CMAJ : Canadian Medical Association journal = journal de l'Association medicale canadienne
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Hyponatremia (serum sodium level less than 134 mmol/L) is a common electrolyte disturbance. Its high prevalence and potential neurologic sequelae make a logical and rigorous differential diagnosis mandatory before any therapeutic intervention. A history of concurrent illness and medication use as well as the assessment of extracellular volume status on physical examination may provide useful clues as to the pathogenesis of hyponatremia. ⋯ A urine osmolality value of less than 100 mOsm/kg indicates complete and appropriate suppression of antidiuretic hormone secretion. A urine sodium level less than 20 mmol/L is indicative of hypovolemia, whereas a level greater than 40 mmol/L is suggestive of the syndrome of inappropriate antidiuretic hormone secretion. Levels of hormones (thyroid-stimulating hormone and cortisol) and arterial blood gases should be determined in difficult cases of hyponatremia.
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The demographic and socioeconomic profile of medical school classes has implications for where people choose to practise and whether they choose to treat certain disadvantaged groups. We aimed to describe the demographic and socioeconomic characteristics of first-year Canadian medical students and compare them with those of the Canadian population to determine whether there are groups that are over- or underrepresented. Furthermore, we wished to test the hypothesis that medical students often come from privileged socioeconomic backgrounds. ⋯ Canadian medical students differ significantly from the general population, particularly with regard to ethnic background and socioeconomic status.
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Comparative Study
Current and former marijuana use: preliminary findings of a longitudinal study of effects on IQ in young adults.
Assessing marijuana's impact on intelligence quotient (IQ) has been hampered by a lack of evaluation of subjects before they begin to use this substance. Using data from a group of young people whom we have been following since birth, we examined IQ scores before, during and after cessation of regular marijuana use to determine any impact of the drug on this measure of cognitive function. ⋯ Current marijuana use had a negative effect on global IQ score only in subjects who smoked 5 or more joints per week. A negative effect was not observed among subjects who had previously been heavy users but were no longer using the substance. We conclude that marijuana does not have a long-term negative impact on global intelligence. Whether the absence of a residual marijuana effect would also be evident in more specific cognitive domains such as memory and attention remains to be ascertained.