Evaluation of Analytical Performance of Variant II Turbo HbA1c Analyzer According to Sigma Metrics.

BACKGROUND: Hemoglobin A1c, (HbA1c) which is the major constituent of glycated hemoglobin, has been used in the follow-up of retrospective glycemia for years and in the diagnosis of diabetes mellitus nowadays. Since the analytical performance of HbA1c should be high likewise all laboratory tests, various quality control measures are used. Sigma metrics is one of these measures and it is the combination of bias, precision and total allowable error that ensures a general evaluation of analytical quality. The aim of our study was to evaluate the analytical performance of Bio-Rad's Variant Turbo II HbA1c analyzer according to sigma metrics. METHODS: Sigma levels were calculated using the data obtained from two levels of internal and 12 external quality control materials (Bio-Rad) of Variant II Turbo HbA1c analyzer according to σ = (TEa% - Bias%) / CV% formula. RESULTS: The mean sigma levels for low and high quality control materials were found to be 3.0 and 4.1, respectively. CONCLUSIONS: The annual mean analytical performance of Variant II Turbo HbA1c analyzer was found to be acceptable according to sigma metrics. In order to be sure of the difference in HbA1c results indicating the success or failure in treatment but not arise from analytical variation, it is thought that more stringent quality control measures should be applied to reach higher sigma levels.

Evaluation of maternal serum ischemia modified albumin and total antioxidant status in ectopic pregnancy.

BACKGROUND: Ectopic pregnancies constitute about 2% of all pregnancies which are the leading cause of pregnancy-related deaths and a considerable cause of maternal morbidity. Oxidative stress can lead to a number of pregnancy related diseases including miscarriage, eclampsia and preterm labor. Ischemia modified albumin (IMA) which reflects the oxidative stress may be used as a marker for ectopic pregnancy. Our aim was to compare the levels of IMA and total antioxidant status (TAS) in ectopic and normal pregnancies and to understand if IMA can be used as a marker to diagnose ectopic pregnancy. MATERIALS AND METHODS: Our case-control study consisted of 38 women with ectopic and 42 women with normal pregnancy. IMA and TAS levels were determined in serum samples with an albumin-cobalt binding test and by commercially available kits, respectively. IMA levels were adjusted according to serum albumin levels. Index of oxidation (IOS) was calculated by dividing adjusted IMA (A-IMA) levels with TAS. A receiver operating characteristics (ROC) curve analysis was made and cut-off values for the biomarkers were investigated in SPSS 21.0 program (SPSS, Chicago, IL). Data were presented as mean ± standard deviation and a p value < .05 was accepted as statistically significant. RESULTS: There was a statistically significant difference in IMA, A-IMA, and IOS levels between ectopic and normal pregnancies. Although TAS level was not different statistically, it was lower in ectopic pregnancy. According to ROC curve analysis, IOS had the largest area under curve. A cut-off value of 0.545 for IOS had 81.6% sensitivity and 59.5% specificity. CONCLUSIONS: According to our study, oxidative stress plays an important role in ectopic pregnancy and either A-IMA or IOS can be evaluated as a marker of ectopic pregnancy after further studies.

Molecular structure, spectroscopic characterization, HOMO and LUMO analysis of 3,3'-diaminobenzidine with DFT quantum chemical calculations.

In this work, infrared, Raman and UV spectra of 3,3'-diaminobenzidine (3,3-DAB) were carried out by using density functional theory (DFT)/B3LYP method with 6-311G(d,p) basis set. FT-IR and FT-Raman spectra were recorded in the region 4000-400 and 4000-50 cm(-1), respectively. The geometrical parameters, energies and wavenumbers were obtained and fundamental vibrations were assigned on the basis of the potential energy distribution (PED) of the vibrational modes. The UV spectrum of the investigated compound was recorded in the range of 200-400 nm in ethanol and water solutions. The electronic properties, such as excitation energies, absorption wavelengths, HOMO and LUMO energies were performed by DFT/B3LYP approach and the results were compared with experimental observations. Thermodynamic properties, Mulliken atomic charges and molecular electrostatic potential (MEP) were calculated for the title molecule. Also the nonlinear optical properties of 3,3-DAB molecule were explored theoretically. As a result, the calculated results were compared with the observed values and generally found to be in good agreement.

Molecular structure investigation of neutral, dimer and anion forms of 3,4-pyridinedicarboxylic acid: a combined experimental and theoretical study.

In this study, the structural and vibrational analysis of 3,4-pyridinedicarboxylic acid (3,4-PDCA) are presented using experimental techniques as FT-IR, FT-Raman, NMR, UV and quantum chemical calculations. FT-IR and FT-Raman spectra of 3,4-pyridinedicarboxylic acid in the solid phase are recorded in the region 4000-400 cm(-1) and 4000-50 cm(-1), respectively. The geometrical parameters and energies of all different and possible monomer, dimer, anion(-1) and anion(-2) conformers of 3,4-PDCA are obtained from Density Functional Theory (DFT) with B3LYP/6-311++G(d,p) basis set. There are sixteen conformers (C1C16) for this molecule (neutral form). The most stable conformer of 3,4-PDCA is the C1 conformer. The complete assignments are performed on the basis of the total energy distribution (TED) of the vibrational modes calculated with scaled quantum mechanics (SQM) method. (1)H and (13)C NMR spectra are recorded and the chemical shifts are calculated by using DFT/B3LYP methods with 6-311++G(d,p) basis set. The UV absorption spectrum of the studied compound is recorded in the range of 200-400 nm by dissolved in ethanol. The optimized geometric parameters were compared with experimental data via the X-ray results derived from complexes of this molecule. In addition these, molecular electrostatic potential (MEP), thermodynamic and electronic properties, HOMO-LUMO energies and Mulliken atomic charges, are performed.

Theoretical study on molecular structure and vibrational analysis included FT-IR, FT-Raman and UV techniques of 2,4,5-trimethylbenzoic acid (monomer and dimer structures).

Theoretical study on the structural and vibrational analysis of monomer and dimer structures of 2,4,5-trimethylbenzoic acid (2,4,5-TMBA, C10H12O2) were presented. The geometry of the molecule was fully optimized. The Fourier transform infrared (FT-IR) and the Fourier transform Raman (FT-Raman) spectra of the title molecule in solid phase were recorded in the region 4000-400 cm(-1) and 4000-50 cm(-1), respectively. The geometrical parameters and energies were investigated with the help of Density Functional Theory (DFT) employing B3LYP method and 6-311++G(d,p) basis set. The spectroscopic data of the molecule in the ground state were calculated by using DFT/B3LYP method with the 6-311++G(d,p) basis set. The vibrational spectra were calculated and fundamental vibrations were assigned on the basis of the potential energy distribution (PED) of the vibrational modes. The geometric parameters were compared with experimental data of the title molecule. The UV absorption spectrum of the studied compound was computed and recorded in the range of 190-400 nm dissolved in water and ethanol. Besides, charge transfer occurring in the molecule between HOMO and LUMO energies, frontier energy gap, molecular electrostatic potential (MEP) were calculated and presented. In addition these, thermodynamic properties and Mulliken atomic charges were performed.

Molecular structure, spectroscopic characterization (FT-IR, FT-Raman, UV and NMR), HOMO and LUMO analysis of 3-ethynylthiophene with DFT quantum chemical calculations.

In this work, FT-IR, FT-Raman, UV and NMR spectra of 3-ethynylthiophene (3-ETP, C6H4S) were carried out by using density functional theory DFT/B3LYP method with the 6-311++G(d,p), 6-311+G(d,p), 6-311G(d,p), 6-31++G(d,p), 6-31+G(d,p), 6-31G(d,p) basis sets. FT-IR and FT-Raman spectra were recorded in the regions of 3500-400cm(-1) and 3500-50cm(-1), respectively. The geometrical parameters, energies and wavenumbers were obtained and the complete assignments of fundamental vibrations were performed on the basis of the total energy distribution (TED) of the vibrational modes, calculated with scaled quantum mechanics (SQM) method and PQS program. The (1)H, (13)C and HMQC ((1)H-(13)C correlation) NMR spectra in chloroform (CDCl3) were recorded and calculated. The UV spectrum of investigated compound were recorded in the region of 200-400nm in ethanol solution. The electronic properties, such as excitation energies, absorption wavelengths, HOMO and LUMO energies were performed by DFT/B3LYP approach and the results were compared with experimental observations. The thermodynamic properties such zero-point vibrational energy, thermal energy, specific heat capacity, rotational constants, entropy, and dipole moment of the studied compound were calculated. As a result, the calculated results were compared with the observed data and found to be in good agreement.

Postmenopausal women with osteoporosis may be associated with high endothelin-1.

AIM: We aimed to find out if there was any difference of the endothelin-1 (ET-1) and asymmetric dimethylarginine (ADMA) levels between osteoporotic and non-osteoporotic healthy postmenopausal women and whether there were any associations between ET-1 and ADMA levels and bone mineral density (BMD). METHODS: A total of 75 healthy postmenopausal women were enrolled in the study. BMD was measured at lumbar spine (LS) and femur neck (FN). Serum ET-1 and ADMA levels were measured by ELISA. In this population, 41 (54%) women had BMD t-scores > or = 2.5 at the LS and/or FN defined as osteoporosis and 34 (46%) of them had normal BMDs (non-osteoporotic group). RESULTS: The mean value of ET-1 serum level in patients was 0.42 +/- 0.30, 0.28 +/- 0.12 fmol/ml in osteoporotic and non-osteoporotic groups, respectively (p = 0.018). In non-osteoporotic group, there was an only significant positive correlation was found between BMD (g/cm(2)) and total t-scores at the lumbar region and ET-1 level. In osteoporotic group, no correlation was found between BMD and total t-scores and ET-1 levels. Serum ADMA level was not significantly different between osteoporotic and non-osteoporotic postmenopausal women (p > 0.05). CONCLUSIONS: ET-1 may be a physiologic regulator in non-osteoporotic healthy postmenopausal women. Osteoporotic postmenopausal women had higher ET-1 levels than non-osteoporotic postmenopausal women. ADMA seems not to have effect on bone in postmenopausal women.

Inverse relationship between adiponectin and plasminogen activator inhibitor-1 in metabolic syndrome patients.

OBJECTIVES: To determine the serum levels of adiponectin and plasminogen activator inhibitor-1 in metabolic syndrome versus healthy controls and to see the relation of them with each other and with the metabolic syndrome components. METHODS: Adiponectin and plasminogen activator inhibitor-1 levels were measured in 53 subjects with metabolic syndrome and 30 healthy controls by ELISA. All subjects of metabolic syndrome had the criterias of metabolic syndrome (obesity, insulin resistance, hypertension, dyslipidemia, glucose metabolism disorders). Adiponectin and plasminogen activator inhibitor-1 levels in serum were compared between the groups and relations of them with each other, with metabolic syndrome components, also HbA1c and C peptide were examined. For statistical analysis student-t test and pearson's correlations were used. RESULTS: Metabolic syndrome group had significantly lower adiponectin and higher plasminogen activator inhibitor-1 levels than healthy controls (p<0.001). There was no difference between the average age of both groups. There was an inverse relationship between plasma adiponectin and plasminogen activator inhibitor-1 ( r= -0.653, p<0.001). Also adiponectin levels were inversely correlated with body mass index (BMI), waist and hip circumferences, systolic and diastolic pressures, fasting plasma glucose, 2 hour postprandial serum glucose, HbA1c, C peptide, triglycerides, total cholesterol, insulin and insulin resistance (HOMA). Plasminogen activator inhibitor-1 levels were correlated positively with these parameters. CONCLUSION: Hypoadiponectinemia and elevated plasminogen activator inhibitor-1 levels were closely associated with the metabolic syndrome and its components, inverse relationship was present between adiponectin and plasminogen activator inhibitor-1 levels in metabolic syndrome patients. It is suggested that measuring and regulating the plasma concentration of adiponectin and plasminogen activator inhibitor-1 may be useful for management of the metabolic syndrome so this may prevent the development of obesity, cardiovascular diseases and diabetes.

The effect of strontium ranelate on serum insulin like growth factor-1 and leptin levels in osteoporotic post-menopausal women: a prospective study.

OBJECTIVE: The aim of this study was to investigate the effects of strontium ranelate on insulin like growth factor-1 (IGF-1), leptin and osteocalcin levels in osteoporotic post-menopausal women. STUDY DESIGN: Thirty-three women were given 2 g/day strontium ranelate for 6 months. Serum IGF-1, leptin and osteocalcin levels were measured before and after the treatment. RESULTS: Strontium ranelate treatment increased IGF-1 levels significantly (P = 0.02). Leptin and osteocalcin levels did not change significantly before and after the treatment. There was no correlation between basal and 6-months treatment levels of IGF-1 and leptin. CONCLUSION: Strontium ranelate increases serum IGF-1 levels in osteoporotic post-menopausal women.