Search PubMed⌕ Search

Biomedical subjects

E A Stone

Publications and source records attributed to E A Stone.

At least 91 records · Page 5Linked to original sources
PubMed1981

Effect of Rush pins on the distal femoral growth plate of young dogs.

Rush pins were placed in the distal portion of the left femur in 15 young (4 months old) mongrel dogs. Microscopic evaluation of the growth plate showed closure beginning 1 month after the pins were implanted and complete closure occurring a month earlier than in the control (right) femur. The left femurs had a mean decrease in length of 22 mm compared with the length of the control femurs at the time of growth plate closure. When the Rush pins were removed 1 month after implantation, the growth plate regained normal microscopic appearance and difference in femur lengths (left vs right) did not occur. Tibial length did not change relative to femur length. Recommendations are made about the use of Rush pins in young dogs.

Animals↗
PubMed1981

Renal function after prolonged hypotensive anesthesia and surgery in dogs with reduced renal mass.

The effect of prolonged hypotensive anesthesia and surgery on renal function was studied in 8 dogs with decreased renal mass. Renal mass was reduced by unilateral nephrectomy and ligation of 4 of the 6 terminal renal artery branches of the opposite kidney. One week after reduction in renal mass, the dogs were azotemic with a serum urea nitrogen (SUN) value of 65.8 +/- 11.5 mg/dl. Glomerular filtration rate, as estimated by 14C-inulin clearance, was 0.66 +/- 0.19 ml/kg of body weight/hour. A mean arterial pressure of less than 75 mm of Hg was maintained for 4 hours in dogs given 2.3 +/- 0.7% halothane. An exploratory laparotomy lasting 1 hour was performed. The day after the hypotensive episode, 3 dogs began vomiting, became dehydrated, and had SUN values greater than 100 mg/dl. The SUN values returned to base-line values after the dogs were rehydrated. Eight days after the hypotensive episode, 14C-inulin clearance decreased 15.2 +/- 8.2% (P less than 0.005) compared with base-line clearance values. Light microscopic and electron microscopic observations of the kidneys did not demonstrate acute renal failure. Prolonged hypotensive anesthesia can cause a decrease in renal function, and may cause prerenal uremia and/or acute renal failure.

Anesthesia, Inhalation↗
PubMed1978

Ammonia tolerance test in clinically normal dogs and in dogs with portosystemic shunts.

The oral ammonia tolerance test was investigated in 20 clinically normal dogs and in 6 dogs with naturally occurring portosystemic shunts. The dogs with portosystemic shunting had a marked rise in venous blood ammonia following the administration of ammonium chloride, as compared with the control dogs. Fasting venous blood ammonia content was not uniformly reliable in separating the dogs with portosystemic shunting from the clinically normal dogs.

Ammonia↗
PubMed1978

Brain and adrenal tyrosine hydroxylase activity after chronic footshock stress.

Rats subjected to 9 daily sessions of electric footshock stress showed marked increases in tyrosine hydroxylase activity in various brain regions and in the adrenal gland. The activity of the brain enzyme was elevated in the cerebral cortex, hypothalamus, locus coeruleus and the pons-medulla indicating a widespread effect of stress throughout the brain. Anatomical specificity of the response was indicated by a greater percent increase in the locus coeruleus, a nucleus containing noradrenergic cell bodies, than in the hypothalamus, cortex and pons-medulla, areas that contain noradrenergic terminals.

Adrenal Glands↗
PubMed1978

Effect of stress on norepinephrine-stimulated cyclic AMP formation in brain slices.

Experiments were conducted to determine if stressful procedures, which increase brain norepinephrine (NE) release in rats, lower the responsiveness of central noradrenergic receptors as measured by the catecholamine (CA)-induced cAMP accumulation in hypothalamic and cerebral cortical slices. No conclusive evidence of subsensitivity was found after either acute or chronic electric footshock or continuous restraint. Failure to find a significant reduction after stress may have resulted from several methodological problems. These include (a) the inhibition of phosphodiesterase activity with isobutylmethylxanthine, which may have obscured possible adaptive changes in cAMP degradation and/or adenosine-dependent adrenergic receptors; (b) a low initial responsiveness to NE in these animals as suggested by the greater case in inducing supersensitivity with reserpine than subsensitivity with amphetamine; and (c) the use as a test agent of exogenous NE which may stimulate a far broader population of receptive sites in brain slices than are activated during stress by the local release of endogenous NE.

Animals↗