Associations between age or sex and prevalence of gastric ulceration in Standardbred racehorses in training

OBJECTIVE: To determine associations between age, sex, or medical treatment and prevalence and severity of gastric ulceration in Standardbred racehorses in training. DESIGN: Cross-sectional study. ANIMALS: 224 Standardbred racehorses in training. PROCEDURE: Gastroscopy was performed on each horse, and mucosal ulceration was graded from 0 (normal mucosa, no lesions) to 3 (extensive, often coalescing, lesions with areas of deep ulceration). Associations between age, sex, or treatment and prevalence and severity of ulcers were evaluated. RESULTS: Prevalence of gastric ulceration was 87%. Although there was little association between age and prevalence of ulcers, there was an association between age and severity of ulcers. Most 2-year-old horses (57.7%) had an ulcer score of 0 or 1. In all other age groups, most (58% to 82.61%) of horses had an ulcer score of 2 or 3. Although overall prevalence of ulceration was comparable among sex groups, the relative risk for gastric ulceration increased with age in castrated males, whereas it decreased in females and sexually intact males. CONCLUSIONS AND CLINICAL RELEVANCE: Gastric ulceration is common in Standardbred horses in race training. Severity is higher in horses > or = 3 years of age than in 2-year-old horses. Relative risk for ulceration increases with age in castrated males.     

Temporal,environmental and management factors influencing the epidemiological patterns of sea lice (Lepeophtheirus salmonis) infestations on farmed Atlantic salmon (Salmo salar) in Scotland

In association with industry, an extensive database has been established on measurements of sea louse counts on farmed Atlantic salmon for the years 1996 to 2000 from 33 Scottish fish farms. These data include extensive counts on the sea louse species, Lepeophtheirus salmonis, at various stages of the life cycle and in particular the chalimus and mobile stages. There has been considerable speculation as to what factors might affect the abundance of sea lice, much of which is based on limited evidence. Our analyses show that there is tremendous variation in sea louse infestation patterns from year to year, whereas stock type, geographical region and coastal exposure do not appear to affect mean levels of abundance. In contrast, treatments lead to pronounced cycles of sea louse infestation with peaks and troughs at 3-week intervals, and these interventions are important if the sea louse levels on fish are to be controlled. There was no evidence of water temperature affecting the mean annual abundance of sea louse infestation.     

Empirical relationships between land use/cover and estuarine condition in the Northeastern United States

Land–water interactions were examined in three regions in the Virginian Biogeographic Province; the southern shore of Cape Cod, Massachusetts; the Hudson/Raritan region of New York; and the eastern shore of the Delmarva (Delaware/Maryland/Virginia) Peninsula. Cumulative distribution functions were used to evaluate similarity in environmental condition among estuaries. Spatial-setting variables (location in a river, coastal lagoon, or in open waters) were associated with variation for some measures of estuarine condition. Patterns of coastal urban and agriculture gradients were measured and their relationship with indicators of estuarine condition was modeled statistically. When estuaries were pooled, the highest variation explained by spatial-setting variables was found for dissolved oxygen (DO, R ² = 0.44) and salinity (R ² = 0.58), with DO decreasing in river locations and salinity decreasing with rainfall and sampling locations near rivers. The explanatory power for the other indicator variables was low and varied from 6% to 27%. Rainfall explained some of the variation (R ² = 0.23) in total suspended solids. Moderate (0.4 < | r | < 0.7) to strong (| r | ≥ 0.7) linear associations were found between total urban area and measures of estuarine condition. Within regions, total urban area was positively associated with Silver (r = 0.59), Cadmium (r = 0.65), and Mercury (r = 0.47) in Cape Cod, and inversely related to DO (r = −0.65) in the Hudson/Raritan region. No associations were found in the Delmarva Peninsula study area. Total area of agriculture showed a moderate association with Arsenic in Cape Cod, but no other associations were found in the other two regions. Our analyses show a measurable impact of urban land use on coastal ecosystem condition over large areas of the northeastern United States. This pattern was most evident when many different landscapes were considered simultaneously. The relationship between urban development and estuarine condition were weaker within the individual regions studied. The use of land use/cover models for predicting estuarine condition is a challenging task that warrants enhancements in the type, quantity, and quality of data to improve our ability to discern relationships between anthropogenic activities on land and the condition of coastal environments.     

Reduction of Salmonella typhimurium concentration in broiler chickens by milk or whey

Whey (5%) in the feed of chicks for the first 10 days of life reduced the mean log10 number of viable S. typhimurium from 5.68 in control chickens to 3.38 in whey-fed chickens. Lactose in drinking water or reconstituted dry milk (5% wt: vol) in drinking water reduced the mean log10 number of S. typhimurium to 2.60 and 2.11, respectively. Milk (5% wt: wt) in feed was not effective in reducing S. typhimurium colonization. The lack of effect of milk in the feed is believed to be because not enough lactose was provided at the 5% (wt: wt) concentration. Lactose in whey or nonfat dried milk offers alternatives to the use of pure lactose in preventing or lowering S. typhimurium numbers in young broiler chickens.     

Clinical trial stirs legal battles

A lawsuit filed in federal court in Atlanta, Georgia, in February 1982 by two private ophthalmologists and seven prospective patients charges a group of academic physicians with attempting to monopolize radial keratotomy, a surgical procedure for correcting myopia, by labeling it experimental and urging restraint in its use. The parties have agreed to a settlement involving a payment of $250,000 by the defendants and a statement that the procedure is effective in qualified patients and should no longer be considered experimental. A second suit, brought by nine physicians in federal court in Chicago in June 1984, accuses the American Academy of Ophthamology of attempting to control the procedure. The broader issue at stake is how new surgical prdocedures should be evaluated before they are brought into widespread use. In the case of radial kerototomy, a large-scale clinical trial funded by the National Eye Institute is proceeding as planned despite the legal controversy.     

A study of the bonding forces between the epithelial cells surrounding the resin canals of slash pine (Pinus elliottii Engelm.) holocellulose

Summary Although the bonds between the cellular components of pine epithelia (isolated from holocellulose) can be strengthened by the addition of multivalent ions such as those of calcium, iron, uranium, etc., it was observed that these bonds are only weakened and not destroyed by the removal of the ions from the tissues. Reagents, such as KOH and K₂SO₄, which do not yield soluble calcium salts, do not cause a discernible weakening of the bonds between the cellulose components of epithelia pretreated with Ca ion. Washing the weakened epithelia with water causes them to swell. The separation of epithelial cells occurs only after the application of mechanical forces to the tissues. Electron microscopic examination of the swollen and unswollen tissues shows that fibrils and lamellae extend between the individual cells which must be destroyed by mechanical action before cell separation can occur. The swelling of the tissues by washing after removal of multivalent ions was attributed to the expansion of electrical double layers and to the increasing osmotic pressure from the increasing Donnan potential, while the difference in swelling as a result of HCl treatment vs. KCl and K₄Fe(CN)₆ was attributed to differences in charge development and to hydrogen bonding between acidic components. The restrengthening of the tissue as a result of the readdition of multivalent ion was attributed to the collapse of the electrical double layers and the reduction of the Donnan potential, with the re-forming of bonds between the components of the epithelia. Evidence suggesting that multivalent ions actually participate in bonding was obtained and although the nature of the bonding cannot be determined, both salt formation and complex formation between the ions and the components of the tissues is suggested.