Yutaka Emoto

Purification and characterization of a new member of the S-100 protein family from human placenta

A novel Ca(2+)-binding protein which is termed S-100P was purified from human placenta with a hydrophobic column followed by an anion exchange column and reverse phase high performance liquid chromatography (HPLC). Molecular mass of the protein was 10 kDa according to sodium dodecyl sulfate (SDS) polyacrylamide gel electrophoresis. Using immunoblotting technique, anti-human calcyclin antibodies did not bind to the S-100P. Isoelectric point of S-100P was pI = 4.6. S-100P did not formed disulfide-linked dimer. Calcium binding ability was proved by UV difference spectrometry, urea/alkaline gel electrophoresis, and 45Ca overlay technique. A ninety amino acid sequence of S-100P was determined. It is 49% identical with human S-100 beta, 38% with human calcyclin, and 37% with human cystic fibrosis antigen.

Effect of hemodialysis on plasma levels of vasoactive peptides: endothelin, calcitonin gene-related peptide and human atrial natriuretic peptide.

To determine the role of vasoactive peptides such as endothelin (ET), calcitonin gene-related peptide (CGRP) and human atrial natriuretic peptide (hANP) in the regulation of blood pressure in uremic patients, and to determine the effect of various types of dialyzer membranes on hemodialysis (HD)-induced changes in plasma levels of such peptides, plasma ET, CGRP and hANP were measured in HD patients and patients on continuous ambulatory peritoneal dialysis (CAPD). Plasma levels of ET, CGRP, and hANP were significantly higher in HD and CAPD patients than in healthy subjects. There were no significant differences in plasma levels of ET, CGRP, and hANP between hypertensive and normotensive HD patients, and no significant correlation was observed between HD-induced changes in plasma levels and changes in blood pressure. Plasma levels of ET decreased when HD was performed using high-flux membranes, such as polyacrylonitrile (PAN), polymethyl methacrylate (PMMA) and cellulose triacetate (CTA), but did not decrease using a saponified cellulose (SC) membrane. Plasma levels of CGRP decreased in the case of PAN, but increased significantly with PMMA and showed no change with SC and CTA. Plasma levels of hANP decreased in all types of dialyzer membranes due to decreased secretion. These results indicate that the effect of HD on plasma levels of ET and CGRP, but not hANP, depends on the type of dialyzer membrane used.

Urinary trehalase activity in chronic glomerulonephritis

To determine the diagnostic role of urinary trehalase in chronic glomerular disease, urinary trehalase activity and other urinary markers such as N-acetyl-beta-D-glucosaminidase (NAG), alanine aminopeptidase (AAP), alkaline phosphatase (ALP), gamma-glutamyltranspeptidase (gamma-GTP), lactate dehydrogenase (LDH), lysozyme and beta 2-microglobulin (BMG) were measured in patients with chronic glomerulonephritis, nephrotic syndrome and chronic renal failure. Urinary trehalase activity was significantly increased in chronic glomerular disease, especially nephrotic syndrome, as compared with that in the healthy subjects. The highest incidence of elevated excretion was observed for trehalase with 52% in chronic glomerular disease, followed by NAG. Urinary trehalase activities in the patients were significantly correlated with the urinary levels of protein, NAG and AAP and total score of tubular damage, but not correlated with urinary levels of BMG or lysozyme. In patients with chronic glomerulonephritis and nephrotic syndrome, there was no significant difference in urinary trehalase activities between with and without hematuria. These results indicate that in some patients with chronic glomerular disease, there is tubular involvement as substantiated by elevation of the other urinary enzymes and BMG. Urinary trehalase is elevated more often in these types of disease than other markers of tubular damage.