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Biomedical subjects

G N Melville

Publications and source records attributed to G N Melville.

At least 19 recordsLinked to original sources

Entrance qualifications and student performance in a hybrid problem based and traditional medical programme.

A hybrid problem based learning (PBL) and traditional medical programme was started at the Trinidad campus of the University of the West Indies in 1989. Analyses were carried out to determine the extent to which the entrance qualifications of the students were related to their performances at the examinations in the Phase I (preclinical and paraclinical) and Phase II (clinical) programmes. Students who were admitted on the basis of their results in the secondary school General Certificate of Examination (GCE), 'A' level scored higher at the Phase I, but not at the Phase II, level than those who already had university education. Among the 'A' level students, there was positive correlation between the total 'A' level scores and the examination marks in the medical programme, particularly at the Phase I level. Furthermore, multiple regression analyses indicated that the grades in 'A' level Chemistry and, to a lesser extent in Biology, had the most influence on performances at the Phase I examinations, with much less influence on performances at the Phase II examinations. These results suggest that good grades at 'A' level examinations are significant factors, but not the only important ones, that favour high achievement in the initial stages of this type of PBL/traditional medical programme.

Education, Medical, Undergraduate↗

Progress in medical education in the Faculty of Medical Sciences, University of the West Indies: implementation of problem-based learning at the St. Augustine Campus.

This paper reviews some of the developmental procedures regarding changes in Medical Education within the Faculty of Medical Sciences, University of the West Indies. Discussed are some of the constraints experienced in attempting curriculum changes in the established Medical School at Mona, Jamaica, as compared with the implementation of a Problem-based Learning Strategy curriculum at the Eric Williams Medical Complex, St. Augustine, Trinidad and Tobago. At Mona, integration of disciplines, Community-health and other programmes were attempted. However, it was at the Eric Williams Complex, a new school, that the Faculty of Medical Sciences was able to implement a problem-based programme.

Curriculum↗

Abnormal thyroid hormone and thyrotropin levels in homozygous sickle cell disease.

Male patients with SS disease had significantly lower T3 and higher TSH levels than a comparison group. Stimulation with TRH in 10 male sibling pairs showed highly significant increases in T3 and TSH in both patients and sibling controls although the increase in TSH was significantly greater in SS disease. The interpretation of these findings is unclear although the thyroid indices indicate an abnormal pituitary-thyroid axis most consistent with a modest primary thyroid failure.

Adolescent↗

Testicular function in rats following immobilization stress.

Stress is believed to influence male reproductive activity. Male rats were subjected to immobilization stress for 2 h/day for 30 days to assess the effects of stress on testicular function. Net mass of the testes, epididymes and the seminal vesicles, sperm morphology, number of epididymal sperms and percent progressive motility of the sperms were determined. Adrenal weights were significantly increased (P less than 0.05) in the stressed animals. There was no significant difference between the control and the stressed animals with respect to testicular and epididymal weight, level of sperm production, progressive motility, seminal vesicular weight and abnormal forms. Histological examination also revealed a similarity in the structure of seminiferous tubules, adequacy of cell types of developing germ cells, structure of Leydig cells and epididymal lumina in both the groups. This study demonstrated a lack of significant effect of immobilization stress on testicular function in rats.

Animals↗

Effect of hypoglycin A on insulin release.

Thirty experimental and fifteen control Wistar rats were studied to determine whether hypoglycin A influences insulin levels in the body to contribute to the state of hypoglycemia usually observed in Jamaican vomiting sickness, a condition arising after ingestion of unripe ackees. This fruit also grows in other Caribbean islands, as well as North and Central America. Hypoglycin A is one of the toxic compounds found in unripe ackees and is capable of inducing hypoglycemia. A fall in blood glucose occurred after administration of hypoglycin A. The lowest level of 42.60 +/- 4.84 mg/dl was attained 3 hr after administration of the drug. This alteration of blood glucose from the fasting level of 80.31 +/- 5.20 mg/dl was significant (P less than 0.01). The blood glucose level in the control rats showed no significant change from the fasting level. The insulin level in portal and peripheral blood showed no significant change. Results showed that, although hypoglycin A induced severe hypoglycemia after intravenous application, there was no significant change in insulin levels. This observation suggests that hypoglycin A has a mechanism of action other than an alteration in insulin levels to induce hypoglycemia.

Animals↗

Insulin release pattern after blockade of catecholamine synthesis with alpha-methyl tyrosine in vivo.

Insulin release pattern in vivo was studied using 30 control rats and 30 rats treated with alpha-methyl tyrosine to block catecholamine synthesis in vivo four days before the time of investigation. The drug treated animals exhibited significantly higher fasting insulin levels, and also the first phase insulin release after the B cell was challenged with a glucose load was significantly higher in these animals than occurred in the controls. This observation implies that the B cell is modulated by the sympathetic nervous system in its function and the insulin release would vary according to the emotional state of the individual.

Animals↗