Water quality in a lagoon in the southeast pampa region of Argentina.

This work evaluates the chemical and bacteriological qualities of the recreational waters of the Sauce Grande lagoon (Argentina). Samples were taken between March 2002 and December 2003. Ninety-six samples from three sampling stations were analyzed in order to determine the density of aerobic heterotrophic microorganisms, the presence of sulphite-reducing clostridia, and the most probable number of total coliforms, E. coli, fecal enterococci and P. aeruginosa. The water pH, temperature and chemical composition (N-NO3-, PO4(3-), Na+, Ca(++) +Mg++, EC and SAR) were also determined. Statistical analysis shows an increase in the microbial parameters of fecal pollution and in the population of heterotrophic microorganisms during the warmest months, influenced by higher temperatures and the more intensive recreational use. Bacterial count indicated that fecal pollution was statistically lower at the recreational area monitoring station; however, P. aeruginosa, an opportunistic pathogen, was present in higher than permitted densities in all determinations. These results show that, from the physico-chemical point of view, anthropogenic activities do not significantly affect the quality of the resource.

Water quality in a lagoon in the southeast pampa region of Argentina / Calidad del agua en una laguna del sudeste pampeano (Argentina)

This work evaluates the chemical and bacteriological qualities of the recreational waters of the Sauce Grande lagoon (Argentina). Samples were taken between March 2002 and December 2003. Ninety-six samples from three sampling stations were analyzed in order to determine the density of aerobic heterotrophic microorganisms, the presence of sulphite-reducing clostridia, and the most probable number of total coliforms, E. coli, fecal enterococci and P. aeruginosa. The water pH, temperature and chemical composition (N-NO3-, PO4³-, Na+, Ca++ +Mg++, EC and SAR) were also determined. Statistical analysis shows an increase in the microbial parameters of fecal pollution and in the population of heterotrophic microorganisms during the warmest months, influenced by higher temperatures and the more intensive recreational use. Bacterial count indicated that fecal pollution was statistically lower at the recreational area monitoring station; however, P. aeruginosa, an opportunistic pathogen, was present in higher than permitted densities in all determinations. These results show that, from the physico-chemical point of view, anthropogenic activities do not significantly affect the quality of the resource.

En el presente trabajo se evaluó la calidad bacteriológica y química en aguas de la laguna Sauce Grande (Argentina). Los muestreos fueron realizados entre marzo de 2002 y diciembre de 2003. Se analizaron un total de 96 muestras provenientes de tres estaciones de monitoreo, determinando: densidad de microorganismos heterótrofos mesófilos, presencia de clostridios sulfito-reductores y número más probable de coliformes totales, Escherichia coli, enterococos fecales y Pseudomonas aeruginosa. También se efectuaron determinaciones de pH, temperatura del agua y composición química (N-NO3-, PO4(3-), Na+, Ca++ + Mg++, CE y RAS). Se observó que en los meses más cálidos se produjo un aumento en los parámetros microbianos indicadores de contaminación fecal y en la población de microorganismos heterotrófos; dicho comportamiento estaría influenciado por el aumento de la temperatura y el mayor uso recreativo del recurso. El recuento de bacterias indicadoras de contaminación fecal fue menor en la estación de monitoreo donde se encuentra ubicado el balneario; no obstante, P. aeruginosa, patógeno oportunista, estuvo presente en todas las determinaciones con densidades mayores a los valores permitidos. Desde el punto de vista fisicoquímico, no hay un aporte antropogénico significativo de contaminantes que afecten la calidad del recurso.

[Dynamics of bacteria from the phyllosphere and leaves of soy (Glycine max L. Merrill) in field conditions]. / Dinámica de las bacterias de la filosfera y hojarasca de soja (Glycine max L. Merrill) en condiciones de campo.

The surfaces of aerial plant provide a habitat for epiphitic microorganisms many of which are capable of influencing the growth of pathogens. In this study, fluctuation of bacterial population occurring in different growth stages of soybean leaves (Glycine max L Merrill) was examined using the dilution plate method. Three culture media were applied; invariably, the numbers of bacteria increased with increasing plant age. The total number of bacteria living on the detached leaves were ten times higher than leaves surfaces of soybean Asgrow 3127 (Group III). One hundred and seventy-five heterotrophic bacteria were obtained from both the phyllosphere and litter of the plant. Of these, fifty-one microorganisms (29%) were classified as members of the genus Bacillus; the remainder were mainly members of the irregular, nonsporing, Gram positive rods (coryneform bacteria). Approximately 52% of the total coryneform bacteria isolated was found to belong to the following two clusters: Arthrobacter and Corynebacterium. There were few Pseudomonas strains and 75% of the total isolated bacteria were able to grow in N-poor culture medium.

The angiotensin II type 1 receptor blocker losartan in clinical practice: a review.

Blockade of angiotensin II receptors was first achieved in the 1970s using a peptide, saralasin acetate. Although it was effective in lowering blood pressure, it required parenteral administration and had a short duration of action and partial agonist activity. These disadvantages are absent with losartan, a selective, orally administered, nonpeptide blocker of the angiotensin II type 1 receptor that recently became available for clinical use. Losartan has a sustained duration of action, permitting once-daily dosing in many patients, and lacks partial agonist activity. More than 3300 hypertensive patients have received losartan in Phase III, controlled clinical trials. Losartan given concomitantly with a low dose (12.5 mg) of hydrochlorothiazide further reduces blood pressure. Its overall incidence of adverse experiences is similar to that of placebo. Because of its efficacy, specificity, duration of action, and safety profile, losartan should be considered as first-line therapy for the treatment of patients with hypertension.