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Biomedical subjects

D E Rounds

Publications and source records attributed to D E Rounds.

48 records · Page 3Linked to original sources
PubMed1965

The laser as a potential tool for cell research.

Freshly prepared hemoglobin solutions were successively irradiated up to five times with 1 MW (monochromatic wavelength) of green (530 mmicro) laser power. Oxygenated hemoglobin showed no detectable change, but the spectral absorption of reduced hemoglobin showed a shift toward the characteristic curve for the oxygenated form. Intact human erythrocytes exposed to a power density of 110 MW/cm(2) of green laser radiation showed no appreciable change in diameter or mass, but they became transparent to a wavelength range from 400 to 600 mmicro. A similar power density from a ruby laser failed to produce this bleaching effect. This response in the erythrocyte demonstrates a principle which suggests the laser as a tool for cell research: specific molecular components within a cell may be selectively altered by laser irradiation when an appropriate wavelength and a suitable power density are applied.

Cell Biology↗
PubMedDate not supplied

Consideration of atherosclerotic plaques as benign neoplasms.

The monoclonal nature of atherosclerotic plaques, as well as their altered cell size, proliferation rate and function have led to the hypothesis that plaque tissue is analogous to benign tumors. To test this hypothesis, we have studied rates of DNA release by histologically-normal human arterial wall tissue and by early atherosclerotic plaques during incubation in a maintenance medium. No DNA was detected in media conditioned by normal arterial tissue after a 24 h incubation period, but plaque tissue (like benign tumors) released 10-100 ng DNA/ml during this period. These data offer additional support for the thesis that atherosclerotic plaques are similar to benign tumors.

Adult↗
PubMedDate not supplied

Ozone sensitivity in aging WI-38 cells based on acid phosphatase content.

Young [16-19 population doubling level (PDL)] and senescing (50-53 PDL) WI-38 cell populations were exposed to 1 ppm ozone for 2 hr and the resultant extracellular and intracellular acid phosphatase concentration was measured. Dose-response curves were also determined for surviving populations of young and old cells after a 1 hr ozone exposure ranging in concentration from 0 to 1.00 ppm. Senescing cells released 8 times more acid phosphatase per million cells than the young cells. Both old and young cells showed a clear dose-response to the 1 hr ozone gradient exposure. However, the older cells demonstrated a consistent 17% average lower survival rate than the young cells. The higher acid hydrolase level in older WI-38 cells is probably related to the lower survival rate observed in the older cells in vitro.

Acid Phosphatase↗