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Biomedical subjects

M Ohhira

Publications and source records attributed to M Ohhira.

80 records · Page 5Linked to original sources

[Mutagenicity test of antithyroid agent, methimazole--dominant lethal mutation test on male mice (author's transl)].

Mutagenicity test of Methimazole (MMI) was performed by means of dominant lethal mutation test in the male mice. Male mice were treated with a single s.c. injection of 45 mg/kg or 90 mg/kg MMI. Mean body weights were slightly decreased and mating rates were low immediately after treatment of MMI. Mean numbers of living implants at any periods examination up to 6 weeks after the treatment were compared with Salin Control, indicating lack of dominant lethality of MMI. On the other hand, EMS and MMC known mutagens and reference agents used in the present study, induced dominant lethalities at a single s.c. injection respectively.

Animals↗

Effects of stress on growth of transplanted hepatic tumours and immune responses.

Growth of transplanted hepatic tumours (T-9) was enhanced in immune rats under stress, compared with immune rats in an unstressed condition. Compared with unstressed immune rats, killer activity of mononuclear cells infiltrating the tumours against T-9 cells was significantly reduced in stressed immune rats. In contrast, killer activity of splenocytes obtained from stressed immune rats against T-9 cells was elevated compared with that from unstressed immune rats. In addition, natural killer cell activity of mononuclear cells infiltrating the tumours obtained from stressed immune rats was significantly reduced compared with that from unstressed immune rats. Cell populations infiltrating tumour tissues were identified by flow cytometric analysis. The percentage of CD8+ cells in mononuclear cells isolated from tumour tissues of stressed immune rats was reduced compared with that of unstressed immune rats. Furthermore, interleukin-2 responsiveness of splenocytes was suppressed in stressed immune rats, whereas T cell function as reflected by phytohaemagglutinin- or Concanavalin A-reactivity was unaffected by stress. Collectively, it is likely that stress suppressed the generation of cytotoxic cells from the spleen cells of immune rats.

Animals↗

Hepatocellular carcinoma developed in a patient with chronic hepatitis C after the disappearance of hepatitis C virus due to interferon therapy.

A 62 year-old man was admitted to Asahikawa Medical College Hospital. Injection therapy of natural interferon-alpha was performed against chronic active hepatitis with hepatitis C virus infection. He successfully responded to interferon therapy with normalization of serum transaminases and disappearance of serum hepatitis C virus RNA. The liver function test remained within normal limits and serum hepatitis C virus RNA was not detected throughout the observation period. Three years later, CT examination demonstrated 2 small hepatic masses. Ultrasound-guided biopsy of the hepatic mass demonstrated well-differentiated hepatocellular carcinoma histologically. Laparoscopic examination revealed chronic hepatitis, but neither active inflammation nor cirrhotic changes were noted as an underlying liver disease. In the liver specimen, hepatitis C virus RNA was not detected by RT-PCR. Percutaneous ultrasound-guided ethanol injection therapy achieved complete necrosis of the hepatocellular carcinoma and there was no recurrence of hepatic cancer during the follow-up period. This case suggests that patients with chronic hepatitis C infection, who have complete disappearance of serum hepatitis C virus RNA by interferon therapy, should be followed-up carefully for the potential development of hepatocellular carcinoma.

Carcinoma, Hepatocellular↗

Surgical treatment for myocardial bridge using intraoperative echocardiography. A report of two cases.

Two cases of symptomatic myocardial bridging of the left anterior descending coronary artery (LAD) requiring surgery for relief of exertional angina are reported. High-frequency intraoperative echocardiography was used for imaging of the intramyocardial coronary artery lesions before and after supraarterial myotomy performed under cardiopulmonary bypass. The constricting band of the myocardial bridge could be clearly demonstrated. Supraarterial myotomy was successfully carried out in each patient. We conclude that intraoperative echocardiography for detecting myocardial bridge is a useful tool for supraarterial myotomy.

Adult↗