Accounting for total variation and robustness in profiling health care providers

Monitoring outcomes of health care providers, such as patient deaths, hospitalizations, and hospital readmissions, helps in assessing the quality of health care. We consider a large database on patients being treated at dialysis facilities in the United States, and the problem of identifying facilities with outcomes that are better than or worse than expected. Analyses of such data have been commonly based on random or fixed facility effects, which have shortcomings that can lead to unfair assessments. A primary issue is that they do not appropriately account for variation between providers that is outside the providers' control due, for example, to unobserved patient characteristics that vary between providers. In this article, we propose a smoothed empirical null approach that accounts for the total variation and adapts to different provider sizes. The linear model provides an illustration that extends easily to other non-linear models for survival or binary outcomes, for example. The empirical null method is generalized to allow for some variation being due to quality of care. These methods are examined with numerical simulations and applied to the monitoring of survival in the dialysis facility data.

Endothelial HSPA12B Exerts Protection Against Sepsis-Induced Severe Cardiomyopathy via Suppression of Adhesion Molecule Expression by miR-126

Heat shock protein A12B (HSPA12B) is predominately expressed in endothelial cells (ECs) and has been reported to protect against cardiac dysfunction from endotoxemia or myocardial infarction. This study investigated the mechanisms by which endothelial HSPA12B protects polymicrobial sepsis–induced cardiomyopathy. Wild-type (WT) and endothelial HSPA12B knockout (HSPA12B^–/–) mice were subjected to polymicrobial sepsis induced by cecal ligation and puncture (CLP). Cecal ligation and puncture sepsis accelerated mortality and caused severe cardiac dysfunction in HSPA12B^–/– mice compared with WT septic mice. The levels of adhesion molecules and the infiltrated immune cells in the myocardium of HSPA12B^–/– septic mice were markedly greater than in WT septic mice. The levels of microRNA-126 (miR-126), which targets adhesion molecules, in serum exosomes from HSPA12B^–/– septic mice were significantly lower than in WT septic mice. Transfection of ECs with adenovirus expressing HSPA12B significantly increased miR-126 levels. Increased miR-126 levels in ECs prevented LPS-stimulated expression of adhesion molecules. In vivo delivery of miR-126 carried by exosomes into the myocardium of HSPA12B^–/– mice significantly attenuated CLP sepsis increased levels of adhesion molecules, and improved CLP sepsis–induced cardiac dysfunction. The data suggest that HSPA12B protects against sepsis-induced severe cardiomyopathy via regulating miR-126 expression which targets adhesion molecules, thus decreasing the accumulation of immune cells in the myocardium.

MicroRNA-214 protects against hypoxia/reoxygenation induced cell damage and myocardial ischemia/reperfusion injury via suppression of PTEN and Bim1 expression

BACKGROUND

Myocardial apoptosis plays an important role in myocardial ischemia/reperfusion (I/R) injury. Activation of PI3K/Akt signaling protects the myocardium from I/R injury. This study investigated the role of miR-214 in hypoxia/reoxygenation (H/R)-induced cell damage in vitro and myocardial I/R injury in vivo.

METHODS AND RESULTS

H9C2 cardiomyoblasts were transfected with lentivirus expressing miR-214 (LmiR-214) or lentivirus expressing scrambled miR-control (LmiR-control) respectively, to establish cell lines of LmiR-214 and LmiR-control. The cells were subjected to hypoxia for 4 h followed by reoxygenation for 24 h. Transfection of LmiR-214 suppresses PTEN expression, significantly increases the levels of Akt phosphorylation, markedly attenuates LDH release, and enhances the viability of the cells subjected to H/R. In vivo transfection of mouse hearts with LmiR-214 significantly attenuates I/R induced cardiac dysfunction and reduces I/R-induced myocardial infarct size. LmiR-214 transfection significantly attenuates I/R-induced myocardial apoptosis and caspase-3/7 and caspase-8 activity. Increased expression of miR-214 by transfection of LmiR-214 suppresses PTEN expression, increases the levels of phosphorylated Akt, represses Bim1 expression and induces Bad phosphorylation in the myocardium. In addition, in vitro data shows transfection of miR-214 mimics to H9C2 cells suppresses the expression and translocation of Bim1 from cytosol to mitochondria and induces Bad phosphorylation.

CONCLUSIONS

Our in vitro and in vivo data suggests that miR-214 protects cells from H/R induced damage and attenuates I/R induced myocardial injury. The mechanisms involve activation of PI3K/Akt signaling by targeting PTEN expression, induction of Bad phosphorylation, and suppression of Bim1 expression, resulting in decreases in I/R-induced myocardial apoptosis.

TLR3 Mediates Repair and Regeneration of Damaged Neonatal Heart through Glycolysis Dependent YAP1 Regulated miR-152 Expression

The present study investigated whether TLR3 is required for neonatal heart repair and regeneration following myocardial infarction (MI). TLR3 deficient neonatal mice exhibited impaired cardiac functional recovery and a larger infarct size, while wild type neonatal mice showed cardiac functional recovery and small infarct size after MI. The data suggest that TLR3 is essential for the regeneration and repair of damaged neonatal myocardium. In vitro treatment of neonatal cardiomyocytes with a TLR3 ligand, Poly (I:C), significantly enhances glycolytic metabolism, YAP1 activation and proliferation of cardiomyocytes which were prevented by a glycolysis inhibitor, 2-deoxyglucose (2-DG). Administration of 2-DG to neonatal mice abolished cardiac functional recovery and YAP activation after MI, suggesting that TLR3-mediated regeneration and repair of the damaged neonatal myocardium is through glycolytic-dependent YAP1 activation. Inhibition of YAP1 activation abolished Poly (I:C) induced proliferation of neonatal cardiomyocytes. Interestingly, activation of YAP1 increases the expression of miR-152 which represses the expression of cell cycle inhibitory proteins, P27kip1 and DNMT1, leading to cardiomyocyte proliferation. We conclude that TLR3 is required for neonatal heart regeneration and repair after MI. The mechanisms involve glycolytic-dependent YAP1 activation, resulting in miR-152 expression which targets DNMT1/p27kip1.

Enhanced Glycolytic Metabolism Contributes to Cardiac Dysfunction in Polymicrobial Sepsis

Background

Cardiac dysfunction is present in >40% of sepsis patients and is associated with mortality rates of up to 70%. Recent evidence suggests that glycolytic metabolism plays a critical role in host defense and inflammation. Activation of Toll-like receptors on immune cells can enhance glycolytic metabolism. This study investigated whether modulation of glycolysis by inhibition of hexokinase will be beneficial to septic cardiomyopathy.

Methods

Male C57B6/J mice were treated with a hexokinase inhibitor (2-deoxy-d-glucose [2-DG], 0.25-2 g/kg, n = 6-8) before cecal ligation and puncture (CLP) induced sepsis. Untreated septic mice served as control. Sham surgically operated mice treated with or without the 2-DG inhibitor served as sham controls. Cardiac function was assessed 6 hours after CLP sepsis by echocardiography. Serum was harvested for measurement of inflammatory cytokines and lactate.

Results

Sepsis-induced cardiac dysfunction was significantly attenuated by administration of 2-DG. Ejection fraction and fractional shortening in 2-DG-treated septic mice were significantly (P < .05) greater than in untreated CLP mice. 2-DG administration also significantly improved survival outcome, reduced kidney and liver injury, attenuated sepsis-increased serum levels of tumor necrosis factor α and interleukin 1β as well as lactate, and enhanced the expression of Sirt1 and Sirt3 in the myocardium, which play an important role in mitochondrial function and metabolism. In addition, 2-DG administration suppresses sepsis-increased expression of apoptotic inducers Bak and Bax as well as JNK phosphorylation in the myocardium.

Conclusions

Glycolytic metabolism plays an important role in mediating sepsis-induced septic cardiomyopathy. The mechanisms may involve regulation of inflammatory response and apoptotic signaling.

Abstract 117: Poly (i:c) Attenuates Myocardial I/R Injury via Glycolytic Dependent Yap Activation and by Suppression of MiR-143

Glycolytic metabolism plays a critical role in ischemia/reperfusion (I/R) injury. The Yes associated protein (YAP) is a core effector of the Hippo pathway that regulates cell proliferation and apoptosis. We observed that poly (I:C) enhanced glycolysis and Yap activation in neonatal cardiomyocytes. This study investigated whether poly (I:C) will attenuate myocardial I/R injury via a glycolytic dependent mechanism. Mice (n=6/group) were treated with poly (I:C) (10 μg/25g body weight) one h before the hearts were subjected to ischemia (45 min) followed by reperfusion (24 h). Sham surgery served as sham control. Poly (I:C) treatment significantly reduced infarct size by 35% and enhanced EF% by 20.5% and FS% by 24.9% compared with I/R group. The expression of miR-143 was markedly reduced and Yap levels were significantly increased in poly (I:C) treated hearts. In vitro data show that poly (I:C) treatment enhanced extracellular acidification rate (ECAR) and lactate production in HL-1 cardiomyocytes. In vivo inhibition of hexokinase 2 abolished poly (I:C)-induced cardioprotection. To determine the role of miR-143 in regulation of glycolysis, we transfected HL-1 cardiomyocytes with anti-miR-143 mimics before the cells were subjected to hypoxia/reoxygenation. We observed that anti-miR-143 significantly enhanced cell viability, reduced LDH release, and increased hexokinase 2 levels and extracellular acidification rate (ECAR). To determine whether suppression of miR-143 will induce protection against myocardial I/R injury, we loaded anti-miR-143 on exosomes (Exo-antimiR-143) by transection of bone marrow stromal cells with anti-miR-143 mimics. MiR-control mimics served as control (Exo-miR-control). Exo-miR-143 was delivered into the myocardium through the right carotid artery immediately before the hearts (n=6/group) were subjected to I/R. We observed that delivery of Exo-antimiR-143 significantly enhanced EF% by 20.5% and FS% by 26.4% and decreased infarct size by 42.2%, when compared with untreated I/R group. Delivery of Exo-miR-control did not alter I/R-induced cardiac dysfunction and infarct size. We conclude that poly (I:C) attenuates myocardial I/R injury via glycolytic dependent YAP mechanism and suppression of miR-143 expression.

Attenuation of cardiac dysfunction and remodeling of myocardial infarction by microRNA-130a are mediated by suppression of PTEN and activation of PI3K dependent signaling

OBJECTIVE

Activation of PI3K/Akt signaling protects the myocardium from ischemia/reperfusion injury. MicroRNAs have been demonstrated to play an important role in the regulation of gene expression at the post-transcriptional level. In this study, we examined whether miR-130a will attenuate cardiac dysfunction and remodeling after myocardial infarction (MI) via PI3K/Akt dependent mechanism.

APPROACHES AND RESULTS

To determine the role of miR-130a in the proliferation and migration of endothelial cells, HUVECs were transfected with miR-130a mimics before the cells were subjected to scratch-induced wound injury. Transfection of miR-130a mimics stimulated the migration of endothelial cells into the wound area and increased phospho-Akt levels. To examine the effect of miR-130a on cardiac dysfunction and remodeling after MI, Lentivirus expressing miR-130a (LmiR-130a) was delivered into mouse hearts seven days before the mice were subjected to MI. Cardiac function was assessed by echocardiography before and for up to 21 days after MI. Ejection fraction (EF%) and fractional shortening (FS%) in the LmiR-130a transfected MI hearts were significantly greater than in LmiR-control and untransfected control MI groups. LmiR-130a transfection increased capillary number and VEGF expression, and decreased collagen deposition in the infarcted myocardium. Importantly, LmiR-130a transfection significantly suppressed PTEN expression and increased the levels of phosphorylated Akt in the myocardium. However, treatment of LmiR-130a-transfected mice with LY294002, a PI3K inhibitor, completely abolished miR-130a-induced attenuation of cardiac dysfunction after MI.

CONCLUSIONS

miR-130a plays a critical role in attenuation of cardiac dysfunction and remodeling after MI. The mechanisms involve activation of PI3K/Akt signaling via suppression of PTEN expression.

Risk Adjustment and the Assessment of Disparities in Dialysis Mortality Outcomes

Standardized mortality ratios (SMRs) reported by Medicare compare mortality at individual dialysis facilities with the national average, and are currently adjusted for race. However, whether the adjustment for race obscures or clarifies disparities in quality of care for minority groups is unknown. Cox model-based SMRs were computed with and without adjustment for patient race for 5920 facilities in the United States during 2010. The study population included virtually all patients treated with dialysis during this period. Without race adjustment, facilities with higher proportions of black patients had better survival outcomes; facilities with the highest percentage of black patients (top 10%) had overall mortality rates approximately 7% lower than expected. After adjusting for within-facility racial differences, facilities with higher proportions of black patients had poorer survival outcomes among black and non-black patients; facilities with the highest percentage of black patients (top 10%) had mortality rates approximately 6% worse than expected. In conclusion, accounting for within-facility racial differences in the computation of SMR helps to clarify disparities in quality of health care among patients with ESRD. The adjustment that accommodates within-facility comparisons is key, because it could also clarify relationships between patient characteristics and health care provider outcomes in other settings.

Poly (I:C) therapy decreases cerebral ischaemia/reperfusion injury via TLR3-mediated prevention of Fas/FADD interaction

Toll-like receptor (TLR)-mediated signalling plays a role in cerebral ischaemia/reperfusion (I/R) injury. Modulation of TLRs has been reported to protect against cerebral I/R injury. This study examined whether modulation of TLR3 with poly (I:C) will induce protection against cerebral I/R injury. Mice were treated with or without Poly (I:C) (n = 8/group) 1 hr prior to cerebral ischaemia (60 min.) followed by reperfusion (24 hrs). Poly (I:C) pre-treatment significantly reduced the infarct volume by 57.2% compared with untreated I/R mice. Therapeutic administration of Poly (I:C), administered 30 min. after cerebral ischaemia, markedly decreased infarct volume by 34.9%. However, Poly (I:C)-induced protection was lost in TLR3 knockout mice. In poly (I:C)-treated mice, there was less neuronal damage in the hippocampus compared with untreated I/R mice. Poly (I:C) treatment induced IRF3 phosphorylation, but it inhibited NF-κB activation in the brain. Poly (I:C) also decreased I/R-induced apoptosis by attenuation of Fas/FasL-mediated apoptotic signalling. In addition, Poly (I:C) treatment decreased microglial cell caspase-3 activity. In vitro data showed that Poly (I:C) prevented hypoxia/reoxygenation (H/R)-induced interaction between Fas and FADD as well as caspase-3 and -8 activation in microglial cells. Importantly, Poly (I:C) treatment induced co-association between TLR3 and Fas. Our data suggest that Poly (I:C) decreases in cerebral I/R injury via TLR3 which associates with Fas, thereby preventing the interaction of Fas and FADD, as well as microglial cell caspase-3 and -8 activities. We conclude that TLR3 modulation by Poly (I:C) could be a potential approach for protection against ischaemic stroke.

The TLR9 ligand, CpG-ODN, induces protection against cerebral ischemia/reperfusion injury via activation of PI3K/Akt signaling

BACKGROUND

Toll-like receptors (TLRs) have been shown to be involved in cerebral ischemia/reperfusion (I/R) injury. TLR9 is located in intracellular compartments and recognizes CpG-DNA. This study examined the effect of CpG-ODN on cerebral I/R injury.

METHODS AND RESULTS

C57BL/6 mice were treated with CpG-ODN by i.p. injection 1 hour before the mice were subjected to cerebral ischemia (60 minutes) followed by reperfusion (24 hours). Scrambled-ODN served as control-ODN. Untreated mice, subjected to cerebral I/R, served as I/R control. The effect of inhibitory CpG-ODN (iCpG-ODN) on cerebral I/R injury was also examined. In addition, we examined the therapeutic effect of CpG-ODN on cerebral I/R injury by administration of CpG-ODN 15 minutes after cerebral ischemia. CpG-ODN administration significantly decreased cerebral I/R-induced infarct volume by 69.7% (6.4±1.80% vs 21.0±2.85%, P<0.05), improved neurological scores, and increased survival rate, when compared with the untreated I/R group. Therapeutic administration of CpG-ODN also significantly reduced infarct volume by 44.7% (12.6±2.03% vs 22.8±2.54%, P<0.05) compared with untreated I/R mice. Neither control-ODN, nor iCpG-ODN altered I/R-induced cerebral injury or neurological deficits. Nissl staining showed that CpG-ODN treatment preserved neuronal morphology in the ischemic hippocampus. Immunoblot showed that CpG-ODN administration increased Bcl-2 levels by 41% and attenuated I/R-increased levels of Bax and caspase-3 activity in ischemic brain tissues. Importantly, CpG-ODN treatment induced Akt and GSK-3β phosphorylation in brain tissue and cultured microglial cells. PI3K inhibition with LY294002 abolished CpG-ODN-induced protection.

CONCLUSION

CpG-ODN significantly reduces cerebral I/R injury via a PI3K/Akt-dependent mechanism. Our data also indicate that CpG-ODN may be useful in the therapy of cerebral I/R injury.

MicroRNA-125b protects against myocardial ischaemia/reperfusion injury via targeting p53-mediated apoptotic signalling and TRAF6

AIMS

The present study examined the role of microRNA-125b (miR-125b) in myocardial ischaemia/reperfusion (I/R) injury. We constructed lentivirus-expressing miR-125b (LmiR-125b) and developed transgenic mice with overexpression of miR-125b.

METHODS AND RESULTS

LmiR-125b was transfected into mouse hearts through the right common carotid artery. Lentivirus vector (LmiR-Con) served as vector control. Untreated mice served as I/R control. Sham operation served as sham control. Seven days after transfection, the hearts were subjected to ischaemia (45 min) followed by reperfusion (4 h). Myocardial infarct size was analysed by 2,3,5-triphenyltetrazolium chloride staining. In separate experiments, hearts were subjected to ischaemia (45 min) followed by reperfusion for up to 7 days. Cardiac function was measured by echocardiography before, as well as 3 and 7 days after myocardial I/R. Increased expression of miR-125b significantly decreased I/R-induced myocardial infarct size by 60% and prevented I/R-induced decreases in ejection fraction (EF%) and fractional shortening (%FS). Transgenic mice with overexpression of miR-125b also showed the protection against myocardial I/R injury. Increased expression of miR-125b attenuated I/R-induced myocardial apoptosis and caspase-3/7 and -8 activities. Western blot showed that increased expression of miR-125b suppresses p53 and Bak1 expression in the myocardium. In addition, transfection of LmiR-125b decreased the levels of TNF receptor-associated factor 6 (TRAF6) and prevented I/R-induced NF-κB activation.

CONCLUSION

miR-125 protects the myocardium from I/R injury by preventing p53-mediated apoptotic signalling and suppressing TRAF6-mediated NF-κB activation.

Toll-like receptor 3 plays a role in myocardial infarction and ischemia/reperfusion injury

Innate immune and inflammatory responses mediated by Toll like receptors (TLRs) have been implicated in myocardial ischemia/reperfusion (I/R) injury. This study examined the role of TLR3 in myocardial injury induced by two models, namely, myocardial infarction (MI) and I/R. First, we examined the role of TLR3 in MI. TLR3 deficient (TLR3(-/-)) and wild type (WT) mice were subjected to MI induced by permanent ligation of the left anterior descending (LAD) coronary artery for 21days. Cardiac function was measured by echocardiography. Next, we examined whether TLR3 contributes to myocardial I/R injury. TLR3(-/-) and WT mice were subjected to myocardial ischemia (45min) followed by reperfusion for up to 3days. Cardiac function and myocardial infarct size were examined. We also examined the effect of TLR3 deficiency on I/R-induced myocardial apoptosis and inflammatory cytokine production. TLR3(-/-) mice showed significant attenuation of cardiac dysfunction after MI or I/R. Myocardial infarct size and myocardial apoptosis induced by I/R injury were significantly attenuated in TLR3(-/-) mice. TLR3 deficiency increases B-cell lymphoma 2 (BCL2) levels and attenuates I/R-increased Fas, Fas ligand or CD95L (FasL), Fas-Associated protein with Death Domain (FADD), Bax and Bak levels in the myocardium. TLR3 deficiency also attenuates I/R-induced myocardial nuclear factor KappaB (NF-κB) binding activity, Tumor necrosis factor alpha (TNF-α) and Interleukin-1 beta (IL-1β) production as well as I/R-induced infiltration of neutrophils and macrophages into the myocardium. TLR3 plays an important role in myocardial injury induced by MI or I/R. The mechanisms involve activation of apoptotic signaling and NF-κB binding activity. Modulation of TLR3 may be an effective approach for ameliorating heart injury in heart attack patients.

Increased expression of microRNA-146a decreases myocardial ischaemia/reperfusion injury

AIMS

We have reported that either toll-like receptor 4 deficiency (TLR4(-/-)) or TLR2 modulation protects against myocardial ischaemia/reperfusion (I/R) injury. The mechanisms involve attenuation of I/R-induced nuclear factor KappaB (NF-κB) activation. MicroRNA-146a (miR-146a) has been reported to target interleukin-1 receptor-associated kinase 1 (IRAK1) and tumor necrosis factor (TNF) receptor associated factor 6 (TRAF6), resulting in inhibiting NF-κB activation. This study examined the role of microRNA-146a in myocardial I/R injury.

METHODS AND RESULTS

We constructed lentivirus expressing miR-146a (LmiR-146a). LmiR-146a was transfected into mouse hearts through the right common carotid artery. The lentivirus vector (LmiR-Con) served as vector control. Untransfected mice served as I/R control. Sham operation served as sham control. Seven days after transfection, the hearts were subjected to ischaemia (60 min) followed by reperfusion (4 h). Myocardial infarct size was analysed by triphenyltetrazolium chloride (TTC) staining. In separate experiments, the hearts were subjected to ischaemia (60 min) followed by reperfusion for up to 7 days. Cardiac function was measured by echocardiography prior to I/R, 3 and 7 days after myocardial I/R. LmiR-146a transfection significantly decreased I/R-induced myocardial infarct size by 55% and prevented I/R-induced decreases in ejection fraction (EF%) and fractional shortening (%FS). LmiR-146a transfection attenuated I/R-induced myocardial apoptosis and caspase-3/7 and -8 activities. LmiR-146a transfection suppresses IRAK1 and TRAF6 expression in the myocardium. In addition, transfection of LmiR-146a prevented I/R-induced NF-κB activation and inflammatory cytokine production.

CONCLUSIONS

MicroRNA-146a protects the myocardium from I/R injury. The mechanisms may involve attenuation of NF-κB activation and inflammatory cytokine production by suppressing IRAK1 and TRAF6.

The Toll-like receptor 9 ligand, CpG oligodeoxynucleotide, attenuates cardiac dysfunction in polymicrobial sepsis, involving activation of both phosphoinositide 3 kinase/Akt and extracellular-signal-related kinase signaling

BACKGROUND

Toll-like receptors (TLRs) play a role in the pathophysiology of sepsis and multiple organ failure. This study examined the effect of CpG oligodeoxynucleotide (CpG-ODN), the TLR9 ligand, on polymicrobial sepsis-induced cardiac dysfunction.

METHODS

Male C57BL/6 mice were treated with CpG-ODN, control CpG-ODN (control-ODN), or inhibitory CpG-ODN (iCpG-ODN) 1 hour prior to cecal ligation and puncture (CLP)-induced sepsis. Mice that underwent sham surgery served as sham controls. Cardiac function was examined by echocardiography before and 6 hours after CLP.

RESULTS

Cardiac function was significantly decreased 6 hours after CLP. CpG-ODN prevented CLP-induced cardiac dysfunction, as evidenced by maintenance of the ejection fraction and fractional shortening. Control-ODN or iCpG-ODN did not alter CLP-induced cardiac dysfunction. CpG-ODN significantly attenuated CLP-induced myocardial apoptosis and increased myocardial Akt and extracellular-signal-related kinase (ERK) phosphorylation levels following CLP. In vitro experiments demonstrated that CpG-ODN promotes an association between TLR9 and Ras, resulting in Akt and ERK phosphorylation. Inhibition of phosphoinositide 3-kinase (PI3K) by Ly294002 or inhibition of ERK by U0126 in vivo abolished CpG-ODN attenuation of CLP-induced cardiac dysfunction.

CONCLUSIONS

CpG-ODN prevents CLP-induced cardiac dysfunction, in part through activation of PI3K/Akt and ERK signaling. Modulation of TLR9 could be an effective approach for treatment of cardiovascular dysfunction in patients with sepsis or septic shock.

SR-A deficiency reduces myocardial ischemia/reperfusion injury; involvement of increased microRNA-125b expression in macrophages

The macrophage scavenger receptor class A (SR-A) participates in the innate immune and inflammatory responses. This study examined the role of macrophage SR-A in myocardial ischemia/reperfusion (I/R) injury and hypoxia/reoxygenation (H/R)-induced cell damage. SR-A(-/-) and WT mice were subjected to ischemia (45min) followed by reperfusion for up to 7days. SR-A(-/-) mice showed smaller myocardial infarct size and better cardiac function than did WT I/R mice. SR-A deficiency attenuated I/R-induced myocardial apoptosis by preventing p53-mediated Bak-1 apoptotic signaling. The levels of microRNA-125b in SR-A(-/-) heart were significantly greater than in WT myocardium. SR-A is predominantly expressed on macrophages. To investigate the role of SR-A macrophages in H/R-induced injury, we isolated peritoneal macrophages from SR-A deficient (SR-A(-/-)) and wild type (WT) mice. Macrophages were subjected to hypoxia followed by reoxygenation. H/R markedly increased NF-κB binding activity as well as KC and MCP-1 production in WT macrophages but not in SR-A(-/-) macrophages. H/R induced caspase-3/7 and -8 activities and cell death in WT macrophages, but not in SR-A(-/-) macrophages. The levels of miR-125b in SR-A(-/-) macrophages were significantly higher than in WT macrophages. Transfection of WT macrophages with miR-125b mimics attenuated H/R-induced caspase-3/7 and -8 activities and H/R-decreased viability, and prevented H/R-increased p-53, Bak-1 and Bax expression. The data suggest that SR-A deficiency attenuates myocardial I/R injury by targeting p53-mediated apoptotic signaling. SR-A(-/-) macrophages contain high levels of miR-125b which may play a role in the protective effect of SR-A deficiency on myocardial I/R injury and H/R-induced cell damage.

Scavenger receptor class a plays a central role in mediating mortality and the development of the pro-inflammatory phenotype in polymicrobial sepsis

Sepsis is a frequent complication in critical illness. The mechanisms that are involved in initiation and propagation of the disease are not well understood. Scavenger receptor A (SRA) is a membrane receptor that binds multiple polyanions such as oxidized LDL and endotoxin. Recent studies suggest that SRA acts as a pattern recognition receptor in the innate immune response. The goal of the present study was to determine the role of SRA in polymicrobial sepsis. SRA deficient (SRA^−/−) and C57BL/6JB/6J (WT) male mice were subjected to cecal ligation and puncture (CLP) to induce polymicrobial sepsis. NFκB activity, myeloperoxidase activity, and co-association of SRA with toll like receptor (TLR) 4 and TLR2 was analyzed in the lungs. Spleens were analyzed for apoptosis. Serum cytokines and chemokines were assayed. Blood and peritoneal fluid were cultured for aerobic and anaerobic bacterial burdens. Long term survival was significantly increased in SRA^−/− septic mice (53.6% vs. 3.6%, p<0.05) when compared to WT mice. NFκB activity was 45.5% lower in the lungs of SRA^−/− septic mice versus WT septic mice (p<0.05). Serum levels of interleukin (IL)-5, IL-6, IL-10 and monocyte chemoattractant protein −1 were significantly lower in septic SRA^−/− mice when compared to septic WT mice (p<0.05). We found that SRA immuno-precipitated with TLR4, but not TLR2, in the lungs of WT septic mice. We also found that septic SRA^−/− mice had lower bacterial burdens than WT septic mice. SRA deficiency had no effect on pulmonary neutrophil infiltration or splenocyte apoptosis during sepsis. We conclude that SRA plays a pivotal, and previously unknown, role in mediating the pathophysiology of sepsis/septic shock in a murine model of polymicrobial sepsis. Mechanistically, SRA interacts with TLR4 to enhance the development of the pro-inflammatory phenotype and mediate the morbidity and mortality of sepsis/septic shock.

Trauma and other critical illnesses can progress to septic shock. The mechanisms that result in this progression are not understood. For this reason, there are no proven treatments available, and the mortality rate from sepsis remains quite high. We have found that mice that lack a certain cell surface protein, scavenger receptor A, have a higher rate of survival from a surgically induced sepsis than those that have the receptor. Previously, this receptor has been found to play a role in atherosclerosis, and more recently, to play a role in the immune response to infection. In this study we have found that in addition to improved survival, mice without scavenger receptor A have fewer bacteria in their abdominal cavities and in their blood. They also have lower levels of inflammation. We demonstrated that scavenger receptor A interacts with another protein involved in inflammation and infection, toll like receptor 4. This interaction might be one mechanism for the effects seen in mice without scavenger receptor A. These studies provide a better understanding of the underlying mechanisms of sepsis. Drugs that target scavenger receptor A could result in better therapies for sepsis.

Activation of myocardial phosphoinositide-3-kinase p110α ameliorates cardiac dysfunction and improves survival in polymicrobial sepsis

Phosphoinositide-3-kinase (PI3K)/Akt dependent signaling has been shown to improve outcome in sepsis/septic shock. There is also ample evidence that PI3K/Akt dependent signaling plays a crucial role in maintaining normal cardiac function. We hypothesized that PI3K/Akt signaling may ameliorate septic shock by attenuating sepsis-induced cardiac dysfunction. Cardiac function and survival were evaluated in transgenic mice with cardiac myocyte specific expression of constitutively active PI3K isoform, p110α (caPI3K Tg). caPI3K Tg and wild type (WT) mice were subjected to cecal ligation/puncture (CLP) induced sepsis. Wild type CLP mice showed dramatic cardiac dysfunction at 6 hrs. Septic cardiomyopathy was significantly attenuated in caPI3K CLP mice. The time to 100% mortality was 46 hrs in WT CLP mice. In contrast, 80% of the caPI3K mice survived at 46 hrs after CLP (p<0.01) and 50% survived >30 days (p<0.01). Cardiac caPI3K expression prevented expression of an inflammatory phenotype in CLP sepsis. Organ neutrophil infiltration and lung apoptosis were also effectively inhibited by cardiac PI3k p110α expression. Cardiac high mobility group box–1 (HMGB-1) translocation was also inhibited by caPI3K p110α expression. We conclude that cardiac specific activation of PI3k/Akt dependent signaling can significantly modify the morbidity and mortality associated with sepsis. Our data also indicate that myocardial function/dysfunction plays a prominent role in the pathogenesis of sepsis and that maintenance of cardiac function during sepsis is essential. Finally, these data suggest that modulation of the PI3K/p110α signaling pathway may be beneficial in the prevention and/or management of septic cardiomyopathy and septic shock.

CpG-ODN, the TLR9 agonist, attenuates myocardial ischemia/reperfusion injury: involving activation of PI3K/Akt signaling

BACKGROUND

Toll-like receptors (TLRs) have been implicated in myocardial ischemia/reperfusion (I/R) injury. The TLR9 ligand, CpG-ODN has been reported to improve cell survival. We examined effect of CpG-ODN on myocardial I/R injury.

METHODS

Male C57BL/6 mice were treated with either CpG-ODN, control-ODN, or inhibitory CpG-ODN (iCpG-ODN) 1h prior to myocardial ischemia (60min) followed by reperfusion. Untreated mice served as I/R control (n=10/each group). Infarct size was determined by TTC straining. Cardiac function was examined by echocardiography before and after myocardial I/R up to 14days.

RESULTS

CpG-ODN administration significantly decreased infarct size by 31.4% and improved cardiac function after myocardial I/R up to 14days. Neither control-ODN nor iCpG-ODN altered I/R-induced myocardial infarction and cardiac dysfunction. CpG-ODN attenuated I/R-induced myocardial apoptosis and prevented I/R-induced decrease in Bcl2 and increase in Bax levels in the myocardium. CpG-ODN increased Akt and GSK-3β phosphorylation in the myocardium. In vitro data suggested that CpG-ODN treatment induced TLR9 tyrosine phosphorylation and promoted an association between TLR9 and the p85 subunit of PI3K. Importantly, PI3K/Akt inhibition and Akt kinase deficiency abolished CpG-ODN-induced cardioprotection.

CONCLUSION

CpG-ODN, the TLR9 ligand, induces protection against myocardial I/R injury. The mechanisms involve activation of the PI3K/Akt signaling pathway.

Glucan phosphate attenuates myocardial HMGB1 translocation in severe sepsis through inhibiting NF-κB activation

Myocardial dysfunction is a major consequence of septic shock and contributes to the high mortality of sepsis. High-mobility group box 1 (HMGB1) serves as a late mediator of lethality in sepsis. We have reported that glucan phosphate (GP) attenuates cardiac dysfunction and increases survival in cecal ligation and puncture (CLP)-induced septic mice. In the present study, we examined the effect of GP on HMGB1 translocation from the nucleus to the cytoplasm in the myocardium of septic mice. GP was administered to mice 1 h before induction of CLP. Sham-operated mice served as control. The levels of HMGB1, Toll-like receptor 4 (TLR4), and NF-κB binding activity were examined. In an in vitro study, H9C2 cardiomyoblasts were treated with lipopolysaccharide (LPS) in the presence or absence of GP. H9C2 cells were also transfected with Ad5-IκBα mutant, a super repressor of NF-κB activity, before LPS stimulation. CLP significantly increased the levels of HMGB1, TLR4, and NF-κB binding activity in the myocardium. In contrast, GP administration attenuated CLP-induced HMGB1 translocation from the nucleus to the cytoplasm and reduced CLP-induced increases in TLR4 and NF-κB activity in the myocardium. In vitro studies showed that GP prevented LPS-induced HMGB1 translocation and NF-κB binding activity. Blocking NF-κB binding activity by Ad5-IκBα attenuated LPS-induced HMGB1 translocation. GP administration also reduced the LPS-stimulated interaction of HMGB1 with TLR4. These data suggest that attenuation of HMGB1 translocation by GP is mediated through inhibition of NF-κB activation in CLP-induced sepsis and that activation of NF-κB is required for HMGB1 translocation.

TLR2 ligands attenuate cardiac dysfunction in polymicrobial sepsis via a phosphoinositide 3-kinase-dependent mechanism

Myocardial dysfunction is a major consequence of septic shock and contributes to the high mortality of sepsis. In the present study, we examined the effect of Toll-like receptor 2 (TLR2) ligands, peptidoglycan (PGN), and Pam3CSK4 (Pam3) on cardiac function in cecal ligation and puncture (CLP)-induced sepsis in mice. We also investigated whether the phosphoinositide 3-kinase (PI3K)/Akt signaling pathway is involved in the effect of TLR2 ligands on cardiac function in CLP mice. PGN was administered to C57B6/L mice 1 h before the induction of CLP. Sham surgically operated mice served as a control. Cardiac function indexes (rate of change in left ventricular pressure, stroke work, cardiac output, and ejection fraction) were examined by a microconductance pressure catheter. Cardiac function was significantly decreased 6 h after CLP-induced sepsis compared with sham-operated control. In contrast, PGN administration attenuated CLP-induced cardiac dysfunction. Importantly, the therapeutic treatment with Pam3 1 h after CLP also significantly attenuated cardiac dysfunction in CLP mice. However, the beneficial effect of TLR2 ligands on cardiac dysfunction in CLP-mice was abolished in TLR2-deficient mice. PGN administration significantly increased the levels of phospho-Akt and phospho-GSK-3beta in the myocardium compared with the levels in untreated CLP mice. PI3K inhibition abolished the PGN-induced attenuation of cardiac dysfunction in CLP mice. In conclusion, these data demonstrate that the administration of TLR2 ligands, PGN, or Pam3 attenuates cardiac dysfunction in septic mice via a TLR2/PI3K-dependent mechanism. More significantly, Pam3 therapeutic treatment will have a potential clinical relevance.

Dopamine receptor gene expression in human amygdaloid nuclei: elevated D4 receptor mRNA in major depression

Previous findings from this laboratory demonstrating changes in dopamine (DA) transporter and D2 receptors in the amygdaloid complex of subjects with major depression indicate that disruption of dopamine neurotransmission to the amygdala may contribute to behavioral symptoms associated with depression. Quantitative real-time RT-PCR was used to investigate the regional distribution of gene expression of DA receptors in the human amygdala. In addition, relative levels of mRNA of DA receptors in the basal amygdaloid nucleus were measured postmortem in subjects with major depression and normal control subjects. All five subtypes of DA receptor mRNA were detected in all amygdaloid subnuclei, although D1, D2, and D4 receptor mRNAs were more abundant than D3 and D5 mRNAs by an order of magnitude. The highest level of D1 mRNA was found in the central nucleus, whereas D2 mRNA was the most abundant in the basal nucleus. Levels of D4 mRNA were highest in the basal and central nuclei. In the basal nucleus, amounts of D4, but not D1 or D2, mRNAs were significantly higher in subjects with major depression as compared to control subjects. These findings demonstrate that the D1, D2 and D4 receptors are the major subtypes of DA receptors in the human amygdala. Elevated DA receptor gene expression in depressive subjects further implicates altered dopaminergic transmission in the amygdala in depression.

Bioavailability of a novel, water-soluble vitamin E formulation in malabsorbing patients

In cystic fibrosis (CF), pancreatic insufficiency and a diminished bile acid pool cause malabsorption of important nutrients and dietary components leading to deficiency, poor nutritional status, and oxidative stress. Of particular significance is the malabsorption of fat-soluble nutrients and antioxidants, which are important for normal immune and neurologic function. Patients with CF often are deficient in these compounds despite supplementation with the current standard of care therapy. The objective was to compare the pharmacokinetic profile of this water-soluble vitamin E formulation (Aqua-E) with an oil-based softgel formulation in a malabsorbing patient population. Patients with CF who had documented malabsorption were recruited for participation in this pharmacokinetic study. Patients who met inclusion and exclusion criteria discontinued vitamin E supplementation, except for that in a multivitamin, for 7 to 21 days before the day of dosing. Patients were randomized to a single dose of 20 ml of Aqua-E or three oil-based softgels, which contained equivalent amounts of tocopherols. Blood was drawn from patients at time 0, 2, 4, 8, 24, 48, and 168 hr and analyzed for tocopherols. Eight patients were enrolled in the study and randomized to Aqua-E or softgels. The primary outcome, the absorption of gamma-tocopherol in Aqua-E (AUC=115 micro g/ml(*)hr), was significantly greater than that of oil-based softgels (AUC=25.3 micro g/ml(*)hr; P=0.013). Total-tocopherols (alpha+gamma+delta) in Aqua-E (AUC=294 micro g/ml(*)hr) showed a strong trend toward increased absorption compared with that of oil-based softgels (AUC=117 micro g/ml(*)hr; P=0.09). In conclusion, this novel, water-soluble formulation showed a marked and statistically significant increase in absorption of gamma-tocopherol in malabsorbing patients with CF compared with an oil-based formulation.

Glucan phosphate attenuates cardiac dysfunction and inhibits cardiac MIF expression and apoptosis in septic mice

Myocardial dysfunction is a major consequence of septic shock and contributes to the high mortality of sepsis. We have previously reported that glucan phosphate (GP) significantly increased survival in a murine model of cecal ligation and puncture (CLP)-induced sepsis. In the present study, we examined the effect of GP on cardiac dysfunction in CLP-induced septic mice. GP was administered to ICR/HSD mice 1 h before induction of CLP. Sham surgically operated mice served as control. Cardiac function was significantly decreased 6 h after CLP-induced sepsis compared with sham control. In contrast, GP administration prevented CLP-induced cardiac dysfunction. Macrophage migration inhibitory factor (MIF) has been implicated as a major factor in cardiomyocyte apoptosis and cardiac dysfunction during septic shock. CLP increased myocardial MIF expression by 88.3% ( P < 0.05) and cardiomyocyte apoptosis by 7.8-fold ( P < 0.05) compared with sham control. GP administration, however, prevented CLP-increased MIF expression and decreased cardiomyocyte apoptosis by 51.2% ( P < 0.05) compared with untreated CLP mice. GP also prevented sepsis-caused decreases in phospho-Akt, phospho-GSK-3β, and Bcl-2 levels in the myocardium of septic mice. These data suggest that GP treatment attenuates cardiovascular dysfunction in fulminating sepsis. GP administration also activates the phosphoinositide 3-kinase/Akt pathway, decreases myocardial MIF expression, and reduces cardiomyocyte apoptosis.

Anterior pituitary cells express pattern recognition receptors for fungal glucans: implications for neuroendocrine immune involvement in response to fungal infections

OBJECTIVES

Hormones and cytokines are known to act as regulatory messengers between the neuroendocrine and immune systems. The innate immune system identifies infectious agents by means of pattern-recognition receptors. These receptors recognize pathogen-specific macromolecules called pathogen-associated molecular patterns. Fungal cell wall glucans nonspecifically stimulate various aspects of innate immunity via interaction with membrane receptors on immune-competent cells. Glucans are also released into the systemic circulation of patients with fungal infections. Recent evidence confirms the existence of glucan-specific receptors on cells outside the immune system. We hypothesized that glucans may directly interact with pituitary cells as an early signaling event in fungal infections.

METHODS

We characterized the receptor-mediated interaction of glucan derived from Candida albicans with pituitary cells using surface plasmon resonance. Prolactin levels were assayed by commercial ELISA. TLR2, TLR4 and CD14 mRNA levels were assessed by RT-PCR.

RESULTS

A single glucan-specific binding site was identified on rodent somatomammotroph (K(D) = 3.9 microM) and human folliculostellate cell (K(D) = 3.6 microM) membranes. Coincubation of glucan with somatomammotroph cells for 72 h significantly (p < 0.01) increased prolactin accumulation by 56-62% over that observed in cells treated with media alone. Glucan also increased TLR4 and CD14 gene expression in human folliculostellate cells.

CONCLUSIONS

Pituitary cells directly recognize and respond to fungal cell wall glucans resulting in stimulation of pituitary cell TLR4 and CD14 gene expression. In addition, glucan stimulates secretion of prolactin, a hormone that plays an important role in the response to infection.

Serum glucan levels are not specific for presence of fungal infections in intensive care unit patients

Fungal infections in the critically ill patient are difficult to diagnose and are associated with a high mortality rate. A major obstacle to managing fungal infection is the lack of a reliable clinical assay that will rapidly identify patients with fungal sepsis. Glucans are polymers of glucose that are found in the cell wall of fungi and certain bacteria. Glucans are also released from the fungal cell wall into the extracellular milieu. Several studies have reported that detection of fungal glucan in serum or plasma is useful in the diagnosis of mycoses. However, recent studies have questioned the clinical utility of this assay. In this study, we examined serum glucan levels in intensive care unit (ICU) patients and attempt to correlate serum glucan levels with the presence of fungal infection. Following attainment of informed consent, serum was harvested from 46 ICU patients with confirmed fungal infections, confirmed bacterial infections, or no evidence of infection. Sera from eight healthy volunteers served as control. Serum glucan was assayed with a glucan-specific Limulus assay. Serum glucan levels were increased (69.6 +/- 17 pg/ml; P < 0.001) in ICU patients versus the normal (11.5 +/- 1.3 pg/ml) and noninfected ICU (27.4 +/- 17 pg/ml) controls. However, serum glucan levels were not different in patients with confirmed fungal infections versus those with confirmed bacterial infections. Thus, serum glucan levels did not show a correlation with the presence of fungal infections and do not appear to be specific for fungal infections. However, the assay may be useful as a negative predictor of infection.

Human vascular endothelial cells express pattern recognition receptors for fungal glucans which stimulates nuclear factor kappaB activation and interleukin 8 production. Winner of the Best Paper Award from the Gold Medal Forum

Fungal cell wall glucans nonspecifically stimulate various aspects of innate immunity via interaction with membrane receptors on macrophages, neutrophils, and natural killer cells. We investigated the binding of water-soluble glucans in primary cultures of normal human coronary or dermal vascular endothelial cells (VECs). Membranes from VECs exhibited saturable binding. Competition studies demonstrated the presence of at least two glucan binding sites on VECs. Glucan phosphate competed for all binding sites with a KD of 3.7 microM for coronary VECs and 11 microM for dermal VECs, respectively. Laminarin, a low molecular weight glucan, competed for 47 to 51 per cent of binding (KD = 2.8-2.9 microM), indicating the presence of at least two binding sites. Glucan (1 microg/mL) stimulated VEC nuclear factor kappaB nuclear binding activity and Interleukin 8 expression--but not that of vascular endothelial growth factor--in a time-dependent manner. This is the first report of pattern recognition receptors for glucan on human VECs. It also provides the first evidence that glucans can directly modulate the functional activity of VECs by stimulating cytokine gene. These results provide new insights into the mechanisms by which the host recognizes and responds to fungal cell wall products and suggests that the response to glucans may not be confined to leukocytes.

Human Vascular Endothelial Cells Express Pattern Recognition Receptors for Fungal Glucans Which Stimulates Nuclear Factor κB Activation and Interleukin 8 Production

Fungal cell wall glucans nonspecifically stimulate various aspects of innate immunity via interaction with membrane receptors on macrophages, neutrophils, and natural killer cells. We investigated the binding of water-soluble glucans in primary cultures of normal human coronary or dermal vascular endothelial cells (VECs). Membranes from VECs exhibited saturable binding. Competition studies demonstrated the presence of at least two glucan binding sites on VECs. Glucan phosphate competed for all binding sites with a KD of 3.7 μm for coronary VECs and 11 μm for dermal VECs, respectively. Laminarin, a low molecular weight glucan, competed for 47 to 51 per cent of binding ( KD = 2.8–2.9 μm), indicating the presence of at least two binding sites. Glucan (1 μg/mL) stimulated VEC nuclear factor κB nuclear binding activity and Interleukin 8 expression—but not that of vascular endothelial growth factor—in a time-dependent manner. This is the first report of pattern recognition receptors for glucan on human VECs. It also provides the first evidence that glucans can directly modulate the functional activity of VECs by stimulating cytokine gene. These results provide new insights into the mechanisms by which the host recognizes and responds to fungal cell wall products and suggests that the response to glucans may not be confined to leukocytes.

A (1-->3)-beta-D-linked heptasaccharide is the unit ligand for glucan pattern recognition receptors on human monocytes

Glucans are fungal cell wall polysaccharides which stimulate innate immune responses. We determined the minimum unit ligand that would bind to glucan receptors on human U937 cells using laminarin-derived pentaose, hexaose, and heptaose glucan polymers. When U937 membranes were pretreated with the oligosaccharides and passed over a glucan surface, only the heptasaccharide inhibited the interaction of glucan with membrane receptors at a K(d) of 31 microM (95% CI 20-48 microM) and 100% inhibition. However, the glucan heptasaccharide did not stimulate U937 monocyte NFkappaB signaling, nor did it increase survival in a murine model of polymicrobial sepsis. Laminarin, a larger and more complex glucan polymer (M(w) = 7700 g/mol), only partially inhibited binding (61 +/- 4%) at a K(d) of 2.6 microM (99% CI 1.7-4.2 microM) with characteristics of a single binding site. These results indicate that a heptasaccharide is the smallest unit ligand recognized by macrophage glucan receptors. The data also indicate the presence of at least two glucan-binding sites on U937 cells and that the binding sites on human monocyte/macrophages can discriminate between glucan polymers. The heptasaccharide and laminarin were receptor antagonists, but they were not receptor agonists with respect to activation of NFkappaB-dependent signaling pathways or protection against experimental sepsis.

Normal human fibroblasts express pattern recognition receptors for fungal (1-->3)-beta-D-glucans

Fungal cell wall glucans nonspecifically stimulate various aspects of innate immunity. Glucans are thought to mediate their effects via interaction with membrane receptors on macrophages, neutrophils, and NK cells. There have been no reports of glucan receptors on nonimmune cells. We investigated the binding of a water-soluble glucan in primary cultures of normal human dermal fibroblasts (NHDF). Membranes from NHDF exhibited saturable binding with an apparent dissociation constant (K(D)) of 8.9 +/- 1.9 microg of protein per ml and a maximum binding of 100 +/- 8 resonance units. Competition studies demonstrated the presence of at least two glucan binding sites on NHDF. Glucan phosphate competed for all binding sites, with a K(D) of 5.6 microM (95% confidence interval [CI], 3.0 to 11 microM), while laminarin competed for 69% +/- 6% of binding sites, with a K(D) of 3.7 microM (95% CI, 1.9 to 7.3 microM). Glucan (1 microg/ml) stimulated fibroblast NF-kappaB nuclear binding activity and interleukin 6 (IL-6) gene expression in a time-dependent manner. NF-kappaB was activated at 4, 8, and 12 h, while IL-6 mRNA levels were increased by 48% at 8 h. This is the first report of pattern recognition receptors for glucan on human fibroblasts and the first demonstration of glucan binding sites on cells other than leukocytes. It also provides the first evidence that glucans can directly modulate the functional activity of NHDF. These results provide new insights into the mechanisms by which the host recognizes and responds to fungal (1-->3)-beta-D-glucans and suggests that the response to glucans may not be confined to cells of the immune system.

Reactive and clonal thrombocytosis: proinflammatory and hematopoietic cytokines and acute phase proteins

BACKGROUND

We quantitated proinflammatory and thrombopoietic cytokines in reactive thrombocytosis (RT) and clonal thrombocytosis (CT) to identify a cytokine profile that might aid in the distinction of these two disorders.

METHODS

Serum levels of cytokines relevant to platelet biology--interleukins 3, 6, 11, and 1beta; thrombopoietin; tumor necrosis factor alpha; and C-reactive protein (CRP)--were measured by enzyme-linked immunosorbent assay in healthy subjects and in patients with CT and RT.

RESULTS

Interleukin-6 and CRP levels were higher in RT patients than in controls or CT patients. Interleukin 1beta levels were higher in the RT group than in the CT and control groups.

CONCLUSIONS

In RT, IL-6, IL-1beta, and CRP levels are elevated. In both RT and CT, IL-11 is elevated, but thrombopoietin levels are not.

Glucans exhibit weak antioxidant activity, but stimulate macrophage free radical activity

Polymeric carbohydrates have been reported to modulate inflammatory responses in vitro and in vivo. Previous reports suggest that certain carbohydrate polymers, such as (1-->3)-beta-D-glucans, may possess free radical scavenging activity. If glucans are free radical scavengers then it might explain, in part, the ability of these ligands to modulate inflammatory responses. The present study examined the free radical scavenging activity of a variety of carbohydrate polymers and the effect of the polymers on free radical levels in a murine macrophage cell line. All of the carbohydrates exhibited concentration dependent antioxidant effects (EC(50) range = 807 to 43 microg/ml). However, the antioxidant activity for the carbohydrates was modest in comparison with PDTC (EC(50) = 0.13 microg/ml) and the carbohydrate concentration required for antioxidant activity was high (x EC(50) = 283 microg/ml). The antioxidant ability of the polymers was greater (p < .05) than their monosaccharide constituents, i.e., dextrose EC(50) = 807 vs. glucan sulfate EC(50) = 43 microg/ml. Coincubation of glucans with murine J774a.1 cells increased free radical levels when compared to controls. Therefore, the weak free radical scavenging activity of glucan polymers cannot explain their modulatory effect on inflammatory responses in tissue culture and/or disease models of inflammation.

Inhibition of LPS-induced NFkappaB activation by a glucan ligand involves down-regulation of IKKbeta kinase activity and altered phosphorylation and degradation of IkappaBalpha

Growing evidence supports the role of transcription factor activation in the pathophysiology of inflammatory disorders, sepsis, ARDS, SIRS, and shock. Kinase mediated phosphorylation of IkappaBalpha is a crucial step in the NFkappaB activation pathway. We investigated IKBalpha phosphorylation in murine liver and lung extracts after cecal ligation and puncture (CLP) in the presence and absence of a glucan ligand. ICR mice were subjected to CLP. Unoperated and sham-operated mice served as the controls. Glucan phosphate (50 mg/kg) was administered 1 h before or 15 min after CLP. CLP increased hepatic and pulmonary levels of phospho-IkappaBalpha by 48-192%. Pre- or post-treatment with glucan phosphate decreased (P < 0.05) tissue phospho-IkappaBalpha levels in CLP mice. Phospho-IkappaBalpha in the glucan-CLP group were not significantly different from the unoperated controls. To investigate mechanisms we examined IKKbeta kinase activity, IkappaBalpha phosphorylation and degradation, and NFkappaB activity in a murine macrophage cell line, J774a.1, treated with LPS (1 microg/mL) and/or glucan phosphate (1 microg/mL) for up to 120 min. The glucan ligand blunted LPS-induced IKKbeta kinase activity, phosphorylation and degradation of IkappaBalpha, and NFkappaB nuclear binding activity. The data indicate that one mechanism by which (1-->3)-beta-D-glucan may alter the response to endotoxin or polymicrobial sepsis involves modulation of IKK3 kinase activity with subsequent decreases in IkappaBalpha phosphorylation and NFkappaB activation.

Ligand binding to the (1 --> 3)-beta-D-glucan receptor stimulates NFkappaB activation, but not apoptosis in U937 cells

Recent data suggest that sepsis stimulates macrophage apoptosis (Ao) with subsequent induction of macrophage dysfunction. Nuclear factor-kappaB (NFkappaB) activation has been linked to Ao in either a pro- or antiapoptotic role. Glucans are biological response modifiers which exert antisepsis activity. This investigation examined the effect of (1-3)-beta-D-glucan receptor binding by a high affinity ligand on Ao and NFkappaB activation in U937 cells in the presence or absence of LPS. A high affinity glucan ligand (IC50 = 23 nM) activated NFkappaB, but did not induce Ao or significantly alter LPS induced U937 Ao. These data indicate that: i) modulation of the macrophage (1-3)-beta-D-glucan receptor stimulates NFkappaB; ii) does not induce Ao or significantly diminish LPS induced Ao and iii) activation of the U937 FAS receptor does not alter the relative Ao responses in glucan and LPS treated cells.

Resolution of the neutropenia of Felty's syndrome by longterm administration of recombinant granulocyte colony stimulating factor

Felty's syndrome is characterized by neutropenia, splenomegaly, and recurrent infection in patients with rheumatoid arthritis. We used recombinant granulocyte colony stimulating factor (rGCSF) in a patient with Felty's syndrome and recurrent sepsis. rGCSF induced a statistically significant increase in the patient's absolute neutrophil and total white blood cell counts. During 14 months of followup taking rGCSF, disseminated varicella zoster was the only infectious complication. Except mild thrombocytopenia and a transient flare of arthritis, no serious adverse effects occurred. rGCSF may be a safe and effective therapy for Felty's syndrome in selected patients.

Acute myocardial infarction in Oklahoma: are we different?

Data regarding 787 patients admitted to Saint Francis Hospital in Tulsa, Oklahoma, with acute myocardial infarction (MI) were analyzed to determine circadian variation and to assess demographic and anatomic characteristics. The study population consisted of 634 men (81%) and 153 women (19%). This cohort displayed a circadian rhythm that nearly duplicated a previously published national data base. As was seen nationally, our patients had a peak incidence between 6 AM and noon. Of the total population, 448 patients had acute cardiac catheterization allowing definition of the infarct vessel. The majority of myocardial infarctions were from right coronary artery occlusions. Men were more likely than women to have an anterior MI. Both men and women were more likely to have an inferior MI if they were less than 65 years of age, though this was more pronounced for women. As the population aged, they were more likely to have an anterior myocardial infarction.

More rapid, complete, and stable coronary thrombolysis with bolus administration of reteplase compared with alteplase infusion in acute myocardial infarction. RAPID Investigators

BACKGROUND

Early restoration and maintenance of normal (TIMI 3) blood flow during acute myocardial infarction is critical for optimal preservation of left ventricular function and survival. Recombinant plasminogen activator (r-PA, reteplase) is a nonglycosylated deletion mutant of wild-type tissue-type plasminogen activator (TPA) that has been shown to achieve more rapid and complete thrombolysis compared with other plasminogen activators in animal models.

METHODS AND RESULTS

The RAPID Trial was designed to test the hypothesis that bolus administration of one or more dosage regimens of r-PA was superior to standard-dose alteplase (TPA) in achieving infarct-related artery patency 90 minutes after initiation of treatment. Six hundred six patients with acute myocardial infarction were randomized to one of four treatment arms: (1) TPA 100 mg i.v. over 3 hours, (2) r-PA as a 15-MU single bolus, (3) r-PA as a 10-MU bolus followed by 5 MU 30 minutes later, or (4) r-PA as a 10-MU bolus followed by 10 MU 30 minutes later. Coronary arteriography was performed at 30, 60, and 90 minutes after initiation of treatment and at hospital discharge. The 10 + 10-MU r-PA group achieved better 90-minute and 5- to 14-day TIMI 3 flow (63% [CI, 55% to 71%] versus 49% [41% to 57%], P = .019, and 88% [82% to 94%] versus 71% [63% to 79%], P < .001, respectively) than the TPA group. The TIMI 3 flow in the 10 + 10-MU r-PA group at 60 minutes was equivalent to that in the TPA group at 90 minutes (51 versus 49%). Global ejection fraction and regional wall motion in the 10 + 10-MU r-PA group were superior to those of the TPA group at hospital discharge (53 +/- 1.3% versus 49 +/- 1.3%, P = .034; -2.19 +/- 0.12 versus -2.61 +/- 0.13 SD per chord, P = .02, respectively). The 15-MU and 10 + 5-MU r-PA patency and left ventricular function results were similar to those of the TPA and inferior to those of the 10 + 10-MU r-PA group. Bleeding complications were similar between the groups.

CONCLUSIONS

r-PA given as a double bolus of 10 + 10 MU achieves more rapid, complete, and sustained thrombolysis of the infarct-related artery than standard-dose TPA, without an apparent increased risk of complications. This was associated with improved global and regional left ventricular function at hospital discharge.

Effects of trimethyltin on acquisition and reversal of a light-dark discrimination by rats

The behavioral deficits produced by trimethyltin (TMT) are usually attributed to the hippocampal damage caused by this toxicant. The purpose of this experiment was to determine the effects of TMT administration on acquisition and reversal of a discrete trial light-dark discrimination. Acquisition of this task is impaired by hippocampal lesions but the effects of TMT on it are not known. Forty-five days after some of the rats were given one of three doses of TMT, adult, male Long-Evans rats were given 100 trials per day for 20 days to acquire a discrete trial lever press discrimination with lit cue lights located above the correct lever. At the end of this time the contingencies were reversed and the rats were given 30 more days of training. No significant group differences occurred during the first 20 days. A significant group effect was found for the 30 days of reversal training. The rats given the highest dose of TMT (6 mg/kg) obtained significantly more reinforcements during reversal training than the other groups. Because surgical hippocampal lesions generally impair both acquisition and reversal of visual discriminations, these data were unexpected and suggest that other factors than hippocampal damage enter into the behavioral effects of TMT.

Evaluation of a prolonged infusion of recombinant tissue-type plasminogen activator (Duteplase) in preventing reocclusion following successful thrombolysis in acute myocardial infarction

The hypothesis that an infusion of recombinant tissue-type plasminogen activator (rt-PA) maintained for up to 24 hours could prevent reocclusion after early coronary patency had been established was evaluated in patients with acute myocardial infarction. The rt-PA studied was an investigational double chain rt-PA (Duteplase, Burroughs Wellcome Co.), administered according to body weight. Coronary patency was documented in 139 of 213 patients who had 90-minute angiograms recorded after an initial lytic dose of rt-PA. In these responders a further 90-minute infusion at one third the initial lytic dose was given before assignment to 1 of 4 maintenance dose rates (0.012, 0.024, 0.036, 0.048 MIU/kg/hour) which were continued for the subsequent 9 to 21 hours. The principal end point was the status of the infarct-related coronary artery 12 to 24 hours after the start of therapy, and before termination of rt-PA, in patients with initially patent vessels at 90 minutes. Of the 103 responders with repeat angiograms after a 9 to 21 hour maintenance infusion of rt-PA, a total of 17 (16.5%) patients reoccluded across all doses administered. There was no significant relationship between the maintenance dose rate and the incidence of reocclusion. However, there was strong association between total dose of rt-PA administered and the incidence (16%) of serious or life-threatening bleeding exclusive of surgery. Other factors associated with serious bleeding included low body weight, female gender, and total duration of rt-PA infusion. Reocclusion was independent of the 90-minute Thrombolysis in Myocardial Infarction trial perfusion grade and diameter of infarct vessel. Rethrombosis after establishment of early patency after rt-PA remains a significant problem that is unaffected by sustained rt-PA infusion in doses that can be tolerated.

Ontogenetic homologous sensitization to the antinociceptive action of quinpirole in rats

Repeated postnatal treatment of rats with the dopamine receptor agonist, quinpirole results in exaggeration of selected behaviors that are induced by quinpirole in adulthood. To determine whether the antinociceptive response to quinpirole could be similarly enhanced, rats were treated daily from birth with quinpirole HCl (3.0 mg/kg per day i.p. x 28 days) and their response time in the hot plate analgesia test was determined at 4 months. An acute dose of quinpirole HCl (100 or 1000 micrograms/kg i.p.) produced an analgesic response in the neonatally primed rats and in the vehicle controls. More significantly, the effect was substantially greater in the quinpirole-primed group at each of these two doses of quinpirole. This effect of quinpirole was fully attenuated in both groups by treatment with the dopamine receptor antagonist, spiperone HCl (0.30 mg/kg i.p., 1 h before quinpirole). The analgesic effect of morphine sulfate (6.0 mg/kg i.p.) was not greater in the quinpirole-primed group. These findings demonstrate that the ontogenetic sensitization of quinpirole receptors results in enhanced antinociceptive responses to quinpirole in adulthood. This animal model may be useful for studying the involvement of dopamine systems in algesia and analgesia.

Adaptation of cholinergic enteric neuromuscular transmission in diabetic rat small intestine

Representative longitudinal muscle strips (6 x 10 mm) from distal small intestine were obtained from rats after 1, 2, and 3 mo of streptozocin-induced diabetes. The strips were stretched to their optimum lengths and subjected to electrical field stimulation (1-ms pulse duration, 30-270 mA, 10 Hz) in the presence of Krebs solution and Krebs solution plus 10(-6) M atropine. Field stimulation produced atropine-sensitive and atropine-resistant contractions in all strips. After 1 mo, significant differences in the amplitudes of the atropine-sensitive contractions were found between the diabetic rats and nondiabetic controls. Insulin-treated diabetic rats showed contraction responses that were intermediate in amplitude. After 2 mo, the difference between the control and diabetic groups was less evident but still significant. After 3 mo, the previously noted difference in the atropine-sensitive contractions between the diabetic and control groups had resolved. No significant differences among the three groups were noted in the amplitudes of the atropine-resistant contractions. Field stimulation delivered at pulse durations of 50 ms in the presence of neural blockade with tetrodotoxin (5 x 10(-6) M) produced similar contraction amplitudes among the three groups at any respective time phase of the study. Dose-response studies of intestinal muscle after 3 mo of untreated diabetes showed normal tension development to both bethanechol chloride and physostigmine. These results indicate that streptozocin-induced diabetes is acutely associated with defective cholinergic neuromuscular transmission in the myenteric plexus of the distal small intestine. The abnormality is less evident after 2 mo of untreated diabetes and resolves spontaneously after 3 mo. Insulin treatment appears to accelerate this resolution.

Cardiovascular effects of pancuronium, vecuronium, and atracurium during induction of anesthesia with sufentanil and lorazepam for myocardial revascularization

The hemodynamic effects of three commonly used muscle relaxants, pancuronium, vecuronium, and atracurium were investigated during induction of anesthesia with sufentanil and lorazepam in patients undergoing coronary artery bypass surgery. Direct hemodynamic variables were recorded, and indirect parameters were calculated using standard formulae. Changes in heart rate differed with the three muscle relaxants. Pancuronium increased the heart rate whereas vecuronium and atracurium produced a decrease 5 minutes after induction (P less than 0.05). No differences were found in any other parameter during the study. A slow induction with sufentanil, lorazepam, and any of the three muscle relaxants was shown to minimize the hemodynamic changes.

Age-related changes in enteric neuromuscular transmission

Proximal and distal rat small intestine from 4-, 5- and 6-month-old rats were cut into strips measuring 6.0 X 10.0 mm. Longitudinal strips were cut along the oral-caudal axis of the intestine while circular strips were cut 90 degrees to that axis. The strips were stretched to their optimum lengths and subjected to electrical field stimulation (0.1-1.0 msec pulse duration, 30-270 mA, 1-26 Hz) in the presence of Krebs' solution and Krebs' solution plus 10(-6) M atropine. Field stimulation produced atropine-sensitive and atropine-resistant contractions in these tissues. Significant differences among the three groups were found in the amplitudes of atropine-sensitive contractions in strips from proximal longitudinal muscle. The 6-month-old animals showed the highest amplitude contractions and the 4-month-old the lowest, whereas the 5-month-old animals showed contractions that were intermediate in amplitude. No significant differences were noted among the atropine-resistant contractions. Field stimulation delivered at pulse durations of 5.0 and 50.0 msec in the presence of neural blockade with tetrodotoxin (5 X 10(-6) M) produced similar contraction amplitudes among the three groups. These results show that tension development produced by field stimulation of the proximal intestine increases significantly with age. The increases appear to be due to age-related differences in cholinergic neuromuscular transmission.

Immunopathological response of C57BL/6 and C3H/HeN mice to Aspergillus fumigatus antigens

C3H/HeN and C57BL/6 mice were exposed to culture filtrate (CF) and mycelial extracts (ME) of Aspergillus fumigatus (Af) intranasally. Animals received 6, 8 or 10 biweekly doses and were sacrificed 2 weeks after the last dose was administered. Specific antibodies against Af were detected in their sera by biotin-avidin-linked immunosorbent assay (BALISA). Antibodies against Af belonging to all isotypes showed an increase in both strains of mice. A progressive increase in IgG and IgA antibody isotypes against both CF and ME antigens was detected in C3H/HeN mice during the entire experimental period, whereas most antibody levels peaked after the 8th dose and remained steady or decreased slightly in the C57BL/6 strain. Lung lavage studies showed a relative decrease in the number of macrophages and an increase in the number of lymphocytes after the 6th and 8th instillation of Af antigens in both strains of mice. Histology of the lung demonstrated a progressive inflammatory reaction in C57BL/6 mice during the experimental period. On the other hand, the C3H/HeN mice showed a negligible inflammatory pulmonary reaction. The antibody responses and inflammatory changes detected in the lungs of mice exposed to Af antigens are comparable to allergic bronchopulmonary aspergillosis (ABPA) in humans and hence this model will be of value in understanding the disease mechanism in ABPA and related diseases.

Detection of circulating Aspergillus fumigatus antigen in bone marrow transplant patients

A competitive inhibition enzyme-linked immunosorbent assay able to detect Aspergillus fumigatus antigenemia at a concentration sensitivity of 68 ng/ml was developed. To test the utility of this assay in the diagnosis of invasive aspergillosis, serum was collected twice weekly from all patients in a bone marrow transplant unit. When analyzed retrospectively, A. fumigatus antigen was detected in three of four patients (75%) with proved invasive aspergillosis at autopsy or biopsy and in a solitary patient with suspected but not proved invasive aspergillosis. No antigen was detected in 17 bone marrow transplant unit patients without proved or suspected invasive aspergillosis or in 16 healthy control subjects. Detection of antigen rose with an increasing number of samples tested. A. fumigatus antibody levels were not helpful in the diagnosis of invasive aspergillosis, although in a few patients antibody levels decreased just before death.

Principles in injury control: lessons to be learned from child safety seats

The effort to increase the use of child safety seats (CSS) over the last decade has been an outstanding success in the field of childhood injury control. This article describes that effort and discusses lessons which can be learned and applied to other injury control problems. These include choosing a specific important problem and addressing it with a particular solution, developing a critical mass of community awareness through broad-based grass roots support, legislation, efforts of primary care physicians, and eventual institutionalization of the program.