Objective To establish a fluorescent recombinase-aided amplification (RAA) assay for detection of Strongyloides stercoralis nucleic acid and to preliminarily evaluate its performance. Methods Six sets of specific primers targeting S. stercoralis 18S ribosomal RNA (18S rRNA) gene and one fluorescent probe were designed and synthesized. The optimal primer-probe set was determined through systematic screening and optimization to establish the fluorescent RAA assay. The assay was evaluated using S. stercoralis genomic DNA at concentrations of 100, 10, and 1 pg/μL, and 100, 10, and 1 fg/μL, as well as recombinant pUC57 plasmids containing the target gene fragments at 1 × 10⁵, 1 × 10⁴, 1 × 10³, 1 × 10², 1 × 10¹, 1 × 10⁰ copies/reaction, to determine the analytical sensitivity. Genomic DNA from Ascaris lumbricoides, Ancylostoma duodenale, Enterobius vermicularis, Angiostrongylus cantonensis, Trichinella spiralis, Clonorchis sinensis, Schistosoma japonicum, and Taenia saginata was used to assess assay specificity. A total of 25 stool samples from patients suspected of S. stercoralis infection were tested by the modified Baermann funnel technique, PCR, and the established fluorescent RAA assay. The sensitivity, specificity, concordance rate and their 95% confidence intervals (CI) of these three techniques were estimated, and agreement between methods was evaluated using the Kappa coefficient. Results Exo-4 was identified as the optimal primer set screened from the six primer sets, and the best amplification performance was achieved when the final concentrations of the forward and reverse primers were 0.44 μmol/L and a probe concentration was 0.20 μmol/L. The limit of detection of the fluorescent RAA assay was 100 fg/μL for genomic DNA of S. stercoralis and 1 × 10⁰ copies/reaction for recombinant plasmids. Specific fluorescence signals were detected within 5 min, with no cross-reactivity observed with A. lumbricoides, A. duodenale, E. vermicularis, A. cantonensis, T. spiralis, C. sinensis, S. japonicum, or T. saginata. Among the 25 clinical stool samples from patients suspected of S. stercoralis infections, the modified Baermann funnel technique and fluorescent RAA assay detected 19 positives and 6 negatives, whereas PCR detected 18 positives and 7 negatives. The fluorescent RAA assay showed a sensitivity of 100.00% [95% CI: (82.35%, 100.00%)], specificity of 100.00% [95% CI: (54.07%, 100.00%)], concordance rate of 100.00% [95% CI: (86.28%, 100.00%)], and a Kappa coefficient of 1.00 [95% CI: (1.00, 1.00)] (P < 0.001) relative to the modified Baermann funnel technique, and a sensitivity of 100.00% [95% CI: (81.47%, 100.00%)], specificity of 85.71% [95% CI: (42.13%, 99.64%)], concordance rate of 96.00% [95% CI: (79.65%, 99.90%)], and a Kappa coefficient of 0.90 [95% CI: (0.70, 1.00)] (P < 0.001). Positive amplification products emitted green fluorescence under a portable blue-light device, enabling visual interpretation of results. Conclusions The fluorescent RAA assay established in this study is rapid, highly sensitive, and highly specific. It enables detection of S. stercoralis nucleic acid under isothermal conditions and allows visual interpretation of results, providing a novel tool for rapid clinical diagnosis and field screening of S. stercoralis infections.

Dendritic cells （DCs）， as key regulatory cells in the immune system， play a significant role in the pathogenesis of autoimmune diseases. This article reviews the mechanism of action of DCs and related research advances in autoimmune liver diseases （including autoimmune hepatitis， primary biliary cholangitis， and primary sclerosing cholangitis） and autoimmune pancreatitis. By summarizing the functions and heterogeneity of DCs in these diseases， this article reveals the crucial role of DCs in the imbalance of immune tolerance and chronic inflammation. Related research findings provide an important basis for a deep understanding of the role of DCs in autoimmune liver diseases and autoimmune pancreatitis and lay a foundation for the development of precise treatment strategies.

Objective To investigate the regulatory role of the programmed cell death protein 1 (PD-1) and its ligand programmed cell death protein ligand 1 (PD-L1) signaling on the subtypes and functions of natural killer (NK) cells at the maternal-fetal interface during the second trimester in mice following Toxoplasma gondii infection during the first trimester. Methods Twelve 6- to 8-week-old female mice of the C57BL/6J strain were divided into a control group and an infection group, of 6 mice in each group. On the 6.5th day of pregnancy (Gd6.5), each pregnant mouse in the infection group was intraperitoneally injected with 150 tachyzoites of the Toxoplasma gondii PRU strain, while mice in the control group were injected with an equal volume of physiological saline. On the 12.5th day of pregnancy (Gd12.5), uterus and placenta tissues were sampled from pregnant mice for pathological observations, and the mRNA expression levels of PD-1, PD-L1, and tumor necrosis factor-α (TNF-α) were quantified in uterus and placenta tissues. The PD-1 and DX5 expression was measured on NK cells at the maternal-fetal interface using flow cytometry. In addition, the in vitro JEG-3 trophoblast cells and NK-92MI cells co-culture system was established as the control group, and the addition of T. gondii tachyzoites in the co-culture system served as the infection group. The PD-1, PD-L1, and DX5 mRNA expression was quantified in cells using real-time fluorescence quantitative reverse transcription PCR (RT-qPCR) assay, and the TNF-α concentration was measured in the cell culture supernatant using enzyme-linked immunosorbent assay (ELISA). Results On Gd12.5, clear and intact cellular structures of placental decidual tissues were seen in pregnant mice in the control group, with no remarkable abnormal changes found in the uterine columnar epithelial cells, and inflammatory cell infiltration and blood stasis at varying degrees were found in uterine and placental tissues from pregnant mice in the infection group. The relative PD-1, PD-L1, and TNF-α mRNA expression was (1.004 ± 0.004), (1.001 ± 0.001), and (1.001 ± 0.001) in uterine tissues from pregnant mice in the control group and (2.480 ± 0.720), (3.355 ± 0.920), and (2.391 ± 0.073) in the infection group, respectively. The relative PD-1, PD-L1, and TNF-α mRNA expression was (1.007 ± 0.010), (1.006 ± 0.006), and (1.001 ± 0.001) in the uterine tissues in the control group and (6.948 ± 1.918), (3.225 ± 1.034), and (1.536 ± 0.150) in the infection group, respectively. The relative PD-1, PD-L1, and TNF-α mRNA expression was higher in both the uterine (t = 3.55, 4.43 and 33.02, all P values < 0.05) and placental tissues (t = 5.36, 3.72 and 6.18, all P values < 0.05) in the infection group than in the control group. Flow cytometry showed that the proportions of PD-1⁺ NK cells, PD-1⁺ DX5⁺ NK cells, and DX5⁺ NK cells were (12.200 ± 1.082)%, (9.373 ± 7.728)%, and (44.000 ± 4.095)% in uterine tissues from pregnant mice in the control group, and (21.733 ± 1.630)%, (18.767 ± 1.242)%, and (73.367 ± 0.611)% in the infection group, respectively. The proportions of PD-1⁺ NK cells, PD-1⁺ DX5⁺ NK cells, and DX5⁺ NK cells were (1.100 ± 0.510)%, (2.277 ± 1.337)%, and (96.167 ± 2.831)% in placental tissues from mice in the control group, and (26.867 ± 9.722)%, (23.433 ± 6.983)%, and (82.467 ± 2.248)% in the infection group, respectively. The proportions of PD-1⁺ NK cells (t = 8.45, P < 0.05) and DX5⁺ NK cells (t = 12.29, P < 0.05) were higher in uterine tissues from pregnant mice in the infection group than in the control group, and no significant difference was seen in the proportion of PD-1⁺ DX5⁺ NK cells (Z = -1.09, P > 0.05). The proportions of PD-1⁺ NK cells (t = 4.58, P < 0.05) and PD-1⁺ DX5⁺ NK cells (t = 5.15, P < 0.05) were higher in placental tissues from pregnant mice in the infection group than in the control group, while the proportion of DX5⁺ NK cells was lower in the infection group than in the control group (t = -6.56, P < 0.05). RT-qPCR assay revealed that the relative PD-1, PD-L1, and DX5 mRNA expression was (1.010 ± 0.005), (1.002 ± 0.003), and (1.001 ± 0.001) in the JEG-3 cells and NK92MI cells co-culture system and (3.638 ± 1.258), (0.397 ± 0.158), and (4.267 ± 1.750) in the control group, and ELISA measured that the TNF-α concentration was higher in the cell culture supernatant in the infection group [(22.056 ± 3.205) pg/mL] than in the control group [(12.441 ± 0.001) pg/mL] (t = 5.20, P < 0.05). The PD-1(t = 3.62, P < 0.05) and DX5 mRNA expression (t = 3.23, P < 0.05) was higher in the infection group than in the control group, and the PD-L1 mRNA expression was lower in the infection group than in the control group (t = -6.63, P < 0.05). Conclusions Following T. gondii infection, both PD-L1 expression and PD-1 expression on DX5⁺ NK cells at the maternal-fetal interface are upregulated in mice during the second trimester; however, the proportion of DX5⁺ NK cells decreases. These findings suggest that PD-1/PD-L1 signaling may suppress NK cell functions by modulating DX5⁺ NK cell subsets.

This article reports a patient with long-term ulcerative colitis (UC) who was initially diagnosed as eosinophilic gastroenteritis due to a increase in peripheral blood eosinophils. During the diagnosis and treatment process, acute myocardial infarction was repeatedly induced. The patient was eventually diagnosed as UC complicated by amoebic infection and improved after anti-infective therapy. Through case analysis and literature review, this article discusses the diagnosis and treatment strategies for UC complicated by rare opportunistic infections.

This article reports a patient with long-term ulcerative colitis (UC) who was initially diagnosed as eosinophilic gastroenteritis due to a increase in peripheral blood eosinophils. During the diagnosis and treatment process, acute myocardial infarction was repeatedly induced. The patient was eventually diagnosed as UC complicated by amoebic infection and improved after anti-infective therapy. Through case analysis and literature review, this article discusses the diagnosis and treatment strategies for UC complicated by rare opportunistic infections.

Objective:To explore the characteristics of SMN1 gene variants and carry out functional verification for two children with Spinal muscular atrophy (SMA). Methods:Two male children with complicated SMA diagnosed at the Children′s Hospital Affiliated to Capital Institute of Pediatrics respectively in July 2021 and April 2022 due to delayed or retrograde motor development were selected as the study subjects. Clinical data of the children were collected. Primary culture of skin fibroblasts was carried out, and peripheral blood samples were collected from both children and their parents. Multiplex ligation-dependent probe amplification, combined long-range PCR and nested PCR, and Sanger sequencing were carried out to detect the copy number and variants of the SMN1 gene. Absolute quantitative real-time PCR, Western blotting and immunofluorescence were used to determine the transcriptional level of the SMN gene, expression of the SMN protein, and the number of functional SMN protein complexes (gems body), respectively. This study was approved by Medical Ethics Committee of the Children′s Hospital Affiliated to Capital Institute of Pediatrics (Ethics No. SHERLLM2021009). Results:Child 1, a 1-year-old boy, was clinically diagnosed with type 1 SMA. Child 2, a 2-and-a-half-year-old boy, was clinically diagnosed with type 3 SMA. Both children were found to harbor a paternally derived SMN1 deletion and a maternally derived SMN1 gene variant, namely c. 824G>T (p.Gly275Val) and c. 884A>T (p.*295Leu). Compared with the normal controls and carriers, the levels of full-length SMN1 transcripts in their peripheral blood and skin fibroblast cell lines were significantly decreased ( P<0.05), and the levels of SMN protein normalized to that of β-actin, and the numbers of gems bodies in the primary fibroblast cells were also significantly lower ( P<0.05). Based on the guidelines from the American College of Medical Genetics and Genomics, both variants were classified as likely pathogenic (PS3+ PM3+ PM5+ PP3; PS3+ PM3+ PM4+ PP3). Following the diagnosis, both children had received nusinersen treatment. Although their motor function was improved, child 1 still died at the age of 2 due to severe pulmonary infection. The walking ability of child 2 was significantly improved, and his prognosis appeared to be good. Conclusion:Two cases of clinically complicated SMA have been confirmed by genetic testing and experimental studies, which has provided a reference for their accurate treatment.

Objective To discuss the clinical features,differential diagnosis and complication treatment of a patient with genetic visceral myopathy.Methods Medical history,physical examination and laboratory results of the patient were collected in detail.The pathology of previous surgery was reviewed.The patient's peripheral blood DNA was extracted and submitted for whole-exome sequencing.Subsequent Sanger sequencing was used to complete the pedigree verification of the mutation site.Results The patient was a young female presented with repeated in-complete intestinal obstruction since early childhood.She used to be misdiagnosed as Hirschsprung's disease for a long period and underwent multiple gastrointestinal segment resections.Her intestinal obstruction symptoms were temporarily relieved by surgeries,but severe diarrhea,mucus and bloody stools and malnutrition gradually occurred after the last operation.The patient had bacterial overgrowth in small intestinal tract and followed by intestinal op-portunistic infections secondary to chronic intestinal pseudo-obstruction.The symptoms improved after anti-infection and enteral element diet treatment.Further pathological consultation and whole-exome gene sequencing confirmed the diagnosis of visceral myopathy related to ATCG2 R148L mutation.Conclusions Patients with early onset of chronic intestinal pseudo-obstruction and have poor response to conventional treatment are recommended to perform genetic test.The patients with hereditary visceral myopathy are susceptible to opportunistic intestinal infection.At-tentions should also be paid to the prevention and treatment of complications to avoid unnecessary surgery.

BACKGROUND: Inflammatory bowel disease (IBD) imposes a significant economic and social burden in China. We aim to assess the epidemiological trends of IBD in China, and to predict the burden in the near future. METHODS: The incidence, mortality, prevalence, and disability-adjusted life year (DALYs) of IBD from 1990 to 2021 were obtained from Global Burden of Disease Study 2021. Estimated annual percentage change (EAPC), average annual percent change, total percent change, and age-period-cohort model were used to access trends. Bayesian age-period-cohort model was utilized to predict the risk of incidence and mortality. RESULTS: In 2021, IBD affected 168,077 people in China, with 24,941 new cases and 5640 deaths. The age-standardized rate (ASR) of incidence and death was 1.4 and 0.3, respectively. The incidence and prevalence in China were lower than the global and high socio-demographic index (SDI) regions, but the ASR of incidence and prevalence (EAPC: 2.93 and 2.54, respectively) had rapidly increased from 1990 to 2021. The ASR of death and DALYs had significantly decreased (EAPC: -3.05 and -2.93, respectively). Middle-aged and elderly populations faced a severe burden of incidence and prevalence, while the elderly population faced a severe mortality burden. It is projected that by 2035, the ASR of incidence will continue to rise, whereas the death rate will continue to decline. CONCLUSIONS The burden of IBD in China is serious and increasingly severe. Establishing a comprehensive disease management system in China will help better control the medical burden of IBD.
Humans ; China/epidemiology* ; Inflammatory Bowel Diseases/epidemiology* ; Male ; Global Burden of Disease/trends* ; Female ; Middle Aged ; Adult ; Prevalence ; Incidence ; Adolescent ; Aged ; Young Adult ; Bayes Theorem ; Disability-Adjusted Life Years ; Quality-Adjusted Life Years ; Child

Background/Aims: Crohn’s disease (CD) has a progressive nature and commonly perianal involvement. The aim of this study is to assess the prevalence, surgical treatment, and outcome of perianal fistulizing CD with associated risk factors in a large Chinese cohort. Methods: Hospitalized patients diagnosed with CD in our center were consecutively enrolled between January 2000 and December 2018. Transition of disease behavior was classified according to the presence or absence of penetrating behavior (B3 in the Montreal classification) at diagnosis and at a median follow-up of 102 months. Results: A total of 504 patients were included, of whom 207 (41.1%) were classified as B3 and 348 (69.0%) as L2/3 at follow-up. Transition of behavior to B3 was observed in 86 patients (17.1%). The incidence of perianal fistulizing lesions was 10.9% at 10 years with a final prevalence of 27.0% (n = 136) at the end of follow-up. Multivariate Cox regression identified independent risks of perianal fistulizing lesions for persistent B3 (hazard ratio, 4.72; 95% confidence interval, 1.91–11.66) and behavior transition of progressed to B3 (hazard ratio, 9.90; 95% confidence interval, 4.60–21.33). Perianal surgical treatments were performed in 104 patients (20.6%). Thirty-six cases (7.1%) were refractory, and it is independently associated with behavior of persistent B3 (P= 0.011). Conclusions Perianal fistulizing lesions occurred frequently in Chinese CD patients. Its incidence and refractory outcome were closely associated with the penetrating CD behavior. An additional risk of perianal fistulizing lesions was indicated for CD patients with behavior of progressing to B3, suggesting further attention.

Objective:To investigate the effect of S100 calcium-binding protein A9(S100A9)activation of nuclear factor kappa-B(NF-κB)on the upregulation of toll-like receptor 7(TLR7)expression and the release of inflammatory factors in microglia,as well as its underlying mechanism.Methods:The viability of BV2 microglia was assessed using CCK-8 kit.Transcriptome sequencing was employed to compare differential genes(DEGs)and identify target genes from the pool of differentially expressed genes.This analysis was complemented by GO analysis,KEGG enrichment analysis and the STRING database.The expression of TLR7 mRNA was verified by real time RT-PCR.The expressions of CD68 and CD206 were detected using immunofluorescence.The expressions of CD68,CD206,TLR7,p65,and p-p65 were detected using Western Blot.The level of interleukin 6(IL-6)and tumor necrosis factor alpha(TNF-α)were verified by ELISA.Results:Moderate concentrations of S100A9 had no inhibitory effect on microglial viability.Compared to the control group,the experimental group showed a significant increase in the expression level of CD68 pro-tein,while the CD206 protein was decreased.This suggests that S100A9 promotes the activation of BV2 microglia into pro-inflammatory types.TAK-242,an inhibitor of toll-like receptor 4(TLR4),significantly inhibited the expression levels of TNF-α and IL-6 after S100A9 stimulated BV2 cells.Activation of the TLR4/NF-κB pathway promoted the ex-pression of TLR7 protein.Conclusion:The moderate concentration of S100A9 can promote the polarization of microglia towards a proinflammatory direction.It also promotes the expression of TLR7 and the release of various inflammatory factors,including TNF-α and IL-6,through the activation of the TLR4/NF-κB pathway.This activation has an obvious proinflammatory effect.