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Biomedical subjects

L Huey

Publications and source records attributed to L Huey.

At least 19 recordsLinked to original sources
PubMed1988

Methylphenidate-induced information processing dysfunction in nonschizophrenic patients.

To examine the relationship of aminergic overactivity to information processing, we gave methylphenidate hydrochloride, oxazepam, or placebo to 12 nonpsychotic patients in one-week blocks in a double-blind, randomized design. Methylphenidate induced a pattern of information processing dysfunction similar to that seen in schizophrenic patients, strengthening the linkage of the schizophrenia-information processing dysfunction-aminergic overactivity relationship. Further, the time course of the observed deficits in both schizophrenic and methylphenidate-induced states is strikingly compatible with the temporal mapping pattern of monoaminergic neuronal systems. More research is needed to identify definitively the aminergic influences on attentional functioning. A psychophysical task-pharmacologic probe strategy should prove useful.

Adult↗
PubMed1987

Measurement of ACTH and prolactin in the dexamethasone suppression test.

Plasma concentrations of ACTH and prolactin were measured in psychiatric inpatients at 8 a.m. and 4 p.m. before and after the standard 1 mg overnight Dexamethasone Suppression Test (DST). Plasma concentrations of cortisol were measured at 8 a.m. and 4 p.m., and 11 p.m. before and after 1 mg dexamethasone. Dexamethasone suppressed plasma concentrations of ACTH, prolactin and cortisol in the subject group as a whole. "Cut Points" obtained using Fisher's Exact Test identified plasma ACTH values at 8 a.m. baseline, 4 p.m. baseline and 8 a.m. post-dexamethasone and plasma prolactin values at all four times that significantly differentiated patients with bipolar depressive disorder and major depressive disorder from other psychiatric patients. There were no cut points found at any of the six times for plasma levels of cortisol that significantly differentiated between these two diagnostic groups. Of interest in this subject population, basal (pre-dexamethasone) plasma concentrations were of more diagnostic information than post-dexamethasone values. These pilot findings suggest that monitoring plasma prolactin and ACTH concentrations before and after dexamethasone might increase the sensitivity and specificity of this laboratory test for depression.

Adrenocorticotropic Hormone↗
PubMed1987

Hyperactivity and the risk for alcoholism.

Thirty-two young adult sons of alcoholic fathers and 32 controls filled out a questionnaire regarding childhood and adult symptoms of hyperactivity. There were no significant family group differences on any of the 48 childhood items or on three scales constructed from those questions. The two groups differed significantly on only 3 of the 56 items regarding adult or residual hyperactivity and on only one of seven possible adult scales, with alcoholics' sons tending to report more evidence of a hot temper and a self-perception of a short attention span. Using DSM-III criteria, the authors found that 2 (6%) of the alcoholics' sons and 4 (12%) of the controls fulfilled criteria for attention deficit disorder (ADD) with hyperactivity in childhood and that none met the criteria for ADD, residual type, in adulthood. For the studied men, the findings do not indicate an elevated risk for ADD in the sons of alcoholics.

Adult↗
PubMed1986

Central muscarinic effects of physostigmine on mood, cardiovascular function, pituitary and adrenal neuroendocrine release.

The mechanism by which physostigmine exerts its behavioral, neuroendocrine and cardiovascular effects was explored in two separate experiments. In the first, the centrally-acting cholinesterase inhibitor physostigmine was compared with the non-centrally-acting agent neostigmine. In contrast to physostigmine, neostigmine caused no effects. In the second experiment, pretreatment with scopolamine, in contrast to methscopolamine, attenuated physostigmine's effects. The results suggest that physostigmine exerts its effects via a central muscarinic mechanism.

Adrenal Cortex↗
PubMed1986

Physostigmine-induced epinephrine release in patients with affective disorder.

Infusion of the cholinomimetic drug physostigmine led to profound increases in serum epinephrine levels and slight increases in serum norepinephrine levels among 38 patients with affective disorder and 22 control subjects. Preliminary results suggest that physostigmine may induce relatively blunted increases in serum epinephrine levels in patients with affective disorders.

Adult↗
PubMed1984

A cholinomimetic model of motion sickness and space adaptation syndrome.

The space adaptation syndrome is one of the more vexing problems confronted by our nation's astronauts during their journeys. This syndrome may be a variant of motion sickness, although this possibility has been questioned. Physostigmine, a centrally active cholinesterase inhibitor which increases brain acetylcholine, was found to cause a motion sickness-like syndrome--in psychiatric patients and normals--including nausea, emesis, malaise, dysphoria, increases in serum ACTH, beta-endorphin, cortisol, and prolactin, Neostigmine, a non-centrally acting cholinesterase inhibitor, and saline placebo caused no such effects. The above effects closely parallel those of motion sickness. Thus, the effects of physostigmine may be a convenient model for screening for treatments for motion sickness or space adaptation syndrome, or for predicting who will develop these syndromes.

Adaptation, Physiological↗
PubMed1981

Adult psychiatric diagnosis and symptoms compatible with the hyperactive child syndrome: a retrospective study.

Characteristics of the hyperactive child syndrome have been described extensively. More recently, reports have indicated that manifestation of the hyperactive child syndrome may persist into adulthood, both as a continuation of childhood symptoms and as psychopathologic entities. This study evaluated 100 adult psychiatric inpatient Veterans for self-report of symptoms of childhood and adulthood hyperactivity, attentional deficit, and impulsivity. Psychotic and non-psychotic psychiatric patients reported a significantly higher incidence of childhood hyperactive syndrome symptoms than did age and sex matched controls. In both childhood and adulthood, character disorder patients reported the highest incidence of target symptoms.

Adult↗
PubMed1979

Marijuana and the perception of affect.

The influence of marijuana on the ability to perceive emotions in others was studied in 30 male volunteers who were experienced marijuana users. Subjects smoked either placebo or active marijuana containing 6 mg delta 9-THC. The Affective Sensitivity Scale, a test developed to measure the ability to perceive emotions in others, was divided at midpoint and the two halves were administered before and after smoking, respectively. Analysis of variance demonstrated a decline in test scores following active marijuana administration, while changes following the placebo treatment were not significant.

Adult↗
PubMed1979

Naloxone effects on serum growth hormone and prolactin in man.

Endogenous and exogenous opiate-like compounds have been found to cause increased serum growth hormone and prolactin levels in animals, and, in some cases, humans. Naloxone, a relatively specific narcotic antagonist, decreases serum prolactin and growth hormone levels in animals. Naloxone (20 mg IV) did not significantly alter serum prolactin levels and, minimally but not significantly, increased growth hormone levels in humans to whom it was administered.

Growth Hormone↗
PubMed1978

Comparison of oral and intravenous methylphenidate.

Oral methylphenidate (1.0 mg/kg) and intravenous methylphenidate (0.5 mg/kg) were compared as to their ability to increase behavioral activation, pulse, blood pressure, and serum growth hormone. Intravenous methylphenidate was considerably more effective than oral methylphenidate in activating behavior and in increasing pulse and blood pressure. Although oral methylphenidate appeared to increase behavioral activation, this effect was not statistically significant.

Administration, Oral↗
PubMed1978

Methylphenidate and serum prolactin in man.

Methylphenidate induces psychostimulation and increases cardiovascular parameters, and its psychostimulant effects have been proposed to occur via a dopaminergic mechanism. The effect of methylphenidate on serum prolactin was utilized as a method of evaluating methylphenidate's central dopamimergic effects. Methylphenidate was not found to exhibit a consistent effect on serum prolactin. Thus, its effect on serum prolactin does not parallel its behavioral activating properties, suggesting that such activation may not involve dopamine. Possibly, norepinephrine or other noncatecholaminergic neurotransmitters are involved in methylphenidate-induced behavioral activation.

Adult↗
PubMed1978

The effect of methylphenidate on serum growth hormone: influence of antipsychotic drugs and diagnosis.

Intravenously administered methylphenidate, 0.5 mg/kg, causes a consistent rise in human serum growth hormone level, with peak values usually occurring 30 minutes after infusion. This rise is attenuated in patients receiving various antipsychotic medications administered on a long-term basis and is decreased in schizophrenic and drug-dependent patients. Methylphenidate causes increases in talkativeness, blood pressure, and pulse that generally parallel increases in serum growth hormone level. However, in contrast to the methylphenidate-induced rise in serum growth hormone level, methylphenidate-induced changes in cardiovascular variables and talkativeness are not altered by antipsychotic medications or diagnostic classification.

Adjustment Disorders↗
PubMed1978

Plasma parathyroid hormone and calcium are related to sleep stage cycles.

To study dynamic interactions among parathyroid hormone (PTH), plasma calcium, and brain states, seven normal subjects were studied for a total of eight nights in our sleep laboratories. Plasma samples were obtained at 10- to 20-min intervals for PTH and calcium determinations. Electroencephalogram, eye movements, and muscle tone were recorded to determine sleep stages. On each night, several distinct peaks in PTH concentration were seen, which in some cases exceeded the all night mean PTH by as much as 300%. Peaks in plasma PTH were significantly nonrandom and tended to recur about every 100 min. PTH concentration was significantly related to cycles of stages 3 and 4 sleep. Total plasma calcium varied less but was significantly related to cycles of rapid eye movement sleep and to cycles of stage 2 sleep. PTH and calcium were significantly interrelated, especially at high frequencies above 40 cycles/day (1 cycle 36 min). In the 14.4 cycles/day (1 cycle/100 min) frequency range where most PTH and calcium variability was found, however, PTH and calcium were more closely related to sleep stages than to each other. These results suggest that the regulation of PTH and calcium is complex and may involve interactions with neural systems.

Adult↗