ContextActivation of the coagulation system and depletion of endogenous anticoagulants
are frequently found in patients with severe sepsis and septic shock. Diffuse
microthrombus formation may induce organ dysfunction and lead to excess mortality
in septic shock. Antithrombin III may provide protection from multiorgan failure
and improve survival in severely ill patients.ObjectiveTo determine if high-dose antithrombin III (administered within 6 hours
of onset) would provide a survival advantage in patients with severe sepsis
and septic shock.Design and SettingDouble-blind, placebo-controlled, multicenter phase 3 clinical trial
in patients with severe sepsis (the KyberSept Trial) was conducted from March
1997 through January 2000.PatientsA total of 2314 adult patients were randomized into 2 equal groups of
1157 to receive either intravenous antithrombin III (30 000 IU in total
over 4 days) or a placebo (1% human albumin).Main Outcome MeasureAll-cause mortality 28 days after initiation of study medication.ResultsOverall mortality at 28 days in the antithrombin III treatment group
was 38.9% vs 38.7% in the placebo group (P = .94).
Secondary end points, including mortality at 56 and 90 days and survival time
in the intensive care unit, did not differ between the antithrombin III and
placebo groups. In the subgroup of patients who did not receive concomitant
heparin during the 4-day treatment phase (n = 698), the 28-day mortality was
nonsignificantly lower in the antithrombin III group (37.8%) than in the placebo
group (43.6%) (P = .08). This trend became significant
after 90 days (n = 686; 44.9% for antithrombin III group vs 52.5% for placebo
group; P = .03). In patients receiving antithrombin
III and concomitant heparin, a significantly increased bleeding incidence
was observed (23.8% for antithrombin III group vs 13.5% for placebo group; P<.001).ConclusionsHigh-dose antithrombin III therapy had no effect on 28-day all-cause
mortality in adult patients with severe sepsis and septic shock when administered
within 6 hours after the onset. High-dose antithrombin III was associated
with an increased risk of hemorrhage when administered with heparin. There
was some evidence to suggest a treatment benefit of antithrombin III in the
subgroup of patients not receiving concomitant heparin.

https://jamanetwork.com/journals/jama/articlepdf/194284/JCE10000.pdf

High-Dose Antithrombin III in Severe Sepsis: A Randomized Controlled Trial

Inflammation and its role in neuroprotection, axonal regeneration and functional recovery after spinal cord injury

Ischemia-reperfusion injury is, at least in part, responsible for the morbidity associated with liver surgery under total vascular exclusion or after liver transplantation. The pathophysiology of hepatic ischemia-reperfusion includes a number of mechanisms that contribute to various degrees in the overall injury. Some of the topics discussed in this review include cellular mechanisms of injury, formation of pro- and anti-inflammatory mediators, expression of adhesion molecules, and the role of oxidant stress during the inflammatory response. Furthermore, the roles of nitric oxide in preventing microcirculatory disturbances and as a substrate for peroxynitrite formation are reviewed. In addition, emerging mechanisms of protection by ischemic preconditioning are discussed. On the basis of current knowledge, preconditioning or pharmacological interventions that mimic these effects have the greatest potential to improve clinical outcome in liver surgery involving ischemic stress and reperfusion.

Molecular mechanisms of hepatic ischemia-reperfusion injury and preconditioning.

In the pathogenesis of sepsis, inflammation and coagulation play a pivotal role. Increasing evidence points to an extensive cross-talk between these two systems, whereby inflammation leads to activation of coagulation, and coagulation also considerably affects inflammatory activity. Molecular pathways that contribute to inflammation-induced activation of coagulation have been precisely identified. Pro-inflammatory cytokines and other mediators are capable of activating the coagulation system and down-regulating important physiologic anticoagulant pathways. Activation of the coagulation system and ensuing thrombin generation is dependent on expression of tissue factor and the simultaneous down-regulation of endothelial-bound anticoagulant mechanisms and endogenous fibrinolysis. Conversely, activated coagulation proteases may affect specific cellular receptors on inflammatory cells and endothelial cells and thereby modulate the inflammatory response.

Inflammation and coagulation.

Spinal cord injury (SCI) provokes an inflammatory response that generates substantial secondary damage within the cord but also may contribute to its repair. Anti-inflammatory treatment of human SCI and its timing must be based on knowledge of the types of cells participating in the inflammatory response, the time after injury when they appear and then decrease in number, and the nature of their actions. Using post-mortem spinal cords, we evaluated the time course and distribution of pathological change, infiltrating neutrophils, monocytes/macrophages and lymphocytes, and microglial activation in injured spinal cords from patients who were ‘dead at the scene’ or who survived for intervals up to 1 year after SCI. SCI caused zones of pathological change, including areas of inflammation and necrosis in the acute cases, and cystic cavities with longer survival (Zone 1), mantles of less severe change, including axonal swellings, inflammation and Wallerian degeneration (Zone 2) and histologically intact areas (Zone 3). Zone 1 areas increased in size with time after injury whereas the overall injury (size of the Zones 1 and 2 combined) remained relatively constant from the time (1–3 days) when damage was first visible. The distribution of inflammatory cells correlated well with the location of Zone 1, and sometimes of Zone 2. Neutrophils, visualized by their expression of human neutrophil α-defensins (defensin), entered the spinal cord by haemorrhage or extravasation, were most numerous 1–3 days after SCI, and were detectable for up to 10 days after SCI. Significant numbers of activated CD68-immunoreactive ramified microglia and a few monocytes/macrophages were in injured tissue within 1–3 days of SCI. Activated microglia, a few monocytes/macrophages and numerous phagocytic macrophages were present for weeks to months after SCI. A few CD8+ lymphocytes were in the injured cords throughout the sampling intervals. Expression by the inflammatory cells of the oxidative enzymes myeloperoxidase (MPO) and nicotinamide adenine dinucleotide phosphate oxidase (gp91phox), and of the pro-inflammatory matrix metalloproteinase (MMP)-9, was analysed to determine their potential to cause oxidative and proteolytic damage. Oxidative activity, inferred from MPO and gp91phox immunoreactivity, was primarily associated with neutrophils and activated microglia. Phagocytic macrophages had weak or no expression of MPO or gp91phox. Only neutrophils expressed MMP-9. These data indicate that potentially destructive neutrophils and activated microglia, replete with oxidative and proteolytic enzymes, appear within the first few days of SCI, suggesting that anti-inflammatory ‘neuroprotective’ strategies should be directed at preventing early neutrophil influx and modifying microglial activation.

The cellular inflammatory response in human spinal cords after injury.

Role of neutrophils in spinal cord injury in the rat

Antithrombin reduces ischemia/reperfusion injury of rat liver by increasing the hepatic level of prostacyclin

We investigated whether antithrombin (AT) can reduce ischemia/reperfusion (I/R)-induced injury of rat liver by promoting prostacyclin release from endothelial cells. Although intravenous administration of AT (250 U/kg) markedly reduced hepatic injury, neither dansyl-Glu-Gly-Arg-chloromethyl ketone-treated factor Xa (DEGR-Xa), a selective inhibitor of thrombin generation, nor Trp49-modified AT, which lacks affinity for heparin, had any effect. Hepatic levels of 6-keto-PGF1, a stable prostacyclin (PGI2) metabolite, were increased significantly after I/R of the rat liver. AT significantly increased the hepatic level of 6-keto-PGF1, whereas neither DEGR-Xa nor Trp49-modified AT increased it. Hepatic tissue blood flow was markedly reduced after I/R. Although AT significantly increased the hepatic tissue blood flow after I/R, neither DEGR-Xa nor Trp49-modified AT increased the blood flow. Hepatic levels of cytokine-induced neutrophil chemoattractant (CINC) and myeloperoxidase (MPO) were significantly increased after hepatic I/R. The levels of these two indicators were reduced by AT but were unaffected by either DEGR-Xa or Trp49-modified AT. Pretreatment of animals with indomethacin (IM) completely inhibited the protective effects of AT on the I/R-induced hepatic damage and the leukocyte activation as well as the AT-induced increase in hepatic 6-keto-PGF1 levels after I/R. Iloprost, a stable analog of PGI2, exhibited effects similar to those of AT and also significantly inhibited the exacerbation of liver injury, the decrease in hepatic tissue blood flow, and the increases in hepatic CINC and MPO levels seen in rats subjected to I/R but pretreated with IM. These findings suggest that AT may prevent I/R-induced hepatic injury by increasing the hepatic levels of PGI2 through the interaction of AT with cell-surface glycosaminoglycans, thus increasing hepatic tissue blood flow and inhibiting leukocyte activation in animals subjected to I/R.

Objective : To investigate the role of granulocyte elastase in ischemia/reperfusion injury of liver, the effect of ONO-5046, a granulocyte elastase inhibitor, was examined in ischemia/reperfusion-induced liver injury in rats. Design : Prospective, randomized, controlled study. Setting : Research laboratory at a university medical center. Subjects : Male Wistar rats, weighing 220 to 280 g. Interventions : Animals receiving continuous intravenous infusion of ONO-5046 (50 mg/kg/hr) were subjected to hepatic ischemia/reperfusion. Hepatic damage was evaluated by effects on bile formation capacity, plasma clearance of indocyanine green, and serum aminotransferase concentrations after ischemia/reperfusion. Measurements and Main Results : Hepatic dysfunction, observed after 60 mins of ischemia/reperlusion, led to a reduction in bile flow and to a decrease in the plasma clearance of indocyanine green. These indicators of hepatic dysfunction were prevented, to a large extent, by administration of ONO-5046. Serum concentrations of aminotransferases increased after hepatic ischemia/reperfusion, peaking at 12 hrs of reperfusion. Increases in serum concentrations of aminotransferases were significantly inhibited by ONO-5046. Conclusion : Granulocyte elastase derived from activated leukocytes may play a critical role in hepatic dysfunction and the subsequent hepatic injury induced by ischemia/reperfusion.

Role of granulocyte elastase in ischemia/reperfusion injury of rat liver

Objective:To investigate whether gabexate mesilate, a synthetic protease inhibitor with anticoagulant properties, prevents hepatic damage by inhibiting leukocyte activation, we examined its effect on ischemia/reperfusion injury of rat liver in which activated leukocytes play a critical role.Design:P

Shigeki Kushimoto

Papers

Role of neutrophils in spinal cord injury in the rat

Antithrombin reduces ischemia/reperfusion injury of rat liver by increasing the hepatic level of prostacyclin

Antithrombin reduces ischemia/reperfusion injury of rat liver by increasing the hepatic level of prostacyclin

Role of granulocyte elastase in ischemia/reperfusion injury of rat liver

Gabexate mesilate, a synthetic protease inhibitor, reduces ischemia/reperfusion injury of rat liver by inhibiting leukocyte activation.