Activin A prevents neuron-like PC12 cell apoptosis after oxygen-glucose deprivation

In this study, PC12 cells were induced to differentiate into neuron-like cells using nerve growth factor, and were subjected to oxygen-glucose deprivation. Cells were treated with 0, 10, 20, 30, 50, 100 ng/mL exogenous Activin A. The 3-（4,5-dimethyl-2-thiazolyl）-2,5-diphenyl tetrazolium bromide assay and Hoechst 33324 staining showed that the survival percentage of PC12 cells significantly decreased and the rate of apoptosis significantly increased after oxygen-glucose deprivation. Exogenous Activin A significantly increased the survival percentage of PC12 cells in a dose-dependent manner. Reverse transcription-PCR results revealed a significant increase in Activin receptor IIA, Smad3 and Smad4 mRNA levels, which are key sites in the Activin A/Smads signaling pathway, in neuron-like cells subjected to oxygen-glucose deprivation, while mRNA expression of the apoptosis-regulation gene caspase-3 decreased. Our experimental findings indicate that exogenous Activin A plays an anti-apoptotic role and protects neurons by means of activating the Activin A/Smads signaling pathway.

Use of RNAi silencing to target preconditioned glial cell line-derived neurotrophic factor in neuronal apoptosis

Several studies have suggested that exogenous glial cell line-derived neurotrophic factor may pro-tect neurons from cerebral ischemic injury. However, the mechanisms underlying the neuroprotec-tive effects of endogenous glial cell line-derived neurotrophic factor remain unclear. The present experiments sought to elucidate the influence of various conditioned media on neuronal apoptosis, using a normal culture medium for astrocytes, an astrocyte medium highly expressing glial cell line-derived neurotrophic factor, and an astrocyte medium in which glial cell line-derived neurotro-phic factor expression was silenced using RNAi technology. The results confirmed that the use of RNAi silencing to target pretreated glial cell line-derived neurotrophic factor expression promoted neuronal apoptosis. In addition, oxygen and glucose deprivation preconditioning was found to upregulate glial cell line-derived neurotrophic factor expression, and significantly reduce neuronal apoptosis.

Comparison of Intraoperative Ultrasound Pachymetry and Postoperative Optical Coherence Tomography of Anterior Segment in the Measurement of Flap Thickness in Eyes Receiving Laser in situ Keratomileusis

Purpose:To compare the measurement of flap thickness using intraoperative ultrasound pachymetry and postoperative visante anterior segment optical coherence tomography (Visante-OCT) in eyes receiving laser in situ keratomileusis (LASIK). Methods: Seventeen patients (34 eyes) received LASIK using a Technolas-217Z100 laser and AMADEUSⅡ mechanical microkeratome(140 μm head). Flap thickness was assessed with an ultrasound pachymeter intraoperatively and a Visante-OCT postoperatively at 1 week and 1 month. Results: The intraoperative mean flap thickness by ultrasound pachymetry was (124±13.9) μm (range: 96.5 to 160 μm), and mean flap thickness by Visante-OCT was (145±7.13) μm (range: 130 to 158 μm) and (143±5.32) μm (range: 132 to 155 μm) postoperatively at 1 week and 1 month respectively (F=63.52,P<0.01). Intraoperative subtraction pachymetry underestimated flap thickness compared with postoperative Visante-OCT.(P<0.01)..There was no significant difference between postoperative Visante-OCT measurements at 1 week and 1 month after LASIK.(P=0.16). The 95% limit of agreement.(LoA).of flap thickness between ultrasound Visante-OCT and pachymetry was -5.40 to 42.10 μm. Conclusion: OCT overestimates flap thickness compared with intraoperative ultrasound pachymetry when using the AMADEUSⅡ mechanical microkeratome.

Effect of scraping therapy on Interleukin-1 in serum of rats with lumbar disc herniation

OBJECTIVE:To explore the effect of scraping therapy on the Interleukin-1 (IL-1) levels of rats with lumbar disc herniation (LDH). METHODS: Fifty male rats were devided into a blank group (A), a sham operation group (B), a model group (C), a scraping group (D), and a drug group (E). The rats in the group B were treated with sham operation, and groups C, D and E were made into the LDH model by operation. After operation group C were treated with no interventions, D were given scraping and E were fed with azathioprine Then the IL-1 levels of different groups were detected by enzyme-linked immuno sorbent assay method. And the transplanted coccygeal vertebra discs were observed by pathological section. RESULTS: The IL-1 levels in the groups C, D, and E were significantly higher than those in the groups A and B (all P<0.01), which proved the operationwas successful.The IL-1 levels in the groups D and E at different periods had statistical significance (F= 414.158, P<0.01). The treatment periods and interventions have interation (F=46.613, P<0.01). Multiple comparison results showed that the IL-1 levels in the groups D and E was significantly lower than that in the group C (P<0.01), while the IL-1 levels between the groups D and E had no statistical significance (P>0.05). Moreover, pathological section indicated that immuno-inflammatory response was hardly found in coccygeal vertebra discs in the groups A and B, while local immuno-inflammatory responses of the groups D and E were much lighter than that of the group C. CONCLUSION: Scraping therapy could inhibit the immuno-inflammatory responses in the rats with LDH caused by transplantation of autologous nu cleus pulposus.