Association of preprocedural antiplatelet use with decreased thromboembolic complications for intracranial aneurysms undergoing intrasaccular flow disruption.

OBJECTIVE: This study was conducted to investigate the impact of antiplatelet administration in the periprocedural period on the occurrence of thromboembolic complications (TECs) in patients undergoing treatment using the Woven EndoBridge (WEB) device for intracranial wide-necked bifurcation aneurysms. The primary objective was to assess whether the use of antiplatelets in the pre- and postprocedural phases reduces the likelihood of developing TECs, considering various covariates. METHODS: A retrospective multicenter observational study was conducted within the WorldWideWEB Consortium and comprised 38 academic centers with endovascular treatment capabilities. Univariable and multivariable logistic regression analyses were performed to determine the association between antiplatelet use and TECs, adjusting for covariates. Missing predictor data were addressed using multiple imputation. RESULTS: The study comprised two cohorts: one addressing general thromboembolic events and consisting of 1412 patients, among whom 103 experienced TECs, and another focusing on symptomatic thromboembolic events and comprising 1395 patients, of whom 50 experienced symptomatic TECs. Preprocedural antiplatelet use was associated with a reduced likelihood of overall TECs (OR 0.32, 95% CI 0.19-0.53, p < 0.001) and symptomatic TECs (OR 0.49, 95% CI 0.25-0.95, p = 0.036), whereas postprocedural antiplatelet use showed no significant association with TECs. The study also revealed additional predictors of TECs, including stent use (overall: OR 4.96, 95% CI 2.38-10.3, p < 0.001; symptomatic: OR 3.24, 95% CI 1.26-8.36, p = 0.015), WEB single-layer sphere (SLS) type (overall: OR 0.18, 95% CI 0.04-0.74, p = 0.017), and posterior circulation aneurysm location (symptomatic: OR 18.43, 95% CI 1.48-230, p = 0.024). CONCLUSIONS: The findings of this study suggest that the preprocedural administration of antiplatelets is associated with a reduced likelihood of TECs in patients undergoing treatment with the WEB device for wide-necked bifurcation aneurysms. However, postprocedural antiplatelet use did not show a significant impact on TEC occurrence.

Dual Layer vs Single Layer Woven EndoBridge Device in the Treatment of Intracranial Aneurysms: A Propensity Score-Matched Analysis.

BACKGROUND: The Woven EndoBridge (WEB) devices have been used for treating wide neck bifurcation aneurysms (WNBAs) with several generational enhancements to improve clinical outcomes. The original device dual-layer (WEB DL) was replaced by a single-layer (WEB SL) device in 2013. This study aimed to compare the effectiveness and safety of these devices in managing intracranial aneurysms. METHODS: A multicenter cohort study was conducted, and data from 1,289 patients with intracranial aneurysms treated with either the WEB SL or WEB DL devices were retrospectively analyzed. Propensity score matching was utilized to balance the baseline characteristics between the two groups. Outcomes assessed included immediate occlusion rate, complete occlusion at last follow-up, retreatment rate, device compaction, and aneurysmal rupture. RESULTS: Before propensity score matching, patients treated with the WEB SL had a significantly higher rate of complete occlusion at the last follow-up and a lower rate of retreatment. After matching, there was no significant difference in immediate occlusion rate, retreatment rate, or device compaction between the WEB SL and DL groups. However, the SL group maintained a higher rate of complete occlusion at the final follow-up. Regression analysis showed that SL was associated with higher rates of complete occlusion (OR: 0.19; CI: 0.04 to 0.8, p = 0.029) and lower rates of retreatment (OR: 0.12; CI: 0 to 4.12, p = 0.23). CONCLUSION: The WEB SL and DL devices demonstrated similar performances in immediate occlusion rates and retreatment requirements for intracranial aneurysms. The SL device showed a higher rate of complete occlusion at the final follow-up.

Registry-Based Retrospective Cohort Study of Mortality among Adults Admitted to Intensive Care Units in Istanbul with Hospital Acquired Pseudomonas aeruginosa Bloodstream-Infection between 2014-2021.

BACKGROUND: Managing Pseudomonas aeruginosa bloodstream infections (BSIs) is challenging due to increasing antimicrobial resistance, limited therapeutic options, and high mortality rates. In this study, we aimed to identify 30-day mortality risk factors and assess infectious diseases consultants' preferences for combination or monotherapy. METHODS: The study was conducted in four hospitals in Istanbul, Turkey, involving 140 adult ICU beds and 336,780 ICU-bed-days between 1 January 2014, and 31 December 2021. A total of 157 patients were included in the study. Cox proportional hazard regression was performed to assess the factors on 30-day mortality. RESULTS: The 30-day mortality rate was 44.6% (70/157). Higher Charlson Comorbidity Index (CCI) score, severe sepsis, primary bloodstream infection, being in COVID-19 pandemic period, and infection caused by MDR strain were associated with higher hazard of 30-day mortality. Combination therapy was more commonly used in patients with BSIs with MDR or DTR (difficult-to-treat) strains but did not significantly improve the hazard of 30-day mortality. CONCLUSIONS: Targeted interventions and vigilant management strategies are crucial for patients with defined risk factors. While infectious disease consultants tended to favor combination therapy, particularly for drug-resistant strains, our analysis revealed no significant impact on 30-day mortality hazard. The increased incidence of P. aeruginosa BSIs during the pandemic emphasizes the need for infection control measures and appropriate antibiotic prescribing practices.

The impact of postoperative aspirin in patients undergoing Woven EndoBridge: a multicenter, institutional, propensity score-matched analysis.

BACKGROUND: The Woven EndoBridge (WEB) device is frequently used for the treatment of intracranial aneurysms. Postoperative management, including the use of aspirin, varies among clinicians and institutions, but its impact on the outcomes of the WEB has not been thoroughly investigated. METHODS: This was a retrospective, multicenter study involving 30 academic institutions in North America, South America, and Europe. Data from 1492 patients treated with the WEB device were included. Patients were categorized into two groups based on their postoperative use of aspirin (aspirin group: n=1124, non-aspirin group: n=368). Data points included patient demographics, aneurysm characteristics, procedural details, complications, and angiographic and functional outcomes. Propensity score matching (PSM) was applied to balance variables between the two groups. RESULTS: Prior to PSM, the aspirin group exhibited significantly higher rates of modified Rankin scale (mRS) mRS 0-1 and mRS 0-2 (89.8% vs 73.4% and 94.1% vs 79.8%, p<0.001), lower rates of mortality (1.6% vs 8.6%, p<0.001), and higher major compaction rates (13.4% vs 7%, p<0.001). Post-PSM, the aspirin group showed significantly higher rates of retreatment (p=0.026) and major compaction (p=0.037) while maintaining its higher rates of good functional outcomes and lower mortality rates. In the multivariable regression, aspirin was associated with higher rates of mRS 0-1 (OR 2.166; 95% CI 1.16 to 4, p=0.016) and mRS 0-2 (OR 2.817; 95% CI 1.36 to 5.88, p=0.005) and lower rates of mortality (OR 0.228; 95% CI 0.06 to 0.83, p=0.025). However, it was associated with higher rates of retreatment (OR 2.471; 95% CI 1.11 to 5.51, p=0.027). CONCLUSIONS: Aspirin use post-WEB treatment may lead to better functional outcomes and lower mortality but with higher retreatment rates. These insights are crucial for postoperative management after WEB procedures, but further studies are necessary for validation.

The role of spleen volume change in predicting immunotherapy response in metastatic renal cell carcinoma.

INTRODUCTION: Resistance to immune checkpoint inhibitors (ICI) is a significant issue in metastatic renal cell carcinoma (mRCC), as it is in the majority of cancer types. An important deficiency in immunooncology today is the lack of a predictive factor to identify this patient group. Myeloid-derived suppressor cells (MDSC) are a type of cell that contributes to immunotherapy resistance by inhibiting T cell activity. While it accumulates in the tumor microenvironment and blood, it can also accumulate in lymphoid organs such as the spleen and cause splenomegaly. Therefore we aimed to evaluate the effect of increase in splenic volume, which can be considered as an indirect indicator of increased MDSC cells, on survival outcomes in mRCC patients. METHODS: We analyzed 45 patients with mRCC who received nivolumab as a second-line or subsequent therapy. Splenic volume was analyzed from baseline imaging before starting nivolumab and from control imaging performed within the first 6 months of treatment initiation. Additionally, we analyzed how patients' body mass index (BMI), IMDC risk score, ECOG performance status, nephrectomy status, neutrophil-lymphocyte ratio (NLR), Platelet-to-lymphocyte ratio (PLR) and sites of metastasis. RESULTS: Median splenic volume change was 10% (ranging from - 22% to + 117%) during follow-up. Change in splenic volume was found to be associated with overall survival (OS) and progression-free survival (PFS) (p = 0.025, 0.04). The median PFS in patients with increased splenic volume was 5 months, while it was 17 months in patients without increased splenic volume. (HR 2.1, 95% CI (1-4), p = 0.04). The median OS in patients with increased splenic volume was 9 months, while it was 35 months in patients without increased splenic volume (HR 2.7, 95% CI (1.1-6.2), p = 0.025). In four patients with decreased splenic volume, neither PFS nor OS could reach the median value. Log-rank p value in respectively (0.015, 0.035), The group in which an increase in volume was accompanied by a high NLR had the shortest survival rate. Basal splenic volume was analyzed separately. However, neither PFS nor OS differed significantly. CONCLUSION: Our findings suggest that the change in splenic volume throughout immunotherapy regimens may be utilized to predict PFS and OS in mRCC patients undergoing treatment.

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.

Cachexia index in predicting outcomes among patients receiving immune checkpoint inhibitor treatment for metastatic renal cell carcinoma.

INTRODUCTION: Immune checkpoint inhibitors (ICI) have transformed treatments for patients with metastatic renal cell carcinoma (mRCC). Although some patients benefit greatly from ICI treatments, an effective marker to determine which patients will benefit from these treatments is lacking. Moreover, chronic inflammation and sarcopenia have been associated with poor survival rates among cancer patients. Accordingly, in this study, we investigated how the cachexia index (CXI), used as a combined score for sarcopenia and chronic inflammation, affects the survival outcomes of patients with mRCC receiving ICI. METHODS: We retrospectively screened data from 52 mRCC patients who had followed up between October 2010 and October 2021 after receiving ICI as a second-line or later treatment. Patients' respective basal CXI score were calculated according to the following formula, based on their L3 vertebral skeletal musculoskeletal area (SMI), neutrophil-lymphocyte ratio (NLR), and albumin (Alb) levels: CXI = (SMI x Alb) / NLR. Additionally, we analyzed how patients' subcutaneous adipose tissue (SAT), body mass index (BMI), ECOG performance status, The International Metastatic Renal Cell Carcinoma Database Consortium (IMDC) risk score, nephrectomy status, sites of metastasis, and histological subtypes affected survival outcomes. RESULTS: Our univariate analysis significantly associated CXI score, NLR, nephrectomy status, and patient age with overall survival (OS). However, only CXI scores' significance was confirmed through multivariate analysis. The median OS (mOS) was 7 months for patients whose CXI score < the median value and 48 months for patients with a CXI score ≥ the median value. (HR 4.5, 95% CI [1.9-11], p = 0.001). Only CXI was significantly associated with progression-free survival (PFS) outcomes. The median progression-free survival (mPFS) was 4 months for patients whose CXI score < the median value and 17 months for patients with a CXI score ≥ the median value. (HR 2.6, 95% CI [1.3, 5.3], p = 0.007). Sarcopenia, sarcopenic obesity, and sarcopenia combined with NLR were not found to significantly affect OS. CONCLUSION: Our findings suggest that CXI score, a combined indicator of sarcopenia and chronic inflammation parameters, may serve as a useful marker in predicting the outcomes of ICI-based treatments for mRCC patients.

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.

Hamlet and radiology.

After I started my radiology training, searching for art in radiology became a passion for me. One of the most concrete examples of my search was a case of CT-guided biopsy we encountered recently. In a patient with metastatic cancer, we searched for the primary lesion. PET/CT showed a focus in the upper lobe of the right lung. During the CT-guided biopsy, this lesion was like a smiling face in shape. The fact that this cute-looking mass was metastatic cancer reminded me of a character from Hamlet. In William Shakespeare's famous work, Prince Hamlet refers to Claudius as a 'smiling villain' and draws attention to the evil behind his smile. In this article, we discuss the similarity of our daily practice with Hamlet through a case.

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.

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.

Placental Elasticity and Histopathological Findings in Normal and Intra-Uterine Growth Restriction Pregnancies Assessed with Strain Elastography in Ex Vivo Placenta.

The aim of this study was to investigate the differences of placental elasticity between intra-uterine growth restriction (IUGR) and normal pregnancies to show whether or not there is any association between histopathological changes and placental elasticity. Fifty-five human placentas were collected at delivery, including 25 with IUGR and 30 controls. Strain elastography (SE) was performed ex vivo and all placentas were examined histopathologically. Elasticity index (EI) and histopathological findings were compared between groups. The placental stiffness and presence of histopathological changes were higher in the IUGR group than in controls (p < 0.05). Also, histopathological findings were associated with decreased EI values, but no specific patterns of histologic abnormalities were identified except villitis and delayed villous maturity. Distinct reduced placental elasticity could be the result of the cumulative effects of all the histologic findings in IUGR.

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.

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.