Comparative study on effects of burn-blast combined injury and burn-firearm combined injury complicated with seawater immersion on vascular endothelial cells.

OBJECTIVE: To comparatively study the effects and mechanisms of burn-blast combined injury and burn-firearm combined injury complicated with seawater immersion on vascular endothelial cells. METHODS: A total of 40 healthy adult hybrid dogs of both sexes, weighing 12-15 kg, were used in this study. Randomly-selected 20 dogs were established as models of burn-blast combined injury (the burn-blast injury group) and the other 20 dogs as models of burn-firearm combined injury (the burn-firearm injury group). Then the wounds of all the dogs were immediately immersed in seawater for 4 hours, and then they were taken out from the seawater. Blood samples were withdrawn from the central vein of the dogs before injury, and at 4, 7, 10, 20, and 28 hours after injury to measure the circulating endothelial cells and the von Willebrand factor. RESULTS: Circulating endothelial cells increased significantly at 4 hours after injury in all the dogs. But they reached peak at 7 hours after injury in the burn-blast injury group and at 28 hours after injury in the burn-firearm injury group. The changes of circulating endothelial cells in the burn-blast injury group were significantly different from those in the burn-firearm injury group at 4, 7, 20, and 28 hours after injury (P < 0.01). The von Willebrand factor reached peak at 4 hours after injury in the burn-blast injury group and at 28 hours in the burn-firearm injury group. The changes of von Willebrand factor in the burn-blast injury group were significantly different from those in the burn-firearm injury group at 4, 20, and 28 hours after injury (P < 0.01). CONCLUSIONS: In burn-blast injury combined with seawater immersion, the vascular endothelial cells changed most significantly at 4 hours or 7 hours after injury, while burn-firearm injury combined with seawater immersion have the same at 20 hours or 28 hours after injury.

[Comparison of resuscitation with Parkland formula and with improved protocol on hemodynamics in projectile-burn combined wound in dogs with seawater immersion].

OBJECTIVE: To compare hemodynamic effects of resuscitation with Parkland formula or with the improved protocol on projectile-burn combined wound in dogs with seawater immersion. METHODS: A model of projectile-burn combined wound in dogs with seawater immersion was reproduced, and 20 dogs were randomized into three groups: projectile-burn combined wound with seawater immersion (immersion group, n=8), Parkland formula resuscitation (lactated Ringer's solution 4 ml/kg per 1%total body surface area for 24 hours, standard resuscitation group, n=6), and improved protocol groups (lactated Ringer's solution 2.5 ml/kg per 1% total body surface area colloid solution 6% hetastarch 0.5 ml/kg per 1% total body surface area for 24 hours, improved group, n=6). Changes of hemodynamics and central temperature (CT) before injury, and 4, 7, 10, 20 and 28 hours after injury were observed. The mortality was observed. RESULTS: After resuscitation with Parkland formula, CT as well as hemodynamic indexes and amount of urine were improved, but central venous pressure (CVP) and the amount of urine were higher in early period of resuscitation. CVP was (14.7+/-3.1)cm H2O and the amount of urine was (2.38+/-0.18)ml.h(-1).kg(-1) at 7 hours after injury. Hemodynamics was not stable during later period of experiment. After resuscitation with the improved protocol, the hemodynamics ameliorated better than resuscitation with Parkland formula. No animals died in improved group, but 4 and 1 died respectively in immersion group and standard resuscitation group. CONCLUSION: Fluid resuscitation according to the improved protocol is more suitable for projectile-burn combined wound in dogs with seawater immersion than resuscitation with Parkland formula.

Efficacy and safety of remifentanil and sulfentanyl in painless gastroscopic examination: a prospective study.

We aim to assess efficacy and safety of remifentanil or sulfentanyl combined with propofol during painless gastroscopic examination in patients. In this study, 270 patients were randomly divided into 3 groups: propofol was given only in group P; propofol and remifentanil in group PR; propofol and sulfentanyl in group PS during the gastroscopic examination. Efficiency of group P was significantly higher than that of group PR and PS (P<0.01) [corrected]. Efficiency of group PR was lower than that of group PS (P<0.05). Incidence of chest wall rigidity and oxygen desaturation in group PR were higher than group P and PS (P<0.05), whereas there was no difference between groups P and PS (P>0.05). Propofol combined with remifentanil could provide satisfying anesthesia and more respiratory depression, whereas sulfentanyl at equivalent dose combined with propofol could also provide with satisfying anesthesia and less respiratory depression. Combined sufentanyl with propofol would be an effective anesthesia technique in the daytime procedure.

Identification of synthetic peptides that inhibit lipopolysaccharide (LPS) binding to myeloid differentiation protein-2 (MD-2).

Many studies have suggested that the synergic effect of myeloid differential protein-2 (MD-2) on bacterial lipopolysaccharide (LPS) stimulation of toll-like receptor 4 (TLR4) may be a critical step during the LPS-TLR4 response signaling pathway. We performed a bioinformatic analysis on the MD-2 protein and identified the amino acid sequence NH2-FSKGKYKCV-COOH (K128-132) as a possible key sequence involved in the binding between MD-2 and LPS. We then screened a random phage display peptide library using this sequence as bait in order to identify antagonistic peptides. After 3 rounds of selection, 3 positive clones were identified. All 3 peptides were shown to inhibit, in a dose-dependent manner the production of tumor necrosis factor-α and interleukin-6 in human U937 and THP-1 cell lines as well as human peripheral blood monocytes stimulated by LPS. Only 2 of the 3 peptides were able to bind MD-2 directly as shown by sulfo-SBED biotin label transfer experiments. BALB/C mice were used to estimate the protection of these peptides from LPS challenge, and 2 of the 3 peptides (Lys-Thr-Val-Pro-Asp-Asn-His and Ile-Gly-Lys-Phe-Leu-Tyr-Arg) reduced mortality of the challenged mice from 100% to 53.8%. This study has demonstrated that interfering with the binding between MD-2 and LPS might be a potential therapeutic strategy for treating LPS-induced sepsis, and in doing so has identified 2 potential peptide candidates.