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Biomedical subjects

A Ito

Publications and source records attributed to A Ito.

At least 991 records · Page 55Linked to original sources
PubMed1980

Induction of intestinal metaplasia in the glandular stomach of rats by X-irradiation prior to oral administration of N-methyl-N'-nitro-N-nitrosoguanidine.

CD/CRJ rats were subjected to localized X-irradiation of the stomach and given N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) in the drinking water. Rats given MNNG alone and non-treated rats were used as controls. Upon sacrifice at 15 months after the initial MNNG administration, intestinal metaplasia was observed; the histology was of complete type and the incidence was 100% in rats treated with X-rays and MNNG, whereas in rats treated with MNNG alone the intestinal metaplasia was of incomplete type and its incidence was 80%. However, the incidence of gastric cancer in rats treated with MNNG alone was 25%.

Adenocarcinoma↗
PubMed1979

Effect of the autonomic blockade on the automaticity of the A-V junctional pacemaker in awake dogs.

The effect of the autonomic blockade on the automaticity of the A-V junctional pacemaker was evaluated in 15 awake dogs with experimentally induced A-V junctional rhythm. The duration of asystole after overdrive (D.A.O.) in these dogs was prolonged significantly in accordance with increase in the drive rate, and the mean +/- SD of the D.A.O. reached 4.7 +/- 1.1 seconds (N = 15) after overdrive at 2.5 times the spontaneous heart rate. After administration of atropine (0.4 mg/kg; i.v.) to eight dogs, the mean +/- SD of the D.A.O. at the same rate decreased from 4.5 +/- 0.9 to 3.4 +/- 1.2 seconds. After administration of practolol (0.5 mg/kg; i.v.) to the seven other dogs, the mean +/- SD of the D.A.O. at the same rate increased remarkably from 4.9 +/- 1.3 to 9.4 +/- 3.0 seconds. Intravenous injection of practolol (0.5 mg/kg) had no effect upon the D.A.O. in the five dogs with sinus rhythm. Thus, it is suggested that (1) the sympathetic nerve might play a more important role in regulating the automaticity of the A-V junctional pacemaker than the vagus and (2) it physiologically might take over 5.0 seconds for the A-V junctional pacemaker to initiate an escape beat during longstanding sinus arrest, if a marked dysfunction of the A-V junctional pacemaker occurs due to a decrease in tension of the sympathetic nerve.

Animals↗
PubMed1979

Toxin-neutralizing effect of antibody against subtilisin-digested tetanus toxin.

A form of systemic tetanus with atypical symptoms was observed in mice injected in the left thigh with a mixture of tetanus toxin and antibody produced in guinea pigs against a fragment of toxin obtained from a subtilisin digest of the crystallized toxin. The mice did not show typical symptoms of the local tetanus such as convulsions or spastic paralysis of the injected limb.

Animals↗
PubMed1979

Changes in optic glass-fibers due to X-ray irradiation.

The purpose of this study was to clarify the relationship between x-ray irradiation and changes in the functional properties of flexible fiberscopes. Scanning electron microscopy, electron spin resonance, and thermoluminescent dosimetry techniques were used to determine the nature of the changes and their possible reversibility. Decreases in light transmission were observed at exposures above 5 roentgens (R), color changes were observed above 25 R, and electron spin resonance absorption changes occurred above 100 R. These changes were proportional to the x-ray doses. The x-ray exposure rates of the segmental and the subsegmental bronchi are about 20 percent that of the patient's thoracic skin surface. The above-mentioned studies showed that, for optimal results, a fiberscope should not be exposed to more than 15 minutes of fluoroscopy by a TV apparatus per week.

Bronchoscopes↗