[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.

[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.

[Pharmacokinetics of amikacin in the subeschar tissue fluid following severe burns].

OBJECTIVE: To investigate the changes of pharmacokinetic parameters of amikacin in the subeschar tissue fluid (STF) in the early stage of severe burns. METHODS: Amikacin concentration in the STF of 10 severely burned patients were determined by fluorescence polarization immunoassay (FPIA) at different time points after intravenous amikacin infusion of the initial dose of 400 mg given within 60 min. The pharmacokinetic parameters of amikacin were measured using 3P97 program and statistically analyzed with SPSS10.0 software. RESULTS AND CONCLUSION: After the initial dose of 400 mg of amikacin, the STF concentration-time curves of amikacin were fitted in two compartment model. The pharmacokinetic parameters of amikacin in the STF were: t(1/2alpha)=(4.35-/+1.66) h, t(1/2beta)= (80.04-/+9.52) h, Vc= (13.17-/+1.32) L, AUC= (1802.49-/+285.68) microg. h.ml(-1), and CLs= (0.2272-/+0.0383) L. h(-1), demonstrating significantly lower clearance and longer elimination half life of amikacin in the STF following amikacin administration in early stage of severe burns. Elimination half-life of amikacin in the STF in severely burned patients was 28.20-44.78 times longer than that in the serum of normal volunteers, and the effective inhibitory concentration of amikacin could maintain for at least 24 h, suggesting antibiotic retention in the third space after early and short-term use of potent antibiotics and formation of antibiotic barrier in the STF, which may help prevent bacterial infection of the wound.

[Effect of intralipid for ameliorating protein loss in severe burned patients].

OBJECTIVE: To investigate the effect of intralipid on protein consumption in severe burned patients. METHODS; Sixty-seven nonoperative patients with severe burns were divided into Intralipid treatment group and non-intralipid treatment group (control group), and the former was treated with 20% intralipid (500 ml once a day) from postburn day 4 for 10 consecutive days. Venous blood samples were collected from these patients for testing total protein, albumin, total cholesterol and triglyceride on postburn days 1, 7 and 14, respectively. RESULTS: The levels of total protein, albumin, total cholesterol and triglyceride were within normal range on postburn day 1 in both groups, and only the albumin level was lowered in the groups on day 7 but at comparable magnitudes (32+/-4.83 vs 31+/-5.04 g/L, P<0.05). In contrast, the levels of total protein, albumin, total cholesterol and triglyceride were below the normal range on postburn day 14 in both groups, but intralipid treatment group showed more albumin loss than the control group (28+/-6.46 vs 23+/-7.03 g/L, P<0.01). CONCLUSION: Intralipid (20%) provides good energy source to ameliorate albumin loss in severe burned patients.

[Effect of asiaticoside on the expression of transforming growth factor-beta mRNA and matrix metalloproteinases in hypertrophic scars].

OBJECTIVE: To investigate the effect of asiaticoside on the expressions of transforming growth factor (TGF)-beta mRNA, matrix metalloproteinases (MMPS) and tissue inhibitors of metalloproteinases (TIMPs) in postburn hypertrophic scars. METHODS: Nine specimens of postburn (5-8 months) hypertrophic scars with asiaticoside treatment and 9 without asiaticoside treatment were collected for testing the expressions of MMPS, TIMPs, type I and III collagen and TGF-beta mRNA by immunohistochemistry and in situ hybridization methods, followed by image analysis of the results. RESULTS: The expressions of TGF-beta mRNA and MMPS/TIMPS were all detected in the fibroblast cytoplasm. The expression of TGF-beta(1) mRNA in asiaticoside-treated scars was significantly lower than that in scars without asiaticoside treatment (P<0.01). In contrast, the expression of TGF-beta(3) mRNA was significantly higher in asiaticoside group (P<0.05). The expression of TIMP1 in asiaticoside group was significantly lower than that in non-asiaticoside group (P<0.01), and the expression of type I collagen in asiaticoside-treated scars was lower than that in non-asiaticoside-treated specimens (P<0.05), but the expression of MMP(1), MMP(2) and TIMP(2) and type III collagen exhibited no significant differences between the two groups (P>0.05). CONCLUSION: Asiaticoside can down-regulate TGF-beta(1) mRNA and TIMP(1) expressions and up-regulate TGF-beta(3) mRNA expression in postburn hypertrophic scars, and is also capable of decomposing the products of type I collagen, contributing to the reduction of hypertrophic scar formation.

[Morphological changes in intestinal villi after severe burns in rats].

OBJECTIVE: To investigate the morphological changes in intestinal villi after severe burns in rats, so as to explore its possible relationship with enteral bacterial translocation. METHODS: Fifty Wistar rats were employed in the study, 10 of them were assigned to the control group (C). The rest 40 rats were subjected to 30% TBSA full-thickness scalding (burn group, B). 4 ml/100 g normal saline was given intra-peritoneally to the injured rats. The changes of the caliber of the central chyliferous vessel, the intestinal water content and the mucosal morphology of the terminal ileum were determined in the rats in C group and in B group at 8, 12, 24 and 48 postburn hours. The morphology of villi was observed with scanning electron microscope and light microscope. RESULTS: The ileal villi appeared normal in C group. The central chyliferous vessel dilated persistently in rats of B group at all postburn time points, and dilatation was more evident in B group compared with control group (P < 0.01). At the same time an abundant amount of lymph was observed in the central chyliferous vessel. The intestinal water contents decreased to (70.5 +/- 2.2)% and (69.5 +/- 3.1)% in rats of B group at 8 and 12 PBHs, respectively, and they were obviously lower than that in C group (76.9 +/- 1.5)%, (P < 0.01). The intestinal water content in B group was similar to that in C group at 24 and 48 PBH (P > 0.05). CONCLUSION: The morphological changes in the intestinal villi of rats with severe burn injury may predispose the invasion of enteral toxin and bacteria. Intestinal lymphatics can be an important route for enteral bacterial translocation. The water reabsorption of the intestinal mucosa can be transiently enhanced during early postburn stage.

[Changes in proinflammatory cytokines and immune function of subeschar tissue fluid during early stage after severe burn].

OBJECTIVE: To evaluate the inflammatory response and immune function of subeschar tissue fluid (STF) in early stage of severe burn. METHODS: Eight patients were observed and samples from blood as well as STF were collected at 16, 24, 32, 40, 48 hours following burn to measure white blood cell (WBC) counts, levels of immunoglobin (IgA, IgG, IgM), complement (C3, C4) values as well as proinflammatory cytokines as tumor necrosis factor-alpha (TNF-alpha), interleukin-6(IL-6) and IL-8. In addition, twenty Balb-c mice were used for the lethal experiment by STF collected at 48 hours after burn. RESULTS: The levels of IgA, IgG, IgM in STF were about half of those in the blood samples (all P<0.01). The WBC counts in STF were 1/100 time of that in the blood (all P<0.01). The contents of TNF-alpha, IL-6 and IL-8 in STF were comparable with those in the blood (P>0.05). Following STF challenge, none of the mice died during 7-day observation period. CONCLUSION: The cells and large molecules seems to be more difficult to enter STF compared with small molecules. No marked local inflammatory response occurs in STF during early stage of severe burn, and STF challenge has no lethal effect. The low WBC counts and low immunoglobin as well as complement levels imply the limited effect of STF on local infection, and effective antibiotics should be timely used after major burn.

[Clinical evaluation of the postburn retention and the metabolism of Imipenem in the third space].

OBJECTIVE: To explore the half life and retention of Imipenem in the third space. METHODS: Eight severely burned patients and eight healthy volunteers were enrolled as the burn group (B) and normal control group (C), respectively. HPLC (high performance liquid chromatography) was employed to determine the contents of Imipenem in the plasma, subeschar tissue fluid (STF) and the changes in its pharmacokinetics. Furthermore, the Imipenem content in the third space was calculated according to the systemic edema degree. RESULTS: The half life of Imipenem in STF (2.53 h) was longer than that in plasma (1.73 h), P < 0.05). The Imipenem content in STF increased gradually along with the lapse of time after repeated intravenous infusion of Imipenem, and at the same the total content of imipenem was increased significantly in the third space. CONCLUSION: There was antibiotic retention in the third space after severe burn injury, and a prolonged action of the drug could be expected when the drug re-entered the blood stream.