Biological Variations of Seven Clinical Chemistry Analytes and Trolox Equivalent Antioxidant Capacity within Salivary Constituents.

BACKGROUND: Data on biological variation in saliva samples are quite limited. This study aimed to obtain well-defined biological variation data for seven common clinical chemistry analytes and Trolox equivalent antioxidant capacity (TEAC) in saliva. METHODS: Unstimulated whole saliva and blood samples were collected from thirty-two healthy volunteers of both genders without any history of disease or metabolic syndrome under standard conditions at six different times within three weeks. The seven clinical chemistry analytes and TEAC, analyzed by photometric methods using automated analyzers, were planned for biological variation analysis. The components of nested analysis of variance were used to perform the biological variation data analysis. RESULTS: The within-subject and between-subject biological variations (CVG and CVI, respectively) for unstimulated whole saliva samples, respectively, were determined to be 19.3% and 25.1% for α-amylase, 25.1% and 51.1% for aspartate aminotransferase, 31.0% and 22.3% for lactate dehydrogenase, 19.0% and 20.8% for uric acid, 16.6% and 23.4% for total calcium, 12.9% and 13.7% for inorganic phosphate, 13.1% and 19.7% for total protein, and 14.9% and 20.0% for TEAC. In addition, the CVI and CVG were 3.4% and 6.3% for serum TEAC. CONCLUSIONS: Considering the evidence that saliva samples can be used to diagnose and monitor oral or non-oral diseases, these biological variation data will contribute to how to use subject-based reference values or population-based reference intervals of these analytes and TEAC.

Assessment of average of normals (AON) procedure for outlier-free datasets including qualitative values below limit of detection (LoD): an application within tumor markers such as CA 15-3, CA 125, and CA 19-9.

Average of normals (AON) is a quality control procedure that is sensitive only to systematic errors that can occur in an analytical process in which patient test results are used. The aim of this study was to develop an alternative model in order to apply the AON quality control procedure to datasets that include qualitative values below limit of detection (LoD). The reported patient test results for tumor markers, such as CA 15-3, CA 125, and CA 19-9, analyzed by two instruments, were retrieved from the information system over a period of 5 months, using the calibrator and control materials with the same lot numbers. The median as a measure of central tendency and the median absolute deviation (MAD) as a measure of dispersion were used for the complementary model of AON quality control procedure. The ubias values, which were determined for the bias component of the measurement uncertainty, were partially linked to the percentages of the daily median values of the test results that fall within the control limits. The results for these tumor markers, in which lower limits of reference intervals are not medically important for clinical diagnosis and management, showed that the AON quality control procedure, using the MAD around the median, can be applied for datasets including qualitative values below LoD.

Cardioprotective effects of Viscum album L. ssp. album (Loranthaceae) on isoproterenol-induced heart failure via regulation of the nitric oxide pathway in rats.

OBJECTIVE: Viscum album L. has favorable cardiovascular effects including antihypertensive and vasorelaxant activity, and the nitric oxide (NO) pathway upregulation has been proposed to be the underlying mechanism. NO also plays an important role in the pathophysiology of heart failure. However, its effects on cardiac systolic function are unclear. METHODS: A total of 30 male Wistar albino rats at 12 weeks of age were randomly divided into three groups: control, isoproterenol-induced heart failure group (ISO), and isoproterenol-induced heart failure + V. album treatment group (VA) groups (n=10 in each group). V. album was orally given at a dose of 250 mg/kg/day by gavage. Parameters of heart failure were compared among the groups. Tamhane's T2 test, paired sample t-test, and Bonferroni methods were used for statistical analysis. RESULTS: V. album resulted in an improvement in all parameters of heart failure including left ventricular diameters (6.34±0.23 mm, 6.98±0.35 mm, and 6.71±0.10 mm for left ventricular end-diastolic diameter in control, ISO, and VA groups, respectively, p<0.05), ejection fraction (73.3±3.1%, 56.7±2.6%, and 65.2±1.5% for control, ISO, and VA groups, respectively, p<0.05), serum NT-proBNP levels, and histopathological changes. V. album treatment resulted in a statistically significant attenuation of increased levels of NO and iNOS (p<0.0001). The levels of hs-CRP were also found to be lower in the VA group compared with the controls and ISO groups (p<0.01). CONCLUSION: V. album exerted favorable effects on left ventricular function in isoproterenol-induced heart failure rats. Upregulation of the NO pathway seems to be the possible pathophysiological mechanism. Favorable vascular outcomes can also be speculated considering the reduction in serum hs-CRP levels.

The effect of extremely high glucose concentrations on 21 routine chemistry and thyroid Abbott assays: interference study.

INTRODUCTION: Extremely high glucose concentrations have been shown to interfere with creatinine assays especially with Jaffe method in peritoneal dialysate. Because diabetes is the fastest growing chronic disease in the world, laboratories study with varying glucose concentrations. We investigated whether different levels of glucose spiked in serum interfere with 21 routine chemistry and thyroid assays at glucose concentrations between 17-51 mmol/L. MATERIALS AND METHODS: Baseline (group I) serum pool with glucose concentration of 5.55 (5.44-5.61) mmol/L was prepared from patient sera. Spiking with 20% dextrose solution, sample groups were obtained with glucose concentrations: 17.09, 34.52, and 50.95 mmol/L (group II, III, IV, respectively). Total of 21 biochemistry analytes and thyroid tests were studied on Abbott c8000 and i2000sr with commercial reagents. Bias from baseline value was checked statistically and clinically. RESULTS: Creatinine increased significantly by 8.74%, 31.66%, 55.31% at groups II, III, IV, respectively with P values of < 0.001. At the median glucose concentration of 50.95 mmol/L, calcium, albumin, chloride and FT4 biased significantly clinically (-0.85%, 1.63%, 0.65%, 7.4% with P values 0.138, 0.214, 0.004, < 0.001, respectively). Remaining assays were free of interference. CONCLUSION: Among the numerous biochemical parameters studied, only a few parameters are affected by dramatically increased glucose concentration. The creatinine measurements obtained in human sera with the Jaffe alkaline method at high glucose concentrations should be interpreted with caution. Other tests that were affected with extremely high glucose concentrations were calcium, albumin, chloride and FT4, hence results should be taken into consideration in patients with poor diabetic control.

The effects of iodixanol and iopamidol on adhesion molecule serum levels in patients with angina pectoris undergoing coronary angiography: a randomized study.

OBJECTIVE: To compare intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) serum levels between patients with stable (SAP) and unstable angina pectoris (USAP) undergoing coronary angiography (CAG), investigate effects of CAG on ICAM-1, VCAM-1 levels in SAP, USAP patients; probable different effects of non-ionic radiocontrast media (RCM), iso-osmotic iodixanol and low osmolar iopamidol, on these adhesion molecules (AM). METHODS: In this randomized, prospective study, 2 groups consisting of patients with SAP (n=22) and USAP (n=22) undergoing CAG were included. For halves of each group iopamidol, for the other halves iodixanol were used as RCM, in turn for randomization. The patients were divided into 4 subgroups according to clinical presentations and used RCM(SAP-iodixanol, SAP-iopamidol USAP-iodixanol, USAP-iopamidol). ICAM-1, VCAM-1 levels were measured just before and 12 hours after CAG. Repeated measurements were compared with two-way ANOVA test. RESULTS: Baseline VCAM-1 concentration was higher in USAP group than SAP group (p=0.001). ICAM-1, VCAM-1 concentrations increased significantly following CAG in SAP, USAP groups. ICAM-1, VCAM-1 concentration increments; didn't reach statistical significance in SAP-iodixanol subgroup, reached a borderline significance in SAP-iopamidol subgroup (p=0.06). In USAP-iodixanol subgroup; only VCAM-1 (p<0.001), in USAP-iopamidol subgroup; ICAM-1 (p=0.009), VCAM-1 (p=0.006) levels increased significantly following CAG. No complication was observed. CONCLUSION: To our knowledge, this is the first study indicating ICAM-1, VCAM-1 inducing effect of CAG in patients with SAP, USAP and differential effects of iodixanol and iopamidol on ICAM-1, VCAM-1 serum levels. Further studies are needed to clarify the effects of CAG and different RCM on vascular inflammation, vessel injury, serum AM levels and their clinical significance. This study should be taken as a pilot, hypothesis-generating study.

Comparing the renal safety of isoosmolar versus low-osmolar contrast medium by renal biomarkers N-acetyl-ß-D-glucosaminidase and endothelin.

Iodixanol and iopamidol are commonly used contrast agents in coronary angiography. We evaluated the nephrotoxic effects of both contrast media in relation to renal biomarkers. A total of 38 low-risk patients who underwent coronary angiography were enrolled. Patients were randomized to receive either low-osmolar nonionic monomer or isoosmolar nonionic dimer contrast medium. N-Acetyl-ß-d-glucosaminidase (NAG), endothelin, blood urea nitrogen, and urine and serum creatinine (SCr) levels were measured before  the procedure (T0), at 6 hours (T6), and at 1 year after the procedure. Plasma endothelin, urine NAG/creatinine, and SCr were higher; accordingly, the urine creatinine values were lower in both the groups when comparing T0 versus T6. The groups were similar with each other when comparing T0 and T6 values. Both the contrast agents may be safely used at a low volume for coronary angiography in low-risk patients. Endothelin and NAG are sensitive to acute renal changes in function. There is a need for further prospective investigations with more patients.