Left coronary artery occlusion caused by a large thrombus on the left coronary cusp in a patient with a continuous-flow ventricular assist device

Despite continual improvements in ventricular assist device (VAD) therapy, various clinical issues are emerging. Importantly, various types of thromboembolic complications have been reported to date. Recently, we encountered a rare continuous-flow VAD-related thromboembolic event that resulted in acute myocardial infarction. A 26-year-old female who just underwent HeartMate II(®) VAD implantation suddenly developed widespread anterolateral myocardial infarction on postoperative day 16. Echocardiography and aortography revealed a large thrombus on the left coronary cusp of the aortic valve that almost completely occluded the left coronary ostium. After VAD implantation, her aortic valve did not open, even at relatively low pump speeds; this was thought to be one of the causes for thrombus formation. Continuous suction of blood from the left ventricle and non-pulsatile flow into the ascending aorta resulted in a continuously closed aortic valve and stagnation of blood in the coronary cusp. Furthermore, both small body size (body surface area <1.3 m(2)) and postoperative right ventricular failure may have exacerbated blood stagnation and thrombus formation in this patient. We should have adjusted the anticoagulation and antiplatelet therapy protocols based on the patient's condition. She underwent off-pump coronary artery bypass surgery and remained in clinically stable condition afterwards.

Effects of medical treatment on the prognosis and risk of embolic events in patients with severe aortic plaque

AIM

The optimal treatment strategy for patients with aortic atheroma is not well established because data regarding medical treatment for such patients are lacking, especially with respect to the Japanese population. The purpose of this study was to clarify the effects of medical treatment on the risk of embolic events and mortality in patients with severe aortic plaque.

METHODS

We retrospectively investigated 75 consecutive patients with severe aortic plaque detected on transesophageal echocardiography (TEE) between 1995 and 2005. The occurrence of embolic events and all-cause death in the period after TEE was assessed. The cumulative incidence of subsequent embolic events and death was evaluated in relation to specific medical treatments, including statins, antiplatelet drugs and warfarin.

RESULTS

Embolic events occurred in 27 patients (36%) and death occurred in 37 patients (49%) during follow-up (5.6±3.0 years). The patients who experienced embolic events had a significantly higher prevalence of previous embolic events, atrial fibrillation and hemodialysis than the patients who did not experience embolic events. Univariate and multivariate analyses showed that the use of statins and/or antiplatelet drugs was significantly associated with a low incidence of death but not with a low incidence of embolic events. On the other hand, warfarin exhibited neither beneficial nor harmful effects on the incidence of embolic events or death.

CONCLUSIONS

Statin and antiplatelet drugs have beneficial effects on the prognosis of patients with severe aortic plaque diagnosed on TEE.

An in vitro demonstration of CMOS-based optoelectronic neural interface device for optogenetics

A CMOS-based neural interface device equipped with an integrated micro light source array for optogenetics was fabricated and demonstrated. A GaInN LED array formed on sapphire substrate was successfully assembled with a multifunctional CMOS image sensor that is capable of on-chip current injection. We demonstrated a functionality of light stimulation onto ChR2-expressed cells in an in vitro experiment. A ChR2-expressed cell were successfully stimulated with the light emitted from the fabricated device.

A novel SCN5A mutation demonstrating a variety of clinical phenotypes in familial sick sinus syndrome

Mutations in SCN5A have been reported to cause several types of hereditary arrhythmias (overlap syndrome). We herein report two patients with the overlapping phenotypes of juvenile sick sinus syndrome (SSS) and Brugada syndrome (BrS). The proband was a man who was in his twenties and had been diagnosed with both SSS and ventricular tachycardia (VT). A pilsicainide challenge test revealed a coved type ST segment elevation. His teenage brother also suffered from SSS, but no VT had been documented. A pilsicainide challenge failed to produce a Brugada-type ST elevation, but there was a marked prolongation of the His-ventricle interval. Their electrocardiograms at rest did not display any Brugada-type ST elevations. We identified a novel SCN5A (F1775Lfs*15) mutation in both patients, even though there was a phenotype discrepancy.

Invasion of brain by neurovirulent influenza A virus after intranasal inoculation

We examined the immunohistochemical localization of neurovirulent influenza A virus (WSN and R404BP) in the brains and lungs of C3H/HeN and A2G mice 3 days after intranasal inoculation, as well as in A2G mice 3 days after intracerebral inoculation. The invasion of brain by R404BP virus was greater than that of WSN in both mouse strains. The areas of infection were less extensive in Mx gene(+) A2G mice than in the Mx gene(-) C3H/HeN mice, which is consistent with previous reports. Major involvement was seen in various catecholaminergic neurons, capillaries, meninges and ependymal areas. Olfactory and trigeminal nerves were not positive for the WSN antigen. These results show that, in the early phase of infection, influenza A virus invades, probably through hematogenous spread, and particularly affects catecholaminergic neurons.

Cordycepin as a sensitizer to tumour necrosis factor (TNF)-α-induced apoptosis through eukaryotic translation initiation factor 2α (eIF2α)- and mammalian target of rapamycin complex 1 (mTORC1)-mediated inhibition of nuclear factor (NF)-κB

Cordycepin (3'-deoxyadenosine) is one of the major bioactive substances produced by Cordyceps militaris, a traditional medicinal mushroom. Cordycepin possesses several biological activities, including both pro-apoptotic and anti-apoptotic properties. In the present report, we investigated an effect of cordycepin on the survival of cells exposed to tumour necrosis factor (TNF)-α. We found that subtoxic doses of cordycepin increased susceptibility of cells to TNF-α-induced apoptosis. It was associated with suppression of nuclear factor-κB (NF-κB), a major prosurvival component involved in TNF-α signalling. The adenosine transporter and A₃ adenosine receptor, but not A₁ and A₂ adenosine receptors, mediated both anti-NF-κB and pro-apoptotic effects. We found that cordycepin had the potential to phosphorylate eukaryotic translation initiation factor 2α (eIF2α) and that activation of eIF2α mimicked the suppressive effect of cordycepin on the NF-κB pathway. Furthermore, activation of eIF2α sensitized cells to TNF-α-induced apoptosis. To identify molecular events downstream of eIF2α, the role of mammalian target of rapamycin complex 1 (mTORC1) was examined. Selective activation of ₃eIF2α, as well as treatment with cordycepin, caused phosphorylation of mTORC1. Rapamycin, an inhibitor of mTORC1, significantly reversed the suppressive effects of eIF2α on NF-κB. These results suggest that cordycepin sensitizes cells to TNF-α-induced apoptosis, at least in part, via induction of the eIF2α-mTORC1 pathway and consequent suppression of NF-κB.

Successful endovascular therapy of a penetrating zone III jugular bulb injury. A case report

Penetrating venous injuries via Zone III of the neck extended over jugular bulb are rare. The optimal strategies for these venous injuries are currently unknown because many of the vital structures in this region are poorly accessible to the surgeon and therefore it is difficult to control bleeding. A 76-year-old man got drunk and fell down onto a paper door. The wooden framework of the paper door was broken and got stuck deep in the right side of his neck. Enhanced computed tomography showed the wood stick had penetrated through the right jugular foramen and injured the jugular bulb. We successfully performed right sigmoid and jugular vein occlusion via an endovascular approach using Guglielmi detachable coils at first and then to draw out the wood stick in order to avoid venous bleeding. To our best knowledge, these venous injuries have reported in only four cases. Only one case was performed by endovascular approach using n-butyl cyanoacrylate (NBCA). Coil embolization is much better than NBCA in the light of reducing complications due to adhesion to the inserted wood stick and embolization of unintended vessels. Venous occlusion using coil embolization is the best way to treat a penetrating jugular bulb injury via zone III because of reducing the hemorrhage and air embolism.

mTORC1 serves ER stress-triggered apoptosis via selective activation of the IRE1-JNK pathway

Mammalian target of rapamycin (mTOR) has a key role in the regulation of an array of cellular function. We found that rapamycin, an inhibitor of mTOR complex 1 (mTORC1), attenuated endoplasmic reticulum (ER) stress-induced apoptosis. Among three major branches of the unfolded protein response, rapamycin selectively suppressed the IRE1-JNK signaling without affecting PERK and ATF6 pathways. ER stress rapidly induced activation of mTORC1, which was responsible for induction of the IRE1-JNK pathway and apoptosis. Activation of mTORC1 reduced Akt phosphorylation, which was an event upstream of IRE-JNK signaling and consequent apoptosis. In vivo, administration with rapamycin significantly suppressed renal tubular injury and apoptosis in tunicamycin-treated mice. It was associated with enhanced phosphorylation of Akt and suppression of JNK activity in the kidney. These results disclosed that, under ER stress conditions, mTORC1 causes apoptosis through suppression of Akt and consequent induction of the IRE1-JNK pathway.