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Biomedical subjects

B Powell

Publications and source records attributed to B Powell.

At least 91 records · Page 5Linked to original sources

The use of extracted teeth to evaluate clinical measurements of periodontal disease.

Clinical indicators of periodontal disease, Gingivitis Index, Gingival crevicular fluid and pocket depth measurements were obtained from the gingiva surfaces of 30 teeth. The gingival margins were marked on the surfaces of the teeth prior to extraction. The extracted teeth were stained with hematoxylin and air dried, and the distances from the groove to the base of the calculus, plaque, and connective tissue attachment were obtained. The plaque-free zone was also measured. Comparisons were made between clinical and tooth surface measurements. A high correlation was found between clinical pocket depth measurements and tooth surface parameters. The correlations between all tooth surface parameters and GCF were statistically significant. The G.I. was significantly correlated only with the penetration of calculus into the pocket. The clinical pocket depth was statistically the same as the distance from the gingival groove to the coronal connective tissue attachment. The plaque-free zone appeared to represent the junctional epithelium.

Dental Calculus↗

A simple method for measuring a picogram of acetylcholine using the clam (Mya arenaria) heart.

1. A simple and reliable method is described for assaying 1 pg or less of acetylcholine (ACh) using a strip of clam (Mya arenaria) heart.2. Clam heart preparations generally are extremely selective for ACh. The preparation described is at least 10(5) times less sensitive to the following: acetyl coenzyme A, adrenaline, choline, dopamine, gamma-aminobutyric acid, glutamic acid, histamine, 5-hydroxytryptamine and noradrenaline.3. Because this preparation is one of the most sensitive known for detecting ACh, it should prove useful for assaying particularly low levels of this substance in biological extracts.

Acetylcholine↗

Alcohol and recall: state-dependent effects in man.

Male vollunteers performed four memory tasks either while sober or lunder effects of alcohol. Twenty-four hours later they were tested under the same or different conditions. In tasks measuiring recall and interference, learning transfer was better when the subject was intoxicated during both sessions than when he was intoxicated only during the learning session. In a task measuring recognition, transfer was not significantly affected by changing state. Thus, alcohol appears to produce "dissociated" or state-dependent effects in man, but not all forms of memory are equally sensitive to the phenomenon.

Alcoholic Intoxication↗