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Biomedical subjects

Y Maehara

Publications and source records attributed to Y Maehara.

At least 343 records · Page 19Linked to original sources
PubMed1986

[In vitro chemosensitivity testing evaluated by intracellular ATP level: ATP assay].

In vitro chemosensitivity was evaluated by bioluminescence ATP assay in 12 human tumors including 7 gastric cancers and 5 colo-rectal cancers. Tumor fragments minced with scissors were exposed to 6 kinds of antitumor drugs: carboquone, adriamycin, aclacinomycin A, mitomycin C, cisplatin and 5-FU at peak plasma concentration or ten times peak plasma concentration. After 3 days at 37 degrees C, each tumor fragment suspension was washed with phosphate-buffered saline, boiled for 3 min and assayed for its intracellular ATP level using the luciferin-luciferase method. The ATP level of the drug-untreated group was 6.01 +/- 4.55 X 10(-10) moles/mg tissue protein in gastric cancers and 9.77 +/- 8.46 X 10(-10) moles/mg tissue protein in colo-rectal cancers. The percentages of cases in which the ATP level was reduced to less than 50% by the antitumor drugs were 70% for carboquone, 11% for adriamycin, 30% for aclacinomycin A, 45% for mitomycin C, 13% for cisplatin and 18% for 5-FU at peak plasma concentration, and 90% for carboquone, 78% for adriamycin, 80% for aclacinomycin A, 82% for mitomycin C, 63% for cisplatin and 82% for 5-FU at ten times peak plasma concentration. The test for chemosensitivity prediction is thus available at peak plasma concentration of antitumor drugs in ATP assay.

Adenosine Triphosphate↗
PubMed1986

[In vitro chemosensitivity of various human tumors evaluated by the succinate dehydrogenase inhibition (SDI) test (2)].

In vitro chemosensitivity was evaluated by succinate dehydrogenase inhibition (SDI) test in 94 human tumors including 59 gastric cancers, 27 colo-rectal cancers and 8 malignant lymphomas. Tumor fragments were exposed to 12 kinds of antitumor drugs at ten times peak plasma concentration. Evaluable rates were 86/94 (91%) for all cases, 56/59 (95%) for gastric cancers, 22/27 (81%) for colo-rectal cancers and 8/8 (100%) for malignant lymphomas. The mean of SD activity was decreased to 48% of that of control cells with aclacinomycin, 49% with carboquone, 53% with actinomycin D, 54% with mitomycin C and 54% with daunomycin for gastric cancers, 59% with adriamycin for colo-rectal cancers and 33% with cyclophosphamide (40487 S), and 33% with actinomycin D, 37% with vinblastine and 39% with adriamycin for malignant lymphomas. When the SD activity was reduced to below 50% by antitumor drugs, the chemosensitivity was defined as positive. The antitumor drugs which had a higher chemosensitive-positive rate were aclacinomycin, carboquone and mitomycin C for gastric cancers, adriamycin for colo-rectal cancers and 40487 S, daunomycin and vinblastine for malignant lymphomas. Our results suggest that the origin of a tumor is a critical factor in its chemosensitivity.

Antineoplastic Agents↗
PubMed1986

[Therapeutic cranial irradiation in patients with metastatic brain tumors from pulmonary carcinoma].

Fifty-three patients with intracranial metastases from pulmonary carcinoma were treated with cranial irradiation between 1976 and 1983. There was improvement in neurologic symptoms in 80%, and the one and two-year survival rates for the entire group of patients were 21% and 4%. Those or patients without metastasis tumor in other organs were 38% and 9%, respectively. It was suggested that the total dose should be in excess of 40 Gy. Histologically, adenocarcinoma and epidermoid carcinoma showed better prognosis than other types of cancer.

Adenocarcinoma↗
PubMed1985

1.5 kb mRNA abundantly expressed in rat tumors encodes a 37 kilodalton protein in vitro.

A cDNA clone, pAH34, corresponding to a 1.5 kb mRNA present abundantly in various rat tumors was examined for its protein coding capacity. Hybridization-selected RNAs from both poly(A)+ RNAs of a rat ascites hepatoma cell line, AH60C and of normal liver produced a polypeptide of 37 kilo daltons in vitro, but at much higher levels in the AH60C than in the normal rat liver. Two dimensional electrophoresis of the translation product revealed that the pI of this protein was 7.1. Nucleotide sequence analysis of pAH34 showed that the insert of the clone consisted of 462bp and contained the 3' portion of mRNA, including poly(A) stretch with AATAAA signal sequence centered 16 nucleotides upstream, a short untranslated region and an open reading frame corresponding to possibly 67 amino acids of the C-terminal portion.

Animals↗
PubMed1985

[Radiotherapy in trimodal combination therapy of maxillary sinus squamous cell carcinoma].

From May 1979 to December 1982, 31 patients with reappraisable preoperative CT were treated with trimodal combination therapy for maxillary sinus squamous cell carcinoma. The three-year cumulative survival rate of all cases was 43% and the two-year cumulative local control rate was 44%. The 5-FU distribution in infusion chemotherapy was reappraised by the dye method and the radiation field was reappraised on the basis of preoperative CT. Only patients who received suitable infusion chemotherapy and radiotherapy showed a good local control rate. Suitably performed infusion chemotherapy and radiotherapy were essential in our trimodal combination therapy. Radiotherapy must be planned according to the individual patient on the basis of the preoperative CT and surgical findings.

Carcinoma, Squamous Cell↗
PubMed1985

[An evaluation of multi-disciplinary treatment combined with intra-arterial chemotherapy of head and neck cancer].

Seventy-five cases of head and neck cancer except of maxillary sinus, 27 cases of mesopharyngeal cancer, 6 cases of oral cancer, 9 cases of thyroid cancer and 9 cases of the other cancer, were treated with this multi-disciplinary treatment and the results were evaluated in this series. An intraarterial infusion drug, 5-FU, was used mainly through the superficial temporal artery. The five year survival rate was 46.1% in mesopharyngeal cancer, 34.4% in oral cancer and 33.3% in thyroid cancer. The results were relatively satisfactory despite the advanced stage of the cancer. Intraarterial chemotherapy has been a common treatment for maxillary cancer but the indication of this treatment should be developed in advanced head and neck cancer with radiotherapy or surgical treatment as a part of multi-disciplinary treatment.

Brachytherapy↗
PubMed1985

[Specificity of gene expression in tumor cells].

We have isolated gene sequences which are expressed abundantly in tumor cells but must less so in normal tissues from a cDNA clone library that was constructed using poly (A)+ RNAs from azo-dye-induced rat ascites hepatomas. These clones were categorized into 2 groups, with respect to their size distribution of mRNAs from which the clones were derived. The first group was complementary to a single distinct species of poly (A)+ RNA, and was considered to be derived from protein-coding genes. The second group showed no distinct bands but a smear on the RNA blot, and was shown to be transcribed from middle repetitive sequences of DNA. On the other hand, a certain species of highly repetitive sequences is also expressed in many lines of ascites hepatomas. Semiquantitative RNA dot blot assays have revealed the sequences of these clones to have a very low level of expression, if at all, in normal and regenerating livers, while being generally high in many species of tumors. The transcription of these gene sequences is considered to be closely related to the establishment of tumor phenotypes.

Animals↗
PubMed1985

[In vitro chemosensitivity of various human tumors evaluated by the SDI (succinate dehydrogenase inhibition) test].

In vitro chemosensitivity was evaluated by SDI test in various human tumors including 1 lymph node metastasis of esophageal cancer, 10 gastric cancers, 4 colo-rectal cancers, 1 hepatoma, 2 lung cancers, 2 breast cancers and 1 gallbladder cancer. Tumor fragments cut with scissors were exposed to twelve kinds of antitumor drugs at five to ten times peak plasma concentration. After 3 days at 37 degrees C, each tumor fragment suspension was washed with phosphate-buffered saline and assayed for succinate dehydrogenase (SD) activity using 3-(4,5- dimethyl-2-thiazolyl)-2, 5-diphenyl-2H tetrazolium bromide (MTT) as a hydrogen acceptor. When the SD activity of the drug-treated cells was reduced to below 50% that of control cells, the chemosensitivity to the antitumor drug was considered positive. The chemosensitivity of each tumor varied individually. Mitomycin C or 5-fluorouracil are regularly used to treat gastric cancer patients, but, some specimens of gastric cancer in this study showed a resistance to these drugs and an unexpected sensitivity to other drugs. Our results show that the SDI test is a convenient method for clinical use and gives significant information about drug sensitivity.

Antineoplastic Agents↗