Acute toxicity and bioaccumulation of aqueous and sediment-bound metals in the estuarine amphipod Melita plumulosa.

The sensitivities of juvenile and adult amphipods to metals (Cd, Cu, Ni, Pb, and Zn) in whole sediment and water-only exposures were compared using a newly developed acute test with the estuarine species Melita plumulosa. Endpoints included survival and bioaccumulation in adults, and survival and growth (body length) in juveniles over 96 h water-only and 10 day sediment exposures. Juveniles were more sensitive than adults to metals, either bound to sediments or in the aqueous phase. Although LOEC values for copper and zinc in juvenile whole-sediment tests (820 and 2290 mg/kg dry weight, respectively) were high in comparison with interim sediment quality guideline values for individual metals (270 and 410 for copper and zinc respectively), they were generally within the range of concentrations found in contaminated sediments in local estuaries. Accumulation of metals, together with the low porewater metal concentrations in whole-sediment tests, indicated that the ingestion of sediment is an important source of zinc and copper and cause of toxicity in this species.

A study on Lu-null families in South Wales.

Red cells of 75614 blood donors in South Wales were screened with anti-Lu(b) revealing 54 Lu(b-) donors of which 15 were also Lu(a-) giving a frequency of 0.0002 for the Lu(a-b-) phenotype in South Wales. The families of 11 Lu-null propositi were investigated to determine which of the three known genetic backgrounds, dominant, recessive or X-linked recessive, was responsible for their Lu-null phenotype. In 10 of the 11 families the Lu-null phenotype was caused by the dominant suppressor gene In(Lu). The first reported family demonstrating independence of In(Lu) and LU, through the Au groups, is described together with the third family demonstrating suppression of P1 by In(Lu). The families showed that In(Lu) is not closely linked to HLA. The genetic background for the 11th propositus was not determined; homozygosity of the silent allele LU is a possible but unproved explanation.

Application of a microtitre plate antiglobulin technique to determine the incidence of donors lacking high frequency antigens.

Approximately 65,000 random blood donors have been screened by a microtitre low ionic strength saline antiglobulin technique over a 12-month period. Antisera to high frequency antigens including: Vel, Lub, k, Kpb, Yta and Era were used. Additional sera including: anti-Lan, -Coa, -Sc1 and an antibody to an unidentified high frequency antigen, Mrs C.A., have been used as they became available. This has enabled the approximate frequencies of donors lacking the corresponding antigen, to be calculated.