The Stockholm classification of stillbirth consists of 17 diagnostic groups allowing one primary diagnosis and if needed, associated diagnoses. Diagnoses are subdivided according to definite, probable and possible relation to stillbirth. Validation showed high degree of agreement regarding primary diagnosis. The classification can provide a useful tool for clinicians and audit groups when discussing cause and underlying conditions of fetal death.

The distribution of alpha and pi class glutathione transferases in autopsy and biopsy samples of normal human tissues was investigated by immunohistochemistry. The class alpha glutathione transferases exhibited restricted distribution. Intensive staining was visible in all hepatocytes, in kidney proximal tubular cells, in the zona reticularis of adrenal cortex and in Leydig cells of testis. Staining of lesser intensity could also be observed in the gastrointestinal epithelium, exocrine pancreas and some bile and pancreas ducts. In colon and gall bladder only nuclei were stained, but in the other tissues both nuclei and cytoplasm contained alpha class glutathione transferases. Glutathione transferase pi exhibited a more general distribution and could be observed in epithelia of the respiratory, gastrointestinal and urinary tracts, in all endocrine cells investigated, and also in the exocrine glands of prostate, in smooth muscle, adipocytes, blood vessel endothelium and placenta. It was also visible in the Schwann cells of peripheral nerves and in the choroid plexus. In gall bladder and colon only nuclei were stained, while in the intrahepatic bile ducts only cytoplasm was stained. All other positive cells exhibited glutathione transferase pi in both nuclei and cytoplasm.

With the aid of immunohistochemical methods the localization of the various isoenzymes of glutathione S-transferase was investigated. The a isoenzyme was present solely in the proximal tubular cells of the human kidney, while the it form was restricted to the distal convoluted tubules, the thin loop of Henle, and the collecting ducts. Damage to the epithelial cell membranes results in the increased excretion of these enzymes with the urine. The cx and t isoenzymes have been isolated in a highly purified form and used for the production of polyclonal antisera. Subsequently, radioimmunological and ELISA techniques were developed for quantitation of these proteins in the urine; the methods exhibited a high specificity and were sufficiently sensitive to determine nanogram quantities or less. Disease affecting tubular function, cyclosporine A treatment, administration of nephrotoxic antibiotics, and exposure to cadmium all resulted in characteristic changes in the pattern of the glutathione transferase isoenzymes present in urine. Such effects were seen also in patients who had previously been exposed to nephrotoxic agents, but in whom conventional tests for kidney function were apparently normal. Thus, it appears that radioimmunologic or immunochemical quantitation of a and ic forms of the enzyme can be used as sensitive and relatively simple markers for the early detection of toxic effects with respect to the renal tubuli. Environ Health Perspect 102(Suppl 3): 293-296 (1994).