Collective In-Plane Molecular Rotator Based on Dibromoiodomesitylene π-Stacks.

Interest in artificial solid-state molecular rotator systems is growing as they enable systems to be designed for achieving specific physical functions. The phase transition behavior of four halomesitylene crystals indicated dynamic in-plane molecular rotator characteristics in dibromoiodomesitylene, tribromomesitylene, and dibromomesitylene crystals. Such molecular rotation in diiodomesitylene crystals was suppressed by effective I···I intermolecular interactions. The in-plane molecular rotation accompanied by a change in dipole moment resulted in dielectric phase transitions in polar dibromoiodomesitylene and dibromomesitylene crystals. No dielectric anomaly was observed for the in-plane molecular rotation of tribromomesitylene in the absence of this dipole moment change. Typical antiferroelectric-paraelectric phase transitions were observed in the dibromomesitylene crystal, whereas the dielectric anomaly of dibromoiodomesitylene crystals was associated with the collective in-plane molecular rotation of polar π-molecules in the π-stack. We found that the single-rope-like collective in-plane molecular rotator was dominated by intermolecular I···I interactions along the π-stacking column of polar dibromoiodomesitylene.

Evaluation of aggressive surgical treatment for advanced carcinoma of the gallbladder.

BACKGROUND/PURPOSE: An aggressive approach is required to resect advanced carcinoma of the gallbladder. Therefore, an extended surgical procedure often brings about a poor surgical outcome. To test whether an aggressive surgical treatment can improve the survival rate for primary advanced carcinoma of the gallbladder, 59 patients with stage IV primary gallbladder carcinoma were studied. METHODS: Patients were divided into three treatment groups for the survival analysis: group A (resectional surgery, n = 29), group B (low-dose cis-diamminedichloroplatinum-II and 5-fluorouracil therapy, n = 10), and group C (exploratory laparotomy, other treatment modalities, or no treatment, n = 20). RESULTS: The prognosis of group A patients was significantly better than that of group B (P = 0.018) or group C (P = 0.0009). Furthermore, group A patients were divided into subgroups. The prognosis of patients resected with no distant metastasis (group A1) was significantly better than that of patients resected with distant metastases of the distant lymph nodes and the liver (group A2) (P = 0.0004). Also, there was no significant difference in the survival rate between the patients resected with distant metastasis (group A2) and chemotherapy cases (group B). CONCLUSIONS: These results indicated that radical surgery should be performed for patients with no distant metastasis, and that chemotherapy might be a useful alternative treatment for patients with distant metastasis in advanced carcinoma of the gallbladder.

Aggressive surgery for liver metastases from gastrointestinal stromal tumors.

BACKGROUND/PURPOSE: The utility of hepatectomy for patients with metastatic liver tumors from gastrointestinal stromal tumors (GISTs) was evaluated in the present study. METHODS: Between 1989 and 2001, ten patients with liver metastases from GIST (four men and six women; age, 34-77 years) underwent hepatectomy at our hospital. All patients underwent complete resection of the primary tumor and hepatectomy with or without microwave coagulation therapy (MCT) for all detectable hepatic tumors. RESULTS: The median survival time after hepatectomy was 39 months (range, 1 to 96 months). There was one postoperative death. One patient is still alive with relapse of hepatic tumors, and the remaining eight patients died of disease (liver in six, peritoneum in one, and bone in one). Relapse of hepatic tumors occurred in seven patients. The disease-free rate after hepatectomy was 22% at 2 years and 11% at 5 years. The survival times of the four patients who received hepatic arterial chemoembolization for recurrent hepatic metastases were 7 months (still alive), 17, 23, and 28 months (average, 19 months). CONCLUSIONS: Our data suggest that aggressive surgery (hepatectomy and MCT) for all detectable hepatic tumors and hepatic arterial chemoembolization for recurrent hepatic metastases improve survival.