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Biomedical subjects

S A Lyons

Publications and source records attributed to S A Lyons.

23 records · Page 2Linked to original sources
PubMed1979

Composition of glycoproteins secreted by tracheal explants from various animal species.

1. The acidic and neutral glycoproteins secreted by cultured tracheal explants from pigs, sheep, rats, mice, monkeys, guinea pigs, dogs and chickens were purified and fractionated by column chromatography on DEAE-cellulose and by electrophoresis on cellulose acetate. 2. The ratios of acidic to neutral mucus glycoproteins were compared for the above animals with that of mucus glycoproteins secreted by cultured human bronchi. 3. The observed ratios of acidic to neutral glycoproteins ranged from 4.0 (mouse) to 7.2 (chicken and pig) from cultured tracheae; secreted human bronchial mucus had a ratio of 2.7. 4. The ratio of acidic to neutral glycoproteins secreted by tracheal explants varied with duration of incubation of the trachea in culture.

Animals↗
PubMed1978

A comparison of selected physical properties of hepatic sorbitol dehydrogenases [L-iditol: NAD oxidoreductases] from four mammalian species.

1. The sorbitol dehydrogenases [L-iditol: NAD oxidoreductase] from livers of cow, man, rat and sheep each possess molecular weights of about 140,000. The beef, rat and sheep liver enzymes are composed of subunits of molecular weight 40,000. 2. The sorbitol dehydrogenases from livers of these four species each possess an isoelectric point of 7.3. 3. The four enzyme preparations show identical mobilities upon disc-gel electrophoresis and yield a single band of enzymic activity. 4. Sorbitol dehydrogenase activity is activated by the presence of ampholines or by increasing ionic strengths, with maximal activation at about 0.5 M salt concentration. These factors may cause the Km for NAD to be lowered.

Animals↗
PubMed1978

Paraquat-induced changes in the rate of collagen biosynthesis by rat lung explants.

Paraquat, bipyridilium herbicide know to cause pulmonary fibrosis, was injected IP into rats. The rate of synthesis of collagen by lung minces from these and control rats was evaluated by measuring the rate of synthesis of hydroxyproline, a specific marker for collagen in lung. Synthesis was measured by incubating lung minces with radioactive proline for various amounts of time, after which proline specific activity and labeled hydroxyproline were determined. The size of the proline pool within the lung minces was significantly elevated in minces from rats that had been injected with paraquat, thus causing the specific activity of the [3H]proline precursor to be lower in these lungs than in those from control animals. Lung minces from rats administered paraquat made more collagen than did those from uninjected controls. The actual increase in rate of collagen synthesis correlated well with other independent estimates of paraquat-induced damage to the lungs.

Animals↗