Objective To explore a suitable plan for the delayed rapid fluid resuscitation in burn patients with shock. Methods 20 patients with total body surface area (TBSA) burned over 40% admitted 4～8h after postburn were enrolled in this study. The patients were randomly divided into plasma and gelofusin groups. Rapid fluid replacement was given immediately after admission under close hemodynamic monitoring. Hemodynamic (PAP, PAWP, CO, PVR, SVR) and hemorrheological parameters, tissue oxygenation (DO 2, VO 2, O 2ext , lactic acid, base deficit) as well as indices reflecting the main visceral functions and damage were investigated. Results The amount of rapid fluid infusion within 2h after admission accounted for 38 8?6 1% of the amount calculated with the formula for the first 24h. When the infusion amount of pre-hospitalization was added, the amount would be (48 3?5 0)% of the amount for the first 24h. The real amount of the infusion for the first 24h was (31 4?14 3)% more than that of the amount calculated with the Evans formula. The real infused fluid amount for the second 24h was almost equal to the amount calculated with the formula. After fast fluid replacement therapy, all the parameters determined were markedly improved. Conclusions It is proposed that the formula for the delayed rapid fluid resuscitation in burn patients with shock should be: the amount infused for the first 24h (ml) =TBSA (%)?body weight (kg)?2 6,the ratio of colloid to electrolytes is 1:1, water=2000ml. Half of the total amount should be infused in the first 2h after admission under close hemodynamic monitoring. The amount infused for the second 24h (ml)=TBSA (%)?body weight (kg)?1,the ratio of colloid to electrolytes is 1:1, water=2000m1.

Objective　To investigate the effect of rapid fluid replacement on hemorheology in delayed resuscitation after burn. Methods　A total of 32 dogs inflicted with 40%TBSA full thickness scalding were randomly divided into 4 groups: scald control group(C group), delayed Gelofusion even replacement group (GE group), rapid fluid replacement group (GR group), and delayed plasma rapid fluid replacement group (PR group). The femoral arterial pressure, viscosity of blood and plasma, packed cell volume and aggregation of RBC were detected at the intervals of before and 2, 6, 8, 12, 24, 36 and 48 hours after scalding. Results　The viscosity of blood markedly increased at 2 hours after scalding, and the hemorheology parameters decreased after fluid resuscitation. The hemorheologic parameters were obviously lower in GR group than in GE group at 2 hours after rapid resuscitation, the viscosity of blood and RBC aggregation in GR group were obviously lower than those in PR group. Conclusion　Under the condition of delayed resuscitation after burn, rapid fluid replacement can quickly decreased the state of blood high viscosity and may play a role in improving microcirculation and treating burn shock.

Objective:To explore the influences of neutrophilic granule protein (NGP) on nitric oxide (NO) production in lipopolysaccharide (LPS)-induced macrophages and the regulatory mechanism.Methods:NGP highexpression RAW264.7 cells (NGP/RAW) and negative control empty vector cells (NC/RAW), NGP knockout RAW264.7 cells (NGP KO/RAW) and wild-type cells (WT/RAW) were cultured in vitro. Cells in logarithmic phase were stimulated with 10 mg/L LPS (LPS group) or phosphate buffered saline (PBS group) respectively. The content of NO in the supernatant was detected by Griess method. The mRNA expression of inducible nitric oxide synthase (iNOS) was detected by quantitative reverse transcription-polymerase chain reaction (RT-qPCR). The protein expressions of iNOS and phosphorylated signal transducer and activator of transcription 1 (p-STAT1) were detected by Western blotting.Results:Compared with PBS group, iNOS mRNA and NO expression were significantly increased at different time after LPS stimulation, the mRNA expression of iNOS peaked at 12 hours after LPS stimulation (2 -ΔΔCt: 38.45±1.34 vs. 1.00±0.00 in NC/RAW cells, 56.24±2.41 vs. 1.45±0.30 in NGP/RAW cells, 37.84±1.52 vs. 1.00±0.00 in WT/RAW cells, 5.47±0.62 vs. 0.98±0.40 in NGP KO/RAW cells, all P < 0.05), and the production of NO peaked at 24 hours after LPS stimulation (μmol/L: 24.15±1.26 vs. 0.15±0.04 in NC/RAW cells, 58.80±2.11 vs. 0.18±0.02 in NGP/RAW cells, 25.04±1.80 vs. 0.16±0.02 in WT/RAW cells, 2.42±0.38 vs. 0.12±0.03 in NGP KO/RAW cells, all P < 0.05). After being stimulated by LPS, the expression of iNOS mRNA and NO in NGP/RAW cells were increased significantly compared with NC/RAW cells [iNOS mRNA (2 -ΔΔCt): 8.42±0.59 vs. 4.63±0.37 at 2 hours, 27.16±1.60 vs. 14.25±1.02 at 6 hours, 56.24±2.41 vs. 38.45±1.34 at 12 hours; NO (μmol/L): 4.12±0.25 vs. 2.23±0.17 at 6 hours, 16.50±1.52 vs. 6.35±0.39 at 12 hours, 58.80±2.11 vs. 24.15±1.26 at 24 hours, all P < 0.05]. At the same time, the protein expressions of p-STAT1 and iNOS were also significantly enhanced (p-STAT1/GAPDH: 4.26±1.84 vs. 1.00±0.32 at 0 hours, 20.59±4.97 vs. 0.93±0.21 at 2 hours, 141.99±10.99 vs. 11.17±2.11 at 6 hours; iNOS/GAPDH: 1.27±0.86 vs. 1.00±0.22 at 0 hours, 7.94±1.94 vs. 2.01±0.92 at 2 hours, 24.24±4.88 vs. 3.72±1.11 at 6 hours, all P < 0.05), indicating that NGP might increase the expression of iNOS by promoting the phosphorylation of the signal transducer and activator of transcription 1 (STAT1) pathway, thereby increasing the production of NO. After being stimulated by LPS, the expression of iNOS mRNA and NO in NGP KO/RAW cells were significantly lower than that of WT/RAW cells [iNOS mRNA (2 -ΔΔCt): 2.46±0.31 vs. 4.22±0.18 at 2 hours, 3.61±0.44 vs. 13.02±1.34 at 6 hours, 5.47±0.62 vs. 37.84±1.52 at 12 hours; NO (μmol/L): 1.22±0.19 vs. 2.01±0.12 at 6 hours, 1.60±0.44 vs. 5.15±0.62 at 12 hours, 2.42±0.38 vs. 25.04±1.80 at 24 hours, all P < 0.05]. It showed that iNOS activation was reduced after NGP knockout, which in turn reduced NO production. Conclusion:NGP can positively regulate NO production in activated macrophages by activating the STAT1/iNOS pathway.

Objective: To investigate the potential effects of cytochrome P450 1A1 (CYP1A1) in regulating macrophages polarize to M2 type and explore the molecular mechanism. Methods: All trials were completely randomized. ① Experiment 1: 6-8 weeks old healthy male C57BL/6J mice were collected, and primary peritoneal cells were extracted, then the cells were divided into phosphate buffered saline (PBS) group and interleukin-4 (IL-4) group. The cells in the IL-4 group were stimulated with 10 mg/L IL-4 (M2 macrophage inducer); and those in the PBS group were given with an equal amount of PBS. The mRNA expressions of intracellular M2 type polarized marker molecules including arginase-1 (Arg-1) and chitinase 3 like protein 1 (YM1) at 2, 4, 6 hours after IL-4 challenge were determined by quantitative reverse transcription-polymerase chain reaction (RT-qPCR). The phosphorylation of tyrosine protein kinase 1/signaling transcriptional and transduced activator 6 (JAK1/STAT6) signaling pathway and protein expressions of CYP1A1 and Arg-1 at 6, 12, 24 hours after IL-4 challenge were determined by Western Blot. ② Experiment 2: RAW264.7 cells with high expression CYP1A1 (CYP1A1/RAW) and their negative control cells (NC/RAW) were cultured in vitro. The cells in logarithmic growth phase were collected, and then they were divided into PBS control group and IL-4 group. The treatment method was the same as experiment 1. The phosphorylations of intracellular JAK1/STAT6 and phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt) pathways in different cells at 1 hour and 2 hours after IL-4 challenge were determined by Western Blot. The mRNA and protein expressions of Arg-1 in different cells at 2 hours and 4 hours after IL-4 challenge were determined by RT-qPCR and Western Blot, respectively. Results: ① Experiment 1: after IL-4 challenge for 2 hours, the mRNA expressions of Arg-1 and YM1 in the primary peritoneal macrophages of mice were significantly increased as compared with the PBS control group [Arg-1 mRNA (2^-ΔΔCt): 1.75±0.82 vs. 1.00±0.21; YM1 mRNA (2^-ΔΔCt): 2.58±0.53 vs. 1.00±0.20, both P < 0.05] which indicated that IL-4 induced macrophage to M2 type polarization successfully. Meanwhile, the mRNA expression of CYP1A1 in polarized mouse peritoneal primary macrophages was also elevated as compared with the PBS control group, and peaked at 4 hours [CYP1A1 mRNA (2^-ΔΔCt): 2.25±0.69 vs. 1.00±0.17, P < 0.01]. The results indicated that CYP1A1 expression was enhanced when macrophages polarized to M2 type. Compared with the PBS control group, the bands of phosphorylated JAK1 (p-JAK1), phosphorylated STAT6 (p-STAT6), Arg-1 and CYP1A1 were enhanced in primary peritoneal macrophages of mice in the IL-4 group, and reached the peak value at 12 hours then gradually decreased. This result indicated that the phosphorylation of JAK1/STAT6 pathway was enhanced in M2 macrophages with high expression of CYP1A1, and the pathway was activated. ② Experiment 2: after IL-4 challenge for 2 hours, the expression of Arg-1 mRNA in CYP1A1/RAW cells was significantly higher than that in NC/RAW cells (2^-ΔΔCt: 3.02±0.60 vs. 1.47±0.43, P < 0.05), and the protein band signal was also stronger, and both peaked at 4 hours. This indicated that CYP1A1 could promote the polarization of macrophages to M2. After IL-4 challenge for 2 hours, the expression of p-JAK1 and p-JAK3 protein bands in both cells were significantly enhanced as compared with the PBS control group, but the enhancement of p-STAT6 band in CYP1A1/RAW cells was stronger than that of NC/RAW cells, indicating that CYP1A1 promoted macrophage polarization by promoting phosphorylation of the JAK1/STAT6 pathway. In the meantime, the protein band of Akt, a downstream protein of the PI3K/Akt pathway, in CYP1A1/RAW cells was significantly lower than that of NC/RAW cells, indicating that CYP1A1 did not promote macrophage polarization through this pathway. Conclusions CYP1A1 promotes the polarization of macrophage to M2 type. The mechanism is related to promoting the phosphorylation of JAK1/STAT6 pathway.