SARS-CoV-2 and its emerging variants continue to pose a significant global public health threat. The SARS-CoV-2 main protease (M^pro) is a critical target for the development of antiviral agents that can inhibit viral replication and transcription. In this study, we identified chebulagic acid (CHLA), isolated from Terminalia chebula Retz., as a potent non-peptidomimetic and non-covalent M^pro inhibitor. CHLA exhibited intermolecular interactions and provided significant protection to Vero E6 cells against a range of SARS-CoV-2 variants, including the wild-type, Delta, Omicron BA.1.1, BA.2.3, BA.4, and BA.5, with EC₅₀ values below 2 μmol/L. Moreover, in vivo studies confirmed the antiviral efficacy of CHLA in K18-hACE2 mice. Notably, CHLA bound to a unique groove at the interface between M^pro domains I and II, which was revealed by the high-resolution crystal structure (1.4 Å) of the M^pro-CHLA complex, shrinking the substrate binding pocket of M^pro and inducing M^pro aggregation. CHLA was proposed to act as an allosteric inhibitor. Pharmacokinetic profiling and safety assessments underscore CHLA's potential as a promising broad-spectrum antiviral candidate. These findings report a novel binding site on M^pro and identify antiviral activity of CHLA, providing a robust framework for lead compounds discovery and elucidating the underlying molecular mechanisms of inhibition.

Objective:To evaluate the safety and efficacy of mild hypothermia arch-clamping technique in the surgical treatment of DeBakey Type Ⅰ aortic dissection.Methods:From December 2019 to November 2023, a total of 97 patients with DeBakey type Ⅰ aortic dissection who underwent arch-clamping technique in Beijing Anzhen Hospital were prospectively enrolled. The patients were divided into mild hypothermia group and moderate hypothermia group according to the lowest rectal temperature during the circulatory arrest period. The perioperative data of the two groups were compared, and complex adverse outcomes consisting of 30-day death, stroke, paraplegia and CRRT were used as the primary endpoint. Multivariate logistic regression was used to determine the predictors of clinical adverse outcomes. Survival analysis was evaluated by the Kaplan- Meier method. Results:The overall incidence of complex adverse outcomes was 20.6%, 13.6% in the mild hypothermia group and 22.7% in the moderate hypothermia group( P=0.535), and the incidence of stroke was 4.6% and 6.7%( P=1.000), respectively. The cardiopulmonary bypass time and aortic-clamping time in the mild hypothermia group were significantly shortened (147.5 min vs. 163.0 min, P=0.032; 89 min vs. 99 min, P=0.042). There was no significant difference in long-term survival and reintervention between the two groups(91.9% vs. 89.3%, P=0.87; 9.1% vs. 5.3%, P=0.13). Conclusion:Mild hypothermia arch-clamping technique is a safe and effective method for the treatment of DeBakey type Ⅰ aortic dissection, with satisfactory short-term and long-term efficacy.

Contralateral radiculopathy, a postoperative complication after transforaminal lumbar interbody fusion, refers to postoperative numbness, pain and other neurological symptoms of the lower limb on the side opposite to the symptomatic or the surgical decompression side. Its main causes include excessive restoration of lordosis, intervertebral space tilt caused by improper cage position, poor screw position, new protrusion of nucleus pulposus or bone graft, and hematoma. At present, attention to this complication is gradually increasing. This review summarizes its risk factors from the recent related reports of the condition and puts forward preventive measures in order to promote the preventive awareness of this complication.

Objective:To investigate the short-term clinical efficacy of implantation with a 3D-printed microporous titanium prosthesis in the treatment of large segmental infectious tibial defects.Methods:A retrospective analysis was conducted of the electronic medical records of the 47 patients with large segmental tibial defects who had been treated with 3D-printed microporous titanium prostheses at Department of Orthopaedics, 920th Hospital of Joint Logistics Support Force from January 2019 to February 2024. The cohort included 36 males and 11 females, with an age of (46.2±11.8) years and a mean bone defect length of 12.3 (8.0, 16.8) cm. In the 19 patients complicated with soft tissue defects, the area of soft tissue defects ranged from 10.0 cm × 6.0 cm to 33.0 cm × 10.0 cm. For the 28 patients without soft tissue defects at the lower leg, the bone defects were filled with vancomycin-loaded calcium sulfate bone cement at the first stage; for the 19 patients complicated with soft tissue defects, the soft tissue defects at the lower limb were repaired using an anterolateral thigh flap with vascular anastomosis at the same time when bone defects were filled with vancomycin-loaded calcium sulfate bone cement at the first stage. After infection control at 2 to 8 months after surgery, individualized 3D-printed microporous titanium prostheses were implanted at the second stage to reconstruct the bone defects. Postoperative observations included the patients' first standing time, crutch walking time, full weight-bearing time, osseointegration of the tibial fracture and the prosthesis, and complications during follow-up.Results:The follow-up period for the 47 patients was (34.7±14.3) months. The first standing time was (2.2±0.6) months, crutch walking time (3.8±1.1) months, and full weight-bearing time (5.3±1.2) for this cohort. The evaluation by the Paley's bone healing score resulted in 25 excellent cases, 18 good cases, 1 medium case, and 3 poor cases, giving an excellent and good rate of 91.5% (43/47). One year after operation, the X-ray films showed that the tibial fractures and prostheses were well integrated in the 43 patients. Two patients developed recurrent tibial infection which was responded to replacement of the vancomycin-loaded calcium sulfate spacer. The fixation screws for tibial prosthesis were broken in one patient, but no recurrence of infection was observed after revision. The overall incidence of complications was 6.4% (3/47).Conclusion:In the treatment of large segmental infectious tibial defects, by facilitating rapid functional recovery and ensuring a low incidence of complications, implantation with a 3D-printed microporous titanium prosthesis demonstrates fine short-term clinical efficacy.

Objective:To evaluate the clinical value of sacral canal posterior wall reconstruction in the treatment of symptomatic sacral canal cysts.Methods:A retrospective cohort study was conducted.The clinical data of 80 patients with symptomatic sacral cysts who underwent surgical treatment at Beijing Friendship Hospital, Capital Medical University, between June 2018 and September 2024 were collected. There were 19 males and 61 females, with an average age of (49.0±11.3) years (ranged from 23-76 years). The patients were divided into the traditional group ( n=30) and the reconstruction group ( n=50) based on the surgical approach. The traditional group underwent the conventional surgical method without reconstruction of the posterior wall of the sacral canal, while the reconstruction group underwent posterior wall reconstruction of the sacral canal. Postoperative observations included the integrity of the sacral canal posterior wall, wound healing, and symptom improvement in both groups. Measurement data with normal distribution were expressed as mean±standard deviation( ± s). Independent samples t-test was used for comparisons of measurement data between groups. Categorical data were compared using the chi-square test or Fisher′s exact test. Ordinal data were analyzed using the Mann-Whitney U test. Pearson correlation analysis was used to assess the relationship between variables. Results:Among the 80 patients, the sacral bone integrity score in the reconstruction group was (1.42±0.49) scores, compared to (3.00±0.00) scores in the traditional group, the reconstruction group showed significantly better results ( P<0.05). Symptom improvement was also significantly different between the two groups ( P=0.038): in the traditional group, 17 patients experienced complete symptom resolution, 6 partial improvement, 7 no improvement, and 0 worsening; in the reconstruction group, 37 had complete symptom resolution, 11 partial improvement, 2 no improvement, and 0 worsening. The effective improvement rate (complete+ partial improvement) in the reconstruction group was significantly better than that in the traditional group ( P=0.012). In terms of wound healing, 76 cases healed well, 4 had delayed healing, and 0 had infections. In the traditional group, 27 healed well, 3 had delayed healing, 0 infections; in the reconstruction group, 49 healed well, 1 had delayed healing, and 0 infections. There was no significant difference in wound healing rate between the two groups ( P=0.146). A significant positive correlation was found between sacral canal posterior wall integrity and symptom improvement ( r=0.288, P=0.010). Conclusion:Sacral canal posterior wall reconstruction significantly improves postoperative anatomical integrity and clinical outcomes without increasing complications, supporting its adoption as a preferred surgical approach for symptomatic sacral canal cysts.

BACKGROUND:Facet joint osteoarthritis is acknowledged as a significant contributor to lower back pain in the geriatric population.The advent of an innovative spinal facet joint fusion device presents a therapeutic option for intervening during the initial stages of facet joint osteoarthritis,and significantly reduces the incidence of a series of complications caused by poor early conservative treatment and late surgical treatment.However,its effect on the biomechanics of the lumbar spine is unknown.OBJECTIVE:To investigate the biomechanical disparities between the novel lumbar zygapophyseal joint fusion device and traditional fusion devices.METHODS:A comprehensive three-dimensional finite element model of the L3-S1 lumbar spine was established and validated.Based on this intact model,three groups of surgical models were constructed:a bilateral pedicle screw fixation model,a bilateral novel facet joint fusion fixation model,and a bilateral facet screw fixation model,with the surgical segment designated as L4-5.Under a load of 500 N,a torque of 7.5 Nm was applied to all lumbar models to calculate the range of motion,displacement values,and intervertebral disc stress values at the L4-5 segment;stress values at the L3-4 and L5-S1 segments were also measured.RESULTS AND CONCLUSION:(1)Compared with the intact model,the range of motion at the L4-5 segment was reduced in all surgical models.(2)The novel device exhibited the smallest range of motion at the L4-5 segment under left and right rotational conditions;the greatest range of motion at the L4-5 segment under extension conditions;and a greater range of motion under other conditions than the bilateral pedicle screw fixation model.(3)The novel device demonstrated the smallest displacement values at the L4-5 segment under left and right rotational conditions;under other conditions,the displacement values at the L4-5 segment were greater than those in the bilateral pedicle screw fixation model.(4)In terms of stress distribution at the L4-5 segment,the novel device consistently exhibited the smallest values across all conditions.(5)For the L3-4 segment,the novel device showed the greatest stress values under extension and left and right rotational conditions,while under other conditions,the values were lower than those in the bilateral pedicle screw fixation model.(6)Compared with pedicle screw fixation,the novel device produced smaller stress values at the L5-S1 segment.(7)This study indicates that,compared with pedicle screw fixation,the novel device impacts the biomechanics of the lumbar spine by fusing the facet joints.It provides stability while preserving the range of motion at the surgical segment and reduces stress on the intervertebral discs of the surgical and adjacent segments,thereby potentially delaying disc degeneration.This suggests that the novel device can achieve biomechanical effects similar to those of pedicle screw fixation in theory.

BACKGROUND:Facet joint osteoarthritis is acknowledged as a significant contributor to lower back pain in the geriatric population.The advent of an innovative spinal facet joint fusion device presents a therapeutic option for intervening during the initial stages of facet joint osteoarthritis,and significantly reduces the incidence of a series of complications caused by poor early conservative treatment and late surgical treatment.However,its effect on the biomechanics of the lumbar spine is unknown.OBJECTIVE:To investigate the biomechanical disparities between the novel lumbar zygapophyseal joint fusion device and traditional fusion devices.METHODS:A comprehensive three-dimensional finite element model of the L3-S1 lumbar spine was established and validated.Based on this intact model,three groups of surgical models were constructed:a bilateral pedicle screw fixation model,a bilateral novel facet joint fusion fixation model,and a bilateral facet screw fixation model,with the surgical segment designated as L4-5.Under a load of 500 N,a torque of 7.5 Nm was applied to all lumbar models to calculate the range of motion,displacement values,and intervertebral disc stress values at the L4-5 segment;stress values at the L3-4 and L5-S1 segments were also measured.RESULTS AND CONCLUSION:(1)Compared with the intact model,the range of motion at the L4-5 segment was reduced in all surgical models.(2)The novel device exhibited the smallest range of motion at the L4-5 segment under left and right rotational conditions;the greatest range of motion at the L4-5 segment under extension conditions;and a greater range of motion under other conditions than the bilateral pedicle screw fixation model.(3)The novel device demonstrated the smallest displacement values at the L4-5 segment under left and right rotational conditions;under other conditions,the displacement values at the L4-5 segment were greater than those in the bilateral pedicle screw fixation model.(4)In terms of stress distribution at the L4-5 segment,the novel device consistently exhibited the smallest values across all conditions.(5)For the L3-4 segment,the novel device showed the greatest stress values under extension and left and right rotational conditions,while under other conditions,the values were lower than those in the bilateral pedicle screw fixation model.(6)Compared with pedicle screw fixation,the novel device produced smaller stress values at the L5-S1 segment.(7)This study indicates that,compared with pedicle screw fixation,the novel device impacts the biomechanics of the lumbar spine by fusing the facet joints.It provides stability while preserving the range of motion at the surgical segment and reduces stress on the intervertebral discs of the surgical and adjacent segments,thereby potentially delaying disc degeneration.This suggests that the novel device can achieve biomechanical effects similar to those of pedicle screw fixation in theory.

Objective:To evaluate the safety and efficacy of mild hypothermia arch-clamping technique in the surgical treatment of DeBakey Type Ⅰ aortic dissection.Methods:From December 2019 to November 2023, a total of 97 patients with DeBakey type Ⅰ aortic dissection who underwent arch-clamping technique in Beijing Anzhen Hospital were prospectively enrolled. The patients were divided into mild hypothermia group and moderate hypothermia group according to the lowest rectal temperature during the circulatory arrest period. The perioperative data of the two groups were compared, and complex adverse outcomes consisting of 30-day death, stroke, paraplegia and CRRT were used as the primary endpoint. Multivariate logistic regression was used to determine the predictors of clinical adverse outcomes. Survival analysis was evaluated by the Kaplan- Meier method. Results:The overall incidence of complex adverse outcomes was 20.6%, 13.6% in the mild hypothermia group and 22.7% in the moderate hypothermia group( P=0.535), and the incidence of stroke was 4.6% and 6.7%( P=1.000), respectively. The cardiopulmonary bypass time and aortic-clamping time in the mild hypothermia group were significantly shortened (147.5 min vs. 163.0 min, P=0.032; 89 min vs. 99 min, P=0.042). There was no significant difference in long-term survival and reintervention between the two groups(91.9% vs. 89.3%, P=0.87; 9.1% vs. 5.3%, P=0.13). Conclusion:Mild hypothermia arch-clamping technique is a safe and effective method for the treatment of DeBakey type Ⅰ aortic dissection, with satisfactory short-term and long-term efficacy.

Contralateral radiculopathy, a postoperative complication after transforaminal lumbar interbody fusion, refers to postoperative numbness, pain and other neurological symptoms of the lower limb on the side opposite to the symptomatic or the surgical decompression side. Its main causes include excessive restoration of lordosis, intervertebral space tilt caused by improper cage position, poor screw position, new protrusion of nucleus pulposus or bone graft, and hematoma. At present, attention to this complication is gradually increasing. This review summarizes its risk factors from the recent related reports of the condition and puts forward preventive measures in order to promote the preventive awareness of this complication.

Objective:To investigate the short-term clinical efficacy of implantation with a 3D-printed microporous titanium prosthesis in the treatment of large segmental infectious tibial defects.Methods:A retrospective analysis was conducted of the electronic medical records of the 47 patients with large segmental tibial defects who had been treated with 3D-printed microporous titanium prostheses at Department of Orthopaedics, 920th Hospital of Joint Logistics Support Force from January 2019 to February 2024. The cohort included 36 males and 11 females, with an age of (46.2±11.8) years and a mean bone defect length of 12.3 (8.0, 16.8) cm. In the 19 patients complicated with soft tissue defects, the area of soft tissue defects ranged from 10.0 cm × 6.0 cm to 33.0 cm × 10.0 cm. For the 28 patients without soft tissue defects at the lower leg, the bone defects were filled with vancomycin-loaded calcium sulfate bone cement at the first stage; for the 19 patients complicated with soft tissue defects, the soft tissue defects at the lower limb were repaired using an anterolateral thigh flap with vascular anastomosis at the same time when bone defects were filled with vancomycin-loaded calcium sulfate bone cement at the first stage. After infection control at 2 to 8 months after surgery, individualized 3D-printed microporous titanium prostheses were implanted at the second stage to reconstruct the bone defects. Postoperative observations included the patients' first standing time, crutch walking time, full weight-bearing time, osseointegration of the tibial fracture and the prosthesis, and complications during follow-up.Results:The follow-up period for the 47 patients was (34.7±14.3) months. The first standing time was (2.2±0.6) months, crutch walking time (3.8±1.1) months, and full weight-bearing time (5.3±1.2) for this cohort. The evaluation by the Paley's bone healing score resulted in 25 excellent cases, 18 good cases, 1 medium case, and 3 poor cases, giving an excellent and good rate of 91.5% (43/47). One year after operation, the X-ray films showed that the tibial fractures and prostheses were well integrated in the 43 patients. Two patients developed recurrent tibial infection which was responded to replacement of the vancomycin-loaded calcium sulfate spacer. The fixation screws for tibial prosthesis were broken in one patient, but no recurrence of infection was observed after revision. The overall incidence of complications was 6.4% (3/47).Conclusion:In the treatment of large segmental infectious tibial defects, by facilitating rapid functional recovery and ensuring a low incidence of complications, implantation with a 3D-printed microporous titanium prosthesis demonstrates fine short-term clinical efficacy.