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.

Objective To explore the relationship among sleep quality, fatigue and work-related musculoskeletal disorders (WMSDs) in firefighters, and to examine the mediating effect of fatigue between sleep quality and the risk of WMSDs. Methods A total of 271 firefighters from three prefecture-level cities in Jiangsu Province were selected as the study subjects by a convenient sampling method. The Chinese Musculoskeletal Disorders Questionnaire, Pittsburgh Sleep Quality Index (PSQI), and Fatigue Scale-14 were used to assess WMSDs, sleep quality and fatigue status among the study subjects. The effect of sleep quality and fatigue on WMSDs was analyzed, as well as the mediating role of fatigue between sleep quality and the risk of WMSDs. Results The annual prevalence of WMSDs among the firefighters was 68.6%. The firefighters who had poor and very poor sleep quality accounted for 36.2% and 7.7%, respectively. There were 88.6% of firefighters reported fatigue. The total scores of PSQI and fatigue of firefighters in WMSDs group were higher than those in non-WMSDs group (all P<0.01). Binary logistic regression analysis showed that the higher the total score of PSQI, the worse the sleep quality, and the higher the risk of WMSDs in firefighters (all P<0.01). The higher the total score of fatigue, the higher the risk of WMSDs (P<0.01), and the risk of WMSDs in the fatigue group was higher than that in the non-fatigue group among the firefighters (P<0.01). The direct effect of sleep quality on WMSDs in firefighters was 0.028 [95% confidence interval (CI): 0.012-0.050, P<0.01], and its indirect effect on WMSDs mediated by fatigue was 0.027 (95%CI: 0.018-0.040, P<0.01). Fatigue played a mediating role in sleep quality and WMSDs, with the mediating ratio of 0.491 (95%CI: 0.304-0.740, P<0.01). Conclusion Poor sleep quality and fatigue are related to an increased risk of WMSDs in firefighters in a dose-response manner. Fatigue plays a mediating role between sleep quality and the risk of WMSDs.

Objective:To analyze the clinical features and prognosis of acute B lymphoblastic leukemia (B-ALL) children carrying a TCF3: : PBX1 fusion gene and to evaluate the prognostic value of this gene.Methods:Retrospective cohort study.A total of 2 164 B-ALL children aged 0-18 years diagnosed and treated at 19 pediatric centers from October 2016 to June 2022 were enrolled.They were divided into the positive group and the negative group according to whether they carried a TCF3: : PBX1 fusion gene.The clinical characteristics, treatment response, adverse reactions, and prognosis of the 2 groups of patients were analyzed.The rank sum and Kruskal-Wallis tests were used to compare two and more than two groups of numerical variables, respectively.Fisher′s exact test was used to compare categorical variables.Results:Among the 2 164 patients, 116 (5.4%) were TCF3: : PBX1 positive, of which 70 patients were female, accounting for 60.3%.There were 840 female patients in the TCF3: : PBX1-negative group, accounting for 41.0%.There was a significant difference in the ratio of females between the TCF3: : PBX1-positive and TCF3: : PBX1-negative groups ( P<0.001).No significant difference was observed in age of onset between the two groups( P>0.05).The proportion of bone marrow naive cells [54.00 (14.00, 76.50)% vs.29.00 (3.00, 68.00)%], white blood cell counts [25.30 (10.46, 60.94)×10 9/L vs.9.03 (4.38, 30.73)×10 9/L] and hemoglobin counts [82.00(63.00, 101.00) g/L vs.74.00(60.00, 90.00) g/L] in the TCF3: : PBX1-positive group were significantly higher than those in the negative group at the onset (all P<0.05).In terms of treatment response, the proportion of peripheral blood naive cells on Day 8 in the TCF3: : PBX1-positive group was significantly higher than that in the negative group [2.00 (0, 9.00)% vs.0 (0, 2.00)%, P<0.001].The proportion of minimal residual disease <0.1% on Day 15 in the TCF3: : PBX1-positive group was significantly higher than that in the negative group ( P=0.038).There were no significant differences in cumulative recurrence rate, treatment-related mortality (TRM), and overall survival (OS) between the TCF3: : PBX1-positive group and TCF3: : PBX1-negative group (all P>0.05).The cumulative recurrence risk of TCF3: : PBX1-positive patients was 9.646 times higher than that of ETV6: : RUNX1-positive patients with better prognosis( HR=9.646, 95% CI: 1.026-90.700, P=0.047).There were no significant differences in TRM and OS between TCF3: : PBX1-positive and ETV6: : RUNX1-positive patients (all P>0.05).A significant enrichment of PAX5 mutations was detected in TCF3: : PBX1-positive patients.Among the 7 high-risk TCF3: : PBX1-positive patients in a single center, 4 patients had PAX5 mutations, and this proportion was significantly higher than that in other patients ( P<0.001). Conclusions:B-ALL children carrying a TCF3: : PBX1 fusion gene have a high remission rate and good long-term prognosis after intensive chemotherapy.It is suggesting that TCF3: : PBX1-positive B-ALL patients should be rated at intermediate risk to receive intensive chemotherapy.

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.

Objective:To analyze the clinical features and prognosis of acute B lymphoblastic leukemia (B-ALL) children carrying a TCF3: : PBX1 fusion gene and to evaluate the prognostic value of this gene.Methods:Retrospective cohort study.A total of 2 164 B-ALL children aged 0-18 years diagnosed and treated at 19 pediatric centers from October 2016 to June 2022 were enrolled.They were divided into the positive group and the negative group according to whether they carried a TCF3: : PBX1 fusion gene.The clinical characteristics, treatment response, adverse reactions, and prognosis of the 2 groups of patients were analyzed.The rank sum and Kruskal-Wallis tests were used to compare two and more than two groups of numerical variables, respectively.Fisher′s exact test was used to compare categorical variables.Results:Among the 2 164 patients, 116 (5.4%) were TCF3: : PBX1 positive, of which 70 patients were female, accounting for 60.3%.There were 840 female patients in the TCF3: : PBX1-negative group, accounting for 41.0%.There was a significant difference in the ratio of females between the TCF3: : PBX1-positive and TCF3: : PBX1-negative groups ( P<0.001).No significant difference was observed in age of onset between the two groups( P>0.05).The proportion of bone marrow naive cells [54.00 (14.00, 76.50)% vs.29.00 (3.00, 68.00)%], white blood cell counts [25.30 (10.46, 60.94)×10 9/L vs.9.03 (4.38, 30.73)×10 9/L] and hemoglobin counts [82.00(63.00, 101.00) g/L vs.74.00(60.00, 90.00) g/L] in the TCF3: : PBX1-positive group were significantly higher than those in the negative group at the onset (all P<0.05).In terms of treatment response, the proportion of peripheral blood naive cells on Day 8 in the TCF3: : PBX1-positive group was significantly higher than that in the negative group [2.00 (0, 9.00)% vs.0 (0, 2.00)%, P<0.001].The proportion of minimal residual disease <0.1% on Day 15 in the TCF3: : PBX1-positive group was significantly higher than that in the negative group ( P=0.038).There were no significant differences in cumulative recurrence rate, treatment-related mortality (TRM), and overall survival (OS) between the TCF3: : PBX1-positive group and TCF3: : PBX1-negative group (all P>0.05).The cumulative recurrence risk of TCF3: : PBX1-positive patients was 9.646 times higher than that of ETV6: : RUNX1-positive patients with better prognosis( HR=9.646, 95% CI: 1.026-90.700, P=0.047).There were no significant differences in TRM and OS between TCF3: : PBX1-positive and ETV6: : RUNX1-positive patients (all P>0.05).A significant enrichment of PAX5 mutations was detected in TCF3: : PBX1-positive patients.Among the 7 high-risk TCF3: : PBX1-positive patients in a single center, 4 patients had PAX5 mutations, and this proportion was significantly higher than that in other patients ( P<0.001). Conclusions:B-ALL children carrying a TCF3: : PBX1 fusion gene have a high remission rate and good long-term prognosis after intensive chemotherapy.It is suggesting that TCF3: : PBX1-positive B-ALL patients should be rated at intermediate risk to receive intensive chemotherapy.

Objective:To evaluate the role of minimal residual disease (MRD) monitoring during early induction therapy for the treatment of childhood acute lymphoblastic leukemia (ALL).Methods:This was a multicenter retrospective cohort study. Clinical data of 1 164 ALL patients first diagnosed between October 2016 and June 2019 was collected from 16 hospitals in South China Children′s Leukemia Group. According to MRD assay on day 15 of early induction therapy, they were divided into MRD<0.10% group, MRD 0.10%-<10.00% group and MRD≥10.00% group. According to MRD assay on day 33, they were divided into MRD<0.01% group, MRD 0.01%-<1.00% group and MRD≥1.00% group. Age, onset white blood cell count, central nervous system leukemia (CNSL), molecular genetic characteristics and other data were compared between groups. Kaplan-Meier method was used for survival analysis. Cox regression model was used to analyze prognostic factors.Results:Of the 1 164 enrolled patients, there were 692 males and 472 females. The age of diagnosis was 4.7 (0.5, 17.4) years. The white blood cell count at initial diagnosis was 10.7 (0.4, 1 409.0) ×10 9/L. Among all patients, 53 cases (4.6%) had CNSL. The follow-up time was 47.6 (0.5, 68.8) months. The 5-year overall survival (OS) and 5-year relapse-free survival (RFS) rates were (93.1±0.8) % and (90.3±1.1) %. On day 15 of early induction therapy, there were 466 cases in the MRD<0.10% group, 523 cases in the MRD 0.10%-<10.00% group and 175 cases in the MRD≥10.00% group. The 5-year OS rates of the MRD<0.10% group, MRD 0.10%-<10.00% group and MRD≥10.00% group were (95.4±1.0) %, (93.3±1.1) %, (85.4±2.9) %, respectively, while the RFS rates were (93.2±1.6) %, (90.8±1.4) %, (78.9±4.3) %, respectively ( χ2=16.47, 21.06, both P<0.05). On day 33 of early induction therapy, there were 925 cases in the MRD <0.01% group, 164 cases in the MRD 0.01%-<1.00% group and 59 cases in the MRD≥1.00% group. The 5-year RFS rates in the MRD 0.01%-<1.00% group was lowest among three groups ((91.4±1.2) % vs. (84.5±3.2) % vs. (87.9±5.1) %). The difference between three groups is statistically significant ( χ2=9.11, P=0.010). Among ALL patients with MRD≥10.00% on day 15 of induction therapy, there were 80 cases in the MRD <0.01% group on day 33, 45 cases in the MRD 0.01%-<1.00% group on day 33 and 45 cases in the MRD≥1.00% group on day 33. The 5-year RFS rates of three groups were (83.9±6.0)%, (67.1±8.2)%, (83.3±6.9)% respectively ( χ2=6.90, P=0.032). Univariate analysis was performed in the MRD≥10.00% group on day 15 and the MRD 0.01%-<1.00% group on day 33.The 5-year RFS rate of children with CNSL was significantly lower than that without CNSL in the MRD≥10.00% group on day 15 ((50.0±20.4)% vs. (80.3±4.4)%, χ2=4.13, P=0.042). Patients with CNSL or MLL gene rearrangement in the MRD 0.01%-<1.00% group on day 33 had significant lower 5-year RFS rate compared to those without CNSL or MLL gene rearrangement ((50.0±25.0)% vs. (85.5±3.1)%, χ2=4.06, P=0.044;(58.3±18.6)% vs. (85.7±3.2)%, χ2=9.44, P=0.002). Multivariate analysis showed that age ( OR=0.58, 95% CI 0.35-0.97) and white blood cell count at first diagnosis ( OR=0.43, 95% CI 0.27-0.70) were independent risk factors for OS. The MRD level on day 15 ( OR=0.55,95% CI 0.31-0.97), ETV6-RUNX1 fusion gene ( OR=0.13,95% CI 0.03-0.54), MLL gene rearrangement ( OR=2.55,95% CI 1.18-5.53) and white blood cell count at initial diagnosis ( OR=0.52,95% CI 0.33-0.81) were independent prognostic factors for RFS. Conclusions:The higher the level of MRD in early induction therapy, the worse the OS. The MRD levels on day 15 is an independent prognostic factor for RFS.The MRD in early induction therapy guided accurate risk stratification and individualized treatment can improve the survival rate of pediatric ALL.

Objective To explore the diagnostic value of musculoskeletal ultrasound in patients with limb pain.Methods A total of 80 patients with limb pain admitted to the First Hospital of Nanchang from January 2021 to December 2022 were included in the study.All patients received magnetic resonance imaging(MRI)and musculoskeletal ultrasound on admission.The consistency and coincidence rate of musculoskeletal ultrasound and MRI in diagnosing the cause of limb pain were compared.Results In the 80 patients,MRI and musculoskeletal ultrasound detected positive results in 78 cases,accounting for 97.50%,and 2 cases had no clear disease type.According to the results of MRI,there were 75 cases in which musculoskeletal ultrasound diagnosis of the cause of limb pain was consistent with the MRI results,and total coincidence rate was 96.15%(75/78),with excellent consistency(Kappa=0.907).Conclusion Musculoskeletal ultrasound can clearly display the fine tissue structure,and the diagnosis accuracy of limb pain is high,and the diagnosis consistency with MRI is excellent.

Objective To examine the mediating role of empathy and emotional competence in the association between family functioning and internalizing and externalizing problem behaviors among adolescents in China.Methods In this study,we used the data from the June-July 2022 survey of Chengdu Positive Child Development(CPCD)cohort.All respondents were 5th-9th graders from six primary or secondary schools in Chengdu.The Achenbach Child Behavior Checklist(CBCL),the Chinese Family Assessment Instrument(C-FAI),the empathy subscale of the Chinese version of the Interpersonal Reactivity Index(C-IRI),and the emotional competence(EC)subscale of the Chinese Positive Youth Development Scale(CPYD)were used to evaluate the respondents'internalizing and externalizing problem behaviors,family functioning,empathy,and emotional competence,respectively.The average score derived from the total score of a scale divided by the number of entries in each dimension was used as the final score of the scale.Independent samples t-tests or one-way analysis of variance(ANOVA)were performed to examine the differences in family functioning,empathy,emotional competence,and internalizing and externalizing problem behaviors across student groups with different demographic characteristics(sex,grade,and region).Pearson correlation analysis was conducted to examine the relationship between family functioning,empathy,emotional competence,and internalizing and externalizing problem behaviors.AMOS 24.0 was used to validate the hypothesized model and structural equation modeling was used to analyze the mediating effects of empathy and emotional competence between family functioning and internalizing and externalizing problem behaviors among adolescents.Results A total of 3026 eligible participants were included,including 1548(51.16%)male students and 1478(48.84%)female students.Among the respondents,798(26.37%)were 5th graders,738(24.39%)were 6th graders,567(18.74%)were 7th graders,614(20.29%)were 8th graders,and 309(10.21%)were 9th graders.In addition,2064(68.21%)of all respondents were from urban areas and 962(31.79%)were from rural areas.The results of the difference analysis showed that the differences in adolescents'internalizing and externalizing problem behaviors were statistically significant between students of different grades(P=0.004),and that the differences in family functioning and empathy scores were also statistically significant between students of different grades(all P<0.001),whereas the differences in adolescents'internalizing and externalizing problem behaviors were not statistically significant between sexes and regions(P=0.919,0.959).The results of correlation analysis showed that family functioning scores(the higher the score,the worse the family functioning)were significantly negatively correlated with empathy and emotional competence(r=-0.482,-0.432,P<0.01),and significantly positively correlated with internalizing and externalizing problem behaviors(r=0.220,P<0.01).Empathy was significantly positively correlated with emotional competence(r=0.402,P<0.01).Empathy and emotional competence were significantly negatively correlated with all the dimensions of internalizing and externalizing problem behaviors(r=-0.115,-0.305,P<0.01).Emotional competence partially mediated the relationship between family functioning and adolescents'internalizing and externalizing problem behaviors,with a mediation effect value being 0.042(95%[confidence interval]CI:0.031-0.057).Empathy and emotional competence had chain mediation effect between family functioning and adolescents'internalizing and externalizing problem behaviors,with the value of the mediation effect being 0.010(95%CI:0.007-0.014).Conclusion Family functioning influences adolescents'internalizing and externalizing problem behaviors in a direct way and through the chain-mediating roles of empathy and emotional competence.

Objective To investigate the effect of empathy on depressive symptoms in adolescents and to explore the potential mediating role of family functioning in the effect of empathy on depressive symptoms.Methods The 2022 cross-sectional data from the Chengdu Positive Child Development(CPCD)cohort were analyzed in the study.A survey was conducted in Chengdu in June 2022,involving 3 020 students in grades 5-8 from three randomly selected stratified schools.The Interpersonal Reactivity Index(IRI-C),the Chinese Family Assessment Instrument(C-FAI),and the Center for Epidemiologic Studies Depression Scale for Children(CES-DC)were used in the survey.Chi-square test or one-way analysis of variance was performed to examine the differences in various demographic characteristics(sex,grade,region,and total monthly household income)between groups of respondents,as well as the differences in family functioning,empathy,and depression.Pearson correlation coefficient was used to examine the correlation between family functioning,empathy,and depressive symptoms.Structural equation modeling and SPSS PROCESS component Model 4 were used to analyze whether family functioning played a mediating role in the effect of empathy on depressive symptoms in adolescents.Results The detection rate of depressive symptoms among survey respondents was 25.40%.The results of the difference analysis revealed significant differences in the detection rates of depressive symptoms among respondents of different grades,regions,and monthly household incomes(P<0.05).There was no significant difference in the detection rates of depressive symptoms between male and female students.There was a significant difference in the detection rate of depressive symptoms between respondents with different scores for family dysfunction and empathy ability(P<0.001).Correlation analysis results showed that empathy scores were negatively correlated with depression(r=-0.11,P<0.001),that family dysfunction was positively correlated with depression(r=0.29,P<0.001),and that empathy scores were negatively correlated with family functioning(r=-0.37,P<0.001).The mediating role of family dysfunction in the relationship between empathy and depressive symptoms was established,with the direct effect being 0.039(95% confidence interval[CI]:0.010-0.069,P<0.001)and the indirect effect value being-0.096(95% CI:-0.115--0.079,P<0.001).The direct effect value accounted for 28.89% of the total effect value,while the mediation effect value accounted for 71.11% of the total effect value.Conclusion The empathy ability of adolescents is correlated to depressive symptoms,and family functioning plays a mediating role between empathy and depressive symptoms in adolescents.It is suggested that adolescents'empathy ability and family functioning should be enhanced through multiple channels to reduce the occurrence of depressive symptoms.

Objective To summarize the clinical characteristics of patients with occupational melanosis. Methods Diagnostic data of 69 patients with occupational melanosis was analyzed using retrospective analysis. Results The main occupational hazards for the 69 patients with occupational melanosis were coal tar, petroleum and its fractionated products, pigments and dyes and their intermediates, rubber additives and rubber products. The median length of occupational exposure and disease latency were 8.0 and 6.0 years, respectively, with a highly positive correlation between them (Spearman correlation coefficients=0.962, P<0.01). Skin lesions were mainly found on exposed areas such as the face-to-neck and limbs, prevalence of 94.2% and 75.4% respectively. And 78.3% of patients had skin lesion on more than two sites. The lesions were mostly in the form of irregular flakes (59.4%), with a gray-black color (44.9%). About 43.5% of patients experienced skin itching. Complete blood count, liver function, and kidney function were all within normal ranges. Skin biopsy results showed that epidermal hyperkeratosis, thinning of the spinous layer, liquefaction degeneration of basal cells, increased superficial dermal melanocytes, and infiltration of lymphocytes, histiocytes, and melanocytes around the blood vessels. Reflectance confocal microscopy (RCM) detection showed focal liquefaction degeneration of basal cells in the lesions, with a significant infiltration of melanocytes and inflammatory cells in the dermal papillae and superficial layers. Conclusion The primary target organ of occupational melanocytes is the skin, and no damage to other organs was identified thus far. Results from skin biopsies and RCM examinations can be used for differential diagnosis.