Aberrant expression of sialidase and cancer progression

Aberrant sialylation is closely associated with the malignant phenotype of cancer cells including metastatic potential and invasiveness. However, its biological significance and molecular mechanisms have yet to be fully elucidated. To determine causes and consequences, we have focused attention on mammalian sialidases, which cleave sialic acids from gangliosides and glycoproteins. The four types of human sialidases identified to date behave in different manners during carcinogenesis. One, found in the lysosomes, shows down-regulation in cancers, promoting anchorage-independent growth and contributing to metastatic ability, while another, found in the plasma membranes, exhibits marked up-regulation, resulting in suppression of apoptosis. The present review summarizes mostly our results on aberrant expression of sialidases and their possible roles in cancer progression.     

Mössbauer spectroscopic study of meteorites recovered on Antarctica

The chemical states of iron in sixteen Antarctic meteorites belonging to H-group chondrites were studied by means of Mössbauer spectroscopy. An Fe-Ni alloy, troilite, paramagnetic Fe(III), and two kinds of paramagnetic Fe(II) were observed in each meteorite. The Mössbauer parameters indicated that the Fe(II) components can be assigned to olivine and some pyroxenes. The relative area intensities of Fe(III) in the chondrites correlated positively with iodine content, which was determined by radiochemical neutron activation analysis, and those of two Fe(II)-species correlated negatively with the content. On the basis of the data on the halogen and the Mössbauer spectrocopy, the terrestrial contamination on Antarctic meteorites is discussed.     

Evaluation of gallbladder emptying in patients with chronic liver disease by 99mTc-EHIDA hepatobiliary scintigraphy

Gallbladder emptying after intramuscular injection of cerulein was investigated by 99mTc-EHIDA hepatobiliary scintigraphy in 23 patients with biliary disease, 55 patients with chronic liver disease, and 21 normal controls. The mean gallbladder ejection fraction in patients with gallstones and liver cirrhosis was significantly reduced compared with normal controls. (gallstones: 56.3 +/- 21.3%, LC with gallstones: 50.8 +/- 29.6%, LC without gallstones: 55.9 +/- 26.7%, vs. normal controls: 74.4 +/- 12.9%, p less than 0.01). The mechanism for sluggish gallbladder emptying in liver cirrhosis is unknown, however impaired emptying with bile stasis provides a potential pathophysiologic basis for the high frequency of pigment stones.     

Synthesis of indole derivatives from 2-bromoanilines by a palladium-assisted reaction

In the presence of palladium(II) acetate, 2-bromoanilines readily react with enamines such as N-vinyl-pyrrolidone or α-piperidinostyrene to produce indole derivatives.     

Spectrophotometric determination of phosphate using lanthanum chloranilate

The spectrophotometric determination of phosphate using lanthanum chloranilate has been investigated. It is possible to determine 3–300 ppm of phosphate with an accuracy of ±2%, if suitable conditions are chosen. Chloride or nitrate ions do not interfere up to 400 ppm. Interference from sulphate ion can be compensated for by adding a large amount of sulphate both to the sample and to the standard solutions. This method is simpler, has less critical reaction conditions, and develops a much more stable coloration than the conventional heteropolyacid methods.     

Effect of oxygen substituents on the regioselectivity of the Pd-assisted biaryl coupling reaction of benzanilides

This study investigated the effect of oxygen substituents in the benzoyl part of N-(2-iodophenyl)benzamide on the coupling position in its Pd-assisted biaryl coupling reaction. Benzamide with methylenedioxy and acyloxy groups yielded the ortho-product formed predominantly by connection to a more hindered carbon. The mechanism is discussed from the perspectives of both steric and coordinated effects.     

Manganese(III) acetate oxidation of 1-acetylindole derivatives

In the presence of malonic acid, the reaction of 1-acetylindole ( 2 ) with manganese(III) acetate resulted in the formation of 4-acetyl-3,3a,4,8b-tetrahydro-2H-furo[3,2-b]indol-2-one ( 5 ). The same reaction of 1-acetyl-2,3-dimethylindole yielded a mixture of 2-acetoxymethyl-1-acetyl-3-methylindole and 4-acetyl-3a,8b-dimethyl-3,3a,4,8b-tetrahydro-2H-furo[3,2-b]indol-2-one, furthermore, the oxidation of 1-acetylindoline proceeded to the formation of 2, 5 and 1-acetylindoline-5-carboxylic acid.     

Synthesis of indoles via amidoselenation

The reaction of 2-styrylacetanilides (2) with N-phenylselenosuccinimide affords 1-N-acetyl-2-phenyl-3-phenylselenoindoles (3) and 1-N-acetyl-2-phenylindoles (4) . The reaction of 2-vinylacetanilides (5) with phenylselenenyl bromide proceeds to form indoles via an intramolecular amidoselenation.