Effects of vascular endothelial growth factor transduction through a Foley's catheter on local vascular endothelial cell growth / 中国组织工程研究

BACKGROUND:Vascular endothelial growth factor(VEGF)can promote vascular endothelial regeneration,inhibit thrombosis,and attenuate neonatal intimal thickness and luminal stenosis degree.OBJECTIVE:The present study established atherosclerosis models in rabbits and observed the effects of local transfection of VEGF gene on restenosis after angioplasty.DESIGN,TIME AND SETTING:A randomized controlled animal experiment was performed at the Laboratory of Microorganism,Tongji Medical College,Huazhong University of Science and Technology between November 2004 and December 2006.MATERIALS:Rabbits were daily raised with high-fat diet to create atherosclerosis models.Twenty successful rabbit models were randomly and evenly divided into a control group and a gene treatment group.METHODS:The DcNDA 3.0 recombinant human VEGF165(hVEGF 165)was trimsferred to the ventral aorta through the use of Foley's catheters.and the pcDNA3.0 was transfefred in the controls.MAIN OUTCOME MEASURES:At 1,2,and 4 weeks after surgery,luminal area of left renal artery opening was measured by MRI.At 2 and 4 weeks after surgery,the ratio for intimal to medial area was obtained through the use of HMIAS-2000 high definition color medical image analysis software.Simultaneously,vascular endothelial cell regeneration was observed by immunohistochemistry of factor Ⅷ related antigen.RESULTS:The pcDNA3.0/hVEGF 165 could be successfully transferred through the use of Foley's catheters.At 2 and 4 weeks after surgery,luminal area was larger in the gene treatment group than in the control group(P<0.01);simultaneously, the ratio of intimal to medial area was significantly smaller in the gene treatment group than in the control group(P<0.05).In the gene treatment group,expanded vascular endothelial cell regeneration was accomplished at 2 weeks after surgery,while in the control group,it took 4 weeks.CONCLUSION:pcDNA3.0/hVEGF 165 gene transduction can promote local vascular endotllelialization and apparently attenuate restenosis degree and intiaml thickening.

A Transmission Electron Microscope Observation of Spiral Organ of Cochleae with Noise-induced Threshold Shift / 第二军医大学学报

Guinea pigs were exposed to either 110dB SPL white noise for 30min (ITS group )or 120 dB SPL for 150 nun (PTS group). At varying postexposure intervals, threshold shifts were assessed using auditory cortex evoked response to tone bursts and intracellular ultrastructural changes in the spiral organ of cochleae were exmained with a transmission electron microscope.. The threshold shifts induced by 110dB noise were reversible while those induced by 120dB noise were generally irreversible. In the TTS cochleae, damage was confined to the third row of OHCs where depolymerization of actin filaments within the stereocilia, slight celluar swelling and small vacuolization were found. The subnuclear area and nerve-endings were not involved. In the PTS cochleae, the inner hair cells (IHCs) and the first row of OHCs were affected. The abnormilities consisted of ruptures and holes in the cuticular plates, fusion of stereocilia, marked edema, tranclucence of subcuticular region, swelling of submembraneous cisterns and large vesiculation in the efferent nerve-endings blow OHCs. Based on the ultrastructural observations, structural bases in cochleae for TTS and PTS, sequence of pathological changes in hair cells as well as reversibility of specific pathologies were suggested.

Ultrastructural Changes in the Spiral Organ of Cochlea after Exposure to Impulse Noise / 第二军医大学学报

Ultrastructural changes in the spiral organ of cochlea at various intervals after exposure to impulse noise were investigated. Guinea pigs were exposed to 10 impulses noise of 166 dB SPL peak level which had duration of 0.1 ms. Thirteen of the exposed animals were used to systematically measure threshold shift at regular intervals from 30 min to 30d post-exposure. The other fourteen animals who had been exposed to the same impulse noise were killed for transmission electron microscopy (TEM) examination at the same intervals, respectively. The recovery pattern of threshold shift showed a nonmonotonic type. There was a progressive deterioration of changes in the hair cells between 30 min and 8h after exposure. Intracellular degeneration reached a peak at 8h and marked edema and swelling leading to deformation of the outer hair cells (OHCs), fused stereocilia, large vesicles in cytoplasm and swollen submembraneous cisterns were found. After that time the extent of degeneration in the hair cells reduced. The time sequence of changes in the spiral organ of cochlea in the present study was associated with the recovery pattern of threshold shift.