[Effects of hypertonic saline on erythrocyte adherence function and bacterial infection of hemorrhagic shock rabbits].

AIM: To explore the effect of hypertonic saline on the erythrocyte adherence function and bacterial infection of hemorrhagic shock rabbits. METHODS: 60 Japanese rabbits were randomly divided into 6 groups, 10 for each group. Artery catheterization and heparin were given to the rabbits in group 1 (sham shock group). Hemorrhagic shock model was set up by bleeding resulting from carotid artery catheter in group 2 (normal saline group )and group 3 (hypertonic saline group). 30 minutes after shock, the rabbits in group 1 and group 2 were treated with normal saline and balanced salt solution containing 1 x 10(9)/kg E.coli, respectively. And the rabbits in group 3 were treated with 75 g/L NaCl solution and balanced salt solution containing 1 x 10(9)/kg E.coli. Then the survival rates of the rabbits in group 1-3 were observed. Rabbits in group 4-6 were same treatment as received, group 1-3, respectively, except that there was no E.coli in balanced salt solution. The erythrocyte immune adherence function of rabbits in group 4-6 were detected 5 hours after shock by RBC-C3bR and RBC-IC rosette forming assays. RESULTS: The survival rate of rabbits in hypertonic saline group was significantly higher than that in normal saline group. The RBC-C3bR rosette forming rate of the normal saline treated rabbits were pronouncedly decreased, while RBC-IC rosette forming rate was notably elevated, as compared with those of either sham shock group or hypertonic saline group(P<0.01). Hypertonic saline markedly increased RBC C3bR rosette forming rate. CONCLUSION: The above findings suggest that hypertonic salt solution can remarkably improve the depressed erythrocyte immune adherence function and enhance the rabbit's resistance to E.coli challenge after hemorrhagic shock.

Experiment and observation on invasion of brain glioma in vivo.

Research on invasion and metastasis of glioma in vivo was performed by implanting C6 glioma cells transfected with enhanced green fluorescent protein (EGFP) gene into the brain of SD rats. Firstly, C6 glioma cells were transfected with a plasmid vector (pEGFP-N3) containing the EGFP gene. Stable EGFP-expressing clones were isolated and examination for these cells by flow cytometry and electron microscope was done. Secondly, EGFP-expressing cells were stereotactically injected into the brain parenchyma of SD rats to establish xenotransplanted tumor. Four weeks later rats were killed and continuous brain sections were examined using fluorescence microscopy after adjacent sections were examined by immunohistochemistry or routine hematoxylin and eosin staining for the visualization and detection of tumor cell invasion. Xenotransplanted tumor was primarily cultured to determine the storage of EGFP gene in vivo. The results showed that EGFP-transfected C6 glioma cells maintained stable high-level EGFP expression in the central nervous system during their growth in vivo. EGFP fluorescence clearly demarcated the primary tumor margin and readily allowed for the visualization of distant micrometastasis and invasion on the single-cell level. Small locally invasive foci, including those immediately adjacent to the leading invasive edge of the tumor, were virtually undetectable by routine hematoxylin and eosin staining and immunohistochemistry. These results suggested that EGFP-transfected C6 cells can be visualized by fluorescence microscopy after intracranial implantation. This model is an excellent experimental animal model in research on invasion and metastasis of brain glioma in vivo.