ABSTRACT
PURPOSE: The impact of cataract maturity on the aqueous humor (AH) oxidant/antioxidant balance is largely controversial. This study was aimed at assessing the relationships between cataract maturity and AH lipid peroxidation markers and enzymatic antioxidants. PATIENTS AND METHODS: The concentrations of conjugated dienes (CD), lipofuscin-like fluorescent end-products (LLF), soluble proteins, as well as the activities of superoxide dismutase (SOD) and catalase (CAT) were measured in AH samples from nondiabetic patients with either immature (n=15) or mature (n=15) cataract. RESULTS: In the overall AH sample, the mean values of CD, LLF, SOD, and CAT were 0.160 ± 0.024 (OD234), 166 ± 27 RFU, 24.5 ± 7.1 U/ml, and 31.9 ± 3.9 pmol/ml, respectively. CD was positively correlated with SOD (r=0.647; P<0.001), CAT (r=-0.394; P=0.031), and LLF (r=-0.399; P=0.029). The LLF was negatively correlated with SOD (r=-0.461; P=0.010). In samples adjusted for confounding factors, differences between immature and mature cataract groups regarding SOD, CD, LLF, and total proteins were significant (P<0.05; for all variables). The multiple logistic regression analysis identified LLF (OR=4.08; P=0.038) and SOD (OR=4.99; P=0.031) as independent predictors of cataract maturity. CONCLUSIONS: These results suggest that AH lipid peroxidation markers and antioxidants may significantly depend on the cataract maturity stage.
Subject(s)
Aqueous Humor/enzymology , Biomarkers/metabolism , Catalase/metabolism , Cataract/pathology , Lipid Peroxidation , Lipid Peroxides/metabolism , Superoxide Dismutase/metabolism , Aged , Aged, 80 and over , Aging/physiology , Antioxidants/metabolism , Female , Humans , Lipofuscin/metabolism , Male , Middle Aged , Oxidation-Reduction , Oxidative StressABSTRACT
BACKGROUND: Tuberculosis (TB) is associated with oxidative stress and is traditionally linked to vitamin C deficiency. OBJECTIVE: To evaluate the time course of the oxidative stress marker, malondialdehyde (MDA), and vitamin C status during the clinical treatment of tuberculous meningitis (TBM). METHOD: MDA and vitamin C reduction/oxidation (redox) status were spectrophotometrically measured at admission and during hospital treatment in cerebrospinal fluid (CSF) and serum from 27 TBM patients and 20 controls. RESULTS: Baseline CSF and serum MDA levels in TBM patients were higher than in controls (both P < 0.05), and remained elevated throughout the study. CSF MDA steadily increased from baseline 0.66 ± 0.24 mol/l to 1.02 ± 0.33 µmol/l at the end of the sixth week of treatment (P < 0.05), and then returned to baseline levels. Baseline CSF and serum total vitamin C were lower in TBM patients than in controls, but were soon normalised. CSF and serum ascorbate, reduced/oxidised vitamin C ratios and ascorbate CSF/serum ratio were markedly decreased in TBM patients (P < 0.05), and showed no improvement during treatment. CONCLUSION: These results indicate increased local and systemic oxidative stress, accompanied by impaired redox status, but not total vitamin C deficiency, which persisted during conventional clinical treatment of TBM.
