Takaaki Eto

Partial purification and characterization of hepatocyte proliferation stimulatory factor from liver of pats treated with D-galactosamine

The partial purification and characterization of a hepatocyte proliferation stimulatory factor (HPSF) isolated from the liver of D-galactosamine-treated rats are described. The HPSF was a heat-labile, acid-stable and trypsin-sensitive protein. The partially purified HPSF stimulated DNA synthesis and increased the labeling index of parenchymal hepatocytes at 5 micrograms/ml and maximally at 50 micrograms/ml. The effect of HPSF in stimulating DNA synthesis was synergistic with that of insulin plus epidermal growth factor (EGF). The HPSF was scarcely detected in normal rat liver. The results obtained indicate that this HPSF is distinct from insulin, multiplication-stimulating activity (MSA), EGF and other hepatocyte growth factors previously reported, and suggest a plausible role for HPSF in the regeneration of liver tissue following hepatotoxic damage.

Angiomyolipoma of the colon: Report of a case

Angiomyolipomas are benign mesenchymal tumors mostly arising from the kidney. Angiomyolipoma of the colon is extremely rare. Here we report the findings of a 51-year-old man who presented with a submucosal tumor covered with normal mucosa and hemorrhage in the descending colon. He underwent a partial resection of the descending colon. A histopathological examination showed that the tumor of 5.7 cm in diameter included smooth muscle (spindle cell type), mature adipose tissue, and vessels, and therefore a diagnosis of angiomyolipoma was made. A submucosal type of angiomyolipoma of the colon is extremely rare. If a renal angiomyolipoma is larger than 4 cm, there is a risk of rupture. When colonoscopy shows a submucosal tumor of the colon with hemorrhage, angiomyolipoma should be considered. If an angiomyolipoma of the colon is large, surgical resection should be considered as a treatment option due to the risk of hemorrhage.