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Biomedical subjects

Y Maehara

Publications and source records attributed to Y Maehara.

At least 361 records · Page 20Linked to original sources
PubMed1984

[Influence of PSK on the metabolism of FT-207].

The influence of PSK on the metabolism of FT-207 was studied in patients with gastric cancer. The 5-FU concentration in the blood was determined 15 min, 30 min, 1 hour and 3 hours after intravenous injection of FT-207, 400mg. The blood level of 5-FU remained constant in 86% of patients after administration of PSK for 7 days, but decreased in 14% of patients. After administration of PSK for 8 to 14 months, no change in the blood level of 5-FU was detected. These results suggest that PSK has no distinct influence on the activation of FT-207.

Antibiotics, Antineoplastic↗
PubMed1984

[Study on radiation-induced malignant neoplasms].

Nineteen patients with newly developed malignant neoplasms following radiotherapy are presented. The primary lesions of 6 patients were tuberculous cervical lymphadenitis, the primary lesions of the other 13 patients were malignant neoplasms. The radiation-induced malignant neoplasms of 15 patients were epithelial, only 4 patients were non-epithelial. The prognosis was not good. However, we think that radiation-induced malignant neoplasms are not highly radioresistant and that the benefits of radiotherapy for malignant neoplasms outweigh the risk of radiation-induced malignant neoplasms.

Adenocarcinoma↗
PubMed1984

[Evaluation of multi-disciplinary treatment combined with intra-arterial chemotherapy for carcinoma of the meso-pharynx].

Forty-seven cases of carcinoma of the mesopharynx , treated from 1973 to 1981 at Gunma Cancer Center, were evaluated. The following results were obtained, According to histopathologic diagnosis, 37 were well-differentiated squamous cell carcinoma and other cases were poorly differentiated squamous cell carcinoma. Classification of the site of the disease showed the most frequent site was lateral wall type (31 cases, 65.9 per cent) followed by anterior wall (9 cases), superior wall (5 cases), and posterior wall types (2 cases). According to TN classification, there were 1 case in T1, 14 cases in T2, 24 cases in T3, and 7 cases in T4, N distribution revealed 27 cases N0, 20 cases N1, N2 and N3. The most common treatment was intraarterial chemotherapy using 5-FU combined with external irradiation (15 cases, 31.9 per cent), external irradiation alone (14 cases, 29.7 per cent), external irradiation with Radium (8 cases, 17.0 per cent), and combined with cryosurgery 5 cases, 10.6 per cent). The five-year cumulative survival rate was 35.3 per cent. The lesion of mesopharyngeal carcinoma takes various forms, so the treatment policy cannot be a standard one. Thus multi-disciplinary treatment should be applied for this disease.

Brachytherapy↗
PubMed1983

Cloning of sequences expressed specifically in tumors of rat.

The sequences specifically transcribed in tumor cells are believed to be closely related to transformed phenotypes. For the isolation of such sequences, a cDNA clone library was constructed by using poly(A)+ RNAs from azo-dye-induced rat ascites hepatomas. Thirty-one tumor RNA-responsive clones were isolated by screening 4,000 clones of this library with conventional techniques, differential colony hybridization, and RNA blot hybridization. These clones were categorized into two groups with respect to their size distribution of mRNAs from which clones were derived. The first group was complementary to a single distinct species, either about 1.5 or 0.6 kilobases in length, of poly(A)+ RNA, and the second showed no distinct bands but a smear on a RNA blot. Semiquantitative RNA dot blot assays revealed that the sequences of these clones were expressed very little, if at all, in normal and regenerating livers, while generally high in ascites hepatomas. This specificity was also true for other solid lines of tumors, such as Morris hepatoma 5123D of Buffalo rat and Walker 256 carcinosarcoma of Wistar rat. The smear class sequences were transcribed from middle-repetitive sequences of DNA, indicating that a class of middle-repetitive sequences is specifically transcribed in tumor cells.

Animals↗
PubMed1983

[Late local recurrence of cervical cancer after initial treatment].

Late local recurrence of cervical cancer more than 10 years after successful initial treatment is very rare. We now present 17 patients with late local recurrence. Only one patient had undergone primary surgery alone; the other 16 patients had received various types of radiotherapy. All 17 patients received radiotherapy as the second treatment. Local control was achieved in 9 patients, 4 of these survived for more than 5 years after the second treatment. Longterm follow-up for more than 10 years is important for the early detection of late local recurrence.

Adult↗
PubMed1983

[Case of yolk sac tumor of the anterior mediastinum with superior vena cava syndrome].

The patient was a 21-year-old man with SVC syndrome due to a large anterior mediastinal mass. Following radiotherapy which improved his condition, thoracotomy was performed, however, total resection failed. Despite postoperative re-irradiation, his condition worsened rapidly and he died five months after the onset of his symptoms. The neoplasm was composed of a yolk sac tumor producing alpha-fetoprotein. Yolk sac tumors of the mediastinum are rare and lethal. Recent reports indicate that cis-platinum may be highly effective in germ cell tumors. Therefore, radiotherapy combined with cis-platinum may be improved the survival of patients with yolk sac tumor.

Adult↗
PubMed1982

Activities of various enzymes of pyrimidine nucleotide and DNA syntheses in normal and neoplastic human tissues.

The activities of the key enzymes of pyrimidine nucleotide and DNA syntheses in 43 human tumors and 28 normal human tissues were investigated. The activities of cytidine triphosphate synthetase, deoxycytidine monophosphate deaminase, uridine kinase, thymidine kinase, thymidine monophosphate kinase and DNA polymerase were markedly increased in tumor tissues, compared with those in the corresponding normal tissues, while the activities of deoxycytidine kinase, cytidine deaminase and deoxycytidine deaminase were only slightly increased. The use of thymidine and deoxyuridine as substrates of human pyrimidine nucleoside phosphorylase gave 1 to 2 orders of magnitude higher activity than that of uridine.

Carbon-Nitrogen Ligases↗
PubMed1981

Metabolism of 5-fluorouracil in various human normal and tumor tissues.

The metabolism of 5-fluorouracil (5-FU) in tumors and normal tissues of humans was investigated in vitro. Phosphorylation of 5-FU was faster in tumor tissues than in normal tissues. Phosphorylating activity with 2-deoxy-alpha-D-ribose 1-phosphate (dRiblP) and ATP as cofactors was more active than that with alpha D-ribose 1-phosphate (RiblP) and ATP, or 5-phospho-alpha-D-ribosyldiphosphate (PPRibP) as cofactors. Phosphorylating activity in squamous cell carcinoma of the lung was similar to that in adenocarcinomas. Degradation of 5-FU was much faster in the liver than in other tissues including tumor tissues.

Adenocarcinoma↗
PubMed1980

Effect of coadministration of thymine or thymidine on the antitumor activity of 1-(2-tetrahydrofuryl)-5-fluorouracil and 5-fluorouracil.

The antitumor activity of 1-(2-tetrahydrofuryl)-5-fluorouracil (FT-207) on sarcoma was enhanced by oral coadministration of uracil, thymine, or thymidine. The activity was enhanced equally by thymine and by uracil than by thymidine, but thymine caused loss in body weight. The antitumor activity of 5-fluorouracil (5-FU) was also enhanced by thymine or uracil, but both caused loss in body weight. Degradation of 5-FU in vitro was inhibited more by thymine than by uracil. Phosphorylation of 5-FU, however, was not inhibited by uracil, thymine, or thymidine, even at 100 times the concentration of 5-FU. These results suggest that the mechanism of enhancement of the antitumor activity of FT-207 by thymine or thymidine was similar to that by uracil, and that uracil had more effect than thymine or thymidine in enhancing antitumor effect of these drugs to FT-207 without toxicity.

Administration, Oral↗
PubMedDate not supplied

Histologic differentiation and chemosensitivity of human head and neck squamous cell carcinomas.

The chemosensitivities of 42 human head and neck squamous cell carcinomas were examined using the in vitro succinate dehydrogenase inhibition (SDI) test. The tumor tissues obtained at surgery or biopsy were exposed to five different antitumor drugs: adriamycin (ADM), cisplatin (CDDP), carboquone (CQ), 5-fluorouracil (5-FU), and 1-hexylcarbamoyl-5-fluorouracil (HCFU). The results were analyzed according to the histopathologic degree of differentiation of well, moderately, and poorly differentiated squamous cell carcinoma. The average decrease in succinate dehydrogenase activity was 43.2 +/- 24.9 for ADM, 29.0 +/- 14.2 for CDDP, 32.9 +/- 17.6 for CQ, 64.2 +/- 20.6 for 5-FU, and 26.8 +/- 16.9 for HCFU. There was a statistically significant difference in the decrease of succinate dehydrogenase activity between well and poorly differentiated squamous cell carcinomas. These data suggest that, for patients with a poorly differentiated squamous cell carcinoma, the response to anti-cancer drugs may be more satisfactory than in those with a well-differentiated squamous cell carcinoma.

Antineoplastic Agents↗
PubMedDate not supplied

Peritoneal dissemination after a curative gastrectomy in patients with undifferentiated adenocarcinoma of the stomach.

Peritoneal dissemination is the major pattern of recurrence in patients with gastric cancer. Among the 1,337 patients with gastric cancer who underwent a curative resection, a multivariate analysis showed that the independent risk factors for the occurrence of peritoneal dissemination were an undifferentiated tissue type and serosal invasion. We focus our attention on 477 patients with undifferentiated type tumor, in which the postoperative prognosis and the pattern of recurrence after curative resection were evaluated with regard to the depth of the cancerous invasion in the gastric wall. Patients with tumors limiting to the subserosal layer had a satisfactory post-operative course, with five-year survival rates of 98.5%, 97.4%, and 82.5% in patients with tumors limiting to the submucosal layer, the muscularis propria and subserosal layer, respectively. In 179 patients with tumors invading to the subserosal layer, however, the five year survival rate was only 48.2%. Seventy-one died of peritoneal dissemination, while 24 and 15 were due to hematogenous and local recurrences, respectively. Only 50 (27.9%) survived over 5 years without any recurrence.

Adenocarcinoma↗
PubMedDate not supplied

Helix pomatia agglutinin binding activity and lymph node metastasis in patients with gastric cancer.

We made use of Helix pomatia agglutinin (HPA) staining to examine 218 gastric cancer tissues (163 primary tumors and 55 metastatic lymph nodes), using the avidin-biotin-peroxidase complex method. The positive HPA staining rate was 59% (96/163) for the primary tumors, and this positive staining correlated well (with statistical significance) with lymphatic invasion and metastasis (P < 0.01). In the metastatic lymph nodes, the majority of cancer cells (49/55:89%) stained positively for HPA. Tumors with positive HPA staining often metastasized to lymph nodes. Patients with gastric cancer and positive HPA staining of their tumor tissues lived for a shorter time than did those with a negative staining, even in the absence of metastasis to the lymph nodes (P < 0.01). Careful follow-up and aggressive therapy are required postoperatively for patients with an HPA-positive gastric cancer.

Animals↗
PubMedDate not supplied

Expression of P-glycoprotein influences resistance against anthracyclines in clinical gastric carcinomas.

In 58 human gastric cancers, the expression of P-glycoprotein (P-gp) was evaluated immunohistochemically and chemosensitivity was determined using the in vitro succinate dehydrogenase inhibition (SDI) test. Tumors which contained over 75% stained cells were scored as positive, and 14 of 58 cases (24%) were positive. There was no significant correlation between P-gp expression and clinicopathologic features. The succinate dehydrogenase (SD) activity for each drug of P-gp positive and negative tumors was as follows: 81.8 +/- 15.2% vs. 66.3 +/- 16.1% for Adriamycin (ADM), 75.5 +/- 14.2% vs. 59.1 +/- 17.6% for aclacinomycin A (ACR), 71.7 +/- 15.0% vs. 61.1 +/- 14.0% for mitomycin C (MMC), and 57.5 +/- 18.4% vs. 47.0 +/- 16.7% for cisplatin (CDDP). The increase in SD activity was evident in P-gp positive tumors compared with negative ones in cases of ADM (P = 0.0044), ACR (P = 0.0105), and MMC (P = 0.0353). We suggested that P-gp expression is closely related to chemosensitivities of human gastric cancers to anthracyclines.

ATP Binding Cassette Transporter, Subfamily B, Mem↗