Small ubiquitin-like modifiers (SUMO) are a family of proteins that modulate important functional properties,including protein interaction,subcellular localization,protein dimerization,DNA binding and/or transactivation of transcription factors.It has been suggested that SUMO proteins may play an important role in breast carcinogenesis by sumoylation of estrogen signaling proteins such as co-regulators,and breast cancer-related proteins.

Relapse is the reinstatement of drug-seeking and drug-taking behaviors following a period of abstinence.It is one of the main characteristics of drug addiction and is also the major problem requiring immediate action for the treatment of drug addiction.In this review,in order to offer new ideas to eventually treat drug addiction,efforts are made to describe the establishment of two animal models of relapse-the drug self-administration (SA) and extinctionreinstatement procedure,and the drug-conditioned place preference(CPP) and extinction-reactivation procedure.Then attention is given to assess the criterion validity of the animal models of relapse and to explore the neurobiological mechanisms involved in relapse.

Objective To construct a 5-lipoxygenase (5-LO) transgenic mouse model of atherosclerosis.Methods Purified 5-LO fragment was injected into male pronucli and the firtilized eggs were transplanted into pseudopregnant mice.PCR and Southern blot were used to detect the genotype of DNA separated from the newborn mouse tail tissues.RT-PCR and Western blot analysis were used to detect the gene transcription and expression.Results PCR and Southern blot results showed that 7 of 25 mice were transgenic mice.Expression of 5-LO and FLAP was found in the bone marrow,spleen,kidney,and peritoneal cells.Results of RT-PCR and Western blot showed that No.9,20,24transgenic mice expressed a higher level of 5-LO and FLAP than those in the wild type C57BL/6 mice.The expression levels in bone marrow and peritoneal cells were significantly different(P<0.05).Conclusion A 5-LO transgenie mouse line has been established in this study and may be used for future study on the function of 5-LO gene.

Objective To study the effect of tail-suspending on myostatin(MSTN)expression in the soleus muscle of rats.Methods The MSTN mRNA levels in soleus muscle of tail-suspended and normal control rats were measured and compared.Results The MSTN mRNA in soleus muscle of tail-suspended rats was 2.2 times(hind limb unloading for 14 days)and 3.5 times(hind limb unloading for 30 days) higher than that in normal control rats (P<0.05).The relative wet weight of the soleus muscle in tail-suspended rats was decreased by 11%(unloading 14 days)and 1 9%(unloading 30 days),respectively,compared with that in normal control rats.Conclusion The expression of MSTN mRNA is elevated in the soleus muscle of tail-suspended rats,probably due to atrophy of the soleus muscle.

Objective The aim of this study was to establish a rat models of pulmonary artery hypertention with monocrotaline, and to study the relationship between the evolution of right ventricular function and the evolution of pulmo-nary artery pressure ( PAP) by magnetic resonance ( MR) imaging of the right ventricular function. Methods Rat models of pulmonary artery hypertension were established by monocrotaline (MCT). The model rats were divided into 4 groups:the 1-week-PAH group, 2-week-PAH group, 3-week-PAH group, and 4-week-PAH group, and pulmonary artery pressure in the rats was measured by right heart catheterization. After injection of MCT, we used MRI to evaluate the ventricular function of the rats every week. All the measurement data of right ventricular function in the model group were compared with the average pulmonary pressure using Pearson' s correlation test. Results There were strong correlations between the parameters of RV function in model group with the average pulmonary pressure ( r= -0. 823 for RV EF, r=0. 732 and 0. 803 for RV EDV and RV ESV) . At 2 weeks after injection of monocrotaline, the mean pulmonary pressure, right ven-tricular eject fraction ( RVEF) , the end-diastolic volume ( EDV) and the end-systolic volume ( ESV) of right ventricle be-tween rats in PAH and the control group showed no significant difference (P>0. 05). But three-four weeks after MCT in-jection, all these parameters were significantly different in the PAH rats than in control rats (P<0. 05). Conclusions As the pulmonary arterial pressure is increased in the rats, the right ventricular function is gradually impaired. For the monito-ring of chronic pulmonary artery hypertension in rats, MRI can be used to accurately measure the changes of parameters. The PAH can be indicated by looking at the changes of parameter such as RV EF, RV EDV and RV ESV.

Objective To optimize the optimal doses of histamine and 4-aminopyridine (4-AP) in the establish-ment of guinea pigs models of itching, and to establish a new guinea pig model of itching. Methods The central composite design-response surface method was used to arrange the experiment. In the experiment different pruritus agents were hypo-dermically injection of 0. 5 mL in the depilated area, and the scratching incubation period and scratching number in 30 mi-nutes were counted after the injection. The guinea pig itching model was evaluated by observing the behavioral changes of guinea pigs and measuring the levels of histamine and interleukin-6 in the blood. Results The behavioral experiments found that the scratching frequency in the the combination group was significantly higher than the histamine group and 4-AP group (P<0. 01). The itching latency of the combination group was significantly shorter than that of the histamine group and 4-AP group (P<0. 01). Compared with the control group, the histamine concentrations of the combination group and histamine group were significantly increased ( P<0. 05 or P<0. 01 ) , and the level of the combination group was lower than that of the histamine group (P<0. 05). Compared with the control group, the serum IL-6 concentrations of histamine group, 4-AP group and combination group were significantly higher (P<0. 01 or P<0. 05), and those in the combination group were significantly higher than the histamine and 4-AP groups. Compared with the control group, pathologic examina-tion showed proliferation of inflammatory cells in all model groups, and the reaction of the combination group was more ob-vious. Conclusions The optimal conditions used in this experiment are easy to achieve and have good reproducibility in the establishment of a guinea pig model of itching.

Objective The aim of this work was to study whether PM2. 5 induces oxidative stress and histopatholog-ical changes in uterine tissue of rats. Methods Thirty 4-week-old female Sprague-Dawley rats were randomly divided into the control group (normal saline), the low dose of PM2.5 group (1. 5 mg/kg) and the high dose of PM2.5 group (37. 5 mg/kg) . After exposed to PM2. 5 for 10 days, the rats were sacrificed to examine the histopathological changes in uterine tissues using H&E staining. The contents of SOD, GSH, MDA and LDH were also determined in the uterine tissues. Results Compared with the control group, PM2. 5 caused changes in the uterine structure, showing a thinner endometrial epithelium and reduction of stromal cells and blood vessels. The assessment of oxidative stress parameters showed that the levels of MDA and LDH in the high dose group were (6. 53 ± 1. 24) nmol/mg prot and (265. 62 ± 24. 65) U/g prot, significantly higher than those in the control group ( P<0. 05 ) . Compared with the control group, the levels of SOD and GSH in the high dose and low dose groups were significantly decreased (P<0. 05). Conclusions PM2.5 exposure can cause damages in the rat uterus by inducing oxidative stress.

Objective To study the effect of electroacupuncture on repair of spinal cord injury and its effect on somatosensory evoked potential ( SEP) in dog models of intervertebral disc prolapse. Methods Nine Beagle dogs were randomly divided into three groups. In the model group and electroacupuncture group, the dog disc prolapse models were made by balloon compression, and in the electroacupuncture group, electroacupuncture was used every day for 14 days after operation. The model group was not treated after surgery. Sham operation was performed in the control group. Each dog was scored according to the Texas Spinal Cord Injury Scale for Dogs (TSCIS) scores before surgery (day 0) and on days 1, 4, 7, 14 after surgery. At the same time, SEP wave was measured using an EMG Evoked Potential Measuring Systerm and its latency and amplitude were analyzed. Results There was a significant difference in TSCIS scores between the model group, electroacupuncture group and control group at 1 day after operation. There was a significant difference between the electroacupuncture and model groups at 14 days after surgery. The amplitude of SEP in the model and electroacupuncture groups was significantly different from that in the control group at 1 day after operation, and there was a significant differ-ence between the electroacupuncture and model groups at 14 days after operation. There was a significant difference in the latency of SEP between the model and electroacupuncture groups at 4 days after operation, and between the electroacupunc-ture and model groups after at 14 days after operation. Conclusions Electroacupuncture can effectively promote healing of spinal cord injury in dogs with intervertebral disc prolapse, improve the TSCIS scores, restore SEP waveform, shorten the latency and enhance the amplitude. SEP can reflect the degree of spinal cord injury to a certain extent, and can be used to evaluate the effect of electroacupuncture treatment in these dogs.

Objective To investigate the effect of prolonged stroboscopic illumination exposure on the growth of eyeball of guinea pig. Methods Thirty 2-week-old guinea pigs were randomized into three groups ( n=10 for each) . Two strobe-reared groups were raised with 20 Hz sinusoidal and 20 Hz square wave stroboscopic illumination, respectively. The control group received usual light illumination. The illumination intensity was 500 lux. All animals underwent refraction and biometric measurements prior to and after 2, 4, 6 and 8 weeks of treatment. Finally, flash electroretinograms were com-pared, and retinal microstructures were examined. Results There was a significant correlation between refractive errors and axial eye elongation, and myopia increasing was observed with eye elongation. After 8 weeks of treatment, the animals raised in 20 Hz sinusoidal and 20 Hz square wave stroboscopic illumination were (-0. 75 ± 0. 79)D and (-1. 50 ± 0. 91) D more myopic than the group raised in continuous illumination. The implicit time of the a-wave was delayed by 3. 8 and 7. 9 ms, respectively. No significant difference was found in retinal ultrastructures among the three groups. Conclusions Chronic exposure to 20 Hz sinusoidal or square wave stroboscopic illumination alters the emmetropization of the guinea pig eye to some extent.

Objective To establish a model of acute gouty arthritis( AGA) in rats and observe its maintenance time. Methods The AGA model of rats was established by injecting monosodium urate ( MSU) at the concentration of 25 mg/mL into the ankle joint cavity. The rats were observed for 8 d at different time points. Skin temperature, degree of joint swelling, gait, inflammatory cells in synovial fluid, histopathological changes of synovial tissue and other indicators were observed to determine whether the modeling and maintenance time were successful. Results At 3 h after modeling, differ-ences in the swelling of ankle joint, increase of skin temperature, abnormal gait, the number of inflammatory cells in syno-vial fluid, synovial hyperplasia, capillary congestion, and disarrangement of synovial cells in the rats were observed in the saline group and the model group (P <0. 01). At 4 hours after modeling, the above mentioned inflammatory changes in the saline group were significantly reduced, compared with that at 3 h, showing a significant difference (P<0. 01), while the inflammatory changes of the model group were increased significantly compared with that at 3 hours ( P<0. 01 ) , and showed significant difference compared with the saline group (P<0. 01). At 24 h after modeling, the indexes in the rats of saline group returned to normal, but the inflammation of the model group was increased. At 48-72 h after modeling, the local inflammation such as ankle swelling, skin temperature, and abnormal gait of the rats in the model group reached a peak. The inflammation of the ankle joint in the model group was gradually reduced from 96 to 168 h after the model was established, but there were still significant differences in the indexes compared with the blank group (P<0. 01). At 192 h after modeling, the joint swelling, skin temperature and abnormal gait of the rats in the model group returned to normal, however, there were significant differences in the number of inflammatory cells and the pathological changes of synovial membrane compared with the blank group ( P<0. 01 ) . Conclusions A rat model of AGA can be successfully prepared and identified at 4 h after modeling by injection of MSU crystal suspension into the ankle joint cavity. This rat model of AGA can be maintained at least 168 hours after modeling.