New diarylheptanoids from the rhizomes of Dioscorea spongiosa and their antiosteoporotic activity

Bioassay-guided fractionation of the water extract of the rhizomes of Dioscorea spongiosa led to the isolation and identification of new diarylheptanoids, diospongins A - C, together with three known lignans. Their structures, including absolute stereochemistry, were determined by analyses of NMR data, chemical conversions and CD spectrum. The isolated compounds, except for diospongin A, exerted potent inhibitory activities on bone resorption induced by parathyroid hormone in a bone organ culture system.     

Acute toxicity of fatty acids to the freshwater green alga Selenastrum capricornutum

The acute toxicity of fatty acids (C14 to C18) commonly found in wood was determined by the standard algal growth inhibition test using the freshwater green alga Selenastrum capricornutum. Toxicity, quantified as IC50 values, varied depending on the number of total carbons and double bonds. Of the tested acids, oleic (cis-9-octadecenoic) acid showed the highest toxicity (72-h IC50 = 0.47 mg/L) to the alga, and triolein, a triglyceride of oleic acid, showed no apparent toxicity. Further examination of a series of C18:1 acids with a double bond at the 6, 11, or 12 position revealed that both double-bond position and cis or trans configuration affected toxicity. The 72-h IC50 data for these fatty acids and related compounds seemed to correlate well with the melting point (mp), showing two separate linear relationships: at mp < 35 degrees C toxicity increased with increasing melting point, and at mp > 40 degrees C toxicity decreased with melting point.     

A case for gastrointestinal stromal tumor (GIST) with reference to its ultrastructure and 'gain-of-function' mutation

A case for primary gastrointestinal stromal tumor (GIST) is described with reference to its ultrastructural characteristics and mutation within the exon 11 of c-kit gene. A forty-seven years old woman complaining of dysphasia was examined by endoscopy, which depicted a submucosal tumor (70 mm in diameter) with ulcerations at the fundus of the stomach. Histopathologically, the tumor cells had large nuclei and eosinophilic cytoplasm and were frequently during mitosis phase. The tumor cells were immunopositive for KIT, CD 34 and vimentin, suggesting their fibroblast-like characteristics. In contrast, desmin and S-100, a smooth muscle and an enteroglial marker, were not immunopositive within the cells. At least 30 % of the tumor cells possessed MIB-I and 20 % of them possessed p53, which are compatible with fast development of the tumor. By electron microscopy, the tumor cells possessed large oval nuclei, abundant mitochondria, caveolae and smooth endoplasmic reticulums, while no gap junctions were seen on the cells: The tumor cells thus possessed interstitial cells-like characteristics at least in part. DNA mutation search for the tumor cells however realized no gain-of-function mutation within the exon 11 of the c-kit gene, suggesting existence of other mechanism for neoplasmic growth of the tumor cells classified as gastrointestinal stromal tumors.     

A case of superficial esophageal cancer complicated with idiopathic muscular hypertrophy of the esophagus

We hereby reported a case of 60-year old man with superficial esophageal cancer complicated with idiopathic muscular hypertrophy of the esophagus. Endoscopic ultrasonography and CT showed the thickness of esophageal muscular layer, but the accurate diagnosis could not be entertained before operation. Idiopathic muscular hypertrophy of the esophagus is an entity rarely encountered, and most cases are diagnosed at postmortem examination. Only a few cases have been reported regarding its clinical symptoms and images. The etiology remains to be elucidated, and the pathologic features are characterized by significant thickness of inner circular muscular layer of esophagus without degeneration of plexus and ganglionic cells. This case report deals with superficial esophageal cancer complicated with idiopathic muscular hypertrophy of esophagus. Literature review is also included.     

Three new C-14 oxygenated taxanes from the wood of Taxus yunnanensis

Three new C-14 oxygenated taxane-type diterpenes, hongdoushans A-C (1-3), were isolated from the wood of Taxus yunnanensis together with four known diterpenes and two lignans. The absolute stereochemistry of the 2-methylbutyryloxy group attached at C-14 of the taxane skeleton was determined to be S by GC analysis of the methyl ester of 2-methylbutyric acid obtained after alkaline hydrolysis of 1 and 4 followed by treatment with CH(2)N(2). The complete stereostructure of the known compound 2alpha,5alpha,10beta-triacetoxy-14beta-[(S)-2-methylbutyryloxy]-4(20),11-taxadiene (4) was established for the first time. The isolates obtained were evaluated for their antiproliferative activity toward murine colon 26-L5 carcinoma and human HT-1080 fibrosarcoma cell lines.     

Local anesthetic cream prepared from lidocaine-tetracaine eutectic mixture

Local anesthetic creams for the clinical treatment of conditions such as postherpetic neuralgia were prepared as an in-house formulation from the eutectic mixture of lidocaine-tetracaine (LT cream) using two eutectic mixtures of local anesthetic (EMLA) type bases. The LT formulation was compared with a lidocaine-prilocaine (LP cream) eutectic mixture formulated using the same base as EMLA. The chemical stability of lidocaine was examined in advance and was found to be stable for more than 3 months either in LT cream or in LP cream. The release rate of lidocaine from the formulated creams was examined using a cellulose ester membrane. The release rate of lidocaine from LT cream was similar to that from LP cream. The release rate of tetracaine was slightly slower than that of lidocaine in LT cream reflecting the larger molecular size of tetracaine. The penetration rate was examined in vitro using a Yucatan micropig skin. The penetration rate of lidocaine was similar between LT and LP creams. Infiltration anesthesia action examined in guinea pigs indicated that the difference between the two creams was statistically insignificant. The present study suggests the equivalence of the LT and LP creams as a local anesthetic and the potential of LT cream for clinical use either in the easy formulation or in the low-cost formulation.