Diagnostic capability of gadoxetate disodium-enhanced liver MRI for diagnosis of hepatocellular carcinoma: comparison with multi-detector CT.

The purpose of this study was to evaluate the diagnostic capability of gadoxetate disodium (Gd-EOB)-MRI for the detection of hepatocellular carcinoma (HCC) compared with multidetector CT (MDCT). Fifty patients with 57 surgically proven HCCs who underwent Gd-EOB-MRI and MDCT from March 2008 to June 2011 were evaluated. Two observers evaluated MR and CT on a lesion-by-lesion basis. We analyzed sensitivity by grading on a 5-point scale, the degree of arterial enhancement and the differences in histological grades in the diffusion-weighted images (DWI). The results showed that the sensitivity of Gd-EOB-MRI was higher than that of MDCT especially for HCCs that were 1 cm in diameter or smaller. The hepatobiliary phase was useful for the detecting of small HCC. We had few cases in which it was difficult to judge HCC in the arterial enhancement between MRI and MDCT. In the diffusion-weighted image, well differentiated HCC tended to show a low signal intensity, and poorly differentiated HCC tended to show a high signal intensity. In moderately differentiated HCC's, the mean diameter of the high signal intensity group was larger than that of the low signal intensity group (24.5 mm vs. 15.8 mm). In conclusion, Gd-EOB-MRI tended to show higher sensitivity compared to MDCT in the detection of HCC.

Trans-differentiation of a duodenal phenotype on duodenal transplantation of different normal tissues in F344 rats.

The mechanisms regulating stem cell differentiation and self-renewal are largely unknown. Our ultimate goal is to be able to regulate somatic stem cell differentiation and proliferation. In the present study the ability of trans-differentiation was studied when different normal tissue types were transplanted into the duodenum in rats. Pieces of ear (skin), bladder, trachea, diaphragm, pyloric gland, and forestomach from 8-week old GFP-F344 rats were transplanted into the duodenum of F344 rats. Goblet cells with alcian-blue PAS positive mucin and brash border with alkaline phosphatase (ALP) activity appeared in tissues implanted into the duodenum. In addition, GFP-positive duodenal mucosa was observed in all cases by immunohistochemical staining. Moreover, the GFP-positive cells were found to carry the GFP transgene by PCR analysis, indicating that the bladder, trachea, ear (skin), diaphragm, pyloric gland, and forestomach tissues showed a multipotential ability for differentiation. These results indicated that stem cells within tissues have a multipotential ability, trans-differentiating into different organs when transplanted into different environments.

Differentiation of a hepatic phenotype after heterotropic transplantation of heart, kidney, brain, and skin tissues into liver in F344 rats.

While organ-specific stem cells with roles in tissue injury repair have been documented, their pathogenic significance in diseases and the factors potentially responsible for their activation remain largely unclear. In the present study, heart, kidney, brain, and skin samples from F344 transgenic rats carrying the GFP gene were transplanted into normal F344 rat liver one day after an intraperitoneal injection (i.p.) of carbon tetrachloride (CCl(4)) to test their differentiation capacity. The transplantation was carried out by female donors to male recipients, and vice versa. One week after transplantation, GFP antigen-positive cells with phenotypic characteristics of hepatocytes were noted. After two weeks, their extent increased, and at 4 weeks, large areas of strongly GFP-stained cells developed. All recipient livers had GFP antigen-positive hepatocyte cells. PCR analysis coupled with laser capture micro-dissection (LCM) revealed those cells to contain GFP DNA. Thus, our results indicate that tissue stem cells have multipotential ability, differentiating into hepatocytes when transplanted into an injured liver.