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 investigate the TCM syndrome of metabolic syndrome. Methods The clinic information of the patients with metabolic syndrome was systematically collected through questionnaire investigation. The information was gathered with EXECL and analyzed by the medical statistic software SPSS14.0. Results Metabolic syndrome was closely related to lung, spleen, and kidney, manifested as spleen deficiency, lung deficiency, kidney deficiency, deficiency of both lung and spleen, deficiency of both lung and kidney, and deficiency of both spleen and kidney. The most frequently seen dyndrome is Qi deficiency, and the syndrome with most serious manifestations is phlegm-dampness. Conelesions Metabolic syndrome has a most closed relationship with the three organs of lung, spleen, and kidney. Qi deficiency, phlegm dampness, and blood stasis are the most frequently seen manifestations.

Objective:To develop a scale used to measure smoking-related attitudes in Chinese secondary school students. Methods:Based on literatures published in China and abroad and suggestions by relevant specialists and teachers, we developed a self-administered scale with 16-item used to measure smoking-related attitudes in Chinese secondary school students. Factor analysis was used to assess the construct validity of the scale. The differences of the scores between trying smokers and non-smoker, and males and females were tested for assessing the discriminant validity of the scale. Cronbach's alpha for the total scale and the sub-scales was calculated for evaluating the internal consistency, and the split-half reliability test analysis was also conducted. Moreover, 112 subjects were re-investigated after two weeks of the first survey, and the difference and correlation of scores between the two surveys were tested for assessing the stability of the scale. Results: Factor analysis identified two potential components that could explain 46.2% of the total variance, and the first factor including 9 items was defined as "The opinions to tobacco and smoking-related behaviors", and the second one including 7 items was defined as "The opinions to measures for preventing and controlling smoking". The mean score of the scale in non-smokers was significantly higher than that of the trying smokers, while the mean score in females was significantly higher than that in males. The Cronbach'? coefficient was 0.87 for Factor One, 0.75 for Factor Two, and 0.86 for the general scale, and the coefficient of the split-half reliability was 0.71 for Factor One, 0.59 for Factor Two, and 0.72 for the general scale. By analyzing the data of 112 students who participated in both surveys, we obtained test-retest reliability of factorⅠas 0.72, of factor Ⅱ as 0.44 and of all items as 0.67, and all the correlation coefficients were statistically significant. There were no differences for the scores of the scale between the two surveys. Conclusion: The results indicated that the smoking-related attitude scale had reasonable validity and reliability,It could provide valuable reference for future similar surveys in China.

Objective: To detect estrogen receptor α and β(ER-α, ER-β)protein expression in different age of mouse thymus.Methods:Protein expression of ER-α and ER-β in thymus was analyzed via immunohistochemistry.Moreover,the relationship between ER-α and cytokeratin 18(epithelial cell marker)was further tested through fluorescence double-staining.Results: Immunohistochemical analysis revealed that both ER-α and β protein was found in nuclei of some thymocytes of 3 month mice.However,expression of ER-β was absence while ER-α was still positive in aged mice, such as 12 months and 16 months old.Double staining further confirmed that lots of ER-α/β positive cells were Foxp3 negative cells.Conclusion: Expression of ER-β is absent while ER-α is still positive in thymus of aged mice, which indicates ER-α is the critical estrogen receptor that involves in thymic involution.Moreover, ER-α/β do not participate in Treg development within thymus.

Objective:To prepare sirolimus ( SRL) dropping pills to improve SRL solubility and dissolution. Methods:The base of SRL dropping pills was screened. The optimal formula and preparation process were also optimized by orthogonal design. The equi-librium solubility, hygroscopicity and drug release in vitro of SRL dropping pills were studied. Results: PEG6000 was chosen as the base. The optimal preparation conditions of SRL dropping pills were as follows: the ratio of SRL and base was 1∶10, the dropping speed was 65 drops/min, the dropping temperature was 95℃ and the temperature of cooling solvent was 5℃. The equilibrium solubili-ty of SRL dropping pills in different solvents was increased significantly compared with that of SRL. The hygroscopicity of the dropping pills was notable. The drug release in vitro of SRL dropping pills was similar to that of the marketed tablets with quick and complete re-lease. Conclusion:SRL dropping pills exhibit increased solubility and improved dissolution, which are valuable to be studied further.

ObjectiveTo establish the reference intervals of serum triiodothyronine (TT3),the thyroxine ( TT4 ),free triiodothyronine ( FT3 ),free thyroxine ( FT4 ) and thyroid-stimulating hormone (TSH)in the apparently healthy individuals of Beijing and Shanghai.Methods According to the requirement for laboratory support for the diagnosis and monitoring of thyroid diseases in the National Academy ofClinicalBiochemistry(NACB)laboratorymedicinepracticeguidelines, therewere 390 apparently healthy individuals tested (221 male,169 female,18 -65 years old) from Beijing and Shanghai for serum TT3,TT4,FT3,FT4 and TSH on American Beckman UniCel DXI 800 Automatic Chemiluminescent Analyzer.All markers were analyzed between gender,region,age group using t test and ANOVA.The reference intervals of all markers were determined by P2.5 - P97.5.ResultsTT3,TT4,FT3,FT4,TSH levels in the male group were ( 1.90 ± 0.32) nmol/L,( 116.77 ± 18.02) nmol/L,( 5.28 ±0.67) pmol/L,( 11.54 ± 1.97) pmol/L,( 1.92 ± 1.12 ) mIU/L,respectively,while the above indicators in the female group were ( 1.82 ± 0.32) nmol/L,( 115.73 ± 14.39 ) nmol/L,(5.04 ± 0.59 ) pmol/L,( 10.94 ± 1.45) pmol/L,( 2.37 ± 1.86 ) mIU/L,respectively.When comparing the results in genders,statistical significance was shown in TF3,FT3,FT4 and TSH of two gender groups( t =2.377,3.642,3.471,2.520,all P ＜ 0.05 ).When comparing different regions,statistical significance was only shown in FT3 ( t =6.410,P ＜ 0.05 ),in which Beijing group was (5.01 ± 0.63) pmol/L,and Shanghai group was (5.41 ±0.61 ) pmol/L,and no significant difference were shown in other four markers.Correlation analysis showed that TT4 was positively correlated with age (r =0.22,P ＜ 0.001 ) while TSH was negatively correlated with age ( r =- 0.12,P ＜ 0.05 ).TT3,TT4,FT3,FT4,TSH reference intervals were ( 1.22 - 2.50 ) nmol/L,(83.37 - 149.37 ) nmol/L,( 3.88 - 6.48 ) pmol/L,( 7.70 - 14.86) pmol/L,( 0.38 - 5.58 ) mIU/L,respectively.ConclusionDifferences of serum thyroid hormones were observed in different areas of China,It is important to establish reference intervals of the serum thyroid hormones in Chinese population.

ObjectiveTo evaluate the suitability of Nordtest guideline in estimating measurement uncertainty of routine tests in clinical laboratory.MethodsData of clinical laboratory of Beijing Tongren Hospital were collected,which came from 176 days of Internal Quality Control ( IQC ) from July 2010 to December 2010 and 6 times of External Quality Assesment ( EQA ) of NCCL from 2009 to 2010.The combined and expanded uncertainties of 21meaurements (sodium, potassium, chlorine,calcium,phosphrous,glucose,urea nitrogen,creatinine,uric acid,total protein,albumin,total bilirubin,direct bilirubin, alanineaminotransferase, aspartateaminotransferase, alkalinephosphatase, lactate dehydrogenase,glutamyl transpeptidase,creatine kinase,triglyceride and total cholesterol) were evaluated according to Nordtest guideline.ResultsOf all the measurements,expanded uncertainty of direct bilirubin ( 17.69％ ) was the highest.For some enzymes such as ALT,AST,ALP and LDH,expanded uncertainties were all over 10％ markedly influenced by the calibrator uncertainty.Expanded uncertainty of triglyceride was 12.7％,also largely influenced by calibrator uncertainty,while that of total cholesterol was 6.96％.ConclusionsNordtest guideline is suitable to evaluate the measurement uncertainty of routine assays in clinical laboratory.However,calibrator uncertainty should be taken into account in the process of evaluation.

Objective To investigate the major risk factors for posterior circulation stroke and the clinical and imaging features of posterior circulation stroke patients with diabetes.Methods The patients with acute cerebral infarction were enrolled.The clinical data of patients with posterior circulation and anterior circulation stroke were compared.The patients with posterior circulation stroke were further divided into either a diabetic group or a non-diabetic group,and the vascular risk factors and imaging features of both groups were compared.The patients with posterior circulation stroke were divided into proximal segment,middle segment and distal segment and mixed groups according to the distribution of vascular lesions.The correlations between diabetes and each group and the imaging features were analyzed.Results A total of 328 patients with posterior circulation stroke (male 194,the diabetic group 108) and 336 patients with anterior circulation stroke (male 214,the diabetes group 59)were enrolled.The proportions of patients with diabetes (32.9％ vs.21.7％ ; x2 =10.501,P =0.001),hyperlipidemia (60.1％ vs.47.9％ ;x2 =9.852,P =0.002),previous stroke or transient ischemic attack (TIA) (29.0％ vs.22.0％ ;x2 =4.213,P =0.040) in the posterior circulation ischemic stroke group were significantly higher than those in the anterior circulation ischemic stroke group,and the proportion of smoking patients was significantly lower than that in the anterior circulation ischemic stroke group (18.3％ vs.26.2％ ; x2 =5.977,P =0.014).The levels of total cholesterol (4.72 ±1.07 mmol/L vs.4.56 ± 0.98 mmol/L; t =2.079,P =0.038),triglycerides (1.54 ± 1.07 mmol/L vs.1.33±0.71 mmol/L; t=3.085,P=0.002) and low-density lipoprotein cholesterol (2.91±0.90 mmol/L vs.2.75 ±0.80 mmol/L; t =2.373,P =0.018) were significantly higher than those in the anterior circulation ischemic stroke group,and the level of high-density lipoprotein cholesterol was significantly lower than that in the anterior circulation ischemic stroke group (1.13 ± 0.31 mmol/L vs.1.18 ±0.32 mmol/L; t =2.045,P=0.041).Multivariate logistic regression analysis showed that diabetes (odds ratio [OR] 1.560,95％ confidence interval [CI] 1.086-2.239; P =0.016) and previous stroke or TIA history (OR 1.455,95％ CI 1.013-2.090; P =0.042) were the independent risk factors for posterior circulation ischemic stroke.In patients with posterior circulation ischemic stroke,the patient's proportions of hyperllpidemia (66.7％ vs.55.5％ ;x2 =5.069,P =0.024) and drinking (13.0％ vs.4.5％;x2 =7.568,P=0.006) in the diabetic group (n =108) were significantly higher than those in the non-diabetic group (n =220); the proportion of atrial fibrillation patients was significantly lower than that in the non-diabetic group (3.7％ vs.11.4％ ;x2 =5.274,P =0.022).The levels of triglycerides (1.70 ± 0.93 rnmol/L vs.1.45 ± 1.11 mmol/L; t =1.989,P =0.048),fasting glucose (8.46 ± 2.96) mmol/L vs.5.30± 0.96 mmol/L; t=10.706,P=0.000) and glycosylated hemoglobin (8.36％ ± 1.94％ vs.6.07％ ± 0.55％ ; t =10.576,P =0.000) in the diabetic group were significantly higher than those in the non-diabetic group.The proportion of patients with large artery atherosclerosis stroke in the diabetic group was significantly higher than that in the non-diabetic group (73.1％ vs.60.0％; x2=5.457,P=0.019); the proportion of the patients with cardioembolism was significantly lower than that of the non-diabetic group (2.8％ vs.9.1％;x2 =4.428,P =0.035).The proportion of patients with posterior circulation middle segment infarction in the diabetic group was significantly higher than that of the non-diabetic group (49.1％ vs.31.4％ ;x2 =9.726,P =0.002).The proportions of the patients with brainstem infarction (60.2％ vs.48.2％ ;x2 =4.182,P =0.041) and single brainstem infarction (55.6％ vs.30.5％ ;x2 =19.235,P =0.000) in the diabetic group were significantly higher than those in the non-diabetic group.In patients with single brainstem infarction,the proportions of the patients with pontine infarction (43.5％ vs.25.9％ ;x2 =10.374,P =0.001) and medulla oblongata infarction (7.4％ vs.1.8％ ; P =0.023) in the diabetic group were significantly higher than those in the non-diabetic group.Conclusions Diabetes and previous stroke or TIA history are the independent risk factor for posterior circulation stroke.Diabetes is closely associated with brainstem infarction,and it is more likely to result in pontine infarction.

Objective:To investigate the expression and clinical significance of PD-L1 in colorectal cancer (CRC). Methods:A total of 210 CRC patients who accepted radical surgery in our hospital from January 2015 to January 2016 were divided into three groups, namely, high-frequency microsatellite instability (MSI-H), low-frequency microsatellite instability (MSI-L), and microsatellite stable (MSS). The expression of PD-L1 was detected by immunohistochemistry, and the expression characteristics of PD-L1 in different types of CRC were analyzed. Results:CRC cases with low differentiation had a higher expression of PD-L1 than CRC patients with high differ-entiation (P<0.05). PD-L1 had a positive rate of 75.8%in the MSI-H group and a rate of 9.3%in the MSI-L and MSS groups, wherein the difference between the two groups was statistically significant (P<0.05). Conclusion:PD-L1 was positively expressed in some CRC tu-mor tissues, and its positive rate was significantly higher in MSI-H than in MSI-L and MSS. The therapeutic effect of a PD-L1 blocker for patients with MSI-H CRC might be preferable.

Objective:To detect estrogen receptor ? and ?(ER-?,ER-?) protein expression in different age of mouse thymus.Methods:Protein expression of ER-? and ER-? in thymus was analyzed via immunohistochemistry.Moreover,the relationship between ER-? and cytokeratin 18(epithelial cell marker) was further tested through fluorescence double-staining.Results:Immunohistochemical analysis revealed that both ER-? and ? protein was found in nuclei of some thymocytes of 3 month mice.However,expression of ER-? was absence while ER-? was still positive in aged mice,such as 12 months and 16 months old.Double staining further confirmed that lots of ER-?/? positive cells were Foxp3 negative cells.Conclusion:Expression of ER-? is absent while ER-? is still positive in thymus of aged mice,which indicates ER-? is the critical estrogen receptor that involves in thymic involution.Moreover,ER-?/? do not participate in Treg development within thymus.