[Vascular hyperpermeable molecules potentially contributing to the development of pulmonary edema in sepsis-associated ARDS].

The acute respiratory distress syndrome (ARDS) is an important cause of respiratory failure in critically ill patients and may become a life-threatening condition where inflammation of the lungs may begin in one lung but eventually affects both, leading to damage to the alveoli and surrounding small blood vessels. ARDS is particularly characterized by noncardiogenic pulmonary edema caused by an increase in pulmonary capillary permeability. Several clinical disorders can precipitate in ARDS, including pneumonia, sepsis, aspiration of gastric contents, and major trauma. The most common cause of ARDS is sepsis, which is a serious and widespread infection of the bloodstream and is now defined as life-threatening organ dysfunction due to a dysregulated reponse of the host to infection. In sepsis, a number of vascular hyperpermeable factors, such as histamine, nitric oxide, thromboxane A2, and vascular endothelial growth factor, can be overproducted and contribute to the development of pulmonary edema. Given that sepsis can be regarded as a gene-related disorder, the nucleic-acid based gene therapeutic strategy to regulate some transcription factors involved in expression of vascular hyperpermeable genes may be considered to be a promising novel approach for treatment of ARDS in sepsis.

Survey on the current status of the indication and implementation protocols for bile replacement in patients with external biliary drainage with special reference to infection control.

PURPOSE: This survey of bile replacement (BR) was conducted on patients with external biliary drainage to assess the current status of indication and implementation protocol of BR with special reference to infection control. METHODS: A 12-item questionnaire regarding the performance of perioperative BR was sent to 124 institutions in Japan. RESULTS: BR was performed in 29 institutions, and the indication protocol was introduced in 19. BR was performed preoperatively in 11 institutions, pre- and postoperatively in 12, and postoperatively in 6. The methods used for BR administration included oral intake (n = 10), nasogastric tube (n = 1), enteral nutrition tube (n = 3), oral intake and enteral nutrition tube (n = 6), oral intake or nasogastric tube (n = 2), nasogastric tube and enteral nutrition tube (n = 2), and oral intake or nasogastric tube and enteral nutrition tube (n = 5). In 10 of 29 institutions, isolation of multidrug-resistant organisms and a high bacterial load were considered contraindications for the use of BR. Seven institutions experienced environmental contamination. CONCLUSIONS: Given the different implementation of BR among institutions, the appropriate indication and protocols for BR should be established for infection control.

The Japanese Clinical Practice Guidelines for Management of Sepsis and Septic Shock 2020 (J-SSCG 2020).

The Japanese Clinical Practice Guidelines for Management of Sepsis and Septic Shock 2020 (J-SSCG 2020), a Japanese-specific set of clinical practice guidelines for sepsis and septic shock created as revised from J-SSCG 2016 jointly by the Japanese Society of Intensive Care Medicine and the Japanese Association for Acute Medicine, was first released in September 2020 and published in February 2021. An English-language version of these guidelines was created based on the contents of the original Japanese-language version. The purpose of this guideline is to assist medical staff in making appropriate decisions to improve the prognosis of patients undergoing treatment for sepsis and septic shock. We aimed to provide high-quality guidelines that are easy to use and understand for specialists, general clinicians, and multidisciplinary medical professionals. J-SSCG 2016 took up new subjects that were not present in SSCG 2016 (e.g., ICU-acquired weakness [ICU-AW], post-intensive care syndrome [PICS], and body temperature management). The J-SSCG 2020 covered a total of 22 areas with four additional new areas (patient- and family-centered care, sepsis treatment system, neuro-intensive treatment, and stress ulcers). A total of 118 important clinical issues (clinical questions, CQs) were extracted regardless of the presence or absence of evidence. These CQs also include those that have been given particular focus within Japan. This is a large-scale guideline covering multiple fields; thus, in addition to the 25 committee members, we had the participation and support of a total of 226 members who are professionals (physicians, nurses, physiotherapists, clinical engineers, and pharmacists) and medical workers with a history of sepsis or critical illness. The GRADE method was adopted for making recommendations, and the modified Delphi method was used to determine recommendations by voting from all committee members. As a result, 79 GRADE-based recommendations, 5 Good Practice Statements (GPS), 18 expert consensuses, 27 answers to background questions (BQs), and summaries of definitions and diagnosis of sepsis were created as responses to 118 CQs. We also incorporated visual information for each CQ according to the time course of treatment, and we will also distribute this as an app. The J-SSCG 2020 is expected to be widely used as a useful bedside guideline in the field of sepsis treatment both in Japan and overseas involving multiple disciplines.

Impact of a long-term high-glucose environment on pro-inflammatory responses in macrophages stimulated with lipopolysaccharide.

Cumulative evidence has established that macrophages orchestrate inflammatory responses that crucially contribute to the pathogenesis of insulin-resistant obesity and type 2 diabetes. In the present study, we examined the impact of hyperglycemia on macrophage pro-inflammatory responses under an inflammatory stimulus. To conduct this study, RAW264.7 macrophages were cultured under normal- (5.5 mM) or high-glucose (22 or 40 mM) conditions for 7 days and stimulated with lipopolysaccharide (LPS). Long-term exposure to high glucose significantly enhanced the increase in the production of pro-inflammatory cytokines, including tumor necrosis-α, interleukin (IL)-1ß, and IL-6, when macrophages were stimulated with LPS. The LPS-induced increases in inducible nitric oxide (NO) synthase (iNOS) expression and NO production were also significantly enhanced by long-term exposure of macrophages to high glucose. Treatment with N-acetyl-L-cysteine, a widely used thiol-containing antioxidant, blunted the enhancement of the LPS-induced upregulation of pro-inflammatory cytokine production, iNOS expression, and NO production in macrophages. When intracellular reactive oxygen species (ROS) were visualized using the fluorescence dye 5-(and-6)-chloromethyl-2',7'-dichlorofluorescein diacetate, acetyl ester, a significant increase in ROS generation was found after stimulation of macrophages with LPS, and this increased ROS generation was exacerbated under long-term high-glucose conditions. LPS-induced translocation of phosphorylated nuclear factor-κB (NF-κB), a transcription factor regulating many pro-inflammatory genes, into the nucleus was promoted under long-term high-glucose conditions. Altogether, the present results indicate that a long-term high-glucose environment can enhance activation of NF-κB in LPS-stimulated macrophages possibly due to excessive ROS production, thereby leading to increased macrophage pro-inflammatory responses.

A case of reexpansion pulmonary edema and acute pulmonary thromboembolism associated with diffuse large B-cell lymphoma treated with venovenous extracorporeal membrane oxygenation.

A 37-year-old man diagnosed with diffuse large B-cell lymphoma two weeks previously, visited our emergency department with sudden dyspnea. He had a severe respiratory failure with saturated percutaneous oxygen at 80% (room air). Chest radiography showed a large amount of left pleural effusion. After 1000 mL of the effusion was urgently drained, reexpansion pulmonary edema (RPE) occurred. Despite ventilator management, oxygenation did not improve and venovenous extracorporeal membrane oxygenation (VV-ECMO) was initiated in the intensive care unit. The next day, contrast-enhanced computed tomography showed a massive thrombus in the right pulmonary artery, at this point the presence of pulmonary thromboembolism (PTE) was revealed. Fortunately, the patient's condition gradually improved with anticoagulant therapy and VV-ECMO support. VV-ECMO was successfully discontinued on day 4, and chemotherapy was initiated on day 8. We speculated the following mechanism in this case: blood flow to the right lung significantly reduced due to acute massive PTE, and blood flow to the left lung correspondingly increased, which could have caused RPE in the left lung. Therefore, our observations suggest that drainage of pleural effusion when contralateral blood flow is impaired due to acute PTE may increase the risk of RPE. .

Vascular endothelial growth factor contributes to lung vascular hyperpermeability in sepsis-associated acute lung injury.

Vascular endothelial growth factor (VEGF) is a prime regulator of vascular permeability. Acute lung injury (ALI) is characterized by high-permeability pulmonary edema in addition to refractory hypoxemia and diffuse pulmonary infiltrates. In this study, we examined whether VEGF can be implicated as a pulmonary vascular permeability factor in sepsis-associated ALI. We found that a great increase in lung vascular leak occurred in mice instilled intranasally with lipopolysaccharide (LPS), as assessed by IgM levels in bronchoalveolar lavage fluid. Treatment with the VEGF-neutralizing monoclonal antibody bevacizumab significantly reduced this hyperpermeability response, suggesting active participation of VEGF in non-cardiogenic lung edema associated with LPS-induced ALI. However, this was not solely attributable to excessive levels of intrapulmonary VEGF. Expression levels of VEGF were significantly reduced in lung tissues from mice with both intranasal LPS administration and cecal ligation and puncture (CLP)-induced sepsis, which may stem from decreases in non-endothelial cells-dependent VEGF production in the lungs. In support of this assumption, stimulation with LPS and interferon-γ (IFN-γ) significantly increased VEGF in human pulmonary microvascular endothelial cells (HPMECs) at mRNA and protein levels. Furthermore, a significant rise in plasma VEGF levels was observed in CLP-induced septic mice. The increase in VEGF released from HPMECs after LPS/IFN-γ challenge was completely blocked by either specific inhibitor of mitogen-activated protein kinase (MAPK) subgroups. Taken together, our results indicate that VEGF can contribute to the development of non-cardiogenic lung edema in sepsis-associated ALI due to increased VEGF secretion from pulmonary vascular endothelial cells through multiple MAPK-dependent pathways.

miR-146a targeted to splenic macrophages prevents sepsis-induced multiple organ injury.

Development of a novel agent against life-threatening sepsis requires the in-depth understanding of the relevant pathophysiology and therapeutic targets. Given the function of microRNAs (miRNAs) as potent oligonucleotide therapeutics, here we investigated the pathophysiological role of exogenously applied miRNA in sepsis-induced multiple organ injury. In vitro, miR-16, miR-126, miR-146a, and miR-200b suppressed the production of pro-inflammatory cytokines in RAW264.7 macrophage cells after lipopolysaccharide (LPS) stimulation. Of these, miR-146a displayed the most highly suppressive effect, wherein the transcriptional activity of nuclear factor kappa B (NF-κB) was decreased via targeting of interleukin 1 receptor-associated kinase 1 and tumor necrosis receptor-associated factor 6. Sepsis was induced in mice via cecal ligation and puncture (CLP) and an intravenous injection of a complex of miR-146a-expressing plasmid and polyethyleneimine. Treatment with this complex significantly decreased the level of serum inflammatory cytokines, attenuated organ injury including kidney injury, and led to increased survival from polymicrobial sepsis induced by CLP. miR-146a-expressing plasmid was abundantly distributed in splenic macrophages, but not in renal parenchymal cells. CLP mice treated with miR-146a displayed significantly decreased NF-κB activation and splenocyte apoptosis. Splenectomy diminished the anti-inflammatory effects of miR-146a. The collective results support the conclusion that the induction of miR-146a expression in splenic macrophages prevents excessive inflammation and sepsis-induced multiple organ injury. This study establishes a novel and critical pathophysiological role for splenic macrophage interference in sepsis-related organ injury.

Anti-inflammatory properties of cilostazol: Its interruption of DNA binding activity of NF-κB from the Toll-like receptor signaling pathways.

Cilostazol, a selective inhibitor of phosphodiesterase type III with anti-platelet, anti-mitogenic, and vasodilating properties, is widely used to treat ischemic symptoms of peripheral vascular disease. Ample evidence has suggested that cilostazol also exhibits an anti-inflammatory effect, but its anti-inflammatory mechanism is not fully understood. Here, we showed that cilostazol specifically inhibited expression of cytokines, which are induced by nuclear factor-κB (NF-κB) activation, in RAW264.7 macrophage cells stimulated with different Toll-like receptor (TLR) ligands. Cilostazol was found to significantly reduce TLR-4 and TLR-3 ligands-stimulated NF-κB transcriptional activity, which was quantified by luciferase reporter assays. However, cilostazol was without effect on IκBα degradation and NF-κB p65 phosphorylation and nuclear translocation after challenge with the TLR-4 ligand lipopolysaccharide (LPS). Cilostazol did not also prevent the LPS-induced increase in phosphorylated levels of the mitogen-activated protein kinase (MAPK) family. On the other hand, using chromatin immunoprecipitation assays, we demonstrated that cilostazol reduced the LPS-induced transcriptional activities of interleukin-6 and tumor necrosis factor-α by preventing the recruitment of NF-κB p65 to these gene promoters. When cilostazol was given to mice by oral gavage daily for 7 days, LPS-induced aberrant pro-inflammatory cytokine production and end-organ tissue injury were significantly reduced. The results of this study suggest that cilostazol is capable of directly interrupting DNA binding activity of NF-κB proteins from the TLR signaling pathways. The therapy to specifically intervene in this pathway may be potentially beneficial for the prevention of different inflammatory disorders.

Role of G protein-coupled receptor kinase 2 in oxidative and nitrosative stress-related neurohistopathological changes in a mouse model of sepsis-associated encephalopathy.

Sepsis-associated encephalopathy (SAE), characterized as diffuse brain dysfunction and neurological manifestations secondary to sepsis, is a common complication in critically ill patients and can give rise to poor outcome, but understanding the molecular basis of this disorder remains a major challenge. Given the emerging role of G protein-coupled receptor 2 (GRK2), first identified as a G protein-coupled receptor (GPCR) regulator, in the regulation of non-G protein-coupled receptor-related molecules contributing to diverse cellular functions and pathology, including inflammation, we tested the hypothesis that GRK2 may be linked to the neuropathogenesis of SAE. When mouse MG6 microglial cells were challenged with lipopolysaccharide (LPS), GRK2 cytosolic expression was highly up-regulated. The ablation of GRK2 by small interfering RNAs (siRNAs) prevented an increase in intracellular reactive oxygen species generation in LPS-stimulated MG6 cells. Furthermore, the LPS-induced up-regulation of inducible nitric-oxide synthase expression and increase in nitric oxide production were negated by GRK2 inhibitor or siRNAs. However, GRK2 inhibition was without effect on overproduction of tumor necrosis factor-α, interleukin (IL)-6, and IL-1ß in LPS-stimulated MG cells. In mice with cecal ligation and puncture-induced sepsis, treatment with GRK2 inhibitor reduced high levels of oxidative and nitrosative stress in the mice brains, where GRK2 expression was up-regulated, alleviated neurohistological damage observed in cerebral cortex sections, and conferred a significant survival advantage to CLP mice. Altogether, these results uncover the novel role for GRK2 in regulating cellular oxidative and nitrosative stress during inflammation and suggest that GRK2 may have a potential as an intriguing therapeutic target to prevent or treat SAE.

Inducible nitric oxide synthase during the late phase of sepsis is associated with hypothermia and immune cell migration.

Hypothermia is a significant sign of sepsis, which is associated with poor prognosis, but few mechanisms underlying the regulation of hypothermia are known. Inducible nitric oxide synthase (iNOS) is a key inflammatory mediator of sepsis. However, the therapeutic benefit of iNOS inhibition in sepsis is still controversial, and requires elucidation in an accurate model system. In this study, wild-type (WT) mice showed temperature drops in a biphasic manner at the early and late phase of sepsis, and all mice died within 48 h of sepsis. In contrast, iNOS-knockout (KO) mice never showed the second temperature drop and exhibited improved mortality. Plasma nitric oxide (NO) levels of WT mice increased in the late phase of sepsis and correlated to hypothermia. The results indicate that iNOS-derived NO during the late phase of sepsis caused vasodilation-induced hypothermia and a lethal hypodynamic state. The expression of the iNOS mRNA was high in the lung of WT mice with sepsis, which reflects the pathology of acute respiratory distress syndrome (ARDS). We obtained the results in a modified keyhole-type cecal ligation and puncture model of septic shock induced by minimally invasive surgery. In this accurate and reproducible model system, we transplanted the bone marrow cells of GFP transgenic mice into WT and iNOS-KO mice, and evaluated the role of increased pulmonary iNOS expression in cell migration during the late phase of sepsis. We also investigated the quantity and type of bone marrow-derived cells (BMDCs) in the lung. The number of BMDCs in the lung of iNOS-KO mice was less than that in the lung of WT mice. The major BMDCs populations were CD11b-positive, iNOS-negative cells in WT mice, and Gr-1-positive cells in iNOS-KO mice that expressed iNOS. These results suggest that sustained hypothermia may be a beneficial guide for future iNOS-targeted therapy of sepsis, and that iNOS modulated the migratory efficiency and cell type of BMDCs in septic ARDS.

The Japanese Clinical Practice Guidelines for Management of Sepsis and Septic Shock 2016 (J-SSCG 2016).

Background and Purpose: The Japanese Clinical Practice Guidelines for Management of Sepsis and Septic Shock 2016 (J-SSCG 2016), a Japanese-specific set of clinical practice guidelines for sepsis and septic shock created jointly by the Japanese Society of Intensive Care Medicine and the Japanese Association for Acute Medicine, was first released in February 2017 in Japanese. An English-language version of these guidelines was created based on the contents of the original Japanese-language version. Methods: Members of the Japanese Society of Intensive Care Medicine and the Japanese Association for Acute Medicine were selected and organized into 19 committee members and 52 working group members. The guidelines were prepared in accordance with the Medical Information Network Distribution Service (Minds) creation procedures. The Academic Guidelines Promotion Team was organized to oversee and provide academic support to the respective activities allocated to each Guideline Creation Team. To improve quality assurance and workflow transparency, a mutual peer review system was established, and discussions within each team were open to the public. Public comments were collected once after the initial formulation of a clinical question (CQ), and twice during the review of the final draft. Recommendations were determined to have been adopted after obtaining support from a two-thirds (>66.6%) majority vote of each of the 19 committee members. Results: A total of 87 CQs were selected among 19 clinical areas, including pediatric topics and several other important areas not covered in the first edition of the Japanese guidelines (J-SSCG 2012). The approval rate obtained through committee voting, in addition to ratings of the strengths of the recommendation and its supporting evidence were also added to each recommendation statement. We conducted meta-analyses for 29 CQs. Thirty seven CQs contained recommendations in the form of an expert consensus due to insufficient evidence. No recommendations were provided for 5 CQs. Conclusions: Based on the evidence gathered, we were able to formulate Japanese-specific clinical practice guidelines that are tailored to the Japanese context in a highly transparent manner. These guidelines can easily be used not only by specialists, but also by non-specialists, general clinicians, nurses, pharmacists, clinical engineers, and other healthcare professionals.

Activator Protein-1 Decoy Oligodeoxynucleotide Transfection Is Beneficial in Reducing Organ Injury and Mortality in Septic Mice.

OBJECTIVES: Inflammation and apoptosis are decisive mechanisms for the development of end-organ injury in sepsis. Activator protein-1 may play a key role in regulating expression of harmful genes responsible for the pathophysiology of septic end-organ injury along with the major transcription factor nuclear factor-κB. We investigated whether in vivo introduction of circular dumbbell activator protein-1 decoy oligodeoxynucleotides can provide benefits for reducing septic end-organ injury. DESIGN: Laboratory and animal/cell research. SETTINGS: University research laboratory. SUBJECTS: Male BALB/c mice (8-10 wk old). INTERVENTIONS: Activator protein-1 decoy oligodeoxynucleotides were effectively delivered into tissues of septic mice in vivo by preparing into a complex with atelocollagen given 1 hour after surgery. MATERIALS AND MAIN RESULTS: Polymicrobial sepsis was induced by cecal ligation and puncture in mice. Activator protein-1 decoy oligodeoxynucleotide transfection inhibited abnormal production of proinflammatory and chemotactic cytokines after cecal ligation and puncture. Histopathologic changes in lung, liver, and kidney tissues after cecal ligation and puncture were improved by activator protein-1 decoy oligodeoxynucleotide administration. When activator protein-1 decoy oligodeoxynucleotides were given, apoptosis induction was strikingly suppressed in lungs, livers, kidneys, and spleens of cecal ligation and puncture mice. These beneficial effects of activator protein-1 decoy oligodeoxynucleotides led to a significant survival advantage in mice after cecal ligation and puncture. Apoptotic gene profiling indicated that activator protein-1 activation was involved in the up-regulation of many of proapoptotic and antiapoptotic genes in cecal ligation and puncture-induced sepsis. CONCLUSIONS: Our results indicate a detrimental role of activator protein-1 in the sepsis pathophysiology and the potential usefulness of activator protein-1 decoy oligodeoxynucleotides for the prevention and treatment of septic end-organ failure.

A subset of cerebrovascular pericytes originates from mature macrophages in the very early phase of vascular development in CNS.

Pericytes are believed to originate from either mesenchymal or neural crest cells. It has recently been reported that pericytes play important roles in the central nervous system (CNS) by regulating blood-brain barrier homeostasis and blood flow at the capillary level. However, the origin of CNS microvascular pericytes and the mechanism of their recruitment remain unknown. Here, we show a new source of cerebrovascular pericytes during neurogenesis. In the CNS of embryonic day 10.5 mouse embryos, CD31+F4/80+ hematopoietic lineage cells were observed in the avascular region around the dorsal midline of the developing midbrain. These cells expressed additional macrophage markers such as CD206 and CD11b. Moreover, the CD31+F4/80+ cells phagocytosed apoptotic cells as functionally matured macrophages, adhered to the newly formed subventricular vascular plexus, and then divided into daughter cells. Eventually, these CD31+F4/80+ cells transdifferentiated into NG2/PDGFRß/desmin-expressing cerebrovascular pericytes, enwrapping and associating with vascular endothelial cells. These data indicate that a subset of cerebrovascular pericytes derive from mature macrophages in the very early phase of CNS vascular development, which in turn are recruited from sites of embryonic hematopoiesis such as the yolk sac by way of blood flow.

Diminished responsiveness to dobutamine as an inotrope in mice with cecal ligation and puncture-induced sepsis: attribution to phosphodiesterase 4 upregulation.

Dobutamine has been used in septic shock for many years as an only inotrope, but its benefit has been questioned. We weighed the effects of dobutamine and milrinone as inotropes in mice with cecal ligation and puncture (CLP)-induced polymicrobial sepsis. CLP-induced septic mice exhibited significant cardiac inflammation, as indicated by greatly increased mRNAs of proinflammatory cytokines and robust infiltration of inflammatory cells in the ventricular myocardium. Elevations of plasma cardiac troponin-I showed cardiac injury in CLP mice. Noninvasive echocardiographic assessment of cardiac function revealed that despite preserved left ventricular function in the presence of fluid replacement, the dobutamine inotropic response was significantly impaired in CLP mice compared with sham-operated controls. By contrast, milrinone exerted inotropic effects in sham-operated and CLP mice in an equally effective manner. Surface expression levels of ß1-adrenoceptors and α-subunits of three main G protein families in the myocardium were unaffected by CLP-induced sepsis. Plasma cAMP levels were significantly elevated in both sham-operated and CLP mice in response to milrinone but only in sham-operated controls in response to dobutamine. Of phosphodiesterase (PDE) isoforms, PDE4D, but not PDE3A, both of which are responsible for cardiac cAMP hydrolysis, was significantly upregulated in CLP mouse myocardium. We define a novel mechanism for the impaired responsiveness to dobutamine as an inotrope in sepsis, and understanding the role of PDE4D in modulating cardiac functional responsiveness in sepsis may open the potential of a PDE4D-targeted therapeutic option in septic patients with low cardiac output who have a need for inotropic support.NEW & NOTEWORTHY Advisability of the usefulness of dobutamine in septic shock management is limited. Here, we reveal that the effect of dobutamine as a positive inotrope is impaired in mice with cecal ligation and puncture-induced sepsis without changes in cardiac ß1-adrenoceptor signaling as a result of cAMP breakdown achieved by upregulated phosphodiesterase 4D.

[Severe infection in critical emergency care].

In the emergency and critical care medicine, infection is easy to merge to various basic conditions and diseases. In the social structure aging in critical care, the immune weakness was revealed as the result of severe infection and septic shock in the reduced function of neutrophils and lymphocytes. In the life-saving emergency care, cardiovascular diseases, diabetes, chronic renal failure and lever dysfunction are often observed, and the underlying diseases have the foundation of biological invasion after a first inflammatory attack of surgery, trauma, burn, and systemic injury. It will be placed into a susceptible situation such as artificial respiratory management. In this review, we discussed severe infection in emergency and critical care. It is necessary to pay attention to the drug resistance bacterias in own critical care setting by trends.

Anti-Inflammatory Profile of Levosimendan in Cecal Ligation-Induced Septic Mice and in Lipopolysaccharide-Stimulated Macrophages.

OBJECTIVES: The calcium sensitizer levosimendan is used in treatment of decompensated heart failure and may also exhibit anti-inflammatory properties. We examined whether treatment with levosimendan is substantially beneficial in mice with cecal ligation and puncture-induced polymicrobial sepsis, and its arbitration mechanism was explored in the mouse macrophage cell line RAW264.7. DESIGN: Laboratory and animal/cell research. SETTING: University research laboratory. SUBJECTS: BALB/c mice (8-10 wk old) and mouse macrophage cell line RAW264.7 cells. INTERVENTIONS: Levosimendan (0.5 µg/kg/min) was administered to mice through an osmotic pump that was implanted into the peritoneal cavity immediately following surgery. In RAW264.7 cells, levosimendan was added to the culture medium 30 minutes before lipopolysaccharide. MEASUREMENTS AND MAIN RESULTS: When levosimendan was continuously administered to cecal ligation and puncture-induced septic mice, a significant improvement of left ventricular function was found without any change in heart rate, and hypotension was significantly mitigated. Furthermore, levosimendan conferred substantial protection against sepsis-associated inflammation in mice, as indicated by reduced lung injury and decreased blood proinflammatory and chemotactic cytokine levels. These beneficial effects of levosimendan led to a significant improvement of survival in mice after cecal ligation and puncture. In endotoxin-stimulated RAW264.7 macrophages, treatment with levosimendan and pimobendan suppressed overproduction of proinflammatory and chemotactic cytokines. Levosimendan and pimobendan were without effect on activation of the nuclear factor-κB, mitogen-activated protein kinase, and Akt pathways. Instead, levosimendan and pimobendan prevented high mobility group box 1 release from the nucleus to the extracellular space in macrophages. This was associated with inhibition of the Rho kinase signaling pathway. The elevated serum high mobility group box 1 levels in cecal ligation and puncture-induced septic mice were also inhibited by continued administration of levosimendan and pimobendan. CONCLUSIONS: We define a novel mechanism for the anti-inflammatory action of levosimendan and suggest that the pharmacological profiles of levosimendan as both an inotrope and an anti-inflammatory agent could contribute to its clinical benefit in patients with sepsis with heart problems.

NOX1/NADPH oxidase is involved in endotoxin-induced cardiomyocyte apoptosis.

The functional significance of NOX1/NADPH oxidase in the heart has not been explored due to its low expression relative to other NOX homologs identified so far. We aimed to clarify the role of NOX1/NADPH oxidase in the septic heart by utilizing mice deficient in the Nox1 gene (Nox1(-/Y)). Sepsis was induced by intraperitoneal administration of lipopolysaccharides (LPS: 25mg/kg) or cecal ligation and puncture (CLP) surgery. A marked elevation of NOX1 mRNA was demonstrated in cardiac tissue, which was accompanied by increased production of reactive oxygen species (ROS). In Nox1(-/Y) treated with LPS, cardiac dysfunction and survival were significantly improved compared with wild-type mice (Nox1(+/Y)) treated with LPS. Concomitantly, LPS-induced cardiomyocyte apoptosis and activation of caspase-3 were alleviated in Nox1(-/Y). The level of phosphorylated Akt in cardiac tissue was significantly lowered in Nox1(+/Y) but not in Nox1(-/Y) treated with LPS or that underwent CLP surgery. Increased oxidation of cysteine residues of Akt and enhanced interaction of Akt with protein phosphatase 2A (PP2A), a major phosphatase implicated in the dephosphorylation of Akt, were demonstrated in LPS-treated Nox1(+/Y). These responses to LPS were significantly attenuated in Nox1(-/Y). Taken together, ROS derived from NOX1/NADPH oxidase play a pivotal role in endotoxin-induced cardiomyocyte apoptosis by increasing oxidation of Akt and subsequent dephosphorylation by PP2A. Marked up-regulation of NOX1 may affect the risk of mortality under systemic inflammatory conditions.

Isoflurane pretreatment preserves adenosine triphosphate-sensitive K(+) channel function in the human artery exposed to oxidative stress caused by high glucose levels.

BACKGROUND: Adenosine triphosphate (ATP)-sensitive K(+) channels contribute to significant regulatory mechanisms related to organ blood flow in both physiological and pathological conditions. High glucose impairs arterial ATP-sensitive K(+) channel activity via superoxide production. However, the effects of anesthetics on this pathological process have not been evaluated in humans. In the present study, we investigated whether pretreatment with the volatile anesthetic isoflurane preserves ATP-sensitive K(+) channel activity in the human artery exposed to oxidative stress caused by high glucose. METHODS: All experiments were performed using human omental arteries without endothelium in the presence of d-glucose (5.5 mmol/L). Some arteries were treated with isoflurane (1.15% or 2.3%) in combination with d- or l-glucose (20 mmol/L) for 60 minutes, and then only isoflurane was discontinued. Relaxation and hyperpolarization of arterial segments in response to an ATP-sensitive K(+) channel opener levcromakalim were evaluated using the isometric force recording or electrophysiological study, respectively. Superoxide production was determined by dihydroethidium fluorescence. Immunohistochemical analysis for a subunit of reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase p47phox was performed. Data were evaluated using repeated-measures analysis of variance or a factorial analysis of variance as appropriate, followed by Scheffé test. RESULTS: The ATP-sensitive K(+) channel antagonist glibenclamide (10(-6) mol/L) abolished relaxation induced by cumulative addition of levcromakalim (10(-8) to 10(-5) mol/L) in arteries treated with l-glucose (20 mmol/L). Incubation with d-glucose (20 mmol/L) impaired the vasorelaxation induced by levcromakalim. The selective NADPH oxidase NOX2 inhibitor gp91ds-tat (10(-6) mol/L) and pretreatment with isoflurane (1.15% and 2.3%) restored relaxation in response to levcromakalim in arteries treated with d-glucose (20 mmol/L). Isoflurane (2.3%), gp91ds-tat (10(-6) mol/L), and their combination similarly restored hyperpolarization in response to levcromakalim (3 × 10(-6) mol/L) in arteries treated with d-glucose (20 mmol/L). Along with these results, isoflurane (2.3%) reduced superoxide production and the intracellular mobilization of the cytosolic NOX2 subunit p47phox toward smooth muscle cell membrane in arteries treated with d-glucose (20 mmol/L). CONCLUSIONS: We have demonstrated for the first time a beneficial effect from the pretreatment with isoflurane on the isolated human artery. Pretreatment with isoflurane preserves ATP-sensitive K(+) channel activity in the human omental artery exposed to oxidative stress induced by high glucose, whereas the effect seems to be mediated by NADPH oxidase inhibition. Volatile anesthetics may protect human visceral arteries from malfunction caused by oxidative stress.

[Sudden increases and decreases in bispectral index values more than 30 within 1 minute during general anesthesia].

We described, in a 40-year-old man, sudden and unexpected increases in bispectral index values during the general anesthesia with total intravenous anesthesia using propofol in a dental surgery. The patient was administered continuous infusion of propofol and remifentanil, and intermittent supplementation of fentanyl. Immediately after the beginning of surgery, the bispectral index value increased abruptly to 90; whereas, heart rate and non-invasive blood pressure were unchanged and no physiological finding was observed. Approximately 25 min later, the value decreased to below 40 without any modification of anesthesia. The extent of unanticipated increase might be compatible with the duration of surgical procedure using dental air turbine. Therefore, the noise from surgical device might induce unpredictable change in bispectral index values.