Junichiro Nakagawa

Systemic involvement of high-mobility group box 1 protein and therapeutic effect of anti-high-mobility group box 1 protein antibody in a rat model of crush injury.

ABSTRACT Patients with crush injury often present systemic inflammatory response syndrome and fall into multiple organ failure. The mechanism by which the local tissue damage induces distant organ failure is still unclear. We focused on high-mobility group box 1 protein (HMGB1) as one of the damage-associated molecular pattern molecules that cause systemic inflammation in crush injury. We investigated involvement of HMGB1 and the effects of treatment with anti-HMGB1 antibody in a rat model of crush injury. Both hindlimbs of rats were compressed for 6 h and then released. In the crush injury group, the level of serum HMGB1 peaked at 3 h after releasing compression, followed by the increasing in the serum levels of interleukin 6 and tumor necrosis factor &agr;. Hematoxylin-eosin staining showed substantial damage in the lung 24 h after the crush injury, with upregulation of the expression of receptor for advanced glycation end products, as revealed by immunohistochemical analysis. Intravenous administration of anti-HMGB1 antibody improved survival (n = 20 each group) and significantly suppressed serum levels of HMGB1, interleukin 6, and tumor necrosis factor &agr; compared with the untreated crush injury group (n = 6–9 each group). Histological findings of lung damage were ameliorated, and the expression of receptor for advanced glycation end products was hampered by the treatment. These results indicate that HMGB1 is released in response to damage immediately after crush injury and acts as a proinflammatory mediator. Administration of anti-HMGB1 antibody reduced inflammatory reactions and improved survival by blocking extracellular HMGB1. Thus, HMGB1 appears to be a therapeutic target, and anti-HMGB1 antibody may become a promising novel therapy against crush injury to prevent the progression to multiple organ failure.

Electrical Vagus Nerve Stimulation Attenuates Systemic Inflammation and Improves Survival in a Rat Heatstroke Model

This study was performed to gain insights into novel therapeutic approaches for the treatment of heatstroke. The central nervous system regulates peripheral immune responses via the vagus nerve, the primary neural component of the cholinergic anti-inflammatory pathway. Electrical vagus nerve stimulation (VNS) reportedly suppresses pro-inflammatory cytokine release in several models of inflammatory disease. Here, we evaluated whether electrical VNS attenuates severe heatstroke, which induces a systemic inflammatory response. Anesthetized rats were subjected to heat stress (41.5°C for 30 minutes) with/without electrical VNS. In the VNS-treated group, the cervical vagus nerve was stimulated with constant voltage (10 V, 2 ms, 5 Hz) for 20 minutes immediately after completion of heat stress. Sham-operated animals underwent the same procedure without stimulation under a normothermic condition. Seven-day mortality improved significantly in the VNS-treated group versus control group. Electrical VNS significantly suppressed induction of pro-inflammatory cytokines such as tumor necrosis factor-α and interleukin-6 in the serum 6 hours after heat stress. Simultaneously, the increase of soluble thrombomodulin and E-selectin following heat stress was also suppressed by VNS treatment, suggesting its protective effect on endothelium. Immunohistochemical analysis using tissue preparations obtained 6 hours after heat stress revealed that VNS treatment attenuated infiltration of inflammatory (CD11b-positive) cells in lung and spleen. Interestingly, most cells with increased CD11b positivity in response to heat stress did not express α7 nicotinic acetylcholine receptor in the spleen. These data indicate that electrical VNS modulated cholinergic anti-inflammatory pathway abnormalities induced by heat stress, and this protective effect was associated with improved mortality. These findings may provide a novel therapeutic strategy to combat severe heatstroke in the critical care setting.

Reduction of thoracic aorta motion artifact with high-pitch 128-slice dual-source computed tomographic angiography: a historical control study.

Objectives Electrocardiogram-gated imaging combined with multi–detector row computed tomography (MDCT) has reduced cardiac motion artifacts, but it was not practical in the emergency setting. The purpose of this study was to evaluate the ability of a high-pitch, 128-slice dual-source CT (DSCT) scanner to reduce motion artifacts in patients admitted to the emergency room. Methods This study comprised 100 patients suspected of having thoracic aorta lesions. We examined 47 patients with the 128-slice DSCT scanner (DSCT group), and 53 patients were examined with a 64-slice MDCT scanner (MDCT group). Six anatomic areas in the thoracic aorta were evaluated. Results Computed tomography images in the DSCT group were distinct, and significant differences were observed in images of all areas between the 2 groups except for the descending aorta. Conclusions The high-pitch DSCT scanner can reduce motion artifacts of the thoracic aorta and enable radiological diagnosis even in patients with tachycardia and without breath hold.

Effect of Histone Acetylation on N-Methyl-D-Aspartate 2B Receptor Subunits and Interleukin-1 Receptors in Association with Nociception-Related Somatosensory Cortex Dysfunction in a Mouse Model of Sepsis.

ABSTRACT Whole-body inflammation (i.e., sepsis) often results in brain-related sensory dysfunction. We previously reported that interleukin (IL)-1 resulted in synaptic dysfunction of septic encephalopathy, but the underlying molecular mechanisms remain unknown, as do effective treatments. Using mice, we examined immunohistochemistry, co-immunoprecipitation, enzyme-linked immunosorbent assay, and behavior analyses, and investigated the role of the N-methyl-D-aspartate 2B subunit (NR2B) of NMDA receptor, IL-1 receptor, and histone acetylation in the pathophysiology underlying sensory dysfunction induced by lipopolysaccharide (LPS). Mice groups of sham-operated, LPS, LPS with an NR2B antagonist, or LPS with resveratrol (a histone acetylation activator) were analyzed. We found that LPS increased NR2B and interleukin-1 receptor (IL-1R) immunoreactivity. The expression of Iba1, a marker for microglia and/or macrophages, increased more significantly in the brain than in the spinal cord, implicating NR2B and IL-1R in brain inflammation. Immunoprecipitation with NR2B and IL-1R revealed related antibodies. Blood levels of IL-1&bgr; (i.e., the IL-1R ligand) increased, though not significantly, suggesting that inflammation peaked at 20 h. Behavioral assessments of central (CNS) and peripheral sensory (PNS) function indicated that LPS delayed CNS but not PNS escape latency. Finally, NR2B antagonist or resveratrol in the lateral ventricle antagonized the effects of LPS in the brain and improved animal survival. In summary, histone acetylation may control expression of NR2B and IL-1R, alleviating inflammation-induced sensory neuronal dysfunction caused by LPS.

Blunt Tracheal Transection Repair Requiring Open Abdominal Management

A 19-year-old man sustained multiple injuries during a motorcycle accident. A computed tomographic scan revealed that the trachea was completely transected, and the endotracheal tube did not reach the distal stump. Extracorporeal membrane oxygenation was used to maintain oxygenation and avoid mediastinal emphysema. Tracheal anastomosis through a right thoracotomy was planned initially, but prior to the operation, extracorporeal membrane oxygenation flow and respiratory condition deteriorated, with evidence of oxygen desaturation. An abdominal compartment syndrome was diagnosed, and open abdominal management was performed. Therefore, the patient had to undergo tracheal anastomosis through a median sternotomy in the supine position. The laparotomy was closed, and the patient was discharged without respiratory complications.

Matrix Metalloproteinase-9 Triggers the Gap Junction Impairment and Somatosensory Neuronal Dysfunction in Septic Encephalopathy

Although septic encephalopathy leads to be the devastating neurological symptoms including sensory dysfunction, cognitive impairment and unconsciousness, potent substrates and their effects inducing the synaptic dysfunction remain obscure. In this study, we successfully characterized the sensory dysfunction with immunohistochemistry, immunoblotting and electrophysiology. A mouse model of septic encephalopathy was examined at 20 hrs after cecal ligation and puncture or intraperitoneal injection of lipopolysaccharide (1 mg). We found several effects of active enzyme of matrix metalloproteinases-9 (active MMP-9) on the somatosensory cortex, thalamus and prefrontal cortex related to the sensory functions in septic encephalopathy. At first, active MMP-9 was up-regulated. Second, both of the occludin, tight junction protein composing blood brain barrier, and the connexin-43, transmembrane protein of gap junction, which were potent substrate of active MMP-9, were disrupted. Third, the evoked local field potentials in cortical and thalamic neurons were impeded during sensory neuronal stimulation. Conversely, matrix metalloproteinase inhibitor GM6001 significantly protected the reduction of occludin, connexin-43 and the regression of neuronal activities. In conclusion, MMP-9 is a prerequisite candidate for protection of the junction proteins reduction and for the potent therapeutics in the sensory dysfunction in septic encephalopathy.

The Beneficial Effects of ETS-GS, a Novel Vitamin E Derivative, on a Rat Model of Crush Injury.

ABSTRACT Crush syndrome is a devastating condition leading to multiple organ failure. The mechanisms by which local traumatic injuries affect distant organs remain unknown. ETS-GS is a novel water-soluble, stable anti-oxidative agent composed of vitamin E derivative. Given that one of the main pathophysiological effects in crush syndrome is massive ischemia-reperfusion, reactive oxygen species (ROS) generated from the injured extremities would be systemically involved in distant organ damage. We investigated whether ETS-GS could suppress inflammatory response and improve mortality in a rat model of crush injury. Crush injury was induced by compression of bilateral hindlimbs for 6 h followed by release of compression. Seven-day survival was significantly improved by ETS-GS treatment. To estimate anti-oxidative and anti-inflammatory effects of ETS-GS, serum was collected 6 and 20 h after the injury. ETS-GS treatment significantly dampened the up-regulation of malondialdehyde and reduction of superoxide dismutase in the serum, which were induced by crush injury. Serum levels of interleukin 6 and high mobility group box 1 were significantly decreased in the ETS-GS group compared with those in the control group. Lung damage shown by hematoxylin-eosin staining at 20 h after the injury was ameliorated by the treatment. Ex vivo imaging confirmed that ETS-GS treatment reduced ROS generation in both the lung and the muscle following crush injury. The administration of ETS-GS could suppress ROS generation, systemic inflammation, and the subsequent organ damage, thus improving survival in a rat model of crush injury. These findings suggest that ETS-GS can become a novel therapeutic agent against crush injury.

Adult case of Stevens–Johnson syndrome possibly induced by Chlamydophila pneumoniae infection with severe involvement of bronchial epithelium resulting in constructive respiratory disorder

membranes, play important roles for organ development and function, including skin, hair, skeletal muscle, nervous system, kidney, lung and vasculature. Laminins are large heterotrimeric glycoproteins composed of one a-, one band one c-chain. There are currently five a-, four band three c-chain genes that have been described in vertebrates and the chains can assemble into at least 15 different heterotrimers. The molecular specificity of anti-laminin autoantibodies generally determines the phenotype of autoimmune subepidermal blistering disease. In patients with anti-laminin-c1 pemphigoid, subepidermal blisters with neutrophil infiltration, which are predominant skin lesions, heal rapidly in response to treatment without scarring resolution. The exact laminin targeted by anti-laminin-c1 antibodies has not yet been identified. On the other hand, a chronic course and debilitating scarring of multiple mucous surfaces are considered to be the common clinical features of most patients with anti-laminin-332 mucous membrane pemphigoid. Previously, two patients with an autoimmune response to both laminin-c1 and laminin-332 were reported. In these cases, tense blisters affecting both skin and mucous membranes, which were characteristics of two distinct clinical phenotypes in anti-laminin-c1 pemphigoid and anti-laminin-332 mucous membrane pemphigoid, were observed. Our case presented with flaccid blisters on the dorsal surface of her body, while mucous membranes were not affected. This is not typical for both anti-laminin-c1 pemphigoid and anti-laminin-332 mucous membrane pemphigoid. It is possible that both antilaminin-c1 and anti-laminin-332 autoantibodies synergistically induced this unusual clinical phenotype. It is also possible that in pemphigoid patients without mucosal involvement showing anti-laminin-332 autoantibodies, unrevealed antibodies triggered the development of skin pemphigoid, which was followed by the epitope-spreading phenomenon of autoantibodies against laminin-332. Interestingly, as in our patient, although the a3and c1-subunits in laminin-6 (a3b1c1) and laminin-7 (a3b2c1) are detectable in alveolar basement membranes, no respiratory complications were reported in anti-laminin-c1 pemphigoid and anti-laminin-332 mucous membrane pemphigoid. Although in contrast to laminin-332, the pathogenicity of antilaminin-c1 autoantibodies could not been shown, we should take into consideration the possibility of dual detection of autoantibodies against laminin-c1 and laminin-332 in patients with subepidermal blistering disease. A higher number of patients with combined autoimmunity against laminin-c1 and -a3 is needed to further define the clinical phenotype in this variant.

Therapeutic Effectiveness of Anti-RAGE Antibody Administration in a Rat Model of Crush Injury

Crush injury patients often have systemic inflammatory response syndrome that leads to multiple organ failure. Receptor for advanced glycation endproducts (RAGE) functions as a pattern recognition receptor that regulates inflammation. We evaluated the effects of anti-RAGE antibody in a crush injury model. Pressure was applied to both hindlimbs of rats for 6 h by 3.0-kg blocks and then released. Animals were randomly divided into the sham (RAGE-Sh) group, crush (RAGE-Ctrl) group or anti-RAGE antibody-treated crush (RAGE-Tx) group. Samples were collected at 3, 6 and 24 h after releasing pressure. In the RAGE-Ctrl group, fluorescent immunostaining in the lung showed upregulated RAGE expression at 3 h. The serum soluble RAGE (sRAGE) level, which reflects the amount of RAGE expression in systemic tissue, increased at 6 h. Serum interleukin 6 (IL-6; systemic inflammation marker) increased immediately at 3 h. Histological analysis revealed lung injury at 6 and 24 h. Administration of anti-RAGE antibody before releasing compression inhibited upregulated RAGE expression in the lung alveoli, suppressed RAGE-associated mediators sRAGE and IL6, attenuated the lung damage and improved the 7-day survival rate. Collectively, our results indicated that the use of anti-RAGE antibody before releasing compression is associated with a favourable prognosis following crush injury.