With rapid ageing population,the extensive application of mechanical ventilation and development of organ transplantation,infection caused by gram-negative (G-) bacilli,which have become the common pathogens causing nosocomial (especially ICU) infection,has increased and accounted for more than 65% of the hospital acquired infections.Severe infections in intensive care units are usually caused by Pseudomonas aeruginosa,Acinetobacter sp.,Enterobacteriaceae bacteria and Stenotrophomonas maltophilia,presenting challenges to the treatment.In addition,drug-resistant G-bacilli strains have increased year by year,accompanying with appearance of muti-drug resistant and pan-resistant strains of Pseudomonas aeruginosa and Acinetobacter baumannii.Several pathways may lead to drug resistance of G-bacilli,including permeability changes in ectal membrane,reformation of penicillin-binding protein,enhancement in level of pump MexAB-OprM,overproduction of antibiotic modification enzymes such as cephalosporinase,new type of beta-lactamases especially extended-spectrum beta-lactamases (ESBLs),AmpC beta-lactamase and Klebsiella pneumoniae carbapenemase (KPC).Clinical work is facing the challenges caused by drug resistance of G-bacilli,so the isolation and cultivation of pathogenic bacteria,drug sensitivity test in vitro,monitoring of drug resistance and researches on resistant mechanism should be enhanced,and proper antibiotics should be selected for treatment of G-bacilli infection.Polymyxin is recommended,if necessary,for treatment of multi-and pan-resistance G-bacilli infection,meanwhile the adverse effects of polymyxin treatment should be closely monitored.

Objective To investigate the inhibitory effects of recombinant T-bet adenovirus (AdT-bet) on airway inflammation in mice with asthma, and to explore the relevant mechanisms. Methods C57BL/6 mice were randomly allocated into 4 groups with 12 mice each. The asthmatic model was reproduced in group A, B and C by administration of ovalbumin (OVA) in aluminum hydroxide. Mice in group A, B and C received 50?l AdT-bet (108pfu) and AdLacZ and PBS, respectively, 19 days prior to OVA challenge. Bronchoalveolar lavage fluid (BALF) was collected on the 26th day after the induction of asthma for the determination of the cellular composition and concentrations of IL-4, IL-5 and IFN ?. Meanwhile, IgE content in serum was determined. The pathological changes and the expression of GATA-3 in the lungs of these mice were investigated. Results The percentage of eosinophils (EOS) and concentrations of IL-4 and IL-5 in BALF of group A were 0.6%?0.2%, 6.8?3.7pg/ml, 12.5?4.8pg/ml, respectively, which were significantly lower than those in group B (20.9%?6.8%, 92.4?23.0pg/ml, 56.5?11.8pg/ml) and group C (20.8%?6.7%, 90.4?22.8pg/ml, 57.3?12.2pg/ml, P

Objective: To investigate the characteristics of lower respiratory tract infection caused by Chryseobacterium and its antimicrobial susceptibility in vitro . Methods: The clinical data of 52 cases of lower respiratory tract infection caused by Chryseobacterium were analyzed, and the antimicrobial susceptibility of commonly used agents was determined with the method of agar dilution. Also the 50% lethal dosage (LD 50 ) (as the marker of virulence) of 20 randomly selected Chryseobacterium strains for mice were determined. Results: (1) Thirty six was over 60 years old;all of 52 cases had underlying diseases, mainly were chronic obstruction pulmonary disease and malignant tumors. Seventeen cases had the history of incubation or tracheotomy for mechanical ventilation, and 35 had history of broad antibiotics treatment. The mean hospitalization time before infection were 35.6 d, and 38.5% of the cases had mixed infection with other bacteria. No specific clinical manifestations and chest X ray appearance revealed. (2) The in vitro activity of 25 agents showed that these strains were highly resistant. (3) The range of the LD 50 of tested strains was 4.11?10 6 5.68?10 8/mouse, suggesting low virulence of this kind of bacteria. Conclusion: The lower respiratory tract infection caused by Chryseobacterium has no unique features; the incidence of the infection increases in immunosuppressed old patients with various underlying diseases, although the virulence is relatively low. Because the clinical isolates are highly resistant, the antibiotics should be selected according to the results of bacterial sensitivity test.

Objective:To investigate the preventive and therapeutic effects of intraperitoneal injectoin of IFN? on bronchial asthma in mice and the relevant mechanism. Methods: Thirty-six BALB/c mice were randomly equalized into 3 groups:group A (normal control group),group B (asthmatic model group) and group C (IFN? treated group). The asthmatic model was established in group B and C by immunization with ovalbumin (OVA) absorbed to aluminum hydroxide. Mice of group B and C received 0.25 ml PBS and 5 ?g IFN? intraperitoneally on days 23 to 30 once daily prior to ovalbumin challenge,respectively. Bronchoalveolar lavage fluid (BALF) was collected on day 31 for determining the cellular composition and the concentrations of IL-4 and IL-5. Meanwhile,IgE in serum was determined. The pathological changes and the expression of GATA-3 were investigated in the lungs of mice. Results: (1) BALF eosinophils was significantly decreased in group C compared with those in group B ( vs ,P

Objective To investigate the role of IFN-? in prevention and treatment of bronchial asthma and the mechanism of its effect. Methods BALB/C mice were randomly divided into three groups: group A (control group, n=12); group B (asthma model group, n=12); group C (IFN-? intraperitoneal treatment group, n=12). The asthma model was reproduced in group B and C with ovalbumin (OVA) adsorbed to aluminum hydroxide. PBS (0.25ml) and IFN-? 5?g was respectively injected intraperitoneally in group B and C on days 23 to 30 once daily prior to ovalbumin challenge. Bronchoalveolar lavage fluid (BALF) was collected on day 31 and its cellular composition was analyzed. The levels of IL-4, IL-5 and the IgE in serum were determined. The pathological changes in the lung and the expression of GATA-3 were observed. Results A notable decrease of eosinophils (0.3?0.2) in BALF was found in group C comparing with the group B (21.1?6.7) (P

Human FceR I a subunit extracellular domain was cloned and expressed with 2 different expressing systems and Dot blot was used to detect its biological activity to bind with IgE,providing reference for binding mechanism of human FceR I a subunit extracellular domain with IgE. It was shown that FceR I a subunit extracellular domain from pBAD/g I A expressing system could bind with IgE, but the one from PQE30 expressing system could not bind with IgE. It is suggested that FceR I a subunit extracellular domain alone is sufficient to bind with IgE without P and Y subunit. The proper space configuration and disulfide bond of FceR I a subunit is necessary for binding with IgE, but its glycosylation is unnecessary.

Objective To determine the surface expression of Fas Ag on RBL 2H3 and its function. Methods RT PCR and Western blot were used to detect the transfection and expression of Fas in RBL 2H3. Surface expression of Fas Ag was studied by immunochemistry. Apoptosis changes following treatment with anti Fas antibody were analyzed using flow cytometic analysis with annexinⅤ. Results It was successful in amplifying gene of rat Fas Ag, and a band of 32kD was detected by Western blot. The Fas Ag expression on the surface of RBL 2H3 by immunochemistry. RBL 2H3 exhibited apoptosis in response to anti Fas treatment. Conclusion Induction of rat mast cell apoptosis by activation of the Fas pathway provide the mechanism by which the number of mast cells may be regulated in the potential therapeutic strategy for anaphylactic diseases

Objective:To observe the expression of GATA-3in asthmatic mice lungs and to explore the feasibility of in-terleukin(IL-12)blockading GATA-3expression in treatment of bronchial asthma.Methods:C57BL/6mice were randomly divided into3groups:control group(group A),asthmatic model group(group B)and IL-12injection group(group C).Asth-matic models were established in group B and C.Normal saline(0.1ml)and IL-12(1?g)were injected in group B and C re-spectively on the1,3,7,9,25,26,27and28d.Six mice from each group were obtained for analyses of bronchoalveolar lavage fluid(BALF)on d31.The airway pathology changes and the expression of GATA-3were observed by hematoxylin/eosin(H-E)and immunohistochemistry respectively.Results:There was no symptom in group A,and the symptoms of group B were more severe than those of group C.Eosinophil(EOS)was not seen in the BALF of group A,while EOS in group B and group C were(20.0?4.0)%and(0.2?0.1)%respectively.In the same microscopic visual field,there was no inflam-mation cell in group A and a large number of inflammation cells in group B,but inflammation cells in group C were signifi-cantly decreased.Immunohistochemistry showed that the expression of GATA-3in group B was strong and no GATA expres-sion was found in group A and group C.Conclusion:The expression of GATA-3in asthmatic mice is high;IL-12can inhibit asthmatic airway and lungs inflammtion,whose mechanism may be the blockade of GATA-3expression in asthmatic models.[

The application of Standardized patient(SP) in Chinese clinical teaching is still in its infancy.The experience of SP in respiratory medicine teaching is also very limited.This article discusses the experience in applying SP in respiratory medicine teaching and several issues of SP training that should he paid attention to,and hrings forward our expectation in SP training in China.