Neutrophil-mediated injury to endothelial cells. Enhancement by endotoxin and essential role of neutrophil elastase

Anti-inflammatory effect of colchicine on organ damage during the perioperative period of cardiac surgery: a study protocol for a multicentre, randomised, double-blind, placebo-controlled clinical trial

INTRODUCTION

The systemic inflammatory response syndrome during the perioperative period of cardiac surgery can lead to serious postoperative complications and significantly increase the hospital mortality rate. Colchicine, a widely used traditional anti-inflammatory drug, has good clinical value in cardiovascular anti-inflammatory therapy. Our preliminary single-centre study had confirmed the protective value of colchicine in patients undergoing cardiac surgery with cardiopulmonary bypass. For this multicentre investigation, we aim to further validate the anti-inflammatory and organ-protective effects of low-dose colchicine during the perioperative period in a low-risk population.

METHODS AND ANALYSIS

This study is a multicentre, randomised, double-blind, placebo-controlled clinical trial. A total of 768 patients undergoing elective cardiac surgery will be enrolled from eight heart centres in China. The participants will be randomly assigned to two groups: the colchicine group will receive low-dose colchicine (0.5 mg once-a-day dosing regimen (QD) orally for 3 days before the surgery and 0.5 mg dosing frequency of every other day (QOD) continuously for 10 days after the surgery), whereas the placebo group will be given starch tablets for the same time and dosage. Primary endpoints are the occurrence of postoperative inflammatory diseases, including postoperative atrial fibrillation, acute respiratory distress syndrome, preoperative myocardial injury and post-pericardiotomy syndrome. Secondary endpoints included laboratory tests on postoperative days 1, 3, 5, 7 and 10, intensive care unit data, APACHE II score, Murray lung injury score, medication-related gastrointestinal reactions, 30-day and 90-day all-cause mortality, surgical data, chest radiograph on postoperative days 1, 2 and 3, and chest CT within 14 days after surgery.

ETHICS AND DISSEMINATION

This research has received approval from the Medical Ethics Committee of Affiliated Nanjing Drum Tower Hospital, Nanjing University Medical College (approval number 2023-366-01). The study findings will be made available by publishing them in an open access journal.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov (NCT06118034).

A dynamic online nomogram for predicting death in hospital after aneurysmal subarachnoid hemorrhage

BACKGROUND

This study aimed to validate the efficacy the multiplication of neutrophils and monocytes (MNM) and a novel dynamic nomogram for predicting in-hospital death in patients with aneurysmal subarachnoid hemorrhage (aSAH).

METHODS

Retrospective study was done on 986 patients with endovascular coiling for aSAH. Independent risk factors associated with in-hospital death were identified using both univariate and multivariate logistic regression analysis. In the development cohort, a dynamic nomogram of in-hospital deaths was introduced and made available online as a straightforward calculator. To predict the in-hospital death from the external validation cohort by nomogram, calibration analysis, decision curve analysis, and receiver operating characteristic analysis were carried out.

RESULTS

72/687 patients (10.5%) in the development cohort and 31/299 patients (10.4%) in the validation cohort died. MNM was linked to in-hospital death in univariate and multivariate regression studies. In the development cohort, a unique nomogram demonstrated a high prediction ability for in-hospital death. According to the calibration curves, the nomogram has a reliable degree of consistency and calibration. With threshold probabilities between 10% and 90%, the nomogram's net benefit was superior to the basic model. The MNM and nomogram also exhibited good predictive values for in-hospital death in the validation cohort.

CONCLUSIONS

MNM is a novel predictor of in-hospital mortality in patients with aSAH. For aSAH patients, a dynamic nomogram is a useful technique for predicting in-hospital death.

The correlation between peripheral complete blood count parameters and diabetic macular edema in proliferative diabetic retinopathy patients: a cross-sectional study

Background

Numerous studies have demonstrated that retinal chronic inflammation plays a critical role in the pathogenesis of diabetic macular edema (DME). However, studies about the association between peripheral complete blood count, an inexpensive and easily measurable laboratory index, and DME are limited.

Research design and methods

The current study was a hospital-based, cross-sectional study. The participants were inpatients with type 2 diabetes who underwent vitrectomy for PDR, and the contralateral eyes in these PDR patients meeting the criteria were included in the study. Central macular thickness (CMT) was measured automatically and the DME was characterized as CMT ≥ 300 μm.

Results

A total of 239 PDR participants were enrolled. The average age was 55.46 ± 10.08 years old, and the average CMT was 284.23 ± 122.09 μm. In the fully adjusted model, for CMT, the results revealed a significantly negative association between CMT and both white blood cell (WBC) count and neutrophil count (β = -11.95, 95% CI: -22.08, -1.82; p = 0.0218; β = -14.96, 95% CI: -28.02, -1.90; p = 0.0259, respectively); for DME, the results showed an inverse association between DME and WBC count, monocyte count, and eosinophil count (OR = 0.75, 95% CI: 0.59, 0.95; p = 0.0153; OR = 0.07, 95% CI: 0.00, 0.92; p = 0.0431; OR = 0.03, 95% CI: 0.00, 0.88; p = 0.0420, respectively).

Conclusions

In conclusion, our results suggest that WBC and its subtypes in circulation may play an important role in the pathogenesis of DME in PDR patients.

Correlation of alpha-1 antitrypsin levels and exosome associated neutrophil elastase endothelial injury in subjects with SARS-CoV2 infection

Background

Severe acute respiratory syndrome caused by a novel coronavirus 2 (SARS-CoV-2) has infected more than 18 million people worldwide. The activation of endothelial cells is a hallmark of signs of SARS-CoV-2 infection that includes altered integrity of vessel barrier and endothelial inflammation.

Objectives

Pulmonary endothelial activation is suggested to be related to the profound neutrophil elastase (NE) activity, which is necessary for sterilization of phagocytosed bacterial pathogens. However, unopposed activity of NE increases alveolocapillary permeability and extracellular matrix degradation. The uncontrolled protease activity of NE during the inflammatory phase of lung diseases might be due to the resistance of exosome associated NE to inhibition by alpha-1 antitrypsin.

Method

31 subjects with a diagnosis of SARS-CoV2 infection were recruited in the disease group and samples from 30 voluntaries matched for age and sex were also collected for control.

Results

We measured the plasma levels of exosome-associated NE in SARS-CoV-2 patients which, were positively correlated with sign of endothelial damage in those patients as determined by plasma levels of LDH. Notably, we also found strong correlation with plasma levels of alpha-1 antitrypsin and exosome-associated NE in SARS-CoV-2 patients. Using macrovascular endothelial cells, we also observed that purified NE activity is inhibited by purified alpha-1 antitrypsin while, NE associated with exosomes are resistant to inhibition and show less sensitivity to alpha-1 antitrypsin inhibitory activity, in vitro.

Conclusions

Our results point out the role of exosome-associated NE in exacerbation of endothelial injury in SARS-CoV-2 infection. We have demonstrated that exosome-associated NE could be served as a new potential therapeutic target of severe systemic manifestations of SARS-CoV-2 infection.

Neutrophil-Derived Proteases Contribute to the Pathogenesis of Early Diabetic Retinopathy

Purpose

Previous studies indicate that leukocytes, notably neutrophils, play a causal role in the capillary degeneration observed in diabetic retinopathy (DR), however, the mechanism by which they cause such degeneration is unknown. Neutrophil elastase (NE) is a protease released by neutrophils which participates in a variety of inflammatory diseases. In the present work, we investigated the potential involvement of NE in the development of early DR.

Methods

Experimental diabetes was induced in NE-deficient mice (Elane-/-), in mice treated daily with the NE inhibitor, sivelestat, and in mice overexpressing human alpha-1 antitrypsin (hAAT+). Mice were assessed for diabetes-induced retinal superoxide generation, inflammation, leukostasis, and capillary degeneration.

Results

In mice diabetic for 2 months, deletion of NE or selective inhibition of NE inhibited diabetes-induced retinal superoxide levels and inflammation, and inhibited leukocyte-mediated cytotoxicity of retinal endothelial cells. In mice diabetic for 8 months, genetic deletion of NE significantly inhibited diabetes-induced retinal capillary degeneration.

Conclusions

These results suggest that a protease released from neutrophils contributes to the development of DR, and that blocking NE activity could be a novel therapy to inhibit DR.

Acute Cerebrovascular Disorders and Vasculopathies Associated with Significant Mortality in SARS-CoV-2 Patients Admitted to The Intensive Care Unit in The New York Epicenter

The current Coronavirus pandemic due to the novel SARS-Cov-2 virus has proven to have systemic and multi-organ involvement with high acuity neurological conditions including acute ischemic strokes. We present a case series of consecutive COVID-19 patients with cerebrovascular disease treated at our institution including 3 cases of cerebral artery dissection including subarachnoid hemorrhage. Knowledge of the varied presentations including dissections will help treating clinicians at the bedside monitor and manage these complications preemptively.

Targeting arachidonic acid-related metabolites in COVID-19 patients: potential use of drug-loaded nanoparticles

In March 2020, The World Health Organization (WHO) has declared that the coronavirus disease 2019 (COVID-19) is characterized as a global pandemic. As of September 2020, infection with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread to 213 countries and territories around the world, affected more than 31.5 million people, and caused more than 970,000 deaths worldwide. Although COVID-19 is a respiratory illness that mainly targets the lungs, it is currently well established that it is a multifactorial disease that affects other extra-pulmonary systems and strongly associated with a detrimental inflammatory response. Evidence has shown that SARS-CoV-2 causes perturbation in the arachidonic acid (AA) metabolic pathways; this disruption could lead to an imbalance between the pro-inflammatory metabolites of AA including mid-chain HETEs and terminal HETE (20-HETE) and the anti-inflammatory metabolites such as EETs and subterminal HETEs. Therefore, we propose novel therapeutic strategies to modulate the level of endogenous anti-inflammatory metabolites of AA and induce the patient's endogenous resolution mechanisms that will ameliorate the virus-associated systemic inflammation and enhance the primary outcomes in COVID-19 patients. Also, we propose that using nanoencapsulation of AA and its associated metabolites will contribute to the development of safer and more efficacious treatments for the management of COVID-19.

Impact of Porcine Arterivirus, Influenza B, and Their Coinfection on Antiviral Response in the Porcine Lung

Interferon (IFN) cytokines induce an autonomous antiviral state in cells of the infected site to restrict virus spreading and critically regulate overall antiviral response. The antiviral state leads to host protection through expression of hundreds of IFN-stimulated genes that restrict viral infection through multiple mechanisms, for example, directly in viral genome degradation and indirectly through cellular metabolic inhibition. Young pigs were split into four treatment groups: control, porcine reproductive and respiratory syndrome virus (PRRSV, also known as porcine arterivirus) infected, influenza B virus (IBV) infected, and IBV/PRRSV coinfection. Lung tissue was collected at 3, 5, and 7 days post infection (dpi) for control, PRRSV and IBV/PRRSV coinfection, and at 3 and 5 dpi for IBV. Transcriptomic analysis, using usegalaxy.org tools, was performed against the S.scrofa 11.1 reference genome. Differentially expressed gene (DEG) analysis was carried out using DeSeq2 based on the model treatment + dpi + treatment:dpi + E. Downstream analysis examined the interaction of DEG at each dpi for over-enriched gene ontology (G.O.) terms and pathways. Comparisons of the infected groups vs. the controls yielded a total of (n = 1412) DEGs for the PRRSV group and (n = 1578) for the IBV/PRRSV group across all timepoints. The IBV group had (n = 64) total DEGs across 3 and 5 dpi. Expression data were considered statistically significant based on false discovery rate (FDR) ⫹ 0.1. Venn diagram comparisons of the DEGs across dpi showed that groups shared only 16 DEGs at 3 dpi, no DEGs were shared at 5 dpi, and for 7 dpi, only the PRRSV and IBV/PRRSV groups were compared and shared a total of 43 DEGs. Across the comparisons, differential expression was observed in antiviral genes such as IRF1, MX1, and OAS2. The IBV and IBV/PRRSV groups showed higher expression of antiviral genes at earlier dpi than the PRRSV group. Additionally, downregulated genes from the comparisons clustered around Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways effecting lung development and cellular integrity. Early expression of host IFN and antiviral genes may lead to viral RNA degradation, and assembly and transcription inhibition in the IBV infections. In comparison, expression of antiviral genes in the PRRSV group decreased across time. The decrease may explain why PRRSV infections persist, while IBV clears. Moreover, all infected groups showed prolonged upregulation in neutrophil degranulation pathway activity, possibly exacerbating symptomatic lung lesion pathology seen in these respiratory infections.

Identifying Downregulation of Autophagy Markers in Kawasaki Disease

Kawasaki disease (KD) is the most common cause of heart disease acquired in childhood. Even if treated with high-dose intravenous immunoglobulin G (IVIG) at the early stage; children are still at risk of developing coronary artery lesions. Accumulating evidence suggests that autophagy is enhanced in various heart diseases. Evaluating the pathogenic role of autophagy in KD and coronary artery lesions (CAL) may aid in identifying a potential therapeutic target for the treatment or prevention of the disease. Blood samples were obtained from 20 children with KD at the onset of disease and 21 days after IVIG therapy. Twenty children with other causes of febrile disease and 20 healthy children were included as controls. Total RNA was extracted from white blood cells; and autophagy-related gene mRNA expression levels were measured using real-time polymerase chain reaction. The patients with KD had downregulated levels of LC3B mRNA (0.50 ± 0.06 vs. 1.67 ± 0.15; p < 0.001), BECN1 mRNA (0.70 ± 0.08 vs. 1.43 ± 0.23; p < 0.05), and ATG16L1 mRNA (0.28 ± 0.04 vs. 0.96 ± 0.16; p < 0.01) compared to the febrile control group. The values of these parameters all increased significantly 21 days after the IVIG therapy as follows: LC3B mRNA (1.77 ± 0.29 vs. 0.50 ± 0.06; p < 0.001), BECN1 mRNA (1.67 ± 0.36 vs. 0.70 ± 0.08; p < 0.05), and ATG16L1 mRNA (2.96 ± 0.43 vs. 0.28 ± 0.04; p < 0.001), while the level of ATG16L1 mRNA persists low in KD patients with CAL. Our results showed the autophagy-related genes expressions in KD and their change after IVIG administration. This suggests that autophagy may have a protective effect on KD.

G-CSF Infusion for Stem Cell Mobilization Transiently Increases Serum Cell-Free DNA and Protease Concentrations

G-CSF for stem cell mobilization increases circulating levels of myeloid cells at different stages of maturation. Polymorphonuclear cells (PMNs) are also mobilized in high numbers. It was previously reported that G-CSF primes PMNs toward the release of neutrophils extracellular traps (NETs). Since NETs are often involved in thrombotic events, we hypothesized that high G-CSF blood concentrations could enhance PMN priming toward NET formation in healthy hematopoietic stem cell donors, predisposing them to thrombotic events. However, we found that G-CSF does not prime PMNs toward NETs formation, but increases the serum concentration of cell-free DNA, proteases like neutrophils elastase and myeloperoxidase, and reactive oxygen species. This could possibly create an environment disposed to induce thrombotic events in the presence of additional predisposing factors.

Ventilation and Perfusion at the Alveolar Level: Insights From Lung Intravital Microscopy

Intravital microscopy (IVM) offers unique possibilities for the observation of biological processes and disease related mechanisms in vivo. Especially for anatomically complex and dynamic organs such as the lung and its main functional unit, the alveolus, IVM provides exclusive advantages in terms of spatial and temporal resolution. By the use of lung windows, which have advanced and improved over time, direct access to the lung surface is provided. In this review we will discuss two main topics, namely alveolar dynamics and perfusion from the perspective of IVM-based studies. Of special interest are unanswered questions regarding alveolar dynamics such as: What are physiologic alveolar dynamics? How do these dynamics change under pathologic conditions and how do those changes contribute to ventilator-induced lung injury? How can alveolar dynamics be targeted in a beneficial way? With respect to alveolar perfusion IVM has propelled our understanding of the pulmonary microcirculation and its perfusion, as well as pulmonary vasoreactivity, permeability and immunological aspects. Whereas the general mechanism behind these processes are understood, we still lack a proper understanding of the complex, multidimensional interplay between alveolar ventilation and microvascular perfusion, capillary recruitment, or vascular immune responses under physiologic and pathologic conditions. These are only part of the unanswered questions and problems, which we still have to overcome. IVM as the tool of choice might allow us to answer part of these questions within the next years or decades. As every method, IVM has advantages as well as limitations, which have to be taken into account for data analysis and interpretation, which will be addressed in this review.

The Effect of Manuka Honey on dHL-60 Cytokine, Chemokine, and Matrix-Degrading Enzyme Release under Inflammatory Conditions

A large body of in vivo and in vitro evidence indicates that Manuka honey resolves inflammation and promotes healing when applied topically to a wound. In this study, the effect of two different concentrations (0.5% and 3% v/v) of Manuka honey on the release of cytokines, chemokines, and matrix-degrading enzymes from neutrophils was examined using a differentiated HL-60 cell line model in the presence of inflammatory stimuli. The results indicate that 0.5% honey decreased TNF-α, IL-1β, MIP-1α, MIP-1β, IL-12 p70, MMP-9, MMP-1, FGF-13, IL-1ra, and IL-4 release, but increased MIP-3α, Proteinase 3, VEGF, and IL-8 levels. In contrast, 3% honey reduced the release of all analytes except TNF-α, whose release was increased. Together, these results demonstrate a dose-dependent ability of Manuka honey to modify the release of cytokines, chemokines, and matrix-degrading enzymes that promote or inhibit inflammation and/or healing within a wound. The findings of this study provide further guidance for the future use of Manuka honey in wounds or tissue engineering templates. Future in vivo investigation is warranted to validate the in vitro results and translate these results to physiologically relevant environments.

Neutrophils and Malaria

Neutrophils are abundant in the circulation and are one of the immune system's first lines of defense against infection. There has been substantial work carried out investigating the role of neutrophils in malaria and it is clear that during infection neutrophils are activated and are capable of clearing malaria parasites by a number of mechanisms. This review focuses on neutrophil responses to human malarias, summarizing evidence which helps us understand where neutrophils are, what they are doing, how they interact with parasites as well as their potential role in vaccine mediated immunity. We also outline future research priorities for these, the most abundant of leukocytes.

Clinical pertinence of neutrophil-to- lymphocyte ratio among hypertensives with different grades and duration of hypertension - an insight

Over the recent years, the pathophysiology of the inflammatory component in hypertension has been a challenge, because this inflammatory response is mainly contributed by an increased oxidative stress with the release of inflammatory mediators. Identification of a simple and early inflammatory marker such as the neutrophil-to-lymphocyte ratio (NLR) is the need of the hour. This study correlates the same specifically taking into account the duration and the grades of hypertension.

OBJECTIVE

The response of the NLR among the hypertensives and its correlation with duration and stages of hypertension.

METHOD

Totally, 80 subjects and 40 controls of age between 20 and 60 years and both genders were included. Three recordings of blood pressure were measured with a standard mercury sphygmomanometer. The differential leukocyte count was estimated with an automated Beckman Coulter.

OBJECTIVE

Variations in the neutrophil and lymphocyte counts were significant among the hypertensives with a p-value < 0.001. The NLR was also significantly altered among the hypertensives with a p-value = 0.001. The NLR showed a rise in value among the normotensives, prehypertensives, and stage 1 of systolic hypertension, though not statistically significant. An increase in the NLR was observed in hypertensives with duration of 1-2 years.

CONCLUSION

Our study gives a new insight with a rise in NLR in early years and even among prehypertensives and stage 1 systolic hypertension under strict criterion. This could be utilized as an early predictive tool, relating the inflammatory process and hypertension which on further intervention could slow the progression of the disease process.

ABBREVIATIONS

NLR: Neutrophil-to-lymphocyte ratio; BP: Blood pressure.

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.

The impact of alpha-1 antitrypsin augmentation therapy on neutrophil-driven respiratory disease in deficient individuals

Alpha-1 antitrypsin (AAT) is the most abundant serine protease inhibitor circulating in the blood. AAT deficiency (AATD) is an autosomal codominant condition affecting an estimated 3.4 million individuals worldwide. The clinical disease associated with AATD can present in a number of ways including COPD, liver disease, panniculitis and antineutrophil cytoplasmic antibody vasculitis. AATD is the only proven genetic risk factor for the development of COPD, and deficient individuals who smoke are disposed to more aggressive disease. Principally, AAT is a serine protease inhibitor; however, over the past number of years, the assessment of AAT as simply an antiprotease has evolved, and it is now recognized that AAT has significant anti-inflammatory properties affecting a wide range of cells, including the circulating neutrophil.

Endothelial Glycocalyx Layer: A Possible Therapeutic Target for Acute Lung Injury during Lung Resection

Background

Shedding of the endothelial glycocalyx layer (EGL) is known to occur during major surgery, but its degradation associated with minimally invasive video-assisted thoracoscopy (VATS) remains unclear. We investigated if serum biomarkers of EGL disruption were elevated during VATS lobectomy, and whether the urinary trypsin inhibitor (UTI) ulinastatin exerted a protective effect during this procedure.

Materials and Methods

Sixty ASA II-III lung cancer patients undergoing elective VATS lobectomy were divided equally into UTI and control groups. UTI group patients received intravenous UTI during surgery. Serum levels of syndecan-1 and heparan sulfate were examined before (T0) and at the end of surgery (T1). Serum albumin and hemoglobin were measured before surgery (BOD) and on the first postoperative day (POD1).

Results

In control group, syndecan-1 levels were significantly elevated at T1 compared with T0 (3.77 ± 3.15 versus 4.28 ± 3.30, P = 0.022^⁎) and increased even more significantly in patients whose surgery lasted >3 h (3.28 ± 2.84 versus 4.31 ± 3.39, P = 0.003^⁎⁎). Serum albumin levels on POD1 were significantly lower in control group compared with UTI group (32.63 ± 4.57 versus 35.76 ± 2.99, P = 0.031^⁎).

Conclusion

EGL degradation occurs following VATS lobectomy. UTI can alleviate this shedding, thus helping preserve normal vascular permeability.

Trail Registration

This trial is registered with ChiCTR-IOC-17010416 (January 13, 2017).

Molecular Modulation of Stress Induced to Abnormal Haematological Indices in Medical Students, Malaysian Perspective

Medical students in Malaysia and globally were considered among the most exposure groups in the community to stress due to several sources. The most significant and severe sources of stress in medical students is an academic sources, includes a lot of exams/tests, lack of time and facilities for entertainment, stay in a hostel, high parental expectations and vastness of syllabus, in addition to emotional problems and others personal sources. Stress is a very important issue that leads to a worsening of health problems. Stress develops in the body and leads to oxidative stress which in turn leads to a disorder in the whole body. Oxidative stress may lead to abnormal haematological indices elevated white blood cells (WBCs) count. Oxidative stress can lead to massive destruction of red blood cells (RBCs). The brain and the gastrointestinal system (GI) are intimately connected as one system. The brain has a direct impact on the GI tract. A stressful brain can send signals to the gut, just as a troubled intestine can send signals to the brain. Therefore, stress can be the cause of block the breakdown and assimilation of food for energy and nutriment. This malabsorption can then lead to a reciprocal negative effect to the stress and can be another cause of anaemia through malabsorption minerals and vitamins that are to erythropoiesis. So, stress can be one of the leading causes of anaemia among medical students. Stress is a chronic epidemic in the most medical students and can directly affect how well body works. This review article discovers the effect of stress in medical students that can be effect on their studies and further create researcher's interest to generate database that help to reduce stress response and bring about the empowerment of balanced life among Malaysian medical students besides the increasing level of health and academic performance.

Plasma Neutrophil Elastase, α1-Antitrypsin, α2-Macroglobulin and Neutrophil Elastase-α1-Antitrypsin Complex Levels in patients with Dengue Fever

Dengue fever (DF) is characterized by systemic inflammatory response including neutrophil activation leading to uncontrolled elastase activity. This study was aimed to measure the activity of plasma neutrophil elastase (NE), its endogenous inhibitors α₁-antitrypsin (α₁-AT) and α₂-macroglobulin (α₂-MG) and elastase in complex with α₁-AT (NE-α₁-AT complex) in DF. 50 dengue patients [39 DF and 11 dengue hemorrhagic fever (DHF)] and 52 healthy subjects were included in the study. NE was measured using N-succinyl-tri-alanine-p-nitroanilide as substrate. α₁-AT, α₂-MG and NE-α₁-AT complex were estimated by ELISA. The result analysis indicated that the dengue patients had significantly higher elastase activity with significantly reduced inhibitor levels compared to controls. Between DF and DHF patients, DHF group had significantly higher elastase activity. In conclusion, significantly elevated NE and reduced inhibitors level in dengue fever indicate these parameters could be of significance in DF particularly for the assessment of progression of inflammatory processes.

Factor VII and incidence of myocardial infarction in a Japanese population: The Jichi Medical School Cohort Study

BACKGROUND

The role of factor VII (FVII) as a risk factor in myocardial infarction (MI) has been the subject of numerous studies. However, it remains uncertain whether the FVII levels are associated with development of MI.

METHODS

The subjects were 4142 men and women whose activated FVII (FVIIa) and FVII coagulant (FVIIc) levels were measured in the Jichi Medical School Cohort Study. Subjects were divided into tertiles by FVIIa and FVIIc levels, and Cox's proportional hazard model was used to calculate hazard ratios (HRs) for MI.

RESULTS

The multivariate-adjusted HRs (95% confidential interval [CI]) for FVIIa in men were 0.67 (0.67-1.78) in tertile 2 (T2), and 0.52 (0.17-1.60) in T3. In women, the multivariate-adjusted HRs (95% CI) were 0.18 (0.02-1.60) in T2, and 0.39 (0.07-2.20) in T3. The multivariate-adjusted HRs (95% CI) for FVIIc in men were 0.54 (0.21-1.36) in T2, and 0.20 (0.04-0.91) in T3. In women, the multivariate-adjusted HRs (95% CI) were 0.44 (0.07-2.85) in T2, and 0.35 (0.06-2.22) in T3. We used T1 as a reference for all measures.

CONCLUSION

Our findings revealed a significant association between low FVIIc level and incidence of MI in men. The FVIIa and FVIIc levels were inversely related to increased MI risk, but did not reach statistical significance. Future studies are needed to confirm this association.

C5a receptor (CD88) promotes motility and invasiveness of gastric cancer by activating RhoA

PURPOSE

Anaphylatoxin C5a is a strong chemoattractant of the complement system that binds the C5a receptor (C5aR). The expression of C5aR is associated with poor prognosis in several cancers. However, the role of C5aR in gastric cancer (GC) is unknown. The aim of this study was to examine the role of C5aR on GC cell motility and invasion.

EXPERIMENTAL DESIGN

The mechanism of invasion via C5aR was assessed by analyzing cytoskeletal rearrangement and RhoA activity after C5a treatment. Moreover, we investigated the relationship between C5aR expression and the prognosis of GC patients.

RESULTS

Two human GC cell lines (MKN1 and MKN7) had high C5aR expression. An invasion assay revealed that C5a stimulation promoted the invasive ability of MKN1 and MKN7 cells and that this was suppressed by knockdown of C5aR using siRNA or a C5aR-antagonist. Moreover, overexpression of C5aR in GC cells enhanced the conversion of RhoA-guanosine diphosphate (RhoA-GDP) to RhoA-guanosine triphosphate (RhoA-GTP) after C5a stimulation and caused morphological changes, including increased expression of stress fibers and filopodia. Examination of tumor specimens from 100 patients with GC revealed that high C5aR expression (35 of 100 samples, 35.0%) was associated with increased invasion depth, vascular invasion and advanced stage. The 5-year overall survival of patients with high or low C5aR expression was 58.2% and 68.5%, respectively (p=0.008).

CONCLUSIONS

This study is the first to demonstrate that C5aR promotes GC cell invasion by activating RhoA and is associated with a poor prognosis in GC patients. Therefore, this study provides a biomarker for GC patients who require an advanced therapeutic strategy.

Differential effects of an infusion of endotoxin on proximal and distal feline jejunal permeability

The effects of an intravenous infusion of endotoxin (750 μg/kg) or an equal volume of saline solution (control) on the proximal and distal jejunal permeability and blood flow were evaluated in cats. In 8 cats, proximal and distal jejunal segments were isolated and mucosal clearance of 51Cr-ethylenediaminetetraacetic acid (EDTA) was measured. The mucosal clearance in the distal loop was not altered by endotoxin infusion in 6 cats given endotoxin or 2 cats given saline solution. In 6 cats given endotoxin, the proximal jejunal segment exhibited a 10-fold increase in mucosal permeability. In contrast, mucosal clearance remained stable in the proximal jejunal loop in 2 cats infused with saline solution.

In a second group of 13 cats (7 cats infused with endotoxin; 6 cats infused with saline solution), blood flow to the proximal and distal segments was measured. Either endotoxin (n = 7) or saline solution (n = 6) did not significantly alter blood flow to the proximal and distal jejunum in these experiments.

Samples of proximal and distal jejunum were collected from 12 cats (6 cats infused with endotoxin and 6 cats infused with saline solution). There was significantly more epithelial necrosis in the endotoxin treated cats than in the saline treated cats. Neutrophil infiltration was greater in the jejunal segments of endotoxin treated cats than in the jejunal segments of saline treated cats. In the endotoxin treated cats, there was significantly greater necrosis in the proximal jejunal segment than in the distal jejunal segment. There were no significant differences in numbers of neutrophils in the proximal and distal jejunal segments.

These results demonstrate that the proximal jejunum is more sensitive to endotoxin-induced increases in mucosal permeability than is the distal jejunum. The increases in mucosal permeability in the proximal jejunum were not accompanied by significant reductions in jejunal arterial blood flow. Endotoxemia induced neutrophil infiltration to the proximal and distal jejunum.

Do we need antiplatelet therapy in thrombocytosis? Contra. Proposal for an individualized risk-adapted treatment

Thrombocytosis is a frequent laboratory finding but not a diagnosis. Therefore, elevated platelet counts (>450 x 10⁹/l) require careful diagnostic work-up to differentiate between reactive thrombocytosis (RT), caused by various conditions, and essential thrombocythemia (ET), a myeloproliferative neoplasm (MPN). In either setting, aspirin is widely used in clinical practice. However, RT (even at platelet counts >1000 x 10⁹/l) has never been shown to cause thrombosis or bleeding due to acquired von Willebrand factor defects in association with high platelet counts. Identification of reactive conditions and appropriate therapy of the underlying disorder are most relevant. By contrast to RT, ET and related MPN can be associated with thrombosis and/or hemorrhage. Current recommendations suggest the use of low-dose aspirin in all patients with ET unless contraindicated. However, the strength of this recommendation is weak, i. e. evidence level IIb grade B. A potential benefit of aspirin used for primary thromboprophylaxis in ET is mostly derived from the ECLAP study in polycythemia vera (PV). However, translating study results from PV to ET appears to be highly questionable and may be biased. In the absence of robust data regarding the benefit-risk balance of aspirin in ET, it appears reasonable (1) to stratify patients according to their individual thrombotic and bleeding risk, (2) to restrict the use of aspirin to high-risk categories and patients with microcirculatory disturbances, (3) to test for pharmacological efficacy (COX-1 inhibition; measurement of TXB₂), and (4) to modify the aspirin dosing regimen (twice instead of once daily) if required.

Neutrophil-Related Inflammatory Mediators in Septic Acute Respiratory Distress Syndrome

To disclose the participation of neutrophils in septic acute respiratory distress syndrome (ARDS), characteristics of various inflammatory mediators were examined in septic patients. Forty-seven gram-negative septic patients were divided into ARDS (n = 23) and non-ARDS (n = 24) groups at the transferred point to the intensive care unit. The mediators were measured simultaneously at the transferred point, and then subsequently on days 1, 3, and 5. At the transferred point, the ARDS group showed significantly higher levels of interleukin-8 (IL-8), macrophage inflammatory peptide-1-alpha (MIP-1-α), soluble intercellular adhesion molecule-1 (sICAM-1), and neutrophil elas-tase despite lower neutrophil counts compared to the non-ARDS group. The ARDS group sustained significantly higher levels of sICAM-1 until day 5 and neutrophil elas-tase until day 1 compare to the non-ARDS group. Furthermore, nonsurviving ARDS patients (n = 8) showed significantly higher levels of tumor necrosis factor-alpha, IL-6, IL-8, and IL-10 compared to surviving ARDS patients (n = 15) at the transferred point. In conclusion, neutrophil-related inflammatory mediators, IL-8, MIP-1-α, sICAM-1, and neutrophil elastase, appear to possibly participate in septic ARDS. Cytokines might also play an important role in the mortality of such cases.

Activated Neutrophils Are Associated with Pediatric Cerebral Malaria Vasculopathy in Malawian Children

Most patients with cerebral malaria (CM) sustain cerebral microvascular sequestration of Plasmodium falciparum-infected red blood cells (iRBCs). Although many young children are infected with P. falciparum, CM remains a rare outcome; thus, we hypothesized that specific host conditions facilitate iRBC cerebral sequestration. To identify these host factors, we compared the peripheral whole-blood transcriptomes of Malawian children with iRBC cerebral sequestration, identified as malarial-retinopathy-positive CM (Ret+CM), to the transcriptomes of children with CM and no cerebral iRBC sequestration, defined as malarial-retinopathy-negative CM (Ret-CM). Ret+CM was associated with upregulation of 103 gene set pathways, including cytokine, blood coagulation, and extracellular matrix (ECM) pathways (P < 0.01; false-discovery rate [FDR] of <0.05). Neutrophil transcripts were the most highly upregulated individual transcripts in Ret+CM patients. Activated neutrophils can modulate diverse host processes, including the ECM, inflammation, and platelet biology to potentially facilitate parasite sequestration. Therefore, we compared plasma neutrophil proteins and neutrophil chemotaxis between Ret+CM and Ret-CM patients. Plasma levels of human neutrophil elastase, myeloperoxidase, and proteinase 3, but not lactoferrin or lipocalin, were elevated in Ret+CM patients, and neutrophil chemotaxis was impaired, possibly related to increased plasma heme. Neutrophils were rarely seen in CM brain microvasculature autopsy samples, and no neutrophil extracellular traps were found, suggesting that a putative neutrophil effect on endothelial cell biology results from neutrophil soluble factors rather than direct neutrophil cellular tissue effects. Meanwhile, children with Ret-CM had lower levels of inflammation, higher levels of alpha interferon, and upregulation of Toll-like receptor pathways and other host transcriptional pathways, which may represent responses that do not favor cerebral iRBC sequestration.

There were approximately 198 million cases of malaria worldwide in 2013, with an estimated 584,000 deaths occurring mostly in sub-Saharan African children. CM is a severe and rare form of Plasmodium falciparum infection and is associated with high rates of mortality and neurological morbidity, despite antimalarial treatment. A greater understanding of the pathophysiology of CM would allow the development of adjunctive therapies to improve clinical outcomes. A hallmark of CM is cerebral microvasculature sequestration of P. falciparum-infected red blood cells (iRBCs), which results in vasculopathy in some patients. Our data provide a global analysis of the host pathways associated with CM and newly identify an association of activated neutrophils with brain iRBC sequestration. Products of activated neutrophils could alter endothelial cell receptors and coagulation to facilitate iRBC adherence. Future studies can now examine the role of neutrophils in CM pathogenesis to improve health outcomes.

Cyclosporine Does Not Prevent Microvascular Loss in Transplantation but Can Synergize With a Neutrophil Elastase Inhibitor, Elafin, to Maintain Graft Perfusion During Acute Rejection

The loss of a functional microvascular bed in rejecting solid organ transplants is correlated with fibrotic remodeling and chronic rejection; in lung allografts, this pathology is predicted by bronchoalveolar fluid neutrophilia which suggests a role for polymorphonuclear cells in microcirculatory injury. In a mouse orthotopic tracheal transplant model, cyclosporine, which primarily inhibits T cells, failed as a monotherapy for preventing microvessel rejection and graft ischemia. To target neutrophil action that may be contributing to vascular injury, we examined the effect of a neutrophil elastase inhibitor, elafin, on the microvascular health of transplant tissue. We showed that elafin monotherapy prolonged microvascular perfusion and enhanced tissue oxygenation while diminishing the infiltration of neutrophils and macrophages and decreasing tissue deposition of complement C3 and the membrane attack complex, C5b-9. Elafin was also found to promote angiogenesis through activation of the extracellular signal-regulated kinase (ERK) signaling pathway but was insufficient as a single agent to completely prevent tissue ischemia during acute rejection episodes. However, when combined with cyclosporine, elafin effectively preserved airway microvascular perfusion and oxygenation. The therapeutic strategy of targeting neutrophil elastase activity alongside standard immunosuppression during acute rejection episodes may be an effective approach for preventing the development of irreversible fibrotic remodeling.

Neutrophil-related factors as biomarkers in EAE and MS

Using a mouse model of multiple sclerosis (MS), the authors show that neutrophils expand in the bone marrow and accumulate in the circulation before clinical onset of disease. Early in disease development, neutrophils infiltrate the CNS, which is suppressed by G-CSF receptor deficiency and blockade of CXCL1 to ameliorate disease. In patients with MS, systemic expression of neutrophil-related mediators correlates with new lesion formation, lesion burden, and clinical disability.

A major function of T helper (Th) 17 cells is to induce the production of factors that activate and mobilize neutrophils. Although Th17 cells have been implicated in the pathogenesis of multiple sclerosis (MS) and the animal model experimental autoimmune encephalomyelitis (EAE), little attention has been focused on the role of granulocytes in those disorders. We show that neutrophils, as well as monocytes, expand in the bone marrow and accumulate in the circulation before the clinical onset of EAE, in response to systemic up-regulation of granulocyte colony-stimulating factor (G-CSF) and the ELR⁺ CXC chemokine CXCL1. Neutrophils comprised a relatively high percentage of leukocytes infiltrating the central nervous system (CNS) early in disease development. G-CSF receptor deficiency and CXCL1 blockade suppressed myeloid cell accumulation in the blood and ameliorated the clinical course of mice that were injected with myelin-reactive Th17 cells. In relapsing MS patients, plasma levels of CXCL5, another ELR⁺ CXC chemokine, were elevated during acute lesion formation. Systemic expression of CXCL1, CXCL5, and neutrophil elastase correlated with measures of MS lesion burden and clinical disability. Based on these results, we advocate that neutrophil-related molecules be further investigated as novel biomarkers and therapeutic targets in MS.

Correlation between the major components of Phyllanthus amarus and Phyllanthus urinaria and their inhibitory effects on phagocytic activity of human neutrophils

Background

Recently, we have highlighted the immunomodulatory activity of the standardized extracts of Phyllanthus amarus and P. urinaria. The present study was carried out to correlate between the prevalent constituents of the herbs and their inhibitory effects on phagocytic activity of human neutrophils.

Methods

The compounds, gallic acid, ellagic acid, corilagin, geraniin, phyllanthin and hypophyllanthin were identified and quantitatively analyzed in the extracts of Phyllanthus amarus and P. urinaria obtained from Malaysia and Indonesia by using a validated reversed phase high performance liquid chromatography (RP-HPLC) method. The standardized extracts and the pure compounds were evaluated for their effects on chemotaxis, β2 integrin (CD18) expression, phagocytosis and chemiluminescence of human phagocytes. Chemotactic activity was assessed using the Boyden chamber technique, inhibition of CD18 expression and phagocytic ability were tested with the aid of flow cytometry, while effect on the respiratory burst was investigated using a luminol-based chemiluminescence assay.

Results

All plant extracts strongly inhibited migration of the phagocytes with the Malaysian P. amarus depicting the highest inhibitory activity. Amongst the compounds tested, geraniin demonstrated the strongest inhibitory activity on chemotaxis of polymorphonuclear leukocytes (PMNs) and monocytes with IC₅₀ values of 1.09 and 1.69 μM, respectively, which were lower than that of ibuprofen. All plant extracts and pure compounds exhibited high inhibitory activity on the oxidative burst of zymosan and PMA stimulated leukocytes. Geraniin and corilagin exhibited exceptionally strong inhibition on the reactive oxygen species (ROS) activity with IC₅₀ values lower than aspirin. The plant extracts exhibited moderate inhibition of E. coli uptake by monocytes but weak effect on PMNs. Of all the compounds, phyllanthin at 50 μg/mL exhibited the highest engulfment inhibitory activity with percentage of phagocytizing cells of 14.2 and 27.1% for PMNs and monocytes, respectively. All plants and compounds tested possessed weak effect on CD18 expression on leukocytes except for hypophyllanthin and phyllanthin which exhibited significant inhibitory effect.

Conclusion

The strong inhibition of the extracts on the phagocytic activity of neutrophils was due to the presence of their major constituents especially geraniin, corilagin, phyllanthin and hypophllanthin which were able to modulate the innate response of phagocytes at different steps.

Activated neutrophils induce epithelial cell apoptosis through oxidant-dependent tyrosine dephosphorylation of caspase-8

Activated neutrophils can injure host cells through direct effects of oxidants on membrane phospholipids, but an ability to induce apoptotic cell death has not previously been reported. We show that neutrophils activated in vivo in patients who have sustained multiple trauma or in vitro by exposure to bacterial lipopolysaccharide promote epithelial cell apoptosis through SHP-1-mediated dephosphorylation of epithelial cell caspase-8. Epithelial cell apoptosis induced by circulating neutrophils from patients who had sustained serious injury depended on the generation of neutrophil-derived reactive oxygen intermediates and was blocked by inhibition of NADPH oxidase or restoration of intracellular glutathione. Caspase-8 was constitutively tyrosine phosphorylated in a panel of resting epithelial cells, but underwent SHP-1-dependent dephosphorylation in response to hydrogen peroxide, activated neutrophils, or inhibition of Src kinases. Cells transfected with a mutant caspase-8 in which tyrosine residues at Tyr397 or Tyr465 are replaced by nonphosphorylatable phenylalanine underwent accelerated apoptosis, whereas either mutation of these residues to phosphomimetic glutamic acid or transfection with the Src kinases Lyn or c-Src inhibited hydrogen peroxide-induced apoptosis. Exposure to either hydrogen peroxide or lipopolysaccharide-stimulated neutrophils increased phosphorylation and activity of the phosphatase SHP-1, increased activity of caspases 8 and 3, and accelerated epithelial cell apoptosis. These observations reveal a novel mechanism for neutrophil-mediated tissue injury through oxidant-dependent, SHP-1-mediated dephosphorylation of caspase-8 resulting in enhanced epithelial cell apoptosis.

Another look at the life of a neutrophil

Neutrophils are considered as the privates of the innate immune system. They are born in the bone marrow, migrate to the tissues where they kill putative intruders. After their job they are quickly removed from the battlefield by macrophages. This view of a predetermined pathway fitted nicely in their short lifespan of 5 h. However, recent studies indicated that their lifespan was in the order of several days. Recently, it became clear that neutrophils have functions beyond killing of pathogens. The reported half-life of 5 h is hardly compatible with those functions. Moreover, the organism actively invests in rescuing primed neutrophils from clearance by the body. It appears that their half-life is highly dependent on the method used to measure their life span. Here, we discuss the literature and show that neutrophils compartmentalize which could explain partially the differences reported for their lifespan. Moreover, the methodology to label neutrophils ex-vivo could have similar deteriorating effects on their lifespan as found for transfused red blood cells.

Beneficial effects of trypsin inhibitors derived from a spider venom peptide in L-arginine-induced severe acute pancreatitis in mice

HWTI is a 55-residue protein isolated from the venom of the spider Ornithoctonus huwena. It is a potent trypsin inhibitor and a moderate voltage-gated potassium channel blocker. Here, we designed and expressed two HWTI mutants, HWTI-mut1 and HWTI-mut2, in which the potassium channel inhibitory activity was reduced while the trypsin inhibitory activity of the wild type form (approximately 5 EPU/mg) was retained. Animal studies showed that these mutants were less toxic than HWTI. The effects of HWTI and HWTI-mut1 were examined in a mouse model of acute pancreatitis induced by intraperitoneal injection of a large dose of L-arginine (4 mg/kg, twice). Serum amylase and serum lipase activities were assessed, and pathological sections of the pancreas were examined. Treatment with HWTI and HWTI-mut1 significantly reduced serum amylase and lipase levels in a dose dependent manner. Compared with the control group, at 4 mg/kg, HWTI significantly reduced serum amylase level by 47% and serum lipase level by 73%, while HWTI-mut1 significantly reduced serum amylase level by 59% and serum lipase level by 72%. Moreover, HWTI and HWTI-mut1 effectively protected the pancreas from acinar cell damage and inflammatory cell infiltration. The trypsin inhibitory potency and lower neurotoxicity of HWTI-mut1 suggest that it could potentially be developed as a drug for the treatment of acute pancreatitis with few side effects.

High-density lipoproteins limit neutrophil-induced damage to the blood-brain barrier in vitro

Breakdown of the blood-brain barrier (BBB) is a key step associated with ischemic stroke and its increased permeability causes extravasation of plasma proteins and circulating leukocytes. Polymorphonuclear neutrophil (PMN) proteases may participate in BBB breakdown. We investigated the role of PMNs in ischemic conditions by testing their effects on a model of BBB in vitro, under oxygen-glucose deprivation (OGD) to mimic ischemia, supplemented or not with high-density lipoproteins (HDLs) to assess their potential protective effects. Human cerebral endothelial cells cultured on transwells were incubated for 4 hours under OGD conditions with or without PMNs and supplemented or not with HDLs or alpha-1 antitrypsin (AAT, an elastase inhibitor). The integrity of the BBB was then assessed and the effect of HDLs on PMN-induced proteolysis of extracellular matrix proteins was evaluated. The release of myeloperoxidase and matrix metalloproteinase 9 (MMP-9) by PMNs was quantified. Polymorphonuclear neutrophils significantly increased BBB permeability under OGD conditions via proteolysis of extracellular matrix proteins. This was associated with PMN degranulation. Addition of HDLs or AAT limited the proteolysis and associated increased permeability by inhibiting PMN activation. Our results suggest a deleterious, elastase-mediated role of activated PMNs under OGD conditions leading to BBB disruption that could be inhibited by HDLs.

Lercanidipine effect on polymorphonuclear leukocyte-related inflammation and insulin resistance in essential hypertension patients

INTRODUCTION

Inflammation, insulin resistance, and oxidative stress (OS) are among the mechanisms that have been implicated in the pathogenesis of essential hypertension (EH). Peripheral polymorphonuclear leukocytes (PMNLs) are primed in EH patients, releasing uncontrolled superoxide anions contributing to OS in these patients. PMNL priming correlates with insulin resistance and PMNL intracellular calcium ([Ca(2+)]i). Recent studies have attributed additional anti-ischemic and antioxidative characteristics to the antihypertensive drug, lercanidipine, a third-generation calcium-channel blocker. The purpose of this study was to evaluate the possible nontraditional effect of 2 months of lercanidipine treatment on insulin resistance and on PMNL-related inflammation in EH patients.

METHODS

Non-smoking EH patients with untreated mild-to-moderate high blood pressure (BP) were included. Low-grade inflammation was reflected by PMNL apoptosis and by white blood cell (WBC) and PMNL counts. Systemic inflammation was measured by plasma fibrinogen, C-reactive protein (CRP), and transferrin and albumin levels. Fasting serum insulin levels served as a marker of insulin resistance.

RESULTS

Two months of lercanidipine treatment showed a significant decrease in BP, WBC, and PMNL counts, PMNL apoptosis, CRP, and serum insulin levels, and a significant increase in serum albumin levels. Rates of superoxide release from PMNLs, WBC and PMNL counts, and insulin levels positively correlated with mean arterial BP values.

CONCLUSION

The use of lercanidipine can be favorable in EH patients due to its combined anti-PMNL priming and anti-inflammatory effects, in addition to its antihypertensive characteristics.

Acute lung injury results from failure of neutrophil de-priming: a new hypothesis

Neutrophils are the most abundant circulating white cell in humans and play a crucial role in the innate immune response. Accumulation and activation of neutrophils, together with delayed clearance, have been shown to be a key event in the pathogenesis of acute lung injury. Previously, it has been proposed that there is substantial pooling of neutrophils within the pulmonary vasculature, even under physiological conditions, making the lung especially vulnerable to neutrophil-mediated tissue injury. However, more recent evidence suggests that only primed neutrophils accumulate in the pulmonary vasculature. This article examines the evidence for these two opposing views and proposes a new two-step model for the recruitment of neutrophils into the lung. Firstly, neutrophils that become primed, by exposure to a range of inflammatory mediators or physicochemical perturbations, become shape changed and stiff because of alterations in their cytoskeleton, and as a result, accumulate within the pulmonary circulation. In the absence of further stimuli, the healthy pulmonary vasculature is able to selectively retained these primed cells, allow them to 'de-prime' and be released back into the circulation in a quiescent, state. If this pulmonary 'de-priming' mechanism fails, or a second insult occurs, such as ventilator-associated barotrauma, which causes loss of alveolar integrity, primed neutrophils migrate from the pulmonary vasculature into the interstitial space with resultant lung injury. This canonical 'two step' model highlights the importance of neutrophil priming in the genesis of lung injury and the importance of adopting strategies to minimise alveolar injury.

Contribution of neutrophil-derived myeloperoxidase in the early phase of fulminant acute respiratory distress syndrome induced by influenza virus infection

Because the pathogenesis of acute respiratory distress syndrome (ARDS) induced by influenza virus infection remains unknown, we can only improve on existing therapeutic interventions. To approach the subject, we investigated immunological etiology focused on cytokines and an acute lung damage factor in influenza-induced ARDS by using a PR-8 (A/H1N1)-infected mouse model. The infected mouse showed fulminant severe pneumonia with leukocyte infiltration, claudin alteration on tight junctions, and formation of hyaline membranes. In addition to interferon (IFN)-α, plenty of keratinocyte-derived chemokines (KC), macrophage inflammatory protein 2 (MIP-2), regulated on activation normal T-cell expressed and secreted (RANTES), and monocyte chemotactic protein 1 (MCP-1) were significantly released into bronchoalveolar lavage fluid (BALF) of the model. We focused on neutrophil myeloperoxidase (MPO) as a potent tissue damage factor and examined its contribution in influenza pneumonia by using mice genetically lacking in MPO. The absence of MPO reduced inflammatory damage with suppression of leakage of total BALF proteins associated with alteration of claudins in the lung. MPO(-/-) mice also suppressed viral load in the lung. The present study suggests that MPO-mediated OCl(-) generation affects claudin molecules and leads to protein leakage and viral spread as a damage factor in influenza-induced ARDS.

The immunologic outcome of enhanced function of mouse liver lymphocytes and Kupffer cells by high-fat and high-cholesterol diet

Dietary lipids/cholesterol may modulate liver immune function. We have recently found that mouse F4/80 Kupffer cells are classified into phagocytic CD68 Kupffer cells and cytokine-producing CD11b Kupffer cells. We here investigate how a high-fat and/or high-cholesterol diet affects innate immune liver mononuclear cells. For 4 weeks, C57BL/6 mice were fed a high-fat and high-cholesterol diet (HFCD), a high-cholesterol diet (HCD), a high-fat diet (HFD), or a control diet (CD). High-fat and high-cholesterol diet and HCD increased liver cholesterol levels; serum cholesterol levels increased in HFCD and HFD mice but not in HCD mice. The increased proportion of natural killer (NK) cells, downregulated NK1.1 expression of natural killer T cells, and enhanced CD69 and IL-12 receptor β mRNA expression of liver lymphocytes indicate the activation of them by HFCD. IL-12 production from Kupffer cells and interferon γ production from NK/natural killer T cells activated by LPS and/or IL-12 both increased. IL-12 pretreatment more effectively improved the survival of HFCD mice relative to the survival of CD mice upon injections of liver metastatic EL-4 cells. In contrast, HFCD mouse survival decreased after LPS injection and generalized Shwartzman reaction. Consistently in HFCD mice, Toll-like receptor 4 mRNA expression of whole Kupffer cells was upregulated, and CD11b Kupffer cells proportionally increased. Although the proportion of CD68 Kupffer cells decreased in HFCD mice, phagocytic activity of them was enhanced. Mice fed with HCD rather than those fed with HFD showed features closer to HFCD mice. Thus, enhanced function of mouse liver mononuclear cells is likely dependent on the liver cholesterol level, rather than the liver triglyceride level.

Role of chemokines in the pathogenesis of acute lung injury

Acute lung injury (ALI) is due to an uncontrolled systemic inflammatory response resulting from direct injury to the lung or indirect injury in the setting of a systemic process. Such insults lead to the systemic inflammatory response syndrome (SIRS), which includes activation of leukocytes-alveolar macrophages and sequestered neutrophils-in the lung. Although systemic inflammatory response syndrome is a physiologic response to an insult, systemic leukocyte activation, if excessive, can lead to end organ injury, such as ALI. Excessive recruitment of leukocytes is critical to the pathogenesis of ALI, and the magnitude and duration of the inflammatory process may ultimately determine the outcome in patients with ALI. Leukocyte recruitment is a well orchestrated process that depends on the function of chemokines and their receptors. Understanding the mechanisms that contribute to leukocyte recruitment in ALI may ultimately lead to the development of effective therapeutic strategies.

Trauma-activated polymorphonucleated leukocytes damage endothelial progenitor cells: probable role of CD11b/CD18-CD54 interaction and release of reactive oxygen species

Endothelial progenitor cells (EPCs) and polymorphonucleated leukocytes (PMNLs) migrate to and accumulate at the site of tissue injury where they express complementary sets of surface receptors (CD11b/CD18, CD54), suggesting a possible cellular interaction. Trauma-activated PMNLs release inflammatory mediators and reactive oxygen species (ROS) produced by the NADPH oxidase, which may negatively impact EPCs. To characterize the interactions between PMNLs and EPCs, we identified common surface receptors and measured the role played by NADPH oxidase and neutrophil elastase. Polymorphonucleated leukocytes were obtained from either healthy volunteers or multiple-trauma patients. After stimulation with either n-formyl-l-methionyl-l-leucyl-l-phenylalanine or phorbol 12-myristate 13-acetate, the PMNLs were incubated with DiL-prestained EPCs in a ratio of 20:1 for 3 h. Early EPCs were isolated from buffy coat. Endothelial progenitor cell killing was measured by flow cytometry, and necrotic EPCs were identified by measuring the uptake of 7-aminoactinomycin. We found that blocking CD11b, CD18, or CD54 on the EPC surface with monoclonal antibodies or blocking the intracellular production of ROS by neutralizing neutrophil's NADPH oxidase with a diphenyliodonium chloride pretreatment protected EPCs, enhancing its survival, whereas inhibiting neutrophil elastase had no effect on survival. Furthermore, we observed that native PMNLs obtained from multiple-trauma patients damaged EPCs, whereas native PMNLs from healthy volunteers did not. Our results demonstrate that EPCs and PMNLs do interact via complementary receptors and that this interaction results in PMNL-derived ROS-induced EPC damage. The effect of neutrophil-derived elastase was found to be negligible. These findings suggest that EPC damage by activated PMNLs may contribute to impaired wound healing observed after severe trauma.

Early administration of sivelestat, the neutrophil elastase inhibitor, in adults for acute lung injury following gastric aspiration

Gastric aspiration is the major cause of acute lung injury (ALI) and acute respiratory distress syndrome. Aspiration-induced ALI is believed to be, at least in part, facilitated by neutrophil-derived mediators and toxic molecules. We conducted a prospective cohort study based on the hypothesis that sivelestat, a specific neutrophil elastase inhibitor, is effective for treating ALI following gastric aspiration. Forty-four ALI patients who showed evidence of aspiration were observed within 12 h before intensive care unit admission and who had been mechanically ventilated within 12 h after admission were included in this study. Lung injury score (LIS) and PAO2/FiO2 (P/F) ratio on day 7 were defined as the primary outcomes of the study. Twenty-three patients were assigned to the sivelestat group and 21 to the control group. In univariate analyses, the proportions of patients with LIS lower than 1.0 on day 7 and a P/F greater than 300 on day 7 were significantly higher in the sivelestat group than in the control group (60.9% vs. 26.3%, P = 0.03; 87.0% vs. 36.8%, P = 0.001). In the logistic regression model, the use of sivelestat was an independent predictor for LIS lower than 1.0 on day 7 (relative risk, 7.4; 95% confidence interval [CI], 1.51-36.48) and for a P/F ratio higher than 300 on day 7 (relative risk, 18.5; 95% CI, 2.72-126.46). In the Cox proportional hazards model, the use of sivelestat was associated with a lower cumulative proportion of patients who received mechanical ventilation during the initial 14 days (hazard ratio, 2.6; 95% CI, 1.17-5.55).

The effect of sivelestat sodium hydrate on severe respiratory failure after thoracic aortic surgery with deep hypothermia

Patients who undergo thoracic aortic surgery with deep hypothermia frequently have postoperative respiratory failure as a complication. Severe lung injury in these patients results in a fatal outcome. A specific neutrophil elastase inhibitor, sivelestat sodium hydrate, is an innovative therapeutic drug for acute lung injury. We evaluated the protective effects of sivelestat sodium hydrate on severe lung injury after thoracic aortic surgery with deep hypothermia. From January 2002 to July 2007, 71 consecutive patients underwent thoracic aortic surgery with deep hypothermia. Of these patients, 22 had postoperative respiratory failure with PaO₂/FiO₂ ratios of less than 150. They were randomly assigned to one of two groups. The first group (Group S, n = 10) was administered sivelestat sodium hydrate continuously at 0.2 mg/kg/h until weaning from mechanical ventilation; the second group (Group C, n = 12) was not administered sivelestat sodium hydrate. The groups were comparable with respect to clinical data. There were no significant differences between the two groups in age, operation duration, total cardiopulmonary bypass time, circulatory ischemia time, cardiac arrest time, intraoperative blood loss, and total transfusion volume. The improvement of pulmonary function was observed in the both groups, but more marked in Group S by statistical analysis using analysis of variance for repeated measurements. Especially, in the early phase, pulmonary function improvement was more marked in Group S. The duration of mechanical ventilation, the length of stay in the intensive care unit, and the length of hospital stay were shorter in Group S, but not significantly. Sivelestat sodium hydrate is a specific neutrophil elastase inhibitor that improves pulmonary function in patients with severe postoperative respiratory failure following thoracic aortic surgery with deep hypothermia. The drug may shorten the duration of postoperative ventilation, intensive care unit stay, and hospital stay.

Urinary trypsin inhibitor attenuates seawater-induced acute lung injury by influencing the activities of nuclear factor-ĸB and its related inflammatory mediators

BACKGROUND

Few data are available on the role of neutrophil elastase (NE) and nuclear factor-κB (NF-κB) in the course of seawater drowning-induced acute lung injury (SWD-ALI), and there is no evidence on the value of giving urinary trypsin inhibitor (UTI) in the case of SWD-ALI.

OBJECTIVE

To investigate the role of NF-κB and NE in the pathogenesis of SWD-ALI and whether UTI treatment can attenuate SWD-ALI in rabbits.

METHODS

Rabbits were randomly assigned to control, seawater drowning, and UTI treatment groups. The rabbits in the control group only suffered from intubation, whereas the rabbits in the seawater drowning group and the UTI treatment group received arterial injection of normal saline without/with 50,000 U/kg body weight of UTI after instillation of seawater into an endotracheal catheter. The activities or contents of NF-κB, MPO, NE, TNF-α, and IL-10 in lung tissue were measured by nonradioactive EMSA, biochemical methods, and ELISA, respectively.

RESULTS

After the seawater challenge, all of the rabbits demonstrated immediate drops in arterial PaO(2)/FiO(2) and pronounced pulmonary edema and inflammatory cell infiltration with evidence of an increase in the ratio of wet weight to dry weight, lung permeability index, lung injury scores, and the activities or contents of NF-κB, NE, MPO, TNF-α, and IL-10. UTI treatment markedly attenuated lung histopathological changes with evidence of a decrease in all of the parameters, except for upregulation of IL-10. Arterial PaO(2)/FiO(2) was significantly improved after 6 h of UTI treatment.

CONCLUSION

These results suggest that NF-κB and NE play an important role in SWD-ALI. UTI protects against SWD-ALI, at least partly, through inhibition of the enhanced local activity of NF-κB, contents of TNF-α and NE, and infiltration of neutrophils and promotion of the level of IL-10.

Reduction of neutrophil activity decreases early microvascular injury after subarachnoid haemorrhage

Background

Subarachnoid haemorrhage (SAH) elicits rapid pathological changes in the structure and function of parenchymal vessels (≤ 100 μm). The role of neutrophils in these changes has not been determined. This study investigates the role of neutrophils in early microvascular changes after SAH

Method

Rats were either untreated, treated with vinblastine or anti-polymorphonuclear (PMN) serum, which depletes neutrophils, or treated with pyrrolidine dithiocarbamate (PDTC), which limits neutrophil activity. SAH was induced by endovascular perforation. Neutrophil infiltration and the integrity of vascular endothelium and basement membrane were assessed immunohistochemically. Vascular collagenase activity was assessed by in situ zymography.

Results

Vinblastine and anti-PMN serum reduced post-SAH accumulation of neutrophils in cerebral vessels and in brain parenchyma. PDTC increased the neutrophil accumulation in cerebral vessels and decreased accumulation in brain parenchyma. In addition, each of the three agents decreased vascular collagenase activity and post-SAH loss of vascular endothelial and basement membrane immunostaining.

Conclusions

Our results implicate neutrophils in early microvascular injury after SAH and indicate that treatments which reduce neutrophil activity can be beneficial in limiting microvascular injury and increasing survival after SAH.

Sivelestat relaxes vascular smooth muscle contraction in human gastric arteries

Sivelestat sodium hydrate (sivelestat) is a novel synthetic drug and specific inhibitor of neutrophil elastase that has been approved in Japan as a treatment for acute lung injury associated with systemic inflammatory response syndrome. It is important to determine how sivelestat affects hemodynamics and the regulatory mechanisms of vascular smooth muscle (VSM). We recently found that sivelestat relaxes porcine coronary artery VSM via selective inhibition of Ca(2+) sensitization induced by a receptor agonist without affecting the normal Ca(2+)-induced contraction. Although sivelestat relaxes porcine artery, its effects on human artery are unknown; therefore, the purpose of the present study was to assess the effects of sivelestat on human artery. In the present study, sivelestat induced concentration-dependent (1 × 10(-6) to 3 × 10(-4) M) vasorelaxation in U46619 (1 nM) and sphingosylphosphorylcholine (SPC) (30 mM)-precontracted human gastric artery with or without endothelium, but sivelestat did not induce vasorelaxation in conditions of high K(+) (40 mM) depolarization. Sivelestat inhibited VSM contraction by an agonist and SPC, and it did not affect Ca(2+)-induced normal physiologic contraction.