The effects of the contemporary-use insecticide (fipronil) in an estuarine mesocosm.

To examine the effects of environmentally realistic fipronil concentrations on estuarine ecosystems, replicated mesocosms containing intact marsh plots and seawater were exposed to three treatments of fipronil (150, 355, and 5000 ng/L) and a Control. Juvenile fish (Cyprinidon variegatus), juvenile clams (Mercenaria mercenaria), oysters (Crassostrea virginica), and grass shrimp (Palaemonetes pugio) were added prior to fipronil in an effort to quantify survival, growth, and the persistence of toxicity during the planned 28-day exposure. Results indicated that there were no fipronil-associated effects on the clams, oysters, or fish. Shrimp were sensitive to the highest two concentrations (40% survival at 355 ng/L and 0% survival at 5000 ng/L). Additionally, the highest fipronil treatment (5000 ng/L) was toxic to shrimp for 6 weeks post dose. These results suggest that fipronil may impact shrimp populations at low concentrations and further use in coastal areas should be carefully assessed.

Anti-D in a D-positive renal transplant patient.

BACKGROUND: The detection of anti-D in a D-positive renal transplant recipient is unusual and may arise by several potential mechanisms. These include passive transfer of alloantibody and the presence of autoanti-D or alloanti-D that is due to microchimerism when the allograft is from a D-negative donor. In the latter case, overt hemolysis has been seen or suspected. The occurrence of anti-D in a D-positive renal transplant recipient without hemolysis, which is most likely attributable to microchimerism, is reported. CASE REPORT: A 51-year-old group O, D-positive woman, who was serologically HLA type A1, A2; B8, B44; DR3, DR6, DR52; DQ1, DQ2, underwent the transplantation of a kidney from a cadaveric donor who was serologically HLA type A1, A2; B8, B44; DR13, DR17, DR52; DQ1, DQ2. The donor was known to be D-negative and immunized to D. No blood components or derivatives were administered at the time of organ graft. Ten weeks after the transplant, the direct antiglobulin test was positive in the recipient, and anti-D was eluted. Polymerase chain reaction amplification using primers to distinguish DR13 (donor) from DR14 alleles (recipient split of DR6) in the peripheral blood showed the recipient to be DR14. No DR13 could be detected, and thus microchimerism could not be confirmed. However, in the peripheral blood, GM and KM allotyping of the serum (GM A,F,X B,G and KM 1,3) and eluate (G1M F, KM 3) showed a pattern of allotypes most consistent with an alloantibody. Eleven months after transplantation, the graft continued to function; the direct antiglobulin test was still positive, and elution of anti-D persisted. CONCLUSION: This case of anti-D in a D-positive renal transplant recipient is attributed to microchimerism, despite the lack of confirmation by genotypic analysis of the peripheral blood. It raises the possibility that microchimerism may be a more common phenomenon in solid allograft recipients than is realized.