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Biomedical subjects

D Lieberman

Publications and source records attributed to D Lieberman.

At least 109 records · Page 6Linked to original sources

Biomass recycle as a means to improve the energy efficiency of CELSS algal culture systems.

Algal cultures can be very rapid and efficient means to generate biomass and regenerate the atmosphere for closed environmental life support systems. However, as in the case of most higher plants, a significant fraction of the biomass produced by most algae cannot be directly converted to a useful food product by standard food technology procedures. This waste biomass will serve as an energy drain on the overall system unless it can be efficiently recycled without a significant loss of its energy content. We report experiments in which cultures of the algae Scenedesmus obliquus were grown in the light and at the expense of an added carbon source, which either replaced or supplemented the actinic light. As part of these experiments we tested hydrolyzed waste biomass from these same algae to determine whether the algae themselves could be made part of the biological recycling process. Results indicate that hydrolyzed algal (and plant) biomass can serve as carbon and energy sources for the growth of these algae, suggesting that the efficiency of the closed system could be significantly improved using this recycling process.

Biomass↗

Improvement by oral metoprolol of exercise-induced ischemic dysfunction in patients with coronary heart disease.

The effect of metoprolol on global left ventricular function during exercise was analyzed with nuclear ventriculography in 17 patients with ischemic heart disease. All had stable angina pectoris and ST-segment depression of more than 0.1 mV during treadmill exercise when not taking metoprolol. Each patient was stressed with supine bicycle exercise to the same load on a maintenance dose of metoprolol (100 mg X 2/day) and on a second occasion without the drug, the two being separated by 7 days. The mean heart rate and systolic blood pressure were significantly reduced both at rest and exercise with metoprolol. There was no significant difference of rest left ventricular ejection fraction with or without metoprolol. At exercise, however, every patient showed improvement of left ventricular function, the average left ventricular ejection fraction increasing by 14% (+/- 6) relative to the same exercise without metoprolol (p less than 0.001). We conclude that chronic metoprolol treatment in patients with ischemic heart disease can ameliorate left ventricular dysfunction induced by exercise and may thereby reduce myocardial ischemia.

Administration, Oral↗

Biochemical correlates of hypnoanalgesia in arthritic pain patients.

Self-reported levels of pain, anxiety, and depression, and plasma levels of beta-endorphin, epinephrine, norepinephrine, dopamine, and serotonin were measured in 19 arthritic pain patients before and after hypnosis designed to produce pain reduction. Correlations were found between levels of pain, anxiety, and depression. Anxiety and depression were negatively related to plasma norepinephrine levels. Dopamine levels were positively correlated with both depression and epinephrine levels and negatively correlated with levels of serotonin. Serotonin levels were positively correlated with levels of beta-endorphin and negatively correlated to epinephrine. Following hypnotherapy, there were clinically and statistically significant decreases in pain, anxiety, and depression and increases in beta-endorphin-like immunoreactive material.

Adult↗