A 69-year-old man visited our hospital with chief complaints of abdominal pain and vomiting. He was diagnosed as having choledocholithiasis and admitted for treatment. Although endoscopic retrograde cholangiopancreatography was attempted with a duodenoscope, the scope could not be advanced because of a stricture caused by esophageal cancer. A forward-viewing endoscope was passed through the esophagus, allowing observation up to the duodenum. Employing the forward-viewing endoscope, we performed endoscopic sphincterotomy and endoscopic papillary balloon dilation, followed by stone removal with a balloon. No complications occurred such that we were subsequently able to make a smooth transition to esophageal cancer treatment. Because there are cases in which stones can be removed with a forward-viewing endoscope, its use appears to be a possible therapeutic approach.
Soils of a mangrove forest composed of the two main species of Rhizophora mucronata and Bruguiera gymnorrhiza in the Nagura estuary, Ishigaki Island, Japan, were studied with special reference to the difference in some properties of soil of the two species. Compared with those under B. gymnorrhiza, the soils of the mixed forest dominated by R. mucronata showed higher levels of water-soluble bases, especially sodium, and electric conductivity, suggesting that R. mucronata can tolerate and grow on more saline conditions of soils than can B. gymnorrhiza. Contents of pyritic iron and sulfur were higher in the soils of the mixed forest dominated by B. gymnorrhiza, where anaerobic conditions were more pronounced probably due to the supply of relatively high amounts of organic debris. There was little difference in the clay mineralogy, but in the silt and sand fractions, aragonite and calcite were abundant in the soils of the mixed forest dominated by R. mucronata.
Summary Low molecular weight organic acids are widespread and reactive in soils, but their distribution among mineral horizons is uncertain. We investigated the distribution of low molecular weight aliphatic carboxylic acids (LACAs) in three Japanese forest soils, two Acid Brown Forest soils and one Podzolic soil. The total LACAs ranged from 207.3 to 411.8 μmol kg –1 and were abundant in the lower horizons as well as in the surface horizons of these soils. The illuvial horizons of the Podzolic soil were rich in adsorbed oxalic acid and citric acid. Total LACAs were similar in the two subtypes of Brown Forest soils derived from different parent materials but formed under similar vegetation and climate, and were larger than that in the Podzolic soil. Among the volatile LACAs, formic acid and acetic acid dominated the moist horizons containing much organic material, whereas the non‐volatile LACAs, the most abundant being oxalic acid and citric acid, increased in the subsurface horizons. The distribution of water‐soluble LACAs in the Brown Forest soil profiles was closely correlated with soil acidity.
