1
|
Wang D, Wang S, Wu H, Gao J, Huang K, Xu D, Ru H. Association Between Platelet Levels and 28-Day Mortality in Patients With Sepsis: A Retrospective Analysis of a Large Clinical Database MIMIC-IV. Front Med (Lausanne) 2022; 9:833996. [PMID: 35463034 PMCID: PMC9021789 DOI: 10.3389/fmed.2022.833996] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2021] [Accepted: 02/28/2022] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND This research focused on evaluating the correlation between platelet count and sepsis prognosis, and even the dose-response relationship, in a cohort of American adults. METHOD Platelet counts were recorded retrospectively after hospitalization for patients admitted to Beth Israel Deaconess Medical Center's intensive care unit between 2008 and 2019. On admission to the intensive care unit, sepsis patients were divided into four categories based on platelet counts (very low < 50 × 109/L, intermediate-low 50 × 109-100 × 109/L, low 100 × 109-150 × 109/L, and normal ≥ 150 × 109/L). A multivariate Cox proportional risk model was used to calculate the 28-day risk of mortality in sepsis based on baseline platelet counts, and a two-piece linear regression model was used to calculate the threshold effect. RESULTS The risk of 28-day septic mortality was nearly 2-fold higher in the platelet very low group when compared to the low group (hazard ratios [HRs], 2.24; 95% confidence interval [CI], 1.92-2.6). Further analysis revealed a curvilinear association between platelets and the sepsis risk of death, with a saturation effect predicted at 100 × 109/L. When platelet counts were below 100 × 109/L, the risk of sepsis 28-day death decreased significantly with increasing platelet count levels (HR, 0.875; 95% CI, 0.84-0.90). CONCLUSION When platelet count was less than 100 × 109/L, it was a strong predictor of the potential risk of sepsis death, which is declined by 13% for every 10 × 109/L growth in platelets. When platelet counts reach up to 100 × 109/L, the probability of dying to sepsis within 28 days climbs by 1% for every 10 × 109/L increase in platelet count.
Collapse
|
2
|
Garami A, Steiner AA, Romanovsky AA. Fever and hypothermia in systemic inflammation. HANDBOOK OF CLINICAL NEUROLOGY 2018; 157:565-597. [PMID: 30459026 DOI: 10.1016/b978-0-444-64074-1.00034-3] [Citation(s) in RCA: 71] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Systemic inflammation-associated syndromes (e.g., sepsis and septic shock) often have high mortality and remain a challenge in emergency medicine. Systemic inflammation is usually accompanied by changes in body temperature: fever or hypothermia. In animal studies, systemic inflammation is often modeled by administering bacterial lipopolysaccharide, which triggers autonomic and behavioral thermoeffector responses and causes either fever or hypothermia, depending on the dose and ambient temperature. Fever and hypothermia are regulated changes of body temperature, which correspond to mild and severe forms of systemic inflammation, respectively. Mediators of fever and hypothermia are called endogenous pyrogens and cryogens; they are produced when the innate immune system recognizes an infectious pathogen. Upon an inflammatory challenge, hepatic and pulmonary macrophages (and later brain endothelial cells) start to release lipid mediators, of which prostaglandin (PG) E2 plays the key role, and cytokines. Blood PGE2 enters the brain and triggers fever. At later stages of fever, PGE2 synthesized within the blood-brain barrier maintains fever. In both cases, PGE2 is synthesized by cyclooxygenase-2 and microsomal PGE2synthase-1. Mediators of hypothermia are not well established. Both fever and hypothermia are beneficial host defense responses. Based on evidence from studies in laboratory animals and clinical trials in humans, fever is beneficial for fighting mild infection. Based mainly on animal studies, hypothermia is beneficial in severe systemic inflammation and infection.
Collapse
Affiliation(s)
- Andras Garami
- Institute for Translational Medicine, Medical School, University of Pécs, Pécs, Hungary.
| | - Alexandre A Steiner
- Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Andrej A Romanovsky
- Thermoregulation and Systemic Inflammation Laboratory (FeverLab), Trauma Research, St. Joseph's Hospital and Medical Center, Phoenix, AZ, United States
| |
Collapse
|
3
|
Evans CE, Zhao YY. Impact of thrombosis on pulmonary endothelial injury and repair following sepsis. Am J Physiol Lung Cell Mol Physiol 2017; 312:L441-L451. [PMID: 28130261 PMCID: PMC5407094 DOI: 10.1152/ajplung.00441.2016] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Revised: 12/20/2016] [Accepted: 01/19/2017] [Indexed: 12/19/2022] Open
Abstract
The prevailing morbidity and mortality in sepsis are largely due to multiple organ dysfunction (MOD), most commonly lung injury, as well as renal and cardiac dysfunction. Despite recent advances in defining many aspects of the pathogenesis of sepsis-related MOD, including acute respiratory distress syndrome (ARDS), there are currently no effective pharmacological or cell-based treatments for the disease. Human and animal studies have shown that pulmonary thrombosis is common in sepsis-induced ARDS, and preclinical studies have shown that anticoagulation may improve outcome following sepsis challenge. The potential beneficial effect of anticoagulation on outcome is unconvincing in clinical studies, however, and these discrepancies may arise from the multiple and sometimes opposing actions of thrombosis on the pulmonary endothelium following sepsis. It has been suggested, for example, that mild pulmonary thrombosis prevents escape of bacterial infection into the circulation, while severe thrombosis causes hypoxia and results in pulmonary endothelial damage. Evidence from both human and animal studies has demonstrated the key role of microvascular leakage in determining the outcome of sepsis. In this review, we describe thrombosis-dependent mechanisms that regulate pulmonary endothelial injury and repair following sepsis, including activation of the coagulation cascade by tissue factor and stimulation of vascular repair by hypoxia-inducible factors. Targeting such mechanisms through anticoagulant, anti-inflammatory, and reparative methods may represent a novel approach for the treatment of septic patients.
Collapse
Affiliation(s)
- Colin E Evans
- Department of Pharmacology, University of Illinois at Chicago, College of Medicine, Chicago, Illinois; and
- Center for Lung and Vascular Biology, University of Illinois at Chicago, College of Medicine, Chicago, Illinois
| | - You-Yang Zhao
- Department of Pharmacology, University of Illinois at Chicago, College of Medicine, Chicago, Illinois; and
- Center for Lung and Vascular Biology, University of Illinois at Chicago, College of Medicine, Chicago, Illinois
| |
Collapse
|
4
|
Ren M, Li R, Luo M, Chen N, Deng X, Yan K, Zeng M, Wu J. Endothelial cells but not platelets are the major source of Toll-like receptor 4 in the arterial thrombosis and tissue factor expression in mice. Am J Physiol Regul Integr Comp Physiol 2014; 307:R901-7. [PMID: 25275013 DOI: 10.1152/ajpregu.00324.2014] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
It is known that Toll-like receptor (TLR)-4 plays an important role in myocardial infarction and atherothrombosis. The role of TLR-4 in arterial thrombosis is undefined. Both TLR-4-deficient (TLR-4(-/-)) and wild-type (WT) mice were subjected to FeCl3 carotid artery injury, and the time required to form an occlusive thrombus was measured. The mean time to occlusion in TLR-4(-/-) mice was significantly greater than that in WT mice after injury (303 ± 32 vs. 165 ± 34 s, P < 0.05). Furthermore, when we used a WT or TLR-4(-/-)-derived platelet reinfusion in a platelet depletion/reinfusion procedure, there was no significant change in the occlusion time and tissue factor (TF) activity in injured arteries between WT mice and platelet-depleted WT mice. Similarly, no significant difference was observed between TLR-4(-/-) mice and platelet-depleted TLR-4(-/-) mice for the WT or TLR-4(-/-)-derived platelet reinfusion. However, TF expression and activity were significantly reduced in the vascular wall of TLR-4(-/-) mice compared with WT mice. In vivo, lipopolysaccharide accelerated the occlusion time in WT mice but not TLR-4(-/-) mice. In vitro, LPS-induced TF activity was reduced in endothelial cells of TLR-4(-/-) mice relative to WT mice. The data demonstrate that TLR-4 contributes to arterial thrombosis formation in vivo and causes increased TF expression and activity in vitro. The results further suggest that the stimulation is mainly derived by endothelial cells but is not due to platelet-derived TLR-4.
Collapse
Affiliation(s)
- Meiping Ren
- Drug Discivery Research Center, Luzhou Medical College, Luzhou, Sichuan, China; and
| | - Rong Li
- Drug Discivery Research Center, Luzhou Medical College, Luzhou, Sichuan, China; and
| | - Mao Luo
- Drug Discivery Research Center, Luzhou Medical College, Luzhou, Sichuan, China; and
| | - Ni Chen
- Drug Discivery Research Center, Luzhou Medical College, Luzhou, Sichuan, China; and
| | - Xin Deng
- Drug Discivery Research Center, Luzhou Medical College, Luzhou, Sichuan, China; and
| | - Kai Yan
- Drug Discivery Research Center, Luzhou Medical College, Luzhou, Sichuan, China; and
| | - Min Zeng
- Drug Discivery Research Center, Luzhou Medical College, Luzhou, Sichuan, China; and
| | - Jianbo Wu
- Drug Discivery Research Center, Luzhou Medical College, Luzhou, Sichuan, China; and Department of Internal Medicine, University of Missouri School of Medicine, Columbia, Missouri
| |
Collapse
|
5
|
Ergin B, Kapucu A, Demirci-Tansel C, Ince C. The renal microcirculation in sepsis. Nephrol Dial Transplant 2014; 30:169-77. [PMID: 24848133 DOI: 10.1093/ndt/gfu105] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Despite identification of several cellular mechanisms being thought to underlie the development of septic acute kidney injury (AKI), the pathophysiology of the occurrence of AKI is still poorly understood. It is clear, however, that instead of a single mechanism being responsible for its aetiology, an orchestra of cellular mechanisms failing is associated with AKI. The integrative physiological compartment where these mechanisms come together and exert their integrative deleterious action is the renal microcirculation (MC). This is why it is opportune to review the response of the renal MC to sepsis and discuss the determinants of its (dys)function and how it contributes to the pathogenesis of renal failure. A main determinant of adequate organ function is the adequate supply and utilization of oxygen at the microcirculatory and cellular level to perform organ function. The highly complex architecture of the renal microvasculature, the need to meet a high energy demand and the fact that the kidney is borderline ischaemic makes the kidney a highly vulnerable organ to hypoxaemic injury. Under normal, steady-state conditions, oxygen (O2) supply to the renal tissues is well regulated; however, under septic conditions the delicate balance of oxygen supply versus demand is disturbed due to renal microvasculature dysfunction. This dysfunction is largely due to the interaction of renal oxygen handling, nitric oxide metabolism and radical formation. Renal tissue oxygenation is highly heterogeneous not only between the cortex and medulla but also within these renal compartments. Integrative evaluation of the different determinants of tissue oxygen in sepsis models has identified the deterioration of microcirculatory oxygenation as a key component in the development AKI. It is becoming clear that resuscitation of the failing kidney needs to integratively correct the homeostasis between oxygen, and reactive oxygen and nitrogen species. Several experimental therapeutic modalities have been found to be effective in restoring microcirculatory oxygenation in parallel to improving renal function following septic AKI. However, these have to be verified in clinical studies. The development of clinical physiological biomarkers of AKI specifically aimed at the MC should form a valuable contribution to monitoring such new therapeutic modalities.
Collapse
Affiliation(s)
- Bulent Ergin
- Department of Translational Physiology, Academic Medical Center, Amsterdam, The Netherlands
| | - Aysegul Kapucu
- Department of Translational Physiology, Academic Medical Center, Amsterdam, The Netherlands Department of Biology and Zoology Division, University of Istanbul, Istanbul, Turkey
| | - Cihan Demirci-Tansel
- Department of Biology and Zoology Division, University of Istanbul, Istanbul, Turkey
| | - Can Ince
- Department of Translational Physiology, Academic Medical Center, Amsterdam, The Netherlands
| |
Collapse
|
6
|
Awad EM, Khan SY, Sokolikova B, Brunner PM, Olcaydu D, Wojta J, Breuss JM, Uhrin P. Cold induces reactive oxygen species production and activation of the NF-kappa B response in endothelial cells and inflammation in vivo. J Thromb Haemost 2013; 11:1716-26. [PMID: 23865569 DOI: 10.1111/jth.12357] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2012] [Accepted: 06/28/2013] [Indexed: 12/13/2022]
Abstract
BACKGROUND Organs intended for transplantation are generally stored in the cold for better preservation of their function. However, following transplantation and reperfusion, the microvasculature of transplanted organs often proves to be activated. Extensive leukocyte adhesion and microthrombus formation contribute to failure of the transplanted organ. OBJECTIVES In this study we analyzed cold-induced changes to the activation status of cultured endothelial cells, possibly contributing to organ failure. METHODS We exposed human umbilical vein endothelial cells (HUVECs) to temperatures below 37 °C (mostly to 8 °C) for 30 min and upon rewarming to 37 °C kept incubating them for up to 24 h. We also in vivo locally exposed mice to cold. RESULTS The exposure to low temperatures induced, in HUVECs, expression of the prothrombotic factors plasminogen activator inhibitor-1 (PAI-1) and tissue factor (TF) and of the inflammatory adhesion molecules, E-selectin, intracellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1). Furthermore, upon rewarming for 30 min, we detected activation of the inflammatory NF-κB pathway, as measured by transient NF-κB translocation to the nucleus and IκBα degradation. Using butylated hydroxytoluene (BHT), a scavenger of reactive oxygen species (ROS), we further demonstrated that cold-induced NF-κB activation depends on ROS production. Local exposure to cold also, in vivo, induced ROS production and ICAM-1 expression and resulted in leukocyte infiltration. CONCLUSIONS Our results point to a causative link between ROS production and NF-κB activation, suppression of which had been shown to be beneficial during hypothermic storage and subsequent rewarming of organs for transplantation.
Collapse
Affiliation(s)
- E M Awad
- Department of Vascular Biology and Thrombosis Research, Center of Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | | | | | | | | | | | | | | |
Collapse
|
7
|
Narasaki R, Xu Z, Liang Z, Fung LCW, Donahue D, Castellino FJ, Ploplis VA. The vitronectin-binding domain of plasminogen activator inhibitor-1 plays an important functional role in lipopolysaccharide-induced lethality in mice. J Thromb Haemost 2012; 10:2618-21. [PMID: 23082983 PMCID: PMC3674865 DOI: 10.1111/jth.12032] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
8
|
Raeven P, Feichtinger GA, Weixelbaumer KM, Atzenhofer S, Redl H, Van Griensven M, Bahrami S, Osuchowski MF. Compartment-specific expression of plasminogen activator inhibitor-1 correlates with severity/outcome of murine polymicrobial sepsis. Thromb Res 2012; 129:e238-45. [DOI: 10.1016/j.thromres.2012.02.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2011] [Revised: 01/24/2012] [Accepted: 02/05/2012] [Indexed: 01/28/2023]
|
9
|
Liu E, Lewis K, Al-Saffar H, Krall CM, Singh A, Kulchitsky VA, Corrigan JJ, Simons CT, Petersen SR, Musteata FM, Bakshi CS, Romanovsky AA, Sellati TJ, Steiner AA. Naturally occurring hypothermia is more advantageous than fever in severe forms of lipopolysaccharide- and Escherichia coli-induced systemic inflammation. Am J Physiol Regul Integr Comp Physiol 2012; 302:R1372-83. [PMID: 22513748 DOI: 10.1152/ajpregu.00023.2012] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The natural switch from fever to hypothermia observed in the most severe cases of systemic inflammation is a phenomenon that continues to puzzle clinicians and scientists. The present study was the first to evaluate in direct experiments how the development of hypothermia vs. fever during severe forms of systemic inflammation impacts the pathophysiology of this malady and mortality rates in rats. Following administration of bacterial lipopolysaccharide (LPS; 5 or 18 mg/kg) or of a clinical Escherichia coli isolate (5 × 10(9) or 1 × 10(10) CFU/kg), hypothermia developed in rats exposed to a mildly cool environment, but not in rats exposed to a warm environment; only fever was revealed in the warm environment. Development of hypothermia instead of fever suppressed endotoxemia in E. coli-infected rats, but not in LPS-injected rats. The infiltration of the lungs by neutrophils was similarly suppressed in E. coli-infected rats of the hypothermic group. These potentially beneficial effects came with costs, as hypothermia increased bacterial burden in the liver. Furthermore, the hypotensive responses to LPS or E. coli were exaggerated in rats of the hypothermic group. This exaggeration, however, occurred independently of changes in inflammatory cytokines and prostaglandins. Despite possible costs, development of hypothermia lessened abdominal organ dysfunction and reduced overall mortality rates in both the E. coli and LPS models. By demonstrating that naturally occurring hypothermia is more advantageous than fever in severe forms of aseptic (LPS-induced) or septic (E. coli-induced) systemic inflammation, this study provides new grounds for the management of this deadly condition.
Collapse
Affiliation(s)
- Elaine Liu
- Department of Pharmaceutical Sciences, Albany College of Pharmacy and Health Sciences, Albany, New York 12208, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
10
|
Huq MA, Takeyama N, Harada M, Miki Y, Takeuchi A, Inoue S, Nakagawa T, Kanou H, Hirakawa A, Noguchi H. 4G/5G Polymorphism of the plasminogen activator inhibitor-1 gene is associated with multiple organ dysfunction in critically ill patients. Acta Haematol 2011; 127:72-80. [PMID: 22134139 DOI: 10.1159/000333130] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2011] [Accepted: 08/31/2011] [Indexed: 11/19/2022]
Abstract
OBJECTIVE Impaired fibrinolysis is associated with a higher incidence of both multiple organ dysfunction and mortality in the intensive care unit (ICU). Plasminogen activator inhibitor (PAI)-1 is the chief inhibitor of fibrinolysis. We investigated the influence of the 4G/5G polymorphism (rs1799768) of the PAI-1 gene on the plasma PAI-1 level and the outcome of critically ill patients. METHODS In 41 consecutive patients admitted to the ICU, PAI-1 gene polymorphism was assessed, plasma PAI-1 and arterial lactate concentrations were measured and clinical severity scores were recorded. RESULTS Homozygotes for the 4G allele had higher plasma levels of PAI-1 antigen. The mean ± SD PAI-1 antigen level was 193.31 ± 167.93 ng/ml for the 4G/4G genotype, 100.67 ± 114.16 ng/ml for the 4G/5G genotype and 0.43 ± 0.53 ng/ml for the 5G/5G genotype. There was a significant correlation between plasma PAI-1 and arterial lactate concentrations, as well as between PAI-1 and severity scores. The mortality rate was 63, 33 and 0% for patients with the 4G/4G, 4G/5G and 5G/5G genotypes, respectively. CONCLUSIONS These results demonstrate that the 4G/5G polymorphism of the PAI-1 gene affects the plasma PAI-1 concentration, which could impair fibrinolysis and cause organ failure, and thus the presence of the 4G allele increases the risk of death.
Collapse
Affiliation(s)
- Muhammad Aminul Huq
- Department of Emergency and Critical Care Medicine, Aichi Medical University, Nagakute, Japan
| | | | | | | | | | | | | | | | | | | |
Collapse
|
11
|
Tyml K. Critical role for oxidative stress, platelets, and coagulation in capillary blood flow impairment in sepsis. Microcirculation 2011; 18:152-62. [PMID: 21199094 DOI: 10.1111/j.1549-8719.2010.00080.x] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Sepsis is a complex multifaceted response to a local infectious insult. One important facet is the circulatory system dysfunction, which includes capillary bed plugging. This review addresses the mechanisms of capillary plugging and highlights our recent discoveries on the roles of NO, ROS, and activated coagulation in platelet adhesion and blood flow stoppage in septic mouse capillaries. We show that sepsis increases platelet adhesion, fibrin deposition and flow stoppage in capillaries, and that NADPH oxidase-derived ROS, rather than NO, play a detrimental role in this adhesion/stoppage. P-selectin and activated coagulation are required for adhesion/stoppage. Further, platelet adhesion in capillaries (i) strongly predicts capillary flow stoppage, and (ii) may explain why severe sepsis is associated with a drop in platelet count in systemic blood. Significantly, we also show that a single bolus of the antioxidant ascorbate (injected intravenously at clinically relevant dose of 10 mg/kg) inhibits adhesion/stoppage. Our data suggest that eNOS-derived NO at the platelet-endothelial interface is anti-adhesive and required for the inhibitory effect of ascorbate. Because of the critical role of ROS in capillary plugging, ascorbate bolus administration may be beneficial to septic patients whose survival depends on restoring microvascular perfusion.
Collapse
Affiliation(s)
- Karel Tyml
- Critical Illness Research, Lawson Health Research Institute, London, Ontario, Canada.
| |
Collapse
|
12
|
Secor D, Li F, Ellis CG, Sharpe MD, Gross PL, Wilson JX, Tyml K. Impaired microvascular perfusion in sepsis requires activated coagulation and P-selectin-mediated platelet adhesion in capillaries. Intensive Care Med 2010; 36:1928-34. [PMID: 20689935 DOI: 10.1007/s00134-010-1969-3] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2009] [Accepted: 05/07/2010] [Indexed: 12/19/2022]
Abstract
PURPOSE Impaired microvascular perfusion in sepsis is not treated effectively because its mechanism is unknown. Since inflammatory and coagulation pathways cross-activate, we tested if stoppage of blood flow in septic capillaries is due to oxidant-dependent adhesion of platelets in these microvessels. METHODS Sepsis was induced in wild type, eNOS(-/-), iNOS(-/-), and gp91phox(-/-) mice (n = 14-199) by injection of feces into the peritoneum. Platelet adhesion, fibrin deposition, and blood flow stoppage in capillaries of hindlimb skeletal muscle were assessed by intravital microscopy. Prophylactic treatments at the onset of sepsis were intravenous injection of platelet-depleting antibody, P-selectin blocking antibody, ascorbate, or antithrombin. Therapeutic treatments (delayed until 6 h) were injection of ascorbate or the glycoprotein IIb/IIIa inhibitor eptifibatide, or local superfusion of the muscle with NOS cofactor tetrahydrobiopterin or NO donor S-nitroso-N-acetylpenicillamine (SNAP). RESULTS Sepsis at 6-7 h markedly increased the number of stopped-flow capillaries and the occurrence of platelet adhesion and fibrin deposition in these capillaries. Platelet depletion, iNOS and gp91phox deficiencies, P-selectin blockade, antithrombin, or prophylactic ascorbate prevented, whereas delayed ascorbate, eptifibatide, tetrahydrobiopterin, or SNAP reversed, septic platelet adhesion and/or flow stoppage. The reversals by ascorbate and tetrahydrobiopterin were absent in eNOS(-/-) mice. Platelet adhesion predicted 90% of capillary flow stoppage. CONCLUSION Impaired perfusion and/or platelet adhesion in septic capillaries requires NADPH oxidase, iNOS, P-selectin, and activated coagulation, and is inhibited by intravenous administration of ascorbate and by local superfusion of tetrahydrobiopterin and NO. Reversal of flow stoppage by ascorbate and tetrahydrobiopterin may depend on local eNOS-derived NO which dislodges platelets from the capillary wall.
Collapse
Affiliation(s)
- Dan Secor
- Critical Illness Research, Victoria Research Laboratories, Lawson Health Research Institute, London, ON, N6C 2V5, Canada
| | | | | | | | | | | | | |
Collapse
|
13
|
|
14
|
Wang X. Lipopolysaccharide augments venous and arterial thrombosis in the mouse. Thromb Res 2008; 123:355-60. [PMID: 18448153 DOI: 10.1016/j.thromres.2008.03.015] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2007] [Revised: 02/11/2008] [Accepted: 03/13/2008] [Indexed: 10/22/2022]
Abstract
BACKGROUND Animal models of diseases are essential for therapeutic target validation, drug discovery and development. Increasing evidence has demonstrated the importance of inflammation in thrombosis. Here, murine models of vena cava thrombosis and carotid arterial thrombosis augmented by lipopolysaccharide (LPS) were established and characterized to study the association between inflammation and thrombosis. MATERIALS AND METHODS Murine (C57BL/6 mice) models of ferric chloride (FeCl(3))-induced carotid arterial and vena cava thrombosis were established. Thrombus formation was measured indirectly by Doppler blood flow (i.e., clot functional interference with blood flow) in the arterial thrombosis model and directly by protein content of the clot in the venous thrombosis model. An optimal concentration of FeCl(3) was defined to induce thrombus formation and used to study the effects of LPS (i.e., a well-known inflammatory stimulus under these conditions). Real-time polymerase chain reaction (PCR) was used to examine the effect of LPS on TNFalpha and IL-1beta mRNA expression in thrombus formation. RESULTS Dose-dependent analysis demonstrated that 2 mg/kg, i.p., LPS provided a maximal prothrombotic effect in 2.5% ferric chloride-induced vena cava thrombosis, with a 60% increase in thrombus size (n=8, p<0.05) compared to vehicle treatment. In contrast, 2 mg/kg LPS had no significant effect on thrombus formation in a more severe, 3.5% FeCl(3)-induced vena cava thrombosis. A similar prothrombotic effect was observed for LPS in 2.5% FeCl(3)-induced carotid arterial thrombosis model. Treatment of 2 mg/kg LPS significantly augmented arterial thrombosis immediately (between 5-30 minutes) following FeCl(3) injury as assessed by change of Doppler blood flow (n=8, p<0.05). Real-time PCR demonstrated significant induction of TNFalpha and IL-1beta mRNA expression in the thrombus formation in the vessels in response to LPS challenge. CONCLUSION These data demonstrate that LPS augments thrombus formation in acute vascular injury and that LPS-augmented thrombosis might be a useful tool to study the relationship between inflammation and thrombosis.
Collapse
Affiliation(s)
- Xinkang Wang
- Discovery Translational Medicine, Wyeth Research, Collegeville, PA 19426, USA.
| |
Collapse
|
15
|
Simkova V, Baumgart K, Radermacher P, Barth E, Calzia E. Year in review 2006: Critical Care--Multiple organ failure, sepsis, and shock. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2008; 11:221. [PMID: 17764584 PMCID: PMC2206506 DOI: 10.1186/cc5938] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
In 2006, Critical Care provided important and clinically relevant research data in the field of multiple organ failure, sepsis, and shock. This review summarizes the results of the experimental studies and clinical trials and discusses them in the context of the relevant scientific and clinical background.
Collapse
Affiliation(s)
- Vladislava Simkova
- Anesteziologicko-resuscitacni klinika, Fakultni nemocnice u sv, Anny, Pekarska 53, 656 00 Brno, Czech Republic
| | | | | | | | | |
Collapse
|