To develop a magnetic nanoparticle chemiluminescence immunoassay (CLIA) for the determination of type Ⅰ procollagen N-terminal peptide (PINP) in human serum, we expressed a recombinant PINP-α1 protein in Corynebacterium glutamicum and used it as an immunogen to immunize BALB/c mice. We obtained three hybridoma cell lines that stably secret antibody against PINP-α1 protein. After further pairing and screening, we chose a monoclonal antibody 8C12 coupled with biotin as the capture antibody, and a monoclonal antibody 1F11 labeled horseradish peroxidase as the detection antibody. The antibodies combined with the serum samples, forming a sandwich complex which was used to detect the concentration of PINP in serum. After optimizing the conditions, we determined that the best working concentration of the capture antibody and the detection antibody were 3 μg/mL, and the incubation time was 30 minutes. The quantitative assay had a detection range of 5-1 100 ng/mL, with recovery rates between 93%-107% and the minimum detection limit of 1.22 ng/mL achieved. The intra-and inter-assay precisions were lower than 10%. The correlation coefficient of PINP results between this CLIA method and the Roche electrochemiluminescence immunoassay system was 0.906 2. Therefore, this CLIA method is specific and can be used to quantitatively detect the content of PINP in serum, which has the potential to become an auxiliary approach for bone disease examination.
Animals ; Humans ; Immunoassay ; Luminescence ; Mice ; Mice, Inbred BALB C ; Peptide Fragments/isolation & purification* ; Procollagen/isolation & purification*

Objective To establish and evaluate a morning check system for linac based on electronic portal image device (EPID).Methods Delivered fluence maps of open and wedge fields at 10 cm×10 cm field size of Synergy Linac were measured by EPID.Figure features from these two images were extracted with matlab codes and analyzed to realize a quick morning check.The repeatability of dose response and mechanical setup,relationship between gray value and machine unit (MU),accuracy of output and field size test were investigated with both EPID and DailyQA3.The status of Synergy linac was monitored both by DailyQA3 and EPID for two months.Results EPID was able to test the linac consistently with a testing error of 0.50 mm,1.00 mm for field size and center,respectively.Both of the test accuracy for flatness and symmetry was 0.17％.The mechanical accuracy test and dosimetric repeatability test were also consistent.The dose response of EPID was linearly related to the linac output (R2＞0.999).EPID was highly sensitive to the change of output and radiation field size.The measurement deviations between EPID and DailyQA3 were consistent and within clinical acceptable tolerance.Conclusions EPID showed great accuracy and stability on monitoring the performance of linac.The established daily check tool based-on EPID is accurate and reliable for clinical usage.

A high performance liquid chromatography-tandem mass spectrometric( HPLC-MS/MS) method was developed for the simultaneous determination of four phenolic and salicylanilide anthelmintics including nitroxinil, oxyclozanide, closantel and rafoxanide in cattle and ovine tissues. Muscle, liverand kidney were extracted with acetonitrile-acetone(60:40, V/V)and fat with 1% triethylamine in acetonitrile, then the extract was purified with MAX solid-phase extraction column. Qualitative and quantitative analysiswas achieved by HPLC-MS/MS undernegative multiple reaction monitoring ( MRM) mode. Good correlation coefficients were obtained (R>0. 99) in the concentration range of 1-100 μg/L. The limits of detection (LOD) and limits of qualification (LOQ) for the four compounds were 1 and 2. 5 μg/kg, respectively. The mean recoveries at the four levels of LOQ, 0. 5 maximum residue limit (MRL), MRL, 2MRL were between 71% and 112%,with the intra-day relative standard deviation(RSD)in the range of 1. 1%-14. 0%and inter-day RSD in the range of 6. 4%-14. 7%. Forty samples from the market were analyzed with the method, only two samples were found to show phenolic and salicylanilide anthelmintics residues.