Highly powerful and practical acylation of alcohols with acid anhydride catalyzed by Bi(OTf)(3).

Bi(OTf)(3)-catalyzed acylation of alcohols with acid anhydride was evaluated in comparison with other acylation methods. The Bi(OTf)(3)/acid anhydride protocol was so powerful that sterically demanding or tertiary alcohols could be acylated smoothly. Less reactive acylation reagents such as benzoic and pivalic anhydride are also activated by this catalysis. In these cases, a new technology was developed in order to overcome difficulty in separation of the acylated product from the remaining acylating reagent: methanolysis of the unreacted anhydride into easily separable methyl ester realized quite easy separation of the desired acylation product. The Bi(OTf)(3)/acid anhydride protocol was applicable to a wide spectrum of alcohols bearing various functionalities. Acid-labile THP- or TBS-protected alcohol, furfuryl alcohol, and geraniol could be acylated as well as base-labile alcohols. Even acylation of functionalized tertiary alcohols was effected at room temperature.

Insulinoma with subsequent association of Zollinger-Ellison syndrome.

We report a patient with insulinoma associated with Zollinger-Ellison syndrome. A 67-year-old woman was first admitted to our hospital for an abdominal mass. Abdominal computed tomography (CT) revealed a large pancreatic tumor, which was then diagnosed as an unresectable pancreatic adenocarcinoma. At the age of 71, she presented symptoms of hypoglycemia. Fasting blood glucose was 21 mg/dl and plasma immunoreactive insulin level was 846 microU/ ml. Plasma gastrin, glucagon, vasoactive intestinal polypeptide and somatostatin levels were all normal. At the age of 73, hypoglycemic attacks occurred more frequently and she was admitted to our hospital. Abdominal CT scan showed multiple liver metastases. Chemotherapy with 5-fluorouracil and doxorubicin was performed. Three months later, she had an emergency laparotomy because of a perforated duodenal ulcer. Plasma gastrin level was 1,960 pg/ml at that time. Gastric hypersecretion was well controlled with a proton pump inhibitor (lansoprazole) but she died of widespread cancer dissemination 8 years after her first admission. On autopsy, histologic examination revealed a mixed acinar-endocrine carcinoma of the pancreas. Immunohistochemical stains were positive for insulin, gastrin, and alpha1-antitrypsin.

MELAS with the mitochondrial DNA 3243 point mutation: a neuropathological study.

We performed a neuropathological examination of the central nervous system from seven autopsied patients with mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS). Five of the seven cases were confirmed to have the mitochondrial DNA (mtDNA) 3243 point mutation. In addition to the changes reported previously, diffuse atrophy of the cerebral and cerebellar cortices, diffuse gliosis of cerebral and cerebellar white matter, and cactus formation of Purkinje cells were observed. Electron microscopy revealed accumulation of mitochondria in the cactus formations. These lesions are common in MELAS with the mtDNA 3243 point mutation, but cannot be explained solely by mitochondrial angiopathy, and suggest that intrinsic mitochondrial malfunction contributes to neuronal damage in MELAS pathology. Moreover, the pathological changes observed in the cerebellum suggest that cerebellar function should be evaluated more carefully at the clinical level.