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Objective To select the largest non-toxic leaching solution concentration through the experimental observation of the cytotoxicity of the ostrich acellular corneal stromal leaching solution to the Chinese hamster lung fibroblasts cells(CHL) for the further chromosome distortion experiment.Methods The leaching solution made from the ostrich acellular corneal stromal material was diluted with concentrate of 1 ∶ 2,1 ∶ 4 and the original concentration were used to culture with the CHL cells,the negative and positive control were also set up at the same time,to evaluate the impact on cell growth after 24 hour by MTT colorimetric method.Results The leaching solution diluted with 1∶4 was non-toxic,and could promote the growth of the cells.Conclusion Combined with the results of classification and cell morphological features,this cytotoxicity test can be used to screen the best benchmark non-toxic concentrations for the chromosome aberration test of the CHL cells.
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Background Fungal corneal ulcer is a visual-threatening eye disease,and drug therapy has a limiting efficacy.Corneal transplantation or eye enucleation sometimes is necessary to the severe patients.Corneal collagen cross-linking (CXL) is an effective method for some corneal diseases,but the study on CXL for fungal corneal ulcer is lack.Objective This study was to evaluate the clinical effectiveness and safety CXL for fungal corneal ulcer.Methods Fifteen 8-week-old healthy New Zealand white rabbits were used in this study and other 5 rabbits served as normal controls.Fungal corneal ulcer models were established in the right eyes of other 10 rabbits by infecting sickle bacteria liquid after corneal scratching and removing corneal epithelium,then decellularized ostrich corneal patch covered the defected cornea.The models were randomly divided into the non-treatment group and the CXL treatment group.Corneal lesions were examined under the slit lamp microscope every day,and cornea was pictured by laser scanning confocal microscope on the 3rd,7th,14th,21st and 28th day individually after CXL.All rabbits were sacrificed and corneal tissues were obtained 4 weeks after treatment,and the collagen fiber diameter and fibrocytes were observed under the scanning electron microscope.Results Fungal corneal ulcer models were successfully established by corneal scratching and decellularized ostrich cornea covering.The gray ulcer lesions and hypbae like bean pod were seen by slit lamp microscope and laser scanning confocal microscope 3 days after modeling.Corneal ulcer deepened and expanded 1 week later,and there were a large number of spore and hyphae criss-crossing as short rod in shallow stroma.Inflammatory cells were observed in corneal endothelial cells and ocular anterior chamber.In the CXL treatment group,the range of corneal epithelial deficiency was less than that in the nontreatment group on the 3rd,7th,14th,and 21st (all at P＜ 0.05).The diameters of collagen fibers were (24.6± 1.8) nm,(24.9 ± 1.9) nm and (43.0 ± 7.4) nm in the normal control group,non-treatment group and CXL treatment group,showing a significant difference among the 3 groups (F =27.05,P =0.00),and the collagen diameters were thicker in the CXL treatment group than those in the normal control group and non-treatment group (t =5.40,-5.30,both at P＜0.05),and fibrocytes were seen among the collagen fibers.No significant difference was found in the collagen diameters between the non-treatment group and normal control group,and the fibrocytes were less in the non-treatment group.Conclusions CXL therapy can treat fungal corneal ulcer by enhancing collagen,promoting fibrocytes proliferation,suppressing fungus and inflammatory response and accelerating tissue repair.
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Background Ostrich acellular corneal stroma possesses a similar constitution to human corneal stroma,so it is expected to become one of ideal biological corneal carriers.Objective This study was to investigate the immunogenicity of acellular stroma carrier of ostrich cornea and offer the information for the development of industrialization and clinical use of acellular stroma carrier of ostrich cornea.Methods Twenty fresh ostrich eyeballs and 20 porcine eyeballs were collected.Acellular corneal stroma carriers of ostriches and pigs were prepared using low temperature freezing joint enzyme digestion method and desiccant dehydration method and sterilized by cobalt-60 irradiation.The corneal stroma carriers were preserved using drying and dehydration method.Forty-five male BALB/c mice were randomly divided into the sham operation group,ostrich acellular corneal stroma group and porcine acellular corneal stroma group.Acellular corneal stroma carriers of ostriches and pigs(wet weight after rewatering was 10 mg/piece) were subcutaneously implanted to the back of BALB/c mice,respectively.Wound healing and inflammatory response on the operative site were observed,and phenotype and activating rate of CD4+,CD8+ and CD25+in peripheral blood of mice were dynamically detected 7,14 and 28 days after ectopically implantation of heterogeneous corneal stroma by immunofluorescence labeling and flow cytometry analysis.Results No swelling and exudation were seen in the skin of operative site of the mice with a good healing of wound after surgery.There were no significant differences in the activating rates of CD4+,CD8+ and CD25+ cells in the peripheral blood of mice among the sham operation group,the porcine acellular corneal stroma group and ostrich acellular corneal stroma group in the three time points after surgery(CD4+:F=0.74,P=0.50;F=0.39,P=0.05;F=3.46,P=0.58.CD8+:F=1.75,P=0.21 ;F=1.14,P=0.35;F=0.78,P=0.48.CD25+:F=0.52,P=0.61 ;F=3.53,P=0.62;F=2.42,P=0.13).Conclusions The ostrich acellular heterogeneous corneal stroma carrier possesses low immunogenicity.It is inferred that ostrich acellular corneal stroma carrier can be used in heterogeneous corneal transplantation.
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The suppression of spiral waves and spatiotemporal chaos in cardiac tissue was studied based on cardiac model. We proposed two strategies of suppressing spiral wave and spatiotemporal chaos. One was to elevate the extracellular potassium ion concentration suddenly. This method can effectively suppress spiral waves and spatiotemporal chaos when the elevated extracellular potassium ion concentration reaches a critical value, especially when the spiral wave pinned to defects also can be suppressed. The other was to let the extracellular potassium ion concentration varies periodically while the amplitude of concentration was limited. We found that the method could effectively suppress spiral waves and spatiotemporal chaos when the related parameters were properly chosen. But it can not suppress the pinned spiral waves. And the control mechanism is discussed in this paper.
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Humans , Action Potentials , Physiology , Arrhythmias, Cardiac , Computer Simulation , Heart , Physiology , Models, Cardiovascular , Potassium , MetabolismABSTRACT
Objective To investigate the effects of divitamins notonginseng and cinnarizine capsule(DNCC) on acute cerebral ischemia.Methods ICR mice were administered three doses of DNCC(420,210,and 105mg/kg;ig.) for ten days,then the gasping time after decapitation was recorded.After three doses of DNCC(292,146,and 73mg/kg;ig.) were given respectively for ten days in rats,the effects of DNCC on the infarct size,histological changes and neurological function scores caused by focal cerebral ischemia which was induced by middle cerebral artery occlusion were investigated.Results DNCC prolonged the gasping time of mice after decapitation and improved the neurological function scores,cerebral ischemia injury and decreased the infarct size in rats.Conclusion DNCC has a protective effect against acute cerebral ischemia.