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 To evaluate the method of establishment of a minipig model of ischemic heart failure(HF) with acute myocardial infarction(AMI) by coronary balloon occlusion and coadministration of injecting of microthrombi and plastic microspheres.Methods A total of eighteen minipigs were selected.After coronary angiography,angioplasty balloons were placed in the mid-distal of left anterior descending(LAD).The balloon was inflated intermittently to occlude the LAD 3 times and then to occlude it continuously for 120 minutes.After the balloon was taken out,4F Judkins-type angiogrphic catheter was superelectively engaged in LAD and 3 mL intermixture of mierothrombi and plastic microspheres were injected at 10 minites interval until TIMI myocardial perfusion was grade<2 and left ventfieular end-diastolic pressure was maintained from 15 to 18 mmHg.Electrocardiogram(ECG),hemodynamic perameters,ultrasonic cardiogram,cTnI and CK-MB were measured.Myocardial infarction area was evaluated by histopathology.Results Fourteen days later,fifteen minipigs survived and fourteen satisfied the criteria(pulmonary capillary wedge pressure.PCWP>18 mmHg and eardio output (CO) decreased beyond 30% ). The changes of ECG, hemodynamic perameters, CKMB, cTnI and cardiac pathologic examination were in accordance with AMI. Conclusion A stable experimental method of establishment of minipig model of ischemic heart failure (HF) with acute myocardial infarction (AMI) by coronary balloon occlusion and coadministration of injecting of microthrombi and plastic mierospheres is succeded. This method has advantages such as closed chest, higher success rate and stability compared with the drug induced, taehycardia-pacing induced, coronary artery ligation induced or microsphere injection alone methods.

Objective Objective In order to better keep up with the development of transplantation immunobiology.we established and compared two types of mouse heterotopic heart transplantation,and hope to help further organ transplantation studies.Methods According to the surgical procedures of Ono's type and Chen's type of mouse model of heterotopic heart transplantation with some modification,we performed celiac and cervical heteropotic heart transplantation between iso-strains and hetero-strains,and compared the operation suecess rate,operation time,allografi survival time,and histopathology of those establishment methods.Results The success rates of mouse celiac and cervical heterotopic heart transplantation were 86.7% and 83.3%,respectively,with a non-significant difference(P>0.05) between the two methods of operation regarding the total operation time,survival time of the allografts,and histopathological findings.Conclusions Based on the mastery of microsurgical techniques,the two models of heterotopic mouse heart transplantation can be established equally,and either of them can be considered depending on the particular requirements of studies.

Objective To characterize the major physiological and biochemical indexes of rabbits introduced to Tibet plateau,to provide the essential reference in experimental studies on rabbits,and to serve the relevant clinical treatment,teaching work and scientific research.Methods Twelve serum biochemical parameters of Californian rabbits and Chinese white rabbits introduced to Tibet since 20 years ago were measured with an automatic biochemistry analyzer.Results In the California rabbits,the values of ALB,TP,A/G,CRE,CHOL and LDH were very significantly higher in males than those in females(P<0.01),and ALT,GLU were significantly higher in females(P<0.05).In the Chinese white rabbits,the value of CRE was significantly higher in males than that in females,but the value of LDH was higher than that in males(P<0.01).There were significant differences between the values of AST,TP,ALB and GLO,A/G,GLU,CRE,LDH(P<0.01),and TG and BUN (P<0.05) in Californian and Chinese white rabbits.The values of AST,TP,BUN and LDH were very significantly different (P<0.01),and those of CRE,ALT,GLO and TG were significantly different (P<0.05) between the female Californian and female Chinese rabbits.Conclusion The experimental results obtained in this study will be valuable reference for relevant clinical diagnosis and treatment,teaching Work and scientific researches in Tibet.

Objective To compare the effects of resuscitation at pure oxygen environment(100% oxygen) or room air environment (21% oxygen) on the uhrastructure of cerebral cortical neurons in hypoxic neonatal rat.Methods Twenty Sprague-Dawley neonatal rats aged 7 days were divided into the pure oxygen environment (POE) and room air environment groups (RAE) after hypoxia,and each group was divided again into 24 h and 72 h subgroups.The pups were placed in an incubator containing 8% O_2 to be at acute hypoxia continued for 2.5 h.The pups were reoxygenated immediately after the above mentioned hypoxia.The pups of POE group were then placed in an incubator containing 100% oxygen and the flow time was 30 rain.The pups of RAE group were reoxygenated with room air in an incubator for 30 rain.According to the planned time points the pups were sacrificed and the brain was removed at 24 h and 72 h after treatment,respectively.The tissue of frontoparietal cortex of the fight cerebral hemisphere was prepared for transmission electron microscopic examination.Results In each reoxygenation group,edema was found in the neurons,neuropil and intercellular space.In the RAE 24 h group,the nuclear membrane in neurons was unclear,the amount of cell organelles was reduced,the mitochondria were swollen with damages of cristae.The rough endoplasmic reticulum was dilatated or vaeuolized and with reduction of ribosomes.The Golgi complex was vacuolized.The number of lysosomes was obviously increased.In the RAE 72 h groups,the changes were similar to those of the former group,but apoptotic-like nuclei and necrotic neurons were more frequently seen. The cellular damages of POE 24 h group were milder than those of RAE 24 h group. The mitochondria and rough endoplasmie reticulum were more abundant and showed less pathological changes in the POE 72 h group as compared with those of RAE 72 h group. Conclusion The rats of POE reoxygenation display milder ultrastructural damages, less apoptosis, necrosis and edema in cerebral neurons than those in rats after RAE reoxygenation.The protective effect of POE resuscitation on cerebral damage of hypoxic neonate rats is superior to that after RAE resuscitation. This hypoxic neonatal rat model may serve as a suitable animal model for research on cerebral cortex neurons caused by hypoxia.

Objective To analyze the Cyt b gene sequences in Tibet mini-pigs and clarify the differences and genetic relationship with other Chinese pigs.Method The sequence of Cyt b gene was amplified from genome DNA of Tibet mini-pig,Bama miniature pigs,Guizhou xiang pigs and Wuzhishan (WZS) pigs.After sequencing,the base sequences were compared and analysed.The blood relationship tree and evolution position of Tibet mini-pig were established.Result There were 14 mutation sites between domestic pigs in China and pigs from Europe.Besides there was a significant differenee in two nucleotide site:a T→C switch in site 420 and the G→A switch in site 883 at the same time.Conclusion Chinese pigs include Bama miniature pigs,Guizhou xiang pigs and WZS pigs,have a very close blood relationship with some of Tibet mini-pigs.It has been confirmed that there is a certain genetic differentiation in the Tibet mini-pig.

Objective To obtain the full-length cDNA sequences of CYP2E1,CYP2D5,ECHS1,which may be related with non-alcoholic fatty liver disease,from Microtus fortis.Methods To construct Microtus fortis liver cDNA plasmid library using SMART technique,to get the purposed colonies through screening libraries by PCR,and to obtain their full-length cDNA sequences by sequencing with pBluescript II SK universal primers M13R.Results Three full-length cDNA sequences of Microtus fortis,CYP2E1,CYP2D5 and ECHS1 were obtained.The CYP2E1 cDNA was 1685 bp in length and contained a 1482 bp open reading frame(ORF) encoding a 494 amino acids.The CYP2D5 cDNA was 1690 bp in length,and contained a 1514 bp ORF encoding 504 amino acids.The ECHS1 cDNA was 1013 bp in length,and containsed an 873 bp ORF encoding 290 amino acids.Sequence analysis revealed that the identity of the three cDNA sequences and deduced amino acids among Microtus fortis,Homo sapiens,Mus musculus and Rattus norvegicus was high.Conclusion The full-length cDNA sequences of CYP2E1,CYP2D5,ECHS1 were obtained from Microtus forti,liver cDNA library.and the gene sequences have been deposited in GenBank (GQ507485,GQ507486,GQ845171),which may lay the foundation for researchies of pathogenesis of non-alcoholic fatty liver disease in Microtus fortis models.