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find Keyword "结构" 276 results
  • MORPHOMETRIC STUDY OF COLLAGEN FIBERS DURING HEALING FOLLOWING PARTIAL AND COMPLETE SECTION OF EXTENSOR TENDONS IN RATS

    In order to study the influence of severity of tendon injury on the morphology of collagen fibers during healing process of extensor tendons, 40 female Wistal rats were used for investigation. The rats were divided into 2 groups. Transection of the tendon of extensor digitorum longus was performed in one group, while partial section of the same tendon was performed in the other group. Morphometric analysis was undertaken on the 15th, 30th, 60th and 90th day after operation. The result was that there was no significant difference between the two groups both in distribution and diameter of collagen fibers on the 15th and 30th days (P gt; 0.05). However, there was significent difference between those on the 60th and 90th days (P lt; 0.05). It was concluded that the severity of the tendon injury could influence the morphology of collagen fibers during the late stage of tendon healing.

    Release date:2016-09-01 11:08 Export PDF Favorites Scan
  • LYMPH NODE TRANSPLANTATION IN RATS: CHANGES IN CELLULAR ARCHITECTURE AND POSSIBLE INFLUENCE ON ITS HISTOLOGICAL AND FUNCTIONAL RESTORATION

    The cellular, architectural and functional changes of transplanted mesenteric lymph nodes in the rats were studied.After the lymph nodes were transplanted with interrupting both of afferent and efferent lymphatics, the nodes gradually depleted the celluar content. One month after operation the recirculating lymphoeytes in the transplanted node were 3.5% of that in the host nodes, while the number of cells of the transplanted node was only 28%. The number of macrophages also decreased obviously. In paracortex,the cells of high endothelial venule (HEV) became flattened ahn HEV disappeared geadually. In the cortex, the germinal centers and follicles also diminished considerbly in number and disappered completely in 3 month. It was difficult to distinguish the normal compartments in the operated nodes 3 months after transplantation. NO regenerated afferent lymphatics were identified in the transplanted nodes. Lacking of antigen and stimulated lymphocytes brought histological and functional involution of the transplanted lymph nodes.

    Release date:2016-09-01 11:37 Export PDF Favorites Scan
  • EFFECTS OF VERAPAMIL AND ENERGY COMPOUNDS ON STRUCTURAL AND FUNCTIONAL CHANGES OF SMALL BOWEL′S IN RABBITS

    Objective To probe the change of the structure and function of the small bowel by injection of different drugs (verapamil, energy compounds or normal saline) via the superior mesenteric artery (SMA) injections.Methods The model of the small intestine ischemia/reperfusion (I/R) injury was made in grey rabbits. Free calcium concentration in mitochondria of the small intestine was determined, and the ultrastructural change was also observed by electron microscopy at the very time of occlusion, 60 minutes after occlusion and 30 minutes after reperfusion. Results The free calcium concentration in mitochondria was more declined in verapamil group (2.976±0.410 nmol/mg.prot) than in N.S. group (4.234±0.542 nmol/mg.prot), P<0.01, at 60 minutes after occlusion. At 30 minutes after reperfusion, free calcium concentration in mitochondria was more decreased in energy compunds group (2.401±0.323 nmol/mg.prot) and verapamil group (3.847±0.610 nmol/mg.prot) than in the N.S. group (5.981±1.031 nmol/mg.prot). Conclusion Verapamil and energy compouds have protective effects on the functions and ultrastructures of the I/R of small intestine.

    Release date:2016-09-08 02:00 Export PDF Favorites Scan
  • Study on abnormal dendrite of retinal ganglion cells in diabetic rats

    Objective To observe the morphological changes of dendrite and soma in retinal ganglion cells (RGCs) which subsisted in early diabetic rats. Methods The RGCs of 3-months-course diabetic rats and coeval normal rats were marked by gene gun techniques. To collect RGCs photographs by Leica microscope with Z axis and CCD camera;to observe the changes of diameter, variance of structural features in dendritic field and somata after classification which according to the size and morphology. Thy-1 antibody marks on the retinal RGCs, taking a photograph under fluorescent microscope, counting the changes of retinal RGCs density in early diabetic rat. Results In three-month diabetic rats,the density of retinal RGCs was decreased obviously. Morphological changes of RGCs in the dendritic fields were observed with gene gun technique. There was no severe variation in all kinds of the bole of cell dendrite, in which some only showed crispation partially and sparseness also twisting in the dendritic ramus. The mean diameter of dendritic field and soma in class A of diabetic rats was (401plusmn;86) mu;m, the mean diameter of dendritic field in control group was (315plusmn;72) mu;m,compared with each other, there is statistically significant differences (t=21.249,Plt;0.001); the mean diameter of soma in class A of diabetic rats was (24plusmn;6) mu;m, the mean diameter of soma in control group was (22plusmn;5) mu;m, compared with each other, there is no statistically significant differences (t=0.927,Pgt;0.05); the mean diameter of dendritic field and soma in class B of diabetic rats were (170plusmn;36)、(14plusmn;2) mu;m respectively, in control group were (165plusmn;36)、(16plusmn;2) mu;m, the mean diameter of dendritic field and soma in class C of diabetic group were(265plusmn;78)、(17plusmn;5) mu;m respectively, in control group were (251plusmn;57)、(17plusmn;4) mu;m , compared with each other, there are on statistically significant differences(t=1.357,0.798,0.835,1.104,Pgt;0.05). Conclusions In short-term diabetes, the survived RGCs show good plasticity in adult diabetic rats, especially in class A. The changes of dendrites were more sensitive than the soma, which could be the leading index of the morphologic changes of RGCs in the early stage. The good plasticity showed by the RGCs and the time window from changing in dendrite to cell death provide us many evidences not only for the research but also for the nerve protection in clinic. (Chin J Ocul Fundus Dis,2008,24:249-254)

    Release date:2016-09-02 05:46 Export PDF Favorites Scan
  • Research progress on hemolysis of rotary blood pump

    Hemolysis is one of the main complications associated with the use of ventricular assist devices. The primary factors influencing hemolysis include the shear stress and exposure time experienced by red blood cells. In addition, factors such as local negative pressure and temperature may also impact hemolysis. The different combinations of hemolysis prediction models and their empirical constants lead to significant variations in prediction results; compared to the power-law model, the OPO model better accounts for the complexity of turbulence. In terms of improving hemolytic performance, research has primarily focused on optimizing blood pump structures, such as adjustments to pump gaps, impellers, and guide vanes. A small number of scholars have studied hemolytic performance through control modes of blood pump speed and the selection of blood-compatible materials. This paper reviews the main factors influencing hemolysis, prediction methods, and improvement strategies for rotary blood pumps, which are currently the most widely used. It also discusses the limitations in current hemolysis research and provides an outlook on future research directions.

    Release date:2025-04-02 10:54 Export PDF Favorites Scan
  • Comparative Studies on the Material Performances of Natural Bone-like Apatite from Different Bone Sources

    The compressive strength of the original bone tissue was tested, based on the raw human thigh bone,bovine bone,pig bone and goat bone. The four different bone-like apatites were prepared by calcining the raw bones at 800℃ for 8 hours to remove organic components. The comparison of composition and structure of bone-like apatite from different bone sources was carried out with a composition and structure test. The results indicated that the compressive strength of goat bone was similar to that of human thigh bone, reached (135.00±7.84) MPa; Infrared spectrum (IR), X-ray diffraction (XRD) analysis results showed that the bone-like apatite from goat bone was much closer to the structure and phase composition of bone-like apatite of human bones. Inductively Coupled Plasma (ICP) test results showed that the content of trace elements of bone-like apatite from goat bone was closer to that of apatite of human bone. Energy Dispersive Spectrometer (EDS) results showed that the Ca/P value of bone-like apatite from goat bone was also close to that of human bone, ranged to 1.73±0.033. Scanning electron microscopy (SEM) patterns indicated that the macrographs of the apatite from human bone and that of goat bone were much similar to each other. Considering all the results above, it could be concluded that the goat bone-like apatite is much similar to that of human bone. It can be used as a potential natural bioceramic material in terms of material properties.

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  • Research on mechanism of action of TXNIP/NLRP3 pathway in the occurrence and development of breast cancer

    ObjectiveTo investigate the regulatory mechanism of thioredoxin binding protein (TXNIP)/nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) pathway in the occurrence and development of breast cancer.MethodsThe resected 15 cases of breast cancer tissues and their adjacent tissues in our hospital from September 2019 to June 2020 were selected, and the immunohistochemistry was used to detect the expression levels of TXNIP and NLRP3 in breast cancer and its adjacent tissues. Three kinds of breast cancer cell lines (MDA-MB231, MCF-7 and SKBR3) and normal breast epithelial cell line (HMEC) were collected. Western blot was used to detect the relative expression levels of TXNIP and NLRP3 in three kinds of breast cancer cell lines and HMEC cell line. MDA-MB231 cancer cells were divided into blank control group (normal culture without any treatment), TXNIP overexpression group (Ad-TXNIP group, transfected with adenovirus vector carrying TXNIP overexpression sequence), Ad-TXNIP negative control group (Ad-eGFP1 group, transfected of empty adenovirus vector without TXNIP overexpression sequence), NLRP3 overexpression group (Ad-NLRP3 group, transfected with adenovirus vector containing NLRP3 overexpression sequence), TXNIP and NLRP3 overexpression co-transfection group (Ad-TXNIP+Ad-NLRP3 group, co-transfection of adenovirus vector carrying TXNIP and NLRP3 overexpression sequence), TXNIP overexpression and Ad-NLRP3 negative control (Ad-eGFP2) co-transfection group (Ad-TXNIP+Ad-eGFP2 group,co-transfection of adenovirus vector carrying TXNIP overexpression sequence and empty adenovirus without NLRP3 overexpression sequence). After 24 hours of transfection and culture, CCK-8 method was used to detect the MDA-MB231 cells proliferation. Transwell chamber method was used to detect MDA-MB231 cells migration and invasion. Nude mice tumorigenicity test was used to detect the tumorigenicity of the MDA-MB231 cells in vivo. Western blot was used to detect the expressions of TXNIP, NLRP3, proliferation marker protein (Ki-67), caspase-1, vascular endothelial growth factor (VEGF), interleukin (IL)-1β, IL-18 and caspase-1 precursor protein (pro-caspase-1) in the MDA-MB231 cells.ResultsCompared with the adjacent tissues, the relative expression level of TXNIP decreased (P<0.05) and the relative expression level of NLRP3 increased (P<0.05) in breast cancer tissues. Compared with normal breast epithelial cell line (HMEC cell line), the relative expression levels of TXNIP in MDA-MB231, MCF-7 and SKBR3 breast cancer cell lines were decreased (P<0.05), and the relative expression levels of NLRP3 were increased (P<0.05). Compared with the blank control group, the relative expression levels of TXNIP, NLRP3, IL-1β, IL-18, pro-caspase-1 and caspase-1 were increased (P<0.05), the relative expression levels of Ki-67 and VEGF, the proliferation activity, invasion and migration ability of MDA-MB231 cells and tumor weight were decreased (P<0.05) in the Ad-TXNIP group and the Ad-NLRP3 group. Compared with the Ad-TXNIP group and the Ad-NLRP3 group, the relative expression levels of TXNIP, NLRP3, IL-1β, IL-18, pro-caspase-1 and caspase-1 were further increased (P<0.05), the relative expression levels of Ki-67 and VEGF, the proliferation activity, invasion and migration ability of MDA-MB231 cells and tumor weight were further decreased (P<0.05) in the Ad-TXNIP+Ad-NLRP3 group.ConclusionsIn breast cancer tissues and breast cancer cell lines, TXNIP is low expression and NLRP3 is high expression. They can interact with each other to promote pyroptosis and inhibit the proliferation, invasion and migration of breast cancer cells.

    Release date:2021-11-30 02:39 Export PDF Favorites Scan
  • 道诺霉素及脂质体对玻璃体切除兔眼视网膜的毒性

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  • 医学类高职教育教师培训方法探讨

    【摘要】 目的 针对高职教育师资存在的问题,探讨其解决的办法和措施。方法 注重师资队伍的建设,建立合理的教师培训制度,改革高职教师评价制度。结果 通过以上措施,教师的教学水平得到了明显的提高,高职教师不仅具有较高的师德水准和系统的专业理论知识,而且还有丰富的实践经验和熟练的操作技能。结论 注重师资队伍的建设,建立合理的教师培训制度,改革高职教师评价制度,是解决高职教育师资问题的有效途径。

    Release date:2016-09-08 09:37 Export PDF Favorites Scan
  • RELATIONSHIP OF OSTEOBLASTS, ENDOTHELIAL CELLS AND CERAMIC SCAFFOLD DURING REPAIR OF CRITICAL SIZE CALVARIAL DEFECTS WITH TISSUE ENGINEERING TECHNOLOGY

    Objective To observe the relationship of osteoblasts, endothelial cells and ceramic scaffold during reconstruction of rat critical size calvarial defects with tissue engineering technique under transmission electron microscope. Methods Fourteen male adult Sprague Dawley rats were divided randomly into experimental and control groups. Bone marrow was obtained from left femurs and tibias of all rats. In experimental group, respective autogenous osteoblasts derived from bone marrow stromal cells(MSCs) different iated and proliferated in vitro and then were seeded and subcultured on porous calcium phosphate ceramics. The cell-ceramic compounds were used to repair critical-sized (8 mm diameter) calvarial defects in the corresponding rats. In control group, the ceramic without autogenous osteoblosts was used. One rat of each group was sacrificed postoperatively in the 4th, 8th, 12th, 24th, 28th weeks respectively and involved samples were removed to make decalcified ultrath in sections and observed under transmissionelectron microscope. Results Osteoblasts or osteoblast-like cells always located next to sprouting capillaries and the relationship between osteoblasts and endothelial cells was relevant in experimental group. There was a calcium depositzone distributed along the boundary of newly formed bone and the remnants of decalcified ceramic, which meant osseointegration between the ceramic and newly formed bone. The above changes did not appear in control group simultaneously.Conclusion The nanometer scale structure of ceramic scaffold benefits to angiogenesis, osteogenesis and extracellular matrix formation in repair bone defects with tissue engineering technique.

    Release date:2016-09-01 09:35 Export PDF Favorites Scan
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