Absorption of light by water in the region of high transparency: recommended values for photon-transport calculations.

Prompted by data requirements for photon-transport simulation, we have surveyed measurements of the absorption coefficient of light by water in the wavelength range 171-2000 nm, covering the whole region where the absorption length exceeds 1 mm. Absorption spectra were compiled for pure water, clean seawater, and seawater containing a moderate amount of organic matter. The intensive and detailed nature of the laboratory and at-sea observations leading to the pure-water and clean-seawater spectra lend confidence to these results.

Factor VIII complex in uraemia and effects of haemodialysis.

Levels of the factor VIII complex were found to be raised in patients with chronic renal failure and further raised by regular dialysis. Increased fibrinogen concentrations were also found. These results suggest the existence of a prothrombotic state in uraemia that is exacerbated by haemodialysis.

Platelet protection and heparin sparing with prostacyclin during regular dialysis therapy.

When prostacyclin (5 ng kg-1 min-1) was given during dialysis it enhanced the biological activity of heparin and prevented the activation and consumption of platelets. No adverse effects were observed. The reduction in heparin requirements produced by prostacyclin should make dialysis, safer, particularly for patients at risk of bleeding, while preserving the biocompatibility of the dialysis circuit.