Risk factors for amputation in diabetic foot ulcers: A retrospective analysis.

Diabetic foot ulcers (DFUs) are chronic, difficult-to-heal wounds with a very high incidence of amputation. For patients with DFUs, prevention of amputation is crucial. However, the risk factors associated with DFU amputation and the extent to which different risk factors increase the risk of amputation are still uncertain. This study intends to provide a clinical basis for early intervention in DFU by retrospectively analysing the risk factors for DFU amputation. A retrospective analysis of 200 patients with DFUs admitted between October 2019 and October 2023 was conducted. Sixty-eight of the 200 underwent amputations. The overall amputation rate was 34%. Multiple logistic regression model showed that neutrophil/lymphocyte ratio (OR = 1.943; 95% CI:1.826-2.139), white blood cell (OR = 1.143; 95% CI:1.034-1.267), C-reactive protein (OR = 1.307; 95% CI:1.113-2.194) and Wagner grading (OR = 2.783; 95% CI: 1.751-4.302) were independent risk factors for amputation, while haemoglobin (OR = 0.742; 95% CI:0.638-0.965) and high density lipoprotein were independent protective factors for amputation (OR = 0.168; 95% CI:0.037-0.716), and further Receiver Operating Characteristic Curve curves showed that they showed high accuracy and were good predictors of amputation of DFUs.

TP53-mediated miR-2861 promotes osteogenic differentiation of BMSCs by targeting Smad7.

Bone defect seriously affects the quality of life. Meanwhile, osteogenic differentiation in BMSCs could regulate the progression of bone defect. Transcription factors are known to regulate the osteogenic differentiation in BMSCs. The study aimed to investigate the detailed mechanism by which TP53 regulates the osteogenic differentiation. To study bone defect in vitro, BMSCs were isolated from spinal cord injury rats. CCK-8 assay was applied to test the cell viability. The mineralized nodules in BMSCs was tested by alizarin red staining. Meanwhile, TUNEL staining and flow cytometry were performed to test the cell apoptosis. mRNA expression was tested by qRT-PCR. Starbase and dual-luciferase reporter assay were used to predict the downstream mRNA of miR-2861. Moreover, western blot was applied to detect the protein expressions (TP53 and Smad7). BMSCs were successfully isolated from rats. The expressions of miR-2861 were significantly upregulated in osteogenic medium, compared with growth medium. MiR-2861 inhibitor significantly decreased the levels of OCN, ALP, BSP, and Runx2 in BMSCs. In addition, miR-2861 inhibitor notably inhibited the mineralized nodules, viability, and induced the apoptosis of BMSCs. Smad7 was identified to be the downstream target of miR-2861, and knockdown of Smad7 notably reversed miR-2861 inhibitor-induced inhibition of osteogenic differentiation and promotion of apoptosis in BMSCs. Moreover, miR-2861 was transcriptionally regulated by TP53 in BMSCs. TP53-meidiated miR-2861 promotes osteogenic differentiation of BMSCs by targeting Smad7. Thereby, our research might provide new methods for bone defect treatment.

Failure of neonatal B-cell tolerance induction by ABO-incompatible kidney grafts in piglets.

BACKGROUND: ABO-incompatible (ABOi) infant heart transplantation results in B-cell tolerance to graft A/B antigens, confirming human susceptibility to acquired immunologic or "neonatal" tolerance as described originally in murine models. Starting with this clinical observation, we sought to model neonatal ABOi organ transplantation to allow mechanistic studies of tolerance. METHODS: Plasma anti-A/B antibodies were measured over time in piglets to establish developmental antibody kinetics. Blood group O piglets received kidney allografts from group A (AO-incompatible) or group O (AO-compatible) donors under cyclosporine immunosuppression. Anti-A antibodies were measured serially after transplantation; A/H antigen expression and allograft rejection were assessed in graft biopsies. RESULTS: Anti-A antibodies developed in naïve piglets in a kinetic pattern analogous to human infants; anti-B remained low. After transplantation, anti-A antibodies developed similarly in AO-incompatible and AO-compatible groups and were not suppressed by cyclosporine. A/H antigen expression was persistent in all graft biopsies; however, A/H antigens were not detected in vascular endothelium. Cellular and antibody-mediated rejection was absent or minimal in early and late biopsies in both groups, with one exception. CONCLUSIONS: Naturally delayed isohemagglutinin production in piglets is analogous to the developmental kinetics in human infants. However, in contrast to deficient anti-A antibody production as seen long-term after "A-into-O" infant heart transplant recipients, normal anti-A antibody production after "A-into-O" piglet kidney transplantation indicates that tolerance did not develop despite graft A antigen persistence. These findings suggest that the impact on the host immune system of exposure to nonself ABH antigens during early life in human heart versus porcine kidney grafts may depend on expression in vascular endothelium.

Vitrification of intact human articular cartilage.

Articular cartilage injuries do not heal and large defects result in osteoarthritis with major personal and socioeconomic costs. Osteochondral transplantation is an effective treatment for large joint defects but its use is limited by the inability to store cartilage for long periods of time. Cryopreservation/vitrification is one method to enable banking of this tissue but decades of research have been unable to successfully preserve the tissue while maintaining cartilage on its bone base - a requirement for transplantation. To address this limitation, human knee articular cartilage from total knee arthroplasty patients and deceased donors was exposed to specified concentrations of 4 different cryoprotective agents for mathematically determined periods of time at lowering temperatures. After complete exposure, the cartilage was immersed in liquid nitrogen for up to 3 months. Cell viability was 75.4 ± 12.1% determined by membrane integrity stains and confirmed with a mitochondrial assay and pellet culture documented production of sulfated glycosaminoglycans and collagen II similar to controls. This report documents successful vitrification of intact human articular cartilage on its bone base making it possible to bank this tissue indefinitely.

Induction of human blood group a antigen expression on mouse cells, using lentiviral gene transduction.

The ABO histo-blood group system is the most important antigen system in transplantation medicine, yet no small animal model of the ABO system exists. To determine the feasibility of developing a murine model, we previously subcloned the human alpha-1,2-fucosyltransferase (H-transferase, EC 2.4.1.69) cDNA and the human alpha-1,3-N-acetylgalactosaminyltransferase (A-transferase, EC 2.4.1.40) cDNA into lentiviral vectors to study their ability to induce human histo-blood group A antigen expression on mouse cells. Herein we investigated the optimal conditions for human A and H antigen expression in murine cells. We determined that transduction of a bicistronic lentiviral vector (LvEF1-AH-trs) resulted in the expression of A antigen in a mouse endothelial cell line. We also studied the in vivo utility of this vector to induce human A antigen expression in mouse liver. After intrahepatic injection of LvEF1-AH-trs, A antigen expression was observed on hepatocytes as detected by immunohistochemistry and real-time RT-PCR. In human group A erythrocyte-sensitized mice, A antigen expression in the liver was associated with tissue damage, and deposition of antibody and complement. These results suggest that this gene transfer strategy can be used to simulate the human ABO blood group system in a murine model. This model will facilitate progress in the development of interventions for ABO-incompatible transplantation and transfusion scenarios, which are difficult to develop in clinical or large animal settings.