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Biomedical subjects

G M Anderson

Publications and source records attributed to G M Anderson.

At least 217 records · Page 12Linked to original sources

Determination of indoles in human and rat pineal.

Tryptophan, serotonin, N-acetylserotonin, melatonin, 5-hydroxyindoleacetic acid and 5-hydroxytryptophol have been determined in rat and human pineal glands. The compounds were measured by directly injecting centrifuged tissue homogenates into a liquid chromatographic-fluorometric system. Normal ranges are reported for these compounds and upper limits established for several other indoles.

Animals↗

The effect of carbidopa and benserazide on human plasma 5-hydroxytryptophan levels.

Peripheral aromatic amino acid decarboxylase inhibitors increase human plasma 5-hydroxytryptophan (5-HTP) levels. However the 5-HTP, which is synthesized in the intestine, is not present in a sufficient quantity to influence brain 5-HT to any significant degree. Thus, peripheral decarboxylase inhibitors are unlikely to affect brain 5-HT function via 5-HTP which is synthesized peripherally.

5-Hydroxytryptophan↗

Clinical neurochemistry of autism and associated disorders.

Advances in information concerning brain function in animals and advances in analytical neurochemical methods for determining extremely low levels of compounds in physiological fluids have opened great opportunities for clinical neurochemical studies of autism. Nevertheless, the behavioral deficits in autistic individuals are major obstacles to clarification of the relations between symptoms and biochemical dysfunction in the brain. The fundamental preclinical and clinical studies of serotonin, dopamine, and norepinephrine metabolism related to infantile autism are reviewed, and new studies are suggested as examples of the productive strategies that will illuminate features of the autistic syndrome in the next decade.

Amines↗

Effects of apomorphine on appetitive conditioning in 6-hydroxydopamine treated rat pups.

Rat pups were treated on postnatal day 5 either with the combination of desmethylimipramine (DMI) and 6-hydroxydopamine (6-OHDA) to produce depletion of brain dopamine, or with control injections of saline. Two days later they were presented a novel anise odor paired with intraoral baby formula, and on the next day were tested for preference for the novel odor. Before conditioning and testing, animals were treated with either apomorphine (0.05 mg/kg) or isotonic saline. Performance of the conditioned appetitive response was impaired in dopamine depleted animals. In DMI/6-OHDA treated pups, apomorphine administration prior to conditioning produced an improvement in performance, but drug treatment prior to testing had no effect. In normal pups, apomorphine administration either before conditioning or testing produced impaired performance at testing.

Animals↗

Massive diphenhydramine overdose resulting in death.

Overdosage of diphenhydramine may result in the development of anticholinergic symptoms, seizures, and coma. A fatal outcome following a diphenhydramine overdose does not commonly occur. This report describes the largest documented overdosage of diphenhydramine (7.5 g) which resulted in the death of a 14-year-old girl. The patient initially developed seizures following by cardiac conduction and hemodynamic compromise resulting in death despite life support measures.

Adolescent↗

Assessment of brain function in clinical pediatric research: behavioral and biological strategies.

Psychobiological research in child psychiatry requires rigorous assessment of behavior and multiple perspectives on brain function through neurochemical, neuroendocrine, psychophysiological, and other advanced methods. The serious neuropsychiatric disorders of childhood, such as autism, attention deficit disorder, and language disorders, can be studied in complementary clinical protocols aimed at explicating patterns of behavioral and metabolic dysfunction which characterize various clinical syndromes. Clinical research with children raises sensitive ethical issues; the ethical problems can be addressed when children and families are active collaborators with the investigators and a long-term relationship is established. In this setting, participation in research can facilitate better treatment for a child. The use of novel biological strategies, such as pharmacological challenge tests, permits evaluation of the relation of specific neuronal systems to behavioral dimensions in clinical disorders. The development of a new treatment for Tourette's syndrome illustrates the integration of basic and clinical research methods.

Catecholamines↗

Factors influencing melatonin, 5-hydroxytryptophol, 5-hydroxyindoleacetic acid, 5-hydroxytryptamine and tryptophan in rat pineal glands.

Using a simple high performance liquid chromatographic method, we measured melatonin, N-acetyl-5-hydroxytryptamine (NAc-5HT), 5-hydroxytryptophol (5HTOL), 5-hydroxyindoleacetic acid (5HIAA), 5-hydroxytryptamine (5HT) and tryptophan in single rat pineal glands. 5-Methoxytryptophol and 5-methoxyindoleacetic acid were not detected at levels which have been reported previously. 5HTOL, 5HIAA and 5HT showed the opposite diurnal rhythm to NAc-5HT and melatonin. Light during the dark period lowered melatonin while increasing 5HTOL, 5HIAA and 5HT. As the peak 5HTOL levels were higher than the peak melatonin levels, the functional significance of 5HTOL deserves consideration. Tryptophan administration increased melatonin and 5HTOL as well as the other indoles.

Animals↗

Discriminative stimulus properties of MDA analogs.

Rats trained to discriminate (+/-) 2,5-dimethoxy-4-methylphenylisopropylamine (DOM) (1.0 mg/kg) from saline, using a standard two-lever operant task, were challenged with various doses of 3,4-methylenedioxyphenylisopropylamine (MDA) and several related agents. The (+/-)-DOM stimulus generalized to (+/-)-MDA, suggesting that both agents apparently produce similar stimulus cues. Related agents, known to produce effects in man similar to those produced by (+/-)-MDA, also resulted in generalization when administered to the DOM-trained animals, e.g., R(-)-MDA and a methoxylated derivative of (+/-)-MDA, (+/-)-2-OMe-4,5-MDA. DOM stimulus generalization was not observed for S(+)-MDA, the N-monomethyl and alpha-demethyl derivatives of MDA, nor for a metabolite of MDA (i.e., 3-methoxy-4-hydroxyphenylisopropylamine). The results suggest that R(-)- and (+/-)-MDA, as well as (+/-)-2-OMe-4,5-MDA, but not the other derivatives of MDA, are capable of producing behavioral (stimulus) effects common to those produced by the training dose of (+/-)-DOM.

DOM 2,5-Dimethoxy-4-Methylamphetamine↗

Determination of indoles and catechols in rat brain and pineal using liquid chromatography with fluorometric and amperometric detection.

Tryptophan, serotonin, 5-hydroxyindoleacetic acid, and homovanillic acid were determined in rat brain by the direct injection of a centrifuged tissue homogenate into a liquid chromatographic-fluorometric/amperometric system. The above indoles, along with melatonin, were also determined in single rat pineal glands. The utility of the system in determining several additional catechols and idoles in brain was examined.

Animals↗