Acinetobacter Infections ; microbiology ; Acinetobacter baumannii ; drug effects ; isolation & purification ; Anthracosis ; microbiology ; Anti-Bacterial Agents ; pharmacology ; Drug Resistance, Bacterial ; Fosfomycin ; pharmacology ; Humans ; Imipenem ; pharmacology ; Pneumonia, Bacterial ; microbiology

Objective To study the effect of different concentration of 1,25-dihydroxyvitamin D3[1,25(OH)2D3] on cell proliferation,differentiation and the expression of vitamin D receptor (VDR) in mouse MC3T3E1 osteoblast.Methods Osteoblast were cultured in medium with different concentrations of 1,25(OH)2D3.Incubated for 48 h,cell proliferation of osteoblast were examined by MTT reduction assay (mono-nuclear cell direc cytotoxicity assay),the osteocalcin (OC) levels in cell medium were detected by ELISA,and the expression of VDR mRNA and protein were examined by using SYBR Green real-time PCR and Western blot,respectively.Results 1.After incubation with 1,25(OH)2D3 for 48 h,the number of MC3T3E1 osteoblast was significantly less than that in control group(P0.05).3.SYBR Green real-time PCR and Western blot results showed that the expression of VDR mRNA as well as VDR protein of osteoblast in 10-8,10-9 mol/L experimental groups were significantly higher than those in control group (Pa0.05).Conclusions Cell proliferation of mouse osteoblast can be inhibited,while the cell differentiation was promoted by 1,25(OH)2D3.1,25(OH)2D3 up-regulated the expression of VDR in mouse osteoblast,which suggested that the VDR signal pathway may play some role in proliferation and differentiation of osteoblast.

OBJECTIVETo study the effect of maternal vitamin D deficiency on lung morphogenesis and platelet-derived growth factor-A (PDGF-A) expression in rat offspring.

METHODSSprague-Dawley (SD) female rats were randomly divided into two groups: normal control and vitamin D deficiency, with 6 rats in each group. The vitamin D deficiecy group was kept away from light and fed with the forage without vitamin D. After 2 weeks, the rats were mated with normal SD male rats. The morphological changes of fetal rat lungs on day 20 of gestation and 1-day-old neonatal rat lungs were observed by light microscope and electronic microscope. The levels of PDGF-A mRNA and protein in fetal and neonatal rat lungs were measured by reverse transcriptase-polymerase chain reaction (RT-PCR) technique and Western blot method respectively.

RESULTSUnder the light microscope, smaller alveolar space, smaller diameter of the respiratory membrane and thicker alveolus mesenchyma were observed in lungs of fetal and neonatal rats from the vitamin D deficiency group compared with the controls (P<0.05). Under the electronic microscope, fewer lamellar bodies but more glycogen deposition in intracytoplasm were observed in the lungs of fetal rats from the vitamin D deficiency group compared with the controls. There was an increased number of empty lamellar bodies in neonatal rats from the vitamin D deficiency group. The levels of PDGF-A mRNA and protein in lungs of fetal and neonatal rats from the vitamin D deficiency group were significantly lower than the controls (P<0.05).

CONCLUSIONSMaternal vitamin D deficiency during pregnancy may inhibit the development of lung morphogenesis and PDGF-A expression in late fetal and neonatal rats. The low expression of PDGF-A may be involved in the inhibitory effect of vitamin D deficiency on the lung development.

Animals ; Calcifediol ; blood ; Female ; Lung ; embryology ; pathology ; ultrastructure ; Platelet-Derived Growth Factor ; analysis ; genetics ; metabolism ; Pregnancy ; RNA, Messenger ; analysis ; Rats ; Rats, Sprague-Dawley ; Vitamin D Deficiency ; embryology ; metabolism

OBJECTIVETo investigate the relationship between the resuscitation promoting role of resuscitation promoting factor and the initial bacteria amount of dormant Mycobacterium tuberculosis.

METHODSMycobacterium tuberculosis (dormant bacteria) was cultured for 100 days, then diluted into 1 mg/ml concentration with 7H9, and further diluted into 0.5, 0.25, 0.125, 0.0625, and 0.03125 mg/ml. Twelve new tubes added with 5 ml 7H9 and divided into two groups: the first group was added with the resuscitation-promoting factor protein, and the second group as control was added with 7H9. In each group the above diluted solutions were added. The tubes were located at 37 degrees C for culture. Optical density (OD) was detected on day 15, 25, 30, and 35. From each tube 1 microl culture solution was plated on 7H11 medium for colony counting.

RESULTSOD detection showed that bacteria proliferation in each group had positive linear correlation (P < 0.05, P < 0.01), indicating that the resuscitation-promoting factor played a similiar role in solutions with different dilution concentrations. 7H11 results and the OD results show that these two detection methods in each group had linear correlation (P < 0.05, P < 0.01), indicating that these two methods showed consistent test results.

CONCLUSIONThe resuscitation-promoting factor has no effect on the resuscitation of dormant Mycobacterium tuberculosis and its initial bacteria amount.

Bacterial Proteins ; metabolism ; Cytokines ; metabolism ; Mycobacterium tuberculosis ; physiology ; Resuscitation

OBJECTIVETo establish a rapid, inexpensive, and simple drug susceptibility test (DST) for Mycobacterium tuberculosis (M. tb) and evaluate its feasibility.

METHODWe used nitrate reductase combined with mycobacteriophage assay (PhaB-NRA) to test 49 clinical M. tb isolates of, and the results were compared with those of PhaB-NRA and traditional absolute concentration method.

RESULTSThe sensitivity, specificity, and accuracy of PhaB-NRA for rifampicin were 89.1%, 91.67%, and 89.8%; on the contrary, those of isonicotinyl hydrazide were 86.21%, 90.0%, and 87.8%, respectively. The coincidence between PhaB-NRA and traditional assay were 0.746 for rifampicin and 0.750 for isonicotinyl hydrazide.

CONCLUSIONSPhaB-NRA is an inexpensive, rapid, and simple DST method. It is a promising rapid screening technique for DST of M. tb.

Anti-Bacterial Agents ; pharmacology ; Biological Assay ; methods ; Humans ; Microbial Sensitivity Tests ; methods ; Mycobacteriophages ; physiology ; Mycobacterium tuberculosis ; drug effects ; Nitrate Reductase ; metabolism ; Rifampin ; pharmacology ; Sensitivity and Specificity

OBJECTIVETo investigate the drug resistance of imipenem-resistant (IR) Gram-negative bacilli (GNB) in coal workers' pneumoconiosis (CWP)-chronic obstructive pulmonary disease (COPD) patients with lower respiratory tract infection (LRTI) and to provide a basis for clinical treatment.

METHODSSixty-six strains of IR-GNB were isolated from the sputum of CWP-COPD patients with LRTI, and the bacterial spectrum was investigated. The drug resistance of bacterial strains was studied by KB disk diffusion method.

RESULTSAmong the 66 strains of IR-GNB, 29 (43.9%) were Pseudomonas aeruginosa, 17 (25.8%) were Acinetobacter baumannii, and 11 (16.7%) were Stenotrophomonas maltophilia. The drug sensitivity test showed that all bacteria had high drug resistance; Pseudomonas aeruginosa had a susceptibility rate higher than 50% to ciprofloxacin, polymyxin B, fosfomycin, and amikacin, Acinetobacter baumannii had a susceptibility rate higher than 55% to fosfomycin, polymyxin B, and cefoperazone/sulbactam, Stenotrophomonas maltophilia had a susceptibility rate higher than 50% to cotrimoxazole, ciprofloxacin, piperacillin/tazobactam, levofloxacin, polymyxin B, and cefoperazone/sulbactam, and Pseudomonas cepacia had a susceptibility rate higher than 50% to piperacillin/tazobactam, ciprofloxacin, cefoperazone/sulbactam, and polymyxin B.

CONCLUSIONThe main species of IR-GNB are such non-fermentative bacteria as Pseudomonas aeruginosa, Acinetobacter baumannii, and Stenotrophomonas maltophilia in CWP-COPD patients with LRTI. These bacteria have high drug resistance and are sensitive to only a limited range of antibiotics.

Aged ; Aged, 80 and over ; Anthracosis ; complications ; microbiology ; Drug Resistance, Multiple, Bacterial ; Gram-Negative Bacteria ; drug effects ; Humans ; Imipenem ; pharmacology ; Microbial Sensitivity Tests ; Middle Aged ; Pulmonary Disease, Chronic Obstructive ; complications ; microbiology

Objective:To study the expression of MMP1 and TIMP1 in simple and radiation-combined wound healing and their effects on the healing process and tissue remodeling. Methods: A rat model of radiation-combined wound healing was used. Immunohistochemistry and in situ hybridization were performed which enabled the detection of MMP1 and TIMP1 expression in the healing process. Ultrastructural changes were observed with transmission EM. Results: The wound healing process was impaired and delayed. In rats receiving 25 Gy of gamma ray locally the irradiated wounds healed 6 days later than non-irradiated controls. The following changes in MMP1 and TIMP1 expression were found: (1) In the early inflammatory phase and in the period of granulation tissue formation, MMP1 expression in the newly-formed epidermis of irradiated wounds approximated that in the controls. Later, the epidermal expression of MMP1 in radiation wounds was comparatively increased with the delay of the healing process.On days 3 to 14 after wounding, TIMP1 was weakly positive in the proliferating keratinocytes of control wounds and became negative after epidermal covering, whereas no or only slight epidermal expression was detected in radiation wounds before epidermal covering.(2)MMP1 and TIMP　1 expression in radiation wounds was markedlydecreased in fibroblasts　, endotheliocytes and macrophages as compared with the controls. The expression phase was prolonged due to the delay of the healing process.Conclusions:The reduced expression of MMP1 and TIMP1 in granulation tissue retards such important processes as cell migration, angiogenesis and tissue remodeling, thus retarding the healing process. The expression of MMP1 in the newly-formed epidermis may help the process of reepithelialization,but in the late healing period, overexpression of MMP1 and decreased expression of TIMP1 in the epidermis may hinder the establishment of basal membrane and the formation of granulation tissue, and thus affect the matrix remodeling process.

OBJECTIVETo obtain the recombinant rv1837c and rv3803c of Mycobacterium tuberculosis using gene engineering technology and explore their prokaryotic expression, purification, and immunogenicity.

METHODSThe Mycobacterium tuberculosis rv1837c and rv3803c genes were amplified by polymerase chain reaction, and then cloned into the vector pTA2, followed by the subclone into the expression vector pET30a (+). The resulting plasmids, named pET30a (+): rv1837c and pET30a (+): rv3803c, encode recombinant protein containing a hexa-histidine tag on its N-terminus. pET30a (+): rv1837c and pET30a (+): rv3803c were introduced into E. coli BL21 (DE3) by transformation respectively, and the recombinant gene was induced with 0.4 mmol/L isopropyl-D-thiogalactopyranoside. The expressed products were identified by Western blot with hexa-histidine tag antibody and serum from tuberculotic patients. The histidine tagged protein was purified by nickel nitrilotriacetic acid His-Bind resin. Rabbits were immunized with purified recombinant Rv1837c and Rv3803c proteins. Then the purified recombinant Rv1837c and Rv3803c proteins were used to detect antibody in rabbit serum, which had been immunized by Western blot.

RESULTSAfter transformation of the E. coli and induction with 0.4 mmol/L of isopropyl-D-thiogalactopyranoside, recombinant target proteins Rv1837c (relative molecular mass: 92000) and Rv3803c (relative molecular mass: 38 000) were expressed in pET30a (+): rv1837c and pET30a (+): rv3803c system. The expressed protein existed in cytoplasm in an unsoluble form and amounted to 30% and 50% of the total proteins of E. coli. The purity of the purified protein reached 90%. The immunogenicity of the recombinant proteins Rv1837c and Rv3803c was strong, as identified by Western blot.

CONCLUSIONThe prokaryotic expression recombinant plasmids pET30a (+): rv1837c and pET30a (+): rv3803c was successfully constructed and the recombinant proteins Rv1837c and Rv3803c were obtained, which laid a basis for the optimized diagnosis of active tuberculosis.

Antibodies ; metabolism ; Bacterial Proteins ; genetics ; immunology ; metabolism ; Blotting, Western ; Escherichia coli ; metabolism ; Genetic Vectors ; Mycobacterium tuberculosis ; genetics ; immunology ; metabolism ; Plasmids ; metabolism ; Polymerase Chain Reaction ; Recombinant Proteins ; genetics ; metabolism

OBJECTIVETo secreted express envelope glycoprotein (E) of dengue virus type 2 extracellularly.

METHODSThe entire prM/E gene was amplified by RT-PCR. An optimized signal sequence gene from Japanese encephalits virus (JEV, SA14-14-2 strain) was introduced using fusion PCR. The impact of E protein transmembrane and cytoplasmatic domains was compared by amplifying prM and E with full length of E gene, with 20% truncation of the E gene at 3' terminus and one chimeric gene, which was generated by replacing the 3' terminal 20% region of E gene with the corresponding sequence of JEV (SA14-14-2 strain). The PCR segments were inserted into the NheI and NotI sites of pcDNA5/FRT vector or into the NheI and XhoI sites of pAcUW51-M. Then they were transfected into 293T cells or Sf9 cells respectively. The expression and secretion of E protein were detected by immunofluorescence assay (IFA) and Western Blot.

RESULTSAfter transected into 293T cells or Sf9 cells, all constructs expressed E protein intracellularly indentified by IFA while only two plasmids could secret detectable E protein into tissue culture using Western Blot analysis.

CONCLUSIONSignal peptide as well as the transmembrane and cytoplasmatic domains is crucial for the secretion of dengue E protein.

Animals ; Cell Line ; Dengue ; metabolism ; virology ; Dengue Virus ; genetics ; metabolism ; Gene Expression ; Humans ; Protein Structure, Tertiary ; Protein Transport ; Spodoptera ; Viral Envelope Proteins ; chemistry ; genetics ; metabolism

OBJECTIVETo investigate the method of constructing small-diameter vascular grafts from xenogenic decellularized arterial matrices and mesenchymal stem cells (MSCs).

METHODSPorcine iliac arteries were decellularized by detergent and trypsin treatment. Histology, mechanical strength and porosity experiments were performed to evaluate the properties of decellularized matrices. MSCs were isolated from bone marrow of dogs and expanded ex vivo. Decellularized matrices were seeded with MSCs and further cultured in a pulsatile bioreactor. Morphological features of the tissue engineered grafts were assayed by HE staining and scanning electron microscopy.

RESULTSAfter cell extraction, absence of cellular components and preservation of extracellular matrix were verified. Mechanical strength of decellularized matrices was slightly reduced compared with native arteries. Porosity of decellularized matrices was 94.9%. Decellularized matrices were successfully seeded with MSCs, which grew to a near-confluent monolayer under flow conditions and MSCs were highly elongated and oriented to the flow direction.

CONCLUSIONSmall-diameter vascular grafts can be constructed by seeding MSCs onto xenogenic decellularized arterial matrices and culturing in a pulsatile bioreactor.

Animals ; Arteries ; Blood Vessel Prosthesis ; Cells, Cultured ; Extracellular Matrix ; Mesenchymal Stromal Cells ; Tissue Engineering