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Öğe Altered kynurenine pathway metabolism and association with disease activity in patients with systemic lupus(Springer Wien, 2023) Onmaz, Duygu Eryavuz; Tezcan, Dilek; Yilmaz, Sema; Onmaz, Mustafa; Unlu, AliSystemic lupus erythematosus (SLE) is an autoimmune disease accompanied by increased release of proinflammatory cytokines that are known to activate the indoleamine 2,3-dioxygenase (IDO-1) enzyme, which catalyzes the rate-limiting step of the kynurenine pathway (KP). This study aimed to measure KP metabolite levels in patients with SLE and investigate the relationship between disease activity, clinical findings, and KP. The study included 100 patients with SLE and 100 healthy controls. Serum tryptophan (TRP), kynurenine (KYN), kynurenic acid (KYNA), 3-hydroxyanthranilic acid (3HAA), 3-hydroxykynurenine (3HK), quinolinic acid (QA) concentrations were measured with tandem mass spectrometry. Serum KYN, KYNA, 3HAA, 3HK, and QA levels of the patients with SLE were significantly higher than the control group. Serum QA levels were elevated in patients with neurological involvement (four patients with peripheral neuropathy and two patients with mononeuropathy), serum KYN levels and KYN/TRP ratio increased in patients with joint involvement, and serum KYN, 3HK, and 3HAA levels and the KYN/TRP ratio were increased in patients with renal involvement. Moreover, KYN and KYN/TRP ratios were positively correlated with the disease activity score. These findings indicated that imbalances in KP metabolites may be associated with the pathogenesis, activation, and clinical manifestations of SLE.Öğe Development and validation of a sensitive, fast and simple LC-MS/MS method for the quantitation of favipiravir in human serum(Elsevier, 2021) Onmaz, Duygu Eryavuz; Abusoglu, Sedat; Onmaz, Mustafa; Yerlikaya, Fatma Humeyra; Unlu, AliFavipiravir is a broad-spectrum inhibitor of viral RNA polymerase. It is currently used as a possible treatment for coronavirus disease 2019 (COVID-19). Pre-clinical or clinical trials of favipiravir require robust, sensitive, and accurate bioanalytical methods for quantitation of favipiravir levels. Recently, several studies have been reported about developing a validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for measuring favipiravir levels. However, these methods were validated predominantly for plasma samples, electrospray ionization was operated only in negative or positive mode, and clinical application of these methods has not been applied for patients with COVID-19. This study aimed was to develop a validated LC-MS/MS method for the measurement of favipiravir levels in positive and negative electrospray ionization mode and to perform a pilot study in patients with COVID-19 receiving favipiravir to demonstrate the applicability of this method in biological samples. Simple protein precipitation was used for the extraction of favipiravir from the desired matrix. Favipiravir levels were quantitated using MS / MS with an electrospray ionization source in positive and negative multiple reaction monitoring (MRM) mode. The chromatographic detection was performed on a reverse-phase Phenomenex C18 column (50 mm x 4.6 mm, 5 mu m, 100 angstrom) with gradient elution using 0.1% formic acid in water and 0.1% formic acid in methanol as mobile phase. The method was linear over the concentration ranges of 0.048-50 mu g/mL (in negative ionization mode) and 0.062-50 mu g/mL (in positive ionization mode) with a correlation coefficient (r2) better than 0.998. The total run time was 3.5 min. The intra-assay and inter-assay % CV values were less than 7.2% and 8.0%, respectively. A simple, rapid and robust LC-MS / MS method was developed for the measurement of favipiravir and validation studies were performed. The validated method was successfully applied for drug level measurement in COVID-19 patients receiving favipiravir.Öğe Effect of cigarette smoking on serum methylarginine and a-klotho levels(Elsevier Sci Ltd, 2023) Onmaz, Mustafa; Demirbas, Nur; Onmaz, Duygu Eryavuz; Kutlu, Ruhusen; Unlu, AliBackground and aims: Smoking causes many diseases such as cardiovascular, lung dis-eases, stroke and premature aging. However, the role of smoking in the pathogenesis of these diseases is unclear. Increasing evidence suggests that methylarginine pathway metabolites and a-klotho may be strong markers for pathologies such as premature aging, endothelial dysfunc-tion, and oxidant damage. Therefore, the study aimed to measure the serum levels of arginine, asymmetric dimethylarginine (ADMA), symmetric dimethylarginine (SDMA), N-monomethyl-L- arginine (L-NMMA), and a-klotho levels in smokers. Methods and results: This case-control analytical study included 65 smokers and 71 non-smokers. Sociodemographic characteristics, routine biochemistry parameters, Framingham risk scores and Fagerstrom Nicotine Dependence Test (FTND) were recorded. Serum methylarginine and a-klotho levels were analyzed by tandem mass spectrometry and enzyme-linked immunosorbent assay (ELISA), respectively. Serum ADMA (p < 0.001), L-NMMA (p Z 0.024), SDMA (p < 0.001) levels of smokers were higher than non-smokers, and serum a-klotho (p < 0.001) and arginine levels (p < 0.001) were lower. There was a positive correlation between serum ADMA levels with FNDT, age and pack/year in smokers, while there was a negative correlation between klotho levels and age. A positive correlation was found between serum ADMA levels, Framingham risk score and age in non-smokers. Conclusion: Smoking is related to premature aging and is a strong risk factor for various diseases such as cardiovascular, inflammatory, and renal diseases. Elevated serum methylarginine and decreased serum klotho levels were found in smokers. Therefore, our findings suggest that smok-ing may be involved in the pathogenesis of these diseases by affecting a-klotho and methylarginine-related pathways. (c) 2023 The Italian Diabetes Society, the Italian Society for the Study of Atherosclerosis, the Ital-ian Society of Human Nutrition and the Department of Clinical Medicine and Surgery, Federico II University. Published by Elsevier B.V. All rights reserved.Öğe Effects of hydroxychloroquine and its metabolites in patients with connective tissue diseases(Springer Basel Ag, 2021) Onmaz, Duygu Eryavuz; Tezcan, Dilek; Abusoglu, Sedat; Yilmaz, Sema; Yerlikaya, Fatma Humeyra; Onmaz, Mustafa; Abusoglu, GulsumHydroxychloroquine has attracted attention in the treatment of COVID-19. Many conflicting findings have been reported regarding the efficacy and safety of this drug, which has been used safely in the rheumatological diseases for years. However, these studies lacked measurement methods that allow accurate assessment of hydroxychloroquine and its metabolite levels. The aim of this study was to measure hydroxychloroquine and its metabolite levels in whole blood samples of patients with rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), Sjogren's syndrome (SS) and scleroderma (Scl) by a robust, simple and accurate validated tandem mass spectrometric method, and to investigate the relationship between these levels with drug-related adverse effects and disease activity scores. The validated LC-MS/MS method was applied to measure blood hydroxychloroquine and its metabolite levels of patients with RA, SLE, SS, Scl. Various haematological and biochemical parameters were measured with Beckman-Coulter AU 5800 and Beckman Coulter LH 780 analyzers, respectively. QTc intervals were calculated with Bazett's formula, and the patients were followed up by clinicians in terms of clinical findings and adverse effects. Hydroxychloroquine levels of patients were similar to previous studies. There was a negative correlation between disease activity scores and hydroxychloroquine levels, while the highest correlation was between QTc interval, creatinine and GFR levels with desethylchloroquine. Bidetylchloroquine had the highest correlation with RBC count and liver function tests. Our findings showed that hydroxychloroquine and its metabolite levels were associated with disease activity scores, renal, hepatic function, QTc prolongation, and hematological parameters.Öğe Sigaranın serum adma, L-NMMA, SDMA, arjinin ve α-klotho düzeyleri üzerine etkisi: vaka kontrol çalışması(Necmettin Erbakan Üniversitesi Meram Tıp Fakültesi, 2022) Onmaz, Mustafa; Demirbaş, NurAmaç: Sigara, başta kardiyovasküler hastalıklar olmak üzere pek çok hastalık için risk faktörüdür ve az sayıda biyobelirteç bu riski öngörmektedir. Bu çalışmanın amacı sigaranın bu konuda aday biyobelirteçlerden olan ADMA (Asimetrik Dimetil Arginin), L-NMMA (NMonometil-L-Arjinin), SDMA (Simetrik Dimetil Arginin), arjinin ve α-klotho düzeylerine etkisini analiz etmek ve yaşa bağlı bu parametrelerin değişimini incelemektir. Gereç ve yöntem: Vaka-kontrol çalışması olarak tasarlanan bu araştırma 01/02/2021- 31/03/2021 tarihleri arasında yapılmıştır. Necmettin Erbakan Üniversitesi Meram Tıp Fakültesi Aile Hekimliği Sigara Bırakma Polikliniği’ne sigara bırakmak için başvuran erkek bireyler vaka grubunu oluşturmuştur. Aile Hekimliği Polikliniği’ne periyodik sağlık muayenesi için başvuran ve sigara içmeyen erkek bireyler de kontrol grubu olarak alınmıştır. Vaka ve kontrol grubunun sosyodemografik özellikleri, vücut kitle indeksleri, sistolik ve diyastolik kan basınçları, kreatin, hemogram ve lipit paneli parametreleri, Framingham risk skorları ve vaka grubunun Fagerström Nikotin Bağımlılık Testi (FNBT)’ne göre bağımlılık düzeyleri kaydedildi. Her iki grubun ADMA, SDMA, L-NMMA, arjinin düzeyleri Selçuk Üniversitesi Tıbbi Biyokimya Anabilim Dalı laboratuvarında tandem kütle spektrometrik yöntemle; α-klotho düzeyleri Enzyme-linked immunosorbent assay (ELISA) yöntemiyle analiz edildi. Veriler Statistical Package for the Social Sciences (SPSS) versiyon 22.0 istatistik paket programında değerlendirildi. İstatistiksel anlamlılık p<0.05 olarak kabul edildi. Bulgular: Sigara içen 65 bireyin yaş ortalaması 46,26±8,72 yıl; sigara içmeyen 71 bireyin yaş ortalaması 47,38±9,36 yıl idi. Sigara içen ve içmeyen bireyler arasında ADMA (p<0,001), SDMA (p<0,001), L-NMMA (p=0,024) ve arjinin (p<0,001) düzeyleri arasında istatistiksel olarak anlamlı fark mevcuttu. Sigara içen bireylerin serum ADMA, L-NMMA, SDMA düzeyleri, sigara içmeyenlere göre yüksek, arjinin seviyeleri ise sigara içmeyenlere göre düşük bulundu. Sigara içenlerin yaşları ile serum ADMA seviyeleri arasında pozitif yönde
