Input and leaching potential of copper, zinc, and selenium in agricultural soil from swine slurry.

Trace elements, such as copper, zinc, and selenium, used as feed additives were determined in samples of both fresh (N = 14) and anaerobically digested (N = 6) swine slurry collected on medium- to large-size farms in northeast Spain. Considering both fresh and anaerobically digested samples, mean concentrations of zinc (1,500 mg kg(-1) dry mass [dm]) were greater than those of copper (mean 239 mg kg(-1 )dm), and the selenium concentrations detected were even lower (mean 139 µg kg(-1) dm). Zinc concentrations were significantly greater in anaerobically digested samples, whereas no significant differences were found for copper or selenium. In addition, the leaching potential of zinc, copper, and selenium in cropped (lettuce heart) and uncropped experimental units subject to drip irrigation was assessed in a greenhouse experiment. Generally, the addition of swine slurry to soil (1.7 g kg(-1) dm) significantly increased zinc, copper, and selenium concentrations in leachates, which decreased in accordance with the volume of leachate eluted. Under the experimental conditions, the leaching potential of zinc and selenium was more strongly correlated with bulk parameters directly associated with the composition of the pig slurry (dissolved organic carbon, electrical conductivity, and ammonium), whereas copper mobility was more strongly associated with the crop root exudates. Although selenium has been shown to be mobile in soil, the selenium content found in the leachates did not pose any appreciable risk according to current drinking water standards.

IgG class antibodies to heat shock-induced streptococcal antigens in psoriatic patients.

BACKGROUND: Psoriasis is a chronic inflammatory skin disease. Probably autoimmune in nature, and associated with streptococcal throat infections as a triggering factor. Although many groups have associated the disease with other pathogens, Streptococcus pyogenes seems to be the most important microorganism related to this disease. Therefore, it is necessary to identify the streptococcal antigens involved in the process. METHODS: In this work IgG class antibodies to soluble antigens obtained from Staphyloccus aureus, Candica albicans or S. pyogenes before and after heat shock induction, were analyzed by ELISA in 28 psoriatic patients and 30 healthy donors. RESULTS: In all cases, the patients and the controls had IgG class antibodies to the four antigens. Nevertheless, the IgG levels to the heat shock-induced S. pyognes were statistically different between the patients and the controls (P < 0.001). There was no difference between the groups when the IgG antibodies to the other antigens, including the noninduced streptococcal extract, were analyzed. Additionally, anti-streptolysin O titers and throat cultures were carried out in all patients and controls. No differences between ASO titers were found but the patients were more frequently colonized by pyogenes. CONCLUSION: Results obtained in this study suggest that heat shock-induced proteins from S. pyogenes are associated with psoriasis.

Prevalence of rheumatoid arthritis in Tucumán, Argentina.

OBJECTIVE: To ascertain the prevalence of rheumatoid arthritis (RA) in Tucumán, Argentina. METHODS: The study was conducted between January 1, 1998, and December 31, 1999, in Tucumán province in northwest Argentina. Outpatient and hospitalization medical records for all patients with RA aged > or = 16 years were reviewed. Diagnosis was by 1987 American College of Rheumatology (ACR) criteria for RA and the population data were based on the 1991 national census. Prevalence rates, with 95% CI, were calculated using the number of San Miguel de Tucumán residents who fulfilled the 1987 ACR criteria for RA as numerator, and the city population aged > or = 16 as denominator. Crude and age-specific prevalence rates were calculated as number of cases/1,000 inhabitants. RESULTS: We identified 695 cases of RA. Sex-specific and overall prevalence rates (per 1,000) were 1.97 (95% CI 1.8-2) for all, 0.6 (95% CI 0.49-0.73) for men, 3.2 (95% CI 2.9-3.5) for women. CONCLUSION: Prevalence of RA is low in residents of Tucumán, Argentina, and comparable with rates observed in epidemiological surveys from Southern European countries.