[Effect of mastoparan-1 on lipopolysaccharide-induced acute hepatic injury in mice].

OBJECTIVE: To observe the effect of mastoparan-1 (MP-1) on lipopolysaccharide (LPS)-induced acute hepatic injury in mice and probe into its possible mechanism. METHODS: One hundred and four BALB/c mice were randomly divided into healthy control group (n = 8, without treatment, HC), LPS group (n = 48, with injection of LPS 5 mg/kg via tail vein), and MP-1 group (n = 48, with injection of LPS 5 mg/kg and MP-1 3 mg/kg via tail vein). Mice in LPS group and MP-1 group were sacrificed at 2nd, 6th, 12th, 24th, 48th and 72nd post injection hour (PIH), 8 mice at each time point in each group. Blood samples were collected for determination of plasma levels of LPS by kinetic turbidimetric limulus test, TNF-alpha and IL-6 by ELISA, serum levels of ALT and AST by automatic biochemistry analyzer respectively. Hepatic tissue samples were collected for determination of TLR4, TNF-alpha and IL-6 mRNA by real-time fluorescent quantitation reverse transcription polymerase chain reaction, along with the observation of pathological changes in hepatic tissue at each time point. Above-mentioned examinations were also performed in HC group. RESULTS: Compared with those of HC group, plasma levels of LPS and TNF-alpha in LPS group significantly increased at 2nd PIH (18,320.50 +/- 2782.50 EU/mL and 988 +/- 130 ng/L, respectively), then decreased gradually to 1.80 +/- 0.80 EU/mL and 150 +/- 44 ng/L at 72nd PIH, which was close to those of HC group. The values of IL-6, ALT and AST peaked at 12th PIH, which declined to the levels close to those of HC group at 72nd PIH. Meanwhile, the expressions of TLR4, TNF-alpha and IL-6 mRNA in liver were remarkably up-regulated after injection, and the pathological changes in hepatic tissue pronounced significantly at 12th, 24th and 48th PIH. Compared with those of LPS group, the levels of LPS, cytokines, ALT and AST decreased in MP-1 group in different degrees after injection (P < 0.05 or P < 0.01), genes expression (P < 0.05 or P < 0.01) and pathological changes was respectively suppressed and alleviated in hepatic tissue. CONCLUSIONS: MP-1 can alleviate LPS-induced acute hepatic injury in mice, which may be associated with its neutralization of LPS and attenuation of synthesis and release of inflammatory mediators.

[The protective effect of high density lipoprotein on the lung function of rats with severe burns].

OBJECTIVE: To explore the protective effect of high density lipoprotein on the lung function of rats with severe burns. METHODS: One hundred and thirty-five Wistar rats were employed in the study and were randomly divided into control (n = 15, without injury), burn (n = 60, with 30% TBSA full-thickness burn on the back) and experimental [(n = 60, with the injection of HDL (80 mg/kg) via the caudal vein immediately after burns)] groups. The rats in the latter two groups were resuscitated with intraperitoneal isotonic saline (50 ml/kg) 30 minutes after burns. The serum content of ICAM-1 and TNF-alpha as well as the blood content of PCO2 and PO2 of the rats in burn and experimental groups were determined at 12, 24, 48 and 72 post-burn hours (PBH) and in control group. The pathological changes in the lung tissue of the rats in all groups were observed under light microscope and electronic microscope at 48 PBH. RESULTS: PCO2 and the contents of ICAM-1 and TNF-alpha in burn group were significantly higher, but the PO2 was lower than those in control group at each time-point (P < 0.05 or P < 0.01). There were no obvious differences in the above indices between the experimental and control groups (P > 0.05), but the ICAM-1 and TNF-alpha levels in experimental group were markedly decreased than those in burn group at each time-point (P < 0.05 or P < 0.01). The ICAM-1 and TNF-alpha contents in burn group at 48 PBH were (3.42 +/- 0.25) microg/L and (4. 04 +/- 0.28) ng/L, respectively, which were markedly higher than those in experimental group [(2.24 +/- 0.14) microg/L, (3.35 +/- 0.22) ng/L, P < 0.05 or P < 0.01]. Dilation of capillaries, congestion and inflammatory infiltration in the pulmonary capillaries, and loosening of conjunction between pulmonary capillary vascular endothelial cells and endothelial swelling were observed in burn group at 48 PBH. Compared with the burn group, the injury was markedly alleviated in the experiment group, and the pulmonary capillary endothelial cells showed tighter junction. CONCLUSION: HDL exhibits a protective effect on the lung function of rats with severe burns via reducing the expression of ICAM-1 and TNF-alpha.

[The protective effect of high density lipoprotein on the cardiac function of rats with severe burns].

OBJECTIVE: To investigate the protective effect of high density lipoprotein on the cardiac function of rats with severe burns. METHODS: One hundred and thirty-five Wistar rats were employed in the study and were randomly divided into control (n = 15, without treatment), burn (n = 60, with 30% TBSA full-thickness burn on the back) and experimental (n = 60, with the injection of HDL (80 mg/kg) via the caudal vein immediately after burns) groups. The rats in the groups with burn injury were resuscitated with intraperitoneal isotonic saline (50 ml/kg) 30 minutes after burn (PBM). The serum contents of CK, ICAM-1 and TNF-alpha of the rats of all the three groups were determined with corresponding methods. The histological changes in the cardiac muscle tissue of the rats in all groups were observed under light microscope and electronic microscope. RESULTS: The serum contents of CK, ICAM-1 and TNF-alpha in the control group were obviously lower than those in burn group (P < 0.01), while those in experimental group were also markedly lower than those in control group (P < 0.05 or 0.01). The average reduction rate was 36.5%, 32.0% and 12.6%, respectively. The size and the structure of the cardiac muscular fiber in the control group were even and normal. Compared with the burn group, degeneration, inflammatory infiltration and mitochondrial swelling were found to be less marked in the experimental group at 48 PBH, and no focal lysis and necrosis were found, which were observed in the burn group. CONCLUSION: High density lipoprotein can be beneficial to the protection of cardiac tissue in protecting from secondary injury in rats with severe burns.

[The application of tourniquet in burn patients during tangential excision on the extremities].

OBJECTIVE: To investigate the application of tourniquet in burn patients during tangential excision on the extremities. METHODS: Seventy - nine burn patients who were arranged to receive tangential excision and skin grafting on the extremities were randomly divided into A and B groups. The patients in A group (n = 41) underwent the operation with the tourniquet applied continuously throughout the operation, while those in B group (n = 38), only with tourniquet applied during tangential excision. The amounts of blood loss and blood transfusion, the operation time and the take rate of grafted skin and the incidence of complications were investigated and recorded. RESULTS: The amounts of blood loss and blood transfusion during operation in A group were 42% and 50% less than those in B group, respectively (P < 0.001). Moreover, the operation time on the upper and lower extremities in A group was much shorter (for 41% and 37%, respectively) than those in B group (P < 0.001). In addition, there was no difference of the take rate of skin graft and the incidence of subcutaneous hematoma between the two groups (P > 0.05). CONCLUSION: Continuous tourniquet application during tangential excision on the extremities in burn patients was proved to be effective in reducing operational blood loss, blood transfusion and in shortening operation time.