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Biomedical subjects

T Takeuchi

Publications and source records attributed to T Takeuchi.

At least 1,711 records · Page 95Linked to original sources

Synthesis and antitumor activity of spergualin analogues. I. Chemical modification of 7-guanidino-3-hydroxyacyl moiety.

Many analogues and derivatives of an antitumor antibiotic, spergualin, were synthesized, and the relationships between the structure and the activity against mouse L-1210 tumor were studied. Both modification of the 15-hydroxyl group and alteration of chain-length of the omega-guanidinoacyl moiety affected the activity. 15-Deoxyspergualin (18, 1-amino-19-guanidino-11-hydroxy-4,9,12-triazanonadecane-10,13-d ion e) and its analogue 25 (1-amino-21-guanidino-11-hydroxy-4,9,12-triazauneicosane-10,13-dio ne) had strong activity, superior to that of spergualin.

Animals↗

Cytotoxicity of spergualin and amine oxidase activity in medium.

The cytotoxicity of spergualin on cultured L5178Y cells is dependent on the kind of serum contained in culture media. Spergualin has stronger cytotoxicity to L5178Y cells in calf serum (IC50 = 2 micrograms/ml) than in horse serum (IC50 = 60 micrograms/ml). This was thought to be caused by amine oxidase in sera. Because calf serum was rich in amine oxidase and horse serum was very poor. Spergualin was found to be oxidized by either calf serum or amine oxidase purified from beef plasma. Aminoguanidine, an amine oxidase inhibitor suppressed the spergualin effect to inhibit the growth of L5178Y cells in calf serum to the level in horse serum. On the other hand, in horse serum the spergualin cytotoxicity was enhanced by addition of amine oxidase. These results suggested to us that spergualin might be inactive in itself and that the amine oxidase-oxidized product might play an essential role in inhibiting the growth of cells.

Amine Oxidase (Copper-Containing)↗

[A case report of infantile testicular cancer: dissection of paraaortic lymph node involvement indicated by gradual rise in serum alpha-fetoprotein after orchiectomy].

We present a case of a 32-month-old boy with teratoma accompanied by yolk sac carcinoma and embryonal carcinoma of the right testicle. To treat the gradual rise in serum AFP value 3 months postoperatively, he received combined chemotherapy including VCR, CPM and ADM followed by bilateral retroperitoneal lymph node dissection. The preaortic lymph node disclosed, pathologically, yolk sac carcinoma and embryonal carcinoma, which demonstrated neither degeneration nor necrosis despite remarkable decrease in serum AFP value after the chemotherapy. The patient had normal AFP value and no evidence of recurrent disease 36 months after the lymph node dissection. We emphasize the discrepancy between the response of the tumor marker after the chemotherapy and the histologic alteration. Furthermore, the management of infantile testicular cancer is discussed.

Child, Preschool↗

Experimental studies on aclacinomycin.

Experimental features of aclacinomycin (ACM), a new antitumour antibiotic of the anthracycline group, are presented. ACM inhibited the growth of experimental mouse tumours and human cancer xenografts from various origins. In CDF1 mice with L1210 cells treated i.p. with ACM in combination with Ara-C for 10 days, a 459% ILS was observed, including 67% of 60-day survivors. The inhibition of RNA and DNA synthesis was examined in L1210 cells. The IC50 values of ACM for incorporations of [14C]-thymidine and [14C]-uridine were 0.30 and 0.038 microgram/ml respectively. The ratio of IC50. DNA/RNA was 7.9, while with adriamycin (ADR) it was 2.5. ACM showed no mutagenic activity in the Ames' test and the rec- assay. The cardiac toxicity of ACM was significantly lower than that of ADR. Lower ECG changes, a return to normal after discontinuation of the drug and slighter ultrastructural modifications of the myocardium were demonstrated in hamsters and rabbits. When administered to hamsters i.v. at 5 mg/kg, ACM was eliminated almost completely from the heart muscle after 2 h, while ADR remained at 8 micrograms/g even after 8 h.

Aclarubicin↗

A silica-based reversed-phase column for single-stranded oligodeoxyribonucleotides.

A novel, silica-based, reversed-phase column targeted to the separation of single-stranded oligodeoxyribonucleotides has been developed by grafting monochlorooctadecylsilane onto silica which is a base material of reversed-phase columns (TSK 120A and 120T), in which polychlorosilane is used as a grafting reagent. By applying a shallow gradient elution of an aqueous acetonitrile solution containing 0.1 M ammonium acetate, chromatography with this column produced well-resolved peaks for large samples such as those having bases up to 26.

Chromatography, High Pressure Liquid↗

[A case of postpartum spontaneous rupture of an angiomyolipoma].

A case of postpartum spontaneous rupture of angiomyolipoma in a 27-year-old woman with the chief complaints of right flank pain and fever was reported. Physical examinations revealed an infant-head sized, hard elastic mass with a smooth surface in the right flank. Laboratory studies showed a decrease of Hb to 9.0 g/dl and Ht to 26.5%, and elevated LDH (2914 IU/l). Angiomyolipoma was suspected with ultrasonography, CT scan and angiography. Transperitoneal right nephrectomy was performed. The right kidney and tumor weighed 1,870 g. Pathological diagnosis also confirmed angiomyolipoma of the kidney. Discussion of the case and a brief review of the literature on spontaneous rupture of angiomyolipoma in the intra- and postpartum are made.

Adult↗

Screening of agents which convert 'transformed morphology' of Rous sarcoma virus-infected rat kidney cells to 'normal morphology': identification of an active agent as herbimycin and its inhibition of intracellular src kinase.

During the course of screening of agents active in converting the transformed morphology of Rous sarcoma virus-infected rat kidney cells to the normal morphology, we identified an active substance produced by Streptomyces sp. MH237-CF8 as herbimycin. Herbimycin converted almost all cells into the normal morphology. The antibiotic was found to be an inhibitor of p60src-associated protein kinase in the cells.

Animals↗

Antitumor spectrum of a new anthracycline, (2"R)-4'-O-tetrahydropyranyladriamycin, and effect on the cellular immune response in mice.

(2''R)-4'-O-Tetrahydropyranyladriamycin (THP), a new anthracycline antibiotic, showed stronger inhibition of the growth of L1210, CCMT (mouse mammary adenocarcinoma) and Yoshida sarcoma in rats than did adriamycin (ADM). The antitumor activity of THP against P388 and Meth-A (mouse fibrosarcoma) was equal or slightly superior to that of ADM. Moreover, THP was active against an ADM-resistant subline of P388. THP at the optimal effective dose against experimental tumors had no toxic effect on the cellular immune system in normal and tumor-bearing mice.

Adenocarcinoma↗

[Effect of danazol on serum prolactin and cortisol levels].

In order to investigate the effect of Danazol (D) on serum prolactin (PRL) and cortisol levels, D was given orally in a daily dose of 400 mg for 2 weeks to 4 women (400 mg group) and 600 mg to 5 women (600 mg group) at one month and more after menopause and oophorectomy. The blood samples were taken through an indwelling catheter into the cubital vein every 20 minutes for 2 hours before and after the administration of D. Serum hormone levels were determined by each specific RIA. In a comparison in each individual of mean hormone levels of 7 serum samples before and after D, (1) serum PRL levels were significantly lowered in 2 women after D of 400 mg (p less than 0.001) and in one woman after D of 600 mg (p less than 0.001), but increased in one woman after D of 600 mg (p less than 0.001), (2) serum cortisol levels were significantly lowered in one woman after D of 400 mg (p less than 0.01) and in 4 women after D of 600 mg (p less than 0.001). When the mean hormone levels in the 400 and 600 mg group (an average of the mean hormone levels of 7 samples in each group) were compared before and after D, (1) the mean serum PRL levels were not significantly affected by D in either group, (2) the mean serum cortisol levels were significantly lowered by D in the 600 mg group, but not in the 400 mg group. The present study demonstrated that serum PRL levels were not consistently affected by D in the condition without ovarian hormones, and serum cortisol levels were lowered after a relatively larger dose of D.

Aged↗

Diagnosis of small pancreatic carcinoma.

A retrospective analysis was performed to evaluate the clinical symptoms and abnormal test findings in small pancreatic carcinoma. Five hundred and thirty-six cases of pancreatic carcinoma with the histology of duct cell carcinoma were collected from 14 medical centers in Japan. In 440 of the cases, tumor size was measured at the time of laparotomy or from the resected specimen. Three hundred and seventy-seven patients (86%) had a carcinoma larger than 3.0 cm; only 30% of these were resectable. Sixty-three patients (14%) had a carcinoma of 3.0 cm or less, with resectability of 97%. Detecting a tumor of "3 cm or less" with a high probability of resectability is the objective of early diagnosis with the resulting possibility of a cure. In most cases these small carcinomas were found easily when obstructive jaundice was present (73%). However, the estimated occurrence of obstructive jaundice associated with carcinomas of 3 cm or less was only 10% among the total cases of pancreatic carcinoma studied. Therefore, it is necessary for early diagnosis to detect carcinomas of 3 cm or less presenting without jaundice. The symptoms of small carcinoma without jaundice are weight loss, anorexia, upper abdominal pain, back pain and a palpable abdominal mass. Among the various available examinations, endoscopic retrograde cholangiopancreatography, computerized tomography and ultrasonography were valuable in diagnosing these small carcinomas.

Cholestasis↗