The effects of interleukin-10 in hemorrhagic shock

Effects of nebulized hypertonic saline on inflammatory mediators in patients with severe COVID-19 pneumonia: A double-blinded randomized controlled trial

INTRODUCTION

An exaggerated immune response is considered the most important aspect of COVID-19 pathogenesis. Hypertonic saline (HS) has shown promise in combating inflammation in several respiratory diseases. We investigated the effects of nebulized HS on clinical symptoms and inflammatory status in patients with severe novel coronavirus infection (COVID-19) pneumonia.

MATERIALS AND METHODS

We randomly assigned 60 adults admitted to the intensive care unit (ICU) due to severe COVID-19 pneumonia to the experimental (received nebulized 5% saline) and control (received nebulized distilled water) groups. All interventions were applied 4 times daily for 5 days. The levels of tumor necrosis factor-α (TNF-α), interleukin 6 (IL-6), and other clinical factors from venous blood were evaluated before and after intervention application. Mortality rate, intubation rate, and durations of ICU and hospital stay were also compared between groups.

RESULTS

The levels of TNF-α (MD: -21.35 [-32.29, -10.40], P  =  0.000) and IL-6 (-9.94 [-18.86, -1.02], P  =  0.003) were lower in the experimental group compared to the control group after applying the interventions. The levels of white blood cell count, PO2, and serum sodium were also statistically significant differences between groups. However, we did not observe significant differences in terms of hospitalization durations and mortality rates.

CONCLUSION

Nebulization of HS in patients with severe COVID-19 pneumonia appears to be effective in reducing inflammation, but does not appear to affect intubation rates, mortality, hospitalization, or length of stay in ICU.

Neuromodulation as a new avenue for resuscitation in hemorrhagic shock

Hemorrhagic shock (HS), a major cause of early death from trauma, accounts for around 40% of mortality, with 33–56% of these deaths occurring before the patient reaches a medical facility. Intravenous fluid therapy and blood transfusions are the cornerstone of treating HS. However, these options may not be available soon after the injury, resulting in death or a poorer quality of survival. Therefore, new strategies are needed to manage HS patients before they can receive definitive care. Recently, various forms of neuromodulation have been investigated as possible supplementary treatments for HS in the prehospital phase of care. Here, we provide an overview of neuromodulation methods that show promise to treat HS, such as vagus nerve stimulation, electroacupuncture, trigeminal nerve stimulation, and phrenic nerve stimulation and outline their possible mechanisms in the treatment of HS. Although all of these approaches are only validated in the preclinical models of HS and are yet to be translated to clinical settings, they clearly represent a paradigm shift in the way that this deadly condition is managed in the future.

Sodium tanshinone IIA sulfonate attenuates hemorrhagic shock-induced organ damages by nuclear factor-kappa B pathway

BACKGROUND

Trauma resulted hemorrhagic shock (HS) leads to increased oxidative stress and inflammatory responses, which contributes greatly to organ failure or dysfunction. Tanshinone IIA sulfonate (TSA), as an antioxidant, may potentially be used in fluid resuscitation to prevent HS-induced organ damages.

METHODS

In this study, a rat HS model was constructed. HS rats received TSA or vehicle drug during resuscitation. Mean arterial pressure and factors associated with organ failure or dysfunction, oxidative stress, and inflammatory response were investigated to evaluate treatment responses. Expression of proteins in NF-кB pathway was evaluated to elucidate the mechanism of TSA in preventing HS-induced organ damage.

RESULTS

Although HS induced organ damage and upregulated oxidative stress and inflammatory response, TSA treatment ameliorated organ dysfunction, reduced oxidative stress, and suppressed inflammatory responses. We also showed that TSA treatment attenuated HS-induced activation in NF-кB pathway.

CONCLUSIONS

TSA can potentially serve as an antioxidant for ameliorating HS-induced organ failure or function. Its mechanism of action may be through inhibiting NF-кB pathway.

Comparison of hypertonic saline versus normal saline on cytokine profile during CABG

Background and the purpose of the study

Blood contact with artificial surfaces of the extracorporeal circuit and ischemia-reperfusion injury in CABG with CPB, may lead to a systemic inflammatory response. Hypertonic saline have been recently investigated as a fluid in order to decrease inflammatory response and cytokines generation in patients undergo cardiac operations. Our purpose is to study the prophylactic effect of HS 5% infusion versus NS on serum IL-6 as an inflammatory & IL-10 as an anti-inflammatory biomarker in CABG patients.

Methods

The present study is a randomized double-blinded clinical trial. 40 patients undergoing CABG were randomized to receive HS 5% or NS before operation. Blood samples were obtained after receiving HS or NS, just before operation, 24 and 48 hours post-operatively. Plasma levels of IL-6 and IL-10 were measured by ELISA.

Results and major conclusion

Patients received HS had lower levels of IL-6 and higher level of IL-10 compared with NS group, however these differences were not statistically significant. Results of this study suggest that pre-treatment with small volume hypertonic saline 5% may have beneficial effects on inflammatory response following CABG operation.

Pulmonary impact of N-acetylcysteine in a controlled hemorrhagic shock model in rats

BACKGROUND

Experimental hemorrhagic shock (HS) is based on controlling bleeding and the treatment of fluid resuscitation to restore tissue oxygenation and perfusion. The HS could promote ischemia/reperfusion injury, which induces a general exacerbation of the inflammatory process, initially compromising the lungs. N-acetylcysteine (NAC), an antioxidant, may attenuate ischemia/reperfusion injury. This study evaluated the effect of NAC in association with fluid resuscitation on pulmonary injury in a controlled HS model in rats.

METHODS

Male Wistar rats were submitted to controlled HS (mean arterial pressure of 35 mm Hg for 60 min). Two groups were constituted according to resuscitation solution administered: RLG (Ringer's lactate solution) and RLG+NAC (Ringer's lactate in association with 150 mg/kg NAC. A control group was submitted to catheterization only. After 120 min of resuscitation, bronchoalveolar lavage was performed to assess intra-alveolar cell infiltration and pulmonary tissue was collected for assessment of malondialdehyde, interleukin 6, and interleukin 10 and histopathology.

RESULTS

Compared with the RLG group, the RLG+NAC group showed lower bronchoalveolar lavage inflammatory cell numbers, lower interstitial inflammatory infiltration in pulmonary parenchyma, and lower malondialdehyde concentration. However, tissue cytokine (interleukin 6 and interleukin 10) expression levels were similar.

CONCLUSION

N-acetylcysteine was associated with fluid resuscitation-attenuated oxidative stress and inflammatory cell infiltration in pulmonary parenchyma. N-acetylcysteine did not modify cytokine expression.

Inhalative IL-10 attenuates pulmonary inflammation following hemorrhagic shock without major alterations of the systemic inflammatory response

Several studies report immunomodulatory effects of endogenous IL-10 after trauma. The present study investigates the effect of inhalative IL-10 administration on systemic and pulmonary inflammation in hemorrhagic shock. Male C57/BL6 mice (8 animals per group) were subjected to pressure-controlled hemorrhagic shock for 1.5 hrs followed by resuscitation and inhalative administration of either 50 μL PBS (Shock group) or 50 μg/kg recombinant mouse IL-10 dissolved in 50 μL PBS (Shock + IL-10 group). Animals were sacrificed after 4.5 hrs of recovery and serum IL-6, IL-10, KC, and MCP-1 concentrations were measured with ELISA kits. Acute pulmonary inflammation was assessed by pulmonary myeloperoxidase (MPO) activity and pulmonary H&E histopathology. Inhalative IL-10 administration decreased pulmonary inflammation without altering the systemic concentrations of IL-6, IL-10, and KC. Serum MCP-1 levels were significantly reduced following inhalative IL-10 administration. These findings suggest that inhalative IL-10 administration may modulate the pulmonary microenvironment without major alterations of the systemic inflammatory response, thus minimizing the potential susceptibility to infection and sepsis.

A dynamic view of trauma/hemorrhage-induced inflammation in mice: principal drivers and networks

BACKGROUND

Complex biological processes such as acute inflammation induced by trauma/hemorrhagic shock/ (T/HS) are dynamic and multi-dimensional. We utilized multiplexing cytokine analysis coupled with data-driven modeling to gain a systems perspective into T/HS.

METHODOLOGY/PRINCIPAL FINDINGS

Mice were subjected to surgical cannulation trauma (ST) ± hemorrhagic shock (HS; 25 mmHg), and followed for 1, 2, 3, or 4 h in each case. Serum was assayed for 20 cytokines and NO(2) (-)/NO(3) (-). These data were analyzed using four data-driven methods (Hierarchical Clustering Analysis [HCA], multivariate analysis [MA], Principal Component Analysis [PCA], and Dynamic Network Analysis [DyNA]). Using HCA, animals subjected to ST vs. ST + HS could be partially segregated based on inflammatory mediator profiles, despite a large overlap. Based on MA, interleukin [IL]-12p40/p70 (IL-12.total), monokine induced by interferon-γ (CXCL-9) [MIG], and IP-10 were the best discriminators between ST and ST/HS. PCA suggested that the inflammatory mediators found in the three main principal components in animals subjected to ST were IL-6, IL-10, and IL-13, while the three principal components in ST + HS included a large number of cytokines including IL-6, IL-10, keratinocyte-derived cytokine (CXCL-1) [KC], and tumor necrosis factor-α [TNF-α]. DyNA suggested that the circulating mediators produced in response to ST were characterized by a high degree of interconnection/complexity at all time points; the response to ST + HS consisted of different central nodes, and exhibited zero network density over the first 2 h with lesser connectivity vs. ST at all time points. DyNA also helped link the conclusions from MA and PCA, in that central nodes consisting of IP-10 and IL-12 were seen in ST, while MIG and IL-6 were central nodes in ST + HS.

CONCLUSIONS/SIGNIFICANCE

These studies help elucidate the dynamics of T/HS-induced inflammation, complementing other forms of dynamic mechanistic modeling. These methods should be applicable to the analysis of other complex biological processes.

Recombinant factor XIII mitigates hemorrhagic shock-induced organ dysfunction

BACKGROUND

Plasma factor XIII (FXIII) is responsible for stabilization of fibrin clot at the final stage of blood coagulation. Since FXIII has also been shown to modulate inflammation, endothelial permeability, as well as diminish multiple organ dysfunction (MOD) after gut ischemia-reperfusion injury, we hypothesized that FXIII would reduce MOD caused by trauma-hemorrhagic shock (THS).

MATERIALS AND METHODS

Rats were subjected to a 90 min THS or trauma sham shock (TSS) and treated with either recombinant human FXIII A(2) subunit (rFXIII) or placebo immediately after resuscitation with shed blood or at the end of the TSS period. Lung permeability, lung and gut myeloperoxidase (MPO) activity, gut histology, neutrophil respiratory burst, microvascular blood flow in the liver and muscles, and cytokine levels were measured 3 h after the THS or TSS. FXIII levels were measured before THS or TSS and after the 3-h post-shock period.

RESULTS

THS-induced lung permeability as well as lung and gut MPO activity was significantly lower in rFXIII-treated than in placebo-treated animals. Similarly, rFXIII-treated rats had lower neutrophil respiratory burst activity and less ileal mucosal injury. rFXIII-treated rats also had a higher liver microvascular blood flow compared with the placebo group. Cytokine response was more favorable in rFXIII-treated animals. Trauma-hemorrhagic shock did not cause a drop in FXIII activity during the study period.

CONCLUSIONS

Administration of rFXIII diminishes THS-induced MOD in rats, presumably by preservation of the gut barrier function, limitation of polymorphonuclear leukocyte (PMN) activation, and modulation of the cytokine response.

Hypertonic sodium pyruvate solution is more effective than Ringer's ethyl pyruvate in the treatment of hemorrhagic shock

Hypertonic sodium pyruvate (HSP), as well as ethyl pyruvate solutions, has been proposed as resuscitative fluids in the treatment of hemorrhagic shock (HS) because of their anti-inflammatory and antioxidant properties. The effectiveness of one pyruvate preparation over the other in the treatment of HS has not been evaluated. The authors aimed to compare two pyruvate solutions for resuscitation and their mechanisms of action in rats during HS. The effects of infusion of low-volume HSP were compared against high-volume Ringer's ethyl pyruvate on hemodynamic parameters, inflammatory cascade, and regulation of stress and apoptosis-related proteins in the liver. Sprague-Dawley rats were either treated as sham animals or subjected to computer-controlled arterial hemorrhage (40 mmHg) for 60 min followed by resuscitation with isotonic sodium chloride solution, hypertonic saline, Ringer's lactate solution, Ringer's ethyl pyruvate, or HSP for 60 min. Animals were continuously monitored for hemodynamic and biochemical parameters in blood. At the end of the experiment, animals were killed, and liver samples were taken for the evaluation of inflammatory and anti-inflammatory markers and mediators of oxidative stress, liver injury, and expression of apoptotic signaling proteins. In comparison with Ringer's ethyl pyruvate, HSP administration after hemorrhage reduced liver injury, which was associated with increased levels of serum and tissue inflammatory cytokines, inflammatory mediators such as NOS and cyclooxygenase 2, lipid peroxidation, and higher hepatocellular adenosine triphosphate. Cellular apoptotic events related to the activation of caspase-3 and poly(ADP-ribose)polymerase cleavage were also decreased by sodium pyruvate. Resuscitation with small-volume HSP offers significant protection against inflammatory and oxidative stress and in preventing liver injury compared with large-volume Ringer's ethyl pyruvate.

An adequately robust early TNF-alpha response is a hallmark of survival following trauma/hemorrhage

Background

Trauma/hemorrhagic shock (T/HS) results in cytokine-mediated acute inflammation that is generally considered detrimental.

Methodology/Principal Findings

Paradoxically, plasma levels of the early inflammatory cytokine TNF-α (but not IL-6, IL-10, or NO₂^-/NO₃^-) were significantly elevated within 6 h post-admission in 19 human trauma survivors vs. 4 non-survivors. Moreover, plasma TNF-α was inversely correlated with Marshall Score, an index of organ dysfunction, both in the 23 patients taken together and in the survivor cohort. Accordingly, we hypothesized that if an early, robust pro-inflammatory response were to be a marker of an appropriate response to injury, then individuals exhibiting such a response would be predisposed to survive. We tested this hypothesis in swine subjected to various experimental paradigms of T/HS. Twenty-three anesthetized pigs were subjected to T/HS (12 HS-only and 11 HS + Thoracotomy; mean arterial pressure of 30 mmHg for 45–90 min) along with surgery-only controls. Plasma obtained at pre-surgery, baseline post-surgery, beginning of HS, and every 15 min thereafter until 75 min (in the HS only group) or 90 min (in the HS + Thoracotomy group) was assayed for TNF-α, IL-6, IL-10, and NO₂^-/NO₃^-. Mean post-surgery±HS TNF-α levels were significantly higher in the survivors vs. non-survivors, while non-survivors exhibited no measurable change in TNF-α levels over the same interval.

Conclusions/Significance

Contrary to the current dogma, survival in the setting of severe, acute T/HS appears to be associated with an immediate increase in serum TNF-α. It is currently unclear if this response was the cause of this protection, a marker of survival, or both. This abstract won a Young Investigator Travel Award at the SHOCK 2008 meeting in Cologne, Germany.

The acute inflammatory response in trauma / hemorrhage and traumatic brain injury: current state and emerging prospects

Traumatic injury/hemorrhagic shock (T/HS) elicits an acute inflammatory response that may result in death. Inflammation describes a coordinated series of molecular, cellular, tissue, organ, and systemic responses that drive the pathology of various diseases including T/HS and traumatic brain injury (TBI). Inflammation is a finely tuned, dynamic, highly-regulated process that is not inherently detrimental, but rather required for immune surveillance, optimal post-injury tissue repair, and regeneration. The inflammatory response is driven by cytokines and chemokines and is partially propagated by damaged tissue-derived products (Damage-associated Molecular Patterns; DAMP's). DAMPs perpetuate inflammation through the release of pro-inflammatory cytokines, but may also inhibit anti-inflammatory cytokines. Various animal models of T/HS in mice, rats, pigs, dogs, and non-human primates have been utilized in an attempt to move from bench to bedside. Novel approaches, including those from the field of systems biology, may yield therapeutic breakthroughs in T/HS and TBI in the near future.

Propofol protects against hemorrhagic shock-induced organ damage in conscious spontaneously hypertensive rats

Patients with hypertension have higher mortality rates from hemorrhagic shock (HS) than normotensive patients. Several inflammatory mediators such as tumor necrosis factor alpha (TNF-alpha) and interleukin 10 (IL-10) can be produced by HS and lead to multiple organ dysfunction and death. We investigated the effects of high dose (10 mg/kg/hr) and low dose (1 mg/kg/hr) propofol treatment after HS in conscious spontaneously hypertensive rats (SHRs). By withdrawing 40% of total blood volume from a femoral arterial catheter (6 ml/100 g body weight [BW]) for more than 30 min, HS was induced. The mean arterial pressure (MAP) and heart rate (HR) were monitored continuously for 24 hr after the start of blood withdrawal. Levels of biochemical parameters, including glutamic oxaloacetic transaminase (GOT), glutamic pyruvic transaminase (GPT), blood urea nitrogen (BUN), creatinine (Cre), creatine phosphokinase (CPK), and lactic dehydrogenase (LDH) were measured 30 min before and 0, 1, 3, 6, 9, 12, 18, and 24 hr after the 30-min blood withdrawal period. Cytokine levels, including TNF-alpha and IL-10 in the serum, were measured 1 hr after HS. The kidney, liver, and lung were removed for pathology assessment at 48 hr after HS. HS significantly increased blood GOT, GPT, BUN, LDH, CPK, TNF-alpha, and IL-10 levels in conscious SHRs. Posttreatment propofol decreased serum TNF-alpha level, increased serum IL-10 level, attenuated the severity of organ damage, and improved survival rate after HS. This treatment protected SHRs against HS-induced organ damage. Moreover, high-dose propofol had a more protective effect than low-dose propofol against HS in conscious SHRs.

Fluvastatin attenuates severe hemorrhagic shock-induced organ damage in rats

OBJECTIVES

Multiple organ dysfunction resulting from hemorrhagic shock (HS) and subsequent resuscitation was mediated by several inflammatory factors such as tumor necrosis factor-alpha (TNF-alpha) and interleukin-10 (IL-10). The present study was designed to investigate the protective effects of fluvastatin on these mediators after HS in rats.

METHODS

The experimental rats were randomly divided into three groups. The vehicle group received only vitamin K without HS, the HS-control group received vitamin K and HS, and the HS-experimental group received both vitamin K and fluvastatin (1mg/kg) before HS. HS was produced by bleeding from a femoral arterial catheter to remove 60% of total blood volume (6ml/100g BW) over 30min. The mean arterial pressure (MAP) and heart rate (HR) were monitored continuously for 12h after the start of blood withdrawal. The biochemical parameters, including arterial blood gas, glutamic oxaloacetic transaminase (GOT), glutamic pyruvic transaminase (GPT), blood urea nitrogen (BUN), creatinine (Cre), lactic dehydrogenase (LDH), creatine phosphokinase (CPK), and lactate were obtained at 30min before induction of HS and at 0, 1, 3, 6, 9 and 12h after HS. Equal volume of normal saline was given to replace blood volume loss. Cytokine levels including TNF-alpha and IL-10 in serum were measured at 1h after HS. Kidney, liver, lung and small intestine were removed for pathology examination at 48h after HS.

RESULTS

HS significantly increased HR, blood GOT, GPT, BUN, Cre, LDH, CPK, lactate, TNF-alpha and IL-10 levels, and also induced metabolic acidosis and decreased MAP in rats. Pre-treatment with fluvastatin was found to improve survival rate, preserved MAP, decreased the markers of organ injury, suppressed the release of TNF-alpha and increased IL-10 after HS in rats.

CONCLUSION

Pre-treatment with fluvastatin can suppress the release of serum TNF-alpha and can also increase serum IL-10 level to protect HS-induced multi-organ damage in rats.

IL-10 deficiency augments acute lung but not liver injury in hemorrhagic shock

In hemorrhagic shock and trauma, patients are prone to develop systemic inflammation with remote organ dysfunction, which is thought to be caused by pro-inflammatory mediators. This study investigates the role of the immuno-modulatory cytokine IL-10 in the development of organ dysfunction following hemorrhagic shock. Male C57/BL6 and IL-10 KO mice were subjected to volume controlled hemorrhagic shock for 3h followed by resuscitation. Animals were either sacrificed 3 or 24h after resuscitation. To assess systemic inflammation, serum IL-6, IL-10, KC, and MCP-1 concentrations were measured with the Luminex multiplexing platform; acute lung injury (ALI) was assessed by pulmonary myeloperoxidase (MPO) activity and lung histology and acute liver injury was assessed by hepatic MPO activity, hepatic IL-6 levels, and serum ALT levels. There was a trend towards increased IL-6 and KC serum levels 3h after resuscitation in IL-10 KO as compared to C57/BL6 mice; however this did not reach statistical significance. Serum MCP-1 levels were significantly increased in IL-10 KO mice 3 and 24 h following resuscitation as compared to C57/BL6 mice. In IL-10 KO mice, pulmonary MPO activity was significantly increased 3 h following resuscitation and after 24 h histological signs of acute lung injury were more apparent than in C57/BL6 mice. In contrast, no significant differences in any liver parameters were detected between IL-10 KO and C57/BL6 mice. Our data indicate that an endogenous IL-10 deficiency augments acute lung but not liver injury following hemorrhagic shock.

Effect of exogenous catecholamines on tumor necrosis factor alpha, interleukin-6, interleukin-10 and beta-endorphin levels following severe trauma

Cytokines and endogenous opioids are mediators of the post traumatic inflammatory response. The aim of this study was to determine the effect of exogenous catecholamines on tumor necrosis factor alpha (TNFa), interleukin-6 (IL-6), interleukin-10 (IL-10) and beta(beta)-endorphin levels in patients with severe trauma, during the first 24 h after injury. Forty four traumatized patients with haemorrhage class III and IV were included in the study. Patients were divided in two groups: Group 1 (adrenergic, n=22) and Group 2 (non adrenergic, n=22), depending on the use of exogenous catecholamines. Blood samples were collected at 0, 2, 4 and 24 h time points. Baseline values were different between the two groups, but an altered pattern of release was observed for TNFa, IL-6, IL-10 and beta-endorphin levels in patients treated with catecholamines. ICU stay was longer for the adrenergic group, while survival after 1 month was significantly lower. Findings support an altered pattern of cytokine release during the early phase after trauma, probably due to catecholamine presence.

Delayed fluid resuscitation in hemorrhagic shock induces proinflammatory cytokine response

STUDY OBJECTIVE

This study is designed to determine the effects of delayed fluid resuscitation on the hemodynamic changes and cytokine responses in a rat model of hemorrhagic shock.

METHODS

Wistar male rats (n=40; 8/group) were subjected to a volume-controlled hemorrhagic shock for 30 minutes and received lactated Ringer's solution resuscitation as follows: (1) immediate resuscitation, (2) delayed resuscitation begun 30 minutes after hemorrhage (delayed resuscitation 30), (3) delayed resuscitation begun 45 minutes after hemorrhage (delayed resuscitation 45), (4) delayed resuscitation begun 60 minutes after hemorrhage (delayed resuscitation 60), or (5) unresuscitated group, induction of hemorrhagic shock without resuscitation. Hemodynamic parameters were recorded and blood samples were collected at 0 minutes and at 30, 90, 150, 210, 270, and 330 minutes after hemorrhage for plasma levels of interleukin (IL) 6, IL-10 and tumor necrosis factor alpha (TNF-alpha). Repeated-measurement analysis of variance was used for within- and between-groups comparisons.

RESULTS

Final mean blood pressure, serum levels of lactate, and hematocrit levels after immediate resuscitation were not different from those in the delayed resuscitation groups. Comparing with the unresuscitated group, TNF-alpha and IL-6 concentrations were significantly higher, whereas IL-10 concentrations were significantly lower in the 4 resuscitation groups. Circulating concentrations of IL-6 were significantly higher in the delayed resuscitation 45 (P<.001) and delayed resuscitation 60 (P<.001) groups. Circulating concentrations of TNF-alpha and IL-10 in the 4 resuscitation groups were comparable throughout the experimental period.

CONCLUSION

Delayed fluid resuscitation in hemorrhagic shock induces increased production of proinflammatory cytokines, and the release of cytokine was correlated with the time delayed for resuscitation.

The role of hepatic type 1 plasminogen activator inhibitor (PAI-1) during murine hemorrhagic shock

Hemorrhagic shock (HS) followed by resuscitation (HS-R) is characterized by profound physiological changes. Even if the patient survives the initial blood loss, these poorly understood changes can lead to morbidity. One of the tissues most often affected is liver. We sought to recognize specific hepatic changes induced by this stressor to identify targets for therapeutic intervention. Gene array analyses using mouse liver mRNAs were used to identify candidate genes that contribute to hepatic damage. To verify the role of one of the genes identified using the arrays, mice were subjected to HS-R, and multiple parameters were analyzed. A profound increase in plasminogen activator inhibitor type 1 (PAI-1) mRNA was observed using hepatic mRNAs from C57Bl/6 mice after HS, both with and without resuscitation. Constitutive loss of PAI-1 resulted in notable tissue preservation and lower (P < .05) alanine aminotransferase (ALT) levels. Fibrin degradation products (FDPs) and interleukins 6 and 10 (IL-6 and IL-10) were unaffected by loss of PAI-1; however, enhanced urokinase activity, an elevation of active hepatocyte growth factor (HGF), an increase in unprocessed transforming growth factor-beta1 (TGF-beta1), and retention of ERK phosphorylation after HS-R were associated with improved hepatic function. In conclusion, PAI-1 protein is a negative effector of hepatic damage after HS-R through its influence on classic regulators of hepatic growth, as opposed to its role in fibrinolysis.

TSC for hemorrhagic shock: effects on cytokines and blood pressure

Previous studies have shown that administering trans-sodium crocetinate (TSC) as a treatment of hemorrhagic shock leads to increased whole-body oxygen consumption and survival as well as protection of the liver and kidney. It has been suggested that TSC increases oxygen delivery by increasing the diffusivity of oxygen through plasma. However, as with any novel mechanism of action, there are always questions about whether the results could also be ascribed to other, previously described mechanisms of action. This study was designed to look at some aspects of that by examining the effect of different TSC dosing regimens on the blood pressure and the production of cytokines after hemorrhage because both responses have been reported with compounds that act via other mechanisms. In a constant-pressure rat model of hemorrhagic shock, it was seen that a singe bolus injection of TSC results in an immediate but transient increase in the arterial blood pressure. This is similar to the effect reported previously for using 100% oxygen. It was also found that if the TSC injections were repeated periodically over an hour, a sustained increase in the blood pressure would occur. Because inflammatory cytokines have been implicated in mortality and tissue damage, it has been suggested that TSC may affect the production of cytokines. Thus, the effect of TSC on the production of TNF-alpha and IL-10 was also examined. The data show that treatment with TSC results in lower concentrations of TNF-alpha in the liver and spleen as well as lower concentrations of IL-10 in the spleen. Again, similar effects on other cytokines have been seen with 100% oxygen. These results support the hypothesis that the effects of TSC on hemorrhagic shock are mediated via an effect on oxygen.

Pathogenesis of malaria and clinically similar conditions

There is now wide acceptance of the concept that the similarity between many acute infectious diseases, be they viral, bacterial, or parasitic in origin, is caused by the overproduction of inflammatory cytokines initiated when the organism interacts with the innate immune system. This is also true of certain noninfectious states, such as the tissue injury syndromes. This review discusses the historical origins of these ideas, which began with tumor necrosis factor (TNF) and spread from their origins in malaria research to other fields. As well the more established proinflammatory mediators, such as TNF, interleukin-1, and lymphotoxin, the roles of nitric oxide and carbon monoxide, which are chiefly inhibitory, are discussed. The established and potential roles of two more recently recognized contributors, overactivity of the enzyme poly(ADP-ribose) polymerase 1 (PARP-1) and the escape of high-mobility-group box 1 (HMGB1) protein from its normal location into the circulation, are also put in context. The pathogenesis of the disease caused by falciparum malaria is then considered in the light of what has been learned about the roles of these mediators in these other diseases, as well as in malaria itself.

Role of IL-10 in regulating proinflammatory cytokine release by Kupffer cells following trauma-hemorrhage

IL-6 and TNF-alpha production by Kupffer cells is markedly stimulated following trauma-hemorrhage (T-H). Because IL-10 is an anti-inflammatory cytokine, the aim of this study was to determine whether IL-10 regulates Kupffer cell proinflammatory cytokine release following T-H. To study this, we subjected adult male Sprague-Dawley rats to sham operation or T-H. The procedure involved a 5-cm midline laparotomy and approximately 90 min of hemorrhagic shock (35 mmHg), followed by resuscitation with four times the shed blood volume in the form of Ringer's lactate. At 2 h after the end of resuscitation, livers were perfused in vitro and perfusate was collected. In separate studies, Kupffer cells were isolated and incubated with different concentrations of anti-IL-10 MAb. IgG was used as control. After 16 h of incubation, IL-6 and TNF-alpha levels were measured by ELISA. Plasma IL-10 levels increased significantly following T-H. IL-10 levels in the perfusate and IL-10 production by cultured Kupffer cells were also significantly higher in the T-H group. When Kupffer cells were incubated with 10 microg/ml of anti-IL-10 MAb, IL-6 and TNF-alpha production were significantly increased in both sham and T-H groups compared with those not treated with anti-IL-10 MAb. However, these changes were not observed when the cells were incubated with irrelevant (control) IgG. These results indicate that IL-10 production by Kupffer cells early after T-H may play a pivotal role in attenuating the proinflammatory cytokine environment, possibly in an autocrine/paracrine manner.

Significance of the determination of proinflammatory cytokines in the serum of polytraumatized patients with sepsis

Severe sepsis and trauma complicated with multiple organ dysfunction syndrome (MODS) are among the leading causes of death in intensive therapy units with mortality rate exceeding 50%. The outcome is not determined only by infection or trauma, but also by the intensity of immuno-inflammatory response, which is essential for host defence, but if uncontrolled leads to MODS. Pro-inflammatory cytokines (tumor necrosis factor-a -TNF-a, IL-1 IL-8, IL-12, IFN-g, etc) represent a part of this immuno-inflammatory response to an insult. The results of the clinical investigation of correlation between pro-inflammatory cytokines (IL-8, IL-12, TNF-a, IFN-g) the outcome (survivors, non-survivors), and the severity (systemic inflammatory response syndrome - SIRS - less severe, and MODS - more severe) in polytraumatised patients with sepsis are presented in this paper. Mean values of IL-8 were 1.3-fold higher in non-survivors (p<0.05), and 60-fold higher in MODS group (p<0.01). Mean values of IL-12 were 1.6-fold higher in survivors (p<0.01), while the values between SIRS and MODS group did not differ significantly; mean values of TNF-a were 3-fold higher in survivors (p<0.05), and 46-fold higher in MODS group (p<0.01). Mean values of IFN-g did not differ significantly between the two groups regarding the outcome and severity. The obtained results indicated that IL-8 was a reliable predictor of lethal outcome and MODS (p<0.01), IL-12 a reliable predictor of survival (p<0.05), and TNF-a a reliable predictor of survival (p<0.05) and MODS (p<0.01).

Impact of alcohol intoxication on hemodynamic, metabolic, and cytokine responses to hemorrhagic shock

BACKGROUND

Alcohol intoxication is associated with a high incidence of traumatic injury, particularly in the young healthy population. The impact of alcohol intoxication on the immediate pathophysiologic response to injury has not been closely examined. We hypothesized that acute alcohol intoxication would aggravate the immediate outcome from hemorrhagic shock by impairing homeostatic counterregulation to blood loss.

METHODS

Chronically catheterized male Sprague-Dawley rats were randomized to receive an intragastric infusion of ethyl alcohol (1.75 g/kg followed by 250-300 mg/kg/h) or isocaloric dextrose (3-mL bolus + 0.375 mL/h) for 15 hours. Before initiating fixed-pressure hemorrhage followed by fluid resuscitation, an additional intragastric bolus of ethyl alcohol (1.75 g/kg) was administered. Hemodynamic, metabolic, cytokine, and acid-base parameters were assessed during the hemorrhage period and at completion of resuscitation. Lungs were obtained for cytokine determinations.

RESULTS

Basal mean arterial pressure was significantly lower in alcohol-intoxicated (blood-alcohol concentration, 135 +/- 12 mg/dL) animals than in controls during baseline (20%) and after the initial fluid resuscitation period (30%). Hemorrhage decreased arterial HCO3 and Pco2, and increased Po2 without significant alteration in arterial blood pH. Alcohol intoxication blunted the decrease in Pco2 and increase in Po2 and decreased blood pH during baseline and throughout the course of the hemorrhage period. Hemorrhage produced marked and progressive elevations in plasma glucose and lactate levels in controls, and this was inhibited by alcohol intoxication. Hemorrhage elevated plasma tumor necrosis factor-alpha (TNF-alpha) (686 +/- 252 pg/mL) and interleukin (IL)-10 (178 +/- 25 pg/mL), and did not alter IL-6 and IL-1 levels. Alcohol blunted the hemorrhage-induced rise in plasma TNF-alpha (142 +/- 48 pg/mL) and enhanced the hemorrhage-induced increase in IL-10 (678 +/- 187 pg/mL). Hemorrhage produced a two- to threefold increase in lung content of TNF-alpha, IL-1alpha, and IL-6 without significantly altering lung IL-10. Alcohol exacerbated the hemorrhage-induced increase in lung TNF-alpha, and did not alter the IL-1alpha, IL-6, and IL-10 lung responses.

CONCLUSION

These results indicate marked alterations in the hemodynamic and metabolic responses to hemorrhagic shock by alcohol intoxication. Furthermore, our findings suggest that alcohol modulates the early proinflammatory responses to hemorrhagic shock. Taken together, these alterations in metabolic and inflammatory responses to hemorrhage are likely to impair immediate outcome and predispose to tissue injury.

Gender differences in the inflammatory response and survival following haemorrhage and subsequent sepsis

Studies have shown gender dimorphism in cell-mediated immune responses following haemorrhage, with depressed responses in young males and maintained or enhanced responses in proestrus females. However, it remains unknown whether or not the sexually dimorphic immune response to haemorrhage provides any protection against a subsequent in vivo polymicrobial septic challenge. To study this, male and proestrus female C3H/HeN mice were subjected to haemorrhage (35+/-5 mmHg for 90 min followed by fluid resuscitation) or sham operation. Twenty-four hours thereafter, all mice were subjected to polymicrobial sepsis by cecal ligation and puncture (CLP) and survival was assessed over a 10 day period. Haemorrhage prior to CLP significantly increased mortality in males as compared to shams. In contrast, mortality in females following CLP was comparable between the sham and haemorrhage groups. Plasma levels of interleukin (IL-)6, tumour necrosis factor (TNF)-alpha and prostaglandin E(2)(PGE(2)) at 5 h after CLP were significantly increased in males subjected to prior haemorrhage. In contrast, plasma levels of IL-6 and TNF-alpha in females did not increase under such conditions. PGE(2)levels were comparable in males and females following CLP, however prior haemorrhage significantly reduced PGE(2)levels in females, whereas no change was observed in males. Liver and splenic expression of cyclooxygenase-2 protein paralleled the changes in plasma PGE(2). Female sex hormones, therefore, appear to play an important role not only in maintaining immune function following haemorrhage, but also provide a survival advantage against subsequent septic challenge.