Sepsis and coagulation

Discovery of Teleost Plasma Kallikrein/Coagulation Factor XI-Like Gene from Channel Catfish (Ictalurus punctatus) and the Evidence that the Protein Encoded by it Acts as a Lectin

Mammalian plasma kallikrein (PK) and coagulation factor XI (fXI) are serine proteases that play in the kinin-kallikrein cascade and in the blood clotting pathway. These proteases share sequence homology and have four apple domains (APDs) and a serine protease domain (SPD) from their N-terminus to C-terminus. No homologs of these proteases are believed to be present in fish species, except for lobe-finned fish. Fish, however, have a unique lectin, named kalliklectin (KL), which is composed of APDs only. In the present study, we found genomic sequences encoding a protein with both APDs and SPD in a few cartilaginous and bony fishes, including the channel catfish Ictalurus punctatus, using bioinformatic analysis. Furthermore, we purified two ~ 70 kDa proteins from the blood plasma of the catfish using mannose-affinity and gel filtration chromatography sequentially. Using de novo sequencing with quadrupole time-of-flight tandem mass spectrometry, several internal amino acid sequences in these proteins were mapped onto possible PK/fXI-like sequences that are thought to be splicing variants. Exploration of APD-containing proteins in the hagfish genome database and phylogenetic analysis suggested that the PK/fXI-like gene originated from hepatocyte growth factor, and that the gene was acquired in a common ancestor of jawed fish. Synteny analysis provided evidence for chromosomal translocation around the PK/fXI-like locus that occurred in the common ancestor of holosteans and teleosts after separation from the lobe-finned fish lineage, or gene duplication into two chromosomes, followed by independent gene losses. This is the first identification of PK/fXI-like proteins in teleosts.

Inflammatory mechanisms and intervention strategies for sepsis-induced myocardial dysfunction

Sepsis-induced myocardial dysfunction (SIMD) is the leading cause of death in patients with sepsis in the intensive care units. The main manifestations of SIMD are systolic and diastolic dysfunctions of the myocardium. Despite our initial understanding of the SIMD over the past three decades, the incidence and mortality of SIMD remain high. This may be attributed to the large degree of heterogeneity among the initiating factors, disease processes, and host states involved in SIMD. Previously, organ dysfunction caused by sepsis was thought to be an impairment brought about by an excessive inflammatory response. However, many recent studies have shown that SIMD is a consequence of a combination of factors shaped by the inflammatory responses between the pathogen and the host. In this article, we review the mechanisms of the inflammatory responses and potential novel therapeutic strategies in SIMD.

Therapeutic Targeting of NF-κB in Acute Lung Injury: A Double-Edged Sword

Acute lung injury/acute respiratory distress syndrome (ALI/ARDS) is a devastating disease that can be caused by a variety of conditions including pneumonia, sepsis, trauma, and most recently, COVID-19. Although our understanding of the mechanisms of ALI/ARDS pathogenesis and resolution has considerably increased in recent years, the mortality rate remains unacceptably high (~40%), primarily due to the lack of effective therapies for ALI/ARDS. Dysregulated inflammation, as characterized by massive infiltration of polymorphonuclear leukocytes (PMNs) into the airspace and the associated damage of the capillary-alveolar barrier leading to pulmonary edema and hypoxemia, is a major hallmark of ALI/ARDS. Endothelial cells (ECs), the inner lining of blood vessels, are important cellular orchestrators of PMN infiltration in the lung. Nuclear factor-kappa B (NF-κB) plays an essential role in rendering the endothelium permissive for PMN adhesion and transmigration to reach the inflammatory site. Thus, targeting NF-κB in the endothelium provides an attractive approach to mitigate PMN-mediated vascular injury, not only in ALI/ARDS, but in other inflammatory diseases as well in which EC dysfunction is a major pathogenic mechanism. This review discusses the role and regulation of NF-κB in the context of EC inflammation and evaluates the potential and problems of targeting it as a therapy for ALI/ARDS.

The Effect of Nanocurcumin Supplementation on Protein C, Partial Thromboplastin Time, Transforming Growth Factor-β1, and Simplified Acute Physiology Score II in Patients With Systemic Inflammatory Response Syndrome: A Randomized Clinical Trial

Systemic inflammatory response syndrome (SIRS) is a general inflammation that involves many patients’ organs in intensive care units and significantly affects the risk of morbidity and mortality. This study aimed to investigate the effect of nanocurcumin on protein C, partial thromboplastin time (PTT), transforming growth factor-β1 (TGF-β1), and simplified acute physiology score II (SAPS II) in patients with SIRS. In this randomized, clinical trial, 40 SIRS-positive patients were randomly assigned to the intervention group who received 160 mg/day of nanocurcumin and the control group that received routine treatment for 10 days. Before, the 5th and 10th days of the study, the SAPS II questionnaire was completed, and protein C, PTT, and TGF-β1 levels were measured. At the end of the study, the PTT levels in the intervention and control groups increased and decreased, respectively. However, the significant increase of protein C levels was shown only in the intervention group. SAPS II scores were also decreased significantly only in the intervention group. There was no significant difference in serum levels of TGF-β1 in both groups. According to the results of this study, supplementation with nanocurcumin can decrease the SAPS II and improve the coagulation status in patients with SIRS.

COVID's Razor: RAS Imbalance, the Common Denominator Across Disparate, Unexpected Aspects of COVID-19

A modern iteration of Occam's Razor posits that "the simplest explanation is usually correct." Coronavirus Disease 2019 involves widespread organ damage and uneven mortality demographics, deemed unexpected from what was originally thought to be "a straightforward respiratory virus." The simplest explanation is that both the expected and unexpected aspects of COVID-19 share a common mechanism. Silent hypoxia, atypical acute respiratory distress syndrome (ARDS), stroke, olfactory loss, myocarditis, and increased mortality rates in the elderly, in men, in African-Americans, and in patients with obesity, diabetes, and cancer-all bear the fingerprints of the renin-angiotensin system (RAS) imbalance, suggesting that RAS is the common culprit. This article examines what RAS is and how it works, then from that baseline, the article presents the evidence suggesting RAS involvement in the disparate manifestations of COVID-19. Understanding the deeper workings of RAS helps one make sense of severe COVID-19. In addition, recognizing the role of RAS imbalance suggests potential routes to mitigate COVID-19 severity.

Plasma Filtration on Mediators of Thrombotic Microangiopathy: An in Vitro Study

Objectives.

Sepsis-induced thrombotic microangiopathy is successfully treated by plasma exchange therapy However, certain putative mediators of thrombotic microangiopathy may not be removed by plasma filtration.

Methods.

We conducted an in vitro study to determine whether plasma filtration can remove ultra-large von Willebrand factor (ULvWF) multimers and other mediators. In separate experiments, human umbilical venous endothelial cell (HUVEC) supernatant enriched with ULvWF or human whole blood was passed through a therapeutic plasma exchange (TPE 2000, PRISMA) filter and samples were taken for measurement of ULvWF, vWF ristocetin cofactor, vWF antigen and PAI-1.

Results.

The sieving coefficients for vWF and PAI-1 were above 0.9. The ULvWF was gradually eliminated, and nearly disappeared after four circulations.

Conclusion.

The TPE 2000 filter can directly remove potential mediators of sepsis-induced thrombotic microangiopathy.

An integrative genomics approach identifies novel pathways that influence candidaemia susceptibility

Candidaemia is a bloodstream infection caused by Candida species that primarily affects specific groups of at-risk patients. Because only small candidaemia patient cohorts are available, classical genome wide association cannot be used to identify Candida susceptibility genes. Therefore, we have applied an integrative genomics approach to identify novel susceptibility genes and pathways for candidaemia. Candida-induced transcriptome changes in human primary leukocytes were assessed by RNA sequencing. Genetic susceptibility to candidaemia was assessed using the Illumina immunochip platform for genotyping of a cohort of 217 patients. We then integrated genetics data with gene-expression profiles, Candida-induced cytokine production capacity, and circulating concentrations of cytokines. Based on the intersection of transcriptome pathways and genomic data, we prioritized 31 candidate genes for candidaemia susceptibility. This group of genes was enriched with genes involved in inflammation, innate immunity, complement, and hemostasis. We then validated the role of MAP3K8 in cytokine regulation in response to Candida stimulation. Here, we present a new framework for the identification of susceptibility genes for infectious diseases that uses an unbiased, hypothesis-free, systems genetics approach. By applying this approach to candidaemia, we identified novel susceptibility genes and pathways for candidaemia, and future studies should assess their potential as therapeutic targets.

AMA0428, A Potent Rock Inhibitor, Attenuates Early and Late Experimental Diabetic Retinopathy

PURPOSE

Diabetic retinopathy (DR) is characterized by an early stage of inflammation and vessel leakage, and an advanced vasoproliferative stage. Also, neurodegeneration might play an important role in disease pathogenesis. The aim of this study was to investigate the effect of the Rho kinase (ROCK) inhibitor, AMA0428, on these processes.

METHODS

The response to ROCK inhibition by AMA0428 (1 µg) was studied in vivo using the murine model for streptozotocin (STZ)-induced diabetes, focusing on early non-proliferative DR features and the oxygen-induced retinopathy (OIR) model to investigate proliferative DR. Intravitreal (IVT) administration of AMA0428 was compared with murine anti-VEGF-R2 antibody (DC101, 6.2 µg) and placebo (H₂O/PEG; 1C8). Outcome was assessed by analyzing leukostasis using fluorescein isothiocyanate coupled concanavalin A (FITC-ConA) and vessel leakage (bovine serum albumin conjugated with fluorescein isothiocyanate; FITC-BSA)/neovascularization and neurodegeneration by immunohistological approaches (hematoxylin and eosin (H&E), terminal deoxynucleotidyl transferase-mediated biotinylated UTP nick end labeling (TUNEL), Brn3a). ELISA and Western blotting were employed to unravel the consequences of ROCK inhibition (1 µM AMA0428) on myosin phosphatase target protein (MYPT)-1 phosphorylation, endothelial nitric oxide synthase (eNOS) phosphorylation, and vascular endothelial growth factor (VEGF) levels in retinas of diabetic mice, on NF-κβ activity and ICAM-1 expression in endothelial cells (ECs).

RESULTS

In vivo, AMA0428 significantly reduced vessel leakage and neovascularization, respectively, in the STZ and OIR model, comparable to DC101 therapy. Additionally, the ROCK inhibitor decreased neurodegeneration in both models and inhibited leukostasis by 30% (p < 0.05) in the STZ model (p < 0.05), while DC101 had no positive effect on the outcome of these latter processes. ROCK activity was upregulated in the diabetic retina and AMA0428 administration resulted in decreased phospho-MYPT-1, enhanced phospho-eNOS, and reduced VEGF levels. In vitro, AMA0428 interfered with NF-κβ activity, thereby inhibiting ICAM-1 expression in ECs.

CONCLUSIONS

Targeting ROCK with AMA0428 effectively attenuated outcome in an early DR model (STZ) and a late vasoproliferative retinopathy model (OIR). These findings make AMA0428 a promising candidate with an additional anti-inflammatory and neuroprotective benefit for DR patients, as compared with anti-VEGF treatment.

Advances in microfluidics in combating infectious diseases

One of the important pursuits in science and engineering research today is to develop low-cost and user-friendly technologies to improve the health of people. Over the past decade, research efforts in microfluidics have been made to develop methods that can facilitate low-cost diagnosis of infectious diseases, especially in resource-poor settings. Here, we provide an overview of the recent advances in microfluidic devices for point-of-care (POC) diagnostics for infectious diseases and emphasis is placed on malaria, sepsis and AIDS/HIV. Other infectious diseases such as SARS, tuberculosis, and dengue are also briefly discussed. These infectious diseases are chosen as they contribute the most to disability-adjusted life-years (DALYs) lost according to the World Health Organization (WHO). The current state of research in this area is evaluated and projection toward future applications and accompanying challenges are also discussed.

Coagulation and complement system in critically ill patients

Activation of coagulation and inflammatory response including the complement system play a major role in the pathogenesis of critical illness. However, only limited data are available addressing the relationship of both pathways and its assessment of a predictive value for the clinical outcome in intense care medicine. Therefore, parameters of the coagulation and complement system were studied in patients with septicaemia and multiple trauma regarded as being exemplary for critical illness. 34 patients (mean age: 51.38 years (±16.57), 15 females, 19 males) were investigated at day 1 of admittance to the intensive care unit (ICU). Leukocytes, complement factors C3a and C5a were significantly (p <  0.0500) higher in sepsis than in trauma, whereas platelet count and plasma fibrinogen were significantly lower in multiple trauma. Activation markers of coagulation were elevated in both groups, however, thrombin-antithrombin-complex was significantly higher in multiple trauma. DIC scores of 5 were not exceeded in any of the two groups. Analysing the influences on mortality (11/34; 32.35% ), which was not different in both groups, non-survivors were significantly older, had significantly higher multiple organ failure (MOF) scores, lactate, abnormal prothrombin times and lower C1-inhibitor activities, even more pronounced in early deaths, than survivors. In septic non-survivors protein C was significantly lower than in trauma. We conclude from these data that activation of the complement system as part of the inflammatory response is a significant mechanism in septicaemia, whereas loss and consumption of blood components including parts of the coagulation and complement system is more characteristic for multiple trauma. Protein C in case of severe reduction might be of special concern for surviving in sepsis. Activation of haemostasis was occurring in both diseases, however, overt DIC was not confirmed in this study to be a leading mechanism in critically ill patients. MOF score, lactate, C1-inhibitor and prothrombin time have been the only statistically significant predictors for lethal outcome suggesting that organ function, microcirculation, haemostasis and inflammatory response are essential elements of the pathomechanism and clinical course of diseases among critically ill patients.

Thromboelastography Parameter Predicts Outcome After Subarachnoid Hemorrhage: An Exploratory Analysis

OBJECTIVE

Hypercoagulability after subarachnoid hemorrhage (SAH) is well described and may be platelet mediated. Thromboelastography (TEG) provides a global assessment of coagulation. We sought to determine whether the maximum amplitude (MA) parameter of TEG, a measure of platelet strength and function, is associated with outcome after SAH.

METHODS

One hundred ten TEG analyses were performed for patients with moderate-to-severe SAH and compared with 6 healthy age- and sex-matched controls. TEG indices included MA, G value (G), alpha angle, and thrombus generation and were correlated to functional outcomes and laboratory tests including complete blood count, erythrocyte sedimentation rate, high sensitivity C-reactive protein, fibrinogen, and d-dimer, obtained on post-bleed days (PBDs) 1, 3, 5, 7, and 10.

RESULTS

MA was significantly elevated compared with controls on PBD 3 (70.0 mm ± 4.5 mm vs. 64.1 mm ± 6.5 mm; P = 0.02), PBD 5 (72.6 mm ± 5.3 mm vs. 64.1 mm ± 6.5 mm; P = 0.003), PBD 7 (73.0 mm ± 5.4 mm vs. 64.1 mm ± 6.5 mm; P = 0.003), and PBD 10 (73.4 mm ± 6.0 mm vs. 64.1 mm ± 6.5 mm; P = 0.005). G was significantly elevated compared with controls on PBD 3 (P = 0.03), PBD 5 (P = 0.01), PBD 7 (P = 0.01), and PBD 10 (P = 0.02). The only biomarker associated with poor outcome was CRP. Multivariate logistic regression demonstrated an association between elevated MA and outcome (odds ratio 39.1, P = 0.006) independent of CRP, age, Hunt Hess grade, and transfusion.

CONCLUSIONS

TEG indices are associated with poor outcome after SAH and may identify a platelet-mediated hypercoagulable state. The association between MA and outcome was stronger than that between traditional biomarkers and was independent of age and Hunt Hess grade.

Impact of kidney donor hemostasis on risk of complications after transplantation--preliminary outcomes

Background

This study analyzes the influence the of kidney donor hemostasis on the risk of complications in the kidney recipient after transplantation.

Material/Methods

We enrolled 38 deceased kidney donors, of whom14 donors died from a physical injury and the others died from ischemic or bleeding central nervous system stroke. The donors were categorized into 2 subgroups. If the recipient’s postoperative period proceeded smoothly, the kidney donor was assigned to the uncomplicated donors (UD) group. If the recipient’s postoperative period was complicated, the donor was assigned to the complicated (CD) Group. The CD group of consisted of 9 donors who died from strokes or bleedings and 2 who died from physical injury. We examined the antithrombin (AT) protein C (PC), complexes of thrombin/antithrombin (TAT), fragments F₁₊₂ of prothrombin (F₁₊₂), plasminogen (Pl), complexes of plasmin/antiplasmin (PAP), and D-dimers (D-d).

Results

In the CD group had decreased activity of AT, PC, and Pl and increased activity of F₁₊₂, TAT, and D-d. The UD group had a higher level of PAP. The CD group had evidence of intensive blood coagulation, but the UD group had evidence of fibrinolysis. Fisher’s exact test revealed an increased risk in recipients who received a kidney from the CD group.

Conclusions

The hemostasis of the kidney donors had a correlation with the occurrence of some complications in the kidney recipients, especially complications connected with activation of blood coagulation. It seems that the activation of fibrinolysis could be positive prognostic factor, but this requires further investigations.

The prognostic value of ADAMTS13 (a disintegrin and metalloprotease with thrombospondin type 1 repeats, member 13) deficiency in septic shock patients involves interleukin-6 and is not dependent on disseminated intravascular coagulation

Introduction

ADAMTS13 (a disintegrin and metalloprotease with thrombospondin type 1 repeats, member 13) deficiency has been reported in patients with sepsis but its clinical relevance and pathophysiology remain unclear. Our objectives were to assess the clinical significance, prognostic value and pathophysiology of ADAMTS13 deficiency in patients with septic shock with and without disseminated intravascular coagulation (DIC).

Methods

This was a prospective monocenter cohort study of patients with septic shock. Von Willebrand Factor, ADAMTS13-related parameters and plasma IL-6 concentration were measured at inclusion to the study. Patients were categorized into three groups according to the presence of ADAMT13 deficiency (<30%) or DIC.

Results

This study included 72 patients with a median age of 59 years (interquartile range (IQR) 50 to 71). Each of the included patients received vasopressors; 55 (76%) were under mechanical ventilation and 22 (33%) underwent renal replacement therapy. Overall, 19 patients (26%) had DIC, and 36 patients had ADMTS13 deficiency (50%). Patients with DIC, ADAMTS13 deficiency or both were more severe at ICU admission. Mortality was higher in septic shock patients from group one. By multivariate analysis, Simplified Acute Physiology Score 2 (SAPS2) score (odds ratio (OR) 1.11/point; 95% CI 1.01 to 1.24) and ADAMTS13 activity <30% (OR 11.86; 95% CI 1.36 to 103.52) were independently associated with hospital mortality. There was no correlation between ADAMTS13 activity and the International Society for Thrombosis and Haemostasis (ISTH) score (r_{s =} -0.97, P = 0.41) suggesting that ADAMTS13 functional deficiency and DIC were independent parameters. IL-6 level was higher in patients with ADAMTS13 activity <30% [895 (IQR 330 to 1843) pg/mL versus 83 (IQR 43 to 118), P = 0.0003).

Conclusions

Septic shock was associated with a functional deficiency of ADAMTS13, independently of DIC. ADAMTS13 functional deficiency is then a prognostic factor for mortality in septic shock patients, independently of DIC.

A review of stress-related mucosal disease

OBJECTIVE

To review and summarize the human and veterinary literature regarding stress-related mucosal disease (SRMD) pathogenesis, patient risk factors, and therapeutic options for prophylaxis and treatment.

ETIOLOGY

SRMD is a common sequela of critical illness in human patients. Development of SRMD results from splanchnic hypoperfusion, reperfusion injury, and exposure of the gastric mucosa to acid, pepsin, and bile acids following breakdown of the gastric mucosal defense system. Human patients with the highest risk of stress ulceration include those with respiratory failure necessitating mechanical ventilation greater than 48 h or coagulopathy. Currently, little is known about the incidence and pathophysiology of SRMD in critically ill veterinary patients.

DIAGNOSIS

A presumptive diagnosis can be made in high-risk patient populations following detection of occult or gross blood in nasogastric tube aspirates, hematemesis, or melena. Definitive diagnosis is achieved via esophagogastroduodenoscopy. Lesions are localized to the acid-producing portions of the stomach, the fundus, and body.

THERAPY

Therapy is aimed at optimization of tissue perfusion and oxygenation. Pharmacologic interventions are instituted to increase intraluminal pH and augment natural gastric defenses. Histamine(2)-receptor antagonists, proton pump inhibitors, and sucralfate are the mainstays of therapy. In people, clinically significant bleeding may necessitate additional interventions (eg, packed red blood cell transfusions, endoscopic, or surgical hemostasis).

PROGNOSIS

Mortality is increased in people with clinically significant bleeding compared to those patients who do not bleed. Institution of prophylaxis is recommended in high-risk patients. However, no consensus exists regarding initiation of prophylaxis, preference of frontline drug class, or indication for discontinuation of therapy. The prognosis of veterinary patients with SRMD remains unknown at this time.

The effect of cause of cadaveric kidney donors death on fibrinolysis and blood coagulation processes

BACKGROUND

Organ donors can be generally divided into two groups according to the cause of their death. The first group is composed of those who died because of physical injuries, especially road traffic injury, and the second group, those who died from central nervous system (CNS) stroke or bleeding. The aim of our work was to examine hemostatic processes among kidney donors.

MATERIALS AND METHODS

The 38 deceased kidney donors (KD) included 11 women and 27 men of overall average age of 37±12 years. The donor group of according to the cause of death, included 14 injured donors (ID) (41%) and 24 noninjured donors (ND) donors (59%). The control group consisted of 25 healthy volunteers matched for sex and age. We determined the following concentrations: antithrombin (AT), thrombin/antithrombin complexes (TAT), and prothrombin F1+2 fragments. The fibrinolytic parameter concentrations were: plasminogen (PL), plasmin/antiplasmin complexes (PAP), and D-dimers.

RESULTS

Deceased kidney donors showed an increased plasma concentrations of TAT complexes (P<.000001) and prothrombin fragments F1+2 (P<.0000001); however, the protein C concentration was decreased (P<.000001). The antithrombin activity was similar to the control group. The concentrations of PAP complexes and d-dimers were higher (both P<.000001), but the level of PL lower among KD compared with controls (P<.0000001). The higher of TAT, PAP complexes, d-dimers, and F1+2 concentrations as well and as lower plasminogen and PC concentrations were evidence for increased activation of blood coagulation and fibrinolysis in cadaveric KD. However, analysis compairing ID versus ND donors revealed increased concentrations of PAP complexes (P<.05) and decreased amounts of TAT complexes (P<.01) among ID subgroup. The positive predictive value (PPV) and negative (NPV) for PAP complexes were 75% and 68% and for TAT, 71% and 57%, respectively. On the basis of these observations, we concluded that an intensive activation of fibrinolytic process occurs among the ID. In contrast, ND show intensive activation of blood coagulation.

Chronic kidney disease and risk of death from infection

BACKGROUND

Infection, bacteremia and sepsis are major sources of morbidity and mortality in patients with end-stage renal disease. This study sought to determine the association between predialysis chronic kidney disease (CKD) and infection-related mortality.

METHODS

We analyzed participants in the Third National Health and Nutrition Examination Survey (NHANES III). The study included adults ≥45- years-old without end-stage renal disease. Estimated glomerular filtration rate (eGFR) was categorized as ≥60, 45-59.9 and <45 ml/min per 1.73 m(2), and urinary albumin-to-creatinine ratio (ACR) as <30, 30-299.9 and ≥300 mg/g. The study identified infection-related mortality, including septicemia, respiratory, abdominal and gastrointestinal, cardiac, kidney and genitourinary, neurologic, and other infections over a median of 13 years using the National Death Index.

RESULTS

Of 7,400 participants included in the study, 206 died from infections. Compared to individuals with eGFR ≥60 ml/min per 1.73 m(2), infection-related mortality was higher for those with lower eGFR [adjusted HR = 1.36 (95% CI: 0.81, 2.30) and 2.36 (1.04, 5.38) for eGFR of 45-59.9 and <45 ml/min per 1.73 m(2), respectively; p trend = 0.06]. Compared to individuals with ACR <30 mg/g, infection-related mortality was higher for ACR levels of 30-299 and ≥300 mg/g [adjusted HR = 1.68 (95% CI: 0.97, 2.92) and 2.84 (0.92, 8.74), p trend = 0.02].

CONCLUSIONS

Reduced eGFR and albuminuria are associated with increased risk for infection-related mortality. Efforts are needed to reduce its incidence and mitigate the effects of infections among individuals with CKD.

Protective cross talk between activated protein C and TNF signaling in vascular endothelial cells: implication of EPCR, noncanonical NF-κB, and ERK1/2 MAP kinases

Activated protein C (APC) is a natural anticoagulant protease that displays cytoprotective and antiinflammatory activities and has been demonstrated to reduce mortality of patients with severe sepsis. However, APC signaling is not fully understood. This study further investigated the antiinflammatory effects of APC in vascular endothelial cells (EC) and examined the cross talk between APC and TNF signaling. Analysis of the regulatory mechanisms mediated by APC on vascular human EC shows that APC impairs TNF signaling by triggering a preemptive activation of intracellular pathways. We found that APC signaling causes a moderate but significant induction of cell adhesion molecules (CAMs) including VCAM-1 at mRNA and protein levels. Activation of the noncanonical NF-κB and ERK1/2 are both pivotal to APC signaling leading to VCAM-1 expression. APC upregulates TNF receptor-associated factor 2 (TRAF2) and phosphorylates NF-κB p65 at Ser276 and Ser536 independently of IκB degradation. The ultimate protective antiinflammatory effect of APC in response to TNF is associated with a sustained activation of ERK1/2 and Akt while phosphorylation of NF-κB p65 is precluded. Inhibitors of ERK (PD98059 and U0126) abolish the antiinflammatory signal mediated by APC. Blocking antibodies and silencing assays also suggest that, in EC, protease-activated receptor 1 and endothelial protein C receptor (EPCR) both conduct ERK activation and VCAM-1 induction in response to APC. To conclude, APC protects EC by attenuating CAM expression during inflammation. APC engages a regulatory cross talk involving EPCR, ERK, and NF-κB that impairs TNF signaling.

Essential role of cofilin-1 in regulating thrombin-induced RelA/p65 nuclear translocation and intercellular adhesion molecule 1 (ICAM-1) expression in endothelial cells

Activation of RhoA/Rho-associated kinase (ROCK) pathway and the associated changes in actin cytoskeleton induced by thrombin are crucial for activation of NF-kappaB and expression of its target gene ICAM-1 in endothelial cells. However, the events acting downstream of RhoA/ROCK to mediate these responses remain unclear. Here, we show a central role of cofilin-1, an actin-binding protein that promotes actin depolymerization, in linking RhoA/ROCK pathway to dynamic alterations in actin cytoskeleton that are necessary for activation of NF-kappaB and thereby expression of ICAM-1 in these cells. Stimulation of human umbilical vein endothelial cells with thrombin resulted in Ser(3) phosphorylation/inactivation of cofilin and formation of actin stress fibers in a ROCK-dependent manner. RNA interference knockdown of cofilin-1 stabilized the actin filaments and inhibited thrombin- and RhoA-induced NF-kappaB activity. Similarly, constitutively inactive mutant of cofilin-1 (Cof1-S3D), known to stabilize the actin cytoskeleton, inhibited NF-kappaB activity by thrombin. Overexpression of wild type cofilin-1 or constitutively active cofilin-1 mutant (Cof1-S3A), known to destabilize the actin cytoskeleton, also impaired thrombin-induced NF-kappaB activity. Additionally, depletion of cofilin-1 was associated with a marked reduction in ICAM-1 expression induced by thrombin. The effect of cofilin-1 depletion on NF-kappaB activity and ICAM-1 expression occurred downstream of IkappaBalpha degradation and was a result of impaired RelA/p65 nuclear translocation and consequently, RelA/p65 binding to DNA. Together, these data show that cofilin-1 occupies a central position in RhoA-actin pathway mediating nuclear translocation of RelA/p65 and expression of ICAM-1 in endothelial cells.

Unfractioned heparin for treatment of sepsis: A randomized clinical trial (The HETRASE Study)

OBJECTIVE

The primary aims of this study were to determine the effects of heparin on length of stay and change from baseline multiple organ dysfunction (MOD) score. Secondary objectives were to estimate the effects of heparin on 28-day all-cause mortality, and to determine the possible effect modification on 28-day all-cause mortality, in subgroups defined by site of infection and baseline values of Acute Physiology and Chronic Health Evaluation II score, MOD score, and d-dimer.

DESIGN

Randomized, double-masked, placebo-controlled, single-center clinical trial, testing low dose continuous infusion of unfractioned heparin (UFH) as complementary treatment for sepsis.

SETTING

Five hundred fifty bed University Hospital and referral center in Medellín, Columbia.

PATIENTS

Three hundred nineteen patients admitted at the emergency room with signs indicative of sepsis.

INTERVENTIONS

Patients were randomly assigned to receive placebo or UFH (500 units/hour for 7 days).

MEASUREMENTS AND MAIN RESULTS

The median length of stay in patients discharged alive in the placebo group was 12.5 days (interquartile range = 8-20), and 12 days (interquartile range = 8-19.5) in the heparin group (p = 0.976). The MOD score improved equally in the two treatments arms with an average decline of 0.13 and 0.11 per day for the placebo and heparin groups (p = 0.240), respectively. The overall 28-day mortality was 16% in the placebo group and 14% in the heparin group (p = 0.652). Subgroup analyses did not show any statistically significant reduction in 28-day mortality with UFH. There was only one serious adverse event on a patient who received heparin but it was fully resolved without complications.

CONCLUSIONS

Our findings suggested that UFH may be a feasible and safe intervention in sepsis. However, this study was not able to demonstrate a beneficial effect on the chosen primary outcomes or in the 28-day mortality rate.

Vascular disorders of the liver

This guideline has been approved by the American Association for the Study of Liver Diseases (AASLD) and represents the position of the association.

Protein kinase C-delta and phosphatidylinositol 3-kinase/Akt activate mammalian target of rapamycin to modulate NF-kappaB activation and intercellular adhesion molecule-1 (ICAM-1) expression in endothelial cells

We have shown that the mammalian target of rapamycin (mTOR) down-regulates thrombin-induced ICAM-1 expression in endothelial cells by suppressing the activation of NF-kappaB. However, the mechanisms by which mTOR is activated to modulate these responses remain to be addressed. Here, we show that thrombin engages protein kinase C (PKC)-delta and phosphattidylinositol 3-kinase (PI3K)/Akt pathways to activate mTOR and thereby dampens NF-kappaB activation and intercellular adhesion molecule 1 (ICAM-1) expression. Stimulation of human vascular endothelial cells with thrombin induced the phosphorylation of mTOR and its downstream target p70 S6 kinase in a PKC-delta- and PI3K/Akt-dependent manner. Consistent with this, thrombin-induced phosphorylation of p70 S6 kinase was defective in embryonic fibroblasts from mice with targeted disruption of PKC-delta (Pkc-delta(-)(/)(-)), p85alpha and p85beta subunits of the PI3K (p85alpha(-)(/)(-)beta(-)(/)(-)), or Akt1 and Akt2 (Akt1(-)(/)(-)2(-)(/)(-)). Furthermore, we observed that expression of the constitutively active form of PKC-delta or Akt was sufficient to induce NF-kappaB activation and ICAM-1 expression, and that co-expression of mTOR suppressed these responses. In reciprocal experiments, inhibition/depletion of mTOR augmented NF-kappaB activation and ICAM-1 expression induced by PKC-delta or Akt. In control experiments, increasing or impairing mTOR signaling by the above approaches produced similar effects on NF-kappaB activation and ICAM-1 expression induced by thrombin. Thus, these data reveal an important role of PKC-delta and PI3K/Akt pathways in activating mTOR as an endogenous modulator to ensure a tight regulation of NF-kappaB signaling of ICAM-1 expression in endothelial cells.

Severe thrombocytopenia and haemolytic anaemia associated with ciprofloxacin: a case report with fatal outcome

Haematological adverse reactions associated with fatal outcome are rare during treatment with ciprofloxacin. A 30-year old Caucasian man reported with abdominal pain and jaundice after 3-day administration of oral ciprofloxacin for a suspect of urinary tract infection. Clinical evaluations suggested an initial diagnosis of severe thrombocytopenia and haemolysis. The patient progressively developed petechiae and purpura on thorax and lower limbs. Despite pharmacological and supportive interventions, laboratory parameters worsened and the patient died 17 hours after admission. An accurate autopsy revealed most organs with diffuse petechial haemorrhages. No signs of bone marrow depression were found. No thrombi or signs of microangiopathies were observed in arterial vessels. Blood and urine cultures did not show any bacterial growth. This case report shows that ciprofloxacin may precipitate life-threatening thrombocytopenia and haemolytic anaemia, even in the early phases of treatment and without apparent previous exposures.

Production of C5a by ASP, a serine protease released from Aeromonas sobria

Aeromonas sobria causes pus and edema at sites of infection. However, the mechanisms underlying these effects have not been elucidated. C5a, the amino-terminal fragment of the complement 5th component (C5), mimics these events. To investigate the involvement of C5a in the pathophysiology of A. sobria infection, we examined release of C5a from human C5 by a serine protease (ASP), a putative virulence factor secreted by this bacterium. C5 incubated with enzymatically active ASP induced neutrophil migration in a dose-dependent manner from an ASP concentration of 3 nM and in an incubation time-dependent manner in as little as 7 min, with neutrophil accumulation in guinea pigs at intradermal injection sites and neutrophil superoxide release. These effects on neutrophils were inhibited by a C5a-receptor antagonist. The ASP incubation mixture with C5 but not C3 elicited vascular leakage in a dose- and incubation time-dependent manner, which was inhibited by a histamine H(1)-receptor antagonist. Together with these C5a-like activities, ASP cleaved C5 to release only one C5a Ag, the m.w. of which was similar to that of C5a. Immunoblotting using an anti-C5a Ab revealed generation of a C5a-like fragment from human plasma incubated with ASP. These results suggest that ASP-elicited neutrophil migration and vascular leakage via C5a production from C5 could occur in vivo, which was supported by that ASP did not affect functions of C5a and neutrophil C5a receptor. Through C5a generation, ASP could be associated with the induction of pus and edema caused by infection with this bacterium.

Gene expression in peripheral blood differs after cardioembolic compared with large-vessel atherosclerotic stroke: biomarkers for the etiology of ischemic stroke

There are no biomarkers that differentiate cardioembolic from large-vessel atherosclerotic stroke, although the treatments differ for each and approximately 30% of strokes and transient ischemic attacks have undetermined etiologies using current clinical criteria. We aimed to define gene expression profiles in blood that differentiate cardioembolic from large-vessel atherosclerotic stroke. Peripheral blood samples were obtained from healthy controls and acute ischemic stroke patients (<3, 5, and 24 h). RNA was purified, labeled, and applied to Affymetrix Human U133 Plus 2.0 Arrays. Expression profiles in the blood of cardioembolic stroke patients are distinctive from those of large-vessel atherosclerotic stroke patients. Seventy-seven genes differ at least 1.5-fold between them, and a minimum number of 23 genes differentiate the two types of stroke with at least 95.2% specificity and 95.2% sensitivity for each. Genes regulated in large-vessel atherosclerotic stroke are expressed in platelets and monocytes and modulate hemostasis. Genes regulated in cardioembolic stroke are expressed in neutrophils and modulate immune responses to infectious stimuli. This new method can be used to predict whether a stroke of unknown etiology was because of cardioembolism or large-vessel atherosclerosis that would lead to different therapy. These results have wide ranging implications for similar disorders.

Coagulation patterns following haemoglobin-based oxygen carrier resuscitation in severe uncontrolled haemorrhagic shock in swine

Massive blood loss due to penetrating trauma and internal organ damage can cause severe haemorrhagic shock (HS), leading to a severely compromised haemostatic balance. This study evaluated the effect of bovine polymerized haemoglobin (Hb) (Hb-based oxygen carrier, HBOC) resuscitation on haemostasis in a swine model of uncontrolled HS. Following liver injury/HS, swine received HBOC (n= 8), Hextend (HEX) (n= 8) or no resuscitation (NON) (n= 8). Fluids were infused to increase mean arterial pressure above 60 mmHg and to reduce heart rate to baseline. At 4 h, the animals were eligible for blood transfusions. Prothrombin time (PT), activated partial thromboplastin time, fibrinogen, thromboelastography (TEG) and platelet function analyser closure time (PFA-CT) were compared by using mixed statistical model. At 4 h, blood loss (% estimated blood volume) was comparable for HBOC (65.5 +/- 18.5%) and HEX (80.8 +/- 14.4%) and less for NON (58.7 +/- 10.1%; P < 0.05). Resuscitation-induced dilutional coagulopathy was observed with HBOC and HEX, as indicated by reduced haematocrit, platelets and fibrinogen (P < 0.05). At 4 h, PT was higher in HEX than in HBOC groups (P < 0.01). In the early hospital phase, a trend to increased TEG reaction time and PFA-CT indicates that dilutional effects persist in HBOC and HEX groups. PFA-CT returned to baseline later with HBOC than with HEX (48 vs. 24 h) following blood transfusion. At 4 h, all surviving HEX animals (n= 3) required transfusion, in contrast to no HBOC (n= 7) or NON (n= 1) animals. In this severe uncontrolled HS model, successful resuscitation with HBOC produced haemodilutional coagulopathy less than or similar to that produced by resuscitation with HEX.