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Biomedical subjects

Y Hayata

Publications and source records attributed to Y Hayata.

At least 91 records · Page 5Linked to original sources
PubMed1982

Hematoporphyrin derivative and laser photoradiation in the treatment of lung cancer.

Photoradiation therapy (PRT) was performed in 13 lung cancer cases and in one case of severely atypical squamous metaplasia following administration of hematoporphyrin derivative (HpD). The HpD is activated by visible red light (630 nm, 90 to 400 mW) from an argon dye laser. The cytocidal effects were due to the activation of the HpD, since 400 mW of power has in itself no effect on normal epithelium, even with long-term exposure. HpD is retained longer by malignant tissue than by normal tissue. Therefore, the lesions were irradiated with the red laser beam, delivered by a quartz fiber inserted through the instrumentation channel of the fiberoptic bronchoscope, 48 hours or more after intravenous injection of 2.5 to 4.0 mg/kg of HpD. A total of 14 cases received PRT. In one, two small, smooth-surfaced, squamous cell carcinoma tumors in the right B2b of a 74-year-old man who had refused surgery disappeared three days after HpD-photoradiation, and the patient remained disease-free 16 months after the treatment. In 12 cases of centrally located lung cancer local effects were obtained in all. However, there was no significant improvement in survival, attributable to the fact that all were advanced-stage cases. One patient with severely atypical squamous metaplasia requested treatment, and complete disappearance of metaplastic atypic was obtained.

Adenocarcinoma↗
PubMed1982

Fiberoptic bronchoscopic laser photoradiation for tumor localization in lung cancer.

Hematoporphyrin derivative (HpD) administration and laser photoradiation were combined to clarify the system's clinical applicability in localizing lung cancer tumors. It was used in 16 cases of lung cancer and in one case of severely atypical squamous metaplasia. Tumors were irradiated 48 hours after intravenous injection of 2.0 to 4.0 mg/kg HpD and fluorescence observed. Fluorescence was seen in 13 lung cancer cases in the case of squamous metaplasia, but results were negative in three of the cases of lung cancer. Among the positive cases was one of occult cancer and two invading the trachea, difficult to recognize by conventional fiberoptic bronchoscopy, as was the severely atypical squamous metaplasia. In the three lung cancer cases not fluorescing, the tumors were obscured by blood, necrotic tissue, or normal mucosa. The method holds promise in the diagnosis of malignant tumors. Nevertheless, it needs further refinement and more studies to elucidate definitive differentiation between malignant and severely atypical, nonmalignant tissue.

Adenocarcinoma↗
PubMed1982

Treatment of vaginal carcinoma with laser photoirradiation following administration of haematoporphyrin derivative. Report of a case.

Laser photoirradiation therapy following the administration of haematoporphyrin derivative (HpD) was performed in a case of primary vaginal carcinoma (stage I) using red light from an argon laser source. The vaginal tumor was destroyed and disappeared completely. No recurrence has been observed during a one-year follow-up. The findings suggest that HpD and laser photoradiation therapy may be effective in the treatment of early vaginal carcinoma.

Aged↗
PubMed1982

Reversibility of bronchial cell atypia.

Various degrees of cellular atypia were induced in the bronchial epithelium of dogs by means of repeated submucous 20-methylcholanthrene injections. Thereafter, the 20-methylcholanthrene treatment was stopped, and the outcome of the bronchial cell atypias in individual dogs was studied using cytomorphological and cytochemical methods. The results suggest that the various degrees of 20-methylcholanthrene-induced cellular atypias, including those cytologically interpreted as malignant, may reflect reversible cellular alterations which disappear after removal of the carcinogen. Similar observations were made in a group of cigarette smokers who, after malignant-appearing cells were observed in the sputum material, stopped smoking or significantly reduced their cigarette consumption.

Animals↗
PubMed1979

Thromboplastic and fibrinolytic activities of cultured human cancer cell lines.

Thromboplastic and fibrinolytic activities of 14 lines of cultured human cancer cells were estimated by modified Astrup's methods. High tissue thromboplastic activity was found in one line of urinary-bladder cancer, 2 lines of gastric cancer and one line of lung cancer, but no activity was found in 6 lines of lung cancer. High fibrinolytic activity was noted in one line of gastric cancer and 2 lines of lung cancer, but no activity was seen in 6 lines of lung cancer and one line of gastric cancer. No plasmin activity was found. The tumour cell lines could be classified into 3 groups on the basis of the 2 activities. Cancer cell lines could also be classified into 2 groups: with high or low release of thromboplastin into culture media. Fibrinolytic activity was found in the culture media of all cell lines with high fibrinolytic activity. Fibrinolytic activity, but not thromboplastic activity, seemed to be influenced by the constituents of culture media. No definite correlation was found between the 2 activities and the histological types of the parent tumours of the cultured cells.

Blood Coagulation↗