[摘 要] 目的：探究miR-1224-5p在前列腺癌细胞增殖、迁移与凋亡中的生物学作用及其表达调控机制。方法：选用人前列腺癌细胞PC3、DU145、LNCaP、22Rv1和正常前列腺上皮细胞RWPE-1，利用qPCR法检测miR-1224-5p在前列腺癌细胞中的表达。使用脂质体转染技术分别将miR-1224-5p模拟物（mimic）、抑制剂（inhibitor）及相应的阴性对照（NC）质粒转染至PC3和DU145细胞中，qPCR法验证转染效率，采用CCK-8实验、平板克隆形成实验、划痕愈合实验和流式细胞术分别检测转染miR-1224-5p mimic与inhibitor对细胞增殖、迁移和凋亡的影响。借助SRAMP网站预测pri-miR-1224-5p序列中潜在的N6-甲基腺苷（m6A）修饰位点，通过甲基化RNA免疫沉淀实验（MeRIP）验证预测结果，qPCR法检测m6A修饰关键调控分子甲基转移酶3（METTL3）在前列腺癌细胞中的表达，CCK-8实验和Transwell实验分别检测转染METTL3 siRNA对PC3和DU145细胞增殖和迁移的影响，qPCR法和MeRIP检测METTL3介导的m6A修饰对miR-1224-5p表达的调控作用。结果：miR-1224-5p在前列腺癌细胞中均呈高表达（均P < 0.01）。转染miR-1224-5p mimic能够促进PC3和DU145细胞增殖、迁移并抑制细胞凋亡（P < 0.05或P < 0.01），转染miR-1224-5p inhibitor能够抑制PC3和DU145细胞增殖、迁移并诱导细胞凋亡（P < 0.05或P < 0.01）。pri-miR-1224-5p具有m6A修饰位点；METTL3在前列腺癌细胞中均呈高表达（均P < 0.01），转染METTL3 siRNA能够抑制PC3和DU145细胞的增殖和迁移（均P < 0.01）；METTL3介导的m6A修饰能够调控miR-1224-5p的表达。结论：miR-1224-5p受METTL3介导的m6A修饰调控，从而在前列腺癌细胞中呈高表达，下调miR-1224-5p能够抑制前列腺癌细胞的增殖、迁移并诱导细胞凋亡。

Objective To investigate the impact of Toxoplasma gondii type I, II and III rhoptry protein 16 (ROP16) on programmed cell death ligand 1 (PD-L1) expression in lung adenocarcinoma cells, and to examine the effects of T. gondii type I ROP16 protein on the relative PD-L1 expression, the relative PD-L1 distribution on the cell membrane surface, and the binding of programmed cell death 1 (PD-1) to PD-L1 in lung adenocarcinoma cells. Methods Lentiviral vectors overexpressing T. gondii type I, II and III ROP16 proteins were generated, and transfected into the human lung adenocarcinoma A549 cell line. A549 cells were used as a blank control group, and A549 cells transfected with an empty lentiviral expression vector were used as a negative control group, while A549 cells transfected with lentiviral vectors overexpressing T. gondii type I, II and III ROP16 proteins served as experimental groups. Stably transfected cells were selected with puromycin and verified using Western blotting, quantitative real-time PCR (RT-qPCR), and immunofluorescence assays. The PD-L1 expression was quantified at translational and transcriptional levels using Western blotting and RT-qPCR assays in A549 cells in the five groups, and the relative PD-L1 distribution was detected on the A549 cell membrane surface using flow cytometry. In addition, the effect of T. gondii type I ROP16 protein on the PD-1/PD-L1 binding was measured in A549 cells using enzyme-linked immunosorbent assay (ELISA). Results The relative ROP16 protein expression was 0, 0, 1.546 ± 0.091, 1.822 ± 0.047 and 2.334 ± 0.089 in the blank control group, negative control group, and the T. gondii type I, II and III ROP16 protein overexpression groups (F = 1 339.00,P < 0.001), and the relative ROP16 mRNA expression was 2.153 ± 0.949, 2.436 ± 1.614, 14.343 ± 0.020, 12.577 ± 0.285 and 15.090 ± 0.420 in the blank control group, negative control group and the T. gondii type I, II and III ROP16 protein overexpression groups, respectively (F = 483.50,P < 0.001). The ROP16 expression was higher in the T. gondii type I, II and III ROP16 protein overexpression groups than in the blank control group at both translational and transcriptional levels (allP values < 0.001). Immunofluorescence assay revealed that T. gondii type I, II and III ROP16 proteins were predominantly localized in A549 cell nuclei. Western blotting showed that the relative PD-L1 protein expression was 0.685 ± 0.109, 0.589 ± 0.114, 1.007 ± 0.117, 0.572 ± 0.151, and 0.426 ± 0.116 in the blank control group, negative control group, and the T. gondii type I, II and III ROP16 protein overexpression groups (F = 9.46,P < 0.05), and RT-qPCR assay quantified that the relative PD-L1 mRNA expression was 1.012 ± 0.190, 1.281 ± 0.465, 1.950 ± 0.175, 0.889 ± 0.251, and 0.230 ± 0.192 in the blank control group, negative control group, and the T. gondii type I, II and III ROP16 protein overexpression groups (F = 14.18,P < 0.05). The PD-L1 expression was higher in the T. gondii type IROP16 protein overexpression group than in the blank control group at both translational and transcriptional levels (both P values < 0.05). Flow cytometry detected that the relative distributions of PD-L1 protein were (10.83 ± 0.60)%, (11.23 ± 0.20)%, and (14.61 ± 0.50)% on the A549 cell membrane surface (F = 28.31, P < 0.05), and the relative distribution of PD-L1 protein was higher in the T. gondii type IROP16 protein overexpression group than in the blank control group and negative control group (both P values < 0.001). ELISA measured significant differences in the absorbance (A) value among the T. gondii type IROP16 protein overexpression group, the blank control group and the negative control group if the concentrations of the recombinant PD-1 protein were 0.04 (F = 10.45, P < 0.05), 0.08 μg/mL (F = 11.68, P < 0.05) and 0.12 μg/mL (F = 52.68, P < 0.05), and the A value was higher in the T. gondii type IROP16 protein overexpression group than in the blank control group and the negative control group (both P values < 0.05), indicating that T. gondii type IROP16 protein promoted the PD-L1/PD-1 binding in A549 cells in a concentration-dose manner. Conclusions T. gondii type IROP16 protein overexpression may up-regulate PD-L1 expression in A549 cells at both transcriptional and translational levels and the relative PD-L1 distribution on the A549 cell membrane surface, and affect the PD-1/PD-L1 binding in a concentration-dependent manner.

Objective To investigate the effects of Toxoplasma gondii type Iand IIrhoptry protein 16 (ROP16) on the polarization and inflammatory response of mouse alveolar macrophages, so as to provide the scientific evidence for unveiling the immunoregulatory mechanisms following T. gondii infection in host cells and the clinical diagnosis and treatment of pulmonary toxoplasmosis. MethodsMouse alveolar macrophages served as blank controls, and mouse alveolar macrophages transfected with the empty lentiviral expression vector served as negative controls, and mouse alveolar macrophages transfected with lentiviral vectors overexpressing T. gondii type I and II ROP16 served as the type I and II ROP16 overexpression groups. Following puromycin selection, stably transfected cells that overexpressed type Iand IIROP16 were generated, observed for green fluorescence expression under a fluorescence microscope and verified using PCR, Western blotting and real-time quantitative reverse transcription PCR (RT-qPCR) assays. The expression of ROP16, inducible nitric oxide synthase (iNOS), arginase (Arg)-1, mannose receptor (CD206), cluster of differentiation 86 (CD86), NOD-like receptor thermal protein domain associated protein 3 (NLRP3), caspase-1, apoptosis-associated speck-like protein containing a CARD (ASC), and interleukin (IL)-1β proteins was determined in mouse alveolar macrophages using Western blotting assay, and the mRNA levels of ROP16, iNOS, IL-1β, IL-4, IL-12, IL-18, Arg-1, IL-10, IL-6, tumor necrosis factor (TNF)-α and transforming growth factor (TGF)-β were detected in mouse alveolar macrophages using RT-qPCR assay. Results Fluorescence microscopy showed 90% of mouse alveolar macrophages producing green fluorescent signals in the type Iand II ROP16 overexpression groups and the negative control group. The relative ROP16 protein expression was 1.000 ± 0.000, 1.003 ± 0.020, 1.349 ± 0.055, and 1.376 ± 0.080 in mouse alveolar macrophages in the blank control group, negative control group, and type Iand IIROP16 overexpression groups (F = 35.30, P < 0.01), and the relative ROP16 mRNA expression was 1.007 ± 0.172, 2.030 ± 0.356, 1 409.579 ± 75.960, and 1 413.581 ± 27.712 in the blank control group, negative control group, and type Iand II ROP16 overexpression groups (F = 811.00, P < 0.01). The ROP16 expression was significantly higher in the type Iand IIROP16 overexpression groups than in the blank control group at both protein and mRNA levels (all P value < 0.01). Western blotting assay detected significant differences among the four groups in terms of iNOS, Arg-1, CD86, CD206, NLRP3, caspase-1, ASC, and IL-1β protein expression (F = 124.70, 82.40, 79.82, 919.40, 84.74, 39.85, 2 354.00 and 65.96, all P values < 0.05), and the expression of Arg-1, CD206, NLRP3, caspase-1, ASC, and IL-1β proteins was significantly higher in the type I ROP16 overexpression group than in the blank control group (all P values < 0.001), while the expression of iNOS, CD86, NLRP3, caspase-1, ASC, and IL-1β proteins was significantly higher in the type II ROP16 overexpression group than in the blank control group (all P values < 0.01). RT-qPCR assay detected significant differences among the four groups in terms of iNOS, IL-1β, IL-4, IL-12, IL-18, Arg-1, IL-10, IL-6, TNF-α, and TGF-β mRNA expression (F = 407.00, 1 528.00, 833.10, 267.90, 989.80, 161.80, 461.10, 5 529.00, 849.60 and 8 836.00, all P values < 0.05), and the Arg-1, IL-4, IL-10, and TGF-β mRNA expression was significantly higher in the type I ROP16 overexpression group than in the blank control group (all P values < 0.001), while the iNOS, IL-1β, IL-12, IL-18, IL-6, and TNF-α mRNA expression was significantly higher in the type II ROP16 overexpression group than in the blank control group (all P values < 0.001). Conclusions T. gondii type IROP16 may induce M2-dominant phenotypes of mouse alveolar macrophages, and type II ROP16 may induce M1-dominant phenotypes of mouse alveolar macrophages. Both T. gondii type I and II ROP16 may activate NLRP3, and mediate the activation of ASC, caspase-1 and IL-1β to promote inflammatory responses.

Objective: To investigate the association between habitual reading/writing postures and the co-occurrence of common health conditions (overweight/obesity, visual impairment, hypertension, and scoliosis) and comorbidities among children and adolescents, in order to provide data support for the joint prevention of common diseases and comorbidities among children and adolescents. Methods: From September 2021 to June 2022, a multi-stage cluster random sampling method was used to select a total of 4 577 children and adolescents from 16 primary and secondary schools in Ningxia: Jinfeng District of Yinchuan City, Shapotou District of Zhongwei City, Yanchi County of Wuzhong City, and Pingluo County of Shizuishan City. A weighted complex sampling design was used to investigate the association of habitual reading and writing postures with common comorbidities in children and adolescents. Results: The prevalence rates of common diseases among children and adolescents in Ningxia were as follows: overweight/obesity was 22.87%, visual impairment was 62.52%, scoliosis was 2.30%, and hypertension was 1.30%. The prevalence of multimorbidity (co-occurrence of ≥2 conditions) among Ningxia children and adolescents was 15.95%. Multivariate unconditional Logistic regression analysis showed that frequent/always collapsing waist and sitting forward with head lowered increased the risk of common comorbidities in children and adolescents ( OR =1.90, P <0.05). Compared with the corresponding reference group, male children and adolescents aged 9 to 12 years and boys had relatively lower risks of overweight/obesity ( OR =0.71, 0.70); the risk of poor vision among children and adolescents aged 9 to 12 years, male, and urban was relatively low ( OR =0.59, 0.60, 0.73)( P < 0.05 ). Children and adolescents who often/always sat leaning to the left or right were at higher risk of poor vision ( OR =1.78); urban children and adolescents had a higher risk of developing scoliosis ( OR =3.71); children and adolescents aged 9 to 12 had a relatively low risk of developing hypertension ( OR =0.09), and children and adolescents who often/always bent their backs and sat forward on their knees had a higher risk of hypertension ( OR =5.03)( P <0.05). Conclusions Ningxia has a high incidence of common diseases and multiple diseases among children and adolescents, frequent or always collapsing waist and sitting forward with head lowered is associated with common comorbidities in children and adolescents in Ningxia. Proper postural measures for reading and writing should be carried out as soon as possible to encourage children and adolescents to develop good reading and writing habits for effectively preventing and controlling the occurrence of common diseases.

[摘 要] 目的：探讨环化自erb-b2受体酪氨酸激酶2（ERBB2）基因的circ_0007766分子在前列腺癌（PCa）细胞中的作用及缺氧对其表达调控的影响。方法：qRT-PCR检测circ_0007766分子在PCa细胞及组织中的表达；分别转染circ0007766的siRNA至PCa细胞DU145和PC3中，平板克隆实验、CCK-8实验和Transwell 实验检测circ_0007766敲低对PCa细胞克隆形成、增殖、迁移和侵袭能力的影响；厌氧袋法建立DU145和PC3细胞的缺氧细胞模型，WB法检测缺氧通路关键分子HIF-1α的蛋白表达，qRT-PCR检测缺氧模型细胞中circ_0007766分子的表达，WB检测RNA结合蛋白真核翻译起始因子4A3（EIF4A3）的蛋白水平表达，RNA免疫沉淀（RIP）法检测缺氧条件下EIF4A3与circ_0007766的结合，qRT-PCR进一步检测缺氧条件下敲低EIF4A3对circ_0007766表达的影响。结果：circ_0007766在PCa细胞（P < 0.01）及PCa组织（P < 0.05）中呈高表达；敲低circ_0007766（P < 0.05或P < 0.01）能显著抑制PCa细胞的增殖、迁移和侵袭能力（均P < 0.01）。缺氧条件下HIF-1α蛋白表达增加，表明缺氧细胞模型建立成功。qRT-PCR检测结果显示，相较于常氧组，缺氧组circ_0007766的表达显著升高（P < 0.01），WB法检测结果显示缺氧组细胞中EIF4A3 的蛋白表达增强。RIP实验结果显示，circ_0007766在EIF4A3富集组高度富集（P < 0.01）。qRT-PCR检测结果显示，缺氧可显著促进circ_0007766的表达，同时，敲低EIF4A3分子可显著降低缺氧诱导的circ_0007766的表达（P < 0.05或P < 0.01）。结论: circ_0007766在PCa细胞中扮演着促癌分子的角色，其表达形成与缺氧条件下EIF4A3分子的调控有关。

Background The pathogenesis of silicosis has not been fully elucidated, and microRNAs (miRNA) may be involved in the occurrence and development of silicosis. Objective To investigate the effect of miR-204-3p inhibitor on the epithelial-mesenchymal transition (EMT) process and silicosis fibrosis in silicon dioxide dust-induced alveolar epithelial cells. Methods A co-culture model of macrophages and epithelial cells was established using a Transwell chamber. NR8383 macrophages were seeded into the upper chamber of the Transwell, and RLE-6TN cells were seeded into the lower chamber. After 24 h of culture, the medium in the lower chamber was discarded, washed three times with phosphate-buffered saline (PBS), and replaced with serum-free medium. The cells were divided into four groups: control group, silicosis group, miRNA NC group, and miR-204-3p inhibitor group. The lower chamber was transfected with miRNA NC for the miRNA NC group or the miR-204-3p inhibitor for the miR-204-3p inhibitor group. The lower chambers of the remaining two groups were added by equal amounts of serum-free medium. After 24 h, except for the control group that received an equal volume of serum-free medium, the upper chambers of the remaining three groups were treated with 800 μg·mL⁻¹ silicon dioxide dust. Morphological changes in each group were observed under a microscope. The mRNA and protein expression levels of EMT-related factors, including α-smooth muscle actin (α-SMA), Vimentin, N-Cadherin, and E-Cadherin, were detected by reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR) and Western blot. The mRNA and protein expression levels of fibrosis-related factors, including Collagen I, Collagen III, and Fibronectin, were also assessed by RT-qPCR and Western blot. The fluorescence expression intensities of α-SMA, N-Cadherin, and E-Cadherin were evaluated by immunofluorescence. Results The morphological observation revealed that RLE-6TN cells in the control group exhibited a regular oval shape. After treatment with silicon dioxide, the cells predominantly displayed a long spindle shape. Following the intervention with the miR-204-3p inhibitor, the number of long spindle-shaped cells increased, and the intercellular gaps widened. The RT-qPCR results showed that, compared with the control group, the silicosis group exhibited significantly higher relative mRNA expression levels of EMT-related markers (α-SMA, Vimentin, and N-Cadherin) (P<0.05), while the relative mRNA expression level of E-Cadherin was significantly reduced (P<0.05); the relative mRNA expression levels of fibrosis-related markers (Collagen I, Collagen III, and Fibronectin) were also significantly elevated (P<0.05). Compared with the miRNA NC group, the miR-204-3p inhibitor group showed significantly increased relative mRNA expression levels of α-SMA, Vimentin, and N-Cadherin (P<0.05), decreased E-Cadherin mPNA expression (P<0.05), and elevated mPNA expression of Collagen I, Collagen III, and Fibronectin (P<0.05). The Western blot analysis indicated that, compared with the control group, the silicosis group had significantly higher protein expression levels of α-SMA, Vimentin, and N-Cadherin (P<0.05), lower E-Cadherin protein expression (P<0.05), and increased protein expression of Collagen I, Collagen III, and Fibronectin (P<0.05). Compared with the miRNA NC group, the miR-204-3p inhibitor group exhibited significantly elevated protein expression levels of α-SMA, Vimentin, and N-Cadherin (P<0.05), reduced E-Cadherin expression (P<0.05), and increased protein expression of Collagen I, Collagen III, and Fibronectin (P<0.05). The immunofluorescence analysis demonstrated that, compared with the control group, the silicosis group showed enhanced fluorescence intensities of α-SMA and N-Cadherin and reduced fluorescence intensity of E-Cadherin. Compared with the miRNA NC group, the miR-204-3p inhibitor group exhibited increased fluorescence intensities of α-SMA and N-Cadherin and decreased fluorescence intensity of E-Cadherin. Conclusion The miR-204-3p inhibitor may exacerbate the EMT process and silicosis fibrosis in silicon dioxide-induced RLE-6TN cells. miR-204-3p plays a negative regulatory role in silicosis fibrosis.

OBJECTIVE To provide a reference for pharmaceutical care in patients with ulcerative colitis （UC） and ankylosing spondylitis （AS） who developed pustular psoriasis induced by infliximab. METHODS Clinical pharmacists participated in the pharmaceutical care process of a patient with UC and AS who developed pustular psoriasis after using infliximab. The clinical pharmacists determined， using Naranjo’s Scale， that the correlation between the patient’s pustular psoriasis and infliximab was “likely”. Regarding the patient’s development of pustular psoriasis after using infliximab， the clinical pharmacists recommended discontinuing infliximab and switching to Upadacitinib extended-release tablets. For the patient’s skin allergic reaction after using upadacitinib， the clinical pharmacists advised continuing the use of upadacitinib and closely monitoring any potential adverse reactions during the treatment period. RESULTS The clinicians adopted the clinical pharmacists’ recommendation. Following the treatment， the patient’s symptoms were significantly alleviated， and the patient was discharged with medication. The follow-up after discharge showed that the treatment was effective and well-tolerated. CONCLUSIONS The clinical pharmacists analyzed the causal relationship between infliximab and pustular psoriasis. Through pharmaceutical care measures such as dynamic monitoring of skin lesions， evaluation of treatment responses， and optimization of drug regimens， they assisted the physicians in formulating an individualized medication plan， ensuring the safety and efficacy of the patient’s medication use.

Objective The prevalence of drug-resistant Mycobacterium tuberculosis (Mtb) strains is exacerbating the global burden of tuberculosis (TB), highlighting the urgent need for new treatment strategies for TB. Methods The recombinant adenovirus vaccine expressing cyclic di-adenosine monophosphate (c-di-AMP) phosphodiesterase B (CnpB) (rAd-CnpB), was administered to normal mice via mucosal immunization, either alone or in combination with drug therapy, to treat Mtb respiratory infections in mice.Enzyme-linked immunosorbent assay (ELISA) was used to detect the levels of antibodies in serum and bronchoalveolar lavage fluid (BALF). Real-time quantitative PCR was performed to assess the transcription levels of cytokines interferon γ(IFN-γ) and interleukin 10(IL-10) in mouse lungs. Flow cytometry was used to determine the proportions of CD4⁺ and CD8⁺ T cell subsets in the lungs and spleens. ELISA was employed to measure the levels of cytokines IFN-γ, IL-2, IL-10, inflammatory factors IL-6, and tumor necrosis factor α (TNF-α) secreted by spleen cells following antigen stimulation. The bacteria loads in the lungs and spleens of Mtb-infected mice were enumerated by plate counting methods. Resluts Intranasal immunization with rAd-CnpB induced high titers of IgG in mouse serum and the production of IgG and IgA in BALF, along with alterations in T lymphocyte subsets in the lungs and spleens. Administration of rAd-CnpB, either alone or in combination with drugs, to Mtb-infected mice significantly increased serum IgG levels as well as IgA and IgG levels in BALF. rAd-CnpB immunization promoted the secretion of CnpB-specific cytokines and inflammatory factors by splenocytes in Mtb-infected mice. However, rAd-CnpB immunotherapy, either alone or combined with drugs, did not significantly affect the bacterial loads in the lungs and spleens of mice with Mtb respiratory infections. Conclusion Mucosal immunization with rAd-CnpB induced significant mucosal, humoral and cellular immune responses in mice, and significantly enhanced CnpB-specific cellular immune responses in Mtb-infected mice.
Animals ; Adenoviridae/immunology* ; Mycobacterium tuberculosis/genetics* ; Mice ; Female ; Phosphoric Diester Hydrolases/genetics* ; Tuberculosis Vaccines/administration & dosage* ; Tuberculosis/prevention & control* ; Mice, Inbred BALB C ; Cytokines ; Lung/microbiology* ; Immunization ; Bronchoalveolar Lavage Fluid/immunology* ; Immunity, Mucosal

OBJECTIVE: To establish a three-dimensional finite element model of a digital wire loop space maintainer for the mandible and primary tooth loss, in order to investigate the stress, deformation, and shear force experienced by patients with the loss of the second primary molar when wearing the wire loop space maintainer. METHODS: Cone beam computed tomography (CBCT) scans were performed on the patients to create a digital model of the mandible with the absence of the second primary molar using Mimics 21.0 software. A digital model integrating the crown's retention and the wire loop structure of the full crown and ring wire loop space maintainer was constructed using pediatric space maintainer design software, utilizing three different materials: cobalt-chromium alloy, polyether ether ketone (PEEK), and titanium alloy. In ANSYS Work Beach 2023 R2 software, vertical loads of 70 N, tilted 45° along the long axis of the tooth loads of 70 N, and a 10 N load on the surface of the wire loop were applied to the occlusal surfaces of models 46 and 84, simulating centric and lateral occlusions during chewing with the wire loop space maintainer in place. The stress states of the wire loop space maintainer and supporting teeth were analyzed. RESULTS: Under various loading conditions, the maximum principal stress of the ring wire loop space maintainer was significantly lower than that of the full crown. Stress contour maps indicated that the peak of the maximum principal stress occurred at the junction of the wire loop and crown structure, indicating that this area was more susceptible to fracture. The ring wire loop space maintainer made from PEEK material exhibited the lowest maximum shear stress on the internal organizational surfaces, with equivalent stresses of 23.18 MPa and 36.35 MPa for models 46 and 84, respectively. Stress contour maps demonstrated that the maximum stress on tooth 46 was located at its mesial, while the maximum stress on tooth 84 was situated near the root area on its distal, in contact with the wire loop space maintainer. CONCLUSION In cases of second primary molar loss, wearing the digital ring wire loop space maintainer can effectively distribute stress, and the ring wire loop space maintainer made from PEEK material reduces the stress experienced by supporting teeth to some extent, demonstrating its superiority in clinical application.
Finite Element Analysis ; Humans ; Tooth, Deciduous ; Cone-Beam Computed Tomography ; Space Maintenance, Orthodontic/methods* ; Imaging, Three-Dimensional ; Orthodontic Wires ; Dental Stress Analysis ; Mandible ; Stress, Mechanical

BACKGROUND: Atrial fibrillation (AF) is a common cardiac arrhythmia in the elderly. This study aimed to evaluate urban-rural disparities in its prevalence and management in elderly Chinese. METHODS: Consecutive participants aged ≥ 65 years attending outpatient clinics were enrolled for AF screening using handheld single-lead electrocardiogram (ECG) from April 2017 to December 2022. Each ECG rhythm strip was reviewed from the research team. AF or uninterpretable single-lead ECGs were referred for 12-lead ECG. Primary study outcome comparison was between rural and urban areas for the prevalence of AF. The Student's t-test was used to compare mean values of clinical characteristics between rural and urban participants, while the Pearson's chi-square test was used to compare between-group proportions. Multivariate stepwise logistic regression analysis was performed to estimate the association between AF and various patient characteristics. RESULTS: The 29,166 study participants included 13,253 men (45.4%) and had a mean age of 72.2 years. The 7073 rural participants differed significantly (P ≤ 0.02) from the 22,093 urban participants in several major characteristics, such as older age, greater body mass index, and so on. The overall prevalence of AF was 4.6% (n = 1347). AF was more prevalent in 7073 rural participants than 22,093 urban participants (5.6% vs. 4.3%, P < 0.01), before and after adjustment for age, body mass index, blood pressure, pulse rate, cigarette smoking, alcohol consumption and prior medical history. Multivariate logistic regression analysis identified overweight/obesity (OR = 1.35, 95% CI: 1.17-1.54) in urban areas and cigarette smoking (OR = 1.62, 95% CI: 1.20-2.17) and alcohol consumption (OR = 1.42, 95% CI: 1.04-1.93) in rural areas as specific risk factors for prevalent AF. In patients with known AF in urban areas (n = 781) and rural areas (n = 338), 60.6% and 45.9%, respectively, received AF treatment (P < 0.01), and only 22.4% and 17.2%, respectively, received anticoagulation therapy (P = 0.05). CONCLUSIONS In China, there are urban-rural disparities in AF in the elderly, with a higher prevalence and worse management in rural areas than urban areas. Our study findings provide insight for health policymakers to consider urban-rural disparity in the prevention and treatment of AF.