Search PubMed⌕ Search

Biomedical subjects

A S Harris

Publications and source records attributed to A S Harris.

52 records · Page 3Linked to original sources

Preparation, characterization, and stability of new prostaglandin E2 gel for local administration.

A new gel delivery system for the local application of prostaglandin E2 consists of drug incorporated in the matrix of a cross-linked starch polymer. The properties of the starch powder provide a stabilizing milieu for the labile prostaglandin E2 and, by addition of saline, a ready-to-use gel for immediate local administration. The gel offers advantages over existing preparations in terms of chemical and microbiological stability, homogeneity, and dosage safety. This report outlines the pharmaceutical aspects involved in the development of the delivery system.

Administration, Topical↗

Role of sympathetic excitation in generating arrhythmias in early and late phases of ectopic responses after coronary arterial occlusion in dog heart.

The three phases of arrhythmias that develop within specific durations of occlusion of a coronary artery of the dog have been reviewed and characterized. The intravenous administration of practolol as described has virtually prevented the occurrence of arrhythmic activity during the first 7-8 hr after occlusion and kept the frequency at a much reduced level as compared with controls through 10 or 11 hr, but not appreciably longer. This means that first and second phase arrhythmias were almost abolished, and development of third phase ventricular tachycardia was significantly retarded, but not prevented. It is concluded that sympathetic stimulation is an important component in the effective excitation of ectopic activity during the first and second phases, but contributed no more than a minor component to the fully developed third phase activity.

Animals↗

Storage and survival of red blood cells with elevated sodium levels.

Approximately 25 percent of black blood donors have an elevated red blood cell (RBC) sodium (Nai) level compared with white donors. This elevation results in a significant increase in the mean Nai from black (9.00 +/- 2.96 mmoles/l RBC) as compared to white blood donors (7.04 +/- 1.48 mmoles/l RBC, p less than 0.001). Red blood cells from four black donors with mean Nai levels of 15 +/- 2.8 mmoles/l RBC were stored for 35 days in citrate-phosphate-dextrose-adenine and compared to that of four donors with normal levels of Nai. Serial measurements of red blood cell adenosine triphosphate, diphosphoglycerate, glucose-6-phosphate dehydrogenase, pyruvic kinase, lactate production rates, and intracellular cations showed no differences between the two donor groups. Furthermore, the mean 24-hour posttransfusion survival was not significantly different for the high Nai group (83.2 +/- 5.6%) as compared with the control group (82.3 +/- 6.9%). Based on this study, it is not necessary to eliminate individuals with an elevated red blood cell Nai level as blood donors.

Adenosine Triphosphate↗