Anti-CGB monoclonal antibody, clone CDJ263/NF.218

The Guadalupian Epoch represents one of the most critical intervals during the Earth history which is characterized by a series of global geological and biological events. However, it is poorly constrained by radioisotopic ages in comparison with the high-precision dates from the Lopingian and lowest Triassic in South China and the Cisuralian in southern Urals, Russia. In this study, we report combined CA-ID-TIMS and SIMS U-Pb zircon geochronology for three ash beds from the base and lower part of the Kuhfeng Formation in the Chaohu area, southeastern China. Zircons from Ash Beds A, C and D were initially analyzed by SIMS and yielded weighted mean Pb-206/U-238 dates of 269.0 +/- 1.4 Ma (MSWD = 1.03, n = 31), 266.3 +/- 2.2 Ma (MSWD = 2.2, n = 29) and 262.2 +/- 1.7 Ma (MSWD = 1.0, n = 20) in ascending order. However, high-precion U-Pb geochronology of the same ash beds by the CA-ID-TIMS method point to important inaccuracies in the SIMS results due to Pb-loss in zircons. Ash Beds A and C yielded two TIMS weighted mean Pb-206/U-238 dates of 272.95 +/- 0.11 Ma (MSWD = 1.9, n = 7) and 271.038 +/- 0.097 Ma (MSWD = 2.2, n = 8), respectively. The depositional age of 272.95 +/- 0.11 Ma for Ash Bed A is postulated as the traditional Cisuralian-Guadalupian boundary (CGB) age in South China. Our new geochronology suggests that the Guadalupian Series in South China had a total duration of 13.85 +/- 0.52 myr given a Guadalupian-Lopingian boundary (GLB) age of 259.1 +/- 0.5 Ma. The new age calibration of the base of the Guadalupian Series is ca. 0.65 (+/- 0.51) myr older than - and improves upon the previous estimates for the CGB age and the duration of the Guadalupian Epoch based on the 2016 International Chronostratigraphic Chart (ICC) and the 2012 Geologic Time Scale (GTS). (C) 2016 Elsevier B.V. All rights reserved.

Objective: CgA has been shown to be an excellent marker for neuroendocrine tumours. However, there are two major drawbacks with CgA measurements; elevated levels are common in patients with decreased renal function and in patients on treatment with proton pump inhibitors. These problems are not seen with CgB measurements. We have recently presented the development of 13 region-specific radioimmunoassays for measurements of CgB. A region-specific assay was identified, which measured higher concentrations of CgB than the other assays and seemed to be very useful as a marker for neuroendocrine tumours. The aim of the present study was therefore to further explore the diagnostic potential of this assay in the clinical management of patients with neuroendocrine tumours. Methods: Measurements of CgB with two methods were compared with CgA in plasma samples from patients investigated for neuroendocrine tumours (N=86), patients with decreased renal function (N=35) and patients on treatment with proton pump inhibitors (N=29). Results: The diagnostic sensitivity for the new CgB assay was almost as good as that for CgA. Furthermore, with CgB measurements we could avoid the falsely elevated levels of CgA found in patients with decreased renal function and treatment with proton pump inhibitors. Conclusions: We conclude that the new CgB assay can serve as a complement to CgA measurements as an important tumour marker for neuroendocrine tumours. (c) 2006 Elsevier B.V. All rights reserved.