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Biomedical subjects

J Bell

Publications and source records attributed to J Bell.

At least 397 records · Page 22Linked to original sources
PubMed1982

Clonidine treatment of schizophrenia. Double-blind comparison to placebo and neuroleptic drugs.

Antipsychotic effects of clonidine were evaluated in one schizoaffective and seven schizophrenic patients, using a double-blind, cross-over design to compare placebo, clonidine, and standard neuroleptic drugs. Mean improvement on clonidine and neuroleptics was equal, and improvement scores on the two treatments were closely correlated for individual patients. Clonidine was selected because it blocks noradrenergic but not dopaminergic neurotransmission. Patients were selected because of co-existing psychosis and tardive dyskinesia, a movement disorder thought to be caused by the antidopaminergic properties of the neuroleptics. For all patients, dyskinesia improved when neuroleptics were discontinued during clonidine and placebo periods of the study. The data provide preliminary evidence that clonidine may be an effective alternative to neuroleptics, particularly for patients for whom the dopaminergic blocking action of the neuroleptics is undesirable. The study also prompts re-evaluation of theories of a unique role for dopamine in schizophrenia.

Adolescent↗
PubMed1981

Undernutrition and recovery from brain damage: a preliminary investigation.

Rats undernourished early in life did not differ from control animals in acquiring a light-dark discrimination. Posterior cortical lesions impaired retention in both nutritional groups, but the relearning scores of the undernourished animals with lesions were significantly worse than those of the lesion group that had been well fed. Amphetamine was found to enhance recovery, especially in the undernourished group. These data thus show that early nutritional history can be an important factor in accounting for differences in performance following later, focal brain damage, but that pharmacological intervention still can be of great value in these cases.

Animals↗
PubMed1981

Effects of one- and two-stage lesions of the posterior hypothalamus on temperature regulation in the rat.

Rats received 1-stage bilateral and sequential unilateral (serial) lesions of the posterior hypothalamus and were tested for the ability to regulate body temperature after a lengthy recovery period. The groups with lesion differed from the sham-operated groups in the cold, although not under ambient or warm conditions. The fact that the serial lesion group performed the same as the 1-stage lesion groups in the cold is significant because earlier tests on these same animals revealed much better recovery after serial lesions in swimming, and a partial serial lesion effect in open field performance.

Animals↗
PubMed1981

Phase plane description of endogenous neuronal oscillators in Aplysia.

Phase plane techniques are used to describe graphically the limit cycle behavior of identified endogenous neuronal oscillators in the isolated abdominal ganglion of Aplysia. Intracellularly recorded membrane potential from a bursting neuron and its first derivative with respect to time are used as coordinates (state variables) in phase space. The derivative is either measured electronically or calculated digitally. Each trajectory in phase space represents the entire output of the bursting neuron, i.e., both the rapid action potentials and slow pacemaker potentials. Phase plane portraits are presented for the free run limit cycle before and after a change in a system parameter (applied transmembrane current) and also for phase resetting produced by direct synaptic inhibition from an identified interneuron. The complex topology of the trajectory suggests that the bursting oscillator is a higher order system. Therefore, the second time derivative is used as another state variable. This type of phase plot can help to relate biophysical and mathematical analyses.

Abdomen↗
PubMed1981

Serum immunoreactive trypsin in cystic fibrosis.

Serum immunoreactive trypsin (IRT) concentrations were measured blind in sera from 33 patients with cystic fibrosis and in 32 age-matched controls. Thirty-two patients had abnormal trypsin concentrations. In 30 of these patients the level of IRT was very low whereas in the other two (the youngest of the group) it was extremely high. All 30 patients with low IRT concentrations had clinical or biochemical evidence of malabsorption. Serum IRT concentration may thus be a useful diagnostic test for cystic fibrosis. In view of the recent observation that neonates with cystic fibrosis consistently have raised IRT concentrations, and the fact that the youngest two patients in our series also had markedly increased IRT, it would appear that the initial elevation of IRT reflects early damage to the pancreas with release of enzyme/zymogen; this is thereafter superseded by a progressive destruction of the pancreas resulting in low IRT concentrations in adults with cystic fibrosis.

Adolescent↗
PubMed1980

handedness in engineering and psychology students.

Patterns of handedness were compared in engineering and psychology students using a questionnaire developed by Oldfield (1971). Engineering students are highly selected in terms of mathematico-spatial skills while psychology students are representative of typical undergraduate populations. In general the incidence of right- and left-handedness was according to expectation for the two groups. However, the engineering sample exhibited a significantly greater dextrality then the psychologists. Some implications of this finding were discussed.

Engineering↗
PubMed1980

Matrical carcinoma of the skin.

Two elderly patients with unusual hair-follicle tumors of the face are reported. The lesions showed some histologic resemblance to pilomatrixomas but differed by the presence at the advancing edge of cytologically-atypical cells without the usual shadow cell transformation and maturation of pilomatrixomas. The term matrical carcinoma is proposed for these tumors.

Aged↗