Sedat Abusoglu

The effects of prophylactic zinc and melatonin application on experimental spinal cord ischemia–reperfusion injury in rabbits: experimental study

Study design:Experimental study.Objectives: To determine the neuroprotective effects of zinc and melatonin on spinal cord ischemia–reperfusion (I/R) injuries of rabbits.Setting: The Experimental Research Centre of Selçuk University, Konya, Turkey.Methods:Twenty-four male rabbits underwent spinal cord ischemia by clamping the thoraco-abdominal aorta for 20 min. Twenty minutes before the aortic clamping, animals received zinc, melatonin or a combination of both. Neurological examination of the animals was performed three times during reperfusion period. The animals were killed 24 h after reperfusion. Spinal cord samples were taken for biochemical and histopathological evaluation.Results:Pre-treated animals with zinc, melatonin or combination displayed better neurological outcomes than the I/R group (P<0.05). Zinc, melatonin and combined treatment prevented spinal cord injury by reducing apoptosis rate (P<0.05) and preserving intact ganglion cell numbers (P<0.05). Zinc pre-treatment protected spinal cord by preventing malondialdehyde (MDA) formation (P=0.002), increasing glutathione peroxidase (GPx) activity (P=0.002) and decreasing xanthine oxidase enzyme activity (P=0.026) at molecular level. Melatonin treatment also resulted with MDA formation (P=0.002), increased GPx activity (P=0.002) and decreased xanthine oxidase activity (P=0.026).Conclusion:The results of the study showed that prophylactic zinc and melatonin use in spinal cord I/R not only suppressed lipid peroxidation by activating antioxidant systems but also had significant neuroprotective effects by specifically improving the neurological and histopathological situation.

Ischemia-Modified Albumin: Could It Be a New Oxidative Stress Biomarker for Colorectal Carcinoma?

Background/Aims An impaired oxidative/antioxidative status plays an important role in the pathogenesis of many diseases, including cancer. The aim of this study was to evaluate the levels of the novel marker ischemia-modified albumin (IMA) and albumin-adjusted IMA (Adj-IMA) in patients with colorectal cancer (CRC) and look for the associations of these with the total antioxidant status (TAS), total oxidant status (TOS), and oxidative stress index (OSI). Methods Forty patients with CRC (19 females and 21 males; mean age, 56.5±2.1 years) and 39 age- and sex-matched healthy people (22 females and 17 males; mean age, 56.0±1.7 years) were included in this study. Serum levels of IMA, TAS, and TOS were analyzed, and the OSI was calculated. Results Serum IMA, TOS, and OSI levels were significantly higher in patients with CRC than in controls (p<0.0001), whereas TAS levels were significantly lower in CRC patients (p=0.03). There was no significant difference in serum Adj-IMA levels between groups (p=0.32). Conclusions In this study, the oxidative/antioxidant status was impaired in favor of oxidative stress in CRC patients. This observation was not confirmed by IMA measurement. Further studies are needed to establish the relationship between IMA and oxidative stress parameters in CRC and other cancers.

8-Hydroxydeoxyguanosine as a Useful Marker for Determining the Severity of Trichloroethylene Exposure

ABSTRACT The aim of this study was to determine 8-hydroxydeoxyguanosine (8-OH-dG) levels in trichloroethylene (TCE)-exposed workers. Oxidative stress biomarkers and biochemical parameters were monitored among 26 TCE-exposed workers and 78 age-matched control subjects. Levels of urinary 8-OH-dG were analyzed by liquid chromatography tandem mass spectrometry. Urinary 8-OH-dG levels were significantly higher for TCE-exposed group (p < .001). Spearmans correlation test revealed positive correlations between urinary trichloroacetic acid levels and age, urinary 8-OH-dG, urinary total oxidant status, and urinary total antioxidant status (p = .042, p < .001, p < .001, and p < .001, respectively). 8-OH-dG may be a useful marker to determine the extent of TCE exposure.

Stability of urine specimens stored with and without preservatives at room temperature and on ice prior to urinalysis

OBJECTIVES Laboratories determine the most appropriate approach for the collection and transport of urine specimens. We investigated the effect of a chlorhexidine-based preservative tube on sample stability, compared the results of refrigerated polystyrene tubes with no additives, and investigated the effect of temperature on the performance of preservative tubes. DESIGN AND METHODS Fresh urine specimen (n=48) aliquots in BD Vacutainer® Plus Urinalysis Preservative Tubes and polystyrene tubes were analyzed on an Iris Diagnostics iQ200. Samples in polystyrene tubes were refrigerated for 4 and 8h. Four aliquots in preservative tubes were kept at room temperature for 4, 8, 24, and 72h, while two aliquots were kept on ice for 4 and 8h. RESULTS There was good agreement for all chemistry and microscopy parameters with the exceptions of white blood cells (WBCs) at 24 and 72h and red blood cells (RBCs) at 72h. Preservative tubes on ice showed a significant decrease in concordance of WBCs and calcium oxalate (CaOx) parameters compared with the results at room temperature. Results of refrigerated polystyrene tubes showed good agreement with the exceptions of WBC clumps and amorphous crystal at 8h. CONCLUSIONS A chlorhexidine-containing preservative tube seems advantageous for urine sample transport from outside healthcare services. A preservative tube offers comparable results with urine samples kept in a refrigerator for 4-8h for the majority of parameters. Keeping samples at room temperature is recommended when preservative tubes are used because ice produces a negative effect on WBCs and CaOx.

Alterations of Thyroid Hormone Levels in Cadmium Exposure

1 Evren Akgöl1, Engin Tutkun2, Hinc Yilmaz3, Fatma Meric Yilmaz4, Meside Gunduzoz3, Ceylan Demir Bal4, Ali Unlu5, Sedat Abusoglu5 1Deparatment of Biochemistry, Birecik State Hospital, Birecik, Sanliurfa, 2Department of Public Health, Bozok University Faculty of Medicine, Yozgat, 3Department Occupational Diseases Service, Occupational Diseases Hospital, Ankara, 4Department of Biochemistry, Yildirim Beyazit University Faculty of Medicine, Ankara, 5Department of Biochemistry, Selcuk University Faculty of Medicine, Konya, Turkey Elevated Thyroid Hormones with Cadmium Toxicity Alterations of Thyroid Hormone Levels in Cadmium Exposure

A short guideline on chronic kidney disease for medical laboratory practice / Kronik böbrek hastalığında tıbbi laboratuvar uygulamaları için kısa kılavuz

Abstract Chronic kidney disease (CKD) is asymptomatic in the early stage. Kidney function might be lost 90% when the symptoms are overt. However, in case of early detection, progression of the disease can be prevented or delayed. If not detected it results in end stage renal disease. Therefore, the level of awareness about CKD should be increased. The role of medical laboratory is utmost important for the diagnosis and staging of CKD. In this paper, the main tasks of the laboratory specialists are described and the outlines are as follows. • Creatinine assays should be traceable to internationally recognised reference materials and methods, specifically isotope dilution mass spectrometry. • When reporting the creatinine result, eGFR should also be reported in adult (>18 years) population. A warning expression should be included in the report form if eGFR result is <60 mL/min/1.73 m2. • eGFR values should be expressed quantitatively up to 90 mL/min/1.73 m2 by CKD-EPI equation. Above 90 mL/ min/1.73 m2, eGFR values can be expressed quantitatively or >90 mL/min/1.73 m2. • eGFR equations of the adult population should not be used for pediatric population. Different equations utilizing also patient height should be used. The enzymatic creatinine assay should be preferred. eGFR based on cystatin C can be used for confirmation in the pediatric population. • Cystatin C measurements, at least when eGFR based on creatinine is not reliable and for confirmation should be encouraged. • Proteinuria or albuminuria values should be measured in spot samples and reported in proportion to creatinine. Özet Kronik böbrek hastalığı (KBH) erken dönemde asemptomatiktir. Semptomlar ortaya cıktığında böbrek fonksiyonu %90 oranında azalmış olabilir. Buna karşılık, eğer erken dönemde saptanırsa hastalığın ilerlemesi önlenebilir veya geciktirilebilir. Eğer saptanamazsa, KBH son dönem böbrek yetmezliği ile sonuclanır. Bu yüzden, KBH hakkında farkındalık artırılmalıdır. KBH tanısı ve derecelendirmesinde tıbbi laboratuvarın rolü son derece önemlidir. Bu derlemede, laboratuvar uzmanlarının temel görevleri tanımlandı. Bunlar anahatlarıyla aşağıda verilmektedir: • Kreatinin ölçümleri uluslararası gecerliliği olan referans materyallere ve izotop seyreltimi kütle spektrometri gibi referans yöntemlere göre izlenebilir olmalıdır. • Kreatinin sonuçları rapor edilirken, erişkin popülasyonda (>18 yaş) eGFR de verilmelidir. Eğer eGFR sonucu <60 mL/ min/1.73 m2 ise raporda bir uyarı ifadesi yer almalıdır. • eGFR sonucları CKD-EPI eşitliği ile 90 mL/min/1.73 m2’ye kadar kantitatif olarak verilmelidir; 90 mL/min/1.73 m2’nin üzerindeki değerler kantitatif olarak veya >90 mL/ min/1.73 m2 olarak ifade edilebilir. • Erişkin popülasyon eGFR değerleri pediyatrik popülasyon için kullanılmamalıdır. Pediyatrik popülasyon için hasta boyunu da içeren farklı eşitlikler kullanılmalıdır ve enzimatik kreatinin yöntemi tercih edilmelidir. Sistatin C’ye dayanan eGFR değeri pediyatrik popülasyonda doğrulama amaclı kullanılabilir. • eGFR’ye dayalı kreatinin sonucu güvenilir olmadığında ve doğrulama gerektiğinde sistatin C ölçümleri teşvik edilmelidir. • Proteinüri ve albüminüri değerleri rastgele örneklerde ölçülmeli ve kreatinine oranlanarak verilmelidir.

The relationship between Polycystic ovary syndrome and vitamin D levels

Objective: The main aim of this study was to determine the association of serum 25-hydroxyvitamin D (25-OH D) levels with hormonal, clinical and metabolic profile in patients with and without Polycystic ovary syndrome (PCOS). Materials and Methods: Forty-eight normal-weight (body mass index (BMI) of 19-24.99 kg/m2) women with PCOS, 36 overweight (BMI of 25-29.9 kg/m2) women with PCOS and 56 normal-weight controls participated in the study. Blood samples were collected in the early follicular phase (between day 2 and day 5 of the menstrual cycle) at 9:00 am after an overnight fast. Circulating concentrations of 25-OH D, luteinizing hormone (LH), follicle stimulating hormone (FSH), prolactin, TSH, free testosterone, dehydroepiandrosterone sulphate (DHEA-SO4), 17-hydroxyprogesterone, sex hormone-binding globulin (SHBG), fasting insulin, fasting glucose, and lipid profile were assessed. Results: Normal weight (BMI 19-24.99 kg/m2) and overweight (BMI 25-29.99 kg/m2) women with PCOS were compared with normal-weight controls and lower 25-OH D levels were found in both PCOS groups (p<0.05 and p<0.01, respectively 25-OH D significantly negatively correlated with waist circumference (WC), waist-to-hip ratio (WHR), free testosterone and modified Ferriman-Gallwey scores, however, there was a positive correlation between 25-OH D and SHBG levels (p<0.05). Conclusion: Our findings suggest that PCOS is associated with hypovitaminosis D.

Elevated Urinary Methylmalonic Acid/creatinine ratio and Serum Sterol levels in Patients with Acute Ischemic Stroke

Abstract Introduction: Sitosterolemia, defined as phytosterolemia, is a rare autosomal recessive disease characterized by elevated blood sterol levels. Our aim was to investigate serum plant sterols, methylmalonic acid, vitamin B12, oxidized-LDL and homocysteine levels in ischemic and hemorrhagic stroke patients and healthy subjects. Material and Methods: 50 healthy subjects (without a family history of coronary artery disease) and 89 patients hospitalized in the Selcuk University neurology clinic or intensive care unit with a diagnosis of stroke were included in this study. Serum plant sterols, homocysteine and methylmalonic acid, oxidized-LDL, total cholesterol, triglycerides, HDL-Cholesterol and vitamin B12 levels were analyzed by gas chromatography-mass spectrometry, liquid-chromatography tandem mass spectrometry, commercially available ELISA kit, spectrophotometry and chemiluminescence methods, respectively. Results: Urinary methylmalonic acid/creatinine ratio (p< 0.05), serum β-sitosterol levels and β-sitosterol/ cholesterol ratio were significantly higher (p <0.01) in patients compared to the control group. There was a significant positive correlation between the serum OxLDL- methylmalonic acid, serum homocysteine- urinary methylmalonic acid /creatinine ratio, serum methylmalonic acid - Urinary methylmalonic acid (p<0.05), serum homocysteine- urinary methylmalonic acid, urinary methylmalonic acid-methylmalonic acid/creatinine ratio, serum methylmalonic acid- methylmalonic acid/creatinine ratio, serum beta-sitosterol- beta-sitosterol /cholesterol, total cholesterol-HDL, total cholesterol-LDL (p <0.01) levels and negative correlation between vitamin B12- serum methylmalonic acid (p<0.05), cholesterol-stigmasterol/cholesterol, LDL- stigmasterol/cholesterol (p <0.01) levels in the patient group. Conclusion: Our findings presented that the serum sitosterol levels were significantly higher in stroke patients compared to controls.

The effect of measurement uncertainty for HOMA-IR in assessment of insulin resistance

In this study, it is aimed to estimate not just the uncertainty measurement for the parameters of glucose and insulin having role when calculating HOMA-IR, but also true positiveness and negativeness in terms of cut-off values. The evaluation of the acceptability of the uncertainty value was also among the goals of the study. The uncertainty measurement for glucose and insulin is calculated as uncertainty measurement of HOMA-IR based on Eurochem/CITAC Guide CG 4. The uncertainty measurement for glucose and insulin was estimated as 3.83% and 4.16%, respectively. The measurement uncertainty for the calculated test HOMA-IR was calculated with cut-off values as 27% (0.27). Based on the cut-off value for HOMA-IR of 2.5%, IR(+) and IR(-) patients were 155 and 265, respectively. If the uncertainty measurement for HOMA-IR was added to its calculation, the cut-off value was detected as 2.23-2.77%. We reported the measurement uncertainty of the calculated test HOMA-IR at 95 % CI as 0.27 between 2.23 - 2.77. Especially for the tests used for screening; determination of cut-off values as a range including measurement uncertainty instead of a single value will be more suitable. No data is found in the literature for the calculated test HOMA-IR up to date.

Serum asymmetric dimethylarginine and nitric oxide levelsin Turkish patients with acute ischemic stroke

BACKGROUND Nitric oxide synthase (NOS) is present in the brain and cerebral arteries and it enables the synthesis of nitric oxide (NO), which plays a critical role in brain perfusion. Asymmetrical dimethylarginine (ADMA) is an endogenous NOS inhibitor. OBJECTIVES The aim of this study was to evaluate serum ADMA levels, which are an indicator of endothelial dysfunction of the renal functions in patients with acute ischemic stroke, and to determine whether there is a possible correlation between ADMA and NO levels and the l-arginine-to-ADMA ratio. MATERIAL AND METHODS Fifty-two patients (22 male and 30 female; mean age: 75.2 ±10.1 years) with a diagnosis of acute ischemic stroke in the first 24 h post-stroke and 48 healthy individuals (controls; 13 male and 35 female; mean age: 60.1 ±7.92 years) were included in this study. The risk factors recorded and evaluated were age and gender of the patients, serum lipid levels, serum ADMA levels, nitrate-to-nitrite ratios, l-arginine, l-arginine-to-ADMA ratios, sedimentation rate, C-reactive protein (CRP), urea and creatinine levels, and glomerular filtration ratio (eGFR). RESULTS The mean serum ADMA level was 0.48 ±0.23 μM for the patients and 0.36 ±0.18 μM for the controls. The mean NO level was 2.78 ±0.59 μM for the patient group and 4.49 ±2.84 μM for the controls. The ADMA levels for the patient group were significantly higher than for the control group (p = 0.011); the NO levels for the patients were significantly lower than for the controls (p < 0.001). The logistic regression method demonstrated that ADMA and NO levels may be independent risk factors for the patient group, and the receiver operating characteristic (ROC) curve analysis showed that both of these variables were discriminative risk factors. CONCLUSIONS An increased serum level of the NOS inhibitor ADMA was found to be a possible independent risk factor for ischemic stroke.