Systemic redox modifications in senile cataract.

UNLABELLED: Recent studies on cataract formation focus on a primary role of systemic oxidative stress, generated outside the lens. Plasma inflammatory markers are associated with senile cataract. OBJECTIVE: The aim of this study was to find correlations between blood oxidative stress markers and some inflammatory plasma markers in cataractous patients. DESIGN AND METHODS: The blood samples were collected from 38 patients (aged 50 to 80). Patients were subdivided according to two criteria. Considering age criteria, presenile and senile cataract groups were formed. According to the absence or presence of other ocular comorbidities (age-related macular degeneration, glaucoma), pure cataract and nonpure cataract groups were constituted. Fifteen age and sex matched healthy subjects were selected for the control group. RESULTS: In our study, for all groups of patients, the measured markers of oxidative stress were modified vs. control values. Plasma antioxidant capacity, plasma antioxidant "gap", cholesterol and albumin/globulin levels were significantly decreased while RBC SOD activity, RBC catalase activity and plasma ceruloplasmin were significantly increased. Inflammatory markers, ceruloplasmin and albumin/globulins were correlated with different parameters of oxidative stress. CONCLUSION: The blood redox values and the level of some inflammatory markers demonstrate that senile cataract is a systemic disease with an inflammatory component.

Plasma redox status and premature onset of senile cataract.

UNLABELLED: Dysfunction of the lens due to opacification is called cataract. Senile cataract is associated with old age. It is estimated that the need for cataract extractions would be diminished by half if onset of cataract would be delayed by only ten years. It thus appears crucial to have a better characterization of the etiology of cataract to detect modifiable factors. It seems that oxidative stress may play an important role in cataractogenesis. Also, it was demonstrated that some plasma constituents correlate with human cataract location. OBJECTIVE: We supposed that in senile cataract the oxidative insult may be systemic and not only at the lens level. The aim of our study was to evaluate the blood redox status in cataractous patients aged between 50-65. DESIGN AND METHODS: The blood samples were collected from 15 patients with pure nuclear cataract and/or posterior subcapsular cataract, without metabolic or somatic diseases and from 15 age and sex matched controls. Carbonyl content of plasma proteins was evaluated with 2,4-dinitro-phenyl-hydrazine method. The a-oxoaldehydes were measured in the presence of Girard T reactive. The lipid peroxides concentration was assessed measuring malondialdehyde concentration using thiobarbituric acid. For the other plasma parameters we used kits. RESULTS: The levels of plasma protein carbonyls and malondialdehyde were significantly increased in the cataract group. The plasma levels of: total proteins, globulins, total thiols, fasting glucose, triglycerides and alpha-oxoaldehydes were not modified comparing the groups. Plasma concentrations of albumin and cholesterol were significantly decreased. CONCLUSION: The study underlies the presence of an increased plasma oxidative stress in cataractous patients. The abnormal oxidative stress parameters are linked to the premature development of senile cataract. Preventive therapy in order to delay the onset of senile cataract requires more research work on plasma oxidative stress markers.

Oxidative stress parameters in hemodialysis patients with or without diabetes.

Oxidative stress (imbalance of antioxidant and prooxidants in favour of the later) is considered to be a feature of diabetes and chronic renal failure. Carbonyl stress defined as accumulation of reactive carbonyl compounds due to excess production or disturbed clearance from the body is thought to amplify oxidative stress in these conditions. The accumulation of carbonyl compounds can be also a consequence of oxidative stress. A vicious cycle can thus be formed. We have studied the association between carbonyl stress markers (dicarbonyl compounds, Amadori products) and oxidative stress markers (total plasmatic thiols and malondialdehyde level) in hemodialysed patients with or without diabetes taking into account the levels of possible excess substrates (glucose and triglycerides). We have concluded that hemodialysed diabetes patients are more susceptible to oxidative stress than hemodialysed patients without diabetes.

Influence of epoietinum therapy on the oxidative stress in haemodialysis patients.

BACKGROUND: The causes of oxidative stress in haemodialysis (HD) patients are still controversial. Beside the uraemic state and dialysis-related factors, adjuvant drug therapies such as epoietinum (rHuEpo) and intravenous iron were involved. METHODS: Several parameters related to oxidative stress were assessed by spectrophotometry in stable HD patients, treated for at least 2 months with epoietinum (n = 14; mean dose = 97.7 +/- 19.1 U/kg/week) or not (n = 15), none of them on iron therapy, and in 13 controls. Plasma thiobarbituric acid-reactive substances (TBARS) were used as markers of reactive species generation. Erythrocyte and plasma antioxidant systems, reflected by non-protein erythrocyte thiols, and erythrocyte enzyme activities -- superoxide dismutase (SOD), glutathione peroxidase, catalase and plasma total thiols, respectively -- were also investigated. RESULTS: There were no differences between HD subgroups regarding haemoglobin levels. Plasma TBARS was increased in all HD patients as opposed to controls, irrespective of rHuEpo therapy. In addition, no change in antioxidant status parameters between rHuEpo-treated and -untreated patients was observed. Except for SOD, the other antioxidant indices were higher in all HD patients versus controls. CONCLUSIONS: These results suggest that (1) chronic HD patients appear to have simultaneously enhanced reactive species generation and antioxidative systems efficiency, and (2) epoietinum therapy did not change their oxidative status, at least in the absence of concomitant iron supplementation and at similar haemoglobin levels.