Thymidine Kinase 1 (TK1) plays an important role in DNA precursor synthesis and serum TK1 activity has been used as a biomarker for prognosis and therapy monitoring of different malignancies. AroCell ...has developed a dual monoclonal antibody ELISA for determination of TK1 protein in clinical samples. The purpose of the study is to validate the ELISA analytically in relation to the gold standard,
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H-deoxythymidine (dThd) phosphorylation assay for TK1 activity using sera from patients with different malignancies. The colorimetric TK 210 ELISA was validated analytically by assessment of precision, linearity, interfering substances, and stability. For the clinical validation, serum samples from patients with hematological malignancies (n = 100), breast cancer (n = 56), prostate cancer (n = 70) and blood donors (n = 159) were analyzed using TK 210 ELISA and TK1 activity by
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H-deoxythymidine (dThd) phosphorylation assay. The sandwich TK 210 ELISA was highly specific for TK1 protein having a detection limit of 0.12 ng/mL, with a functional sensitivity of 0.25 ng/mL. Within-run CVs ranged from 5.5% to 10% and between-run CVs ranged from 5% to 15%. The ratio of observed to expected dilutional parallelism of 5 serum samples was in the range of 80–120%. Samples exhibited stability through four freeze/thaw cycles and 5 days at 4°C. Further, the ROC curve analysis showed that TK 210 ELISA and
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H-dThd phosphorylation assay had similar sensitivity (62% vs 59%) in hematological malignancies. However, in the case of breast and prostate cancer sera, TK 210 ELISA had higher sensitivity (59% and 44%) compared to
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H-dThd phosphorylation assay (47% and 25%) at a specificity of 98%. These data demonstrate that the dual monoclonal antibody based AroCell TK 210 ELISA is a robust, accurate and precise tool for measuring TK1 protein in different malignancies that can improve the clinical applications of TK1 as a biomarker in cancer management.
Thymidine Kinase 1 (TK1) plays an important role in DNA precursor synthesis and serum TK1 activity has been used as a biomarker for prognosis and therapy monitoring of different malignancies. AroCell ...has developed a dual monoclonal antibody ELISA for determination of TK1 protein in clinical samples. The purpose of the study is to validate the ELISA analytically in relation to the gold standard, 3H-deoxythymidine (dThd) phosphorylation assay for TK1 activity using sera from patients with different malignancies. The colorimetric TK 210 ELISA was validated analytically by assessment of precision, linearity, interfering substances, and stability. For the clinical validation, serum samples from patients with hematological malignancies (n = 100), breast cancer (n = 56), prostate cancer (n = 70) and blood donors (n = 159) were analyzed using TK 210 ELISA and TK1 activity by 3H-deoxythymidine (dThd) phosphorylation assay. The sandwich TK 210 ELISA was highly specific for TK1 protein having a detection limit of 0.12 ng/mL, with a functional sensitivity of 0.25 ng/mL. Within-run CVs ranged from 5.5% to 10% and between-run CVs ranged from 5% to 15%. The ratio of observed to expected dilutional parallelism of 5 serum samples was in the range of 80–120%. Samples exhibited stability through four freeze/thaw cycles and 5 days at 4°C. Further, the ROC curve analysis showed that TK 210 ELISA and 3H-dThd phosphorylation assay had similar sensitivity (62% vs 59%) in hematological malignancies. However, in the case of breast and prostate cancer sera, TK 210 ELISA had higher sensitivity (59% and 44%) compared to 3H-dThd phosphorylation assay (47% and 25%) at a specificity of 98%. These data demonstrate that the dual monoclonal antibody based AroCell TK 210 ELISA is a robust, accurate and precise tool for measuring TK1 protein in different malignancies that can improve the clinical applications of TK1 as a biomarker in cancer management.
BACKGROUND
Current non-invasive diagnostic methods for endometriosis lack sensitivity and specificity. In search for new diagnostic biomarkers for ovarian endometriosis, we used a ...hypothesis-generating targeted metabolomics approach.
METHODS
In a case–control study, we collected plasma of study participants and analysed their metabolic profiles. We selected a group of 40 patients with ovarian endometriosis who underwent laparoscopic surgery and a control group of 52 healthy women who underwent sterilization at the University Clinical Centre Ljubljana, Slovenia. Over 140 targeted analytes included glycerophospholipids, sphingolipids and acylcarnitines. The analytes were quantified by electrospray ionization tandem mass spectrometry. For assessing the strength of association between the metabolite or metabolite ratios and the disease, we used crude and adjusted odds ratios. A stepwise logistic regression procedure was used for selecting the best combination of biomarkers.
RESULTS
Eight lipid metabolites were identified as endometriosis-associated biomarkers due to elevated levels in patients compared with controls. A model containing hydroxysphingomyelin SMOH C16:1 and the ratio between phosphatidylcholine PCaa C36:2 to ether-phospholipid PCae C34:2, adjusted for the effect of age and the BMI, resulted in a sensitivity of 90.0%, a specificity of 84.3% and a ratio of the positive likelihood ratio to the negative likelihood ratio of 48.3.
CONCLUSIONS
Our results suggest that endometriosis is associated with elevated levels of sphingomyelins and phosphatidylcholines, which might contribute to the suppression of apoptosis and affect lipid-associated signalling pathways. Our findings suggest novel potential routes for therapy by specifically blocking highly up-regulated isoforms of phosphpolipase A2 and lysophosphatidylcholine acyltransferase 4.
In order to assess the mercury exposure of pregnant and lactating women in Slovenia, levels of total mercury (THg) and methylmercury (MeHg) were determined in hair, cord blood and breast milk. In ...addition, the frequency of fish consumption was estimated, because fish is generally the main pathway for human exposure to MeHg. Hair samples were collected from 574 women participating in this study, while cord blood and breast milk samples were collected from 446 and 284 women, respectively. As expected, the levels of THg in hair (median (Med)=297ng/g, 10th percentile (P10)=73ng/g, 90th percentile (P90)=781ng/g), cord blood (Med=1.5ng/g, P10=0.5ng/g, P90=4.2ng/g) and breast milk (Med=0.2ng/g, P10=0.06ng/g, P90=0.6ng/g) were low, due to low consumption of fish (X=25g/day). A significant linear correlation was found between levels of lnTHg in hair and lnTHg in cord blood (r=0.87, 95% confidence interval (CI): 0.84–0.89), between levels of lnTHg in hair and lnMeHg in cord blood (r=0.94, 95% CI: 0.90–0.96) and between lnTHg levels in cord blood and lnTHg levels in breast milk (r=0.36, 95% CI: 0.25–0.47). Spearman's rank correlations between the frequency of fish consumption and THg in hair (rs=0.35, 95% CI: 0.28–0.42), and between the frequency of fish consumption and THg in cord blood (rs=0.43, 95% CI: 0.36–0.51) or MeHg in cord blood (rs=0.31, 95% CI: 0.06–0.52) were weak. This could be due to the approximate information on fish consumption obtained from the questionnaires, the high variability of MeHg concentrations in fish and a relatively high proportion of inorganic mercury in the biomarkers which originates from sources other than fish. In conclusion, THg levels in cord blood, THg levels in hair and MeHg levels in cord blood are suitable biomarkers of low-level Hg exposure through fish consumption. Compared to cord blood, hair samples are easy to collect, store and analyse.
► THg in hair, THg, MeHg in cord blood are suitable biomarkers of MeHg exposure. ► THg measurements in hair are the most appropriate for large epidemiological studies. ► Almost 100% of MeHg was found in cord blood and hair at higher levels of THg. ► Lower and variable % of MeHg was found in breast milk. ► Lower % of MeHg in cord blood was found at lower levels of THg.
Thymidine kinase (TK1) is an enzyme involved in DNA synthesis that leaks into the blood as a result of high cell turnover, particularly in the case of cancer. Serum TK1 activity has been used for ...prognosis and monitoring of leukemia and lymphoma patients for many years. Here, we describe the first clinical results with the newly developed TK 210 ELISA from AroCell AB. Sera from 124 breast cancer patients with known TNM classification along with sera from 53 healthy females were analyzed by TK 210 ELISA for TK1 protein and TK1 activity levels by the
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H-deoxythymidine (dThd) phosphorylation assay. The limit of detection for the TK 210 ELISA was 0.17 ng/ml, and 60 % of the sera from female blood donors were below this value. The median TK1 levels found in sera from breast cancer patients with T1 to T4 stage disease were 0.31, 0.46, 0.47, and 0.55 ng/ml, and these levels significantly differed from healthy controls. The median values of the biomarker CA 15-3 were also increased in patient sera from T1 to T4 patients (16, 34, 36, 40 U/ml, respectively). TK 210 ELISA showed significantly higher sensitivity for the T1 and T2 breast cancer patients compared to the TK activity assay. The combination of the TK1 ELISA and CA 15-3 biomarkers demonstrated a significant increase in sensitivity up to 15 % compared to each marker alone. This evaluation of the TK 210 ELISA strongly suggests that it can provide independent and complementary information for patients with breast cancer.
Thymidine Kinase 1 (TK1) plays an important role in DNA precursor synthesis and serum TK1 activity has been used as a biomarker for prognosis and therapy monitoring of different malignancies. AroCell ...has developed a dual monoclonal antibody ELISA for determination of TK1 protein in clinical samples. The purpose of the study is to validate the ELISA analytically in relation to the gold standard, .sup.3 H-deoxythymidine (dThd) phosphorylation assay for TK1 activity using sera from patients with different malignancies. The colorimetric TK 210 ELISA was validated analytically by assessment of precision, linearity, interfering substances, and stability. For the clinical validation, serum samples from patients with hematological malignancies (n = 100), breast cancer (n = 56), prostate cancer (n = 70) and blood donors (n = 159) were analyzed using TK 210 ELISA and TK1 activity by .sup.3 H-deoxythymidine (dThd) phosphorylation assay. The sandwich TK 210 ELISA was highly specific for TK1 protein having a detection limit of 0.12 ng/mL, with a functional sensitivity of 0.25 ng/mL. Within-run CVs ranged from 5.5% to 10% and between-run CVs ranged from 5% to 15%. The ratio of observed to expected dilutional parallelism of 5 serum samples was in the range of 80-120%. Samples exhibited stability through four freeze/thaw cycles and 5 days at 4°C. Further, the ROC curve analysis showed that TK 210 ELISA and .sup.3 H-dThd phosphorylation assay had similar sensitivity (62% vs 59%) in hematological malignancies. However, in the case of breast and prostate cancer sera, TK 210 ELISA had higher sensitivity (59% and 44%) compared to .sup.3 H-dThd phosphorylation assay (47% and 25%) at a specificity of 98%. These data demonstrate that the dual monoclonal antibody based AroCell TK 210 ELISA is a robust, accurate and precise tool for measuring TK1 protein in different malignancies that can improve the clinical applications of TK1 as a biomarker in cancer management.
Children's blood-lead concentration (B-Pb) is well studied, but little is known about cadmium (B-Cd) and mercury (B-Hg), in particular for central Europe. Such information is necessary for risk ...assessment and management. Therefore, we here describe and compare B-Pb, B-Cd and B-Hg in children in six European, and three non-European cities, and identify determinants of these exposures. About 50 school children (7–14years) from each city were recruited (totally 433) in 2007–2008. Interview and questionnaire data were obtained. A blood sample was analyzed: only two laboratories with strict quality control were used. The European cities showed only minor differences for B-Cd (geometric means 0.11–0.17μg/L) and B-Pb (14–20μg/L), but larger for B-Hg (0.12–0.94μg/L). Corresponding means for the non-European countries were 0.21–0.26, 32–71, and 0.3–3.2μg/L, respectively. For B-Cd in European samples, traffic intensity close to home was a statistically significant determinant, for B-Hg fish consumption and amalgam fillings, and for B-Pb sex (boys higher). This study shows that European city children's B-Cd and B-Pb vary only little between countries; B-Hg differs considerably, due to varying tooth restoration practices and fish intake. Traffic intensity seemed to be a determinant for B-Cd. The metal concentrations were low from a risk perspective but the chosen non-European cities showed higher concentrations than the cities in Europe.
► Very small differences between European cities in children's lead and cadmium levels. ► Mercury varies more. ► No evidence for elevated cadmium, lead or mercury exposures in Eastern Europe in general. ► Higher levels in three studied non-European cities. ► Cd exposure may be related to traffic intensity.
Abstract Objective To analyze the relationship between QTc interval and cardiovascular risk factors in women with polycystic ovary syndrome (PCOS). Methods Study group included 119 PCOS women (age: ...32.2 ±5.2 years) and the control group 64 age-matched healthy women; they all underwent QT interval measurement, and plasma levels of high-sensitivity CRP (hsCRP), endothelin-1 (ET1), insulin, and testosterone determinations. Results In PCOS women hsCRP (2.35 ± 2.14 mg/L vs. 1.01 ± 1.28 mg/L; P = 0.04), ET1 (23.6 ± 10.3 ng/L vs. 7.7 ± 15.9 ng/L; P = 0.01), and insulin (16.5 ± 7.8 mIU/L vs. 11.8 ±10.7 mIU/L; P = 0.03) levels were significantly higher, and QTc interval significantly shorter than in controls (401 ± 61 ms vs. 467 ± 61 ms; P = 0.007). In 67 (56%) PCOS patients with a short QTc interval (< 400 ms), plasma testosterone levels were significantly higher than in PCOS women with normal QTc interval (2.3 ± 2.1 nmol/L vs. 1.4 ± 1.7 nmol/L; P = 0.02). Conclusions In patients with polycystic ovary syndrome increased testosterone levels may attenuate the effects of coronary risk factors.
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