We found that the relationship between the molecular mass of a protein and its mobility in polyacrylamide gel electrophoresis in the presence of sodium dodecylsulfate on an inverse-gradient (15-5%) gel is linear on a double logarithmic plot. In contrast, this relationship is not linear for proteins resolved on a standard 10% gel, but is fitted to two straight lines. Both gel types gave a similar slope in resolving proteins smaller than 100 kDa but inverse-gradient (15-5%) gel separated proteins with wider range of molecular mass. On the other hand, the standard 10% gel provided better separation of proteins larger than 100 kDa. These results suggest that the 15-5% inverse-gradient gel is best suited for the separation of proteins smaller than 100 kDa. The advantage of inverse-gradient gel SDS-PAGE may stem from the fact that unstacking of SDS-protein complexes in inverse-gradient gels is faster and more complete than in standard 10% gels.

View full abstract

Background/aim: Electrophoresis is useful for examining the lipoprotein fraction patterns. A simultaneous and cost-effective addition of cholesterol levels in each lipoprotein fraction to the lipoprotein patterns can more assist clinical decision-making. This study' aim was to develop the formulas for estimating the fractionated lipoproteins cholesterol levels in a recent system, the agarose gel Sebia HYDRAGEL LIPO+Lp(a) electrophoresis. Methods: Serum samples were analyzed by two Sebia electrophoresis, HYDRAGEL LIPO+Lp(a) and the quantitative HYDRAGEL LDL/HDL-CHOL Direct methods. The formulas for estimation of relative cholesterol (%) of individual lipoprotein fractions were developed using linear regression models. Thereafter, the calculated lipoproteins cholesterol values by multiplying the relative cholesterol with total cholesterol concentrations were compared with the standardized enzymatic assayed values. Results: The equations for calculating % relative cholesterol (y) from % relative lipoprotein (x) were y=x-8, x+21 and 0.75x-6.5 for high-density lipoprotein (HDL), low-density lipoprotein (LDL) and very low-density lipoprotein (VLDL) fractions, respectively. Regression statistics obtained between the calculated assays (y) and the standardized enzymatic assays (x') in samples with and without Lp(a) were y=1.07x'- 0.18 and 1.06x'-0.06, respectively for HDL-cholesterol, y=0.90x'+0.32 and 0.92x'+0.29 for LDL-cholesterol, and y=0.85x'-0.03 and 0.95x'+0.02 for VLDL-cholesterol. Conclusions: The proposed formulas can provide a reliable estimation of cholesterol levels in each major lipoprotein fraction by the HYDRAGEL LIPO+Lp(a) electrophoresis. Further studies with its application are needed.

View full abstract

In ureterolithiasis and nephrolithiasis patients, urinary total protein (TP), albumin (Alb), and IgG levels were significantly higher than those in control subjects, whereas THP was unchanged, Alb/TP ratio was significantly increased, and THP/TP ratio was significantly decreased in ureterolithiasis patients only. All proteins in patients with initial and recurrent ureterolithiasis were unchanged. However, TP and Alb levels in patients with recurrent nephrolithiasis were 10 times higher than those in patients with initial nephrolithiasis; IgG and THP levels were also higher in recurrent diagnosis patients. In patients with initial and recurrent ureterolithiasis, the rate of increase of urinary proteins before and after extracorporeal shockwave lithotripsy (ESWL) treatment was 8.9±12.5 and 8.4±1.7 fold. TP level of initial and recurrent nephrolithiasis patients before and after ESWL was 48.8±28.2 and 12.8±9.5 fold rate of increase, respectively. Alb level of initial patients was 58.9±50.4 fold rate of increase and that of recurrent patients was 9.9±8.2 fold. We observed changes in levels and molecular heterogeneity of Alb, THP, and IgG proteins. The Alb, THP, and IgG bands with various molecular sizes in patients were detected when compared to control subjects. This study suggested that the heterogeneity of Alb, THP, and IgG proteins may be involved in stone formation.

View full abstract

We tried to determine the variations of levels and molecular heterogeneities of various proteins which occur in type 2 diabetes patients during short-term hospitalization for glycemic control. Type 2 diabetes patients were classified into 2 groups: only oral diabetes medicine therapy (group I) and only insulin and/or insulin plus oral diabetes medicine therapy (group II). All urinary proteins in group I tended to decrease on discharge day. Tamm-Horsfall protein (THP) levels of group II significantly increased on discharge day. There were significant correlations between each protein except with THP on day of admission and discharge of group I. In addition, there were no correlations between THP and other proteins except with α₁-antitrypsin (α₁-AT) in group II. Comparison of blood glucose level and HbA1c on admission day and first clinic day after discharge revealed that HbA1c level on discharge day was significantly lower in group II. We examined the molecular size of various proteins by SDS-PAGE and western blotting. In both groups, 9 α₁-AT bands of different molecular sizes were detected besides a main band, but in group II, a 43 kDa α₁-AT fragment, in urine collected closer to discharge day was found to be more densely stained than that in urine collected on admission day. These results revealed that glycemic control by insulin increased THP levels, remarkably reduced other protein levels, and caused urinary α₁-AT to be of low molecular size.

View full abstract