Hydroxyethyl Starch Improves the Prognosis of Rats with Traumatic Shock via Activation of the ERK Signaling Pathway in Lymphocytes

OBJECTIVE

Severe traumatic shock is one of the leading causes of death in young adults. A large number of studies have shown that effective volumetry resuscitation on the basis of controlled injury can not only increase the success rate of early resuscitation but also reduce systemic inflammatory response and improve the cure rate of severe traumatic shock. The study explored the effects of hydroxyethyl starch (HES) on the survival rate, lymphocyte function and proliferation of rats with traumatic shock, and the potential mechanisms.

METHODS

Traumatic shock was constructed in rats as experimental model, and liquid resuscitation was performed using HES and lactated Ringer's (LR). 24-h mortality was recorded, and lymphocytes were isolated. The expressions of signaling pathway factors was detected by qPCR and Western blot. ELISA was performed to determine the expression of interleukin 6 (IL-6) and tumor necrosis factor-α (TNF-α) in cell supernatant.

RESULTS

HES for fluid resuscitation augmented the survival of traumatic shock rats, upregulated the expressions of MEK and ERK1/2, and downregulated the expressions of IL-6 and TNF-α. However, inhibition of ERK signaling pathway reversed the effect of HES on the immune improvement and the 24-h survival rate of the traumatic shock rats (P < 0.05).

CONCLUSION

HES could exert the anti-inflammatory effects on lymphocytes by mediating the phosphorylation of proteins of the ERK signaling pathway. HSE demonstrated a high efficacy in effectively treating traumatic shock, thus could be used in clinical practice.

Organ-Specific Oxidative Events under Restrictive Versus Full Reperfusion Following Hemorrhagic Traumatic Shock in Rats

Background aim: Reperfusion after hemorrhagic traumatic shock (HTS) is often associated with complications that are partly ascribed to the formation of reactive oxygen species (ROS). The aim of our study was to compare the effects of restrictive reperfusion (RR) to rapid full reperfusion (FR) on ROS formation and/or oxidative events.

MATERIALS AND METHODS

Anesthetized male rats were randomly subjected to HTS followed by FR (75 mL/kg/h) or RR (30 mL/kg/h for 40 min, followed by 75 mL/kg/h) with Ringer's solution (n = 8/group). Compartment-specific ROS formation was determined by infusion of ROS scavenger 1-hydroxy-3-carboxy-2,2,5,5-tetramethyl-pyrrolidine hydrochloride (CP-H) during resuscitation, followed by electron paramagnetic resonance spectroscopy. Sham-operated animals (n = 8) served as controls. The experiment was terminated 100 min post-shock.

RESULTS

Mean arterial pressure was significantly higher in the FR compared to the RR group during early reperfusion. Only RR animals, not FR animals, showed significantly higher ROS concentrations in erythrocytes (1951 ± 420 vs. 724 ± 75 AU) and in liver (474 ± 57 vs. 261 ± 21 AU) compared to sham controls. This was accompanied by elevated alanine aminotransferase and creatinine levels in RR animals compared to both shams and FR animals, while lipid peroxidation products (thiobarbituric acid reactive substances) were significantly increased only in the kidney in the FR group (p < 0.05). RR animals showed significantly higher plasma peroxiredoxin-4 values when compared to the FR group (20 ± 2 vs. 14 ± 0.5 RLU).

CONCLUSION

Restrictive reperfusion after HTS is associated with increased ROS formation in erythrocytes and liver compared to sham controls. Moreover, the restrictive reperfusion is associated with a more pronounced injury to the liver and kidney, which is likely mediated by other than lipid peroxidation process and/or oxidative stress reactions.

Modulating the Biologic Activity of Mesenteric Lymph after Traumatic Shock Decreases Systemic Inflammation and End Organ Injury

Introduction

Trauma/hemorrhagic shock (T/HS) causes the release of pro-inflammatory mediators into the mesenteric lymph (ML), triggering a systemic inflammatory response and acute lung injury (ALI). Direct and pharmacologic vagal nerve stimulation prevents gut barrier failure and alters the biologic activity of ML after injury. We hypothesize that treatment with a pharmacologic vagal agonist after T/HS would attenuate the biologic activity of ML and prevent ALI.

Methods

ML was collected from male Sprague-Dawley rats after T/HS, trauma-sham shock (T/SS) or T/HS with administration of the pharmacologic vagal agonist CPSI-121. ML samples from each experimental group were injected into naïve mice to assess biologic activity. Blood samples were analyzed for changes in STAT3 phosphorylation (pSTAT3). Lung injury was characterized by histology, permeability and immune cell recruitment.

Results

T/HS lymph injected in naïve mice caused a systemic inflammatory response characterized by hypotension and increased circulating monocyte pSTAT3 activity. Injection of T/HS lymph also resulted in ALI, confirmed by histology, lung permeability and increased recruitment of pulmonary macrophages and neutrophils to lung parenchyma. CPSI-121 attenuated T/HS lymph-induced systemic inflammatory response and ALI with stable hemodynamics and similar monocyte pSTAT3 levels, lung histology, lung permeability and lung immune cell recruitment compared to animals injected with lymph from T/SS.

Conclusion

Treatment with CPSI-121 after T/HS attenuated the biologic activity of the ML and decreased ALI. Given the superior clinical feasibility of utilizing a pharmacologic approach to vagal nerve stimulation, CPSI-121 is a potential treatment strategy to limit end organ dysfunction after injury.

Corticotropin-releasing factor is present in intestinal tissue of patients with gastrointestinal dysfunction following shock and abdominal surgery

OBJECTIVE

Corticotropin-releasing factor (CRF) is implicated in stress-related gastrointestinal dysfunction, possibly causing gut dysfunction following trauma and surgery. We investigated plasma and intestinal tissue CRF levels and gut function in patients with traumatic shock or those undergoing elective abdominal surgery.

RESEARCH METHODS AND PROCEDURES

In a prospective, parallel, observational study in a university hospital surgical intensive care unit (ICU), 8 shocked patients (systolic blood pressure <90 mmHg and/or acidosis and/or urine output <1 mL/kg/hr and/or requiring >2 L of intravenous fluid resuscitation) undergoing small bowel resection during emergency laparotomy following abdominal injury and 17 stable patients undergoing elective hepatobiliary surgery were included if they required postoperative ICU management. Serial plasma and intestinal CRF was measured and postoperative gastric emptying and intestinal permeability were evaluated.

RESULTS

Plasma CRF was significantly increased in the shocked patients compared with the elective surgery patients at all times. CRF peptide was quantified in intestinal tissue at similar levels in both groups. Intestinal permeability was increased and associated with shock and resuscitation fluid volume. Gastric emptying was retarded and correlated significantly with shock but not with plasma CRF. Delayed gastric emptying in shocked patients was associated with longer ICU stay.

CONCLUSIONS

The novel finding is the presence of CRF in the small bowel of both elective and emergency gastrointestinal surgery patients with concomitant gastrointestinal dysfunction. Circulating CRF is associated with poor gastric emptying, which prolongs ICU stay, whereas shock significantly impairs gastric emptying and gut permeability.

[Pharmacological prophylaxis of reperfusion syndrome in patients with severe polytrauma accompanied by shock]

A comparative assessment of buffer activity of reamberin and polyoxyfumaren was made. Their influence on systemic consumption of oxygen, content of lactate in blood, parameters of central hemodynamics were followed. The research includes 44 victims (aged 25-70 years) with severe shockogenic injuries. Reamberin was included in composition of fluid therapy of I group (n=30)and polyoxyfumaren was used in 11 group (n=14). Parameters of acid-base balance of arterial blood, VO2, VCO,, contents of lactate in mixed venous blood, parameters of central hemodynamics were measured in monitor regimen before the infusion. It was proved, that the intravenous infusion of reamberin and polyoxyfumaren accompanied by reliable rise of minute consumption of oxygen (27 and 18% respectively). The drugs decrease the lactate level in blood, reliably increase buffer capacity of blood, correct the metabolic acidosis. Both antihy-poxanthines allow the increase of minute volume of circulation: reamberin on 15%, polyoxyfumaren on 34,9%. The volemic effect of polyoxyfumaren resulted in the increase of circular plasma volume after finishing the infusion on 49,5%, in the case of reamberin - on 16%.

[Strategy of the metabolic acidosis correction and indices of coagulation profile in patients with severe traumatic shock]

The strategy for correction of metabolic acidosis and coagulation profile disorders in severe traumatic shock was adduced. There was established, that severe traumatic shock is characterized by prominent metabolic acidosis, the bases deficiency reduction, the lactate content in arterial blood enhancement, as well as ionized calcium in the blood serum, significant enhancement of the partially activated thromboplastin time and protrombin time, what witnesses the prominent coagulation disorders presence on the metabolic acidosis background. The "Soda-buffer" (manufactured by "Yuriya Pharm", Ukraine) preparation application in a complex of infusion-transfusion therapy permits in early terms to correct effectively the metabolic acidosis and coagulopathy signs in the injured persons, suffering severe trauma. Effective correction of metabolic acidosis and disorders of coagulation profile permits to lower trustworthily the erythrocytic mass volume transfused as well as fresh-frozen plasm while the infusion-transfusion therapy conduction.

[The effect of the membrane attack complex C5b-9 on liver cells during traumatic hemorrhagic shock in rat]

OBJECTIVE

To observe whether the membrane attack complex C5b-9 would accumulate in the rats' liver after receiving the assault of traumatic hemorrhagic shock, and whether the membrane attack complex deals an impact on liver apoptosis.

METHODS

Fifty male healthy Wistar rats were randomly divided into five groups: normal group, 1, 3, 6, 24 hour model groups. The model of traumatic hemorrhagic shock was reproduced by withdrawal of blood from carotid artery after a bone fracture till the blood pressure lowered to 40 mm Hg (1 mm Hg=0.133 kPa). Plasma membrane attack complex C5b-9 concentration was assayed using enzyme linked immunoadsorbent assay. Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in blood was determined by Rate method. Immunohistochemistry was used to detect C5b-9 deposition in the liver. Apoptosis of liver cells was then detected by the terminal deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL) assay. The pathological changes in paraffin sections stained with hematoxylin eosin (HE) were observed under light microscope.

RESULTS

A small amount of C5b 9 in plasma was found in normal group, and the values (ng/L) of 1, 3, 6 hour models were significantly higher than those of the normal group (272.91 ± 9.56, 192.01 ± 9.04, 156.78 ± 8.37 vs. 25.98 ± 5.87, all <0.05 ). ALT (U/L) in 3 hour model group and AST (U/L) in 1 hour model group were increased significantly (92.90 ± 8.83, 264.83 ± 31.4), peaked at 24 hours (184.30 ± 12.98, 647.36 ± 60.02), and there was significant difference compared with normal group (38.75 ± 5.40, 66.69 ± 19.95, all P <0.05). In the normal group and the 1 hour and 6 hour model groups, no C5b 9 was found in liver, but in the 3 hour model group a large number of liver parenchymal cells in the portal area were found to contain C5b 9 22.60 ± 1.06), however the number decreased significantly in the 24 hour model (2.20 ± 0.60, P<0.05). In normal group there was no apoptotic cell, and in 1, 6, 24 hour model groups there were scattered apoptotic cells (1.20 ± 0.25, 5.60 ± 0.37, 1.60 ± 0.26). In the 3 hour model group apoptosis of hepatic cells around the central vein was increased to the peak (20.60 ± 0.47), and there was significant difference compared with other groups (all P <0.05) . In the model groups the liver cells became edematous, and the integrity of the membrane was lost, and some cells were even lysed.The pathological damage is most serious in 24 hour model group.

CONCLUSION

The membrane attack complex C5b-9 insulted the rats' liver after a traumatic hemorrhagic shock, and apoptosis of hepatic cells and the content of C5b-9 peaked in 3 hour model , though they do not occur in the same site. A low level of C5b-9 in blood 3 hours after shock predict a poor prognosis.

[The condition of oxidation-antioxidation balance of kidney and suprarenal tissue in experimental traumatic shock with white rats and the influence of Plaferon LB]

The aim of the work is the study of the oxidation-ant oxidation balance of kidney and suprarenal tissue and the influence on them of Plapherone LB preparation. The objects for experiment were 30 white rats which weigh was about 200gr. The traumatic shock was reproduced according to Kennon. White rats were divided into two groups. In 15 minutes after shock intraperitonealy were made: first group - 0,3 ml of physiologic solution, second group - Plapherone LB 0,06 mg on 0,3 mg of physiologic solution. Separately was studied control group of animals. The tissues were studied by the method of electronic paramagnet resonance on RE-1304 radiometer (Russia). The rough upset of oxidation-antioxidation balance was revealed. The use of Plapherone LB in this case promotes the optimization of these changes.

[Plasma membrane depolarization and activation of receptors for endogenous vasoconstrictors as possible mechanisms of potentiation of vasoconstrictive response to serotonin in traumatic shock in rats]

The goal of this work was to study possible mechanisms underlying the potentiation of vasopressor response to serotonin observed in traumatic shock. Experiments with isolated aorta and mesenteric artery of the rat showed that vasoconstriction is caused by the activation of 5HT2A receptors. Agonists of 5HT1B, 5HT1D, 5HT2B, and 5HT4 receptors induced vasodilation. Agonists of 5HT1A receptors had a dual effect determined by interaction with alpha1-adrenergic receptors and 5HT1A receptors. Plasma membrane depolarization with 15 mM KCl increased the vasoconstrictive force in response to serotonin. This effect was determined by the ability of KCl to activate voltage-gated calcium channels, as a result of which the intracellular calcium stores are replenished. Inhibition of serotonin response by ketanserin, a 5HT2A receptor blocker, did not depend on the presence of 15 mM KCl. Constriction in response to serotonin was potentiated after its addition to vessels preconstricted with noradrenaline or endothelin-1. The constriction response partially retained in the presence of 2 x 10(-7) M ketanserin, which completely suppressed the serotonin-induced constriction of dilated vessels both at normal membrane potential and after plasma membrane depolarization. It can be assumed that noradrenalin and endothelin-1 alter the characteristics of 5HT2A receptors and possibly 5HT1A receptors as a result of their heterodimerization with the receptors for these vasoconstrictive hormones or interreceptor interaction at the level of signaling systems. Along with the potentiating effect of KCl, this mechanism may underlie the enhancement of vasopressor response to serotonin in shock.

[Traumatic shock--physiopathologic aspects]

Traumatic shock is a complex phenomenon that represents the culminating element of a series of events. It is, in fact, the outcome of an imbalance-decompensation of the organism's defence mechanisms, in which the oxygen supply to the mitochondria is hampered by a macro and/or microcirculation failure. Basically, it is a form of hypovolemic shock in which further factors have a role, including the activation of inflammation mediators. It should also be stressed that part of the cellular damage is caused by tissue reperfusion. Good hemodynamic compensation is maintained with loss of up to 30% of the circulation mass but, beyond this amount, a fall of the cardiac index, peripheral pO2, and an increase of blood lactates will ensue. Hypoxia causes capillary injury and increased permeability, resulting in the formation of edema and finally in loss of the self-regulating power of the microcirculation. Moreover, it strongly stimulates pro-inflammatory activation of the macrophages and the release of vasoactive substances, such as prostaglandins and thromboxanes. The inflammatory response is triggered by cascade systems (such as the complement, coagulation, kinins, fibrinolysis), cell elements (endothelium, leukocytes, macrophages, monocytes, mast cells) and the release of mediators (cytokines, proteolytic enzymes, histamine, etc.) and others interacting factors. In severe trauma, the inflammatory process extends beyond the local limits, maintaining and aggravating the state of shock and causing a Systemic Inflammatory Response Syndrome (SIRS), with involvement and injury of healthy organs and tissues even at a distance from the site of trauma, raising a risk of onset of ARDS (Acute Respiratory Distress Syndrome), sepsis, MODS (Multiple Organ Dysfunction Syndrome). Tissue reperfusion (reoxygenation) also induces the production of toxic metabolites, such as hydroxylated anions, superoxide, hydrogen peroxide: peroxidation of the phospholipid cell membranes alters the barrier functions, permitting entry of substances such as calcium, which interfere with the intracellular enzymatic systems.

[Parenteral nutrition in children with traumatic shock]

Results of inclusion of parenteral nutrition in the complex of medical measures in 300 children at the age of 1-15 years with multitrauma complicated by shock are presented. Concepts of parenteral nutrition in children with traumatic shock are formulated. Indications, terms of parenteral nutrition onset are substantiated. Characteristics, dosages, rules of parenteral nutrition components apply in children with traumatic shock are described. Influence of developed regimen of parenteral nutrition on the course of traumatic shock on children is evaluated.

SEX DIFFERENCES IN THE LONG-TERM OUTCOME AFTER A SEVERE THERMAL INJURY

We have recently shown that during the acute phase, postburn female pediatric burn patients had significantly increased levels of anabolic hormones with an associated decreased hypermetabolism leading to a significant shorter intensive care unit stay compared with male patients. The aim of the present study was to determine possible differences between girls and boys in body composition, hypermetabolism, and hormone pattern in the long term. Sixty-two children (1-16 years old) who sustained a severe thermal injury (>or=40% total body surface area) were included into the study. Patients were further divided into girls (n = 22) and boys (n = 40). Patient demographics, nutritional support, and mortality were noted. Resting energy expenditure (REE) was measured by indirect calorimetry, body composition by dual-energy x-ray absorptiometry (Hologic Inc, Waltham, Mass) at discharge, 3, 6, 9, 12, 18, and 24 months after burn. In addition, blood was drawn at the same time points, and serum hormones were measured. There were no significant differences between girls and boys for demographics, nutritional intake, or concomitant injuries. Predicted REE was significantly decreased in girls at discharge, 6, 12, and 18 months postburn (P < 0.05). Dual-energy x-ray absorptiometry scan showed that girls had improved change in bone mineral content and percent fat compared with boys (P < 0.05). There were no differences in changes in height, body weight, lean body mass, and total fat between groups. Girls had significantly higher levels of insulinlike growth factor 1, insulinlike growth factor binding protein 3, free thyroxine index, T4, and insulin when compared with boys (P < 0.05). No differences were found for T3 uptake, osteocalcin, cortisol, growth hormone, and parathyroid hormone (PTH) between groups. Data indicate that girls have a reduced REE associated with changes in bone content and endogenous anabolic hormones.

[The role of desensitization of glucocorticoid receptors in the development of vascular resistance to endogenous vasoconstrictors in traumatic shock]

The fact that the activity of cytosol glucocorticoid receptors decreases in shock have been shown before [Golikov P. P. et al., 2001]. The connection between the development of vascular hyporeactivity to endogenous vasoconstrictors and desensitization of glucocorticoid receptors was studied in this investigation. On Kenton traumatic model in a rat experiment, it was shown that the strength of the isometric constriction of the isolated aorta in response to angiotensin II, endothelin-1, phenylephrine, noradrenaline, and vasopressin falls on the second day after a severe mechanical injury (3.3, 2.1, 1.7, 1.6, and 1.5 times, respectively; p < 0.01). On the contrary, the strength of the constriction in response to serotonin increases more then twice. Artificial desensitization of glucocorticoid receptors by long-term administration of dexamethasone (3 mg per kg during five days) results in similar changes of vascular reactivity i.e. a 2.5, 2, 7, and 1.4-fold decrease in the strength of aortal constriction in response to angiotensin II, vasopressin, and endothelin-1, respectively. The strength of the constriction in response to serotonin tended to increase as well. Carbahol-induced relaxation of the aorta pre-constricted with noradrenaline did not change compared with control, being 70 to 80%, both in shock and after desensitization of glucocorticoid receptors with dexamethasone. Presumably, the pathogenetic mechanism of pressor reaction suppression, connected with a decrease in cytosol glucocorticoid receptor activity and thus with inhibition of glucocorticoid-induced expression of the membrane receptors of endogenous vasoconstrictors, is realized in traumatic shock together with other mechanisms.

Large animal models: baboons for trauma, shock, and sepsis studies

A few limited examples of large animal models are outlined, with the main emphasis on baboon models. The baboon offers all the advantages of a large animal and is comparable with humans in nearly all physiological and immunological aspects. In addition, cross-reactivity with human therapeutic and diagnostic reagents allows testing of new species-specific therapies such as antihuman antibodies, on the one hand, and monitoring with available human analytical procedures, on the other.

Dynamics of tissue ubiquitin pools and ubiquitin-proteasome pathway component activities during the systemic response to traumatic shock

Based on the biological significance of the ubiquitin-proteasome pathway (UPP) and its potential role during sepsis, burns and ischemia-reperfusion injury, we hypothesized that the systemic response to traumatic shock (TS) is accompanied by tissue-specific UPP alterations. Therefore, we studied tissue ubiquitin pools, chymotryptic- and tryptic-like proteasome peptidase activities and ubiquitin-protein ligation (UbPL) rates in skeletal muscle, heart, lung, liver, spleen and kidney using a clinically relevant porcine model (bilateral femur fracture/hemorrhage followed by fluid resuscitation). TS induced a systemic reduction of tissue-specific high molecular mass ubiquitin-protein conjugates (>50 kDa). Free ubiquitin was unaffected. The dynamic organ patterns of ubiquitin pools paralleled the typical physiological response to TS and resuscitation. Reduction of ubiquitin-protein conjugates was most pronounced in heart and lung (p<0.05 vs. control) and accompanied by significant increases in proteasome peptidase and UbPL activities in these organs. Unlike all other tissues, spleen proteasome peptidase and UbPL activities were significantly reduced 10 h after TS. These findings support the concept that the UPP could play an important role in regulation of cell functions during the early whole-body response to TS. The UPP might be a therapeutic target to improve the metabolic care after TS, particularly in the heart, lung, and spleen.

Disturbances in hormonal regulation of vascular tone during traumatic shock

Changes in hormonal regulation of the vascular tone in Wistar rats were studied on Cannon model of traumatic shock. The pressor response to angiotensin II decreased by 30-40% 3 h after the incidence of trauma. The reaction to vasopressin remained unchanged. However, phenylephrine in medium and high doses produced a more pronounced pressor response under these conditions. One day after trauma we revealed a decrease in vascular sensitivity not only to angiotensin II, but also to vasopressin and alpha1-adrenoceptor agonist phenylephrine. The vascular response was observed only after treatment with phenylephrine in maximum doses. Traumatic shock was accompanied by inverse response to serotonin: hypertensive effect instead of blood pressure drop. Our results show that traumatic shock is accompanied by specific changes in vascular reactivity.

Decreased fluid volume to reduce organ damage: a new approach to burn shock resuscitation? A preliminary study

OBJECTIVE

To evaluate the impact of decreased fluid resuscitation on multiple-organ dysfunction after severe burns. This approach was referred to as "permissive hypovolaemia".

METHODS

Two cohorts of patients with burns>20% BSA without associated injuries and admitted to ICU within 6 h from the thermal injury were compared. Patients were matched for both age and burn severity. The multiple-organ dysfunction score (MODS) by Marshall was calculated for 10 days after ICU admission. Permissive hypovolaemia was administered by a haemodynamic-oriented approach throughout the first 24-h period. Haemodynamic variables, arterial blood lactates and net fluid balance were obtained throughout the first 48 h.

RESULTS

Twenty-four patients were enrolled: twelve of them received the Parkland Formula while twelve were resuscitated according to the permissive hypovolaemic approach. Permissive hypovolaemia allowed for less volume infusion (3.2+/-0.7 ml/kg/% burn versus 4.6+/-0.3 ml/kg/% burn; P<0.001), a reduced positive fluid balance (+7.5+/-5.4 l/day versus +12+/-4.7 l/day; P<0.05) and significantly lesser MODS Score values (P=0.003) than the Parkland Formula. Both haemodynamic variables and arterial blood lactate levels were comparable between the patient cohorts throughout the resuscitation period.

CONCLUSIONS

Permissive hypovolaemia seems safe and well tolerated by burn patients. Moreover, it seems effective in reducing multiple-organ dysfunction as induced by oedema fluid accumulation and inadequate O2 tissue utilization.

[The time for beginning of enteral nutrition in traumatic shock]

OBJECTIVE

To explore the value of monitoring CO(2) partial pressure of gastric mucosa (PiCO(2)) in patients with traumatic shock under enteral nutrition (EN) support.

METHODS

Ninety-six patients who were clinically diagnosed as having traumatic shock were randomly divided into two groups: the test group and the control group. In the test group, EN was given after tissue oxygenation, indicated by the value of PiCO(2), approached normal and the clinical symptoms ameliorated. In control group EN was given at the early stage of recovery from shock. The course of convalescence of the primary disease, gastro-intestinal symptoms, the monitoring indexes, and the complications etc. were compared between the two groups.

RESULTS

Acute physiology and chronic health evaluation II (APACHE II) scores were both gradually lowered in both groups. It was more significant in the control group than that in the test group 5 days later (both P<0.01). Compared with the control group, the cure rate in the test group was increased obviously (91.3% vs. 75.0%, P<0.01), and the hospital stay days were significantly less [(6.0+/-1.8) days vs. (7.5+/-2.3) days, P<0.01].

CONCLUSION

It is very important to choose the suitable time to give EN support in patients with traumatic shock, for it can protect and promote the recovery of the function of their intestinal tract, raise the survival rate.

Trauma-hemorrhagic shock mesenteric lymph from rat contains a modified form of albumin that is implicated in endothelial cell toxicity

It has been proposed that factors originating from the gut after severe trauma/shock are introduced into the systemic circulation through the mesenteric lymphatics and are responsible for the cellular injury and inflammation that culminates in acute multiple organ dysfunction syndrome (MODS). Indeed, it has been shown that lymph collected from shocked but not sham-shocked animals causes endothelial cell death, neutrophil activation, and bone marrow (BM) colony growth suppression in vitro. In an attempt to isolate the factor(s) in lymph responsible for endothelial cell toxicity, lymph from shock and sham animals was fractionated by solid phase extraction (SPE) and ion exchange chromatography (IEX). The separation of shock lymph by both methodologies yielded two fractions having major detectable toxicity to endothelial cells, whereas no toxicity was detected from sham lymph separations by either method. Subsequent analysis of each SPE toxic fraction by gel electrophoresis and mass spectrometry suggests the toxicity is associated with a modified form of rat serum albumin (mod-RSA) and multiple lipid-based factors. Therefore, we have been able to demonstrate by two different separation techniques that shock lymph contains two or more factors that may account for the toxicity to endothelial cells. Further investigations are needed to determine the type of RSA modification and the identity of the lipid factors and their role in MODS.

[Influence of trauma-hemorrhagic shock on endotoxin, tumor necrosis factor-alpha and interleukin-6 levels in mesenteric lymph and blood of rats]

OBJECTIVE

To investigate the influence of trauma-hemorrhagic shock on endotoxin (ET), tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) levels in mesenteric lymph and blood of rats.

METHODS

Mesenteric lymph from trauma-hemorrhagic shock rats were collected, levels of ET, TNF-alpha and IL-6 in mesenteric lymph were compared with those from blood samples.

RESULTS

Levels of ET, TNF-alpha and IL-6 in mesenteric lymph were elevated during shock period (all P<0.05), and they were decreased to normal range after resuscitation, with an exception of high IL-6 level up to 2 hours following resuscitation.

CONCLUSION

The bacterial translocation could occur during shock period via lymphatic pathway, thereby leading to the increase in TNF-alpha and IL-6 levels, as well as systemic inflammatory response syndrome.

Bench-to-bedside review: oxygen debt and its metabolic correlates as quantifiers of the severity of hemorrhagic and post-traumatic shock

Evidence is increasing that oxygen debt and its metabolic correlates are important quantifiers of the severity of hemorrhagic and post-traumatic shock and and may serve as useful guides in the treatment of these conditions. The aim of this review is to demonstrate the similarity between experimental oxygen debt in animals and human hemorrhage/post-traumatic conditions, and to examine metabolic oxygen debt correlates, namely base deficit and lactate, as indices of shock severity and adequacy of volume resuscitation. Relevant studies in the medical literature were identified using Medline and Cochrane Library searches. Findings in both experimental animals (dog/pig) and humans suggest that oxygen debt or its metabolic correlates may be more useful quantifiers of hemorrhagic shock than estimates of blood loss, volume replacement, blood pressure, or heart rate. This is evidenced by the oxygen debt/probability of death curves for the animals, and by the consistency of lethal dose (LD)_25,50 points for base deficit across all three species. Quantifying human post-traumatic shock based on base deficit and adjusting for Glasgow Coma Scale score, prothrombin time, Injury Severity Score and age is demonstrated to be superior to anatomic injury severity alone or in combination with Trauma and Injury Severity Score. The data examined in this review indicate that estimates of oxygen debt and its metabolic correlates should be included in studies of experimental shock and in the management of patients suffering from hemorrhagic shock.

[Protective effects of ulinastatin on ischemia/reperfusion injury in the rabbit lung in traumatic hemorrhagic shock]

OBJECTIVE

To investigate the effects and mechanisms of ulinastatin on activities of myeloperoxidase (MPO) in lung tissue and neutrophil elastase (NE) in bronchoalveolar lavage fluid and to evaluate the protective effects of ulinastatin on rabbit lung in traumatic hemorrhagic shock.

METHODS

Thirty rabbits were randomly assigned to three groups: control group, traumatic hemorrhagic shock group and ulinastatin-treatment group. The traumatic hemorrhagic shock model was reproduced by producing: femur fracture and femoral artery bleeding to reduce the mean artery pressure to (40+/-5) mmHg (1 mmHg=0.133 kPa). The hypotension was maintained 90 minutes before the shed blood and equivalent amount of Ringer's lactate was infused. Four hours after blood volume compensation, the activities of MPO in lung tissue and NE in bronchoalveolar lavage fluid (BALF) were measured, and the extravascular lung water volume was determined.

RESULTS

Compared with control group, the activities of either MPO in lung tissue or NE in BALF appeared to be increased in the ulinastatin-treatment group (both P<0.05), but their levels were significantly higher in traumatic hemorrhagic shock group(both P<0.05). The extravascular lung water volume was increased significantly in the two experimental group (both P<0.05), however it was more pronounced in traumatic hemorrhagic shock group (all P<0.05).

CONCLUSION

Ulinastatin can inhibit the increase in the activities of MPO in lung tissue and NE in BALF, and possesses potential protective effects on the lung tissue in traumatic hemorrhagic shock.

[Effects of escharectomy during burn shock stage on the mRNA expression of IFN-gamma and IL-4 in spleen T lymphocytes in rats after thermal injury]

OBJECTIVE

To determine the serum level and mRNA expression of type-1/type-2 cytokines of T lymphocytes in spleens of rats after thermal injury and to investigate the effects of escharectomy during burn shock stage on IFN-gamma and IL-4.

METHODS

One hundred and sixty male Wistar rats were randomized into four groups. In group A, animals were not subjected to escharectomy. In groups B, C and D, escharectomy and skin allograft were performed at 8, 24, 96 hours postburn (PB) respectively. At 4, 12, 24, 48, 96, 120 and 168 hours PB, animals were killed and blood and spleens samples were harvested. ELISA was applied to determine the concentration of IFN-gamma and IL-4 in serum. The expression pattern of IFN-gamma and IL-4 were observed at mRNA level in T lymphocytes isolated from spleen by RT-PCR.

RESULTS

The serum level of IFN-gamma and IL-4 rose rapidly and significantly after scald injury, expression of IFN-gamma and IL-4 mRNA in rats' T lymphocyte were also up-regulated spontaneously. The serum level of IFN-gamma and its mRNA expression began to rise within 4 hours PB, peaking at 24 hours PB. Whereas IL-4 and its mRNA expression showed a persistent elevation. Thereby leading to a dominant tendency of Th2 cytokine response on 7 d PB. In group A all above parameters revealed most obvious changes compared with controls, then ranked in group D, B and C.

CONCLUSION

Escharectomy during burn shock stage is helpful to decrease the harmful over expression of Th2-type lymphocyte after severe thermal injury.

Metabolic disturbances in shock, and the role of ATP-MgCl2 and sex steroids

Hemorrhage following accidental injuries is a common cause of death in the industrialized world. Moreover, the impact of elective surgery and solid organ transplantation sometimes results in low flow conditions similar to those seen following hemorrhagic shock. A shortage in O(2) availability, or hypoxia, leads to sequential changes in cell metabolism and morphology, including inflammatory responses and the expression of hypoxia-inducible transcription factor-1, which controls the cellular adaptation to hypoxia. These endogenous adaptive responses show that O(2) deprivation is not an unforeseen event for cells. The purpose of this review article is to discuss the pathophysiologic principles of shock and the metabolic alterations that cells undergo during low flow conditions. Moreover, the rationale for therapeutic intervention by administering ATP-MgCl(2) and sex steroids following shock and trauma will also be discussed.

[Modern principles of the pathogenetic therapy of the burn shock]

The article is devoted to the review of main directions of anti-shock therapy improvement for patients with severe burns. It is shown that the treatment efficiency can be considerably increased both by optimization of infusion volume and by the use of modern infusion drugs with anti-hypoxic and anti-oxidant effects. The use of anti-hypoxic and anti-oxidant drugs permits to change the burn shock course and to decrease its duration. Decrease in severity of tissue hypoxia, prevention of cellular membrane injury interrupt one of the circuits of burn disease pathogenesis and create the favorable conditions for realization of acute adaptation mechanisms in terms of traumatic disease conception. The modern schemes of anti-shock therapy approved at the department of thermal injuries were used in the treatment of casualties with combined burns after the armed conflict in the territory of Chechnia (1999-2001).

[Manifestations of oxidative stress and its correction in traumatic shock]

The case study purpose was to investigate the oxidation-antioxidation process in the affected organism after traumatic shock and under the impact of Plapherone LB. A randomized experiment involved 94 patients who were shared between 2 groups: group 1--routine intensive therapy, group 2--it received additionally Plapherone LB (sublingually, 2 mg protein/day). Ten persons of the control group were investigated separately. It was found by the method of electron paramagnet resonance that the antixidant system became weaker (in patients with traumatic chock), the lipoid oxidants got more intensified, the activity of their oxidant enzymes went up and the concentration of free radical got to be higher. Finally, Plapherone LB was found to promote the optimization of such systemic changes, since it normalized the xanthine oxidase activity in experimental traumatic shock.

The gene expression of cytokines and chemokines induced by tourniquet shock in mice

Traumatic shock is one of the major fields in forensic pathology, but its mechanism remains elusive from the pathophysiological aspects. Tourniquet shock has been established as one of the animal models of traumatic shock, and we examined the gene expression of cytokines and chemokines in the lung and liver in tourniquet shock using mice. Tourniquet was conducted by the application of elastic bands with five turns at both the thighs as high as possible for 2 h, followed by reperfusion. In this procedure, more than 90% mice died within 48 h after reperfusion. Serum hepatic transaminase and hematocrit values significantly increased at 2 h after reperfusion, and their elevation was still evident after 10 h. Histopathologically, hemorrhages, congestion and leukocyte recruitment were observed in the lung and liver specimens after 6 h of reperfusion. Immunohistochemical analysis with anti-myeloperoxidase antibody demonstrated a massive neutrophil infiltration in the lung and liver at 2 h or more after reperfusion. RT-PCR analyses demonstrated that the gene expression of interleukin-1beta, tumor necrosis factor-alpha, monocytes chemoattractant protein-1, macrophage inflammatory protein (MIP)-1alpha, MIP-2, KC and vascular endothelial adhesion molecule-1 was most enhanced in the lung and liver at 2 h after reperfusion. Thus, the gene expression of cytokines and chemokines is presumed to be closely related with the onset of tourniquet shock. From the forensic aspects, these cytokines and chemokines are considered to be useful markers for the early diagnosis of tourniquet shock.

[L-arginine decreases P-selectin expression in traumatic shock]

OBJECTIVE

To investigate the changes of P-selectin distribution in the vital organs and plasma during traumatic shock and explore the significance of these changes.

METHODS

Twenty-four normal SD rats were randomly assigned into 3 groups (n=8), namely traumatic shock group, L-arginine (L-Arg) treatment and control group. The rats in the former 2 groups were subjected to traumatic shock with L-Arg treatment group given 100 mg/kg L-Arg during resuscitation while the other receiving no medication. The control group received only intubation without trauma or phlebotomy. P-selectin expression in the vital organs including the heart, lungs, spleen, liver and small intestine was determined by means of streptavidin-biotin (SABC) immunocytochemical staining technique and serum P-selectin level assayed by enzyme-linked immunosorbent assay.

RESULTS

Before traumatic shock, P-selectin was scarcely detected in the vital organs except the lungs, and the serum was positive for P-selectin expression. Four hours after shock, intense P-selectin expression was observed in almost all the vital organs and the serum P-selectin level was significantly higher than that of the control group. In L-Arg treatment group, P-selectin levels were significantly lowered than those of shock group.

CONCLUSIONS

P-selectin expression in the vital organs and serum is up-regulated during traumatic shock in rats, possibly due to severe microcirculatory disorder and endothelial dysfunction in this condition. L-Arg may decrease the expression of P-selectin very likely through promoting endothelial NO synthesis.

[Clinical investigation of the correlation between blood concentration of lactic acid and tissue oxygenation in severely burned patients]

OBJECTIVE

To investigate the relationship between blood concentration of lactic acid (LA) and tissue oxygenation in severely burned patients with shock.

METHODS

Thirty-four severely burned patients admitted during early postburn stage were included in this study and were randomly divided into A (n = 18) and B (n = 16) groups. The patients in A group were resuscitated with modified anti-shock programme by which the patients' urine output was maintained roughly around 100ml per hour, while the patients in B group were treated by our traditional resuscitation formula by which the patients urine was kept at 40 ml per hour. The blood concentration of LA and usual indices (urine output, blood pressure, heart rate, and mental status) were simultaneously monitored before and 1, 8, 16, 24, 48 and 72 hours after resuscitation in patients of both groups.

RESULTS

(1) The average blood LA level in patients of A group was (3.2 +/- 0.4) mmol/L within 24 hours of resuscitation, while the monitored indices remained within normal range. Nevertheless the LA level in B group was (7.4 +/- 1.6) mmol/L (P < 0.01, compared with that of A group), and hyperlactacidemia lasted for more than 72 hours while other indices were normal. (2) The mortality in B group was high (31.2%), whilst that in A-group was only 5.5% (P < 0.01). (3) There was negative correlation between blood LA and urine output and positive correlation between blood LA and heart rate.

CONCLUSION

(1) Blood LA concentration might be taken as an immediate, sensitive, simple and useful index of tissue oxygenation of the whole body during burn shock stage. (2) It was suggested by our results that fluid resuscitation should be extended to 72 PBHs (postburn hours) with urine output over 100 ml/h, so as to ensure the quality and effects of the resuscitation of burn shock.

[The protective role of hyperoxic Ringer's solution on the hepatic injury in rats with burn shock]

OBJECTIVE

To explore the dynamic postburn changes in rat hepatic function and the effects of hyperoxic Ringer's solution resuscitation on the function.

METHODS

One hundred and ninety Wistar rats of both sexes with body weight of 250 - 300 g were employed as the model and were divided into 6 groups as A, B, C, D, E and F groups as follows: normal control (A, n = 10), early resuscitation with Ringer's solution (B, n = 40), delayed resuscitation with Ringer's solution (C, n = 30), early resuscitation with hyperoxic Ringer's solution (D, n = 40), delayed hyperoxic Ringer's solution resuscitation (E, n = 30) and burn control (F, n = 40). Blood samples were drawn from the injured rats under anesthesia at 6, 12, 24 and 48 postburn hours (PBHs), and the serum contents of ALT, AST and MDA in these blood samples were determined. Hepatic tissue samples were also harvested at the same time and served histologically.

RESULTS

The plasma ALT level at 6 PBH in all groups was higher than that in A group (P < 0.05). There was significant difference of plasma ALT levels between hyperoxic Ringer's solution treatment group an other treatment groups (P < 0.05). And there was evident difference of plasma ALT levels between hyperoxic Ringer's solution treatment groups and other treatment groups (P < 0.05). The dynamic change in plasma AST was almost similar to that of ALT. The plasma MDA level was increased obviously after injury, especially in F group (highest level). Furthermore, the MDA level in C group was higher than that in B group. The plasma MDA levels in D and E groups were evidently lower than that in all other groups (P < 0.05). It was revealed by histological examination that there were different degrees of degeneration an necrosis of hepatocytes during early postburn stage, but less so in D group.

CONCLUSION

Fluid resuscitation during early postburn stage with hyperoxic Ringer's solution could inhibit the production of oxygen free radicals and blunt lipid peroxidation, and it could also enhance the host tolerance to hypoxia and prevent hepatocytes from injury, thus hepatic function was protected.

[Clinical study on the postburn change in the hypothalamus-pituitary-adrenal hormones in severely burned patients]

OBJECTIVE

To investigate the postburn dynamic changes in the hypothalamus-pituitary-adrenal hormones in severely burned patients.

METHODS

Fifty burn patients were enrolled in the study. The plasma contents of total GC (cortisol), ACTH and aldosterone (ALDO) and urinary contents of 17-OHO and 17-KS were determined with radio-immunological assay (RIA) method after burn injury to compare with the normal values which were well established clinically.

RESULTS

The postburn plasma and urinary contents of the above indices were increased evidently with two peak values in shock and infectious stages, whilst the majority of he indices were lower than the normal values after 6 postburn weeks (PBWs). The values of these hormones were the lowest in dying patients. On the other hand, the values approached normal levels in those patients whose burn wounds were healing.

CONCLUSION

Increases of the plasma and urinary levels of hypothalamus-pituitary -adrenal hormones in severely burned patients were constantly seen. Burn shock and infection seemed to be the two major factors in inducing postburn stress reaction in burn victims. Abrupt decrease of the hormone levels in plasma and or urine indicated adrenal failure predicting a poor prognosis of the burn patients.

Intervention with nitric oxide synthase inhibitors for traumatic shock in rats

OBJECTIVE

To evaluate the effects of a selective inhibitor of inducible nitric oxide synthase (iNOS) aminoguanidine (AG) and a non-selective inhibitor of nitric oxide synthase (NOS) N(G)-nitro-L-arginine methylester (L-NAME) on traumatic shock in rats.

METHODS

Animal models of traumatic shock were established in 44 Sprague-Dawley rats following fractures in both femur shafts and subsequent depletion until the mean arterial pressure in the femoral artery dropped to 35 to 45 mmHg(4.67-6.00 kPa). Hypotension was maintained for 30 min before the collected blood was infused back into the rats supplemented with Ringer's solution of the same volume. The rat models were then randomly divided into 3 groups, namely traumatic shock group (n=10), AG group (which was subdivided into AGI, AGII, and AGIII groups, each consisting of 8 rats and receiving 2, 8, and 60 mg/kg x b.w AG infusion respectively during resuscitation), and L-NAME group (with 8 mg/kg x b.w L-NAME infusion during resuscitation, n=10). Plasma NO levels were determined before and after shock, immediately after resuscitation and 0.5, 2, 4 h after resuscitation, and the survival rates within 24 h were recorded with tissue samples of the lung, liver, kidney and intestine obtained 24 h after shock for microscopic examination.

RESULTS

Plasma NO level was seen to increase markedly after traumatic shock in the rat models. In the 3 AG groups, the elevated NO levels following the shock were obviously reduced after resuscitation with less tissue damages and higher survival rates, as compared with the other 2 groups. The best protective effect against traumatic shock was observed in AGIII group. In spite of obvious plasma NO level-lowering effect after resuscitation, L-NAME exhibited little efficacy in alleviating the tissue damages in the organs and hence failed to improve the survival rate of the rats.

CONCLUSIONS

NO plays an important role in the pathological process of traumatic shock, and the application of AG may improve the condition. L-NAME can decrease plasma NO level after resuscitation, but fail to improve the outcome of traumatic shock in rats.

[Influence of different volumes of infusion therapy on transport and consumption of oxygen in the period of shock in patients with severe burns]

In patients with severe burns during the shock period leading are severe disorders of hemodynamics which are the cause of secondary alterations in the organs and systems. The main method of treatment of such patients is infusion therapy. The approach to determination of the solution volume is ambiguous. A comparative analysis of the influence of infusion medium volumes equal to 10% of the body mass and calculated by the Parkland formula on transport and consumption of oxygen which is the main parameter of the perfusion quality of tissues and organs was made in 58 severe burn patients. The results obtained have confirmed that severe burn patients mainly have the hypodynamic type of blood circulation with altered perfusion of organs and tissues and have shown that the infusion therapy calculated by the Parkland formula results in more valuable stabilization of the function of transport and consumption of oxygen. So, the parameters of blood oxygenation and of oxygen extraction become normalized, metabolic disorders and functional instability of the organs disappear in shorter terms.

Pulmonary tissue factor mRNA expression during murine traumatic shock: effect of P-selectin blockade

Tissue factor (TF) is the primary cellular initiator of the coagulation protease cascade and serves as a cell surface receptor and a specific cofactor for plasma factors VII/VIIa. Because there is evidence that TF is regulated by a P-selectin dependent gene, we examined TF mRNA expression in the lungs during murine traumatic shock in the presence and absence of recombinant soluble P-selectin glycoprotein ligand-1 (rsPSGL.Ig) by using ribonuclease protection assays. Moreover, we studied the level of TF mRNA expression in mice with their P-selectin gene deleted (P-selectin -/-). Our data show that TF mRNA was significantly increased (+143%; P < 0.001) in the lungs 2 h after trauma compared with control rats subjected to sham trauma, which exhibited reduced TF mRNA expression (-34%; P < 0.001) after systemic administration of rsPSGL.Ig. The expression of TF mRNA was also significantly decreased (-29%; P < 0.05) in the lungs of P-selectin -/- mice compared with wild-type control C57B16 mice. The present results provide evidence for a P-selectin-dependent mechanism that enhances TF gene expression in traumatic shock. The major support for this mechanism is that either blockade of P-selectin by rsPSGL.Ig or deletion of the P-selectin gene leads to significant decreases in TF mRNA expression in the lung. These results are consistent with the concept that TF interacting with P-selectin may play a significant role in the pathophysiology of trauma.

Deficiency in peripheral glutamine production in pediatric patients with burns

Plasma glutamine levels decrease in association with severe injury, which suggests that the consumption of glutamine exceeds the production of glutamine or possibly represents a deficit in the release of glutamine from skeletal muscle. The goal of this study was to assess the peripheral glutamine kinetic response to prolonged stress in children with critical injuries. To accomplish this purpose, we quantitated peripheral glutamine kinetics in vivo with the use of 5N15 glutamine in 5 children with severe burns (total body surface area, 74%+/-14%; mean +/- SEM) and 3 children who underwent elective scar reconstruction. In the children with severe burns, leg blood flow was significantly elevated (16.2+/-2.1 vs 7.5 +/-0.3 mL/min/100 mL leg volume, P < .02) and the arterial concentration of glutamine was significantly reduced (0.31+/-0.04 vs 0.84+/-0.05 mmol/L, P < .001). The rate of glutamine turnover within the leg was significantly reduced in the patients with acute burns, whereas the net efflux of glutamine was similar between the 2 groups. These findings suggest that plasma glutamine concentrations decrease during severe stress as a result of a deficit in peripheral glutamine release in conjunction with an increased central consumption. This preliminary study supports the notion that exogenous glutamine supplementation in pediatric patients with severe injuries may be needed because of this inadequate skeletal muscle response.

[Effect of escharectomy and skin grafting of minipigs during burn shock stage on postburn energy expenditure]

OBJECTIVE

To determine the changes in resting energy expenditure (REE) of minipigs in normal and postburn stage, and the effect of escharectomy during burn shock stage on energy expenditure.

METHODS

Swine model with 35% TBSA III degree flame burn was used. Eighteen male minipigs were randomly divided into three groups: control group, escharectomy during burn shock stage group and escharectomy after burn shock stage group. REEs were monitored by means of Cardiorespiratory Diagnostic Systems (Medical Graphics Corporation, USA).

RESULTS

The levels of REE in escharectomy during burn shock stage group decreased early and were obviously lower than those in other two groups.

CONCLUSION

These findings suggest that escharectomy and skin grafting during burn shock stage could ameliorate hypermetabolism in major burn patients.

[The effect of escharectomy during burn shock stage on the expression of ICAM-1 and TNF-alpha mRNA of rat pulmonary tissue]

OBJECTIVE

To study the rules of postburn expression of IGAM-1 and TNF-alpha and the rule of the change in the MPO activity in pulmonary tissue; to explore the influence of escharectomy on the changes in the above indices and to clarify the importance of escharectomy during shock stage.

METHODS

One hundred and seventy six Wistar rats with 30% TBSA III degree back scald were used. RT-PCR was used in the examination of the expression of pulmonary tissue ICAM-1 and TNF-alpha mRNA and of the change in pulmonary MPO activity after escharectomy.

RESULTS

The expressions of pulmonary ICAM-1 and TNF-alpha mRNA began to increase at 4 hour postburn and reached peak level at 12 and 24 hours postburn, respectively. Their expressions returned to near control level 96 hours postburn in rats undergone escharectomy during shock stage. On the contrary, they remained at a relative high level even on 7th postburn day in both non-operated rats and the rats receiving escharectomy 96 hours postburn. In addition, pulmonary tissue MPO activity fell to near control level in rats undergone escharectomy during shock stage, but it maintained a high level in rats in which escharectomy was not done during shock stage.

CONCLUSION

These findings suggest that eschar could induce the production of endothelial adhesion molecules. Therefore escharectomy as early as possible is very important to prevent the expression and release of adhesion molecules and the development of SIRS.

Tissue factor expression in vital organs during murine traumatic shock: role of transcription factors AP-1 and NF-kappaB

BACKGROUND

Tissue factor (TF) is a cell-surface glycoprotein responsible for initiating the extrinsic pathway of coagulation that has been shown to have a role in the pathophysiology of sepsis and reperfusion injury. The purpose of this study was to investigate TF expression in vital organs and to determine possible regulatory mechanisms of TF expression in the lung during traumatic shock in rats.

METHODS

Noble-Collip drum trauma was induced in anesthetized Sprague-Dawley rats. Anesthetized rats without trauma served as controls. TF activity was measured in plasma and lung tissue. TF messenger RNA (mRNA) was measured in the lung, liver, and small intestine using ribonuclease protection assays. Electromobility shift assays were used to quantify binding of nuclear extracts from lung to TF-specific consensus domains for transcription factors NF-kappaB and AP-1.

RESULTS

TF activity in plasma increased up to 14-fold and +232% in the lung (P < 0.001 for plasma and lung) 2 h after trauma. TF mRNA level was significantly increased in the lungs (P < 0.01), small intestine (P < 0.01), and liver (P < 0.05) 1 h after trauma compared to sham-operated control rats. TF mRNA expression continued to increase in the lungs and the liver (both, P < 0.001) 2 h after trauma TF sequence-specific complex binding to AP-1 and NF-kappaB domains was enhanced in the lungs of trauma rats (+395%, P < 0.001 and +168%, P < 0.001, respectively).

CONCLUSIONS

These results suggest that TF may play an important role in the pathophysiology of severe trauma and that regulatory elements AP-1 and NF-kappaB may be involved in the regulation of TF mRNA expression in traumatic shock.

Elevation in pulmonary neutrophils and prolonged production of pulmonary macrophage inflammatory protein-2 after burn injury with prior alcohol exposure

Various studies have shown that alcohol exposure before thermal injury leads to increased morbidity and mortality. Pulmonary failure is a major complication seen in these patients. This study examines the effects of prior alcohol exposure on lung pathology after burn injury. There is a marked increase in neutrophil recruitment in the lung after thermal injury, and herein we show that this appears to be significantly elevated in animals given alcohol before burn injury. Consequently, we chose to determine whether there is a difference in pulmonary production of macrophage inflammatory protein (MIP)-2, a potent neutrophil chemoattractant, in mice subjected to a 15% total body surface area scald (or sham) injury with or without prior ethanol treatment. Lung tissue was obtained at various time points after injury and homogenates were assayed for MIP-2 by enzyme-linked immunosorbent assay. At 2 h after injury, peak levels of the chemokine were produced in both burn and burn + alcohol-treated mice. This represents a 7-fold increase above baseline. In mice exposed to burn injury alone, the level of MIP-2 returned to baseline within 8 h. In contrast, mice given alcohol before burn injury continued to show elevated levels of the chemokine at 8 h, after which MIP-2 decreased. This study may provide a basis for understanding the mechanism responsible for the increased neutrophil presence in the lung after thermal injury in individuals who have consumed alcohol. Subsequently, this may lead to the enhanced neutrophil-mediated pulmonary damage observed in these patients.

Inhibition of nitric oxide synthesis aggravates hepatic oxidative stress and enhances superoxide dismutase inactivation in rats subjected to tourniquet shock

The role of nitric oxide (NO) on liver oxidative stress and tissue injury in rats subjected to tourniquet shock was investigated. This shock model differs from others in that injury is a consequence of remote organ damage. Liver oxidative stress becomes evident after hind limb reperfusion, as evidenced by the loss of total tissue thiols; by increases in tissue oxidized glutathione (GSSG), lipid peroxidation (LPO), plasma aminotransferases (alanine aminotransferase (ALT) and (aspartate aminotransferase (AST)), and plasma nitrites; and by a 36% loss in total superoxide dismutase (SOD) activity. Portal blood flow is reduced by 54.1% after 2 h of hind limb reperfusion. Inhibition of NO synthesis with Nomega-nitro-L-arginine methyl ester or L-arginine methyl ester increased mean arterial blood pressure; further reduced portal blood flow; and aggravated liver injury as assessed by further loss in total thiols, increased LPO and GSSG content, and further increases in plasma ALT and AST. Total plasma nitrites were lower than in control animals, and total tissue SOD activity decreased by more than 80%. Treatment with the NO donor sodium nitroprusside reverted the decrease in portal blood flow and also reverted tissue thiol loss, LPO, and GSSG increases, as well as the loss of ALT and AST to plasma and of SOD activity to levels comparable to untreated control shock animals. As expected, plasma nitrites were greater than in tourniquet control animals. These data support the hypothesis that endogenous NO formation protects the rat liver from the consequences of oxidative stress elicited by hind limb reperfusion in rats subjected to tourniquet shock.

P-selectin is up-regulated in vital organs during murine traumatic shock

Murine traumatic shock is associated with increased adherence of neutrophils to the vascular endothelium resulting in neutrophil infiltration and tissue damage. We examined the effects of trauma on the expression of the adhesion molecule P-selectin in several vital organs (i.e., heart, lungs, liver, kidneys, and small intestine) 2 h after induction of Noble-Collip drum trauma in anesthetized rats. Total RNA was extracted from these organs and P-selectin mRNA was quantified by RNase protection assays. P-selectin mRNA was significantly increased over control nontraumatized, anesthetized rats in all vital organs (P<0.05 or less), with the largest increase occurring in the lung (P<0.01). Immunohistochemical analysis showed increased expression of P-selectin protein in postcapillary venules of all vital organs after trauma. To further investigate the possible mechanisms of increased P-selectin mRNA transcription promoter activity during trauma, we quantified binding of proteins from nuclear extracts to the kappaB site (-218GGGGGTGACCC[-207]) of the P-selectin gene by electrophoretic mobility shift assay. We confirmed the results of NF-kappaB binding by demonstrating increases in p50 and p52, as well as decreases in IkappaB in cytoplasmic and nuclear extracts from the lungs of trauma rats by Western blotting. Increased activity of the transcription factor, nuclear factor kappaB (NF-kappaB), occurred in all vital organs of the trauma rats compared to sham-operated controls. Our findings suggest that severe trauma results in up-regulation of P-selectin at the transcriptional level, which is partly controlled by an NF-kappaB-responsive element in the region of the P-selectin promoter. This increased activation of NF-kappB binding may contribute to the widespread increases in P-selectin expression observed in several vital organs 2 h after trauma, which in turn may play a key role in the pathogenesis of traumatic shock.

Base deficit after major trauma directly relates to neutrophil CD11b expression: a proposed mechanism of shock-induced organ injury

OBJECTIVE

To determine whether expression of neutrophil integrin receptors is related to the degree of post-traumatic shock.

DESIGN

Data were collected prospectively on patients with major trauma admitted to the surgical intensive care unit.

SETTING

Denver General Hospital, Colorado.

PATIENTS AND PARTICIPANTS

17 severely injured adults.

MEASUREMENTS AND RESULTS

The mean fluorescence intensity and per cent positive of neutrophil integrin receptors CD11 b, CD18 and CD11 a, and systolic blood pressure, blood transfusion, lactate and base deficit as indices of shock. CD11 b expression on circulating neutrophils was increased 6 and 12 h after trauma. After correcting for the other shock indices, base deficit predicted CD11 b expression at 12 h. CD11 b expression was negatively correlated with the circulating neutrophil count.

CONCLUSIONS

The degree of metabolic acidosis after trauma correlates directly with CD11 b receptor expression on circulating neutrophils. This relation may be the mechanism whereby post-traumatic shock results in neutrophil sequestration and neutrophil-mediated organ injury and failure.

Pteridine and nitrite/nitrate formation in experimental septic and traumatic shock

Bacterial lipopolysaccharides (LPS) induce the activity of guanosine triphosphate (GTP)-cyclohydrolase I (GTP-CHI), the first enzyme in the biosynthesis of tetrahydrobiopterin (H4bip) from GTP in endothelial cells and macrophages. In these and other cells, LPS also acts costimulatory with cytokines, i.e., mainly tumor necrosis factor-alpha (TNF-alpha). H4bip is the cofactor for nitric oxide synthase (NOS). We were interested in comparing the pteridine and nitrate levels in two baboon models: a hyperdynamic sepsis model and a hemorrhagic traumatic shock model. Our results show a similar response of pteridines (H4bip, neopterin) and nitrite/nitrate levels to an immune stimulus. LPS, which peaks rapidly, induces a sustained increase in pteridine levels in septic animals. Since hemorrhagic animals show very little response in terms of cytokine production, it was not possible to measure the induction of neopterin and nitrite/nitrate. This information could aid our understanding of the regulatory mechanisms in various forms of experimental shock.

[Effect of morphine derivatives on the function of glucocorticoid receptors in shock]

The effects of opiate receptor agonists and antagonists on the function of glucocorticoid receptors in the hepatic cytosol were examined in male Wistar rats weighing 180-240 g. With the Scatchard analysis, in vitro experiments by using labelled ligands revealed that the pure opiate agonist morphine in the wide range of concentrations (0,01-10,0 mM) failed to affect the function Type II glucocorticoid receptors, though inhibited the function of Type III glucocorticoid receptors in the dose-dependent manner. Buprenorphine and diprenorphine depressed the function of Types II and III glucocorticoid receptors. Buterphanol, an opiate receptor antagonist-agonist, like naltrexone, an opiate receptor antagonist, decreased the function of Type III glucocorticoid receptors, but modulated that of Type II glucocorticoid receptors by lowering the association constant of the ligand-Type II glucocorticoid receptor complex, but by enhancing the density of Type II glucocorticoid receptors. In vivo studies established that butorphanol dose-dependently increased the density of Type II glucocorticoid receptors in the hepatic cytosol and elevating blood pressure in rat traumatic shock. Whether glucocorticoid receptors involve in the mechanism of the antishock effect of morphine derivatives is discussed in the paper.

[The injury of liver and kidney of rats sustaining delayed fluid resuscitation of burn shock]

Delayed fluid resuscitation of burn shock may lead to many harmful effects. We investigated the injury of liver and kidney of rats sustaining non-fluid perfusion, immediate perfusion, and delayed perfusion of burn shock. The electron spin reonance (ESR) was used to determine the existence of oxygen free radicals (OFR) successfully. We tested the activity of ATP enzyme in kidney, lactate dehydrogenase isoenzyme 5 (LDH5), GPT and GOT. We also tested the contents of malonaldehyde (MDA) and ATP in liver and kidney, urea nitrogen (BUN) and creatinine (Cr) in blood. We found that OFR plays an important role in the injury of liver and kidney sustaining delayed fluid resuscitation of burn shock. Immediate fluid perfusion can not protect the liver and kidney perfectely. And some OFR scavengers should be added to the fluid resuscitation of burn shock.