Asli Pinar

Heat shock protein70: a new marker for subsequent atrial fibrillation development?

Atrial fibrillation (AF) is a common arrhythmia, after cardiac surgery, and it is associated with a twofold increase in cardiovascular mortality and morbidity. Reperfusion injury and inflammation associated with cardiac surgery are thought to be involved in its pathogenesis. Heat shock proteins (HSPs) are a family of chaperone proteins which assist in preservation of cellular integrity by maintaining proteins in their correctly folded state. The aim of this study was to investigate pre-postoperative heat shock protein70 (HSP70) and high-sensitivity C-reactive protein in serum from patients in preoperative sinus rhythm. We prospectively screened 45 consecutive patients admitted to the hospital for elective coronary artery bypass surgery (CABG). Electrocardiogram characteristics and cardiovascular risk profile were documented. Pre- and postoperative blood samples were collected. HSP70 value was 8.9 +/- 4.8 ng/mL in Group A (study group) preoperatively and decreased to 7.7 +/- 7.0 ng/mL postoperatively. In contrast, preoperative value of HSP70 was 4.2 +/- 2.2 ng/mL and decreased to 2.7 +/- 2.6 ng/mL postoperatively in Group B (control group). Statistical analysis showed significant difference regarding preoperative HSP70 levels in Group A compared to Group B. To our knowledge, with this study, the association of pre- and postoperative circulating HSP70 with postoperative AF was demonstrated for the first time.

Classification of reasons for rejection of biological specimens based on pre-preanalytical processes to identify quality indicators at a university hospital clinical laboratory in Turkey

OBJECTIVES Specific types of error should be identified and corrected in each laboratory to ensure quality results. The objectives of this study were: DESIGN AND METHODS Data on rejected biological specimens in the laboratory information system from January 2013 to January 2014 were analyzed. SSRs according to the type of pre-preanalytical error and collection area were determined. RESULTS In total, 971,780 biological specimens were received during the period and 26,070 (2.7%) specimens were rejected based on our laboratory rejection criteria. The most frequent reason for the rejection was the clotted specimen (55.8% of total rejections), followed by inadequate volume (29.3% of total rejections). Most of the clotted specimens were received from adult hospital inpatient services (54.3%), followed by pediatric hospital inpatient services (26.8%). High rates of inadequate volume were also observed in samples originating from adult and pediatric hospital inpatient services, especially in the premature, neonatal, intensive care, and oncology units. CONCLUSIONS The SSR of clotted specimens was selected as the QI for the preanalytical phase in our laboratory. The selected QI will help to define the effects of our specific interventions and corrective actions, and thus allow monitoring of quality improvement in our hospitals.

Specimen rejection in laboratory medicine: Necessary for patient safety?

Introduction The emergency laboratory in Hacettepe University Hospitals receives specimens from emergency departments (EDs), inpatient services and intensive care units (ICUs). The samples are accepted according to the rejection criteria of the laboratory. In this study, we aimed to evaluate the sample rejection ratios according to the types of pre-preanalytical errors and collection areas. Materials and methods The samples sent to the emergency laboratory were recorded during 12 months between January to December, 2013 in which 453,171 samples were received and 27,067 specimens were rejected. Results Rejection ratios was 2.5% for biochemistry tests, 3.2% for complete blood count (CBC), 9.8% for blood gases, 9.2% for urine analysis, 13.3% for coagulation tests, 12.8% for therapeutic drug monitoring, 3.5% for cardiac markers and 12% for hormone tests. The most frequent rejection reasons were fibrin clots (28%) and inadequate volume (9%) for biochemical tests. Clotted samples (35%) and inadequate volume (13%) were the major causes for coagulation tests, blood gas analyses and CBC. The ratio of rejected specimens was higher in the EDs (40%) compared to ICUs (30%) and inpatient services (28%). The highest rejection ratio was observed in neurology ICU (14%) among the ICUs and internal medicine inpatient service (10%) within inpatient clinics. Conclusions We detected an overall specimen rejection rate of 6% in emergency laboratory. By documentation of rejected samples and periodic training of healthcare personnel, we expect to decrease sample rejection ratios below 2%, improve total quality management of the emergency laboratory and promote patient safety.

Serum vitamin D deficiency and its association with systemic disease in exfoliation syndrome.

Purpose To determine the association of serum vitamin D levels with exfoliation syndrome (XFS) and evaluate its impact on co-associated systemic diseases. Methods Forty patients with XFS and 40 control subjects without XFS were recruited for this study. Serum concentrations of 25-hydroxy vitamin D [25(OH) D] were measured by high-performance liquid chromatography. Vitamin D deficiency was defined as a serum 25(OH) D concentration of <20 ng/mL. A detailed medical history including hypertension, diabetes mellitus, ischemic heart disease, cerebrovascular stroke, autoimmune disease, and neurologic disorders such as Parkinson disease and Alzheimer disease was recorded. Student t test and chi-square test was used for statistical evaluations. Results The mean age of patients with XFS and control subjects was 69.6 ± 8.1 years (range 58–90 years) and 67.1 ± 6.3 years (range 60–86 years), respectively (p>0.05). Mean 25(OH) D levels did not differ between XFS (19.8 ± 8.3 ng/mL) and control (19.9 ± 10.3 ng/mL) groups (p = 0.978). Patients with XFS had higher prevalence of cerebrovascular (p = 0.026) and cardiovascular disease (p = 0.001). There was no association between the systemic disease status and serum vitamin D levels of patients with XFS. Conclusions Although vitamin D levels were similar between XFS and control subjects, the levels were found to be decreased in both groups. Patients with XFS had a significantly higher prevalence of cerebrovascular and cardiovascular disease as compared to controls independent of their serum 25(OH) D levels. Low vitamin D level does not appear to be linked to XFS in the studied population.

Ti(IV) carrying polydopamine-coated, monodisperse-porous SiO2 microspheres with stable magnetic properties for highly selective enrichment of phosphopeptides

A marked decrease in the saturation magnetization by the formation of functional shells around the magnetic core is an important disadvantage of magnetic core-shell nanoparticles. Another drawback of Ti(IV)-functionalized immobilized metal affinity chromatography (IMAC) sorbents is the acidic character of the binding medium used for Ti4+ attachment onto composite magnetic nanoparticles, which causes an additional decrease in the saturation magnetization owing to the chemical interaction between the acidic moiety and the magnetic core. An IMAC sorbent in the form of magnetic microspheres with superior and stable magnetic properties with respect to magnetic core-shell nanoparticles was designed for phosphopeptide enrichment. Magnetic, monodisperse-porous silica microspheres (MagSiO2) 6μm in size were synthesized by a new staged-shape template hydrolysis-condensation protocol. A porous-silica shell layer was generated around the microspheres to protect the magnetic core from the acidic medium during Ti4+ attachment (MagSiO2@SiO2). The MagSiO2@SiO2 microspheres were coated with a polydopamine shell (MagSiO2@SiO2@PDA) and Ti4+ was attached onto the composite microspheres (MagSiO2@SiO2@PDA@Ti(IV)). Formation of the PDA layer and Ti4+ attachment did not cause any significant decrease in the saturation magnetization. The platform exhibited excellent performance for phosphopeptide enrichment from the digests of phosphorylated proteins. Selectivity was investigated by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The detection limit for phosphopeptide enrichment by the MagSiO2@SiO2@PDA@Ti(IV) microspheres from the tryptic digests of β-casein was 50 fmol/mL. Usability of the proposed magnetic sorbent with complex biological samples was demonstrated by successful enrichment of four phosphopeptides from human serum. The proposed sorbent showed stable performance over five repeated uses.

Highly selective enrichment of phosphopeptides by titanium (IV) attached monodisperse-porous poly(vinylphosphonic acid-co-ethylene dimethacrylate) microspheres

A seeded polymerization protocol was developed for the synthesis of monodisperse-porous poly(vinylphosphonic acid-co-ethylene dimethacrylate), [poly(VPA-co-EDMA)] microspheres with superior porous properties. The protocol allowed the direct synthesis of phosphonic acid functionalized porous microspheres with the mean size of ∼4μm and the specific surface area of 420m2g-1 without applying any complicated post-derivatization protocol for the attachment of phosphonic acid group. The phosphonic acid content of poly(VPA-co-EDMA) microspheres was determined as 1.5mmol H2PO3g-1 microspheres. Ti(IV) ions were attached onto the microspheres via metal-chelate complex formation by phosphonate-groups and Ti(IV) carrying monodisperse-porous poly(vinylphosphonic acid-co-ethylene dimethacrylate), [Ti(IV)@poly(VPA-co-EDMA)] microspheres were obtained as a new sorbent for phosphopeptide enrichment via immobilized metal affinity chromatography. The phosphopeptides in the enriched samples were identified by matrix-assited laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). Four different phosphopeptides were detected with extremely high intensity by the treatment of β-casein digest prepared with the concentration of 10 fmol/mL with Ti(IV)@poly(VPA-co-EDMA) microspheres. Highly selective enrichment of phosphopeptides was also successfully carried out even at trace amounts in a complex mixture of digested proteins (molar ratio of β-casein to BSA, 1:1000) and eight different phosphorylated peptides from BSA digest were successfully identified. Moreover, four highly intense signals of the phosphopeptides in human serum were observed with high S/N ratio and clear background after enrichment by using Ti(IV)@poly(VPA-co-EDMA) microspheres.

Plasma leptin levels increase to a greater extent following on-pump coronary artery surgery in type 2 diabetic patients than in nondiabetic patients

AIMS We aimed to evaluate whether leptin and ghrelin responses to cardiopulmonary bypass (CPB) are dependent on type 2 diabetes and whether these responses are associated with interleukin-6 (IL-6), high-sensitivity C-reactive protein (hsCRP), cortisol and insulin. METHODS We examined stress-response patterns in plasma leptin, ghrelin, hsCRP, IL-6, cortisol and insulin levels before and up to 5 days after cardiopulmonary bypass in 20 patients with type 2 diabetes and 20 patients without diabetes. RESULTS Plasma leptin levels increased significantly in both groups (p<0.05) and rose significantly higher in diabetics when compared with nondiabetic patients (p=0.004). Plasma ghrelin levels increased significantly only in diabetics (p=0.033). Patients with and without diabetes showed significantly elevated serum concentrations of IL-6, hsCRP, cortisol and insulin (p<0.005 for IL-6, hsCRP; p<0.05 for cortisol, insulin) but the difference between the two groups was nonsignificant. Leptin was independently predicted by hsCRP (p<0.05, F=2.9), gender (women p<0.001, F=4.7), body mass index (BMI p<0.0001, F=6.1) whereas ghrelin levels were not associated with any variables in the total patient population. (critical F=2.26, p≤0.05). CONCLUSIONS Acute phase response in diabetics differs by higher leptin levels independent of BMI, gender and IL-6, hsCRP, insulin and cortisol levels.

Birleşik Modelleme Yaklaşımı ile Tekrarlı C-Reaktif Protein Ölçümlerinin Tanısal Performansını Etkileyen Faktörlerin İncelenmesi

Objective: Serial C-Reactive Protein (CRP) measurements are frequently taken in Adult Intensive Care Units. In this study it’s aimed to evaluate the factors affecting diagnostic accuracy of this biomarker’s serial measurements in predicting the risk of death at Intensive Care Units (ICU) at the end of follow-up period, 30 days. Material and Methods: Joint Modelling Approach is used to model repeated CRP measurements taken from Hacettepe University Adult Intensive Care Units and survival times simultaneously. With the help of this model, time-dependent Area Under ROC Curve (td-AUC) values are calculated and assessed as diagnostic performance criteria. Results: Diagnostic performance of serial CRP values in predicting the risk of death is found as moderate. However, it’s found that neither the distribution of survival times in survival sub-model nor utilizing more detailed function in random-effects part of longitudinal sub-model affect the diagnostic performance. Also it’s determined that the highest diagnostic performance is obtained with standart standard joint model. Conclusion: To reach the highest diagnostic accuracy, standard joint model with Piecewise Constant Distribution in survival sub-model and random intercepts random slope structure in longitudinal sub-model should be used.

Cerebrospinal fluid oligoclonal banding patterns and intrathecal immunoglobulin synthesis: Data comparison from a wide patient group

Corresponding Author: Aslı Pınar E-mail: aapinar2009@gmail.com Submitted: 10 April 2017 Accepted: 11 December 2017 You may cite this article as: Pınar A, Tuncer Kurne A, Lay İ, Acar NP, Karahan S, Karabudak R. Cerebrospinal fluid oligoclonal banding patterns and intrathecal immunoglobulin synthesis: Data comparison from a wide patient group. Neurol Sci Neurophysiol 2018; 35: 21-28. Abstract Objective: This study aimed to evaluate laboratory oligoclonal band (OCB) patterns together with related IgG results and compare these results with data obtained through final clinical diagnosis. Also, to evaluate electrophoretic patterns based on reibergrams and the diagnostic value of OCBs in patients with multiple sclerosis (MS).

The Scope, Quality and Safety Requirements of Drug Abuse Testing

The aim of this review is to inform about the scopes and requirements of drug abuse testing. Drug abuse testing is one of the tools for determination of drug use. It must fulfill the quality and safety requirements in judgmental legal and administrative decisions. Drug abuse testing must fulfill some requirements like selection of the appropriate test matrix, appropriate screening test panel, sampling in detection window, patient consent, identification of the donor, appropriate collection site, sample collection with observation, identification and control of the sample, specimen custody chain in preanalytical phase; analysis in authorized laboratories, specimen validity tests, reliable testing METHODS, strict quality control, two-step analysis in analytical phase; storage of the split specimen, confirmation of the split specimen in the objection, result custody chain, appropriate cut-off concentration, the appropriate interpretation of the result in postanalytical phase. The workflow and analytical processes of drug abuse testing are explained in last regulation of the Department of Medical Laboratory Services, Ministry of Health in Turkey. The clinical physicians have to know and apply the quality and safety requirements in drug abuse testing according to last regulations in Turkey.