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Biomedical subjects

H Ohara

Publications and source records attributed to H Ohara.

At least 217 records · Page 12Linked to original sources

A new in vitro cell line established from human oat cell carcinoma of the lung.

A new tissue culture line, OAT-1975, has been established from explant cultures of human oat cell carcinoma of the lung, characterized and maintained for more than 1 year. The cells grew in a monolayered sheet with 24 hr of population-doubling time and are capable of clonal growth with about 60% plating efficiency. The cells still retain unique morphological and structural characteristics of oat cell carcinoma and showed "tumor takes" when transplanted into nude mice and conditioned young Syrian Golden hamsters. The chromosome constitution of the cells is hypertriploid with a modal peak at 74. The permanent growth integrity of the present cell line made it possible to utilize it for cell biological studies. Cell inactivation experiments indicated that the cells are sensitive to X-rays and Mitomycin C when compared to the responses of HeLa S3 cells.

Animals↗

Cell cycle dependent response and combined treatment of tumor.

Attempt was made to summarize data indicating cell cycle dependence of survival response to various antitumor agents. Normalized patterns of survival response permitted us to group agents into two major categories. It was known that effect of agents on cell progression was not only related to respective periods of the cell cycle but also rather specific for each category of agents. The extent of progression inhibition was not compared on a quantitative basis. On the basis of above findings a rational combination and a scheduled administration of agents for effective sterilization of tumor cells were considered.

Animals↗

Total one-stage repair of interrupted aortic arch associated with aortic septal defect and patent ductus arteriosus.

Successful total repair in one stage was performed in a 3-year-old girl who had interrupted aortic arch associated with aortic septal defect and patent ductus arteriosus. Surface-induced deep hypothermia and interrupted perfusion were used. The results of postoperative catheterization and angiocardiographic studies are analyzed, and the literature and results of previous surgical attempts at correction are reviewed.

Adolescent↗

Health hazard among cash register operators and the effect of improved working conditions.

The health condition of female cash register operators in relation to their working conditions was investigated. A questionnaire study revealed that cash register operators more frequently complained of general fatigue, headache, sleeplessness, and low back pain than female office machine operators or other female workers. Dullness and pain in the shoulder, arm, hand, and fingers especially on the right side were characteristic of cash register operators. Physical examinations in 1973 showed that 31.3% of 371 cash register operators suffered from muscle rigidity or tenderness; 13 were severely afficted and, 69 operators had to be either laid off, reassigned to other jobs, or given shorter working hours. Occupational cervicobrachial disorders were suggested to have been caused by repetitive upper limb motions combined with static load, an unfavorable working environment, and mental stress. Implementation of some improvements including shorter operation time, worker rotation, and adoption of electronic registers proved effective in reducing the number of sufferers of cervicobrachial disorders found during the 1975 physical examinations. But the improvements were not effective enough to alleviate fatigue of the neck, shoulder, and back due presumably to sustaining upper limbs while operating the keyboard.

Adolescent↗

Occupational health hazards resulting from elevated work rate situations.

Some occupational health hazards resulting from an elevated rate of work due to recent mechanization and automatization are discussed on the basis of results of health examinations. A rapid increase of a cervicobrachial disorder among young cash register and packing machine operators has been observed. Switching to the use of electronic cash registers has been shown to have only limited efficacy due to increased operation speed, and high-speed complex finger and hand movements of packer operators have also proven to be as hazardous as key-board operations. The high incidence of low-back pain, in particular gradually developing pain, among workers in electric power supply work has been suggested to be the result of quick and intensified work to meet increasing supply demand. Likewise, the workload of electric locomotive and bullet train drivers has increased in accordance with increased train speeds, and has been shown to have had significant effects on their health particularly in regards to neural strain, intra-cab environment such as air pressure change, vibration, and noise, and rotation on irregular shifts. New steps seem required therefore to meet the new health problems arising from a combination of modern technological changes and elevated working speeds.

Atmospheric Pressure↗

Beta-glucuronidase of rat preputial gland. Crystallization, properties, carbohydrate composition, and subunits.

Rat preputial gland beta-glucuronidase [ED 3.2.1.31] was purified by ammonium sulfate precipitation, ethanol fractionation, gel filtration on Sephadex G-200 and crystallization. The purified enzyme appeared homogeneous on electrophoresis in polyacrylamide gel, and on analytical ultracentrifugation and had a molecular weight of approximately 320,000, and a sedimentation coefficient of 12S. SDS polyacrylamide gel electrophoresis indicated that the enzyme consisted of subunits with molecular weight of 79,000, so the native enzyme appeared to be a tetramer. The Km with p-nitrophenyl beta-D-glucosiduronic acid as substrate was about 0.53 mM. The enzyme had a single pH optimum at 4.5. The enzyme had a very low content of sulphur-containing amino acid and contained 5.7 per cent carbohydrate, consisting of mannose, glucose, fucose, galactose, and glucosamine in a ratio of 44;9;6;2;41. Sialic acid was not detected in the crystallized enzyme.

Amino Acids↗