Buqi-Huoxue-Tongnao decoction drives gut microbiota-derived indole lactic acid to attenuate ischemic stroke via the gut-brain axis.

BACKGROUND: Ischemic stroke belongs to "apoplexy" and its pathogenesis is characterized by qi deficiency and blood stasis combining with phlegm-damp clouding orifices. Buqi-Huoxue-Tongnao decoction (BHTD) is a traditional Chinese medicine formula for qi deficiency, blood stasis and phlegm obstruction syndrome. However, its efficacy and potential mechanism on ischemic stroke are still unclear. This study aims to investigate the protective effect and potential mechanism of BHTD against ischemic stroke. MATERIALS AND METHODS: Middle cerebral artery occlusion (MCAO) surgery was carried out to establish an ischemic stroke model in rats. Subsequently, the rats were gavaged with different doses of BHTD (2.59, 5.175, 10.35 g/kg) for 14 days. The protective effects of BHTD on the brain and gut were evaluated by neurological function scores, cerebral infarction area, levels of brain injury markers (S-100B, NGB), indicators of gut permeability (FD-4) and bacterial translocation (DAO, LPS, D-lactate), and tight junction proteins (Occludin, Claudin-1, ZO-1) in brain and colon. 16S rRNA gene sequencing and metabolomic analysis were utilized to analyze the effects on gut microecology and screen for marker metabolites to explore potential mechanisms of BHTD protection against ischemic stroke. RESULTS: BHTD could effectively mitigate brain impairment, including reducing neurological damage, decreasing cerebral infarction and repairing the blood-brain barrier, and BHTD showed the best effect at the dose of 10.35 g/kg. Moreover, BHTD reversed gut injury induced by ischemic stroke, as evidenced by decreased intestinal permeability, reduced intestinal bacterial translocation, and enhanced intestinal barrier integrity. In addition, BHTD rescued gut microbiota dysbiosis by increasing the abundance of beneficial bacteria, including Turicibacter and Faecalibaculum. Transplantation of the gut microbiota remodeled by BHTD into ischemic stroke rats recapitulated the protective effects of BHTD. Especially, BHTD upregulated tryptophan metabolism, which promoted gut microbiota to produce more indole lactic acid (ILA). Notably, supplementation with ILA by gavage could alleviate stroke injury, which suggested that driving the production of ILA in the gut might be a novel treatment for ischemic stroke. CONCLUSION: BHTD could increase gut microbiota-derived indole lactic acid to attenuate ischemic stroke via the gut-brain axis. Our current finding provides evidence that traditional Chinese medicine can ameliorate central diseases through regulating the gut microbiology.

The relationship between intraoperative hypothermia and postoperative delirium: The PNDRFAP study.

OBJECTIVE: Our study aimed to investigate the correlation between intraoperative hypothermia and postoperative delirium (POD) in patients undergoing general anesthesia for gastrointestinal surgery. METHODS: The study comprised 750 participants from the Perioperative Neurocognitive Disorder Risk Factor and Prognosis (PNDRFAP) study database, which ultimately screened 510 individuals in the final analysis. Preoperative cognitive function was evaluated using the Mini-Mental State Examination (MMSE). The occurrence of POD was determined using the Confusion Assessment Method, and the severity of POD was evaluated using the Memorial Delirium Assessment Scale. Logistic regression was employed to scrutinize the association between intraoperative hypothermia and the incidence of POD, and the sensitivity analysis was conducted by introducing adjusted confounding variables. Decision curves and a nomogram model were utilized to assess the predictive efficacy of intraoperative hypothermia for POD. Mediation analysis involving 10,000 bootstrapped iterations was employed to appraise the suggested mediating effect of numeric rating scale (NRS) scores at 24 and 48 h post-surgeries. The receiver-operating characteristic (ROC) was utilized to evaluate the effectiveness of intraoperative hypothermia in predicting POD. RESULTS: In the PNDRFAP study, the occurrence of POD was notably higher in the intraoperative hypothermia group (62.2%) compared to the intraoperative normal body temperature group (9.8%), with an overall POD incidence of 17.6%. Logistic regression analysis, adjusted for various confounding factors (age [40-90], gender, education, MMSE, smoking history, drinking history, hypertension, diabetes, and the presence of cardiovascular heart disease), demonstrated that intraoperative hypothermia significantly increased the risk of POD (OR = 4.879, 95% CI = 3.020-7.882, p < .001). Mediation analyses revealed that the relationship between intraoperative hypothermia and POD was partially mediated by NRS 24 h after surgery, accounting for 14.09% of the association (p = .002). The area under the curve of the ROC curve was 0.685, which confirmed that intraoperative hypothermia could predict POD occurrence to a certain extent. Decision curve and nomogram analyses, conducted using the R package, further substantiated the predictive efficacy of intraoperative hypothermia on POD. CONCLUSION: Intraoperative hypothermia may increase the risk of POD, and this association may be partially mediated by NRS scores 24 h after surgery.

The relationship between mild cognitive impairment and postoperative delirium undergoing total knee arthroplasty: The PNDABLE study.

Background: Patients undergoing surgery are at a higher risk of developing postoperative delirium (POD) as a result of anesthesia and surgical procedures. This study examined the association between POD and mild cognitive impairment (MCI) and whether MCI influences POD through the core pathology of POD. Methods: We enrolled Chinese Han patients undergoing unilateral total knee arthroplasty (aged 50-90, weighing 50-80 kg, and using ASAI-II), combined with epidural anesthesia between October 2020 and June 2021. All the participants were assessed using Winblad's criteria for diagnosing MCI on pre-operation and using the Confusion Assessment Method (CAM) and the Memorial Delirium Assessment Scale (MDAS) postoperative 1-7 days (or before discharge) for diagnosing POD by an anesthesiologist. Cerebrospinal fluid (CSF) biomarkers of POD were measured by enzyme-linked immunosorbent assay (ELISA). To examine the mechanism by which POD pathologies affect cognition, causal mediation analyses were performed. Results: POD incidence was 20.2%, including 32.5% in the MCI group and 12.4% in the non-mild cognitive impairment (NMCI) group. The MCI and CSF levels of T-tau and P-tau were risk factors, and the CSF levels of Aß42, Aß42/ T-tau, and Aß42/ P-tau were protective factors in POD (p < 0.05). Part of the effects of MCI on cognition can be attributed to amyloid pathology and tau. Conclusion: MCI may be a reasonably good prognostic factor in POD development. Overall, amyloid pathology and tau protein might partially mediate the influence of MCI on POD. Clinical trial registration: www.clinicaltrials.gov, identifier: ChiCTR2000033439.

The Relationship Between Cardiovascular Disease Risk Score and Postoperative Delirium: The PNDABLE Study.

Objective: We aimed to investigate the relationship between Framingham Heart Study general cardiovascular disease risk score (FHS-CVD risk score) and postoperative delirium (POD) among patients who had unilateral total knee arthroplasty performed under epidural anesthesia. Furthermore, we examined whether such a hypothesized relationship was mediated by the cerebrospinal fluid (CSF) biomarkers. Methods: A total of 750 participants were included in the current study. And the data were drawn from the database obtained from the Perioperative Neurocognitive Disorder And Biomarker Lifestyle (PNDABLE) study. The preoperative cognitive function of participants was measured by using Mini-Mental State Examination (MMSE). The incidence of POD was assessed using the Confusion Assessment Method (CAM). The POD severity was measured using the Memorial Delirium Assessment Scale (MDAS). The POD CSF biomarkers included in the current study were: Aß42, T-tau, P-tau, Aß42/T-tau, and Aß42/P-tau. The level of the CSF biomarkers was measured using the enzyme-linked immune-sorbent assay (ELISA) in the PNDABLE study. Linear regression analysis was performed to examine the relationship between the FHS-CVD risk score and the POD CSF biomarkers. Logistic regression was used to analyze the relationship between FHS-CVD risk score, POD CSF biomarkers, and POD incidence. The proposed mediating effect of CSF biomarkers was evaluated using Mediation Analysis with 10,000 bootstrapped iterations. The receiver operating characteristic (ROC) curve is chosen as the evaluation metric for assessing the efficacy of the FHS-CVD risk score in predicting POD. Results: In the PNDABLE study, the overall incidence of POD was 22.9% with 37.2% in the higher vascular risk group and 7.9% in the lower vascular risk group. Multiple linear regression models showed that a higher preoperative FHS-CVD risk score was positively correlated with CSF T-tau (ß = 0.218, P = 0.015) and P-tau level (ß = 0.309, P < 0.001) in the higher vascular risk group. After adjusting for age (40-90 years), gender, education, MMSE, smoking history, drinking history, hypertension, diabetes, and the presence of CHD (cardiovascular heart disease), the results of the logistic regression analysis demonstrated the effect of Aß42 (OR = 0.994, 95% CI 0.992-0.996, P < 0.001), Aß42/T-tau (OR = 0.353, 95% CI 0.254-0.491, P < 0.001), and Aß42/P-tau (OR = 0.744, 95% CI 0.684-0.809, P < 0.001) in protecting patients against POD. However, the FHS-CVD risk score (OR = 1.142, 95% CI 1.017-1.282, P = 0.025) and the remaining two biomarkers: T-tau (OR = 1.005, 95% CI 1.004-1.007, P < 0.001) and P-tau (OR = 1.045, 95%CI 1.029-1.062, P < 0.001) were identified as the risk factors. Mediation analyses revealed that the association between FHS-CVD risk score and POD was partially mediated by T-tau (proportion: 31.6%) and P-tau (proportion: 23.6%). The predictive power of the FHS-CVD risk score was validated by the ROC curve with an AUC of 0.7364. Conclusion: Higher vascular risk score is one of the preoperative risk factors for POD, which is partly mediated by CSF biomarker tau protein. Clinical Trial Registration: [www.clinicaltrials.gov], identifier [ChiCTR2000033439].

Vascularization of Lando® dermal scaffold in an acute full-thickness skin-defect porcine model.

The Lando® dermal scaffold is a newly developed, tissue-engineered dermal scaffold material. This study sought to observe its vascularization in an acute full-thickness skin-defect porcine model. There were eight Tibetan pigs in this research. Six 5 × 5 cm full-thickness skin-defect wounds were prepared on the dorsal area of each pig, which were divided into two groups. The experimental group wounds were covered by Lando® dermal scaffolds, while the other received Vaseline gauzes as blank control. At day 3, 7, 14 and 21 after injury, the general condition of wounds was observed, and wound specimens were obtained for HE staining, Masson staining and the expression of CD31, α-SMA and VEGF, which were examined by immunohistochemistry. The results showed the wounds in the experimental group (Lando) were drier with a lower incidence of infection, and the granulation tissues grew better and smoother than the control group. In the experimental group, the hyperemia, edema and inflammatory reactions were milder, the fibroblasts ingrew earlier, the capillaries grew mostly parallel to the wound surface which resembled normal skin, and the collagen fibers were thicker with more regular arrangement than in the control group. The CD31 + microvessel count, α-SMA + microvessel count and VEGF expression of the experimental group were significantly higher than the control group at day 7 and 14 after injury (p < .05). In conclusion, the Lando® dermal scaffold showed good vascularization at day 14 post grafting in an acute full-thickness skin-defect porcine model, which may be associated with increased expression of VEGF.

Seawater immersion aggravates burn-associated lung injury and inflammatory and oxidative-stress responses.

With the increasing frequency of marine development activities and local wars at sea, the incidence of scald burns in marine accidents or wars has been increasing yearly. Various studies have indicated that immersion in seawater has a systemic impact on some organs of animals or humans with burn. Thus, for burn/scald injuries after immersion in seawater, it is desirable to study the effects and mechanisms of action on important organs. In the present study, we aimed to investigate the effect of immersion in seawater on lung injury, inflammatory and oxidative-stress responses in scalded rats. The structural damage to lungs was detected by hematoxylin and eosin staining and the results showed that seawater immersion aggravated structural lung injury in scalded rats. The expression of HMGB1 in lung tissues was detected by immunohistochemical analysis and the results showed that seawater immersion increased HMGB1 expression in lung tissues of scalded rats. Apoptosis in lung tissues was detected by terminal deoxynucleotidyl transfer-mediated dUTP nick end-labeling (TUNEL) staining and the results showed that seawater immersion increased apoptosis rate in lung tissues of scalded rats. In addition, the expression levels of TNF-α, IL-6, IL-8, SOD, and MDA in serum were analyzed by enzyme-linked immunosorbent assays (ELISAs) and the results showed that seawater immersion induced secretion of proinflammatory factors (TNF-α, IL-6, and IL-8), increased MDA protein level, and suppressed SOD activity in the serum of scalded rats. Furthermore, measurement of plasma volume and pH showed that seawater immersion decreased plasma volume and pH value. Overall, the results indicated that all effects induced by immersion in seawater in scalded rats are more pronounced than those induced by freshwater. In conclusion, seawater immersion may aggravate lung injury and enhance inflammatory and oxidative-stress responses after burn.

[Effects of vacuum sealing drainage combined with irrigation of oxygen loaded fluid on wounds of pa- tients with chronic venous leg ulcers].

OBJECTIVE: To evaluate the therapeutic effects of VSD combined with irrigation of oxygen loaded fluid on the growth of granulation tissue and macrophage polarization in chronic venous leg ulcers. METHODS: Thiry-four patients with chronic venous leg ulcers hospitalized in our department from December 2010 to July 2014 were divided into VSD group ( A, n = 11) , VSD + irrigation group ( B, n = 11) , and VSD + oxygen loaded fluid irrigation group ( C, n = 12) according to the random number table. After admissian, debridement was performed, and granulation tissue in the center of the wound was harvested during the operation. After dehridement, the patients in group A were treated with VSD only (negative pressure from -30 to -25 kPa, the same below) ; the patients in group B were treated with VSD combining irrigation of normal saline; the patients in group C were treated with VSD combining normal saline loaded with oxygen irrigation (flow of 1 L/min) . On post treatment day (PTD) 7, the VSD devices were removed. Cross observation was conducted before debridement and on PTD 7. On PTD 7, the granulation tissue in the center of the wound was harvested for histopathological observation with HE staining and Masson staining, following calculation of granulation tissue coverage rate. After debridement but before the negative pressure therapy (hereinafter referred to as before treatment) and on PTD 7, partial pressure of oxygen of the skin around the wound was measured by transcutaneous tissue oxygen tension survey meter. On PTD 7, expression of vascular endothelial growth factor (VECF) was determined with immunohistochemistry. Before treatment and on PTD 7, cells with double positive expressions of induced nitric oxide synthase plus CD68 ( type I macro- phage) and arginase 1 plus CD68 ( type II macrophage) were observed with immunofluorescence staining and quantified. Data were processed with Fisher's exact test, one-way analysis of variance, covariance analysis, paired test, and LSD test. RESULTS: (1) The gross observation showed that before debridement there was a certain amount of necrotic tissue and little granulation tissue in the wounds of patients in all the 3 groups. On PTD 7, new granulation tissue was found in the wounds of patients in all the 3 groups, and in group C its amount was the largest. (2) On PTD 7, the granulation tissue coverage rate of wounds in pa- tients of group C was higher than that of group A or B ( P <0.05 or P <0.01). (3) On PTD 7, HE staining showed that there appeared more abundant new born microvessels and fibroblasts in the wounds of patients in group C than those in groups A and B; Masson staining showed that there was more abundant fresh collagen distributed orderly in the wounds of patients in group C compared with group A or B. (4) On PTD 7, it was found that partial pressure of oxygen of the skin around the wounds in patients of group C [(40.7 +/- 4.1) mmHg, 1 mmHg = 0.133 kPa] was higher than that of group A [ (35.0 +/- 3.1) mmHg] or B [(35.4 +/- 2.7) mmHg, with P values below 0.01]; the partial pressure of oxygen of the skin around the wounds of patients in all the 3 groups was increased significantly compared with that before treatment (with values from 10.38 to 22.52, P values below 0.01). (5) On PTD 7, the expression of VECF in the wounds of patients in group C was higher than that in group A or B ( P <0.05 or P < 0.01). (6) On PTD 7, the number of type I macrophages in granulation tissue of patients was respectively 14.3 +/- 2.3, 11.5 +/- 3.0, and 10.7 +/- 2.3 per 400 times vision field in groups A , B, and C ( F = 25.14, P < 0.01), while the number in group C was less than that in group A or B ( P < 0.05 or P < 0.01). Compared with that before treatment, the number of type I macrophages was significantly decreased on PTD 7 in all the 3 groups (with values from 14.76 to 23. 73, P values below 0. 01). On PTD 7, the number of type II macrophages in granulation tissue of patients was respectively 32.7 +/- 3.2, 35.1 +/- 3.3 , and 41.3 +/- 3.2 per 400 times vision field in groups A, B, and C ( F = 81.10, P < 0.01), and the number in group C was lager than that in group A or B ( with P values below 0. 01). Compared with that before treatment, the number of type II macrophages in all the 3 groups was significantly increased (with t values from -69.34 to -47.95, P values below 0.01). CONCLUSIONS: VSD combined with irrigation of oxygen loaded fluid can raise the partial pressure of oxygen of the skin around the wounds effectively, promoting the transition of macrophages from type I to type II, thus it may promote the growth of granulation tissue, resulting in a better recipient for skin grafting or epithelization.

[Seawater exposure exacerbates scald burns-induced intestinal injury in rabbits: study of the mechanisms].

OBJECTIVE: To investigate the effect of seawater exposure on intestinal injury in rabbits with scald burns and explore the mechanisms. METHODS: Sixty-three rabbits with scald burns covering 20% total body surface area were randomized equally into scald control group (group A), scald with freshwater exposure group (group B), and scald with seawater exposure group (group C). At 2, 4 and 8 h after scald burns, 7 rabbits from each group were sacrificed for detecting plasma superoxide dismutase (SOD) and lipid peroxide (LPO) levels and intestinal contents of prostaglandins (PGs) and for examining the intestinal pathologies; immunohistochemistry was used to detect the expression of Bax and Bcl-2 proteins in the small intestinal epithelium. RESULTS: The rabbits in group C showed severer intestinal mucosal and barrier function damages than those in groups A and B. The plasma SOD activity and intestinal PGs contents were significantly lowered in group C than in groups A and B at 2, 4, and 8 h postburn (P<0.01) and reduced as the postburn time extended (P<0.01). In group C, plasma LPO content was the highest among the groups (P<0.01) and increased significantly with the seawater exposure time (P<0.01). The expression of Bax and Bcl-2 in the intestinal mucosal tissues was also the highest in group C (P<0.01) at 4 h and 8 h postburn and increased significantly with time (P<0.01). CONCLUSION: Seawater exposure exacerbates scald burn-induced intestinal mucosal and barrier function damages in rabbits mainly by aggravating intestinal inflammation and structural damage, as evidenced by decreased intestinal PGs contents and plasma SOD activity, increased plasma PLO content, and enhanced Bax and Bcl-2 protein expressions in the intestinal mucosa.

Expression of vascular endothelial growth factor in deep second-degree scald wounds in rats.

OBJECTIVE: To observe the expression of vascular endothelial growth factor(VEGF)in deep second-degree scald wounds,with an attempt to further explore the role of VEGF in burn wound healing. METHODS: Totally 36 adult Wistar rats were randomized into two groups: the scald group(30 rats)and the control group(6 rats). In the scald group,rat models of deep second-degree scald wounds were established. Full-thickness tissues of the wounds were collected respectively 1,3,7,14,and 21 days after the modeling. The expressions of the VEGF mRNA and protein were detected with real-time quantitative PCR and Western blot,respectively. In the control group,the same procedures were performed but without modeling. RESULTS: Compared with the control group,the expressions of VEGF mRNA and proteins were significantly higher in the scald group(P<0.05). The expression levels reached the peak on day 1,gradually decreased on day 3,reached the lowest points on day 14,but increased again on day 21. CONCLUSIONS: VEGF is involved in the healing of scald burns. The expression of VEGF during the wound healing is closely correlated with the wound angiogenesis.

[Effects of exendin-4 on rat cardiomyocyte apoptosis early after severe scald injury].

OBJECTIVE: To observe the effect of exendin-4 on cardiomyocyte apoptosis in the early stage after scald injury in rats and explore the mechanisms. METHODS: Fifty-four healthy adult SD rats were randomly divided into normal control group (n=6), scald group (n=24) and scald with exendin-4 treatment group (n=24). In the latter two groups, the rats were subjected to 30% TBSA full-thickness scald burns on the back, and Parkland formula was used for determining the resuscitation fluid volume. In exendin-4 treatment group, the rats received intraperitoneal injection of 5 µg/kg exendin-4 after the scald. Apoptosis of the cardiomyocytes from the left ventricle was determined by TUNEL assay and the activity of caspase-3 in the myocardium was assessed. RESULTS: In the scald group, the apoptotic index of the cardiomyocytes was increased at 6 h post-burn, reaching the peak level at 12 h, and maintained a significantly higher level than that in the normal control at 48 h (P<0.05). Myocardial caspase-3 activity in the scald group was increased at 6 h post-burn and reached the peak at 12 h, still maintaining a high levels at 24 h (P<0.05). In exendin-4 treatment group, the apoptotic index of the cardiomyocytes was significantly lower than that in the scald group at 6, 12, 24 and 48 h post-burn (P<0.05), and so was the caspase-3 activity at 6, 12 and 48 h (P<0.05). A significant positive correlation was found between the apoptotic index of the cardiomyocytes and myocardial caspase-3 activity in the rats (P<0.05). CONCLUSION: Exdendin-4 can inhibit rat cardiomyocyte apoptosis early after scald injury possibly by suppressing caspase-3 activity in the myocardium.

[Effect of nuclear factor-kappaB activation on expression of proinflammatory cytokines in rat lung tissues in early stage of burn injury].

OBJECTIVE: To investigate the effect of nuclear factor-kappaB (NF-kappaB) activation on the expression of proinflammatory cytokines in the lung tissues of rats with early-stage burn injury. METHODS: Wistar rats were randomly divided into 3 groups, namely the normal control, burn, burn and PDTC treatment groups, and in the latter two groups, the rats were subjected to 35% TBSA full-thickness burns. Activation of pulmonary NF-kappaB at 1, 3, 6, 12, and 24 postburn hour (PBH) was tested by electrophoretic mobility shift assay , and the expressions of pulmonary tumor necrosis factor alpha (TNF alpha) and interleukin-8 (IL-8) mRNAs at 3, 6, 12, and 24 h were detected by RT-PCR. RESULTS: Compared to that of the control group, activity of pulmonary NF-kappaB in burned rats was markedly increased within 1 PBH and kept increasing till 24 h. Expressions of pulmonary TNF alpha and IL-8 mRNAs increased gradually, reaching the peak level at 6 PBH, and PDTC could effectively inhibit pulmonary NF-kappaB activation and expression of the pulmonary cytokines induced by the burn injury. CONCLUSION: Severe burn injury may activate pulmonary NF-kappaB, which ultimately leads to secretion of cytokines in the lung tissues.

[Sequential management of residual wounds in burn patients].

OBJECTIVE: To seek a sequential method for the management of residual wounds in burn patients. METHODS: Three chronic residual wounds on each of 25 burn patients were either covered with vaseline gauze (A group), human tissue-engineered active skin (Active Skin, B group) or Active Skin after rinsing with fluid containing oxygen and vacuum assisted drainage ( C group) on wounds. The contents of (TNF)a in granulation tissue were assayed by enzyme linked immunosorbent assay (ELISA). Expression of metalloproteinase-13 (MMP-13) mRNA in granulation tissue was determined with reverse transcription polymerase chain reaction (RT-PCR). Moreover, quantity of wound bacteria in the wounds and wound healing rate were determined with usual method. RESULTS: The quantities of wound bacteria in C group on 3,6,9, 12 post-treatment day( PTD) were (5.30 +/- 1.60), (1.30 +/-0.80) , (1.70 +/- 0. 60)and (0.60 +/-0. 10)clone formation unit/ml( CFU/ml) , respectively, which were obviously lower than those in A and B groups. The contents of TNFa and expression of metalloproteinase-13 (MMP-13) mRNA in granulation tissue in C group on 6 PTD were [ (0. 650 +/- 0. 040) ng/mg and 0. 210 +/- 0. 010,] ,respectively, and they were evidently lower than those in A group [(1.550 +/-0. 370)ng/mg,1. 040 +/- 0. 050, P <0.01] and B group (0. 810 +/- 0.080) ng/mg, 0.640 +/- 0.030, P <0.01]. Meanwhile, the contents of (TNF)a and expression of MMP-13 mRNA in B group were also obviously lower than those in A group. The wound healing ratio in C group on 15 and 30 PTD were markedly higher than those in A or B group ( P <0.01). CONCLUSION: Covering the residual burn wounds with Active Skin after rinsing with fluid containing oxygen followed by vacuum assisted drainage can improve repairing of residual burn wounds.

[Experimental study of gene transfer of insulin-like growth factor I on wound healing of scald rats].

OBJECTIVE: To probe into the effect of IGF-I gene transfer on wound healing of scald rats. METHODS: Eukaryotic recombinant plasmid of pcDNA3.1/ IGF-I (successfully constructed by our study group earlier) transported by liposome were injected subdermally in wound region of scald rats. Changes of body weight and tendency of wound healing were observed carefully within 5 weeks postburn. The expression of IGF-I gene transfer in serum and liver was observed with immunohistochemical staining. RESULTS: The results of animal experiment showed that IGF-I gene transported by liposome expressed positively in fibroblast in burn wound, but expressed negatively in liver tissue with immunohistochemical staining, There were no significant differences for IGF-I concentrations in serum among treatment group and control group (P > 0.05). The speed of wound healing for animals injected with IGF-I reconstruct was faster than those which didn't injected IGF-I (P < 0.05); The body weight of the animals in the group injected with IGF-I hadn't a loss in 5 weeks postburn, but those which didn't injected IGF-I had a loss in body weight during postburn days ( P < 0.05). CONCLUSIONS: Gene transfer of IGF-I transported by liposome can promote wound healing, and it also could avoid some adverse effect brought by application of IGF-I systematically .

[Influence of substance P on the proliferation and apoptosis of fibroblasts of pathological scars].

OBJECTIVE: To further explore the effects of substance P on the proliferation and apoptosis of fibroblasts obtained from pathological scars in vitro. METHODS: Fibroblasts from keloid (KSF) , hypertrophic scar (HSF) and normal dermis (NDF) of 12 burn patients were cultured in vitro and divided into control, SP (with 1 x 10 (-6) mol/L SP added to the culture medium) , and SP + spantide( with 1 x 10 (-6) mol/L SP and 3 x 10 (-5) mol/L spantide added to the culture medium) groups. MTT method or flow cytometry assay was used for the determination of the proliferative activities or apoptotic rate of fibroblasts obtained from KSF, HSF and NDF with SP or Spantide. And then the fibroblasts in SP group were subdivided into 1 x 10( -9) -1 x 10 (-5) mol/L groups to examine the time-or dose-effect of SP to fibroblasts from different sources. RESULTS: In control group, different types of fibroblasts exhibited similar proliferative activities and apoptotic rates. But there was significant difference in these indices between control and SP group (the proliferative activity of KSF, HSF, NDF was 0. 656+/-0. 071, 0. 525 +/-0. 064, 0. 404+/-0. 063, respectively; and the apoptotic rate of KSF, HSF, NDF was [( 1.5+/-0.3) % , (4.0+/-0.5) % , (5.5+/-0.7) % , respectively],( P < 0. 05). SP had stronger effect on KSF than it did to HSF, as well as it had stronger effect on HSF than it did to NDF. In SP + spantide group, the effect of SP on KSF was partially inhibited, while it was completely inhibited in cultures of HSF and NDF. KSF was more sensitive to SP and the effect was longer when compared with HSF. CONCLUSION: SP may play an important role in the process of pathological scar formation due to its diverse effects on fibroblasts from different sources.

[Influence of sea water immersion on inflammation and healing of the wounds in scalded rats].

OBJECTIVE: To investigate the influence of sea water immersion on inflammation and healing of the wounds in scalded rats. METHODS: One hundred and forty-four male Wistar rats with 10% TBSA superficial partial-thickness scald were randomly divided into A (n=72, with scald) and B (n=72, with seawater immersion for 4hrs immediately after scald) groups. The serum contents of K+, Na+, Cl- were determined at 0 post-scald hour (PSH), 6PSH, 12PSH and 24 PSH with electrocyte analysis apparatus, and the changes in serum interleukin-6 (IL-6) and tumor necrosis factor (TNF-alpha) levels were determined at 0 PSH, 6PSH and 12 PSH with enzyme-linked immunosorbent assay (ELISA). The histopathological changes in the rats of the two groups were observed, and wound healing time was respectively calculated. RESULTS: The serum contents of K+, Na+, Cl- in B group were obviously higher than those in A group. And the serum content of TNF-alpha and IL-6 in B group at 6 PSH [(140 +/- 22) ng/L, (160 +/- 41) ng/L] were significantly higher than those before scald [(29 +/- 15) ng/L, (62 +/- 17)] ng/L and in A group [(120 +/- 12) ng/L, (124 +/- 22) ng/L, ( P < 0.05)]. Compared with A group, re-epithelization of the wound differentiation in all layers of epidermis were delayed in B group, with more severe wound swelling, exudation, and topical inflammatory response. The wound healing time in B group was (16.3 +/- 1.6) d, which was obviously longer than that in A group [(14.1 +/- 1.8) d, P < 0.05)]. CONCLUSION: Sea water immersion combined with scald injury can aggravate the inflammatory response of the wound and delay the wound healing process.

[Effect of NF-kappaB activation on the early expression of tumor necrosis factor alpha and myocardial dysfunction in burned rats].

OBJECTIVE: To investigate the effect of NF-kappaB activation on the early expression of proinflammatory cytokines in myocardium and early myocardial dysfunction in burn rats. METHODS: One hundred and seventy Wistar rats were enrolled in the study and randomly divided into three groups, i. e. control( C, n = 20, with isotonic saline solution) , burn ( B, n = 90, with isotonic solution after burns) and pyrrolidine dithiocarbamate (PDTC, n =60, with isotonic saline and 250 mg/kg PDTC after burns) groups. The rats in B and PDTC groups were inflicted with 35% TBSA full-thickness burns on the back. The activity of myocardial NF-kappaB was determined by electrophoretic mobility shift assay at 1 , 3, 6, 12,24 postburn hours (PBH), with expression of integral absorbance ( A ) value . The expression of myocardial tumor necrosis factor alpha ( TNF-alpha) mRNA was assessed by reverse transcription polymerase chain reaction( RT-PCR) and in situ hybridization at 6, 12 PBH, with expression ofA value. The left ventricular systolic pressure( LVSP) , the left ventricular end diastolic pressure (LVEDP) ,the maximum rate of rise of left ventricular pressure ( +/- dp/dt max) were also observed at 3, 6, 12,24 PBH. RESULTS The activity of myocardial NF-KB in B group was markedly increased at 1 PBH [ (20. 3+/-3. 4) x 104A ] ,which was obviously higher than that in C group (2. 2 +/- 0. 4) x 104A , P <0.01]. It peaked at 3 PBH, and was still evidently higher than that in C group at 24 PBH ( P <0. 01). The expression of TNF-alpha mRNA was obviously higher than that in C group at 3 PBH ( P < 0. 01) , peaking at 6 PBH, and it was mainly expressed in myocardium. The expression of LVSP and +/- dp/dt max were lower, but LVEDP was higher than that in C group during 3 -24 PBH ( P <0.01).

[Anti-inflammatory activity and healing-promoting effects of topical application of emu oil on wound in scalded rats].

OBJECTIVE: To investigate the effects of topical application of emu oil on wound healing in scalded rats. METHODS: In 144 male Wistar rats with 10%; total body surface superficial II degree scald treated on a random basis with physiological saline, povidone iodine and emu oil, respectively, the changes of the wound were observed and the wound tissue and blood samples harvested at different times after injury for evaluation of histopathological changes, total tissue water content (measured by wet:dry weight ratios), and tumor necrosis factor (TNF)-alpha levels in the wound tissue and plasma by enzyme-linked immunosorbent assay (ELISA). The general condition of the wound healing was also observed. RESULTS: After application of emu oil, the swelling and effusion of the burn wound were alleviated and evidences of wound infection or adverse effects were not observed. Pathological examination showed that emu oil could alleviate topical inflammation, which was particularly obvious on days 1 and 3 after injury as compared with the other two groups. On day 3 after injury, water content and TNF-alpha level in the tissues was markedly decreased with the application of emu oil (P<0.05), with a significant correlation between their changes (P<0.001) and shortened wound healing time (P<0.05). Pathological examination showed that emu oil could promote epithelialization and differentiation of various epidermal layers. CONCLUSION: Emu oil has topical anti-inflammatory activity in rats with superficial II degree scald, possibly in association with decreased levels of the proinflammatory cytokines in the tissues and can promote wound healing by inhibiting local secondary inflammation.

[Changes in the expression of apoptotic genes in the intestinal tissue of scalded rats before and after resuscitation].

OBJECTIVE: To explore the dynamic changes in the expression of c-fos, proliferation cell nuclear antigen (PCNA) and Bax in the intestinal tissue of scalded rats before and after resuscitation. METHODS: Wistar rats inflicted with 30% TBSA full thickness scald were employed as the model and randomly divided into four groups with 8 in each group, i.e. 2.0, 2.5, 4.0, 6.0 postscald hour (PSH) groups. Rats in each group received routine fluid infusion at 2 PSH, and were sacrificed at 2, 2.5, 4, 6 PSH, respectively. Then the intestinal tissue of the rats was harvested for the detection of the expression of c-fos, PCNA and Bax. RESULTS: The expression of c-fos, PCNA and Bax at 2.0 PSH group (65.8 +/- 4.2%, 74.5 +/- 2.4%, 26.3 +/- 5.7%, respectively) significantly increased when compared with those in 2.5 PSH group (92.4 +/- 5.7%, 85.6 +/- 4.5%, 67.1 +/- 6.6%, respectively) (P < 0.01). The expression of 3 genes increased dramatically at 2.5 and 4.0 PSH, and reached the peak at 2.5 PSH. There was no obvious difference in the gene expression between 4 PSH and 2 PSH groups. CONCLUSION: The expression of apoptotic genes in the intestinal tissue of scalded rats increased significantly during early resuscitation stage after burn injury.

[Influence of nuclear factor-kappaB activation on the expression of cytokines in monocytes stimulated by burn serum].

OBJECTIVE: To investigate the effects of NF-kappaB activation on the expression of cytokines in monocytes stimulated by burn serum, so as to explore the mechanism in monocyte activation by burn serum. METHODS: Peripheral blood monocytes (PBMCs) isolated from healthy volunteers were employed as the target cells. The cells were stimulated by serum from healthy volunteers (control), by serum from burn patients (burn serum), and by burn serum with addition of PDTC (pyrrolidine dithiocarbamate). Activation of monocytic NF-kappaB before stimulation and at 0.5, 1.0, 2.0 and 4.0 poststimulation hours (PSH) was assessed with electrophoretic mobility shift assay (EMSA). Expression of TNF-alpha and IL-8 mRNA at 1.0, 2.0, 4.0, 6.0 PSHs was assayed with in situ hybridization (ISH). Meanwhile, the contents of TNF-alpha and IL-8 in the supernatants were assayed by enzyme linked immunosorbent assay (ELISA). RESULTS: The monocytic NF-kappaB activity in burn serum group increased significantly and reached the peak level at 1 PSH [(30.2 +/- 3.5) x 10(4) integration gray scale value] after the PBMCs were stimulated by burn serum, and it was obviously higher than that in control group [(4.4 +/- 0.8) x 10(4) integration gray scale value], (P < 0.01). It gradually decreased and returned to the pre-stimulation state at 2 PSH. The monocytic NF-kappaB activity in PDTC group decreased to [(6.8 +/- 0.9) x 10(4) integration gray scale value at 1 PSH] after the stimulation. The expression of TNF-alpha mRNA of the monocytes and the TNF-alpha level in the supernatant of the cultured PBMCs reached peak level at 1 PSHs after being stimulated by burn serum, and they were obviously higher than those in control group (P < 0.01). While the expression of IL-8 mRNA and the IL-8 level in the supernatant of the cultured PBMCs reached peak level at the 4 PSHs after being stimulated by burn serum, which were obviously higher than those in control group (P < 0.01) too. In addition, the synthesis and release of TNF-alpha (peaked at 1 PSH: 0.52 +/- 0.06 microg/L) and IL-8 (peaked at 4 PSH: 239 +/- 20 ng/L) in the supernatant of PBMCs in PDTC group were evidently higher than those in control group [(0.13 +/- 0.07) microg/L, < 156 ng/L] (P < 0.01). CONCLUSION: Burn serum can induce the activation of NF-kappaB which lead to the synthesis and release of cytokines from PBMC. This result indicates that the activation of NF-kappaB plays important role in the secretion of cytokines from PBMCs induced by the burn serum.

[Effects of early administration of imipenem on subeshcar and plasma TNF-alpha in rabbits with severe burns].

OBJECTIVE: To study the changes in subeschar fluid and plasma TNF-alpha in rabbits with severe burns in response to early administration of imipenem (IPM). METHODS: Sixteen rabbits with severe burns were randomized into 2 two equal groups to receive treatment with 100 mg (100 ml) of IPM q8 hx3 days and equivalent volume of saline , respectively. The levels of TNF-alpha in the subeschar tissue fluids and plasma were determined by double-antibody sandwich enzyme-linked immunosorbent assay (ELISA) after the first initial dose of 100 mg of imipenem/cilastatin, lasting 3 days. RESULTS: The plasma TNF-alpha levels in rabbits increased after the burn injury, reaching the peak level 16 h postburn and sustained the high levels till 72 h. At the same time point, TNF-alpha levels in the subeschar tissue fluids increased evidently in comparison with the plasma level, but both were lowered with early administration of imipenem (P<0.05). CONCLUSION: Subeschar and plasma levels of TNFalpha can be significantly lowered with early-stage administration of imipenem, suggesting that IPM inhibits the release of TNFalpha and endotoxin to relieve or prevent endotoxemia after sever burn injury in rabbits.