Objective: To investigate the mechanism of shed syndecan-4 (sSDC4) in temporomandibular joint osteoarthritis (TMJOA) in rats, aiming to provide experimental evidence for its prevention and treatment. Methods: This study was approved by the Institutional Animal Ethics Committee. Twelve 6-week-old female Sprague Dawley (SD) rats were randomly divided into two groups. They received a single intra-articular injection into the bilateral superior cavity of temporomandibular joint, which consisted of either 50 μL of 4 mg/mL monosodium iodoacetate (TMJOA model group) or 50 μL of phosphate-buffered saline (PBS, control group). After 4 weeks, the mandibular condylar cartilage was harvested for hematoxylin & eosin (H&E) staining, Safranin O-fast green (SO) staining, and type II collagen (Col-Ⅱ) immunohistochemical staining to assess the degree of cartilage degeneration. The synovium of the temporomandibular joint was collected for immunohistochemical staining to detect the expression levels of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) to evaluate the degree of synovial inflammation. Synovial fluid from the temporomandibular joint cavity was collected to measure sSDC4 levels by enzyme-linked immunosorbent assay (ELISA). In addition, 12 6-week-old female SD rats were randomly divided into a His-SDC4 group and a control group, receiving injections into the bilateral superior cavity of temporomandibular joint of either 100 ng/mL (50 μL) of His-SDC4 protein or 50 μL of PBS once every 3 days for a total of 28 days. The same experimental procedures were performed for H&E staining, SO staining, and immunohistochemical staining (Col-Ⅱ IL-6, TNF-α) to observe condylar cartilage degeneration and detect synovial inflammation. Rat synovial fibroblasts and condylar chondrocytes were cultured in vitro and randomly divided into a His-SDC4-stimulated (10 ng/mL) group and control group. Perform CCK-8 cytotoxicity assays and observe cellular morphology under optical microscopy, the mRNA expression levels of IL-6 and TNF-α were detected by real-time quantitative polymerase chain reaction (RT-qPCR), and the levels of IL-6 and TNF-α in cell culture supernatants were measured by ELISA. Results: Compared with the control group, the TMJOA group showed decreased condylar cartilage thickness, percentage of SO-positive area, and percentage of Col-Ⅱ-positive area (all P<0.001); an increased synovitis score (P<0.001) and increased percentages of IL-6- and TNF-α-positive cells in the synovium (all P<0.001); and a significant increase in sSDC4 levels in the synovial fluid (P=0.011). Following intra-articular injection of His-SDC4, condylar cartilage thickness, percentage of SO-positive area, and percentage of Col-Ⅱ-positive area all decreased (all P<0.001); the synovitis score increased (P=0.006), and the percentages of IL-6- and TNF-α-positive cells in the synovium increased (all P<0.001). In vitro experiments showed that His-SDC4 stimulation significantly upregulated the expression levels of IL-6 and TNF-α in both synovial fibroblasts and condylar chondrocytes (all P<0.01), and the levels of these two cytokines in the culture supernatants also significantly increased (all P<0.01). Conclusion During TMJOA progression, the level of sSDC4 in the synovial fluid is significantly elevated, which can directly stimulate synovial fibroblasts and condylar chondrocytes to secrete more pro-inflammatory cytokines, forming a vicious cycle that accelerates TMJOA progression.

Isoflavones which mainly distributed in leguminous plants have plenty of health benefits.Isoflavone synthase(IFS)is a membrane-associated cytochrome P450 enzyme(CYP450)which carries out the unique aryl-ring migration and hydroxylation.So far,few crystal structures of plant P450s have been obtained.We determined the crystal structure of IFS from Medicago truncatula at 1.9 ? by MAD method using a selenomethionine substituted crystal and conducted molecular docking and mutagenesis study.The structure of IFS complexed with imidazole exhibits the helix Ⅰa-loop-helix Ⅰβ motif which cor-responds to helix Ⅰ of other P450s.Compared with structures of common P450s,IFS/imidazole structure contains an extra domain,i.e.,the γ-domain.The structure reveals a homodimer in which the γ-domain of one molecule interacts with the β-domain of another.The plane of heme group makes an angle of ap-proximately 40° with the helix Ⅰa-loop-helix Ⅰβ motif.Molecular docking combined with mutagenesis study suggested that Trp-128 and Asp-300 might play important roles in substrate binding and recogni-tion.Phe-301,Ser-303 and Gly-305 from the helix Ⅰa-loop-helix Ⅰβ motif may play important roles in the aryl-ring migration.These novel structural features reveal insights into the unique reaction mechanism of IFS and provide a basis for engineering IFS in leguminous crops for health purpose.

Objective:Varicocele(VC)induces male infertility by mediating changes in the testicular microenvironment,in which testicular hypoxia and high-pressure are important pathological conditions.This study aims to compare the mouse spermatogenesis(GC-2spd)cells and Sertoli(TM4)cells of mouse testis after hypoxic modeling and hypoxic and high-pressure combined modeling,and to explore the feasibility of establishing a hypoxic and high-pressure combined cell model.Methods:On the basis of cell hypoxia induced by CoCl2,the complex model of testicular cell hypoxia and high pressure was constructed by changing the osmotic pressure of GC-2 and TM4 cell medium with a high concentration of NaCl solution.After selecting the intervention concentration of CoCl2 by MTT test and detecting the expression level of HIF-1α for the determination of the optimal osmotic pressure conditions of the cell model,the cells were divided into normal group,hypoxia model group and composite model group.And the levels of OS,programmed cell death,inflammatory factors,and the expression levels of pyroptosis-related proteins were compared between the normal group and the groups with different modeling methods.Results:The optimal intervention concentration of CoCl2 in GC-2 and TM4 cells was 150 and 250μmol/L,respectively,and the expression of HIF-1α was the highest in both cells under osmotic pressure of 500 mOsmol/kg(P＜0.05).Compared with the normal group,the SOD levels of GC-2 and TM4 cells decreased(all P＜0.05),CAT level decreased(all P＜0.05),and MDA level increased(all P＜0.01),and the OS level of GC-2 and TM4 cells was more obvious than that of the hy-poxia model group(all P＜0.05).Compared with the normal group,apoptosis occurred in GC-2 and TM4 cells after composite model-ing(all P＜0.05).Compared with the normal group,the mRNA expressions of IL-1β,IL-18,TNF-α and COX-2 in GC-2 and TM4 cells significantly increased(P＜0.01)and higher than those in hypoxia model group(P＜0.05)and induced pyroptosis(P＜0.01).The expression level of GSDMD increased(P＜0.05).Conclusion:The cell model with hypoxia and high pressure com-bined modeling can not only induce oxidative stress and apoptosis of cells better than that with hypoxia alone,but also further cause in-flammatory response damage and pyroptosis,which simulates the changes of testis microenvironment mediated by hypoxia and high pressure combined conditions in VC.This cell model can be used for studying the pathogenesis of VC-associated male infertility,evalu-ating drug efficacy,and exploring pharmacological mechanisms.

Accurate timing of myelination is crucial for the proper functioning of the central nervous system. Here, we identified a de novo heterozygous mutation in TMEM63A (c.1894G>A; p. Ala632Thr) in a 7-year-old boy exhibiting hypomyelination. A Ca²⁺ influx assay suggested that this is a loss-of-function mutation. To explore how TMEM63A deficiency causes hypomyelination, we generated Tmem63a knockout mice. Genetic deletion of TMEM63A resulted in hypomyelination at postnatal day 14 (P14) arising from impaired differentiation of oligodendrocyte precursor cells (OPCs). Notably, the myelin dysplasia was transient, returning to normal levels by P28. Primary cultures of Tmem63a^-/- OPCs presented delayed differentiation. Lentivirus-based expression of TMEM63A but not TMEM63A_A632T rescued the differentiation of Tmem63a^-/- OPCs in vitro and myelination in Tmem63a^-/- mice. These data thus support the conclusion that the mutation in TMEM63A is the pathogenesis of the hypomyelination in the patient. Our study further demonstrated that TMEM63A-mediated Ca²⁺ influx plays critical roles in the early development of myelin and oligodendrocyte differentiation.
Animals ; Cell Differentiation/physiology* ; Oligodendroglia/metabolism* ; Mice, Knockout ; Mice ; Male ; Myelin Sheath/metabolism* ; Humans ; Child ; Cells, Cultured ; Oligodendrocyte Precursor Cells/metabolism*

Psoraleae Fructus is derived from the dried fruit of the Psoralea corylifolia L. It has the effects of tonifying the kidney, strengthening the Yang, warming the spleen and stopping diarrhea, and is used for the treatment of kidney deficiency and impotence, lumbar soreness and cold pain, osteoporosis and other diseases, and it is a commonly used tonic traditional Chinese medicine in Chinese medicine clinics in China. However, in recent years, the clinical adverse reactions of Psoraleae Fructus (PF) and related preparations have been increasingly reported, especially hepatotoxicity, which has become a bottleneck in the clinical application of PF and associated preparations. The safety of PF was rarely recorded in ancient texts, but modern clinical and experimental research has shown that PF not only has direct toxicity but also has immune-idiosyncratic toxicity. For this reason, this study comprehensively analyzes the evolution of PF effect/toxicity records in ancient and modern canonical literature, and combines with the progress of modern pharmacology and toxicology research, to conduct an in-depth discussion on the clinical characteristics, causative mechanisms and risk factors of PF hepatotoxicity. On this basis, based on the three-dimensional "human-medicine-use" precise prevention and control strategy for the safety risk of traditional Chinese medicine proposed by the author's team, safety risk prevention and control measures for PF and related preparations were developed, aiming at guiding the safe and rational use of PF and related preparations in the clinic and promoting the healthy and sustainable development of PF-related industries.

[Objective] To explore the effectiveness of applying the PDCA (Plan-Do-Check-Act) cycle to enhance the compatibility rate of five Rh blood group antigen phenotypes between donors and recipients across multiple hospital campuses. [Methods] Clinical blood transfusion data from May to July 2022 were selected. Specific improvement measures were formulated based on the survey results, and the PDCA cycle management model was implemented from August 2022. The post-intervention phase spanned from August 2022 to October 2023. The Rh phenotype compatibility rate, the detection rate of Rh system antibodies, and the proportion of Rh system antibodies among unexpected antibodies were compared between the pre-intervention phase (May to July 2022) and the post-intervention phase. [Results] After the continuous improvement with the PDCA cycle, the compatibility rate for the five Rh blood group antigen phenotypes between donors and recipients from August to October 2023 reached 81.90%, significantly higher than the 70.54% recorded during the pre-intervention phase (May to July 2022, P<0.01), and displayed a quarterly upward trend (β=0.028, P<0.05). The detection rate of Rh blood group system antibodies (β=-9.839×10^-5, P<0.05) and its proportion among all detected antibodies (β=-0.022, P<0.05) showed a quarterly decreasing trend, both demonstrating a negative correlation with the enhanced compatibility rate (r values of -0.981 and -0.911, respectively; P<0.05). [Conclusion] The implementation of targeted measures through the PDCA cycle can effectively increase the compatibility rate of five Rh blood group antigen phenotypes between donors and recipients, reduce the occurrence of unexpected Rh blood group antibodies, thereby lowering the risk of transfusion and enhancing the quality and safety of medical care.

Isoflavones which mainly distributed in leguminous plants have plenty of health benefits.Isoflavone synthase(IFS)is a membrane-associated cytochrome P450 enzyme(CYP450)which carries out the unique aryl-ring migration and hydroxylation.So far,few crystal structures of plant P450s have been obtained.We determined the crystal structure of IFS from Medicago truncatula at 1.9 ? by MAD method using a selenomethionine substituted crystal and conducted molecular docking and mutagenesis study.The structure of IFS complexed with imidazole exhibits the helix Ⅰa-loop-helix Ⅰβ motif which cor-responds to helix Ⅰ of other P450s.Compared with structures of common P450s,IFS/imidazole structure contains an extra domain,i.e.,the γ-domain.The structure reveals a homodimer in which the γ-domain of one molecule interacts with the β-domain of another.The plane of heme group makes an angle of ap-proximately 40° with the helix Ⅰa-loop-helix Ⅰβ motif.Molecular docking combined with mutagenesis study suggested that Trp-128 and Asp-300 might play important roles in substrate binding and recogni-tion.Phe-301,Ser-303 and Gly-305 from the helix Ⅰa-loop-helix Ⅰβ motif may play important roles in the aryl-ring migration.These novel structural features reveal insights into the unique reaction mechanism of IFS and provide a basis for engineering IFS in leguminous crops for health purpose.

Objective To analyze the epidemiological characteristics of confirmed malaria cases reported by hospitals in Beijing from 2014 to 2023 among individuals who traveled abroad within the previous year and to provide a scientific basis for preventing the re-transmission of imported malaria. Methods Case data were derived from the“China Information System for Disease Control and Prevention. ”Imported malaria cases reported in Beijing from January 1, 2014, to December 31, 2023, were selected. Descriptive epidemiological method were applied for the analyses. The chi-square test was used to compare the infected species and the distribution of occupation and year among imported malaria cases with different onset times. The Mann-Whitney U test was used to compare the time interval from the return date to diagnosis between recurrent cases and cases diagnosed for the first time, as well as the difference between cases with disease onset before and after entry. Results A total of 334 imported malaria cases were included in this study. The cases were mainly young and middle-aged males(91.32%), and 135 cases(40.42%)were employees of large state-owned enterprises. Falciparum malaria accounted for the highest proportion(84.73%), and 94.61% of all confirmed imported malaria cases were from Africa. For the recurrent and first-diagnosed cases, the difference in the time interval from entry to diagnosis was statistically significant(U=2129.500, P＜ 0.05). Among patients with disease onset over 7 days after entry, the proportion of falciparum malaria was lower than those of other types of malaria infections(χ2=11.180, P=0.004). Conclusions Imported falciparum malaria from Africa remains the main challenge to maintaining and consolidating China's achievements in malaria elimination. It is recommended to further strengthen health education for outbound workers and port inspection for key inbound personnel, standardize epidemiological investigations and information notifications, and comprehensively enhance the capability for detecting and managing imported malaria cases.

Objective To understand the molecular genetic background of the reported case of reemerging visceral leishmaniasis in Beijing.Methods The PCR was used to amplify the hydrophilic acylated surface protein B(K26)gene and internal transcribed spacer 1(ITS-1)sequence of ribosomal DNA.The amplified fragments were cloned and sequenced to analyze their genetic polymorphisms and to construct phylogenetic trees to determine the causative parasitic species in the infected patient and its genetic relationships.Results The K26 gene yielded a 626 bp amplicon,which exhibited significant differences in length compared to domestic epidemic strains.The amino acid sequence of this amplicon consisted of a repetitive arrangement of a 14-amino-acid motif,but amino acid substitutions were observed at certain positions.Phylogenetic analysis of the K26 sequence revealed that the Beijing strain was closely related to Leishmania infantum strains from France and Spain but distant from those in other regions of China,such as Xinjiang,Sichuan,and Hebei.Moreover,phylogenetic analysis of a 314 bp fragment amplified from the ITS-1 sequence also showed that the Beijing strain belonged to the same branch as L.infantum strains.Conclusion These results indicate that the infection in this patient was caused by L.infantum,with the strain having some differences from those in other endemic areas in China.

Objective This study aimed to understand the infection rates of Leishmania parasites in sandflies,dogs,and humans in Wangping Street,Mentougou District,Beijing,to provide decision-making recommendations for the prevention and control of the Leishmania infection(Kala-Azar).Methods From early April to late November 2021,sandflies were trapped to screen for Leishmania parasites using Leishmania-specific PCR in Mentougou District,Beijing.Simultaneously,residents and suspected dogs were tested to detect possible Leishmania infections using the rk39 immunochromatographic test strip and Leishmania-specific PCR tests.Results A total of 4 280 Phlebotomus chinensis were captured from Mentougou District and no Leishmania parasites were detected.Nine of 36 suspected sick dogs tested positive for Leishmania parasites.No positive human blood samples were obtained from the 73 residents around the index patient's activity area.Conclusions A canine Kala-Azar outbreak occurred in Wangping town.Timely surveillance and control measures are urgently needed in the Mentougou District.