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Biomedical subjects

A N Johnson

Publications and source records attributed to A N Johnson.

31 records · Page 2Linked to original sources
PubMed1981

Antifertility and endocrine activities of gossypol in rodents.

Reversible male antifertility activity was obtained with orally administered gossypol acetic acid in rats at 20 mg/kg/day and in hamsters at 10 mg/kg/day but not in mice at dosages up to 40 mg/kg/day. An increased number of degenerating spermatocytes was found in the testicular tubular lumens of rats. Pigment-laden cells containing an intracytoplasmic lipofuscin-like material were noted in the testis and epididymal interstitium in rats and mice. Gossypol was also tested in the female for effects on ovulation and pregnancy. Gossypol did not inhibit ovulation in the rat at dosages up to 80 mg/kg/day but did cause 90% inhibition of pregnancy in mice treated with 80 mg/kg/day during the first two weeks of pregnancy. In several standard endocrine bioassays, gossypol did not demonstrate estrogenic, antiestrogenic, androgenic or antiandrogenic activities, but it did potentiate the androgenicity of methyltestosterone.

Animals↗
PubMed1977

Exertion of stairclimbing in normal subjects and in patients with chronic obstructive bronchitis.

The exertion of stairclimbing has been studied in 10 normal young men, 10 healthy middle-aged men, and 10 middle-aged men with chronic bronchitis. Subjects climbed a staircase with a total vertical ascent of 40.8 m. They were allowed to adopt the most comfortable pattern of ascent, the patients having to stop at intervales for rest pauses. Work rate was determined by timing the raising body weight over measured sections of the staircase. Perception of exertion estimated with a numerical scale, heart rate, and increase of blood lactate concentration were closely similar in all three groups at the top of the staircase. In the patients, average power output was directly dependent on lung function, as indicated by the forced expired volume in 1 second. Stairclimbing offers a simple way of studying a patient's spontaneous activity pattern in a 'real life' environment. Studies of the kind described here could usefully complement formal exercise testing in the laboratory.

Adult↗
PubMedDate not supplied

Neonatal response to control of noise inside the incubator.

PURPOSE: The purpose of this study was to test the effect of acoustical foam on the level of noise inside the incubator and examine neonatal response behaviors to changes in environmental noise. METHOD: The study used a repeated measure, within subject, comparative design. Data on 65 premature neonates were collected over a 14-month period at a large teaching hospital in Delaware. Sound levels, oxygen saturation, and infant states were measured and recorded during three study conditions: pre-study neonate in incubator, neonate in incubator with 5 x 5 x 1 inch acoustical foam pieces placed in each of four corners, and post-study recovery of neonate in incubator with foam removed. All state assessments were measured with oxygen saturation and sound level measurements every 2 minutes of the study for a total 40 minutes. FINDINGS: The findings demonstrate a significant treatment effect of acoustical foam on decreasing environmental noise measurements inside the incubator (p = 0.006). Findings also demonstrate significantly changed neonatal state response behaviors with decreasing environmental noise measurements inside the incubator (p = 0.00). CONCLUSIONS: The results of this study support the use of acoustical foam as one method of environmental noise management in the intensive care nursery. Because there was a significant correlation between higher noise levels and oxygen support therapy, the findings suggest that special nursing considerations should be taken when caring for ventilator-dependent infants. Noise control protocols should focus on essential environmental interventions for care of these infants.

Acoustics↗
PubMedDate not supplied

A case management approach to immunizing patients at high risk for influenza.

The influenza season affects not only the people afflicted with influenza, but the healthcare system as a whole. An estimated dollar 12 billion is the annual cost to care for these patients. An existing problem is that although there is an immunization for influenza, many patients at high risk are not immunized. This article will describe an innovative program of a large Midwest suburban hospital to immunize patients at high risk.

Case Management↗