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Burn medicine of China started in 1958. Great progress has been achieved in discipline construction, scientific research, clinical treatment level, and talent team construction in 60 years. A large number of severely burned patients have been successfully treated, and plans for treatment of burn patients with Chinese characteristics have been established with world-leading treatment level. At the same time, in the continuous improvement of clinical treatment level, extensive experimental researches for the key scientific problems in clinical treatment of burn patients have been conducted, and a large number of innovative research results have been achieved by Chinese burn medicine workers. The theoretical research of burn medicine in China has stepped into advanced ranks of the world. Burn medicine will confront development opportunity and tough challenge in the future. We can take advantage of wound repair of burn discipline to deal with the situation of decreasing incidence of burn and undiminished importance of burn medicine. To establish and improve the chain of burn treatment is an important direction for burn discipline development in the future.
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Objective To investigate the genetic mutation of the norA gene and its promotor from the wild-type drug-resistance Staphylococeus aureus(S.aureus)strains. Methods A total of 10 antibiotic-resistant S.aureus strains were isolated and screened from the burn wound for the sequencing and analysis of the nora gene and its promoter. Results There isolated 87 S.aureus strains from the burn wound flora,which were completely sensitive to vacomycin,highly sensitive to Quinupristin and Nitrofurantoin,but highly resistant to the other antibiotics,even up to91.7% of MRSA.There found the same point mutation(G→A) located at 1 349 sites of the norA gene coding region in all the S.aureus strains,saying that the amino acid was changed from Gly(glycin)to Asp(agpartic acid) in 291 sites.The resetpine reverse test showed that the MICs value of three antibiotics was lowered at various degrees in all 10strains.Conclusion NorA gene mutation is one of the mechanisms for antibiotic-resistance of S.aureus.
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Objective To investigate the mechanism of mastoparan-1 (MP-1) antagonizing lipopolysaecharide (LPS) in vitro. Methods The affinity of MP-1 for lipid A was assayed by biosensor, and the neutralization of MP-1 on LPS (2 μg/L) was detected by kinetic turbidimetric limulus test. After exposing fluorescin isothiecyanate (FITC) labeled LPS (FITC-LPS) to MP-1 at different concentrations (5, 10, 20, 40 μmol/L), the binding of FITC-LPS to murine RAW264.7 cells was analyzed by laser scanning confocal microscopy. The influence of MP-1 on TLR4 expression in RAW264.7 cells stimulated by LPS (100 μg/L) was detected by immunoeytochemieal staining. The expressions of TLR4, TNF-α and IL-6 at the gene and protein level were detected by RT-PCR and ELISA after exposing LPS (100 μg/ L) stimulated RAW264.7 cells to MP-1 at different concentrations. The effect of MP-1 on the viability of RAW264.7 cells was detected by MTT assay. Results MP-1 had high affinity to lipid A and could neutralize LPS. MP-1 at 10 μmol/L significantly inhibited not only binding of FITC-LPS to RAW264.7 (P < 0.05), but also protein and gene expressions of TLR4, TNF-α and IL-6 in LPS stimulated RAW264.7 cells in a dose-dependent manner (P < 0.05). No toxic effect of MP-1 on the viability of RAW264.7 cells was found (P > 0.05). Conclusions MP-1 inhibits cell viability mediated by LPS, which may be related to its neutralization of LPS and inhibition of binding of LPS to RAW264.7 cell membrane receptors.
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OBJECTIVE: To determine the content of tobramycin in Tobramycin Dexamethasone Eye Drops by HPLC-ELSD.METHODS: The sample was separated on VP-ODS C18 column.The mobile phase was 1.0% trifluoroacetic acid-methanol(95∶5) at a flow rate of 1.0 mL?min-1.The drift tube temprature was 45 ℃;the pressure of nebulizing gas was 3.5 bar,and the detection wavelength was set at 254 nm.RESULTS: The liner range of tobramycin was 156.0~436.0 ?g?mL-1(r=0.999 7).The limit of detection was 0.523 ?g and the limit of quantification was 1.744 ?g.The average recovery was 99.57%(RSD=0.92%).CONCLUSION: The method is accurate,reliable,specific,and suitable for the quality control of Tobramycin Dexamethasone Eye Drops.
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Objective To evaluate the endotoxin-neutralizing activity of modeling peptides from the limulus antilipopolysaccharide factor (MPLALFs, Ms) in vitro. Methods The endotoxin-binding activity of Ms was examined by biosensor technique and shown in values of Kon and Kd. The endotoxin-neutralizing effect was analyzed by limulus amebocyte lysate test. Results The biosensor technique results showed that the Kon values of M_0, M_1, M_2, M_3, M_4, M_6, M_8 and M_ 10 binding to LPS 055∶B5 were (840?5.716), (549?6.532), (842?6.530), (627?2.450), (996?5.716), (814?8.982), (556?1.633) and (635?2.449) arc second, of which M_4 and M_1 had the highest and lowest endotoxin-binding activity, respectively. The M_4 reacted to LPS with a Kd of 72.377 ?mol/L. The results obtained by the limulus amebocyte lysate test were the same with those from the biosensor technique. Conclusion M_4 has a potential good endotoxin-neutralizing effect in vitro.
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Objective To study the effect of Bifidobacterium spent culture supernatant (SCS) on adhesion of Pseudomonas aeruginosa to intestinal epithelial cells. Methods The intestinal epithelial cells were cultured,then divided into three groups: control,Pseudomonas aeruginosa adhesion group,SCS and Pseudomonas aeruginosa adhesion group. The effects of SCS on cell viability,the number of adhering and invasive bacteria were evaluated with MTT assay and lysis-counting assay in 1,3,6 h. Results At 3 h after SCS treatment,the amount of Pseudomonas aeruginosa decreased significantly,and the number of adhering and invasive bacteria decreased by 71% and 87% respectively. Conclusion SCS could protect the intestinal epithelial cells by inhibiting the adhesion and invasion of Pseudomonas aeruginosa.
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<p><b>OBJECTIVE</b>To investigate the potential role of intestinal bifidobacteria in the pathogenesis of gut-origin bacteria/endotoxin translocation in scalded rats.</p><p><b>METHODS</b>Wistar rats inflicted with 30% III degree scalding on the back were employed as the model with the rats undergoing sham injury as the control. The intestinal bacteria/endotoxin translocation and the changes in cecal mucosal microflora were determined by routine methods. And the plasma IL-6 concentration was measured with ELISA.</p><p><b>RESULTS</b>The incident of bacterial translocation into internal organs increased markedly in scalded rats (P = 0.001). The plasma LPS levels on 1, 3 and 5 postburn days (PBDs) in scalded rat group were much higher than those in sham injury group. The number of bifidobacteria decreased sharply 20 - 250 fold, the fungi increased 5 - 60 fold and E. coli increased 0.5 - 30 fold in the caecal mucosal microflora in the scalding group. The ratio of bifidobacteria to E. coli in the scalding group (4 - 800:1) was much lower than that in the sham injury group (25000:1). Furthermore, the plasma IL-6 level increased evidently in the scalding group. It was indicated by further analysis that compared with the rats without bacterial translocation, the bifidobacteria decreased 120 fold, the fungal number increased 50 fold and the E. coli number increased 30 fold in the scalded rats. The bifidobacterial number in the caecal mucosal microflora was negatively correlated with the plasma concentrations of IL-6 and LPS (P < 0.01) in the scalding rat group, and the plasma concentration of IL-6 was significantly and positively correlated with that of LPS.</p><p><b>CONCLUSION</b>Severe scalding injury could lead to an the imbalance of intestinal microflora and the increased intestinal translocation of bacteria and LPS. The decrease of the ratio and number of bifidobacteria in the caecal mucosal microflora might be a contribute to the occurrence of postburn intestinal bacteria/endotoxin translocation.</p>
الموضوعات
Animals , Female , Male , Rats , Bacterial Infections , Blood , Microbiology , Bacterial Translocation , Physiology , Bifidobacterium , Physiology , Burns , Microbiology , Colony Count, Microbial , Escherichia coli , Physiology , Interleukin-6 , Blood , Intestines , Microbiology , Kidney , Microbiology , Lipopolysaccharides , Metabolism , Liver , Microbiology , Lymph Nodes , Microbiology , Rats, Wistar , Spleen , Microbiology , Time Factorsالملخص
<p><b>OBJECTIVE</b>To explore the modulating effects mediated by recombinant IkappaBalpha gene by adenovirus vector transfection on the NF-kappaB activity of hepatic tissue in scalded rats.</p><p><b>METHODS</b>After being primed by recombinant defect adenovirus (AdIkappaBalpha) vector, the rats were scalded. The hepatic tissue was harvested at different time points and the nuclear protein was extracted and reacted with [r(-23) P] ATP labelled NF-kB specific probe. NF-Kb/DNA combining activity was determined with electrophoretic mobility shifty assay (EMSA). The total RNA in hepatic tissue was extracted and the expressions of IL-1beta and TNFalpha mRNA were determined with RT-PCR.</p><p><b>RESULTS</b>When compared to those in normal control, the NF-kappaB/DNA combining activity increased significantly in scalded rats at half an hour after scalding, and it lasted for 24 PBDs with rather strong activity. But in AdIkappaBalpha priming group, the rat NF-kappaB/DNA binding activity was slightly higher than that of normal control group, but was obviously lower than that of scalding group.</p><p><b>CONCLUSION</b>The intracellular NF-kappaB in hepatic tissue was activated rapidly after that the rats were severely scalded, and the expression of IL-1beta and TNFalpha was enhanced significantly simultaneously. Priming of AdIkappaBalpha could evidently inhibit the activation of hepatic tissue NF-kB in rats injured by severe scalding, and down-regulated the expressions of IL-1beta and TNFalpha.</p>
الموضوعات
Animals , Rats , Adenoviridae , Genetics , Burns , Genetics , Metabolism , Therapeutics , Genetic Therapy , Methods , Genetic Vectors , Genetics , I-kappa B Proteins , Genetics , Metabolism , Interleukin-1 , Genetics , Liver , Metabolism , NF-KappaB Inhibitor alpha , NF-kappa B , Metabolism , RNA, Messenger , Genetics , Metabolism , Rats, Wistar , Reverse Transcriptase Polymerase Chain Reaction , Transfection , Methods , Tumor Necrosis Factor-alpha , Geneticsالملخص
<p><b>OBJECTIVE</b>To observe the role of four modeling peptides (10342, 10343, 10344, 10345) derived from bactericidal/permeability increasing protein (BPI) in neutralizing endotoxin (LPS) in vitro and in vivo.</p><p><b>METHODS</b>Quantitative limulus amoebocyte lysate assay was employed to evaluate the capacity of BPI peptides in neutralizing endotoxin in vitro. The protective capacity of the peptides was observed in mice challenged with endotoxin by intravenous administration via the tail vein. The influence of the peptides on serum TNFalpha and IL-6 levels in rats with endotoxemia were also observed.</p><p><b>RESULTS</b>All of the four peptides possessed endotoxin-neutralizing capacity which was strengthened along with the increase in their concentration. Among the peptides, 10342 is the strongest one. All of the peptides had strong power to protect mice from endotoxin with 90% protective rate. In the rats with endotoxemia, the four peptides could reduce the levels of serum TNFalpha and IL-6 significantly at different time-points.</p><p><b>CONCLUSION</b>Four BPI modeling peptides possessed not only endotoxin-neutralizing capacity in vitro, but also potential protective capacity in animals challenged with endotoxin.</p>
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Animals , Female , Male , Mice , Rats , Anti-Infective Agents , Allergy and Immunology , Pharmacology , Antimicrobial Cationic Peptides , Blood Proteins , Allergy and Immunology , Pharmacology , Endotoxemia , Metabolism , Interleukin-6 , Blood , Lipopolysaccharides , Allergy and Immunology , Membrane Proteins , Neutralization Tests , Rats, Wistar , Time Factors , Tumor Necrosis Factor-alpha , Metabolismالملخص
<p><b>OBJECTIVE</b>To explore the effects of different beta-lactam antibiotics on the inducing of LPS release from gram-negative bacteria and on the protection of infected animals.</p><p><b>METHODS</b>Wistar rats were employed as the model and were inflicted by 30% TBSA III degree scalding and sepsis caused by PA103. The rats were randomly divided into 3 groups, i.e. simple antibiotic treatment group (A), treatment after sensitization with galactosamine (GalN) group (G) and treatment after blocking with carrageenan (CGN) group (C). The rats were injected intra-peritoneally with imipenem (IMP, 5 mg) and ceftazidime (CTZ, 10 mg) for single time, respectively. Same amount of aseptic normal saline was injected in the control group, and GalN (50 mg) was added in G and CGN (1 mg) in C groups. The blood bacterial concentration and plasma LPS levels were determined at different time points after the treatment by antibiotics. The mortality was observed in G and C groups at 10 days after treatment.</p><p><b>RESULTS</b>The blood bacterial amount could be decreased by both IMP and CTZ evidently. Large amounts of LPS released from PA103 could be induced by IMP and CTZ during their bactericidal process. But the plasma LPS level in rats treated by CTZ was markedly higher than that by IMP (P < 0.05 approximately 0.01). The mortality in G group treated by CTZ was much higher than that by IMP (P < 0.05). Nevertheless, the mortality in C groups was the same no matter CTZ or IMP was applied (P < 0.05).</p><p><b>CONCLUSION</b>There was no difference of the bactericidal power between IMP and CTZ. But CTZ was more powerful in inducing LPS release from bacteria than IMP. It was implied by the difference between these two antibiotics that IMP might be better choice in clinical application for burn infection due to its lower potential of inducing LPS release from the bacteria.</p>
الموضوعات
Animals , Female , Male , Rats , Anti-Bacterial Agents , Pharmacology , Burns , Ceftazidime , Pharmacology , Cell Division , Colony Count, Microbial , Galactosamine , Pharmacology , Imipenem , Pharmacology , Lipopolysaccharides , Metabolism , Pseudomonas Infections , Mortality , Pseudomonas aeruginosa , Metabolism , Rats, Wistar , Sepsis , Blood , Survival Rate , Time Factorsالملخص
<p><b>OBJECTIVE</b>To explore the activation of polymorphonuclear cells (PMNs) and vascular endothelial cells co-cultured with and stimulated by lipopolysaccharide.</p><p><b>METHODS</b>PMNs in concentration of 2 x 10(6)/ml isolated from healthy volunteers by Percoll gradient were added to monolayer of ECV-304 cells grown to confluency, then different groups were prepared according to final concentration of lipopolysaccharide. The morphological change was observed under invert microscope. The changes in TNFalpha and IL-6 levels of the supernatant of the cultured cells were determined at 4, 8, 12 and 24 hours after culturation.</p><p><b>RESULTS</b>The TNFalpha production of cultured pure ECV-304 exhibited no remarkable change when stimulated by different concentrations of LPS. But the TNFalpha production of the ECV-304 increased significantly when co-cultured with PMNs at 4 hr and stimulated by LPS in concentration of 10 micro g/ml, and increased at 8 hours and lasted up to 24 hours of culturation in higher levels (P < 0.05). The IL-6 production of cultured pure ECV-304 increased obviously along with the increase of LPS concentration, and it showed no change when PMNs co-cultured with ECV-304. While the IL-6 level in the supernatant of co-cultured ECV-304 with PMNs increased sharply when stimulated by both low (100 ng/ml) and high (1 micro g/ml) concentrations of LPS and maintained at high levels up to 24 hours of culturation. The higher the concentration of LPS was, the quicker the IL-6 level increased.</p><p><b>CONCLUSION</b>Co-cultured PMNs and endothelial cells could be activated and activation state could be maitained by low concentrations of LPS.</p>
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Adult , Humans , Cell Line , Cells, Cultured , Coculture Techniques , Dose-Response Relationship, Drug , Endothelium, Vascular , Cell Biology , Metabolism , Interleukin-6 , Metabolism , Lipopolysaccharides , Pharmacology , Neutrophils , Cell Biology , Metabolism , Time Factors , Tumor Necrosis Factor-alpha , Metabolismالملخص
<p><b>OBJECTIVE</b>To investigate the postburn change in the intestinal biological barrier in severely burned rats.</p><p><b>METHODS</b>Wistar rats inflicted by 30% TBSA III degree scalding on the back were employed as the model. The samples were harvested at 24, 48, 72 and 96 postburn hours (PBHs), respectively with the employment of microorganism analysis, biochemical and radio-immune methods for the study. The membranous flora in cecum, the mucin and sIgA in intestinal content, the intestinal endotoxin and bacterial translocation rate and quantification analysis and the endotoxin content in cava vein were observed.</p><p><b>RESULTS</b>The total intestinal membranous flora amount decreased, especially and obviously did the anaerobic bacteria such as bifidobacteria. But aerobic ones increased. In addition, The fungus and enterobacteria exhibited rapid overgrowth. This lead to evident imbalance between anaerobic and aerobic bacteria and to the destruction of intestinal biological barrier and the decrease of colonization resistance. As a result, the intestinal bacterial translocation rate increased markedly. The endotoxin content in the cava and intestinal containing increased, while the mucin and sIgA contents decreased.</p><p><b>CONCLUSION</b>Intestinal biological barrier could be severely damaged after major burn, which might be one of the causes of postburn intestinal infection.</p>
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Animals , Female , Male , Rats , Bacterial Infections , Burns , Cell Membrane , Microbiology , Intestinal Diseases , Microbiology , Intestinal Mucosa , Microbiology , Rats, Wistarالملخص
<p><b>OBJECTIVE</b>In vitro model of hydrogen peroxide induced apoptosis of SW-480 cells was used to investigate the role of NF-kappaB in the pathogenesis of reactive oxygen species induced apoptosis of intestinal epithelial cells.</p><p><b>METHODS</b>Ultra-structural changes were observed. Apoptosis of SW-480 cell line was determined by Annexin-V and PI double-stained flow cytometry. Nuclear translocation of NF-kappaB was determined by anti-NF-kappaB polyclonal antibody and EB double-staining. NF-kappaB activity was studied by electrophoretic mobility shift assays. RT-PCR was performed to study expression of NF-kappaB mRNA.</p><p><b>RESULTS</b>Hydrogen peroxide led to apoptosis of SW-480 cells, condensed or semilunar chromatin even apoptotic bodies could be observed. Nuclear translocation of NF-kappaB, increase of NF-kappaB activity and expression of NF-kappaB mRNA were found simultaneously.</p><p><b>CONCLUSIONS</b>Early activation of NF-kappaB may be one of the mechanisms of apoptosis in intestinal epithelial cells by reactive oxygen species.</p>
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Humans , Apoptosis , Hydrogen Peroxide , Toxicity , Intestinal Mucosa , Metabolism , Microscopy, Confocal , NF-kappa B , Metabolism , Reactive Oxygen Species , Toxicity , Tumor Cells, Culturedالملخص
Objective To investigate the effects and mechanism of silicone gel sheeting on hypertrophic scar. Methods Using human hypertrophic scar as a research object, the changes of fibroblast, collagen metabolism and cytokine expression were observed to study the effects of silicone gel sheeting on hypertrophic scar by clinical observation, histomorphology and immunohistochemistry. Results Compared with the control group, the hypertrophic scar became thin, soft and light markedly, and the expression of TGF ? 1, TGF ? (RI) and ? SM actin were significantly decreased in therapeutic group. Conclusion Silicone gel sheeting may have an influence on scar via inhibiting the expression of TGF ? 1, TGF ?(RI) and ? SM actin in fibroblasts.
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Objective To study the effects of measures for preventing early postburn damage in improving survival rate of burn patients during the third stage. Methods 12 568 burn cases admitted to our institute were chronically divided into three groups (1958-1980;1981-1990;1991-2000). Total burn surface area (TBSA), survival rate, incidence of burn shock, systemic infection and organ damage as well as the main treatments adopted in the recent decade were retrospectively analyzed. Results Incidence of burn shock, systemic infection and organ damage were significantly lower, and the total survival rate and the survival rate in patients with different TBSA were markedly higher in the third group as compared with those in the first and the second group. Incidence of organ damage in patients treated with delayed fast fluid infusion, early escharectomy en masse, early enteral feeding, early prevention of inhalation injury and gut bacterial translocation were also significantly lower than in the control. Conclusion Measures taken in the third group for preventing early postburn damage play an important role in improving the survival rate of burn patients.
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OBJECTIVE:To apply the biosensor technology to screening of the best method to extract and separate anti-endotoxin effective materials in Radix Paeoniae rubra.METHODS:The affinities of samples extracted by three different methods binding to lipopolysaccride(LPS)were determined with biosensor technology.Extracted materials were incubated with0.25EU/ml endotoxin for determination of change of binding activity.RESULTS:Material extracted by water showed high binding capa?bility with LPS,after incubation with endotoxin,still had highly effective anti-endotoxin component;1∶40diluted water extract could neutralize78.1%endotoxin.Determination results by biosensor technology and traditional limulus reagent showed no dif?ference.CONCLUSION:Water extraction could obtain more anti-endotoxin effective materials.Compared with traditional methods,biosensor technology is a fast,highly effective,direct and accurate method.
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Objective To study the effects of early enteral feeding on the preservation of intestinal mucosal barrier in severely burned patients. Methods Twenty-two patients with severe burn were randomly divided into early enteral feeding group (EF) and delayed enteral feeding group (DF). The levels of serum endotoxin and TNF-? were dynamically detected in the patients of both groups, and two unmetabolized sugars (lactose and mannitol) were orally administered in these patients on 1d, 3d and 5d of postburn. The concentrations of lactose and mannitol in urinary and the L/M ratio were observed. Intestinal permeability was assessed by the L/M ratio. Results The levels of serum endotoxin and TNF-? in severely burned patients were significantly higher than in normal (P
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OBJECTIVE:To isolate anti-endotoxin monomer component from Radix Paeoniae Rubra by means of biosen?sor technique.METHODS:The surface of biosensor cuvette was embedded by Lipid A;the screening target was established,tracking the silica gel column chromatogram and the binding ability of effluent component from HPLC with Lipid A with the ultraviolet scan result of the reclaimed material from biosensor as reference;anti-endotoxin monomer component was isolated;the component of monomer and the synthetic action of extrinsic lipopolysaccharides were also assayed by LAL test method.RESULTS:Components binding to Lipid A was reclaimed from cuvetee by biosensor technique,with the wavelength of UV absorption peak at194nm,215nm and275nm respectively.Anti-endotoxin monomers of higher binding activity with Lipid A isolated by HPLC method were1,2,3,4,6—O—pentagalloyl—?—D—glucose(PGG).PGG at concentration of8,4,2?g/ml respectively neutralized68.8%,43.7%and31.4%of LPS at an activity of0.1EU/ml respectively.CONCLUSION:It is fea?sible to isolate anti-endotoxin monomer component from Radix Paeoniae Rubra by means of biosensor technique,which is a fast,accurate and efficient and can be used to isolate anti-endotoxin monomer component from Radix Paeoniae Rubra on a large scale.
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Objective To investigate the protective effect of chloroquine on endotoxemia mice and its inhibition on the release of cytokines induced by LPS. Methods A total of 40 mice of Kunming species were randomly divided into four groups: LPS group received LPS at 10 mg/kg, chloroquine group received chloroquine at 20 mg/kg, LPS plus chloroquine group received chloroquine at 20 mg/kg first, then LPS at 10 mg/kg and control group received only 0.9%sodium chloride at 200 ?l/20 g. The mortality was observed within seven days after injection via caudal vein. ANA 1 cell lines were cultivated in vitro . After chloroquine was first added into the cells for 3 hours, the releases of TNF ? and IL 6 in the supernatants induced by different concentrations of LPS were measured. Results Chloroquine could decrease the death of mice due to endotoxin. Mortality dropped from 100% to 50% ( P
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Objective To explore the mechanism of intestinal epithelial cell membrane injury due to Pseudomonas aeruginosa adhesion. Methods The intestinal epithelial cells were cultured and adhered with Pseudomonas aeruginosa . The changes in the viability of the cells and the activity of membranous PLA 2, the calcium content of cell, contents of phospholipid and membrane fluidity were observed. Results At 3rd h after the adhesion of Pseudomonas aeruginosa , the viability of the intestinal epithelial cells decreased significantly, but the activity of membranous PLA 2, the calcium content of cell increased significantly; the contents of phospholipid(PL), phosphatidylinositol(PI) and phosphatidylcholine(PC) in cell membrane decreased gradually, but the membrane fluorescence polarization and microviscosity of intestinal epithelial cell membrane increased significantly. Conclusion The activation of PLA 2 and the degradation of phospholipid due to the overloading of calcium in intestinal epithelial cells after the adhesion of Pseudomonas aeruginosa to intestinal epithelial cells might be the fundamental factors to result in the reduction of membrane fluidity.