1.Lead and cadmium co-exposure triggers genetic damage through oxidative stress and impaired expression of DNA repair genes
Xin LIU ; Zhiyuan HAN ; Kuibin HAN ; Yuhan PANG ; Xiaoyue ZHAO ; Yuting WANG ; Xiaoyan WU ; Tuanwei WANG
Journal of Environmental and Occupational Medicine 2026;43(5):556-564
Background Lead smelting workers are exposed to mixed heavy metals such as lead (Pb) and cadmium (Cd). However, the specific associations and molecular mechanisms by which their combined exposure induces genetic damage remain unclear. Objective To clarify the association between combined Pb-Cd exposure and genetic damage and to explore the possible biological mechanisms through occupational epidemiological investigations and animal experiments. Methods (1) Population study: A cross-sectional study was conducted on 374 lead smelting workers in northern China. Inductively coupled plasma mass spectrometry (ICP-MS) was used to detect urinary levels of 8 metals including Pb and Cd, and graphite furnace atomic absorption spectroscopy (GFAAS) was used to quantify blood levels of Pb and Cd. The cytokinesis-block micronucleus assay (CBMN) was used to assess genetic damage. Poisson regression was used to analyze the association between metal exposure and micronucleus rates. (2) In vivo experiment: Thirty SD rats were randomly assigned to five groups: control (pure water), Pb (300 mg·L−1 lead acetate), Cd (50 mg·L−1 cadmium chloride), combined exposure (Pb + Cd), and resveratrol intervention (Pb + Cd + 50 mg·L−1 resveratrol). After 8 weeks of ad libitum drinking water exposure, liver pathology, oxidative stress indicators [reactive oxygen species (ROS), reduced glutathione (GSH), oxidized glutathione (GSSG), malondialdehyde (MDA), catalase (CAT), and superoxide dismutase (SOD)], genetic damage (Comet assay and γ-H2AX) were evaluated. Furthermore, cell cycle distribution, apoptosis rates, and mRNA expression of DNA damage response (DDR), DNA repair, and apoptosis-related genes were measured. Results (1) The geometric mean (GM, 95%CI) of urinary Pb and Cd were 14.69 (13.14, 16.51) µg·L−1 and 2.11 (1.90, 2.33) µg·L−1, respectively; the blood Pb and Cd levels were 117.10 (105.59, 129.87) µg·L−1 and 4.55 (4.23, 4.89) µg·L−1, respectively among the 374 workers. The mean micronucleus rate was (1.64±0.081) ‰, with significantly higher rates in males (1.65±0.083) ‰ than females (1.53±0.334) ‰ (U=4.166, P=0.041). All Pb and Cd biomarkers were positively correlated with micronucleus rate (FR>1, P<0.05), with a significant interaction effect observed between Pb and Cd (FR>1, P<0.05). (2) In rats, co-exposure to Pb and Cd caused liver tissue damage and inflammatory infiltration. Significant increases were observed in lymphocyte ROS; GSSG and MDA in lung tissue increased, while GSH and CAT activity decreased. Comet assay indicators and γ-H2AX levels were significantly elevated. Co-exposure induced S-phase arrest and increased apoptosis. mRNA levels of DDR (ATM, ATR, Chk2, and P53) and pro-apoptotic genes (Bax and Caspase-3) were upregulated, while the anti-apoptotic gene Bcl-2 and DNA repair genes (BRCA1, BRCA2, RAD51, RAD52, and CtIP) were downregulated. Two-way ANOVA confirmed synergistic effects on GSSG, Comet assay indicators, and ATR/Chk2 mRNA expression. Conclusion Occupational co-exposure to Pb and Cd synergistically induces genetic damage. This damage is mediated by oxidative stress and DNA damage, which activates the DDR pathway and inhibits the expression of DNA repair genes, ultimately leading to cell cycle arrest and apoptosis.
2.Lead and cadmium co-exposure triggers genetic damage through oxidative stress and impaired expression of DNA repair genes
Xin LIU ; Zhiyuan HAN ; Kuibin HAN ; Yuhan PANG ; Xiaoyue ZHAO ; Yuting WANG ; Xiaoyan WU ; Tuanwei WANG
Journal of Environmental and Occupational Medicine 2026;43(5):556-564
Background Lead smelting workers are exposed to mixed heavy metals such as lead (Pb) and cadmium (Cd). However, the specific associations and molecular mechanisms by which their combined exposure induces genetic damage remain unclear. Objective To clarify the association between combined Pb-Cd exposure and genetic damage and to explore the possible biological mechanisms through occupational epidemiological investigations and animal experiments. Methods (1) Population study: A cross-sectional study was conducted on 374 lead smelting workers in northern China. Inductively coupled plasma mass spectrometry (ICP-MS) was used to detect urinary levels of 8 metals including Pb and Cd, and graphite furnace atomic absorption spectroscopy (GFAAS) was used to quantify blood levels of Pb and Cd. The cytokinesis-block micronucleus assay (CBMN) was used to assess genetic damage. Poisson regression was used to analyze the association between metal exposure and micronucleus rates. (2) In vivo experiment: Thirty SD rats were randomly assigned to five groups: control (pure water), Pb (300 mg·L−1 lead acetate), Cd (50 mg·L−1 cadmium chloride), combined exposure (Pb + Cd), and resveratrol intervention (Pb + Cd + 50 mg·L−1 resveratrol). After 8 weeks of ad libitum drinking water exposure, liver pathology, oxidative stress indicators [reactive oxygen species (ROS), reduced glutathione (GSH), oxidized glutathione (GSSG), malondialdehyde (MDA), catalase (CAT), and superoxide dismutase (SOD)], genetic damage (Comet assay and γ-H2AX) were evaluated. Furthermore, cell cycle distribution, apoptosis rates, and mRNA expression of DNA damage response (DDR), DNA repair, and apoptosis-related genes were measured. Results (1) The geometric mean (GM, 95%CI) of urinary Pb and Cd were 14.69 (13.14, 16.51) µg·L−1 and 2.11 (1.90, 2.33) µg·L−1, respectively; the blood Pb and Cd levels were 117.10 (105.59, 129.87) µg·L−1 and 4.55 (4.23, 4.89) µg·L−1, respectively among the 374 workers. The mean micronucleus rate was (1.64±0.081) ‰, with significantly higher rates in males (1.65±0.083) ‰ than females (1.53±0.334) ‰ (U=4.166, P=0.041). All Pb and Cd biomarkers were positively correlated with micronucleus rate (FR>1, P<0.05), with a significant interaction effect observed between Pb and Cd (FR>1, P<0.05). (2) In rats, co-exposure to Pb and Cd caused liver tissue damage and inflammatory infiltration. Significant increases were observed in lymphocyte ROS; GSSG and MDA in lung tissue increased, while GSH and CAT activity decreased. Comet assay indicators and γ-H2AX levels were significantly elevated. Co-exposure induced S-phase arrest and increased apoptosis. mRNA levels of DDR (ATM, ATR, Chk2, and P53) and pro-apoptotic genes (Bax and Caspase-3) were upregulated, while the anti-apoptotic gene Bcl-2 and DNA repair genes (BRCA1, BRCA2, RAD51, RAD52, and CtIP) were downregulated. Two-way ANOVA confirmed synergistic effects on GSSG, Comet assay indicators, and ATR/Chk2 mRNA expression. Conclusion Occupational co-exposure to Pb and Cd synergistically induces genetic damage. This damage is mediated by oxidative stress and DNA damage, which activates the DDR pathway and inhibits the expression of DNA repair genes, ultimately leading to cell cycle arrest and apoptosis.
3.Analysis of risk factors for severe postpartum hemorrhage during vaginal delivery of twin pregnancy
Xiaoyue GUO ; Pengbo YUAN ; Yuan WEI ; Yangyu ZHAO
Chinese Journal of Obstetrics and Gynecology 2025;60(4):260-267
Objective:To investigate the risk factors for severe postpartum hemorrhage (SPPH) during vaginal delivery of twin pregnancy.Methods:A retrospective analysis was conducted on clinical data from twin pregnancies ≥28 weeks′ gestation undergoing vaginal delivery at Peking University Third Hospital between January 2016 and December 2023. The twin pregnant women were divided into the SPPH group (postpartum hemorrhage ≥1 000 ml within 24 hours) with 22 cases and the non-SPPH group with 171 cases. The differences between the two groups were compared and the risk factors for SPPH were analyzed.Results:(1) The incidence of SPPH during vaginal delivery in twin pregnancies was 11.4% (22/193). The causes of SPPH included 12 cases (54.5%, 12/22) of simple uterine atony, 4 cases (18.2%, 4/22) of uterine atony combined with vaginal lacerations after forceps delivery, and 6 cases (27.3%, 6/22) of uterine atony combined with placental factors. (2) The age and postpartum hospital stay in the SPPH group were significantly higher than those in the non-SPPH group (all P<0.05). Compared to the non-SPPH group, the proportion of hypertensive disorders in pregnancy, accreta placenta implantation, and anemia in the SPPH group were significantly increased, and the birth weight of newborn 1st, the sum of the birth weights of two newborns, the duration of the second stage of labor, and the proportion of labor followed induction were also significantly increased (all P<0.05). (3) Multivariate analysis showed that age ≥38 years ( OR=16.785, 95% CI: 2.679-105.166; P=0.003), the second stage of labor ≥90 minutes ( OR=9.670, 95% CI: 2.532-36.930; P=0.001), hypertensive disorders in pregnancy ( OR=5.945, 95% CI: 1.702-20.761; P=0.005), and anemia ( OR=8.048, 95% CI: 2.086-31.049; P=0.002) were independent risk factors for SPPH in twin pregnancies during vaginal delivery. Conclusions:Anemia should be actively corrected during twin pregnancy. For twin pregnant women with advanced age, hypertensive disorders in pregnancy, or other risk factors of SPPH, if vaginal delivery is chosen, attention should be paid to the management of labor duration, dynamic assessment of the risk of postpartum hemorrhage, and proactive measures should be taken to ensure a smooth vaginal delivery and effectively reduce the incidence of SPPH.
4.Health economic evaluation of minimally invasive surgery in treatment of digestive tract cancers: a Meta-analysis
Xiaoyue YIN ; Ning ZHOU ; Xueli YANG ; Zhuoyu SUN ; Yinghui BAO ; Shengshu WANG ; Ke HAN ; Jing LONG ; Min ZHAO ; Haowei LI ; Rongrong LI ; Shimin CHEN ; Junhan YANG ; Huaihao LI ; Yueting SHI ; Guoning ZHU ; Jianhua WANG ; Shanshan YANG ; Boyan LI ; Wenchang WANG ; Shengyan DU ; Yao HE ; Enqiang LING-HU ; Huikai LI ; Miao LIU ; Juan XIE
Chinese Journal of Epidemiology 2025;46(1):154-165
Objective:To compare minimally invasive surgery with traditional open surgery, analyze the current application status of health economic evaluations in the treatment of digestive tract cancers, such as esophageal cancer, gastric cancer, and colorectal cancer by minimally invasive surgery and provide evidence for the rational selection of clinical treatment, alleviation of disease-related economic burdens, and rational allocation of healthcare resources.Methods:By using five databases, i.e. China National Knowledge Infrastructure, Wanfang data, Chinese Biomedical Literature Database, PubMed, and Embase, a database was established to retrieve all the papers about health economic studies of minimally invasive surgery for esophageal cancer, gastric cancer, and colorectal cancer published until December 31, 2023. Literature was analyzed by using software NoteExpress 3.8, and data were processed using Excel 2021. The quality of included papers was evaluated using the CHEERS 2022 checklist, and Meta-analysis was conducted by using software Stata 17.0.Results:A total of 10 919 relevant papers were retrieved, and 59 studies were included. Only 14 studies (23.7%) used standard health economic evaluation methods. Meta-analysis results revealed no significant differences in direct medical expenditure and total expenditure between minimally invasive surgery and open surgery. However, the expenditure for minimally invasive surgery exhibited a significant increase [mean difference ( MD)=5 973.12 yuan, P<0.001], while hospital stay and indirect expenditure significantly decreased ( MD: -4.85 days and -733.79 yuan, P<0.001). In China, for gastric cancer, the direct medical expenditure of endoscopic surgery was lower than that of open surgery ( MD=-33 000.00 yuan) with no significant difference ( P<0.001). In colorectal cancer cases, the direct medical and surgical expenditures for laparoscopic surgery were higher than those for open surgery ( MD: 4 277.94 yuan and 4 267.80 yuan, P<0.001), while the indirect and total medical expenditures decreased ( MD: -768.34 yuan and -159.10 yuan). Hospital stays in patients who had minimally invasive surgery for all three types of cancer were shorter than those who had open surgery ( P<0.001). Conclusions:In the treatment of gastrointestinal cancer, compared with open surgery, minimally invasive surgery shows higher expenditure, but has advantages, such as shorter hospital stay and lower indirect expenditure, and there were no significant differences in direct medical and total expenditures between the two approaches. When conducting health economic evaluation, factors such as postoperative complications, hospital stay, and patient's economic status should be considered for their impact on total medical expenditure. It is necessary to pay attention to the application of health economic evaluations in healthcare decision-making.
5.Construction and identification of a sizeable naive human Fab phage display antibody library
Yakun ZHAO ; Xiaoyue WEI ; Fanliang MENG ; Wentao LIU ; Jiaming FAN ; Lijin LONG ; Wanting WANG ; Jianling CHEN ; Jianzhong ZHANG ; Lihua HE ; Liyong LIU ; Rui ZHAO ; Di SUN ; Xuezhen YUAN ; Xiaomei YAN
Chinese Journal of Epidemiology 2025;46(2):288-295
Objective:To construct a sizeable naive human Fab phage display antibody library to screen high-affinity specific antibodies in vitro. Methods:Total RNA was extracted from peripheral blood mononuclear cells (PBMCs) of 126 healthy individuals, subsequently reverse-transcribed into cDNA, and used as a template. PCR amplification was performed to obtain the V H from IgG, IgM and light chain κ, λ, separately, with the initial PCR products serving as templates for a second round of PCR. Overlap extension PCR was employed to generate fragments of the κ and λ light chains. These fragments were ligated with the phage vector pNC3, which harbors the variable region 1 of the heavy chain, to construct a recombinant phage plasmid. This plasmid was then electroporated into competent Escherichia Coli TG1 cells to establish a naive human Fab phage display antibody library. One hundred clones were randomly selected for identification and sequencing, and antibody gene polymorphisms were analyzed using the IMGT database and MAFFT software. Recombinant α-hemolysin from Staphylococcus aureus was utilized to screen Fab antibody fragments through biopanning of the antibody library, followed by random selection of phage ELISA-identified clones. The positive clones (antigen A450∶blank control A450≥2.1) were sequenced. Results:Two large naive Fab phage display antibody libraries were successfully constructed, in which the capacity of κ and λ chain antibody libraries were 1.25×10 11 and 1.54×10 11, respectively. The titers for two antibody libraries were 6.04×10 13 CFU/ml and 3.50×10 13 CFU/ml. The positive transformation insertion rates for κ and λ chain antibody libraries were 96% (96/100) and 100% (100/100), respectively. Sequence analysis revealed that all antibody sequences were unique. The amino acid sequences in the skeletal region were relatively conserved. In contrast, significant variations in the length of the complementarity determining region (CDR) were found, and the diversity of amino acid sequence of the complementary determining region was high, especially the CDR3. Analysis using the IMGT database indicated that the sequences exhibited a broad distribution across variable-diversity-joining gene families. After six rounds of panning, specific phage antibodies enrichment targeting α-hemolysin were achieved. A total of 142 monoclonal antibodies were sequenced, yielding 8 distinct Fab antibody sequences. Conclusion:This study successfully constructed two naive human Fab phage display antibody libraries with large capacity and good diversity, which can be used for screening human antibodies for serum epidemiology.
6.Investigation on past human parvovirus B19 infection among blood donors in Xi 'an, China
Boya ZHAO ; Xiaoyue CHU ; Yuqi JIN ; Chaofeng MA
Chinese Journal of Blood Transfusion 2025;38(5):711-716
Objective: To investigate the distribution characteristics of previous infection of human parvovirus B19(HPV B19) among blood donors in Xi 'an, and to provide data support and theoretical basis for formulating individualized and precise blood screening strategies. Methods: A total of 970 qualified blood samples tested at Shaanxi Blood Center from August to September 2024 were randomly selected. The levels of HPV B19 IgG antibodies in the serum were detected by enzyme-linked immunosorbent assay (ELISA). The distribution characteristics of the samples were analyzed from the perspectives of age, gender, education level, occupation, blood type and region. Results: The positive rate of HPV B19 IgG antibodies among blood donors in Xi 'an was 25.26%(245/970), which increased gradually with age (P<0.05). There was no significant difference in the positive rate of HPV B19 IgG antibodies among blood donors of different genders, education levels, occupations, or blood types (P>0.05). Univariate logistic regression analysis showed that past HPV B19 infection was only related to age (P<0.05). The distribution of positive blood samples in 13 districts and counties of Xi 'an was counted based on the blood collection sites. The results showed that there was no significant global spatial autocorrelation in the distribution of positive samples. Among them, the Weiyang District and Beilin District exhibited a "high-high" cluster (P<0.05), while Chang'an District exhibited a "low-high" cluster (P<0.01). Conclusion: A certain proportion of blood donors in Xi'an showed past infection with HPV B19, which was only correlated with age and demonstrated an upward trend. It is recommended to continue expanding the screening scope and incorporate screening for this virus in blood transfusion processes involving susceptible populations.
7.Analysis of clinical value of platelet antibody screening in 95 987 inpatients.
Ping CHEN ; Yang SUN ; Xiaoyue CHU ; Fenfang TIAN ; Yingqun YANG ; Wenhua WANG ; Jiameng NIU ; Boya ZHAO ; Jingyan CHANG ; Jiangcun YANG ; Chaofeng MA
Chinese Journal of Cellular and Molecular Immunology 2025;41(2):143-147
Objective To analyze the distribution of platelet antibodies in hospitalized patients and explore the clinical significance of platelet antibody detection. Methods A total of 95 987 hospitalized patient cases from a tertiary hospital in Xi'an from April 1, 2021 to December 31, 2023 were collected. Platelet antibodies were detected by solid-phase agglutination method. Statistical analysis was performed on variables including gender, age, blood type, department, history of blood transfusion, pregnancy history, and disease type. Results Among 95 987 hospitalized patients, the positive rate of platelet antibody detection reached 4.35%. The positive rate of platelet antibodies in female hospitalized patients (5.29%) was higher than that in male patients (3.31%), and the difference was statistically significant (x2=224.124). The positive rate of platelet antibodies in those with pregnancy history (7.92%) was higher than that in those without pregnancy history (4.19%), and the difference was significant (x2=292.773). Similarly, the positive rate of platelet antibodies in those with transfusion history (7.79%) was higher than that in those without transfusion history (3.97%), and the difference was significant (x2=300.209). There was a significant correlation between the positive rate of platelet antibodies and the number of pregnancies (x2=91.061). Conclusion The positive rate of platelet antibodies in 95 987 inpatient cases was 4.35%. The positive rate of platelet antibodies had a close relationship with a history of blood transfusions and pregnancies, and it increased with the number of pregnancies. For patients with multiple transfusion histories and pregnancy histories, screening for platelet antibodies holds significant diagnostic value.
Humans
;
Female
;
Male
;
Adult
;
Middle Aged
;
Blood Platelets/immunology*
;
Inpatients
;
Aged
;
Pregnancy
;
Young Adult
;
Adolescent
;
Aged, 80 and over
;
Autoantibodies/blood*
8.Analysis of gene detection results of next-generation sequencing of liquid based cytological specimens of lung adenocarcinoma cavity effusion and evaluation of clinical efficacy
Shuo LIANG ; Yuan WANG ; Zihan SUN ; Jiameng ZHANG ; Xiaoyue XIAO ; Cong WANG ; Yue SUN ; Xinxiang CHANG ; Linlin ZHAO ; Huan ZHAO ; Huiqin GUO ; Zhihui ZHANG
Chinese Journal of Oncology 2025;47(9):905-912
Objective:To analyze the results of next generation sequencing (NGS) gene testing in liquid-based cytological specimens of lung adenocarcinoma cavity and evaluate the clinical efficacy of epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) treatment.Methods:Liquid based cytological specimens of 222 cases of lung adenocarcinoma with cavity effusion and 201 cases of metastatic lymph node biopsy were collected. Specimens were obtained from the Cytology Laboratory of the Cancer Hospital of the Chinese Academy of Medical Sciences. The collection period was from January 2018 to December 2022. The results of NGS gene detection were compared. The clinical efficacy of 91 patients treated with EGFR-TKI was evaluated, and the survival curve was analyzed by Kaplan-Meier and other statistical methods.Results:The mutation rates of cancer-related genes detected by NGS were 82.0% (182/222) vs 79.1% (159/201), ( P=0.455) in liquid-based cytological specimens and histological specimens of metastatic lymph node biopsy, respectively. However, the mutation rate of EGFR T790M was significantly higher in cavity effusion than in lymph node biopsy specimens [12.2%(27/222)>3.5%(7/201), P=0.001]. The results of gene mutation were identical in 10 of the 13 cases with cavity effusion and metastatic lymph node biopsy, and the agreement rate of EGFR was 84.6%(11/13). In 3 inconsistent cases, EGFR mutations were detected in 2 cavity effusion cases that were not detected by lymph node biopsy. Results of genetic analysis of fluid-based cytological samples of 91 patients with cavity effusion were evaluated after drug treatment with EGFR-TKI. The mean progression-free survival (PFS) of the patients was 11.4 months (95% CI: 9.9-12.9). The mean PFS of patients harboring EGFR mutation was 12.3 months (95% CI: 10.8-13.9), and the mean PFS of EGFR wild type was 4.1 months (95% CI: 2.1-6.2). Conclusions:The results of NGS gene detection in liquid-based cytological specimens of lung adenocarcinoma patients with cavity effusion show that the PFS time is similar to that of histological specimens after clinical treatment with EGFR-TKI, which proves the reliability of NGS gene detection results in liquid cytological specimens. NGS gene testing appears higher sensitivity in cavity liquid-based samples than in metastatic lymph node samples.
9.Health economic evaluation of minimally invasive surgery in treatment of digestive tract cancers: a Meta-analysis
Xiaoyue YIN ; Ning ZHOU ; Xueli YANG ; Zhuoyu SUN ; Yinghui BAO ; Shengshu WANG ; Ke HAN ; Jing LONG ; Min ZHAO ; Haowei LI ; Rongrong LI ; Shimin CHEN ; Junhan YANG ; Huaihao LI ; Yueting SHI ; Guoning ZHU ; Jianhua WANG ; Shanshan YANG ; Boyan LI ; Wenchang WANG ; Shengyan DU ; Yao HE ; Enqiang LING-HU ; Huikai LI ; Miao LIU ; Juan XIE
Chinese Journal of Epidemiology 2025;46(1):154-165
Objective:To compare minimally invasive surgery with traditional open surgery, analyze the current application status of health economic evaluations in the treatment of digestive tract cancers, such as esophageal cancer, gastric cancer, and colorectal cancer by minimally invasive surgery and provide evidence for the rational selection of clinical treatment, alleviation of disease-related economic burdens, and rational allocation of healthcare resources.Methods:By using five databases, i.e. China National Knowledge Infrastructure, Wanfang data, Chinese Biomedical Literature Database, PubMed, and Embase, a database was established to retrieve all the papers about health economic studies of minimally invasive surgery for esophageal cancer, gastric cancer, and colorectal cancer published until December 31, 2023. Literature was analyzed by using software NoteExpress 3.8, and data were processed using Excel 2021. The quality of included papers was evaluated using the CHEERS 2022 checklist, and Meta-analysis was conducted by using software Stata 17.0.Results:A total of 10 919 relevant papers were retrieved, and 59 studies were included. Only 14 studies (23.7%) used standard health economic evaluation methods. Meta-analysis results revealed no significant differences in direct medical expenditure and total expenditure between minimally invasive surgery and open surgery. However, the expenditure for minimally invasive surgery exhibited a significant increase [mean difference ( MD)=5 973.12 yuan, P<0.001], while hospital stay and indirect expenditure significantly decreased ( MD: -4.85 days and -733.79 yuan, P<0.001). In China, for gastric cancer, the direct medical expenditure of endoscopic surgery was lower than that of open surgery ( MD=-33 000.00 yuan) with no significant difference ( P<0.001). In colorectal cancer cases, the direct medical and surgical expenditures for laparoscopic surgery were higher than those for open surgery ( MD: 4 277.94 yuan and 4 267.80 yuan, P<0.001), while the indirect and total medical expenditures decreased ( MD: -768.34 yuan and -159.10 yuan). Hospital stays in patients who had minimally invasive surgery for all three types of cancer were shorter than those who had open surgery ( P<0.001). Conclusions:In the treatment of gastrointestinal cancer, compared with open surgery, minimally invasive surgery shows higher expenditure, but has advantages, such as shorter hospital stay and lower indirect expenditure, and there were no significant differences in direct medical and total expenditures between the two approaches. When conducting health economic evaluation, factors such as postoperative complications, hospital stay, and patient's economic status should be considered for their impact on total medical expenditure. It is necessary to pay attention to the application of health economic evaluations in healthcare decision-making.
10.Construction and identification of a sizeable naive human Fab phage display antibody library
Yakun ZHAO ; Xiaoyue WEI ; Fanliang MENG ; Wentao LIU ; Jiaming FAN ; Lijin LONG ; Wanting WANG ; Jianling CHEN ; Jianzhong ZHANG ; Lihua HE ; Liyong LIU ; Rui ZHAO ; Di SUN ; Xuezhen YUAN ; Xiaomei YAN
Chinese Journal of Epidemiology 2025;46(2):288-295
Objective:To construct a sizeable naive human Fab phage display antibody library to screen high-affinity specific antibodies in vitro. Methods:Total RNA was extracted from peripheral blood mononuclear cells (PBMCs) of 126 healthy individuals, subsequently reverse-transcribed into cDNA, and used as a template. PCR amplification was performed to obtain the V H from IgG, IgM and light chain κ, λ, separately, with the initial PCR products serving as templates for a second round of PCR. Overlap extension PCR was employed to generate fragments of the κ and λ light chains. These fragments were ligated with the phage vector pNC3, which harbors the variable region 1 of the heavy chain, to construct a recombinant phage plasmid. This plasmid was then electroporated into competent Escherichia Coli TG1 cells to establish a naive human Fab phage display antibody library. One hundred clones were randomly selected for identification and sequencing, and antibody gene polymorphisms were analyzed using the IMGT database and MAFFT software. Recombinant α-hemolysin from Staphylococcus aureus was utilized to screen Fab antibody fragments through biopanning of the antibody library, followed by random selection of phage ELISA-identified clones. The positive clones (antigen A450∶blank control A450≥2.1) were sequenced. Results:Two large naive Fab phage display antibody libraries were successfully constructed, in which the capacity of κ and λ chain antibody libraries were 1.25×10 11 and 1.54×10 11, respectively. The titers for two antibody libraries were 6.04×10 13 CFU/ml and 3.50×10 13 CFU/ml. The positive transformation insertion rates for κ and λ chain antibody libraries were 96% (96/100) and 100% (100/100), respectively. Sequence analysis revealed that all antibody sequences were unique. The amino acid sequences in the skeletal region were relatively conserved. In contrast, significant variations in the length of the complementarity determining region (CDR) were found, and the diversity of amino acid sequence of the complementary determining region was high, especially the CDR3. Analysis using the IMGT database indicated that the sequences exhibited a broad distribution across variable-diversity-joining gene families. After six rounds of panning, specific phage antibodies enrichment targeting α-hemolysin were achieved. A total of 142 monoclonal antibodies were sequenced, yielding 8 distinct Fab antibody sequences. Conclusion:This study successfully constructed two naive human Fab phage display antibody libraries with large capacity and good diversity, which can be used for screening human antibodies for serum epidemiology.

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