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.

To establish an immunochromatographic method for rapid detection of caprine enterovir-us(CEV),the monoclonal antibody against CEV VP1 protein was used as gold-labeled monoclonal antibodies,and the purified rabbit-derived polyclonal antibody of CEV-VP1 and sheep anti-mouse IgG were used as the detection line and quality control line,respectively.The colloidal gold immu-nochromatographic test strips for CEV were prepared according to the principle of double antibody sandwich,evaluated,and applied for clinical specimen detection.The results showed that the meth-od specifically recognized CEV without cross-reaction with bovine enterovirus and bovine viral di-arrhea virus.The minimum detection limit of the method was 102.49 TCID50/mL and had good re-producibility.The prepared test strips had a shelf life of three months kept at 4 ℃.Detection of clin-ical samples using the immunochromatographic test strips showed 100％coincidence rate with RT-PCR method.In conclusion,the colloidal gold immunochromatographic test strips for detection of the emerging CEV with good specificity,sensitivity and repeatability,which provides a new techni-cal means easily used for the rapid detection/diagnosis and epidemiological investigation on CEV infection.

Objective To investigate the antibacterial activity of the antifungal peptide Mt6-21DLeu derived from Musca domestica against Acinetobacter baumannii (AB) and unravel its underlying mechanisms, so as to provide insights into development of novel agents against AB. Methods The minimum inhibitory concentrations (MICs) of Mt6-21DLeu, M. domestica-derived antifungal peptide-1 (MAF-1A), and polymyxin B were determined against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and AB using the broth microdilution assay, and the antibacterial activity of Mt6-21DLeu and polymyxin B was dynamically assessed against AB over 24 hours with time-kill curves. The inhibitory effects of Mt6-21DLeu and polymyxin B on biofilm formation in AB at concentrations of 1/4 × MIC, 1/2 × MIC and MIC, and the eradication effects of Mt6-21DLeu and polymyxin B on mature biofilms in AB at concentrations of MIC, 2 × MIC, and 4 × MIC were evaluated using crystal violet staining. Structural changes in the cell membrane of AB were observed 3 hours post-exposure to Mt6-21DLeu at concentrations of MIC and 2 × MIC using scanning electron microscopy, and alterations in the cell membrane permeability of AB were analyzed 3 hours post-treatment with Mt6-21DLeu at concentrations of MIC and 2 × MIC by means of fluorescence microscopy and propidium iodide (PI) staining. Intracellular reactive oxygen species (ROS) levels in AB were measured 3 hours post-treatment with Mt6-21DLeu at concentrations of MIC, 2 × MIC, and 4 × MIC using flow cytometry. The survival of Caenorhabditis elegans exposed to Mt6-21DLeu at concentrations of MIC, 2 × MIC, and 4 × MIC was monitored for 7 consecutive days, and survival curves were plotted to evaluate the in vivo toxicity of Mt6-21DLeu. In addition, C. elegans infected with AB and treated with Mt6-21DLeu at a concentration of 4 × MIC served as the treatment group, and uninfected C. elegans served as the control group, while infected but untreated C. elegans served as the infection group. The in vivo antibacterial efficacy of Mt6-21DLeu at a concentration of 4 × MIC was evaluated by comparing the survival curves and bacterial load among the three groups. Results The MICs of MAF-1A were all >128 μg/mL against S. aureus, B. subtilis, E. coli, K. pneumoniae, P. aeruginosa, and AB. In contrast, the MICs of Mt6-21DLeu were >128, 32, 8, 8, 16, and 4 μg/mL against these strains, respectively, and the MIC of Mt6-21DLeu against AB was close to that of polymyxin B (2 μg/mL). Time-kill curve analysis showed that both Mt6-21DLeu at concentrations of MIC and 2 × MIC and polymyxin B at a concentration of MIC inhibited AB growth over the 24-hour study period. The biofilm biomass in AB was (52.38 ± 6.92)%, (40.88 ± 9.17)% and (14.77 ± 6.00)% post-exposure with Mt6-21DLeu at concentrations of 1/4 × MIC, 1/2 × MIC and MIC, (61.58 ± 7.35)%, (47.42 ± 5.51)% and (20.85 ± 10.48)% post-treatment with polymyxin B at concentrations of 1/4 × MIC, 1/2 × MIC and MIC, and (100.00 ± 15.92)% in the control group (only bacterial suspension), respectively (F = 68.38, P < 0.001), and pairwise comparisons indicated that Mt6-21DLeu and polymyxin B at all concentrations significantly inhibited biofilm formation as compared to the control group (all P values < 0.001). The mature biofilm biomass in AB was (73.44 ± 11.41)%, (72.56 ± 13.08)% and (49.65 ± 9.23)% post-exposure to Mt6-21DLeu at concentrations of MIC, 2 × MIC, and 4 × MIC, (84.38 ± 8.60)%, (72.31 ± 9.63)% and (58.85 ± 4.96)% post-treatment with polymyxin B at concentrations of MIC, 2 × MIC, and 4 × MIC, and (100.00 ± 6.36)% in the control group (F = 35.63, P < 0.001), and pairwise comparisons revealed that Mt6-21DLeu at all concentrations significantly eradicated biofilm biomass (all P values < 0.05); however, polymyxin B showed no clear-cut eradication effect at a concentration of MIC (P > 0.05). Scanning electron microscopy revealed pore formation and content leakage in the cell membrane of AB 3 hours post-treatment with Mt6-21DLeu at concentrations of MIC and 2 × MIC. Fluorescence microscopy showed that the proportions of PI-stained AB were (24.79 ± 11.51)% and (68.44 ± 15.80)% post-treatment with Mt6-21DLeu at concentrations of MIC and 2 × MIC, and (0.96 ± 0.94)% in the phosphate-buffered saline (PBS) treatment group (F = 105.90, P < 0.001), with the highest proportion of PI-stained AB seen post-treatment with Mt6-21DLeu at a concentration of 2 × MIC (P < 0.05). Flow cytometry revealed that the relative intracellular ROS levels in AB were (652.00 ± 141.90), (694.33 ± 14.19), and (974.33 ± 160.02) 3 hours post-treatment with Mt6-21DLeu at concentrations of MIC, 2 × MIC and 4 × MIC, and (403.67 ± 86.56) in the PBS treatment group, respectively (F = 12.27, P < 0.05), with the highest intracellular ROS level measured following treatment with Mt6-21DLeu at a concentration of 4 × MIC (P < 0.05). Survival curve analysis revealed that Mt6-21DLeu posed no impact on C. elegans survival at concentrations of MIC (χ² = 0.02, P > 0.05), 2 × MIC (χ² = 0.06, P > 0.05) or 4 × MIC (χ² = 0.16, P > 0.05), and there was a significant difference in the survival period of C. elegans among the control group, the infection group, and the treatment group (χ² = 82.66, P < 0.05), with a significantly longer survival period in the treatment group than in the infection group (χ² = 45.00, P < 0.05). In addition, the log-transformed bacterial colony counts in C. elegans were (0.00 ± 0.00), (5.46 ± 0.03), and (3.91 ± 0.47) CFU/mL in the control group, the infection group, and the treatment group, respectively (F = 324.80, P < 0.001), and the log-transformed bacterial colony counts in C. elegans were significantly lower in the treatment group than in the infection group (P < 0.05). Conclusions Mt6-21DLeu exerts potent antibacterial effects through disrupting the cell membrane integrity of AB and promoting intracellular ROS accumulation in AB, and exhibits promising potential for treatment of AB infections both in vivo and in vitro, which may serve as a candidate drug molecule against multidrug-resistant AB infections.

Kidney transplantation is an effective treatment for end-stage renal disease.However,post transplantation diabetes mellitus(PTDM)is a common complication after kidney transplantation,affecting 10%to 40%of recipients and increasing the risk of cardiovascular disease,infections,sepsis and other conditions.The pathogenesis of PTDM is complex,including pancreatic β-cell dysfunction and insulin resistance.Tacrolimus,a commonly used immunosuppressive drug,is an independent risk factor for PTDM.Its mechanisms include damaging pancreatic β-cells,mediating impaired mitochondrial autophagy,etc.In addition,tacrolimus also raises blood glucose levels through various pathways,such as affecting gut microbiota metabolism and activating bile acid signaling pathways.In recent years,some new anti-diabetic drugs have shown certain application prospects in kidney transplant recipients,but the evidence-based medical evidence for their combined use still needs further exploration.In the future,it is necessary to conduct in-depth research on the multiple sites of action of tacrolimus to reduce the occurrence of PTDM and improve the prognosis of kidney transplant recipients.

To establish an immunochromatographic method for rapid detection of caprine enterovir-us(CEV),the monoclonal antibody against CEV VP1 protein was used as gold-labeled monoclonal antibodies,and the purified rabbit-derived polyclonal antibody of CEV-VP1 and sheep anti-mouse IgG were used as the detection line and quality control line,respectively.The colloidal gold immu-nochromatographic test strips for CEV were prepared according to the principle of double antibody sandwich,evaluated,and applied for clinical specimen detection.The results showed that the meth-od specifically recognized CEV without cross-reaction with bovine enterovirus and bovine viral di-arrhea virus.The minimum detection limit of the method was 102.49 TCID50/mL and had good re-producibility.The prepared test strips had a shelf life of three months kept at 4 ℃.Detection of clin-ical samples using the immunochromatographic test strips showed 100％coincidence rate with RT-PCR method.In conclusion,the colloidal gold immunochromatographic test strips for detection of the emerging CEV with good specificity,sensitivity and repeatability,which provides a new techni-cal means easily used for the rapid detection/diagnosis and epidemiological investigation on CEV infection.

Kidney transplantation is an effective treatment for end-stage renal disease.However,post transplantation diabetes mellitus(PTDM)is a common complication after kidney transplantation,affecting 10%to 40%of recipients and increasing the risk of cardiovascular disease,infections,sepsis and other conditions.The pathogenesis of PTDM is complex,including pancreatic β-cell dysfunction and insulin resistance.Tacrolimus,a commonly used immunosuppressive drug,is an independent risk factor for PTDM.Its mechanisms include damaging pancreatic β-cells,mediating impaired mitochondrial autophagy,etc.In addition,tacrolimus also raises blood glucose levels through various pathways,such as affecting gut microbiota metabolism and activating bile acid signaling pathways.In recent years,some new anti-diabetic drugs have shown certain application prospects in kidney transplant recipients,but the evidence-based medical evidence for their combined use still needs further exploration.In the future,it is necessary to conduct in-depth research on the multiple sites of action of tacrolimus to reduce the occurrence of PTDM and improve the prognosis of kidney transplant recipients.

Circular RNA(circRNA)represents a unique class of closed-loop structured non-coding RNAs involved in various biological processes such as cell proliferation,differentiation,and apopto-sis.They play a significant role in the development of numerous diseases,and also serve as poten-tial biomarkers and therapeutic targets.To explore the impact of circRNA on viral replication,this study performed an omics measurement and analysis of circRNA differential expression in MC38 cells infected with HY12 enterovirus.It was found that,following HY12 virus infection,the ex-pressionlevels of 570 circRNAs were upregulated,while 381 circRNAs were downregulated.A-mong the upregulated circRNAs,the significantly upregulated circRNA mmu_circ_0001083 was selected for further investigation into its association with HY12 infection and its impact on viral replication.The results indicated that after HY12 virus infection,the expression of host circRNA mmu_circ_0001083 significantly increased,and its expression level was dependent on the virus dos-age and time.Compared to normal MC38 cells infected with the HY12 virus,cells with knocked down expression of circRNA mmu_circ_0001083 showed reduced expression of the 2C protein and significantly lower viral titers.Conversely,after HY12 virus infection in MC38 cells with overexpressed circRNA mmu_circ_0001083,there was an increase in the expression of the 2C pro-tein and a significant rise in viral titers.These results suggest that the upregulation of host cir-cRNA mmu_circ_0001083 is significantly positively correlated with the replication of HY12 virus,meaning mmu_circ_0001083 plays a positive regulatory role in the replication of HY12.This find-ing lays a foundation for future in-depth studies on the regulatory mechanisms of circRNA on viral replication.

The NMGCF-19 strain is an E.coli strain isolated and identified in our laboratory from lambs manifesting severe diarrhea and meningitis.Previous analysis of the genome sequence of NMGCF-19 strain showed that the outer membrane protein A(ompA)gene was a potential viru-lent gene.In order to determine whether the ompA gene is associated with the pathogenicity of NMGCF-19 strain and the underlying mechanism,the NMGCF-19 strain with ompA knockout(NMGCF-19△ompA)was generated in this study using CRISPR/Cas9 technology and used to de-termine the role of ompA gene in mediating the encephalitis by NMGCF-19 infection and the un-derlying mechanism using the mouse model system.The results showed that the neuronal cell nec-rosis in the hippocampus in mice infected by NMGCF-19△ompA was significantly reduced and was not focal compared with that of mice infected with the wild-type NMGCF-19 strain.The number of bacteria in brain of mice infected by NMGCF-19 △ompA was significantly reduced in comparison to that of mice infected by NMGCF-19.Simultaneously,the mRNA and protein expression levels of the tight junction proteins ZO-1 and Occludin were both increased in mice infected by NMGCF-19 △ompA strain compared with the mice infected by NMGCF-19 strain.These results suggest that the ompA gene is a virulent gene and plays an important role in the invasion of the blood-brain barrier by NMGCF-19 strain in mice.

A recombinant enzyme-mediated nucleic acid amplification(RAA)technology combined with colloidal gold test strips was developed for the rapid detection of bovine enterovirus(BEV).Using the highly conserved BEV 5'UTR as the target sequence,the primers were designed and screened.Downstream primer labeled with biotin at the 5'end and the probe labeled with 6-FAM at the 5'end were used to establish the RT-RAA method.The test strips were assembled by using mouse-derived anti-6-FAM monoclonal antibody as the gold standard antibody,with a streptavidin encapsulated in the detection line and sheep anti-mouse IgG encapsulated in the quality control line.A RT-RAA-LFD method was established by combing RAA technique with the prepared later-al flow device test strips for the detection of bovine enterovirus nucleic acids.The specificity,sensi-tivity,repeatability,and clinical application of the method are also evaluated.The results showed that the optimal primer concentration of this method was 5 μmol/L,and the amplification of BEV nucleic acids was accomplished by reacting at 35 ℃ for 8 min with the lowest detection limit of 101 copies/μL.No cross-reactivity with bovine viral diarrhea virus,bovine parvovirus,and foot-and-mouth disease virus was observed.The efficacy for the prepared test strips was at least for 90 d kept at 4 ℃.Detection of 74 clinical samples yielded a similar result compared with RT-PCR method.The above results demonstrated that the BEV RT-RAA-LFD method established in this study has high sensitivity,specificity,and more convenient to use,which is suitable for clinical de-tection on-site and provides a new technical tool for the diagnosis and epidemiological investigation of BEV infection.

Objective:This study aims to explore the influence of vowels and sound intensity on formant, so as to provide reference for the selection of sound samples and vocal methods in acoustic detection. Methods:Thirty-eight healthy subjects, 19 male and 19 female, aged 19-24 years old were recruited. The formants of different vowels（/a/, //, /i/ and /u/） and different sound intensities（lowest sound, comfort sound, highest true sound and highest falsetto sound） were analyzed, and pairings were compared between groups with significant differences. Results:①The vowels /a/ and // in the first formant were larger than /i/ and /u/, and /i/ was the largest in the second formant. The minimum value of the first formant is the lowest sound of /i/ and the maximum is the highest sound of /a/. ②In the first formant, the chest sound area increases with the increase of sound intensity, while the second formant enters the highest falsetto and decreases significantly. Conclusion:Different vowels and sound intensity have different distribution of formant, that is, vowel and sound intensity have different degree of influence on formant. According to the extreme value of the first formant, the maximum normal range is determined initially, which is helpful to improve the acoustic detection.
Humans ; Male ; Female ; Young Adult ; Speech Acoustics ; Voice Quality ; Phonetics ; Voice/physiology* ; Adult