Relationship between plasma Cystatin C and creatinine in chronic renal diseases and Tx-transplant patients

OBJECTIVES

Glomerular filtration rate (GFR) is the best overall index of renal function in health and disease. Recently, Cystatin C (Cyst C), a low molecular weight protein freely filtered through the glomerulus, and almost completely reabsorbed and catabolized by tubular cells, has been proposed as a new and very sensitive serum marker of change in GFR. This study investigated the relationship between Cyst C and creatinine (CR) in renal disease patients.

METHODS

Serum Cyst C was determined by particle-enhanced immunoturbidimetry using the Cyst C PET-kit. The results could be obtained within 1 h. Cuvettes were washed before the Cyst C assay as recommended. Serum CR, BUN and albumin were determined by auto-analyzer.

RESULTS

A strong correlation was observed between Cyst C and CR (P = 0.001, r = 0.764 and P = 0.0001, r = 0.888, respectively) in prehemodialysis (pre-HD) and kidney transplantation (Tx-kidney), whereas there was a weak correlation in continuous ambulatory peritoneal dialysis (CAPD) (P = 0.05, r = 0.535).

CONCLUSION

These findings suggest that serum Cyst C may be considered as a sensitive predictive parameter for reduced GFR. It is of value for the laboratory diagnosis of chronic renal failure and should be preferentially used for CR clearance.

The Effects of Hyperbaric Oxygen Treatment on Oxidant and Antioxidants Levels during Liver Regeneration in Rats

The effects of hyperbaric oxygen (HBO) therapy on oxidant/antioxidant metabolism are controversial and its effects on hepatic regeneration are not known. In this study, we investigated a possible beneficial effect of HBO therapy on oxidant and antioxidants levels during liver regeneration. To conduct this study, seventy percent hepatectomy was performed on forty-eight Spraggue-Dawley rats and the rats were divided into two equal groups: HBO-treated group and untreated group (non-HBO group). We determined the levels of malondialdehyde (MDA), an oxidative stress marker, and the levels of antioxidant enzymes/reagents, including glutathione (GSH), superoxide dismutase (SOD) activity, copper (Cu) and zinc (Zn), in the remnant liver samples. We also measured mitotic index (MI) and proliferating cell nuclear antigen (PCNA) levels to assess the degree of liver regeneration. HBO treatment significantly decreased MDA levels, whereas it increased SOD activity, GSH and Zn levels. In contrast, Cu levels were lower in the HBO-treated livers than the levels in the untreated remnant livers. The effect of HBO treatment may be mediated by the suppression of certain enzymes that are responsible for lipid peroxidation. In addition, HBO treatment may induce the production of antioxidant enzymes/reagents by remnant liver tissues. The HBO-treated rats maintained their body weights but the untreated rats lost body weights. HBO treatment also increased MI and PCNA levels, indicating HBO treatment enhances liver regeneration. These results indicate that HBO treatment has beneficial effects on liver regeneration by decreasing MDA and by increasing antioxidant activities. We therefore suggest that HBO therapy may be useful after liver resection.

The evaluation of lipid peroxidation and acute effect of octreotide on lipid peroxidation in patients with active acromegaly

BACKGROUND

Although lipid peroxidation has been suggested to play a role in the etiology of many diseases, there is no report about its role in acromegaly in the literature. In the present study, we analyzed the basal levels of lipid peroxides (LPO) in newly diagnosed acromegalic patients, and to evaluate whether octreotide (OCT) has any effect on lipid peroxidation in these patients.

METHODS

Plasma lipid peroxide levels before and after acute OCT administration were measured in 12 newly diagnosed acromegalic patients. Blood samples were drawn at basal and 4, 8, and 24 h after octreotide injection (100 microg s.c.). Plasma concentrations of lipid peroxides were estimated from measurement of thiobarbituric acid reactive substance (TBARS), using 1,1,3,3-tetra-ethoxypropane as a standard.

RESULTS

This study shows that acromegalic patients have significantly higher basal plasma lipid peroxides levels compared to hours after OCT injection (p<0.001). Although a significant decrease was observed after 8 and 24 h in comparison to basal level (p<0.001), the lipid peroxide levels tended to increase at 24 h though still low when compared to basal level.

CONCLUSION

Acromegalic patients have high basal lipid peroxide levels, which was significantly decreased after OCT administration.