Peceleganan Spray for the Treatment of Skin Wound Infections: A Randomized Clinical Trial.

Importance: Peceleganan spray is a novel topical antimicrobial agent targeted for the treatment of skin wound infections. However, its efficacy and safety remain unclear. Objective: To assess the safety and efficacy of peceleganan spray for the treatment of wound infections. Design, Setting, and Participants: This multicenter, open-label, phase 3 randomized clinical trial recruited and followed up 570 adult patients diagnosed with secondary open wound infections from 37 hospitals in China from August 23, 2021, to July 16, 2022. Interventions: Patients were randomized to 2 groups with a 2:1 allocation. One group received treatment with 2% peceleganan spray (n = 381) and the other with 1% silver sulfadiazine (SSD) cream (n = 189). Main Outcomes and Measures: The primary efficacy outcome was the clinical efficacy rate (the number of patients fulfilling the criteria for efficacy of the number of patients receiving the treatment) on the first day following the end of treatment (day 8). The secondary outcomes included the clinical efficacy rate on day 5 and the bacterial clearance rate (cases achieving negative bacteria cultures after treatment of all cases with positive bacteria cultures before treatment) on days 5 and 8. The safety outcomes included patients' vital signs, physical examination results, electrocardiographic findings, blood test results, and adverse reactions. Results: Among the 570 patients randomized to 1 of the 2 groups, 375 (98.4%) in the 2% peceleganan treatment group and 183 (96.8%) in the 1% SSD control group completed the trial (n = 558). Of these, 361 (64.7%) were men, and the mean (SD) age was 48.6 (15.3) years. The demographic characteristics were similar between groups. On day 8, clinical efficacy was achieved by 339 patients (90.4%) in the treatment group and 144 (78.7%) in the control group (P < .001). On day 5, clinical efficacy was achieved by 222 patients (59.2%) in the treatment group and 90 (49.2%) in the control group (P = .03). On day 8, bacterial clearance was achieved by 80 of 334 patients (24.0%) in the treatment group and in 75 of 163 (46.0%) in the control group (P < .001). On day 5, bacterial clearance was achieved by 55 of 334 patients (16.5%) in the treatment group and 50 of 163 (30.7%) in the control group (P < .001). The adverse events related to the application of peceleganan spray and SSD cream were similar. Conclusions and Relevance: This randomized clinical trial found that peceleganan spray is a safe topical antimicrobial agent with a satisfactory clinical efficacy rate for the treatment of skin wound infections, while the effectiveness of bacterial clearance remains uncertain. Trial Registration: Chinese Clinical Trial Registry Identifier: ChiCTR2100047202.

Efficacy and Safety of PL-5 (Peceleganan) Spray for Wound Infections: A Phase IIb Randomized Clinical Trial.

OBJECTIVE: To assess the safety and efficacy of antimicrobial peptide PL-5 (Peceleganan) spray in the treatment of wound infections. BACKGROUND: Antimicrobial peptide PL-5 spray is a novel topical antimicrobial agent. METHODS: We conducted a multicenter, open-label, randomized, controlled phase IIb clinical trial to evaluate the efficacy and safety of PL-5 spray, as compared with silver sulfadiazine, in patients with skin wound infections. The primary efficacy outcome was the clinical efficacy rate on the first day after ending the treatment (D8). The secondary efficacy outcome was the clinical efficacy rate on the fifth day posttreatment (D5), the bacteria clearance rate, and the overall efficacy rate at the mentioned 2 time points. The safety outcomes included adverse reactions and pharmacokinetic analysis posttreatment. RESULTS: A total of 220 patients from 27 hospitals in China were randomly assigned to 4 groups. On D8, the efficacy rate was 100.0%, 96.7%, 96.7% for the 1‰ PL-5, 2‰ PL-5, 4‰ PL-5 groups, respectively, as compared with 87.5% for the control group. The efficacy rate among the 4 groups was significantly different ( P <0.05). On D5, the efficacy rate was 100.0%, 93.4%, 98.3% for the 1‰ PL-5, 2‰ PL-5, 4‰ PL-5 groups, respectively, as compared with 82.5% for the control group. The efficacy rate among the 4 groups was significantly different ( P <0.05). The blood concentration of PL-5 was not detectable in pharmacokinetic analysis. No severe adverse event related to the application of PL-5 was reported. CONCLUSIONS: Antimicrobial peptide PL-5 spray is safe and effective for the treatment of skin wound infections. TRIAL REGISTRATION: ChiCTR2000033334.

Upregulation of MAOA in the hippocampus results in delayed depressive-like behaviors in burn mice.

OBJECTIVE: To observe depressive-like behavior and hippocampus monoamine oxidase A (MAOA) changes in burned mice. METHODS: We tested depression and anxiety like behaviors of burn C57 mice with the sucrose preference test, forced swimming test (FST), open field test and elevated plus maze test and then detected the MAOA content and MAOA gene transcriptional levels in the hippocampus with western blot analysis and real-time quantitative PCR analysis. We then sought to reverse depressive-like behavior of burned mice with an MAOA inhibitor. RESULTS: (1) Mice showed depressive and anxiety like behaviors one week after they were burned; (2) The content of MAOA in the hippocampus of burned mice was significantly higher than that in control mice (P<0.05); (3) MAOA gene transcription in the hippocampus of burned mice was significantly increased (MAOA mRNA was increased, P<0.05); (4) treatment with a MAOA inhibitor (phenelzine) significantly increased the sucrose preference rate and decreased FST immobility time in burned mice, and also decreased elevated expression of MAOA in the hippocampus of burned mice. CONCLUSION: Burned mice showed "delayed" depressive-like behavior combined with a degree of anxiety; this phenomenon is likely associated with the increase in MAOA expression in the hippocampus.

[Effects of different concentrations of putrescine on proliferation, migration and apoptosis of human skin fibroblasts].

OBJECTIVE: To explore the effects of different concentrations of putrescine on the proliferation, migration and apoptosis of human skin fibroblasts (HSF). METHODS: HSF cultured in the presence of 0.5, 1.0, 5.0, 10, 50, 100, 500, and 1000 µg/ putrescine for 24 h were examined for the changes in the cell proliferation, migration, and apoptosis using MTS assay, Transwell migration assay, and flow cytometry, respectively. RESULTS: Compared with the control cells, HSF cultured with 0.5, 1.0, 5.0, and 10 µg/ putrescine showed significantly increased cell proliferation (P<0.01), and the effect was the most obvious with 1 µg/ putrescine, whereas 500 and 1000 µg/ putrescine significantly reduced the cell proliferation (P<0.01); 50 and 100 µg/ did not obviously affect the cell proliferation (P>0.05). Putrescine at 1 µg/ most significantly enhanced the cell migration (P<0.01), while at higher doses (50, 100, 500, and 1000 µg/) putrescine significantly suppressed the cell migration (P<0.05); 0.5, 5.0, and 10 µg/ putrescine produced no obvious effects on the cell migration (P>0.05). HSF treated with 0.5, 1.0, 5.0, and 10 µg/ putrescine obvious lowered the cell apoptosis rate compared with the control group (P<0.01), and the cell apoptosis rate was the lowest in cells treated with 1 µg/ putrescine; but at the concentrations of 100, 500, and 1000 µg/, putrescine significantly increased the cell apoptosis rate (P<0.01), while 50 µg/ml putrescine produced no obvious effect on cell apoptosis (P>0.05). CONCLUSION: Low concentrations of putrescine can obviously enhance the proliferation ability and maintain normal migration ability of HSF in vitro, but at high concentrations, putrescine can obviously inhibit the cell migration and proliferation and induce cells apoptosis, suggesting the different roles of different concentrations of putrescine in wound healing.

[Biologic effects of different concentrations of putrescine on human umbilical vein endothelial cells].

OBJECTIVE: To explore the effects of different concentrations of putrescine on proliferation, migration, and apoptosis of human umbilical vein endothelial cells (HUVECs). METHODS: HUVECs were routinely cultured in vitro. The 3rd to the 5th passage of HUVECs were used in the following experiments. (1) Cells were divided into 500, 1 000, and 5 000 µg/mL putrescine groups according to the random number table (the same grouping method was used for following grouping), with 3 wells in each group, which were respectively cultured with complete culture solution containing putrescine in the corresponding concentration for 24 h. Morphology of cells was observed by inverted optical microscope. (2) Cells were divided into 0.5, 1.0, 5.0, 10.0, 50.0, 100.0, 500.0, 1 000.0 µg/mL putrescine groups, and control group, with 4 wells in each group. Cells in the putrescine groups were respectively cultured with complete culture solution containing putrescine in the corresponding concentration for 24 h, and cells in control group were cultured with complete culture solution with no additional putrescine for 24 h. Cell proliferation activity (denoted as absorption value) was measured by colorimetry. (3) Cells were divided (with one well in each group) and cultured as in experiment (2), and the migration ability was detected by transwell migration assay. (4) Cells were divided (with one flask in each group) and cultured as in experiment (2), and the cell apoptosis rate was determined by flow cytometer. Data were processed with one-way analysis of variance, Kruskal-Wallis test, and Dunnett test. RESULTS: (1) After 24-h culture, cell attachment was good in 500 µg/mL putrescine group, and no obvious change in the shape was observed; cell attachment was less in 1 000 µg/mL putrescine group and the cells were small and rounded; cells in 5 000 µg/mL putrescine group were in fragmentation without attachment. (2) The absorption values of cells in 0.5, 1.0, 5.0, 10.0, 50.0, 100.0, 500.0, 1 000.0 µg/mL putrescine groups, and control group were respectively 0.588 ± 0.055, 0.857 ± 0.031, 0.707 ± 0.031, 0.662 ± 0.023, 0.450 ± 0.019, 0.415 ± 0.014, 0.359 ± 0.020, 0.204 ± 0.030, and 0.447 ± 0.021, with statistically significant differences among them (χ(2) = 6.86, P = 0.009). The cell proliferation activity in 0.5, 1.0, 5.0, and 10.0 µg/mL putrescine groups was higher than that in control group (P < 0.05 or P < 0.01). The cell proliferation activity in 500.0 and 1 000.0 µg/mL putrescine groups was lower than that in control group (with P values below 0.01). The cell proliferation activity in 50.0 and 100.0 µg/mL putrescine groups was close to that in control group (with P values above 0.05). (3) There were statistically significant differences in the numbers of migrated cells between the putrescine groups and control group (F = 138.662, P < 0.001). The number of migrated cells was more in 1.0, 5.0, and 10.0 µg/mL putrescine groups than in control group (with P value below 0.01). The number of migrated cells was less in 500.0 and 1 000.0 µg/mL putrescine groups than in control group (with P value below 0.01). The number of migrated cells in 0.5, 50.0, and 100.0 µg/mL putrescine groups was close to that in control group (with P values above 0.05). (4) There were statistically significant differences in the apoptosis rate between the putrescine groups and control group (χ(2)=3.971, P=0.046). The cell apoptosis rate was lower in 0.5, 1.0, 5.0, and 10.0 µg/mL putrescine groups than in control group (with P values below 0.05). The cell apoptosis rate was higher in 500.0 and 1 000.0 µg/mL putrescine groups than in control group (with P values below 0.01). The cell apoptosis rates in 50.0 and 100.0 µg/mL putrescine groups were close to the cell apoptosis rate in control group (with P values above 0.05). CONCLUSIONS: Low concentration of putrescine can remarkably enhance the ability of proliferation and migration of HUVECs, while a high concentration of putrescine can obviously inhibit HUVECs proliferation and migration, and it induces apoptosis.

[Influence of exogenous putrescine on the function of liver and apoptosis of liver cells in rats].

OBJECTIVE: To explore the influence of exogenous putrescine on the function of liver and apoptosis of liver cells in rats. METHODS: Ninety healthy clean SD rats were divided into control group (C, n = 10, intraperitoneally injected with 2 mL normal saline), low dosage putrescine group (LP, n = 40), and high dosage putrescine group (HP, n = 40) according to the random number table. Rats in the latter two groups were intraperitoneally injected with approximately 2 mL putrescine (2.5 or 5.0 g/L) with the dosage of 25 or 50 µg/g. Ten rats from group C at post injection hour (PIH) 24 and 10 rats from each of the latter two groups at PIH 24, 48, 72, 96 were sacrificed. Heart blood was obtained for determination of serum contents of ALT and AST. Liver was harvested for gross observation and histomorphological observation with HE staining. Apoptosis was shown with in situ end labeling, and apoptosis index (AI) was calculated. Data among the three groups and those at different time points within one group were processed with one-way analysis of variance or Welch test; LSD or Dunnett's T3 test was used for paired comparison; factorial design analysis of variance of two factors was applied for data between group LP and group HP. RESULTS: (1) No obvious abnormality was observed at gross observation of liver of rats in each group. Liver tissue of rats in group C was normal. Light edema was observed occasionally in liver of rats in groups LP and HP, but necrotic cells were not seen. (2) Content of ALT at PIH 24, 48, 96 and content of AST at PIH 72 and 96 in group LP were respectively (38 ± 10), (45 ± 6), (34 ± 4), (207 ± 18), (196 ± 19) U/L, and content of ALT at PIH 72 and 96 and content of AST at PIH 24, 72, 96 in group HP were respectively (38 ± 6), (48 ± 5), (213 ± 43), (209 ± 40), (230 ± 29) U/L. They were significantly higher than those of rats in group C [(29 ± 5), (163 ± 42) U/L, with P values all below 0.01]. There were statistically significant differences between group LP and group HP in the content of ALT at PIH 48, 72, 96 and content of AST at PIH 96 (with P values all below 0.05). Compared with that at PIH 24 of each group, content of ALT of rats in group LP at PIH 48 and that of rats in group HP at PIH 96, as well as content of AST of rats in group LP at PIH 48, 72, 96 and that of rats in group HP at PIH 48 were significantly increased or decreased (with P values all below 0.05). Factorial analysis showed that the differences due to different concentration of putrescine on content of AST were statistically significant (F = 12.21, P = 0.001), but not on content of ALT (F = 0.01, P = 0.974) between group LP and group HP. (3) AI values of rats in group LP at PIH 24, 48, 72 were respectively (5.69 ± 0.38)%, (13.80 ± 1.66)%, (11.56 ± 1.74)%, and AI values of rats in group HP at PIH 72 and 96 were respectively (10.29 ± 1.43)%, (15.29 ± 1.41)%. They were all obviously higher than AI value of control group at PIH 24 [(3.50 ± 0.30)%, with P values all below 0.01]. There were statistically significant differences between group LP and group HP in AI value at PIH 24, 48, 96 (with P values all below 0.05). Compared with that at PIH 24 of each group, AI value of rats in groups LP and HP at PIH 48, 72, 96 were significantly increased or decreased (with P values all below 0.05). Factorial analysis showed that the differences in the influence of concentration of putrescine and stimulation time on AI value were statistically significant (with F values respectively 22.95 and 130.44, P values all below 0.01). CONCLUSIONS: Intraperitoneal injection of exogenous putrescine in the dosage of 25 or 50 µg/g could lead to certain degree of functional damage of liver and apoptosis of liver cells of rat. The higher the dosage and the longer the stimulation time, the more obvious the damage and apoptosis would be.

[Effect of mannitol on serum tumor necrosis factor-α and interleukin-6 levels and the mechanism of its organ-protective effect in rabbits early after severe burn injury].

OBJECTIVE: To investigate the protective effect of mannitol therapy on the vital organs and explore the underlying mechanisms in New Zealand rabbits with severe burn injury. METHODS: Twelve New Zealand rabbits with severe burn injury (30% of TBSA) were randomized to receive fluid resuscitation with saline (control) or mannitol therapy starting at 1 h after the injury. Serum and urine samples were collected before and at 1, 4, 8, 24, and 48 h after the injury for detection of TNF-α, IL-6, ALT, AST, GGT, CK, CK-MB, BUN and Cr levels using sandwich ELISA. RESULTS: One hour after sever burn injury, the serum levels of TNF-α and IL-6 began to increase along with ALT, AST, GGT, CK, CK-MB, BUN and Cr levels. Compared with control group, the rabbits in mannitol group showed significantly higher 48 h urine excretion of TNF-α (145 ± 8 vs 78 ± 1 0 pg/ml, P<0.05) and IL-6 (93 ± 6 vs 40 ± 8 pg/ml, P<0.05) but with lowered serum levels of TNF-α (0.62 ± 0.02 vs 0.83 ± 0.02 pg/ml, P<0.05) and IL-6 (0.45 ± 0.03 vs 0.56 ± 0.03 pg/ml, P<0.05) as well as lowered serum ALT, AST, GGT, CK, CK-MB, BUN and Cr levels (P<0.05). CONCLUSION: In rabbits with severe burn injury, mannitol therapy can decrease serum TNF-α and IL-6 levels early after the injury to ameliorate potential functional impairment of the heart, liver and kidneys.

Application of crystalline cellulose membrane (Veloderm) on split-thickness skin graft donor sites in burn or reconstructive plastic surgery patients.

The present study was performed in China to compare the efficacy and safety of an advanced wound dressing made of crystalline cellulose (Veloderm) to a conventional treatment of three Vaseline gauzes in the management of skin donor sites of burns or reconstructive plastic surgery. In this prospective, multicenter, open-labeled, randomized clinical trial performed in three Chinese burn centers in China, 96 patients who required autologous split skin graft were randomized into either the test (Veloderm) group or the control (Vaseline gauze) group. Average healing times in the test group and in the control group were 8.40±2.90 and 8.92±2.58 days, respectively, with median values of 7.00 and 8.00 days, respectively: the difference between two groups was statistically significant (P=.045). Scores for exudates, pain intensity, and peripheral erythema showed no difference between the groups; however, composite scores of three variables on day 10 postoperatively was significantly lower in the test group (0.00±0.00 vs. 0.13±0.49; P = .043). The need for a dressing change was also significantly lower in the test group (12.5 vs. 31.25%; P = .036). Veloderm is a safe and effective dressing that may offer some advantages over the traditional application of Vaseline gauze in the management of donor sites in burn or reconstructive plastic surgery patients.

[Determination and correlation analysis of contents of putrescine, cadaverine, and histamine in necrotic tissue, blood, and urine of patients with diabetic foot].

OBJECTIVE: To determine and perform a correlation analysis of the contents of putrescine, cadaverine, and histamine in necrotic tissue, blood, and urine of patients with diabetic foot (DF). METHODS: Ten patients with severe wet necrotizing DF hospitalized from January 2011 to January 2012 were assigned as group DF, and 10 orthopedic patients with scar but without diabetes or skin ulcer hospitalized in the same period were assigned as control group. Samples of necrotic tissue from feet of patients in group DF and normal tissue from extremities of patients in control group, and samples of blood and 24-hour urine of patients in both groups were collected, and the amount of each sample was 10 mL. Contents of putrescine, cadaverine, and histamine were determined with high performance liquid chromatography-mass spectrometry. The data got from the determination of blood and urine were processed with t test, and those from necrotic or normal tissue with Wilcoxon rank sum test. The correlation of contents of polyamines between necrotic tissue and blood, blood and urine were processed with simple linear regression analysis. RESULTS: (1) Contents of putrescine, cadaverine, and histamine in the necrotic tissue of group DF were (186.1 ± 26.8), (78.553 ± 12.441), (33 ± 10) mg/kg, which were significantly higher than those in normal tissue of control group [(2.2 ± 1.2), (1.168 ± 0.014), 0 mg/kg, with Z values respectively -3.780, -3.781, -4.038, P values all below 0.01]. The content of putrescine in necrotic tissue of group DF was significantly higher than those of cadaverine and histamine (with Z values respectively -3.780, -3.630, P values all below 0.01). (2) Contents of putrescine, cadaverine, and histamine in the blood of group DF were (0.075 ± 0.013), (0.022 ± 0.003), (0.052 ± 0.014) mg/L, and they were significantly higher than those in the blood of control group [(0.014 ± 0.009), (0.013 ± 0.003), (0.016 ± 0.008) mg/L, with t values respectively 6.591, 2.207, 3.568, P < 0.05 or P<0.01]. The content of putrescine in the blood of group DF was significantly higher than those of cadaverine and histamine (with t values respectively 13.204, 3.096, P values all below 0.01). (3) Contents of putrescine, cadaverine, and histamine in the urine of group DF were (0.735 ± 0.088), (0.450 ± 0.012), (0.1623 ± 0.0091) mg/L, and only the contents of putrescine and cadaverine were significantly higher than those in the urine of control group [(0.050 ± 0.014), (0.035 ± 0.007) mg/L, with t values respectively 3.270, 4.705, P<0.05 or P<0.01]. The content of putrescine in the urine of group DF was significantly higher than that of cadaverine (t = 6.686, P < 0.01). (4) There were significant and positive correlations in contents of putrescine, cadaverine, and histamine between necrotic tissue and blood in patients of group DF (with r values respectively 0.981, 0.994, 0.821, P values all below 0.01). There were no significant correlations in contents of putrescine, cadaverine, and histamine between blood and urine in patients of group DF (with r values respectively 0.150, 0.239, 0.177, P values all above 0.05). CONCLUSIONS: Putrescine, cadaverine, and histamine exist in the necrotic tissue of patients with DF in high concentrations, among which putrescine predominates. These polyamines can be absorbed into the blood through wound and excreted through the urine.

[Exogenous putrescine causes renal function impairment and cell apoptosis in rats].

OBJECTIVE: To explore the effect of exogenous putrescine on renal function and cell apoptosis in rats. METHODS: Ninety SD rats were randomized into control group (n=10), high-dose putrescine group (P1 group, n=40), and low-dose putrescine group (P2 group, n=40) with intraperitoneal injections of 2 ml of normal saline, 50 µg/g putrescine, and 25 µg/g putrescine, respectively. At 24, 48, 72 and 96 h after the injections, 10 rats from each group were sacrificed to examine serum Cr and BUN levels, histological changes in the kidneys, and renal cell apoptosis (TUNEL assay). RESULTS: The rats in the two putrescine- treated groups showed mild edema in some renal tissues without obvious necrosis. In P1 and P2 groups, serum Cr and BUN levels differed significantly at each time point of measurement (P<0.01 and P<0.05, respectively), and were significantly higher than the levels in the control group (P<0.01 and P<0.05, respectively). The two putrescine-treated groups showed gradually increased renal cell apoptosis with time, reaching the peak levels at 96 h and 48 h, respectively. The peak renal cell apoptosis rates in P1 [(24.78∓2.19)%] and P2 [(26.27∓2.13)%] group were significantly higher than the rate in the control group [(4.47∓0.33)%, P<0.01]. CONCLUSION: Exogenous putrescine can lead to renal function impairment and induce renal cell apoptosis in rats, and the severity of these changes appeared to be associated with the blood concentration of exogenous putrescine.

[Effect of necrotic wound tissue decomposition products on serum inflammation factors in rabbits].

OBJECTIVE: To observe the effect of the decomposition products of necrotic tissues from wounds on the serum levels of inflammation factors in comparison with endotoxin. METHODS: Thirty adult New Zealand rabbits were randomly divided into 3 groups and received injections of saline, necrotic tissue homogenate or endotoxin. From each rabbit, blood samples (2 ml) were collected from the central artery of the ears at 0, 2, 6, 12, 24, 30, 36, 48, and 60 h after the injection for measurement of serum levels of tumor necrosis factor-alpha (TNF-α), interleukin-1 (IL-1) and IL-6. RESULTS: The serum level of TNF-α, IL-1 and IL-6 in the rabbits increased 2-4 h after injection of the necrotic tissue homogenate and reached the peak level at 12 h, followed by a gradual reduction since 36 h. No obvious changes in the levels of the inflammatory factors were found in saline group (P<0.01). Compared with endotoxin, necrotic tissue homogenate resulted in an early increment (2-4 h vs 5-6 h) and significantly higher peak levels (at 30 h) of the inflammation factors (P<0.05). Curve fitting showed a distinct difference between necrotic tissue homogenate and endotoxin in their effect on the inflammatory factors. CONCLUSION: The necrotic tissue decomposition products contain toxic substances that possess a different toxicity profile from endotoxin, and their toxicity can be even stronger.

[Influence of exogenous putrescine and cadaverine on pro-inflammatory factors in the peripheral blood of rabbits].

OBJECTIVE: To explore the influence of exogenous putrescine and cadaverine on pro-inflammatory factors in the peripheral blood of rabbits. METHODS: Forty ordinary adult New Zealand rabbits were divided into saline, necrotic tissue homogenate (NTH), putrescine, and cadaverine groups according to the random number table, with 10 rabbits in each group. Saline, NTH, 10 g/L putrescine, and 10 g/L cadaverine were respectively peritoneally injected into rabbits of corresponding group in the amount of 1 mL/kg. The blood sample in the volume of 2 mL was collected from the central artery of rabbit ears before injection and at 2, 6, 12, 24, 30, 36, 48, 60 hours post injection (PIH). Contents of TNF-α, IL-1, and IL-6 in the serum were determined with enzyme-linked immunosorbent assay. Data were processed with repeated measurement data analysis of variance and Spearman correlation analysis, and cubic model curve was applied in curve fitting for the contents of inflammatory factors. RESULTS: (1) The serum contents of TNF-α, IL-1, and IL-6 were increased in NTH, putrescine, and cadaverine groups in different degrees at most post injection time points. There was no significant change in the concentrations of the three pro-inflammatory factors in saline group, and they were significantly lower than those of the other three groups at most post injection time points (with F values from 3.49 to 13.58, P values all below 0.05). The serum contents of TNF-α, IL-1, and IL-6 in putrescine group began to increase at PIH 2, 6, and 6, which was similar to the trend of NTH group, but the changes were delayed compared with those of cadaverine group(all at PIH 2). The peak values of TNF-α, IL-1, and IL-6 in putrescine group were respectively (339 ± 36), (518 ± 44), and (265.9 ± 33.5) pg/mL, which were significantly lower than those of cadaverine group [ (476 ± 86), (539 ± 22), and (309.4 ± 27.1) pg/mL], with F values respectively 5.11, 1.90, and 5.56, P values all below 0.05. (2) The period of time in which contents of TNF-α, IL-1, and IL-6 began to increase (PIH 3-4) and the peaking time of the three pro-inflammatory cytokines (PIH 18-30) in putrescine group appeared later than those of cadaverine group (PIH 2 and 12-30). The duration of peaking time of the three pro-inflammatory cytokines in putrescine group was shorter than that of cadaverine group (PIH 18-30 vs. PIH 12-30). The increasing period and the duration of peaking time of TNF-α, IL-1, and IL-6 in putrescine group were close to those of NTH group (PIH 3-5 and 18-30). The correlation coefficient test analysis showed that the trends of changes in contents of three pro-inflammatory cytokines in putrescine group were significantly correlated with those of NTH group (r(TNF-α) = 0.933, P < 0.01; r(IL-1) = 0.967, P < 0.01; r(IL-6) = 0.950, P < 0.01). The obvious correlation between cadaverine group and NTH group was only found in the contents of IL-1 and IL-6 (r(IL-1) = 0.913, P < 0.01; r(IL-6) = 0.883, P < 0.05). CONCLUSIONS: Both exogenous putrescine and cadaverine can cause inflammatory reaction in rabbits. The trend of the inflammatory reaction induced by putrescine was similar with that by NTH, suggesting that putrescine may play a leading role in the inflammatory reaction induced by necrotic tissue decomposition.

[Effect of burn blister fluid on human mesenchymal stem cell (MSC) in vitro and its phenotypic modulation in culture].

OBJECTIVE: To study the effect of blister fluid obtained from burn patient on human MSCs in vitro and its phenotypic modulation in culture. METHODS: Blister fluid from burn patients was collected at 12, 24, 48 post burn hour (PBH). The human MSCs were isolated, cultured, amplified and identified in vitro, then were divided into A (culture with 20% blister fluid collected at 12 PBH) , B (culture with 20% blister fluid collected at 24 PBH), C (culture with 20% blister fluid collected at 48 PBH), N (with ordinary culture medium) groups. The growth of MSCs and micro-organisms in blister fluid were observed. Positive expression rates of CD44 and CK7 were detected by flow cytometry after culture for 8 days. RESULTS: Bacterial and fungal growths were absent in 15 blister fluid samples. There was no obvious change in MSC morphology in each group. Compared with that of N group, the number of MSCs in A, B, C groups was decreased, especially in C group. CD44 positive expression rate in A, B, C groups was (83.0 +/- 3.1)%, (77.2 +/- 2.9)% and (65.1 +/- 2.3)%, respectively,which was obviously lower than that in N group [(89.5 +/- 3.2)%, P < 0.01]. CK7 positive expression rate in A, B, C groups was (24.06 +/- 0.11)%, (16.41 +/- 0.09)% and (4.48 +/- 0.07)%, respectively, which was obviously higher than that in N group [(3.87 +/- 0.04)%, P < 0.01]. CONCLUSIONS: Burn blister fluid can obviously inhibit the growth of human MSC cultured in vitro, and may promote modulation of its phenotype to certain extent.

[Distribution and drug resistance analysis of bacteria in different wound infections].

OBJECTIVE: To analyze the distribution and drug resistance of bacteria in different wound infections and provide evidence for wound infection control in subtropical regions. METHODS: This study involved 265 patients from 4 different departments of our hospital who experienced wound infections between July, 2007 and July, 2008. The bacterial strain distribution in the wounds and drug resistance of the bacteria were analyzed. RESULTS: Acinetobacter baumanii (39% of the total strain identified) was the most frequent bacterial strain causing infection of the burn wounds, followed by Proteus mirabilis (20%) and Pseudomonas aeruginosa (20%). E. coli infection was prevalent in the departments of general surgery (37%) and urinary surgery (64%), and Pseudomonas aeruginosa and Pseudomonas pneumonia infections were detected at the rate of 30% and 43% in the urinary surgery department, respectively. Different bacterial strains were found at similar rates around 10% in the wounds of patients undergoing traumatic surgery. CONCLUSION: Despite that the commonly seen pathogenic bacteria in burn patients including Staphylococcus aureus have been effectively controlled by early application of antibiotics, the opportunistic pathogens such as Acinetobacter baumanii and Proteus mirabilis often survive these antibiotics, and some strains evolve to be drug-resistant and even multi-drug-resistant. E. coli infection is prevalent in general surgery and urinary surgery departments, where Staphylococcus aureus and Pseudomonas aeruginosa infections can also be found frequently. All kinds of bacteria infection are present in trauma surgery department, each found at the rate around 10%.

Pharmacokinectics of vancomycin and amikacin in the subeschar tissue fluid in patients with severe burn.

The specific aim of this study was to investigate the pharmacokinetic parameters of antibiotics represented by vancomycin and amikacin in the subeschar tissue fluid (STF) in patients with early stage severe burn. Twenty patients were studied: age 30.7+/-8.0 years old, weight 60.6+/-8.4 kg, total burn surface area (TBSA) 68.39+/-17.85%, creatinine clearance (CCr) 95.45+/-23.14 ml/min, mean+/-S.D. Patients received intravenous infusion of 500 mg vancomycin (10 patients) or 400mg amikacin (10 patients) for 60 min at 24h after burn. Subeschar tissue fluid (STF) samples were collected at 1, 2, 4, 8, 24, 48, 96, 144, 192, 240 h at the end of infusion. Concentrations of these antibiotics in the samples were determined by fluorescence polarization immunoassay (FPIA) method. Pharmacokinetic parameters of vancomycin and amikacin were calculated by the use of Program 3P97 and statistical analyses were performed by the use of Program Package SPS S10.0. The concentration-time curves of vancomycin and amikacin in the STF were both fitted in two-compartment model. Pharmacokinetic parameters of vancomycin in the STF were: distribution half-life (t(1)/2alpha)=3.74+/-2.64 h, elimination half-life (t(1)/2beta)=92.18+/-11.73 h, apparent volume of distribution (V(c))=25.64+/-5.68 L, area under the curve (AUC)=1279.42+/-256.12 microg h ml(-1), clearance (CLs)=0.4048+/-0.0788 L h(-1). Pharmacokinetic parameters of amikacin in the STF were: t(1)/2alpha=4.35+/-1.66 h, t(1)/2beta=80.04+/-9.52 h, V(c)=13.17+/-1.32 L, AUC=1802.49+/-285.68 microg h ml(-1), CLs=0.2272+/-0.0383 L h(-1). This study demonstrated significant low clearance, long half life of vancomycin and amikacin in the STF in patients with severe burn compared to the parameters obtained in the serum of normal volunteers in previous studies. Elimination half-lives (t(1)/2beta) of vancomycin and amikacin in the STF of severe burns were 18.75-34.87 times and 28.20-44.78 times longer than those in the serum of normal volunteers, respectively. Concentrations of vancomycin and amikacin in STF at 24h after the end of a single dose infusion was higher than MIC on common pathogenic bacteria. Their effective inhibitory concentration were maintained at least for 24h. There was antibiotic retention in the third space after early and short-term use of potent antibiotics. An antibiotic barrier could form in the STF, and could prevent an invasive bacterial infection from burn wound.

[Absorption of albumin in subeschar tissue fluid in early stage after burn in rabbit and its pharmacokinetics].

OBJECTIVE: To observe the change in albumin concentration in the subeschar tissue fluid of rabbits in early stage after burn, and to analyze its regular pattern. METHODS: Thirty-four adult male New Zealand rabbits were divided into control group and experiment group according to the random number table, with 17 rabbits in each group. Rabbits in experiment group were subjected to 8% TBSA full-thickness scald on the back and were injected with human serum albumin in subeschar tissue serving as tracing albumin. 1.5 mL blood sample was collected at post scald hour (PSH) 2, 4, 8, 16, 24, 48, 72 respectively. Rabbits in control group were dealt with the above-mentioned procedures except for scald. The concentration of tracing albumin was measured with the enzyme-linked immunosorbent assay kit. The concentration of the serum albumin of rabbits were determined with biochemical analyzer. Pharmacokinetics parameters of tracing albumin were calculated with fitting model of 3P97 practical pharmacokinetics calculating program. RESULTS: (1) Concentration of tracing albumin of rabbits in experiment group was respectively higher than that in control group (P < 0.01) at each time point, and it peaked at PSH 8 [(421 +/- 10) microg/L]. (2) The concentration of serum albumin of rabbits in experiment group decreased in the beginning and increased later, while no significant change was observed in control group. (3) The distribution phase half-life of tracing albumin of rabbits in experiment group (4.0271 h) was about 1/3 of that of the control group (12.0907 h); while the area under the curve in the experiment group (22 336.38 microg.h.mL(-1)) was about 4 times of that in the control group (5827.77 microg.h.mL(-1)). CONCLUSIONS: The albumin in the subcutaneous tissue could be absorbed into blood circulation in normal conditions. The resorption occurs earlier and faster and more when obvious inflammation occurs (such as deep burn). Exudation and resorption of albumin co-exist in the early stage after burn.

[Pharmacokinetics changes of amikacin in severe burn patients at early stage].

OBJECTIVE: To investigate the concentration and pharmacokinetics changes of amikacin in the serum and blister fluid in severe burn patients at early stage. METHODS: Twenty severe burn patients during early postburn stage were divided into four groups with five patients in each group. Each patient was given a single dose of 400 mg amikacin in 30 minutes during 3-4 postburn hour (PBH) in A group, at 10 PBH in B group, at 20 PBH in C group, and at 30 PBH in D group. The concentration of amikacin in blister fluid was examined at 0.25, 0.5 min and 1, 2, 3, 4, 5, 6, 7 h after treatment by fluorescence polarization immunoassay, meanwhile, the venous blood of 9 patients among them was also collected to determine the concentration of amikacin at the same time points. Pharmacokinetics parameters of model were produced by program 3P97. RESULTS: Among all groups, the concentration of amikacin in blister fluid in A group increased quickest and maintained longest, that of B group ranked second. The amikacin concentration of blister fluid in A, B groups were obviously higher than those in C, D groups at each time point (P <0.05 orP < 0.01), especially at 1PBH (12.53 +/- 1.76, 9.52 +/- 1.51 microg/mL vs 4.65 +/- 0.77, 3.10 +/- 0.41 microg/ml, P < 0.01). The serum concentration of amikacin in 9 patients were decreasing along with elapse of time. The amikacin concentration-time curves in blister fluid and serum were best fit in two compartment models. Compared with that in normal value, t1/2beta of amikacin from burn patient was shortened in serum and prolonged in blister fluid. CONCLUSION: Early administration of amikacin in burn patients (within 10 PBH) may form an effective and continuous antibiotics barrier around the wound to prevent bacterial infection.

[Dynamic changes of blister fluid amikacin concentration after its early-stage administration in severely burned patients].

OBJECTIVE: To determine the adequate timing of antibiotics application in severely burned patients by observing the dynamic changes of amikacin in blister fluid during early postburn stage. METHODS: Twenty patients in early stage of sever burns were divided into 4 groups (n=5) according to the timing of amikacin administration, namely at 3-4 h (group A), 10 h (group B, 20 h (group C), and 30 h (group D) postburn. Amikacin was administered intravenously via a single dose of 400 mg within 30 min, and at the time points of 0.25 to 7 h after completion of the infusion, the blister fluid was collected from each patient for determination of amikacin concentration with fluorescence polarization immunoassay. RESULTS: Fifteen minutes after intravenous administration, amikacin could be detected in the blister fluid, reaching the highest level at 1-2 h after administration followed by gradual declination. In group B, blister fluid amikacin concentration reached 4.96+1.60 microg/ml 15 min after administration, and at the subsequent time points until 4 h, amikacin concentration was significantly higher in groups A and B than in groups C and D (P<0.05). Amikacin concentration in the blister fluid in group D was not sufficient for effective antibacterial therapy. CONCLUSION: Amikacin administration in the early postburn stage may ensure higher amikacin concentration in the blister fluid and wound exudate. Better antibacterial effect can be expected when amikacin is applied within the initial 10 h postburn.

[Changes in pharmacokinetic parameters of vancomycin in the subeschar tissue fluid in patients with severe burns].

OBJECTIVE: To investigate the changes in pharmacokinetic parameters of vancomycin in the subeschar tissue fluid (STF) at early post-burn stage in patients with severe burns. METHODS: Ten patients with severe burns were enrolled in the study and received intravenous injection of 500 mg vancomycin at an even rate within 60 mins 1 to 2 hours after admission. A total of 0.5 ml STF was collected each time and the concentration of vancomycin in the STF was determined by fluorescence polarization immunoassay (FPIA) method at 1, 2, 4, 8, 24, 48, 96, 144, 192, 240 post-burn hours (PBH). Pharmacokinetic parameters of vancomycin were produced by program 3P97 and statistically analyzed by program package SPSS10. 0. RESULTS: The STF concentration-time curves of vancomycin were best fit in two compartment model. Pharmacokinetic parameters of vancomycin in the STF were: t1/2alpha = (3.7 +/- 2.6) h, t1/2beta = (92 +/- 12)h, Vc = (26 +/- 6)L, AUC = (1279 +/- 256) microg x h x ml(-1), CLs = (0.40 +/- 0.08) L/h. CONCLUSION: When vancomycin is used early after severe burns, the drug can be retained in the third space, and the concentration of the drug can be maintained for over 24hrs, and it is beneficial to form an antibiotic barrier around the wound to prevent an invasive bacterial infection to the burn wound.

[Effect of Soluvit on stress reaction and leucocyte function in serious burn patients in shock stage].

OBJECTIVE: To investigate the effect of Soluvit on stress reaction and leucocyte function in serious burn patients in shock stage. METHODS: Eighty-seven serious burn patients, who did not undergo operation, were divided into Soluvit treatment group and control group randomly. Patients in Soluvit treatment group were treated with two bottles of Soluvit everyday from postburn 1 st to 14 th day. Patients in control group were given 500 ml normal saline infusion instead. Blood samples were collected for determination of cortisol and malondialdehyde every 4 hours on postburn 1 st day. Leucocyte were isolated for testing chemotaxis distance and phagocytic power on postburn 7 th and 14 th day respectively. RESULTS: The serum cortisol contents in serious burn patients were significantly elevated at 2-4 hours after treatment in Soluvit treatment and control groups. Serum cortisol and malondialdehyde levels were higher than normal values in all serious burn patients in shock stage at 10-12 hours after treatment. But the changes of serum cortisol and malondialdehyde in Soluvit treatment group were all lower than those in control group at 10-48 and 14-48 hours after treatment, respectively (all P<0.05). Leucocyte chemotaxis distance in Soluvit treatment group was longer than that in control group on both postburn 7 th and 14 th day (P<0.05 and P<0.01). In contrast, there were no significant differences in phagocytic power between two groups (both P>0.05). CONCLUSION: Above results suggest that Soluvit can mitigate stress reaction and lipid peroxidation action, but enhance leucocyte chemotaxis function in severe burn patients.