Browsing by Author "Selek, S."

Now showing 1 - 5 of 5

Association of Paraoxonase Activity and Atherosclerosis in Patients With Chronic Hepatitis B
(Makerere Univ, Fac Med, 2012) Karsen, H.; Binici, I; Sunnetcioglu, M.; Baran, A., I; Ceylan, M. R.; Selek, S.; Celik, H.
Background: The hepatitis B virus is a significant pathogen that causes cirrhosis, and hepatocellular cancer as a result of the damage it causes to liver cells. Its infection affects more than 400 million people globally. Although there is an effective vaccine and treatment methods, almost 1, 000, 000 people die every year. Objective: To investigate paraoxonase and arylesterase activities along with oxidative status parameters and serum lipid levels, and to find out if there is any increased susceptibility to atherogenesis. Methods: Thirty-four subjects with chronic hepatitis B and 39 healthy subjects as control were enrolled in the study. Age, body mass index and gender, Serum Triglycerides (TG), High-density Lipoprotein (HDL) and Low-Density lipoprotein (LDL) levels, serum paraoxonase-1 and arylesterase activities were determined. Oxidative and antioxidative statuses were evaluated by measuring serum-free sulfhydryl groups, lipid hydroperoxide levels, total antioxidant capacity, total oxidant status, and oxidative stress index. Results: Serum TG and LDL levels were higher while serum HDL levels were lower in patients with chronic hepatitis B than in controls but the differences did not reach statistical significance. Serum paraoxonase-1 and arylesterase activities, plasma free sulfhydryl groups, and total antioxidant capacity were significantly lower in patients than in controls (p=0.018, p=0.005, p<0.001, p=0.037 respectively), while lipid hydroperoxide, total oxidant status, and oxidative stress index were significantly higher (for all p<0.001). Conclusion: The diminution in the paraoxonase-1 and arylesterase activities could contribute to the accelerated development of atherosclerosis in patients with chronic hepatitis B.
Decreased Serum Paraoxonase and Arylesterase Activities in Patients With Rosacea
(Wiley, 2015) Takci, Z.; Bilgili, S. G.; Karadag, A. S.; Kucukoglu, M. E.; Selek, S.; Aslan, M.
Background: Recent evidence suggests that oxidative stress may be an important phenomenon in the pathophysiology of rosacea. Paraoxonase-1 (PON1) is an antioxidant enzyme with three activities: paraoxonase, arylesterase and dyazoxonase. In this study, we evaluated serum paraoxonase and arylesterase activities, and serum lipid hydroperoxide (LOOH) levels in patients with rosacea in comparison to healthy controls. Material and methodThe study included 39 rosacea patients and healthy controls, consisting of 40 age- and sex-matched healthy volunteers. Serum paraoxonase and arylesterase activities were measured using paraoxon and phenylacetate substrates. Serum LOOH levels were measured with the ferrous ion oxidation-xylenol orange assay. ResultsIn rosacea group mean serum paraoxonase and arylesterase activities were 74.5438.30UL(-1) and 141.29 +/- 22.27kUL(-1) respectively, which were significantly lower than controls (P=0.010, 0.005; respectively). Mean serum LOOH level of rosacea group was 8.17 +/- 1.91molL(-1) which was significantly higher than controls (P=0.009). There were no statistically significant differences between the clinical subtypes of the disease, menopause situation or ocular involvement with the respect to the serum paraoxonase and arylesterase activities and LOOH levels (all; P>0.05). ConclusionsSerum PON1 enzyme activities have decreased significantly in rosacea. These findings support that decreased PON1 activity and increased oxidative stress may play a role in the pathogenesis of rosacea. Further studies are needed to elucidate the role of PON1 activity in the pathophysiology of rosacea.
Oxidative Stress Markers in Ivf Patients and Their Association With Pregnancy Results
(Turkiye Klinikleri, 2014) Güler Okyay, A.; Aslan, M.; Taşkin, A.; Selek, S.; Ceng Altin, G.; Kahraman, S.
Objective: Oxidative stress has been well recognized as a component in the pathogenesis of many diseases, including female infertility. In this study, we aimed to investigate serum paraoxonase (PON1), arylesterase and myeloperoxidase (MPO) activities, and lipid hydroperoxide (LOOH) levels as oxidative stress markers along with their relationship with the pregnancy rate in women undergoing in vitro fertilization (IVF) treatment. Material and Methods: Serum samples of 179 subjects were collected immediately before starting ovarian stimulation and on ovum pick-up (OPU) day during IVF treatment. Stimulation protocol and starting doses were determined individually. When the leading follicle reached at least 17 mm in size, recombinant human chorionic gonadotropin (Ovitrelle, 250 mcg, Serono) was administered for ovulation induction. Serum basal/salt-stimulated paraoxonase, arylesterase activities, myeloperoxidase activity, and lipid hydroperoxide levels were compared between two samples. Subjects were also divided into two groups according to the presence of pregnancy, and the groups were compared in terms of oxidative stress markers studied. Results: Serum MPO activity and LOOH levels were significantly higher on ovum pick up day (p<0.05, p<0.001, respectively), while basal/salt-stimulated paraoxonase and arylesterase activities were significantly lower (p=0.012, p=0.041, respectively) than those before ovarian stimulation. Serum LOOH levels on OPU day were significantly higher in non-pregnant group than pregnant one (p<0.001). Although basal/salt-stimulated paraoxonase, arylesterase and myeloperoxidase activities were higher in the non-pregnant group compared to the pregnant group, it was not statistically significant (p>0.05). Conclusion: Ovarian stimulation during IVF treatment resulted in increased oxidative stress and decreased PON1 activity. However, changes in the studied parameters were not found to be significantly associated with the pregnancy results. Further studies are required to clarify our results. © 2014 by Türkiye Klinikleri.
The Preoperative and Postoperative Oxidative Status of Children With Chronic Adenotonsillar Hypertrophy
(Soc Editrice Univ, 2013) Abuhandan, M.; Bozkus, F.; Demir, N.; Eren, E.; Koca, B.; Guler, O. Kadir; Selek, S.
Aim. This study aimed to evaluate the preoperative and postoperative oxidative status of children with chronic adenotonsillar hypertrophy. Materials and Methods. The study comprised 25 patients with indications for tonsillectomy and/or adenoidectomy following a diagnosis of chronic adenotonsillar hypertrophy and 25 age-gender matched control patients were included to the study. Blood samples were taken from the patients preoperatively and at four weeks postoperatively. Preoperative and postoperative serum total oxidant (TOS) and total antioxidant (TAS) levels were measured and the oxidative stress index (OSI) was calculated. Results. The serum total oxidant level and oxidant stress index values in the preoperative and postoperative periods of the patients were found to be significantly high compared to those of the control group. While the preoperative serum total oxidant level values were found to be significantly high compared to the postoperative values, no statistical significance was found between the total antioxidant and oxidative stress index values. Conclusion. The development of chronic adenotonsillar hypertrophy plays a role in oxidative status and therefore, to neutralize high levels of oxidants in patients, the use of antioxidants for a period preoperatively and postoperatively is thought to be necessary.
Response To 'letter To the Editor' by Agilli Et Al. Entitled 'assessment of Decreased Serum Paraoxonase Activity in Patients With Rosacea in Terms of Methodology
(Wiley-blackwell, 2016) Takci, Z.; Bilgili, S. G.; Karadag, A. S.; Kucukoglu, M. E.; Selek, S.; Aslan, M.