Biotin augments acetyl CoA carboxylase 2 gene expression in the hypothalamus, leading to the suppression of food intake in mice.

It is known that biotin prevents the development of diabetes by increasing the functions of pancreatic beta-cells and improving insulin sensitivity in the periphery. However, its anti-obesity effects such as anorectic effects remain to be clarified. Acetyl CoA carboxylase (ACC), a biotin-dependent enzyme, has two isoforms (ACC1 and ACC2) and serves to catalyze the reaction of acetyl CoA to malonyl CoA. In the hypothalamus, ACC2 increases the production of malonyl CoA, which acts as a satiety signal. In this study, we investigated whether biotin increases the gene expression of ACC2 in the hypothalamus and suppresses food intake in mice administered excessive biotin. Food intake was significantly decreased by biotin, but plasma regulators of appetite, including glucose, ghrelin, and leptin, were not affected. On the other hand, biotin notably accumulated in the hypothalamus and enhanced ACC2 gene expression there, but it did not change the gene expression of ACC1, malonyl CoA decarboxylase (a malonyl CoA-degrading enzyme), and AMP-activated protein kinase α-2 (an ACC-inhibitory enzyme). These findings strongly suggest that biotin potentiates the suppression of appetite by upregulating ACC2 gene expression in the hypothalamus. This effect of biotin may contribute to the prevention of diabetes by biotin treatment.

Sporadic gastric neurofibroma underneath early cancer: MDCT gastrography and histological findings.

We report the case of a sporadic gastric submucosal neurofibroma underneath a T1 stage cancer. A 61-year-old man underwent gastroscopy because of epigastralgia and was diagnosed as having T1 stage gastric cancer by an experienced gastroenterologist. Subsequently performed computed tomography (CT) showed poorly circumscribed wall thickening underneath the converged folds on three-dimensional images. On a dynamic enhancement study, the thickened wall was seen to be enhanced gradually from the arterial phase to the equilibrium phase. Based on these findings, we diagnosed stage T2 cancer. Total gastrectomy was performed, and the surgically removed specimen revealed that the wall thickening was caused by a submucosal neurofibroma and that cancer existed in this neurofibroma, invading the submucosa. This patient had no family history of neurofibromatosis, and so the lesion was diagnosed as early gastric cancer with a sporadic submucosal neurofibroma. Coexistence of gastric cancer and a submucosal tumor is rare, but such a case is one of the pitfalls of a CT diagnosis of T stage gastric cancer.

Magnetic resonance imaging for multiple macronodular localized splenic tuberculosis.

Splenic tuberculosis is usually associated with disseminated miliary tuberculosis; it typically exhibits a multiple micronodular form. We report on magnetic resonance imaging findings of an extremely rare case of multiple macronodular splenic tuberculosis without extrasplenic involvement. The nodules showed hypointensity on T(2)-weighted images and gradual peripheral enhancement with complete fill-in. These findings are consistent with observations in disseminated splenic tuberculosis, except for the nodule and spleen sizes.

Fluorinated diamond-like carbon as antithrombogenic coating for blood-contacting devices.

Diamond-like carbon (DLC) is being considered for widespread clinical use as a surface coating for cardiovascular devices. We synthesized fluorinated DLC (F-DLC) coatings in order to create a more hydrophobic surface with improved antithrombogenicity and flexibility when compared with conventional DLC coatings by combining the inertness of DLC films with the advantage of fluorination. The purpose of this study was to evaluate the in vitro hemocompatibility and in vivo biocompatibility of the F-DLC coating for medical devices. The in vitro whole blood model confirmed that platelet loss was lower in the F-DLC group than in the noncoated group (SUS316L), which suggests the adhesion of a smaller number of platelets to F-DLC-coated materials. Furthermore, the biomarkers of mechanically induced platelet activation (beta-thromboglobulin) and activated coagulation (thrombin-antithrombin-three complex) were markedly reduced in the F-DLC-coated group. In vivo rat implant model studies revealed no excessive local and systemic inflammatory responses in the F-DLC group. The thickness of the fibrous tissue capsule surrounding the F-DLC-coated disk was almost equal to that of the noncoated SUS316L disk, which has the favorable biocompatibility for metallic implant materials. F-DLC coating thus appears to be a promising candidate for use as a coating material in blood-contacting devices.