Multiple enteric muco-submucosal elongated polyps causing intussusception.

A 20-year-old woman presented to our hospital with abdominal pain. Abdominal computed tomography revealed multiple masses in the upper jejunum, which were suspected as lipomas. Partial resection of the small intestine, including the masses, was performed on the same day due to intussusception secondary to the masses. Pathological examination revealed that the masses consisted of mucosa and edematous submucosa with multiple dilated blood vessels and lymphatic ducts without muscularis propria. The masses were diagnosed as multiple muco-submucosal elongated polyps (MSEP), a type of non-neoplastic polyp. MSEP was originally named colonic MSEP, but with the development of endoscopic techniques and imaging tests, similar polyps have been reported to occur not only in the colon but also in the entire intestinal tract. In this case, multiple MSEPs in the upper jejunum caused intussusception. As reported cases of multiple lesions causing intussusception are few, our case may help to clarify the pathogenesis of this disease.

Dual antiplatelet therapy inhibits neutrophil extracellular traps to reduce liver micrometastases of intrahepatic cholangiocarcinoma.

The involvement of neutrophil extracellular traps (NETs) in cancer metastasis is being clarified, but the relationship between intrahepatic cholangiocarcinoma (iCCA) and NETs remains unclear. The presence of NETs was verified by multiple fluorescence staining in clinically resected specimens of iCCA. Human neutrophils were co-cultured with iCCA cells to observe NET induction and changes in cellular characteristics. Binding of platelets to iCCA cells and its mechanism were also examined, and their effects on NETs were analyzed in vitro and in in vivo mouse models. NETs were present in the tumor periphery of resected iCCAs. NETs promoted the motility and migration ability of iCCA cells in vitro. Although iCCA cells alone had a weak NET-inducing ability, the binding of platelets to iCCA cells via P-selectin promoted NET induction. Based on these results, antiplatelet drugs were applied to these cocultures in vitro and inhibited the binding of platelets to iCCA cells and the induction of NETs. Fluorescently labeled iCCA cells were injected into the spleen of mice, resulting in the formation of liver micrometastases coexisting with platelets and NETs. These mice were treated with dual antiplatelet therapy (DAPT) consisting of aspirin and ticagrelor, which dramatically reduced micrometastases. These results suggest that potent antiplatelet therapy prevents micrometastases of iCCA cells by inhibiting platelet activation and NET production, and it may contribute to a novel therapeutic strategy.

The arginine transporter Can1 acts as a transceptor for regulation of proline utilization in the yeast Saccharomyces cerevisiae.

Proline is the most abundant amino acid in wine and beer, because the yeast Saccharomyces cerevisiae hardly assimilates proline during fermentation processes. Our previous studies showed that arginine induces endocytosis of the proline transporter Put4, resulting in inhibition of proline utilization. We here report a possible role of arginine sensing in the inhibition of proline utilization. We first found that two basic amino acids, ornithine, and lysine, inhibit proline utilization by inducing Put4 endocytosis in a manner similar to arginine, but citrulline does not. Our genetic screening revealed that the arginine transporter Can1 is involved in the inhibition of proline utilization by arginine. Intriguingly, the arginine uptake activity of Can1 was not required for the arginine-dependent inhibition of proline utilization, suggesting that Can1 has a function beyond its commonly known function of transporting arginine. More importantly, our biochemical analyses revealed that Can1 activates signaling cascades of protein kinase A in response to extracellular arginine. Hence, we proposed that Can1 regulates proline utilization by functioning as a transceptor possessing the activity of both a transporter and receptor of arginine.

Chronic expanding hematoma in the liver: a case report.

BACKGROUND: A hematoma that gradually increases over a chronic course of months or longer is defined as a chronic expanding hematoma (CEH). CEHs often develop in the limbs and on body surfaces that are susceptible to external stimuli. CEHs in the intrathoracic or intraperitoneal organs are uncommon, with liver CEHs being particularly rare worldwide. CASE PRESENTATION: A 57-year-old woman was previously diagnosed with a giant cyst in the right liver lobe, with a longer axis of approximately 15 cm. Abdominal ultrasonography findings suggested a complex cyst, and she was referred to our hospital for further inspection. Although CEH was suspected, it was difficult to exclude malignant diseases such as intraductal papillary neoplasm of the bile duct and cystadenocarcinoma. There was a possibility of malignant disease and the exclusion of surrounding organs due to tumor growth. Therefore, a right hepatectomy was performed. Pathological examination revealed a pseudocyst containing a clot, which was consistent with CEH. CONCLUSIONS: CEH rarely occurs in the liver; however, it is necessary to consider CEH when a slow-growing hepatic mass that shows a mosaic pattern on magnetic resonance imaging is found.