Paracrine action of bone marrow mesenchymal stem cells and cell apoptosis following cerebral ischemia / 中国组织工程研究

BACKGROUND: One of mechanisms involved in treating cerebral ischemia with bone marrow mesenchymal stem cells (BMMSCs) implantation is paracrine action. However, few studies have reported this mechanism.OBJECTIVE: To observe the inhibitory effect of BMMSCs paracrine action on apoptosis and its mechanism after cerebral ischemia. METHODS: BMMSCs were isolated from rats with adherent culture. Rat cerebral ischemia model was established by the middle cerebral artery occlusion. A total of 24 rats were divided into 4 groups, with 6 animals in each group. Cell implantation medication group: rats were received U0126 medication after BMMSCs implantation; Non-implantation medication group: rats were received U0126 medication after PBS injection; Cell implantation control group: received solvent medication after BMMSCs implantation; Non-implantation control group: received solvent medication after PBS injection. At 7 days after operation, the expressions of vascular endothelial cell growth factor (VEGF) and p-ERK1/2 protein were measured by Western blot analysis, and the apoptosis cells in the area of ischemic penumbra and cortex were examined by TUNEL. RESULTS AND CONCLUSION: The VEGF protein content in the brain tissue was significantly greater in the cell implantation groups than that of the non-implantation group, with increased p-ERK1/2 and decreased apoptosis cells. The expression of p-ERK1/2 was down-regulated in rats which were administrated U0126 while the number of the apoptosis cells was increased, but the VEGF protein expression had no statistical difference. It suggested that BMMSCs can paracrine VEGF in the striatum of brain and play an inhibitory effect on apoptosis in the ischemia area via activating ERK1/2.

Combined therapy of methylprednisolone and brain-derived neurotrophic factor promotes axonal regeneration and functional recovery after spinal cord injury in rats / 中华医学杂志(英文版)

<p><b>OBJECTIVE</b>To investigate the effects of combination therapy with methylprednisolone (MP) and brain-derived neurotrophic factor (BDNF) on axonal remyelination and functional recovery after spinal cord injury in rats.</p><p><b>METHODS</b>Forty-five rats were randomly divided into three groups: Group A received MP and BDNF; group B received MP and cerebrospinal fluid (CSF); and group C received CSF only. Contusion injury to adult rat spinal cord was produced at the T(10) vertebra level followed by immediate intravenous MP or CSF, and was thereafter infused intrathecally with BDNF or CSF for 6 weeks. Axonal remyelination and functional recovery was observed using RT-PCR, immunohistochemistry and open field locomotion.</p><p><b>RESULTS</b>An increase of 28.4% +/- 2.3% in the expression of proteolipid protein (PLP) gene, an endogenous indicator of axonal remyelination, was demonstrated in group A 24 hours after injury. Ten weeks later, there were significant decreases in hematogenous inflammatory cellular infiltration in groups A and B compared to C (P < 0.05). Concomitantly, a significant amount of axonal remyelination was observed in group A compared to groups B and C (P < 0.05). Furthermore, combination therapy using MP and BDNF in group A resulted in stimulation of hindlimb activity as well as improvement in the rate of functional recovery in open field locomotion (P < 0.05).</p><p><b>CONCLUSIONS</b>Combined therapy of MP and BDNF can improve functional recovery through mechanisms that include attenuating inflammatory cellular infiltration and enhancing axonal remyelination at the injury site. Such a combination may be an effective approach for treatment of spinal cord injury.</p>

Facial nerve preservation in acoustic neuroma microsurgery / 中华显微外科杂志

Objective To study the skills of facial nerve preservation in acoustic neuroma microsurgery. Methods Seventy four cases of acoustic neuromas treated microsurgically by suboccipital retrosigmoid transmeatus approach were analyzed retrospectively, including their clinical symptoms and characteristic image, the pathological anatomic relationships of facial nerve and tumor, microsurgical technique. Results Total resection of the tumor was achieved microsurgically in 72 cases, subtotal resection in 2 cases. Facial nerve was kept anatomic intact in 67(90.5%) of the patients. Intracranial end to end anastomosis of the facial nerve was performed in 4 cases. No patient died in this series. Conclusions Microneurosurgical technique is a safe and effective method for total resection of acoustic neuroma. It is key point for keeping facial nerve anatomic intact to understand the pathological anatomic relationships of facial nerve and tumor.