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Biomedical subjects

M West

Publications and source records attributed to M West.

At least 199 records · Page 11Linked to original sources
PubMed1982

Concussion in rats causes an immediate change in occupancy but not affinity of hypothalamic cholinergic receptors.

Experimental concussion in rats is associated with subsequent enhanced binding in vitro of certain ligands to hypothalamic tissue but not to other brain regions. Scatchard analysis shows that the number of specific binding sites for [3H]quinuclidinylbenzilate increases within 3 s after concussion with no significant change in binding affinity. The apparent increase in receptors is likely the result of a deficit in binding of endogenous ligand. We propose that concussion produces a pressure wave that deforms cholinergic and possibly other receptors selectively in the hypothalamus, resulting in a transient deficit in transmitter binding and interruption of neuronal circuits concerned with the state of consciousness.

Animals↗
PubMed1982

Spectral analysis of the electroencephalographic response in experimental concussion in the rat.

The phenomenon of concussion was studied in 32 non-anesthetized Sprague-Dawley male rats, previously implanted with chronic epidural electrodes for bipolar recording of the electroencephalogram (EEG). EEG records were taken continuously preceding during and following concussion, which was produced by a lead-tipped dart, shot from a spring-loaded pistol. The mass and velocity of the striking instrument were measured, so that its momentum and kinetic energy could be calculated. Spectral analysis of the EEG was performed by means of computer, using Fast Fourier Transform. In stage 1-2 of concussion, the power spectra of alpha, beta, and theta frequency bands were decreased by 25%, 37% and 10%, respectively. The delta spectrum alone was increased by 15%. Stage 3-4 of concussion was characterized by more profound depression of the power spectra of alpha, beta, theta and delta frequency bands (56%, 49%, 34% and 31%, respectively). EEG depression occurred immediately, reached a peak at 5 min and recovered at an average of 2 h in the concussed rats. In 5 rats, which did not recover completely, post-mortem examination revealed cerebral contusion or intracranial hematomas. These rats were not included in the analysis of 'concussion'. The EEG changes suggest the involvement of the cerebral cortex in the traumatic unconsciousness of concussion and are similar to those of spreading depression, as noted by previous investigators.

Animals↗
PubMed1982

Personality type and curriculum preference in primary care.

The study was conducted to examine the impact which personality types may have on the selection process of two preclinical medical school curricula. The two curricula run concurrently at the University of New Mexico School of Medicine. One curriculum has a conventional-lecture format, and the other a new student-centered curriculum, which is designed to graduate students planning careers in rural primary-care. Results indicated that those students preferring the innovative curriculum were personality types unlikely to enter rural primary-care, whereas students preferring the conventional curriculum had personality profiles more consistent with those making rural primary-care career choices. Discussion deals with the implications of personality type and curriculum choice in terms of the curriculum goals and educational method.

Career Choice↗
PubMed1982

Medical students' attitudes toward basic sciences: influence of a primary care curriculum.

The emerging popularity of family medicine and primary care among medical students with an attendant pressure for clinical relevance in pre-clinical coursework and early clinical exposure has raised questions in the minds of many academicians about the students' perceived value of basic sciences in such an educational environment. A comparison was made of attitudes toward the basic sciences between students in two, concurrent, pre-clinical medical school curricula at the University of New Mexico School of Medicine. The conventional curriculum offers a teacher-centered, 2-year curriculum of basic sciences taught predominantly by basic scientists in a lecture format. The experimental curriculum entitled the Primary Care Curriculum (PCC), offers a student-centered, 2-year curriculum in which pertinent basic and clinical science learning is derive primarily from common, primary care, patient problems, discussed in small group tutorials. There are no formal lectures. Half the tutors are primary care clinicians, half basic scientists. Attitude scales were administered in two successive classes of students in both curricula at the beginning of the first and second terms of the first year. Increased cynicism toward the curriculum and its relevance to future practice was observed among conventional, but not among PCC students. This findings lends supports to the hypothesis that modification in educational methods in general and relevant, primary care experience in particular can favourably influence students' attitudes toward basic sciences.

Attitude of Health Personnel↗
PubMed1981

Cerebral concussion in rats rapidly induces hypothalamic-specific effects on opiate and cholinergic receptors.

Conscious male adult rats were concussed by a blow to the occiput with a blunt dart, shot from a spring-loaded pistol. Animals were decapitated within 2 sec, brains quickly removed, several brain regions homogenized in cold buffer and radioreceptor assays carried out. There was a 20% increase in binding of [3H]naloxone and [3H]QNB in the hypothalamus but not in the amygdala, striatum, hippocampus, cortex, midbrain and hindbrain. For animals killed 5-10 sec after concussion, when normal conscious behavior had returned, there were no changes in binding between control and concussed rats. Binding of [3H]spiroperidol and [3H]ouabain was unaffected by concussion. To rule out changes due to non-specific stress, one series of rats received a blow to the lower body. There was no change from control in [3H]QNB binding to hypothalamic tissues by a body blow as compared with the blow to the head. The findings suggests decreased binding of endogenous endorphins and acetylcholine to their respective receptors as a result of concussion. The transient deficit in endogenous transmitter binding may temporarily interrupt hypothalamic circuits concerned with the state of consciousness.

Animals↗
PubMed1981

Familial abnormality of erythrocyte cation transport in essential hypertension.

Cation transport across the red-cell membrane was studied in subjects with essential hypertension and their relatives using rubidium-86 as an analogue of potassium. The activity of the ouabain-sensitive sodium-potassium pump was significantly greater in patients with untreated essential hypertension than in controls (p less than 0.001). No clear separation was seen between normotensive and hypertensive subjects. Activity of the sodium-potassium pump was also increased in a proportion of normotensive relatives of subjects with essential hypertension. Rubidium uptake was significantly lower in normotensive black subjects than in normotensive whites, the difference being in a ouabain-resistant pathway of cation transport. These results provide further evidence that a defect in membrane cation transport contributes to the pathogenesis of essential hypertension.

Adult↗
PubMed1980

Traumatic intracranial aneurysms.

Eleven cases of traumatic intracranial aneurysms, six saccular and five arteriovenous, are presented with an operative mortality of 22.2%, which compares favorably with the few reports in the literature. These lesions are usually associated with serious head injuries. The diagnosis is often delayed or overlooked as the surgeon's attention is distracted by the presence of an accompanying intracranial hematoma. With increasing replacement of angiography by computerized tomography in aneurysm diagnosis, these aneurysms are even more likely to escape detection. They should be suspected in any patient who deteriorates within 2 weeks of the trauma. Conservative management carries a mortality rate of about 50%. Because of their superficial location, they are amenable to successful surgical extirpation. Improved mortality depends on early recognition and surgical obliteration.

Adolescent↗
PubMed1979

Activity of dentate granule cells during learning: differentiation of perforant path input.

Experiments were conducted which extended previous findings regarding the activity of the perforant path and its synaptic relationship to the granule cells of the dentate gyrus during conditioning. A differential conditioning paradigm was utilized in which rats were trained to respond to one of two different tone frequencies. Results demonstrated that (1) tone elicited averaged evoked potentials recorded from the perforant path terminal zone in the outer molecular layer of the dentate gyrus were similar for both the positive and negative tones regardless of frequency or reversal of the reinforcement condition; (2) extracellular unit discharge patterns of dentate granule cells were differentially associated with the positive and negative tones as demonstrated by post stimulus histograms (PSHs); (3) this differential pattern of unit discharges could be reversed following establishment of criterion differential behavioral responding after reversal of the reinforcement contingency between the two tone stimuli and (4) the differential unit discharge pattern was not present when behavioral responding was not differentiated to the two tone stimuli, e.g., immediately following reversal of the reinforcement contingency. The results are discussed within the context of other anatomically defined functional circuits within the hippocampus which could serve as the basis for alteration of the non differentiated excitatory perforant path input into a differential dentate granule cell discharge pattern for behaviorally relevant sensory stimuli.

Acoustic Stimulation↗
PubMed1979

Synaptically identified hippocampal slow potentials during behavior.

Averaged evoked slow-wave potentials (AEPs) were recorded from various locations within the dentate gyrus and CA1 field of the hippocampus of 16 rats during the performance of an operant tone discrimination task. Consistent time-locked tone averaged evoked potentials (AEPs) were recorded from the perforant path zone in the outer molecular layer of the dentate gyrus. Tone AEPs were never present in this region (1) prior to development of the discrimination, (2) during behavioral extinction, or (3) during the performance of other operant behaviors. Results are discussed in terms of the functions of the perforant path in neural and behavioral plasticity.

Acoustic Stimulation↗
PubMed1979

A microdrive for use with glass or metal microelectrodes in recording from freely-moving rats.

A new subminiature microdrive assembly is described for electrophysiological recording from behaving rats. This very small, lightweight system allows excellent precision in electrode placement and can maintain stable recordings over extended periods. Since the electrode is nonrotating, tissue damage is minimized. Either metal or glass microelectrodes may be used with the system, offering the possibility of iontophoresis for cell marking or neuropharmacological manipulations.

Animals↗
PubMed1979

Meditation.

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Cross-Cultural Comparison↗
PubMed1979

An interdisciplinary health care setting's experience with groups for parents of children having specific disabilities.

This paper describes the planning, implementation, use, and evaluation of a group for parents of children with Williams elfin facies syndrome in an interdisciplinary health care setting. The group utilized a modified educational approach that resulted in significant gains reported by participants in learning about educational opportunities and rights of the handicapped, terminology and labeling of Williams syndrome, and meeting and sharing with other parents. The experience has implications applicable in interdisciplinary health care settings for use of groups as an aid in reducing the conflict that may result from the frequent combination of research and service to individuals with specific disabilities.

Abnormalities, Multiple↗