Objective The aim of our study was to develop a robust LC-MS/MS method for determination of MN and NMN in blood plasma.Methods A liquid chromatography -tandem mass spectrometric ( LC-MS/MS) method was used, with signal linearity, lower limits of quantitation, precision and accuracy being evaluated.The study recruited 126 healthy volunteers, and MN and NMN in blood plasma were determined.At the same time samples from 21 patients ( 17 pheochromocytoma, 4 ectopic pheochromocytoma) , a hypertension group of 108 persons, and a control group of 84 persons were analyzed. A paired T test was used to compare the MN and NMN levels between the different groups.Results The performance characteristics for the method in terms of linearity, lower limits of quantitation, precision and accuracy were verified.Significant differences were found between the concentration levels of MN and NMN in the diseased and healthy groups.Conclusion A robust and reliable LC-MS/MS method for the determination of MN and NMN in blood plasma has been developed and was shown to be suitable for clinical application.

Objective: To investigate the value of serum hepcidin in assessment of liver inflammation activity among patients with chronic hepatitis B ( CHB ), so as to provide insights into the assessment of liver inflammation activity among CHB patients. Methods: A total of 79 CHB patients who were admitted to the Affiliated Hospital of Hangzhou Normal University were selected as the experimental group, while 40 healthy volunteers were randomly sampled as controls. Subjects'demographic data, liver function tests and iron metabolism parameters were collected from medical records, and serum hepcidin was measured using enzyme-linked immunosorbent assay ( ELISA ). In addition, ultrasound-guided liver biopsy was performed in CHB patients, and mild and moderate-to-severe CHB were classified according to liver inflammation activity and degree of liver fibrosis. Serum hepcidin levels were compared between the experimental and control groups and between patients with mild and moderate-to-severe CHB. The value of serum hepcidin in assessment of liver inflammation activity was examined among CHB patients using the receiver operating characteristic ( ROC ) curve analysis. Results: Subjects in the experimental group included 54 men ( 68.35% ) and had a mean age of ( 39.06±10.67 ) years, while the controls included 24 men (60.00%) and had a mean age of ( 42.43±11.44 ) years. Lower hepcidin levels were measured in the experimental group than in the control group [( 11.70±5.64 ) vs. ( 17.82±3.63 ) μg/L; P<0.05 ]. There were 54 patients with mild CHB ( 68.35% ) and 25 cases with moderate-to-severe CHB ( 31.65% ), and lower hepcidin levels were detected in patients with moderate-to-severe CHB than in those with mild CHB [ ( 6.92±2.21 ) vs. ( 13.95±5.36 ) μg/L; P<0.05 ]. The area under the ROC curve, optimal cut-off, sensitivity and specificity of serum hepcidin were 0.903 ( P<0.05 ), 10.365 μg/L, 100.0% and 72.2% for assessment of moderate-to-severe CHB, respectively. Conclusion Serum hepcidin is feasible to evaluate the liver inflammatory activity among patients with CHB.

Anti-HBcAg monoclonal antibodies from mouse ascites were purified by using immobilized metal ion affinity chromatography. We optimized the conditions of sample loading and elution. The results showed that when the pH stepwise elution was used, the best solution for sample loading was 20 mmol/L phosphate buffer containing 0.5 mol/L sodium chloride at pH 8.0 and the mAb was eluted at pH 5.0. The purity of obtained mAb was more than 85% and recovery reached 80%. When the adsorbed proteins were eluted by using gradient elution of an imidazole, the best solution for loading condition was 20 mmolL phosphate buffer containing 5 mmol/L imidazole at pH 8.0. The purity and recovery of antibody were up to 95%.
Animals ; Antibodies, Monoclonal ; isolation & purification ; Chromatography, Affinity ; methods ; Chromatography, Ion Exchange ; methods ; Hepatitis B Core Antigens ; immunology ; Hydrogen-Ion Concentration ; Imidazoles ; chemistry ; Metals ; chemistry ; Mice

Objective:To synthesize a novel site-specifically labelled probe 68Ga-1, 4, 7, 10-tetraazacyclododecane-1, 4, 7, 10-tetraacetic acid (DOTA)-Cys-Asp-Val (CDV)-Nb109 and explore its potential for detection of the programmed cell death ligand 1 (PD-L1) expression level in different tumors. Methods:Firstly, CDV was inserted into the tail of the sequence of Nb109 by genetic engineering. Then the precursor DOTA-CDV-Nb109 was prepared by mixing the maleimide-DOTA and the single-domain antibody CDV-Nb109 (amount of substance ratio 1∶1) via the maleimide-cysteine site-specific coupling strategy. Subsequently, the DOTA-CDV-Nb109 was labeled with 68Ga and purified by PD-10 column. Human melanoma A375, human PD-L1 transfected melanoma A375-hPD-L1 and human glioma U87 tumor-bearing mice models were established, and the diagnostic value of 68Ga-DOTA-CDV-Nb109 was evaluated by stability assay, cellular uptake, and microPET imaging. One-way analysis of variance and the least significant difference t test were used to analyze the data. Results:The probe 68Ga-DOTA-CDV-Nb109 was obtained with the radiochemical yield of (69.79±4.69)%, radiochemical purity more than 97%, and molar activity of (12.85±1.51) GBq/μmol. 68Ga-DOTA-CDV-Nb109 had strong binding affinity for A375-hPD-L1 with the dissociation constant ( Kd) of (66.43±17.89) nmol/L. The uptake of 68Ga-DOTA-CDV-Nb109 in A375-hPD-L1 and U87 cells were (3.17±0.15) percentage of the added radioactivity dose (%AD) and (2.08±0.03) %AD respectively, which were significantly higher than that in A375 cells ((1.21±0.14) %AD; F=82.87, t values: 15.23, 9.98, P values: <0.001, 0.003). The tumor uptake of the probe in A375-hPD-L1 ((5.21±0.35) percentage of injected dose per ml (%ID/ml)) and U87 tumor-bearing mice ((3.44±0.69) %ID/ml) were significantly higher than that in A375 tumor-bearing mice ((2.17±0.36) %ID/ml; F=249.72, t values: 35.70, 3.43, both P<0.001). Conclusion:The site-specifically labelled probe 68Ga-DOTA-CDV-Nb109, which can non-invasively and dynamically monitor the change of PD-L1 expression level in different tumors and help screen patients who can benefit from PD-L1 immune checkpoint blocking therapy, is successfully synthesized with high radiochemical purity.

Despite advances in immunotherapy for the treatment of cancers,not all patients can benefit from programmed cell death ligand 1(PD-L1)immune checkpoint blockade therapy.Anti-PD-L1 therapeutic effects reportedly correlate with the PD-L1 expression level;hence,accurate detection of PD-L1 expression can guide immunotherapy to achieve better therapeutic effects.Therefore,based on the high affinity antibody Nb109,a new site-specifically radiolabeled tracer,68Ga-NODA-cysteine,aspartic acid,and valine(CDV)-Nb109,was designed and synthesized to accurately monitor PD-L1 expression.The tracer 68Ga-NODA-CDV-Nb109 was obtained using a site-specific conjugation strategy with a radiochemical yield of about 95％and radiochemical purity of 97％.It showed high affinity for PD-L1 with a dissociation constant of 12.34±1.65 nM.Both the cell uptake assay and positron emission tomography(PET)imaging revealed higher tracer uptake in PD-L1-positive A375-hPD-L1 and U87 tumor cells than in PD-L1-negative A375 tumor cells.Meanwhile,dynamic PET imaging of a NC1-H1299 xenograft indicated that doxorubicin could upregulate PD-L1 expression,allowing timely interventional immunotherapy.In conclusion,this tracer could sensitively and dynamically monitor changes in PD-L1 expression levels in different cancers and help screen patients who can benefit from anti-PD-L1 immunotherapy.

Background/Aims: Low educational attainment is a well-established risk factor for nonalcoholic fatty liver disease (NAFLD) in developed areas. However, the association between educational attainment and the risk of NAFLD is less clear in China. Methods: A cross-sectional study including over 200,000 Chinese adults across mainland China was conducted. Information on education level and lifestyle factors were obtained through standard questionnaires, while NAFLD and advanced fibrosis were diagnosed using validated formulas. Outcomes included the risk of NAFLD in the general population and high probability of fibrosis among patients with NAFLD. Logistic regression analysis was employed to estimate the risk of NAFLD and fibrosis across education levels. A causal mediation model was used to explore the potential mediators. Results: Comparing with those receiving primary school education, the multi-adjusted odds ratios (95% confidence intervals) for NAFLD were 1.28 (1.16 to 1.41) for men and 0.94 (0.89 to 0.99) for women with college education after accounting for body mass index. When considering waist circumference, the odds ratios (95% CIs) were 0.94 (0.86 to 1.04) for men and 0.88 (0.80 to 0.97) for women, respectively. The proportions mediated by general and central obesity were 51.00% and 68.04% for men, while for women the proportions were 48.58% and 32.58%, respectively. Furthermore, NAFLD patients with lower educational attainment showed an incremental increased risk of advanced fibrosis in both genders. Conclusions In China, a low education level was associated with a higher risk of prevalent NAFLD in women, as well as high probability of fibrosis in both genders.