The porcine reproductive and respiratory syndrome virus (PRRSV) can cause reproductive barriers in breeding pigs and respiratory symptoms in piglets. In this review, we summarize research progress of the infection and replication mechanisms of the PRRSV. We also review the virulence determinants of the PRRSV. All these fundamental studies are important for the control and elimination of the PRRSV.
Animals ; Porcine Reproductive and Respiratory Syndrome ; virology ; Porcine respiratory and reproductive syndrome virus ; genetics ; pathogenicity ; physiology ; Swine ; Virulence ; Virus Replication

Objective To evaluate the effect of driving forces similar to those found in dental plaque fluid on the enamel demineralization and ultrastructure of surface layer.Methods The sections of human enamel were exposed to lactic acid solutions with degree of saturation with respect to enamel and degree of saturation with respect to fluoroapatite for 96 h at 25 ℃,using the deionized water as control in the same conditions.Enamel demineralization was monitored using SEM and confocal laser scanning microscopy(CLSM).Results Only was enamel subsurface demineralization detected in solutions with DS_(EN)(0.1-0.3).Enamel mineral loss and micropores of surface layer decreased significantly with increasing DS_(EN) and DS_(FA) values.However,no mineral loss and micropores of surface layer was observed in sections of enamel exposed to solutions with DS_(EN) values of 0.4 and 0.5,which were covered with homogeneous remineralization layer.Conclusion The demineralization driving forces similar to dental plaque fluid under different DS_(EN) and DS_(FA) have significant effects on the surface layer of enamel and the subsurface demineralization process.

Objective To investigate the reliability of Berg Balance Scale (BBS) applied in patients with Parkinson's disease (PD). Methods 121 PD inpatients from March to December, 2011 were assessed with BBS by 2 raters, and the testing procedure was videoed. One of the raters assessed with BBS via video 4 weeks later. The intraclass correlation coefficient (ICC) and Kappa coefficient between raters and between tests were investigated. Results The ICC was 1.00 of the total score between raters and 0.99 between tests, while the Kappa co-efficient were 0.66 to 0.93 and 0.69 to 0.99 of the items. Conclusion BBS is reliable in interrater and test-retest as applied in PD patients.

AIM:To select an optiomal formulation of liposome entrapped alkanin prepared with ethanol injection in the combination of orthogonal design and central composite design/Response surface method.METHODS:Five influencing factors,including ratio of alkanin to liposome and soyabean lecithin to cholesterol,volume ratio of ethanol phase to water phase,soybean concentration and mannitol concentration were chosen as indices by orthogonal design.Then the method utilized the central composite design,which fitted multivariate linear and second/third order nonlinear regression equation,to find out the optimal formulation.RESULTS:Third order regression equation gained made the good prediction about entrapment(85.4%)and alkanin load(5.16%),and exhibited no significant difference between theoretic value and measured value.CONCLUSION:The combination of orthogonal design with central composite design is a feasible and convenient method to optimize the prescription of alkanin-liposome.

AIM:To select an optiomal formulation of liposome entrapped alkanin prepared with ethanol injection in the combination of orthogonal design and central composite design/Response surface method.METHODS:Five influencing factors,including ratio of alkanin to liposome and soyabean lecithin to cholesterol,volume ratio of ethanol phase to water phase,soybean concentration and mannitol concentration were chosen as indices by orthogonal design.Then the method utilized the central composite design,which fitted multivariate linear and second/third order nonlinear regression equation,to find out the optimal formulation.RESULTS:Third order regression equation gained made the good prediction about entrapment(85.4%) and alkanin load(5.16%),and exhibited no significant difference between theoretic value and measured value.CONCLUSION:The combination of orthogonal design with central composite design is a feasible and convenient method to optimize the prescription of alkanin-lipo-some.

ObjectiveTo investigate the effects of transcranial magnetic stimulation(TMS)on motor function after acute cerebral infarction.Methods60 patients who suffered acute cerebral infarction were assigned to experiment group and control group(30 cases each group). Both groups received rehabilitation theropy. Meanwhile,experiment group received TMS. Fugl-Meyer Assessment(FMA), National Institute of Health Scale of Stroke(NIHSS), Barthel Index(BI) were used to measure the outcome.ResultsThe scores of FMA and BI increased significantly(P<0.05) while that of NIHSS decreased significantly(P<0.05) in both groups after treatment. However, these scores in experiment group improved more compared with those of control group(P<0.05).ConclusionTMS is helpful to improve the motor function, ability of daily living and neurological function.

Objectives:The time of Carotid intervention for recently symptomatic,severe carotid stenosis which cause a transient ischemic attack or minor stroke is still a controversial issue.Early studies showed that carotid endarterectomy (CEA) caused a high risk if performed within days follow an acute ischemic stroke.However,The National Stroke Strategy posted by UK Department of Health advocated that this situation should be regarded as an emergency procedure,and carotid intervention should ideally be performed within 48 hours.We designed this study to discuss the effect of urgent CEA on operative risk and benefit.Methods: we analyze 12 urgent CEA with primary closure performed during 1996 to 1998.All 12 patients were underwent CEA within 2 weeks,and 2 of them within 2 days.Operative risks and overall benefit from surgery were discussed in relation to the time from the last symptomatic event to CEA.Results: 2 urgent CEA performed in 2 days are recovery uneventful.1 of 12 patients,who underwent urgent CEA within 2 weeks,occurred restenosis after 3 months follow up.No 30-day perioperative recurrent TIA,stroke and death.Conclusions:CEA performed within 2 weeks is feasible and reliable procedure in preventing recurrent TIA and stroke after presenting manifestations.The future aim is to perform CEA within 48 hours after TIA or stroke symptoms.

ObjectiveTo examined how autoregulation is affected by vasospasm after subarachnoid hemorrhage (SAH) by using transcranial Doppler. MethodsThe moving correlation coefficient between slow changes of arterial blood pressure and mean or systolic flow velocity (FV), termed Mx and Sx, respectively, was used to characterize cerebral autoregulation. Vasospasm was declared when the mean FV increased to more than 120 cm/s and the Lindegaard ratio was more than 3. This occurred in 15 of 32 SAH patients.On the basis of the bilateral transcranial Doppler recordings of the middle cerebral artery in vasospastic patients, Mx and Sx were calculated for baseline and vasospasm. ResultsMx increased during vasospasm (0.46±0.32) and was significantly higher (P=0.03) than at baseline (0.21±0.24) Sx was also increased (0.22±0.26 vs 0.05±0.21,P=0.03). Mx correlated with mean FV (P=0.577, P=0.006) and the Lindegaard ratio (r=0.672,P<0.01).Mx(P=0.006) and Sx (P=0.044) were higher on the vasospastic side compared with the contralateral side.ConclusionThe increased Mx and Sx during cerebral vasospasm demonstrate impaired cerebral autoregulation. Mx and Sx provide additional information on changes in autoregulation in SAH patients.

Objective To investigate the regulation role of gastric cancer related miR-148a on gastrin receptor CCKBR expression, and find the correct binding sites of miR-148a in CCKBR 3’UTR.Methods The potential binding sites of miR-148a in the CCKBR 3’UTR were predicted with the bioinformatic tools;The miR-148a expressing plasmid was constructed by PCR, and miR-148a expression was verified by Northern Blot;The luciferase report plasmids containing the wild type and mutated binding sites of CCKBR 3’ UTR were constructed, and were used to study the regulation mechanism and identify the binding sites of miR-148a by luciferase activity analysis; The regulation effect of miR-148a on CCKBR protein expression was checked by Western Blot.Results Three potential binding sites of miR-148a in the CCKBR 3’ UTR were found; The miR-148a expressing plasmid was constructed successfully, and highly expressed miR-148a after transfected to gastric cancer cells;The inhibitory effect of miR-148a on CCKBR protein expression was checked by Western Blot.Over-expression of miR-148a inhibited CCKBR expression by directly binding to the binding site in CCKBR 3’UTR 423bp.Conclusion CCKBR is a target of miR-148a, and its expression is inhibited by the binding of miR-148a on its 3’ UTR, indicating that miR-148a may participates in the progression of gastric cancer by regulating CCKBR expression.

Solid papillary carcinoma of the breast is a rare breast papillary lesion that accounts for less than 1％ of breast cancers.The tumor is most common in elderly patients with imaging abnormalities or painless breast masses,histopathological manifestations of solid structure,frequent with mucous and/or neuroendocrine characteristics.The choice of surgical methods is mastectomy and simple mastectomy.At present,it is not well understood by clinicians and pathologists.In this paper,the clinicopathological features,treatment and prognosis of solid papillary carcinoma of the breast diagnosed by pathology in our hospital were retrospectively analyzed in order to improve the further understanding of this disease.