Effector-dependent structural transformation of a crystalline framework with allosteric effects on molecular recognition ability.

Structurally flexible porous crystals that combine high regularity and stimuli responsiveness have received attracted attention in connection with natural allostery found in regulatory systems of activity and function in biological systems. Porous crystals with molecular recognition sites in the inner pores are particularly promising for achieving elaborate functional control, where the local binding of effectors triggers their distortion to propagate throughout the structure. Here we report that the structure of a porous molecular crystal can be allosterically controlled by local adsorption of effectors within low-symmetry nanochannels with multiple molecular recognition sites. The exchange of effectors at the allosteric site triggers diverse conversion of the framework structure in an effector-dependent manner. In conjunction with the structural conversion, it is also possible to switch the molecular affinity at different recognition sites. These results may provide a guideline for the development of supramolecular materials with flexible and highly-ordered three-dimensional structures for biological applications.

Evaluation of an e-learning system for diagnosis of gastric lesions using magnifying narrow-band imaging: a multicenter randomized controlled study.

Background and study aim Magnifying narrow-band imaging (M-NBI) is useful for the accurate diagnosis of early gastric cancer (EGC). However, acquiring skill at M-NBI diagnosis takes substantial effort. An Internet-based e-learning system to teach endoscopic diagnosis of EGC using M-NBI has been developed. This study evaluated its effectiveness. Participants and methods This study was designed as a multicenter randomized controlled trial. We recruited endoscopists as participants from all over Japan. After completing Test 1, which consisted of M-NBI images of 40 gastric lesions, participants were randomly assigned to the e-learning or non-e-learning groups. Only the e-learning group was allowed to access the e-learning system. After the e-learning period, both groups received Test 2. The analysis set was participants who scored < 80 % accuracy on Test 1. The primary end point was the difference in accuracy between Test 1 and Test 2 for the two groups. Results A total of 395 participants from 77 institutions completed Test 1 (198 in the e-learning group and 197 in the non-e-learning group). After the e-learning period, all 395 completed Test 2. The analysis sets were e-learning group: n = 184; and non-e-learning group: n = 184. The mean Test 1 score was 59.9 % for the e-learning group and 61.7 % for the non-e-learning group. The change in accuracy in Test 2 was significantly higher in the e-learning group than in the non-e-learning group (7.4 points vs. 0.14 points, respectively; P < 0.001). Conclusion This study clearly demonstrated the efficacy of the e-learning system in improving practitioners' capabilities to diagnose EGC using M-NBI.Trial registered at University Hospital Medical Information Network Clinical Trials Registry (UMIN000008569).

[Sarcomatoid carcinoma of the liver: a case report and review of the literature].

A 66-year-old woman presented to our outpatient clinic with abdominal discomfort in April, 2008. Ultrasound revealed a hypo-echoic 10cm mass in the right hepatic lobe but no indication of chronic liver disease, with similar results in her history, on physical exam, and imaging. Serum testing did not identify any systemic disease. The mass was suspected to be intrahepatic cholangiocarcinoma and right hepatic lobectomy was performed. Histologic examination of the specimen revealed numerous spindle cells, and immunostaining confirmed a definitive diagnosis of sarcomatoid carcinoma of the liver. On subsequent review of the case, an abdominal CT performed 2.5 years earlier for unrelated symptoms had shown a 1cm faint low density area in the same location as the mass. The doubling time of this tumor was about 95 days.

[A case of primary retroperitoneal mucinous cystadenocarcinoma].

We encountered a case of primary retroperitoneal mucinous cystadenocarcinoma with ovarian-type stroma, an extremely rare condition. The patient was a 56-year-old woman with complaints of diarrhea, nausea, and abdominal fullness. Abdominal ultrasound revealed a nodular multi-cystic mass in the left lower quadrant of the abdomen. Subsequent contrast-enhanced CT and MRI determined it to be of retroperitoneal origin, consistent with a mucinous cystadenocarcinoma. Numerous small nodules were confirmed during the operation around the tumor suggesting local dissemination of the cancer and a left partial colectomy that included these nodules was performed. On histological examination, mucinous fluid was found trapped inside the cavity and poorly differentiated adenocarcinoma was observed in the solid portions. The ovarian-type stroma was confirmed in the layer beneath the epithelial lining and eventually a final diagnosis of mucinous cystadenocarcinoma was reached.

Recurrence of primary hepatic carcinoid tumor in the remnant liver 13 yr after resection.

We report here a case of primary hepatic carcinoid tumor (PHCT) recurring in the remnant liver 13 yr and 10 mo after first resection. A 70-yr-old man developed four hypervascular tumors in the liver in December 2003. He had undergone curative left-lobe hepatectomy for PHCT in February 1990. Histopathological examination of the tumor biopsy specimen showed that the tumor was composed of uniform round-to-oval cells with solid arrangement and the tumor cells stained positive for chromogranin A, synaptophysin, and neuron-specific enolase. We diagnosed this case as an intrahepatic metastasis of PHCT with a long latency period, based on the fact that no primary site of carcinoid tumor could be found despite intensive examination and the immunohistochemical findings of the resected tumors were essentially same as those of PHCT in 1990. Although PHCT is reported to have a more favorable prognosis than other hepatic cancer or metastatic carcinoid tumor in the liver, long-term observation is recommended.