Developing preclinical dog models for reconstructive severed spinal cord continuity via spinal cord fusion technique.

Background: Spinal cord injury (SCI) is a severe impairment of the central nervous system, leading to motor, sensory, and autonomic dysfunction. The present study investigates the efficacy of the polyethylene glycol (PEG)-mediated spinal cord fusion (SCF) techniques, demonstrating efficacious in various animal models with complete spinal cord transection at the T10 level. This research focuses on a comparative analysis of three SCF treatment models in beagles: spinal cord transection (SCT), vascular pedicle hemisected spinal cord transplantation (vSCT), and vascularized allograft spinal cord transplantation (vASCT) surgical model. Methods: Seven female beagles were included in the SCT surgical model, while four female dogs were enrolled in the vSCT surgical model. Additionally, twelve female dogs underwent vASCT in a paired donor-recipient setup. Three surgical model were evaluated and compared through electrophysiology, imaging and behavioral recovery. Results: The results showed a progressive recovery in the SCT, vSCT and vASCT surgical models, with no statistically significant differences observed in cBBB scores at both 2-month and 6-month post-operation (both P>0.05). Neuroimaging analysis across the SCT, vSCT and vASCT surgical models revealed spinal cord graft survival and fiber regrowth across transection sites at 6 months postoperatively. Also, positive MEP waveforms were recorded in all three surgical models at 6-month post-surgery. Conclusion: The study underscores the clinical relevance of PEG-mediated SCF techniques in promoting nerve fusion, repair, and motor functional recovery in SCI. SCT, vSCT, and vASCT, tailored to specific clinical characteristics, demonstrated similar effective therapeutic outcomes.

[Effect of High-Concentration Uric Acid on Nitric Oxide].

Uric acid (UA) is the final product of purine metabolism in human body,and its metabolic disorder will induce hyperuricemia (HUA).The occurrence and development of HUA are associated with a variety of pathological mechanisms such as oxidative stress injury,activation of inflammatory cytokines,and activation of renin-angiotensin-aldosterone system.These mechanisms directly or indirectly affect the bioavailability of endogenous nitric oxide (NO).The decrease in NO bioavailability is common in the diseases with high concentration of UA as an independent risk factor.In this review,we summarize the mechanisms by which high concentrations of UA affect the endogenous NO bioavailability,with a focus on the mechanisms of high-concentration UA in decreasing the synthesis and/or increasing the consumption of NO.This review aims to provide references for alleviating the multisystem symptoms and improving the prognosis of HUA,and lay a theoretical foundation for in-depth study of the correlations between HUA and other metabolic diseases.

[Microsurgical thinned anterolateral thigh perforator flap to repair soft tissue defects of foot and ankle].

OBJECTIVE: To explore method and clinical effect of microsurgical thinned anterolateral thigh perforator flap to repair soft tissue defects of foot and ankle. METHODS: From March 2017 to January 2022, totally 20 patients with soft tissue defects of ankle joint were treated with micro-thinning anterolateral perforator flap for free transplantation, included 13 males and 7 females, aged from 22 to 58 years old with an average of (36.45±12.36) years old. The size of flap ranged from 8.0 cm×5.0 cm to 20.0 cm×12.0 cm. Before operation, perforating vessels on the anterolateral thigh region were detected and marked with a portable Doppler detector. For the defect width less than 8 cm, 11 patients were repaired with a single flap. For the defect width more than 8 cm, the wound could not be sutured directly, and the lobulated flap technique was used in 9 patients, the width was converted to length, and the donor site was closed directly. Under the microscope, all flaps were thinened in a stepwise manner from the center of the pedicle to the periphery. After operation, survival of the flap, the shape, texture, sensory function recovery were observes, and recovery of foot function was evaluated by Maryland foot function evaluation standard. RESULTS: All 20 patients with microsurgical thinned anterolateral thigh perforator flaps were survived. Venous crisis occurred in 1 patient due to subcutaneous hematoma, after removal of the hematoma, the crisis was relieved and the flap survived successfully. The wounds in the donor and recipient sites healed well, and only linear scars left in the donor sites. Twenty patients were followed up for 3 to 26 months after operation, good shape of flaps without bloated, and good texture. The two-point discrimination of free flaps ranged from 9.0 to 16.0 mm, and the protective sensation was restored. The ankle flexion and extension function recovered well and patients could walk normally. According to Maryland foot function evaluation standard, 8 patients got excellent result, 10 patients good and 2 middle. CONCLUSION: Microsurgical thinned anterolateral thigh perforator flap is an ideal method to repair soft tissue defects in functional area of foot and ankle, with good appearance and texture of the flap, no need for re-plastic surgery, reduced hospitalization costs, and less donor site damage.

Partial restoration of spinal cord neural continuity via vascular pedicle hemisected spinal cord transplantation using spinal cord fusion technique.

AIMS: Our team tested spinal cord fusion (SCF) using the neuroprotective agent polyethylene glycol (PEG) in different animal (mice, rats, and beagles) models with complete spinal cord transection. To further explore the application of SCF for the treatment of paraplegic patients, we developed a new clinical procedure for SCF called vascular pedicle hemisected spinal cord transplantation (vSCT) and tested this procedure in eight paraplegic participants. METHODS: Eight paraplegic participants (American Spinal Injury Association, ASIA: A) were enrolled and treated with vSCT (PEG was applied to the sites of spinal cord transplantation). Pre- and postoperative pain intensities, neurologic assessments, electrophysiologic monitoring, and neuroimaging examinations were recorded. RESULTS: Of the eight paraplegic participants who completed vSCT, objective improvements occurred in motor function for one participant, in electrophysiologic motor-evoked potentials for another participant, in re-establishment of white matter continuity in three participants, in autonomic nerve function in seven participants, and in symptoms of cord central pain for seven participants. CONCLUSIONS: The postoperative recovery of paraplegic participants demonstrated the clinical feasibility and efficacy of vSCT in re-establishing the continuity of spinal nerve fibers. vSCT could provide the anatomic, morphologic, and histologic foundations to potentially restore the motor, sensory, and autonomic nervous functions in paraplegic patients. More future clinical trials are warranted.

Partial Restoration of Spinal Cord Neural Continuity via Sural Nerve Transplantation Using a Technique of Spinal Cord Fusion.

BACKGROUND: Spinal cord injury (SCI) can cause paralysis and serious chronic morbidity, and there is no effective treatment. Based on our previous experimental results of spinal cord fusion (SCF) in mice, rats, beagles, and monkeys, we developed a surgical protocol of SCF for paraplegic human patients. We designed a novel surgical procedure of SCF, called sural nerve transplantation (SNT), for human patients with lower thoracic SCI and distal cord dysfunction. METHODS: We conducted a clinical trial (ChiCTR2000030788) and performed SNT in 12 fully paraplegic patients due to SCI between T1 and T12. We assessed pre- and postoperative central nerve pain, motor function, sensory function, and autonomic nerve function. Conduction of action potentials across the sural nerve transplant was evaluated. Neural continuity was also examined by diffusion tensor imaging (DTI). RESULTS: Among the 12 paraplegic patients enrolled in this clinical trial, seven patients demonstrated improved autonomic nerve functions. Seven patients had clinically significant relief of their symptoms of cord central pain. One patient, however, developed postoperative cord central pain (VAS: 4). Five patients had varying degrees of recovered sensory and/or motor functions below the single neurologic level 1 month after surgery. One patient showed recovery of electrophysiologic, motor-evoked potentials 6 months after the operation. At 6 months after surgery, DTI indicated fusion and nerve connections of white cord and sural nerves in seven patients. CONCLUSION: SNT was able to fuse the axonal stumps of white cord and sural nerve and at least partially improve the cord central pain in most patients. Although SNT did not restore the spinal cord continuity in white matter in some patients, SNT could restore spinal cord continuity in the cortico-trunco-reticulo-propriospinal pathway, thereby restoring in part some motor and sensory functions. SNT may therefore be a safe, feasible, and effective method to treat paraplegic patients with SCI. Future clinical trials should be performed to optimize the type/technique of nerve transplantation, reduce surgical damage, and minimize postoperative scar formation and adhesion, to avoid postoperative cord central pain. CLINICAL TRIAL REGISTRATION: [http://www.chictr.org.cn/showproj.aspx?proj=50526], identifier [ChiCTR2000030788].