AIM:To observe the therapeutic efficacy of 25G+minimally invasive vitrectomy for retinal arterial macroaneurysm.METHODS:Totally 40 patients(40 eyes)who admitted to Jinan Mingshui Eye Hospital from January 2021 to May 2024 and with vitreous hemorrhage or dense premacular hemorrhage in the macular area caused by retinal arterial macroaneurysm, underwent 25G+minimally invasive vitrectomy. Preoperative and postoperative best-corrected visual acuity(BCVA), complications, and special cases were analyzed.RESULTS: The general patient data aligned with previous literature reports. The postoperative BCVA was significantly improved(t=9.72, P<0.01), and no significant serious surgical complications were observed. Notably, intraoperative findings revealed secondary macular holes in 3 eyes, resulting in poor visual prognosis.CONCLUSION: For vitreous hemorrhage or dense premacular hemorrhage caused by retinal arterial macroaneurysm, 25G+ minimally invasive vitrectomy is a safe and effective treatment. Visual prognosis was excluded for secondary macular holes.

AIM:To explore the central mechanisms by which metformin(Met)attenuates insulin resistance in high-fat diet(HF)-fed rats.METHODS:Forty healthy male Sprague-Dawley rats were randomly divided into 4 groups:normal chow(NC)group,HF group,HF+Met group,and HF+Met+SHU9119[melanocortin 4 receptor(MC4R)antagonist]group,with 10 rats per group.Treatments with HF and Met lasted for 12 weeks,while SHU9119 was injected for the last 10 d.Skeletal muscle AMP-activated protein kinase(AMPK)and silent information regulator 1(SIRT1)ex-pression and activity were measured,along with mitochondria oxidative stress markers,mitochondrial function and quanti-ty.Systemic and skeletal muscle insulin sensitivity were assessed using the average glucose infusion rate from 60 to 120 min(GIR60-120)and 2-deoxyglucose uptake(DGU)during hyperinsulinemic-euglycemic clamp.RESULTS:The rats in HF group exhibited significantly reduced expression and activity of AMPK/SIRT1 in skeletal muscles(P<0.05).More-over,mitochondrial oxidative stress markers,reactive oxygen species(ROS)and malondialdehyde(MDA),were marked-ly elevated(P<0.05),and the activity of antioxidant enzymes glutathione peroxidase(GPX)and manganese superoxide dismutase(MnSOD)was significantly decreased in HF group(P<0.05).There was also a notable decline in the activity of citrate synthase(P<0.05),a marker of mitochondrial oxidative capacity,and the copy number of mitochondrial DNA in HF group.These changes were correlated with significantly decreased GIR60-120 and DGU(P<0.05).Notably,Met treat-ment(HF+Met)restored the AMPK/SIRT1 expression and activity,improved mitochondrial function,and reduced oxida-tive stress,leading to improved insulin sensitivity(P<0.05).However,these beneficial effects of Met were reversed by the MC4R antagonist SHU9119 in HF+Met+SHU9119 group.CONCLUSION:Treatment with Met enhances skeletal muscle AMPK/SIRT1 expression and activity,reverses mitochondrial dysfunction,and improves insulin resistance in HF-fed rats.These effects might be mediated through the activation of hypothalamic MC4R.

Objective To explore the effect of exenatide on oxidative stress in the hypothalamus of diabetes mice and its potential mechanism.Methods After one week of adaptive feeding,C57BL/6J mice were randomly divided into the CON group(normal chaw diet),the T2DM group(high-fat diet,HFD),and the T2DM+Exe group(HFD+exenatide).After 8 weeks of HFD,mice in the T2DM+Exe group were intraperitoneally injected with exenatide[24 nmol/(kg·d)]for 8 weeks.The weight and glucose and lipid metabolism levels of the mice were measured,and the levels of inflammatory and adipokine factors in mice were detected using the ELISA method.Western Blot was used to detect the expression of melanocortin receptor-4(MC4R)and proopiomelanocor-tin(POMC)in the hypothalamus.Hypothalamic mitochondria were extracted,and the content of mitochondrial reactive oxygen species(ROS)was measured using a flow cytometer.The content of malondialdehyde(MDA)and the activities of superoxide dismutase(SOD)in the mitochondria were detected using assay kits.Changes in the ultrastructure of mitochondria were observed using a transmission electron microscope.In vitro experiments,pal-mitic acid(PA)and exenatide were used to treat hypothalamic GT1-7 cells,and short hairpin RNA(shRNA)was used to silence the melanocortin 4 receptor(MC4R),and observe the cellular oxidative stress and lipid deposition.Results Compared with the CON group,the T2DM group mice showed a significant increase in glucose and lipid metabolism indicators,pro-inflammatory factors,and adipose factor levels(P<0.05),the expression of MC4R and POMC proteins in the hypothalamus were decreased(P<0.05),and the mitochondrial ROS and MDA content in the hypothalamus significantly were increased(P<0.05),while SOD and CAT activities were decreased(P<0.05).Mitochondrial morphology was abnormal.After intervention with exenatide,the above indicators were signifi-cantly improved.After inhibiting MC4R expression in vitro experiments,compared with the intervention group with exenatide,the ROS and MDA content was significantly increased(P<0.05),SOD activity was decreased(P<0.05),and lipid deposition occurred in the cells.Conclusions Exenatide exhibits a protective effect on hypotha-lamic oxidative stress injury in diabetic mice,and this mechanism may be associated with the upregulation of MC4R expression.

Objective To investigate the effect of postoperative reduction quality in femoral neck fracture internal fixation on mechanical properties of the femoral head from the perspective of trabecular bone biomechanics.Methods From patients who underwent hip replacement surgery for femoral neck fractures,a total of 26 femoral head slice specimens were obtained.The central axis of the primary compressive trabeculae was defined as the 0° group,with the intersection point of the primary compressive trabeculae and the femoral calcar serving as the center.By rotating the specimens to simulate different reduction angles,the cut femoral head slice specimens were randomly divided into five groups:-10°,-5°,0°,5°,and 10°,representing femoral heads with varying reduction qualities.The specimens were subjected to single compression load tests and fatigue load tests.The load was set from 70 N to 1 400 N,at a frequency of 1 Hz,with 10 000 cycles.Axial stiffness,displacement,and the number of collapse cycles were measured,to compare the biomechanical properties of femoral head specimens under different reduction qualities.Results There were differences in the axial stiffness,displacement,and number of collapse cycles among the femoral head specimens in different groups.Under 800 N load,the axial stiffness of 0° group was significantly greater than that of±10° groups(P＜0.05).The axial stiffness of 0° group was also greater than that of the±5° groups,but the differences were not statistically significant(P＞0.05).The axial stiffness of±5° groups was greater than that of±10° groups(P＜0.05).0° group had a lower displacement than±5° groups and±10° groups.However,the differences in displacement between 0° group and±5° groups were not statistically significant(P＞0.05),while the differences between the 0° group and±10° groups were statistically significant(P＜0.05).The differences in displacement between±5° groups and±10° groups were also statistically significant(P＜0.05).0° group had a significantly higher number of collapse cycles than±10° groups(P＜0.05).The number of collapse cycles in 0° group was also higher than that in±5° groups,but the differences were not statistically significant(P＞0.05).The number of collapse cycles in±5° groups was significantly higher than that±10° groups(P＜0.05).Conclusions The quality of reduction after internal fixation of femoral neck fractures significantly affects the biomechanical properties of the femoral head.This study provides a scientific basis for optimizing treatment and postoperative management,aiming to improve clinical outcomes and patients' quality of life.

Objective To investigate the effect of postoperative reduction quality in femoral neck fracture internal fixation on mechanical properties of the femoral head from the perspective of trabecular bone biomechanics.Methods From patients who underwent hip replacement surgery for femoral neck fractures,a total of 26 femoral head slice specimens were obtained.The central axis of the primary compressive trabeculae was defined as the 0° group,with the intersection point of the primary compressive trabeculae and the femoral calcar serving as the center.By rotating the specimens to simulate different reduction angles,the cut femoral head slice specimens were randomly divided into five groups:-10°,-5°,0°,5°,and 10°,representing femoral heads with varying reduction qualities.The specimens were subjected to single compression load tests and fatigue load tests.The load was set from 70 N to 1 400 N,at a frequency of 1 Hz,with 10 000 cycles.Axial stiffness,displacement,and the number of collapse cycles were measured,to compare the biomechanical properties of femoral head specimens under different reduction qualities.Results There were differences in the axial stiffness,displacement,and number of collapse cycles among the femoral head specimens in different groups.Under 800 N load,the axial stiffness of 0° group was significantly greater than that of±10° groups(P＜0.05).The axial stiffness of 0° group was also greater than that of the±5° groups,but the differences were not statistically significant(P＞0.05).The axial stiffness of±5° groups was greater than that of±10° groups(P＜0.05).0° group had a lower displacement than±5° groups and±10° groups.However,the differences in displacement between 0° group and±5° groups were not statistically significant(P＞0.05),while the differences between the 0° group and±10° groups were statistically significant(P＜0.05).The differences in displacement between±5° groups and±10° groups were also statistically significant(P＜0.05).0° group had a significantly higher number of collapse cycles than±10° groups(P＜0.05).The number of collapse cycles in 0° group was also higher than that in±5° groups,but the differences were not statistically significant(P＞0.05).The number of collapse cycles in±5° groups was significantly higher than that±10° groups(P＜0.05).Conclusions The quality of reduction after internal fixation of femoral neck fractures significantly affects the biomechanical properties of the femoral head.This study provides a scientific basis for optimizing treatment and postoperative management,aiming to improve clinical outcomes and patients' quality of life.

AIM:To explore the central mechanisms by which metformin(Met)attenuates insulin resistance in high-fat diet(HF)-fed rats.METHODS:Forty healthy male Sprague-Dawley rats were randomly divided into 4 groups:normal chow(NC)group,HF group,HF+Met group,and HF+Met+SHU9119[melanocortin 4 receptor(MC4R)antagonist]group,with 10 rats per group.Treatments with HF and Met lasted for 12 weeks,while SHU9119 was injected for the last 10 d.Skeletal muscle AMP-activated protein kinase(AMPK)and silent information regulator 1(SIRT1)ex-pression and activity were measured,along with mitochondria oxidative stress markers,mitochondrial function and quanti-ty.Systemic and skeletal muscle insulin sensitivity were assessed using the average glucose infusion rate from 60 to 120 min(GIR60-120)and 2-deoxyglucose uptake(DGU)during hyperinsulinemic-euglycemic clamp.RESULTS:The rats in HF group exhibited significantly reduced expression and activity of AMPK/SIRT1 in skeletal muscles(P<0.05).More-over,mitochondrial oxidative stress markers,reactive oxygen species(ROS)and malondialdehyde(MDA),were marked-ly elevated(P<0.05),and the activity of antioxidant enzymes glutathione peroxidase(GPX)and manganese superoxide dismutase(MnSOD)was significantly decreased in HF group(P<0.05).There was also a notable decline in the activity of citrate synthase(P<0.05),a marker of mitochondrial oxidative capacity,and the copy number of mitochondrial DNA in HF group.These changes were correlated with significantly decreased GIR60-120 and DGU(P<0.05).Notably,Met treat-ment(HF+Met)restored the AMPK/SIRT1 expression and activity,improved mitochondrial function,and reduced oxida-tive stress,leading to improved insulin sensitivity(P<0.05).However,these beneficial effects of Met were reversed by the MC4R antagonist SHU9119 in HF+Met+SHU9119 group.CONCLUSION:Treatment with Met enhances skeletal muscle AMPK/SIRT1 expression and activity,reverses mitochondrial dysfunction,and improves insulin resistance in HF-fed rats.These effects might be mediated through the activation of hypothalamic MC4R.

Objective To explore the effect of exenatide on oxidative stress in the hypothalamus of diabetes mice and its potential mechanism.Methods After one week of adaptive feeding,C57BL/6J mice were randomly divided into the CON group(normal chaw diet),the T2DM group(high-fat diet,HFD),and the T2DM+Exe group(HFD+exenatide).After 8 weeks of HFD,mice in the T2DM+Exe group were intraperitoneally injected with exenatide[24 nmol/(kg·d)]for 8 weeks.The weight and glucose and lipid metabolism levels of the mice were measured,and the levels of inflammatory and adipokine factors in mice were detected using the ELISA method.Western Blot was used to detect the expression of melanocortin receptor-4(MC4R)and proopiomelanocor-tin(POMC)in the hypothalamus.Hypothalamic mitochondria were extracted,and the content of mitochondrial reactive oxygen species(ROS)was measured using a flow cytometer.The content of malondialdehyde(MDA)and the activities of superoxide dismutase(SOD)in the mitochondria were detected using assay kits.Changes in the ultrastructure of mitochondria were observed using a transmission electron microscope.In vitro experiments,pal-mitic acid(PA)and exenatide were used to treat hypothalamic GT1-7 cells,and short hairpin RNA(shRNA)was used to silence the melanocortin 4 receptor(MC4R),and observe the cellular oxidative stress and lipid deposition.Results Compared with the CON group,the T2DM group mice showed a significant increase in glucose and lipid metabolism indicators,pro-inflammatory factors,and adipose factor levels(P<0.05),the expression of MC4R and POMC proteins in the hypothalamus were decreased(P<0.05),and the mitochondrial ROS and MDA content in the hypothalamus significantly were increased(P<0.05),while SOD and CAT activities were decreased(P<0.05).Mitochondrial morphology was abnormal.After intervention with exenatide,the above indicators were signifi-cantly improved.After inhibiting MC4R expression in vitro experiments,compared with the intervention group with exenatide,the ROS and MDA content was significantly increased(P<0.05),SOD activity was decreased(P<0.05),and lipid deposition occurred in the cells.Conclusions Exenatide exhibits a protective effect on hypotha-lamic oxidative stress injury in diabetic mice,and this mechanism may be associated with the upregulation of MC4R expression.

Objective:To propose a method to measure the femoral anteversion angle based on the three-dimensional model of femur.Methods:From January 2019 to December 2023, a total of 50 patients (100 femurs) with patellar instability who underwent full-length CT examination of both lower limbs in Tianjin Hospital were retrospectively analyzed, including 16 males and 34 females, aged 28.5±11.9 years (range, 16-57 years). All patients underwent CT examination of both lower limbs, and the imaging data were imported into Mimics 21.0 software as DICOM format files. The femur was extracted by the threshold segmentation function, and the 3D model of the femur was reconstructed by appropriate trimming and smoothing. Three-dimensional models of the femur from 30 patients (60 femurs) were selected and imported into 3-matic 13.0 software for labeling of anatomical points and drawing of axes. The angle between the axis of the distal femur and the axis of the proximal femur was the femoral anteversion angle. Two observers positioned the spatial coordinates of the intercondylar fossa apex, the greater trochanter apex, the center of the femoral head, the femoral through-condylar axis and the posterior condylar tangent marker points on a 3D model of the femur to compare the differences between the groups. The femoral anteversion angles measured by different three-dimensional measurement methods were compared with the clinically reported femoral anteversion angles.Results:The difference between the femoral head center and intercondylar fossa apex coordinate data of 30 patients (60 femurs) measured by the two observers was not statistically significant ( P>0.05), whereas the data for the Y-axis coordinate of the greater trochanter apex were 25.77±23.21 and 22.08±25.73, respectively, and the difference was statistically significant ( t=2.906, P=0.017). The difference between the data of femoral through condylar and posterior condylar tangential coordinates of 30 patients (60 femurs) measured by the two observers was not statistically significant ( P>0.05). Using the femoral mechanical axis as the projection direction, the angle between the transcondylar axis and the posterior condylar tangent line was 5.97°±2.02° (range, 1.48°-12.08°). The anterior tilt of the femur measured by the two observers in the femoral neck cylinder fitting method was 23.35°±7.45° and 24.94°±9.01°, respectively, and the difference was statistically significant ( t=-2.147, P=0.040). The anterior inclination of the femur measured by the two observers in the femoral head ball enlargement method was 24.63°±7.66° and 25.12°±8.84°, the difference was not statistically significant ( t=-0.820, P=0.419). Using the femoral head ball expansion method to locate the proximal femoral axis, two observers measured the anterior tilt angle of the femur in 50 patients (100 femurs) according to the method described above, which was 23.30°±9.41° and 23.57°±9.97°, respectively, without a statistically significant difference ( t=-0.664, P=0.508), both smaller than the 29.56°±8.74° measured based on two-dimensional images in the imaging report, and the difference was statistically significant ( P<0.05). Conclusion:The femoral anteversion angle measured by the angle between the axis of the femoral condyle and the axis of the femoral neck based on the three-dimensional model is accurate and effective, and the measured value is smaller than that based on the two-dimensional images in clinical practice.

Objective To observe the changes in the subfoveal choroidal thickness(SFCT)of children and adoles-cents with different refractive states using optical coherence tomography angiography.Methods A total of 171 children and adolescents were followed.They were divided into the lower primary school group(6-8 years old),upper primary school group(9-11 years old),and junior high school group(12-14 years old)according to their age at the time of en-rollment.Dioptric examinations(including best corrected visual acuity,diopter,intraocular pressure,corneal curvature,axial length and SFCT)were performed,data collection was conducted twice in half a year(initial examination and review after half a year),and the eyeball parameters and changes in eyeball parameters after half a year among all groups were compared.Results The axial length and SFCT of subjects had significant differences among all groups(both P＜0.05).In children and adolescents,the axial length gradually lengthened and SFCT gradually thickened with age,while intraocular pressure and corneal curvature were not associated with age(both P＞0.05).In the initial examination and review after half a year,there was no significant difference in intraocular pressure,corneal curvature and SFCT of subjects with differ-ent refractive states in all groups(all P＞0.05),while the axial length of myopic subjects was greater than that of non-my-opic subjects in all groups(all P＜0.05).In the review after half a year,the SFCT of non-myopic subjects in the lower pri-mary school group and upper primary school group was significantly thickened(P＜0.001,P=0.003),while there was no significant difference in SFCT of myopic subjects in all groups compared with the value half a year ago(all P＞0.05).The axial length of all subjects showed a positive correlation with the SFCT in the initial examination and review after half a year(r=0.354,0.228,P＜0.05).Conclusion Myopia affects the increase in SFCT in children and adolescents.

Objective:To explore the optimal index of rotational displacement of femoral neck fractures by modeling the axial rotational displacement of femoral neck fractures after reduction and based on X-ray projections.Methods:Six dry human femur specimens, comprising 2 males and 4 females, were utilized in the study. Design and manufacture a proximal femur ortholateral and oblique X-ray casting jigs and mounts. The femoral neck fracture was modeled on the femoral specimen, with Pauwells 30°, 50°, and 70° models (2 each) made according to Pauwells typing. The fractures were manually repositioned with residual anterior 20°, 40° and 60° axial rotational displacements. Each fracture model was projected at different angles (pedicled 40°, pedicled 20°, vertical 0°, cephalad 20°, and cephalad 40°), and the trabecular angle and Garden's alignment index of the model were measured to observe the imaging characteristics of the fracture line on the medial oblique and lateral oblique radiographs.Results:In the presence of a 20° and 40° anterior rotational displacement following reduction of a femoral neck fracture, the trabecular angle in the rotationally displaced group was not significantly different from that of the anatomically repositioned group in various projection positions. However, when a residual rotational displacement of 60° was present, the trabeculae appeared blurred at most projection angles in the Pauwells 30° and 50° models, failing to measure trabecular angles. In the Pauwells 70° fracture model, the trabecular angle in the rotational displacement group was significantly different from that in the anatomical reduction group. In anteroposterior radiographs, when the anterior rotation displacement was 60° in the Pauwells 70° group, Garden's contralateral index showed an unsatisfactory restoration (150°, 142°), whereas all rotationally displaced models in the Pauwells 30° and Pauwells 50° groups had a Garden's contralateral index of >155°, which achieved an acceptable restoration. In lateral radiographs, all rotational displacement models with Garden's alignment index>180° failed to achieve acceptable repositioning, and the larger the Pauwells angle the greater the Garden's alignment index at the same rotational displacement. In the internal oblique position with a bias towards the foot side, the image showed partial overlap between the femoral head and the shaft, making it difficult to assess the quality of the reduction. Conversely, when projected cephalad, the femoral neck appeared longer, particularly at a projection angle of 40° cephalad, allowing for clear observation of the fracture line and the anatomy of the proximal femur. The trabeculae were not well visualized in the external oblique position.Conclusion:There are limitations in applying the trabecular angle to assess the axial rotational displacement of the femoral head after reduction of femoral neck fractures. The Pauwells 70° with residual rotational anterior displacement of 60° was the only way to detect axial rotational displacement of the femoral head on anteroposterior radiographs Garden's alignment index. For the determination of axial rotational displacement of the femoral head, the Garden's alignment index on lateral radiographs provides higher reliability.