The Effects of the Harmful Algal Bloom Species Karenia brevis on Survival of Red Porgy (Pagrus pagrus) Larvae.

The harmful algal bloom species, Karenia brevis, forms annual, often intense blooms in the Gulf of Mexico, particularly along the west Florida shelf. Though the ability of K. brevis blooms to cause mass mortalities in juvenile fish are well documented, the direct effect of bloom concentrations on larval fish has not been studied extensively. To better understand the potential effect of K. brevis on larval fish survival, laboratory spawned red porgy (Pagrus pagrus) larvae from 4-26 days post-hatch were exposed to concentrations of K. brevis observed in the field for either 24 or 48 h. This species is representative of fish which spawn in regions of the Gulf of Mexico and whose larvae are epipelagic and may encounter K. brevis blooms. In this study, three different K. brevis strains varying in the amount of brevetoxin produced were tested. Larval survivorship was found to be inversely proportional to the amount of brevetoxin produced by each strain. The EC50 value from the combined 24 h experiments was ~163,000 K. brevis cells L-1, which corresponds to cell concentrations found in moderately dense blooms. Larval mortality also increased substantially in the 48 h versus 24 h exposure treatments. These findings indicate K. brevis blooms have the potential to contribute to natural mortality of fish larvae and further reduce inter-annual recruitment of fishery species whose stocks in the Gulf of Mexico may already be depleted.

Contrast enhanced ultrasound characterization of surgically resected renal masses in patients on dialysis.

Objective: Diagnostic work-up of suspicious renal masses has traditionally been conducted with contrast-enhanced computed tomography (CECT) and/or magnetic resonance imaging (MRI). However, patients who are not candidates for intravenous contrast due to allergy, renal insufficiency, or those on dialysis are discouraged from utilizing traditional contrast imaging due to risks of anaphylaxis, nephrotoxicity, or further kidney damage. We evaluated contrast-enhanced ultrasound (CEUS) in patients on dialysis who would benefit from alternative imaging options to CECT or MRI.Methods: Following IRB approval, nine renal masses from eight patients (aged 54-74 years) with chronic renal insufficiency were evaluated with CEUS and shown to be enhancing after the intravenous administration of ultrasound contrast agent. The ultrasound contrast agent Lumason (Sulfur hexafluoride lipid type-A microspheres, Bracco Diagnostics, Monroe Township, NJ, USA) was utilized. Enhancement was considered present when microbubble contrast agent was visualized within the lesion of interest.Results: Nine CEUS enhancing masses were pathologically examined following laparoscopic radical nephrectomy. Eight of the nine lesions were renal cell carcinoma (two clear cell, four papillary, two cystic). One resected mass was an unspecified benign renal lesion.Conclusions: In this sample of surgically resected tumors, CEUS was effective in characterizing renal lesions as solid neoplasms or complex cystic lesions suspicious for neoplasm-findings which merit further investigation.