Isolation of the drug-resistant Staphylococcus aureus strains from burn wound flora and analysis of norA genetic mutation / 中华创伤杂志

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.

Expressions of CD44, CD44V3, CD44V6 and PCNA in human osteosarcoma and the clinical significance / 第三军医大学学报

Objective To explore the expressions of CD44, CD44V3, CD44V6 and PCNA and the relationship between the expressions and clinical pathologic changes of human osteosarcoma Methods The expressions of CD44, CD44V3, CD44V6 and PCNA in 15 osteochondromas and 40 osteosarcomas were detected immunohistochemically Results (1) The positive expression rates of CD44, CD44V3 and CD44V6 in osteosarcoma were markedly higher than those in osteochondroma (2) The positive expression rate of CD44V6 was higher than those of CD44 and CD44V3 in osteochondroma (3) The expression of CD44V6 was not involved in the pathological type or the prognosis in osteochondroma (4) The expressions of CD44 and CD44V6, particularly that of CD44V6, were closely involved in the PCNA positive rate Conclusion CD44V6 might act as a marker of malignancy of the bone tumors, but the relationship with the prognosis in malignant bone tumors waits to be further studied

The role of LPS in the CD14 expression and the activation of Kupffer cells / 中华烧伤杂志

<p><b>OBJECTIVE</b>To explore the effect of LPS on the expression of CD14 and the activation of Kupffer cells (KCs).</p><p><b>METHODS</b>Rat KCs were isolated and cultured with LPS. Immunohistochemistry and RT-PCR methods were employed to determine the changes in the CD14 expression and the concentration of TNFalpha, IL-6 and NO in the supernatant of the cultured KCs with LPS.</p><p><b>RESULTS</b>(1) The expression of CD14mRNA and the synthesis of CD14 protein in the KCs increased evidently when stimulated by various concentrations of LPS, and the CD14mRNA expression was correlated in dose-dependent manner with LPS levels. (2) The expression of CD14mRNA and the synthesis of CD14 protein in KCs induced by LPS (10 micro g/ml) increased significantly and peaked at 3 approximately 6 hours. (3) The expression of CD14mRNA and the synthesis of CD14 protein in freshly cultured KCs were obviously up-regulated by the active mediators produced by KCs after being stimulated by LPS. (4) The release of TNFalpha, IL-6 and NO from cultured KCs was evidently down-regulated by the addition of anti-CD14McAb in the presence of serum or by the addition of LPS in the absence of serum, but up-regulated by the concomitant addition of LPS and LBP.</p><p><b>CONCLUSION</b>(1) The CD14mRNA expression and the protein synthesis in cultured KCs were closely related to LPS and the active mediators produced from the KCs.The increased CD14 expression was possibly caused by LPS, and the further increase of the expression might be closely correlated to the cytokines released from the KCs. (2) The KC activation by low concentration of LPS was CD14 dependent.</p>

Experimental study on early liver injury and expressions of TNF-alpha mRNA in burn rats with endotoxemia / 中华创伤杂志(英文版)

OBJECTIVE: To observe tissue distribution and cell localization of TNF-alpha mRNA and its protein and study their role in the pathogenesis of liver injury in burn rats. METHODS: An animal model of rats subjected to 20% TBSA III degree burns combined with intraperitoneal injection of lipopolysaccharide (LPS) was used for this experiment. The changes of hepatic morphology and functions and serum TNF-alpha content and expression and localization of liver TNF-alpha and TNF-alpha mRNA were determined with light microscope (LM) and electron microscope (EM), quantitative analysis, immunohistochemistry (IHC) and in situ hybridization (ISH). RESULTS: It showed that there were sinusoid reaction, KCs activation and degeneration, necrosis of HCs, and platelets aggregation, fibrins deposition and PMNs attachment in sinusoid. The activity of ALT was obviously elevated and ALB content was slightly decreased. The serum content of TNF-alpha showed peak at 3 hours. TNF-alpha was mainly localized in sinusoid endothelial cells (SECs) and Kupffer cells (KCs), and TNF-alpha mRNA was mainly distributed in KCs, polymorphonuclears neutrophils (PMNs) and macrophages (MPs). CONCLUSIONS: It suggests that TNF-alpha mRNA and its protein expression and localization are coincident with the pathological changes of liver injury. TNF-alpha is one of the key cytokines in the pathogenesis of liver injury in burn rats with endotoxemia.

The expression of CD14 in rat Kupffer cells / 中国病理生理杂志

AIM: To explore the expression of CD14 in rat Kupffer cells (KCs). METHODS: In rat KCs induced by LPS or the mediators from KCs induced by LPS,the changes of CD14 expression were measured by RT-PCR and immunohistochemistry.The expressions of TNF? mRNA?IL-6 mRNA or the concentrations of TNF??IL-6 were estimated by in situ hybridization and radioimmunoassay,respectively. RESULTS: LPS increased the expression of CD14 in KCs in a dose-dependent fashion (LPS,1 ?g/L-10 mg/L) and in a time-dependent fashion(0.5 h-24 h,peaked at 3-6 hours). While the expression of CD14 in KCs stimulated by the active mediators from KCs which had been exposed to LPS 1 hour were obviously increased. CONCLUSIONS: There was a close relationship between LPS or the active mediators from KCs induced by LPS and the expressions of CD14. It is implied that the increase in CD14 expression may be induced by LPS and the cytokines produced by KCs,it also reveals that there is a auto-regulated loop in CD14 expression.