Binge drinking and bone metabolism in a young actively growing rat model.

BACKGROUND: Chronic alcohol consumption has been demonstrated to be deleterious to bone health. However, binge drinking is the prevalent form of drinking in young people, which was the impetus for the present study to determine the effect of week-end and week-long binge drinking on bone health in a young actively growing animal model. METHODS: Four-week-old, female, Sprague-Dawley rats were given the amount of 5% alcohol by gavage to be equivalent to a 63 kg woman drinking six beers a day for either 2 or 5 consecutive days per week. RESULTS: There were no changes in the 5-day binge animals, but the 2-day binge animals were hypocalcemic. Similarly, 2-day binge animals had slightly increased bone chemistry and histomorphometric values for both tibia and femur, but only femur length, dry weight, and ash weight as well as femur density, presented either as g/ml or ash weight per unit volume, were increased by a statistically significant level. Cross-section periosteal Mineral Apposition Rate (MAR) was significantly decreased in the 2-day alcohol fed animals. CONCLUSIONS: Actively growing rats given 5% alcohol by gavage for 2 days per week have an increased bone length, bone weight, and bone density. The interpretation of these results must be viewed with great caution because studies of chronic alcohol consumption, and many studies of acute drinking, clearly indicate deleterious effects of alcohol on bone health. Those fed alcohol for 5 days per week showed no change.

Microaggregations of oceanic plankton observed by towed video microscopy.

Oceanic plankton have been hypothesized to occur in micropatches (<10 meters) that can have a large impact on marine ecosystem dynamics. Towed video microscopy was used to unobtrusively determine distributions of oceanic plankton over a continuum of scales from microns to hundreds of meters. Distinct, taxa-specific aggregations measuring less than 20 centimeters were found for copepods but not for nonmotile (cyanobacterial colonies) or asexual (doliolid phorozooids) forms, which suggests that these small patches are related to mating. Significant patchiness was also found on larger scales and was correlated among taxa, indicating physical control. These video observations provide new insights into basic plankton ecology by allowing quantitative assessment of individual plankton in their natural, undisturbed state.