ObjectiveTo understand the seropositivity of neutralizing antibodies (NAb) and low-level NAb against SARS-CoV-2 infection in the community residents, and to explore the impact of COVID-19 vaccination and SARS-CoV-2 infection on the levels of NAb in human serum. MethodsOn the ground of surveillance cohort for acute infectious diseases in community populations in Shanghai, a proportional stratified sampling method was used to enroll the subjects at a 20% proportion for each age group (0‒14, 15‒24, 25‒59, and ≥60 years old). Blood samples collection and serum SARS-CoV-2 NAb concentration testing were conducted from March to April 2023. Low-level NAb were defined as below the 25^th percentile of NAb. ResultsA total of 2 230 participants were included, the positive rate of NAb was 97.58%, and the proportion of low-level NAb was 25.02% (558/2 230). Multivariate logistic regression analysis indicated that age, infection history and vaccination status were correlated with low-level NAb (all P<0.05). Individuals aged 60 years and above had the highest risk of low-level NAb. There was a statistically significant interaction between booster vaccination and one single infection (aOR=0.38, 95%CI: 0.19‒0.77). Compared to individuals without vaccination, among individuals infected with SARS-CoV-2 once, both primary immunization (aOR=0.23, 95%CI: 0.16‒0.35) and booster immunization (aOR=0.12, 95%CI: 0.08‒0.17) significantly reduced the risk of low-level NAb; among individuals without infections, only booster immunization (aOR=0.28, 95%CI: 0.14‒0.52) showed a negative correlation with the risk of low-level NAb. ConclusionsThe population aged 60 and above had the highest risk of low-level NAb. Regardless of infection history, a booster immunization could reduce the risk of low-level NAb. It is recommended that eligible individuals , especially the elderly, should get vaccinated in a timely manner to exert the protective role of NAb.

Objective: To investigate the impact of intergenerational parent-child separation (PCS) on allergic diseases among rural preschool children, providing theoretical guidance for developing targeted public health interventions. Methods: From March to June 2024, 10 kindergartens were selected from Nanling, Wuhu City, Anhui Province. A total of 2 279 children aged 3-6 years and their parents/primary caregivers participated in the survey by a combination of convenience sampling and cluster sampling method. Children s fathers and mothers reported the experiences of PCS during their childhood. The children s PCS experiences and allergies were reported by their primary caregivers. The International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire was used to supplement the allergies (allergic asthma, allergic rhinitis and atopic dermatitis). Analysis of variance (ANOVA) and Chi square tests were used to compare differences between children in different PCS groups. Logistic regression models assessed the association between PCS and the risk of allergic diseases in preschool children. Results: Among the preschoolers enrolled, the prevalence of allergic diseases in only parent-child separation group in childhood, only child separation group, and the intergenerational continuity of PCS groups were significantly higher than those of the none separation group (38.0%, 41.8%, 48.1%,30.4%; χ 2=40.45, P < 0.01 ). After adjusting for covariates including child age, sex and body mass index, Logistic regression model revealed that compared to children in the group without PCS, those in the only parent-child separation in childhood( OR =1.43, 95% CI =1.06-1.94), only child separation ( OR =1.82, 95% CI =1.22-2.71), and intergenerational continuity of PCS ( OR =2.33, 95% CI =1.68-3.24) exhibited higher allergic disease risk (all P <0.05). Conclusions Intergenerational continuity of PCS is related to the increased risk of allergies in preschool children. The multigenerational accumulation of adverse effects from PCS underscores the importance of breaking the cycle of disadvantage across generations.

Objective To investigate the neuroprotective effect and potential mechanism of rehabilitation training combined with citicoline on cerebral hemorrhage model in mice based on Keap1/Nrf2/ARE signaling pathway.Methods The C57BL/6 male mice were randomly divided into sham operation group(sham operation treatment),model group(right caudate putamen hemorrhage model induced by type Ⅶcollagenase),choline group(model+choline 64 mg·kg-1),rehabilitation training group(rehabilitation training)and combined group(model+rehabilitation training+choline 64 mg·kg-1).The study observed the modified neurological severity score(mNSS)in mice with cerebral hemorrhage;colorimetric assays were used to detect the expression of malondialdehyde(MDA),superoxide dismutase(SOD)and catalase(CAT)in brain tissues;protein imprinting and reverse transcription-quantitative polymerase chain reaction were employed to assess the expression of Kelch-like ECH-associated protein 1(Keap1),nuclear factor erythroid 2-related factor 2(Nrf2)/antioxidant response element(ARE),heme oxygenase-1(HO-1),quinone oxidoreductase 1(NQ01)proteins and mRNA in brain tissues.Results The mNSS scores of sham operation group,model group,citicoline group,rehabilitation training group and combined group were 0,1.56±0.73,1.00±0.00,0.78±0.44 and 0.67±0.50;the MDA contents were(6.93±0.92),(22.97±0.77),(19.26±1.73),(13.21±0.78)and(7.25±0.97)nmol·mgprot-1;the relative expression of Keap1 protein were 0.79±0.03,1.02±0.04,0.95±0.10,0.90±0.09 and 0.86±0.05;the relative expression levels of Nrf2 protein were 0.94±0.12,0.71±0.08,0.90±0.07,0.98±0.12 and 1.33±0.25.There were significant differences in the above indexes between the model group and the sham operation group(P＜0.05,P＜0.01);there were significant differences between the citicoline group and the rehabilitation training group,the model group(P＜0.05,P＜0.01);there were significant differences between the combined group and the citicoline group,the rehabilitation training group except for protein expression of Keap1(all P＜0.01).Conclusion Rehabilitation training and citicoline can reduce the symptoms of neurological deficits in mice with cerebral hemorrhage.The mechanism way be that they can activate the Keap1/Nrf2/ARE signaling pathway to exert anti-oxidative stress,and the combined effect is the best.

Objective To explore the protective mechanism of icariin on neuronal oxidative damage,providing a basic pharmacological basis for the treatment of cognitive impairment.Methods Glutamate was used to induce oxidative stress injury in HT22 cells.HT22 cells were divided into control group(normal cultured cells),model group(glutamate injury model)and experimental-L,-M,-H groups(5,10 and 20 μmol·L-1 icariin pretreatment for modeling,respectively).Cell proliferation was detected by cell counting kit-8(CCK-8)method;cytotoxicity was detected by lactate dehydrogenase(LDH)method;reactive oxygen species(ROS)levels were detected by flow cytometry;superoxide dismutase(SOD)levels were detected by biochemical kits;the expression levels of Kelch-like epichlorohydrin-related protein-1(Keap1),nuclear factor E2-related factor 2(Nrf2)were detected by Western blotting;the corresponding mRNA expression was detected by real-time fluorescence quantification polymerose chain reaction.Results The cell viability of control group,model group and experimental-L,-M,-H groups were(100.00±1.31)％,(66.38±2.44)％,(72.07±4.95)％,(82.41±3.57)％and(87.97±4.98)％;LDH release were(0.48±0.52)％,(18.82±2.09)％,(15.32±1.17)％,(10.37±1.39)％and(6.51±0.87)％;ROS level were(14.23±1.13)％,(41.74±1.60)％,(35.69±1.08)％,(33.28±1.69)％and(30.32±2.03)％;SOD levels were(54.84±1.17),(37.95±1.13),(48.02±1.28),(50.56±1.34)and(52.55±1.04)U·mg-1;Keap1 protein levels were 0.36±0.01,0.52±0.03,0.46±0.04,0.39±0.09 and 0.35±0.12;Nrf2 protein levels were 0.29±0.02,0.13±0.08,0.18±0.03,0.21±0.11 and 0.26±0.04;catalase(CAT)mRNA levels were 1.01±0.08,0.81±0.06,0.90±0.04,1.05±0.15 and 1.33±0.26;SOD mRNA levels were 1.09±0.12,0.83±0.03,0.86±0.08,0.94±0.08 and 1.09±0.16.Among the above indicators,the differences between the model group and the control group were statistically significant(all P＜0.01);the differences between the experimental-M,-H groups and the model group were statistically significant(P＜0.01,P＜0.05).Conclusion Icariin may activate the Keap1/Nrf2/antioxidant response element(ARE)signaling pathway,regulate the expression of related proteins,and reduce the level of ROS to effectively alleviate oxidative stress injury in neuronal cells.

ABATRACT OBJECTIVE To utilize the pharmacophore model-molecular docking combined with the virtual screening strategy of free energy calculation and the chemical bioinformatics method of traditional Chinese medicine in cell biology experiments to investigate the components of Guiqi Baizhu prescription that target phosphatidylinositol 3-kinase(PI3K) and inhibit the proliferation of uveal melanoma(UM) cells. METHODS The pharmacophore model of PI3K inhibitor was constructed, and the compounds of Guiqi Baizhu prescription were virtual screened. The components that fit the pharmacophore model were calculated by molecular docking and binding free energy, and the potential inhibitory components were selected for biological experimental evaluation. The effects of potential inhibitory components on UM cell proliferation were detected by CCK-8 and clonal formation assay. Flow cytometry was used to detect the cell cycle and apoptosis of UM cells. The mitochondrial membrane potential of UM cells was detected using JC-10 staining. The expressions of PI3K and downstream pathway proteins were detected by Western blotting.RESULTS The pharmacophore model included 2 hydrogen bond receptors, 2 aromatic ring centers, and exclusion volumes. The results of the CCK-8 experiment showed that quercetin, tangerine, and nobiletin at concentrations of 10, 20, 40, 80 μmol·L−1, and cyrtin at concentrations of 20, 40, 80 μmol·L−1, were able to inhibit the proliferation of UM cells. The clonal formation experiment showed that quercetin, tangerine, nobiletin, and morusin, at different concentrations, could significantly inhibit the clonal proliferation of UM cells. Flow cytometry showed that UM cells were arrested in the G0/G1 phase by tangeretin and quercetin, while UM cells were arrested in the G2/M phase by nobiletin and morusin. The results of JC-10 staining showed that quercetin, nobiletin, tangeretin, and morusin could reduce the mitochondrial membrane potential of UM cells. Western blotting results showed that 4 compounds could target PI3K, but their downstream pathways were different.CONCLUSION Based on the method of chemical bioinformatics in traditional Chinese medicine, this study explores the material basis for the inhibition of UM cell proliferation by the Guiqi Baizhu prescription. It also provides insights for the modern development of traditional Chinese medicine prescription.

In recent years, the development of host-acting antibacterial compounds has gradually become a hotspot in the field of anti-infection. Through research on the interaction mechanism between hosts and pathogenic bacteria, it has been found that the immune system is one of the key targets of host-acting antibacterial compounds. There is a communication system called the quorum sensing system in microorganisms, which mainly adjusts the structure of multi-microbial community and coordinates the group behavior. When the quorum sensing molecules secreted by microorganisms reach a threshold concentration, the quorum sensing system is activated and the overall gene expression of the microorganism is changed. In addition to regulating the density of microorganisms, quorum sensing molecules can also act as a link between pathogenic microorganisms and hosts, entering the host immune system and playing a role in affecting the morphological structure of immune cells, secreting cytokines, and inducing apoptosis, leading to host immune injury and causing host immune dysfunction.The key mechanism of 3-oxo-C12-HSL and other acyl-homoserine lactone (AHL) molecules in the innate immune system has been extensively studied. The lipid solubility allows AHLs to pass through the plasma membrane of host immune cells easily and induce dissolution of lipid domains. Then, it acts through signaling pathways such as p38MAPK and JAK-STAT, further influencing the immune cell’s defense response to bacteria and potentially leading to cell apoptosis. Additionally, the human lactonase paraoxonase 2, which can degrade3-oxo-C12-HSL, has been found in macrophage. It acts as an immune regulator that promotes macrophage phagocytosis of pathogens and is hypothesized to have the ability to reduce bacterial resistance. The mechanism of quorum sensing molecules in the adaptive immune system is less studied, the current results suggest that 3-oxo-C12-HSL is closely related to the mitochondrial pathway in host immune cells. For example, 3-oxo-C12-HSL induces apoptosis of Jurkat cells by inhibiting the expression of three mitochondrial electron transport chain proteins; it can also trigger mitochondrial dysfunction and induce mast cell apoptosis through Ca²⁺ signaling.Among the quorum sensing molecules, the AHLs have the greatest impact on plant immune system. The different effects on plant resistance depends on the chain lengths of acyl groups in bacterial-produced AHLs. Short-chain AHLs (C4-HSL and C8-HSL) induce plant resistance to pathogenic bacteria mainly through the auxin pathway and jasmonic acid pathway. Long-chain AHL (3-oxo-C14-HSL) is commonly used in hosts against fungal pathogens by inducing stomata defense responses, and the reaction process is related to salicylic acid. Diffusible signal factor molecules also interfere with the stomatal immunity caused by pathogens. It may act through the formin nanoclustering-mediated actin assembly and MPK3 pathway to inhibit the innate immunity of Arabidopsis. In summary, AHLs induced different plant pathways and affects the plant-bacteria interactions to trigger plant immunity. As a quorum sensing molecule of fungi, farnesol has similar effects on host immunity as AHLs, such as stimulating cytokine secretion and activating an inflammatory response. It also plays a unique role on dendritic cell differentiation and maturation. In addition, studies have found that farnesol has a protective effect on autoimmune encephalomyelitis, which may be related to its effect on the composition of intestinal microorganisms of the host.Therefore, targeting the host immune system and quorum sensing molecules to develop antibacterial compounds can effectively inhibit the invasion of pathogens and subserve the host to resist the influence of pathogenic bacteria. This article will review the mechanism of host immune responses triggered by important quorum sensing molecules, aiming to explore the targets of host-acting antibacterial compounds and provide new directions for the prevention or treatment of causative infectious sources and the development of related drugs.

Objective To evaluate the malaria diagnostic capability in Shanghai Municipal Malaria Diagnostic Reference Laboratory from 2017 to 2022 and to analyze factors affecting the diagnosis results, so as to provide the scientific evidence for increasing the laboratory malaria diagnostic capability during the post-elimination stage. Methods Plasmodium-negative blood smears were randomly sampled using a proportional sampling method each quarter during the period from 2017 to 2022 and scored by Shanghai Municipal Malaria Diagnostic Reference Laboratory. Malaria cases’ blood samples from district centers for disease control and prevention in Shanghai Municipality were re-reviewed using microscopy and multiplex PCR assay to evaluate the capability of malaria diagnosis. Results A total of 7 746 quality control blood smears were collected from district centers for disease control and prevention in Shanghai Municipality from 2017 to 2022, with a mean score of (76.74 ± 14.34) points and a qualification rate of 86.65% (6 712/7 746). A total of 387 blood smears were re-reviewed from 2017 to 2022, with an overall coincidence of 96.38% (373/387) for malaria diagnosis and 95.06% (308/324) for parasite species identification, and there were no significant differences in the coincidence for either malaria diagnosis (χ² = 2.57, P > 0.05) or parasite species identification among years (χ² = 1.04, P > 0.05). A total of 384 whole blood samples were collected from district centers for disease control and prevention, and the detection of whole blood samples was 70.31% (270/384) in district centers for disease control and prevention. All 384 whole blood samples were re-reviewed by Shanghai Municipal Malaria Diagnostic Reference Laboratory using a multiplex PCR assay from 2017 to 2022, with an overall coincidence of 94.07% (254/270) for malaria diagnosis and 99.55% (223/224) for parasite species identification, and there were no significant differences in the coincidence for either malaria diagnosis (χ² = 5.77, P > 0.05) or parasite species identification among years (χ² = 8.37, P > 0.05). The overall coincidence rates of Plasmodium-positive and negative whole blood samples were 100.00% (224/224) and 65.22% (30/46) in district centers for disease control and prevention, with a significant difference (χ² = 82.82, P < 0.001), and there was a significant difference in the coincidence rate for identification of P. falciparum, P. vivax, P. malariae and P. ovale (χ² = 24.28, P < 0.001). A total of 1 584 blind blood smears subjected to microscopic examinations by centers for disease control and prevention and medical institutions across all districts in Shanghai Municipality from 2017 to 2022, with a 96.15% (1 523/1 584) correct rate for malaria diagnosis and 85.07% (1 003/1 179) for parasite species identification, and there were significant differences in the correct rate of both malaria diagnosis (χ² = 20.98, P < 0.001) and parasite species identification among years (χ² = 70.77, P < 0.001). A total of 320 blind nucleic acid samples from malaria cases were tested, with a 99.38% (318/320) correct rate for malaria diagnosis and 100.00% (225/225) for parasite species identification, and there was no significant difference in the correct rate of malaria diagnosis among years (χ² = 6.04, P > 0.05). Conclusions There were still shortcomings in blood smears preparation, microscopic examinations and nucleic acid testing in centers for disease control and prevention across all districts in Shanghai Municipality from 2017 to 2022. A greater role in the quality control of malaria diagnosis is recommended for Shanghai Municipal Malaria Diagnostic Reference Laboratory to prevent the re-establishment of imported malaria and consolidate the elimination achievements.

Objective:To discuss the regulatory effect of physiological tensile stress on the differentiation of chondrocytes,and to clarify the associated signaling pathway mechanism.Methods:The ATDC5 chondrocytes were cultured in vitro and subjected to physiological tensile stress by four-point bending cell mechanical loading device.Initially,the cells were divided into control group and tensile stress group(2 000 μstrain/2 h group),and further divided into different stress magnitudes(1 000,2 000,and 3 000 μstrain)for 2 h,and 2 000 μstrain for different duration time(1,2,and 4 h)groups;the cells without tensile stress were used as control group.Real-time fluorescence quantitative PCR(RT-qPCR)method was used to detect the expression levels of type Ⅱ collagen(Col-Ⅱ),type Ⅹ collagen(Col-Ⅹ),aggregated proteoglycom(Aggrecan),sex-determining region Y-box protein 9(SOX9),vascular endothelial growth factor(VEGF),proliferating cell nuclear antigen(PCNA),Nel-like molecule tyep 1(Nell-1),Runt-related transcription factor 2(Runx2),Indian hedgehog(Ihh),patched homolog 1(Ptch-1),GLI family zinc finger protein 1(Gli-1),and hedgehog interacting protein 1(Hhip-1)mRNA in the cells in various groups;Western blotting method was used to detect the expression levels of Nell-1,Runx2,and Ihh proteins in the cells in various groups.The ATDC5 cells were divided into control group,cyclopamine group,tensile stress group,and cyclopamine + tensile stress group.RT-qPCR method was used to detect the expression levels of Nell-1,Ihh,Ptch-1,Gli-1,and Hhip-1 mRNA in the cells in various groups;Western blotting method was used to detect the expression levels of Nell-1 and Ihh proteins in the cells in various groups.Results:Compared with control group,the expression levels of Col-Ⅱ,Col-Ⅹ,Aggrecan,SOX9,VEGF,and PCNA mRNA in the cells in 2 000 μstrain/2 h group were significantly increased(P<0.01);after treated with 2 000 μstrain tensile stress for different duration time(1,2,and 4 h)or different tensile stresses(1 000,2 000,and 3 000 μstrain)for 2 h,compared with control group,the expression levels of Runx2 mRNA in the cells in other groups were increased with the prolongation of time or the increasing of tensile stress(P<0.01),and the expression levels of Nell-1,Ihh,Ptch-1,Gli-1,and Hhip-1 mRNA were gradually increased(P<0.01),the expression levels reached the peaking at 2 000 μstrain/2 h,and then decreased but remained significantly higher than that in control group(P<0.01).The Western blotting results showed that the expression levels of Nell-1,Runx2,and Ihh proteins in the cells were consistent with the change trend of mRNA expression levels.After pre-treated with cyclopamine,compared with control group,the expression levels of Ihh,Ptch-1,Gli-1,and Hhip-1 mRNA in the cells in cyclopamine group were significantly decreased(P<0.01),and the expression levels of Ihh,Ptch-1,Gli-1,and Hhip-1 mRNA in the cells in tensile stress and cyclopamine+tensile stress groups were significantly increased(P<0.01);compared with cyclopamine group,the expression levels of Nell-1,Ihh,Ptch-1,Gli-1,and Hhip-1 mRNA in the cells in cyclopamine+tensile stress group were significantly increased(P<0.01);compared with tensile stress group,the expression levels of Ihh,Ptch-1,Gli-1,and Hhip-1 mRNA in the cells in cyclopamine + tensile stress group were significantly decreased(P<0.01).Compared with control group,the expression level of Ihh protein in the cells in cyclopamine group was significantly decreased(P<0.01),but there was no significant difference in expression level of Nell-1 protein in the cells between control group and cyclopamine group(P>0.05),while the expression levels of Nell-1 and Ihh proteins in the cells in tensile stress group and cyclopamine + tensile stress group were significantly increased(P<0.01);compared with cyclopamine group,the expression levels of Nell-1 and Ihh proteins in the cells in tensile stress group and cyclopamine + tensile stress group were significantly increased(P<0.01);compared with tensile stress group,in the expression levels of Nell-1 and Ihh proteins in the cells in cyclopamine + tensile stress group had no significant differences(P>0.05).Conclusion:After stimulated with physiological tensile stress,Nell-1 can activate the Ihh signaling pathway upstream,and regulate the differentiation of the ATDC5 chondrocytes.

Objective To investigate the protective effect and mechanism of acellular nerve allografts(ANA)combined with electroacupuncture on spinal ganglia in rats with sciatic nerve injury(SNI).Methods Totally 50 male adult SD rats were randomly selected for this experiment.Ten rats were prepared for the ANA.Forty male SD rats were randomly divided into normal group,model group,ANA group and combinational group,with 10 rats in each group.The SNI model was established by cutting off the nerves 10 mm at the 5 mm on the inferior border of piriformis after separating the right sciatic nerves.The rats in the ANA group were bridged with ANA to the two broken ends of injured nerves.The rats in the combinational group were treated with electroacupuncture 2 days after ANA bridging,Huantiao(GB30)and Yanglingquan(GB34)were performed as the acupuncture points,each electroacupuncture lasted 15 minutes and 7 days as a course of treatment,4 courses in all.Sciatic nerve conduction velocity was measured by electrophysiology to evaluate the regeneration of damaged axons.Morphology of spinal ganglia was observed by Nissl staining.The expression of nerve growth factor(NGF)and brain-derived neurotrophic factor(BDNF)were detected by Western blotting and immunofluorescent staining.Results Compared with the normal group,the sciatic nerve conduction velocity in model group decreased significantly(P<0.01),Nissl bodies in neurons of spinal ganglia were swollen and dissolved,with incomplete structure and the number decreased dramatically(P<0.01),while the level of NGF and BDNF also decreased significantly(P<0.01).Compared with the model group,the sciatic nerve conduction velocity in ANA and combinational groups strongly increased(P<0.01),the damage of Nissl bodies in neurons of spinal ganglia reduced and the number obviously increased(P<0.01),the level of NGF and BDNF increased considerably(P<0.01).Compared with the ANA group,the sciatic nerve conduction velocity in combinational group increased significantly(P<0.01),the morphology of Nissl bodies in neurons of spinal ganglia were more regular and the number increased(P<0.01),moreover,the level of NGF also increased significantly(P<0.01).Conclusion ANA combined with electroacupuncture can enhance the sciatic nerve conduction velocity,improve the morphology of neurons in spinal ganglia and play a protective effect on spinal ganglia.The mechanism can be related to the higher expression of NGF and BDNF proteins,especially the expression of NGF protein.

Objective To investigate the feasibility of energy spectrum CT material separation technology for quantitative evaluation of nonalcoholic fatty liver patients,to compare the accuracy of this method with the conventional liver/spleen CT ratio for grading liver fat content.Methods Sixty patients diagnosed with nonalcoholic fatty liver and 20 healthy volunteers were chosen to undergo liver MR multi-echo(ME)Dixon and energy spectrum CT scans.The proton density fat fraction(PDFF),fat concentration(FC),and liver/spleen CT ratio were then measured for each participant.According to PDFF,nonalcoholic fatty liver patients were divided into mild fatty liver group,moderate fatty liver group,and severe fatty liver group.Results With the increase in PDFF,FC increased and the liver/spleen CT ratio decreased.The difference between FC groups in normal,mild,moderate and severe fatty liver groups was statistically significant(P<0.05),while the difference between the liver/spleen CT ratio of normal group and mild fatty liver group was not statistically significant(P>0.05).The receiver operating characteristic(ROC)curve analysis showed that when the critical value of FC was 351.19 mg/mL,the sensitivity,specificity and area under the curve for normal group and fatty liver group were 0.95,0.1 and 0.99,respectively.Conclusion The energy spectrum CT material separation technology has a good correlation between the fat content measured by the MR ME Dixon,which is superior to the fat content measured by the liver/spleen CT ratio.For patients with nonalcoholic fatty liver,FC in energy spectrum CT has high accuracy in differentiating normal and mild fatty liver.