Demyelination and remyelination play key roles in spinal cord injury (SCI), affecting the recovery of motor and sensory functions. Research in rodent models is extensive, but the study of these processes in non-human primates is limited. Therefore, our goal was to thoroughly study the histological features of demyelination and remyelination after contusion injury of the cervical spinal cord in Macaca fascicularis. In a previous study, we created an SCI model in M. fascicularis by controlling the contusion displacement. We used Eriochrome Cyanine staining, immunohistochemical analysis, and toluidine blue staining to evaluate demyelination and remyelination. The results showed demyelination ipsilateral to the injury epicenter both rostrally and caudally, the former mainly impacting sensory pathways, while the latter primarily affected motor pathways. Toluidine blue staining showed myelin loss and axonal distension at the injury site. Schwann cell-derived myelin sheaths were only found at the center, while thinner myelin sheaths from oligodendrocytes were seen at the center and surrounding areas. Our study showed that long-lasting demyelination occurs in the spinal cord of M. fascicularis after SCI, with oligodendrocytes and Schwann cells playing a significant role in myelin sheath formation at the injury site.
Animals ; Spinal Cord Injuries/physiopathology* ; Demyelinating Diseases/etiology* ; Remyelination/physiology* ; Macaca fascicularis ; Disease Models, Animal ; Myelin Sheath/pathology* ; Oligodendroglia/pathology* ; Schwann Cells/pathology* ; Female ; Spinal Cord/pathology* ; Axons/pathology*

Peroxisome proliferator activated receptor-α (PPAR-α) is significantly expressed in various tissues such as the liver, kidney, myocardium, and skeletal muscle, which plays a central role in the development of various diseases by regulating key physiological processes such as energy homeostasis, redox balance, inflammatory response, and ferroptosis. As an important metabolic and excretory organ of the body, renal dysfunction can lead to water and electrolyte imbalance, toxin accumulation, and multiple system complications. The causes of kidney injury are complex and diverse, including acute injury factors (such as ischemia/reperfusion, nephrotoxic drugs, septic shock, and immune glomerulopathy), as well as chronic progressive causes [such as metabolic disease-related nephropathy, hypertensive nephropathy (HN)], and risk factors such as alcohol abuse, obesity, and aging. This review briefly describes the structure, function, and activity regulation mechanism of PPAR-α, systematically elucidates the molecular regulatory network of PPAR-α in the pathological process of kidney injury including acute kidney injury (AKI) such as renal ischemia/reperfusion injury (IRI), drug-induced AKI, sepsis-associated acute kidney injury (SA-AKI), glomerulonephritis, chronic kidney disease (CKD) such as diabetic nephropathy (DN), HN, and other kidney injury, and summarizes the mechanisms related to PPAR-α regulation of kidney injury, including regulation of metabolism, antioxidation, anti-inflammation, anti-fibrosis, and anti-ferroptosis. This review also evaluates PPAR-α's medical value as a novel therapeutic target, and aims to provide theoretical basis for the development of kidney protection strategies based on PPAR-α targeted intervention.
Humans ; PPAR alpha/metabolism* ; Acute Kidney Injury/therapy* ; Animals ; Kidney/metabolism*

Objective To investigate the effects of inclined axial compressive force and flexion moment on the anterior and posterior shear stiffness of the lumbosacral segment.Methods Six fresh-frozen human cadaveric L5-S1 segments were tested under intact and two progressively impaired structural conditions:intact,a 4-mm bilateral facet joint gap,and anterior discectomy with nucleus pulposus removal plus circumferential release of the inner annular fibers(disc injury).A 300 N axial compressive force was applied either vertically downward or with a 10° or 20° anterior inclination through the disc's shear center.Anterior(0 N to 250 N)and posterior(-50 N to 0 N)shear tests were conducted using a material testing machine.These tests were repeated under a 5 N-m flexion moment.The relative motion between L5 and Si was measured using a three-dimensional motion capture system.Results In the intact state,the inclination of the axial compressive force did not significantly alter anterior or posterior shear stiffness.However,the application of a flexion moment increased anterior shear stiffness by 49.3％.Progressive structural damage resulted in incremental increases in anteroposterior shear translation and corresponding reductions in stiffness.Notably,under combined loading with axial compression and flexion moment,anterior stiffness decreased from 939 N/mm(intact)to 224 N/mm(disc injury),while posterior stiffness decreased from 572 N/mm to 217 N/mm.Within the low-load range,no significant differences in shear stiffness were observed across any structural conditions,regardless of axial force inclination or combined with a flexion moment.Conclusions This study supports the clinical view that retro-inclination of the pelvis serves as a compensatory mechanism to enhance segmental shear stability.However,this compensatory capacity gradually diminishes and ultimately fails as spinal degeneration progresses.

Objective:To investigate the differences in acute intestinal injury and regulatory mechanisms in mice following carbon ion FLASH radiotherapy (FLASH-RT) and conventional dose rate radiotherapy (CONV-RT).Methods:Healthy C57BL/6J mice were randomly divided into three groups: control group, FLASH-RT group (100 Gy/s), and CONV-RT group (0.1 Gy/s), with 9 mice in each group. All mice received carbon ion whole abdominal radiotherapy. DNA double-strand breaks (DSB) and cell proliferation were evaluated by measuring the expression of phosphorylated histone H2AX (γ-H2AX) and nuclear-associated antigen 67 (Ki67) using immunohistochemistry; apoptosis was analyzed using terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL); transcriptome sequencing was used to analyze the differences in molecular pathways between FLASH-RT and CONV-RT.Results:Compared with the CONV-RT group, the FLASH-RT group showed significantly reduced intestinal γ-H2AX signal at 3 h after radiotherapy ( t=3.80, P<0.01), significantly increased expression of Ki67 at the base of intestinal crypts at 6 h after radiotherapy ( t=4.30, P<0.001), and a significantly decreased number of TUNEL-positive cells at 12 h after radiotherapy ( t=3.08, P<0.01). Transcriptome sequencing analysis showed that FLASH-RT specifically activated the insulin-like growth factor (IGF) pathway, avoiding the excessive activation of CONV-RT-induced nuclear factor-κB and B cell receptor inflammatory pathways as well as the inhibition of energy metabolism. Conclusions:Compared with CONV-RT, carbon ion FLASH-RT can reduce DSB damage, preserve the proliferative activity of intestinal stem cells, activate the IGF pathway, and regulate inflammatory, immune, and metabolic pathways, thereby significantly alleviating acute intestinal epithelial injury. Specifically, the regulation of repair pathways mediated by reduced DSB and the inhibition of inflammatory pathways are potential protective mechanisms for normal tissues.

Objective:To explore the clinical efficacy of "four-step" aortic valve anatomic repair for bicuspid aortic valve(BAV) with aortic regurgitation(AR).Methods:From August 2021 to November 2024, a total of 298 consecutive patients with BAV-AR underwent aortic valve anatomic repair(AVr) in Shanghai Zhongshan Hospital Fudan University, 266 males and 32 females, with age of 39(29.5, 48.5) years. All patients underwent " four-step" three-dimensional anatomic repair of the aortic annulus and leaflets, 129(43.3%) patients via upper mini-sternotomy and 169(56.7%) patients via conventional median sternotomy, with the main steps including: (1) deep dissecting and annuloplasty of the virtual basal ring(VBR); (2) symmetrical repairing of leaflets; (3) replacement or remodeling of the sinus of Valsalva; (4) annuloplasty of the sinotubular junction(STJ). Basal and perioperative data were retrospectively collected, and statistical analysis was performed in conjunction with follow-up data.Results:All patients successfully underwent anatomical repair without transferring to valve replacement during operation. Among them, 43 patients underwent aortic root reimplantation technique(Reimplantation group), while 255 patients underwent modified aortic root sleeve remodeling technique(Sleeve group). The median cardiopulmonary bypass time for the Reimplantation and Sleeve groups were 154(134, 169) minutes and 111(95, 129) minutes, respectively( P<0.05); the median aortic cross-clamp time were 112(100, 131) minutes and 80(67, 94) minutes, respectively( P<0.05). Preoperative TEE showed 35 patients(81.4%) and 229 patients(89.8%) with moderate and severe AR in Reimplantation and Sleeve groups, respectively. Postoperative TEE showed 41 patients(95.3%) with no/trace AR and 2 patients(4.7%) with central mild AR in Reimplantation group, while 212 patients(83.1%) with no/trace AR and 43 patients(16.9%) with central mild AR in Sleeve group. Follow-up was completed in all patients, with a median follow-up of 12.9(4.7, 21.2) months. Echocardiography was obtained in 271 patients(90.9%) at the latest follow-up, including no/trace AR in 167 patients(56.0%), mild AR in 89 patients(29.9%), moderate AR in 14 patients(4.7%), and severe AR in 1 patient(0.3%). Conclusion:Aortic valve anatomic repair by standardized "four-step" approach is safe and reproducible. Satisfied short- and mid-term outcome have obtained in selected BAV-AR patients.

OBJECTIVE To explore the indexes affecting the prognosis of the ICU patients with sepsis,establish the nomogram model for prediction of 28-day mortality rate,and validate it.METHODS On the basis of criteria for diagnosis of sepsis(3.0 version),the related data of the sepsis patients were extracted from Medical Information Mart for Intensive Care-Ⅳ(MIMIC-Ⅳ)database for retrospective study and were randomly divided into the train-ing set and the validation set in a 7∶3 ratio.Univariate analysis and multivariate Cox proportional risk regression analysis were performed for the screening of influencing factors for prediction of 28-day mortality of the sepsis pa-tients.The nomogram prediction model was established based on the screened factors and was validated by the val-idation set,and the effect was evaluated.RESULTS A total of 7 955 sepsis patients were included.Seven variables were selected to establish the nomogram model for prediction of the 28-day mortality rate.The nomogram showed favorable performance in identification between the two cohorts,the area under receiver operating characteristic curves(AUROCs)were 0.748 and 0.721,respectively.Calibration curves and Hosmer-Lemeshow test(x2=8.689,10.614;P=0.369,0.225)indicated that the model had remarkable effect on correction.With the per-formance of decision curve analysis(DCA)and clinical impact curve(CIC),the model was considered to have high clinical application value.CONCLUSIONS The nomogram model shows favorable performance in prediction of the 28-day mortality rate and calibration capability.It is worthy to be further promoted and applied.

Objective To investigate the effects of inclined axial compressive force and flexion moment on the anterior and posterior shear stiffness of the lumbosacral segment.Methods Six fresh-frozen human cadaveric L5-S1 segments were tested under intact and two progressively impaired structural conditions:intact,a 4-mm bilateral facet joint gap,and anterior discectomy with nucleus pulposus removal plus circumferential release of the inner annular fibers(disc injury).A 300 N axial compressive force was applied either vertically downward or with a 10° or 20° anterior inclination through the disc's shear center.Anterior(0 N to 250 N)and posterior(-50 N to 0 N)shear tests were conducted using a material testing machine.These tests were repeated under a 5 N-m flexion moment.The relative motion between L5 and Si was measured using a three-dimensional motion capture system.Results In the intact state,the inclination of the axial compressive force did not significantly alter anterior or posterior shear stiffness.However,the application of a flexion moment increased anterior shear stiffness by 49.3％.Progressive structural damage resulted in incremental increases in anteroposterior shear translation and corresponding reductions in stiffness.Notably,under combined loading with axial compression and flexion moment,anterior stiffness decreased from 939 N/mm(intact)to 224 N/mm(disc injury),while posterior stiffness decreased from 572 N/mm to 217 N/mm.Within the low-load range,no significant differences in shear stiffness were observed across any structural conditions,regardless of axial force inclination or combined with a flexion moment.Conclusions This study supports the clinical view that retro-inclination of the pelvis serves as a compensatory mechanism to enhance segmental shear stability.However,this compensatory capacity gradually diminishes and ultimately fails as spinal degeneration progresses.

Objective:To investigate the differences in acute intestinal injury and regulatory mechanisms in mice following carbon ion FLASH radiotherapy (FLASH-RT) and conventional dose rate radiotherapy (CONV-RT).Methods:Healthy C57BL/6J mice were randomly divided into three groups: control group, FLASH-RT group (100 Gy/s), and CONV-RT group (0.1 Gy/s), with 9 mice in each group. All mice received carbon ion whole abdominal radiotherapy. DNA double-strand breaks (DSB) and cell proliferation were evaluated by measuring the expression of phosphorylated histone H2AX (γ-H2AX) and nuclear-associated antigen 67 (Ki67) using immunohistochemistry; apoptosis was analyzed using terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL); transcriptome sequencing was used to analyze the differences in molecular pathways between FLASH-RT and CONV-RT.Results:Compared with the CONV-RT group, the FLASH-RT group showed significantly reduced intestinal γ-H2AX signal at 3 h after radiotherapy ( t=3.80, P<0.01), significantly increased expression of Ki67 at the base of intestinal crypts at 6 h after radiotherapy ( t=4.30, P<0.001), and a significantly decreased number of TUNEL-positive cells at 12 h after radiotherapy ( t=3.08, P<0.01). Transcriptome sequencing analysis showed that FLASH-RT specifically activated the insulin-like growth factor (IGF) pathway, avoiding the excessive activation of CONV-RT-induced nuclear factor-κB and B cell receptor inflammatory pathways as well as the inhibition of energy metabolism. Conclusions:Compared with CONV-RT, carbon ion FLASH-RT can reduce DSB damage, preserve the proliferative activity of intestinal stem cells, activate the IGF pathway, and regulate inflammatory, immune, and metabolic pathways, thereby significantly alleviating acute intestinal epithelial injury. Specifically, the regulation of repair pathways mediated by reduced DSB and the inhibition of inflammatory pathways are potential protective mechanisms for normal tissues.

OBJECTIVE To explore the indexes affecting the prognosis of the ICU patients with sepsis,establish the nomogram model for prediction of 28-day mortality rate,and validate it.METHODS On the basis of criteria for diagnosis of sepsis(3.0 version),the related data of the sepsis patients were extracted from Medical Information Mart for Intensive Care-Ⅳ(MIMIC-Ⅳ)database for retrospective study and were randomly divided into the train-ing set and the validation set in a 7∶3 ratio.Univariate analysis and multivariate Cox proportional risk regression analysis were performed for the screening of influencing factors for prediction of 28-day mortality of the sepsis pa-tients.The nomogram prediction model was established based on the screened factors and was validated by the val-idation set,and the effect was evaluated.RESULTS A total of 7 955 sepsis patients were included.Seven variables were selected to establish the nomogram model for prediction of the 28-day mortality rate.The nomogram showed favorable performance in identification between the two cohorts,the area under receiver operating characteristic curves(AUROCs)were 0.748 and 0.721,respectively.Calibration curves and Hosmer-Lemeshow test(x2=8.689,10.614;P=0.369,0.225)indicated that the model had remarkable effect on correction.With the per-formance of decision curve analysis(DCA)and clinical impact curve(CIC),the model was considered to have high clinical application value.CONCLUSIONS The nomogram model shows favorable performance in prediction of the 28-day mortality rate and calibration capability.It is worthy to be further promoted and applied.

Objective:To explore the clinical efficacy of "four-step" aortic valve anatomic repair for bicuspid aortic valve(BAV) with aortic regurgitation(AR).Methods:From August 2021 to November 2024, a total of 298 consecutive patients with BAV-AR underwent aortic valve anatomic repair(AVr) in Shanghai Zhongshan Hospital Fudan University, 266 males and 32 females, with age of 39(29.5, 48.5) years. All patients underwent " four-step" three-dimensional anatomic repair of the aortic annulus and leaflets, 129(43.3%) patients via upper mini-sternotomy and 169(56.7%) patients via conventional median sternotomy, with the main steps including: (1) deep dissecting and annuloplasty of the virtual basal ring(VBR); (2) symmetrical repairing of leaflets; (3) replacement or remodeling of the sinus of Valsalva; (4) annuloplasty of the sinotubular junction(STJ). Basal and perioperative data were retrospectively collected, and statistical analysis was performed in conjunction with follow-up data.Results:All patients successfully underwent anatomical repair without transferring to valve replacement during operation. Among them, 43 patients underwent aortic root reimplantation technique(Reimplantation group), while 255 patients underwent modified aortic root sleeve remodeling technique(Sleeve group). The median cardiopulmonary bypass time for the Reimplantation and Sleeve groups were 154(134, 169) minutes and 111(95, 129) minutes, respectively( P<0.05); the median aortic cross-clamp time were 112(100, 131) minutes and 80(67, 94) minutes, respectively( P<0.05). Preoperative TEE showed 35 patients(81.4%) and 229 patients(89.8%) with moderate and severe AR in Reimplantation and Sleeve groups, respectively. Postoperative TEE showed 41 patients(95.3%) with no/trace AR and 2 patients(4.7%) with central mild AR in Reimplantation group, while 212 patients(83.1%) with no/trace AR and 43 patients(16.9%) with central mild AR in Sleeve group. Follow-up was completed in all patients, with a median follow-up of 12.9(4.7, 21.2) months. Echocardiography was obtained in 271 patients(90.9%) at the latest follow-up, including no/trace AR in 167 patients(56.0%), mild AR in 89 patients(29.9%), moderate AR in 14 patients(4.7%), and severe AR in 1 patient(0.3%). Conclusion:Aortic valve anatomic repair by standardized "four-step" approach is safe and reproducible. Satisfied short- and mid-term outcome have obtained in selected BAV-AR patients.