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PubMed1999

Medical curriculum reform in North America, 1765 to the present: a cognitive science perspective.

Since 1765, five major curricular reform movements have catalyzed significant changes in North American medical education. This article describes each reform movement in terms of its underlying educational practices and principles, inherent instructional problems, and the innovations that were carried forward. When considering the motivating factors underlying these reform movements, a unifying theme gradually emerges: increasing interest in, attention to, and understanding of the knowledge-base structures and cognitive processes that characterize and distinguish medical experts and novices. Concurrent with this emerging theme is a growing realization that medical educators must call upon and utilize the literature, research methods, and theoretical perspectives of cognitive science if future curricular reform efforts are to move forward efficiently and effectively. The authors hope that the discussion and perspective offered herein will broaden, stimulate, and challenge educators as they strive to create the reform movements that will define 21st-century medical education.

Curriculum↗
PubMed1997

Evolution of H5 subtype avian influenza A viruses in North America.

The phylogenetic relationships of the hemagglutinin (HA) and non-structural (NS) genes from avian influenza (AI) H5 subtype viruses of North American origin are presented. Analysis of the HA genes of several previously uncharacterized isolates from waterfowl and turkeys provided clear evidence of significant sequence variation and existence of multiple virus clades or sub-lineages, maintained in migratory waterfowl. Phylogenetic analysis of NS gene sequences further demonstrated multiple sub-lineages and also demonstrated re-assortment of two NS alleles in wild duck populations. Based on currently available HA1 gene sequences, at least four clades exist with waterfowl isolates included in three of the four groups. The most genetically unstable of these sub-lineages is composed of recent poultry isolates from the outbreak of AI in Central Mexico. This group of viruses, which replicated unabated in chickens for at least 16 months, exhibited an increased rate of mutation in both the HA and NS gene. Comparison of the HA1 sequence data for all available North American H5 subtype viruses demonstrated minimal variation both in and around the amino acids predicted to be involved in the HA receptor binding site. The sequences also revealed that migratory waterfowl, live poultry market chicken, and turkey isolates uniformly lack a glycosylation site at amino acid 236 in the HA protein which is present in commercial chicken isolates.

Animals↗
PubMed1990

[Development of fetal semiology in North America].

A survey of the emergence of fetal semiology in the 17 editions of the Williams' Textbook of Obstetrics used by North-American medical students since 1900 was carried out. Three periods were identified: 1906-1950: the fetus, seen as a part of its mother, is ignored until birth and is of no interest to the obstetricians. From the fifties', the decrease in maternal mortality and progress in physiology and therapeutics permitted to study the fetus and a greater attention given to the care of the sick newborn. Since 1970, the availability of ultrasonography has contributed in making the fetus the second patient for obstetricians. It is now possible to study its growth, integrity, health, and well-being. Furthermore, the fetus is now accessible to establish a prenatal diagnosis.

Embryonic and Fetal Development↗