Social constructs of curricular change

The adoption of problem-based approaches to teaching and learning in dental and medical education requires educators to consider a significantly different role and responsibilities as teacher from what they have experienced previously. This qualitative study explored how some educators experienced and interpreted changes in the newly merged dental and medical curriculum at the University of British Columbia. Our findings present how educators explained and dealt with change. In-depth interviews provided considerable insight into factors influencing the resistance or acceptance to change. The educators' beliefs about teaching and learning and their understanding of the development and implementation process of change mediated these factors. Findings from this study should help administrators, faculty developers, and educators themselves to understand better how curricular change is experienced and to plan effective and appropriate faculty development.     

An alternative splinting and rehabilitation protocol for metacarpophalangeal joint arthroplasty in patients with rheumatoid arthritis.

This prospective study was completed to establish results obtained using a static splinting regimen as an alternative to the dynamic extension splint. Fifteen patients with rheumatoid arthritis, who had undergone metacarpophalangeal (MCP) joint arthroplasties and a postoperative rehabilitation program of alternating MCP joint flexion and extension static splints, were assessed pre-operatively and reviewed postoperatively. Total active arc of MCP joint motion and ulnar deviation were measured, and an activities-of-daily-living questionnaire was completed by each patient at 19 months (mean) postoperatively. Mean total active arc of MCP joint motion showed statistical improvement from 21.6 degrees (range, 5 degrees-60 degrees) pre-operatively to 47.2 degrees (range, 15 degrees-84 degrees) postoperatively. The little finger gained the most improvement, with a 50.2 degree arc, showing that this regimen does not compromise flexion gains at this joint. Ulnar deviation improved from a mean of 30.4 degrees (range, 5 degrees-65 degrees) pre-operatively to 9.7 degrees (range, 0 degrees-30 degrees) postoperatively. These initial results reinforce the clinical impression that this alternating static splint regimen can be used as an effective alternative to the dynamic extension splint.     

Evaluation of the mouse TgTP6.3 tauGFP transgene as a lineage marker in chimeras

The mouse TgTP6.3 transgene, encoding a tauGFP fusion protein, is becoming widely used but has yet to be fully characterized and evaluated as suitable lineage marker. The aim of the present study was to investigate the phenotype of TgTP6.3(+/+) homozygotes and TgTP6.3(+/-) hemizygotes, characterize the expression of the TgTP6.3 transgene in different tissues and critically evaluate its use as a lineage marker. TgTP6.3(+/+) homozygotes died between embryonic day 14.5 and weaning, whereas TgTP6.3(+/-) hemizygotes were mostly viable and fertile but smaller than non-transgenic siblings. TgTP6.3 expression began in the late two-cell stage, persisted in most fetal and adult tissues and was uniformly expressed in many (but not all) tissues. TgTP6.3(+/-) cells were readily identified in many chimeric tissues and their contribution appeared to be quantitatively and spatially normal. Overall, tauGFP expression in hemizygous TgTP6.3(+/-) cells fulfils the main criteria of a good lineage marker for many tissues. It provides a useful lineage marker, which should be particularly suitable for axons, blood vessels and pre-implantation embryos.     

Corticostriatal-hypothalamic circuitry and food motivation: integration of energy, action and reward

Work over the past decade has supported the idea that discrete aspects of appetitive motivation are differentially mediated by separate but interacting neurochemical systems within the nucleus accumbens (Acb). We review herein a series of studies in rats comparing the effects of manipulating Acb amino acid, opioid, acetylcholine, and dopamine systems on tests of free-feeding and food-reinforced operant responding. Results from our laboratory and in the literature support three general conclusions: (1) GABA output neurons localized exclusively within the Acb shell directly influence hypothalamic effector mechanisms for feeding motor patterns, but do not participate in the execution of more complex food-seeking strategies; (2) enkephalinergic neurons distributed throughout the Acb and caudate-putamen mediate the hedonic impact of palatable (high sugar/fat) foods, and these neurons are under modulatory control by striatal cholinergic interneurons; and (3) dopamine transmission in the Acb governs general motoric and arousal processes related to response selection and invigoration, as well as motor learning-related plasticity. These dissociations may reflect the manner in which these neurochemical systems differentially access pallido-thalamo-cortical loops reaching the voluntary motor system (in the case of opioids and dopamine), versus more restricted efferent connections to hypothalamic motor/autonomic control columns (in the case of Acb shell GABA and glutamate systems). Moreover, we hypothesize that while these systems work in tandem to coordinate the anticipatory and consummatory phases of feeding with hypothalamic energy-sensing substrates, the striatal opioid network evolved a specialized capacity to promote overeating of energy-dense foods beyond acute homeostatic needs, to ensure an energy reserve for potential future famine.     

An update on master's degrees in medical education

Planning and implementing educational programs in medicine optimally requires a background in educational theory and practice. An avenue of training open to such practitioners is a master's degree in medical education. A single 1998 report lists the programs known at that time and information about them remains scarce. The authors have re-examined all current programs offering master's degrees in medical or health sciences education in the English-speaking world, including the Netherlands. The authors contacted the programs identified in the 1998 report to establish how many were still in operation. The search was extended using Pubmed and other search engines. A further verification targeted a selected sample of 10 prominent US medical schools. Twenty-one currently operating programs were identified: six in the US, eight in the UK, three in Canada, three in Australia and one in Holland. Seven of nine original master's programs were still in existence. URLs, website and other logistical information about each program are tabled. A master's degree in medical or health sciences education is the most specific method for medical faculty to obtain a credentialed grounding in educational theory and practice. The authors provide up-to-date contact information for current programs and summarize other related essential logistical data.     

Iron and vitamin A deficiency in long-term African refugees

Five cross-sectional surveys were conducted in African refugee camps to assess the level of iron deficiency anemia and vitamin A deficiency in populations dependent on long-term international food aid and humanitarian assistance. The prevalence of anemia in children [hemoglobin (Hb) <110 g/L] was high, with >60% affected in 3 of 5 camps. Iron deficiency [serum transferrin receptor (sTfR) >8.5 mg/L] was also high, ranging from 23 to 75%; there was also a strong ecological correlation between the prevalence of iron deficiency and anemia among different camps. Within camps, sTfR predicted the concentration of Hb with adjusted R(2) values ranging from 0.19 to 0.51. Although children were more affected, anemia was also a public health problem in adolescents and women. The effect of recent recommendations on Hb cutoff values for African populations was assessed and found to produce decreases in the prevalence of anemia of between 5 and 21%; this did not affect the public health categorization of the anemia problem within the most affected camps. Mean serum retinol in children, after adjustment for infection status, ranged from 0.72 +/- 0.2 to 0.88 +/- 0.2 micromol/L in the 4 camps assessed and vitamin A deficiency (<0.7 micromol/L) was present at levels ranging from 20.5 to 61.7%. In areas in which vitamin A capsule distribution programs were in effect, coverage ranged from 3.5 up to 66.2%. The high level of micronutrient deficiencies seen in long-term refugees argues in favor of further enhancements in food aid fortification and the strengthening of nutrition and public health programs.     

Shockwave lithotripsy: dose-related effects on renal structure, hemodynamics, and tubular function

BACKGROUND AND PURPOSE: Shockwave lithotripsy (SWL) predictably damages renal tissue and transiently reduces function in both kidneys. This study characterized the effects on renal function of a supraclinical dose of shockwaves (SWs) (8000) in porcine kidneys and tested the hypothesis that such excessive treatment would intensify and prolong the resulting renal impairment. MATERIALS AND METHODS: Pigs aged 6 to 7 weeks were anesthetized and assigned to one of three groups. Groups 1 (N=8) and 2 (N=6) each received 8000 SWs at 24 kV (Dornier HM3) to the lower-pole calix of one kidney. Group 3 (7 pigs) received sham treatment. Renal function was monitored for the first 4 hours after SW treatment in Group 1 and for 24 hours in Group 2. Plasma renin activity was measured in Groups 2 and 3. RESULTS: The renal lesions produced by 8000 SWs comprised 13.8%+/-1.4% of the renal mass. In the 4-hour protocol, this injury was associated with marked reduction of the glomerular filtration rate (GFR), renal plasma flow (RPF), and urinary sodium excretion in both kidneys, although fractional sodium excretion was reduced only in the shocked kidneys. In the 24-hour protocol, GFR and RPF remained below baseline in shocked kidneys at 24 hours. Evidence of progressive ischemic injury was noted in shocked tissue at 24 hours after SW treatment. CONCLUSIONS: These findings support the hypothesis that the severity of the renal injury caused by SWL is related to the number of SWs administered and demonstrate the connection in this relation between renal structure and function.     

Lipid-soluble 3-pyridinol antioxidants spare alpha-tocopherol and do not efficiently mediate peroxidation of cholesterol esters in human low-density lipoprotein

Because alpha-tocopherol (alpha-TOH) mediates the peroxidation of cholesterol-esterified lipids in human low-density lipoprotein (LDL) in vitro and has displayed disappointing results against the onset and development of atherosclerosis, it may not be appropriate for use as a therapeutic in the prevention and/or treatment of the disease. Herein are described the experimental results demonstrating that 3-pyridinols spare alpha-TOH, do not efficiently mediate lipid peroxidation, and protect lipoprotein tryptophan residues in human LDL.