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Biomedical subjects

E S Flamm

Publications and source records attributed to E S Flamm.

At least 109 records · Page 6Linked to original sources
PubMed1976

Experimental alterations in cyclic adenosine monophosphate concentrations in the cat basilar artery.

Levels of cyclic adenosine monophosphate (AMP) in the basilar artery and in circulating blood of cats were determined after the production of spasm by topical application of blood to the vessel and following treatment with agents known to alter cyclic AMP. Isoproterenol, known to stimulate adenyl cyclase, and aminophylline, a phosphodiesterase inhibitor, were studied alone and in combination. Cyclic AMP of the basilar artery fell from a mean control value of 43 to 26 pmoles per milligram of protein following the production of vasospasm. Intravenous administration of isoproterenol alone and in combination with aminophylline produced dilatation of the basilar artery, which was associated with a marked rise in the cyclic AMP concentration in the vessel. The finding that cerebral vasospasm is associated with a fall and vasodilation with a rise in cyclic AMP concentration supports the hypothesis of an active role for cyclic nucleotides in the regulation of cerebrovascular smooth muscle tone.

Aminophylline↗
PubMed1976

Effect of dopamine-beta-hydroxylase inhibition on cerebral vasospasm in the cat.

Inhibitors of dopamine beta hydroxylase (DBH) administered intraperitoneally were shown to prevent spasm of the basilar artery caused by blood application in cats. A low or nondetectable blood DBH activity level may be related to the absence of spasm. In several instances, however, moderate spasm did occur with a low blood DBH activity level. Possible mechanisms for these findings are discussed.

Animals↗
PubMed1976

Treatment of cerebral vasospasm by control of cyclic adenosine monophosphate.

Twelve patients with cerebral vasospasm following subarachnoid hemorrhage were treated with intravenous aminophylline and isoproterenol. After angiographic demonstration of spasm, all patients were begun on a continuous intravenous infusion of isoproterenol, 125 mug/hr, and aminophylline, 125 mg/hr, for a period of up to two weeks. The infusion was continued until there was clinical or angiographic evidence that spasm had diminished. Nine patients improved on this regimen and three remained unchanged. The use of isoproterenol and aminophylline is based on their effect on the enzymes responsible for the formation and degradation of cyclic adenosine monophosphate (cyclic AMP). An increase in cyclic AMP has been noted to produce relaxation of vascular smooth muscle. It is proposed that manipulation of these biochemical pathways may provide a method for influencing blood flow through cerebral vessels.

Adult↗
PubMed1975

Phosphodiesterase inhibitors and cerebral vasospasm.

Experimental cerebral vasospasm was studied in cat and monkey models. In the cat, the basilar artery was exposed by a transclival approach and spasm induced by the application of blood to the vessel. In the monkey, spasm was produced by injecting blood into the subarachnoid space. Vessel size was determined in the cat by direct observation and, in the monkey, by cerebral angiography. Several agents known to alter the synthsis and degradation of cyclic adenosine monophosphate (AMP) were used to modity the vasospasm produced. Isoproterenol (Norisodrine) and aminophyline were effective in reversing cerebral vasospasm when applied topically and when administered parenterally. It is suggested that manipulation of the cyclic AMP pathways may be an effective method of controlling cerebral vasospasm.

4-(3-Butoxy-4-methoxybenzyl)-2-imidazolidinone↗
PubMed1966

Cerebral concussion in the monkey: an experimental model.

A statistically significant experimental model has been developed for reproducing head injury by impact in the monkey. Results with 80 monkeys subjected to occipital impact under specified conditions ( duration of phenomena, 1 to 10 milliseconds) enable the construction of curves relating the production of experimental cerebral concussion in 10, 50, and 90 percent of the monkeys to the average impulse of the blow in pounds-seconds, as well as to the average linear acceleration of the head. These curves are proposed as a baseline from which blows to various parts of the head, as well as nonimpacting impulsive loads, can be studied under various conditions of protection and according to varioucs time regimes.

Acceleration↗