Determination of N-acetyl-ß-hexosaminidase in serum from hemolyzed blood.

BACKGROUND: Determination of lysosomal N-acetyl-ß-hexosaminidase (HEX) in serum from hemolyzed blood, creates serious analytical problems, because hemoglobin absorbs light at a similar wavelength like 4-nitrophenol, which is released from artificial substrate. OBJECTIVE: The objective of the work was to adapt a manual method to allow analysis of HEX in hemolyzed samples. METHODS: Serums without and with hemolysis were incubated with 4-nitrophenol-N-acetylglucosamine as a substrate. Released 4-nitrophenol was determined colorimetrically. After the incubation of the serum from hemolyzed blood with substrate, hemoglobin was precipitated with trichloroacetic acid (TCA) before 4-nitrophenol determination. RESULTS: The mean concentration of HEX activity in non-hemolyzed and hemolyzed blood of the same patients, determined with non-modified and modified methods had no significant differences, and they are: 243.12±119.76 and 233.99±108.76pkat/mL, respectively. A coefficient of correlation between non-modified and modified methods equals the 0.98. For HEX determination with the modified method in serum from hemolyzed blood, optimal reaction time was 60min, pH of reaction mixture was 4.7, and Km was 0.11mMm. CONCLUSION: HEX determinations in the same serums from non-hemolyzed blood by the non-modified method and hemolyzed blood with the modified method, gave similar results with a 0.98 coefficient of correlation. The modified method is appropriate for HEX determination in serum from hemolyzed blood.

Urinary monocyte chemoattractant protein-1 excretion in children with glomerular proteinuria.

OBJECTIVE: The aim of the study was to examine the urinary levels and clinical significance of monocyte chemoattractant protein-1 (uMCP-1) in children according to histological diagnosis and degree of proteinuria. MATERIAL AND METHODS: Group I comprised 20 children with idiopathic nephrotic syndrome (INS), examined twice (A, during INS relapse; and B, after proteinuria subsided). Group II comprised 17 children with persistent proteinuria due to focal segmental glomerulosclerosis (FSGS). Group III included 12 children with immunoglobulin A nephropathy (IgAN). The control group (C) contained 22 healthy children. uMCP-1 was determined by enzyme-linked immunosorbent assay and expressed in pg/ml. RESULTS: The median uMCP-1/creatinine ratio (uMCP-1/cr) in children with minimal change disease in relapse (IA) was significantly higher than in controls (p < 0.05), but when controlling for cyclosporine A (CsA) treatment the median uMCP-1 in children with INS, who were not treated with CsA, was 12.01 pg/mg cr (range 1.82-261.56 pg/mg cr) and did not differ from healthy controls. In examination IB the uMCP-1/cr concentration decreased and did not differ from healthy controls (p > 0.05). Children from groups II and III also had higher uMCP-1/cr levels than groups I and C (p < 0.01). uMCP-1/cr positively correlated with serum total cholesterol, low-density lipoprotein and protein/creatinine ratio in relapse (IA), and with serum cholesterol level in group B. A positive correlation between uMCP-1/cr and protein/creatinine ratio was also confirmed in groups II and III. CONCLUSION: Increased uMCP-1 was found in children with IgAN and FSGS correlated with proteinuria. A slight increase in uMCP-1 in children with INS was probably associated with CsA treatment.

[WT1 mutation as a cause of progressive nephropathy in Frasier syndrome--case report]. / Mutacja genu WT1 jako przyczyna postepujacej nefropatii w zespole Frasiera--opis przypadku.

Frasier syndrome is an uncommon genetic disorder featuring progressive glomerulopathy, male pseudohermaphroditism and gonadal dysgenesis. It is caused by mutations in intron 9 of the WT1 gene. Because of its rarity there is limited literature available on the diagnosis and treatment of this syndrome. The aim of the study was to present the clinicopathological findings and molecular analysis of phenotypically female adolescent presenting with severe proteinuria and primary amenorrhea. The significance of early recognition of Frasier syndrome and its differentiation from Denys-Drash syndrome was discussed. WT1 mutation analysis should be routinely done in females with steroid-resistant nephritic syndrome.

[Matrix metalloproteinases 2 and 9 and their tissue inhibitors 1 and 2 in the urine of children with pyelonephritis]. / Metaloproteinazy 2 i 9 oraz ich tkankowe inhibitory 1 i 2 w moczu dzieci chorych na odmiedniczkowe zapalenie nerek.

UNLABELLED: In small children, pyelonephritis (PN) is an important cause of scarring in the renal and disturbed in the production and degradation of extracellulare matrix proteins (ECM). Aim of the study was to assess the urinary levels metalloproteinases 2 and 9 (MMP-2 and MMP-9) and their inhibitors 1 and 2 (TIMP-1 and TIMP-2) in children with pyelonephritis (PN). MATERIALS AND METHODS: Study group (I) consisted of 42 children with PN, aged 1-15 years, examined twice: A--prior to treatment (1-3 days of fever), B--after antibacterial treatment (10-14 days). The control group (K) consisted of 30 healthy children. Enzyme-linked immunosorbent assay kits were used for measurements of total human MMP-2, MMP-9, TIMP-1 and TIMP-2 in first morning urine. RESULTS: In children with PN (I) prior to treatment (A), urinary concentration of all parameters were increased as compared to the control (K) (p<0.05). After treatment (B), only the levels of TIMP-1 was still elevated (p = 0.02). In PN before (A) and after (B) treatment MMP-9/TIMP-1 ratio. However MMP-2/TIMP-2 ratio was normal. CONCLUSION: In children with PN the balance MMP-9/TIMP-1 is disturbed, with the predominance of TIMP-1 production over MMP-9. It may lead to renal fibrosis.

[Role of matrix metalloproteinases (MMP) and their tissue inhibitors (TIMP) in nephrology]. / Rola metaloproteinaz (MMP) i ich tkankowych inhibitorów (TIMP) w nefrologii.

Metalloproteinases (MMP) and their tissue inhibitors (TIMP) play a crucial role to keep the balance between the synthesis and degradation of extracellular matrix protein. Balance disturbances of those two systems lead to abnormal tissue remodeling. There is evidence that matrix metalloproteinases activity changes in many pathological conditions, including inflammatory, degenerative disorders as well as tumor progression. Recent investigations indicate that MMPs and TIMPs play a pivotal role in pathogenesis of most of kidney diseases. Studies describing dysregulated activity of MMPs and/or their tissue inhibitors in various experimental and clinical models of kidney disease, including chronic kidney disease, glomerulonephritis, pyelonephritis, diabetic and hypertensive nephropathy, polycystic kidney disease and renal cancer are reviewed.