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Biomedical subjects

G R DeLong

Publications and source records attributed to G R DeLong.

At least 55 records · Page 3Linked to original sources
PubMed1982

Encephalopathy of Reye's syndrome: a review of pathogenetic hypotheses.

The pathogenesis of Reye's syndrome encephalopathy was analyzed in terms of uniform criteria designed to clarify and assist evaluation of the leading hypotheses. Three of these hypotheses derive from known metabolic sequelae of hepatic mitochondrial dysfunction and the severe systemic catabolism of protein, fats, and carbohydrates that characterize the syndrome biochemically: hyperammonemia, hyperfattyacidemia, and hyperlactatemia. In addition, there is a fourth hypothesis of generalized mitochondrial insult affecting brain, muscle, and other organs as well as liver. The weight of evidence favors hyperammononemia as a sufficient factor while recognizing important interrelationships with the other observed biochemical derangements. How the catabolism and hepatic mitochondrial dysfunction are produced by the triggering viral infection remains unknown. Therapeutic efforts have thus far not succeeded in definitive metabolic intervention. Such reversal of the clinical syndrome would lead to confirmation of the necessary pathogenetic factors; this type of intervention remains the chief goal of metabolic research in Reye's syndrome.

Acidosis↗
PubMed1981

Acquired reversible autistic syndrome in acute encephalopathic illness in children.

In seeking the neurologic substrate of the autistic syndrome of childhood, previous studies have implicated the medial temporal lobe or the ring of mesolimbic cortex located in the mesial frontal and temporal lobes. During an acute encephalopathic illness, a clinical picture developed in three children that was consistent with infantile autism. This development was reversible. It was differentiated from acquired epileptic aphasia, and the language disorder was differentiated aphasia. One child has rises in serum herpes simplex titers, and a computerized tomographic (CT) scan revealed an extensive lesion of the temporal lobes, predominantly on the left. The other two, with similar clinical syndromes, had normal CT scans, and no etiologic agent was defined. These cases are examples of an acquired and reversible autistic syndrome in childhood, emphasizing the clinical similarities to bilateral medial temporal lobe disease as described in man, including the Klüver-Bucy syndrome seen in postencephalitic as well as postsurgical states.

Acute Disease↗
PubMed1980

Autism and mental retardation: neuropathologic studies performed in four retarded persons with autistic behavior.

Four persons who exhibited prominent autistic features throughout life died when 4, 14, 27, and 33 years old. All were mentally retarded. One had documented phenylketonuria, but the cause of mental retardation and autistic behavior was undefined in three. At the time of autopsy, brain weights were within 2 SDs of the norm for age. Complete neuropathologic examination, including analysis of cortical neurons impregnated with the rapid Golgi method, failed to provide clues as to cause or the pathoanatomic substrate of autistic behavior in these cases.

Autistic Disorder↗
PubMed1979

Neurologic sequelae in the survivors of neonatal intraventricular hemorrhage.

We report our experience with the neurologic sequelae (at a mean follow-up of 24 months) among the 15 surviving infants who have had neonatal intraventricular hemorrhage (IVH) documented by computerized tomographic (CT) brain scan. Neurologically six infants (40%) are normal, six infants (40%) mildly impaired, and three infants (20%) moderate to severely impaired. The neurologic outcome correlated to the degree of hemorrhage seen in the CT scans when IVH was classified into four grades. None of the other neonatal factors examined showed significant correlation with the outcome.

Cerebral Hemorrhage↗
PubMed1978

Lithium carbonate treatment of select behavior disorders in children suggesting manic-depressive illness.

Twelve children with severe chronic behavior disorders who benefited from treated with lithium carbonate over an extended period of time (6 to 33 months) are described. Behavioral features common to all included hostility, aggressiveness, and distractibility. Nine had cyclic mood swings, with periods of withdrawal and periods of manic excitement; six of these had neurovegetative disorders. These nine children may have manic-depressive disease of childhood. Three children had no cyclic symptoms, though their hostile and aggressive behavior was similar to that of the cyclic group; they responded similarly to lithium. Family histories were strongly positive for manic-depressive disease, depression, and alcoholism. A double-blind placebo-controlled crossover study in four patients supported the specific behavioral effect of lithium.

Adolescent↗
PubMed1977

Evaluation of neonatal intracranial hemorrhage by computerized tomography.

Computerized tomographic (CT) brain scan was performed on 28 infants with unexplained cardiorespiratory and neurologic deterioration and bloody lumbar cerebrospinal spinal fluid. Fourteen of 20 with intraventricular hemorrhage (IVH) died; the six infants with lesser degrees of IVH survived. Significant subarachnoid hemorrhage (SAH) was demonstrable in three infants and three had negative scans despite bloody CSF. We have found that CT scans provide useful information about the size and extent of neonatal IVH and distinguished it from SAH. It also confirms the diagnosis of post-hemorrhagic hydrocephalus in these infants. Continued use of the CT scan will help us to understand the natural history and the effects of neonatal intracranial hemorrhage among the survivors of intensive care.

Cerebral Hemorrhage↗
PubMed1977

Temporary contacts formed between developing optic fibers in the chick.

Temporary junctions were observed between developing optic fibers of the chick embryo and were distributed along the entire length of the axons from the cell body to the tip of the growth cone. These junctions were present in all material studied between days E-3 and E-18, the latter being the start of myelin formation of the optic tract. Junctions between adjacent axons were focal in nature and showed a decrease in the size of the intercellular space caused by a close apposition of the plasma membrane. With the experimental techniques used final identification of these junctions could not be made but are thought to be of two types--the gap and occludens junctions. Temporary fasciae adherentes junctions were observed at the end of the axon, between the growth cone and adjacent neural tissue. Speculation was made on the functional role of these temporary junctions.

Animals↗
PubMed1976

Urea-cycle enzyme deficiencies and an increased nitrogen load producing hyperammonemia in Reye's syndrome.

Assay of urea-cycle enzymes in liver tissue showed ornithine transcarbamylase activities of 18 to 72 per cent of the normal mean in eight patients with Reye's syndrome, below the range of normal in seven of eight, and, in six cases, as low as those in females with X-linked deficiency of this enzyme. Carbamyl phosphate synthetase activities were less than 32 per cent of controls in two patients. Argininosuccinate synthetase and lyase activities were normal in seven patients. Arginase was normal in two biopsy specimens, but below normal in four of five autopsy specimens. The Km's for ornithine and carbamyl phosphate, pH optimum, and heat lability of ornithine transcarbamylase were normal. Two patients excreted 0.64 and 0.58 g per kilogram per day of urinary nitrogen at the peak of hyperammonemia, in spite of peritoneal dialysis. The hyperammonemia of Reye's syndrome apparently results from excess waste nitrogen that overwhelms the ability of reduced ornithine transcarbamylase (and occasionally carbamyl phosphate synthetase) to detoxify the ammonia load.

Adolescent↗
PubMed1976

Cholesterol metabolism in cultured fibroblasts in adrenoleukodystrophy.

The basic biochemical defect of X-linked adrenoleukodystrophy (sudanophilic leukodystrophy, Schilder's disease) is unknown. To investigate reported abnormalities in cholesterol metabolism in vitro, we examined cultured skin fibroblasts of four patients and four normal control subjects. The kinetics of retention and accumulation of [14C]cholesterol by these cells was studied. After 3 days of exposure to tracer amounts of [14C]cholesterol, an apparent steady state between the medium and cellular cholesterol was established. The specific radioactivity expressed per mg of protein was similar for both Schilder and control fibroblasts. tafter labeling the pre-existing cellular cholesterol pool, the rate of loss of label was followed up for a 6-day period. About 23% and 14%, respectively, of the cellular radioactivity in both Schilder's disease and control cells were released into the medium after the consecutive change with fresh nonlabeled medium. No significant differences in [14C]cholesterol rates of uptake or release were observed between control and Schilder's disease fibroblasts. About 44% of the labeled cholesterol was present in an esterfied form after incubation in the presence of unheated serum in both Schilder's and control cultures.

Adolescent↗
PubMed1975

Pneumographic findings in the infantile autism syndrome. A correlation with temporal lobe disease.

Pneumoencephalographic findings are described in a group of 18 children who presented to us with a history of retarded language development and autistic behaviour disturbances. None had specific diagnosable neurological diseases nor gross motor disorders. PEG findings included, most prominently, pathological enlargement of the left temporal horn in 15 cases; some cases showed enlargement of both temporal horns or mild variable enlargement of the lateral ventricles, especially the left. Comparisons between infantile autism and recognized patterns of temporal lobe disease (especially Korsakoff syndrome and Kluver-Bucy syndrome) are drawn. We have suggested that medial temporal lobe dysfunction may be a major factor in the pathogenesis of the syndrome of infantile autism.

Autistic Disorder↗
PubMedDate not supplied

Headaches in childhood.

The diagnosis and management of headache in children is a challenge to the clinician, covering as it does a wide range of diagnostic possibilities and enlisting a range of skills from neurosurgery and infectious disease to the psychological. The task is best undertaken, as in so many medical problems, by taking careful history and physical examination, including the past history, family history, and life circumstance of the child. After this is done, only in a minority of cases will it be necessary to request a specific special test, such as a CT scan, lumbar puncture or EEG. In those cases where doubt remains after initial careful evaluation or even after special studies have not resolved the question, careful follow up of the child over time, with re-examination as necessary, will allow definitive diagnosis and prevent the physician from missing obscure or in apparent disease.

Child↗