Arnold M. Seligman

Acute reaction to arterial adhesive in healing skin wounds

Summary The acute effect of a synthetic arterial adhesive, methyl alpha-cyanoacrylate, on healing wounds was investigated experimentally by using 22 albino rats. The adhesive was applied on one of two excised wounds, made in a dorsal area of each animal. The rats were killed 1/2, 1, 2, 4, 8, 16, 24, 48, 72, 96 and 120 hours after injury. The wounds were studied histologically, and histochemically, by using three methods for esterase activity. The glue caused a necrosis which was about twice as deep as that seen in the immediate vicinity of the edge of nontreated wounds. The imminent necrosis appeared histochemically as a loss of esterase activity one hour after injury. The first histologic signs of necrosis could be demonstrated in 8-hour wounds. Surrounding the central or superficial area with diminishing vitality, there was an increase in esterase activity in a peripheral wound zone. The intensification was demonstrable in both types of wounds from one to 24 hours after injury, the enzyme activity remaining strong subsequently. The glue caused a continuous granulocytic response in the peripheral zone from 8 hours on. By contrast, polymorphonuclear leukocytes began to be superseded by mononuclear cells in 16-hour, nontreated wounds. Further research work should be directed toward developing an adhesive of the same type, but less irritating to tissue.

Nutritional cirrhosis in rhesus monkeys: Electron microscopy and histochemistry

Abstract A choline-deficient low protein diet was fed to twelve Rhesus monkeys for two years. Eight of the animals died, most of them during the latter part of the first year. Mortality among males was higher than in females. Three of the four surviving animals developed fatty metamorphosis followed by cirrhosis. Eight sequential liver biopsies from each of these animals were studied. Control specimens showed paracrystalline mitochondrial inclusions in the hepatocytes and cytoplasmic crystalloids in the endothelial cells of the hepatic sinusoids and portal vessels. The significance of both structures remains unknown. Striking cytoplasmic vacuoles, possibly produced by anoxia during surgical liver biopsy, were observed in some specimens. The hepatocytes of the animals on the experimental diet, in addition to fatty change, showed mitochondria with bizarre shapes, circular cristae or increased electron opacity. Focal cytoplasmic degradation and Golgi dilatation were prominent. Microvilli developed along the intercellular spaces and became more prominent in the space of Disse. Basement membranes which were rarely continuous could be seen between hepatocytes and sinusoidal lining cells. In Disse spaces and intercellular spaces microfibrils and increased collagen fibers developed. In the later biopsies septa were formed which contained a higher proportion of typical collagen to microfibrils than the fibrillar material in the Disse spaces. The hepatocytes in the cirrhotic nodules stained more strongly for glycogen and were more active in nearly all histochemical enzyme reactions than the hepatocytes in non-nodular areas. This suggests that the nodules differed metabolically from the rest of the parenchyma.