【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.
OBJECTIVE: To observe the effect of nerve growth factor (NGF) and nimodipine (NP) on fetal spinal cord graft in repair of injury of spinal cord. METHODS: A total of 144 adult Wistar rats were included in this study. All were made as the hemi-section cavity injury model at the lumbar enlargement and divided into three groups: fetal spinal cord graft (group Tr), fetal spinal cord graft with NGF (group TN), and fetal spinal cord graft with NGF and NP (group TNN). The intracellular concentration of free ionic calcium was measured at the 4th, 8th, and 24th hour, and superoxidase (SOD) and malondialdehyde (MDA) at 3rd, 6th, 12th, 24th and 72nd hour after operation. RESULTS: After spinal cord was injured, the concentration of MDA and intracellular concentration of free ionic calcium increased and reached to the peak at the 6th and 8th hour respectively, but SOD decreased and at 24th hour to its vale. The MDA was significantly lower in group TN than in group Tr, while the SOD was higher (P lt; 0.05). There was no significant difference on intracellular free ionic calcium concentration between group Tr and TN. The concentration of SOD of group TNN was the highest and the intracellular concentration of free ionic calcium was the lowest in the three groups (P lt; 0.05). The weekly mortality was 33%, 31%, 17% respectively in group Tr, TN and TNN. The mortality of group TNN was significantly lower than the other two groups (P lt; 0.01). CONCLUSION: Although the fetal spinal cord graft is an effective method to repair laboratory spinal cord injury, NGF and ND can interrupt secondary injury and increase survival rate of the host.
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.
ObjectiveTo explore the expressions of nerve growth factor (NGF) and leukemia inhibitory factor (LIF) in both asthmatic mice and respiratory syncytial virus(RSV)-infected mice,explore if there is a same neurogenic mechanism between ashtma and RSV infection,in order to find a new treatment target for asthma. MethodsOne hundred healthy Balb/c inbred mice were randomly divided into a control group,a RSV group,an asthma group,an asthma with RSV group,and a dexamethasone group. The lung tissue pathology was observed by hematoxylin-eosin staining(HE). The quantitative analysis of NGF mRNA and LIF mRNA of lung tissue was detected by RT-PCR. The expression of NGF protein and LIF protein was detected by immunohistochemical method. ResultsUnder light mocroscope,there were alveolar septum widening,alveolar epithelium swelling,and interstitial edema in the RSV group. There were widen alveolar septum,narrowed bronchial lumen,thicken bronchial wall and a large number of inflammatory cells infiltration around the small blood vessels,alveolar and bronchioles both in the asthma group and the asthma with RSV group,with the latter being more serious. Compared with the RSV group,the inflammation was relieved significantly in the dexamethason group. There were mRNA and protein expressions of NGF and LIF in all groups, which were highest in the asthma with RSV group,then the RSV group and the asthma group,and lowest in the dexamethasone group. ConclusionsThe expressions of LIF and NGF in the lung of mice after RSV infection and futher increase when combined with asthma. Dexamethason can inhibit the expression of NGF and LIF to some extent.
Objective Using nerve growth factor ( NGF) and anti-NGF microspheres injected directly into the asthmatic rat adrenal gland, to explore the possible role of anti-NGF microsphere treatment in asthma.Methods 32 male SD rats were randomly divided into a normal control group, an asthma group, a NGF microspheres group, and an anti-NGF microspheres group. The behavior of rats, lung function testing, light microscopy of lung biopsy, electron microscopy of adrenal medulla cell ultrastructure changes, NGF and phenylethanolamine N-methyltransferase ( PNMT) expressions in the adrenal gland were assayed by immunohistochemistry method, and serum NGF, cortisol, corticosterone, epinephrine and norepinephrine concentrations were detected by ELISA. Results Behavior in the asthma rats showed varying degrees of sneezing, runny nose, wheezing, scratching the head and face, irritability holes, incontinence, increased aggression and other acts, while in the anti-NGF rats showed relatively slighter symptoms. The rats in the asthma, anti-NGF and NGF groups showed significant airway hyperresponsiveness, while RL value reduced and Cdyn value increased in the anti-NGF group compared with the asthma group. HE staining of lung tissue revealed obvious bronchoconstriction, inflammatory cell infiltration around small vessels and alveolar spaces and in interstitum, bronchial epithelial cells desquamation in the asthma group. In anti-NGF group, tracheal epithelium was relatively complete, inflammatory exudation, bronchoconstriction and inflammatory cell infiltration were milder compared to the asthma group. Electron microscopy showed vacuolated changes of adrenal medulla cells, uneven distribution of chromaffin granules in the asthma group and the NGFgroup, and the quantity and concentration of chromaffin granules were significantly lower than normal. There were villous clubbing processes on the adrenal medulla cell membrane in the NGF group. While the anti-NGF group had no significant vacuolar changes in chromaffin granules and the concentration was close to normal. Image analysis showed that mean gray values of PNMT and NGF in the anti-NGF group were significantly different fromthe asthma group. The ELISA results showed that: ( 1) The average concentrations of epinephrine in each group were as follows, ie. the control group gt; anti-NGF group gt; asthma group gt; NGF group. ( 2) The average concentrations of norepinephrine in each group were as follows, ie. the NGF group gt; asthma group gt; anti-NGF group gt; control group. ( 3) There was no significant difference among the groups in the average concentration of cortisol. ( 4) The average concentrations of norepinephrine in each group were as follows, ie. , the control group gt; anti-NGF group gt; asthma group gt; NGF group. Conclusions Local embedding of anti-NGF microspheres can alleviate inflammatory infiltration in lung tissue and improve lung function of rat model with asthma. The mechanismmay be the anti-NGF antagonists the NGF receptor and reverse adrenal medulla cell transdifferentiation process primined by NGF.
Objective To study the effect of local appl ication of different concentrations of nerve growth factor (NGF) on fracture heal ing, and to further search for the appropriate concentration gradient of NGF to promote fracture heal ing. Methods Seventy-five adult male Sprague Dawley rats, weighing (220.0 ± 2.5) g, were made the right tibia fracture model at 1 cm distal from the tibial tubercle and randomly divided into 5 groups (groups A, B, C, D, and E, n=15). Fractures were treated with 0.3 mL normal sal ine containing different concentration of NGF (0.006 48 × 10-2, 0.032 40 × 10-2, 0.162 00 ×10-2, and 0.810 00 × 10-2 μg/g) in groups A, B, C, and D, respectively, and the same amount of normal sal ine in group E. After2, 4, and 6 weeks, the specimens were harvested from 5 rats of each group to perform the biochemical test and histological observation. Before the rats were sacrificed, the arteriovenous blood was taken from the eye-ball to test the alkal ine phosphatase (ALP) activity. Results After 2, 4, and 6 weeks, the gross observation showed that the size and hardness of bone tissue and callus tissue growth gradually increased in groups A, B, C, and D, and group D was higher than groups A, B, C, and E. The X-ray films showed that the calcified area gradually increased in groups A, B, C, and D, and group D was higher than groups A, B, C, and E. The histological observation showed that the trabecular qual ity and maturity in group D were better than those in groups A, B, C, and E. Group D was significantly higher than groups A, B, C, and E (P lt; 0.05) in the gray values of callus tissue and the calcium content of callus tissue at 4 and 6 weeks, in the wet weight of callus tissue at 2 and 4 weeks, and in the ALP content of serum at 2 weeks. The trabecula surface index of osteoblast, the trabecular volume, and the trabecular width decreased as time in the order of groups A, B, C, and D, which were higher than those of group E; group D was the highest, showing significant differences when compared with the other groups (P lt; 0.05). Conclusion The local appl ication of NGF can promote fracture heal ing in rats. The high concentration gradient of NGF (0.810 00 × 10-2 μg/g) has an obvious promotion role on fracture heal ing.
Objective To explore the effect of controlled release of nerve growth factor (NGF) on peripheral nerve defect repaire by acellular nerve graft. Methods The microspheres of NGF were prepared with drug microsphere technologyand fixed with the fibrin glue to make the compl icated controlled release NGF. Twenty healthy male SD rats weighing 280-300 g were adopted to prepare acellular xenogenous nerve, 52 male Wistar rats weighing 250-300 g were adopted to prepare the 10 mm defect model of left sciatic nerve. and thereafter were randomly divided into 4 groups: autograft group(group A), acellular nerve allograft combined with the double controlled release NGF (group B), acellular nerve allograft (group C) and acellular nerve allograft combined with fibrin glue (group D). Without any operation, the right sciatic nerve was regarded as control group. General observation was conducted after operation. The nerve axon regeneration length was measured 2 weeks after operation. The effects of peripheral nerve regeneration were evaluated by neural electrophysiology, the recovery rate of triceps surae muscular tension and weight and histological assessment 16 weeks after operation. Results All the animals survived till the end of experiment. The length of nerve regeneration was measured at 2 weeks after transplantation. The regeneration nerve of group A was longer than that of other groups (P lt; 0.05), group B longer than groups C and D (P lt; 0.05), and there were no difference between group C and group D (P gt; 0.05). At 16 weeks after operation, the recovery rates of nerve conduction velocity of groups A and B (73.37% ± 7.82% and 70.39% ± 8.45%) were larger than that of groups C and D (53.51% ± 6.31% and 55.28% ± 5.37%) (P lt; 0.05). The recovery rates of the triceps surae muscular tension in group A (85.33% ± 5.59%) were larger than that in groups B, C and D (69.79% ± 5.31%, 64.46% ± 8.49％ and 63.35% ± 6.40%) (P lt; 0.05). There were no significant differences among groups B, C and D (P gt; 0.05). The recovery rates of the triceps surae weight in group A (62.54% ± 8.25%) werelarger than that in groups B, C and D (53.73% ± 4.56%, 46.37% ± 5.68% and 45.78% ± 7.14%, P lt; 0.05). There was significant difference between group B and groups C, D (P lt; 0.05) and no significant differences between group C and group D (P gt; 0.05). The histological observation indicated that axon number and myel in thickness in group B were larger than those in group C and group D (P lt; 0.05). The axonal diameter in group B was significantly less than that in group A (P lt; 0.05). Conclusion Acellular nerve graft combined with the controlled release NGF is a satisfactory alternative to repair the peripheral nerve defect.
OBJECTIVE: To investigate the effect of electroacupuncture on mRNA expression of NGF and IGF-1 in injured nerve. METHODS: Sciatic nerve injury model was established by transection of right side sciatic nerve in 90 male SD rats, which were randomly divided into two groups. The experimental group was treated with electroacupuncture, no treatment in the control group. The distal part of the injured nerve was harvested after 1, 2, 4, 6 and 10 weeks of operation and stored in the liquid nitrogen. The total RNA was extracted by the TRIzol reagent. Reverse transcriptase-polymerase chain reaction(RT-PCR) was used to detected the mRNA expression of NGF and IGF-1. RESULTS: The mRNA expression of NGF in the experimental group was increased quickly from the second week, and reached to highest level in the fourth week. It was much higher than that of the control group (P lt; 0.05). Then it began to decline in following time and approximately reached to the level of the first week after 10 weeks of operation. The mRNA expression of IGF-1 in the experimental group was remarkably increased in the second and fourth week, and which was much higher than that of the control group respectively(P lt; 0.05). Although the mRNA expression of IGF-1 after 10 weeks of operation in the experimental group was higher than that of the control group, but there was no significant difference between the two groups(P gt; 0.05). There was linear correlation in the fourth week between mRNA expression of NGF and IGF-1 in the experimental group. CONCLUSION: The mRNA expression of NGF and IGF-1 can be elevated in injured nerve at early stage interfered with electroacupuncture.
Objective To establish an animal model for repairing the sciatic nerve defect with a biodegradable poly D,L-lactic acid/nerve growth factor (PDLLA/NGF) that can control the release conduit in rats and to observe an effect of the conduit on the sciatic nerve regeneration. Methods The PDLLA conduit and the PDLLA/NGF-controlled release conduit (NGF 450 U per conduit) were madewith the solvent-volatilixation method. Forty male SD rats were randomly and equally divided into 4 groups. The middle segments (10 mm) of the sciatic nerves of the rats were excised and were then repaired with the sciatic nerve autograft(Group A), with the PDLLA conduit (Group B), with the PDLLA conduit and an injection of NGF (30 U) into the conduit (Group C), and with the PDLLA/NGF controlled-release conduit (Group D), respectively, with the 10-mm nerve defect left behind. Three months after operation, the morphologic parameters of the nerve regeneration were observed and evaluated under light microscope and electron microscope, and the image analysis was also made. Results Three months after operation, porous adherence between the conduit and the surrounding tissues could be observed. The conduit presented a partial biodegradation but still remainedintact in the outline and the proximal nerve regenerated through the conduit cavity. Based on the histological observation, the quantity, uniformity, and maturity of the nerve fiber regeneration in Groups A and D were better than those in Groups B and C. The image analysis indicated that there were no significant differences in the nerve fiber diameter, axon diameter or myelin thickness between Group A and Group D (P＞0.05). However, all the parameters in Groups A and D were better than those in Groups B and C (P＜0.05). Conclusion The PDLLA/NGF-controlled release conduit can effectively promote the sciatic nerve regeneration of rats. Its morphological index is similar to that of the nerve autograft.
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.