In an attempt to search for risk factors which can explain the increasing prevalence of coronary heart disease (CHD) in Indian population, we conducted a case-control study to assess the association of Lipoprotein (a)(Lp(a)) with CHD. One hundred and fifty one consecutive patients with clinical and angiographic evidence of CHD and forty-nine healthy controls were drawn for the study. Triglycerides, very low density cholesterol (VLDL-C), total cholesterol (total-C)/high density cholesterol (HDL-C) ratio, low density cholesterol (LDL-C)/HDL cholesterol ratio and Lp(a) were found to be higher in patients than controls. In female sex and in those with family history of CHD, higher total and LDL cholesterol levels were observed to be associated with higher Lp(a) levels. Lp(a) levels were also found to be higher in triple vessel disease than other vessel disease patients. Significant difference in Lp(a) levels were observed between normal coronaries vs. single and triple vessel disease(P<0.05) and also between single vs. double and triple vessel disease (P<0.01).Lp(a) levels correlated positively with vessel severity(P<0.005). Lp(a) levels >25 mg/dl were associated with coronary heart disease (Odds ratio 1.98 P<0.05 95% CI 0.007-1.18). Our findings suggest a cut-off level of 25mg/dl for determination of risk of CHD. Studies from different areas involving larger sample size are needed to confirm the findings of the present study.

Oxidative stress is likely to be involved in the development of complications due to haemodialysis. Though there is evidence for production of oxygen free radicals during haemodialysis, reports on net oxidative imbalance due to a single dialysis session are conflicting. Hence, a time-course analysis of changes in lipid peroxides (LPO) along with antioxidant enzymes and vitamins was carried out. Hourly changes in LPO and antioxidants were studied during a first-use cuprophan membrane and acetate dialysis in 20 patients on regular haemodialysis treatment. Data were corrected for haemoconcentration and standardised to measure the rate of change before statistical evaluation using analysis of variance for repeated measures. The results of the study showed a net oxidative stress due to a single dialysis session in the form of increased plasma and erythrocyte lipid peroxidation, decrease in plasma vitamin E, slight increase in plasma superoxide dismutase and erythrocyte glutathione peroxidase and no change in plasma glutathione peroxidase. erythrocyte superoxide dismutase and plasma vitamin A levels. The oxygen radical production was found to be maximum in the first hour of dialysis.

Postoperative hyperbilirubinemia is one of the complications of cardiopulmonary bypass. This prospective study was conducted on 77 patients who underwent open-heart surgery, to evaluate the incidence, risk factors, and prognostic significance of postoperative hyperbilirubinemia. Liver function tests were conducted preoperatively, immediately after surgery and on the 1st, 3rd, and 7th postoperative days. The overall incidence of postoperative hyperbilirubinemia was 26%. The incidence was significantly higher in patients who underwent prosthetic valve replacements (31%) than in those without prostheses (22%) and very high in patients undergoing double valve replacement (50%) compared to single valve replacement (27%). Most (90%) of the increase in serum bilirubin was due to a rise in unconjugated bilirubin on the 1st postoperative day. There was no mortality related to postoperative hyperbilirubinemia but it prolonged intensive care stay when it occurred early after surgery and prolonged hospital stay when it occurred later. Preoperative total bilirubin concentration, number of valves to be replaced, and preoperative high right atrial pressure were the factors associated with increased risk of postoperative hyperbilirubinemia by logistic regression analysis.

Oxygen free radicals have been implicated in the long-term complications of maintenance haemodialysis. Studies that have probed into the mechanisms of oxygen radical production have implicated the bio-incompatibility of dialysis membranes. Changes between the arterial (inlet) and venous (outlet) points of a dialyser may give a better picture of blood±membrane interaction. There are very few studies on changes across the dialyser. Hence, it was planned to study the immediate changes that occur due to passage of blood through the dialyser. Changes between the arterial and venous ends of the dialyser after 1 h of dialysis were studied in four combinations of dialysate and membrane. There was a signi®cant decrease in plasma vitamin E concentrations in all the groups during ®rst-use dialysis. This was not observed with re-use dialysis. A decrease in plasma lipid peroxides was also observed in all the groups with both ®rst and re-use dialysis. There was no signi®cant difference in the parameters studied among the four types of dialysis. A less severe, reactive oxygen radical generation was observed with re-use of membranes.

Analyses of body fluids in clinical chemistry laboratory are subject to a number of interferences that affect the analytical accuracy. The interferents arise from exogenous sources like drugs and additives as well as such endogenous sources like lipemia, hemolysis and icteria. Our studies demonstrate matrix interference in the form of analytical bias between serum and aqueous matrix calibrators. The clinical chemist should constantly be aware of this factor. Correction of interferences is recommended as an integral part of the quality assurance program.