Biomedical subjects

G A Yang

Publications and source records attributed to G A Yang.

3 recordsLinked to original sources

PubMed1990

Age-related increase in c-fos expression in the sympathetic neurons of the rat superior cervical ganglion.

C-fos expression was studied immunocytochemically in sympathetic neurons of the rat superior cervical ganglion (SCG). Fos-like immunoreactivity was confined to the principal neurons of the ganglion and was exclusively localized within their nuclei. In 2-month-old rats, the immunoreactivity was detected in 1.2% of the principal neurons with a density of 4.95 Fos-positive cells/mm2 of ganglion area. This proportion increased with age and reached a value which was 6.5-fold higher in the 26-month-old rats than that in the young adult. A density of 24.5 Fos-positive cells/mm2 of ganglion area was seen in the 26-month-old animals. The age-enhanced c-fos expression suggests that Fos may be involved in regulation of the genetic events associated with the adaptive changes in neuronal activity of the sympathetic ganglion during aging.

Aging↗

PubMed1990

Administration of adrenocorticotropic hormone (ACTH) enhances Fos expression in the rat adrenal cortex.

The effect of ACTH on the expression of Fos in rat adrenal glands was investigated immunocytochemically at both light and electron microscopic levels. An approximately 4-fold increase in the number of Fos-positive cortical cells per unit area of the adrenal cortex was found 45 min following a single injection of ACTH (i.v., 2 IU/kg b.w.), as compared with the control animals. The number of immunoreactive cells reached a maximum 90 min after ACTH injection and remained high 150 min after the injection. However, 5 h following the injection it declined significantly. At the ultrastructural level, the ACTH-induced Fos-like immunoreactivity was localized in the nuclei of cortical cells, exclusively confined to the nuclear regions associated with the euchromatin. The result that ACTH enhances Fos-like immunoreactivity suggests that ACTH is involved in c-fos induction in adrenal cortical cells. The characteristic intracellular localization of Fos-like immunoreactivity implies that Fos, once synthesized, may be rapidly translocated into the nuclei of the cells, where it participates in transcriptional regulation of genetic events.

Adrenal Cortex↗

PubMed1987

Changes in relative weight among institutionalized elderly adults.

Weight-for-height and weight changes over a 2-year period among 335 institutionalized elderly adults at a geriatric care facility are described. Weight-for-height at admission was compared with several current standards for elderly persons. Mean relative weight and proportions of underweight and obese patients varied with the standards used. Although changes in group mean weights were slight, 73% of the patients gained or lost 4.5 kg or more in 2 years. Patients who lost 4.5 kg or more in the interval had a lower 4-year survival rate (p less than .05) than patients who gained weight or remained stable. Fluctuations in weight may be more prevalent among institutionalized elderly persons than previously thought, or than are apparent in analyses of group trends. Monitoring an individual's weight is simple and may be more meaningful than comparison to a standard, especially because weight loss is associated with mortality, until age appropriate standards are developed.

Age Factors↗