Pancreaticopleural fistula: a rare complication of chronic pancreatitis.

Pancreaticopleural fistula is an uncommon sequelae of pancreatitis. The condition is often elusive, as respiratory rather than abdominal symptoms usually predominate and the fistula can be difficult to demonstrate radiologically. Confirmation is by demonstrating a high amylase content in the pleural aspirate relative to the serum. About half the fistulae will close with conservative treatment but persistent or recurrent effusions, often associated with stenosis or disruption of the main pancreatic duct, are an indication for surgery. The long-term outcome is good in 80-95% of cases. We report five patients with pleural effusion of pancreatic origin due to pancreaticopleural fistula.

The ras oncogene and tumour metastasis: observations on murine cells transfected with activated human c-Ha-ras.

Transfection of cells with cloned genes or total genomic DNA offers a means for studying aspects of neoplastic behaviour. We have used this method to examine whether incorporation of the cloned 6.6-kilobase (kb) fragment of DNA containing the mutant c-Ha-ras human oncogene can confer metastatic capability on murine NIH 3T3 cells. Cells co-transfected with the mutated ras gene and the neomycin resistance marker pSV2neo were selected by culture in neomycin. On subcutaneous inoculation into MF 1 nude mice, these cells proved to be tumourigenic with short latent periods (approximately 14 days)--nude mice were used to circumvent immunological rejection of the mouse cells expressing the product of the human oncogene. Transfectants were capable of lung colonisation after intravenous injection, but there was no evidence of spontaneous metastasis at autopsy, or on histological examination of the lungs and other organs, 90 days after inoculation. Incorporation of the transfected oncogene was confirmed by Southern blotting and its expression by dot-blot hybridisation and immunoprecipitation. The results in this experimental system indicate that transfection of a mutated human ras oncogene into non-neoplastic 3T3 cells can confer part of the metastatic phenotype, namely lung colonisation, but is not by itself sufficient to induce spontaneous metastatic behaviour.