Objective:To improve the genetic stability of HBV gene in transgenic mice.Methods:HBV transgenic mice were bred by backcross and double cross.The HBV gene expression and replication were studied with real-time PCR,ELISA and chemiluminescence.Results:The HBV transgenic mice have stably bred to 23rd generation.The serum HBsAg level is 4122.31?2044.74IU/ml;The rate of HBV transgenic mice whose serum HBV DNA reach 104~106copies/ml was 93.93%.The HBV replication and expression were improved markedly.There is no difference between male and female mice about serum HBsAg level.Conclusion:After breeding the HBV gene was expressed stably with high-level in transgenic mice.

OBJECTIVETo study the effect of gamma linolenic acid (GLA) on atherogenesis in rats.

METHODSixty healthy male rats were randomly divided into 6 groups: normal contro 1, fed by normal feed; atherogenesis mode 1, fed by high lipid diet; positive control group 0.9 mg x kg(-1) x d(-1) of lovastatin and group IV 250 mg x kg(-1) x d(-1) duoxikang; high dose of 375 mg x kg(-1) x d(-1) GLA; low dose of 187.5 mg x kg(-1) x d(-1) GLA. After the model group received atherogenic diet for six weeks, serum triglyceride (TG), total cholesterol (TC), low density lipoprotein cholesterol (LDL-C) and high density lipoprotein cholesterol (HDL-C) were detected by enzyme method to confirm the formation of atherogenic. After fed for another five weeks, morphologic atherosclerosis of aorta in rats was observed by HE staining methods. The blood samples were collected and serum TC, TG, HDL-C, LDL-C, T-AOC, HL, LPL, NO, NOS, MDA and GSH were determined.

RESULTGLA attenuated the formation of atherosclerotic plaques, inhibited the level of serum TC, TG, MDA, OX-LDL, NO, NOS, HL, LPL and LDL-C and increased the level of T-AOC.

CONCLUSIONGLA might significantly attenuate the development of atherosclerosis in rats fed with high lipid diet through improving the antioxidation capacity of the body.

Animals ; Atherosclerosis ; blood ; drug therapy ; metabolism ; Cholesterol ; metabolism ; Diet, Atherogenic ; Lipids ; blood ; Male ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; gamma-Linolenic Acid

Gut dysbiosis,a well-known risk factor to triggers the progression of Alzheimer's disease(AD),is strongly associated with metabolic disturbance.Trimethylamine N-oxide(TMAO),produced in the dietary choline metabolism,has been found to accelerate neurodegeneration in AD pathology.In this study,the cognitive function and gut microbiota of TgCRND8(Tg)mice of different ages were evaluated by Morris water maze task(MWMT)and 16S rRNA sequencing,respectively.Young pseudo germ-free(PGF)Tg mice that received faecal microbiota transplants from aged Tg mice and wild-type(WT)mice were selected to determine the role of the gut microbiota in the process of neuropathology.Excessive choline treatment for Tg mice was used to investigate the role of abnormal choline metabolism on the cognitive functions.Our results showed that gut dysbiosis,neuroinflammation response,Aβ deposition,tau hyper-phosphorylation,TMAO overproduction and cyclin-dependent kinase 5(CDK5)/transcription 3(STAT3)activation occurred in Tg mice age-dependently.Disordered microbiota of aged Tg mice accelerated AD pathology in young Tg mice,with the activation of CDK5/STAT3 signaling in the brains.On the contrary,faecal microbiota transplantation from WT mice alleviated the cognitive deficits,attenuated neuro-inflammation,Aβ deposition,tau hyperphosphorylation,TMAO overproduction and suppressed CDK5/STAT3 pathway activation in Tg mice.Moreover,excessive choline treatment was also shown to aggravate the cognitive deficits,Aβ deposition,neuroinflammation and CDK5/STAT3 pathway activation.These findings provide a novel insight into the interaction between gut dysbiosis and AD progression,clarifying the important roles of gut microbiota-derived substances such as TMAO in AD neuropathology.

Objective To investigate whether minicircle DNA-mediated shRNA can inhibit the replication and expression of HBV in HBV transgenic mice.Methods First,a universal plasmid shRNA,pU6-shRNA HBV and a minicircle shRNA vector pMC-U6-shRNA HBV targeting HBV gene was prepared by molecular cloning technique.Then,the HBV transgenic mice were divided into three groups and the pMC-U6-shRNA HBV,pU6-shRNA HBV and control vector pU6-control were transfected into them respectively by hydrodynamic injection (HDI).Sera were collected at different time points after injection.The changes of HBV DNA and HBsAg in serum of transgenic mice were detected by real-time PCR and chemiluminescence microparticle immunoassay (CMIA).Immunohistochemistry was used to analyze the expression of HBcAg in the liver of transgenic mice.Results Compared with pU6-control group,HBsAg and HBV DNA in serum of transgenic mice were significantly inhibited by pU6-shRNA HBV and pMC-U6-shRNA from day 7 to day 21 after HDI (P＜0.05).After that,the serum HBsAg and HBV DNA recovered and returned to the control level on the 35th day in pU6-shRNA HBV group.However,pMC-U6-shRNA HBV still maintained a strong inhibitory effect in vivo until 35 days post-injection compared with the other two groups (P＜0.05).Immunohistochemical results also suggest that pMC-U6-shRNA HBV could more significantly inhibit HBcAg expression than pU6-shRNA HBV in mouse liver tissue.Conclusion The minicircle DNA-based shRNA vector pMC-U6-shRNA HBV is of longer inhibitory effect on HBV replication and gene expression in HBV transgenic mice than pU6-shRNA HBV.Minicircle DNA is superior to pRNAT-U6.1/Neo for shRNA delivery in vivo.

OBJECTIVE To evaluate the effects of flavonoids from Xindakang (Hippophae Fructus flavone) on myo?cardial systolic and diastolic functions of isolated frog hearts and explore the possible mechanism, and provide experi?mental basis for improving the effect and efficacy of Xindakang on cardiac function. METHODS The isolated frog heart perfusion specimens were prepared by Yagi's method, and the effects of different concentrations of Xindakang on myo?cardial contractility (0.0125, 0.025, 0.05, 0.1 and 0.2 g·L-1), heart rate and cardiac output of isolated frog heart were stud?ied. Acetylcholine, atropine and epinephrine were administered successively to analyze the effects of Xindakang on car?diac systolic function of isolated frogs under the action of different drugs, and compared with propranolol. The effect of extracellular calcium ion concentration on the action of Xindakang was studied by using low calcium concentration, high cal?cium concentration and normal Ren's solution. To study the effect and possible mechanism of Xindakang on cardiac systolic function of frog. RESULTS The concentration of Xindakang in the range of 0.0125-0.1 g·L-1 could weaken the contractility of isolated frog heart and increase the concentration of Xindakang. The inhibitory effect of Xindakang on con?tractility of isolated frog heart was enhanced, and showed obvious dose-effect relationship. Cardiac output was signifi?cantly decreased by Xindakang (P<0.01), slow heart rate (P<0.05); M receptor blocker atropine could not antagonize the contractile effect of Xindakang, and Xindakang could not completely antagonize the contractile effect of adrenalin. Xindakang could inhibit the isolated frog heart in low calcium concentration, high calcium concentration and normal Ren's solution, and increased with the increase of extracellular calcium concentration (P<0.01). CONCLUSION Xinda?kang has inhibitory effect on isolated frog heart, which may be achieved by blocking the calcium channel on myocardial cell membrane and reducing the calcium concentration in myocardial cells.

OBJECTIVEIn order to explore the existence of SARS coronavirus (Co-V) and/or its RNA in sewage of hospitals administered SARS patients.

METHODSA novel electropositive filter was used to concentrate the SARS-CoV from the sewage of two hospitals administered SARS patients in Beijing, including twelve 2,500 ml sewage samples from the hospitals before disinfection, and ten 25,000 ml samples after disinfection; as well as cell culture, RT-PCR and sequencing of gene to detect and identify the viruses from sewage.

RESULTSThere was no live SARS-CoV detected in the sewage in this study. The nucleic acid of SARS-CoV had been found in the 12 sewage samples before disinfection from both hospitals by semi-nested PCR. After disinfection, SARS-CoV RNA could only be detected from the samples from the 309th Hospital, and the others were negative.

CONCLUSIONIt provides evidence that there is no live SARS-Cov in the sewage from hospitals with SARS patients though SARS-CoV RNA can be detected.

Hospitals ; Humans ; Nucleocapsid ; analysis ; RNA, Viral ; analysis ; Reverse Transcriptase Polymerase Chain Reaction ; SARS Virus ; genetics ; isolation & purification ; Severe Acute Respiratory Syndrome ; virology ; Sewage ; virology

OBJECTIVETo explore the effect and mechanism of norcantharidin (NCTD) on hematopoiesis function in leucopenia model rat induced by cyclophosphamide (CTX).

METHODSLeucopenia model was replicated in SD rat with cyclophosphamide(CTX) and model animal was treated with NCTD. Peripheral blood and bone marrow tissue samples were collected from the rats in each experimental group. Peripheral white blood cells (WBC) were counted and analyzed by automatic blood cell analyzer. Histopathologic changes of the biopsied bone marrow tissues were observed by histopathological techniques. The cell cycle and apoptosis rate of bone marrow cells were detected by flow cytometry. Immunohistochemical method was applied to observe the expression of apoptosis-related proteins BCL-2 and BAX in bone marrow.

RESULTSAfter NCTD treatment in model rats, the WBC count of peripheral blood obviously increased, the cell structure of bone tissue significantly recovered, NCTD could promote the cell proliferation and cycle changes of bone marrow cells, inhibit the bone marrow cell apoptosis and necrosis induced with CTX, up-regulate the expression of apoptosis-related protein BCL-2 and downregulated the BAX.

CONCLUSIONNCTD can stimulate the bone marrow hematopoiesis and promote recovery of peripheral white blood cell level in the leukopenia model induced by CTX, and its mechanism may be related with NCTD regulating bone marrow cell cycle and with NCTD inhibiting cell apoptosis.

Animals ; Apoptosis ; Bone Marrow ; Bone Marrow Cells ; Bridged Bicyclo Compounds, Heterocyclic ; Cell Cycle ; Cell Proliferation ; Cyclophosphamide ; Disease Models, Animal ; Flow Cytometry ; Hematologic Diseases ; Hematopoiesis ; Rats ; Rats, Sprague-Dawley