[A case of hilar bile duct cancer which recurred at abdominal and cervical lymph nodes 8 years after curative resection].

A 40-year-old man underwent right hemihepatectomy with biliary reconstruction for hilar bile duct cancer, and the surgical margin being negative. The tumor, showing atypical intraductal growth, was solid adenocarcinoma with rich mucinous component, although it was negative for MUC1, MUC2 and MUC5AC, suggesting that the tumor was not an intraductal papillary neoplasm of the bile duct (IPN-B). Eight years after operation, abdominal and cervical lymph node metastases were found on computed tomography and (18)F-deoxyglucose positron emission tomography examination. Late remote recurrence after curative resection of the extrahepatic bile duct cancer is relatively rare. The recurrence in the present case maybe explained by the tumor dormancy theory.

Ligand-assisted J-type aggregates of zinc porphyrin: anticooperative molecular organization in self-assembled bolaamphiphile.

Bolaamphiphilic zinc porphyrins bearing a 2-pyridylethynyl or 4-methoxyphenylethynyl group, Zn(PyPor) or Zn(ArPor), respectively, were newly synthesized in order to explore the molecular organizing behaviours within the interior hydrophobic layer of aqueous self-assemblies. Well-ordered J-type aggregates of Zn(PyPor) were formed in aqueous self-assembled bolaamphiphile, whereas J-type aggregates of Zn(ArPor) were disordered. The titration experiments suggest that axial coordination bond improves the structural uniformity of the J-type aggregates of Zn(PyPor). In a homogeneous isotropic media, on the other hand, Zn(PyPor) formed an antiparallel dimer through self-complementary coordination. Unprecedented molecular organization of ligand-assisted J-type aggregates is described in the term of anticooperative effect under the bulk conditions.

Effects of ghrelin on neuronal activity in the ventromedial nucleus of the hypothalamus in infantile rats: an in vitro study.

Ghrelin is an endogenous ligand for the growth hormone (GH) secretagogue (GHS) receptor (GHS-R) and a potent stimulant for GH secretion even in infantile rats before puberty. Although the ventromedial nucleus of the hypothalamus (VMH) might be a site of action for ghrelin to induce GH release, the electrophysiological effect of ghrelin on VMH neurons in infantile rats remains to be elucidated. Thus, the purpose of the present study was to investigate the effect of ghrelin on VMH neurons using hypothalamic slices of infantile rats. Ghrelin excited a majority of VMH neurons in a concentration-dependent manner. VMH neurons that were excited by GH releasing peptide-6 (GHRP-6), a synthetic GHS, were also excited by ghrelin and vice versa. Repeated application of ghrelin to the same VMH neuron decreased progressively the excitatory responses depending on the number of times it was administered. The excitatory effect of ghrelin on VMH neurons in normal artificial cerebrospinal fluid (ACSF) persisted in low Ca2+-high Mg2+ ACSF. The present results indicate that (1) ghrelin excites a majority of VMH neurons dose-dependently and postsynaptically and (2) the excitatory effects of ghrelin are mimicked by GHRP-6 and desensitized by repeated applications of ghrelin.