Objective To observe the therapeutic effect of poly tetrahydrofurfuryl co-lactic acid(copolymer C4) as the biodegradable vitreous substitutes on rhegmatogenous retinal detachment.Methods Vitreoretinal surgery with copolymer C4 tamponades was performed on 32 pigmented rabbits (64eyes) with rhegmatogenous retinal detachment. The rate of reattached retina and the post operative cornplications were observed.Results Three months after the operation, reattached retina was found in 96. 4%, glaucoma in 5.5%, cataract in 10.9%, and copolymer emulsion in 10.2% of all the eyes.Conclusion copolymer C4 may withstand the retinal tear effectively for 3 months, and can be a valuable vitreous substitutes. (Chin J Ocul Fundus Dis，2004，20：27-28)
Objective To study the influence of in vitro force-vascularization on in vivo vascularization of porous polylactic glycolic acid copolymer(PLGA) scaffolds with internal network channels (PPSINC). Methods After the in vitro forcevascula ization of PPSINCs covered with microvessel endothelial cells (MVEC) of mice, they were divided into two groups: the force-vascularization group (group A) and the control group with only PSINCs (group B). All the PPSINCs were planted in the mesentery of 12 mice for 2 and 4 weeks, the PPSINCs were cut out, the vascular ization of PPSINCs was investigated by histology and immunohistochemistry, and the vascularization area of the histologic section of the PPSINCswas measured with the computer-assistant image analysis system. Result After the in vitro forcevascularization of PPSINCs, the MVEC of the mice sticking on the channel wall could be seen. After the scaffold was im planted into the mice for 2 weeks, the vascularization area of the histologic section of PPSINCs (VA) in group A (2 260.91±242.35 μm2) was compared with that in group B (823.64±81.29 μm2)，and the difference was sig nificant in statistics（P＜0.01).The VA for 4 weeks in group A (17 284.36 ±72.67 μm2) was compared with that in group B (17 041.14±81.51 μm2), and the difference was not significant in statistics（P＞0.05）.The area of the actin positivestaining (AA) in the histologi c section of PPSINCs for 2 weeks’ implantation in group A (565.22±60.58 μm2) was compared with that in group B (205.91±16.25 μm2), and the difference was signi ficant in statistics（P＜0.01). After the implantation for 4 weeks, the VA in group A (4 321.09±19.82 μm2) was compared with group B (4 260.28±27.17 μm2), and the difference was not significant in statistics（P＞0.05）. Conclusion The PPSINC is a good simple scaffold model of vasculariazation. The in vitro force-vascularization can increase the in vivo vascularization of PPSINCs in the early stage.
OBJECTIVE: To investigate the selection and manufacture of ideal extracellular matrix materials in bone tissue engineering. METHODS: The recent literatures about biodegradable polymers served as culture scaffolds of osteoblasts were widely reviewed, the advantages and disadvantages of biodegradable synthetic polymers and natural polymers were analysed. RESULTS: The ideal extracellular matrix material in bone tissue engineering should be made up of inorganic materials, synthetic polymers and natural polymers, which possesses morphological structure of three-dimensional foam with self-mediated drug slow delivery system of bone growth factors. CONCLUSION: The design and manufacture of combined extracellular matrix materials in bone tissue engineering is a very important and urgent challenge.
OBJECTIVE To study the relationship between the changes of mRNA expression in wound tissues of diabetic ulcers and tissue repair. METHODS The mRNA expression of TGF-beta 1 and IL-6 in eight bioptic samples of diabetic ulcers were detected by RT-PCR and pathologic methods, and the surrounding normal skins from the same patients were measured as control group. RESULTS The mRNA expression levels of TGF-beta 1 were markedly decreased in the diabetic ulcers compared with control group, while the mRNA expression levels of IL-6 were increased at the same reaction conditions. CONCLUSION The different changes of mRNA expression level of TGF-beta 1 and IL-6 in wound tissue result in low production and decreased activity of TGF-beta 1 and IL-6, which lower the reparative ability of wound tissue.
Objective To explore the effect of connective tissue growth factor on the pathogenesis of hypertrophic scar and keloid tissue. Methods The content of hydroxyproline was determined and the expression of connective tissue growth factor gene was detected by the reverse transcription-polymerase chain reaction and image analysis technique in 5 normal skins, 15 hypertrophic scars and 7 keloid tissues. Results The contents of hydroxyproline in the hypertrophic scar(84.10±1.76) and keloid tissue (92.38±2.04) were significantly higher than that of normal skin tissue (26.52 ± 4.10) (P lt; 0.01). The index of connective tissue growth factor mRNA in the hypertrophic scar (0.78 ± 0.63) and keloid tissue (0.84 ± 0.04) were higher than that of normal skin tissue ( 0.09 ± 0.25) (P lt; 0.01). Conclusion Connective tissue growth factor may play an important role in promoting the fibrotic process of hypertrophic scar and keloid tissue.
ObjectiveBased on the method of bibliometrics, to visually analyze the current research status of DNA polymerase epsilon catalytic/DNA polymerase delta catalytic subunit (POLE/POLD1) mutations in colorectal cancer, and further to explore its current hot spots and to look forward to future development trends.MethodsUsed the Web of Science database as the data source to retrieve the published related literatures in the 30 years from the establishment of the database to September 2020, and used VOSviewer 1.6.11 and CiteSpace 5.7 software to analyze the the distribution of research countries/institutions, authors and keywords in the included published literatures. And to perform cluster analysis, time evolution analysis and Burst analysis on keywords, draw corresponding visual maps and analyzed them.ResultsA total of 299 published articles were included. Bibliometric analysis showed that the application of POLE/POLD1 mutations in colorectal cancer had developed steadily in recent years. After 2012, the number of published studies had increased significantly; the journals with the most articles were Familial Cancer and Proceedings of the National Academy of Sciences of the United States of America. The author with the highest number of articles was Tomlinson I. The analysis of countries and regions showed that the United States was the main country for research in this field and had contributed the most to the amount of publications. After analyzed the academic institutions/universities where the researchers were located, it could be seen that the University of Oxford was the research university/institution with the most publications. Keyword cluster analysis and time evolution analysis showed that the research hotspots in this field focus on the impact of this gene mutation on immunotherapy. Burst analysis showed that the current published research in this field started two years after publication and continues to be highly cited.ConclusionsPOLE/POLD1 mutation has undoubtedly become a hot area of current research in colorectal cancer research. Among them, tumor immunotherapy is the focus of research in this field.
Objective To investigate the effect of hypoxia on expressions of erythropoietin（EPO）mRNA and protein in retinal Muuml;ller cells cultured in vitro. Methods Retina tissues from the new-born Wistar rats were dissected into cell suspension after digested by pancreatin.Muuml;ller cells were separated and purified by mechanical concussion and blowing and striking method.The expression of EPO mRNA and protein under the condition of hypoxia was detected by semi-quantitative reverse transcriptase（RT）-polymerase chain reaction（PCR）and immunocytochemical method. Results Retinal Muuml;ller cells were cultured successfully，95% of which were positively stained by glial fibrillary acidic protein（GFAP）.Positively stained EPO protein was located in the cytoplasm and protuberance.The expression of EPO mRNA and protein was faint in the normal retinal Muuml;ller cells，but increased obviously and time-dependently after hypoxia. Conclusion Expression of EPO mRNA and protein increases in Muuml;ller cells after hypoxia，which may be one of the protective factors for the nerves in anoxic retinopathy. (Chin J Ocul Fundus Dis, 2006, 22: 196-199)
Biodegradable stents (BDSs) are the milestone in percutaneous coronary intervention(PCI). Biodegradable polymeric stents have received widespread attention due to their good biocompatibility, moderate degradation rate and degradation products without toxicity or side effects. However, due to the defects in mechanical properties of polymer materials, the clinical application of polymeric BDS has been affected. In this paper, the BDS geometric configuration design was analyzed to improve the radial strength, flexibility and reduce the shrinkage rate of biodegradable polymeric stents. And from the aspects of numerical simulation, in vitro experiment and animal experiment, the configuration design and mechanical properties of biodegradable polymeric stents were introduced in detail in order to provide further references for the development of biodegradable polymeric stents.
【Abstract】 Objective To investigate the expression and significance of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) receptors in pancreatic cancer. Methods Thirty-two samples of pancreatic cancer tissue were collected from year 2002 to 2004. All of them were verified by histopathology and there were 9 cases of well-differentiated, 12 of moderately differentiated, and 11 of poorly differentiated, in which 12 cases were in the stage of Ⅰor Ⅱand 20 in the stage of Ⅲ or Ⅳ according to the TNM staging method. Eighteen normal pancreatic tissues were used as control group. The expressions of TRAIL receptors (death receptor 4, death receptor 5, decoy receptor 4 and decoy receptor 5) mRNA were assayed by semi-quantitive reverse transcription polymerase chain reaction (RT-PCR) in the pancreatic cancer tissues and the normal pancreatic tissues. Results The expressions of death receptor 4 (DR4) and death receptor 5 (DR5) were detected in all the pancreatic cancer tissues and the normal pancreatic tissues and the levels of DR4 and DR5 were significantly higher than those of the normal pancreatic tissues (P＜0.01). Decoy receptor 1 (DcR1) and decoy receptor 2 (DcR2) were also expressed in normal pancreatic tissues, whereas DcR1 and DcR2 were only expressed in 18 and 20 pancreatic cancer tissues, respectively. However, there were no significant difference of the expression of DcR1 and DcR2 between the pancreatic cancer tissues and the normal pancreatic tissues （Pgt;0.05）. The expression level of DR5 in pancreatic cancer tissue was correlated with tumor differentiation and clinical stage, and the levels in stage Ⅲ and stage Ⅳwere significantly lower than those of stageⅠand stageⅡ(P＜0.05). The expressions of DR4, DcR1 and DcR2 were not correlated with tumor differentiation and clinical stage (Pgt;0.05). Conclusion ①The expression of TRAIL receptors in pancreatic cancer tissues is prevalent, but the types of receptors expressed in different tissues were also different. High expression of death receptors may play an important role in TRAIL recptors regulated pancreatic cancer apoptosis. ②The expression of DR5 is correlated with the differentiation degree of pancreatic cancer cell and clinical stage of tumor. The expressions of DR4, DcR1 and DcR2 should not be considered as related indexes of differentiation degree or clinical stage of pancreatic cancer.
Objective To investigate the expression of ADAM9 in breast cancer and its clinical significance. Methods The expressions of ADAM9 in normal breast tissues and breast cancer tissues were detected by reverse transcription polymerase chain reaction (RT-PCR) and immunohistochemistry, and whose relationship with clinicopathologic features was analyzed. Results The expression of ADAM9 mRNA increased in the breast cancer tissues, but which was not detected in the normal breast tissues. The expression of ADAM9 protein in the breast cancer tissues was significantly higher than that in the normal breast tissues (Plt;0.05), and which in the metastatic lymph nodes was significantly higher than that in the negative lymph nodes or corresponding primary lesions (Plt;0.05). The expression of ADAM9 in the breast cancer tissues was correlated with the lymph node metastasis and histological grade (Plt;0.05). Conclusion ADAM9 is overexpressed in the breast cancer tissues, which might involve in the pathological progression of breast cancer.