[A multi-center, randomized controlled study on the effect of Saccharomyces boulardii combined with triple therapy for the initial eradication of Helicobacter pylori infection]

Objective: To assess the efficacy and safety of Saccharomyces boulardii (S. boulardii) in combination with triple therapy as a first-line regimen for the eradication of Helicobacter pylori (H. pylori) in non-ulcer dyspepsia (NUD) patients. Methods: A total of 497 Helicobacter pylori-positive patients who underwent gastroscopy and diagnosed with NUD were enrolled from June 2018 to January 2020 in 9 medical centers across China. Participants were segmentedly randomly divided into 3 groups. Patients in group A received S. boulardii for 14 days and triple therapy for 10 days, while patients in group B received bismuth quadruple group for 10 days, and patients in group C received triple therapy for 10 days. The H. pylori status was determined by the ¹³C-urea breath test on the 44th day of the treatment. Symptom improvement and adverse reactions were assessed on the 14th and 44th day. Results: There were 229 males and 268 females in all 497 patients enrolled. They were aged 18-69 (46.1±11.8) years and 472 of them (158 cases in group A, 159 cases in group B, and 155 cases in group C) completed the trial. The intention-to-treat (ITT) eradication rates in patients in patients A, B and C were 77.8% (126/162), 80.1% (137/171) and 65.2% (107/164) respectively, and per protocol-based (PP) eradication rates were 79.7% (126/158), 86.2% (137/159) and 69.0% (107/155) respectively. The differences were statistically significant in ITT and PP analysis among 3 groups (ITT: χ²=11.14, P<0.01; PP: χ²=13.86, P<0.01). There was no significant difference between eradication rates of two quadruple therapys(all P>0.05), but both of them were significantly higher than that of standard triple therapy (both P<0.05). Statistics revealed that both quadruple therapys led to significantly higher symptom improvement of belching compared with that of standard triple therapy in day 14 (P<0.05). The relief of abdominal distension and belching symptom scores of group A were significantly higher than those of group C in day 44(all P<0.05). There was no serious adverse event reported. The incidence of diarrhea in group A was significantly lower than those in the other two groups (both P<0.05). Conclusions: The combination of S. boulardii and triple therapy can achieve a better eradication effect on H. pylori infection with NUD, and has advantages in symptom relief and safety.

COVID-19 prevention measures reduce dengue spread in Yunnan Province, China, but do not reduce established outbreak

The COVID-19 pandemic and measures against it provided a unique opportunity to understand the transmission of other infectious diseases and to evaluate the efficacy of COVID-19 prevention measures on them. Here we show a dengue epidemic in Yunnan, China, during the pandemic of COVID-19 was dramatically reduced compared to non-pandemic years and, importantly, spread was confined to only one city, Ruili. Three key features characterized this dengue outbreak: (i) the urban-to-suburban spread was efficiently blocked; (ii) the scale of epidemic in urban region was less affected; (iii) co-circulation of multiple strains was attenuated. These results suggested that countermeasures taken during COVID-19 pandemic are efficient to prevent dengue transmission between cities and from urban to suburban, as well to reduce the co-circulation of multiple serotypes or genotypes. Nevertheless, as revealed by the spatial analysis, once the dengue outbreak was established, its distribution was very stable and resistant to measures against COVID-19, implying the possibility to develop a precise prediction method.

De-ubiquitination of p300 by USP12 Critically Enhances METTL3 Expression and Ang II-induced cardiac hypertrophy

Stresses, such as neurohumoral activation, induced pathological cardiac hypertrophy is the main risk factor for heart failure. The ubiquitin-proteasome system (UPS) plays a key role in maintaining protein homeostasis and cardiac function. However, research on the role and mechanism of deubiquitinating enzymes (DUBs) in cardiac hypertrophy is limited. Here, we observe that the deubiquitinating enzyme ubiquitin-specific protease 12(USP12) is upregulated in Ang II-induced hypertrophic hearts and primary neonatal rat cardiomyocytes (NRCMs). Inhibition of USP12 ameliorate Ang II-induced myocardial hypertrophy, while overexpression of USP12 have the opposite effect. USP12 deficiency also significantly attenuate the phenotype of Ang II-induced cardiac hypertrophy in vivo. Moreover, we demonstrate that USP12 aggravate Ang II-induced cardiac hypertrophy by enhancing METTL3, a methyltransferase which catalyze N⁶-methyladenosine (m⁶A) modification on messenger RNA and acts as a harmful factor in pathological cardiac hypertrophy. Upregulation of METTL3 reverse the reduction of myocardial hypertrophy induced by USP12 silencing in NRCMs. In contrast, knockdown of METTL3 attenuate the aggravation of myocardial hypertrophy in USP12-overexpressing NRCMs. Furthermore, we discover that USP12 promote the expression of METTL3 via upregulating p300. Mechanistically, USP12 binds and stabilizes p300, thereby activating the transcription of its downstream gene METTL3. Finally, our data show that USP12 is partially dependent on the stabilization of p300 to activate METTL3 expression and promote myocardial hypertrophy. Taken together, our results demonstrate that USP12 acts as a pro-hypertrophic deubiquitinating enzyme via enhancing p300/METTL3 axis, indicating that targeting USP12 could be a potential treatment strategy for pathological cardiac hypertrophy.

[Update in immune regulatory dysfunction of dendritic cells in sepsis]

Sepsis is a life-threatening organ dysfunction caused by a dysregulated host response to infection. Further development of sepsis usually leads to septic shock or even death. Many previous studies have focused on the abnormal reactions of monocytes/macrophages, neutrophils, complement system, or cytokine inflammation in sepsis. Many evidences in recent years suggest that dendritic cells, as the most powerful antigen-presenting cells in innate immune system of body, play important role during the process of immune disorders of sepsis. In this article, I review the main classification, immune function, monitoring method, regulatory pathways of dendritic cells and their clinical significance in immune disorders of sepsis, so as to find new strategies for immune regulation of sepsis.

Genomic signatures of 60 years of bidirectional selection for 8-week body weight in chickens

Sixty years, constituting 60 generations, have passed since the founding of the Virginia body weight lines, an experimental population of White Plymouth Rock chickens. Using a stringent breeding scheme for divergent 8-week body weight, the lines, which originated from a common founder population, have responded to bidirectional selection with an approximate 15-fold difference in the selected trait. They provide a model system to study the genetics of complex traits in general and the influences of artificial selection on quantitative genetic architectures in particular. As we reflect on the 60th anniversary of the initiation of the Virginia body weight lines, there is opportunity to discuss the findings obtained using different analytical and experimental genetic and genomic strategies and integrate them with a recent pooled genome resequencing dataset. Hundreds of regions across the genome show differentiation between the 2 lines, reinforcing previous findings that response to selection relied on standing variation across many genes and giving insights into the haplotype complexity underlying regions associated with body weight.

Effect of tumor necrosis factor-α induced protein 8 like-2 on immune function of dendritic cells in mice following acute insults

Tumor necrosis factor-α induced protein 8 like-2 (TNFAIP8L2, TIPE2) is a lately discovered negative regulator of innate immunity and cellular immunity. The present study was designed to investigate whether naturally occurring dendritic cells (DCs) could express TIPE2 mRNA/protein and its potential significance. Expressions of co-stimulatory molecules on DC surface and cytokines were analyzed to assess the functional role of TIPE2 in controlling DC maturation as well as activation. The activated DCs were assessed for their capacity to stimulate the proliferation and differentiation of T cells. It was found that TIPE2 was a cytoplasmic protein expressed in DCs, and the percentage of DCs which expressed co-stimulatory molecules and cytokines were obviously up-regulated when TIPE2 gene silenced by siRNA in vitro and in vivo. DCs undergone TIPE2 knockdown were found to promote the maturation of DCs, T-cell proliferation as well as differentiation, and they were significantly elevated IL-2 level and intranuclear NF-AT activation. Conversely, in over-expressing TIPE2 DC cells, it could inhibit T-cell proliferation and differentiation, and markedly down-regulate IL-2 expression and intranuclear NF-AT activation after scald injury. The results suggested that TIPE2 appeared to be a critical immunoregulatory molecule which affected DC maturation and subsequent T-cell mediated immunity.

Expression and clinical significance of Nectin-4 in hepatocellular carcinoma

OBJECTIVE

Nectin-4 is a member of the Nectin family of four Ca(+)-independent immunoglobulin-like cell adhesion molecules and implicated in cell adhesion, movement, proliferation, differentiation, polarization, and survival. The aberrant expression of Nectin-4 has been found in a variety of tumors; however, its expression in hepatocellular carcinoma (HCC) is still poorly understood. This study was to investigate the expression of Nectin-4 and its clinical significance in the patients with HCC.

METHODS

The expression of Nectin-4 was assessed at mRNA and protein levels by quantitative reverse transcription polymerase chain reaction (qRT-PCR) and Western blotting assays in 20 HCC specimens and adjacent non-tumor live tissues. Furthermore, the clinical significance of Nectin-4 in 87 cases of HCC was confirmed by immunohistochemistry.

RESULTS

The mRNA and protein levels of Nectin-4 were higher in HCC tumor tissues than in the matched non-tumor tissues. Nectin-4 was located in the cytoplasm of tumor cells and over-expressed in 67.82% (59/87) HCC tissues by immunohistochemical staining. Positive Nectin-4 expression was significantly correlated with tumor size (P=0.029), status of metastasis (P=0.023), vascular invasion (P=0.018) and tumor-node-metastasis stage (P=0.003). In addition, Kaplan-Meier survival analysis indicated that positive Nectin-4 expression was associated with worse recurrence-free survival (RFS) and overall survival (OS) (P=0.006 and P=0.005, respectively). In multivariate analysis, Nectin-4 was an independent prognostic factor for RFS and OS in the patients with HCC.

CONCLUSION

Nectin-4 is upregulated in HCC and may be a novel prognostic biomarker for the patients after surgical resection.

Pyruvate alleviates lipid peroxidation and multiple-organ dysfunction in rats with hemorrhagic shock

OBJECTIVE

Pyruvate can reduce lipid peroxidation, which plays a critical role in organ injury, in various models. However, it is not fully understood if this inhibition occurs in resuscitation of hemorrhagic shock (HS). This study examines effects of pyruvate Ringer solution (PR) in this respect in rats.

METHODS

Rats, subjected to 45% blood loss, were randomly allocated to the 3 groups (n = 18): HS with no fluid resuscitation (group NR), HS resuscitated with lactated Ringer solution (LR) (group LR), and HS resuscitated with PR (group PR). Mean arterial pressure, plasma levels of thiobarbituric acid reactive substances (TBARS), and superoxide dismutase were measured at various time points until 360 minutes after hemorrhage. Visceral organs were harvested at the end for evaluations of the TBARS, antioxidant enzyme, and tissue water content. Other 54 rats with identical procedures without sampling were documented for 24-hour survival rates (n = 18) after fluid resuscitation.

RESULTS

Pyruvate Ringer solution significantly increased mean arterial pressure and decreased blood TBARS levels after lethal HS. It also reduced TBARS concentrations and glutathione peroxidase activities but significantly enhanced glutathione reductase activities in most organs and greatly improved the ratios of reduced glutathione over oxidized glutathione in various organs in group PR, compared to group LR. Furthermore, PR significantly improved various organ function and water contents relative to LR. Group PR showed a more than 2-fold higher 24-hour survival rate of group LR.

CONCLUSIONS

Pyruvate Ringer solution alleviated organ edema and injury and prompted survival partially through inhibition of lipid peroxidation in various organs in severe HS rats.

Serum Total Cholinesterase Activity on Admission Is Associated with Disease Severity and Outcome in Patients with Traumatic Brain Injury

BACKGROUND

Traumatic brain injury (TBI) is one of the leading causes of neurological disability. In this retrospective study, serum total cholinesterase (ChE) activities were analyzed in 188 patients for diagnostic as well as predictive values for mortality.

METHODS AND FINDINGS

Within 72 hours after injury, serum ChE activities including both acetylcholinesterase and butyrylcholinesterase were measured. Disease severity was evaluated with Acute Physiology and Chronic Health Evaluation (APACHE) II score, Glasgow Coma Score, length of coma, post-traumatic amnesia and injury feature. Neurocognitive and functional scores were assessed using clinical records. Of 188 patients, 146 (77.7%) survived and 42 (22.3%) died within 90 days. Lower ChE activities were noted in the non-survivors vs. survivors (5.94±2.19 vs. 7.04±2.16 kU/L, p=0.023), in septic vs. non-infected patients (5.93±1.89 vs. 7.31±2.45 kU/L, p=0.0005) and in patients with extremely severe injury vs. mild injury (6.3±1.98 vs. 7.57±2.48 kU/L, p=0.049). The trajectories of serum ChE levels were also different between non-survivors and survivors, septic and non-infected patients, mild and severely injured patients, respectively. Admission ChE activities were closely correlated with blood cell counts, neurocognitive and functional scores both on admission and at discharge. Receiver operating characteristic analysis showed that the area under the curve for ChE was inferior to that for either APACHE II or white blood cell (WBC) count. However, at the optimal cutoff value of 5 kU/L, the sensitivity of ChE for correct prediction of 90-day mortality was 65.5% and the specificity was 86.4%. Kaplan-Meier analysis showed that lower ChE activity (<5 kU/L) was more closely correlated with poor survival than higher ChE activity (>5 kU/L) (p=0.04). After adjusting for other variables, ChE was identified as a borderline independent predictor for mortality as analyzed by Binary logistic regression (P=0.078).

CONCLUSIONS

Lowered ChE activity measured on admission appears to be associated with disease severity and outcome for TBI patients.

Pathophysiological aspects of sepsis: an overview

Sepsis is defined as severe systemic inflammation in response to invading pathogens, or an uncontrolled hyperinflammatory response, as mediated by the release of various proinflammatory mediators. Although some patients may die rapidly from septic shock accompanied by an overwhelming systemic inflammatory response syndrome (SIRS) triggered by a highly virulent pathogen, most patients survive the initial phase of sepsis, showing multiple organ damage days or weeks later. These patients often demonstrate signs of immune suppression accompanied by enhanced inflammation. Sepsis is a result of a complex process; there is interaction of various pathways, such as inflammation, immunity, coagulation, as well as the neuroendocrine system. This treatise is an attempt to provide a summary of several key regulatory mechanisms and to present the currently recognized molecular pathways that are involved in the pathogenesis of sepsis.

Novel insights for high mobility group box 1 protein-mediated cellular immune response in sepsis: A systemic review

BACKGROUND

High mobility group box 1 protein (HMGB1) is a highly conserved, ubiquitous protein in the nuclei and cytoplasm of nearly all cell types. HMGB1 is secreted into the extracellular milieu and acts as a proinfl ammatory cytokine. In this article we reviewed briefl y the cellular immune response mediated by HMGB1 in infl ammation and sepsis.

METHODS

This systemic review is mainly based on our own work and other related reports.

RESULTS

HMGB1 can actively affect the immune functions of many types of cells including T lymphocytes, regulatory T cells (Tregs), dendritic cells (DCs), macrophages, and natural killer cells (NK cells). Various cellular responses can be mediated by HMGB1 which binds to cell-surface receptors [e.g., the receptor for advanced glycation end products (RAGE), Toll-like receptor (TLR)2, and TLR4]. Anti-HMGB1 treatment, such as anti-HMGB1 polyclonal or monoclonal antibodies, inhibitors (e.g., ethyl pyruvate) and antagonists (e.g., A box), can protect against sepsis lethality and give a wider window for the treatment opportunity.

CONCLUSION

HMGB1 is an attractive target for the development of new therapeutic strategies in the treatment of patients with septic complications.

Septic encephalopathy: when cytokines interact with acetylcholine in the brain

Sepsis-associated encephalopathy (SAE) is a brain dysfunction that occurs secondary to infection in the body, characterized by alteration of consciousness, ranging from delirium to coma, seizure or focal neurological signs. SAE involves a number of mechanisms, including neuroinflammation, in which the interaction between cytokines and acetylcholine results in neuronal loss and alterations in cholinergic signaling. Moreover, the interaction also occurs in the periphery, accelerating a type of immunosuppressive state. Although its diagnosis is not specific in biochemistry and imaging tests, it could potentiate severe outcomes, including increased mortality, cognitive decline, progressive immunosuppression, cholinergic anti-inflammatory deficiency, and even metabolic and hydroelectrolyte imbalance. Therefore, the bilateral communication between SAE and the multiple peripheral organs and especially the immune system should be emphasized in sepsis management.

Valproic acid treatment inhibits hypoxia-inducible factor 1α accumulation and protects against burn-induced gut barrier dysfunction in a rodent model

Objective

Burn-induced gut dysfunction plays an important role in the development of sepsis and multiple organ dysfunction. Emerging evidence suggests that hypoxia-inducible factor-1α (HIF-1α) is critical in paracelluar barrier functions via regulating vascular endothelial growth factor (VEGF) and myosin light chain kinase (MLCK) expression. Previous studies have also demonstrated that histone deacetylase inhibitors (HDACIs) can repress HIF-1α. This study aims to examine whether valproic acid (VPA), a HDACI, protects against burn-induced gut barrier dysfunction via repressing HIF-1α-dependent upregulation of VEGF and MLCK expression.

Methods

Rats were subjected to third degree 55% TBSA burns and treated with/ without VPA (300mg/kg). Intestinal barrier dysfunction was evaluated by permeability of intestinal mucosa to fluorescein isothiocyanate (FITC)-dextran and histologic evaluation. Histone acetylation, tight junction protein zonula occludens 1 (ZO-1), VEGF, MLCK and HIF-1α were measured. In addition, CaCO₂ cells were transfected with siRNA directed against HIF-1α and were stimulated with CoCl2 (1mM) for 24 hours with/without VPA (2mM) followed by analysis of HIF-1α, MLCK, VEGF and ZO-1.

Results

Burn insults resulted in a significant increase in intestinal permeability and mucosal damage, accompanied by a significant reduction in histone acetylation, ZO-1, upregulation of VEGF, MLCK expression, and an increase in HIF-1α accumulation. VPA significantly attenuated the increase in intestinal permeability, mucosa damage, histone deacetylation and changes in ZO-1 expression. VPA also attenuated the increased VEGF, MLCK and HIF-1α protein levels. VPA reduced HIF-1α, MLCK and VEGF production and prevented ZO-1 loss in CoCl2-stimulated Caco-2 cells. Moreover, transfection of siRNA directed against HIF-1α led to inhibition of MLCK and VEGF production, accompanied by upregulation of ZO-1.

Conclusions

These results indicate that VPA can protect against burn-induced gut barrier dysfunction. These protective effects may be due to its inhibitory action on HIF-1α, leading to a reduction in intestinal VEGF and MLCK expression and minimizing ZO-1 degradation.

The tumor necrosis factor-alpha-induced protein 8 family in immune homeostasis and inflammatory cancer diseases

Within the immune system homeostasis is maintained by a myriad of mechanisms that include the regulation of immune cell activation and programmed cell death. The breakdown of immune homeostasis may lead to fatal inflammatory diseases. We set out to identify genes of tumor necrosis factor-alpha-induced protein 8 (TNFAIP8) family that has a functional role in the process of immune homeostasis. Tumor necrosis factor-alpha-induced protein 8 (TNFAIP8), which functions as an oncogenic molecule, is also associated with enhanced cell survival and inhibition of apoptosis. Tumor necrosis factor-alpha-induced protein 8-like 2 (TIPE2) governs immune homeostasis in both the innate and adaptive immune system and prevents hyper-responsiveness by negatively regulating signaling via T cell receptors and Toll-like receptors (TLRs). There also exist two highly homologous but uncharacterized proteins, TIPE1 and TIPE3. This review is an attempt to provide a summary of TNFAIP8 family associated with immune homeostasis and inflammatory cancer diseases.

The effects of ulinastatin on systemic inflammation, visceral vasopermeability and tissue water content in rats with scald injury

BACKGROUND

The aim of this study was to examine whether administration of ulinastatin inhibits pro-inflammatory mediators and ameliorate visceral vasopermeability both in a rat model of major burn, and also in rat cultured endothelial cells stimulated with permeability-evoking mediators.

METHODS

Plasma levels of tumor necrosis factor-alpha (TNF-α), C-reactive protein (CRP), myeloperoxidase (MPO), microvascular permeability, and water content of organ tissues were evaluated in a rodent model of a 55% TBSA full-thickness scald injury. Microvascular permeability was also evaluated with a cultured pulmonary microvascular endothelial cells (PMECs) monolayer after stimulation with trypsin, bradykinin, histamine, prostaglandin E2 and burn serum.

RESULTS

We found that the plasma levels of TNF-α, CRP, MPO, vascular permeability and water content of heart, lung, kidney, and small intestine tissues were significantly increased in animals after scald injury, and administration of ulinastatin lowered the levels TNF-α, CRP, MPO, vascular permeability and water content of those organ tissues. In vitro, ulinastatin lowered the levels of TNF-α, interleukin-6 (IL-6) and attenuated permeability in PMEC monolayers after being stimulated with burn serum or trypsin, but not by bradykinin, histamine or prostaglandin E2.

CONCLUSIONS

These results indicate that ulinastatin attenuates the systemic inflammatory response and visceral vasopermeability both in vivo and vitro, and may serve as a therapeutic agent for prevention of systemic inflammatory response and leakage of fluid into tissue after major burn.

Burn injury induces gelsolin expression and cleavage in the brain of mice

Gelsolin is an actin filament-severing and capping protein, affecting cellular motility, adhesiveness and apoptosis. Whether it is expressed in the brain of burned mice has not yet been characterized. Mice were subjected to a 15% total body surface area scald injury. Neuropathology was examined by hematoxylin and eosin staining. Cerebral gelsolin mRNA, distribution and cleavage were demonstrated by quantitative polymerase chain reaction (QPCR), immunohistochemistry and Western blot, respectively. Cysteinyl aspartate-specific protease (caspase)-3-positive cells and activity were also measured. Burn injury could induce pathological alterations in the brain including leukocyte infiltration, necrosis, microabscess and gliosis. Compared with sham-injured mice, gelsolin mRNA was up-regulated at 8h post-burn (pb) in a transient manner in the cortex and striatum of burned mice, while it remained at higher levels in the hippocampus up to 72 hpb. Of interest, gelsolin was further cleaved into 42 and 48 kDa (kilo Dalton) fragments as illustrated in the hippocampus at 24 hpb, and was widely expressed in the brain by activated monocyte/macrophages, astrocytes and damaged neurons. In the meantime, caspase-3-positive cells were noted in the striatum of burned mice and its activity peaked at 24 hpb. To clarify inflammation-induced gelsolin expression and cleavage in the brain, rat pheochromocytoma cells were exposed to lipopolysaccharide to show increased gelsolin expression and caspase-3-dependent cleavage. The results suggest that burn-induced cerebral gelsolin expression would be involved in the activation of both the monocytes and astroglial cells, thereby playing a crucial role in the subsequent inflammation-induced neural apoptosis following burn injury.

The role of regulatory T cells in the pathogenesis of sepsis and its clinical implication

Sepsis is denoted as a complex syndrome that results from a serious infection followed by amplified and dysregulated inflammatory response. The complex immune response associated with sepsis results in a high rate of morbidity and mortality, despite substantial basic science and clinical advances. Recently, accumulating evidence have demonstrated that regulatory T cells (Tregs) play important roles in suppression of immune response, as demonstrated by the number increase and functional enhancement following the onset of severe sepsis or septic shock. This article reviews recent advances in understanding the potential role of Tregs in the pathophysiology of septic response, as well as implications in the development of novel therapeutic strategies for improving the clinical outcome of patients with severe injury and subsequent septic complications.

The effect of valproic acid in alleviating early death in burn shock

The aim of this study was to examine whether administration of valproic acid (VPA) improves blood circulation and survival after lethal burn shock. Forty adult male Beagle dogs underwent a 50% TBSA full-thickness flame injury. In the first 24 h after burn, animals were randomly divided into four groups: NR group received no treatment. VPA group and 2M2P(2-methyl-2-pentenoic acid) group received either VPA or 2M2P (100 mg of the either drug in 20 mL of normal saline) intravenously. VR group received intravenous infusion of lactated Ringer's solution according to Parkland formula. In the second 24 h after burn the animals of all groups received delayed IV fluid resuscitation. Hemodynamic variables and biochemical parameters were determined with animals in the conscious and cooperative state. From 4 h after burn on, the levels of mean arterial pressure, cardiac index, plasma volume and intestinal mucosal blood perfusion in VPA group were significantly higher, and the levels of parameters of organ function and serum tumor necrosis factor-α were lower than those in NR group and 2M2P group (all P<0.05). Survival at 72 h after burn was in following order: VR (100%)>VPA (60%)>2M2P (30%)>NR (10%). Our results showed that histone deacetylace inhibitor (HDACI) valproic acid significantly improved hemodynamics, intestinal perfusion, and the survival rate after lethal burn shock. The mechanism may be attributable partly to the lowering of the level of proinflammatory factors, ameriolation of vasopermeability-induced visceral edema, reduction of blood volume loss, and protection of vital organs through inhibition of histone deacetylase activity of cell of vital organs.

Treatment with gelsolin reduces brain inflammation and apoptotic signaling in mice following thermal injury

Background

Burn survivors develop long-term cognitive impairment with increased inflammation and apoptosis in the brain. Gelsolin, an actin-binding protein with capping and severing activities, plays a crucial role in the septic response. We investigated if gelsolin infusion could attenuate neural damage in burned mice.

Methods

Mice with 15% total body surface area burns were injected intravenously with bovine serum albumin as placebo (2 mg/kg), or with low (2 mg/kg) or high doses (20 mg/kg) of gelsolin. Samples were harvested at 8, 24, 48 and 72 hours postburn. The immune function of splenic T cells was analyzed. Cerebral pathology was examined by hematoxylin/eosin staining, while activated glial cells and infiltrating leukocytes were detected by immunohistochemistry. Cerebral cytokine mRNAs were further assessed by quantitative real-time PCR, while apoptosis was evaluated by caspase-3. Neural damage was determined using enzyme-linked immunosorbent assay of neuron-specific enolase (NSE) and soluble protein-100 (S-100). Finally, cerebral phospho-ERK expression was measured by western blot.

Results

Gelsolin significantly improved the outcomes of mice following major burns in a dose-dependent manner. The survival rate was improved by high dose gelsolin treatment compared with the placebo group (56.67% vs. 30%). Although there was no significant improvement in outcome in mice receiving low dose gelsolin (30%), survival time was prolonged against the placebo control (43.1 ± 4.5 h vs. 35.5 ± 5.0 h; P < 0.05). Burn-induced T cell suppression was greatly alleviated by high dose gelsolin treatment. Concurrently, cerebral abnormalities were greatly ameliorated as shown by reduced NSE and S-100 content of brain, decreased cytokine mRNA expressions, suppressed microglial activation, and enhanced infiltration of CD11b+ and CD45+ cells into the brain. Furthermore, the elevated caspase-3 activity seen following burn injury was remarkably reduced by high dose gelsolin treatment along with down-regulation of phospho-ERK expression.

Conclusion

Exogenous gelsolin infusion improves survival of mice following major burn injury by partially attenuating inflammation and apoptosis in brain, and by enhancing peripheral T lymphocyte function as well. These data suggest a novel and effective strategy to combat excessive neuroinflammation and to preserve cognition in the setting of major burns.

Carbachol promotes gastrointestinal function during oral resuscitation of burn shock

AIM

To investigate the effect of carbachol on gastrointestinal function in a dog model of oral resuscitation for burn shock.

METHODS

Twenty Beagle dogs with intubation of the carotid artery, jugular vein and jejunum for 24 h were subjected to 35% total body surface area full-thickness burns, and were divided into three groups: no fluid resuscitation (NR, n = 10), in which animals did not receive fluid by any means in the first 24 h post-burn; oral fluid resuscitation (OR, n = 8), in which dogs were gavaged with glucose-electrolyte solution (GES) with volume and rate consistent with the Parkland formula; and oral fluid with carbachol group (OR/CAR, n = 8), in which dogs were gavaged with GES containing carbachol (20 μg/kg), with the same volume and rate as the OR group. Twenty-four hours after burns, all animals were given intravenous fluid replacement, and 72 h after injury, they received nutritional support. Hemodynamic and gastrointestinal parameters were measured serially with animals in conscious and cooperative state.

RESULTS

The mean arterial pressure, cardiac output and plasma volume dropped markedly, and gastrointestinal tissue perfusion was reduced obviously after the burn injury in all the three groups. Hemodynamic parameters and gastrointestinal tissue perfusion in the OR and OR/CAR groups were promoted to pre-injury level at 48 and 72 h, respectively, while hemodynamic parameters in the NR group did not return to pre-injury level till 72 h, and gastrointestinal tissue perfusion remained lower than pre-injury level until 120 h post-burn. CO(2) of the gastric mucosa and intestinal mucosa blood flow of OR/CAR groups were 56.4 ± 4.7 mmHg and 157.7 ± 17.7 blood perfusion units (BPU) at 24 h post-burn, respectively, which were significantly superior to those in the OR group (65.8 ± 5.8 mmHg and 127.7 ± 11.9 BPU, respectively, all P < 0.05). Gastric emptying and intestinal absorption rates of GES were significantly reduced to the lowest level (52.8% and 23.7% of pre-injury levels) in the OR group at about 2 and 4 h post-burn, and did not return to 80% of pre-injury level until 24 h. In the first 24 h post-burn, the rate of gastric emptying and intestinal water absorption were elevated by a mean 15.7% and 11.5%, respectively, in the OR/CAR group compared with the OR group. At 5 days, the mortality in the NR group was 30% (3/10), 12.5% in the OR group (1/8), and none in the OR/CAR group.

CONCLUSION

Carbachol had a beneficial effect on oral resuscitation of burn shock by promoting gastric emptying and intestinal absorption in our canine model.

High mobility group box-1 protein regulate immunosuppression of regulatory T cells through toll-like receptor 4

INTRODUCTION

High mobility group box-1 protein (HMGB1), a recently recognized mediator of immune response might contribute to immune suppression when released extracellularly. The present study was performed to clarify effects of HMGB1 on regulatory T cells (Tregs) and the involvement of toll-like receptor (TLR) 4 signaling.

METHODS

CD4(+)CD25(+)Tregs, isolated from spleens of normal mice and treated with HMGB1 in vitro, and those isolated from HMGB1-treated C3H/HeN (wild type) or C3H/HeJ (TLR4 mutant type) mice, were analyzed for expressions of cytotoxic T lymphocyte-associated antigen (CTLA)4, forkhead/winged helix transcription factor p3 (Foxp3) and interleukin (IL)-10 secretion.

RESULTS

HMGB1-treatment was found to markedly decrease the expressions of CTLA4 and Foxp3, as well as IL-10 secretion. Administration of TLR4 neutralizing antibody abolished the phenotypic and functional changes in Tregs induced by HMGB1. Tregs from HMGB1-treated normal mice showed lower expression of CTLA4, Foxp3, and IL-10 secretion when compared with non-treated mice. Yet opposite results were observed in that of C3H/HeJ mice. Moreover, HMGB1 stimulation could down-regulate the expression of TLR4 on Tregs.

CONCLUSION

Our data suggest that HMGB1 has the ability to directly modulate the suppressive capacity of CD4(+)CD25(+)Tregs, and TLR4 might be a potential receptor essential for the negative effect of HMGB1 on CD4(+)CD25(+)Tregs activity.

Association between high-mobility group box-1 protein release and immune function of dendritic cells in thermal injury

The present study was performed to investigate in vivo the effect of high-mobility group box-1 protein (HMGB1) on the maturation of dendritic cell (DC) and the influence on T-cell-mediated immunity after thermal injury. Rats were randomly divided into 3 groups as follows: sham burn group, burn group, and burn with ethyl pyruvate (EP) treatment group, and they were sacrificed on post burn days (PBD) 1, 3, 5, and 7 respectively. MACS microbeads were used to isolate splenic DCs and column of nylon wool to obtain T cells. Phenotypes were analyzed by flow cytometry and cytokines were determined with ELISA kits. The expression levels of splenic HMGB1 were significantly elevated during PBD 1-7. DC expressed similar CD80 levels, strongly enhanced CD86, and slightly elevated MHC class II levels in comparison to DC from sham-injured rats, and protein levels of IL-12 were not increased after thermal injury. Administration of EP to inhibit HMGB1 could significantly enhance expression levels of CD80, MHC class II on DC surface, and IL-12 production after burns. Simultaneously, proliferative activity and expression levels of IL-2 as well as IL-2R alpha of T cell were restored. These results suggested that the excessively released HMGB1 might stimulate splenic DC to mature abnormally and down-regulate the IL-12 production, and further shifting of Th1 to Th2 with suppression of T-lymphocyte immune function following burn injury.

[Cellular phenotype transdifferentiation of adipose-derived stem cells into endothelial cells]

OBJECTIVE

To investigate the possibility of adipose derived stem cells (ADSCs) for wound healing by detecting cellular phenotype conversion of ADSCs into endothelial cells (ECs).

METHODS

ADSCs were isolated and cultured from adipose tissue derived from SD rats (n = 8), and maintained in Dulbecco's modified Eagle's medium (DMEM) containing 10% fetal bovine serum (FBS) in vitro. The marker antigen of P3 ADSCs was detected by analysis CD49d and CD106 antigens expression using flow cytometry, and the multipotential differentiation of P3 ADSCs were identified by specific medium inducing to differentiate into osteoblasts and adipocytes. And then, the ADSCs were cultured and induced for 3 days by condition culture medium (containing 30% superior of homogenating rat blood vessels in 10%FBS DMEM) as experimental group, and were cultured by 10% FBS DMEM as control group, and the expression of CD34 and von Willebrand factor (vWF) in ADSCs were analyzed by flow cytometry.

RESULTS

Flow cytometry analysis showed that the expression of CD49d and CD106 in ADSCs were positive (98.32 ± 0.37)% and negative (1.67 ± 0.61)%, respectively. The multipotential differentiation experiment demonstrated that the cultured P3 ADSCs can be induced to differentiate into osteoblasts and adipocytes in vitro. The positive rate of CD34 and vWF were (77.14 ± 0.76)% and (75.46 ± 0.37)% in condition medium group, higher than (1.38 ± 0.31)% and (1.70 ± 0.23)% in 10% FBS DMEM control group, respectively (P < 0.01).

CONCLUSION

The ADSCs can be induced to differentiated into ECs, suggesting that ADSCs have potential to take part in wound repair and angiogenesis.

Association between regulatory T cell activity and sepsis and outcome of severely burned patients: a prospective, observational study

Introduction

To investigate the significance of changes in regulatory T cells (Tregs) activity and its relationship with sepsis, as well as outcome of patients with major burns.

Methods

The periphery blood samples of 106 patients were collected on post-burn days 1, 3, 7, 14, and 21. Tregs were isolated and their phenotypes (cytotoxic T-lymphocyte-associated antigen 4 and forkhead/winged helix transcription factor p3) were analyzed by flow cytometry, and the contents of cytokines (interleukin-10 and transforming growth factor-β1) released into supernatants by Tregs were also determined by enzyme-linked immunosorbent assay kits. Gene expressions of cytokines were assessed by real-time quantitative polymerase chain reaction.

Results

Expressions of Tregs phenotypes and gene/protein expression of cytokines were all elevated after burn, and there were obvious differences among patients with various burn sizes. They were also higher in septic patients than those without sepsis. Among septic patients, the expressions of Tregs phenotypes and the levels of cytokines were markedly lower in the survival group than those in patients with fatal outcome.

Conclusions

Severe burn injury per se could lead to the changes in Tregs activities. Elevated levels of cytokines produced by Tregs and activation markers on Tregs surface might play an important role in the pathogenesis of sepsis and mortality in burned patients.

[Effects of early oral fluid resuscitation on hemodynamic and tissue perfusion during shock stage in dogs with a 50% total body surface area full-thickness burn.]

OBJECTIVE

To investigate the effect of early oral fluid resuscitation on hemodynamic and tissue perfusion in dogs with severe burn shock.

METHODS

Eighteen male Beagle dogs with intubation of carotid artery, jugular vein, stomach, jejunum and bladder for 24 h were subjected to a 50%TBSA full-thickness burn, then were equally divided into non fluid resuscitation (NR), oral resuscitation (OR) and intravenous resuscitation(IR) groups, (each n = 6). Dogs in IR and OR groups were given glucose-electrolyte solution (GES) by gastric tube or intravenous infusion according to Parkland formula within 24 h after burn, while those in NR group were not given any treatment. Dogs in each group were given intravenous fluid resuscitation from 24 h after burn. The mean arterial pressure (MAP), cardiac output (CO), systemic vascular resistance (SVR), dp/dt max of left ventricular contractility (dp/dt(max)), gastric carbon dioxide pressure (PgCO2), intestinal mucosal blood flow (IMBF), and urinary output were determined before burn (0 h) and 2, 4, 8, 24, 48 and 72 h after burn at no anaesthesia state. Mortality rate of 72 h after burn was also recorded.

RESULTS

MAP, CO, dp/dt(max), IMBF greatly decreased, and SVR and PgCO2 obviously increased from 2 h after burn in each group (P < 0.01). The measurements except IMBF of IR group returned to pre-injury levels at 72 h after burn, while CO, SVR, PgCO2 and IMBF of OR group still worse compared with 0 h (P < 0.01). All measurements of NR group kept on worsen, and died with anuria within 24 h after burn. Parameters of hemodynamic and tissue perfusion of OR group were significantly superior to those of NR group, but it inferior to those of IR group. At 72 h after burn, 6 (6/6) survived in IR group, 3 (3/6) in OR group and 0 (0/6) in NR group.

CONCLUSIONS

Although oral resuscitation with GES is not as efficient as intravenous resuscitation in a 50%TBSA burn injury, it still can promote hemodynamic, improve the tissue perfusion and reduce the mortality comparing to no resuscitation. Oral resuscitation might be an ideal alternative way of intravenous resuscitation, especially in wars or other site of mass casualties.

[Vitamin alleviates visceral lipid peroxidative injury in dogs during oral fluid resuscitation of burn shock]

OBJECTIVE

To investigate the effect of vitamin C (VC) on visceral lipid oxidative injury during oral fluid resuscitation of burn shock.

METHODS

Twelve male Beagle dogs were surgically prepared for arterial and venous cannulation, and 24 hours later they were subjected to a 50% TBSA full-thickness flame injury. In the first 24 hours after burn dogs were resuscitated with gastric infusion of either glucose-electrolyte solution (GES group, n = 6) or GES containing 250 mg/kg of VC (GES/VC group, n = 6). The delivery rate and volume of GES was in accordance with that of Parkland formula (4 ml x kg(-1) x 1% TBSA(-1) in the first 24 hours). In the second 24 hours all animals received delayed i.v. fluid resuscitation. At end of 72 hours after injury, animals were sacrificed, and specimens of heart, lung, liver, kidney and jejunum were harvested for evaluation of xanthine oxidase (XOD), malondialdehyde (MDA) and assessment of the tissue water content (ratio of dry to wet weight) of organs. The plasma levels of alanine aminotransferase (ALT), creatinine (Cr), MB isoenzyme of creatine kinase (CK-MB) and diamine oxidase (DAO) were determined at same time.

RESULTS

At 72 hours after burn it was showed significant higher activities of XOD in GES/CAR than GES group in heart, kidney and jejunum, and lower contents of MDA in heart, lung, liver, kidney and jejunum (P all < 0.01). Tissue water contents were significantly lower in GES/CAR than GES group in heart [(75.4 +/-1.1)% vs (78.5 +/- 0.8)%], lung [(68.1 +/- 0.9)% vs (73.9 +/- 1.0)%], liver [ (75.2 +/- 0.8)% vs (78.3 +/- 1.2)%], kidney [(73.8 +/- 1.1)% vs (78.1 +/- 0.8)%] and jejunum [(76.3 +/- 0.8)% vs ( 80.4 +/- 0.6)] respectively, all P < 0.01. The levels of ALT, CK-MB, Cr and DAO in GES/CAR group were (46.6 +/- 2.49) U/L, (43.4 +/- 7.05) mol/L, (7156 +/- 596) U/L and (1.86 +/- 0.45) U/L respectively, all significantly lower than those of the GES group [(86.9 +/- 7.89) U/L, (95.2 +/- 1.23) mol/L, (8023 +/- 384) U/L and (2.68 +/- 0.61) U/L respectively, all P < 0.05].

CONCLUSION

The results indicated that vitamin C alleviated visceral tissue edema and organ injury by inhibiting free radical production during oral fluid resuscitation of burn shock.

Angiotensin II induces type I collagen gene expression in human dermal fibroblasts through an AP-1/TGF-beta1-dependent pathway

Angiotensin II is critically involved in skin wound healing, but the underlying mechanism remains unclear. This study investigated the effect of angiotensin II on type I collagen gene activation in human dermal fibroblasts and the possible mechanism involved. Angiotensin II stimulated the mRNA and protein expression of type I collagen and TGF-beta1. Effects were abolished by the angiotensin AT1 receptor antagonist ZD7155 but not by the AT2 blocker PD123319. Blockade of TGF-beta1 markedly inhibited angiotensin II-induced type I collagen gene expression. Activator protein-1 (AP-1) decoy ODNs transfection suppressed angiotensin II-induced TGF-beta1 expression, and also, diminished type I collagen expression. These data indicated that angiotensin II induces collagen gene activation in human dermal fibroblasts through an AT1-mediated AP-1/TGF-beta1 signaling pathway.

[Distribution and clinical significance of CD14 promoter-159C/T polymorphism in patients with extensive burn]

OBJECTIVE

To investigate association of CD14-159C/T polymorphism with expression of leukocyte CD14 mRNA and plasma soluble CD14 (sCDI4) level in severe burn patients.

METHODS

Seventy-seven patients with total burn surface area equal to or over 30% TBSA were hospitalized in the First Hospital Affiliated to the PLA General Hospital and Beijing You'anmen Hospital from June 2004 to June 2006. Blood samples were collected on 1st, 3rd, 5th, 7th, 14th, 21st, and 28th postburn day (PBD) for determination of CD14-159C/T polymorphism by PCR-subsequent restriction fragment length polymorphism (RFLP) analysis,plasma level of sCD14 and leukocyte CD14 mRNA expression were measured by ELISA and RT-PCR.

RESULTS

Frequency of the T and C allele was 59.1%, 40.9%, respectively. Seven cases (9.1%) were homozygote (CC genotype), 49 cases (63.6%) were heterozygote (TC genotype), and 2 cases (27.3%) were TT homozygous allele,which reached the Hard-Weinberg equilibrium. Three cases with CC homozygote, 38 cases with TC heterozygote, and 15 cases with TT homozygous allele were complicated with sepsis, ending in MODS in 1, 19, 10 cases, respectively. Expression of leukocyte CD14 mRNA +/- 35, re- spectively), which were markedly higher than that in patients with CC homozygote during 7th-21st PBD (P < 0.05 or 0.01). The plasma level of sCD14 in patients with CC homozygote was significantly lower than that in patients with TC heterozygote on 5 PBD (85 +/- 46 microg/L vs 134 +/-43 mmicrog/L, P < 0.01), which were higher in patients with TC heterozygote and TT homozygous allele than that in patients with CC homozygote on 21st, 28thh PBD (P < 0.01). Conclusions In CD14 gene promoter-159C/T polymorphism, the gene and protein expression of CD14 in patients with TT, TC genotype are much higher than those in patients with CC homozygote. CD14 gene promoter-159 C/T polymorphism with TT homozygote may be one of the major markers in extensive burn patients in whom infection may progress to MODS. Compared with other genetypes, the incidence of MODS in sepsis patients with TT genotype increase markedly.

Effect of electro-acupuncture at Zusanli points on gastric emptying and plasma contents of NO and MTL during oral fluid resuscitation of hemorrhagic shock in rats with blood volume loss

AIM: To investigate the effects of electro-acupuncture (EA) at Zusanli points (ST36) on gastric emptying, plasma contents of NO and MTL during oral fluid resuscitation of hemorrhagic shock in rats with 40% blood volume loss.

METHODS: Twenty-four SD rats were randomly divided into three groups: oral GES without hemorrhage (GES group, n = 8), hemorrhage resuscitated with oral GES+EA (H+GES/EA group, n = 8), and hemorrhage resuscitated with oral GES+sham-EA (H+GES/SEA group, n = 8). Hemorrhagic shock model was established by loss of 40% of total blood volume from carotid artery of rats. GES, at the dosage of two times of blood loss, was given twice intragastrically at a 30 min interval beginning from 30 min post bleeding. Bilateral Zusanli points (ST36) and sham points were electro-acupunctured with constant voltage (2-3 mA, 2-100 HZ) to animals with no anesthesia for 1 hour after a second intragastric administration. Rats were sacrificed 4 h after hemorrhage/operation and bloods were harvested for evaluation of plasma nitrogen monoxidum (NO) and motilin (MTL). Gastric emptying rates (GE) were determined by phenol red emptying.

RESULTS: Four hours after blood loss, gastric emptying rate of H+GES/EA group was 21.6% higher than H+GES/SEA group, but 17.6% lower than GES group (P < 0.05). The plasma contents of NO in H+GES/EA group were significantly lower than H+GES/SEA group (90.2 ± 8.3 vs 103.9 ± 12.5, P < 0.01), and significantly higher than GES group (90.2 ± 8.3 vs 53.6 ± 6.9, P < 0.01). The plasma contents of MTL were significantly in H+GES/EA than H+GES/SEA (101.3 ± 18.7 vs 73.7 ± 14.1, P < 0.01), and significantly decreased than GES group (101.3 ± 18.7 vs 132.26 ± 24.1, P < 0.01).

CONCLUSION: The results indicate that electro-acupuncture at Zusanli points have significant effects on promoting gastric emptying rate, inhibiting the contents of plasma NO and increasing the contents of plasma MTL after early oral fluid resuscitation of hemorrhagic shock in rats with 40% blood volume loss.

[Effects of early oral fluid resuscitation on organ functions and survival during shock stage in dogs with a 50% total body surface area full-thickness burn]

OBJECTIVE

To investigate the effects of early oral fluid resuscitation on organ functions and survival in severe burn shock.

METHODS

Eighteen male Beagle dogs were surgically prepared for measurement, subjected to 50% total body surface area (TBSA) full-thickness flame injury 24 hours later, and then randomly divided into 3 equal groups: oral fluid resuscitation group (OR group) undergoing gastric infusion of glucose-electrolyte solution(GES)according to Parkland formula 0.5 hour after burn with the dose of 4 ml x kg(-1).%TBSA(-1), 1/2 being given in the first 8 h and 1/2 in the latter 16 h. Intravenous (IV) resuscitation of GES group (VR group) undergoing IV infusion of GES with the same dose as mentioned above, and no fluid resuscitation (NR) group given with GES during the first 24 h. In the second 24 hours all dogs received IV fluid resuscitation. At the end of 72-hours-period experiment, the mortality was recorded. The mean arterial pressure (MAP), plasma blood volume (PV), hematocrit (HCT), urinary output, alanine aminotransferase (ALT), creatinine (Cr), and MB isoenzyme of creatine kinase (CK-MB) were examined before injury and at 2, 4, 8, 24, 48 and 72 hours after injury.

RESULTS

At the end of 72-hours-period experiment, all dogs died in the NR group, 3 dogs died in the OR group, and no dog died in the VR group. The MAP and PV were significantly reduced after burn compared with those before-injury in the NR group, with the lowest levels of (34 +/- 9) mm Hg and (32.7 +/- 3.5) ml/kg (both P < 0.05) 8 h after burn, and the HCT, ALT, Cr, and CK-MB levels of the NR group peaked 8 h after burn to the levels of (61.7 +/- 2.7)%, (121.1 +/- 4.8) U/L, (91.0 +/- 6.1) micromol/L, and (13 891 +/- 297) U/L respectively. Eight hours after burn 4 dogs of the NR group showed anuria, and the rest two had the urine volume of 1.2 and 2.1 ml/kg respectively. Eight hours after burn the MAP, PV, and urinary output levels of the OR group were (84.3 +/- 17.1) mm Hg, (41.7 +/- 3.6) ml/kg, and (2.6 +/- 1.8) ml/kg respectively, all significantly higher than those of the NR group (all P < 0.05), but significantly lower than those of the VR group [(113.0 +/- 10.0) mm Hg, (50.3 +/- 5.2) ml/kg, and (7.0 +/- 1.9) ml/kg respectively, all P < 0.05]. The plasma ALT level of the OR group was (81.4 +/- 10.8) U/L, significantly lower than that of the NR group (P < 0.05), but significantly higher than that of the VR group [(66.3 +/- 7.6) U/L, P < 0.05]. The levels of plasma ALT at other time points, as well as the Cr and CK-MB levels at all time points of the OR group were all significantly higher than those of the VR group (all P < 0.05). The MAP, PV, HCT and urinary output levels of the two resuscitation groups returned to the pre-injury levels 72 h after burn, but the ALT, Cr, and CK-MB levels were still significantly higher than the pre-injury levels.

CONCLUSIONS

Although oral resuscitation with GES is not as efficient as IV resuscitation in 50%TBSA burn, it still can maintain the MAP and PV, protect the organ functions and reduce the mortality comparing to no resuscitation. Oral resuscitation may be an ideal alternative way of IV resuscitation, especially in wars or other site of mass casualties.

Influencing factors for gastric emptying rate during oral fluid resuscitation of hemorrhagic shock in rats with 40% blood volume loss

AIM: To observe the changes of plasma nitrogen monoxidum (NO), motilin (MTL) content and gastric emptying (GE) rate and to investigate the relationship between NO, MTL content and GE during early oral fluid resuscitation of hemorrhagic shock in rats with 40% blood volume loss.

METHODS: Twenty-four SD rats were randomly divided into three groups: sham operation group (GES group, n = 8), hemorrhage with no resuscitation group (H group, n = 8) and hemorrhage with oral administration of a glucose-electrolyte solution group (H + GES group, n = 8). Rats of H group and H + GES group were subjected to a 40% hemorrhagic injury from the right common carotid artery, while GES group only to a ligation of the artery. GES was intragastrically administrated with a total amount double of blood loss at 0.5 h and 1 h post-hemorrhage in GES group and H + GES group. Rats were sacrificed 4 h after hemorrhage/operation and blood samples were harvested for evaluation of plasma NO and MTL contents. Gastric emptying rates (GE) were determined using method of phenol red emptying.

RESULTS: Gastric emptying rate was significantly lower in H + GES group than in GES group. (62.4% ± 11.4% vs 92.4% ± 12.5%, P < 0.01). The plasma NO level was significantly higher (105.7 ± 13.2 μmol/L vs 53.6 ± 6.9 μmol/L, 75.4 ± 10.5 μmol/L, both P < 0.01) but plasma MTL content was significantly lower in H + GES group than in GES group or than in H group (72.5 ± 14.3 ng/L vs 132.3 ± 24.1 ng/L, 95.7 ± 15.5 ng/L, both P < 0.01). Gastric emptying rate was negatively correlated with plasma NO content but positively correlated with plasma MTL content (P < 0.01).

CONCLUSION: The results indicate that gastric emptying rate is lowered after early oral fluid resuscitation of hemorrhagic shock in rats with 40% blood volume loss, which might be caused by the increased plasma No content and decreased plasma MTL content during hemorrhagic shock.

[The significance and characteristics of distribution of beta-endorphin and mu-opioid receptors in normal skin and hyperplastic scar]

OBJECTIVE

To detect the distribution of beta-endorphin and mu-opioid receptors (MOR) in normal skin tissue and scar tissue from healthy volunteers and patients with hypertrophic scar.

METHODS

Normal skin samples from 10 healthy individuals and 10 patients with hypertrophic scar, and scar samples from the same 10 patients were investigated. The beta-endorphin and MOR protein in the samples were detected by immunofluorescence (IF). The reverse transcription polymerase chain reaction (RT-PCR) was used to detect MOR mRNA.

RESULTS

Beta-endorphin and MOR protein were expressed in all samples. There were no significant differences in the expression of beta-endorphin and MOR protein between normal skin from healthy volunteers and patients with hypertrophic scar (P > 0.05). The expression of beta-endorphin, MOR protein and mRNA in hyperplastic scar was significantly stronger than that in normal skin (P < 0.01).

CONCLUSIONS

The expression of beta-endorphin and MOR is different in normal skin and hypertrophic scar. This maybe the possible reason of scar paresthesia.

[Effect of high mobility group B1 protein on the function of phagocytosis and the expression of I-A/-E of peritoneal macrophages in mice]

AIM

To investigate the effect of extracellular high mobility group B1 protein (HMGB1) on the immunological function of macrophages.

METHODS

Peritoneal macrophages from mice were stimulated by concentration gradient HMGB1 in vitro. Male BALB/c mice were divided randomly into control group (normal saline, i.p.), low or high dose group (treated with HMGB1 0.2 microg or 20 microg per mouse, respectively, i.p.). Phagocytosis of neutral red and I-A/-E expression of macrophages was assayed.

RESULTS

(1) HMGB1 regulated the phagocytosis of macrophages in a time- and dose-dependent manner, but it did not regulate the expression of I-A/-E in vitro. Moreover, the phagocytosis of macrophages was significantly enhanced by stimulating of HMGB1 at a concentration of 10 microg/L as compared with other stimulating concentrations at culture-hour 6 and 12 (P<0.05 or P<0.01). (2) The capacity for phagocytosis of macrophages was reduced from 43% to 67% when the mice were challenged with HMGB1 in vivo. However, as compared with animals in control group, neutral red phagocytosis of macrophages was depressed markedly in the animals inflicted with high dose HMGB1 for 24 hours (P<0.05). The I-A/-E expression of macrophages was up-regulated markedly in the animals inflicted with low dose HMGB1 for 48 hours as compared to animals treated with normal saline and high dose HMGB1(P<0.05 or P<0.01).

CONCLUSION

High dose HMGB1 can depress the phagocytosis of macrophages, and low dose HMGB1 can enhance macrophage-mediated immunity. Moderate HMGB1 loading is beneficial to immune defense.

Effect of carbachol on expression of TNF-α and aquaporin-1 in small intestine during enteral resuscitation of scald injury in rats

AIM: To investigate the effects of carbachol (a cholinergic agent) on expression of tumor necrosis factor-α (TNF-α) and aquaporin-1 (AQP-1) water channels in small intestine of scalded rats.

METHODS: Wistar rats were randomly assigned to five groups: shame scald (N), scald without fluid resuscitation (S), scald resuscitated with enteral GES alone (GES), scald resuscitated with enteral carbachol alone (CAR) and scald resuscitated with enteral carbachol plus GES (GES/CAR) (n = 10). About 35% TBSA of scald injury was formed with boiling water on back of rats in all groups except the shame scald group. N, GES and GES/CAR groups were enterally administered 30 min after scald injury. The specimens of jejunum of all groups were harvested and analyzed. AQP-1 expression in intestines was evaluated using immunohistochemical method, TNF-α was measured using ELISA and the liquid absorption rate was determined using phenol red.

RESULTS: Compared with the shame scald group, AQP-1 expression in small intestine was significantly decreased in scalded animals (90.3 ± 18.4 vs 4851.6 ± 654.5, P < 0.01), but significantly increased in CAR, GES and GES/CAR groups (1806.1 ± 110.1, 2272.3 ± 113.8, 3322.0 ± 595.9 vs 90.3 ± 18.4, all P < 0.01). TNF-α level in intestinal tissues of GES/CAR and CAR groups were markedly suppressed compared with those in S and GES groups (0.9 ± 0.3, 1.0 ± 0.47 vs 1.8 ± 0.3, 1.9 ± 0.2, P < 0.05). TNF-α expression level was negatively correlated with AQP-1 of small intestine in GES/CAR, CAR and S groups (r = -0.9030, -0.9602, -0.9866, all P < 0.05). Liquid absorption rate of small intestine in GES/CAR group was significantly increased compared with GES group (21.0% ± 0.1% vs 12.7% ± 0.1%, P < 0.05).

CONCLUSION: Carbachol have significant effects on improving the liquid absorption by inhibiting TNF-α and up-regulating AQP-1 expression in small intestine.

[Change in T cell-mediated immunity and its relationship with high mobility group box-1 protein levels in extensively burned patients]

OBJECTIVE

To investigate the change in T cell-mediated immunity and its relationship with plasma high mobility group box-1 protein (HMGB1) levels in severely burned patients.

METHODS

Thirty-five extensively burned patients (> 30% total body surface area) were included in this study, and were divided into MODS group (n = 13) and non-MODS group (n = 22). The blood samples were collected on post burn days 1, 3, 5, 7, 14, 21 and 28. The plasma levels of HMGB1 were measured by using ELISA, and T lymphocyte proliferation response and its IL-2 production ability in peripheral blood were determined too. In addition, the ratio of CD4+/CD8+ T cells were detected by using flow cytometry.

RESULTS

Plasma HMGB1 levels were markedly elevated on post burn day 1 in severely burned patients, and HMGB1 level was significantly higher in MODS group than in non-MODS group (P < 0.05). Lymph proliferation response and IL-2 production of T cells in peripheral blood, and the ratio of CD4+/CD8+ T cells in MODS group were markedly lower than those in non-MODS group on post burn days 1, 14, 21 and 28 (all P < 0.05). It indicated that plasma HMGB1 levels were negatively correlated to T cellular immune function parameters, including lymphocyte proliferation response, IL-2 production, and the ratio of CD4+/ CD8+ T cells in extensively burned patients (all P < 0.05).

CONCLUSIONS

Extensive burns could lead to T cellular immune dysfunction, which appears to be associated with the development of MODS. HMGB1, as an important late mediators of inflammation, might be involved in the pathogenesis of suppression of T cell-mediated immunity in these patients.

[A brief account of prevention and treatment of infection in burn patients]

Prevention and treatment of infection in burn patients involve a wide range of issues. This present article is to introduce only briefly clinical experience focusing on this problem. Among them, satisfactory timely prevention and treatment of burn shock is imperative because it exerts tremendous impact on homeostasis, including especially deterioration of immune functions. Early gastro-intestinal feeding is known to help restore gastro-intestinal circulation after shock, and it is an important avenue to give important nutritional elements like glutamine. It is also very important to excise devitalized tissue, followed by total coverage of all open wounds as early as possible, so that nidus of infection is removed. Rational use of antibiotic, immunological modulation and other measured were also important contributory factors in successfully preventing and treating infection in patients with major burns.

Carbachol alleviates oxygen free radical injury in gut during enteral resuscitation of burn shock in rats

AIM: To investigate the effects of carbachol on oxygen free radical injury in gut during enteral resuscitation of burn shock in rats.

METHODS: A 35% TBSA full thickness scald injury was induced in 38 Wistar rats. The rats were divided randomly into four groups: scald with no therapy (scald alone, n = 8), scald with enteral infusing either a glucose electrolyte solution (GES, n = 10) or GES containing carbachol (60 μg/kg, GES/CAR, n = 10), and scald with enteral infusing only carbachol (CAR, n = 10). GES was infused into intestine through a duodenal stomy according to Parkland formula (4 mL·1%TBSA/kg) 30 min after scald and carbachol was administered simultaneously through the same path. Four hours after injury, the initial jejunum was collected for evaluation of xanthine oxidase (XOD), malondialdehyde (MDA), myeloperoxidase (MPO) and assessment of the pathologic damages.

RESULTS: The activity of XOD and MPO, and the MDA level were 13.2%, 21.3% and 21.1% higher in the GES containing carbachol treatment groups than in the scald alone group (P < 0.05). Resuscitation with GES/CAR resulted in significantly lower levels of XOD (1.36 ± 0.37 vs 2.51 ± 0.56, P < 0.01), MDA (3.97 ± 1.57 vs 6.59 ± 1.50, P < 0.01) and MPO (0.47 ± 0.14 vs 0.83 ± 0.21, P < 0.01) than resuscitation with GES. The parameters in the CAR group were the lowest. The gut lesions were mild in the CAR and GES/CAR groups, severe in the CAR alone group, and most severe in the GES group.

CONCLUSION: Carbachol can alleviate gut oxygen free radical injury during enteral resuscitation of burn shock, which might be associated with its anti-inflammation effects, inhibition of XOD activity and generation of oxygen free radicals in gut tissue.

[Influence of high mobility group box-1 protein on the correlation between regulatory T cells and CD4+ CD25- T cells of spleen in mice]

OBJECTIVE

To investigate the influence of high mobility group box-1 protein (HMGB1) on the immunosuppression function of splenic regulatory T cells (Tregs) and its potential regulatory mechanism underlying the effect on CD4+ CD25- T cells in mice.

METHODS

CD4+ CD25+ Tregs isolated from the spleens of male BALB/c mice by magnetic beads were seeded on 96-well (1 x 10(5) cells/well) cell culture plates coated with 1 microg/ml anti-CD3 and soluble CD28. After being stimulated with HMGB1 for different time and concentrations, the secretions of IL-2 and IL-10 were analyzed by ELISA. Tregs stimulated for 72 hours were cultured with CD4+ CD25- T cells together. The suppressive activity of CD4+ CD25+ Treg to CD4+ CD25- T cells was analyzed by MTT test. IL-2, IL-10, IL-4, and interferon (IFN)-gamma in the cell suspensions were determined by ELISA.

RESULTS

After stimulation with HMGB1, the suppressive activity of splenic Tregs in mice were significantly down-regulated at 72 hours, when the proportion of Tregs to CD4+ CD25- T cells was 1 : 1. The secretion of IL-2 of Tregs stimulated by HMGB1 was not markedly changed (P > 0.05), while a dose-dependent decrease between IL-10 induction and HMGB1 concentration was obviously (P < 0.05). When CD4+ CD25- T cells were cultured with stimulated Tregs, comparing with unstimulated-Treg group, levels of IL-2 and IFN-gamma were elevated following the increased concentration of HMGB1 (P < 0.05 or P < 0.01). Meanwhile the secretion of IL-4 and IL-10 significantly decreased when cultured with stimulated Tregs (P < 0.05).

CONCLUSIONS

These data suggested that HMGB1 stimulation can result in significant down-regulation of immunosuppression of splenic Tregs in mice. HMGB1 might be a potential immunoregulatory signal that influences the proliferation of effector T cells, secretion of IL-2 and cells-polarization by inhibiting CD4+ CD25+ Tregs activity.

[The receptor mechanism of high mobility group box-1 protein induced apoptosis in peritoneal macrophages in mice]

OBJECTIVE

To investigate the influence of high mobility group box-1 protein (HMGB1) on apoptosis of peritoneal macrophages in mice and its receptor mechanism.

METHODS

The peritoneal macrophages were isolated from female BALB/c mice and divided into 4 groups according to different stimuli: i. e, HMGB1 group (with treatment of 10 microg/ml HMGB1 for 24 hours), HMGB1 and anti-receptor advanced glycation end products (RAGE) antibody group (with treatment of 5 microg/ml anti-RAGE antibody for 2 hours followed by HMGB1 stimulation), Recombinant mouse RAGE/Fc chimera (rmRAGE/Fc) and HMGB1 group (10 microg/ml of rmRAGE/Fc and 10 microg/ml HMGB1 were pre-mixed for 2 hours, then the peritoneal macrophages were treated with the mixture), control group (with treatment of phosphate buffer). Expression of RAGE on the surface of macrophages, and the apoptotic rate of the cells were determined by flow cytometry. Laser scanning confocal microscopy was used to observe the apoptosis of the cells.

RESULTS

The percentage of macrophages with positive RAGE expression in HMGB1 group [(54 +/- 12%)] was markedly increased compared to the controls [(13 +/- 5)%, P < 0.01], and fluorescence density of RAGE expression was also significantly different between two groups (126 +/- 10 vs 34 +/- 8, P < 0.01). The occurrence of apoptosis in HMGB1 and rmRAGE/Fc group, as well as in HMGB1 plus anti-RAGE group were much higher than that in control group, and the number of macrophages with apoptosis and necrosis at late stage was obviously increased in HMGB1 group. The apoptic rate in HMGB1 group was (39.5 +/- 2.3)%, which was significantly higher than those in HMGB1 and rmRAGE/Fc group (17.3 +/- 3.6)%, and HMGB1 and anti RAGE group (14.8 +/- 4.8)%, (P < 0.01), which were significantly higher than those in control groups (5.4 +/- 2.3)%, (P < 0.01).

CONCLUSION

RAGE is one of the major receptor to induce apoptosis of macrophages, and the up-regulation of its expression is induced by HMGB1.

Role of Janus kinase/signal transducer and activator of transcription pathway in regulation of expression and inflammation-promoting activity of high mobility group box protein 1 in rat peritoneal macrophages

Signal transduction mechanism in the regulation of high mobility group box protein 1 (HMGB1) has not yet been well elucidated. Our data showed for the first time that Janus kinase-signal transduction and activator of transcription (JAK/STAT) pathway played a major role in the regulation of expression and inflammatory effect of HMGB1. The study was carried out in the following sequence. Firstly, the role of JAK/STAT pathway in the regulation of expression of HMGB1 was examined. After stimulation with 75 ng/mL LPS in vitro, significant increases in HMGB1 expression and prompt activation of JAK/STAT pathway were demonstrated in cultured macrophages. On the other hand, administration of AG490 (specific inhibitor for JAK2), fludarabine (specific inhibitor for STAT1) or rapamycin (specific inhibitor for STAT3) markedly suppressed HMGB1 expression. Secondly, the role of JAK/STAT pathway in the regulation of TNF-alpha expression induced by HMGB1 was examined. When macrophages were stimulated with 10 microg/mL HMGB1 in vitro, significant increases in TNF-alpha expression and prompt activation of JAK/STAT pathway were demonstrated, whereas inhibitors of JAK/STAT pathway significantly suppressed TNF-alpha expression. Taken together, our data strongly indicated that expression and inflammatory effect of HMGB1 could be mediated by JAK/STAT pathway and suggested a possible clinical strategy to control an inflammatory effect of HMGB1 in sepsis.

Preparation of laser micropore porcine acellular dermal matrix for skin graft: An experimental study

In our previous study, we used composite grafts consisting of meshed porcine acellular dermal matrix (PADM) and thin split-thickness autologous epidermis to cover full thickness burn wounds in clinical practice. However, a certain degree of contraction might occur because the distribution of dermal matrix was not uniform in burn wound. In this study, we prepare a composite skin graft consisting of PADM with the aid of laser to improve the quality of healing of burn wound.

METHODS

PADM was prepared by the trypsin/Triton X-100 method. Micropores were produced on the PADM with a laser punch. The distance between micropores varied from 0.8, 1.0, 1.2 to 1.5mm. Full thickness defect wounds were created on the back of 144 SD rats. The rats were randomly divided into six groups: micropore groups I-IV in which the wound were grafted with PADM with micropores, in four different distances, respectively and split-thickness autograft; mesh group rats received meshed PADM graft and split-thickness autograft; control group received simple split-thickness autografting. The status of wound healing was histologically observed at regular time points after surgery. The wound healing rate and contraction rate were calculated.

RESULTS

The wound healing rate in micropore groups I and II was not statistically different from that in control group, but was significantly higher than that in mesh group 6 weeks after grafting. The wound healing rate in micropore groups III and IV was lower than that in mesh and control groups 4 and 6 weeks after grafting. The wound contraction rate in micropore groups I and II was remarkably lower than that in control group 4 and 6 weeks after surgery and it was significantly much lower than that in mesh group 6 weeks after surgery. Histological examination revealed good epithelization, regularly arranged collagenous fibers and integral structure of basement membrane.

CONCLUSION

Laser micropore PADM (0.8 or 1.0mm in distance) grafting in combination with split-thickness autografting can improve wound healing. The PADM with laser micropores in 1.0mm distance is the better choice.

[Regulative effect of lipopolysaccharide on the mRNA expression of procollagen type I and type III and collagenase of normal human skin fibroblasts and its significance]

OBJECTIVE

To explore the regulative effect of lipopolysaccharide (LPS) on the mRNA expression of procollagen type I and type III and collagenase of normal skin fibroblasts of hypertrophic scar patients and its biological role in the formation of hypertrophic scar.

METHODS

Scar tissue and normal skin were obtained from 20 patients with hypertrophic scar. Fibroblasts were isolated, underwent passaged culture, and exposed to LPS from Escherichia coli of the concentrations of (0.005 - 1.0) microg/ml till they reached stable phenotype (at the eighth passage). The expression of procollagen type I and type III and collagenase mRNAs were tested by RT-PCR. Fibroblasts from hypertrophic scar tissue obtained from the same patients and normal skin fibroblasts without stimulation of LPS in the same culture passage were used as positive control and negative control respectively.

RESULTS

When LPS was of the concentrations of 0.005 - 0.5 microg/ml, the mRNA expression levels of procollagen type I and type III were markedly increased, but the mRNA expression of collagenase was significantly decreased, compared with negative control group (all P < 0.01). The effect reached the peak when the LPS concentration was 0.1 microg/ml. When the concentration of LPS reached 1.0 microg/ml, the mRNA expression levels of procollagen type I and type III were inhibited and the mRNA expression level of collagenase began to increase, but still lower than that of the negative control group (P < 0.01). When the concentration of LPS was 0.1 microg/ml, the mRNA expression levels of procollagen type I and type III and collagenase were similar to that of the positive control group (all P > 0.05).

CONCLUSION

LPS enhances the mRNA expression of procollagen type I and type III, inhibits the mRNA expression of collagenase within certain range of concentrations. LPS may be a primitive factor in hypertrophic scar formation.

Sodium butyrate prevents lethality of severe sepsis in rats

This study was performed to investigate a novel strategy to pharmacologically inhibit high-mobility group box 1 protein (HMGB1) expression with sodium butyrate, a short-chain fatty acid. Using a sepsis model induced by cecal ligation and puncture (CLP), 100 male Wistar rats were randomly divided into 4 groups as follows: control group (10 rats), sham operation group (10 rats), CLP group (further randomized into 2, 6, 12, 24, 48, and 72 h post-CLP subgroups, each 10 rats), and sodium butyrate treatment group (further randomized into 12 and 24 h post-CLP subgroups, each 10 rats). Animals of all groups were killed at designated time points, and blood and tissue samples from livers, lungs, kidneys, and small intestines were harvested to determine organ damage-related variables, and HMGB1 mRNA expression was assessed by the reverse-transcription-polymerase chain reaction. In addition, we observed the effect of treatment with sodium butyrate on survival rate in septic rats. The results showed that early treatment with sodium butyrate can markedly reduce serum alanine aminotransferase, creatinine levels at 12 h, and pulmonary myeloperoxidase activity at 24 h post-CLP, and significantly improve the 1- to 6-day survival rates in animals subjected to CLP (P < 0.05-0.01). These findings suggest that HMGB1 is excessively expressed and produced in sepsis. Sodium butyrate can markedly inhibit HMGB1 mRNA expression and may have protective effect on multiple organ damage in sepsis.