Utility of the Virtual Liver Parenchymal Perfusion Area Using a Commercially Available Workstation in Transarterial Chemoembolization for Hepatocellular Carcinoma.

PURPOSE: To evaluate the accuracy of the virtual liver parenchymal perfusion area using a commercially available workstation and liver analysis software in conventional transarterial chemoembolization (cTACE) for hepatocellular carcinoma (HCC). MATERIALS AND METHODS: This method was retrospectively applied to 29 treated HCCs in 23 patients. The virtual embolic area (VEA) was estimated based on cone beam computed tomography during hepatic arteriography using a commercially available workstation and liver analysis software by two observer groups (group A: experts; group B: semi-experts). The real embolic area (REA) was defined as the area where iodized oil accumulated on computed tomography at 1 week after cTACE. The REA was estimated by each of the two groups, and the mean REA between the groups (mREA) was used as a standard reference. Agreement of volume and cross-sectional area in three orthogonal planes between the VEA and mREA were analyzed using intraclass correlation coefficients (ICCs) and Bland-Altman plots. RESULTS: The ICCs for volume between VEA and mREA were 0.97 and 0.88 for groups A and B, respectively, and those for cross-sectional area were 0.94 and 0.88 for the axial plane, 0.95 and 0.83 for the coronal plane, and 0.87 and 0.74 for the sagittal plane, respectively. Thus, the overall agreement was excellent, except for the sagittal imaging plane in group B. CONCLUSION: This method using a commercially available workstation and liver analysis software can be useful for estimating the embolic area in cTACE.

Expression of neuropeptide Y and agouti-related peptide in the hypothalamic arcuate nucleus of newborn neurogenin3 null mutant mice.

Mice deficient in neurogenin 3 (Ngn3) fail to generate pancreatic endocrine cells and intestinal endocrine cells. Hypothalamic neuropeptides implicated in the control of energy homeostasis might also be affected in Ngn3 homozygous null mutant mice. We investigated the expression of two prominent orexigenic neuropeptides, neuropeptide Y (NPY) and agouti-related protein (AgRP), in the hypothalamic arcuate nucleus of newborn wild-type and Ngn3 null mutant mice. Immunohistochemical analysis demonstrated that, in Ngn3 null mutants, the number of NPY-immunoreactive neurons and nerve fibers was markedly increased in the arcuate nucleus, and the nerve fibers were widely distributed in the hypothalamic area, including the paraventricular and dorsomedial nuclei. Little increase of AgRP immunoreactivity was detected in the arcuate nucleus of mutant mice. In situ hybridization analysis confirmed the increased population of the NPY neurons in the arcuate nucleus of the mutants. The NPY mRNA level, as estimated by laser capture microdissection and real-time quantitative polymerase chain reaction, was 371% higher in Ngn3 null mutants than in wild-type mice. AgRP mRNA levels did not differ significantly between the null mutants and wild-type mice. Thus, up-regulation of the hypothalamic NPY system is probably a feature characteristic of Ngn3 null mice.

Ultrastructural localization of vimentin immunoreactivity and gene expression in tanycytes and their alterations in hamsters kept under different photoperiods.

Tanycytes are located in the basolateral walls of the third ventricle. By light- and electron-microscopic immunohistochemistry, we demonstrated that the tanycytes of Djungarian hamsters were intensely immunostained with the vimentin monoclonal antibody V9. The cells always extended long radial processes in which aggregations of vimentin-immunoreactive intermediate filaments were prominent. The tanycytes showed photoperiod-dependent changes. The population of vimentin-immunoreactive tanycytes was increased in hamsters exposed to continuous lighting for 1 month or to a long photoperiod (16 h light:8 h dark) for 2 months. On the other hand, the immunoreactive cells were significantly decreased in hamsters exposed to complete darkness for 1 month or to a short photoperiod (8 h light:16 h dark) for 2 months. The pericapillary spaces of the primary plexus of the portal circulation system were lined by the end-feet of tanycytic processes. Electron microscopy confirmed that the tanycytic processes were markedly decreased in number and size after exposure to complete darkness. Expression of vimentin mRNA in the hamster mediobasal hypothalamus was detected by the reverse transcription-polymerase chain reaction (RT-PCR). The alterations of vimentin mRNA expression under different photoperiods were analyzed using laser capture microdissection and real-time quantitative PCR. The level of vimentin mRNA in the mediobasal hypothalamus was enhanced after exposure to continuous lighting for 1 month or to a long photoperiod for 2 months, whereas it was significantly diminished after exposure to constant darkness or short photoperiod. These changes in the tanycytes under different photoperiods may influence the portal circulation system and also the cell activity of the pars tuberalis, and may thus participate in photoperiodic regulation of the endocrine system.