Catalases are well studied enzymes that play critical roles in protecting cells against the toxic effects of hydrogen peroxide. The ubiquity of the enzyme and the availability of substrates made heme catalases the focus of many biochemical and molecular biology studies over 100 years. In human, this has been implicated in various physiological and pathological conditions. Advancement in proteomics revealed many of novel and previously unknown features of this mysterious enzyme, but some functional aspects are yet to be explained. Along with discussion on future research area, this mini-review compile the information available on the structure, function and mechanism of action of human catalase.
Objective: Interaction between reactive oxygen species (ROS) and reactive nitrogen species (RNS) is a crucial determinant in the etiology of oral squamous cell carcinoma (OSCC), and antioxidants protect against cellular and molecular damage caused by these. This study aims to evaluate ROS and RNS, together with the total antioxidant capacity (TAC), in serum and tissues of OSCC patients. Method: Total nitric oxide (TNO), malondialdehyde (MDA), and TAC were evaluated using a UV visible spectrophotometer in the serum of 30 controls, 30 precancer and 30 OSCC patients and in tissues of 10 controls and 30 OSCC patients. Results: MDA and TNO were significantly elevated with concomitant depletion of TAC in serum and tissues of OSCC patients when compared to controls. A significant positive correlation (p = 0.01), at different levels between TNO and MDA in OSCC patients, was found, which increased with the grade of OSCC. Conclusion: An increase in the levels of TNO, NO-mediated lipid peroxidation, resulting in an increase in MDA levels, the positive TNO-MDA correlation with a deranged antioxidant defense system as demonstrated by significantly low levels of TAC; when all these facts are taken together, we can conjecture that oxidative DNA damage, a vital phenomenon for carcinogenesis, occurs due to the interplay of ROS, RNS and TAC.
Objective: To analyse the use of BMI and bioelectrical impedance analysis (BIA) in assessment of adiposity among young and elderly population. Materials and methods: Age, height, weight and percent body fat (PBF) of 101 young and 276 elder subjects were recorded. PBF was measured directly by BIA instrument (PBFb) and also calculated from BMI (PBFf). The classification of subjects into underweight, normal, overweight and obese was based on the age- and sex-specific BMI cutoff values and PBFb following standard guidelines. Results: The calculated mean BMI values of young and old age groups were statistically same. PBF was significantly high in elder subjects. There was no statistical difference in mean PBFb and PBFf in young subjects but the difference was significant in elder subjects. The PBFf values were highly correlated (r: 0.92 to 0.96) with PBFb values in young age groups unlike elder groups of both males and females. PBFb based categorization of subjects’ presented totally different scenario compared to results obtained by BMI analysis to assess adiposity. Conclusion: The cases such as increasing fatness with aging even when BMI remains constant, the causes of country or ethnic differences in BMI analysis, poor correlation in PBFb and PBFf values in elder age group emphasize on the limitations of BMI based analysis. PBFb within limitations seems to be an improved phenotypic characteristic over BMI
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