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08 January 2022, Volume 26 Issue 在线 Previous Issue    Next Issue

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Application of knee joint motion analysis in machanism based on three-dimensional image registration and coordinate transformation Wang Jianping, Zhang Xiaohui, Yu Jinwei, Wei Shaoliang, Zhang Xinmin, Xu Xingxin, Qu Haijun 2022, 26 (在线):  1-5.  Abstract ( 385 )   PDF (20010KB) ( 36 )   Save BACKGROUND: Research on movement process, data, and mechanism of the knee joint is helpful to design and modify a knee joint prosthesis, and improve the knee joint movement function according to its movement characteristics and biomechanical characteristics, so as to avoid sports injuries, improve sports performance and prolong sports life. The movement data of the knee joint are the basis for studying its mechanical properties.   OBJECTIVE: According to the three-dimensional geometric model of the knee joint, to determine the movement data of the tibiofemoral joint and the patellofemoral joint at different flexion angles, thereby providing a new approach and reference for the kinematic analysis of complex spatial mechanisms such as robots and for the mechanical analysis and design of artificial prostheses. METHODS: First, the three-dimensional point cloud of the knee joint at 0°-120° static knee flexion was captured using computed tomography. Secondly, the combination of three-dimensional image registration and coordinate transformation was proposed to accurately analyze the relative motion of the knee joint. Three-dimensional images of the knee joint (including the femur, tibia, patella) in different flexion positions and their coordinates, were presented in the same coordinate system. The orthogonal coordinate system of each bone tissue of the knee joint was then established. The movement of the knee joint was studied based on coordinate transformation using the Z-Y-X Euler angle method around the motion coordinate system.   RESULTS AND CONCLUSION: The motion data of the tibiofemoral and patellofemoral joints with 0°-120° of knee flexion were obtained in the five degrees of freedom, which offers a support for studying the mechanical properties of the knee joint and prosthetic design. This method could be used for the motion analysis of kinematics pairs under complex kinematics in mechanism. To conclude, this method is proposed based on multi-static discrete medical images for kinematic measurement and analysis in human body. It can be conducted based on existing computed tomography scanning equipment and existing software, which has low cost and is easily understood. Moreover, this method is characterized by high measurement accuracy and the accuracy error is less than 1 mm. Figures and Tables | References | Related Articles | Metrics

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Effect of uniaxial fatigue exercise on patellofemoral cartilage injury in a rabbit Tan Xinfang, Guo Yanxing, Qin Xiaofei, Zhang Binqing, Zhao Dongliang, Pan Kunkun, Li Yuzhuo, Chen Haoyu 2022, 26 (在线):  1-6.  Abstract ( 108 )   PDF (940KB) ( 89 )   Save BACKGROUND: There is a high incidence of patellofemoral cartilage injury in clinical practice. However, the current research on its etiology is insufficient. Hyperactivity is one of the pathological mechanisms widely recognized in clinic, and understanding the occurrence and development of patellofemoral injury is of great significance. OBJECTIVE: To study the effect of uniaxial fatigue exercise on the patellofemoral articular cartilage, and to explore patellofemoral cartilage injuries caused by fatigue in rabbits, so as to provide an experimental basis for understanding the effect of hyperactivity on patellofemoral cartilage lesions. METHODS: Eight New Zealand white rabbits were adaptively fed for 1 week. The right knee of each rabbit was selected as the experimental side and the left knee as the control side. The right knee was fixed on a modeling machine for uniaxial fatigue exercise, and the activity angle was set to be 0°-95° and the activity frequency was set at 60 beats per minute, 90 minutes a day, for 2 weeks. The left knee of each rabbit was untreated. After modeling, MRI images of the rabbit knee joints were collected. The animals were then sacrificed and sampled, and the cartilage tissue sections of the patellofemoral joint were observed and assessed by the Mankin score. RESULTS AND CONCLUSION: The patellar cartilage of the experimental side was significantly damaged. After 2 weeks of uniaxial fatigue exercise, the patellar cartilage of the experimental side had dull color, visible fissures, rough surface, and hyperplasia at the edge of the patellofemoral interface, while no obvious cartilage degeneration was observed on the control side. The results of knee MRI showed that the signal intensity of the patellar cartilage on the experimental side was heterogeneous. Hematoxylin-eosin staining results revealed that the cartilage surface of the experimental side was not smooth, and chondrocyte proliferation, disarrangement, and multiple tidal lines were observed under a light microscope. The Mankin score of the experimental side was significantly higher than that of the control side (P < 0.05). These findings indicate that 2-week uniaxial fatigue exercise can cause mild damage to the cartilage of the patellofemoral joint in rabbits, accompanied by pathological changes such as cartilage swelling and fissures. Figures and Tables | References | Related Articles | Metrics

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Inhibiting NOX alleviates alcoholic liver damage and lipid metabolism disorder Cui Wei, Cui Di, Ouyang Ting, Li Xiang, Wei Huiting, Xue Weiyue, Zhou Gang, Qiu Ye 2022, 26 (在线):  1-8.  Abstract ( 116 )   PDF (8064KB) ( 19 )   Save BACKGROUND: Studies have shown NOX protein expression up-regulated in myocardium, skeletal muscle, kidney, and brain under stess conditions, while its role in alcoholic liver damage pathology was unclear. OBJECTIVE: To investigate the role of NOX mediated oxidative stress under liver normal physiology and alcoholic liver damage pathology. METHODS: 6 Male C57BL/6J mice were randomly divided into normal control group and normal drug group, with 3 mice in each group. Mice in normal drug group were intraperitoneally injected by 10 mg/Kg Apocynin for 4 consecutive days, while normal control group was injected with the same dose of solvent. Lipid metabolism related indexes in serum and liver tissues of mice were detected, and the protein expressions of NOX2 and NOX4 in liver tissues were determined. 18 Male C57BL/6J mice were randomly divided into common group, alcoholic liver damage (ALD) group and ALD combined with drug group, with 6 mice in each group. ALD model was constructed by Lieber-DeCarli liquid diet with TP4030C in common group as well as TP4030B in ALD group and ALD combined with drug group. Mice in ALD combined with drug group was intraperitoneally injected with 10 mg/Kg Apocynin 6 days a week for 6 weeks, while mice in other two groups were injected with the same dose of solvent. The mice body weight, epididymal fat relative content, liver index and skeletal muscle relative content, was either recorded or calculated. Glucose tolerance test was used to detect mice insulin sensitivity, and the serum liver function damage (alanine aminotransferase, ALT and Aspartate aminotransferase, AST) and lipid metabolism indexes were measured by commercial chemical kits. The liver tissue malondialdehyde (MDA), superoxide dismutase (SOD), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) was determined by colorimetry. The change of hepatocyte damage was observed by using HE staining. Western blot was applied to detect NOX2, and NOX4 protein expression in liver tissue. Ethic approval was obtained from the Experimental Animal Ethics Committee of Hunan University in China (approval No. HNUBI0202101007). RESULTS AND CONCLUSION: Compared with normal control group, the content of TG in liver tissue and the levels of serum ALT and AST increased significantly in normal drug group; the level of HDL-C and the expressions of NOX2 and NOX4 decreased evidently in liver tissue. Compared to common group, the relative content of epididymal fat, as well as the content of HDL-C in both serum and liver tissue were strikingly decreased in ALD group and the level of serum ALT increased; the levels of TG, LDL-C and the protein expression of NOX4 were particularly increased in liver tissue. Compared to ALD group, the levels of HDL-C in both serum and liver tissue increased notably in ALD combined with drug group ; the serum ALT level, the content of LDL-C in liver and the protein expression of NOX4 decreased remarkably. In conclusion, inhibiting NOX alleviates hepatocyte damage and lipid metabolism disorder; Apocynin has different effects on liver physiology and pathological state of ALD. Figures and Tables | References | Related Articles | Metrics

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Effect of electroacupuncture on apoptosis of neurons in cerebral cortex of rats with cerebral ischemia-reperfusion injury at "Shuigou" and "Baihui" points LIU Danni, SUN Guanghua, ZHOU Guijuan, LIU Hongya, ZHOU Jun, TAN Jinqu, HUANG Xiarong, PENG Ting, FENG Wei-bin, LUO Fu 2022, 26 (在线):  1-6.  Abstract ( 119 )   PDF (3860KB) ( 32 )   Save BACKGROUND: Cerebral ischaemia-reperfusion injury is commonly seen in patients with ischaemic stroke and seriously affects their prognosis, so it is important to explore effective treatments to alleviate ischaemia-reperfusion injury. Electroacupuncture can effectively improve the symptoms of neurological deficits in ischaemic stroke.  Objective To investigate the neuroprotective effect of electroacupuncture treatment on cerebral ischemia-reperfusion injury rats and its effect on neuronal apoptosis in the cerebral cortex.  Methods Forty-eight male 3-month-old SD rats were randomly divided into sham-operated group, model group, and electroacupuncture group, 16 rats each. Cerebral ischemia-reperfusion experiments were performed on all rats in the model and electroacupuncture groups on the left middle cerebral artery for 2 h of ischemia and 6 h of reperfusion. Rats in the sham-operated group, only the carotid artery was exposed and freed. Then, 16 rats in the electroacupuncture group were subjected to "Baihui" and "Shuigou" interventions, choosing sparse and dense waves at 3 Hz/15 Hz and 1 mA, for 20 min, once a day for 5 d. On the 5th day after the model was made, all rats were assessed for neurological impairment using the Longa Neurological Function Score; TTC solution was used to determine the infarct volume; Elisa was used to detect the level of inflammatory factors; TUNEL was used to detect apoptosis; RT-PCR and Western blot were used to detect the expression of Caspase-3 and Caspase-8, respectively.  Results Compared with the sham-operated group, the neurological function scores of rats in the model group were significantly higher (P < 0.01); the brain infarct volume of rats was significantly higher (P < 0.01); the number of TUNEL-positive cells in the left cerebral cortex area of rats was significantly increased (P < 0.01); the levels of serum inflammatory factors IL-1β, IL-18 and TNF-a were increased (P < 0.05, P < 0.01,P < 0.01); Caspase-3 and Caspase-8 mRNA expression in the cerebral cortex area of rats was significantly higher (P < 0.01, P < 0.01); Caspase-3 and Caspase-8 protein expression in the cerebral cortex area of rats was significantly higher (P < 0.01,P < 0.01). Compared with the model group, the neurological function scores of rats in the electroacupuncture group were reduced (P < 0.05); the volume of cerebral infarction in rats was reduced(P < 0.05); the number of TUNEL-positive cells in the left cerebral cortex area of rats was significantly reduced (P < 0.01); the levels of serum inflammatory factors IL-1β, IL-18 and TNF-a were reduced (P < 0.01, P < 0.05, P < 0.05); Caspase-3 and Caspase-8 mRNA expression in the cerebral cortex area of rats was significantly reduced (P < 0.01, P < 0.01); Caspase-3 and Caspase-8 protein expression in the cerebral cortex area of rats was significantly reduced (P < 0.01,P < 0.01).  Conclusion Electroacupuncture treatment may exert neuroprotective effects by inhibiting neuronal apoptosis in the rat cerebral cortex and alleviating cerebral ischemia-reperfusion injury. Figures and Tables | References | Related Articles | Metrics

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Characterization and photothermal effect of indocyanine green encapsulated poly lactic acid-co-glycolic acid microspheres FAN Yaru, LI Ruixin , LI Fengji, LUO Rui, LIU Hao, YAN Yingbin 2022, 26 (在线):  1-6.  Abstract ( 164 )   PDF (2066KB) ( 20 )   Save BACKGROUND: Indocyanine green, an efficient photothermal conversion agent, can be used for photothermal therapy of oral squamous cell carcinoma, but it has some shortcomings such as water instability and photodegradation. Using carrier to encapsulate indocyanine green to improve its stability was of great significance for exploring photothermal therapy of oral squamous cell carcinoma.   Objective: Indocyanine green encapsulated poly lactic acid-co-glycolic acid microspheres were fabricated to delay the photodegradation of indocyanine green and improve its photothermal stability to develop reagents for photothermal treatment of oral squamous cell carcinoma. Methods: The microspheres were prepared by emulsion-solvent evaporation method. The morphology, particle size distribution, surface charge, drug loading and encapsulation efficiency were characterized. The photothermal effect of free indocyanine green and microspheres were investigated at different concentrations, four laser on/off cycles, and left exposed to light for 0, 3, 6 and 9 days. Morphological changes of SCC-25 cells after different treatments were observed under light microscope, and in vitro photothermal anti-tumor effect of microspheres were evaluated by CCK8.  Results: The microspheres had smooth surfaces with particle sizes of (2.54±0.29)μm, zeta potential of -(20.2±1.58)mV, encapsulation efficiency and loading efficiency were (69.24±1.29) % and (4.87±0.15) %, respectively. Compared with free indocyanine green, microspheres have more stable photothermal properties, and tumor cells shrink to spherical shape after photothermal, which can effectively reduce the viability of SCC-25 cells.  Conclusion: Indocyanine green encapsulated poly lactic acid-co-glycolic acid microspheres possessed efficient photothermal conversion ability and can obviously delay photobleaching and photodegradation of indocyanine green. Poly lactic acid-co-glycolic acid is a suitable vehicle of indocyanine green and can be used for photothermal therapy of oral squamous cell carcinoma. Figures and Tables | References | Related Articles | Metrics

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Effect of M2 macrophage-derived exosomes on osteogenic differentiation of bone marrow mesenchymal stem cells Liu Wentao, Feng Xingchao, Yang Yi, Bai Shengbin 2022, 26 (在线):  1-6.  Abstract ( 131 )   PDF (9563KB) ( 61 )   Save BACKGROUND: At present, studies have shown that M2 macrophages can promote osteogenic differentiation and regulate it in a network, and exosomes can carry a lot of information to participate in intercellular signal transduction. Whether M2 macrophage-derived exosomes can promote the osteogenic differentiation of bone marrow mesenchymal stem cells remains to be studied.   OBJECTIVE: To investigate the effect of M2 macrophage-derived exosomes on osteogenic differentiation of bone marrow mesenchymal stem cells. METHODS:  Rat derived macrophage line RAW264.7 was cultured with rat bone marrow mesenchymal cell line CP-M131 to the third generation. Interleukin 4 was used to induce macrophages to polarize into M2 macrophages. Exosomes were extracted from M2 macrophage culture supernatant. Exosomes at the final mass concentration of 0, 30, 60, 90 mg/L were cocultured with bone marrow mesenchymal stem cells for 72 hours, and 60 mg/L M2 macrophage-derived exosomes were cocultured with bone marrow mesenchymal stem cells for 24, 48 and 72 hours. The expression levels of osteogenic related factors RUNX2 and alkaline phosphatase protein in bone marrow mesenchymal stem cells were detected by western blot assay, and the mineral deposition was detected by alizarin red staining.   RESULTS AND CONCLUSION:  (1) The expression levels of osteogenic related factors RUNX2 and alkaline phosphatase were closely related to the mass concentration of macrophage exosomes. Compared with the blank control group, the expression of RUNX2 and alkaline phosphatase in 60 mg/L exosome group increased significantly (P < 0.05), and the expression of RUNX2 and alkaline phosphatase after 72 hours of intervention increased significantly (P < 0.05). (2) The results of alizarin red experiment showed that compared with the blank control group, the content of calcium ion in 60 mg/L exosome group was higher (P < 0.05), and the content of calcium ion after 72 hours of intervention was higher (P < 0.05). (3) The results showed that the exosomes secreted by M2 macrophages in vitro could induce the differentiation of bone marrow mesenchymal stem cells into osteoblasts. Figures and Tables | References | Related Articles | Metrics