Browsing by Author "Oguz, Esra Firat"

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    Determining biological variation of serum parathyroid hormone in healthy adults
    (CROATIAN SOC MEDICAL BIOCHEMISTRY \& LABORATORY MEDICINE, 2019-01-01) Ercan, Mujgan; Akbulut, Emis Deniz; Avci, Esin; Yucel, Cigdem; Oguz, Esra Firat; Turhan, Turan; Serdar, Muhittin
    Introduction: Measurement of parathyroid hormone (PTH) is essential in the investigation and management of calcium metabolism disorders. To assess the significance of any assay result when clinical decision making biological variation (BV) of the measurand must be taken into consideration. The aim of the present study is determining the BV parameters for serum PTH. Materials and methods: Blood samples were taken at weekly intervals from 20 healthy subjects for ten weeks in this prospective BV study. Serum ``intact PTH{''} concentrations were measured with electrochemiluminescence method. Biological variation parameters were estimated using the approach proposed by Fraser. Results: The values of within-subject biological variation (CVI), between-subject biological variation (CVG), analytical variation (CVA), reference change value (RCV) and individuality index (II) for serum PTH were 21.1\%, 24.9\%, 3.8\%, 59.4\% and 0.8\%, respectively. Within-subject biological variation and CVG were also determined according to gender separately
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    Evaluation of four different HPLC devices for hemoglobinopathy screening
    (WALTER DE GRUYTER GMBH, 2021-01-01) Karadag, Mujgan Ercan; Akbulut, Emis Deniz; Avci, Esin; Oguz, Esra Firat; Kader, Saadet; Abusoglu, Gulsum; Serdar, Muhittin; Yamaz, Fatma Meric
    Objective: Hemoglobinopathies are a common public health problem in Turkey. In the screening of these disorders in population, cation-exchange high performance liquid chromatography (HPLC) is accepted as the gold standard method. In this study, the aim was to assess four different HPLC devices used in hemoglobinopathy screening. Materials and methods: A total of 58 blood samples were analyzed with four different HPLC methods (Bio-Rad variant II, Agilent 1100, Tosoh G8 and Trinity Ultra2 trademarks). Results: The comparison study demonstrated a good correlation between the results of each HPLC analyzer and the reference value obtained by averaging all the HbA(2) results belonging to the methods tested in the study {[}(Tosoh G8 (r=0.988), Bio-Rad variant II (r=0.993), Agilent 1100 (r=0.98) and Trinity Ultra2 (r=0.992)]. HbA(2) determination in the presence of HbE was interfered in both BioRad variant II and Tosoh G8. Conclusion: The analyzers were found to have compatible HbA(2) results but with accompanying different degrees of proportional and systematic biases. HPLC analyzers may be affected by different hemoglobin variants at different HbA(2) concentrations, which is an important point to take into consideration during the evaluation of HbA(2) results in thalassemia screening.