Crescentic glomerulonephritis with positive antineutrophil cytoplasmic autoantibody specific for myeloperoxidase associated with autoimmune hemolytic anemia and thrombocytopenic purpura.

A 41-year-old woman was admitted to the hospital with severe uremia, hemolytic anemia, and thrombocytopenic purpura. Emergency hemodialysis with plasmapheresis was started in view of consideration of hemolytic uremic syndrome (HUS), which resulted in improvement of renal function and platelet count. Positive antineutrophil cytoplasmic autoantibody specific for myeloperoxidase (MPO-ANCA) suggested crescentic glomerulonephritis, which was pathologically evidenced by renal biopsy. The diagnosis of MPO-ANCA associated crescentic glomerulonephritis with autoimmune hemolytic anemia (AIHA) and thrombocytopenic purpura were confirmed. Three courses of steroid pulse therapy with heparin were successfully performed, followed by oral prednisolone and warfarin. Such a case has not been previously reported to our knowledge.

Improved sensitivity and decreased sample size in a cytotoxicity test for biomaterials: a modified colony microassay using a microplate and crystal violet staining.

Modified Eagle's minimum essential medium supplemented with 5% fetal calf serum was highly sensitive to cytotoxicity and formed large control colonies in the V79 colony assay. A highly sensitive cytotoxicity test was developed using 96-well microtiter plates. Test chemicals or extracts of polyurethane materials containing the same chemicals were added 24 h after inoculation of cell suspensions. The cells were fixed and stained with crystal violet after additional culture for 6 days (V79 cells) or 10 days (Balb/3T3 cells). In terms of sensitivity and rapid quantitative measurement, this modified colony microassay, using a low cell density in 96-well microplates, was superior to various cytotoxicity tests such as colony, growth inhibition, cytolethality, and agar diffusion assays.

Rabbit eye irritation caused by wearing toxic contact lenses and their cytotoxicities: in vivo/in vitro correlation study using standard reference materials.

To clarify the relationship between eye irritancy and cytotoxic potential induced by irritant materials, we made lenses coated with standard reference materials (SRMs) prepared from various amounts of zinc diethyldithiocarbamate (ZDEC) and polyurethane (PU). Zinc diethyldithiocarbamate was classified as a mild irritant by the Draize eye irritation test. When ZDEC-SRM coated contact lenses were applied to rabbit eyes, Draize scores increased in proportion to both the ZDEC and PU concentrations used for coating. Furthermore, correlation with the cytotoxic potential (gamma = -0.93) was better than with lactate dehydrogenase (LDH) activities of tears from rabbit eyes wearing these coated lenses (gamma = 0.78). In conclusion, in vivo eye irritancy induced by wearing lenses could be estimated quantitatively with the cytotoxic potentials using a colony assay. Furthermore, we could compare different sensitivities caused by the same set of SRMs among three different sites of tissue. As a result, the order of sensitivity was eye > muscle >> skin.