AIM:To investigate the effect of peripheral defocus design rigid gas permeable contact lenses(defocus RGPCL)in controlling myopia progression in children aged 6-12 y with high myopia, and to compare the outcomes with traditional single-vision RGPCL and single-vision spectacles.METHODS:This prospective cohort study enrolled children aged 6-12 y with high myopia who visited the Ophthalmology and Optometry Center of Xi'an No.1 Hospital between January 2022 and January 2023. Based on parental preference, participants were divided into three groups: defocused RGPCL group, single-vision RGPCL group, and single-vision spectacles group. The axial length(AL)and cycloplegic spherical equivalent(SE)refraction were compared at baseline, 0.5, 1, 1.5, and 2 y after lens wear. Additionally, AL and SE delay rates were calculated for each group.RESULTS: This study enrolled a total of 90 children with high myopia(180 eyes), with no participants lost to follow-up. Participants were allocated into three groups based on parental preference. Thirty children(60 eyes)were assigned to the peripheral defocus RGPCL group, consisting of 12 boys and 18 girls with a mean age of 9.96±1.56 y; 30 children(60 eyes)to the single-vision RGPCL group, including 15 boys and 15 girls with a mean age of 9.40±1.52 y; and 30 children(60 eyes)to the single-vision spectacles group, with 14 boys and 16 girls and a mean age of 9.80±1.37 y. At 0.5, 1, 1.5, and 2 y lens fitting, AL and SE increased significantly in all three groups(all P<0.05), with the growth rates in the defocused RGPCL group being significantly lower than those in the single-vision RGPCL and single-vision spectacles groups(all P<0.05). At 2 y lens fitting, the AL elongation was 0.22±0.24 mm and the mean SE progression was 0.70±0.70 D in the peripheral defocus RGPCL group; 0.49±0.38 mm and 1.34±0.60 D in the single-vision RGPCL group; and 0.50±0.21 mm and 1.72±0.47 D in the single-vision spectacles group. Using the single-vision spectacles group as the control, the AL delay rate and SE delay rate at 2 y lens fitting were 56.0% and 59.3%, respectively, in the defocused RGPCL group.CONCLUSION:For children with high myopia aged 6-12 y, defocus RGPCLs can effectively and significantly delay AL elongation and SE progression, demonstrating markedly superior control efficacy compared to single-vision RGPCL or single-vision spectacles. Defocused RGPCL can serve as an effective optical intervention for high myopia children.

Objective To investigate the causes and management strategies for lower limb ischemic necrosis following xenogeneic heterotopic heart transplantation from a multigene-edited pig to a rhesus monkey. Methods A xenogeneic heterotopic heart transplantation was performed on December 16, 2023, at the Institute of Experimental Animals of Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, using a quintuple-gene-edited pig as the donor and a rhesus monkey as the recipient. On postoperative day (POD) 9, the recipient monkey underwent left lower limb amputation due to ischemic necrosis. Blood samples were collected at various time points after transplantation for analysis of hematologic parameters, liver and renal function, myocardial enzymes, and coagulation profiles. Ultrasound and computed tomography (CT) were used to evaluate anastomotic patency and cardiac structure. Immunological assays, including complement-dependent cytotoxicity (CDC) and IgG/IgM antibody detection, combined with clinical observations, were employed to assess rejection type and therapeutic response. Results The recipient monkey survived for 46 days after transplantation. Echocardiography demonstrated preserved biventricular systolic function in the recipient’s native heart, with left ventricular ejection fraction (LVEF) consistently exceeding 50%. In the donor pig heart, left ventricular endocardial thickening was noted on POD 9, followed by right ventricular endocardial thickening on POD 24, while LVEF remained around 35%. No hyperacute or acute rejection was detected immunologically. CDC positivity ranged between 3.4% and 5.1%, with IgG/IgM antibody binding trends consistent with CDC results. Following amputation, the recipient exhibited elevated inflammatory markers, coagulopathy, and reactive thrombocytosis, which later normalized. Immunohistochemical staining of the necrotic limb revealed arterial and venous thrombosis; however, no T-cell or B-cell infiltration was observed in vascular structures, thrombi, nerves, muscles, fascia, or skin tissues, with CD3 and CD20 staining both negative. Conclusion Limb ischemia after xenogeneic heart transplantation may be associated with lower extremity vascular thrombosis triggered by local trauma in the context of transplantation-induced inflammatory activation and coagulation dysfunction. While no clear lymphocyte-mediated rejection was observed, further studies are needed to explore the potential role of non-lymphocyte-mediated immune mechanisms.

BACKGROUND: The primary limitation to kidney transplantation is organ shortage. Recent progress in gene editing and immunosuppressive regimens has made xenotransplantation with porcine organs a possibility. However, evidence in pig-to-human xenotransplantation remains scarce, and antibody-mediated rejection (AMR) is a major obstacle to clinical applications of xenotransplantation. METHODS: We conducted a kidney xenotransplantation in a brain-dead human recipient using a porcine kidney with five gene edits (5GE) on March 25, 2024 at Xijing Hospital, China. Clinical-grade immunosuppressive regimens were employed, and the observation period lasted 22 days. We collected and analyzed the xenograft function, ultrasound findings, sequential protocol biopsies, and immune surveillance of the recipient during the observation. RESULTS: The combination of 5GE in the porcine kidney and clinical-grade immunosuppressive regimens prevented hyperacute rejection. The xenograft kidney underwent delayed graft function in the first week, but urine output increased later and the single xenograft kidney maintained electrolyte and pH homeostasis from postoperative day (POD) 12 to 19. We observed AMR at 24 h post-transplantation, due to the presence of pre-existing anti-porcine antibodies and cytotoxicity before transplantation; this AMR persisted throughout the observation period. Plasma exchange and intravenous immunoglobulin treatment mitigated the AMR. We observed activation of latent porcine cytomegalovirus toward the end of the study, which might have contributed to coagulation disorder in the recipient. CONCLUSIONS 5GE and clinical-grade immunosuppressive regimens were sufficient to prevent hyperacute rejection during pig-to-human kidney xenotransplantation. Pre-existing anti-porcine antibodies predisposed the xenograft to AMR. Plasma exchange and intravenous immunoglobulin were safe and effective in the treatment of AMR after kidney xenotransplantation.
Transplantation, Heterologous/methods* ; Kidney Transplantation/methods* ; Heterografts/pathology* ; Immunoglobulins, Intravenous/administration & dosage* ; Graft Survival/immunology* ; Humans ; Animals ; Sus scrofa ; Graft Rejection/prevention & control* ; Kidney/pathology* ; Gene Editing ; Species Specificity ; Immunosuppression Therapy/methods* ; Plasma Exchange ; Brain Death ; Biopsy ; Male ; Aged

Objective To evaluate the efficacy of a combined immunosuppression regimen in modulating rejection in genetically modified pig-to-macaque xenogeneic heart transplantation.Methods Two xenogeneic heart transplantation models were constructed using genetically modified pigs and macaques.Dynamic monitoring of recipient peripheral blood immune parameters and observation of graft pathological changes were performed.Results Regimen 1,featuring B-cell depletion,T-cell inhibition,and C3 complement suppression,reduced lymphocyte levels but failed to control acute humoral rejection and macrophage infiltration.Regimen 2,adding C5 complement inhibition and interleukin-6 inhibition to Regimen 1,more effectively lowered lymphocyte levels,inhibited acute humoral rejection and complement activation,and decreased antibody deposition.However,a late-phase cytokine storm and residual T cells emerged.Conclusions Regimen 2 reduces the hyperacute and acute rejection risks through multi-target intervention.Yet,it requires balancing medication complexity and safety.This indicates the need to optimize cellular immune regulation and adjust the plan through dynamic multidimensional monitoring.

Objective To evaluate the efficacy of a combined immunosuppression regimen in modulating rejection in genetically modified pig-to-macaque xenogeneic heart transplantation.Methods Two xenogeneic heart transplantation models were constructed using genetically modified pigs and macaques.Dynamic monitoring of recipient peripheral blood immune parameters and observation of graft pathological changes were performed.Results Regimen 1,featuring B-cell depletion,T-cell inhibition,and C3 complement suppression,reduced lymphocyte levels but failed to control acute humoral rejection and macrophage infiltration.Regimen 2,adding C5 complement inhibition and interleukin-6 inhibition to Regimen 1,more effectively lowered lymphocyte levels,inhibited acute humoral rejection and complement activation,and decreased antibody deposition.However,a late-phase cytokine storm and residual T cells emerged.Conclusions Regimen 2 reduces the hyperacute and acute rejection risks through multi-target intervention.Yet,it requires balancing medication complexity and safety.This indicates the need to optimize cellular immune regulation and adjust the plan through dynamic multidimensional monitoring.

Objective To investigate the differences and the immunocompatibility of wild-type (WT), four-gene modified (TKO/hCD55) and six-gene modified (TKO/hCD55/hCD46/hTBM) pig erythrocytes with human serum. Methods The blood samples were collected from 20 volunteers with different blood groups. WT, TKO/hCD55, TKO/hCD55/hCD46/hTBM pig erythrocytes, ABO-compatible (ABO-C) and ABO-incompatible (ABO-I) human erythrocytes were exposed to human serum of different blood groups, respectively. The blood agglutination and antigen-antibody binding levels (IgG, IgM) and complement-dependent cytotoxicity were detected. The immunocompatibility of two types of genetically modified pig erythrocytes with human serum was evaluated. Results No significant blood agglutination was observed in the ABO-C group. The blood agglutination levels in the WT and ABO-I groups were higher than those in the TKO/hCD55 and TKO/hCD55/hCD46/hTBM groups (all P<0.001). The level of erythrocyte lysis in the WT group was higher than those in the ABO-C, TKO/hCD55 and TKO/hCD55/hCD46/hTBM groups. The level of erythrocyte lysis in the ABO-I group was higher than those in the TKO/hCD55 and TKO/hCD55/hCD46/hTBM groups (both P<0.01). The pig erythrocyte binding level with IgM and IgG in the TKO/hCD55 group was lower than those in the WT and ABO-I groups. The pig erythrocyte binding level with IgG and IgM in the TKO/hCD55/hCD46/hTBM group was lower than that in the WT group and pig erythrocyte binding level with IgG was lower than that in the ABO-I group (all P<0.05). Conclusions The immunocompatibility of genetically modified pig erythrocytes is better than that of wild-type pigs and close to that of ABO-C pigs. Humanized pig erythrocytes may be considered as a blood source when blood sources are extremely scarce.

Effective preoperative matching of organ transplantation is essential for the success of organ transplantation.The current methods of preoperative matching for xenotransplantation are derived from human allogeneic organ transplantation.However,these methods are simple and cannot accurately predict whether rejection will occur after transplantation.A noteworthy feature of xenotransplantation lies in the stability of the donor source and the clarity of its genotype,which facilitate convenient sampling and ensure robust repeatability.The multi-link and multi-dimensional preoperative matching is conducive to accurately screening suitable donors and reducing the occurrence of postoperative rejection after xenotransplantation,including making full use of the advantages of donor control in xenotransplantation,expanding tissue level matching methods on the basis of improving traditional cytological matching,paying attention to the role of endothelial cells in matching,and developing organic-level matching methods.Therefore,this article reviews the methods of allogeneic organ transplantation matching,current methods,existing problems and possible breakthroughs of xenotransplantation matching,in order to provide reference for further research on xenotransplantation matching.

Objective To investigate the isolation and culture of porcine bone marrow mesenchymal stem cell (BMSC) with α-1, 3-galactosyltransferase (GGTA1) gene knockout (GTKO), GTKO/ human CD46 (hCD46) insertion and cytidine monopho-N-acetylneuraminic acid hydroxylase (CMAH)/GGTA1 gene knockout (Neu5GC/Gal), and the protective effect of co-culture with porcine islets on islet cells. Methods Bone marrow was extracted from different transgenic pigs modified with GTKO, GTKO/hCD46 and Neu5GC/Gal. Porcine BMSC were isolated by the whole bone marrow adherent method and then cultured. The morphology of BMSC was observed and the surface markers of BMSC were identified by flow cytometry. Meantime, the multi-directional differentiation induced by BMSC was observed, and the labeling and tracing of BMSC were realized by green fluorescent protein (GFP) transfection. The porcine BMSC transfected with GFP were co-cultured with porcine islet cells. Morphological changes of porcine islet cells were observed, and compared with those in the porcine islet cell alone culture group. Results BMSC derived from pigs were spindle-shaped in vitro, expressing biomarkers of CD29, CD44, CD73, CD90, CD105 and CD166 rather than CD34 and CD45. These cells were able to differentiate into adipocytes, osteoblasts and chondrocytes. Porcine BMSC with GFP transfection could be labeled and traced, which could be stably expressed in the daughter cells after cell division. Porcine BMSC exerted certain protective effect on islet cells. Conclusions GFP-labeled porcine BMSC modified with GTKO, GTKO/hCD46 and Neu5GC/Gal are successfully established, which exert certain protective effect upon islet cells.

Objective To discuss the perioperative care and wound protection of xenotransplantation from genetically edited pigs to monkeys, with the goal of improving the success rate of such experimental procedures. Methods From October 2022 to October 2023, perioperative care and wound protection were performed on 7 recipient rhesus monkeys undergoing xenotransplantation of genetically edited pig tissues and organs. Customized wound protective garments were designed based on monkeys' size and surgical area to protect the wounds, alongside meticulous perioperative care. This included preoperative preparation and medication, intraoperative monitoring of physiological indicators and anesthesia management, and postoperative care comprising wound protection, observation and monitoring, and nutritional support. Results All seven monkeys successfully underwent xenotransplantation. With the aid of protective garments and detailed care, all surgical wounds healed by first intention, and postoperative recovery was satisfactory. Conclusion Proper care and wound protection during xenotransplantation from genetically edited pigs to monkeys not only promote wound healing, but also alleviate pain and harm to animals. This has significant implications for advancing experimental research in pig-monkey xenotransplantation and enhancing animal welfare.

Objective:To investigate the changing trends in cardiac function following xenogeneic heterotopic heart transplantation of multi-gene edited pig hearts and assess the impact of recipient immune responses on donor heart, laying experimental groundwork for the clinical application of gene editing technology.Methods:On December 16, 2023, xenogeneic heterotopic heart transplantation was performed between pigs and rhesus monkeys. Functional status of the graft under post-transplantation load conditions and recipient immune indicators were observed.Results:The recipient monkeys survived for 40 days with satisfactory functionality of both donor and recipient hearts, and no hyperacute or acute immune rejection reactions were observed.Conclusion:Multi-gene editing technology provides potential for xenotransplantation, yet further exploration is needed for its clinical application.