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Objective • To investigate the effect of medium frequency electrical stimulation on the expression of neurotrophin-3(NT-3) in the mandibular protrusion of SD rats. Methods • Sixty male SD rats were randomly divided into three groups (n=20): blank control group, conditioned control group (treated with functional appliance, but without medium frequency electrical stimulation) and experimental group (treated with functional appliance and medium frequency electrical stimulation). Five rats in each group were sacrificed on the 3rd, 7th, 14th and 21st day to prepare the samples of masseter muscle. Immunohistochemistry and quantitative real-time PCR methods were used to detect the protein and mRNA expressions of NT-3 in the masseter muscle of rats. Results • The protein and mRNA expressions of NT-3 were increased firstly and then decreased in the conditioned control group and the experimental group, compared with those in the blank control group. Moreover, the protein and mRNA expressions of NT-3 in the conditioned control group were still higher than those in the blank control group on the 21st day (both P<0.05), while the protein and mRNA expressions of NT-3 in the experimental group almost returned to the normal level on the 21st day. Conclusion • Medium frequency electrical stimulation may accelerate the rate of neuromuscular reconstruction and shorten the time of functional orthopedic therapy in rats.
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Objective To explore the effects of aripiprazole on clinical symptoms and neurotrophic factor levels in patients with schizophrenia. Methods Forty patients with schizophrenia and 40 normal controls were included in the study. The clinical symptoms of patients receiving aripiprazole only for 12 weeks were evaluated by using the Positive and Negative Syndrome Scale (PANSS). Stroop Color-Word Test (SCWT), Continuous Performance Test, Digit-Symbol Coding Test and Trail Making Test-A were used to evaluate the cognitive function both in patients and controls. Serum levels of Nerve Growth Factor (NGF), Brain Derived Neurotrophic Factor (BDNF) and Neurotrophin 3 (NT-3) were measured using enzyme linked immunosorbent assay. Results The clinical scores, cognitive function and levels of neurotrophic factors were different before and after treatment (P<0.01). And those were significantly lower in patients than in control group (P<0.05). Before treatment, BDNF was negatively correlated with PANSS negative symptom score (r=-0.362, P=0.022);NGF was related to the total score of PANSS (r=0.332, P=0.037) and positive symptoms (r=0.401, P=0.010); NT-3 was associated with negative symptom scores (r=-0.376, P=0.017) and SCWT-color words (r=0.332, P=0.037) in patient group. After treatment, the increase in BDNF was correlated with the reduction in PANSS total score (r=0.371, P=0.018), negative symptom score (r=0.345, P=0.029) and general pathology score (r=0.342, P=0.031). There was a correlation of the increase of NGF with the decrease of PANSS total scores (r=0.437, P=0.005) and with positive symptom scores (r=0.357, P=0.024). Conclusion Treatment with Aripiprazole can improve the clinical symptoms and cognitive functiona impairments in patients with schizophrenia, which may be related to the increase in serum levels of BDNF, NGF and NT-3.
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Objective To study the inhibitory effect of panax notoginseng saponins (PNS) on 3-nitrotyrosine (3-NT) formation in brain induced by heme/NO2 -/H2O2 or ONOO - pathways in vitro. Methods According to the two major pathways of 3-NT formation in vivo, the models of protein nitration induced by heme/NaNO2/H2O2 or ONOO-system were established, respectively, in vitro. Bovine serum albumin (BSA)/rat plasma protein or rat brain homogenate protein were utilized as reactive substrates in both systems. Samples were divided into blank-control group, 3-NT group and PNS group (including low-, medium-and high-concentration subgroups). In 3-NT group, samples were exposed to heme/NaNO2/H2O2 or ONOO-system, respectively, at 37℃for 30 min, whereas in PNS group, samples were pre-incubated with PNS (at final concentrations of 50 mg/L, 100 mg/L, and 200 mg/L) at 37℃for 5 min before the nitrating system exposure. The 3-NT level in each group was detected by Western blot assy. Results Compared with the blank-control group, both heme/NaNO2/H2O2 and ONOO-system can induce significant 3-NT generation in BSA/rat plasma protein or rat brain homogenate protein (P0.05). Medium- and high-concentrations of PNS pre-treatment markedly inhibited 3-NT accumulation, with maximum effect at the concentration of 200 mg/L (P<0.05). Conclusion Medium- and high-concentrations of PNS can inhibit 3-NT formation in brain tissue mediated by either heme/NO2-/H2O2 or ONOO-pathways, implying that potential neuroprotective action against 3-NT involves pathological conditions, like trauma, stroke, and neurodegenerative diseases.
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Objective To construct and identify the recombinant retroviral vector containing five copies of hypoxia responsive elements (5HRE)and neurotrophin-3 (NT-3 ).Methods Using PCR,enzyme digestion and DNA ligase,5HRE and human derived NT-3 were cloned into the retroviral vector plasmid (pLNCX)to construct the recombinant retroviral vector plasmid pLNCX-5HRE-SV40-NT3-IRES-EGFP.The retrovirus RV-5HRE-NT3 was packaged in the PT67 cells,and then it was purified and concentrated by high-speed centrifugation.After infected for 48 h with the concentrated retrovirus,the number of the EGFP positive cells in the NIH 3T3 cells was counted by fluorescence activated cells and sorted to calculate the retrovirus titer.Results The retroviral vector plasmid,pLNCX-5HRE-SV40-NT3-IRES-EGFP,was successfully constructed,and the retrovirus was packaged and defined as RV-5HRE-NT3.After purification and concentration,the retrovirus titer reached 9.1 × 10 6 cfu/mL. Conclusion The recombinant retroviral vector which carried out hypoxia-regulated expression of NT-3 was successfully constructed.It may provide basis for studies on hypoxia-regulated expression of the exogenous genes.
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Objective:To observe the effect of tannic acid on renal morphology and function of diabetes mellitus model rats ,and to explore the mechanism of improving effect of tannic acid from oxidative stress , nitrosative stress angle.Methods: 8 rats were randomly selected from 68 6-week-old male Wistar rats as normal control group and the remaining 60 rats accepted high-sugar and high-fat diet for 4 weeks, then were injected streptozotocin ( STZ, 52 mg/kg ) intraperitoneally in order to manufacture a diabetic rat model.Further the diabetic rats were randomly divided into model group ,aminoguanidine group ,low-dose of tannic acid group and high dose of tannic acid group.The rats in aminoguanidine group were injected aminoguanidine [AG,40 mg/(kg· d)] intraperitoneally, those in low-dose of tannic acid group were injected tannic acid [TA,20 mg/(kg· d)] and those in high-dose of tannic acid group were injected tannic acid [TA,30 mg/(kg· d)].The rats in normal control group and model group were injected normal saline [NS, 30 mg/(kg· d)] and all rats were sacrificed and tissues were derived at the end of the week 10.Morphologic changes of kidney in diabetic rats were observed by HE staining and correlative biochemical indices of renal function were detected by biochemical analyzer.8-hydroxy deoxyguanosine (8-OHdG) and 3-nitrotyrosine (3-NT) content of renal tissue in rats in different groups were detected by ELISA method.Mesangial cells cultured in vitro were treated with high concentration of glucose (30 mmol/L) and AGEs (250 mg/L) and at the same time with different concentration of tannic acid (10,20,40 and 80μmol/L) on the basis of setting corre-sponding control group.The contents of 8-OHdG and 3-NT in the culture supernatant were measured by ELISA method after 48 hours.Results:Tannic acid can effectively improve the renal pathological changes and improve renal function of diabetic rats .The contents of 8-OHdG and 3-NT in kidney tissue homogenate of diabetic rats and in the supernatant of GMC cultured with high glucose or AGEs were all significantly increased and can be reduced by tannic acid.Conclusion:Tannic acid improving the structure and function damage of kidney in diabetic rats might be achieved by oxidative stress and nitrosative stress mechanism .
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Objective To explore the effects of Ganoderma spore(germination activated Ganoderma spore) on survival and expression of neurotrophin_3(NT_3) and nitric oxide synthase(NOS) of injured motor neurons in rat spinal cord. Methods Different dosages of Gandoerma spore were irrigated into the rat's stomach respectively in experimental groups after oneside ventral root cut.The survival ratio of injured motor neurons was counted.NT_3 expression of surviving motor neurons was measured by immunohistochemistry and in situ hybridization methods and NOS activity was measured by enzymo_histochemistry method. Results Thirty_five days after ventral root cut,the survival ratio of motor neurons was 47.32% in control group,and those were 67.11%,72.67% and 81.67% respectively in low,medial and high dosage Ganoderma spore groups.Expressions of NT_3 and NOS of surviving motor neurons in high dosage Ganoderma spore group were higher than those in control group.Conclusion Ganoderma spore may promote the survival of injured spinal motor neurons,and survival ratio of injured motor neurons is related to the dosages of Ganoderma spore.Ganoderma spore may also enhance the expressions of NT_3 and NOS of surviving spinal motor neurons.
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This study was aimed at to investigating the protective effect of a combined treatment with glial cell line derived neurotrophic factor (GDNF) and neurotrophin 3 (NT 3) on noise induced outer hair cell (OHC) damage. Guinea pigs were subjected to receiving infusion of an artificial perilymph containing GDNF (100ng/ml) and NT 3 (2 5?g/ml) into one cochlea via a mini osmotic pump. Three days later, the animals were exposed to a 4kHz narrow band noise at 115 dB SPL for 4h. The control animals received the same treatment except GDNF and NT 3. Thresholds of auditory brainstem responses (ABRs), elicited by clicks, were measured before and 3 days after the surgery of the pump implantation, and 10 days following noise exposure. Then, the subjects were sacrificed and the cochleas were stained with Hoechst 33342. The specimens were examined under a fluorescence microscope for quantitative assessment of the OHC nuclear morphology. The results showed that compared with the control animals, the drug treated ones had significant less swollen OHC nuclei ( P
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Objective To observe the influence of ATP protection after brachial plexus injuries. Methods A total of 80 female Wistar rats,weighting 280～300 g,were randomly divided into ATP and con- trol groups.The right C_5～T_1 nerve roots were transected and then the intraperitoneal injection of 4m[ of ATP or normal saline was given immediately and once daily to the rats,respectively.The rats were sacrificed on postoperative days 14,28 and 42 respectively.The C_5-T_1 segments of the spinal cord were harvested.NT-3 activity was measured by enzymo-histochemistry method.Four weeks and 6 weeks postoperatively,ultrastruc- ture of the denervated skeletal muscles was observed.Results Compared to the control group,the expres- sions of NT-3 was increased in the treated groups with ATP injection (P
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Though initial report from Japan showed positive association of schizophrenia with dinucleotide repeat polymorphism in the NT-3 gene, subsequent studies showed mixed results. Therefore we conducted a replication study with Korean schizophrenics and matched controls who share similar ethnic background with Japanese population. The frequency of allele of dinucleotide repeat at 147 base pairs in the NT-3 gene was slightly increased, however, failed to reach statistical significance(X2=1.884, df=1, p<0.170) between the two groups. These findings do not support on association of NT-3 gene polymorphism with schizophrenia in Korean sample.