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.

Objective To improve the classic Vannucci method for establishing a model of hypoxic-ischemic brain damage in the neonatal mice. Methods Postnatal day 11 KM mice were randomly assigned into normal control group ( N group, n=20) and hypoxic-ischemic brain damage group (HIBD group, n=160). For the HIBD group, the left common carotid artery of mice was ligated and exposed to hypoxia according to different conditions in the groups C1-C8, then com-pared the mortality and the success rates of all groups. TTC staining and relative infarct volume was measured to select the most stable conditions of modeling. In all groups, the growth and development of mice were evaluated by body weight growth curve at different time points after modeling. Longa test, grip test and hanging test were porformed to assess the neu-romotor function. HE staining was used to detect cerebral neuronal pathological changes. Results Neonatal mouse models of hypoxic-ischemic brain damage were established by the left common carotid artery ligation and hypoxia for 45 min under conditions of 8% O2 and 35℃, which resulted a low mortality rate (8. 3%) and high success rate (47. 92%). Compared with the normal group, mice of the HIBD group grew slowly in body weight and showed severe motor dysfunction. The liga-tion side of cerebral artery showed infarction area which accounted for 7. 76 ± 0. 70% of the total brain. The cortex and hip-pocampus of ligated brain tissue showed neuron degeneration and necrosis. Conclusions The neonatal mouse model of hy-poxic-ischemic brain damage is successfully established by our modified method , i. e. to ligate the left common carotid ar-tery and to expose the mice to hypoxia at 8% O2 and 35℃ for 45 min. This model provides a liable and stable experimental animal model for research of neonatal hypoxic-ischemic brain damage.

Objective To study the expression and regulation of polycystic ovary syndrome ( PCOS) susceptibility gene Hmga2 in endometrial receptivity and decidualization. Methods Experiments including early pregnancy, delayed implantation and activation, artificial decidualization and ovarian steroid hormone treatment were performed, and Q-PCR and Western blot analyses were applied to explain the role of Hmga2 in endometrial receptivity. Results The Hmga2 ex-pression increased gradually with pregnancy. Its expression at the implantation site was significantly higher than that at the inter-implantation site,in the embryo activation group than in delayed implantation group, and in the artificial decidualiza-tion than the non-decidualization. The expression of Hmga2 was positively correlated with the expression of estrogen and progesterone, and was positively regulated by estrogen and progesterone in vivo. Conclusions Our findings indicate that the expression of Hmga2 is closely related to the embryo implantation process in early pregnancy in mice, is involved in the process of endometrial decidualization, and is influenced by the activated blastocyst and steroid hormones.

Objective This study aimed to explore the possibility of establishing a model of sick sinus syndrome by using miR-5572 transgenic mice. Methods F1 and F2 miR-5572 transgenic mice were bred and genotyped, and then observed the phenotype levels of miR-5572 transgenic mice by morphology, electrocardiogram record ( ECG ) and the Cav1. 2 and Cav1. 3 expressions levels of mRNA and protein in sinoatrial node tissue of homozygous, heterozygote and wild type mice. Results Compared with the wild type and heterozygous mice,the miR-5572 homozygous mice showed a devel-opment delay and smaller body shape,and had slower average heart rate. The mRNA and protein levels of Cav1. 2 and Cav1. 3 in the sinoatrial node tissues were significantly lower. Conclusions The results of this study indicate that miR-5572 homozygous mice may be an efficient approach to establish the model of sick sinus syndrome

With the good progress of bone tissue engineering, various kinds of seed cells have emerged. Adipose derived stem cells ( ASCs) have many advantages, and become one of the hot seed cells in bone tissue engineering. This review focused on their induction method, induction process and verification method, and the donor factors and experimen-tal factors affecting the osteogenic differentiation were summarized. We also looked forward the future research interest of ASCs' osteogenic differentiation.