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OBJECTIVE To study the antimicrobial activity of antimicrobial plastics and its depressing effect to biofilm on the plastics′s surface. METHODS Test tube dilution method was adopted to study the antimicrobial activity and spectrum of antimicrobial plastics. Plate live bacterial recording method and scanning electron microscope(SEM) were introduced to study the formation of biofilm. RESULTS Wide inhibiting spectrum to pathogenic microbe such as Pseudomonas aeruginosa,Staphylococcus aureus,and Escherichia coli was confirmed,and the biofilm was formed after four stages,ie deposit,adhesion,propagation and biofilm formation,and propagation of microbe was found to be inhibited greatly in the surface of antimicrobial plastics,so that the formation of biofilm in the surface of antimicrobial plastics was held back,and the observation of SEM also confirmed that no biofilm was formed in the antimicrobial plastics′s surface. CONCLUSIONS Antimicrobial plastics could inhibit pathogenic microbe remarkably with wide inhibiting spectrum,and it could also depress the formation of biofilm in the surface,which indicated that it is a promising approach to prevent catheter related infections by adopting antimicrobial catheters.
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Objective To investigate the prevention of distant multiple organ dysfunction caused by lower limb ischemia/reperfusion with taurine.Methods Wistar rats were randomly divided into 3 groups.(1)Reperfusion group:rats underwent 2-hour bilateral artery femoralis of hind limbs ischemia and followed by 5 hours reperfusion.(2)Taurine group:each rat was oraled 20% taurine 3ml every day for 7 days and underwent 2hrs ischemia followed by 5 hrs reperfusion.(3)Control group:sham animals didn't undergo ischemia.The count of leukocyte,myocardial and liver enzymes were measured.Ultrastructural pathological change of distant organs were observed.Superoxide dismutase(SOD) of erythrocyte,malondialdehyde(MDA) glutathione(GSH) and tumor necrosis factor(TNF) in tissue homogenization was assayed.Results The count of leukocyte was decreased significantly in reperfusion group,myocardial and liver enzymes were significantly increased compared with control group ultrastructural pathological change of extensive injury of distant multiple organs was occurred in perfusion group.SOD of erythrocyte and GSH in serum were decreased compared with control group,while MDA and tumor necrosis factor in tissue homogenization of liver and lung were significantly increased.The pathological changes of taurine group was obviously alleviate.Conclusion Limb ischemia/reperfusion can produce quantities of oxygen free radicals and TNF which were released by activated polymornuclear leukocytes.This made the body plunge into systemic inflammation response syndrome and induce distant multiple organ dysfunction.Taurine can prevent it obviously.
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Objective To study the toxicity and physical, chemi ca l and antimicrobial properties of the tracheal catheter made with nanometer anti microbial plastics. Methods For examining the toxicity of the n ew tracheal catheter, 30 Kunming mice were divided into 3 groups. The mice in gr oup A received 2ml of fluid sucked through the catheter by intra-abdominal inje ction, the mice in group B received 1ml of suction fluid, and the mice in group C received 2 ml of normal saline. Multiple proportional dilutions were used to d etect the antimicrobial property of the tracheal catheter against both positive and negative Gram bacteria. Results No noxious effects or toxic ity was found in tested mice, and all the physical and chemical data of the cath eter were up to the National Standard. The catheter showed a certain antimicrobi al effects on some of common pathogenic bacteria. Conclusion Th e tracheal catheter made with nanometer antimicrobial plastics had no noxious ef fects on mice, it showed a certain antimicrobial effects on to some of common pa thogenic bacteria, and its physical and chemical properties were up to the Natio nal Standard.
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Fifty three Wistar rats were randomly divided into healthy control group, COPD model group and NAC group, PKC inhibitor H7 intervention group and TGF ? monocolonal antibody group(TGF ? MA group).To study the role of matrix metalloproteinases(MMPs) and the tissue inhibitor of MMPs(TIMP 1) in the airway extracellular matrix(ECM) remodelling of COPD rat models and to observe the effects of NAC, H7 and TGF ? MA intervention on the regulation of MMPs and TIMP 1 and on ECM remodelling of the airway walls. Compared with control group, the airway collagen, the hydroxyproline(Hy) content of lung homogenates ,the number of fibroblasts(Fb) , the protein and/or mRNA expressions of MMP 2, MMP 9, TIMP 1 and TGF ? Ⅰ, Ⅱ receptor and the enzyme activities of MMP 2 (72kD), MMP 9 (92kD) were significantly increased in COPD model group. In all the drug intervention groups, the expressions of the above parameters were significantly decreased than those in model group except for Hy and Fb in H7 group, protein expression of TGF ? I receptor in NAC group and MMP 9 in TGF ? MA group. The results suggested that increased MMPs as matrix degrading enzymes might be responsible for the excessive degradation of ECM in airway, whereas incresed TIMPs might promote excessive ECM synthesis and deposition. The imbalance of MMP 9/TIMP 1 was related to the airway ECM remodelling. An antioxidant NAC and TGF ? MA might regulate the MMPs/TIMP 1 expression and reduce the airway fibrosis.H7 had strong collagenase inhibitory action,resulting increse in Hy and Fbs. The data may be helpful for searching effective prevention and treatment of airway ECM remodelling.
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AIM: To establish rat chronic obstructive pulmonary disease(COPD) models by passive cigarette smoking plus intratracheal instillation of lipopolysacchride(LPS) or passive cigarette smoking only, which would be similar to the pathogenesis of human COPD. METHODS: 48 Wistar rats were randomly divided into 4 groups.(1) Healthy control I group( n =12), rats were bred 4 weeks;healthy control II group( n =12), rats were bred for 3 months. (2) Model group I ( n =12), 200 ?g lipopolysaccharide(LPS) was instilled intratracheally once for every two weeks and the rats were exposured to 5% of cigarette smoke, 0.5 h/d for 4 weeks.(3) Model group II(n=12),rats were exposed to 5% of cigarette smoke, 0.5 h/d for 3 months. The pathologic changes of airways and lung tissues, pulmonary function and blood gas analysis were determined. The airway wall lymphocytes and alveolar macrophages were counted. The cross areas of epithelial layer, smooth muscle layer and lamina propria of bronchi were measured. The hydroxyproline of lung tissue homogenates was determined by biochemistry method. RESULTS: The pathologic changes of airways and lung tissue of two models were similar to but milder than those of COPD patients(biopsy data). The collagen deposition and the cross areas of epithelial layer and smooth muscle layer in airway walls of two model groups were significantly increased than those of control groups( P
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To explore the adhesion of peripheral blood lymphocytes and eosinophils and lung microvascular endothelial cells (LMEC) in asthma. Guinea pigs were divided into asthma model group and control group; the adhesion rates of isolated peripheral lymphocytes, eosinophils and the cultured LMEC monolayers were assayed.The mRNA expressions of VCAM 1 and eotaxin in LMEC were determined by RT PCR.The DNA binding activities of NF ?B and AP 1 of LMEC were detected by electrophoretic mobility shifts assay (EMSA). Under the stimulation with serum of asthma group:①the adhesion rates of lymphocytes, activated eosinophils and LMEC were significantly elevated( P
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The von willebrand factor (vWF) and angiotensin converting enzyme(ACE) were measured in asthmatic patients in stages of attack and remission, using ELISA and ultraviolet methods. The results showed that the vWF and ACE were (72.1 ? 58.3)%, and 22.9 ? 6.9U in the stage of attack, and (68.8 ? 42.1)% and 23.2? 7.9U in the stage of remission, respectively. All these values were significantly lower than that of healthy controls [(117.1 ? 50.30)% and 31.3 ? 9.3U, respectively, P