The amino-terminal pro-C-type natriuretic peptide(NT-proCNP)is a diagnostic inflam-matory marker clinically used for diagnosing bacterial infections.This study aims to establish a phage display library of single-chain variable fragment(scFv)antibodies against canine NT-proC-NP and to screen for scFvs with high binding affinity to NT-proCNP.Initially,NT-proCNP was prepared using prokaryotic expression system and was used to immunize New Zealand White rab-bits.Upon achieving the desired serum titer,total RNA was extracted from the splenocytes of rab-bits and reverse transcribed into cDNA.Using this cDNA as a template,degenerate primers were employed to amplify the genes of the rabbit antibody light chain variable region(VL)and heavy chain variable region(VH).The VL and VH regions were spliced together to form a complete scFv fragment via overlap extension PCR.The scFv was then ligated into the phagemid pComb3XSS and electroporated into competent E.coli TG1 cells to construct a rabbit-derived anti-NT-proCNP scFv immunological library.This library underwent four rounds of enrichment and screening to isolate specific single-chain antibodies.The selected antibody was subsequently ex-pressed in a soluble form within a prokaryotic system,and its immunological activity was evalua-ted.Using phage display technology,this study successfully identified a single-chain antibody scFv-1-CNP with strong antigen-binding activity and genetic sequence characteristics of scFvs,providing a research direction for further exploration of scFv applications in the detection of NT-proCNP.

BACKGROUND:We have successfully established an animal model of small ear pig in southern Yunnan province with internal tension relieving technique combined with autologous Achilles tendon for anterior cruciate ligament reconstruction,and verified the stability and reliability of the model.However,whether internal tension relieving technique can promote the ligamentalization process of autologous Achilles tendon graft has not been studied. OBJECTIVE:To investigate the differences in the process of ligamentalization between conventional reconstruction and internal reduction reconstruction of the anterior cruciate ligament by gross view,histology and electron microscopy. METHODS:Thirty adult female small ear pigs in southern Yunnan province were selected.Anterior cruciate ligament reconstruction was performed on the left knee joint with the ipsilateral knee Achilles tendon(n=30 in the normal group),and anterior cruciate ligament reconstruction was performed on the right knee joint with the ipsilateral knee Achilles tendon combined with the internal relaxation and enhancement system(n=30 in the relaxation group).The autogenous right forelimb was used as the control group;the anterior cruciate ligament was exposed but not severed or surgically treated.At 12,24,and 48 weeks after surgery,10 animals were sacrificed,respectively.The left and right knee joint specimens were taken for gross morphological observation to evaluate the graft morphology.MAS score was used to evaluate the excellent and good rate of the ligament at each time point.Hematoxylin-eosin staining was used to evaluate the degree of ligament graft vascularization.Collagen fibers and nuclear morphology were observed,and nuclear morphology was scored.Ultrastructural remodeling was evaluated by scanning electron microscopy and transmission electron microscopy. RESULTS AND CONCLUSION:(1)The ligament healing shape of the relaxation group was better at various time points after surgery,and the excellent and good rate of MAS score was higher(P<0.05).Moreover,the relaxation group could obtain higher ligament vascularization score(P<0.05).(2)The arrangement of collagen bundles and fiber bundles in the two groups gradually tended to be orderly,and the transverse fiber connections between collagen gradually increased and thickened,suggesting that the strength and shape degree of the grafts were gradually improved,but the ligament remodeling in the relaxation group was always faster than that in the normal group at various time points after surgery.(3)The diameter,distribution density,and arrangement degree of collagen fibers in the relaxation group were better than those in the normal group at all time points,especially in the comparison of collagen fiber diameter between and within the relaxation group(P<0.05).

Background: s/Aims: Anti-mitochondrial M2 antibody (AMA-M2) is a specific marker for primary biliary cholangitis (PBC) and it could be also present in non-PBC individuals. Methods: A total of 72,173 Chinese health check-up individuals tested AMA-M2, of which non-PBC AMA-M2 positive individuals were performed follow-up. Baseline data of both clinical characteristics and laboratory examinations were collected in all AMA-M2-positive individuals. Least absolute shrinkage and selection operator (LASSO) regression was performed to investigate the potential variables for developing PBC. Results: A total of 2,333 individuals were positive with AMA-M2. Eighty-two individuals had a medical history of PBC or fulfilled the diagnostic criteria of PBC at baseline, and 2,076 individuals were non-PBC. After a median follow-up of 6.6 years, 0.6% developed PBC, with an accumulative 5-year incidence rate of 0.5%. LASSO regression showed that levels of alkaline phosphatase (ALP), gamma-glutamyl transpeptidase (GGT), immunoglobulin M (IgM), eosinophilia proportion (EOS%), gamma globulin percentage, and hemoglobin (HGB) were potential variables for developing PBC. Multivariate Cox regression is used to construct a predictive model based on 7 selected variables, and time-dependent receiver operating characteristic analysis showed that the area under the curve of the prediction model at 3, 5, and 10 years were, respectively, 1.000, 0.875, and 0.917. Conclusions This study offers insights into the onset of PBC among individuals who tested positive for AMA-M2 during routine health check-ups. The prediction model based on ALP, GGT, IgM, EOS%, gamma globulin percentage, HGB, and sex has a certain predictive ability for the occurrence of PBC in this population.

Background: s/Aims: Anti-mitochondrial M2 antibody (AMA-M2) is a specific marker for primary biliary cholangitis (PBC) and it could be also present in non-PBC individuals. Methods: A total of 72,173 Chinese health check-up individuals tested AMA-M2, of which non-PBC AMA-M2 positive individuals were performed follow-up. Baseline data of both clinical characteristics and laboratory examinations were collected in all AMA-M2-positive individuals. Least absolute shrinkage and selection operator (LASSO) regression was performed to investigate the potential variables for developing PBC. Results: A total of 2,333 individuals were positive with AMA-M2. Eighty-two individuals had a medical history of PBC or fulfilled the diagnostic criteria of PBC at baseline, and 2,076 individuals were non-PBC. After a median follow-up of 6.6 years, 0.6% developed PBC, with an accumulative 5-year incidence rate of 0.5%. LASSO regression showed that levels of alkaline phosphatase (ALP), gamma-glutamyl transpeptidase (GGT), immunoglobulin M (IgM), eosinophilia proportion (EOS%), gamma globulin percentage, and hemoglobin (HGB) were potential variables for developing PBC. Multivariate Cox regression is used to construct a predictive model based on 7 selected variables, and time-dependent receiver operating characteristic analysis showed that the area under the curve of the prediction model at 3, 5, and 10 years were, respectively, 1.000, 0.875, and 0.917. Conclusions This study offers insights into the onset of PBC among individuals who tested positive for AMA-M2 during routine health check-ups. The prediction model based on ALP, GGT, IgM, EOS%, gamma globulin percentage, HGB, and sex has a certain predictive ability for the occurrence of PBC in this population.

Background: s/Aims: Anti-mitochondrial M2 antibody (AMA-M2) is a specific marker for primary biliary cholangitis (PBC) and it could be also present in non-PBC individuals. Methods: A total of 72,173 Chinese health check-up individuals tested AMA-M2, of which non-PBC AMA-M2 positive individuals were performed follow-up. Baseline data of both clinical characteristics and laboratory examinations were collected in all AMA-M2-positive individuals. Least absolute shrinkage and selection operator (LASSO) regression was performed to investigate the potential variables for developing PBC. Results: A total of 2,333 individuals were positive with AMA-M2. Eighty-two individuals had a medical history of PBC or fulfilled the diagnostic criteria of PBC at baseline, and 2,076 individuals were non-PBC. After a median follow-up of 6.6 years, 0.6% developed PBC, with an accumulative 5-year incidence rate of 0.5%. LASSO regression showed that levels of alkaline phosphatase (ALP), gamma-glutamyl transpeptidase (GGT), immunoglobulin M (IgM), eosinophilia proportion (EOS%), gamma globulin percentage, and hemoglobin (HGB) were potential variables for developing PBC. Multivariate Cox regression is used to construct a predictive model based on 7 selected variables, and time-dependent receiver operating characteristic analysis showed that the area under the curve of the prediction model at 3, 5, and 10 years were, respectively, 1.000, 0.875, and 0.917. Conclusions This study offers insights into the onset of PBC among individuals who tested positive for AMA-M2 during routine health check-ups. The prediction model based on ALP, GGT, IgM, EOS%, gamma globulin percentage, HGB, and sex has a certain predictive ability for the occurrence of PBC in this population.

Objective:To detect the expression levels of 12 cytokines in the plasma of patients with primary biliary cholangitis (PBC) and explore their association with PBC disease activity and ursodeoxycholic acid (UDCA) therapeutic response.Methods:This study enrolled 127 patients with PBC who visited Peking Union Medical College Hospital between December 2021 and November 2023 (PBC group) and 32 healthy controls who underwent physical examinations during the same period (control group). The expression of 12 cytokines was measured using flow cytometry, and compared between groups. Spearman correlation analysis was performed to assess the relationship between cytokine levels and five laboratory indicators reflecting PBC disease activity [alkaline phosphatase (ALP), glutamyl transpeptidase (GGT), total bilirubin (TBil), aspartate aminotransferase (AST), and total bile acid (TBA)]. Furthermore, the receiver operating characteristic (ROC) curve analysis was performed to evaluate the effectiveness of cytokines in distinguishing between patients who responded to UDCA treatment and those who did not.Results:The plasma interleukin (IL)-8 levels between the PBC group and healthy controls showed no significant differences, and the plasma IFN-γ levels in PBC patients were significantly higher than those in health controls ( P<0.05). Spearman analysis showed that IL-8 was positively correlated with ALP, GGT, TBil, AST, and TBA ( R2=0.348, 0.401, 0.406, 0.495, 0.417; all P<0.01), and negative correlation was observed between IFN-γand ALP, GGT, and TBA levels ( R2=-0.265, -0.253, -0.232; all P<0.05). The plasma IL-8 level in 52 PBC patients who did not respond to UDCA treatment was significantly higher, while the IFN-γ level was significantly lower than those in 56 PBC patients who responded to UDCA treatment (both P<0.05). ROC analysis showed that the area under the curve for distinguishing plasma IL-8 and IFN-γlevels between PBC patients responding to UDCA treatment and not is 0.631 and 0.783, respectively. The sensitivities were 87.5% and 90.5%, and the specificities were 44.2% and 57.9%, respectively. Conclusion:The levels of plasma IL-8 and IFN-γ are correlated with the disease activity of PBC and can be used to reflect the therapeutic responses to UDCA in PBC patients.

The amino-terminal pro-C-type natriuretic peptide(NT-proCNP)is a diagnostic inflam-matory marker clinically used for diagnosing bacterial infections.This study aims to establish a phage display library of single-chain variable fragment(scFv)antibodies against canine NT-proC-NP and to screen for scFvs with high binding affinity to NT-proCNP.Initially,NT-proCNP was prepared using prokaryotic expression system and was used to immunize New Zealand White rab-bits.Upon achieving the desired serum titer,total RNA was extracted from the splenocytes of rab-bits and reverse transcribed into cDNA.Using this cDNA as a template,degenerate primers were employed to amplify the genes of the rabbit antibody light chain variable region(VL)and heavy chain variable region(VH).The VL and VH regions were spliced together to form a complete scFv fragment via overlap extension PCR.The scFv was then ligated into the phagemid pComb3XSS and electroporated into competent E.coli TG1 cells to construct a rabbit-derived anti-NT-proCNP scFv immunological library.This library underwent four rounds of enrichment and screening to isolate specific single-chain antibodies.The selected antibody was subsequently ex-pressed in a soluble form within a prokaryotic system,and its immunological activity was evalua-ted.Using phage display technology,this study successfully identified a single-chain antibody scFv-1-CNP with strong antigen-binding activity and genetic sequence characteristics of scFvs,providing a research direction for further exploration of scFv applications in the detection of NT-proCNP.