Salinity is a serious threat to freshwater ecosystems, particularly those near coastal areas. An increase in salinity producesdrastic changes in community structure of freshwaters, sometimes in an irreversible fashion. Thus, freshwater species must copewith salinity stress in a manner proportional to their degree of tolerance. Bearing this in mind, we studied the acute and chroniceffects of different salinity concentrations in two species of cladocerans: Daphnia magna Straus, a standard test organism, andDaphnia longispina O. F. Müller, an autochthonous species. Salinity experiments were based on successive dilutions of a stocksolution of NaCl in a synthetic medium. The results showed that D. magna is more tolerant than D. longispina, both in acute(EC50 5.9 and 2.9 g/L, respectively) and chronic (EC50 5.0 and 2.2 g/L, correspondingly) exposures. In the chronic exposure,salinity caused a significant reduction in fecundity and a developmental delay (increase in age at first reproduction), as well asa decrease in the growth rate of daphnids. However, these effects were mainly observed at salinity concentrations where mortalityoccurred.

This study evaluates the efficacy and systemic tolerability of licensed doses of mometasone furoate (Nasonex®) and betamethasone sodium phosphate (Betnesol®) in allergic chronic rhinosinusitis patients. It also assesses the diagnostic accuracy of morning salivary cortisol (MSC) concentrations to screen for adrenal suppression inthese patients.

Forty-eight patients were prospectively randomized to two treatment limbs. Symptom scores and adrenal function assessments were performed immediately prior to commencement and at the end of treatment.

One (4 per cent) mometasone furoate and 14 (58 per cent) betamethasone sodium phosphate patients developed biochemical evidence of adrenal suppression. There were statistically significant (p < 0.005) reductions in symptom scores following treatment, but no significant difference (p > 0.05) between the drug groups regarding post-treatment symptom scores. As a screening tool for iatrogenic adrenal suppression, MSC had a sensitivity of 100 per cent and a specificity of 97 per cent.

This study demonstrates the high risk of developing adrenal suppression secondary to betamethasone sodium phosphate therapy. The salivary cortisol assay is an accurate tool for monitoringadrenal function and is ideally suited to the out-patient setting.