Browsing by Author "Coskun, Cihan"

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An important source of preanalytical error in medical laboratories: centrifugation
(WALTER DE GRUYTER GMBH, 2021-01-01) Sonmez, Cigdem; Gumus, Alper; Senes, Mehmet; Aykal, Guzin; Taneli, Fatma; Aksungar, Fehime; Avci, Esin; Coskun, Cihan; Cinaroglu, Ipek; Colak, Ayfer; Eker, Pinar; Gucel, Funda; Hakligor, Aylin; Inal, Berrin Bercik; Orhan, Bagnu; Yilmaz, Canan
Centrifugation separates particles within the specimen according to their shape, dimensions, and density and basically can be defined as a separation method. The centrifuge is an essential device in medical laboratories to prepare the serum, plasma, and urine samples for analysis. It is basically an electric device composed of the stationary (motor) and the motile (rotor) part. The centrifugation depends on two main variables: relative centrifugal force (RCF) and centrifugation time. The physical impact separating the specimen into its components in the centrifuge known as RCF is expressed as the multiples of gravitational acceleration (xg). RPM, defined as the number of rotations of the centrifuge perminute, shows the speed of the centrifuge. RCF value can be calculated by using RPM, and the centrifuge radius. Because models and sizes of centrifuges vary considerably, the use of gravity (g) forces instead of RPM is suggested. The centrifuges can be classified according to their usage, speed, technical specifications, and rotor type. An accurate and precise centrifugation process is essential to prevent errors in the preanalytical phase. The purpose of this document is to ensure the standardization of a good, precise protocol for the centrifugation process among the medical laboratories.
COVID-19 laboratory biosafety guide
(WALTER DE GRUYTER GMBH, 2020-01-01) Zengi, Oguzhan; Aykal, Guzin; Coskun, Cihan; Serdar, Muhittin; Yucel, Dogan
Utilization of biological variation data in the interpretation of laboratory test results - survey about clinicians' opinion and knowledge
(CROATIAN SOC MEDICAL BIOCHEMISTRY \& LABORATORY MEDICINE, 2021-01-01) Emre, Humeyra Ozturk; Karpuzoglu, Fatma Hande; Coskun, Cihan; Sezer, Ebru Demirel; Ozturk, Ozlem Goruroglu; Ucar, Fatma; Cubukcu, Hikmet Can; Arslan, Fatma Demet; Deniz, Levent; Senes, Mehmet; Serteser, Mustafa; Yazici, Cevat; Yucel, Dogan; Coskun, Abdurrahman
Introduction: To interpret test results correctly, understanding of the variations that affect test results is essential. The aim of this study is: 1) to evaluate the clinicians' knowledge and opinion concerning biological variation (BV), and 2) to investigate if clinicians use BV in the interpretation of test results. Materials and methods: This study uses a questionnaire comprising open-ended and close-ended questions. Questions were selected from the real-life numerical examples of interpretation of test results, the knowledge about main sources of variations in laboratories and the opinion of clinicians on BV. A total of 399 clinicians were interviewed, and the answers were evaluated using a scoring system ranked from A (clinician has the highest level of knowledge and the ability of using BV data) to D (clinician has no knowledge about variations in laboratory). The results were presented as number (N) and percentage (\%). Results: Altogether, 60.4\% of clinicians have knowledge of pre-analytical and analytical variations
Within- and between-subject biological variation data for serum zinc, copper and selenium obtained from 68 apparently healthy Turkish subjects
(WALTER DE GRUYTER GMBH, 2022-01-01) Coskun, Abdurrahman; Carobene, Anna; Aarsand, Aasne K.; Aksungar, Fehime B.; Serteser, Mustafa; Sandberg, Sverre; Diaz-Garzon, Jorge; Fernandez-Calle, Pilar; Karpuzoglu, Fatma H.; Coskun, Cihan; Kizilkaya, Emine; Fidan, Damla; Jonker, Niels; Ugur, Esra; Unsal, Ibrahim; Chem, European Federation Clinical; Database, Task Grp Biol Variation
Objectives Trace elements (TrEL) are nutritionally essential components in maintaining health and preventing diseases. There is a lack of reliable biological variation (BV) data for TrELs, required for the diagnosis and monitoring of TrEL disturbances. In this study, we aimed to provide updated within- and between-subject BV estimates for zinc (Zn), copper (Cu) and selenium (Se). Methods Weekly serum samples were drawn from 68 healthy subjects (36 females and 32 males) for 10 weeks and stored at -80 degrees C prior to analysis. Serum Zn, Cu and Se levels were measured using inductively-coupled plasma mass spectrometry (ICP-MS). Outlier and variance homogeneity analyses were performed followed by CV-ANOVA (Roraas method) to determine BV and analytical variation estimates with 95\% CI and the associated reference change values (RCV) for all subjects, males and females. Results Significant differences in mean concentrations between males and females were observed, with absolute and relative (\%) differences for Zn at 0.5 mu mol/L (3.5\%), Cu 2.0 mu mol/L (14.1\%) and Se 0.06 mu mol/L (6.0\%). The within-subject BV (CVI {[}95\% CI]) estimates were 8.8\% (8.2-9.3), 7.8\% (7.3-8.3) and 7.7\% (7.2-8.2) for Zn, Cu and Se, respectively. Within-subject biological variation (CVI) estimates derived for male and female subgroups were similar for all three TrELs. Marked individuality was observed for Cu and Se. Conclusions The data of this study provides updated BV estimates for serum Zn, Cu and Se derived from a stringent protocol and state of the art methodologies. Furthermore, Cu and Se display marked individuality, highlighting that population based reference limits should not be used in the monitoring of patients.