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Biomedical subjects

E R Ritvo

Publications and source records attributed to E R Ritvo.

12 recordsLinked to original sources
PubMed1992

Hyperserotoninemia and antiserotonin antibodies in autism and other disorders.

This study examined the linkage between elevated blood serotonin in autism and the presence of circulating autoantibodies against the serotonin 5HT1A receptor. Information was also obtained on the diagnostic and receptor specificity of these autoantibodies. Blood serotonin was measured as was inhibition of serotonin binding to human cortical membranes by antibody-rich fractions of blood from controls and from patients with childhood autism, schizophrenia, obsessive-compulsive disorder, Tourette's, and multiple sclerosis. The results showed elevated blood serotonin was not closely related to inhibition of serotonin binding by antibody-rich blood fractions. Inhibition of binding was highest for patients with multiple sclerosis and was not specific to the 5HT1A receptor as currently defined. Although inhibition was not specific to autism, the data were insufficient to establish if people with autism differed from normal controls on this measure.

Adolescent↗
PubMed1992

Magnetic resonance imaging of the posterior fossa in autistic adults.

Magnetic resonance imaging measurements were obtained for 12 adults with DSM-III-defined autism and a matched group of 12 normal subjects. No significant differences were found for mean midsagittal areas of pons, fourth ventricle, cerebellar vermis, or vermis lobules. No significant brain abnormalities were observed in either group.

Adolescent↗
PubMed1991

Fenfluramine effects on serotonergic measures in vervet monkeys.

Chronic fenfluramine treatment reduced whole blood serotonin and CSF 5-hydroxyindoleacetic acid, but increased aggressive and locomotor behavior, in adult male vervet monkeys (Cercopithecus aethiops sabaeus). Following a drug-free washout period to monitor the drug recovery course, we initiated a second period of fenfluramine treatment in the same animals. When whole blood serotonin concentrations were reduced by about 40% from predrug baseline levels, we examined 11 cortical and subcortical brain regions for their content of 5-hydroxytryptamine, 5-hydroxyindoleacetic acid, norepinephrine, and dopamine. We observed correspondence between the reduction in whole blood serotonin and the reduction in brain 5-hydroxytryptamine. Similarly, there was a correspondence between the reduced 5-hydroxyindoleacetic acid levels observed in CSF and brain. No alterations were noted in the concentrations of norepinephrine or dopamine. These observations suggest that the behavioral effects observed in monkeys after chronic fenfluramine treatment result from reduced central serotonin.

Animals↗
PubMed1976

The effects of response contingent vestibular stimulation on the behavior of autistic and retarded children.

The purpose of the present experiment was to examine the reinforcing effects of repetitive vestibular stimulation. While both autistic and retarded children would push a button for vestibular stimulation, frequency of stimulation was an important parameter for autistics but not for retardates. These results were interpreted as evidence for central rather than peripheral locus of control of motility disturbances in autistic children.

Autistic Disorder↗
PubMed1976

Rapid eye movement (REM) activity in normal and autistic children during REM sleep.

Thirty normal children (aged 3--68 months) and 16 autistic children (aged 36--62 months) were recorded during nonmedicated sleep and data pertaining to rapid eye movements (REM) were measured during the first three REM periods of the night. When time of night from which data were gathered was held constant, normal children showed a significant relationship between age and the organization of eye movements into discrete bursts. When autistic children were compared to age-matched normal controls, they showed an immaturity in this phenomena, their results being similar to those found in children less than 18 months of age. Such an immaturity could result from dysfunction at a number of diverse levels and sites in the central nervous system.

Age Factors↗
PubMed1976

The syndrome of autism: a critical review.

The authors review the clinical features and behavioral characteristics of autism; differential diagnosis of the syndrome; clinical, neurophysiological, and biochemical research; and its medical management and treatment. They conclude that autism is a behaviorally defined, specific syndrome that is manifested at birth or shortly thereafter. Its symptoms are expressive of an underlying neuropathophysiological process that affects developmental rate; modulation of perception; language, cognitive, and intellectual development; and the ability to relate. The long-term prognosis is guarded; almost all patients manifest severe symptomatology throughout their lives. Further basic research into the neuropathophysiological process underlying the syndrome is necessary in order to reach the ultimate goal of developing etiologically specific treatment programs.

Age Factors↗