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Biomedical subjects

J G Young

Publications and source records attributed to J G Young.

At least 19 recordsLinked to original sources
PubMed1990

Growth hormone and prolactin response to methylphenidate in children with attention deficit disorder.

Utilizing a double-blind, drug-placebo design, we examined growth hormone (GH) and prolactin (Pro) response to oral administration of methylphenidate (MPH) in 14 boys (ages 7.0-12.4 years) with Attention Deficit Disorder (ADD). Four conditions representing three different MPH doses (0.3 mg/kg O.D., 0.3 mg/kg B.I.D., 0.6 mg/kg O.D.) and Placebo were compared in each subject, each condition lasting for a period of 3 weeks. GH and Pro response were measured both as maximum peak GH (DGH) or nadir of Pro (DPro) as well as area under the curve for the first four hours after MPH administration (AUCGH, AUCPro). Behavioral measures included parent ratings on the Yale Children's Inventory and teacher ratings on the Yale and Conners Behavior Rating Scales and Kagan's Matching Familiar Figures Test (MFFT). Prolactin response as measured by AUCPro was significantly increased after MPH compared to placebo (t = 2.04, p less than 0.05, placebo vs all doses MPH). This difference observed for AUCPro between placebo and MPH was evident as well when we considered the number of times AUCPro declined after MPH as compared to placebo (p = .018, Fisher's exact test). Within-subjects analysis of covariance demonstrated significant correlations between the improvement in reaction time on the MFFT and 1) GH response (AUCGH, r = .58, p less than .001) and 2) prolactin response (AUCPro, r = .40, p less than .05) and between improvement in attention as measured on the Yale BRS and GH response (AUCGH, r = .57, p less than .05). Our findings suggest that measures other than GH and prolactin may be more desirable measures of brain catecholaminergic functioning.

Attention Deficit Disorder with Hyperactivity↗
PubMed1990

Validation of hyperactive, aggressive, and mixed hyperactive/aggressive childhood disorders: a research note.

Eighty-five non-referred school children were divided into four groups based upon the IOWA Conners Teacher's Questionnaire: pure hyperactive (HYP), pure aggressive (AGG), mixed hyperactive/aggressive (HYP/AGG), and normal controls. The groups were compared on neurobehavioral tests believed to assess inattention and impulsivity. A continuous performance test indicated that the HYP group was more inattentive than the other groups and the HYP/AGG group was most impulsive. The AGG group did not differ from controls. The data support the distinction between HYP, AGG and HYP/AGG groups of children selected by the IOWA Conners.

Aggression↗
PubMed1990

Guns and suicide: possible effects of some specific legislation.

The authors describe suicide rates in Toronto and Ontario and methods used for suicide in Toronto for 5 years before and after enactment of Canadian gun control legislation in 1978. They also present data from San Diego, Calif., where state laws attempt to limit access to guns by certain psychiatric patients. Both sets of data indicate that gun control legislation may have led to decreased use of guns by suicidal men, but the difference was apparently offset by an increase in suicide by leaping. In the case of men using guns for suicide, these data support a hypothesis of substitution of suicide method.

Adult↗
PubMed1989

Preventable pediatric trauma deaths in a metropolitan region.

All pediatric trauma deaths occurring in metropolitan Toronto (population, 2.2 million) in 1986 were analyzed from the regional coroner's records. Injuries sustained were scored using the Abbreviated Injury Scale (1985; AIS) and Injury Severity Score (ISS). Victims with injuries graded AIS 6 (any region), AIS 5 head/neck (excluding acute epidural hematoma), or ISS greater than 59 were deemed unsalvageable. All other injuries were considered survivable and the deaths from them preventable. Use of these objective criteria indicated that 8/38 of the children (21%) who died from trauma had survivable injuries. Since in three cases medical aid was not sought because of social circumstances, 5/38 (13%) was considered a realistic estimate of preventable death rate (PDR). These results suggest that when objective criteria are used, the PDR in pediatric trauma may be less than that reported in adult trauma victims. Defining the PDR on the basis of objective criteria may prove useful in the conduct of further studies of this kind and permit valid comparisons to be made.

Adolescent↗
PubMed1989

Are ADDH and ADHD the same or different?

To assess the relationship between the DSM-III criteria for attention deficit disorder with hyperactivity (ADDH) and the DSM-III-R criteria for attention-deficit hyperactivity disorder (ADHD), children from an inner city parochial school were evaluated using a 30-item teacher questionnaire consisting of the DMS-III and DSM-III-R criteria for these disorders, the revised Conners Parent and Teacher Questionnaires, and a continuous performance test. Diagnostic groups were established based on teacher ratings of the DSM items and evaluated in relation to the rating scale data and continuous performance test. While children who were identified by teachers as having ADDH almost always satisfied the criteria for ADHD, a new group of children who were hyperactive and impulsive but less clearly inattentive also met the criteria for ADHD. Implications of the change in diagnostic criteria are discussed.

Attention↗
PubMed1987

L-dihydroxyphenylalanine-induced asymmetric changes in striatal uric acid peak: determination by in vivo electrochemical detection in rats with unilateral nigrostriatal lesions.

Rats were unilaterally lesioned with 6-hydroxydopamine to destroy the nigrostriatal pathway. Following injection with 25 mg/kg L-dopa, circling behavior away from the lesioned side was monitored. Concurrently, in vivo electrochemical detection was used to compare changes in striatal extracellular levels of ascorbic acid (Peak 1) and uric acid (Peak 2) on the lesioned and unlesioned sides. Peak 1 changes did not differ, but Peak 2 changed asymmetrically on the two sides. The difference in the changes in Peak 2 was highly correlated with the circling behavior, with the greater increase on the lesioned side.

Animals↗
PubMed1987

Whole blood serotonin in autistic and normal subjects.

Whole blood serotonin and tryptophan were measured in 87 normal subjects and in 40 autistic subjects. Whole blood serotonin concentrations (mean +/- SE) were significantly higher in drug-free (N = 21) autistics (205 +/- 16 ng/ml) than in normals (136 +/- 5.4 ng/ml). The Gaussian distribution of serotonin levels in the unmedicated autistic group suggests the elevation was not due to a subgroup of autistic subjects. Autistics medicated with anticonvulsants or neuroleptics had significantly lower serotonin levels than did drug-free autistic subjects. Whole blood tryptophan levels and platelet counts were similar in the autistic and normal groups. The possible causes of the hyperserotonemia of autism are discussed.

Adolescent↗
PubMed1984

Dopaminergic but not noradrenergic mediation of hyperactivity and performance deficits in the developing rat pup.

The relative contribution of dopamine (DA) and norepinephrine (NE) in behavioral arousal was examined in developing rat pups using intracisternal 6-hydroxydopamine (6-OHDA) either alone or following pretreatment with desmethylimipramine (DMI). Such treatments were designed to examine the effects of preferential reduction of DA (DA depletion), NE (NE depletion), or both catecholamines (CA depletion) in the development of motor activity and escape performance. General motor activity increased with age and, over all ages, DA-depleted pups tended to exhibit greater activity. This was most apparent at 15 days of age, where DA-depleted pups were significantly more active than controls, NE-depleted, or CA-depleted pups. DA-depleted pups failed to exhibit the steep decline in activity over time (habituation of activity) demonstrated by the control and NE-depleted pups, while pups depleted of both CA fell into an intermediate position in habituation. Escape latency in a T-maze at 20 days and shuttle box at 26 days of age indicated comparable performance to controls for NE-depleted pups, while those animals in DA-depleted and CA-depleted groups appeared unable to perform the task. Brain CA concentrations (determined by a radioenzymatic assay) indicated preferential reduction of DA in the DA-depleted group to concentrations 25% of controls, reduction of NE to 62% of controls in the NE-depleted group, and reductions of DA to 42% and NE to 60% in the CA-depleted group. These results suggest that preferential reduction of brain DA in the developing rat pup increases motor activity and impairs habituation of activity during the stage of behavioral arousal in week 3 of postnatal life.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗
PubMed1984

The effect of ultra-violet and visible radiation on CaSO4:Dy in Teflon discs used for personnel gamma-radiation monitoring.

The influence of ultra-violet and visible radiation (UV/VIS) on the read-out obtained from the main dosimetry peak of CaSO4:Dy in Teflon discs exposed to the gamma-radiation levels measured by a personnel-monitoring service has been studied as a function of wavelength, irradiance and radiant exposure. The results have been explained by the net effect of three separate factors, namely (i) an inherent response, (ii) a phototransfer and (iii) an optical bleaching. The response obtained from unirradiated discs illuminated with fluorescent room lighting became saturated after 16 hrs at a value corresponding to 0.33 microC kg-1 whilst gamma-irradiated discs faded to 90% of their initial exposure for the same illumination period.

Calcium Sulfate↗
PubMed1984

CSF neurochemistry of women with anorexia nervosa and normal women.

CSF tyrosine, tryptophan, 5-hydroxyindoleacetic acid, 3-methoxy-4-hydroxyphenylglycol (MHPG), homovanillic acid (HVA), gamma-aminobutyric acid, choline, and calcium were compared in 33 anorexic and 14 normal women. The only significant difference between groups was a lower tyrosine level in the anorexic patients; their MHPG level was nonsignificantly higher. No significant group differences in body weight or depressive subgroup were found. HVA levels were positively related to body weight, and choline was negatively correlated with anorexia severity. The role of tyrosine requires further research, but these findings do suggest that HVA and choline increase with some recovery measures and MHPG is increased with this illness.

Adolescent↗
PubMed1984

CSF neurochemistry in depressed, manic, and schizophrenic patients compared with that of normal controls.

A total of 114 subjects (41 depressed, 20 schizophrenic, 15 manic, and 38 normal controls) underwent lumbar puncture and their CSF was analyzed for levels of tyrosine, tryptophan, homovanillic acid (HVA), 5-hydroxyindoleacetic acid (5-HIAA), 3-methoxy-4-hydroxyphenylglycol (MHPG), choline, gamma-aminobutyric acid (GABA), and calcium. Results showed that depressed patients, particularly those over 40 years of age, had lower levels of GABA than did controls, and that their level of HVA increased with age, while controls' decreased. Schizophrenic subjects tended to have higher levels of 5-HIAA and manic subjects tended to have higher levels of HVA and MHPG. Age-associated changes were found in HVA, 5-HIAA, MHPG, GABA, and choline concentrations.

Adolescent↗
PubMed1984

Poor outcome and low platelet MAO activity in chronic schizophrenia.

Platelet monoamine oxidase (MAO) activity was significantly lower among 21 chronic schizophrenic patients, 19 of whom were receiving stable doses of antipsychotic medication, than among 16 control subjects. Poor ego functioning and poor outcome were significantly correlated with low MAO activity; current dose of major tranquilizer was negatively but not significantly correlated. The degree of psychopathology, rather than presence or absence of specific symptom constellations, was the significant characteristic of patients with low enzyme levels. This finding is in accordance with those of earlier studies of schizophrenic patients as well as with recent findings in nonschizophrenic samples.

Adult↗