Objective:Turner syndrome (TS) is a chromosomal disorder caused by complete or partial X chromosome monosomy that manifests various clinical features depending on the karyotype and on the genetic background of affected girls. This study aimed to systematically investigate the key clinical features of TS in relationship to karyotype in a large pediatric Turkish patient population.Methods:Our retrospective study included 842 karyotype-proven TS patients aged 0-18 years who were evaluated in 35 different centers in Turkey in the years 2013-2014.Results:The most common karyotype was 45,X (50.7%), followed by 45,X/46,XX (10.8%), 46,X,i(Xq) (10.1%) and 45,X/46,X,i(Xq) (9.5%). Mean age at diagnosis was 10.2±4.4 years. The most common presenting complaints were short stature and delayed puberty. Among patients diagnosed before age one year, the ratio of karyotype 45,X was significantly higher than that of other karyotype groups. Cardiac defects (bicuspid aortic valve, coarctation of the aorta and aortic stenosis) were the most common congenital anomalies, occurring in 25% of the TS cases. This was followed by urinary system anomalies (horseshoe kidney, double collector duct system and renal rotation) detected in 16.3%. Hashimoto’s thyroiditis was found in 11.1% of patients, gastrointestinal abnormalities in 8.9%, ear nose and throat problems in 22.6%, dermatologic problems in 21.8% and osteoporosis in 15.3%. Learning difficulties and/or psychosocial problems were encountered in 39.1%. Insulin resistance and impaired fasting glucose were detected in 3.4% and 2.2%, respectively. Dyslipidemia prevalence was 11.4%.Conclusion:This comprehensive study systematically evaluated the largest group of karyotype-proven TS girls to date. The karyotype distribution, congenital anomaly and comorbidity profile closely parallel that from other countries and support the need for close medical surveillance of these complex patients throughout their lifespan.

Asthma is a disease where there is an accumulation of collagen in the reticular basal membrane of the airway leading to chronic inflammation. The enzyme prolidase plays an important role in the breakdown of collagen and the breakdown of intracellular protein especially in the final stage when peptides and dipeptides contain a high level of proline. To evaluate the relationship between prolidase activity and oxidative status in asthma patients. Comparison was made between 42 patients diagnosed with bronchial asthma and 32 healthy children of similar age and gender. Serum prolidase activity was measured spectrophotometrically. Oxidative status was determined using total antioxidant capacity (TAC) and total oxidant status (TOS) measurement. The prolidase activity of the asthma patient group was statistically significant compared with the control group (P< or =0.001). TAC and TOS levels in the asthma patient group were higher than the control group (P< or =0.001, P< or =0.002, respectively). No correlation was found between the prolidase and oxidative levels of the two groups. A positive correlation was determined between the prolidase activity and TAC in the asthma patient group (P< or =0.001, r=0.501). The prolidase enzyme activity, which plays a role in the collagen turnover, was low in the asthma patients; therefore, their collagen metabolism had undergone a change and this indicates that there may be an effect on the accumulation of collagen in the reticular basal membrane. Moreover, the high level of TOS indicates that these patients were exposed to severe oxidative stress with an increased TAC response.

Objective: To compare paraoxonase activity and changes in oxidative status in asthmatic children and healthy children by determining serum paraoxonase activity and total oxidative status, total antioxidant capacity and lipid hydroperoxidation. Methods: Forty two asthmatic children were compared with 32 healthy children of similar age and sex. To evaluate the paraoxonase and oxidative status, total antioxidant capacity and lipid hydroperoxidation were examined. Serum paraoxonase activity was evaluated by measuring the rate of paraoxon hydrolosis. Oxidative status was evaluated by the method developed by Erel. Lipid hydroperoxide was measured by an iodometric method. Results: In comparison with the healthy control group, the paraoxonase activity of the asthmatic children was found to be low (163.7 ± 73.0 (U/L) and 349.2 ± 153.9 (U/L), P = 0.002) and total oxidant status (9.0 ± 3.5 µmol H2O2 Eq/L and 13.4 ± 7.0 µmol H2O2 Eq/L, P =0.002), total antioxidant capacity (5.5 ± 2.5 µmol Trolox Eq/L and 1.0 ± 0.6 µmol Trolox Eq/L, P < 0.001), and lipid hydroperoxidation values (9.9 ± 3.4 µmol H2O2 Eq/L and 4.4 ± 1.5 µmol H2O2 Eq/L, P < 0.001) were found to be high. The high density lipoprotein (HDL) concentration of the asthmatic children was lower than that in the control group (40.1 ± 9.2 mg/dl and 54.5 ± 15.9 mg/dl, P < 0.001) Conclusion: In asthmatic children, when total oxidant status, total antioxidant capacity and lipid hydroperoxidation levels increase, paraoxonase activity decreased.Coronary heart disease (CHD) is a major killer and the most common cause of mortality and morbidity in the world. 1 It usually involves middle and older age groups but, recently, the incidence of CHD in younger individuals has been increasing. 2 Atherosclerosis is a process that starts in childhood and has a long preclinical phase before leading to clinical manifestations which usually appear in middle age. 3 Changes in the peripheral vascular endothelium are the earliest signs of atherosclerosis and CHD. 4 This has been demonstrated in asymptomatic children and young adults who are healthy but carry risk factors for atherosclerosis (e.g., high cholesterol, smoking, diabetes). 5 HDL retards the accumulation of lipid peroxides on LDL cholesterol 6 apparently due to paraoxonase which is an enzyme located on HDL particles. 7 Paraoxonase has two functions. First, it contributes to detoxification of organophosphorous compounds, including the pesticide paraoxon. Secondly, it hydrolyzes lipid peroxides and prevents LDL oxidation. 8 In both asthma and atherosclerosis, leukotrienes, which are potential inflammation mediators, play a role. 9,10 Some studies have suggested that asthma itself could be a risk factor for stroke and heart ORIGINAL RESEARCH

Increased production of reactive oxygen species leading to an imbalance between the oxidative forces and the antioxidant defense systems favoring an oxidative injury has been implicated in the pathogenesis of asthma. The aim of the study was to investigate the peripheral DNA damage, and its association with oxidative and antioxidative measurements in children with asthma bronchiale. The study population contained 42 children with asthma bronchiale and 32 healthy controls. DNA damage was assessed by alkaline comet assay in peripheral lymphocytes. Plasma levels of total antioxidant status (TAS), total peroxide concentration (LOOHs), and total oxidant status (TOS) were determined. In asthma bronchiale patients, DNA damage was significantly higher than in controls (17.9 +/- 11.8 AU vs. 1.2 +/- 2.0 AU, p < 0.001). Plasma TOS and LOOHs were higher in patients than in healthy controls (13.4 +/- 7.0 vs. 9.0 +/- 3.5, p = 0.002; 9.9 +/- 3.4 vs. 4.4 +/- 1.5, p < 0.001, respectively). Plasma TAS level in patients was higher than in healthy controls (5.5 +/- 2.5 vs. 1.0 +/- 0.6, p < 0.001). DNA damage was correlated with TOS (r = 0,616, p < 0.001). The findings indicated that lymphocyte DNA damage level increases in children with asthma bronchiale. Elevated DNA damage may be related to increased oxidative stress. However, the mechanism of this association, and whether it is direct or indirect, remains to be explored.

Regular physical activity may play a protective role against cardiovascular disease in adults, and paraoxonase activity may serve to mediate this effect. This study compared paraoxonase activity and that of other antioxidative agents in adolescent athletes compared with inactive youth. Paraoxonase level was 177.32 +/- 100.10 (U/L) in children with regular physical activity and 98.11 +/- 40.92 (U/L) in the control group (P < 0.0001). The levels of total antioxidative capacity, total oxidative status, oxidative stress index, and lipid hydroperoxide were significantly higher in the athlete group compared with controls (P < 0.0001). Paraoxonase activity was found to be greater in adolescent athletes, suggesting that regular exercise might provide a cardio-protective effect by this means.