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AimsThe intraportal pancreatic islet transplantation (IPIT) model of diabetic rats is an insulin mediated model of hepatocarcinogenesis characterized by the induction of clear cell foci (CCF) of altered hepatocytes, which are pre-neoplastic lesions excessively storing glycogen (glycogenosis) and exhibiting activation of the AKT/mTOR protooncogenic pathway. In this study, we transferred the IPIT model to the mouse and combined it with the knockout of the transcription factor carbohydrate responsive element binding protein (chREBP).MethodsC57BL/6J Wild-type (WT) and chREBP-knockout (chREBP-KO) mice (n = 297) were matched to 16 groups (WT/ chREBP-KO, experimental/control, streptozotocine-induced diabetic/not diabetic, one/four weeks). Experimental groups received the intraportal transplantation of 70 pancreatic islets. Liver and pancreatic tissue was examined using histology, morphometry, enzyme- and immunohistochemistry and electron microscopy.ResultsCCF emerged in the liver acini downstream of the transplanted islets. In comparison to WT lesions, CCF of chREBP-KO mice displayed more glycogen accumulation, reduced activity of the gluconeogenic enzyme glucose-6-phosphatase, decreased glycolysis, lipogenesis and reduced levels of the AKT/mTOR cascade members. Proliferative activity of CCF was ∼two folds higher in WT mice than in chREBP-KO mice.ConclusionsThe IPIT model is applicable to mice, as murine CCF resemble preneoplastic liver lesions from this hepatocarcinogenesis model in the rat in terms of morphological, metabolic and molecular alterations and proliferative activity, which is diminished after chREBP knockout. chREBP appears to be an essential component of AKT/mTOR mediated cell proliferation and the metabolic switch from a glycogenotic to lipogenic phenotype in precursor lesions of hepatocarcinogenesis.

Purpose: The implantation of a gastric balloon (also known as intragastric balloon) is an established and reversible endoscopic procedure for adiposity therapy. Structural changes of the stomach wall are expected to occur with gastric balloon implantation; however, until now these changes have rarely been investigated. Methods: We compared the histological structure of the stomach wall after gastric-sleeve resection in a group of patients following gastric balloon implantation and a group without previous gastric balloon implantation. Results: Following gastric balloon implantation, the tunica muscularis was found to be significantly thicker than without gastric balloon implantation. The enlarging of the tunica muscularis is not caused by hyperplasia of the leiomyocytes, but by hypertrophy of the leiomyocytes and an increase in collagen fibers (fibrosis). Conclusion: A longer-lasting hypertrophy of the tunica muscularis, particularly in the corpus, should be taken into account when surgical treatment follows gastric balloon implantation. The staple suture height should be adjusted to the altered tissue composition since reduced tissue elasticity must be expected due to fibrosis.

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