Unexpectedly superior enantioselectivity for trans-stilbene cis-dihydroxylation over anchored triosmium carbonyl species in confined Al-MCM-41 channels.

Superior enantioselectivity in the dihydroxylation of trans-stilbene catalysed by anchored triosmium carbonyl species without using a chiral modifier is observed inside sterically congested MCM-41 channels; this effect is more pronounced through the introduction of surface Al sites into the silicate.

Natural course of inoperable esophageal cancer treated with metallic expandable stents: quality of life and cost-effectiveness analysis.

BACKGROUND AND AIM: The aim of this study was to evaluate the efficacy and safety of endoscopic therapy with self-expanding metallic endoprostheses in the management of malignant esophageal obstruction or stenosis and the cost-effectiveness of the method in patients suffering from primary esophageal carcinoma. All patients with inoperable esophageal cancers treated with either laser palliation or endoprosthesis insertion were studied retrospectively. METHOD: Between May 1997 and December 2002 obstruction of the esophagus was diagnosed in 78 patients (52 male, 26 female, age range 53-102 years, mean 72.3 years). The etiology of obstruction was squamous cell carcinoma (n = 42) and adenocarcinoma of the esophagus (n = 36). The site of obstruction was in the upper (n = 1), in the middle (n = 38) and in the lower esophagus (n = 39). In 16 cases the gastroesophageal junction was also involved. Four patients had broncho-esophageal fistulas. In all cases the tumor was considered non-resectable. A total of 89 Ultraflex metal stents were introduced endoscopically. In 46 patients dilation with Savary dilators prior to stent placement was required. RESULTS: Stents were placed successfully in all patients. After 48 h, all patients were able to tolerate solid or semisolid food. During the follow-up period eight patients developed dysphagia due to food impaction (treated successfully endoscopically). Eleven patients presented with recurrent dysphagia 4-16 weeks after stenting due to tumor overgrowth and were treated with placement of a second stent. The median survival time was 18 weeks. There was no survival difference between squamous cell and esophageal adenocarcinoma. A cost-effective analysis was performed, comparing esophageal stenting with laser therapy. The mean survival and the cost were similar. A small difference of 156 Euro was noted (3.103 Euro and 2.947 Euro for each group of patients, respectively). A significant improvement in quality of life was noted in patients that underwent stenting (96% and 75%vs 71% and 57% for the first 2 months). CONCLUSION: Placement of self-expanding metal stents is a safe and cost effective treatment modality that improve the quality of life, as compared with other palliative techniques, for patients with inoperable malignant esophageal obstructions. In cases of expansion of the mass a second stent can be used; however, the overall survival of these patients, is poor.

Scintigraphic detection of carcinoid tumors with a cost effectiveness analysis.

AIM: To evaluate the diagnostic sensitivity and accuracy and the cost-effectiveness of this technique in the detection of gastroenteropancreatic carcinoid tumors and their metastases in comparison with conventional imaging methods. METHODS: Somatostatin receptor scintigraphy (SRS) was performed in 24 patients with confirmed carcinoids and 7 under investigation. The results were compared with those of conventional imaging methods (chest X-ray, upper abdominal ultrasound, chest CT, upper and lower abdominal CT). Also a cost-effectiveness analysis was performed comparing the cost in Euro of several combinations of SRS with conventional imaging modalities. RESULTS: SRS visualized primary or metastatic sites in 71.0% of cases and 61.3% of conventional imagings. The diagnostic sensitivity of the method was higher in patients with suspected lesions (85.7% vs 57.1%). SRS was less sensitive in the detection of metastatic sites (78.9% vs 84.2%). The undetectable lesions by SRS metastatic sites were all in the liver. Between several imaging combinations, the combinations of chest X-ray/upper abdominal CT/SRS and chest CT/upper abdominal CT/SRS showed the highest sensitivity (88.75%) in terms of the number of detected lesions. The combinations of chest X-ray/upper abdominal US/SRS and chest CT/upper abdominal ultrasound /SRS yielded also a quite similar sensitivity (82%). Compared to the cost of the four sensitive combinations the combination of chest X-ray/upper abdominal ultrasound/SRS presented the lower cost, 1183.99 Euro vs 1251.75 Euro for chest CT/upper abdominal ultrasound/SRS, 1294.93 Euro for chest X/ray/upper abdominal CT/SRS and 1362.75 Euro for chest CT/upper abdominal CT/SRS. CONCLUSION: SRS imaging is a very sensitive method for the detection of gastroenteropancreatic carcinoids but is less sensitive than ultrasound and CT in the detection of liver metastases. Between several imaging combinations, the combination of chest X-ray/upper abdominal CT/SRS shows the highest sensitivity with a cost of 1294.93 Euro.