Abstract: Objective　To investigate the antimicrobial activity of omadacycline (OMC) against clinical Streptococcus agalactiae (GBS) isolates, as well as its relationship with biofilm formation, resistance genes and virulence genes. Methods　A total of 136 strains of Streptococcus agalactiae isolated from Shenzhen Nanshan People's Hospital between 2015 to 2020. The minimum inhibitory concentration (MIC) of OMC against Streptococcus agalactiae was determined by broth microdilution. Crystal violet staining was used to detect the biofilm formation ability of GBS. Resistance genes (tetM, tetO, tetK, ermB, OptrA) and virulence genes (cpsⅢ, bca, fbsA, cpsA, scpB) were investigated by polymerase chain reaction (PCR). Results　Among the 136 clinical isolates of GBS, 20 strains (14.7%) were resistant to OMC, 64 (47.1%) were intermediate, and 52 (38.2%) were sensitive. Fifty-seven strains (41.9%) were biofilm-positive, 20 of which (35.1%) were sensitive to OMC. Seventy-nine strains (58.1%) were biofilm-negative, 32 of which (40.5%) were susceptible to OMC. There was a statistically significant difference in the sensitivity rates between the two groups of strains (χ2=63.062, P<0.001), but there was no significant difference in the sensitivity of OMC among the biofilm-positive strains (Fisher's exact test, P=0.824). The resistance rates of tetM, tetO, ermB and OptrA positive strains were higher than those of negative strains, while tetK was opposite. The presence of tetM (Z=0.815, P=0.415), tetO (Z=0.151, P=0.88), tetK (Z=0.567, P=0.571), ermB (Z=1.198, P=0.231) resistance genes in Streptococcus agalactiae had no significant impact on the sensitivity of OMC. However, the presence of the OptrA resistance gene showed a statistically significant effect on the sensitivity of OMC (Z=2.913, P=0.004). The virulence factors cpsⅢ, bca, fbsA, cpsA and scpB were all detected at a rate higher than 50%. The presence of the virulence genes cpsⅢ (Z=0.222, P=0.824), bca (Z=0.141, P=0.888), fbsA (Z=0.813, P=0.416), and cpsA (Z=1.615, P=0.106) in Streptococcus agalactiae had no significant impact on the sensitivity of OMC. However, there was a significant inter-group difference in the scpB virulence gene (Z=2.844, P=0.004), but the rank mean values and resistance rates of scpB-positive strains were lower than those of the negative strains. Conclusions　The formation of biofilm in Streptococcus agalactiae reduces its sensitivity to OMC, but there was no significant difference in the sensitivity to OMC among the biofilm-positive strains. The presence of resistance genes tetM, tetO, tetK, ermB, and virulence genes cpsⅢ, bca, fbsA, cpsA, scpB in Streptococcus agalactiae is not associated with OMC resistance, but the presence of the resistance gene OptrA is correlated with OMC resistance..

Qi-Gui-Yin (QGY) compound, which composes of five herbal medicines of Astragalus membranaceus (Fisch.) Bge., Angelica sinensis (Oliv.) Diels, Lonicera japonica Thunb., Artemisia annua L., and Polygonum cuspidatum Sieb.et Zucc., which is able to treat antibiotic-resistant bacteria with antibiotics, and also to delay or even reverse the bacterial resistance producing. However, QGY compound is a complex mixture. And it is very difficult to elaborate its material foundation. Therefore, chemical constituents in five herbal medicines were summarized through searching of the related literatures. And then, 170 kinds of bioactive ingredients were classi-fied in order to provide evidences for the study on chemical constituent of QGY compound and identify its mate-rial foundation of delaying drug resistance .

Objective To investigate the safty and feasibility of simultaneous minimally invasive technique for congenital heart disease (CHD) and pectus excavatum (PE).Methods From July 2006 to June 2011,6 children with PE associated with CHD were treated by simultaneous minimally invasive technique.They were 4 boys and 2 girls,aged from 4 years to 6 years 5 months ( average 5 years and 4 month),.The body weight were from 16 kg to 20 kg [ average ( 18.00 ± 1.79kg ].CT Hailer index were 3.9 - 5.0 ( average 4.35 ± 0.43 ).4 patients with ventricular septal defect (VSD) were treated by minimally invasive closure device,including 3 membranous VSD and 1 subaortic VSD.The defect diameter was 4 - 5 mm.2 cases with atrial septal defect (ASD) were treated using the same technique.the diameter of ASD was 12 - 16 mm.After minimally invasive heart surgery,Nuss operation was carried out in all 6 patients for their PE.Results All operations were successful and patients were extubated 5 - 11 h after operation [ mean ( 8.17 ± 2.04) h ].The pericardial mediastinal drainage was removed at 48 h postoperatively.There were no operative mortality and severe postoperative complications.1 patient had delayed wound healing and was successfully discharged.The plate was removed in 3 cases,and they all had satisfactory outcomes.Conclusion Simultaneous minimally invasive technique is a safe and effeictive mothod for treating pectus excavatum and congenital heart disease.

OBJECTIVETo investigate the effect of human serum albumin (HSA) on cell attachment of human gingival epithelial cells (HGE).

METHODSHGE were primary cultured with keratinocyte serum-free medium (KSFM) and dispase. The cultured cells were immunohistochemically stained by monoclonal anti-pan cytokeratin. MTT test was employed to investigate the influence of HSA on the cell attachment on polystyrene surface. The cell growth curve of HGE which were cultured in KSFM with 50 g/L HSA was observed.

RESULTSThe results showed significant decrease in cell numbers within 8 hours after HGE were inoculated, in which the polystyrene surface was preincubated with 50 g/L HSA. But it did not prove to be the case from 10 hours to 24 hours after HGE were inoculated. There were no significant difference within 24 hours in cell numbers between cultured in KSFM with 50 g/L HSA and control. The cell numbers in cell growth curve of HGE in KSFM with and without 50 g/L HSA did not show significant difference.

CONCLUSIONSHSA preincubation on polystyrene were produce inhibitory effect of HGE attachment in early stage.

Cell Adhesion ; drug effects ; Cell Count ; Cell Division ; drug effects ; Cells, Cultured ; Epithelial Cells ; cytology ; drug effects ; Gingiva ; cytology ; drug effects ; Humans ; Polystyrenes ; Serum Albumin ; pharmacology

OBJECTIVETo investigate separation and purification of skeletal muscle satellite cells with improved incontinuous density Percoll gradient centrifugation technique.

METHODSThe primary skeletal muscle satellite cells of New Zealand white rabbits were cultured with different adhesion time method and incontinuous density Percoll gradient centrifugation technique. The cells were observed under invert microscope and scanning electron microscope. The degree of purification was examined by celluar immunochemical stain. The growth curve was tested by thiazolyl blue assay.

RESULTSOver 90% satellite cells were harvested by incontinuous density Percoll gradient centrifugation technique, in contrast to which, only 30%-40% cells were harvested by different adhesion time. Morphological observation accorded with satellite cells. The growth curve indicated that the cells grew in a good status.

CONCLUSIONThe high purification satellite cells can be obtained by incontinuous density Percoll gradient centrifugation technique. It is a good method to culture seed cells for tissue engineering applications.

Animals ; Bioartificial Organs ; Cell Culture Techniques ; methods ; Cell Separation ; methods ; Centrifugation, Density Gradient ; Male ; Povidone ; Rabbits ; Satellite Cells, Skeletal Muscle ; cytology ; Silicon Dioxide ; Tissue Engineering ; Urinary Bladder

OBJECTIVETo study the role of BH3-only gene in oxaliplatin-induced apoptosis of human colon cancer cell line, and to explore the associated mechanisms.

METHODSTwo strains of human colon cancer cell line SW480 and HT29 were selected, and treated respectively with different concentrations of oxaliplatin (0.3, 0.6, 1.25, 2.5, 5, 10 and 20 mg/L). Cell growth and inhibition were detected by MTT method. Apoptosis was measured by flow cytometry. Bim and PUMA expressions were examined by fluorescence quantitative PCR.

RESULTSAfter treatment of different oxaliplatin concentrations in human colon carcinoma cells SW480 line, the cell growth was inhibited in a dose-dependent manner, while Bim and PUMA expressions were significantly up-regulated. While HT29 cell lines received the same treatment, no obvious inhibition of cell growth and up-regulation of Bim and PUMA expression were found. When SW480 cells were exposed to 5 mg/L and 10 mg/L of oxaliplatin for 24 h, the early apoptotic rates were (4.87±0.55)% and (12.10±1.04)%; for 48 h, the early apoptotic rates were (11.47±0.85)% and (30.07±2.01)%; for 72 h, the early apoptotic rates were (28.99±2.12)% and (38.32±3.15)% respectively, which were all significantly higher than those in control group [(0.30±0.10)%, (0.40±0.10)% and (0.50±0.20)%, all P<0.01]. In HT29 cells, the differences of apoptotic rates between oxaliplatin treatment group and control group were not statistically significant (all P>0.05).

CONCLUSIONSOxaliplatin can inhibit colon cancer cell line SW480 growth and induce apoptosis. Induction of apoptosis of colon cancer cells by oxaliplatin may be associated with the up-regulation of BH3-only proteins, Bim and PUMA.

Apoptosis ; drug effects ; Apoptosis Regulatory Proteins ; metabolism ; Bcl-2-Like Protein 11 ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Colonic Neoplasms ; pathology ; Humans ; Membrane Proteins ; metabolism ; Organoplatinum Compounds ; pharmacology ; Proto-Oncogene Proteins ; metabolism ; Proto-Oncogene Proteins c-bcl-2 ; genetics ; metabolism

OBJECTIVETo further study the binding character of hepatitis B surface antigen (HBsAg) and beta 2-glycoprotein I (beta2GP I) and to explore whether beta2GP I plays an important role in the hepatotropism of hepatitis B virus.

METHODSUsing Western blot technique, we observed the binding character of the HBsAg with reduced and non-reduced beta2GP I.

RESULTSrHBsAgs with reduced and non-reduced beta2GP I showed identical binding activity.

CONCLUSIONSThe binding activity of HBsAg is dependent on tandem residues, but not on conformational structures of beta2GP I. There is a specific binding between HBV and beta2GP I, which may play an important role in HBV infection and is one of the reasons of hepatotropism of HBV.

Hepatitis B ; virology ; Hepatitis B Surface Antigens ; metabolism ; Hepatitis B virus ; pathogenicity ; Humans ; Viral Envelope Proteins ; blood ; beta 2-Glycoprotein I ; blood

OBJECTIVETo construct a eukaryotic expression vector encoding the gene of extracellular region of type II transforming growth factor beta receptor (sTGFbetaR II), to express the protein in CHO cell line and to determine its biological activity.

METHODSThe extracellular region (amino acids 1-159) of the human TGFbetaR II cDNA was amplified by PCR from a TGFbetaR II chimeric plasmid,and the eukaryotic expression plasmid pCDNA3.1/myc-his(-)B-sTGFbetaR II(pCDNA-sTGFbetaR II) was constructed by inserting the sTGFbetaR II cDNA into the EcoR I/Hind III-digested pCDNA. The DNA sequence was confirmed by double digestion and the pCDNA-sTGFbetaR II plasmid was transfected into the CHO cell line. The sTGFbetaR II protein was confirmed by Western blotting analysis and its biological function was determined.

RESULTSThe specific protein was observed in western blotting, and the protein abrogated the growth-inhibitory effects of TGF-beta1 on mink lung epithelial cells (Mv1Lu).

CONCLUSIONThe eukaryotic expression plasmid pCDNA-sTGFbetaR II has been successfully constructed and the sTGFsTGFbetaR II protein with biological activity obtained.

Amino Acid Sequence ; Animals ; Base Sequence ; CHO Cells ; Cloning, Molecular ; Cricetinae ; DNA, Complementary ; Eukaryotic Cells ; metabolism ; Genetic Vectors ; Humans ; Molecular Sequence Data ; Plasmids ; genetics ; Protein-Serine-Threonine Kinases ; Receptors, Transforming Growth Factor beta ; biosynthesis ; genetics ; Recombination, Genetic ; genetics ; Transfection

Adenocarcinoma ; metabolism ; pathology ; surgery ; Adult ; Aged ; Aged, 80 and over ; Carcinoembryonic Antigen ; metabolism ; Carcinoma, Neuroendocrine ; metabolism ; pathology ; surgery ; Chromogranins ; metabolism ; Female ; Follow-Up Studies ; Gastrointestinal Neoplasms ; metabolism ; pathology ; surgery ; Humans ; Ki-67 Antigen ; metabolism ; Lymphatic Metastasis ; Male ; Middle Aged ; Prognosis ; Synapsins ; metabolism

Objective To access the prevalence of prehypertensive stage and its associated risk factors in rural inhabitants from Lanxi county in Heilongjiang province.Methods Through cluster multistage and random sampling methods,local people aged≥15 years old in Lanxi county were selected.A survey on blood pressure and associated risk factors wasearried out.Overnight fasting blood specimen of people aged≥35 years old Was collected.Chi square test,t-test and logistic regression analyses were then performed.Results 5272 residents were surveyed including 2539 male and 2733 female subjects.The overall prevalence of prehypertension Was 36.34％.The prevalence of prehypertension appeared to be higher in males(39.50％)than in females(33.41％)(X2=58.9887,P<0.0001),The prevalence of prehypertension decreased with increasing age in men≥25 years old(x=96.0698,P<0.0001),and in women≥35 years old(X2=11.5784,p=0.0208).Data from multivariable logistic regression showed that being male.Aged(≥55 years old),with waist circumference As≥85 cm for men and≥80 cm for women.BMI≥25.0 kg/m2 and fasting plasma glucose≥7.0 mmol/L were risk factors of prehypertension while high.Density Iipoprotein cholesterol<0.9 mmol/L was shown as a protective factor(OR=0.740,P=0.0036).Dose-response relationships were seen between prehypertension and age,BMI and FPG.Conclusion Prehypertension Was popular in the rural area,with high prevalence seen in teenagers.Programs on prehypertension prevention should start from teenagers.Risk factors of prehypertension increased when people became age 55 or older.There was a need to monitot BP more often and to eontror BP through non-drug methods.