Pharmacological Inhibition of Epidermal Growth Factor Receptor Prevents Intracranial Aneurysm Rupture by Reducing Endoplasmic Reticulum Stress

BACKGROUND

Multiple pathways and factors are involved in the rupture of intracranial aneurysms. The EGFR (epidermal growth factor receptor) has been shown to mediate inflammatory vascular diseases, including atherosclerosis and aortic aneurysm. However, the role of EGFR in mediating intracranial aneurysm rupture and its underlying mechanisms have yet to be determined. Emerging evidence indicates that endoplasmic reticulum (ER) stress might be the link between EGFR activation and the resultant inflammation. ER stress is strongly implicated in inflammation and apoptosis of vascular smooth muscle cells, both of which are key components of the pathophysiology of aneurysm rupture. Therefore, we hypothesized that EGFR activation promotes aneurysmal rupture by inducing ER stress.

METHODS

Using a preclinical mouse model of intracranial aneurysm, we examined the potential roles of EGFR and ER stress in developing aneurysmal rupture.

RESULTS

Pharmacological inhibition of EGFR markedly decreased the rupture rate of intracranial aneurysms without altering the formation rate. EGFR inhibition also significantly reduced the mRNA (messenger RNA) expression levels of ER-stress markers and inflammatory cytokines in cerebral arteries. Similarly, ER-stress inhibition also significantly decreased the rupture rate. In contrast, ER-stress induction nullified the protective effect of EGFR inhibition on aneurysm rupture.

CONCLUSIONS

Our data suggest that EGFR activation is an upstream event that contributes to aneurysm rupture via the induction of ER stress. Pharmacological inhibition of EGFR or downstream ER stress may be a promising therapeutic strategy for preventing aneurysm rupture and subarachnoid hemorrhage.

The 2024 Noto Peninsula Earthquake and the Strategy of Medical Assistance from the Tohoku University Hospital

A moment magnitude (Mw) 7.5 earthquake (the Global IDentifire (GLIDE) number: # Q-2024-000001-JPN) struck the Noto Peninsula of Ishikawa Prefecture on 1 January 2024 at 16:10 (Japan Standard Time). The reversed fault, 150 km in length and subducting beneath the peninsula, resulted in maximum seismic intensity 7 shaking, triggered the tsunami, destroyed over 43 thousand buildings, and disrupted roads and lifelines. The disaster claimed 236 deaths, including 15 indirect disaster deaths as of Jan. 28, 2024. There were Disaster Base Hospitals (DBHs) in the region, which survived structurally but suffered from impaired functions and the surge of medical needs of affected people. The disaster medical system of Japan immediately responded and coordinated the hundreds of emergency medical teams (EMTs), i.e., the Japan Disaster Medical Assistance Team (DMAT), from all over the country. Tohoku University Hospital, which had the experience of the 2011 Great East Japan Earthquake (GEJE), joined the coordinated response, dispatching a chain of DMATs, which helped the medical and public health coordination in Wajima City. The medical and public health needs included injuries, non-communicable diseases, infectious diseases, mental health issues, and maternal and child health issues, which were similar in the affected communities in GEJE. Although the actual damage far exceeded expectations, the structural retrofitting and business continuity plans of DBHs and the coordinated response of the national disaster medical system enhanced the effectiveness of medical and public health response.

Hepatic compartment syndrome treated with damage control surgery and transarterial embolization: A case report

Background

Hepatic compartment syndrome (HCS) is a complication of nonoperative management in patients with blunt hepatic injury. Although decompression of elevated intrahepatic pressure through surgical exploration or drainage and hemorrhage control are required to manage this condition, evidence for such a management for this complication is insufficient. Herein, we report a pediatric patient treated with a planned combination strategy of surgical decompression with perihepatic packing to reduce intrahepatic pressure and subcapsular hemorrhage control as well as angioembolization to control intraparenchymal hemorrhage.

Case presentation

A 12-year-old boy was referred to our emergency department 5 h after sustaining severe bruising in the upper abdomen in a traffic accident. Computed tomography (CT) showed an intraparenchymal hematoma in the right lobe of the liver; nonoperative management was selected based on stable hemodynamic status. Two days after the injury, he complained of severe abdominal pain and shock. CT showed an intraparenchymal and large subcapsular hematoma with right branch compression of the portal vein and extravasation of contrast material. Laboratory data showed progression of hepatocellular damage. We successfully managed this patient with a planned combination strategy of surgical decompression with perihepatic packing for reduction of intrahepatic pressure and subcapsular hemorrhage control, followed by angioembolization for control of intraparenchymal hemorrhage.

Conclusion

Our study suggests that for the management of HCS, a planned combination strategy of damage control surgery and angioembolization is a therapeutic option.

Temperature-dependent sugar accumulation in interspecific Capsicum F1 plants showing hybrid weakness

In plants, F₁ hybrids showing hybrid weakness exhibit weaker growth than their parents. The phenotypes of hybrid weakness are often suppressed at certain temperatures. However, it is unclear whether hybrid weakness in Capsicum annuum × C. chinense is temperature-dependent or not. Our study showed that Capsicum hybrid weakness was suppressed at 30 and 35 °C and was induced at 15, 20, and 25 °C. Moreover, we investigated the time course of hybrid weakness in cell death, metabolite content, and gene expression in leaves of plants transferred to 20 °C after growing at 30 °C for 21 days. The expression of pathogen defense-related genes was upregulated at 1 day after transfer to 20 °C (DAT). Cell death was detected at 7 DAT, plant growth had almost stopped since 14 DAT, and sugars were accumulated at 42 DAT in hybrid plants. The study revealed that some sugar transporter genes, which had been upregulated since 7 DAT, were involved in sugar accumulation in Capsicum hybrid weakness. Thus, our results demonstrated that gene expression changes occur first, followed by physiological and morphological changes after induction of hybrid weakness. These responses observed in this study in Capsicum hybrid weakness are likely to be owed to plant defense responses-like reactions.

Blood purification therapy for severe sepsis: a multicenter, observational cohort study in northern Japan

Background

Sepsis is associated with life-threatening organ dysfunction caused by a dysregulated host response to infection. However, no specific therapy has been shown to improve mortality in patients with sepsis. We conducted a study to clarify the utilization status of various BPTs and the clinical characteristics of patients who received BPTs in northern Japan. In addition, the association of various BPTs with clinical outcomes was examined.

Methods

This is a sub-analysis of the Tohoku Sepsis Registry, a multicenter, prospective, observational cohort study. To determine whether BPT was independently associated with in-hospital mortality in patients with severe sepsis, the following analyses were performed. Differences between survivors and non-survivors were assessed using Wilcoxon rank sum tests for continuous variables and Chi-square tests for categorical variables. Univariate logistic regression analysis was used to evaluate the factors associated with in-hospital mortality. In the multivariate logistic regression analysis, adjustments were made for the variables that were significant in the univariate logistic regression analysis. Clinical factors associated with mortality were analyzed.

Results

We enrolled 616 consecutive patients (≥ 18 years) with median Sequential Organ Failure Assessment scores of 8.0. During median of 22 days hospitalization, 139 patients died (mortality 22.6%). 20.7% of patients with severe sepsis received any type of BPT (mortality 38.6%). BPT consisted of 65.1% continuous renal replacement therapy (CRRT) with renal indication (mortality 48.8%), 26.0% CRRT with non-renal indication (mortality 21.2%), 22.2% intermittent renal replacement therapy (mortality 32.1%), and 33.1% polymyxin B-immobilized fiber column-direct hemoperfusion (mortality 42.9%). Meanwhile, no BPT group (mortality 18.5%) showed a significantly lower mortality than any BPT group. Besides, in multivariate analyses, all BPT modes were not independently associated with all-cause mortality.

Conclusions

This study suggested the clinical status of BPTs for severe sepsis patients in northern Japan. Among all types of BPT, continuous renal replacement therapy (CRRT) for renal indication was most frequently selected. Severe sepsis patients received BPT had a higher mortality and severity; however, the BPT implementation may not be associated with mortality.

Trial registration UMIN-CTR, UMIN000010297, Registered on 22 March 2013, https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000012055).

Associations between low body mass index and mortality in patients with sepsis: A retrospective analysis of a cohort study in Japan

Background

The distribution of body mass in populations of Western countries differs from that of populations of East Asian countries. In East Asian countries, fewer people have a high body mass index than those in Western countries. In Japan, the country with the highest number of older adults worldwide, many people have a low body mass index. Therefore, this study aimed to determine the association between a low body mass index and mortality in patients with sepsis in Japan.

Methods

We conducted this retrospective analysis of 548 patients with severe sepsis from a multicenter prospective observational study. Multivariate logistic regression analyses determined the association between body mass index and 28-day mortality adjusted for age, sex, pre-existing conditions, the occurrence of septic shock, Acute Physiology and Chronic Health Evaluation II scores, and Sequential Organ Failure Assessment scores. Furthermore, the association between a low body mass index and 28-day mortality was analyzed.

Results

The low body mass index group represented 18.8% of the study population (103/548); the normal body mass index group, 57.3% (314/548); and the high body mass index group, 23.9% (131/548), with the 28-day mortality rates being 21.4% (22/103), 11.2% (35/314), and 14.5% (19/131), respectively. In the low body mass index group, the crude and adjusted odds ratios (95% confidence intervals) for 28-day mortality relative to the non-low body mass index (normal and high body mass index groups combined) group were 2.0 (1.1–3.4) and 2.3 (1.2–4.2), respectively.

Conclusion

A low body mass index was found to be associated with a higher 28-day mortality than the non-low body mass index in patients with sepsis in Japan. Given that older adults often have a low body mass index, these patients should be monitored closely to reduce the occurrence of negative outcomes.

Scoping Review of Hospital Business Continuity Plans to Validate the Improvement after the 2011 Great East Japan Earthquake and Tsunami

During a disaster, all hospitals are expected to function as "social critical institutions" that protect the lives and health of people. In recent disasters, numerous hospitals were damaged, and this hampered the recovery of the affected communities. Had these hospitals business continuity plans (BCPs) to recover quickly after the disaster, most of the damage could have been avoided. This study conducted a scoping review of the historical trend and regional differences in hospital BCPs to validate the improvement of the BCP concept based on our own experience at Tohoku University Hospital, which was affected by the 2011 Great East Japan Earthquake and Tsunami (GEJET). We searched PubMed by using keywords related to BCP and adapted 97 articles for our analysis. The number of articles on hospital BCPs has increased in the 2000s, especially after Hurricane Katrina in 2005. While there are regional specificity of hazards, there were many common topics and visions for BCP implementation, education, and drills. From our 2011 GEJET experience, we found that BCPs assuming region-specific disasters are applicable in various types of disasters. Thus, we suggest the following integral and universal components for hospital BCPs: (1) alternative methods and resources, (2) priority of operation, and (3) resource management. Even if the type and extent of disasters vary, the development of BCPs and business continuity management strategies that utilize the abovementioned integral components can help a hospital survive disasters in the future.

Neutrophil Extracellular Traps Promote the Development of Intracranial Aneurysm Rupture

[Figure: see text].

Mast Cell Promotes the Development of Intracranial Aneurysm Rupture

BACKGROUND AND PURPOSE

Inflammation has emerged as a key component of the pathophysiology of intracranial aneurysms. Mast cells have been detected in human intracranial aneurysm tissues, and their presence was associated with intramural microhemorrhage and wall degeneration. We hypothesized that mast cells play a critical role in the development of aneurysmal rupture, and that mast cells can be used as a therapeutic target for the prevention of aneurysm rupture.

METHODS

Intracranial aneurysms were induced in adult mice using a combination of induced systemic hypertension and a single injection of elastase into the cerebrospinal fluid. Aneurysm formation and rupture were assessed over 3 weeks. Roles of mast cells were assessed using a mast cell stabilizer (cromolyn), a mast cell activator (C48/80), and mice that are genetically lacking mature mast cells (Kit^W-sh/W-sh mice).

RESULTS

Pharmacological stabilization of mast cells with cromolyn markedly decreased the rupture rate of aneurysms (80% versus 19%, n=10 versus n =16) without affecting the aneurysm formation. The activation of mast cells with C48/80 significantly increased the rupture rate of aneurysms (25% versus 100%, n=4 versus n=5) without affecting the overall rate of aneurysm formation. Furthermore, the genetic deficiency of mast cells significantly prevented aneurysm rupture (80% versus 25%, n=10 versus n=8, wild-type versus Kit^W-sh/W-sh mice).

CONCLUSIONS

These results suggest that mast cells play a key role in promoting aneurysm rupture but not formation. Stabilizers of mast cells may have a potential therapeutic value in preventing intracranial aneurysm rupture in patients.

Modulation of methotrexate-induced intestinal mucosal injury by dietary factors

Methotrexate (MTX)-induced intestinal mucosal injury in animals has been studied to understand how MTX can cause gastrointestinal disorders, but the pathogenesis of gastrointestinal disorders is still uncertain. We have attempted to reveal how dietary factors influence intestinal toxicity due to MTX. Mice were fed normal chow (NC) or a high-fat high-sucrose diet (HFHSD) before oral administration of MTX. While MTX significantly decreased the survival rates of mice fed HFHSD, the intestinal epithelial injury was detected. MTX excretion in the feces of mice fed HFHSD was reduced. Change of diets between NC and HFHSD influences the survival. The survival rates of the mice fed a high-sucrose diet or control diet were higher than those fed HFHSD. Higher survival rates were observed in mice fed a high-fat high-sucrose diet modified (HFHSD-M) in which casein was replaced by soybean-derived proteins. The survival rates of mice treated with vancomycin were lower than those administered neomycin. Microbiome and metabolome analyses on feces suggest a similarity of the intestinal environments of mice fed NC and HFHSD-M. HFHSD may modify MTX-induced toxicity in intestinal epithelia on account of an altered MTX distribution as a result of change in the intestinal environment.

TLR4 (Toll-Like Receptor 4) Mediates the Development of Intracranial Aneurysm Rupture

Inflammation is emerging as a critical factor in the pathophysiology of intracranial aneurysm. TLR4 (toll-like receptor 4) contributes not only to the innate immune responses but also to the inflammatory processes associated with vascular disease. Therefore, we examined the contribution of the TLR4 pathway to the development of the rupture of intracranial aneurysm. We used a mouse model of intracranial aneurysm. TLR4 inhibition significantly reduced the development of aneurysmal rupture. In addition, the rupture rate and levels of proinflammatory cytokines were lower in TLR4 knockout mice than the control littermates. Macrophage/monocyte-specific TLR4 knockout mice had a lower rupture rate than the control littermate mice. Moreover, the deficiency of MyD88 (myeloid differentiation primary-response protein 88), a key mediator of TLR4, reduced the rupture rate. These findings suggest that the TLR4 pathway promotes the development of intracranial aneurysmal rupture by accelerating inflammation in aneurysmal walls. Inhibition of the TLR4 pathway in inflammatory cells may be a promising approach for the prevention of aneurysmal rupture and subsequent subarachnoid hemorrhage.

Potential Influences of Gut Microbiota on the Formation of Intracranial Aneurysm

Gut microbiota modulates metabolic and immunoregulatory axes and contributes to the pathophysiology of diseases with inflammatory components, such as atherosclerosis, diabetes mellitus, and ischemic stroke. Inflammation is emerging as a critical player in the pathophysiology of an intracranial aneurysm. Therefore, we hypothesized that the gut microbiota affects aneurysm formation by modulating inflammation. We induced intracranial aneurysms in mice by combining systemic hypertension and a single injection of elastase into the cerebrospinal fluid. Depletion of the gut microbiota was achieved via an oral antibiotic cocktail of vancomycin, metronidazole, ampicillin, and neomycin. Antibiotics were given 3 weeks before aneurysm induction and either continued until the end of the experiment or stopped 1 day before aneurysm induction. We also assessed the effects of the gut microbiota depletion on macrophage infiltration and mRNA levels of inflammatory cytokines. Gut microbiota depletion by antibiotics reduced the incidence when antibiotics were started 3 weeks before aneurysm induction and continued until the end of the experiment (83% versus 6%, P<0.001). Even when antibiotics were stopped 1 day before aneurysm induction, the gut microbiota depletion significantly reduced the incidence of aneurysms (86% versus 28%, P<0.05). Both macrophage infiltration and mRNA levels of inflammatory cytokines were reduced with gut microbiota depletion. These findings suggest that the gut microbiota contributes to the pathophysiology of aneurysms by modulating inflammation. Human studies are needed to determine the exact contribution of the gut microbiota to the pathophysiology of aneurysm formation and disease course in humans.

Roles of Nicotine in the Development of Intracranial Aneurysm Rupture

Background and Purpose- Tobacco cigarette smoking is considered to be a strong risk factor for intracranial aneurysmal rupture. Nicotine is a major biologically active constituent of tobacco products. Nicotine's interactions with vascular cell nicotinic acetylcholine receptors containing α7 subunits (α7*-nAChR) are thought to promote local inflammation and sustained angiogenesis. In this study, using a mouse intracranial aneurysm model, we assessed potential contributions of nicotine exposure and activation of α7*-nAChR to the development of aneurysmal rupture. Methods- Intracranial aneurysms were induced by a combination of deoxycorticosterone-salt induced hypertension and a single-dose elastase injection into cerebrospinal fluid in mice. Results- Exposure to nicotine or an α7*-nAChR-selective agonist significantly increased aneurysm rupture rate. Coexposure to an α7*-nAChR antagonist abolished nicotine's deleterious effect. In addition, nicotine's promotion of aneurysm rupture was absent in smooth muscle cell-specific α7*-nAChR subunit knockout mice but not in mice lacking α7*-nAChR on endothelial cells or macrophages. Nicotine treatment increased the mRNA levels of vascular endothelial growth factor, platelet-derived growth factor-B, and inflammatory cytokines. α7*-nAChR antagonist reversed nicotine-induced upregulation of these growth factors and cytokines. Conclusions- Our findings indicate that nicotine exposure promotes aneurysmal rupture through actions on vascular smooth muscle cell α7*-nAChR.

Local extensive granulomatous inflammation of the neck region and lymphangitis caused by Lichtheimia corymbifera infection in a Japanese Black calf

A 7-month-old female Japanese Black calf developed elongated, nodular mass measuring 30 × 16 cm extended from the retropharyngeal region to mid lateral neck region. Histological examination revealed granulomatous lymphangitis with non-septate fungal hyphae recognized throughout the lesions. Fungal culture, DNA sequencing and molecular phylogenetic tree analysis confirmed the sequence of Lichtheimia corymbifera. The lymphogenous route was speculated to be the main route of fungal spread leading to the characteristic nodular appearance of this case.

Role of Myeloid Lineage Cell Autophagy in Ischemic Brain Injury

BACKGROUND AND PURPOSE

Inflammatory cells play a significant role in secondary injury after ischemic stroke. Recent studies have suggested that a lack of autophagy in myeloid cells causes augmented proinflammatory cytokine release and prolonged inflammation after tissue injury. In this study, we investigated the roles of myeloid cell autophagy in ischemic brain injury.

METHODS

Focal cerebral ischemia was induced via transient middle cerebral artery occlusion in mice with autophagy-deficient myeloid lineage cells (Atg5flox/flox LysMCre+) and in their littermate controls (Atg5flox/flox). Infarct volume, neurological function, inflammatory cell infiltration, and proinflammatory cytokine expression levels were evaluated.

RESULTS

Mice lacking autophagy in myeloid lineage cells had a lower survival rate for 14 days than control mice (20% versus 70%; P<0.05). Although there was no difference in infarct volume at 12 hours between the 2 groups, mice lacking autophagy in myeloid lineage cells had larger infarct volumes at later time points (3 and 7 days after reperfusion) with worse neurological deficit scores and lower grip test scores. There were a higher number of ionized calcium binding adaptor molecule 1-positive cells and cells expressing M1 marker CD16/32 in mice lacking autophagy in myeloid cells at the later time points. Moreover, these mice had higher expression levels of proinflammatory cytokines at later time points; however, there was no difference in ionized calcium binding adaptor molecule 1-positive cells or mRNA levels of proinflammatory cytokines at the earlier time point (12 hours after reperfusion).

CONCLUSIONS

These data suggest that the lack of myeloid cell autophagy aggravates secondary injury by augmenting and prolonging inflammation after ischemic stroke without affecting the initial injury.

Ex Vivo Reperfusion Model to Evaluate Utility of Machine Preservation for Porcine Liver Donated After Cardiac Death

BACKGROUND

Machine perfusion (MP) techniques are expected to prove useful for preserving the organ viability and recovering organ function for organ transplantation. Furthermore, an accurate assessment of organ viability using MP is important for expanding the donor criteria. In this study, an ex vivo reperfusion model (ERM) simulating transplantation using diluted autologous blood under normothermic conditions was evaluated for its utility of MP under subnormothermic conditions for livers donated after cardiac death (DCD).

METHODS

The liver preservation methods for DCD porcine livers were evaluated using the ERM. This investigation was performed using a novel perfusion system developed by our research group. Porcine livers were procured with a warm ischemia time (WIT) of 60 minutes. The organs were then preserved using subnormothemic machine perfusion (SNMP) or static cold storage (CS) for 4 hours. We also compared these tissues with SNMP livers procured under a WIT of 0 minutes. After the preservation, the livers were reperfused for 2 hours using the ERM with diluted autologous blood oxygenated by a membrane oxygenator under NMP conditions. Reperfusion was evaluated based on perfusion flow dynamics and outflow of deviating enzymes.

RESULTS

In the early stages of reperfusion, pressure in the blood vessels increased sharply in the CS group. Furthermore, the amount of aspartate aminotransferase accumulation was lower in the SNMP group than in the other groups. These results suggest ischemia-reperfusion injury is suppressed in SNMP conditions.

CONCLUSION

An ERM has use in evaluating the utility of MP for the DCD liver.

Optimum Perfusate Volume of Purified Subnormothermic Machine Perfusion for Porcine Liver Donated After Cardiac Death

INTRODUCTION

Subnormothermic machine perfusion (SNMP) shows some advantages for the preservation of grafts donated after cardiac death (DCD) and improvements in machine perfusion (MP) technology are important to enhance organ preservation outcomes for liver transplantation. In this study, we focused on purified subnormothermic machine perfusion (PSNMP) and volumes of perfusate removed to substitute for purification and replaced by modified University of Wisconsin-gluconate after the start of perfusion and investigated, in particular, the optimum perfusate purification volume. Several purification volumes under SNMP were compared. In addition, the perfusate purification during MP was indicated as a potential technique to enhance the organ quality of DCD grafts and extended-criteria donors.

METHODS

The PSNMP at several volumes (0.5 L, 1.5 L, and 3 L) were compared with regular SNMP without any purification treatment (untreated control). In the PSNMP group, all perfusate was removed to substitute for purification of the perfusate by modified University of Wisconsin-gluconate solution after the start of perfusion. After removing the perfusate, new perfusate with the same components was perfused to preserve the porcine livers obtained under warm ischemia for 60 minutes using SNMP at 22°C porcine liver for 4 hours.

RESULTS

The concentrations of aspartate aminotransferase and lactate dehydrogenase in the untreated group were significantly higher during perfusion compared to those of the intervention group. There are no significant differences among the volume conditions of the purification groups.

CONCLUSIONS

The optimal volume of perfusate purification was confirmed with a simple experimental comparison between untreated and PSNMP conditions.

Vesiculobullous melanoma: an unusual manifestation of in-transit metastasis

Malignant melanoma (MM), a well-known skin cancer with a poor prognosis, has various clinical manifestations, but vesiculobullous lesions have seldom been reported. We report a case of MM forming amelanotic vesicles at the site of an in-transit metastasis, and we also review the published reports on vesiculobullous MM. Our patient was an 87-year-old man with a history of a treated plantar MM 2 years previously, who had recurrence of the MM and development of an in-transit metastasis in his lower leg. Histopathological findings revealed vesicles caused by infiltration of the tumour. A review of the English literature revealed nine cases with various clinical presentations of the vesicles or blisters. For patients with MM with vesiculobullous lesions, an accurate medical history and examination of biopsies are of primary importance for management.

In-situ straining and time-resolved electron tomography data acquisition in a transmission electron microscope

This paper reports the preliminary results of a new in-situ three-dimensional (3D) imaging system for observing plastic deformation behavior in a transmission electron microscope (TEM) as a directly relevant development of the recently reported straining-and-tomography holder [Sato K et al. (2015) Development of a novel straining holder for transmission electron microscopy compatible with single tilt-axis electron tomography. Microsc. 64: 369-375]. We designed an integrated system using the holder and newly developed straining and image-acquisition software and then developed an experimental procedure for in-situ straining and time-resolved electron tomography (ET) data acquisition. The software for image acquisition and 3D visualization was developed based on the commercially available ET software TEMographyTM. We achieved time-resolved 3D visualization of nanometer-scale plastic deformation behavior in a Pb-Sn alloy sample, thus demonstrating the capability of this system for potential applications in materials science.

Abstract 147: Role of Nicotine in the Development of Intracranial Aneurysm Rupture

Background: Nicotine is one of main chemicals of tobacco smoke and promotes atherosclerosis and stroke. Tobacco smoke is considered an independent risk factor for intracranial aneurysm formation, growth, and rupture. There are mainly 5 subtypes of nicotine receptors. Roles of alpha7 nicotinic acetylcholine receptor (α7nAChR) in inflammation and vascular remodeling are diverse and context-dependent. Notably, endothelial α7nAChR is considered to mediate nicotine-induced inflammation. Activation of endothelial α7nAChR by nicotine may promote aneurysm rupture by increasing the aneurysm wall inflammation. Using a mouse model of intracranial aneurysm, we examined effects of nicotine in aneurysm rupture. Moreover we investigated potential roles of α7nAChR stimulation by nicotine in the pathophysiology of intracranial aneurysms.

Methods: Intracranial aneurysms were induced by a combination of elastase injection into the cerebrospinal fluid and deoxycorticosteron acetate-salt (DOCA-salt) hypertension in male mice. Mice were treated with (1) nicotine (5 mg/kg/day, n=25); (2) saline sc (n=22) for three weeks after aneurysm induction. To investigate the effect of α7nAChR, mice were treated with (1) saline sc + saline ip (n=11); (2) saline sc + α7nAChR antagonist (Methyllycaconitine, MLA 5mg/kg/day) ip (n=13); (3) nicotine (5 mg/kg/day, sc, 28 days) + saline ip (n=18); (4) nicotine sc + MLA ip (n=18).

Results: Nicotine alone significantly increased aneurysmal rupture compared with saline treatment (89% vs 46%, p=0.009). While α7nAChR antagonist did not affect the incidence of aneurysm or rupture rates, the α7nAChR antagonist significantly reduced the deleterious effect of nicotine as indicated by the reduction of the rupture rates (41% vs 100%: nicotine sc + MLA ip group vs nicotine sc + saline ip group, p=0.027).

Conclusion: Our data indicate the promotion of aneurysm rupture by nicotine may be mediated by its stimulation of alpha7nAChR.

Abstract 197: Roles of Neutrophil Extracellular Trap in the Rupture of Intracranial Aneurysm

Introduction: Neutrophil extracellular traps (NETs) are originally described as proinflammatory, antimicrobial structures consisting of extracellular chromatin decorated with granular and cytoplasmic proteins. The formation of NETs requires peptidylarginine deiminase (PAD) 4. Recent studies revealed that NETs can play an important role in promoting inflammation in vascular diseases. Inflammation is emerging as a key component of the pathophysiology of intracranial aneurysm. In both human and mouse studies, activated neutrophils were shown to be associated with formation and rupture of intracranial aneurysms. Therefore, we hypothesized that the formation of NETs by PAD4 promotes the development of aneurysm rupture. We tested this hypothesis utilizing both pharmacological and genetic approaches in mice.

Methods: We used 8- to 10-week-old male C57BL/6J mice, global PAD4 knock out (KO) and granulocyte-specific PAD4 KO mice. Aneurysm was induced by a combination of elastase injection and hypertension as we previously describes. We used deoxycorticosterone acetate (DOCA)-salt hypertension. A single dose of elastase was injected into the cerebrospinal fluid using a stereotaxic approach.

Results: Cl-amidine, an inhibitor for PAD4, significantly decreased the rupture rates (92 vs 36%, P < 0.01). At the same time, Cl-amidine decreased the number of neutrophils and the formation of NETs analyzed by Ly-6G staining and citrullinated histone H3 staining, respectively. In the inhibitor treated mice, the messenger ribonucleic acid (RNA) level of ICAM-1, MCP-1 and TNFα in the cerebral arteries were lower than that of vehicle control treated mice. Furthermore, the rupture rates were decreased in the global PAD4 KO mice and the granulocyte-specific PAD4 KO mice than in the corresponding wild type mice groups. Finally, inhibition of the formation of NETs by DNase treatment also reduced the rupture rates.

Conclusions: Our data indicate that the formation of NETs by granulocyte PAD4 promotes the development of aneurysm rupture. NETs may be represented a potential therapeutic target for the prevention of aneurysm rupture.

Subnormothermic Machine Perfusion Preservation With Rewarming for Donation After Cardiac Death Liver Grafts in Pigs

BACKGROUND

The use of grafts from donors after cardiac death (DCD) would greatly contribute to the expansion of the donor organ pool. However, the implementation of such a strategy requires the development of novel preservation methods to recover from changes owing to warm ischemia. The aim of this study was to evaluate the effectiveness of subnormothermic machine perfusion (MP) preservation with rewarming for porcine DCD liver grafts for transplantation.

METHODS

Porcine livers were perfused with newly developed MP system. The livers were perfused for 4 hours with modified University of Wisconsin gluconate solution. Group 1 grafts were preserved with no warm ischemia time (WIT) and hypothermic MP (HMP) for 4 hours. Group 2 grafts were preserved with WIT 60 minutes and HMP for 4 hours. Group 3 grafts were preserved with WIT 60 minutes and rewarming up to 25°C by MP (RMP) for 4 hours.

RESULTS

The aspartate aminotransferase and lactate dehydrogenase in the effluent maintained at lower level in group 3 compared with group 2. However, tissue ATP levels did not recover in groups 2 and 3. Histologically, the fatty degenerate and swelling of the hepatocyte was slightly seen in all groups. The normal structure of the hepatocellular cords, the bile duct and the sinusoid endothelium were preserved in all groups.

CONCLUSIONS

Potentially, subnormothermic preservation with rewarming is expected to help the recovery of function for DCD liver grafts.

Anti-Human Immunodeficiency Virus Type 1 Activity of R-95288, a Phosphodiester Hexadeoxyribonucleotide Modified by Dibenzyloxybenzyl and Hydroxyethyl Residues at the 5′- and 3′-Ends

The phosphodiester hexadeoxyribonucleotide R-95288 is a potent anti-human immunodeficiency virus type 1 (HIV-1) agent in vitro which consists or a TGGGAG nucleoside sequence with dibenzyloxybenzyl and hydroxyethyl substituents at the 5′- and 3′-ends, respectively. In this study, the antiviral activity of R-95288 against various strains of HIV-1 in vitro was assessed and its mechanism of action was analysed. R-95288 inhibited replication of all strains of HIV-1 used including laboratory strains with the syncytium-inducing (SI) phenotype and clinical isolates with both SI and non-SI (NSI) phenotypes. The 50% inhibitory concentrations (IC50s) were 0.62–18 μg mL−1 (0.21–6.2 μM). R-95288 inhibited the binding and fusion of HIV-1-infected T cells with CD4+ cells. In addition, R-95288 specifically blocked the binding of monoclonal antibodies, recognizing the anti-V3 loop or the CD4-binding site of the virus envelope glycoprotein gp120. Furthermore, the target site of R-95288 within the V3 loop was found in the putative heparin-binding region by binding inhibition assays using various anti-V3 loop antibodies. These results suggest that R-95288 can inhibit various strains of HIV-1, possibly by specific interaction with gp120.

Contamination of environmental surfaces by methicillin-resistant Staphylococcus aureus (MRSA) in rooms of inpatients with MRSA-positive body sites

Methicillin-resistant Staphylococcus aureus (MRSA) can contaminate environmental surfaces that are frequently touched by the hands of patients with MRSA colonization/infection. There have been many studies in which the presence or absence of MRSA contamination was determined but no studies in which MRSA contamination levels were also evaluated in detail. We evaluated MRSA contamination of environmental surfaces (overbed tables, bed side rails, and curtains) in the rooms of inpatients from whom MRSA was isolated via clinical specimens. We examined the curtains within 7–14 days after they had been newly hung. The environmental surfaces were wiped using gauze (molded gauze for wiping of surface bacteria; 100% cotton, 4 cm × 8 cm) moistened with sterile physiological saline. The MRSA contamination rate and mean counts (range) were 25.0% (6/24 samples) and 30.6 (0–255) colony-forming units (cfu)/100 cm², respectively, for the overbed tables and 31.6% (6/19 samples) and 159.5 (0–1620) cfu/100 cm², respectively, for the bed side rails. No MRSA was detected in 24 curtain samples. The rate of MRSA contamination of environmental surfaces was high for the overbed tables and bed side rails but low for the curtains. Therefore, at least until the 14th day of use, frequent disinfection of curtains may be not necessary.

Angiotensin-(1-7) protects against the development of aneurysmal subarachnoid hemorrhage in mice

Angiotensin-(1-7) (Ang-(1-7)) can regulate vascular inflammation and remodeling, which are processes that have important roles in the pathophysiology of intracranial aneurysms. In this study, we assessed the effects of Ang-(1-7) in the development of intracranial aneurysm rupture using a mouse model of intracranial aneurysms in which aneurysmal rupture (i.e., aneurysmal subarachnoid hemorrhage) occurs spontaneously and causes neurologic symptoms. Treatment with Ang-(1-7) (0.5 mg/kg/day), Mas receptor antagonist (A779 0.5 mg/kg/day or 2.5 mg/kg/day), or angiotensin II type 2 receptor (AT2R) antagonist (PD 123319, 10 mg/kg/day) was started 6 days after aneurysm induction and continued for 2 weeks. Angiotensin-(1-7) significantly reduced the rupture rate of intracranial aneurysms without affecting the overall incidence of aneurysms. The protective effect of Ang-(1-7) was blocked by the AT2R antagonist, but not by the Mas receptor antagonist. In AT2R knockout mice, the protective effect of Ang-(1-7) was absent. While AT2R mRNA was abundantly expressed in the cerebral arteries and aneurysms, Mas receptor mRNA expression was very scarce in these tissues. Angiotensin-(1-7) reduced the expression of tumor necrosis factor-α and interleukin-1β in cerebral arteries. These findings indicate that Ang-(1-7) can protect against the development of aneurysmal rupture in an AT2R-dependent manner.

Protective Role of Peroxisome Proliferator-Activated Receptor-γ in the Development of Intracranial Aneurysm Rupture

BACKGROUND AND PURPOSE

Inflammation is emerging as a key component of the pathophysiology of intracranial aneurysms. Peroxisome proliferator-activated receptor-γ (PPARγ) is a nuclear hormone receptor of which activation modulates various aspects of inflammation.

METHODS

Using a mouse model of intracranial aneurysm, we examined the potential roles of PPARγ in the development of rupture of intracranial aneurysm.

RESULTS

A PPARγ agonist, pioglitazone, significantly reduced the incidence of ruptured aneurysms and the rupture rate without affecting the total incidence aneurysm (unruptured aneurysms and ruptured aneurysms). PPARγ antagonist (GW9662) abolished the protective effect of pioglitazone. The protective effect of pioglitazone was absent in mice lacking macrophage PPARγ. Pioglitazone treatment reduced the mRNA levels of inflammatory cytokines (monocyte chemoattractant factor-1, interleukin-1, and interleukin-6) that are primarily produced by macrophages in the cerebral arteries. Pioglitazone treatment reduced the infiltration of M1 macrophage into the cerebral arteries and the macrophage M1/M2 ratio. Depletion of macrophages significantly reduced the rupture rate.

CONCLUSIONS

Our data showed that the activation of macrophage PPARγ protects against the development of aneurysmal rupture. PPARγ in inflammatory cells may be a potential therapeutic target for the prevention of aneurysmal rupture.

Impact of machine perfusion preservation of liver grafts from donation after cardiac death

Because of the critical shortage of deceased donor grafts, using a donation after cardiac death (DCD) donor is an important resource. However, the ischemic damage of those DCD grafts jeopardizes organ viability during cold storage. Maintaining organ viability after donation until transplantation is important for optimal graft function and survival. This review describes the effective preservation in transplantation for DCD livers. Concepts and development of machine perfusion for DCD liver grafts to reduce ischemia/reperfusion injury are discussed. Despite the fact that hypothermic machine perfusion might be superior to static cold preservation, DCD livers are exposed to hypothermia-induced damage. Recently, some groups introduced the beneficial effects of normothermic or subnormothermic machine perfusion in DCD liver preservation and transplantation.

Roles of estrogen in the formation of intracranial aneurysms in ovariectomized female mice

BACKGROUND

Epidemiological studies have indicated that postmenopausal women have a higher incidence of intracranial aneurysms than men in the same age group.

OBJECTIVE

To investigate whether estrogen or estrogen receptors (ERs) mediate protective effects against the formation of intracranial aneurysms.

METHODS

Intracranial aneurysms were induced in mice by combining a single injection of elastase into the cerebrospinal fluid with deoxycorticosterone acetate salt hypertension. The mice were treated with estrogen (17β-estradiol), an ERα agonist (propyl pyrazole triol), and an ERβ agonist (diarylpropionitrile) with and without a nitric oxide synthase inhibitor.

RESULTS

The ovariectomized female mice had a significantly higher incidence of aneurysms than the male mice, which was consistent with findings in previous epidemiological studies. In ovariectomized female mice, an ERβ agonist, but not an ERα agonist or 17β-estradiol, significantly reduced the incidence of aneurysms. The protective effect of the ERβ agonist was absent in the ovariectomized ERβ knockout mice. The protective effect of the ERβ agonist was negated by treatment with a nitric oxide synthase inhibitor.

CONCLUSION

The effects of sex, menopause, and estrogen treatment observed in this animal study were consistent with previous epidemiological findings. Stimulation of estrogen receptor-β was protective against the formation of intracranial aneurysms in ovariectomized female mice.

In Vitro Absorption and Metabolism of Nobiletin, a Chemopreventive Polymethoxyflavonoid in Citrus Fruits

The polymethoxyflavonoid (PMF), nobiletin (NOB), specifically occurs in citrus fruits, and is currently believed to be a promising anti-inflammatory and antitumor promoting agent. In the present study, we investigated the in vitro absorption and metabolism of NOB and compared them with those of the polyhydroxyflavonoid (PHF), luteolin (LT). NOB preferentially accumulated in a differentiated Caco-2 cell monolayer, which is a model for small intestinal epithelial cells, while LT did not. Treatment of NOB with a rat liver S-9 mixture led to the formation of 3'-demethyl-NOB, while that of LT did not. We thus suggest that PMFs including NOB have properties distinct from those of general flavonoids for absorption and metabolism in vitro.

Development and external validation of a nomogram for overall survival after curative resection in serosa-negative, locally advanced gastric cancer

BACKGROUND

Few nomograms can predict overall survival (OS) after curative resection of advanced gastric cancer (AGC), and these nomograms were developed using data from only a few large centers over a long time period. The aim of this study was to develop and externally validate an elaborative nomogram that predicts 5-year OS after curative resection for serosa-negative, locally AGC using a large amount of data from multiple centers in Japan over a short time period (2001-2003).

PATIENTS AND METHODS

Of 39 859 patients who underwent surgery for gastric cancer between 2001 and 2003 at multiple centers in Japan, we retrospectively analyzed 5196 patients with serosa-negative AGC who underwent Resection A according to the 13th Japanese Classification of Gastric Carcinoma. The data of 3085 patients who underwent surgery from 2001 to 2002 were used as a training set for the construction of a nomogram and Web software. The data of 2111 patients who underwent surgery in 2003 were used as an external validation set.

RESULTS

Age at operation, gender, tumor size and location, macroscopic type, histological type, depth of invasion, number of positive and examined lymph nodes, and lymphovascular invasion, but not the extent of lymphadenectomy, were associated with OS. Discrimination of the developed nomogram was superior to that of the TNM classification (concordance indices of 0.68 versus 0.61; P < 0.001). Moreover, calibration was accurate.

CONCLUSIONS

We have developed and externally validated an elaborative nomogram that predicts the 5-year OS of postoperative serosa-negative AGC. This nomogram would be helpful in the assessment of individual risks and in the consideration of additional therapy in clinical practice, and we have created freely available Web software to more easily and quickly predict OS and to draw a survival curve for these purposes.

A national survey of patients with intestinal motility disorders who are potential candidates for intestinal transplantation in Japan

Intestinal motility disorders are a major cause of intestinal failure. Severe cases such as idiopathic pseudo-obstruction represent life-threatening illnessed. Intestinal transplantation is a treatment for severe motility disorders with irreversible intestinal failure. However, the prevalence of severe motility disorders is unknown. We performed a national survey to identify patients with intestinal motility disorders who require an intestinal transplant. The national survey of 302 institutions treating intestinal motility disorders identified 147 patients treated from 2006 to 2011 at 46 institutions. The mean patient age was 12.1 years (range, 0.3-77.5). The mean age of onset was 3.0 years (range, 0.0-68.8). Diagnoses included chronic idiopathic intestinal pseudo-obstruction (n = 96), Hirschsprung disease (n = 29), megacystis microcolon intestinal hypoperistalsis syndrome (n = 18), and other (n = 6). There were 126 survivors and 21 patients who died during the last 5 years. The mortality rate was 14.3%. Eighty-five percent of patients required parenteral nutrition for more than 6 months, which was defined as irreversible intestinal failure. Among surviving patients with irreversible intestinal failure, 8 (9.4 %) developed hepatic failure with jaundice and 27 (31.8%) 2 or more central vein thromboses. In all, at least 35 patients (41%) with irreversible failure due to intestinal motility disorders may be candidates for transplantation. The prevalence of severe intestinal motility disorders was elucidated in Japan. Severe cases should be referred to transplant centers.

Association of a single nucleotide polymorphism in the SH2D1A intronic region with systemic lupus erythematosus

SH2D1A, also known as signaling lymphocytic activation molecule (SLAM)-associated protein (SAP), is an adaptor protein. Recently, it was reported that SAP deficient mice were protected from systemic lupus erythematosus (SLE). In this study, we postulated SH2D1A gene to be a candidate susceptibility gene for SLE and analyzed its association with SLE. A case-control association study was conducted on 5 tag single nucleotide polymorphisms (SNPs) in SH2D1A region in 506 Japanese female SLE patients and 330 healthy female controls. The luciferase assay was performed to determine the functional role of the SNP associated with SLE. One SNP in the intron 2, rs2049995, showed association with SLE (p=0.0110, odds ratio (OR) 1.97, 95% confidence interval (CI) 1.16-3.34, under the dominant model). The association of rs2049995 seemed to be stronger in the subset with the age of onset less than 20 years (p=0.0067, OR 2.65, 95% CI 1.28-5.46). Functional evaluation of rs2049995 showed that reporter gene activity was increased 1.9-fold for the susceptible allele compared with the resistant allele. An intronic SNP of SH2D1A is associated with SLE.