Nobuo Hiratsuka

Analysis of urinary albumin, transferrin, N-acetylβ-D-glucosaminidase and β2-microglobulin in patients with impaired glucose tolerance

We investigated the changes in urinary albumin and urinary transferrin as glomerular proteins, and in urinary N‐acetyl‐β‐D‐glucosaminidase and urinary β2‐microglobulin as tubular proteins, in patients with impaired glucose tolerance. We attempted to compare the proteins of normal subjects to those of diabetics with pre‐nephropathy. Transferrin and N‐acetyl‐β‐D‐glucosaminidase levels were significantly increased in patients with impaired glucose tolerance, while albumin and β2‐microglobulin levels were only slightly increased. In addition, there was no significant difference in transferrin levels between patients with impaired glucose tolerance and type 2 diabetics with pre‐nephropathy.

Rapid and highly sensitive colloidal silver staining on cellulose acetate membrane for analysis of urinary proteins

In order to establish a rapid staining method sensitive enough to stain the protein bands on cellulose acetate membrane and suitable for the analysis of urinary proteins in healthy subjects, we conducted a detailed examination of Kovariks method designed for the analysis of proteins in cerebrospinal fluid in detail. For purpose of our study, we changed the pH of the staining solution used in Kovariks method to pH 4.4 by adding acetic acid. With this solution, our staining method revealed a degree of sensitivity about three times higher than that of the original method, but specific sensitivity for albumin and γ‐globulin remained almost unchanged. The solution preparation we used was much more simple and the reagent much more stable than in the original method. Our method also showed better reproducibility and linearity than the original method. These results point to the suitability of this method for the analysis of low‐concentration proteins, such as urinary proteins, in healthy subjects.