Objective: To explore the association between the HLA antibody positivity rate in female blood donors and pregnancy history, number of pregnancies, interval from the last pregnancy to blood donation, and age, to identify associated variables using a univariate generalized additive model (GAM), and to further analyze the predictive role of characteristic variables for HLA antibody positivity using a random forest model. Methods: HLA antibody detection was performed on 391 female blood donors using the Luminex immunomagnetic bead method. The correlation between pregnancy-related factors and HLA antibodies was analyzed using the Chi-square test. Based on R software, a univariate GAM was first constructed to analyze the association types between characteristic variables and the HLA antibody positivity rate, followed by the construction of a random forest model to evaluate the predictive value of the variables. Results: Among the 391 female blood donors without a transfusion history, the overall HLA antibody positivity rate was 26.34%. The positivity rate in donors with a pregnancy history was significantly higher than that in those without (30.09% vs 9.72%, P<0.05), and HLA antibody positivity rate increased linearly with the number of pregnancies (P<0.05). In the univariate GAM, age and number of deliveries exhibited a non-linear association with the HLA antibody positivity rate (the positivity rate increased sharply between 25-35 years of age and stabilized after 3 deliveries). Besides, the interval from the last pregnancy to blood donation showed a linear association with the HLA antibody positivity rate, and the positivity rate decreased as the interval prolonged (P<0.05). In the random forest model, age (mean decrease gini=29.26) and interval from the last pregnancy to blood donation (mean decrease gini=22.02) were core predictive variables: age was more conducive to identifying positive samples, while the interval from the last pregnancy to blood donation was more helpful for excluding negative samples. The number of deliveries (mean decrease accuracy=16.98) made a significant contribution to predicting positive samples, whereas the number of abortions had no impact. The model had an AUC of 0.583 (95% CI: 0.593 8-0.770 2), indicating a certain predictive value. Conclusion: The associated variables identified by the univariate GAM model, including age, interval from the last pregnancy to blood donation, and number of deliveries, provide a basis for key variables in the random forest model. All three variables have predictive value for HLA antibody positivity, which can provide evidence-based support for personalized transfusion management and stratified screening of female blood donors in this region.

The aim of this study is to identify the cause of death of a South China tiger cub at the Meihuashan breeding institute of Fujian Province.Pathogenic bacteria were isolated and cultured from liver,spleen,lung and other tissue samples of the dead South China tiger aseptically.The iso-lated bacteria were identified through morphological observation,biochemical characterization,sequence analysis of housekeeping gene gyrB,virulence gene detection,animal pathogenicity test and drug sensitivity test.A pathogenic Aeromonas hydrophila strain,designated FJ/Tiger-201809 was successfully isolated from the trachea of dead South China tiger.The nucleotide sequence ho-mology between the isolate and 11 strains of Aeromonas gyrB ranged from 91.2％to 99.1％,with the highest homology of 99.1％observed with Aeromonas hydrophila(AF208251.1).Genetic evo-lution analysis showed that the isolated strain FJ/Tiger-201809 was in the same evolutionary branch as other reference strains of Aeromonas hydrophila and was closely related.The pathoge-nicity test in mice showed artificial infection of mice with the strain resulted in varying degrees of lesions in several organs of the mice,and the median lethal dose(LD50)was 1 × 107.8 CFU/mL.Virulence gene test results showed that the isolate FJ/Tiger-201809 carried two virulence genes,aer and act.The results of drug sensitivity test showed that FJ/Tiger-201809 was highly sensitive to enrofloxacin and ampicillin among 18 commonly used antibiotics,relatively sensitive to penicil-lin G and doxycycline,and resistant to the other 14 antibiotics.In conclusion,this study isolated and identified a strain of Aeromonas hydrophila from a dead South China tiger with multiple drug resistance and strong pathogenicity,which provided an important reference for the prevention and control of bacterial diseases in South China tiger.

The Split-Cre system consists of two inactive polypeptides: NCre and CCre, which can be recombined into an active full-length Cre under certain conditions. This system is typically used with LoxP. To develop an efficient Split-Cre system, this study used Rma intein from Rhodothermus marinus to split Cre and screened out the split site S102 which could efficiently mediate the recombination of Cre in the "Traffic Light" reporter cell line. Moreover, the S102 Split-Cre system was delivered to mice by dual-adeno-associated virus (AAV), and it was demonstrated that the efficiency of the Rma intein-mediated S102 Split-Cre system was comparable to the full-length Cre in mice. This system lays a foundation for both basic and applied research on Split-Cre.
Inteins/genetics* ; Animals ; Integrases/biosynthesis* ; Mice ; Dependovirus/metabolism* ; Bacterial Proteins/genetics* ; Recombination, Genetic ; Humans

Image 1.

Objective:To explore the effect of necroptosis inhibitor necrosulfonamide (NSA) on traumatic brain injury (TBI) mouse model and BV2 cell pyroptosis model and their mechanisms.Methods:(1) In vivo experiments: 50 mice were randomly divided into sham-operated group, TBI group, TBI+1 mg/kg NSA group, TBI+5 mg/kg NSA group, and TBI+10 mg/kg NSA group, with 10 mice in each group. TBI model was established using a modified Feeney's weight-drop method; 4 h after modeling, 90% corn oil, 1 mg/kg NSA, 5 mg/kg NSA, or 10 mg/kg NSA was administered into the mice, respectively. Mice in the sham-operated group only had circular bone window opened without being subjected to impact. At 48 hours after modeling, neurological function was evaluated by modified neurological function score (mNSS), serum lactate dehydrogenase (LDH) content was detected by LDH detection kit, contents of interleukin (IL)-18, IL-1β and tumor necrosis factor-α (TNF-α) in the brain tissues were detected by enzyme-linked immunosorbent assay (ELISA), and expressions and localizations of ionized calcium binding adaptor molecule 1 (IBA-1), cysteinyl aspartate specific proteinase-1 (Caspase-1) p20 and gasdermin D (GSDMD) in the injured parietal cortex were detected by double immunofluorescent staining. (2) In vitro experiments: BV2 cells were divided into control group, lipopolysaccharide (LPS)+adenosine triphosphate (ATP)+dimethyl sulfoxide (DMSO) group, LPS+ATP+5 μmol/L NSA group, LPS+ATP+10 μmol/L NSA group, and LPS+ATP+15 μmol/L NSA group. Cells in the latter 4 groups were induced by LPS+ATP to establish BV2 cell pyroptosis model, and incubated with 2 μL DMSO, 5 μmol/L NSA, 10 μmol/L NSA, and 15 μmol/L NSA for 1 hour, respectively; cells in the control group were cultured conventionally. Contents of LDH, IL-1β, IL-18, and TNF-α in the cell culture supernatant were detected by ELISA; pyroptosis was detected by calcein acetoxymethyl ester (CAM)/propidium iodide (PI) double staining; protein expressions of nucleotide binding domain-like receptor protein 3 (NLRP3), Caspase-1 p20, GSDMD, and N-terminal fragment of GSDMD (GSDMD-N) were detected by Western blotting. Results:(1) Compared with the TBI group, the TBI+1 mg/kg NSA group, TBI+5 mg/kg NSA group and TBI+10 mg/kg NSA group had decreased mNSS score and serum LDH content, decreased IL-1β and IL-18 contents in the brain tissues and number of Caspase-1 p20 + cells in the injured parietal cortex, successively, with significant differences ( P<0.05). Compared with the TBI group ([287.80±12.26] cells/mm 2), the TBI+1 mg/kg NSA group, TBI+5 mg/kg NSA group, and TBI+10 mg/kg NSA group had decreased number of Iba-1 +GSDMD + cells in the injured parietal cortex ([213.70±11.87] cells/mm 2, [205.30±9.15] cells/mm 2, [131.70±13.69] cells/mm 2),successively, with significant differences ( P<0.05). Compared with the TBI group, the TBI+5 mg/kg NSA group and TBI+10 mg/kg NSA group had significantly decreased number of Iba-1 + cells in the injured parietal cortex, and the TBI+10 mg/kg NSA group had significantly decreased TNF-α content in the brain tissues and number of GSDMD + cells in the injured parietal cortex ( P<0.05). Compared with the TBI group ([247.20±9.88] cells/mm 2), the TBI+10 mg/kg NSA group had significantly decreased number of Iba-1 +Caspase-1 p20 + cells in the injured parietal cortex ([181.70±9.37] cells/mm 2, P<0.05). (2) Compared with the LPS+ATP+DMSO group, the LPS+ATP+5 μmol/L NSA group, LPS+ATP+10 μmol/L NSA group, and LPS+ATP+15 μmol/L NSA group had decreased IL-18 content in the supernatant, successively, with significant differences ( P<0.05); and compared with the LPS+ATP+DMSO group, the LPS+ATP+10 μmol/L NSA group and LPS+ATP+15 μmol/L NSA group had significantly decreased contents of LDH, IL-1β, and TNF-α in the supernatant and ratio of PI +/CAM + cell counts ( P<0.05). Compared with the LPS+ATP+DMSO group (2.62±0.50), the LPS+ATP+10 μmol/L NSA group and LPS+ATP+15 μmol/L NSA group had significantly decreased Caspase-1 p20 protein expression (1.36±0.14, 1.32±0.07, P<0.05). Compared with the LPS+ATP+DMSO group (5.00±1.67), the LPS+ATP+5 μmol/L NSA group and LPS+ATP+15 μmol/L NSA group had significantly decreased GSDMD protein expression (1.42±0.26, 1.68±0.32, P<0.05). Compared with the LPS+ATP+DMSO group (2.28±0.24), the LPS+ATP+15 μmol/L NSA group had significantly decreased GSDMD-N protein expression (1.23±0.08, P<0.05). Conclusion:NSA can inhibit microglial pyroptosis after TBI by inhibiting the Caspase-1 p20/GSDMD pathway, thereby playing a neuroprotective role.

This study was aimed at identifying the pathogenic bacteria responsible for the death of a young tiger at the Fujian Meihua Mountain South China Tiger Breeding Research Institute.Tissue samples from the lungs,liver,and intestines of the deceased tiger were collected,and the bacteria were cultured inasterile environment.The bacterial strains were characterized according to their morphological and molecular biological properties,including assessment of virulence genes and antibiotic resistance genes,mouse lethality tests,and antibiotic susceptibility evaluations.A predominant bacterial strain isolated from the liver of the deceased tiger was identified as enterotoxigenic Escherichia coli(ETEC)strain Tiger22513F.Phylogenetic analysis of the 16S rRNA gene revealed that the Tiger22513F strain exhibited close genetic similarity to the reference strain ETEC(MF919609.1),with 99.9%nucleotide similarity,and resided on the same evolutionary branch.The Tiger22513F strain contained 11 antibiotic resistance genes(tetA,sul1,sul3,cmlA,floR,blaTEM,blaSHV,blaCMY-2,qnrA,qnrS,and qnrD)along with five virulence genes(VT1,fyuA,tsh,iucD,and ST).Mouse lethality tests indicated significant pathogenicity toward mice,affecting primarily the lungs,liver,and intestines.Antibiotic susceptibility testing demonstrated that this strain exhibited resistance to various classes of beta-lactam antibiotics,as well as quinolones and aminoglycosides.This investigation successfully isolated a multi-drug resistant enterotoxigenic Escherichia coli strain with pronounced pathogenicity from the liver of a deceased tiger;thus providing valuable scientific insights for clinical diagnosis,as well as prevention and control measures,against ETEC infections in South China tigers.

Objective:To develop a scale to measure the sense of gain of the elderly, and to evaluate its reliability and validity.Methods:According to the content of the sense of gain, combined with the literature research method and interview method, the scale entry pool was established.After the expert consistency evaluation and the optimal test assembly method (OTA) analysis, the formal version of the scale was formed.The stratified sampling method was used to select 1 043 community-dwelling elders for the survey, and the reliability and validity of the scale were evaluated by methods based on classical test theory.Results:The scale of elderly sense of gain, which was screened by OTA method, included four dimensions: health status, relationship and communication, social security, and ideal expectation, with a total of 17 items. The Cronbach's α value of the formal version of the scale was 0. 850, and the Cronbach's α coefficients of the four dimensions were 0.721, 0.772, 0.779, and 0.930, respectively. The CR values of the combined reliabilities of each dimension were all above 0.7. In terms of AVE values, except for the health status dimension was acceptable, the other three dimensions were all above 0.36. The correlation coefficient between the sense of health acquisition and life satisfaction of the elderly was 0.531 ( P<0.01). Conclusion:The developed scale for measuring the sense of gain of the elderly has good reliability and validity, which can be used as an effective tool for measuring the sense of gain of the elderly.

Objective:To develop a scale to measure the sense of gain of the elderly, and to evaluate its reliability and validity.Methods:According to the content of the sense of gain, combined with the literature research method and interview method, the scale entry pool was established.After the expert consistency evaluation and the optimal test assembly method (OTA) analysis, the formal version of the scale was formed.The stratified sampling method was used to select 1 043 community-dwelling elders for the survey, and the reliability and validity of the scale were evaluated by methods based on classical test theory.Results:The scale of elderly sense of gain, which was screened by OTA method, included four dimensions: health status, relationship and communication, social security, and ideal expectation, with a total of 17 items. The Cronbach's α value of the formal version of the scale was 0. 850, and the Cronbach's α coefficients of the four dimensions were 0.721, 0.772, 0.779, and 0.930, respectively. The CR values of the combined reliabilities of each dimension were all above 0.7. In terms of AVE values, except for the health status dimension was acceptable, the other three dimensions were all above 0.36. The correlation coefficient between the sense of health acquisition and life satisfaction of the elderly was 0.531 ( P<0.01). Conclusion:The developed scale for measuring the sense of gain of the elderly has good reliability and validity, which can be used as an effective tool for measuring the sense of gain of the elderly.

This study was aimed at identifying the pathogenic bacteria responsible for the death of a young tiger at the Fujian Meihua Mountain South China Tiger Breeding Research Institute.Tissue samples from the lungs,liver,and intestines of the deceased tiger were collected,and the bacteria were cultured inasterile environment.The bacterial strains were characterized according to their morphological and molecular biological properties,including assessment of virulence genes and antibiotic resistance genes,mouse lethality tests,and antibiotic susceptibility evaluations.A predominant bacterial strain isolated from the liver of the deceased tiger was identified as enterotoxigenic Escherichia coli(ETEC)strain Tiger22513F.Phylogenetic analysis of the 16S rRNA gene revealed that the Tiger22513F strain exhibited close genetic similarity to the reference strain ETEC(MF919609.1),with 99.9%nucleotide similarity,and resided on the same evolutionary branch.The Tiger22513F strain contained 11 antibiotic resistance genes(tetA,sul1,sul3,cmlA,floR,blaTEM,blaSHV,blaCMY-2,qnrA,qnrS,and qnrD)along with five virulence genes(VT1,fyuA,tsh,iucD,and ST).Mouse lethality tests indicated significant pathogenicity toward mice,affecting primarily the lungs,liver,and intestines.Antibiotic susceptibility testing demonstrated that this strain exhibited resistance to various classes of beta-lactam antibiotics,as well as quinolones and aminoglycosides.This investigation successfully isolated a multi-drug resistant enterotoxigenic Escherichia coli strain with pronounced pathogenicity from the liver of a deceased tiger;thus providing valuable scientific insights for clinical diagnosis,as well as prevention and control measures,against ETEC infections in South China tigers.

The aim of this study is to identify the cause of death of a South China tiger cub at the Meihuashan breeding institute of Fujian Province.Pathogenic bacteria were isolated and cultured from liver,spleen,lung and other tissue samples of the dead South China tiger aseptically.The iso-lated bacteria were identified through morphological observation,biochemical characterization,sequence analysis of housekeeping gene gyrB,virulence gene detection,animal pathogenicity test and drug sensitivity test.A pathogenic Aeromonas hydrophila strain,designated FJ/Tiger-201809 was successfully isolated from the trachea of dead South China tiger.The nucleotide sequence ho-mology between the isolate and 11 strains of Aeromonas gyrB ranged from 91.2％to 99.1％,with the highest homology of 99.1％observed with Aeromonas hydrophila(AF208251.1).Genetic evo-lution analysis showed that the isolated strain FJ/Tiger-201809 was in the same evolutionary branch as other reference strains of Aeromonas hydrophila and was closely related.The pathoge-nicity test in mice showed artificial infection of mice with the strain resulted in varying degrees of lesions in several organs of the mice,and the median lethal dose(LD50)was 1 × 107.8 CFU/mL.Virulence gene test results showed that the isolate FJ/Tiger-201809 carried two virulence genes,aer and act.The results of drug sensitivity test showed that FJ/Tiger-201809 was highly sensitive to enrofloxacin and ampicillin among 18 commonly used antibiotics,relatively sensitive to penicil-lin G and doxycycline,and resistant to the other 14 antibiotics.In conclusion,this study isolated and identified a strain of Aeromonas hydrophila from a dead South China tiger with multiple drug resistance and strong pathogenicity,which provided an important reference for the prevention and control of bacterial diseases in South China tiger.