OBJECTIVE: To evaluate the nerve regeneration after implantation of chitin tubes containing nerve growth factor(NGF) in the rabbit facial nerve. METHODS: Bilateral 8 mm defect of superior buccal divisions of the facial nerves were made in 16 New Zealand rabbits. Chitin tubes containing NGF were implanted into the gaps, and autologous nerves were implanted into the right gaps as control. The nerve regeneration was evaluated with electrophysiological and ultrastructural examination after 8 and 16 weeks of operation. RESULTS: Chitin tubes containing NGF successfully induced the nerve regeneration, regularly arranged myelinated and unmyelinated axons could be observed across the 8 mm gaps, and the myelin sheath was thick with clear lamellar structure at 8 weeks after operation, The regenerated nerve fibers increased and were more mature at 16 weeks after operation. There were no significant difference in electrical impulse conduction velocity through the neural regeneration between the experimental and control sides (P gt; 0.05). CONCLUSION: Chitin tubes containing NGF can provide optimal conditions for regeneration of rabbit facial nerve.
Objective To investigate the interference effect of nerve growth factor (NGF) on apoptosis of retinal cells in experimental retinal detac hment (RD). Methods Twenty seven Sprague-Dawely rats were selected, and the left and right eyes were in the experimental control group and NGF group, respectively. After the RD model was set up by subretinal injection with sodium hyaluronate, 5mu;l NGF（1mu;g/mu;l）was injected into the vitreous body of the right eyes which were in the NGF group; 5mu;l PBS was injected into vitreous body of left eyes which were in the experimental control group. The injection was performed once every 4 days till the end of the observation period. The eye balls of the 27 rats were extrafted 1.5, 3, 6, 12 hours, 1 day, 2, 4, 8 , 16, and 32 days after the RD model was established. Another 2 rats were selected as the normal control, which underwent none of the injections but eyeball extraction at the end of the observation period. TUNEL and transmission electron microscopy were used to detect the apoptosis of the retinal cells. Cell counts and statis tical analysis were used to assess results. Results Typical apoptosis cells were observed in the early time of RD. Apoptosis was found in each retinal layers, especially in inner and outer nuclear layers. The number of apoptosis cells increased as the time of RD was prolonged（Plt;0.01）. It was also found that apoptosis cells in NGF group were less than that in the experimenta l control group（Plt;0.01）. Conclusion Intravitreous injection exogenous NGF may inhibit the apoptosis of retinal cells in experimental RD. (Chin J Ocul Fundus Dis, 2006, 22: 333-335)
Objective To observe the effects of the bone marrow mesenchymal stem cells (BMSCs) on the expression of neurotrophic factor protein gene in the retinal detachment (RD) rabbits. Methods 60 healthy rabbits were randomly divided into control group (group A), retinal detachment with PBS group (group B), retinal detachment with BMSCs group (group C), 20 rabbits in each group. RD model were established for rabbits in group B and C. 10 μl PBS was injected into the subretinal space of rabbits in group B, while 10 μl CM-Dil labeled BMSC PBS was injected into subretinal space of rabbits in group C. The rabbits in the group A received no treatment. At 1, 2 and 4 weeks after modeling, the mRNA expression of basic fibroblast growth factor (bFGF), brain derived neurotrophic factor (BDNF) and ciliary neurotrophic factor (CNTF) were measured by real-time quantitative PCR. Results At 1, 2 and 4 weeks after modeling, the mRNA expression of bFGF, BDNF, CNTF on retinal tissue were increased significantly in group C as compared with group A and B (P < 0.01). At 1 week after modeling, the mRNA expression of bFGF and CNTF on retinal tissue were increased significantly in group B as compared with group A, the mRNA expression of BDNF on retinal tissue in group B was similar with group C. At 2 and 4 weeks after modeling, the mRNA expression of bFGF, BDNF, CNTF were decreased in group B as compared with group A. Conclusion Subretinal transplantation of BMSC can increase the mRNA expression of bFGF, BDNF and CNTF on retinal tissue in RD rabbits.
Objective To evaluate the expressive varieties of Nogo-A mRNA in injured optic nerves of rats. Methods Reverse transcription polymerase chain reaction (RT-PCR) method was used to hemi-quantitatively analyze the levels of Nogo-A mRNA in the optic nerves 3, 7, 9, 15, 21, and 25 days respectively after injury.Results The level of the expression of Nogo-A mRNA was low in the normal optic nerves, while it was significantly high in the optic nerves 3 days after in jury, and kept the high level still after 25 days.Conclusion The expression of Nogo-A mRNA in injured optic nerves is increased. (Chin J Ocul Fundus Dis，2003，19：201-268)
Abstract In case of sciatic nerve injury, there is degeneration of neuron in the corresponding segment of spinal cord. To study whether NGF could protect the dorsal root ganglia in this situation, the following experiments were performed: 72 SD mice were divided into 2 groups. In each mouse, the sciatic nerve was sectioned at the middle of the right thigh, and then,the proximal end of the sciatic nerve was inserted into a one ended silastic tube. The NGF 0.15ml (contain 2.5S NGF 0.15mg) was injected into the tubes of the experimental group, while a equal amount of normal saline was injected into the tubes of the control group. After 1, 3, 5, 9, 20 and 30 days, 6 mice of each groupwere sacrificed respectively, and 5th to 6th lumbar segments of the spinal cords were resected for examination. By histochemical study, the activity of fluoride resistant acid phosphatase (FRAP) of each animal was detected. The results showed: (1) Excision of the sciatic nerve led to decrease of FRAP activity, it suggested that the injury of sciatic nerve could damage the dorsal root ganglia; (2) The use of exogenous NGF could protect the FRAP activity. It was concluded that NGF played an important role in protecting the dorsal root ganglia in peripheral nerve injury, in vivo.
ObjectiveTo construct recombinant adenovirus expressing nerve growth factor (NGF) and myelin associated glycoprotein (MAG) (Ad-NGF-MAG) and to investigate its effect on repair and regeneration of sciatic nerve injury in rats. MethodsNGF and MAG gene sequences were cloned into shuttle plasmid pCA13 of adenovirus type 5. After packed in HEK293 cells, the recombinant Ad-NGF-MAG underwent sequence and identification. Thirty-two male Sprague Dawley rats were randomly divided into 4 groups (n=8): control group (normal control), adenovirus vector group (Ad group), Ad-NGF group, and Ad-NGF-MAG group. The sciatic nerve injury model was established by transection of the right sciatic nerve; then, the empty adenovirus vector, Ad-NGF, and Ad-NGF-MAG were injected into the gastrocnemius muscle of the affected limb at a dose of 1×108 PFU every other day for 3 times in Ad group, AdNGF group, and Ad-NGF-MAG group, respectively. The right sciatic nerve was exposed only, and then the incision was closed in the control group. The sciatic nerve function index (SFI) was measured, and neuro-electrophysiology was observed; mRNA and protein expressions of NGF and MAG were detected by RT-PCR and Western blot; and histological examination was performed at 31 days after operation. ResultsRecombinant adenovirus vectors of Ad-NGF and Ad-NGF-MAG were constructed successfully. All rats survived and incision healed by first intension. The SFI, nerve conduction velocity, evoked potential amplitude, and latent period of Ad-NGF-MAG group were significantly better than those of Ad group and Ad-NGF group (P < 0.05). MAG mRNA and protein expressions of Ad-NGF-MAG group were the highest in all the groups (P < 0.05). The expressions of NGF mRNA and protein increased in Ad-NGF group and AdNGF-MAG group when compared with control group and Ad group (P < 0.05). Histological examination showed that the nerve had good continuity in control group; nerve fibers disarranged in Ad group; neurons connections formed in some nerve fibers of Ad-NGF group, but nerve fibers arrange disorderly; and the growth of the nerve were ordered and wellstructured in Ad-NGF-MAG group. ConclusionAd-NGF-MAG can effectively promote the growth of the nerve and inhibit the form of abnormal branches, facilitating the repair of sciatic nerve injury in rats.
It has been proved that the bovine seminal plasma contains rich source of NGF around 0.1mg of pure NGF can be isolated from 10ml bovine seminal plasma. Modifying Gregory s method, we first successfully obtained the low molecular weight form of bovine NGF in China.We chose the dorsal root sensory ganglia (DRG) of embryonic chicken as a cultured nerve tissue, the NGF purified from seminal plasma is added to cultural plate with 96 holes. The cultural process was without plus serum and showed the high biological activity. It was found that this method has the advantages of simple technique, satisfactory result. It is an ibeal method for assaying the biological effect of NGF.
Objective:To study the effects of growth factor on the proliferation of the cultured huamn retinal glial cells. Methods:EGF(0.5～100.0ng/ml) and NGF (0.5～10.0ng/ml) were added to cultures of human retinal glial cells and the proliferation rates of the cells were measured by MTT method. Results:EGF at a dosage ranging from 0.5ng/ml to 100.0ng/ml and NGF (0.05～10.0ng/ml) stimulated the cellular proliferation effectively with their EC 50 of 17ng/ml and 0.7 ng/ml respectively. Conclusion:Both EGF and NGF NGF had an effective stimulation on human retinal glial cell proliferation.They may play a role in the formation of PVR. (Chin J Ocul Fundus Dis,1998,14:33-34)
OBJECTIVE: To investigate the effect of nerve growth factor(NGF) on the burn wound healing and to study the mechanism of burn wound healing. METHODS: Six domestic pigs weighting around 20 kg were used as experimental animals. Twenty-four burn wound, each 2.5 cm in diameter, were induced on every pigs by scalding. Three different concentrations of NGF, 1 microgram/ml, 2.5 micrograms/ml, 5 micrograms/ml were topically applied after thermal injury, and saline solution used as control group. Biopsy specimens were taken at 3, 5 and 9 days following treatment and immunohistochemistry method was used to detect the epidermal growth factor(EGF), EGF receptor (EGF-R), NGF, NGF receptor (NGF-R), NGF, NGF-R, CD68 and CD3. RESULTS: The expression of EGF, EGF-R, NGF, NGF-R CD68 and CD3 were observed in the experimental group, especially at 5 and 9 days, no expression of those six items in the control group. CONCLUSION: NGF can not only act directly on burn wound, but also modulate other growth factors on the burn wound to accelerate the healing of burn wound.
【Abstract】Objective To evaluate the distribution of nerve growth factor receptor( P75 NGFR) in congenital choledochal cyst(CCC) and its clinical implication. Methods Specimens from 18 children with CCC and normal choledochal specimens from 9 controls were immuno-stained with P75 NGFR antibody. Results Extensive P75 NGFR staining was found in the nerve fibres of normal comnon bile duct，bly staining of ganglion cells were observed on the normal specimens. There was very little immunoreactive fibre in the CCC. Conclusion The abnormal distribution of P75 NGFR in the aganglionic choledochal suggests that abnormal P75 NGFR is related to the occurrance of the CCC.