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Biomedical subjects

J A Michael

Publications and source records attributed to J A Michael.

34 records · Page 2Linked to original sources
PubMed1976

Oxygen microelectrode response to oxygen pressures up to 15 ATA.

Polarographic measurements of oxygen at high pressures were made at 21-22 degrees C with open-type Wood's metal microelectrodes with tip diameter about 5 mu. Although the sensitivity of the individual electrodes ranged from 3.1 x 10(-10) to 8.8 x 10(-12) amps/mm Hg of O2, the oxygen current was always a straight line function of Po2 from 21% O2 at ambient pressure (Po2 = 160 mm Hg) to 100% O2 at 200 psig (Po2 = 11,102 mm Hg). Compression to 200 psig with 100% nitrogen produced no significant change in microelectrode current, showing that the microelectrodes are insensitive to pressure alone.

Microelectrodes↗
PubMed1970

Effect of intravenous sodium bicarbonate, disodium edetate (Na2EDTA), and hyperventilation on visual and oculomotor signs in multiple sclerosis.

The effects of procedures believed to produce a decrease in serum ionized calcium were tested on visual and oculomotor function in nine multiple sclerosis (MS) patients. Transient improvement in scotomas, nystagmus, and oculomotor paresis occurred with intravenous infusions of NaHCO(3) or Na(2)EDTA. Hyperventilation was also tested for its effect on nystagmus and caused marked decreases in frequency. Control experiments with saline infusions did not produce any effect. The probable mechanism and site of action for these effects is discussed. This study demonstrates that certain signs and symptoms in MS can be altered favourably by changes in the internal chemical environment and offers a new approach to the search for a symptomatic therapy in MS.

Adult↗
PubMedDate not supplied

Mass gathering medical care: a twenty-five year review.

INTRODUCTION: The purpose of this study was to critically review the provision of medical care at mass gatherings as described in 25 years of case reports. Specifically measured was the relationship between the size of a mass gathering and the frequency of patients seeking medical aid and the effects of certain event characteristics on this relationship. METHODS: Data were obtained through a retrospective literature review. Medline and CINHAL computerized databases were searched for English language articles using several keywords: "mass gathering", "concert", "festival", "Olympics", "crowd"; "riot", "stadium", "sports", "games", "papal", and "football". Only articles containing complete information on the number of spectators, number of patients, type, location, and duration of the mass gathering were included in the primary analysis. As available, additional information was added including the described weather patterns, number of patients transported to a hospital, and number of patients suffering a cardiac arrest. Thirty-five of the approximately 100 articles reviewed, met these criteria. RESULTS: A Spearman Rank Correlation Coefficient was calculated for number of spectators and patients and a significant relationship was identified (p = 0.0001). Mann-Whitney U-tests indicated that papal masses (p = 0.04), rock concerts (p = 0.005), hot climatic conditions (p = 0.03), and events held in the British Commonwealth (p = 0.03) had a significantly higher frequency of patient visits. Significantly more cardiac arrests occurred at papal masses (p = 0.04) and sporting events (p = 0.0002). CONCLUSIONS: Type of event, country, weather, and the size of the mass gathering had a significant effect on the numbers of spectators seeking medical care. A uniform classification scheme is necessary for future prospective studies of mass gatherings.

First Aid↗