Objective To investigate the effects of montelukast(MK),a selective cysteinyl leukotriene receptor 1 antagonist on interleukin(IL)-5 and eotaxin expression as well as serum total immunoglobulin E(IgE) production during MK treatment of mouse acute asthma airway inflammation.Methods Sensitized Balb/c mice were challenged by ovabumin(OVA)to establish the acute asthmatic mo-(del).Twenty-five mg/kg of MK(MK group) or Saline(Saline group)were given by intravenously for 3 days.Cellular infiltration of bronchoalveolar larvage fluid(BALF) were assessed by Wright staining.Production of IL-5 and eotaxin in the lung or BALF and serum IgE were determined by enzyme linked immunosorbent assay(ELISA).The expression of IL-5 and eotaxin mRNA were measured by semi-quantified reverse transcriptase-polymerase chain reaction(RT-PCR).Plasma MK level was determined by liquid chromatography.Results After 24 h OVA challenge,the numbers of total white blood cells,neutrophils and eosinophils(EOS)of BALF were(26.0?18.9)?10~7/L,(5.92?8.09)?10~7/L and(0.74?0.88)?10~7/L in MK treatment group.They were significantly reduced compared with those in Saline group,respectively(P80%.The level of IL-5 in BALF and lung tissue were(48.52?14.45) ng/L and(27.40?9.62) ng/g protein in MK group,which significantly declined compared with that in saline group;BALF eotaxin level declined too.Serum IL-5 and total IgE level were also significantly reduced;IL-5 mRNA expression in lung significantly decreased.Eotaxin and its mRNA expression in lung were not decreased significantly.Conclusion MK(exerts) its anti-inflammatory effect mainly through the suppression of IL-5 and IgE production.

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.

BACKGROUND:The homing ability of mesenchymal stem cells after transplantation can decrease along with culture and passage in vitro. And the decline of homing abilities can further influence the implantation of mesenchymal stem cells in the target tissue, thus seriously affecting the repair effect.
OBJECTIVE:To investigate the effect and its related mechanisms by which in vitro culture and passage affect the homing ability of mesenchymal stem cells.
METHODS:Mesenchymal stem cells were isolated from the bone marrow using Ficol density gradient centrifugation, and then purified using adhesion method. The mesenchymal stem cells were cultured into the seventh generations with the normal cultural condition, and the morphological features of the 3rd, 5th and 7th generations of mesenchymal stem cells were observed. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide chromatometry was used to detect the growth feature of the 3rd, 5th and 7th generations of mesenchymal stem cells, and the growth curve was drawn. Real-time PCR was used to detect the expression of CXCR4, CXCR6, CXCL12, CD44 in the 3rd, 5th and 7th generations of mesenchymal stem cells, 2-△△Ct was calculated to get the relative value of each target gene, and the differences in expression of CXCR4, CXCR6, CXCL12, CD44 between different generations were compared.
RESULTS AND CONCLUSION:Mononuclear cells could be obtained from the bone marrow by using Ficol density gradient centrifugation. High-purity mesenchymal stem cells could be obtained using adherent method. The ability of in vitro growing was strong, but fol owing the passage, the cellmorphology became wider and shorter. And the proliferation rate, the overal proliferated multiple and the expression of homing related factors decreased fol owing the passage. The expression of CXCR4, CXCR6, CXCL12 and CD44 of mesenchymal stem cells decreased fol owing the passage. The homing ability of mesenchymal stem cells was decreased fol owing the passage, and may be relevant with the lower expression of CXCR4, CXCR6, CXCL12 and CD44 in cultured mesenchymal stem cells.

Objective To evaluate the diagnostic value of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI)for the differential diagnosis of the adenoid cystic carcinoma and pleomorphic adenoma of the head and neck.Methods Thirty-one pa-tients with histopathologically proved adenoid cystic carcinoma and pleomorphic adenoma were examined with DCE-MRI,in which 10 cases were benign and 21 cases were malignant.The data of the conventional 3.0T DCE-MRI were improved by the 3D fast spoiled gradient-echo sequence (FSPGR)method.Z-test was performed on the quantitative parameters for benign and malignant le-sions,including volume transfer constant (Ktrans ),rate constant (Kep )and extravascular extracellular space fraction (Ve ).The re-ceiver operating characteristic (ROC)curves were plotted to investigate the diagnosis.Results The mean Ktranss of the adenoid cystic carcinoma group and pleomorphic adenoma group were (0.266 ± 0.103 )min-1 and (0.1 55 ± 0.080)min-1 respectively,and the difference between them were statistically significant (Z =-2.699,P < 0.05).The difference between the keps of the aforementioned two groups was of statistical significance (Z =-2.263,P < 0.05),while that of the ves is without statistical significance (Z =-1.132, P >0.05).The areas under the ROC curves of the Ktrans and kep were 0.813 and 0.763 respectively.Choosing the optimal diagnostic cut-off points corresponding to the maximum Youden indexes 0.173 min-1 and 0.818 min-1 ,the sensitivities of Ktrans and kep for identifying the adenoid cystic carcinoma and pleomorphic adenoma were 90.9% and 81.8%,and the specificities were 77.8% and 66.7%.Ktrans was of the highest sensitivity and specificity for the identification of the adenoid cystic carcinoma and pleomorphic adenoma.Conclu-sion The dynamic contrast-enhanced parameter Ktrans plays a certain role in the differential diagnosis of the adenoid cystic carcinoma and pleomorphic adenoma of the head and neck.

Objective To evaluate the quality of Isatidis Radix from different ecotypes by using projection pursuit model. Methods Totally 11 batches of Isatidis Radix from different ecotypes in Gansu Province were used as evaluation samples. With the contents of epigoitrin, uridine, guanosine, adenosine, benzoic acid, salicylic acid, indigo, indirubin, and alcohol extract as evaluating indexes, combined with projection pursuit model established by DPS V 9.50 statistics software, the quality of Isatidis Radix was evaluated. Results Based on the evalution of nine main indexes, quality order of the 11 batches of Isatidis Radix was acquired: S2>S1>S9>S7>S8>S3>S5>S10>S11>S4>S6. Conclusion The projection pursuit model was available for the quality evaluation of different ecotype Isatidis Radix. The quality of Isatidis Radix from different ecotypes is different significantly, and the quality of tetraploid Isatidis Radix of Shijiazhuang is the best.

Objective To prepare a glycerol reference material.Methods The material was prepared and characterized according to the primary standard substance technological specification(JJG 1006- 1994).Glycerol was dissolved in water containing 0.5% sodium azide and dispersed to glass ampules.The homogeneity and stability of this material were tested with an HPLC method.Glycerol concentration was determined by a titration method as specified in the Pharmacopoeia of China.Results The three time measuring result of glycerol reference material was 1.297 5?0.014 3,1.302 0?0.008 9,1.313 7? 0.007 8,respectively.Statistical analysis showed that this material was homogeneous (F=1.462,P=0.166) .It was stable for at least 4 years at 4℃.The assigned reference value was 0.103 6 g/g and the expanded uncertainty was 0.000 4 g/g.Conclusions This material meet the technical requirements of national primary standard reference material.It is approved as the Certified Reference Material (GBW 09149) by General Administration of Quality Supervision,Inspection,Quarantine of the People's Republic of China in May,2006.

Objective:To investigate the relationship between serum vascular endothelial growth factor (VEGF), peripheral blood microRNA-126 (miR-126) and the number and distribution of cerebral microbleeds (CMBs).Methods:Consecutive patients with non-acute ischemic cerebrovascular disease admitted to the Department of Neurology, the First Affiliated Hospital of Baotou Medical College from June 2019 to June 2020 were enrolled. The clinical data were collected, 3.0 T MRI examination was performed, and susceptibility-weighted imaging was used to detect CMBs. The serum VEGF concentration was detected by enzyme-linked immunosorbent assay, and miR-126 was detected by fluorescence quantitative polymerase chain reaction. Multivariate logistic regression analysis was used to determine the independent influencing factors of CMBs. Multiple linear regression analysis was used to determine the correlation between serum VEGF concentration, miR-126 in peripheral blood and the number of CBMs. Receiver operating characteristic (ROC) curve was used to evaluate the predictive value of serum VEGF concentration and relative expression of miR-126 in peripheral blood for CMBs. Results:A total of 193 patients with non-acute ischemic cerebrovascular disease were enrolled, including 110 patients (57.0%) in the non-CMBs group, 20 (10.4%) in the strictly lobar CMBs group and 63 patients (32.6%) in non-strictly lobar CMBs group. The comparison among the three groups showed that age might be a risk factor for strictly lobar CMBs, while higher VEGF, higher cystatin C level, lower relative expression of miR-126 in peripheral blood, hypertension and previous stroke or transient ischemic attack might be the risk factors for non-strictly lobar CMBs. Multivariate logistic regression analysis showed that higher serum VEGF concentration was an independent risk factor for non-strictly lobar CMBs (odds ratio 1.186, 95% confidence interval 1.035-1.358; P=0.014), while the higher relative expression of miR-126 was an independent protective factor for non-strictly lobar CMBs (odds ratio 0.154, 95% confidence interval 0-0.269; P=0.026). Multiple linear regression analysis showed that higher serum VEGF concentration ( r=0.848, P<0.001) and the lower relative expression of miR-126 ( r=-0.043, P=0.035) significantly increased the number of CMBs. ROC curve analysis showed that the area under the curve of serum VEGF for predicting non-strictly lobar CMBs was 0.803 (95% confidence interval 0.741-0.865), the optimal cut-off value was 120.55 ng/L, the sensitivity was 70.7%, and the specificity was 75.5%. Conclusions:In patients with non-acute ischemic cerebrovascular disease, there is a significant correlation between serum VEGF concentration and the relative expression of miR-126 in peripheral blood and the number and distribution of CMBs. Serum VEGF can be used as a biomarker for predicting the presence of non-strictly lobar CMBs.

Objective To prepare specific polyclonal antibodies to outer membrane protein (Opr) D_2 of Pseudomonas aeruginosa (PA),and explore the relationship between loss of OprD_2 and imipenem resistance.Methods The genomic DNA of PA was ex- tracted with phenol:chloroform.OprD_2 coding gene was amplified by PCR and prokaryotic expression vector pRSET-OprD_2 was constructed.OprD_2 protein was expressed by IPTG induction in E.coli BL21(DE3),and purified with SDS-PAGE.The new protein band was recovered and used as antigens to subcutaneously immunize two New Zealand rabbits to prepare poly- clonal antibody.The specificity of the antibody was determined by Western blot.The expression of OprD_2 in 32 clinical isolates of PA was detected with the prepared polyclonal antibody by Western blot.Results The vector pRSET-OprD_2 has been success- fully expressed in E.coli BL21 (DE3).The polyclonal anti-OprD_2 antibody with high specificity has been successfully pre- pared.Present results show that of the 27 imipenem-resistant PA clinical isolates,OprD2 protein was low-expressed in 5 iso- lates (18.5%) and normally expressed in 2 isolates (7.4%) but not expressed in 20 isolates (74.1%).Conclusions The loss or low-expression of OprD_2 is one of the essential mechanisms accounting for imipenem resistance in clinical isolates of PA.

Objective To investigate the effects of early rehabilitative training program on patients with acute myocardial infarction(AMI).Methods One hundred and twenty-two patients with AMI were randomly divided into early rehabilitation group(n=62)and control group(n=60).In addition to routine treatment,patients in rehabilitation group received early rehabilitative training mainly by walking exercise for two weeks.Results There were no significant differences in ventricular arrhythmia(Lown≥Ⅲ), extension of infarction and heart rate variability(HRV)between the two groups(P＞0.05).Forty of 62 patients(64.5%)in rehabilitation group had their left ventricular ejection fraction(LVEF)more than or equal to 50% in the 3~(rd)～4~(th)week after admission,significantly higher than that in control group(45.0%, 27/60 ;P＜0.01 ).By the end of the 4~(th)week after admission,25.8% of the patients in rehabilitation group showed positive in treadmill test,significantly lower than that in control group(38.3%,P＜0.01). Occurrence of angina pectoris and reinfarction and fatality in rehabilitation group were significantly lower than those in control group(P＜0.05)during their hospitalization and follow-up period.Patients in rehabilitation group stayed at hospital for(16?3)days in average,significantly less than that in control group[(27?4) days],with statistically significant difference(P＜0.05).Conclusion Early rehabilitative training for patients with uncomplicated AMI is not only safe and feasible,but also useful in improvement for their prognosis and quality of life.

In order to study the chondrogenic phenotype differentiation of adult sheep bone marrow-derived mesenchymal stem cells (MSCs) in a defined medium as potential seed cells for cartilage tissue engineering. MSCs were isolated by density centrifugation with Percoll solution from bone marrow aspirated from sheep iliac crest. The third passage of MSCs were induced with H-DMEM containing TGF-beta3, IGF-I, Dexamethasone and VitC. The shape and ultrastructure of cells were observed, toluidine blue stain for GAG and immunohistochemistry for type II collagen were applied for chondrogenic phenotype identification. After 14 days of induction, MSCs changed from a spindle-like appearance to a polynal shape, a large amount of endoplasmic reticulum, Golgi complex and mitochondria were observed, and the differentiation of MSCs chondrogenic phenotype was verified by positive staining of toluidine blue and immunohistochemistry. MSCs derived from bone marrow can differentiate to chondrogenic phenotype when induced in vitro and can be used as optimal seed cells for cartilage tissue engineering.
Bone Marrow Cells/*cytology ; Cell Differentiation ; Cell Separation ; Cells, Cultured ; Chondrocytes/*cytology ; *Chondrogenesis ; Mesenchymal Stem Cells/*cytology ; Phenotype ; Sheep ; Tissue Engineering