OBJECTIVE: To investigate the impact of bone mass and volume of low-density zones beneath the tibial plateau on the maximum von Mises stresses experienced by the cartilage and meniscus in the knee joint. METHODS: The study included one healthy adult volunteer, from whom CT scans were obtained, and one patient diagnosed with knee osteoarthrisis (KOA), for whom X-ray films were acquired. A static model of the knee joint featuring a low-density zone was established based on a normal knee model. In the finite element analysis, axial loads of 1 000 N and 1 800 N were applied to the weight-bearing region of the upper surface of the femoral head for model validation and subsequent finite element studies, respectively. The maximum von Mises stresses in the femoral cartilage, as well as the medial and lateral tibial cartilage and menisci, were observed, and the stress percentage of the medial and lateral components were concurrently analyzed. Additionally, HE staining, as well as alkaline magenta staining, were performed on the pathological specimens of patients with KOA in various low-density regions. RESULTS: The results of model validation indicated that the model was consistent with normal anatomical structures and correlated with previous calculations documented in the literature. Static analysis revealed that the maximum von Mises stress in the medial component of the normal knee was the lowest and increased with the advancement of the hypointensity zone. In contrast, the lateral component exhibited an opposing trend, with the maximum von Mises stress in the lateral component being the highest and decreasing as the hypointensity zone progressed. Additionally, the medial component experienced an increasing proportion of stress within the overall knee joint. HE staining demonstrated that the chondrocyte layer progressively deteriorated and may even disappear as the hypointensity zone expanded. Furthermore, alkaline magenta staining indicated that the severity of microfractures in the trabecular bone increased concurrently with the expansion of the hypointensity zone. CONCLUSION The presence of subtalar plateau low-density zone may aggravate joint degeneration. In clinical practice, it is necessary to pay attention to the changes in the subtalar plateau low-density zone and actively take effective measures to strengthen the bone status of the subtalar plateau low-density zone and restore the complete biomechanical function of the knee joint, in order to slow down or reverse the progression of osteoarthritis.
Humans ; Finite Element Analysis ; Knee Joint/physiology* ; Tibia/anatomy & histology* ; Cartilage, Articular/physiology* ; Menisci, Tibial/physiopathology* ; Tomography, X-Ray Computed ; Osteoarthritis, Knee/diagnostic imaging* ; Weight-Bearing ; Bone Density ; Adult ; Stress, Mechanical ; Male ; Middle Aged ; Biomechanical Phenomena ; Female

Objective:To establish and evaluated a logistic regression model for predicting the acute biliary pancreatitis (ABP) based on liver-injury related indexes.Methods:Clinical data of 210 patients diagnosed with acute pancreatitis (AP) at the Affiliated Hospital of Jiangnan University from October 2020 to December 2022 were retrospectively analyzed, including 113 males and 97 females, with a median age of 52 years (range, 43 to 58). Among these, 88 were diagnosed with ABP and 122 with acute non-biliary pancreatitis (ANBP). Additionally, a test cohort was created using data from 101 AP patients diagnosed between January and December 2023, including 60 males and 41 females, with a median age of 53 years (range, 43 to 63). Based on the original dataset, univariate and multivariate logistic regression analyses were conducted to identify the factors influencing ABP. A prediction probability formula (Pre) was then established based on the multivariate results. The effectiveness of each indicator in predicting ABP was evaluated using the receiver operating characteristic (ROC) curve. The ROC curve analysis determined the optimal cutoff value of Pre, which was subsequently used to diagnose ABP and ANBP in the test cohort.Results:Multivariate logistic regression analysis showed the factors influencing ABP include direct bilirubin (DBIL), alanine aminotransferase (ALT), aspartate aminotransferase (AST), cholinesterase (CHE), and fibrinogen (FIB). Based on the multivariate analysis results, the prediction probability formula (Pre) for ABP was established as follows: P=1/{1+ exp[-(4.807+ 0.134×DBIL-1.859×AST/ALT-0.0003×CHE-0.387×FIB)]}. ROC curve analysis revealed that the area under the curve (AUC) for Pre in predicting ABP was 0.858, with an optimal cutoff value of 0.56, at which the sensitivity was 69.3% and the specificity was 91.0%. Using the cutoff value of 0.56 for Pre, ABP was diagnosed when Pre≥0.56 and ANBP was diagnosed when Pre<0.56. This criterion was applied to diagnose patients in the test cohort, where the sensitivity and specificity of Pre for diagnosing ABP were 86.1% and 92.3%, respectively.Conclusion:The logistic regression model based on liver injury-related indicators is a valuable tool for clinically assessing the incidence of ABP.

Objective:To analyze the changes of serum metabolites in patients with acute pancreatitis (AP) by non-targeted metabolomics method.Methods:Serum samples and clinical data of 15 AP patients hospitalized in the Affiliated Hospital of Jiangnan University from August to September 2024 were collected and included in the AP group, including 9 males and 6 females, aged (55.4±15.3) years. The serum and clinical data of 25 patients with colon polyps in the same hospital during the same period of time were collected, including 15 males and 10 females, aged (61.2±11.5) years, and were included in the control group. Serum metabolomic detection was performed using the ultra-high performance liquid chromatography tandem Fourier transform mass spectrometer. The modeling method was orthogonal partial least square discriminant analysis, and principal component analysis was performed on the data matrix to screen the differential metabolites in serum of AP patients. The Kyoto Encyclopedia database of Genes and Genomes was used to annotate differential metabolites, and the pathway of differential metabolite enrichment was analyzed by software.Results:The principal component analysis showed that the contribution ratio of the first principal component was 15.1%, the proportion of the second principal component was 10.8%, and the total proportion of the two was 25.9%. In principal component analysis, two groups of samples can be clearly distinguished and show obvious clustering characteristics. According to the analysis of OPLS-DA model, there were significant differences in serum metabolic profiles between AP group and control group. There were 683 differentially expressed metabolites between the two groups, with 367 differentially expressed metabolites up-regulated compared with the control group and 316 differentially expressed metabolites down-regulated compared with the control group. It is mainly Phosphatidic Acid (Lte4/8: 0) (+ 218%), Omeprazole Sulphone (-38%), and 2-(Propylthio) Nicotinic Acid (2-propyl thionicotinic acid) (-58%), Gein (salicyricetin) (-47%) and so on. Pathway enrichment analysis showed that the differential metabolites in AP patients were mainly concentrated in citric acid cycle, arginine biosynthesis and glycerophospholipid metabolism pathways.Conclusion:Serum metabolites in AP patients change significantly, including citric acid cycle, arginine biosynthesis, glycerophospholipid metabolism.

Objective To establish a cell bank of extrahepatic cholangiocarcinoma (ECC)-derived organoids and investigate the key factors influencing the organoids generation. Methods The tumor samples from patients with portal cholangiocarcinoma (pCCA) and distal cholangiocarcinoma (dCCA) were used to isolate cells, and these cells were cultured using three-dimensional (3D) technique to establish ECC organoids. Histological characteristics of the organoids were evaluated and identified through hematoxylin-eosin (HE) and immunohistochemistry stainings. The success rates of organoids generation from different tumor types were compared. And clinical characteristics of patients between successful and failure culture groups were compared. Results The success rates of organoids establishment from pCCA and dCCA were all low, with 42.4% (14/33), 51.9% (14/27), respectively. The tumor was larger in successful group than that in failure group (P＜0.001); there was no statistical difference in tumor differentiation status, microvascular invasion, and perineural invasion between the two groups. Conclusions The successful rate of ECC-derived organoids establishment is low, and larger tumor has higher successful culture rate.

Objective:To establish and evaluated a logistic regression model for predicting the acute biliary pancreatitis (ABP) based on liver-injury related indexes.Methods:Clinical data of 210 patients diagnosed with acute pancreatitis (AP) at the Affiliated Hospital of Jiangnan University from October 2020 to December 2022 were retrospectively analyzed, including 113 males and 97 females, with a median age of 52 years (range, 43 to 58). Among these, 88 were diagnosed with ABP and 122 with acute non-biliary pancreatitis (ANBP). Additionally, a test cohort was created using data from 101 AP patients diagnosed between January and December 2023, including 60 males and 41 females, with a median age of 53 years (range, 43 to 63). Based on the original dataset, univariate and multivariate logistic regression analyses were conducted to identify the factors influencing ABP. A prediction probability formula (Pre) was then established based on the multivariate results. The effectiveness of each indicator in predicting ABP was evaluated using the receiver operating characteristic (ROC) curve. The ROC curve analysis determined the optimal cutoff value of Pre, which was subsequently used to diagnose ABP and ANBP in the test cohort.Results:Multivariate logistic regression analysis showed the factors influencing ABP include direct bilirubin (DBIL), alanine aminotransferase (ALT), aspartate aminotransferase (AST), cholinesterase (CHE), and fibrinogen (FIB). Based on the multivariate analysis results, the prediction probability formula (Pre) for ABP was established as follows: P=1/{1+ exp[-(4.807+ 0.134×DBIL-1.859×AST/ALT-0.0003×CHE-0.387×FIB)]}. ROC curve analysis revealed that the area under the curve (AUC) for Pre in predicting ABP was 0.858, with an optimal cutoff value of 0.56, at which the sensitivity was 69.3% and the specificity was 91.0%. Using the cutoff value of 0.56 for Pre, ABP was diagnosed when Pre≥0.56 and ANBP was diagnosed when Pre<0.56. This criterion was applied to diagnose patients in the test cohort, where the sensitivity and specificity of Pre for diagnosing ABP were 86.1% and 92.3%, respectively.Conclusion:The logistic regression model based on liver injury-related indicators is a valuable tool for clinically assessing the incidence of ABP.

Objective:To analyze the changes of serum metabolites in patients with acute pancreatitis (AP) by non-targeted metabolomics method.Methods:Serum samples and clinical data of 15 AP patients hospitalized in the Affiliated Hospital of Jiangnan University from August to September 2024 were collected and included in the AP group, including 9 males and 6 females, aged (55.4±15.3) years. The serum and clinical data of 25 patients with colon polyps in the same hospital during the same period of time were collected, including 15 males and 10 females, aged (61.2±11.5) years, and were included in the control group. Serum metabolomic detection was performed using the ultra-high performance liquid chromatography tandem Fourier transform mass spectrometer. The modeling method was orthogonal partial least square discriminant analysis, and principal component analysis was performed on the data matrix to screen the differential metabolites in serum of AP patients. The Kyoto Encyclopedia database of Genes and Genomes was used to annotate differential metabolites, and the pathway of differential metabolite enrichment was analyzed by software.Results:The principal component analysis showed that the contribution ratio of the first principal component was 15.1%, the proportion of the second principal component was 10.8%, and the total proportion of the two was 25.9%. In principal component analysis, two groups of samples can be clearly distinguished and show obvious clustering characteristics. According to the analysis of OPLS-DA model, there were significant differences in serum metabolic profiles between AP group and control group. There were 683 differentially expressed metabolites between the two groups, with 367 differentially expressed metabolites up-regulated compared with the control group and 316 differentially expressed metabolites down-regulated compared with the control group. It is mainly Phosphatidic Acid (Lte4/8: 0) (+ 218%), Omeprazole Sulphone (-38%), and 2-(Propylthio) Nicotinic Acid (2-propyl thionicotinic acid) (-58%), Gein (salicyricetin) (-47%) and so on. Pathway enrichment analysis showed that the differential metabolites in AP patients were mainly concentrated in citric acid cycle, arginine biosynthesis and glycerophospholipid metabolism pathways.Conclusion:Serum metabolites in AP patients change significantly, including citric acid cycle, arginine biosynthesis, glycerophospholipid metabolism.

ObjectiveTo analyze the characteristics of plantar pressure of diabetic patients during gait cycle, and to design a offloading insole with variable stiffness. MethodsThe plantar pressure experiment was carried out and a database including 157 subjects was established. The differences of plantar pressure distribution were analyzed among diabetic patients with and without peripheral neuropathy, and healthy people. The insole pressure area was divided, and porous units were filled in different insole areas according to the pressure gradient. The fed-calf-insole finite element model of diabetic patients was constructed. The simulation analysis of different insole schemes was carried out under the conditions of push-off, footheel-strike and dynamic neutrality posture, and to explore the most reasonable insole stiffness design. ResultsCompared with the healthy group, the percentage of peak pressure and high pressure in the left and right heel areas of diabetic neuropathy patients showed a decreasing trend, in which the left peak pressure was significantly reduced by 11% (P = 0.026) and the percentage of high pressure was significantly reduced by 9.8% (P = 0.02). When the porous elements of 2.5 MPa and 1.9 MPa were used in the high pressure area of the insole metatarsal and high pressure area of the heel, the peak plantar pressure of footheel-strike, dynamic neutral and push-off was reduced by 42.4%, 27.4% and 26.4%, and the peak stress of the soft tissue was reduced by 49.8%, 43.6% and 25.1%, respectively. ConclusionThere is a higher risk of ulcer in the metatarsal region than in the heel region for diabetic patients. The variable stiffness insoles based on the optimization of plantar pressure and internal stress under multi-posture can effectively reduce the peak pressure of plantar and peak stress of soft tissue during walking, which provides a reference for the design of variable stiffness insoles.

Objective Aiming at the problem that mechanical properties for the continuum of muscle tissues cannot be considered in active and passive behaviors of different structurally coupled muscles, a method of passive and active coupling in the same constitutive equation was proposed to construct ahyperelastic active and passive constitutive model of skeletal muscle continuum. Methods In order to calibrate parameters of the passive constitutive model, the uniaxial tensile experiment method and conditions were given, and through theoretical derivation, the specific method of using experimental data to solve the passive model parameters was introduced. In order to verify effectiveness of the active model, the model was verified with an example. Results The curves predicted by the model were in good agreement with the experimental output stress-stretch ratio curves. At the same strain, the maximum error of passive stress and total stress were only 20 kPa and 40 kPa. Conclusions The continuum hyperelastic constitutive model can better simulate active and passive behavior of skeletal muscles, which is beneficial for modeling and simulation of human muscles in further study.

Since December 2019, the corona virus disease 2019 (COVID-19) caused by the 2019 novel coronavirus (2019-nCoV) has been reported in Wuhan, Hubei Province. Almost 70% of patients susceptible to 2019-nCoV are over age of 50 years, with extremely large proportion of critical illness and death of the elderly patients. Meanwhile, the elderly patients are at high risk of osteoporotic fractures especially osteoporotic vertebral compression fractures (OVCF). During the prevention and control of COVID-19 epidemic, orthopedists are confronted with the following difficulties including how to screen and protect OVCF patients, how to accurately diagnose and assess the condition of OVCF patients with suspected or confirmed COVID-19, and how to develop reasonable treatment plans and comprehensive protective measures in emergency and outpatient clinics. In order to standardize the diagnosis and treatment of patients with OVCF diagnosed with COVID-19, the authors jointly develop this expert consensus. The consensus systematically recommends the standardized emergency and outpatient screening and confirmation procedures for OVCF patients with suspected or confirmed COVID-19 and protective measures for emergency and outpatient clinics. Moreover, the consensus describes the grading and classification of OVCF patients diagnosed with COVID-19 according to the severity of illness and recommends different treatment plans and corresponding protective measures based on the different types and epidemic prevention and control requirements.

Objective: To explore how to select osteotomy line and its significance in mandibular distraction osteogenesis in infants and young children. Methods: From May 2013 to July 2018, 208 infants and young children with mandibular deformity were admitted to the Department of Oral and Maxillofacial Surgery, Guangzhou Women and Children Medical Center, including 131 males and 77 females, with the age range of 8 days to 4 years, mean age of 6 months. Their clinical records were retrospectively analyzed. There were 162 cases of Robin sequence, 37 cases of the first and branchial arch anomalies, 2 cases of Treacher-Collins syndrome, and 7 cases of other congenital malformations. During the distraction osteogenesis, different osteotomy lines were selected according to the characteristics of the mandibular deformity: (1) For short mandibular body, the straight osteotomy line was used to extend the mandibular body. (2) For short mandibular ramus, a polygonal osteotomy line was used to extend the ramus. (3) For the increased mandibular angle, a curved osteotomy line was used to change the angulation. Results: Linear osteotomy was used in 38 patients, polygonal line osteotomy were used in 129 patients, and curved osteotomy was performed in 41 patients. Among them, 4 patients with linear osteotomy had deciduous embryo injury, 6 patients with linear osteotomy and 2 patients with polygonal osteotomy had open occlusion, and patients with curved osteotomy did not have tooth and mandible damage, or malocclusion. All patients were followed up for 3 months to 5 years. The average follow-up time was 6.2 months. All osteotomy healed well, without osteonecrosis or nonunion. Conclusions For the mandibular distraction osteogenesis, osteotomy line could be individualized, according to the characteristics of mandibular deformity of infants and young children, which can reduce complications such as dental damage and open occlusion.