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Biomedical subjects

A J Adams

Publications and source records attributed to A J Adams.

6 recordsLinked to original sources

Marijuana, alcohol, and combined drug effects on the time course of glare recovery.

The time course of light adaptation after intense light exposure is significantly delayed by alcohol, marijuana, and a combined dose of alcohol and marijuana. These effects were found in a double blind experiment, using 10 subjects. The experimental treatments were placebo, 0.75 ml/kg of 95% ethanol, 8 and 15 mg of delta9 tetrahydrocannabinol (THC). and 0.75 ml/kg of 95% ethanol together with 15 mg of THC. The marijuana-induced delay in recovery is doserelated. Both drugs produce delayed recovery for at least 2 h after drug ingestion. The combined alcohol and marijuana treatment produces little more than the effect produced by either drug alone, suggesting some antagonism between the drugs--a suggestion supported by a significantly lower blood alcohol level for the alcohol dose when combined with marijuana than when taken alone.

Adaptation, Ocular

Pupil size after use of marijuana and alcohol.

In an experiment using ten subjects, marijuana produced a dose-related constriction of the pupil at low photopic light levels; alcohol produced no effect on pupil size. The two drugs in combination produced no change in pupil size.

Adult

Lung phosphatidylcholine synthesis and cholinephosphotransferase activity in anencephalic rat fetuses with corticosteroid deficiency.

Adrenocortical insufficiency was produced in rat fetuses by surgical decapitation. These animals show low plasma corticosterone levels compared to littermate controls. Lung slices from anencephalic fetuses were found to have reduced incorporation of [14C]choline into phosphatidylcholine, hence diminished choline pathway activity; this abnoramlity was present at 21 days of gestation but not at term. Cholinephosphotransferase (CPT), the terminal catalyst of the choline pathway, also showed diminished activity in lungs of anencephalic fetuses, with a mean of 120 pmol/min/mg protein compared to a control value of 190. Dexamethasone treatment of these animals for 6-12 hr led to enhanced choline incorporation rates. Corticosteroid administration also restored CPT activity and even elevated the enzyme to a mean level (340 pmol/min/mg protein) greater than that found in normal fetuses at 21-22 days of gestation. The early pulmonary biochemical effects of dexamethasone in this model were not accompanied by recognizable ultrastructural changes.

Adrenal Cortex Hormones

Spatial summation properties of goldfish ganglion cells.

At threshold the eye is known to sum quanta as though the total catch were important and not the distribution on the retina. In humans, spatial summation is larger under dark adapted conditions. The extent of this spatial summation is studied in goldfish retinal ganglion cells which are known to receive both rod and cone inputs. The area of summation in single ganglion cells is found to be much larger for rod input compared to cone input. It seems that in single ganglion cells, the spatial summating properties increase markedly in the dark due largely to the neural organization of rod and cone input.

Adaptation, Ocular