Changes in cytokines in lymph and T lymphocyte subsets in lymph node of burned rats / 中华烧伤杂志

<p><b>OBJECTIVE</b>To observe the effect of burn on cytokines in lymph and T lymphocyte subsets in lymph node of rats.</p><p><b>METHODS</b>Eighteen Wistar rats were used in the experiment. One of the hind limbs of each rat was immersed in 70 °C hot water for 30 s to reproduce 4%TBSA deep partial-thickness scald model (burn group), while the other hind limb was immersed in 22 °C warm water for 30 s to simulate scald (sham injury group). On post injury hour (PIH) 6, 24, and 72, 6 rats were chosen according to the random number table. Lymph fluid in the lymph vessel of each animal (two groups) was obtained for determination of levels of tumor necrosis factor α (TNF-α), interferon-γ (IFN-γ) and interleukin-4 (IL-4) by ELISA, and IFN-γ/IL-4 ratio was calculated. Common iliac lymph node of each animal (two groups) was obtained for determination of ratios of CD4(+), CD8(+)T lymphocytes with flow cytometry, and CD4(+)/CD8(+) ratio was calculated. Data were processed with t test.</p><p><b>RESULTS</b>(1) On PIH 6, 24, and 72, TNF-α level in burn group was respectively (51.6 ± 5.4), (27.4 ± 2.6), (23.0 ± 2.7) pg/mL, which were significantly higher than those in sham injury group [(17.8 ± 1.6), (16.4 ± 1.2), (17.2 ± 2.0) pg/mL, with t value respectively 15.346, 11.854, 4.189, P values all below 0.01]. (2) On PIH 6, 24, and 72, there was no significant statistical difference between burn group and sham injury group in IFN-γ level (with t value respectively 2.059, -0.805, -0.415, P values all above 0.05); IL-4 level in burn group was respectively higher than that in sham injury group (with t value respectively 9.141, 11.669, 6.940, P values all below 0.01); IFN-γ/IL-4 ratio in burn group (2.27 ± 0.34, 1.54 ± 0.19, 1.60 ± 0.16) was respectively lower than that in sham injury group (3.33 ± 0.25, 3.34 ± 0.22, 2.52 ± 0.24, with t value respectively -6.298, -11.313, -8.893, P values all below 0.01). (3) On PIH 6 and 24, there was no significant statistical difference between burn group and sham injury group in ratios of CD4(+) and CD8(+)T lymphocytes and also CD4(+)/CD8(+) ratio (with t values from -2.486 to -0.215, P values all above 0.05). On PIH 72, ratio of CD4(+)T lymphocytes and CD4(+)/CD8(+) ratio in burn group was respectively (38.6 ± 2.3)% and 2.13 ± 0.16, which were significantly lower than those in sham injury group [(48.9 ± 2.9)% and 2.68 ± 0.12, with t value respectively -7.551, -5.068, P values below 0.01]; there was no significant statistical difference between burn group and sham injury group in ratio of CD8(+)T lymphocytes (t = 0.845, P > 0.05).</p><p><b>CONCLUSIONS</b>Burn may decrease IFN-γ/IL-4 ratio in locally drained lymph and CD4(+)/CD8(+) ratio in locally drained lymph node of rat, which may indicate lowering of local immune function.</p>

Attach importance to research on lymph circulation system after burns / 中华烧伤杂志

A series of pathophysiological changes in lymph circulation system occur after severe burns. We try to elucidate the importance through summarizing our experiments on some of the changes in lymph circulation based on rat and goat lymphatic fistula model since 1998. The lymphatic contraction frequency decreased while the lymph flow speed increased during burn shock stage. Contents of several key inflammatory factors, such as TNF-alpha, IL-6, IL-8, IL-10, IL-18, and HMGB-1, were increased in lymph or lymph nodes, and they were higher than those in blood and liver. The protein concentration increased in lymph while decreased in plasma. The endotoxin was translocated to lymph earlier than to blood, therefore, the number of E. coli or the number of endotoxin translocated via lymph route were more than those via blood. The bacteria and endotoxin of pseudomonas aeruginosa could invade through local lymphatic route from infected burn wound. Th2 shift from Th1/Th2 occurred in lymph and the ratio of CD4+/CD8+ T lymph cells decreased in lymph nodes after burns, denoting local immunosuppression. The apoptosis of lymphocytes in lymph organ might contribute to this immunosuppression.

Role of lymphatics in bacterial translocation from intestine in burn rats / 中华烧伤杂志

<p><b>OBJECTIVE</b>To investigate the role of lymphatics in bacterial translocation from intestine of rats with burn.</p><p><b>METHODS</b>Escherichia coli (E. coli) labeled with chloromethylbenzamidodialkylcarbocyanine (CM-DIL) were prepared. Sixty adult male Wistar rats were randomly divided into scald group and sham injury group according to the envelope method, with 30 rats in each group. Rats in both groups were gavaged with 0.5 mL fluid containing CM-DIL-labeled E. coli. Rats in scald group were inflicted with 30% TBSA deep partial-thickness scald (verified by pathological section) and resuscitated with fluid. Rats in sham injury group were sham injured by bathing in 25 degrees C water for 10 s (verified by pathological section) and also received with fluid infusion. Mesenteric lymph node (MLN), liver, mesenteric lymph fluid (MLF), and liver vein blood (LVB) were harvested at post injury hour (PIH) 2, 24, and 72. Bacteria translocation was detected with fluorescent tracing technique and bacteria culture. The endotoxin content in above-mentioned four kinds of specimens was quantitatively determined with chromogenic substrate limulus amebocyte lysate. The carrying capacity of endotoxin in MLF and LVB was calculated. Data were processed with t test or one-way analysis of variance.</p><p><b>RESULTS</b>(1) Living bacteria were in short-stick form, and they were seen moving in single or in doubles or triples in sample fluid. Dead bacteria were in irregular aggregates. Labeled bacteria in small amount were detected in sham injury group, their number peaked at PIH 24. A large amount of labeled bacteria were detected in scald group at PIH 2, which peaked at PIH 24 and decreased at PIH 72. The largest amount of labeled bacteria were found in MLN in scald group as compared to those in the other samples, and the number peaked at PIH 24 [(5872 +/- 1976) x 10(3) CFU/g], which was obviously higher than that [(216 +/- 110) x 10(3) CFU/g, t = 30.129, P = 0.000] in sham injury group. The number of bacteria decreased at PIH 72, but it was still significantly different from that in sham injury group ( t = 4.323, P = 0.000). The number of bacteria in LVB was the smallest. (2) 29 (24.2%) samples out of the 120 samples in sham injury group were positive for bacteria. 72 (60.0%) samples out of the 120 samples in scald group were positive for bacteria. No alive bacterium was detected at any time point in LVB sample in both group; the other three samples were detected with alive bacteria since PIH 2. There were more alive bacteria detected in MLN and liver as compared with the other two kinds of samples in scald group. The amount of bacteria in MLN, liver, and MLF in scald group were higher than those in sham injury group (with t value respectively 4.353, 4.354, 4.965, P values all equal to 0.000). (3) The endotoxin level in each kind of sample at each time point was obviously higher in scald group than that in sham injury group, and it peaked at PIH 2 in liver and MLF. The difference of endotoxin level among 4 kinds of samples in scald group at PIH 2 was statistically significant ( F = 258.47, P = 0.000), and the endotoxin level was higher in liver, MLN, and MLF. They were obviously higher than those in sham injury group (with t value respectively 43.378, 43.123, 22.423, P values all equal to 0.000). The endotoxin level in MLF was 9 times of that in LVB. (4) The carrying capacity of endotoxin in LVB and MLF at each time point in scald group was higher than that in sham injury group.</p><p><b>CONCLUSIONS</b>CM-DIL marked bacteria can reflect the microbial translocation condition. The lymphatic route is an important pathway for bacteria translocation.</p>

The significance of TGF-beta expression in scar in adenosine receptor A(2A) knockout mice / 中华整形外科杂志

<p><b>OBJECTIVE</b>To discuss the mechanism of scar hypertrophy in adenosine receptor A(2A) (A(2A) R) knockout mice.</p><p><b>METHODS</b>Animal models of hypertrophic scar were established in 12 A(2A) R knockout mice and 12 wild-type mice as control. The thickness and the size of transverse section of the hypertrophic scar were observed by H-E staining. The hydroxyproline (HYP) in the scar was measured colorimetrically. The TGF-beta expression was tested by Western blotting method.</p><p><b>RESULTS</b>The hypertrophic scar in wild-type mice was more severe than that in knockout mice. Compared with self-control, the increase of the thickness and the size of transverse section of hypertrophic scar was markedly higher in wild-type group than in the knockout group (P < 0.01). There was significant difference in HYP content between the two groups (P < 0.01). Compared with self-control, the increase of TGF-beta expression in wild-type group was much more than that in knockout group (P < 0.01).</p><p><b>CONCLUSIONS</b>The TGF-beta expression decreases in the A(2A) R knockout mice. The scar hypertrophy is also much less in the A(2A) R knockout mice.</p>

Expression of tumor necrosis factor related apoptosis inducing ligand and its receptor in thymus during early post-burn stage in rat with severe burns / 中华烧伤杂志

<p><b>OBJECTIVE</b>To investigate the effect of tumor necrosis factor related apoptosis inducing ligand (TRAIL) and its receptor on apoptosis in thymus during early post-burn stage in rat with severe burns.</p><p><b>METHODS</b>Fifty Wistar rats were randomly divided into sham scald group (SS, n = 10) and burn group (n = 40). The apoptosis in thymus in rats was detected with annexin V/FITC-PI double staining at 4, 12, 24, 48 post-burn hours (PBH). The expression of TRAIL death receptor DR5, DR4 and its decoy receptor DcR1, DcR2 in thymus were detected by RT-PCR and Western blot at above time-points.</p><p><b>RESULTS</b>Compared with that in SS group (6.7 +/- 0.8)%, the apoptosis in the thymus in burn group started to increase at 4 PBH [(17.1 +/- 0.4)%], peaked at 12 PBH [(25.2 +/- 1.1)%], and it was still evidently higher than that in SS group at 48 PBH (P < 0.05). There was no obvious difference in the apoptosis rate in rats in burn group among all the time-points. The expression of DR5 in burn group at each time-points was significantly higher than those in SS group, while that of DcR2 shown an opposite tendency (P < 0.05). The expression of DR4, DcR1 was similar in both groups.</p><p><b>CONCLUSION</b>The marked increase in apoptosis rate in rat thymus at early post-burn stage, and the significant change in the expression of DR5 and DcR2 show that TRAIL pathway may participate in apoptosis.</p>

A basic study and clinical trial of 585 nm pulsed dye laser in the treatment of congestive scars / 中华整形外科杂志

<p><b>OBJECTIVE</b>To study the biological effects of 585 nm pulsed dye laser (FLPDL) in the treatment of congestive scar.</p><p><b>METHODS</b>By histological study, collagen VG staining and microvascular staining, we investigated the changes of collagen fibers and the density of microvessels in the congestive scars after FLPDL treatment.</p><p><b>RESULTS</b>Histological and immunohistochemistry examinations showed that FLPDL achieved normal vascularity in the scar after over 3 times of treatment.</p><p><b>CONCLUSIONS</b>PDL treatment can change fundamentally the physiology of wound healing if applied in the early phases.</p>

Expression and significance of TRAIL receptors in fibroblasts of hypertrophic scar / 中华整形外科杂志

<p><b>OBJECTIVE</b>To detect the expression of TRAIL receptors in fibroblasts of hypertrophic scar in the proliferative stage and explore its significance.</p><p><b>METHODS</b>30 samples of hypertrophic scar were taken from 30 burn cases in the proliferative stage. 30 samples of normal skin were taken as the control. The expressions of TRAIL receptors in the fibroblasts of hypertrophic burn scar and the normal skin were assayed by semiquantitative RT-PCR and flowcytometry.</p><p><b>RESULTS</b>The expression level of DR5 in the fibroblasts of hypertrophic burn scar is much lower than the control (P < 0.05); the expression level of DcR1 in the fibroblasts of hypertrophic burn scar is much higher than the control (P < 0.05).</p><p><b>CONCLUSIONS</b>The down-regulated DR5 expression and elevated DcR1 expressions in the fibroblasts of hypertrophic burn scar may attribute to the apoptosis change induced by TRAIL and explain the apoptosis differences between the fibroblasts of hypertrophic scar and normal skin to a certain extent.</p>

The changes in the tumor necrosis factor alpha, interleukin-6 and interleukin-8 levels in the lymph and of the dynamics of the lymphokines during shock stage of rats with major burns / 中华烧伤杂志

<p><b>OBJECTIVE</b>To study the dynamic changes in the lymphokines and the changes in tumor necrosis factor alpha (TNF-alpha), interleukin-6 (IL-6), interleukin-8 (IL-8) levels in the lymph during shock stage of rats with major burns.</p><p><b>METHODS</b>Forty-two male adult Wistar rats were randomly divided into burn resuscitation group (A, n = 18), burn non-resuscitation (B, n = 18) and the control (C, n = 6) groups. The TNF-alpha, IL-6 and IL-8 levels in the lymph were determined with radioimmunoassay at 6, 24, 48 postburn hours (PBH). The lymphokines in the mesenteric lymphatic vessels was observed at 6, 24 and 48 PBH with inverted microscopy and digital image processing, and the contraction frequency of the lymphatic was calculated. The lymph was collected by cannulation of the chylous cistern, and its speed of flow was calculated.</p><p><b>RESULTS</b>The lymphatic contents of TNF-alpha and IL-6 in both A and B groups began to increase at 6PBH, reaching the peak values at 24 PBH (TNF-alpha in A and B groups were 1.61 +/- 0.27 ug/L and 1.86 +/- 0.34 ug/L, respectively; IL-6 in A and B groups were 398 +/- 67 ng/L and 572 +/- 97 ng/L, respectively), and they were significantly higher than those in C group at each time points (P < 0.01), meanwhile there was also obvious difference in them between A and B groups (P < 0.01). The lymphatic contents of IL-8 in A and B groups began to increase at 24 PBH, and continued to increase till 48PBH (540.29 +/- 0.32 ng/L in A group, 863.48 +/- 105.16 ng/L in B group), which were evidently higher than those in C group (P < 0.01). There was significant difference in IL-8 contents between A and B groups (P < 0.01). The contraction frequency of the mesenteric lymphatic vessels in A and B groups were decreased, especially so at 24 PBH (P < 0.01). The speed of lymphatic flow in A and B groups was increased at each time points (P < 0.01). The central chylous vessels in the villi of the small intestine were extremely dilated as seen under microscope.</p><p><b>CONCLUSION</b>After burn injury, the lymphatic vessels dilated, with its motility decreased and speed of flow increased, and the contents of TNF-alpha, IL-6 and IL-8 in lymph were increased during the shock stage of burn rats. Fluid resuscitation could improve the lymph circulation.</p>

Clinical analysis of severe burn patients with sepsis during shock stage / 中华烧伤杂志

<p><b>OBJECTIVE</b>To investigate the pathogenesis, management and prognosis of severe burn patients with sepsis during shock stage.</p><p><b>METHODS</b>Fourty-four patients inflicted with over 60% TBSA burn injury and admitted to our hospital within 48 hours after injury during the past 8 years were enrolled in the study. The application of antibiotics in this group of patients was analyzed. The incidence of burn sepsis during shock stage in this group was calculated according to the results of the bacterial culture of the blood samples and burn wound samples,as well as the diagnostic criteria of sepsis. The relationship between sepsis during shock stage and the possibility of enteral bacterial translocation was discussed. Other postburn complications in patients with burn sepsis during shock stage were also observed and their prognosis was explored.</p><p><b>RESULTS</b>This group of patients were all treated with 3rd and 4th generation of Cephalosporins and Imipenem/Cilastatin sodium after hospitalization. Burn sepsis during shock stage occurred in 4 cases (9.09%), in which one was caused by Pseudomonas aeruginosa and other three possibly by Escherichia coli, Streptococcus faecalis and Bacillus gasoformans. Among the 4 cases, severe disorder in water and electrolytes happened in 1 case, stress ulcer in 2 and acute renal failure in 2. As a result, only one out of the 4 patients survived.</p><p><b>CONCLUSION</b>Bacterial translocation was probable cause of sepsis during shock stage. Shock might predispose sepsis. Early postburn applications of antibiotics sensitive to enteric bacteria could be beneficial to the management of burn sepsis during shock stage.</p>