Endothelial cells: role in infection and inflammation

Noise, Air, and Heavy Metal Pollution as Risk Factors for Endothelial Dysfunction

During the last two decades, large epidemiological studies have shown that the physical environment, including noise, air pollution or heavy metals, have a considerable impact on human health. It is known that the most common cardiovascular risk factors are all associated with endothelial dysfunction. Vascular tone, circulation of blood cells, inflammation, and platelet activity are some of the most essential functions regulated by the endothelium that suffer negative effects as a consequence of environmental pollution, causing endothelial dysfunction. In this review, we delineate the impact of environmental risk factors in connection to endothelial function. On a mechanistic level, a significant number of studies suggest the involvement of endothelial dysfunction to fundamentally drive the adverse endothelium health effects of the different pollutants. We focus on well-established studies that demonstrate the negative effects on the endothelium, with a focus on air, noise, and heavy metal pollution. This in-depth review on endothelial dysfunction as a consequence of the physical environment aims to contribute to the associated research needs by evaluating current findings from human and animal studies. From a public health perspective, these findings may also help to reinforce efforts promoting the research for adequate promising biomarkers for cardiovascular diseases since endothelial function is considered a hallmark of environmental stressor health effects.

Current Status of ABO-incompatible Liver Transplantation

By 2014, strategies to prevent antibody-mediated rejection (AMR) after ABO-incompatible (ABO-I) living donor liver transplantation (LDLT) were established in Japan and expanded primarily to Asia, where LDLT is now the predominant form of LT owing to the scarcity of brain-dead donors. A desensitization protocol consisting of rituximab (375 mg/m 2 ), plasma pheresis, tacrolimus, and mycophenolate mofetil before LDLT, followed by standard immunosuppression, is currently the best option in terms of safety and efficacy. Rituximab administration is now known not to increase the risk of hepatocellular carcinoma recurrence, and the feasibility of rituximab for LDLT for acute liver failure and the need for desensitization before LDLT in children older than 1 y have been documented. Strategies are needed to distinguish patients at high risk of AMR from those at low risk and to adjust immunosuppression to prevent both AMR and infection. Specific single-nucleotide polymorphisms in genes encoding Fcγ receptors affecting the cytotoxicity of rituximab on B cells could be useful for adjusting immunosuppression levels to decrease infectious complications. Immunological accommodation after ABO-I transplantation could be provided by immune factors in both the grafts and recipients.

Role of Acute Thrombosis in Coronavirus Disease 2019

Patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are prone to venous, cerebrovascular, and coronary thrombi, particularly those with severe coronavirus disease 2019 (COVID-19). The pathogenesis is multifactorial and likely involves proinflammatory cascades, development of coagulopathy, and neutrophil extracellular traps, although further investigations are needed. Elevated levels of D-dimers are common in patients with COVID-19 and cannot be used in isolation to predict venous thromboembolism in people with SARS-CoV-2. If given early in hospital admission, therapeutic-dose heparin improves clinical outcomes in patients with moderate COVID-19. To date, antithrombotics have not improved outcomes in patients with severe COVID-19.

Thromboplasminflammation in COVID-19 Coagulopathy: Three Viewpoints for Diagnostic and Therapeutic Strategies

Thromboplasminflammation in coronavirus disease 2019 (COVID-19) coagulopathy consists of angiotensin II (Ang II)-induced coagulopathy, activated factor XII (FXIIa)- and kallikrein, kinin system-enhanced fibrinolysis, and disseminated intravascular coagulation (DIC). All three conditions induce systemic inflammation via each pathomechanism-developed production of inflammatory cytokines. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) downregulates angiotensin-converting enzyme 2, leading to an increase in Ang II levels. Ang II-induced coagulopathy comprising platelet activation, thrombin generation, plasminogen activator inhibitor-1 expression and endothelial injury causes thrombosis via the angiotensin II type 1 receptor. SARS-CoV-2 RNA and neutrophil extracellular trap (NET) DNA activate FXII, resulting in plasmin generation through FXIIa- and kallikrein-mediated plasminogen conversion to plasmin and bradykinin-induced tissue-type plasminogen activator release from the endothelium via the kinin B2 receptor. NETs induce immunothrombosis at the site of infection (lungs), through histone- and DNA-mediated thrombin generation, insufficient anticoagulation control, and inhibition of fibrinolysis. However, if the infection is sufficiently severe, immunothrombosis disseminates into the systemic circulation, and DIC, which is associated with the endothelial injury, occurs. Inflammation, and serine protease networks of coagulation and fibrinolysis, militate each other through complement pathways, which exacerbates three pathologies of COVID-19 coagulopathy. COVID-19 coagulopathy causes microvascular thrombosis and bleeding, resulting in multiple organ dysfunction and death in critically ill patients. Treatment targets for improving the prognosis of COVID-19 coagulopathy include thrombin, plasmin, and inflammation, and SARS-CoV-2 infection. Several drugs are candidates for controlling these conditions; however, further advances are required to establish robust treatments based on a clear understanding of molecular mechanisms of COVID-19 coagulopathy.

Chemical Inhibitors of Dynamin Exert Differential Effects in VEGF Signaling

VEGFR2 is the main receptor and mediator of the vasculogenic and angiogenic activity of VEGF. Activated VEGFR2 internalizes through clathrin-mediated endocytosis and macropinocytosis. As dynamin is a key regulator of the clathrin pathway, chemical inhibitors of dynamin are commonly used to assess the role of the clathrin route in receptor signaling. However, drugs may also exert off-target effects. Here, we compare the effects of three dynamin inhibitors, dynasore, dyngo 4a and dynole, on VEGFR2 internalization and signaling. Although these drugs consistently inhibit clathrin-mediated endocytosis of both transferrin (a typical cargo of this route) and VEGFR2, surprisingly, they exert contradictory effects in receptor signaling. Thus, while dynasore has no effect on phosphorylation of VEGFR2, the other two drugs are strong inhibitors. Furthermore, although dyngo does not interfere with phosphorylation of Akt, dynasore and dynole have a strong inhibitory effect. These inconsistent effects suggest that the above dynamin blockers, besides inhibiting dynamin-dependent endocytosis of VEGFR2, exert additional inhibitory effects on signaling that are independent of endocytosis; i.e., they are due to off-target effects. Using a recently developed protocol, we comparatively validate the specificity of two endocytic inhibitors, dynasore and EIPA. Our findings highlight the importance of assessing whether the effect of an endocytic drug on signaling is specifically due to its interference with endocytosis or due to off-targets.

Coronary thrombosis in a young male with COVID-19

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COVID-19 can present with a broad clinical spectrum of cardiac manifestations.

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The procoagulant state in COVID-19 can independently increase the risk of coronary thrombosis in otherwise healthy patients.

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COVID-19 patients who develop typical chest pain should be investigated for acute myocardial infarction.

COVID-19 predominantly presents with respiratory symptoms, but other presentations are reported, including cardiac manifestations and thromboembolism. We present a healthy young gentleman with COVID-19 pneumonia, who developed acute ST-segment elevation myocardial infarction (STEMI) due to coronary thrombosis. He was managed successfully by primary percutaneous coronary intervention (PPCI).

Rab46 integrates Ca2+ and histamine signaling to regulate selective cargo release from Weibel-Palade bodies

It is unclear how a plethora of stimuli evoke differential cargo secretion from endothelial cells to produce stimulus-appropriate responses. Miteva et al. show that Rab46 integrates histamine signaling and Ca²⁺ signals to regulate selective cargo release from Weibel-Palade bodies.

Endothelial cells selectively release cargo stored in Weibel-Palade bodies (WPBs) to regulate vascular function, but the underlying mechanisms are poorly understood. Here we show that histamine evokes the release of the proinflammatory ligand, P-selectin, while diverting WPBs carrying non-inflammatory cargo away from the plasma membrane to the microtubule organizing center. This differential trafficking is dependent on Rab46 (CRACR2A), a newly identified Ca²⁺-sensing GTPase, which localizes to a subset of P-selectin–negative WPBs. After acute stimulation of the H₁ receptor, GTP-bound Rab46 evokes dynein-dependent retrograde transport of a subset of WPBs along microtubules. Upon continued histamine stimulation, Rab46 senses localized elevations of intracellular calcium and evokes dispersal of microtubule organizing center–clustered WPBs. These data demonstrate for the first time that a Rab GTPase, Rab46, integrates G protein and Ca²⁺ signals to couple on-demand histamine signals to selective WPB trafficking.

Neutrophil elastase inhibition effectively rescued angiopoietin-1 decrease and inhibits glial scar after spinal cord injury

After spinal cord injury (SCI), neutrophil elastase (NE) released at injury site disrupts vascular endothelium integrity and stabilization. Angiopoietins (ANGPTs) are vascular growth factors that play an important role in vascular stabilization. We hypothesized that neutrophil elastase is one of the key determinants of vascular endothelium disruption/destabilization and affects angiopoietins expression after spinal cord injury. To test this, tubule formation and angiopoietins expression were assessed in endothelial cells exposed to different concentrations of recombinant neutropil elastase. Then, the expression of angiopoietin-1, angiopoietin-2, and neutrophil elastase was determined at 3 h and at 1, 3, 5, 7, 14, 21, and 28 days in a clinically relevant model of moderate compression (35 g for 5 min at T10) spinal cord injury. A dichotomy between the levels of angiopoietin-1 and angiopoietin-2 was observed; thus, we utilized a specific neutrophil elastase inhibitor (sivelestat sodium; 30 mg/kg, i.p., b.i.d.) after spinal cord injury. The expression levels of neutropil elastase and angiopoietin-2 increased, and that of angiopoietin-1 decreased after spinal cord injury in rats. The sivelestat regimen, optimized via a pharmacokinetics study, had potent effects on vascular stabilization by upregulating angiopoietin-1 via the AKT pathway and preventing tight junction protein degradation. Moreover, sivelestat attenuated the levels of inflammatory cytokines and chemokines after spinal cord injury and hence subsequently alleviated secondary damage observed as a reduction in glial scar formation and the promotion of blood vessel formation and stabilization. As a result, hindlimb locomotor function significantly recovered in the sivelestat-treated animals as determined by the Basso, Beattie, and Bresnahan scale and footprint analyses. Furthermore, sivelestat treatment attenuated neuropathic pain as assessed by responses to von Frey filaments after spinal cord injury. Thus, our result suggests that inhibiting neutropil elastase by administration of sivelestat is a promising therapeutic strategy to inhibit glial scar and promote functional recovery by upregulating angiopoietin-1 after spinal cord injury.

Mercury Exposure and Endothelial Dysfunction: An Interplay Between Nitric Oxide and Oxidative Stress

Vascular endothelium plays a vital role in the organization and function of the blood vessel and maintains homeostasis of the circulatory system and normal arterial function. Functional disruption of the endothelium is recognized as the beginning event that triggers the development of consequent cardiovascular disease (CVD) including atherosclerosis and coronary heart disease. There is a growing data associating mercury exposure with endothelial dysfunction and higher risk of CVD. This review explores and evaluates the impact of mercury exposure on CVD and endothelial function, highlighting the interplay of nitric oxide and oxidative stress.

Circulating endothelial mediators in human pancreatitis-associated lung injury

OBJECTIVES

To investigate the role of endothelial cell mediators, E-selectin (ES), intercellular adhesion molecule-1 (ICAM-1), tissue factor (TF), and von Willebrand factor (vWF), in the early phase of severe acute pancreatitis (SAP) complicated with respiratory failure [pancreatitis-associated lung injury (PALI)].

PATIENTS AND METHODS

This study included 30 patients with SAP and 39 patients with PALI. Blood samples were taken from SAP and PALI patients on presenting to the hospital (day 1), and days 2, 3, 5, and 10. The relationship between blood concentrations of the studied endothelial mediators and lung function tests was analyzed.

RESULTS

PALI patients had significantly higher ES, ICAM-1, TF, and vWF blood levels than those with SAP as early as at admission and throughout the period studied. We found the highest concentration of ES on the second day, ICAM-1 and TF at admission, and vWF level on the fifth day. There were adverse correlations between ES, ICAM-1, TF, vWF concentrations, and the index of oxygenation--PaO2/FiO2 ratio (Rs=-0.385, Rs=-0.523, Rs=-0.505, Rs=-0.408, P<0.001, respectively). The most accurate prediction of PALI was provided by ICAM-1 and TF levels on the day of admission [areas under curve (AUCs): ES, 0.704; ICAM-1, 0.787; TF, 0.757; and vWF, 0.686].

CONCLUSION

Endothelium-related mediators ES, ICAM-1, TF, and vWF appear to participate in pancreatitis-associated lung injury. In SAP, the measurement of endothelial mediator levels (especially ICAM-1 and TF) may be used as an early prognostic indicator that would predict the development of respiratory failure and to monitor the severity of lung dysfunction.

Combination therapy with sivelestat and recombinant human soluble thrombomodulin for ARDS and DIC patients

BACKGROUND

Neutrophil elastase, alveolar thrombin generation, and fibrin deposition play crucial roles in the development of acute respiratory distress syndrome (ARDS) and disseminated intravascular coagulation (DIC). However, the usefulness of combination therapy with a selective neutrophil elastase inhibitor, sivelestat, and recombinant human soluble thrombomodulin (rhTM) for patients with ARDS and DIC remains unknown.

METHODS

We conducted a retrospective data analysis of 142 ARDS patients with DIC to assess the effects of sivelestat combined with rhTM. Patients were divided into four groups: control (no sivelestat or rhTM treatment), sivelestat treatment alone, rhTM treatment alone, and combined treatment with sivelestat and rhTM. A Cox proportional hazard model was used to assess subject mortality rates. The efficacy of these drugs was evaluated based on survival rate, number of ventilator-free days, and change in PaO2/FIO2 (P/F) ratios and DIC scores before and at 7 days after a diagnosis of ARDS with DIC.

RESULTS

Multivariate analysis showed that patient age, combination therapy, gas exchange, organ failure, cause, associated disease score, and serum C-reactive protein levels were predictors of mortality for patients with ARDS and DIC. As compared with untreated controls, combination therapy significantly improved the 60-day survival rate of patients with ARDS and DIC. There were significantly more ventilator-free days for those who received combination therapy than for untreated controls. P/F ratios and DIC scores were significantly improved with sivelestat alone, rhTM alone, or their combination as compared with untreated controls.

CONCLUSION

Our results suggest that combined treatment with sivelestat and rhTM has beneficial effects on survival and the respiratory and DIC status of patients with ARDS and DIC.

Serum adhesion molecules as outcome predictors in adult severe sepsis patients requiring mechanical ventilation in the emergency department

BACKGROUND AND AIM

Serum adhesion molecules play a pivotal role in the pathogenesis of sepsis syndrome. This study aimed to evaluate the prognostic value of serum adhesion molecules in patients with severe sepsis and mechanical ventilation (MV) at the emergency department.

METHODS

Eighty-seven consecutive patients with severe sepsis, including 35 with MV, were evaluated. Serum samples were collected for analysis of serum adhesion molecules. The patients' clinical and laboratory data on admission were also recorded.

RESULTS

The maximum 24-h APACHE II and 24-h SOFA scores were significantly higher in the severe sepsis patients requiring MV than in patients without MV (p=0.02 and p<0.001). Mortality rate was significantly higher in severe sepsis patients requiring MV than in patients without MV (40% [14/35] vs. 9.6% [5/52], p=0.001). Both VCAM-1 level (p=0.03) and lactate concentration (p=0.04) on admission had significant differences between survivors and non-survivors in patients requiring MV. In the logistic regression model, only VCAM-1 level (p=0.049) was independently predictive of mortality. By correlation analysis, lactate concentration significantly correlated with the mean VCAM-1 level on admission (γ=0.484, p=0.004). The area under the ROC curve for VCAM-1 level was 0.747 (p=0.02, 95% CI: 0.576-0.918). The cut-off value of VCAM-1 level for predicting hospital mortality in severe sepsis patients receiving MV was 1870ng/mL, with 77% sensitivity and 71% specificity; then the likelihood ratio equals 2.7.

CONCLUSIONS

In this study, VCAM-1 level is a more powerful outcome predictor of hospital mortality in severe sepsis patients requiring MV than lactate concentration and other conventional parameters on admission. This suggests that increased plasma VCAM-1 concentration may be useful in identifying who are at risk of hospital mortality among severely septic patients requiring MV.

Homocysteine in dogs with systemic inflammatory response syndrome

OBJECTIVES

To compare serum concentrations of homocysteine in healthy dogs and those fitting the criteria for systemic inflammatory response syndrome and to compare these values to commonly measured B-vitamins.

METHODS

Study dogs were classified into non-infectious systemic inflammatory response syndrome or sepsis groups and blood was drawn on Day 1 of the patient's hospitalisation for measurement of serum homocysteine, folate and cobalamin concentrations. Homocysteine concentration was measured in 51 clinically healthy dogs to serve as the control group.

RESULTS

A statistically significant difference was found between the homocysteine concentrations of the healthy group when compared to non-infectious systemic inflammatory response syndrome and sepsis groups. Homocysteine values were not correlated with folate, cobalamin or APPLEfast severity scores. Homocysteine concentrations were significantly lower in sick dogs when compared to the control group, which is dissimilar to the human population.

CLINICAL SIGNIFICANCE

The clinical significance of homocysteine changes in critically ill dogs is currently unknown.

Usefulness of a selective neutrophil elastase inhibitor, sivelestat, in acute lung injury patients with sepsis

BACKGROUND

Neutrophil elastase plays a crucial role in the development of acute lung injury (ALI) in patients with systemic inflammatory response syndrome (SIRS). The clinical efficacy of the neutrophil elastase inhibitor, sivelestat, for patients with ALI associated with SIRS has not been convincingly demonstrated. The aim of this study was to determine if there are clinical features of patients with this condition that affect the efficacy of sivelestat.

METHODS

This was a retrospective study of 110 ALI patients with SIRS. Clinical information, including the etiology of ALI, the number of organs failing, scoring systems for assessing the severity of illness, and laboratory data, was collected at the time of diagnosis. Information on the number of ventilator-free days (VFDs) and changes in PaO(2)/F(I)O(2) (ΔP/F) before and 7 days after the time of ALI diagnosis was also collected. The effect of sivelestat on ALI patients was also examined based on whether they had sepsis and whether their initial serum procalcitonin level was ≥0.5 ng/mL.

RESULTS

There were 70 patients who were treated with sivelestat and 40 control patients. VFDs and ΔP/F were significantly higher in the treated patients than in the control patients. However, there was no significant difference in the patient survival rate between the two groups. Sivelestat was more effective in ALI patients with a PaO(2)/F(I)O(2) ratio ≥ 140 mmHg or sepsis. Sivelestat significantly prolonged survival and led to higher VFDs and increased ΔP/F in septic patients and patients with initial serum procalcitonin levels ≥ 0.5 ng/mL.

CONCLUSION

The results may facilitate a future randomized controlled trial to determine whether sivelestat is beneficial for ALI patients with sepsis.

Use of a special bioreactor for the cultivation of a new flexible polyurethane scaffold for aortic valve tissue engineering

Background

Tissue engineering represents a promising new method for treating heart valve diseases. The aim of this study was evaluate the importance of conditioning procedures of tissue engineered polyurethane heart valve prostheses by the comparison of static and dynamic cultivation methods.

Methods

Human vascular endothelial cells (ECs) and fibroblasts (FBs) were obtained from saphenous vein segments. Polyurethane scaffolds (n = 10) were primarily seeded with FBs and subsequently with ECs, followed by different cultivation methods of cell layers (A: static, B: dynamic). Group A was statically cultivated for 6 days. Group B was exposed to low flow conditions (t₁= 3 days at 750 ml/min, t₂= 2 days at 1100 ml/min) in a newly developed conditioning bioreactor. Samples were taken after static and dynamic cultivation and were analyzed by scanning electron microscopy (SEM), immunohistochemistry (IHC), and real time polymerase chain reaction (RT-PCR).

Results

SEM results showed a high density of adherent cells on the surface valves from both groups. However, better cell distribution and cell behavior was detected in Group B. IHC staining against CD31 and TE-7 revealed a positive reaction in both groups. Higher expression of extracellular matrix (ICAM, Collagen IV) was observed in Group B. RT- PCR demonstrated a higher expression of inflammatory Cytokines in Group B.

Conclusion

While conventional cultivation method can be used for the development of tissue engineered heart valves. Better results can be obtained by performing a conditioning step that may improve the tolerance of cells to shear stress. The novel pulsatile bioreactor offers an adequate tool for in vitro improvement of mechanical properties of tissue engineered cardiovascular prostheses.

In vivo and in vitro inhibitory effects of a traditional Chinese formulation on LPS-stimulated leukocyte-endothelial cell adhesion and VCAM-1 gene expression

AIM OF THE STUDY

A traditional Chinese formulation Huang-Lian-Jie-Du-Tang (HLJDT) exerts anti-inflammatory effects. The present study aimed to investigate the effect of HLJDT on the LPS-stimulated leukocyte-endothelial cell adhesion and VCAM-1 gene expression both in vivo and in vitro.

MATERIALS AND METHODS

HLJDT was extracted from rhizoma coptidis, radix scutellariae, cortex phellodendri and fructus gardeniae in a weight rario of 1:1:1:1. In vivo leukocyte-endothelial cell adhesion was observed in rat lung after LPS stimulation (5mg/kg, i.p.) with or without HLJDT (350 or 700mg/kg, i.g.) pretreatment. The protein expression of vascular cell adhesion molecule 1 (VCAM-1) was analyzed by immunohistochemical method. In vitro leukocyte-endothelial cell adhesion was performed by examining the adhesion of THP-1cells to LPS-stimulated human vascular endothelial cells with or without HLJDT pretreatment. The VCAM-1 expression at the RNA and protein levels was investigated by RT-PCR and western blot analysis, respectively. The activation of NF-κB was examined by the nuclear translocation of NF-κB by immunocytochemical method.

RESULTS

In vivo, HLJDT dose-dependently reduced the number of leukocytes adhered to endothelium and VCAM-1 protein expression in lung venules of LPS-challenged rats. In vitro, HLJDT dose-dependently decreased the number of THP-1cells adhered to LPS-stimulated endothelial cells and the expression of VCAM-1 both at the RNA and protein levels. The LPS-induced nuclear translocation of NF-kappa B in endothelial cells was also dose-dependently inhibited by HLJDT.

CONCLUSIONS

The present study demonstrated an additional mechanism underlying the anti-inflmmatory effect of HLJDT by inhibiting the leukocyte-endothelial cell adhesion and VCAM-1 gene expression. The inhibition of NF-kappa B activation by HLJDT might suggest a profound anti-inflammatory consequences.

Bacterial lipoprotein TLR2 agonists broadly modulate endothelial function and coagulation pathways in vitro and in vivo

TLR2 activation induces cellular and organ inflammation and affects lung function. Because deranged endothelial function and coagulation pathways contribute to sepsis-induced organ failure, we studied the effects of bacterial lipoprotein TLR2 agonists, including peptidoglycan-associated lipoprotein, Pam3Cys, and murein lipoprotein, on endothelial function and coagulation pathways in vitro and in vivo. TLR2 agonist treatment induced diverse human endothelial cells to produce IL-6 and IL-8 and to express E-selectin on their surface, including HUVEC, human lung microvascular endothelial cells, and human coronary artery endothelial cells. Treatment of HUVEC with TLR2 agonists caused increased monolayer permeability and had multiple coagulation effects, including increased production of plasminogen activator inhibitor-1 (PAI-1) and tissue factor, as well as decreased production of tissue plasminogen activator and tissue factor pathway inhibitor. TLR2 agonist treatment also increased HUVEC expression of TLR2 itself. Peptidoglycan-associated lipoprotein induced IL-6 production by endothelial cells from wild-type mice but not from TLR2 knockout mice, indicating TLR2 specificity. Mice were challenged with TLR2 agonists, and lungs and plasmas were assessed for markers of leukocyte trafficking and coagulopathy. Wild-type mice, but not TLR2 mice, that were challenged i.v. with TLR2 agonists had increased lung levels of myeloperoxidase and mRNAs for E-selectin, P-selectin, and MCP-1, and they had increased plasma PAI-1 and E-selectin levels. Intratracheally administered TLR2 agonist caused increased lung fibrin levels. These studies show that TLR2 activation by bacterial lipoproteins broadly affects endothelial function and coagulation pathways, suggesting that TLR2 activation contributes in multiple ways to endothelial activation, coagulopathy, and vascular leakage in sepsis.

Sivelestat (selective neutrophil elastase inhibitor) improves the mortality rate of sepsis associated with both acute respiratory distress syndrome and disseminated intravascular coagulation patients

Neutrophil elastase plays an important role in the development of acute respiratory distress syndrome (ARDS) and disseminated intravascular coagulation (DIC) in sepsis. Sivelestat is a selective neutrophil elastase inhibitor. It is possible that sivelestat improves the outcome of septic patients associated with ARDS and DIC. A retrospective data analysis of septic patients associated with ARDS and DIC was conducted to investigate the effects of sivelestat. Observational period was 5 days after admission to intensive care unit (ICU). The study included 167 septic patients associated with ARDS and DIC. Control group included 133 patients without sivelestat, and sivelestat group included 34 patients started to deadministered sivelestat on the admission to ICU. The lung injury scores and Pa(O2)/Fl(O2) ratio of the sivelestat group were significantly more severe than those of the control group from days 1 to 4. On day 5, the lung injury score and Pa(O2)/Fl(O2) ratio of the sivelestat group improved to the same levels of those of the control group. The DIC score of sivelestat group improved on day 3 in comparison to day 1, and those of control group remained unchanged until day 4. The length of ICU stay of the sivelestat group was significantly shorter than that of the control group. A stepwise multiple logistic-regression analysis showed the sivelestat administration to be an independent predictor of survival of the septic patients associated with both ARDS and DIC. The length of ICU stay of the sivelestat group was significantly shorter than that of the control group. In addition, sivelestat administration was found to be an independent predictor of survival of those patients.

A murine model of sepsis following smoke inhalation injury

Acute lung injury (ALI) by smoke inhalation with subsequent pneumonia and sepsis represents a major cause of morbidity and mortality in burn patients. The aim of the present study was to develop a murine model of ALI and sepsis to enhance the knowledge of mechanistic aspects and pathophysiological changes in patients with these injuries. In deeply anesthetized female C57BL/6 mice, injury was induced by four sets of cotton smoke using an inhalation chamber. Afterward, live Pseudomonas aeruginosa (3.2x10(7) colony-forming units) was administered intranasally. The indicated dose of bacteria was determined based on the results of a dose-response study (n=47). The following study groups were monitored for survival over 96h: (1) sham injury group, (2) only smoke inhalation group, (3) only bacteria group, and (4) smoke inhalation plus bacteria group. Each group included 10 mice. The survival rates were 100%, 90%, 30%, and 10%, respectively. The double hit injury was associated with excessive releases of pro-inflammatory cytokines in the plasma, and enhanced neutrophil accumulation, increased lipid peroxidation, and excessive formation of reactive nitrogen species in the lung. In mice receiving only smoke inhalation injury, no systemic cytokine release and increased lung tissue lipid peroxidation were observed. However, smoke alone significantly increased neutrophil accumulation and formation of reactive nitrogen species in lung tissue. In conclusion, bacterial pneumonia is predominantly responsible for mortality and morbidity in this novel murine model of smoke inhalation and pulmonary sepsis. Reactive oxygen and nitrogen species mediate the severity of lung injury.

Increased endothelial monocyte adhesiveness is related to clinical outcomes in chronic heart failure

BACKGROUND

Vascular inflammation and endothelial dysfunction are evident in patients with chronic heart failure (CHF). We hypothesized that circulating peripheral blood mononuclear cells (PBMCs) may be activated and the resultant increased endothelial monocyte adhesion may be functionally and pathophysiologically relevant in CHF. In the present study, we investigated the clinical significance of the activity of PBMCs in patients with CHF.

METHODS

PBMCs were isolated from 34 CHF patients, from 10 healthy volunteers (normal control group) and from 17 patients admitted for investigation of suspected coronary artery disease (disease control group). In each patient, the adhesiveness of PBMCs to cultured human aortic endothelial cells (HAECs) with or without tumor necrosis factor-alpha (TNF-alpha) stimulation was determined. Major adverse cardiac events (death, heart transplantation or hospitalization with worsening heart failure) were determined in the 34 CHF patients during a median follow-up period of 182 days.

RESULTS

Compared with those from both control groups and from mild CHF patients, PBMCs isolated from severe CHF patients adhered more to the HAECs. The endothelial adhesiveness of PBMCs correlated positively with the circulating levels of CAMs and can supply prognostic information in CHF patients. The difference between event-free curves based on the median levels of endothelial-PBMC adhesion was significant (log rank test, p=0.0139).

CONCLUSIONS

Endothelial adhesiveness of PBMCs is increased and correlated to clinical outcomes, and may be pathophysiologically relevant to the progression of CHF.

An alternative pathway for fibrinolysis is activated in patients who have undergone cardiopulmonary bypass surgery and major abdominal surgery

INTRODUCTION

We conducted this prospective study in order to investigate the hypotheses that an alternative pathway for fibrinolysis is activated in patients who have undergone cardiopulmonary bypass (CPB) surgery and major abdominal surgery and that the levels of fibrin degradation products digested by polymorphonuclear neutrophil elastase (elastase-XDP) and the D-dimer increase in the patients' plasma.

MATERIALS AND METHODS

We studied a total of 77 patients who were scheduled to undergo either CPB surgery (36 patients) or major abdominal surgery (41 patients) and then measured the elastase-XDP and D-dimer levels at several time points both during and after the surgeries. The CPB surgery was divided into surgery for aortic dissection (AD) and cardiac surgery. The major abdominal surgery consists of hepatic resection and esophagectomy.

RESULTS

The elastase-XDP and D-dimer levels significantly increased in the patients who underwent both CPB surgery and major abdominal surgery. The elastase-XDP levels in AD surgery showed highest values at the end of the CPB, while the levels in the other surgeries reached their peak on the day after the surgery. Statistical difference was seen in the levels of elastase-XDP among the three subgroups undergoing a hepatic resection. While we found significant correlations between the levels of elastase-XDP and D-dimer in patients undergoing CPB surgery and a subsegmentectomy of a cirrhotic liver, the correlation coefficients were markedly low in comparison to those of the other surgeries.

CONCLUSIONS

Our findings demonstrated that the elastase-mediated pathway of fibrinolysis is activated to varying degrees depending on the surgery performed. Variations in the correlation coefficients between the levels of elastase-XDP and D-dimer may suggest that elastase-mediated fibrinolysis play a different role from the physiological fibrinolysis mediated by plasmin.

Experimental Sepsis: Characteristics of Activated Macrophages and Apoptotic Cells in the Rat Spleen

Sepsis, being characterized by massive translocation of bacteria into tissues, induces the suppression of the function of both leukocytes and macrophages. The aim of the study was to count activated macrophages (AMs) and apoptotic (Ao) cells in the rat spleen during the period of experimental sepsis and to clarify the associations of these parameters with each other and with leukocyte migration and bacterial translocation into different organs. The Wistar rats were intraperitoneally inoculated with Escherichia coli (E. coli) and were sacrificed after 2, 6, 24, 48, and 120 h. Bacteria and leukocytes in tissues were specifically stained. AMs were identified by immunohistological staining and Ao cells by the TUNEL assay. The high counts of E. coli at 6 h were strongly associated with a low level of the total counts of leukocytes, accompanied by the high translocation of microbes into tissues. In the spleen, lymphocytes, macrophages, and neutrophils with pyknotic nuclei were identified. The count of AMs was highest at 24 h after the inoculation with E. coli; at the same time the Ao cell count began to rise and achieved the highest level 24 h later. Our investigation indicates that the molecular peculiarities of macrophages and their responses to the inflammation process are tissue-specific. In the spleen the activation process involving hematopoietic cells and macrophages was remarkable at the late stage of sepsis, characterized by a high count of Ao cells.

Adhesion molecules in pediatric intensive care patients with organ dysfunction syndrome

Objective

To determine serum concentrations of the soluble forms of vascular cell adhesion molecule 1 (VCAM-1), intracellular adhesion molecule 1 (ICAM-1), and E-selectin in ventilated neonatal and pediatric intensive care patients with varying severity of multiorgan dysfunction syndrome (MODS) with or without infection-triggered organ failure.

Design and setting

Prospective pilot study, a level III neonatal and pediatric intensive care unit at a University children's Hospital.

Patients

We studied 22 ventilated pediatric (n = 15) and neonatal (n = 7) intensive care patients (aged 3 days–16 years). Inclusion criteria were mechanical ventilation and signs of at least one additional organ dysfunction (cardiovascular, respiratory, neurological, hematological, or renal).

Measurements and results

Serum concentrations of the adhesion molecules were analyzed on the day of maximum organ dysfunction score and were quantitated by a sandwich ELISA technique. The overall mortality rate was 36% (8/22). Dysfunction of three or more organ systems was defined as MODS and was associated with a significant increase in VCAM-1 serum levels relative to dysfunction of three or fewer organ systems [median 1239 ng/ml (IQR 928–1615) vs. 766 ng/ml (644–915)]. A significant difference in E-selectin serum levels was found between organ failure of infectious (median 131 ng/ml, IQR 112–146) and noninfectious origin (68 ng/ml 49–105).

Conclusions

Determination of adhesion molecules in pediatric intensive care patients raises the possibility of more specific pathophysiological understanding. E-selectin showed significantly different serum levels between infectious and noninfectious causes of organ failure.

Endothelial dysfunction and decreased vascular responsiveness in the anterior cruciate ligament-deficient model of osteoarthritis

Chronic inflammation associated with osteoarthritis (OA) may alter normal vascular responses and contribute to joint degradation. Vascular responses to vasoactive mediators were evaluated in the medial collateral ligament (MCL) of the anterior cruciate ligament (ACL)-deficient knee. Chronic joint instability and progressive OA were induced in rabbit knees by surgical transection of the ACL. Under halothane anesthesia, laser speckle perfusion imaging (LSPI) was used to measure MCL blood flow in unoperated control (n = 12) and 6-wk ACL-transected knees (n = 12). ACh, bradykinin, histamine, substance P (SP), and prostaglandin E(2) (PGE(2)) were applied to the MCL vasculature in topical boluses of 100 microl (dose range 10(-14) to 10(-8) mol). In normal joints, ACh, bradykinin, histamine, and PGE(2) evoked a dilatory response. Substance P caused a biphasic response that was dilatory from 10(-14) to 10(-11) mol and constricting at higher doses. In ACL-deficient knees, ACh, bradykinin, histamine, and SP decreased perfusion, whereas PGE(2) had a biphasic response that decreased perfusion at 10(-14) to 10(-11) mol and was dilatory at higher concentrations. Sodium nitroprusside increased perfusion in resting and phenylephrine-precontracted vessels with no significant differences between ACL-transected and control knees. Femoral artery occlusion and release increased perfusion by 74.3 +/- 11.1% in control knees but only by 25.8 +/- 4.4% in ACL-deficient knees. The altered responsiveness of the MCL vasculature to these inflammatory mediators may indicate endothelial dysfunction in the MCL, which may contribute to the progression and severity of OA and to the adaptation of the joint in an altered mechanical environment.

Porcine Endothelial Cells and Iliac Arteries Transduced with AdenoIL-4 Are Intrinsically Protected, through Akt Activation, against Immediate Injury Caused by Human Complement

Vascular endothelial cells (ECs) can be injured in a variety of pathologic processes that involve activated complement. We reported previously that porcine ECs incubated with exogenous IL-4 or IL-13 are protected from cytotoxicity by human complement and also from apoptosis by TNF-alpha. The resistance to complement consists of an intrinsic mechanism that is lost a few days after cytokine removal. In our current study, we investigated whether transfer of the IL-4 gene into porcine ECs in vitro and into porcine vascular tissues in vivo would induce efficient and durable protection from human complement. We found that ECs transduced with adenoIL-4 or adenoIL-13 exhibited continuous production of the cytokine and prolonged protection from complement-mediated killing. IL-4 also protected ECs from activation: ECs incubated with IL-4 did not develop cell retraction and intercellular gaps upon stimulation with sublytic complement. The endothelium and subendothelium of pig iliac arteries that were transduced with the IL-4 gene were effectively protected from complement-dependent immediate injury after perfusion with human blood. However, after similar perfusion, the endothelium was immediately lost from arteries that were transduced with a control adenovirus. The protection was not due to up-regulation of the complement regulators decay accelerating factor, membrane cofactor protein, and CD59, or to reduced complement activation, but required the participation of Akt. Although our studies model protection in pig-to-primate xenotransplantation, our findings of IL-4 induction of Akt-mediated protection may be more broadly applicable to EC injury as manifested in ischemia-reperfusion, allotransplantation, and various vascular diseases.

In vivo antiatherogenic properties of olive oil and its constituent lipid classes in hyperlipidemic rabbits

BACKGROUND AND AIM

The consumption of olive oil has been associated with lower incidence of cardiovascular disease in the Mediterranean countries. This may be due in part to the action of platelet-activating factor (PAF) antagonists which we have previously demonstrated to be present in olive oil. In order to assess the in vivo effects of olive oil lipids and PAF in the development of atherosclerosis, the effects of diet supplementation with olive oil (OO), olive oil polar lipid extract (OOPLE) and olive oil neutral lipid extract (OONLE) were studied in rabbits fed a cholesterol-enriched diet.

METHODS AND RESULTS

Rabbits were fed for 45 days with atherogenic diet (Group A) supplemented with OO (Group B), OOPLE (Group C) or OONLE (Group D). Lipoprotein profiles, plasma in vitro oxidation, blood PAF levels, PAF-induced platelet aggregation and PAF-acetylhydrolase (PAF-AH) activity, were measured on day 0 and 45. Atherosclerotic lesions formed in the aortic wall and wall elasticity were assessed on day 45. Changes in lipid profile were in accordance with previous studies. Blood PAF levels were higher in group A and decreased in group D on day 45. In rabbits fed an atherogenic diet (Group A) blood PAF and PAF-AH increased, atherosclerotic lesions formed and the elasticity of vessel walls declined. In animals fed olive oil (Group B) or OOPLE (Group C) blood PAF-AH increased, platelet aggregation was attenuated, less oxidation occurred in plasma, lesion thickness was reduced and vessel walls retained elasticity. Most of these beneficial changes were not seen in animals fed OONLE (Group D) although blood PAF and plasma oxidation were lower.

CONCLUSIONS

The antiatherogenic effects of OO result from OOPLE. The beneficial effect of these factors is linked to PAF metabolism and proaggregant activity.

Interleukin-8 expression by mammary gland endothelial and epithelial cells following experimental mastitis infection with E. coli

Epithelial and endothelial cells play a pivotal role in initiating and controlling the movement of leukocytes into tissues during inflammation through the production of cytokines and chemokines such as interleukin-8 (IL-8). In situ hybridization with an IL-8 riboprobe was used to determine IL-8 mRNA expression by mammary gland epithelial and endothelial cells in cows with experimental Escherichia coli mastitis. Epithelial cells of the gland, especially surrounding the alveoli, had increased IL-8 mRNA levels at all time points at which tissue samples were collected (8, 12, and 24h) after E. coli challenge. Levels of IL-8 expression in the epithelial cells decreased at 24h post-infection. IL-8 expression by mammary gland endothelial cells was low, but did increase slightly at 24h post-infection. Both epithelial and endothelial cells of the mammary gland can contribute to the production of IL-8 that is typically seen in coliform mastitis.

IL-4 and IL-13 induce protection of porcine endothelial cells from killing by human complement and from apoptosis through activation of a phosphatidylinositide 3-kinase/Akt pathway

Vascular endothelial cells (EC) perform critical functions that require a balance of cell survival and cell death. EC death by apoptosis and EC activation and injury by the membrane attack complex of complement are important mechanisms in atherosclerosis and organ graft rejection. Although the effects of various cytokines on EC apoptosis have been studied, little is known about their effects on complement-mediated EC injury. Therefore, we studied the abilities of various cytokines to induce protection of porcine aortic EC against apoptosis and killing by human complement, a model of pig-to-human xenotransplantation. We found that porcine EC incubated with IL-4 or IL-13, but not with IL-10 or IL-11, became protected from killing by complement and apoptosis induced by TNF-alpha plus cycloheximide. Maximal protection required 10 ng/ml IL-4 or IL-13, developed progressively from 12 to 72 h of incubation, and lasted 48-72 h after cytokine removal. Protection from complement was not associated with reduced complement activation, C9 binding, or changes in CD59 expression. Inhibition of PI3K prevented development of protection; however, inhibition of p38 MAPK or p42/44 MAPK had no effect. IL-4 and IL-13 induced rapid phosphorylation of Akt. Although protection was inhibited by an Akt inhibitor and a dominant negative Akt mutant transduced into EC, it was induced by transduction of EC with the constitutively active Akt variant, myristylated Akt. We conclude that IL-4 and IL-13 can induce protection of porcine EC against killing by apoptosis and human complement through activation of the PI3K/Akt signaling pathway.

Systemic inflammation and disseminated intravascular coagulation in early stage of ALI and ARDS: role of neutrophil and endothelial activation

To determine the existence of a close link between inflammation and coagulation in patients with acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) and to examine their prognostic value in the development of ARDS and clinical outcome, we made a prospective cohort study. The study subjects consisted of 57 patients: 19 patients with ARDS and 38 patients with ALI as defined by a Lung Injury Score of > or =2.5 and 1.0 to less than 2.5, respectively. According to the outcome, the patients were subdivided into the survivors and the nonsurvivors. Ten normal healthy volunteers served as control subjects. Plasma levels of soluble L-, P-, and E-selectins, intercellular adhesion molecule-1 (sICAM-1), vascular cell adhesion molecule-1 (sVCAM-1), thrombomodulin (sTM), and neutrophil elastase were measured within 24 h after the diagnosis of ALI or ARDS. The number of systemic inflammatory response syndrome (SIRS) criteria being met by the patients and the disseminated intravascular coagulation (DIC) scores were determined simultaneously. The number of SIRS criteria and the DIC scores of the patients with ALI or ARDS showed high values, and more than half of the patients were complicated by DIC. The levels of sL-selectin in both groups of the patients were significantly lower than those of the control subjects. All other soluble adhesion molecules, neutrophil elastase, and sTM in the patients with ALI and ARDS were markedly elevated than those in the control subjects. The levels sICAM-1, sVCAM-1, and sTM in the ARDS patients significantly increased compared with the ALI patients. The number of SIRS criteria and the DIC scores in the nonsurvivors showed higher values than those in the survivors. In addition, we found significant differences in the levels of soluble adhesion molecules, neutrophil elastase, and sTM between the survivors and the nonsurvivors. In conclusion, we found a concurrent activation of both inflammation and coagulation in the patients with ALI or ARDS. The results also suggest that systemic activation of inflammation and coagulation associated with endothelial injury has prognostic value for the development of ARDS and poor outcome.

The effects of surgical fracture fixation on the systemic inflammatory response to major trauma

Early stabilization of major long bone fractures is beneficial in reducing the incidence of acute respiratory distress syndrome and multiple organ failure, both of which are caused by activation of the systemic inflammatory response. This activation results in tissue recruitment of and injury by circulating polymorphonuclear leukocytes. The reasons for clinical benefits of early fracture stabilization in major trauma are unknown. Published studies indicate that fracture surgery increases the posttraumatic inflammatory response. Major surgery to stabilize fractures carries a higher complication rate when performed on patients whose hypovolemic shock is not fully corrected. Thus, fracture care should be tailored to the patient, not dictated by the injured bone. Understanding the impact of fracture surgery on the systemic inflammatory response to major trauma is necessary to refine treatment and to apply it optimally to all patients.

Isolation and transcription profiling of purified uncultured human stromal stem cells: alteration of gene expression after in vitro cell culture

Stromal stem cells proliferate in vitro and may be differentiated along several lineages. Freshly isolated, these cells have been too few or insufficiently pure to be thoroughly characterized. Here, we have isolated two populations of CD45-CD34+CD105+ cells from human adipose tissue which could be separated based on expression of CD31. Compared with CD31+ cells, CD31- cells overexpressed transcripts associated with cell cycle quiescence and stemness, and transcripts involved in the biology of cartilage, bone, fat, muscle, and neural tissues. In contrast, CD31+ cells overexpressed transcripts associated with endothelium and the major histocompatibility complex class II complex. Clones of CD31- cells could be expanded in vitro and differentiated into cells with characteristics of bone, fat, and neural-like tissue. On culture, transcripts associated with cell cycle quiescence, stemness, certain cytokines and organ specific genes were down-regulated, whereas transcripts associated with signal transduction, cell adhesion, and cytoskeletal +CD105+CD31- cells from human adipose tissue have stromal stem cell properties which may make them useful for tissue engineering.

Serial changes in neutrophil-endothelial activation markers during the course of sepsis associated with disseminated intravascular coagulation

INTRODUCTION

For systematic elucidation of serial changes in neutrophil-endothelial activation markers as well as to investigate the correlationship among the inflammation markers, disseminated intravascular coagulation (DIC), and multiple organ dysfunction syndrome (MODS) in patients with sepsis, we made this prospective study.

MATERIALS AND METHODS

Forty-five patients with sepsis, severe sepsis, and septic shock were subdivided into two groups, 27 with DIC and 18 without DIC. Eight normal healthy volunteers served as control subjects. Serial levels of soluble L-, P-, and E-selectins, intercellular adhesion molecule-1 (sICAM-1), vascular cell adhesion molecule-1 (sVCAM-1), thrombomodulin (sTM), and neutrophil elastase were measured within 12 h after the diagnosis of sepsis (day 0) and on days 1-4 after the diagnosis. The numbers of systemic inflammatory response syndrome (SIRS) criteria that patients met and the DIC score were determined simultaneously.

RESULTS

Acute Physiology and Chronic Health Evaluation (APACHE) II score was identical between the two groups. In the DIC patients, higher DIC scores, lower platelet counts, and more maximum numbers of SIRS criteria being met were observed compared with the non-DIC patients. The incidence of MODS and the number of the dysfunctioning organs were higher in the patients with DIC than those without DIC, and the DIC patients had poor outcome. Soluble L-selectin (sL-selectin) levels in both groups tended to be lower than those in the control subjects. All other parameters both in the two groups were continuously higher than those in the control subjects during study period. The levels of soluble E-selectin (sE-selectin), sICAM-1, sVCAM-1, neutrophil elastase, and sTM were more elevated in the DIC patients than those in the non-DIC patients. There were no differences in the sP-selectin levels between the two groups; however, more increased sP-selectin levels per platelet were found in the DIC patients compared with the non-DIC patients. Maximum DIC scores in the DIC group positively correlated with the peak levels of neutrophil elastase and sTM and the number of the dysfunctioning organs.

CONCLUSIONS

We found close relations among the neutrophil-endothelial cell interactions, DIC, and MODS in patients with sepsis, severe sepsis, and septic shock. The results indirectly confirm the concept that DIC can produce organ dysfunction and that DIC reflects an inflammatory disorder of the microvasculature.

Coagulation in Sepsis

Activation of the coagulation cascade during invasive infection can result in purpura fulminans, with rapid progression of tissue ischemia, or may manifest as abnormal clotting indices alone. Although severe derangements in coagulation are associated with organ dysfunction and increased mortality, the contribution of coagulopathy to the pathophysiology of sepsis remains incompletely understood. Over the past decade, investigators have evaluated several therapeutic anticoagulant strategies in sepsis, and manipulation of the coagulation system has emerged as a key concept in the current management of this disease. Clinical observations during treatment of septic patients with the endogenous anticoagulant activated protein C have stimulated additional study of interactions between endothelial injury, coagulation, and inflammation. This review describes clotting abnormalities during sepsis and discusses the clinical experience with therapeutic strategies intended to oppose excessive coagulation.

Modulation of adhesion molecule expression on endothelial cells after induction by lipopolysaccharide-stimulated whole blood

The relative contribution of the pro-inflammatory cytokines tumour necrosis factor (TNF)-alpha and interleukin (IL)-1 beta and the lipopolysaccharide (LPS)-induced pathways that result in endothelial activation during sepsis are not fully understood. We have examined the effects of plasma obtained from LPS-treated human whole blood on the expression of E-selectin and intercellular adhesion molecule-1 (ICAM-1) on human endothelial cells. Stimulation of blood with 10 pg/ml of LPS is sufficient to produce plasma that induces E-selectin and ICAM-1 expression, while direct induction by LPS alone requires a 100-fold higher concentration. Characteristics for the plasma-induced adhesion molecule expression were similar to the LPS-induced production of TNF-alpha and IL-1 beta in blood. A complete inhibition of E-selectin and ICAM-1 expression was observed when antibodies against TNF-alpha and IL-1 beta were added to plasma prior to the incubation to endothelial cultures. Significant inhibition was even observed if antibodies were added to the cultures up until 3 h after LPS-conditioned plasma. The plasma-induced adhesion molecule response could also be prevented with inhibitors of nuclear factor (NF)-kappaB, such as pyrollidine dithiocarbamate. These findings emphasize the central role of TNF-alpha and IL-1 beta in LPS-induced endothelial activation and suggest that simultaneous neutralization of these cytokines or their common pathways may, even after the initial stimulus, prevent endothelial response during sepsis.

Cancer and the microenvironment: myeloma-osteoclast interactions as a model

We have investigated the interaction between tumor cells and specific cells in their microenvironment using myeloma as a model. The role of myeloma-induced osteoclastogenesis in the disease was studied ex vivo. Myeloma plasma cells freshly purified from patients' bone marrow attracted committed osteoclast (OC) precursors (n = 9; P < 0.01) and in 22 experiments directly induced their differentiation to multinucleated, bone-resorbing OCs (P < 0.00002) in a receptor activator of nuclear factor-kappaB ligand-mediated mechanism that was inhibited by the receptor activator of nuclear factor-kappaB (RANK-Fc) in 13 experiments by 71 +/- 12% (P < 0.008). In contrast, myeloma cells did not induce differentiation of peripheral blood mononuclear cells. Myeloma plasma cells cocultured with OCs retained their viability and proliferative activity for >13 weeks. After 14 days in coculture, the plasma cells from 29 patients had higher viability (P < 2 x 10(-6)), fewer apoptotic cells (P < 4 x 10(-15)), and a higher bromodeoxyuridine labeling index (P < 0.0006) than controls. Physical contact between OCs and myeloma cells was required for these effects to take place. No differences were observed between OCs from healthy donors and those from myeloma patients. Blocking interleukin 6 activity, while reducing survival of myeloma cells, had no effect on their proliferative activity. These results support data obtained from animal models and clinical observations on the essential role of the microenvironment in tumor sustenance and progression.

Inhibition of Heme Oxygenase-1 in Microvascular Lung Pericytes Diminishes at High Concentrations of an Inflammatory Mediator

Post-traumatic inflammation and sepsis induce changes in the lung microvasculature causing increased permeability. Pericytes, contractile cells positioned abluminally to endothelial cells, play a role in regulating this response. An in vitro model of microvascular lung pericytes (MLP) was used to investigate the effect of inhibiting heme oxygenase-1 (HO-1), a stress-induced enzyme, in the presence of varying levels of lipopolysaccharide (LPS), a mediator in the initiation of inflammation, on pericyte contractility. Rat MLP were cultured on collagen gel matrices. Cells were exposed to three concentrations of LPS in the presence of zinc protoporphyrin IX (ZnPP-9), a known inhibitor of HO-1. After 24 hours, the surface area of the collagen disks was quantified, thereby measuring pericyte contraction. ZnPP-9 caused a significant attenuation of the LPS-induced relaxation of the pericytes ( P ≤ 0.003). The effects of ZnPP-9, however, depended on the concentration of LPS to which the pericytes were exposed. Greater concentrations of LPS decrease the attenuating power of ZnPP-9. The inhibition of HO-1 diminished MLP relaxation triggered by LPS. The effect of ZnPP-9, however, is dependent on the concentration of LPS to which the MLP are exposed, indicating its saturation. ZnPP-9 may antagonize the microvascular response to trauma.

The prognostic value of circulating soluble cell adhesion molecules in patients with chronic congestive heart failure

BACKGROUND

Circulating soluble (s) cell adhesion molecules (CAMs) are elevated in patients with congestive heart failure (CHF) and may play an important role in the pathogenesis of CHF by mediating the cell-cell interactions of the immune response. However, clinical data about the prognostic value of sCAMs are sparse. The purpose of this study is to determine whether various sCAMs can provide prognostic information in patients with CHF.

METHODS

We measured circulating levels of three sCAMs (vascular cell adhesion molecule-1, intercellular adhesion molecule-1, and sP-selectin) in 74 patients with symptomatic chronic CHF and left ventricular ejection fraction (LVEF) <50%. We compared these levels with those of a group of 19 age-matched control subjects. Major adverse cardiac events (death, heart transplantation or hospitalization with worsening CHF) during a median follow-up period of 240 days were determined.

RESULTS

The concentrations of the three sCAMs in the 74 patients with CHF were significantly associated with one another. Their levels were higher than those of the control subjects and increased with the severity of CHF. Significantly higher sCAM levels were noted in those patients who had major adverse cardiac events during the follow-up period. There were significant negative correlations between LVEF and sCAMs. However, only high levels of sP-selectin were found to be an independent significant predictor of CHF by Cox proportional hazards analysis.

CONCLUSIONS

These findings indicate that the levels of these three sCAMs increase with the severity of CHF and are related to clinical outcomes. Among them, high levels of sP-selectin can provide prognostic information independently in patients with CHF.

Concurrent oral shedding of feline calicivirus and feline herpesvirus 1 in cats with chronic gingivostomatitis

Oral mucosal salivary samples were collected from 25 cats with chronic gingivostomatitis and 24 cats with periodontal disease. Viral culture and isolation of feline calicivirus and feline herpesvirus 1 were performed. Eighty-eight per cent of cats with chronic gingivostomatitis were shedding both viruses, compared to 21% of cats without chronic oral inflammatory disease. Cats with chronic gingivostomatitis are significantly more likely to concurrently shed both feline calicivirus and feline herpesvirus 1 than are cats with classical periodontal disease.

Interleukin-1 beta rapidly inhibits aortic endothelium-dependent relaxation by a DNA transcription-dependent mechanism

OBJECTIVES

This study examined the effects of interleukin-1 beta on isometric tension development and relaxation in isolated rat aortic rings in response to the alpha-1 adrenergic agonist phenylephrine, the endothelium-dependent vasodilator acetylcholine, and the endothelium-independent vasodilator sodium nitroprusside.

DESIGN

Randomized, controlled, paired design.

SETTING

Animal laboratory within a university department of physiology. SUBJECTS Paired aortic thoracic aortic rings from specific pathogen-free Sprague-Dawley rats.

INTERVENTIONS

Series I examined the potential for interleukin-1 beta to cause early arterial endothelial dysfunction. Paired aortic rings were incubated for 2 hrs with interleukin-1 beta or vehicle. Series II examined the potential for inhibition of DNA transcription to attenuate interleukin-1 beta-mediated endothelial dysfunction. Paired rings received either dactinomycin or vehicle before interleukin-1 beta incubation. Series III quantified the degree to which inhibition of DNA transcription inhibited early interleukin-1 beta-mediated endothelial dysfunction. Paired rings received either dactinomycin pretreatment followed by interleukin-1 beta incubation, or pretreatment and incubation with inert vehicles. Series IV assessed the effects of interleukin-1 beta on responsiveness to an exogenous nitric oxide donor, sodium nitroprusside, in the presence of the nitric oxide synthesis inhibitor N omega-nitro-L-arginine methyl ester.

MEASUREMENTS AND MAIN RESULTS

Incubation with interleukin-1 beta for 2 hrs had no effect on contractile response but attenuated endothelium-dependent relaxation significantly relative to control. Dactinomycin pretreatment inhibited early interleukin-1 beta-mediated endothelial dysfunction. The combination of interleukin-1 beta and dactinomycin produced effects on endothelium-dependent relaxation that were not different from that seen in rings not exposed to interleukin-1 beta. Interleukin-1 beta attenuated responsiveness to sodium nitroprusside relative to control.

CONCLUSIONS

Interleukin-1 beta causes an early impairment of endothelium-dependent vasorelaxation with an onset that precedes its effects on systemic contractility. This impairment occurs via a mechanism that is wholly or predominantly dependent on DNA transcription. The altered vasorelaxation induced by interleukin-1 beta is at least partly mediated by a reduction in nitric oxide responsiveness.

[Strategies for endoscopic and surgical treatment of biliary tract calculi]

INTRODUCTION

Common bile duct calculi represent a pathologic entity involving obstructive icterus, cholangitis, hepatic cirrhosis or pancreatitits. Common bile duct calculi mostly have a secondary origin (from gallbladder) in 95% of cases, while primary choledocholithiasis is rare.

CLASSIFICATION

From surgical aspect, common bile duct calculi can be: 1. Asymptomatic, without manifested symptoms or signs, 2. Mobile, with intermittent biliar obstruction and disobstruction, 3. Fixed, with obstruction and signs of hepato-biliary and/or bilio-pancreatic duct, 4. Transitory, microcalculi which pass through Vater's Papilla by propulsion into duodenum with symptoms.

DISCUSSION

Modern biliary surgery includes diagnosis of common bile duct calculi, and if possible preoperative endoscopic (endoluminal) surgery, which is less invasive for patients. If such approach is not possible, it is necessary to perform stone extraction and cholecystectomy.

CONCLUSION

Common bile duct calculi represent a common disease of the digestive system. Endoscopic diagnostic procedure is very important in management of choledocholithiasis. Endoscopic treatment of common bile duct calculi prior to cholecystectomy is a method of choice and a strategy for associated cholecysto-choledocholithiasis.

Coagulation/fibrinolysis abnormality and vascular endothelial damage in the pathogenesis of thrombocytopenic multiple organ failure

OBJECTIVE

Until recently, attention has been directed to disseminated intravascular coagulation as a cause of multiple organ failure (MOF). On the other hand, it has now become clear that humoral mediators play important roles in the pathogenesis of MOF. Therefore, we performed the present study in patients with thrombocytopenic MOF to investigate the relationship between various humoral mediators and vascular endothelial damage reported to be triggered by such humoral mediators in the pathogenesis of MOF.

DESIGN

A retrospective clinical study.

SETTING

Intensive care unit of a university hospital.

PATIENTS

The study included 18 thrombocytopenic patients whose conditions progressed to septic MOF (MOF group) and 20 others who did not progress to MOF (non-MOF group). The MOF group and non-MOF group were also presented with infection and with platelet counts of <100,000/mm3.

MEASUREMENTS AND MAIN RESULTS

The MOF group had fibrinolysis abnormality, as indicated by increased plasminogen activator inhibitor-1 level. On the other hand, the MOF group had increased polymorphonuclear elastase and polymorphonuclear-mediated fibrinogen degradation product levels with consequent prolonged elevation of thrombomodulin. In addition, both polymorphonuclear elastase and polymorphonuclear-fibrinogen degradation products were significantly positively correlated with thrombomodulin in the MOF group, but no such positive correlation was observed between interleukin-6 or plasminogen activator inhibitor-1 and thrombomodulin. In the non-MOF group, on the other hand, thrombomodulin exhibited no significant positive correlation with polymorphonuclear elastase, polymorphonuclear-fibrinogen degradation products, interleukin-6, or plasminogen activator inhibitor-1.

CONCLUSIONS

Our study provided evidence that vascular endothelial damage was the primary cause of organ failures in patients with thrombocytopenic MOF and that humoral mediators played a major role in the development of vascular endothelial damage in such patients. These results suggest that it is important to treat thrombocytopenic MOF as a condition of vascular endothelial damage, with weight placed on countermeasures against disorders of humoral mediators.

Tumor necrosis factor-alpha and interleukin-1beta mediate endothelial permeability induced by lipopolysaccharide-stimulated whole blood

OBJECTIVE

To investigate the role of endotoxin-induced inflammatory mediators in blood on the permeability of endothelial monolayers.

DESIGN

Whole blood of healthy volunteers was treated with bacterial lipopolysaccharide (Escherichia coli, B55:05), and the resultant plasma was added to human umbilical venular endothelial cells (HUVEC) cultured on semipermeable membrane inserts (Transwells).

SETTING

University hospital laboratory.

SUBJECTS

Whole blood of healthy volunteers.

INTERVENTIONS

Donor plasma was treated with excess antibodies against either tumor necrosis factor-alpha, interleukin-1beta, or both, before the incubation on HUVEC.

MEASUREMENTS AND MAIN RESULTS

The permeability of HUVEC monolayers to fluorescent-labeled albumin and dextran was measured over a 6-hr period, after removal of the stimulus. The production of tumor necrosis factor-alpha and interleukin-1beta in lipopolysaccharide-treated whole blood was determined by radioimmunoassay. Individually, lipopolysaccharide (10 microg/mL), tumor necrosis factor-alpha (10 ng/mL), and interleukin-1beta (50 ng/mL) all increased endothelial permeability by about 2.5-fold. A much larger increase could be achieved by preincubation of lipopolysaccharide (10 microg/mL) in whole blood: the resultant plasma induced a ten-fold increase of the permeability. The permeability response after preincubation of lipopolysaccharide in whole blood was time- and dose-dependent. Moreover, this treatment increased the sensitivity of endothelial monolayers to lipopolysaccharide by a factor of several thousand-fold: Whereas high doses of lipopolysaccharide were required for direct stimulation of the permeability, picomolar amounts of lipopolysaccharide in whole blood induced a similar increase. Significant amounts of tumor necrosis factor-alpha and interleukin-1beta were produced in blood at similar doses of lipopolysaccharide. The addition of antibodies against tumor necrosis factor-alpha or interleukin-1beta to plasma partially but significantly abrogated the permeability increase. However, a complete inhibition could be achieved by the simultaneous addition of anti-tumor necrosis factor-alpha and anti-interleukin-1beta to plasma.

CONCLUSIONS

Although lipopolysaccharide is capable of directly inducing endothelial permeability, blood-borne tumor necrosis factor-alpha and interleukin-1beta mediate lipopolysaccharide-induced endothelial permeability at low endotoxin concentrations. These findings support the idea that multifactorial inhibition of inflammatory mediators may improve survival in septic patients.

Effect of pretreatment with interleukin-1 beta on inflammatory infiltrates and tissue damage after experimental endotoxic challenge

OBJECTIVE

To evaluate the effect of treatment with murine recombinant interleukin-1 beta on inflammatory infiltrate and tissue damage after experimental endotoxic challenge.

DESIGN

Randomized, controlled study.

SETTING

Experimental Unit, Virgen de las Nieves University Hospital.

SUBJECTS

Seventy-two female CBA/H mice, 20-21 g, supplied by the animal center of the Experimental Unit.

INTERVENTION

The mice were randomized into three groups of 24. Group 1 (sham) received two intraperitoneal doses of 0.1 mL of phosphate-buffered saline; group 2 (lipopolysaccharide) was injected with 125 mg/kg lipopolysaccharide (Escherichia coli, intraperitoneally) 24 hrs after 0.1 mL of phosphate-buffered saline; group 3 was pretreated with 80 ng of recombinant interleukin-1 beta per mouse (intraperitoneally) 24 hrs before the endotoxic challenge.

MEASUREMENTS AND MAIN RESULTS

At 1, 2, 4, and 24 hrs after the endotoxic challenge, we studied inflammatory infiltrate and tissue damage in lung, liver, and intestine by determining myeloperoxidase and malondialdehyde tissue concentrations. When we compared the pretreated group with the lipopolysaccharide group, myeloperoxidase concentrations decreased significantly in lung (p <.001) and liver (p <.001) at all study times, and in intestine (p <.001) at 2, 4, and 24 hrs; malondialdehyde concentrations significantly decreased in lung at 1 (p <.05), 2 (p <.01), and 24 (p <.001) hrs, in liver at 2 (p <.001), 4 (p <.01), and 24 (p <.001) hrs, and in intestine at 1 (p <.001), 2, 4 (p <.05), and 24 (p <.001) hrs.

CONCLUSION

Pretreatment with recombinant interleukin-1 beta significantly reduces inflammatory infiltrate and tissue damage in mouse lung, liver, and intestine after an experimental endotoxic challenge.

Recombinant human activated protein C attenuates the inflammatory response in endothelium and monocytes by modulating nuclear factor-kappaB

OBJECTIVE

To review the anti-inflammatory and anti-apoptotic properties of drotrecogin alfa (activated) (recombinant human activated protein C), emphasizing its modulatory effects on endothelial nuclear factor-kappaB. We propose a broad anti-inflammatory effect of drotrecogin alfa (activated), acting on both endothelium and monocytes.

DATA SOURCES

A selected review of the published literature on nuclear factor-kappaB, severe sepsis, and the use of drotrecogin alfa (activated) in clinical and preclinical models, together with data derived from preclinical gene profiling of model systems.

DATA EXTRACTION AND SYNTHESIS

Data from the PROWESS trial support the preclinical evidence of an antithrombotic effect of drotrecogin alfa (activated). Anti-inflammatory effects through reduction of thrombin generation and through thrombin-independent mechanisms in mononuclear and endothelial cells are reviewed. Inhibition of apoptosis is used as an example of the protective effect of drotrecogin alfa (activated) on endothelial and mononuclear cell dysfunction.

CONCLUSIONS

Drotrecogin alfa (activated) acts as a modulator of nuclear factor-kappaB to aid in the host immune response in endothelium and monocytes. Extrapolation of gene array findings to explain apoptosis in endothelium and monocytes, coupled with emerging preclinical reports, provides evidence to support the role of drotrecogin alfa (activated) in modulating nuclear factor-kappaB.