticancer agents was not affected by GLA. Pharmacokinetic studies on VCR and CDDP demonstrated that intracellular accumulation of [3H]-VCR was about 1.5-fold increased in the cells pretreated by GLA, while, on the contrary, that of CDDP was rather decreased; cellular efflux of either drug was not affected. Malon dialdehyde (MDA) formation induced by supplemented GLA was not influenced by either VCR or CDDP. These results indicate that GLA exerts differential effects on the kinetics of anticancer drugs.

Antineoplastic Agents↗

PubMedDate not supplied

Increased levels of alpha V-associated integrins in association with growth inhibition of cultured tumor cells by bromodeoxyuridine.

Treatment of three small-round-cell-tumor cell lines, TC-32 (peripheral neuroepithelioma), 6647 (Ewing's sarcoma), and GOTO (neuroblastoma), with bromodeoxyuridine (BrdU) (5 micrograms/ml) for 6 days markedly inhibited cell growth in both culture medium and soft agar and induced morphological alteration into large flat cells. These BrdU-treated cells showed markedly increased levels of alpha V-associated integrins, including alpha V beta 3, and no uniform changes in other beta 1 subfamilies (alpha 1-6). Cell attachment to vitronectin was found to be increased in these BrdU-treated cells. These results suggest that increased levels of alpha V-associated integrins are associated with growth inhibition of cultured tumor cells induced by BrdU.

Androgens↗