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Objective To observe the protective effect and molecular mechanism of C-phycocyanin (CPC) on acute lung injury (ALI) in septic rats. Method 75 SD rats were randomly divided into control group, model group and CPC group. Cecal ligation and puncture was used to establish a septic acute lung injury rats (model group). For the CPC groups, septic acute lung injury rats were administrated by 20, 40 and 60 mg/kg CPC by intraperitoneal injection. 72 h after the operation, serum and lung tissue were obtained, the wet to dry weight ratio, the content of TNF-α、IL-6 and IL-10 in bronchoalveolar lavage fluid, the activity of myeloperoxidase (MPO) was analyzed. Expression of heme oxygenase (HO)-1,activation of nuclear factor erythroid 2-related factor 2 (Nrf 2) and nuclear factor-kappa B (NF-B) were detected by Western blot. Superoxide and Nitrite/Nitrate Level production in Lungs and bronchoalveolar lavage fluid were measured by chemiluminescence and reduction method, respectively. Results Treatment with CPC significantly inhibited septic-induced inflammatory responses including elevation of superoxide formation, myeloperoxidase activity, leucocytes and protein infiltration in lung tissues, and production of proinflammatory cytokine, and nitrite/nitrate in bronchoalveolar lavage fluid (P<0.05). In addition, CPC could activate Nrf 2 and induce HO-1 expression, and inhibit NF-B activation in ALI rats. However, blocking HO-1 activity by tin protoporphyrin IX (SnPP), an HO-1 inhibitor, markedly abolished these beneficial effects of CPC in septic-induced ALI. Conclusion The protection mechanism of CPC may be through HO-1 induction and suppressing of NF-kB-mediated inflammatory responses.
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BACKGROUND:Previous studies of our research group have confirmed that the texture of porcine reticular dermis at lateral ventral part is softer and has more extensibility than other parts. Therefore, it may serve as the raw material of xenogenic aceluar dermal matrix. However, its comparison with human and rat reticular dermis has not been reported systematicaly in aspects of histomorphology and material characterization. OBJECTIVE:To compare the reticular dermis from the lateral region of porcine abdomen and rat dorsal part with the reticular dermis from human in histology, biomechanics, molecular structure, thermal stability and other properties. METHODS:The reticular dermis samples were taken from adult human, the lateral region of porcine abdomen, the back of rats, for gross observation. Paraffin sections were observed by hematoxylin and eosin staining and sirius red staining under a light microscopy. The relevant data of micrograph were measured by imagine analysis software. These samples were also vacuum-freezing dried and rehydrated, and then their mechanical properties were tested with a electronic tensile machine to calculate the Young’s modulus. Some vacuum-freezing dried samples were powdered and detected by Fourier transform infrared spectrometer and simultaneous thermal analyzer. RESULTS AND CONCLUSION:There were no differences in colagen fiber bundle diameter of the reticular dermis from adult human and the lateral region of porcine abdomen, but the reticular dermis from the back of rats was thinner than that from adult human (P 0.05). There was no significant difference in the Young’s modulus of the three kinds of reticular dermises. Hydrogen bonds involved in the reticular dermal colagen molecules ranged as folows: rats > swine > human. Rat reticular dermis has better thermal stability than that of swine and adult human.
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OBJECTIVE To investigate the resistance of Acinetobacter baumannii(ABA),and the mechanism of imipenem resistance in A.baumannii.METHODS All specimens were identified by VITEK-60 and the drug resistance was detected by Kirby-Bauer test.Three dimensional test was used to detect ESBLs and AmpC.PCR and DNA sequencing were performed to determine VIM,IMP,OXA-23 and OXA-24 ?-lactamases.Outer membrane protein was analyzed by SDS-PAGE,Reserpine synergistic inhibition test was used to study the active efflux mechanism.RESULTS Totally 120 strains were isolated from sputum(76.9%),and 16 strains from secretion(10.3%).ICU was the main infected department(51 strains,32.7%).The resistance to sulperazone was the lowest(20.5%),and to imipenem accounted for 38.5%,Of the 20 imipenem resistant strains,10 strains were ESBLs positive(50%),and 20 strains were AmpC positive(100%).VIM,IMP and OXA-24 ?-lactamases were not detected out,19 strains(95%) produced OXA-23.Compared to the imipenem-sensitive strains,the resistant strains lacked the outer membrane protein of 22?103,29?103 and 33?103.The MICs of A.baumannii to imipenem were not decreased by reserpine which demonstrated that excretive mechanism was negative.CONCLUSIONS ICU is the main infected department for ABA.The resistance rate is increasing for longer-term usage of carbopenem;OXA-23 production is the important resistance mechanism in ABA,AmpC production and outer membrane protein lacking show close relation to the drug-resistance in A.baumannii.