Kenzo Kato

Antibody against synthetic multiple antigen peptides (MAP) of JC virus capsid protein (VP1) without cross reaction to BK virus: a diagnostic tool for progressive multifocal leukoencephalopathy☆

Antibody against JC virus (JCV) was raised in rabbits with the use of synthetic multiple antigen peptides. The peptide sequences were derived from three regions of JCV VP1 protein, which showed less similarity with BK virus (BKV) counterpart. The antibodies raised with these peptides were designated as JCAb1, 2 and 3. JCAb1 specifically reacted with JCV and not with BKV, while JCAb2 and 3 reacted both with JCV and BKV. All of these antibodies reacted with JCV antigen of formalin-fixed paraffin sections of progressive multifocal leukoencephalopathy (PML) brain tissue. As JCAb1 is JCV-specific and reacted with JCV in formalin-fixed paraffin sections, it will contribute not only to rapid and accurate immunohistochemical diagnoses of PML but also to clarification of the pathogenesis of JCV infection.

1H- and 13C-NMR spectroscopic study of the metabolites in young adult Angiostrongylus cantonensis maintained in vitro

1H- and 13C-nuclear magnetic resonance (NMR) spectroscopy were used to study metabolites excreted by young adult Angiostrongylus cantonensis maintained aerobically in the presence of D-[13C6]glucose. End-products of glucose metabolism identified and quantitated by means of 1H-NMR were lactate, acetate and alanine, in the molar ratio of 1:0.13:0.05 for males and 1:0.07:0.04 for females. 13C-NMR analyses proved that all the three products originated from the glucose present in the medium.

Cerebral metabolism in brain tumor of mice studied by in vivo 31P-NMR spectroscopy

We now report a mouse model system of brain tumor for 31P-NMR spectroscopic study of in vivo cerebral metabolism. In vivo 31P-NMR (109 MHz) spectra were taken on the 9th day by the Faraday shield method of the brain of mice (3-week-old) transplanted intracerebrally with mKS X A tumor cells. In tumor-bearing mice, the amount of creatine phosphate decreased markedly and that of inorganic phosphate plus sugar phosphate increased accordingly. Furthermore, the broadening and splitting of individual signals were also noted with tumor-bearing mice; this is interpreted as indicating a variety of changes in chemical shift occurring in the brain of the animals due to heterogeneous distribution of pH. Binding or detaching of divalent cations to and from phosphometabolites may also be responsible for these changes.

In vitro study of the binding of terbium to tryptophan by 1H-NMR and fluorescence spectroscopy

Terbium (Tb), a rare earth element having an ionic radius similar to that of Ca2+, is used as an antagonist of Ca2+. Recently, we found that when giant axon membrane of a loligo treated with Tb was excited at 290 nm, where tryptophan (Trp) gives absorption mechanism, emits fluorescence of Tb at 490 nm and 545 nm in addition to that of Trp at 345 nm. The present study was undertaken to locate on the Trp molecule the interaction between Trp and Tb by carrying out in vitro binding experiments with Tb and Trp and the molecular mechanism was analyzed by 1H-NMR spectroscopy and fluorescence spectroscopy. Fluorescence spectroscopy showed that Tb and Trp are combined at a molecular ratio close to 1:1. 1H-NMR spectroscopy revealed that Tb interacts with the amino group at the alpha-position and the imido group of the indole ring of Trp. Since all amino groups of Trp are involved in peptide linkages in vivo, it seems likely that the binding of Tb to Trp is undertaken by the imido group of the indole ring.