Evaluation of oxidative stress and antioxidant activity in pre and post hemodialysis in chronic renal failure patients from Western region of Nepal.

Objective: To evaluate the oxidative stress and antioxidant activity in pre and post hemodialy- sis in chronic renal failure patients using a diacetate cellulose membrane. Background: Chronic Renal Failure is a gradual, progressive and irreversible loss of normal functioning of kidneys. This is associated with increased formation of reactive oxygen species and increased oxidative stress. No studies have been undertaken in this area in Nepal. Method: The study groups were devided into chronic renal failure patients undergoing hemodialysis (n=52) and healthy controls (n=52). Diacetate cellulose was used as dialyzer membrane for chronic renal failure patients. Blood samples were collected in EDTAbottles and plasma was used for the estimation of oxidative stress marker, total antioxidant activity, vita- min C, α-tocopherol, urea and creatinine. Results: There was significant reduction in the levels of vitamin C,α -tocopherol and total antiox- idant activity in post dialysis patients compared to predialysis and control groups (p<0.001). Plasma urea and creatinine levels were high in predialysis patients compared to controls and was significantly reduced after dialysis. Significantly elevated malondialdehyde levelswere found in chronic renal failure patients before and after dialysis when compared with controls. Conclusion: The results of our study indicate that there are reduced levels antioxidants in chronic renal patients in pre and post dialysis condition and also more loss of antioxidants after dialysis. All these condition leads to increased oxidative stress in these patients.

Cigarette smoke induced oxidative insult in local population of Pokhara.

OBJECTIVES: To assess the effect of cigarette smoking on lipid peroxidation induced oxidative stress, antioxidants, uric acid and blood sugar in normal subjects. METHODS: The study included 61 normal subjects with regular smoking habit and 57 never-smokers normal subjects matched in respect to socio-economic status, age and BMI. Information regarding smoking habit and other personal details were collected by oral questionnaire. Total antioxidant activity (TAA), reduced glutathione (GSH), alpha-tocopherol (alpha-T), ascorbic acid (AA), uric acid (UA), plasma and urinary thiobarbituric acid reactive substances (TBARS), fasting blood sugar (FBS) and urinary creatinine (Cr) were estimated by standard procedures in both the groups. Ferric Reducing Antioxidant Power (FRAP) procedure is used to estimate TAA which measures total dietary antioxidants. Statistical analysis was done with SPSS version 10. RESULTS: The mean pack years smoked by smokers was 14.4 +/- 15.8. The plasma TBARS level in smokers and never-smokers was 2.6 +/- 0.8 and 2.5 +/- 0.6 micromol/L respectively. The respective figure for urinary TBARS level was 4.6 +/- 2.7 and 3.7 +/- 1.4 micromol/gmCr. Smokers did not show any significant difference from never-smokers with respect to GSH, alpha-T, AA, plasma TBARS and FBS. However, the smokers had significantly lower levels of TAA (p<0.05) and raised level of urinary TBARS (p<0.05) and uric acid (p<0.01) as compared to never-smokers. CONCLUSION: Our study suggests that smoking induces mild lipid peroxidation but the body is able to compensate for it by removing its adducts. Importantly it also indicates enhanced oxidation of purines which are essential components of both DNA and RNA. Dietary antioxidants are consumed to scavenge free radicals (FR) and other reactive species (RS) in smoke. Female smokers are more prone to oxidative insult than male smokers. In summary RS present in smoke induce mild lipid peroxidation but are not the major contributors of redox imbalance in smoke induced toxicity in the selected subjects.

Vitamin C status in cancer patients and healthy subjects from the local population of Pokhara.

OBJECTIVES: To assess vitamin C status by determining plasma ascorbic acid level in 55 cancer patients and 55 matched normal subjects serving as control. METHODS: The proven cancer patients were selected from those attending Manipal Teaching Hospital, Pokhara. Matched controls were from the staff of Manipal Teaching Hospital or attendants of the patients. Plasma ascorbic acid was determined by the method of Natelson. Unpaired student 't' test was used for the statistical evaluation. Statistical analysis was done by SPSS version 9 software. RESULTS: The mean level of vitamin C in normal subjects and patients was 1.03+/-0.26 mg/dl and 0.90+/-0.30 mg/dl respectively. None of the subjects in either group had deficient status (<0.2 mg/dl). Although its status was normal in both the groups but patients had lower level than normal subjects. Smokers and alcohol consumers had significantly lower level than non-smoker and non-alcoholics. CONCLUSION: In the local population, vitamin C deficiency is not an etiologic factor in malignancy. Smoking and alcohol adversely affects the status of this vitamin.