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Biomedical subjects

T Ohka

Publications and source records attributed to T Ohka.

44 records · Page 3Linked to original sources
PubMed1979

Reduction in mutagenicity of cigarette smoke condensate by added sugars.

The effects of adding sugars to high- and low-tar cigarettes on the mutagenicity of their smoke condensates were studied using Salmonella typhimurium TA100 and TA98 with and without metabolic activation. The sugars tested were glucose, fructose, galactose, sorbitol, sucrose and lactose. The lowest mutagenicities observed with these sugars per mg of smoke condensate assayed on TA98 with metabolic activation were 37% (high-tar cigarettes) and 22% (low-tar cigaretts) of that of smoke condensate from untreated cigarettes. Addition of sugars increased the total amounts of smoke condensates, but the mutagenicities of the total condensates were also decreased by all the sugars, the lowest values being 35% (high-tar cigarettes) and 36% (low-tar cigarettes) of that of smoke condensates from cigarettes without added sugar. On assay with TA100 with metabolic activation, decreases in both specific and total mutangenicities of condensates of high-tar cigarettes were observed with all the sugars tested except galactose and sucrose. Treatment with glucose, fructose or sorbitol decreased the specific mutagenicity of condensates of low-tar cigarettes and glucose and fructose reduced also their total mutagenicity. The effects of added sugars were more marked when assayed on TA98 than on TA100 and of the sugars tested fructose and sorbitol had the greatest effects. Addition of sugars had no effect of the mutagenicity of cigarette-smoke condensate without metabolic activation.

Carbohydrates↗
PubMed1977

Mutagenicity of smoke condensates from cigarettes, cigars and pipe tobacco.

Smoke condensates from cigarettes, cigars and pipe tobacco were mutagenic on Salmonella typhimurium TA100 and TA98 when activated with rat liver microsomal system. Mutagenicity of a unit weight of smoke condensate was rather high in cigars, low in pipe tobacco and intermediate in cigarettes. Specific mutagenic activity was almost comparable among smoke condensates from low- to high-tar cigarettes, although some variations were observed depending upon the country producing the cigarettes. Marked mutagenicity of cigarette smoke condensate could not be explained by the benzo (a) pyrene or nitroso compounds it actually contained, suggesting the presence of other very potent mutagens in tobacco smoke condensates.

Animals↗
PubMedDate not supplied

MR and CT in the evaluation of sarcoid myopathy.

Sarcoid myopathy is a relatively rare extrapulmonary complication of sarcoidosis. We evaluated the diagnostic utility of MR at 1.5 T in four patients with sarcoid myopathy of the lower extremities established by biopsy. Two of the patients were of the "atrophic type" and two of the "nodular type." The findings on MR were compared with the findings on CT, gallium scanning, and electromyography. Only MR was positive in all cases. The T2-weighted scans (spin echo 2,000/80) revealed two distinctly different patterns of abnormality (i.e., discrete foci of high signal intensity lesions in the patients with the nodular type of sarcoid myopathy and atrophic muscle of high signal intensity in the patients with the atrophic type). Due to its ability to provide objective findings of the extent and distribution of muscle involvement, MR should prove useful in the detection, diagnosis, and monitoring of sarcoid myopathy.

Adult↗
PubMedDate not supplied

Complete atrioventricular block following radiation therapy for malignant thymoma.

Complete atrioventricular block following radiation is very rare. We present a case which developed after radiation therapy for malignant thymoma. The etiology of conduction disturbances due to radiation is unknown. In our case, serial electrocardiograms showed stepwise progression of the conduction disturbance, and His bundle electrocardiograms revealed new prolongation of the H-V interval. Endomyocardial biopsy specimens demonstrated occlusion in small arteries and diffuse degenerative changes in the myocardium. We therefore attributed the complete atrioventricular block in our patient to secondary damage to the conduction system, caused by radiation-induced occlusive changes in the small arteries supplying the conduction system.

Aged↗
PubMedDate not supplied

Primary myelofibrosis terminating in megakaryoblastic crisis.

Primary myelofibrosis terminating in megakaryoblastic crisis is uncommon. A case with this condition is reported. The patient, a 62-year-old female, having had primary myelofibrosis for 13 years and a splenectomy 4 years before, was admitted because of high fever, hepatomegaly, thrombocythemia and leukocytosis. On admission, blasts appeared in the peripheral blood and thereafter gradually increased in number. The blasts were proven to be of megakaryocytic lineage. To our knowledge this is the third case of primary myelofibrosis terminating in megakaryoblastic crisis to be reported in Japan.

Female↗
PubMedDate not supplied

Left atrial myxoma presenting as acute myocardial infarction.

A 58-year-old man with left atrial myxoma complicated with acute myocardial infarction is presented. On coronary arteriography, 50% stenosis and a saccular aneurysm was found just below the stenosis at segment 1 of the right coronary artery. Ergonovine provocation study was negative. It was proposed that the myocardial infarction probably was caused by coronary embolization from the left atrial myxoma.

Coronary Aneurysm↗
PubMedDate not supplied

Pulmonary infiltrates with eosinophilia due to naproxen.

An increasing number of drugs have been implicated in the etiology of eosinophilic pneumonia characterized by the development of pulmonary infiltrates, and peripheral blood eosinophilia. Naproxen is a commonly used nonsteroidal anti-inflammatory drug which may be added to the growing list of pharmacologic agents associated with infiltrative pulmonary lesions. A case of eosinophilic pneumonia induced by Naproxen is described. The results of TBLB, a lymphocyte stimulation test, and a challenge test supported this diagnosis.

Aged↗