BACKGROUND:Alzheimer’s disease causes and pathogenesis remain unclear, which greatly restrict the screening of drugs. And the main reason is lack of suitable animal models. The developing transgenic animal technology al ows studying the role of certain pathogenic gene in vivo, and has regarded the ideal animal models for Alzheimer’s disease.
OBJECTIVE:To summarize the research advance of Alzheimer’s disease transgenic animal models. METHODS:Using“Alzheimer’s disease, transgenic mouse, animal model, dementia”in Chinese and English as the key words, the first author retrieved PubMed and CNKI databases published before July 2013. Final y, 41 articles were included in result analysis.
RESULTS AND CONCLUSION:The etiology of Alzheimer’s disease is diverse, and genetic factor is one important factor. The existing transgenic animal models of Alzheimer’s disease include single genetical y modified models, double genetical y modified models and multiple transgenic models. Single transgenic animal models can make a kind of mutated exogenous gene integrate into the genomes of animals by using recombinant DNA technology. This kind of models can be applied to only study one specific pathological change of Alzheimer’s disease. Double transgenic animal models can make two kinds of mutated exogenous gene integrate into the genomes of animals and simultaneously transfect animals by using recombinant DNA technology. This kind of models is closer to the pathological changes of Alzheimer’s disease than single transgenic animal models, but stil cannot simulate Alzheimer’s disease. Multiple genetical y modified models are obtained with different transgenic mice hybridization or several genes transfection, which are most similar to clinical process and pathological features of Alzheimer’s disease. However, this kind of models may develop a decline in consanguinity. Each kind of animal model has their advantages and shortcomings, and a better transgenic animal model is urgently needed to completely simulate pathological characteristics of Alzheimer’s disease.

Objective To investigate the effects of surgical trauma on Toll?like receptor 4 ( TLR4) expression in the hippocampus of aged mice. Methods Ninety male Kunming mice, aged 16-18 months, weighing 30-40 g, were randomly divided into 3 groups ( n=30 each) using a random number table:control group ( group C), anesthesia group ( group A), and partial hepatectomy group ( group PH). Normal saline 0.1 ml∕10 g was injected intraperitoneally in group C. In group A, fentanyl 0.2 mg∕kg and droperidol 5 mg∕kg were injected intraperitoneally. In group PH, fentanyl 0. 2 mg∕kg and droperidol 5 mg∕kg were injected intraperitoneally, and the mice underwent partial hepatectomy. Cognitive function was assessed using Morris water maze test at 1, 3, and 7 days after anesthesia or surgery. After the end of the test, the hippocampus was immediately harvested for determination of the TLR4, tumor necrosis factor?alpha ( TNF?α) and interleukin?1 beta ( IL?1β) protein and mRNA expression by Western blot and real?time reverse transcriptase?polymerase chain reaction, respectively. Results Compared with group C, no significant changes were found in group PH in the escape latency, percentage of swimming distance in the target quadrant, and TLR4, TNF?α and IL?1β protein and mRNA expression at each time point after anesthesia in group A (P>0.05), and the escape latency was significantly prolonged, the percentage of swimming distance in the target quadrant was decreased, and the expression of TLR4, TNF?α and IL?1βprotein and mRNA was up?regulated at 1 and 3 days after surgery in group PH ( P<0. 05 or 0. 01 ) . Compared with group A, the escape latency was significantly prolonged, the percentage of swimming distance in the target quadrant was decreased, and the expression of TLR4, TNF?αand IL?1βprotein and mRNA was up?regulated at 1 and 3 days after surgery in group PH (P<0.05 or 0.01). Conclusion Surgical trauma can up?regulate the expression of TLR4 in the hippocampus of aged mice, which may be involved in the mechanism of surgical trauma?induced postoperative cognitive dysfunction.

Objective To investigate the effect of postoperative analgesia with difference methods on immunity in patients after thoracic tumour surgery. Methods Forty ASA Ⅰ-Ⅱ patients aged 35-65 years old undergoing thoracic tumour surgery were randomized to receive either postoperative patient- controlled intravenous analgesia (PCIA) (group Ⅰ, 20 cases) or patient-controlled epidural analgesia (PCEA) (group E, 20 cases) for 48 h. Medicine compatibility in group Ⅰ: sulfentanyl 1μg/ml, tropisetron 0.05 mg/ml, the PCIA pump was set up to deliver a 5 ml bolus dose with a 15-min lockout interval and background infusion at 2 ml/h. Epidual catheter was placed at T4-5interspace before induction of anesthesia in group E. The PCEA solution contained 2 mg/ml ropivacaine. The PCEA pump was set up to deliver a 2 ml bolus dose with a 15-min lockout interval and background infusion at 2 ml/h after a loading dose of 0.33% ropivacame 6 ml. The VAS score, Ramsay sedation score and complications were reeorded. Blood samples were taken before induction (baseline) and at 2 h and 1st, 3rd and 7th day after surgery for determination of plasma concentrations of cortisol, interleukin 2 (IL-2) and the level of natural killer (NK) cells and eytokine-induced killer (CIK) cells. Results There was no significant difference in VAS score at 2 h after operation between two groups [(1.8±0.3) scores in group Ⅰ and (1.8±0.5)scores in group E].Ramsay sedation score at Ist, 3rd and 7th day after operation in group E were significantly lower than those in group Ⅰ (P<0.05), The plasma concentration of cortisol at 2 h and Ist, 3rd, 7th day after operation in group Ewere significantly lower than those in group Ⅰ (P<0.05), the levels of IL-2, NK cells and CIK cells in group E were significantly higher than those in group Ⅰ (P<0.05). Conclusions The efficacy of postoperative PCEA in improving immunity after thoracic tumour surgery is better than that of postoperative PCIA.

Objective To evaluate the effects of dexmedetomidine on the expression of spinal matrix metalloproteinase-9 (MMP-9) in a rat model of neuropathic pain (NP).Methods Eighty-one adult male SpragueDawley rats,weighing 190-230 g,were randomly divided into 3 groups (n =27 each) using a random number table:sham operation group (group S); group NP; dexmedetomidine group (group Dex).The animals were anesthetized with intraperitoneal 10％ chloral hydrate 350 mg/kg.The right sciatic nerve was exposed and 4 loose ligatures were placed on the sciatic nerve at 1 mm intervals with 4-0 silk thread in NP and Dex groups.In group Dex,dexmedetomidine 50 μg/kg was injected intraperitoneally once a day starting from the end of operation until the animals were sacrificed.The equal volume of normal saline was given instead of dexmedetomidine in S and NP groups.Paw withdrawal threshold to von Frey filament stimulation (MWT) and paw withdrawal latency to thermal stimulation (TWL) were measured at 1 day before operation (To,baseline) and 5,9 and 16 days after operation (T1-3).Nine animals were sacrificed after measurement of pain threshold at T1-3 and their lumbar segments (L4,5) of the spinal cord were removed for detection of MMP-9 expression (by immuno-histochemistry) and tumor necrosis factor-alpha (TNF-α) content (by ELISA).Results Compared with group S,MWT was significantly decreased,TWL was shortened,and the levels of MMP-9 and TNF-α were increased at T1-3 in NP and Dex groups.Compared with NP group,MWT was significantly increased,TWL was prolonged,and the levels of MMP-9 and TNF-α were decreased at T1-3 in Dex group.Conclusion Dexmedetomidine can inhibit up-regulation of MMP-9 expression,and decrease inflammatory responses,thus attenuating NP in rats.

Objective To evaluate the effects of propofol on the expression of hippocampal γ-aminobutyric acid (GABAA) and NMDA receptor in a rat model of inflammatory pain (IP).Methods A total of 32 female Sprague-Dawley rats,weighing 180-220 g,were randomly divided into 4 groups (n =8 each):control group (group C),group IP,and different doses of propofol groups (P1,2 groups).IP was induced by injection of formalin.In group C,normal saline and dimethyl sulfoxide (DMSO) 0.1 ml/kg were injected intraperitoneally.In group IP,normal saline and DMSO 0.1 ml/kg were injected intraperitoneally,and 5 min later formalin was injected.In P1,2 groups,propofol 30 and 100 mg/kg were intraperitoneally injected,respectively,and 5 min later formalin was injected.The pain behavior of rats was observed within 1 h after injection of formalin and pain intensity scoring (PIS) value was calculated.The animals were sacrificed at 1 h after injection of formalin and the hippocampi were isolated for determination of GABAA and NMDA receptor expression by immunohistochemisty.Results Compared with group C,PIS value was significantly increased,GABAA and NMDA receptor expression was up-regulated in IP and P1.2 groups.Compared with group IP,PIS value was significantly decreased,GABAA receptor expression was up-regulated,and NMDA receptor expression was down-regulated in P1,2 groups.PIS value was significantly lower,GABAA receptor expression was higher,and NMDA receptor expression was lower in group P2 than in group P1.Conclusion Intraperitoneal propofol can down-regulate NMDA receptor expression in hippocampi of rats with IP,thus inhibiting responses to pain sensitivity; intraperitoneal propofol can up-regulate hippocampal GABAA receptor expression,thus enhancing endogenous mechanism of analgesia.

Objective To investigate the effects of astragalus injection on the morphology and expression of Apaf-1 in hippocampal neurons after cerebral ischemia reperfusion in rats. Methods The male SD rats were randomly divided into 3 groups, sham-operated group, cerebral ischemia-reperfusion group (reperfusion group) and astragalus injection interven-tion group (experiment group). The global cerebral ischemia-reperfusion rat model was established by Pulsinelli four-vessel occlusion method. The astragalus injection group was intraperitoneally injected with astragalus 6 mL/kg, 30 mins before sur-gery and repeated every 24 h. Rat brains were removed 24 h after reperfusion in each group. HE staining was used to observe the pathological changes of the hippocampal neurons under the light microscope. The ultrastructural changes of hippocam-pal neurons were observed by transmission electron microscopy. Immunohistochemistry and Western blot methods were used to measure the expression of apoptotic protease activating factor-1(Apaf-1) protein. Results Compared with sham-operat-ed group, nuclear and mitochondrial damage was found in reperfusion group, and the expression of Apaf-1 protein increased obviously in hippocampus(Immunohistochemistry result:0.024 ± 0.001 vs 0.109 ± 0.011;Western blot result:0.270 ± 0.018 vs 0.894±0.072, P<0.01). Compared with reperfusion group, the damage in nuclear and mitochondria was relieved obviously in experiment group, and the expression of Apaf-1 protein in hippocampus was significantly decreased (Immunohistochemistry result:0.048±0.005;Western blot result:0.392±0.046, P<0.01). Conclusion Astragalus injection can reduce pathological damage of hippocampal neurons after cerebral ischemia and reperfusion in rats, and the mechanism is related with inhibiting of Apaf-1 protein.

Objective To evaluate the role of spinal AMP-activated protein kinase (AMPK) signaling pathway in reduction of neuropathic pain (NP) by dexmedetomidine in rats.Methods One hundred twenty adult male Sprague-Dawley rats, weighing 180-220 g, were randomly divided into 4 groups (n=30 each) using a random number table: sham operation group (group S);group NP;dexmedetomidine group (group Dex) and AMPK inhibitor group (group AI).The animals were anesthetized with intraperitoneal 10％ chloral hydrate 350 mg/kg.The right sciatic nerve was exposed, and 4 loose ligatures were placed on the sciatic nerve at 1 mm intervals with 4-0 silk thread in NP and Dex groups.In group Dex, dexmedetomidine 50 μg/kg was injected intraperitoneally once a day starting from the end of operation until the animals were sacrificed.In group AI, AMPK inhibitor Compound C 20 mg/kg was injected intraperitoneally at the end of operation, and the other treatments were similar to those previously described in group Dex.The equal volume of normal saline was given instead of dexmedetomidine in S and NP groups.The mechanical paw withdrawal threshold to von Frey filament stimulation (MWT) and thermal paw withdrawal latency (TWL) were measured at 1 day before operation (baseline) and 2, 8 and 14 days after operation (T0-3).Results Compared with group S, the MWT was significantly decreased, and the TWL was shortened at T1-3 in NP, Dex and AI groups (P＜0.05).Compared with group NP, the MWT was significantly increased, and the TWL was prolonged at T1-3 in group Dex (P＜0.05) , and no significant change was found in MWT and TWL in group AI (P＞0.05).Conclusion Spinal AMPK signaling pathway is involved in reduction of NP by dexmedetomidine in rats.

OBJECTIVE:To observe the influence and safety of dexmedetomidine (DEX) on intraoperative wake-up quality of patients underwent neurosurgical surgery. METHODS:126 patients with general anesthesia in neurosurgery were enrolled and randomized equally into observation group and control group,with 63 cases in each group. Control group was given target con-trolled infusion of propofol with plasma target concentration of 3-5 μg/ml and remifentanil with target effect site concentration of 2-6 ng/ml for anesthesia induction and maintenance,and then plasma target concentration of remifentanil decreased to 0.5 ng/ml 30 min before wake-up. Observation group received target controlled infusion of propofol with plasma target concentration of 3-5 μg/ml and remifentanil with target effect site concentration of 2-6 ng/ml for anesthesia induction and maintenance,and then given DEX 0.3 μg/kg intravenously 30 min before wake-up and maintained at 0.1 μg/(kg·h). MAP,HR,SBP,SaO2,serum levels of IgA,IgM,IgG,IL-6,IL-8 and TNF-α were observed in 2 groups 2 h before operation(T1)and after extubation(T2)as well as the occurrence of ADR during wake-up. RESULTS:There was no statistical significance in HR,MAP,SBP,SaO2,IgA,IgM, IgG,IL-6,IL-8 and TNF-α levels at T1 and SaO2 levels at T2 between 2 groups(P>0.05). HR,MAP,SBP,IL-6 and TNF-α lev-els of observation group decreased significantly at T2 and lower than those of control group;IgA,IgM and IgG increased signifi-cantly and higher than those of control group,with statistical significance (P<0.05). The incidence of bucking in observation group was significantly lower than control group,with statistical significance(P<0.05);there was no statistical significance in the incidence of ADR as dysphoria,awareness rate during operation,respiratory depression,body movement,bradycardia between 2 groups (P>0.05). CONCLUSIONS:DEX influence intraoperative wake-up quality of patients underwent neurosurgical surgery slightly,and can reduce inflammatory reaction with less ADR.

Objective To investigate the effects of Epimedium ,Astragalus ,Radix Puerariae on DMT1 expression in the cere‐bral cortex of APPswe/PS1ΔE9 double transgenic mice model of AD .Methods A total of 60 specific‐pathogen‐free male APPswe/PS1ΔE9 double transgenic mice aged 6 months were equally and randomly assigned to model ,Epimedium ,Astragalus ,Radix puerari‐ae ,compound and DFO groups .An additional 10 6‐month‐old C57BL/6J mice served as negative control group .Using immunohisto‐chemistry and molecular biology methods to investigate the effects of a compound combining the effective components of Epimedi‐um ,Astragalus ,Radix puerariae on DMT1 expression in the cerebral cortex of APPswe/PS1ΔE9 double transgenic mice model of AD . Results Immunohistochemical staining results revealed that DM T 1 positive cell did not show in negative control group .DM T1 ex‐pression was higher in model group compared with the negative control group .DMT1 expression was lower in the compound and deferoxamine groups than in the model group .No significant difference was detected in DM T 1 expression between deferoxamine and compound groups .RT‐PCR ,Western blot and immunohistochemical staining results showed no significant difference .Conclusion These compounds can downregulate DMT1 expression and inhibit iron overload in the cerebral cortex of mice with Alzheimer′s dis‐ease ,reduce iron overload induced impairment of the central nervous system .

Aim To observe the effects of effective fraction of Epimedium,Astragalus,Radix Puerariae on behavioral and pathological changes in a transgenic mouse model of Alzheimer’s disease.Methods Six-month-old APPswe /PS1 ΔE9 transgenic mice were ran-domly divided into 2 groups:model group and effective fraction group,1 0 mice each group.The mice in the effective fraction group were treated with the effective fraction of Astragalus,Radix Puerariae,Epimedium compound for 8 weeks.The C57BL/6J mice were used as negative control group.After 8 weeks,the learning and memory function were measured by Morris water maze,the pathological changes in brain tissue were ob-served by Modified Bielschowsky staining and Nissl 's staining.Results During place navigation trial,the escape latency in the APPswe /PS1 ΔE9 double transgenic model mice was longer than those of the mice of C57 (P <0.05),the escape latency in the mice of effec-tive fraction group was significantly reduced than those of the mice in model group (P <0.05).During spatial probe trail,the platform-crossing times in the APPswe /PS1 ΔE9 double transgenic mice were different from the mice of C57 (P <0.05),the platform-crossing times in the mice of effective fraction group were significantly increased than those of the mice in model group (P <0.05).The average swimming velocity in the APPswe /PS1 ΔE9 double transgenic model mice was increased than that of mice of C57 (P <0.05 ),there was no significant difference between effective fraction group and model group (P > 0.05 ). The Modified Bielschowsky staining shows that the neuron fibers of the cerebral cortex of APPswe /PS1 ΔE9 double transgenic mice were enlarged,swelling,and dense.There were senile plaques and nerve fiber tangles in the cerebral cortex of APPswe /PS1 ΔE9 double transgenic mice.The neuron fibers of mice in the effective fraction group were relieved;there was a small amount of senile plaque.The Nissl’s staining shows that the neurons of the cerebral cortex of APPswe /PS1 ΔE9 mice were edema, the number of cells were decreased.The mice in the effective fraction group were free of the disease.Con-clusion The double transgenic APPswe /PS1 ΔE9 mice of AD can simulate the specific pathogenesis of AD, which may be the efficient experimental animal model. The effective fraction of epimedium,astragalus and ra-dix puerariae may have a neuroprotective effect against AD via improving the learning and memory ability,and reduce the cerebral cortex nerve fiber tangles,senile plaques and neurons edema changes.