Can moderate alcohol intake limit the size of myocardial infarction?

Several observational and epidemiologic analyses suggest that moderate drinking of alcohol (usually two drinks per day) may have beneficial effects on the heart. Specifically it may reduce the incidence of ischemic heart disease and improve the outcome after a myocardial infarction. The purpose of this study was to test the hypothesis that long-term, moderate consumption of alcohol has a direct cardioprotective effect, reducing myocardial infarct size in rats subjected to ischemia/reperfusion. Two groups of rats were given alcohol in their drinking water at concentrations of 15% or 36%; control rats received water (n = 10 for all groups). After 16 weeks of treatment, the rats were anesthetized and subjected to 60 min of coronary artery occlusion and reperfusion. The ischemic risk region (% LV) was not significantly different among groups. Infarct size (% risk zone) was 49+/-7%, 44+/-4%, and 50+/-8%, respectively (p = 0.79). Thus no significant differences in infarct size between control and alcohol-fed rats were observed. There was no correlation between alcohol level and infarct size in alcohol-treated rats (r = 0.20, p = 0.45). Arterial pressures were lower in the 36% group at baseline and throughout the study compared with the control and 15% groups, but heart rates were similar in all groups. Moderate consumption of alcohol failed to alter infarct size compared with control and thus it is unlikely that alcohol drinking has a direct myocardial-protecting effect on the outcome of ischemia and reperfusion.

Onset of puberty in heifers of diverse beef breeds and crosses.

Puberty traits of straightbred and crossbred heifers (n = 301) were evaluated under pasture conditions. Breed groups represented were straightbred Hereford and Red Poll, reciprocal crosses of these two breeds, Angus X Hereford, Angus X Charolais-Cross, Brahman X Hereford and Brahman X Angus. Breed group was an important (P less than .01) source of variation in heifer weights and in age at puberty. Straight-bred Red Poll and Red Poll cross heifers were youngest at puberty, Angus X Hereford and Angus X Charolais-Cross were intermediate, and straightbred Hereford and Brahman crosses were oldest at the onset of puberty. At the beginning of their first mating season at 19.5 mo of age, 96% of the straightbred Red Polls, 95% of Red Poll crosses, 81% of Angus X Herefords, 89% of Angus X Charolais-Crosses, 68% of straightbred Herefords, 48% of Brahman X Herefords and 74% of the Brahman X Angus had attained puberty. Results of a diallel analysis of Hereford-Red Pool matings indicated that maternal influence of the Red Poll breed was superior (P less than .01) to Herefords for body weight up to 24 mo of age and incidence of puberty at 11.5 mo. Red Polls also exceeded Herefords in direct effects for puberty percentage at 11.5, 15 and 19.5 mo of age. Heterosis was significant for puberty percentage and weight. Breed group differences in pregnancy rate at 24 mo were not significantly.

An ultrastructural study of the biocompatibility of poly(2-hydroxyethyl methacrylate) in bone.

Because of the unique properties for swelling in a fluid medium and variable modulus of elasticity, hydrophilic methacrylates may be of potential usefulness for implanting prosthetic devices in bone. To investigate the biocompatibility, electron micrographic studies were done on specimens of poly(2-hydroxyethyl methacrylate) imbedded in bone for varying periods of time. Ultrastructural examination revealed progressive ossification of surrounding connective tissue up to the tissue polymer junction over a 6 month period. There was no evidence of inflammatory response. Based upon this study, it would appear that bone adjusts to an implant of hydrophilic methacrylate by ossification to the implant junction. This supports continued studies into the usefulness of this material as an implant.