Gülten Toprak

Cytoprotective effects of amifostine,ascorbic acid and N-acetylcysteine against methotrexate-induced hepatotoxicity in rats

AIM To investigate the potential role of oxidative stress and the possible therapeutic effects of N-acetyl cysteine (NAC), amifostine (AMF) and ascorbic acid (ASC) in methotrexate (MTX)-induced hepatotoxicity. METHODS An MTX-induced hepatotoxicity model was established in 44 male Sprague Dawley rats by administration of a single intraperitoneal injection of 20 mg/kg MTX. Eleven of the rats were left untreated (Model group; n = 11), and the remaining rats were treated with a 7-d course of 50 mg/kg per day NAC (MTX + NAC group; n = 11), 50 mg/kg per single dose AMF (MTX + AMF group; n = 11), or 10 mg/kg per day ASC (MTX + ASC group; n = 11). Eleven rats that received no MTX and no treatments served as the negative control group. Structural and functional changes related to MTX- and the various treatments were assessed by histopathological analysis of liver tissues and biochemical assays of malondialdehyde (MDA), superoxide dismutase (SOD), catalase, glutathione (GSH) and xanthine oxidase activities and of serum levels of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase and total bilirubin. RESULTS Exposure to MTX caused structural and functional hepatotoxicity, as evidenced by significantly worse histopathological scores [median (range) injury score: control group: 1 (0-3) vs 7 (6-9), P = 0.001] and significantly higher MDA activity [409 (352-466) nmol/g vs 455.5 (419-516) nmol/g, P < 0.05]. The extent of MTX-induced perturbation of both parameters was reduced by all three cytoprotective agents, but only the reduction in hepatotoxicity scores reached statistical significance [4 (3-6) for NAC, 4.5 (3-5) for AMF and 6 (5-6) for ASC; P = 0.001, P = 0.001 and P < 0.005 vs model group respectively]. Exposure to MTX also caused a significant reduction in the activities of GSH and SOD antioxidants in liver tissues [control group: 3.02 (2.85-3.43) μmol/g and 71.78 (61.88-97.81) U/g vs model group: 2.52 (2.07-3.34) μmol/g and 61.46 (58.27-67.75) U/g, P < 0.05]; however, only the NAC treatment provided significant increases in these antioxidant enzyme activities [3.22 (2.54-3.62) μmol/g and 69.22 (61.13-100.88) U/g, P < 0.05 and P < 0.01 vs model group respectively]. CONCLUSION MTX-induced structural and functional damage to hepatic tissues in rats may involve oxidative stress, and cytoprotective agents (NAC > AMF > ASC) may alleviate MTX hepatotoxicity.

Effect of pneumatic tube delivery system rate and distance on hemolysis of blood specimens.

We evaluated the effects of pneumatic tube system (PTS) transport rates and distances on routine hematology and coagulation analysis. PTS effects on centrifuged blood samples were also examined.

The association between NT-proBNP levels, functional capacity and stage in patients with heart failure

Objective — Amino-terminal probrain natriuretic peptide (NT-proBNP), a biologically inactive derivative of BNP, is clinically more useful owing to its longer half-life, higher plasma concentrations, lesser variation among individuals, and higher in vitro stability. In this regard, NT-proBNP may be a better indicator of the severity of ventricular dysfunction. In this study, the association of NT-proBNP levels with functional capacity and stage of heart failure was explored in patients with CHF. Also, we particularly focused on the presence and significance of neurohormonal activation in the group of patients classified as stage-A according to ACC/AHA guidelines. Methods and results — 64 patients with CHF (31 men, 33 women; mean age 58.26 ± 10.59 y) and 36 healthy controls (24 men, 12 women; mean age 57.47 ± 10.83) were included in this study.The New York Heart Association (NYHA) classification system (I, II, III, IV) was used to define the functional capacity; and the stage of the heart failure was based on the ACC/AHA guidelines (A, B, C, D). Healthy female participants had higher NT-proBNP levels compared to their male counterparts (p < 0.001). Left ventricular ejection fraction (LVEF) did not correlate significantly with functional capacity and stage of the disease. CHF patients had higher NT-proBNP compared to controls (p < 0.001). There was a positive correlation between NT-proBNP and functional capacity in patients, and NT-proBNP increased significantly with each increasing class of the disease. Similarly, a positive correlation existed between the stage of heart failure and NT-proBNP levels, which increased significantly with increasing stages of the disease. Patients with NYHA I and stage A disease had higher NT-proBNP levels compared to controls (p = 0.04). Conclusions — The severity of CHF can be objectively assessed by measuring the circulating levels of NT-proBNP. Even in NYHA I and stage A disease, NT-proBNP levels are higher compared to controls (p = 0.04).NT-proBNP can provide objective information regarding the severity of the disease and also aid in treatment decisions in patients with CHF.

Oxytocin ameliorates remote liver injury induced by renal ischemia-reperfusion in rats.

Renal ischemia-reperfusion (IR) causes remote liver damage. Oxytocin has anti-inflammatory and antioxidant effects. The main purpose of this study was to evaluate the protective function of oxytocin (OT) in remote liver damage triggered by renal IR in rats. Twenty four rats were randomly divided into four different groups, each containing 8 rats. The groups were as follows: (1) Sham operated group; (2) Sham operated+OT group (3) Renal IR group; (4) Renal IR+OT group. OT (500µg/kg) was administered subcutaneously 12 and 24 hours before and immediately after ischemia. At the end of experimental procedure, the rats were sacrificed, and liver specimens were taken for histological assessment or determination of malondialdehyde (MDA), total oxidant status (TOS), total antioxidant status (TAS), paraoxonase (PON-1) activity and nitric oxide (NO). The results showed that renal IR injury constituted a notable elevation in MDA, TOS, Oxidative stress index (OSI) and significantly decreased TAS, PON-1 actvity and NO in liver tissue (p<0.05). Additionally renal IR provoked significant augmentation in hepatic microscopic damage scores. However, alterations in these biochemical and histopathological indices due to IR injury were attenuated by OT treatment (p<0.05). These findings show that OT ameliorates remote liver damage triggered by renal ischemia-reperfusion and this preservation involves suppression of inflammation and regulation of oxidant-antioxidant status.

Effects of antioxidant agents against cyclosporine-induced hepatotoxicity

BACKGROUND To investigate the potential protective antioxidant role of ursodeoxycholic acid (UDCA), melatonin, and allopurinol treatment in cyclosporine (CsA)-induced hepatotoxicity. METHODS Hepatotoxicity was established in Sprague-Dawley rats by daily administration of CsA. Treatment groups were additionally administered UDCA, melatonin, or allopurinol treatments. Rats that received no CsA and no treatments served as a control group. Liver samples from each group were examined by histopathologic analysis to determine the effects of CsA treatment on liver morphology. Biochemical assays were also used to determine the effect of CsA treatment on liver function, in the presence or absence of UDCA, melatonin, or allopurinol. RESULTS CsA treatment induced hepatotoxicity, resulting in sinusoidal dilatation, congestion, infiltration, hydropic degeneration, and loss of glycogen storage in the liver. From a molecular perspective, the CsA treatment increased levels of malondialdehyde (MDA) levels, decreased levels of reduced glutathione and xanthine oxidase, and decreased activities of superoxide dismutase and catalase. The CsA treatment also resulted in decreased serum total antioxidant capacity, whereas alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, total bilirubin levels, and total oxidant status were increased. Treatment with UDCA, melatonin, or allopurinol reduced the CsA-induced histopathologic changes, as compared with CsA-treated samples. In addition, UDCA, melatonin, or allopurinol treatment mitigated the CsA-induced effects on glutathione and MDA levels, and on superoxide dismutase and catalase activities, as well as reduced the CsA-mediated perturbations in serum levels of total antioxidant capacity, total oxidant status, and alkaline phosphatase. CONCLUSIONS UDCA, allopurinol, and melatonin may each help to protect against CsA-induced damage to liver tissues, possibly through effects on the antioxidant system.

Effects of Storage Temperature and Time on Stability of Serum Tacrolimus and Cyclosporine A Levels in Whole Blood by LC-MS/MS

Tacrolimus and cyclosporine A are immunosuppressant drugs with narrow therapeutic windows. The aim of this study was to investigate the stability of tacrolimus and cyclosporin A levels in whole blood samples under different storage conditions. Whole blood samples were obtained from 15 patients receiving tacrolimus and 15 patients receiving cyclosporine A. Samples were immediately analyzed and then stored at different conditions (room temperature (24°C−26°C) for 24 hours, +4°C for 24 and 48 hours, and −20°C for one month) and then analyzed again. For tacrolimus, there was a significant difference between samples analyzed immediately and those kept 24 hours at room temperature (P = 0.005) (percent change 32.89%). However, there were no significant differences between the other groups. For cyclosporine A, there was a significant difference between samples analyzed immediately and those kept 24 hours (P = 0.003) (percent change 19.47%) and 48 hours (P = 0.002) (percent change 15.38%) at +4°C and those kept 24 hours at room temperature (P = 0.011) (percent change 9.71%). Samples of tacrolimus should be analyzed immediately or stored at either +4°C or −20°C, while samples of cyclosporine A should be analyzed immediately or stored at −20°C.

A questionnaire study among nurses: awareness of blood and urine sample collection procedures

*Corresponding author: Hatice Yuksel, MD, Assistant Professor, Department of Biochemistry, Dicle Universitesi Tip Fakultesi, Tibbi Biyokimya Anabilim Dali Seyrantepe mevkii 21280-Diyarbakir, Turkey, Phone: +90 532 5902037, Fax: +90 412 2488520, E-mail: hkyuksel@gmail.com Ibrahim Kaplan, Gulten Toprak, Osman Evliyaoglu, Seyit Kus, and Nuriye Mete: Faculty of Medicine, Department of Biochemistry, Dicle University, Diyarbakir, Turkey Mustafa Azizoglu: Faculty of Medicine, Dicle University, Diyarbakir, Turkey

İdrar kültürü testi gerekliliğini öngörmede tam otomatik idrar analizi sonuçlarının performansı

Objective: Urinalysis and urine culture are most common tests for diagnosis of urinary tract infections. The aim of our study is to examine the diagnostic performance of urine analysis and the role of urine analysis to determine the requirements for urine culture. Methods: Urine culture and urine analysis results of 362 patients were retrospectively analyzed. Culture results were taken as a reference for chemical and microscopic examination of urine and diagnostic accuracy of the test parameters, that may be a marker for urinary tract infection, and the performance of urine analysis were calculated for predicting the urine culture requirements. Results: A total of 362 urine culture results of patients were evaluated and 67% of them were negative. The results of leukocyte esterase and nitrite in chemical analysis and leukocytes and bacteria in microscopic analysis were normal in 50.4% of culture negative urines. In diagnostic accuracy calculations, leukocyte esterase (86.1%) and microscopy leukocytes (88.0%) were found with high sensitivity, nitrite (95.4%) and bacteria (86.6%) were found with high specificity. The area under the curve was calcu lated as 0.852 in ROC analysis for microscopic examination for leukocytes. Conclusion: Full-automatic urine devices can provide sufficient diagnostic accuracy for urine analysis. The evaluation of urine analysis results in an effective way can predict the necessity for urine culture requests and especially may contribute to a reduction in the work load and cost. J Clin Exp Invest 2014; 5 (2): 286-289