As a pivotal strategy to alleviate the shortage of organ donors, xenotransplantation has achieved remarkable advances in both pre-clinical and clinical studies in recent years, driven by continuous optimization of gene modification techniques and immunosuppressive regimens. Nevertheless, clinical translation still confronts formidable challenges, including rejection and heightened infection risks, which severely compromise long-term graft survival. Consequently, the role of immunosuppressive regimens in xenotransplantation has become increasingly prominent. This article summarizes the mechanisms underlying xenogeneic immune rejection, the latest developments in immunosuppressive regimens, cutting-edge strategies for inducing immune tolerance and the major hurdles facing clinical xenotransplantation. It delves into potential optimization strategies and directions for future clinical research, aiming to offer theoretical insights and practical guidance for the safe and effective application of clinical xenotransplantation.

ObjectiveTo measure the distance from the surface of Fengfu （GV 16） to the deep important bony structures in children aged 4 to 8 years based on CT three-dimensional reconstruction technology， thereby providing imaging reference data for clinical acupuncture safe operations in terms of different age groups and needle insertion angles. MethodsCervical CT image data were collected from healthy children aged 4 to 8 years with five age groups （4-， 5-， 6-， 7-， 8-year-old groups）， 20 cases in each group. The images were imported into Mimics 21.0 software for three-dimensional reconstruction. The straight-line distances from the skin model surface of the Fengfu （GV 16） to the first underlying bony barrier （such as the lower edge of the occipital bone， the posterior arch of the atlas vertebra） were measured at intervals of 5° on both the transverse section （0° ± 35°） and the sagittal section （40° upward to 40° downward on the diagonal）. The correlation between the measured distance， age， and angle was analyzed. ResultsIn the transverse and sagittal sections， the measured distance from the skin surface to the underlying bone of Fengfu （GV 16） at each angle increased with age. In the transverse section， the increase was relatively small within the 0° to 20° angle range， whereas a more pronounced increase was observed when the angle exceeded 20°； at measurement angles of 30° to 35°， the distance of the skin surface to the bone at Fengfu （GV 16） in the 7- and 8-year-old groups was significantly greater than that in the 4-year-old group （P＜0.05）. In the sagittal section， the measured distance from the skin surface to the bone at Fengfu （GV 16） was shortest and changed greatly at oblique upward angles of 15° to 40° within each age group， and increased markedly at near-vertical angles of 0° to 10°； it was longest at oblique downward angles of -40° to -5° and showed relatively gradual changes. ConclusionThis study obtained the imaging distance data from Fengfu （GV 16） to the surrounding bony structures in children aged 4 to 8 years through three-dimensional modeling， finding that this distance has clear age and angle dependence， which can provide quantitative evidence for developing individualized and precise safe acupuncture schemes at Fengfu （GV 16） in pediatric clinical practice.

ObjectiveTo measure the distance from the surface of Fengfu （GV 16） to the deep important bony structures in children aged 4 to 8 years based on CT three-dimensional reconstruction technology， thereby providing imaging reference data for clinical acupuncture safe operations in terms of different age groups and needle insertion angles. MethodsCervical CT image data were collected from healthy children aged 4 to 8 years with five age groups （4-， 5-， 6-， 7-， 8-year-old groups）， 20 cases in each group. The images were imported into Mimics 21.0 software for three-dimensional reconstruction. The straight-line distances from the skin model surface of the Fengfu （GV 16） to the first underlying bony barrier （such as the lower edge of the occipital bone， the posterior arch of the atlas vertebra） were measured at intervals of 5° on both the transverse section （0° ± 35°） and the sagittal section （40° upward to 40° downward on the diagonal）. The correlation between the measured distance， age， and angle was analyzed. ResultsIn the transverse and sagittal sections， the measured distance from the skin surface to the underlying bone of Fengfu （GV 16） at each angle increased with age. In the transverse section， the increase was relatively small within the 0° to 20° angle range， whereas a more pronounced increase was observed when the angle exceeded 20°； at measurement angles of 30° to 35°， the distance of the skin surface to the bone at Fengfu （GV 16） in the 7- and 8-year-old groups was significantly greater than that in the 4-year-old group （P＜0.05）. In the sagittal section， the measured distance from the skin surface to the bone at Fengfu （GV 16） was shortest and changed greatly at oblique upward angles of 15° to 40° within each age group， and increased markedly at near-vertical angles of 0° to 10°； it was longest at oblique downward angles of -40° to -5° and showed relatively gradual changes. ConclusionThis study obtained the imaging distance data from Fengfu （GV 16） to the surrounding bony structures in children aged 4 to 8 years through three-dimensional modeling， finding that this distance has clear age and angle dependence， which can provide quantitative evidence for developing individualized and precise safe acupuncture schemes at Fengfu （GV 16） in pediatric clinical practice.

Circadian rhythm is an endogenous biological clock mechanism that enables organisms to adapt to the earth’s alternation of day and night. It plays a fundamental role in regulating physiological functions and behavioral patterns, such as sleep, feeding, hormone levels and body temperature. By aligning these processes with environmental changes, circadian rhythm plays a pivotal role in maintaining homeostasis and promoting optimal health. However, modern lifestyles, characterized by irregular work schedules and pervasive exposure to artificial light, have disrupted these rhythms for many individuals. Such disruptions have been linked to a variety of health problems, including sleep disorders, metabolic syndromes, cardiovascular diseases, and immune dysfunction, underscoring the critical role of circadian rhythm in human health. Among the numerous systems influenced by circadian rhythm, the skin—a multifunctional organ and the largest by surface area—is particularly noteworthy. As the body’s first line of defense against environmental insults such as UV radiation, pollutants, and pathogens, the skin is highly affected by changes in circadian rhythm. Circadian rhythm regulates multiple skin-related processes, including cyclic changes in cell proliferation, differentiation, and apoptosis, as well as DNA repair mechanisms and antioxidant defenses. For instance, studies have shown that keratinocyte proliferation peaks during the night, coinciding with reduced environmental stress, while DNA repair mechanisms are most active during the day to counteract UV-induced damage. This temporal coordination highlights the critical role of circadian rhythms in preserving skin integrity and function. Beyond maintaining homeostasis, circadian rhythm is also pivotal in the skin’s repair and regeneration processes following injury. Skin regeneration is a complex, multi-stage process involving hemostasis, inflammation, proliferation, and remodeling, all of which are influenced by circadian regulation. Key cellular activities, such as fibroblast migration, keratinocyte activation, and extracellular matrix remodeling, are modulated by the circadian clock, ensuring that repair processes occur with optimal efficiency. Additionally, circadian rhythm regulates the secretion of cytokines and growth factors, which are critical for coordinating cellular communication and orchestrating tissue regeneration. Disruptions to these rhythms can impair the repair process, leading to delayed wound healing, increased scarring, or chronic inflammatory conditions. The aim of this review is to synthesize recent information on the interactions between circadian rhythms and skin physiology, with a particular focus on skin tissue repair and regeneration. Molecular mechanisms of circadian regulation in skin cells, including the role of core clock genes such as Clock, Bmal1, Per and Cry. These genes control the expression of downstream effectors involved in cell cycle regulation, DNA repair, oxidative stress response and inflammatory pathways. By understanding how these mechanisms operate in healthy and diseased states, we can discover new insights into the temporal dynamics of skin regeneration. In addition, by exploring the therapeutic potential of circadian biology in enhancing skin repair and regeneration, strategies such as topical medications that can be applied in a time-limited manner, phototherapy that is synchronized with circadian rhythms, and pharmacological modulation of clock genes are expected to optimize clinical outcomes. Interventions based on the skin’s natural rhythms can provide a personalized and efficient approach to promote skin regeneration and recovery. This review not only introduces the important role of circadian rhythms in skin biology, but also provides a new idea for future innovative therapies and regenerative medicine based on circadian rhythms.

Organ transplantation faces the challenge of a shortage of donors. Although xenotransplantation holds great potential, it is limited by rejection. Extracellular histones, as key members of damage-associated molecular patterns, have been proven in recent years to play a crucial role in transplant rejection by activating innate immunity, regulating the coagulation-inflammation network, and modulating adaptive immune responses. However, the specific functions and key mechanisms remain to be clarified. Therefore, this article reviews the structural characteristics of histones, their release pathways, the biological functions of extracellular histones, and their potential roles in xenotransplantation. It summarizes the latest research progress of extracellular histones in xenotransplantation, analyzes the shortcomings of existing research and the direction for future research, with the expectation of providing references for the application of extracellular histones in xenogeneic kidney transplantation.

The study aims to investigate the impacts of prolyl oligopeptidase (POP) on the replication of foot-and-mouth disease virus (FMDV) in BHK-21 cells. Firstly, the effects of FMDV replication on POP expression in BHK-21 cells were analyzed by Western blotting and Real-time reverse transcription polymerase chain reaction (RT-qPCR). Secondly, a eukaryotic expression plasmid for POP was constructed, and the effects of POP overexpression on the replication of two different serotypes of FMDV were assessed by Western blotting, RT-qPCR, and virus titer assays. Thirdly, specific small interfering RNAs (siRNAs) targeting POP were synthesized, and their efficiency in interfering with endogenous POP expression was identified by RT-qPCR. The impacts of downregulating endogenous POP expression on FMDV replication were further evaluated by Western blotting, RT-qPCR, and virus titer assays. The results indicated that FMDV infection did not significantly affect POP expression in BHK-21 cells. Overexpression of POP dose-dependently enhanced the replication of both FMDV/O and FMDV/A serotypes. Conversely, siRNA-mediated downregulation of endogenous POP expression markedly suppressed FMDV/O replication. This study is the first to demonstrated that the role of the host POP protein in promoting FMDV replication in BHK-21 cells, thereby providing a critical theoretical foundation and potential molecular targets for developing efficient candidate cell strains for foot-and-mouth disease inactivated vaccines.
Foot-and-Mouth Disease Virus/genetics* ; Virus Replication/genetics* ; Prolyl Oligopeptidases ; Serine Endopeptidases/physiology* ; Animals ; Cell Line ; RNA, Small Interfering/genetics* ; Foot-and-Mouth Disease/virology* ; Cricetinae

Senecavirus A (SVA) is a major viral pathogen causing disease in pigs, and effective monitoring of SVA infection is critical for disease control. In this study, we aimed to develop a reliable ELISA method for rapidly detecting neutralizing antibodies against SVA. We used HEK293F cells to express an SVA-specific porcine Fab antibody and verified the biological activity of the Fab antibody by indirect ELISA, immunofluorescence assay, virus neutralization test, and Western blotting. The Fab antibody was biotinylated and used as a competitive antibody to establish a competitive ELISA (C-ELISA) for detecting neutralizing antibodies against SVA. We then evaluated the C-ELISA in terms of sensitivity, specificity, repeatability, and result agreement rate with the VNT. The results showed that we successfully prepared an SVA-specific porcine Fab antibody, which showed high affinity for SVA. We named this antibody 1M33Fab and designated it as Bio-1M33Fab after biotin labeling. The assay conditions were optimized as follows: the coating concentration of SVA particles being 1 μg/mL, the working concentration of Bio-1M33Fab being 0.5 μg/mL, the optimal serum dilution of 1:10, and the optimal dilution of enzyme-labeled avidin being 1:30 000. At a percent inhibition (PI) of 47%, the assay demonstrated the highest sensitivity (96.88%) and specificity (100%), with no cross-reactivity observed with the positive sera of major porcine viral diseases. The intra-assay coefficient of variation ranged from 1.12% to 7.34%, while the inter-assay coefficient of variation ranged from 1.10% to 8.97%, indicating good repeatability. In the detection of 224 clinical pig serum samples, C-ELISA and VNT showed a result agreement rate of 93.75%. In conclusion, we successfully develop a C-ELISA method for detecting neutralizing antibodies against SVA by using a porcine-derived Fab antibody, which lays a foundation for the development of detection kits.
Animals ; Swine ; Antibodies, Neutralizing/immunology* ; Enzyme-Linked Immunosorbent Assay/methods* ; Immunoglobulin Fab Fragments/immunology* ; Antibodies, Viral/immunology* ; Picornaviridae/immunology* ; Humans ; HEK293 Cells ; Swine Diseases/diagnosis* ; Picornaviridae Infections/diagnosis*

Objective To study the effects of Hedysarum polysaccharides polysaccharide(HPS)on the farnesoid X receptor(FXR)-fibroblast growth factor-19(FGF19)signaling pathway of diabetes rats.Methods Twelve Wistar male rats were randomly selected as the normal group,and the other rats were fed with a single intraperitoneal injection of streptozotocin(50 mg·kg-1 STZ)and a high sugar and high-fat diet to replicate the diabetes rat model.Model rats were randomly divided into model group,positive control group(given 400 mg·kg-1·d-1 suspension of Bifidobacterium quadruplex live bacterial tablets by gavage),experimental-H,-M,-L groups(given 200,100,and 50 mg·kg-1·d-1 doses of HPS suspension by gavage);normal group,and model group were given equal volume of purified water by gavage once a day for 8 consecutive weeks.Glucose(Glu)was detected by a blood glucose meter;and serum total glyceride(TG)and total cholesterol(TC)were detected by enzyme-linked immunosorbent assay reagent kit;the expressions of FXR、fibroblast growth factor receptors 4(FGFR4)relative mRNA expression level and protein were detected by real-time fluorescence quantitative polymerase chain reaction method and Western blot.Results The Glu concentrations in the normal group,model group,positive control group,and experimental-H groups were(7.66±0.61),(29.25±1.64),(23.31±3.02)and(19.31±5.13)mmol·L-1,respectively;the TG content were(957.00±113.73),(1 345.00±246.44),(958.00±96.53)and(964.00±130.22)μmol·L-1,respectively;the TC content were(161.65±4.53),(302.19±5.35),(236.09±5.14)and(165.58±2.58)μmol·L-1,respectively;the expression of FXR relative mRNA expression level were 1.00±0.06,0.48±0.02,0.67±0.04 and 0.92±0.04,respectively;the expression of FGFR4 relative mRNA expression level were 1.00±0.04,0.17±0.01,0.48±0.04 and 0.41±0.03;respectively.The above indexes of the model group were compared with the control group,and the above indexes of the control group and the experimental-H group were compared with the model group,and the differences were statistically significant(all P＜0.01).Conclusion HPS improves blood sugar,lowers blood lipids,and protects liver and intestinal tissues,possibly by regulating the FXR-FGF19 signaling pathway in intestinal tissue,and regulating bile acid synthesis.

Debates persist regarding the efficacy and safety of azvudine, particularly its real-world outcomes. This study involved patients aged ≥60 years who were admitted to 25 hospitals in mainland China with confirmed SARS-CoV-2 infection between December 1, 2022, and February 28, 2023. Efficacy outcomes were all-cause mortality during hospitalization, the proportion of patients discharged with recovery, time to nucleic acid-negative conversion (T _NANC), time to symptom improvement (T _SI), and time of hospital stay (T _HS). Safety was also assessed. Among the 5884 participants identified, 1999 received azvudine, and 1999 matched controls were included after exclusion and propensity score matching. Azvudine recipients exhibited lower all-cause mortality compared with controls in the overall population (13.3% vs. 17.1%, RR, 0.78; 95% CI, 0.67-0.90; P = 0.001) and in the severe subgroup (25.7% vs. 33.7%; RR, 0.76; 95% CI, 0.66-0.88; P < 0.001). A higher proportion of patients discharged with recovery, and a shorter T _NANC were associated with azvudine recipients, especially in the severe subgroup. The incidence of adverse events in azvudine recipients was comparable to that in the control group (2.3% vs. 1.7%, P = 0.170). In conclusion, azvudine showed efficacy and safety in older patients hospitalized with COVID-19 during the SARS-CoV-2 omicron wave in China.

Neuropathic pain is a chronic condition caused by damage or dysfunction in the nervous system. While the spleen may influence neuropathic pain, its role has been poorly understood. This study demonstrates that the spleen plays a crucial role in regulating neuropathic pain through the bed nucleus of the stria terminalis (BNST) - paraventricular nucleus of the hypothalamus (PVN) neural circuit in a chronic constriction injury (CCI) mouse model. Splenectomy, splenic denervation, or splenic sympathectomy significantly increased the mechanical withdrawal threshold (MWT) and reduced macrophage infiltration in the dorsal root ganglia (DRG) of CCI mice. Pseudorabies virus injections into the spleen revealed connections to the BNST and PVN in the brain. Chemogenetic inhibition of the BNST-PVN circuit increased macrophage infiltration in the DRG and decreased the MWT; these effects were reversed by splenectomy, splenic denervation, or sympathectomy. These findings underscore the critical role of the spleen, regulated by the BNST-PVN circuit, in neuropathic pain.
Animals ; Neuralgia/pathology* ; Septal Nuclei/physiopathology* ; Male ; Spleen/physiopathology* ; Paraventricular Hypothalamic Nucleus/physiopathology* ; Mice, Inbred C57BL ; Splenectomy ; Mice ; Neural Pathways/physiopathology* ; Disease Models, Animal ; Ganglia, Spinal/physiopathology* ; Sympathectomy ; Macrophages