CONTEXT: The section of a research article most likely to be read is the abstract, and therefore it is particularly important that the abstract reflect the article faithfully. OBJECTIVE: To assess abstracts accompanying research articles published in 6 medical journals with respect to whether data in the abstract could be verified in the article itself. DESIGN: Analysis of simple random samples of 44 articles and their accompanying abstracts published during 1 year(July 1, 1996-June 30, 1997) in each of 5 major general medical journals (Annals of Internal Medicine, BMJ, JAMA, Lancet, and New England Journal of Medicine) and a consecutive sample of 44 articles published during 15 months (July 1, 1996-August 15, 1997) in the CMAJ. MAIN OUTCOME MEASURE: Abstracts were considered deficient if they contained data that were either inconsistent with corresponding data in the article's body (including tables and figures) or not found in the body at all. RESULTS: The proportion of deficient abstracts varied widely (18%-68%) and to a statistically significant degree (P<.001) among the 6 journals studied. CONCLUSIONS: Data in the abstract that are inconsistent with or absent from the article's body are common, even in large-circulation general medical journals.

Abstracting and Indexing↗

PubMedDate not supplied

Maternal and fetal plasma levels of 3-methylhistidine in pregnant nonhuman primates.

Available data indicate little reutilization of 3-methylhistidine (3-MH) in the rat and man. These data led to the use of urinary 3-MH excretion as a measure of muscle protein catabolism in those animal species. However, 3-MH excretion does not accurately measure protein catabolism in the sheep, pig, and rabbit. This is due, at least in part, to the fact that renal amino acid (AA) transport systems reabsorb 3-MH from the glomerular filtrate. The monkey differs from man in that its plasms contains significant quantities of 3-MH, suggesting an active renal transport system for this AA. The present study measured maternal and fetal plasma 3-MH levels in 33 pregnant rhesus monkeys to determine whether the non-human primate placenta contained transport sites concentrating this AA to the fetal plasma. Mean fetal plasma 3-MH concentrations were 16.4 +/- 6.71 micrometers/100 ml, while maternal levels were 9.45 +/- 3.69 micrometers/100 ml. The fetal to maternal gradient was maintained between 1.6 to 1.7 during the course of maternal infusions of various AA. Since placental AA transport systems are similar to those in the kidney and intestine, the data also suggest the presence of AA transport systems for 3-MH in the monkey, indicating that urinary 3-MH excretion would be a poor method for measuring muscle protein catabolism in this species.

Animals↗

PubMedDate not supplied

Nutritional requirements in normal pregnancy.

Additional intakes of virtually all nutrients are needed for the support of pregnancy. Energy requirements average 300 kcal/day above nonpregnant needs, which should provide for a weight gain of 400 g/wk during the last two trimesters. Total protein intake of 1.3 g/kg/day is recommended for the adult gravida. Gestational needs for iron and perhaps for folacin cannot be met by the usual diet and supplementation is advised. Other nutrients, although needed in increased amounts, can be provided by a well-balanced diet.

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