Piscinoodinium, a fish-ectoparasitic dinoflagellate, is a member of the class dinophyceae, subclass gymnodiniphycidae: convergent evolution with Amyloodinium.

All dinoflagellates that infest the skin and gills of fish have traditionally been placed within the class Blastodiniphyceae. Their relatedness was primarily based upon a similar mode of attachment to the host, i.e., attachment disc with holdfasts. Results of recent molecular genetic analyses have transferred these parasites, including Amyloodinium, to the class Dinophyceae, subclass Peridiniphycidae. In our study, a small subunit rDNA gene from a parasitic dinoflagellate that has features diagnostic for species in the genus Piscinoodinium, i.e., typical trophont with attachment disc having rhizocysts, infesting the skin of freshwater tropical fish, places this organism within the dinophycean subclass Gymnodiniphycidae. This suggests a close relationship of Piscinoodinium spp. to dinoflagellates that include symbionts, e.g., species of Symbiodinium, and free-living algae, e.g., Gymnodinium spp. These molecular and morphological data suggest that evolution of this mode of fish ectoparasitism occurred independently in 2 distantly related groups of dinoflagellates, and they further suggest that the taxonomic status of parasites grouped as members of Piscinoodinium requires major revision.

Long-Term Treatment with Oral Torsemide and Its Effect on Body Weight and Fluid Balance in Patients with Chronic Renal Insufficiency.

Long-term treatment with oral torsemide was studied to determine its effectiveness in maintaining steady-state fluid balance in patients with chronic renal insufficiency by using a placebo-controlled, double-blind, random-off design. Patients with stable chronic renal insufficiency were initially titrated and then stabilized on torsemide. Once stabilized on torsemide, patients were randomly assigned in a double-blind fashion to continue on their titrated dose of torsemide or to receive a placebo. Of the 82 patients enrolled in the study, 68 were randomized to torsemide (n = 34) or placebo (n = 34). Patients who received the placebo showed a significantly greater (p < 0.001) mean increase in body weight (3.55 lb) than did patients who remained on torsemide (0.46 lb). Approximately two-thirds of the weight gain observed in the placebo group occurred during the first 3 days after randomization. Patients continued to receive treatment unless they developed fluid accumulation that was considered deleterious to their clinical state as determined by the investigator. In the placebo group a greater number of patients discontinued treatment because of weight gain or fluid accumulation. The mean number of days on treatment after randomization was significantly higher (p < 0.001) for patients who received torsemide (26 days) than for patients who received the placebo (16 days). The lack of weight gain in the torsemide group was associated with a higher percentage of patients who showed no change or an improvement in peripheral edema status (79%) than in placebo patients (35%). No patient was withdrawn from the study because of hyperkalemia or hypokalemia. The adverse effects reported during the study were as anticipated for patients with chronic renal insufficiency that is often complicated by other underlying illnesses.