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Objective To investigate the promoting repair effects of chitosan/gelatin electrospinning membrane implantation on conjunctival injury.Methods Chitosan/gelatin electrospinning membrane was prepared using electrospinning technique,and the general characteristics of the membrane was examined under the scanning electron microscope.Conjunctival injury models were established in the right eyes of 30 New Zealand white rabbits by surgical resection of 6 mm×8 mm bulbar conjunctiva,bums of weak acid at injury site and then randomized into model group,human amniotic membrane (AM) implanted group and electrospinning membrane implanted group.AM or electrospinning membrane was interlayerly implanted between conjunctiva and sclera during operation according to grouping.The inflammatory response and histopathological change at injury site were examined by slit lamp microscope and optical microscope in 4,8,14 and 28 days after surgery.The use and care of the animals followed by code of ethics for animal experiments at the animal experiment center of He University.Results Chitosan/gelatin electrospinning membrane presented with a crosslinked network structure like AM,with the nano-microstructure of 0.1-0.5 μm fibre.No obvious inflammatory symptom was seen in the experimental eyes of various groups in 4 days after operation.In 8 days after operation,conjunctival edema and erosion were found in the model group,and slight conjunctival congestion was exhibited in the eyes of AM implanted group and electrospinning membrane implanted group.In 14 to 28 days after operation,conjunctival edema and new blood vessels were seen in the model group,and the conjunctivas were well recovered in the AM implanted group and electrospinning membrane implanted group.Histopathological examination showed dissociation,attaching,thickening and epithelization of injuried conjunctivas gradually in the model group from 4 to 28 days after operation.In the AM implanted group,attaching of AM was in 4 days,melting of AM was in 8 days,epithelization of injuried conjunctivas was in 14 days and renovation of conjunctivas was in 24 days after operation,and a rapid repairing procedure was found in the electrospinning membrane implanted group under the optical microscope.Conclusions Compared with the self-repairing process of conjunctival injury,implantion of chitosan/gelatin electrospinning membrane or AM can speed up the renovation of injuried conjunctivas,and the effects of chitosan/gelatin electrospinning membrane are better than those of AM in promoting conjunctiva repair and inhibiting scarring.
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Objectvi e To investigate whether promoting gap junctions may contribute to the radiosensi-tivity in triple negative breast cancer( TNBC)cells.Methods HCC70(triple-negative),MCF-7(ER-posi-tive)or SK-BR3(HER2-positive )cells were transfected with pcDNA/5 -Cx43 expression plasmid using liposome 2000.The transfected cells were treated with various doses of radiation(0,5,10,15 Gy),and the level of Cx43 protein was determined by Western blot and the cell connectivity was determined by fluorescent tracer technique. Cell proliferation inhibition,clone formation ability and apoptosis were detected using MTT,clone formation assay, AnnexinV-FITC/PI double staining and flow cytometer,respectively.Results The level of Cx43 protein signifi-cantly increased in HCC 70 -Cx43 ,MCF-7 -Cx43 and SK-BR3 -Cx43 cells.After transfection the cells were treated with various doses of radiation,level of Cx43protein was gradually enhanced in dose dependent fashion .The re-sults form fluorescent tracer technique showed that fluorescence intensity was gradually elevated with increase of radiation doses.Cell viability and clone formation ability were decreased gradually in dose dependent manner in HCC70-Cx43 ,MCF-7 -Cx43 and SK-BR3-Cx 43 cells.Unexpectedly,the inhibitive effect of proliferation ability and clone formation ability in HCC70 -Cx43 cell was higher than in MCF-7 -Cx43 and SK-BR3 -Cx43 cells under same conditions.The results from AnnexinV-FITC/PI and flow cytometer showed that apoptosis rate was enhanced gradually accompanying with increase of radiation doses.Conclu sion Enhancing the function of cell gap junc-tions promoted radiosensitivity of breast cancer cells,particularly in TNBC cells.Radiation can strengthen cell gap junctions in breast cancer cell and cytotoxicity of TNBC cell can be enhanced by both synergistic effects.
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Background Scarring of filter bleb is a main cause of failure after trabeculectomy.Administration of anti-proliferation dugs during filtering surgery can maintain the opening of filtering pathway,but some serious complications occure after the drug use.Researches showed that polylactic acid caprolactone (PLCA) drug-loaded electrospinning film can release drug slowly,but its application in glaucoma is seldom.Objective The aim of this study was to evaluate the anti-scarring effects of non-penetrating trabeculectomy combined with sclera interlayer implantation of triamcinolone acetonide (TA)/PLCA drug-loaded electrospinning film in rabbit.Methods TA/PLCA drug-loaded electospinning film was prepared by electrospinning and its surface ultrastructure was observed under the scanning electron microscope.The drug release properties were detected by high performance liquid chromatograph.Ocular hypertensive models were established in New Zealand white rabbits by injecting carbomer into the anterior chamber of the right eyes,and the 40 models were randomized into 5 groups,8 eyes for each group.TA/PLCA drugloaded electrospun membrane,PLCA electrospun membrane or amniotic membrane was implanted beneath the scleral flap during trabeculectomy respectively in the TA/PLCA group,PLCA group or amniotic group,and 40 mg/ml TA was subconjunctivally injected in the TA group.Only trabeculectomy was performed in the simple trabeculectomy group.Intraocular pressure (IOP) was measured,and the shape of filtering bleb was examined under the slit lamp 1 week,2,4,8 and 12 weeks after surgery.The section of filtering bleb was prepared 12 weeks after surgery for the histopathological examination.The use and management of experimental animals was in line with animal ethics.Results The similar three-dimensional reticular structure was seen between TA/PLCA and electrospun membrane with the fiber diameter 0.5-1.5 μm.TA was released stably for 14 days.All the filtering blebs were disappeared in the simple trabeculectomy group during 8-week duration after operation.At 12 weeks after operation,the functional bleb was found in all the 8 eyes of the TA/PLCA group,5 eyes of PLCA group,4 eyes of the amniotic group and 4 eyes of the TA group.The IOP was significantly different among the groups,with the lowest IOP in the TA/PLCA group and the highest IOP in the simple trabeculectomy group (all at P =0.000).Histopathological examination showed that the filtering pathway remained opening in all 8 eyes with the epithelization of bleb surface in the TA/PLCA group,and interspaces of the filtering pathway was explayed in the PLCA group,amniotic group and TA group,while fibrosis of filtering pathway was seen in the simple trabeculectomy group at 12 weeks after surgery.Conclusions TA/PLCA drugloading electrospun membranes presents with nanoscale microstructure and good drug-release properties in vitro.Implantaion of TA/PLCA beneath the scleral flap during trabeculectomy can inhibit the fibrosis of filtering pathway.
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OBJECTIVE: To investigate the incidence rate of the ampC gene and AmpC enzyme of gram-negative(G-) bacterium in children,to analyze drug resistance of produced AmpC enzyme and un-produced AmpC enzyme strain.METHO_DS: 4 022 clinical G-isolates collected from 2002 to 2004 were identified and tested using K-B method.Selection 108 ESBLs bacterium,the ampC genes were amplified by PCR using common primers to AmpC and the AmpC enzymes were tested using the enzymatic rough extraction cefoxitin three-dimensional test.The drug resistance of bacterium produced AmpC enzymes were compared with the ones without AmpC enzymes.RESULTS: In 108 G-bacterium,the ampC genes positive bacterium were 70 strain(accounting for 64.8%),and 7 bacterium produced AmpC enzymes(accounting for 6.5%) were detected.The drug resistance of bacterium produced AmpC enzymes to ceftazidime(CAZ),ceftriaxone(CRO),piperacillin(PIP),ampicillin(AMP),aztreonam(ATM) were 85.7%,85.7%,71.4%,79.4%,79.4% respectively.The drug resistance of bacterium non-produced AmpC enzymes to CRO,PIP,gentamicin,AMP,ATM were 50.8%,55.6%,55.6%,70.3%,54.0% respectively,the drug resistance of bacterium to imipenem were the lowest,lower to ciprofloxacin.CONCLUSIONS: Detection rate of ampC gene were higher than AmpC-producing enzymes strains obviously,whereas the drug resistance to antibiotic of AmpC-producing enzymes strains were higher than non-producing enzymes strains.
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2h.The shape of bacterium was changed by amikacin from sphero-rhabditiform to dolicho-rhabditiform,while by ceftriaxone changed from rhabditiform to long-chain-form or filament-form.Conclusion The capability of ceftriaxone-induced release of endotoxin from Escherichia coli is significantly stronger than that of amikacin,and the morphologic changes of bacteria caused by ceftriaxone were more significant.For clinical treatmentg of infectious diseases the first dosage of medication should increase to reach the effective bactericidal concentration but not the bacteriostasis concentration in order to receive better therapeutic effects.