The endothelium is the primary target for biochemical or mechanical injuries caused by the putative risk factors of atherosclerosis. Endothelial dysfunction represents the ultimate link between atherosclerotic risk factors that promote atherosclerosis. HDL-C is thought to exert at least some parts of its antiatherogenic facilities via stimulating endothelial NO production, nearby inhibiting oxidative stress and inflammation. HDL-C is capable of opposing LDL's inductive effects and avoiding the ox-LDL's inhibition of eNOS. Paraoxonase 1 (PON1) is an HDL-associated enzyme esterase which appears to contribute to the antioxidant and antiatherosclerotic capabilities of HDL-C. “Healthy HDL,” namely the particle that contains the active Paraoxonase 1, has the power to suppress the formation of oxidized lipids. “Dysfunctional HDL,” on the contrary, has reduced Paraoxonase 1 enzyme activity and not only fails in its mission but also potentially leads to greater formation of oxidized lipids/lipoproteins to cause endothelial dysfunction. The association of HDL-C PON1 and endothelial dysfunction depends largely on the molecules with exact damaging effect on NO synthase coupling. Loss of nitric oxide bioavailability has a pivotal role in endothelial dysfunction preceding the appearance of atherosclerosis. Analyses of HDL-C and Paraoxonase1 would be more important in the diagnosis and treatment of atherosclerosis in the very near future.

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Background: Impaired oxidative/antioxidative status plays an important role in the pathogenesis of many diseases like cancer. The aim of this study was to evaluate the levels of the novel marker ischemia modified albumin (IMA) and albumin adjusted-IMA (Adj-IMA) in patients with bladder cancer (BC) as well as its association with total antioxidant status (TAS), total oxidant status (TOS) and oxidative stress index (OSI). Materials and Methods: Forty male patients with BC (mean age, 67.4±12 years) and forty age-sex matched healthy persons (mean age 56.0±1.7 years) were included in this study. Serum levels of IMA, TAS, TOS were analyzed and Adj-IMA and OSI was calculated. Results: Serum IMA, TOS and OSI values were significantly higher in patients with BC compared to controls (p<0.0001, p=0.01 and p=0.01, respectively), whereas TAS was significantly lower in BC patients (p=0.04). There was no significant difference for serum albumin-adjusted IMA levels between groups (p=0.4). Conclusions: In this study, it was found that there was an impaired oxidative/antioxidant status in favor of oxidative stress in BC patients. This observation was not confirmed by Adj-IMA calculation. There is no published report about serum concentrations of IMA in patients with BC. Further studies are needed to establish the relationship of IMA and oxidative stress parameters in BC and the significance of IMA to other cancers.

Background: Several lines of evidence, including postmortem studies, suggest increased oxidative stress and inflammation in patients with schizophrenia. Alteration of oxidative stress markers has been reported in schizoprenia studies, but with inconsistent results. Oxidized low-density lipoproteins (oxLDL) have been reported to be capable of eliciting neurocytotoxicity. On the other hand, paraoxonase (PON1), an arylesterase(ARE), plays a role in protection against oxidative modifications of LDL and is considered to be one of the antioxidant enzymes. There are no studies showing the changes in oxidative stress and inflammation together, nor the activities of PON1 and ARE in schizophrenic patients. In this study, we examined PON1, ARE activities and oxidative/anti-oxidative markers in patients with chronic schizophrenia and healthy controls. Methods: We recruited 30 male chronic schizophrenic patients and 30 male healthy control subjects and examined C-reactive protein(CRP), fibrinogen, PON1, ARE and plasma total antioxidant status (TAS) and total oxidant status (TOS), oxidative stress index(OSI) in both groups. Schizophrenia symptoms were assessed using the positive and negative syndrome scale (PANSS). The related routine lipid profile parameters including HDL were also examined. Results: Patients had significantly higher CRP, fibrinogen, TOS and OSI levels; but the patients and control subjects did not differ on activities of the antioxidant enzymes PON1 and ARE. Interestingly, there were not any group differences in the lipid profile parameters except the triglyceride levels, that increased significantly in the patient group. Conclusions: In the present study, reporting the ARE activities besides the PON1 activities in schizophrenic patients for the first time, we showed that PON1 and ARE enzyme activities were not statistically different in patients with chronic schizophrenia. This study provides additional evidence of increased oxidative stress and inflammation in chronic schizophrenia, but no alterations in the antioxidant status were observed. Our results suggest that other mechanisms than the high density lipoprotein(HDL)-disfunctionality, namely decreases in PON1 or ARE enzyme activities, are more important in oxidative or antioxidative pathophysiological processes in schizophrenia.