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Biomedical subjects

J G Cunningham

Publications and source records attributed to J G Cunningham.

At least 19 recordsLinked to original sources

Low-abundance 32-kilodalton nuclear protein specifically enriched in the central nervous system.

Recently, a low-abundance nuclear protein, p32/6.3, has been identified in brain tissue (Egle and Shelton: Journal of Biological Chemistry 261:2294-2298, 1986). Using a Western blot procedure, we describe its distribution in the nervous system, determine its relative enrichment in brain versus liver, kidney, and certain other tissues, and describe an isolation procedure from brain. Selective enrichment occurs in basal ganglia, diencephalon, hippocampus, cerebellum, brainstem, spinal cord, and cerebral cortex but not in retina, dorsal root ganglia, and sympathetic ganglia. Thus, enrichment is limited to areas of the central nervous system. p32/6.3 appears to be preferentially enriched in neurons, because in bulk-isolated fractions from rat grey matter it is more abundant in neuron-enriched fractions than in astrocyte-enriched fractions. p32/6.3 is approximately 20-fold more concentrated in an insoluble nuclear protein or matrix fraction from forebrain than from kidney, liver, adrenal gland, or retina. This degree of enrichment is an ancient trait, detectable in the chicken as well as mammals.

Animals

Young children's knowledge of their memory span: effects of task and experience.

This study investigated the hypothesis that young children have knowledge about their memory that they may be unable to articulate, but are able to reflect on and use in problem-solving. Forty-eight kindergarteners made one of two types of judgments about their memory span for words. Half of the children made prospective verbal predictions about the number of words they thought they could recall from a list of 10. The other half made concurrent, nonverbal predictions by listening to words on a tape and manually stopping the tape when they heard as many words as they thought they could recall. Children's actual recall for words was then assessed. All children participated in multiple trials to assess the effect of task experience on their predictions. Analyses revealed that predictions made in the concurrent task were significantly more accurate than those made in the prospective task. All children lowered their predictions across trials, although only in the concurrent task were children's final-trial predictions not significantly greater than their actual recall. No meaningful effects or interactions were associated with actual recall scores. These results revealed that young children manifested greater memory knowledge when this knowledge was assessed through their concurrent problem-solving behavior rather than through their prospective verbal predictions.

Child

Caprine beta-mannosidosis: phenotypic features.

The clinical features of caprine beta-mannosidosis were evaluated in 10 newborn goats, one stillborn goat and one goat fetus. The phenotypic abnormalities observed in all 10 live affected animals included an inability to rise from a recumbent position, moderate to marked intention tremor, eye movements resembling pendular nystagmus, clinical deafness, bilateral Horner's syndrome, carpal contractures, pastern joint hyperextension, thickened skin and to a varying degree, a dome-shaped skull. Subjective evaluation suggested that most animals had a decreased muscle mass. Together, these characteristics represent a common phenotype which is expressed at birth in caprine beta-mannosidosis.

Animals

Influence of phentolamine and propranolol on the length of tonus and clonus in pentylenetetrazol-induced seizures in dogs.

The goal of this study was to test the hypothesis that phentolamine and propranolol premedication would affect tonus differently than clonus in pentylenetetrazol (PTZ)-induced tonic-clonic seizures in dogs. Tonic-clonic seizures were induced with IV infusion of PTZ, given as an initial 300-mg bolus and then 100-mg boluses every 10 S until a seizure began. Premedication with phentolamine (2 mg/kg of body weight) significantly shortened clonus (P less than 0.05), whereas propranolol (1 mg/kg) significantly lengthened clonus (P less than 0.05). Neither phentolamine nor propranolol significantly altered the length of tonus or the dose of PTZ required to induce seizures (P greater than 0.05). This indicates that tonus and clonus may have different neural mechanisms and that adrenergic receptors may be involved in the neural mechanisms of clonus.

Animals

Therapeutic serum concentrations of primidone and its metabolites, phenobarbital and phenylethylmalonamide in epileptic dogs.

Fifteen dogs with idiopathic epilepsy were included in a 9-month clinical trial to determine the therapeutic serum concentrations of primidone and its active metabolites, phenobarbital and phenylethylmalonamide. Dogs with a seizure frequency greater than 1/mo or with a record of multiple seizures greater than 1/day were chosen for the study. Each dog was given primidone 3 times daily at dosages intended to maximize seizure control and to minimize undesired side effects. Maintenance period blood samples were taken from fasted dogs 7 hours after dosing in the 3rd, 5th, 7th, and 9th months of the trial to determine therapeutic serum concentrations of primidone and its metabolites. Two blood samples also were taken from all dogs 7 hours after dosing, during an enforced drowsy period, to establish upper limits of desirable serum concentrations of the drug. Seizure frequencies during the trial were controlled in 13 dogs, 7 of which had no seizures during the 9-month trial. The mean percentage reduction in seizure frequency from pretrial frequency was 85%. Two dogs appeared refractory to primidone therapy. Serum phenobarbital was the best metabolite of primidone to use to assess therapeutic serum concentrations. The therapeutic antiepileptic serum concentration of phenobarbital was found to be between 25 and 40 micrograms/ml of serum. Serum phenobarbital concentrations greater than 40 micrograms/ml resulted in side effects in most dogs.

Animals

Caprine beta-mannosidosis: clinical and pathological features.

Beta-mannosidosis, an inherited defect of glycoprotein catabolism associated with deficiency of tissue beta-mannosidase and accumulation of Man(beta 1-4)GlcNAc and Man(beta 1-4)GlcNAc(beta 1-4)GlcNAc, appeared in four of 13 offspring of a single pair of clinically normal, related Nubian goats. Neurological examinations revealed that all four affected goats were unable to rise or walk. All had facial dysmorphism, dome-shaped skulls, small palpebral fissures, carpal contractures, hyperextension of the pastern joints, proximal muscle atrophy, intermittent ocular oscillations resembling pendular nystagmus, marked intention tremor, and deafness. With intensive care, three affected kids were hand-reared and then killed at 1, 7, and 21 days of age. Macroscopically, there were paucity of myelin in the cerebral and cerebellar hemispheres and ventricular dilatation. Microscopically, the extent and distribution of cytoplasmic vacuolation, myelin paucity, axonal spheroids, and filamentous expansions were evaluated in the cerebrum, cerebellum, brainstem, spinal cord, and peripheral nerves of the four affected kids and two age-matched, clinically normal kids. Widespread cytoplasmic vacuolation correlated with the previously reported accumulation of oligosaccharides in the brain and kidney and the deficiency of tissue beta-mannosidase. beta-Mannosidosis, not yet identified in man or other species, is characterized by distinctive neonatal clinical, pathological and biochemical features which differentiate it from the alpha-mannosidosis and other inherited diseases of glycoprotein catabolism.

Animals

Vaccine-induced rabies in four cats.

Vaccine-induced rabies in 4 cats was characterized by rigid posterior paralysis. In 3 cats, paralysis began in 1 hindlimb and rapidly spread to the other hindlimb. Later, forelimb and cranial nerve deficits were noticed. Onset of clinical signs was 13 to 17 days after IM vaccination with an ERA-strain modified live-virus rabies vaccine approved for use in cats. Each cat eventually was euthanatized. In each case, brain tissue was found to contain rabies virus on fluorescent antibody and mouse inoculation studies. An antibody titer and mouse inoculation studies. An antibody titer against rabies virus was found in the CSF of 1 cat. In each case, viral isolates were shown to be of an ERA strain rather than natural ("street") rabies.

Animals

Clinical evaluation of the new compound diphenylsilanediol for ani-epileptic efficacy and toxicity.

A controlled clinical trial of the anti-epileptic efficacy and toxic side effects of diphenylsilanediol was conducted on 24 client-owned epileptic dogs. Data obtained from an abbreviated procedural treatment program indicated that diphenylsilanediol compared favorably with primidone as an anti-epileptic compound, but had limiting toxic side effects to the liver, pancreas, and possibly to other tissues. There was a mean reduction of 60.7% in seizure frequency in 15 epileptic dogs treated with diphenylsilanediol when compared with their pretreatment frequency. There was a mean reduction of 55.6% in seizure frequency in 9 spileptic control dogs treated with primidone. Samples of blood obtained from the dogs in the program on the 4th, 8th, 12th, 24th, and 36th weeks of treatment were examined for complete blood cell count, blood urea nitrogen, liver function, and pancreatic function. Toxic side effects were not seen among the primidone-treated control dogs, with the exception of occasional dose-related drowsiness. Among the diphenylsilanediol-treated dogs, 3 developed liver disease, 2 developed definite pancreatic changes, and 2 showed evidence of bone marrow suppression. Four dogs died during treatment with diphenylsilanediol, whereas no deaths occurred during the same interval of primidone therapy.

Animals

The role of perceptual salience in the development of analysis and synthesis processes.

The ability of 6- and 11-year-old children to solve problems requiring the analysis or the synthesis of salience-assessed stimulus relations was investigated. The relative salience of the relations of form, color, and position was assessed and a salience hierachy determined for each child. Following salience assessment, children were given a recall problem in which the salience of the relations and the type of evaluation required for solution were varied. In analysis problems, the relative salience of the irrelevant relation was either higher or lower than that of the relevant relation. In synthesis problems, the two relations to be evaluated were either more or less salient. Both younger and older children were able to solve problems requiring the analysis or the synthesis of relations, but the rate of solution varied as a function of the salience of the relations involved. There was no evidence that either analysis or synthesis preceded the other in the course of development.

Age Factors

Effects of perceptual salience on the matrix task performance of four- and six-year-old children.

The effects of salience on 4- and 6-year-old children's ability to classify multiplicatively was investigated. A rank-ordered salience hierachy consisting of 3 dimensions was first assessed for each S. Several weeks later half the Ss of each age group were presented with a series of 9 3 times 3 matrix problems consisting of values from 2 dimensions ranked high in salience. The remaining half received identically structured matrices consisting of values from 1 highly salient dimension and of others from a dimension ranked low in salience. The goal in each problem was to select that compound stimulus from a set of alternatives that appropriately filled an empty cell in the matrix. Prior to the matrix problems, half the Ss in each matrix condition received sensitization training designed to increase the salience of the relevant dimensions in the matrix problems. The results showed that the pre-assessed salience of the relevant dimensions affected matrix solution in that more accurate performance was associated with those problems with both relevant dimensions relatively high in salience than those with one high and one low. Although the older Ss solved more problems, the evidence for coordination in the younger Ss was clear. No effects of sensitization training were found.

Age Factors