Analysis of Ischemia-Modified Albumin (IMA) and Coagulation Parameters in Patients with SARS-CoV-2 Pneumonia.

BACKGROUND: Coronavirus disease 2019 (COVID-19) is a systemic disease which causes an increased inclination to thrombosis by leading to coagulation system activation and endothelial dysfunction. Our objective in this study is to determine whether ischemia-modified albumin (IMA) can be used as a new marker in patients with COVID-19 for evaluating the increased coagulation risk, pneumonic infiltration, and thus, prognosis. METHODS: Our study included 59 patients with COVID-19 compatible pneumonic infiltration on lung computed tomography (CT) who applied to and were hospitalized in the Internal Diseases Outpatient Clinic, then followed up and treated, as well as 29 healthy individuals with a negative COVID-19 rRT-PCR test without any additional disease. Hemogram, coagulation, routine biochemistry, and serum IMA activity parameters were studied. RESULTS: In our study, the higher serum IMA level in COVID-19 patients with pneumonic infiltration compared to that of the healthy control group was found to be statistically significant. No significant correlation was found between the serum IMA levels and the coagulation and inflammation parameters in the 59 COVID-19 patients included. CONCLUSIONS: Serum IMA levels in COVID-19 patients with pneumonic infiltration on CT were found to be higher than in the control group. Examination of biochemical parameters, especially thrombotic parameters that affect prognosis such as IMA, can be a guide in estimating pneumonic infiltration.

Serum Vitamin D, Zinc Levels and the Relationship between them in Children and Adolescents.

BACKGROUND: Along with vitamin D deficiency, a common global health problem in developed and developing countries, zinc deficiency also remains one of the most common micronutrient deficiencies-related public health problems in some parts of the world. Determination of vitamin D and Zn status is important for the growth, development, and health of school-age children, as well as their intellectual achievement and academic performance. In this study, we aimed to evaluate serum 25(OH)D and Zn levels and the relationship between them in a nationally representative sample of Turkish children and adolescents. METHODS: A total of 541 children and adolescents aged 1 - 16 years were included in our study whose vitamin D and zinc test levels were measured and who applied to the Basaksehir Cam and Sakura City Hospital Pediatric Outpatient Clinic. Cases were examined by dividing them into subgroups according to their vitamin D levels (≤ 15 ng/mL deficiency; 15 - 20 ng/mL insufficiency; ≥ 20 ng/mL sufficiency) and age (< 5 years preschool; 5 - 10 years middle childhood; 11 - 16 years adolescence). RESULTS: The levels of 25(OH)D were lower than 20 ng/mL in 33% of the children. There was deficiency in 80 (15%) and insufficiency in 99 (18%) cases. A statistically significant difference was found in 25(OH)D and Zn levels in groups separated by 25(OH)D level and age (p < 0.001). A positive significant correlation was found between serum 25(OH)D and Zn levels (r = 0.468; p < 0.001). A negative correlation was found between 25(OH) D levels and age (r = -0.261; p < 0.001) and body mass index (BMI) (r = -0.308; p < 0.001). CONCLUSIONS: In our study, we found high levels of vitamin D deficiency and insufficiency and a significant positive correlation between serum 25(OH)D and Zn levels in the pediatric population. Based on this possible contribution, we think that providing vitamin D support to children of all ages, including adolescents, and thus improving zinc levels may be beneficial in protecting from diseases that lead to morbidity and mortality as a result of reducing the rate of growth and development retardation, regulating of bone development, and contributing to the development of the immune system.

Investigation of the nephroprotective effect of dexmedetomidine on colistin-induced nephrotoxicity in rats.

ACKGROUND: There are very few studies in the literature focusing on whether dexmedetomidine exerts a protective effect on colistin nephrotoxicity. Our study aims to investigate the nephroprotective effect of dexmedetomidine in an experimental model of nephrotoxicity in rats. METHODS: The control group was administered saline (SF) intraperitoneally twice a day. The colistin group received an intraperitoneal (ip) injection of 10 mg/kg of colistin twice a day. The DX10 group received 10 mg/kg of colistin 20 minutes after the intraperitoneal injection of 10 mcg/kg of dexmedetomidine. The DX20 group received 10 mg/kg of colistin 20 minutes after the intraperitoneal injection of 20 mcg/kg of dexmedetomidine. Applications were continued for 7 days, twice a day. All rats were sacrificed on the 8th day after blood and kidney tissue samples were taken. BUN, Creatine, KIM-1 and Endothelin-1 were studied in blood samples. RESULTS: There was a significant difference in the median values of Urea, BUN and Creatine between the groups (p<0.001, p<0.001, p<0.001, respectively). There was a significant difference in the median values of KIM-1 and Endothelin-1 between the groups (p=0.009, p=0.001, respectively). A significant difference was observed between the histopathological scores of the groups (p<0.001). CONCLUSION: Dexmedetomidine significantly decreased the elevated levels of BUN, Creatinine, KIM-1, and Endothelin-1 induced by colistin. Dexmedetomidine, at both doses, histopathologically prevented apoptosis and reduced the number of necrotic cells in the kidneys. Dexmedetomidine provides renoprotective effects, therefore it is a valuable sedation agent for clinicians working in intensive care units (Tab. 2, Fig. 4, Ref. 19). Text in PDF www.elis.sk Keywords: rat, colistin, nephrotoxicity, dexmedetomidine.

Neutrophil Lymphocyte Ratio, Monocyte Lymphocyte Ratio, Platelet Lymphocyte Ratio in Covid-19 Patients.

BACKGROUND: Covid-19 is a pandemic viral infection with high pathogenicity and contagiousness. Our aim is to evaluate the preliminary hematological findings analyzed during admission in order to determine the diagnostic value of hematological parameters in Covid-19 patients and to reveal their relationship with the severity of the disease. METHODS: Our study includes a total of 169 patients, whose diagnosis was confirmed and 93 of whom were treated in the ward, 76 of whom were treated in the Intensive Care Unit (ICU), and 67 control patients. Neutrophil-to-lymphocyte ratio (NLR), monocyte-lymphocyte (MLR) ratio, platelet-lymphocyte ratio (PLR), mean platelet volume/platelet count ratio (MPV/PLT) data on admission were analyzed retrospectively and compared. RESULTS: ICU patients had significantly higher values of NLR, MLR, PLR, and MPV/PLT (p < 0.001 for each) but had lower values of lymphocyte count and hemoglobin (p < 0.001 for each) compared to that of ward patients. According to the results of ROC analysis, the diagnostic values of NLR, MLR, PLR, and MPV/PLT parameters were statistically significant (p < 0.05). CONCLUSIONS: According to the results of our study, abnormal routine peripheral blood examination results were detected in Covid-19 patients. NLR, MLR, and PLR can be considered as independent, reliable biomarkers for assessing disease severity, hospitalization, and clinical classification in Covid-19. Therefore, it was concluded that fast, cost-effective, easily accessible admission hemogram parameters are reasonably important to predict the prognosis of Covid-19 patients.

Association between reverse electrical remodeling and cardiac fibrosis markers in patients with cardiac resynchronization therapy.

OBJECTIVE: Cardiac resynchronization therapy (CRT) induces structural and electrical reverse remodeling of the failing heart. However, the association between native QRS narrowing and cardiac fibrosis markers has not been investigated in patients with an implanted CRT device. METHODS: A total of 41 symptomatic patients diagnosed with systolic heart failure who underwent CRT implantation were included in this study. Electrocardiogram findings and cardiac fibrosis marker levels [galectin-3, growth-differentiation factor-15 (GDF-15) and procollagen III N-terminal propeptide (P3TD)] were collected before and 12 months after initiation of biventricular pacing. Reverse electrical remodeling was defined as a decrease in 12-month intrinsic QRS (iQRS) duration by ≥20 milliseconds after CRT implantation. RESULTS: The median QRS duration decreased from 155 milliseconds (interquartile range [IQR]: 142-178 milliseconds) before CRT to 142 milliseconds (IQR: 130-161 milliseconds) (p=0.001) after 12 months of CRT. According to the predefined criteria, electrical remodeling was detected in 16 (39.0%) patients. The median galectin-3, GDF-15, and P3TD levels were significantly decreased after CRT implantation in patients with electrical remodeling [27.65 ng/mL (IQR: 24.4-35.2 ng/mL) vs 23.00 ng/mL (IQR: 16.0-36.7 ng/mL), p=0.017; 3104 pg/mL (IQR: 2923-4825 pg/mL) vs 2276 pg/mL (IQR: 1294-3209 pg/mL), p=0.002; 0.43 ng/mL (IQR: 0.23-0.64) vs 0.15 ng/mL (IQR: 0.04-0.29 ng/mL), p=0.034, respectively]. The galectin-3, GDF-15, and P3TD levels were not significantly changed in patients without electrical remodeling [26.80 ng/mL (IQR: 23.9-31.5 ng/mL) vs 28.80 ng/mL (IQR: 23.0-34.8 ng/mL), p=0.211; 4221 pg/mL (IQR: 2709-4995 pg/mL) vs 3035 pg/mL (IQR: 2038-4872 pg/mL), p=0.143; and 0.34 ng/mL (IQR: 0.11-0.68 ng/mL) vs 0.21 ng/mL (IQR: 0.09-0.37 ng/mL), p=0.112, respectively]. CONCLUSION: The results from the small sample used in this study indicated that electrical reverse remodeling after CRT was associated with a decrease in cardiac fibrosis.

Evaluating the effects of cardiac resynchronization therapy on pathophysiological pathways of heart failure using surrogate biomarkers.

BACKGROUND: Several studies have investigated the effects of cardiac resynchronization therapy (CRT) on heart failure (HF), but none have evaluated the pathophysiological pathways involved in a single group of patients. Therefore, this study aims to assess the long-term effects of CRT on six different patho-physiological pathways involved in the process of HF by the use of surrogate biomarkers. METHODS: In a group 44 patients with HF, six groups of biomarkers were measured, both at baseline and 1 year after CRT implantation: inflammation (interleukin [IL]-4, IL-6, tumor necrosis fac-tor [TNF]-a, high sensitive C-reactive protein [hsCRP]); oxidative stress (myeloperoxidase [MPO], oxidized low-density lipoprotein [oxLDL], uric acid); extracellular matrix (ECM) remodeling (matrix metalloproteinase [MMP]-2 and -9, galectin-3, procollagen III N-terminal propeptide [prokol-3NT]); neurohormonal pathways (endothelin-1, chromogranin-A); myocyte injury (troponin T, creatine kinase MB fraction [CK-MB]), myocyte stress (B-type natriuretic peptide [BNP]). CRT responders were de-fined as patients with ≥ 15% reduction in left ventricular end-systolic volume at 12 months post-CRT. RESULTS: At 1-year follow-up, 72.7% (n = 32) of the patients were categorized as CRT responders. In these patients, the levels of IL-6, MPO, oxLDL, MMP-2, galectin-3, troponin T, and BNP were significantly reduced as compared to baseline values. While the biomarkers for myocyte stress (effect size = 0.357; p = 0.001), ECM remodeling (effect size = 0.343; p = 0.015) and oxidative stress (effect size = 0.247; p = 0.039) showed a significant change in the CRT responders during follow-up, the biomarkers for other pathophysiological pathways did not show a significant alteration. CONCLUSIONS: In the present study, a significant reduction was only observed in the biomarkers of myo-cardial stress, ECM remodeling, and oxidative stress among all the CRT responder subjects. (Cardiol J 2018; 25, 1: 42-51).

Comparison of serum acetyl hydrolase (PAF-AH) and paraoxonase 1 (PON1) values between prostate cancer patients and a control group.

The aim of the study was to measure platelet-activating factor acetyl hydrolase (PAF-AH) and paraoxonase (PON1) enzyme activity levels in patients with high Psa values to compare with healthy peers and also to determine the efficacy of these parameters in predicting pathologic results of patients with high Psa values. This study included 66 patients with Psa value > 4 ng/dl (Group 1) and 44 patients with Psa <4 ng/dl (Group 2) for a total of 110 patients. Parameters measured in serum of PON1, PAF-AH, and MDA were compared between the groups. Additionally the same parameters were compared between patients with prostate biopsy performed due to high Psa and diagnosed with cancer and the control group with normal Psa values. The PAF-AH activity in Group 1 was 125.17 ± 8.64 and in Group 2 was 120.08 ± 9.23 U/ml (p = 0.003). The PON1 activity was 63.12 ± 6.74 and 65.91 ± 7.77 U/ml in the groups, respectively (p = 0.04). Additionally, there were significant differences identified between the control group and PCa diagnosis group in terms of PAF-AH and PON1 activities (p = 0.004 and p = 0.02, respectively). The enzyme activity of PAF-AH and PON1 measured in serum of patients with high Psa value and patients with diagnosis of prostate cancer (PCa) were identified to have changed by a significant amount compared to healthy peers with normal Psa value. It was concluded that these parameters may be beneficial markers for use in assessment of patients with high Psa value.

The effect of HDL-bound and free PON1 on copper-induced LDL oxidation.

Oxidative modification of LDL plays an important role in the development of atherosclerosis. High-density lipoprotein (HDL) confers protection against atherosclerosis and the antioxidative properties of paraoxonase 1 (PON1) has been suggested to contribute to this effect of HDL. The PON1 exist in two major polymorphic forms (Q and R), which regulate the concentration and activity of the enzyme and alter its ability to prevent lipid oxidation. However, the association of Q192R polymorphism with PON1's capacity to protect against LDL lipoperoxidation is controversial. The aim of this study was to evaluate the effects of the purified PON1 Q192R and the partially purified HDL-bound PON1 Q192R isoenzymes (HDL-PON1 Q192R) on LDL oxidation, with respect to their arylesterase/homocysteine thiolactonase (HTLase) activities. Cupric ion-induced LDL oxidation was reduced up to 48% by purified PON1 Q192, but only 33% by an equivalent activity of PON1 R192. HDL-PON1 Q192 isoenzyme caused a 65% reduction, whereas HDL-PON1 R192 isoenzyme caused only 46% reduction in copper ion-induced LDL oxidation. These findings reflect the fact that PON1 Q and PON1 R allozymes may have different protective characteristics against LDL oxidation. The protection against LDL oxidation provided by HDL-PON1 Q192R isoenzymes is more prominent than the purified soluble enzymes. Inhibition of the Ca(+2)-dependent PON1 Q192R arylesterase/HTLase by the metal chelator EDTA, did not alter PON1's ability to inhibit LDL oxidation. These studies indicate that the active site involvement of the purified enzyme is not similar to the HDL-bound one, in terms of both PON1 arylesterase/HTLase activity and the protection of LDL from copper ion-induced oxidation. Moreover, PON1's ability to protect LDL from oxidation does not seem to require calcium.

Vitamin D levels predict the response to cardiac resynchronization therapy in patients with systolic heart failure.

OBJECTIVE: The aim of this study was to examine the relationship between vitamin D levels in patients with heart failure (HF) and response to cardiac resynchronization therapy (CRT). METHODS: We studied 57 patients (mean age: 60.47±13.09 years) with New York Heart Association Class II or III heart failure, QRS duration ?120 milliseconds, and ejection fraction <35% (mean: 27.1±4.4%) who underwent CRT. All patients were taking optimal medical treatment for HF. Patients were classified as CRT responders if they had >15% decrease in left ventricular end-systolic volume at 6 months compared with baseline measurements. Vitamin D levels were evaluated before CRT implantation with ELISA. RESULTS: Of the 57 patients, 34 patients (59.6%) were classified as responders and 23 patients (40.4%) were classified as non-responders. Baseline features, laboratory findings, and echocardiographic characteristics were nearly the same in both groups. High vitamin D level was detected in responder group compared to non-responder group (26.17±7.5 ng/mL vs 21.15±5.9 ng/mL; p=0.009). Age, hypertension, diabetes mellitus, ischemic cardiomyopathy, QRS morphology and duration, and levels of B-type natriuretic peptide (BNP) and vitamin D were associated with CRT response in our study population. In multivariate regression analysis, preimplantation QRS duration, and BNP and vitamin D levels remained independent predictors (QRS duration Odds ratio [OR]: 1.047, CI: 1.019-1.417, p=0.006; BNP OR: 0.997, 95% CI: 0.994-0.999, p=0.029; vitamin D OR: 1.121, 95% CI: 1.011-1.242, p=0.030). CONCLUSION: In the present study, preimplantation level of vitamin D was found to be predictor of response to CRT.

Effect of Ventilation Support on Oxidative Stress and Ischemia-Modified Albumin in Neonates.

BACKGROUND AND OBJECTIVE: Mechanical ventilation (MV) can induce oxidative stress, which plays a critical role in pulmonary injury in intubated neonates. Ischemia-modified albumin (IMA)-a variant of human serum albumin-is a novel biomarker of myocardial ischemia that occurs due to reactive oxygen species during ischemic insult. This study aimed to investigate IMA production due to oxidative stress induced during MV in neonates. MATERIALS AND METHODS: This study included 17 neonates that were ventilated using synchronized intermittent mechanical ventilation (SIMV; SIMV group) and 20 neonates ventilated using continuous positive airway pressure (CPAP; CPAP group). Blood samples were collected from each neonate during ventilation support and following cessation of ventilation support. Total antioxidant capacity (TAC) and total oxidant status (TOS) were measured using the Erel method. IMA was measured via an enzyme-linked immunosorbent assay kit (Cusabio Biotech Co., Ltd., Wuhan, China). The oxidant stress index (OSI) was calculated as OSI = TOS/TAC. Statistical analysis was performed using SPSS v.18.0 (SPSS Inc., Chicago, IL) for Windows. RESULTS: Among the neonates included in the study, mean gestational age was 34.7 ± 3.8 weeks, mean birth weight was 2,553 ± 904 g, and 54% were premature. There were not any significant differences in mean gestational age or birth weight between the SIMV and CPAP groups. Among the neonates in both the groups, mean IMA, TOS, and OSI levels were significantly higher during ventilation support (102.2 ± 9.3 IU mL(-1), 15.5 ± 1.3 µmol H2O2 equivalent L(-1), and 0.85 ± 0.22 arbitrary units [ABU], respectively), as compared with following cessation of ventilation support (82.9 ± 11.9 IU mL(-1), 13.4 ± 1.3 µmol H2O2 equivalent L(-1), and 0.64 ± 0.14 ABU, respectively) (p = 0.001). Among all the neonates in the study, mean TAC was significantly lower during ventilation support than the postventilation support (1.82 ± 0.28 mmol 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid [Trolox] equivalent L(-1) vs. 2.16 ± 0.31 mmol Trolox equivalent L(-1)) (p = 0.001). There were no significant differences in mean TAC, OSI, or IMA levels between the SIMV and CPAP groups. The mean TOS level during ventilation support and the mean difference in TOS between during and postventilation support was significantly greater in the CPAP group than in the SIMV group. There were no significant relationships between the mean TOS, TAC, OSI, or IMA levels, and gestational age of the neonates. CONCLUSION: SIMV and CPAP activated the oxidative stress and increased the IMA level in neonates; therefore, measurement of IMA and oxidant markers may be useful in the follow-up of lung injury in neonates due to ventilation support. Additional prospective studies are needed to compare the effects of various ventilation methods on oxidative stress and the IMA level in neonates.

Effect of paraoxonase 1 192 Q/R polymorphism on paraoxonase and acetylcholinesterase enzyme activities in a Turkish population exposed to organophosphate.

Organophosphate (OP) compounds are the most commonly used pesticide groups and they are commercially used in the market for local and industrial purposes. Paraoxonase 1 (PON1) enzyme plays an important role in biotransformation of OP compounds, which shows toxic effects via inhibiting the acetylcholinesterase (AChE). The aim of this study was to determine the effects of PON1 gene polymorphism and its effects on PON and AChE enzyme activities in individuals who were exposed to organophosphorus insecticides due to occupational reasons, and to profile the probability of susceptibility to organophosphorus compounds. For this purpose, 54 individuals who were exposed to OPs and 54 healthy unrelated controls were studied. First, PON1 and AChE enzyme activities were measured. Second, PON1 192 Q/R polymorphism was determined by standard polymerase chain reaction-restriction fragment length polymorphism technique. When the PON1 192 Q/R polymorphism was compared with PON1 enzyme activities, statistically significant association was found in both OP-exposed and control groups (p < 0.05). PON1 192 R(+) (QR + RR genotypes) genotype carriers had higher PON1 activities than 192 R(-) (QQ) genotype carriers. On the other hand, results were statistically analyzed in terms of AChE enzyme activities and there were statistically significant differences only in the OP-exposed group (p < 0.05). The mean AChE concentration in the OP-exposed group was determined as 33.79 ± 6.84 U/g haemoglobin (Hb) for PON1 192 R(+) carriers and 30.37 ± 7.62 U/g Hb for PON1 192 R(+) carriers. As a conclusion, PON1 and AChE activities were increasing according to the genotypes found in individuals having been exposed to OPs at a chronic level; 192 R(+) > 192 R(-), respectively.

Paraoxonase lactonase activity (PON-HTLase), asymmetric dimethylarginine (ADMA) and platelet activating factor-acetylhydrolase (PAF-AH) activity in non-obese women with PCOS.

OBJECTIVE: Paraoxonase1 (PON1), exhibits both esterase activity (PON1-AREase) and homocysteine thiolactonase activity (PON1-HTLase) which respectively prevent LDL oxidation and detoxify homocysteine thiolactone (HTL). Platelet-activating factor-acetylhydrolase (PAF-AH) is an antioxidant enzyme preventing LDL oxidation by hydrolysis of oxidized phospholipids. Both of these enzymes exhibit a proatherogenic role. ADMA is an endogenous inhibitor of nitric oxide (NO) synthesis causing endothelial dysfunction. The aim was to compare non-obese PCOS patients with a BMI matched control group using the following characteristics: serum PON1-HTLase, ADMA, PAF-AH, and lipid and hormonal parameters. RESULTS: 77 women with PCOS and 25 healthy subject were recruited for this study, The controls were non-obese BMI and age matched with the patients. There were no significant differences with respect to age, BMI, FSH, free testosterone, DHEA, androstenadion, total cholesterol, triglycerides, HDL, LDL, VLDL, fasting glucose/insulin ratio and HOMA-IR among the groups (p > 0.05). However, total testosterone and fasting glucose levels were significantly higher in the PCOS group (p < 0.05). On the other hand, PON1-HTLase levels (39.6 ± 5.77 vs. 33.8 ± 8.2, p = 0.02) were significantly lower in the PCOS group while ADMA levels (1.14 ± 0.6 vs. 3.37 ± 6.4, p = 0.004) were significantly higher in the PCOS group. However, there was no significant difference in PAF-AH activity among the groups. CONCLUSIONS: Decreased PON1-HTLase and increased ADMA levels might be a relevant marker for the development of future atherosclerotic heart disease (AHD) in non-obese PCOS patients. Further studies are needed to confirm our results.

Serum PON-1 activity but not Q192R polymorphism is related to the extent of atherosclerosis.

AIM: Paraoxonase-1 (PON1) is an antioxidant enzyme located in high density lipoprotein (HDL). PON1 was defined as a protective factor against atherosclerosis. The aim of this study was to investigate the possible relationship between serum paraoxonase (PONase), homocysteine thiolactonase (HTase) activities and PON1 Q192R polymorphism, and the extent and severity of atherosclerosis. METHODS: Blood specimens were collected from 142 individuals who had no coronary artery lesions angiographically (control group) and 128 individuals who had angiographically documented coronary artery disease of several degrees (patient group). The extent and severity of arterial lesions were evaluated by the Gensini scoring system. PONase and HTase activities were measured in serum using a spectrophotometric method. PON1 Q192R polymorphism was evaluated using PCR-RFLP after DNA isolation from blood. RESULTS: Serum PONase and HTase activities were significantly lower in the patient group than in healthy controls (135.7±56.0U/mL vs 153.8±62.0U/mL, p< 0.05; 36.0±6.1 U/mL vs 43.0±4.04 U/mL, p< 0.01; respectively). In the patient group, there was a negative correlation between PONase, HTase activities and the Gensini score (r=-0.168, p= 0.039; r=-0.164, p= 0.006, respectively). In both groups, there was no significant difference in the distribution of PON1 Q192R polymorphism. In the patient group, the distribution of Gensini scores according to genotypes was not significant. CONCLUSION: It has been concluded that serum PONase and HTase activities might be a more relevant marker than PON1 genotype in evaluating the extent and severity of atherosclerosis.

Serum paraoxonase 1 activity, asymmetric dimethylarginine levels, and brachial artery flow-mediated dilatation in women with polycystic ovary syndrome.

OBJECTIVE: To evaluate endothelial function via serum asymmetric dimethylarginine (ADMA) levels, paraoxonase 1 (PON1) activity, and brachial artery flow-mediated dilatation (FMD) in women with polycystic ovary syndrome (PCOS). DESIGN: Prospective case-control study. SETTING: University hospital. PATIENT(S): Thirty patients with PCOS with a mean age of 24.33 ± 4.50 years and 30 healthy controls matched for body mass index (BMI) and age. INTERVENTION(S): Endothelial function was assessed biochemically with serum ADMA levels and serum PON1 activity and functionally with brachial artery FMD by ultrasonography. MAIN OUTCOME MEASURE(S): Serum ADMA levels, serum PON1 activity, brachial artery FMD, hormonal and biochemical parameters. RESULT(S): Patients with PCOS had higher levels of free testosterone and insulin, and higher waist-hip ratio and Ferriman Gallwey scores when compared with the controls. Fasting glucose and homeostasis model assessment of insulin resistance were not different between the groups. There was no statistically significant difference in ADMA levels between two groups. Serum PON1 activity and brachial artery FMD were statistically significantly lower in women with PCOS. There was negative correlation between ADMA and PON1 in patients with PCOS. CONCLUSION(S): Serum PON1 activity and brachial artery FMD, as markers of endothelial dysfunction and cardiovascular risk, were statistically significantly lower in women with PCOS compared with healthy controls matched for age and BMI. Endothelial dysfunction may be seen at earlier ages in patients with PCOS.

Differential hydrolysis of homocysteine thiolactone by purified human serum (192)Q and (192)R PON1 isoenzymes.

Human serum paraoxonase 1 (PON1) is a HDL-associated enzyme that catalyzes the hydrolysis of a variety of aromatic carboxylic acid esters and several organophosphates. Recently it has been suggested that a physiological substrate of serum PON1 is homocysteine thiolactone which is a putative risk factor in atherosclerosis. In this study, human (192)Q and (192)R PON1 isoenzymes were purified from the respective phenotype human serum, using a protocol consisting of ammonium sulfate precipitation and four chromatography steps: gel filtration, ion-exchange, non-specific affinity, and a second ion-exchange. Using paraoxon as substrate, overall purification fold was found as 742 for (192)R PON1 and 590 for (192)Q PON1. The final purified enzymes were shown as single protein bands close to 45kDa on SDS-PAGE and confirmed by Western blot. Substrate kinetics were studied with phenyl acetate, paraoxon and homocysteine thiolactone. Both PON1 isoenzymes showed mixed type inhibition with phenyl acetate. K(m) values of (192)Q and (192)R PON1 for homocysteine thiolactone were 23.5mM and 22.6mM respectively. For (192)R PON1, the V(max) was 2.5-fold and k(cat)/K(m) was 2.6-fold higher than those for (192)Q PON1 when homocysteine thiolactone is used as substrate. The present data suggest that defining (192)Q and (192)R PON1 isoforms could be a good predictor and prognostic marker in the cardiovascular risk assessment.

Purification and kinetic properties of rabbit liver paraoxonase 1.

Paraoxonase 1 (PON1) is synthesized in the liver and secreted into the blood, where it is associated exclusively with HDL. In this study, rabbit liver PON1 enzyme was purified to homogeneity using a new purification approach, and the kinetic properties of the enzyme were investigated using phenyl acetate and homocysteine thiolactone as substrates. Rabbit liver PON1 was purified through the preparation of liver microsomal fraction, Sephacryl S300 HR gel filtration chromatography, DEAE Trisacryl M ion-exchange chromatography and hydroxyapatite chromatography steps. Using this method, rabbit liver PON1 was purified 576 times with a specific activity of 2726 U/mg protein. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis revealed the obtained enzyme as a single protein band close to 40 kDa. The Km of the this enzyme was found as 0.55+/-0.024 mM for phenyl acetate and 17.31+/-1.2 mM for homocysteine thiolactone. In this study, a new approach was used to purify PON1 enzyme from rabbit liver and for the first time in the literature, its kinetics was studied with homocysteine thiolactone as substrate.

The effect of hormone replacement therapy on the levels of serum lipids, apolipoprotein AI, apolipoprotein B and lipoprotein (a) in Turkish postmenopausal women.

OBJECTIVES: Estrogen replacement therapy alters the lipid profiles favorably for delaying atherosclerosis in postmenopausal women. The effects of estrogen plus progesterone combination therapy on lipids are controversial. This study was designed to evaluate the effect of female sex hormones on lipids and lipoproteins and to clarify the influence of progesterone on the effect of estrogen in postmenopausal women. METHODS: Of the 60 postmenopausal women admitted to our menopause clinic, 40 had intact uterus and received continuous 0.625 mg conjugated equine estrogen (CEE) plus 2.5 mg medroxyprogesterone acetate (MPA), whereas the remaining 20 were hysterectomized and received 0.625 mg CEE daily. To assess the alterations in lipids and lipoproteins during menopause, 45 healthy premenopausal women were investigated. Lipid and lipoprotein levels were assessed in each subject at baseline and at the 6th and 18th months of therapy. RESULTS: In menopause, a shift towards more atherogenic lipid and lipoprotein profiles than those of the premenopausal state was found. Following 18 months of treatment, both regimens reduced total cholesterol (TC) levels as compared with the baseline (6.4 vs. 6.9% in the CEE/MPA and CEE groups, respectively). The CEE group had a more pronounced increase in high-density lipoprotein (HDL) cholesterol than the CEE/MPA group (10.3 vs. 8.8%, respectively). Both groups displayed reduced TC, low-density lipoprotein (LDL) cholesterol and apolipoprotein-B (ApoB) concentrations, whereas triglycerides increased, with a greater tendency to increase in the CEE/MPA group at the end of the trial. Also, the lipoprotein (a) [Lp(a)] levels decreased significantly (27.6 vs. 24.5% in the CEE/MPA and CEE groups, respectively). This decrease was more pronounced in subjects with a relatively higher basal Lp(a) concentration. CONCLUSION: Both treatment regimens caused positive alterations in the lipid and lipoprotein profiles. This association might play a pivotal role in the postmenopausal increases in atherosclerotic diseases and cardioprotective effect of estrogen in postmenopausal women.