Objective:To investigate and summarize the imaging and pathological features of non-acute occlusion following flow diverter (FD) implantation in animal models.Methods:Four experimental pigs (experimental group) that experienced non-acute occlusion (occlusion time exceeding 24 hours) within the FD stent implanted in the common carotid artery, and 19 pigs (control group) that did not experience stent occlusion during the same period were involved. Using an interventional approach under digital subtraction angiography (DSA), the 4 occluded FD lumens were mechanically opened. Optical coherence tomography (OCT), intravascular ultrasound (IVUS) and histopathological examinations were performed to evaluate the intraluminal composition and characteristics of the occlusive tissues. These findings were compared with non-occluded FD stents to summarize the imaging and pathological changes within the occluded FD lumen.Results:The occlusion times of the FD stents in the 4 experimental pigs were 16 weeks, 20 weeks, 20 weeks, and 24 weeks postoperatively. All occluded stents were successfully recanalized under DSA, with a technical success rate of 4/4. Among the 19 non-occluded FD stents, OCT and IVUS revealed uniform (16 stents) or non-uniform (3 stents) neointimal coverage of the stent struts, presenting as homogeneous high/slightly high signal intensity or medium echogenicity. Histopathological examination indicated that the neointima was primarily composed of smooth muscle cells and a small amount of fibrous connective tissues. In contrast, the 4 occluded FD stents demonstrated excessive neointimal proliferation and plaque formation, leading to luminal loss, as shown by OCT and IVUS. The occlusion tissues predominantly presented as homogeneous high signal intensity with weak attenuation (fibrous plaques) on OCT, with some regions showing blurred low signal intensity and strong attenuation (lipid plaques). IVUS presented homogeneous echogenicity (fibrous plaques) and hypoechogenic zones (lipid plaques). Histopathological examination showed that the occlusion tissues mainly consisted of smooth muscle cells, fibrous connective tissues, and lipids, accompanied by numerous foam cells and a minor presence of inflammatory cells.Conclusions:Histopathological examinations confirm that non-acute occlusion of FD is mainly caused by excessive hyperplasia of intima along with the formation of fibrous plaques and lipid plaques. OCT and IVUS have typical finding in imaging that can assist in determining the cause of stent occlusion as well as the lesion's nature, thereby providing crucial guidance for subsequent clinical treatment and drug selection.

Objective:To compare the therapeutic efficacy of the dual anteromedial and anterolateral approaches versus that of the anterior midline approach in the treatment of Wahlquist type C medial tibial plateau fractures accompanied by posterior column collapse.Methods:A retrospective study was conducted to analyze the 21 patients who had been treated for Wahlquist type C medial tibial plateau fractures plus posterior column collapse at The Fourth Orthopedic Ward, The 72nd Group Army Hospital of PLA between January 2019 and August 2023. The cohort included 13 males and 8 females, with an age of (43.3±6.7) years. The left side was involved in 14 fractures and the right side in 7 ones. The patients were divided into 2 groups based on their surgical approaches: a dual-approach group ( n=13) undergoing fixation via the dual anteromedial and anterolateral approaches, and a single-approach group ( n=8) undergoing fixation via the anterior midline approach. Comparative parameters included operative time, intraoperative blood loss, fracture healing time, quality of fracture reduction, medial proximal tibial angle (MPTA), incision complications, postoperative bone mass reduction quality (evaluated according to the Rasmussen anatomical criteria for tibial condyle fracture reduction), lateral tibial plateau instability, incidence of genu varum, and post-traumatic arthritis. Functional recovery of the lower limb joints was assessed at the final follow-up using the Merchant criteria. Results:No statistically significant differences were observed in the baseline characteristics between the 2 groups preoperatively, indicating comparability ( P>0.05). All patients were followed up for a mean duration of (38.1±11.3) months. The postoperative MPTA in the dual-approach group (86.8°±0.8°) was significantly larger than that in the single-approach group (85.5°±0.9°) ( P<0.05). Genu varum occurred in 1 patient in the dual-approach group and in 4 patients in the single-approach group, while lateral tibial plateau instability was observed in 1 patient in the dual-approach group and in 4 patients in the single-approach group, showing statistically significant differences between the 2 groups ( P<0.05). No statistically significant differences were found between the 2 groups regarding operative time, intraoperative blood loss, fracture healing time, quality of fracture reduction, incidence of incision complications, or incidence of post-traumatic arthritis ( P>0.05). At the final follow-up, no statistically significant difference was observed in the functional recovery of the lower limb joints assessed by the Merchant criteria between the 2 groups ( P>0.05). Conclusion:In the treatment of Wahlquist type C medial tibial plateau fractures accompanied by posterior column collapse, compared with the single anterior midline approach, the dual anteromedial and anterolateral approaches can restore more effectively the MPTA, and reduce the incidences of genu varum and lateral tibial plateau instability.

AIM:To investigate the effect of intrinsic specific transforming growth factor-β(TGF-β)signaling on regeneration and repair of myofibers in acute skeletal myositismice model induced by cardiotoxin(CTX).METHODS:One hundred and eighty-six wild C57BL/6 mice and one hundred and thirty-eight mice with conditional knockout of TGF-β receptor 2(TGF-βr2)in myofibers(SM TGF-βr2-/-mice)were selected.CTX injection to anterior tibial muscle(TA)in-duced acute myoinjury in mice.Some SM TGF-βr2-/-mice were given Smad signaling agonist SRI-011381(SRI)intramus-cular injection.All mice were mainly divided into the following groups:control group,SM TGF-βr2-/-group and SM TGF-βr2-/-+SRI group.Twenty-four mice were selected in each group.RT-qPCR and immunofluorescence staining were used to detect the relative mRNA level,protein expression of inflammatory cytokines and low-density lipoprotein receptor-related protein 1(LRP1),respectively,while the relative protein expression of myosin heavy chain 3(MHY3)and embryonic myosine heavy chain(eMHC)in damaged muscle was detected by Western blot and immunofluorescence staining.In vi-tro,after being extracted from neonatal mice,myogenic precursor cells(MPCs)were cultured in an pro-inflammatory mi-lieu and treated with SRI,recombinant mouse extracellular matrix protein 1(rmECM1)alone or in combination.Hereby,they were divided into the following seven groups:control-MPCs group,control-MPCs+LPS group,TGF-βr2-/--MPCs group,TGF-βr2-/--MPCs+LPS group,TGF-βr2-/--MPCs+LPS+SRI group,TGF-βr2-/--MPCs+LPS+rmECM1 group,and TGF-βr2-/--MPCs+LPS+SRI+rmECM1 group.Six mice were selected in each group.RT-qPCR and Western blot were used to detect the relative mRNA level,protein expression of major histocompatibility complex class I molecules(MHC-I/H-2Kb),major histocompatibility complex class II molecules(MHC-II/H2-Eα),Toll-like receptor 3(TLR3),and LRP1.And the relative protein expression of MoyD and myogenin in myotubes was detected by immunofluorescence staining.RE-SULTS:In vivo,compared with control group,SM TGF-βr2-/-group showed the significant upregulation of pro-inflamma-tory cytokines(P<0.05),and the opposite trend of anti-inflammatory cytokines,LRP1,MHY3,eMHC in the injured muscle(P<0.05),with delayed regeneration and repair of myofibers.In vitro,compared with control-MPCs+LPS group,LRP1,MoyD and myogenin significantly downregulated in TGF-βr2-/--MPCs+LPS group,but the downregulation trend was corrected after giving SRI treatment(P<0.05).In addition,compared with the TGF-βr2-/--MPCs+LPS group,the combi-nation of rmECM1 and SRI significantly upregulated the protein expression of MyoD and myogenin(P<0.05).CONCLU-SION:In a mouse model of acute skeletal myositis,intrinsic TGF-β signaling specifically in myofibers regulates local im-mune behavior.It promotes the expression of LRP1 in damaged muscle via Smad2/3 signaling,and LRP1 can then fully bind to ECM1,thereby facilitating muscle regeneration and repair,and improving the prognosis of acute skeletal myositis.

AIM:To investigate the effect of intrinsic specific transforming growth factor-β(TGF-β)signaling on regeneration and repair of myofibers in acute skeletal myositismice model induced by cardiotoxin(CTX).METHODS:One hundred and eighty-six wild C57BL/6 mice and one hundred and thirty-eight mice with conditional knockout of TGF-β receptor 2(TGF-βr2)in myofibers(SM TGF-βr2-/-mice)were selected.CTX injection to anterior tibial muscle(TA)in-duced acute myoinjury in mice.Some SM TGF-βr2-/-mice were given Smad signaling agonist SRI-011381(SRI)intramus-cular injection.All mice were mainly divided into the following groups:control group,SM TGF-βr2-/-group and SM TGF-βr2-/-+SRI group.Twenty-four mice were selected in each group.RT-qPCR and immunofluorescence staining were used to detect the relative mRNA level,protein expression of inflammatory cytokines and low-density lipoprotein receptor-related protein 1(LRP1),respectively,while the relative protein expression of myosin heavy chain 3(MHY3)and embryonic myosine heavy chain(eMHC)in damaged muscle was detected by Western blot and immunofluorescence staining.In vi-tro,after being extracted from neonatal mice,myogenic precursor cells(MPCs)were cultured in an pro-inflammatory mi-lieu and treated with SRI,recombinant mouse extracellular matrix protein 1(rmECM1)alone or in combination.Hereby,they were divided into the following seven groups:control-MPCs group,control-MPCs+LPS group,TGF-βr2-/--MPCs group,TGF-βr2-/--MPCs+LPS group,TGF-βr2-/--MPCs+LPS+SRI group,TGF-βr2-/--MPCs+LPS+rmECM1 group,and TGF-βr2-/--MPCs+LPS+SRI+rmECM1 group.Six mice were selected in each group.RT-qPCR and Western blot were used to detect the relative mRNA level,protein expression of major histocompatibility complex class I molecules(MHC-I/H-2Kb),major histocompatibility complex class II molecules(MHC-II/H2-Eα),Toll-like receptor 3(TLR3),and LRP1.And the relative protein expression of MoyD and myogenin in myotubes was detected by immunofluorescence staining.RE-SULTS:In vivo,compared with control group,SM TGF-βr2-/-group showed the significant upregulation of pro-inflamma-tory cytokines(P<0.05),and the opposite trend of anti-inflammatory cytokines,LRP1,MHY3,eMHC in the injured muscle(P<0.05),with delayed regeneration and repair of myofibers.In vitro,compared with control-MPCs+LPS group,LRP1,MoyD and myogenin significantly downregulated in TGF-βr2-/--MPCs+LPS group,but the downregulation trend was corrected after giving SRI treatment(P<0.05).In addition,compared with the TGF-βr2-/--MPCs+LPS group,the combi-nation of rmECM1 and SRI significantly upregulated the protein expression of MyoD and myogenin(P<0.05).CONCLU-SION:In a mouse model of acute skeletal myositis,intrinsic TGF-β signaling specifically in myofibers regulates local im-mune behavior.It promotes the expression of LRP1 in damaged muscle via Smad2/3 signaling,and LRP1 can then fully bind to ECM1,thereby facilitating muscle regeneration and repair,and improving the prognosis of acute skeletal myositis.

Objective:To investigate and summarize the imaging and pathological features of non-acute occlusion following flow diverter (FD) implantation in animal models.Methods:Four experimental pigs (experimental group) that experienced non-acute occlusion (occlusion time exceeding 24 hours) within the FD stent implanted in the common carotid artery, and 19 pigs (control group) that did not experience stent occlusion during the same period were involved. Using an interventional approach under digital subtraction angiography (DSA), the 4 occluded FD lumens were mechanically opened. Optical coherence tomography (OCT), intravascular ultrasound (IVUS) and histopathological examinations were performed to evaluate the intraluminal composition and characteristics of the occlusive tissues. These findings were compared with non-occluded FD stents to summarize the imaging and pathological changes within the occluded FD lumen.Results:The occlusion times of the FD stents in the 4 experimental pigs were 16 weeks, 20 weeks, 20 weeks, and 24 weeks postoperatively. All occluded stents were successfully recanalized under DSA, with a technical success rate of 4/4. Among the 19 non-occluded FD stents, OCT and IVUS revealed uniform (16 stents) or non-uniform (3 stents) neointimal coverage of the stent struts, presenting as homogeneous high/slightly high signal intensity or medium echogenicity. Histopathological examination indicated that the neointima was primarily composed of smooth muscle cells and a small amount of fibrous connective tissues. In contrast, the 4 occluded FD stents demonstrated excessive neointimal proliferation and plaque formation, leading to luminal loss, as shown by OCT and IVUS. The occlusion tissues predominantly presented as homogeneous high signal intensity with weak attenuation (fibrous plaques) on OCT, with some regions showing blurred low signal intensity and strong attenuation (lipid plaques). IVUS presented homogeneous echogenicity (fibrous plaques) and hypoechogenic zones (lipid plaques). Histopathological examination showed that the occlusion tissues mainly consisted of smooth muscle cells, fibrous connective tissues, and lipids, accompanied by numerous foam cells and a minor presence of inflammatory cells.Conclusions:Histopathological examinations confirm that non-acute occlusion of FD is mainly caused by excessive hyperplasia of intima along with the formation of fibrous plaques and lipid plaques. OCT and IVUS have typical finding in imaging that can assist in determining the cause of stent occlusion as well as the lesion's nature, thereby providing crucial guidance for subsequent clinical treatment and drug selection.

Objective:To compare the therapeutic efficacy of the dual anteromedial and anterolateral approaches versus that of the anterior midline approach in the treatment of Wahlquist type C medial tibial plateau fractures accompanied by posterior column collapse.Methods:A retrospective study was conducted to analyze the 21 patients who had been treated for Wahlquist type C medial tibial plateau fractures plus posterior column collapse at The Fourth Orthopedic Ward, The 72nd Group Army Hospital of PLA between January 2019 and August 2023. The cohort included 13 males and 8 females, with an age of (43.3±6.7) years. The left side was involved in 14 fractures and the right side in 7 ones. The patients were divided into 2 groups based on their surgical approaches: a dual-approach group ( n=13) undergoing fixation via the dual anteromedial and anterolateral approaches, and a single-approach group ( n=8) undergoing fixation via the anterior midline approach. Comparative parameters included operative time, intraoperative blood loss, fracture healing time, quality of fracture reduction, medial proximal tibial angle (MPTA), incision complications, postoperative bone mass reduction quality (evaluated according to the Rasmussen anatomical criteria for tibial condyle fracture reduction), lateral tibial plateau instability, incidence of genu varum, and post-traumatic arthritis. Functional recovery of the lower limb joints was assessed at the final follow-up using the Merchant criteria. Results:No statistically significant differences were observed in the baseline characteristics between the 2 groups preoperatively, indicating comparability ( P>0.05). All patients were followed up for a mean duration of (38.1±11.3) months. The postoperative MPTA in the dual-approach group (86.8°±0.8°) was significantly larger than that in the single-approach group (85.5°±0.9°) ( P<0.05). Genu varum occurred in 1 patient in the dual-approach group and in 4 patients in the single-approach group, while lateral tibial plateau instability was observed in 1 patient in the dual-approach group and in 4 patients in the single-approach group, showing statistically significant differences between the 2 groups ( P<0.05). No statistically significant differences were found between the 2 groups regarding operative time, intraoperative blood loss, fracture healing time, quality of fracture reduction, incidence of incision complications, or incidence of post-traumatic arthritis ( P>0.05). At the final follow-up, no statistically significant difference was observed in the functional recovery of the lower limb joints assessed by the Merchant criteria between the 2 groups ( P>0.05). Conclusion:In the treatment of Wahlquist type C medial tibial plateau fractures accompanied by posterior column collapse, compared with the single anterior midline approach, the dual anteromedial and anterolateral approaches can restore more effectively the MPTA, and reduce the incidences of genu varum and lateral tibial plateau instability.

Objective To investigate the effect of E2 signaling in myofibers on muscular macrophage efferocytosis in mice with cardiotoxin-induced acute skeletal muscle injury.Methods Female wild-type C57BL/6 mice with and without ovariectomy and male C57BL/6 mice were given a CTX injection into the anterior tibial muscle to induce acute muscle injury,followed by intramuscular injection of β-estradiol(E2)or 4-hydroxytamoxifen(4-OHT).The changes in serum E2 of the mice were detected using ELISA,and the number,phenotypes,and efferocytosis of the macrophages in the inflammatory exudates and myofiber regeneration and repair were evaluated using immunofluorescence staining and flow cytometry.C2C12 cells were induced to differentiate into mature myotubes,which were treated with IFN-γ for 24 before treatment with β-Estradiol or 4-OHT.The treated myotubes were co-cultured with mouse peritoneal macrophages in a 1:2 ratio,followed by addition of PKH67-labeled apoptotic mouse mononuclear spleen cells induced by UV irradiation,and macrophage efferocytosis was observed using immunofluorescence staining and flow cytometry.Results Compared with the control mice,the female mice with ovariectomy showed significantly increased mononuclear macrophages in the inflammatory exudates,with increased M1 cell percentage,reduced M2 cell percentage and macrophage efferocytosis in the injured muscle,and obviously delayed myofiber regeneration and repair.In the cell co-culture systems,treatment of the myotubes with β-estradiol significantly increased the number and proportion of M2 macrophages and macrophage efferocytosis,while 4-OHT treatment resulted in the opposite changes.Conclusion In injured mouse skeletal muscles,myofiber E2 signaling promotes M1 to M2 transition to increase macrophage efferocytosis,thereby relieving inflammation and promoting muscle regeneration and repair.

Objective:To investigate the application value of optical coherence tomography (OCT) and intravascular ultrasound (IVUS) in evaluating flow diverter (FD) apposition and endothelialization in aneurysm animal models, and analyze the effect of incomplete stent apposition (ISA) on aneurysm lumen healing and stent endothelialization.Methods:Lateral common carotid artery aneurysm models in swines were established by surgical method and then FD was implanted. Immediately after surgery, OCT and IVUS were used to evaluate the locations and degrees of ISA, and difference between these 2 methods in evaluating FD apposition was compared. DSA was performed at 12 weeks after surgery to evaluate the aneurysm occlusion (Kamran grading) and stent patency. OCT and IVUS were used again to observe the stent endothelial situation; by comparing with histopathologic results, effect of ISA on aneurysm healing and stent endothelialization was analyzed.Results:Lateral common carotid artery aneurysm models in 6 swines were established, and 6 Tubridge FDs were successfully implanted. Compared with IVUS (3 stents, 4 locus), OCT could detect more ISA (6 stents, 14 locus); and the vascular diameter change area (7 locus), aneurysm neck area (4 locus) and the head and tail of FD (3 locus) were the main sites of FD malapposition; average distance between stent wire and vessel wall was (560.14±101.48) μm. At 12 weeks after surgery, DSA showed that 1 patient had a little residual contrast agent at the aneurysm neck (Kamran grading 3), and the remaining 5 had complete aneurysm occlusion (Kamran grading 4). One FD had moderate lumen stenosis, and the other 5 FDs had lumen patency. OCT indicated mostly disappeared acute ISA; ISA proportion decreased to 21.4 % (3/14), including 2 in the aneurysm neck and 1 in the partial stent. Histopathological results showed bare stent woven silk, without obvious endothelial coverage; in one FD with luminal stenosis, intimal hyperplasia was mainly composed of vascular smooth muscle cells.Conclusion:In carotid artery aneurysm model with FD implantation, OCT can detect more ISA than IVUS; most acute ISA have good outcome at 12 th week of follow-up, while severe ISA can cause delayed FD endothelialization and delayed aneurysm occlusion.

Objective To investigate the effect of E2 signaling in myofibers on muscular macrophage efferocytosis in mice with cardiotoxin-induced acute skeletal muscle injury.Methods Female wild-type C57BL/6 mice with and without ovariectomy and male C57BL/6 mice were given a CTX injection into the anterior tibial muscle to induce acute muscle injury,followed by intramuscular injection of β-estradiol(E2)or 4-hydroxytamoxifen(4-OHT).The changes in serum E2 of the mice were detected using ELISA,and the number,phenotypes,and efferocytosis of the macrophages in the inflammatory exudates and myofiber regeneration and repair were evaluated using immunofluorescence staining and flow cytometry.C2C12 cells were induced to differentiate into mature myotubes,which were treated with IFN-γ for 24 before treatment with β-Estradiol or 4-OHT.The treated myotubes were co-cultured with mouse peritoneal macrophages in a 1:2 ratio,followed by addition of PKH67-labeled apoptotic mouse mononuclear spleen cells induced by UV irradiation,and macrophage efferocytosis was observed using immunofluorescence staining and flow cytometry.Results Compared with the control mice,the female mice with ovariectomy showed significantly increased mononuclear macrophages in the inflammatory exudates,with increased M1 cell percentage,reduced M2 cell percentage and macrophage efferocytosis in the injured muscle,and obviously delayed myofiber regeneration and repair.In the cell co-culture systems,treatment of the myotubes with β-estradiol significantly increased the number and proportion of M2 macrophages and macrophage efferocytosis,while 4-OHT treatment resulted in the opposite changes.Conclusion In injured mouse skeletal muscles,myofiber E2 signaling promotes M1 to M2 transition to increase macrophage efferocytosis,thereby relieving inflammation and promoting muscle regeneration and repair.

Objective:To evaluate the prognostic value of pretreatment systemic immune-inflammation index (SII) and lactate dehydrogenase (LDH) in non-metastatic nasopharyngeal carcinoma (NPC).Methods:We retrospectively collected the data of 839 patients with non-metastatic NPC from National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital and Sun Yat-sen University Cancer Center between January 2007 and October 2015. All patients received intensity modulated radiation based treatment. Optimal cutoff value of SII and LDH were determined by X-title software. The association between SII, LDH and clinical prognosis of non-metastatic NPC patients were analyzed. Kaplan-Meier method was used for survival analysis, and Log rank test was used for comparison of survival rates between groups. Propensity score matching (PSM) analysis was carried out to minimize the effects of confounding factors. The risk stratification model of prognosis by combining N stage, SII and LDH was constructed to compare the prognosis of patients in high risk group, middle risk group and low risk group, and the receiver operating characteristic (ROC) curve analysis was used to evaluate its prognostic value.Results:The optimal cutoff value of SII is 447.2×10 9/L for predicting the 5-year overall survival (OS) of NPC patients, and the best cutoff value of LDH is 198.9 U/L. The proportion of patients with stage T3-4 and stage III-IVB in high SII group was higher than that in low SII group ( P<0.001). Multivariate Cox regression analysis showed that N stage, SII and LDH were independent factors of OS, progression-free survival (PFS) and distant metastasis-free survival (DMFS) of NPC patients (N stage, HR=1.705, 95% CI: 1.247-2.332; HR=1.755, 95% CI: 1.342-2.295; HR=2.161, 95% CI: 1.515-3.082. SII, HR=1.525, 95% CI: 1.097-2.119; HR=1.518, 95% CI: 1.150-2.004; HR=1.837, 95% CI: 1.272-2.653. LDH, HR=2.041, 95% CI: 1.403-2.968; HR=1.725, 95% CI: 1.233-2.414; HR=2.492, 95% CI: 1.690-3.672, respectively). After PSM, SII was still an independent prognostic factor of OS, PFS and DMFS in NPC patients ( HR=1.52, 95% CI: 1.09-2.12; HR=1.52, 95% CI: 1.15-2.00; HR=1.82, 95% CI: 1.26-2.63, respectively). Combined with N 2-3 stage, SII (>447.2×10 9/L), and LDH (>198.9 U/L), patients were divided into high-(3 risk factors), intermediate- (2 risk factors) and low-risk (0-1 risk factors) groups. The 5-year OS rates of patients in low-, intermediate- and high-risk groups were 86.1%, 79.8% and 41.2% respectively, the 5-year PFS rates were 80.7%, 70.2% and 33.9% respectively, and the 5-year DMFS rates were 88.9%, 79.2% and 47.5% respectively. There were significant differences in OS, PFS and DMFS among these three groups ( P<0.001). Distant metastasis was the main failure pattern in low-, intermediate- and high-risk groups, and the highest rate of distant metastasis was 83.3% (15/31) in high-risk group. ROC curve of the risk stratification model for predicting 5-year OS of NPC patients is 0.610, which is higher than TNM stage (0.609), SII (0.574) and LDH (0.558). Conclusions:Pretreatment SII and LDH are significantly correlated with the prognosis of patients with non-metastatic NPC. The combination of SII, LDH and N stage can stratify the prognostic risk of NPC patients. The risk stratification model can enhance the accuracy of prognosis.