The cortexes were obtained from new-born rats and dissociated to single cells by triturating. The cells were cultured in neural stem cell (NSC) culture medium (DMEM supplemented with bFGF, EGF and B27) and formed primary neurospheres after 7 days. Single cells dissociated from neurosphere were cultured in 96-well plates and formed single-cell cloning neurosphere 7 days later. The primary and single-cell cloning neurospheres were both positive for the immunofluorescent staining of nestin and were identified as NSC. It was proved that NSC can be expandedin vitro and provide seed cells for neural tissue engineering.
An experimental model of rhegmatogenous retinal detachment (RRD) in rabbits was established to simulate the pathophysiologic condition of human RRD, 24 rabbits were randomly divided into 3 groups and underwent vitrectomy with a vitrector and/or retinotomy with a Charles flute needle, with 12 in group I (vitrectomy and retinotomy), 7 in group II (retinotomy) and 5 in group III (vitrectomy). All animals underwent follow-up examinations with direct and indirect ophthalmoscopy and fundus photography 12 h and day 1, 3, 5, 7, 10, 14, 21, and 28 after the procedure(s). Retinal changes were recorded. As a result, 10 RRDs were successfully established in group I. Direct and indirect ophthalmoscopy and fundus photography demonstrated typical features of RRD. No RRD developed in group II and III. It was concluded that the experimental rhegmatogenous retinal detachment produced in a rabbit model after vitrectomy with retinotomy in this study was a convenient and reliable one. This RRD model mimicked the typical pathophysiological changes in humans.
The changes of tumor necrosis factor-α (TNF-α) and brain ultrastructure during cardiopulmonary resuscitation and the effects of ulinastation injection were observed, and the mechanism was investigated. Twenty-four adult healthy Sprague-Dawley rats were randomly divided into control group (8 rats), resuscitation group (8 rats) and ulinastatin (UTI) group (8 rats). Rats in control group underwent tracheotomy without clipping the trachea to induce circulatory and respiratory standstill. Rats in resuscitation and ulinastatin group were subjected to the procedure of establishing the model of cardiopulmonary cerebral resuscitation (CPCR). Rats in ulinastatin group were given with UTI 104 U/kg once after CPCR. In the control group, the plasma was collected immediate, 30 min, 2 h, 4 h, and 6 h after tracheotomy. In resuscitation group and UTI group, plasma was collected immediate after tracheotomy, 30 min, 2 h, 4 h and 6 h after successful resuscitation. The plasma levels of TNF-α were determined by radioimmunoassay (RIA). At the end of the experiment, 2 rats were randomly selected from each group and were decapitated. The cortex of the brain was taken out immediately to observe the ultrastructure changes. In control group, there were no significant differences in the level of TNF-α among different time points (P>0.05). In resuscitation group, the level of TNF-α was increased obviously after resuscitation (P<0.01) and reached its peak 2 h later after resuscitation. An increasing trend of TNF-α showed in UTI group. There were no differences in TNF-α among each sample taken after successful resuscitation and that after tracheotomy. The utrastructure of brains showed the injury in UTI group was ameliorated as compared with that in resuscitation group. In early period of CPCR, TNF-α was expressed rapidly and kept increasing. It indicated that TNF-α might take part in the tissue injury after CPCR. The administration of UTI during CACR could depress TNF-α and ameliorate brain injury. By regulating the expression of damaging mediator, UTI might provide a protective effect on the tissue injury after CPCR.
To investigate the anti-vasculature effects and the anti-glioma effects of attenuatedSalmonella typhimurium vaccine strain expressing VEGFR2 (flk-1) gene, plasmid pcDNA3, 1-flk1 was constructed and electro-transfected into live attenuatedSalmonella typhimurium strain SL7207. Mouse models of intracranial Gl261 glioblastoma were treated with an orally administered attenuatedSalmonella typhimurium expressing flk-1 gene. The survival period was recorded and vessel density was observed by immunofluorescence. CTLs activity was measured by MTT assay. Our results showed that attenuatedSalmonella typhimurium vaccine strain expressing flk-1 gene could significantly inhibit glioblastoma growth, reduce vessel density, prolong the survival period and improve the survival rate in these mice. The flk-1 specific CTLs activity was increased obviously after the vaccination. Our study showed that attenuatedSalmonella typhimurium vaccine strain expressing flk-1 gene could break peripheral immune tolerance a in glioma gainst this self-antigen and kill endothelial cells by the orally administered vaccine and can be used for both prophylactic and therapeutic purposes.
The expression of VEGF-C and molecular mechanisms of lymphangiogenesis in rat corne after alkali injury was studied. The rat alkali injured corneal models were made. Under electron microscopy, the lymphatic vessels in the rat injured corneas were examined. The expression of VEGF-C proteins was detected by using immunohistochemical assay at day 1, 3, 5, 7, 9 after injury. The expression levels of VEGF-C mRNA were quantified with reverse transcription polymerase chain reaction (RT-PCR). The results showed that the lymphatic vessels were found in the injured rat corneas 14 days after the injury. The VEGF-C protein was detectable 3 days after injury, reached the peak 5 days after injury, and gradually decreased. In the control group, no VEGF-C proteins were detected. The VEGF-C mRNA was minimally detected in the normal rat corneas, but it was highly expressed 5 days after the injury. The difference was statistically significant. It was concluded that VEGF-C might be one of the most important relevant factors in corneal lymphangiogenesis after alkali injury.