Abrupt transition from ferromagnetic to antiferromagnetic of interfacial exchange in perpendicularly magnetized L1(0)-MnGa/FeCo tuned by Fermi level position

An abrupt transition of the interfacial exchange coupling from ferromagnetic to antiferromagnetic was observed in the interface of perpendicularly magnetized L10-MnGa/Fe1-xCox epitaxial bilayers when x was around 25%. By considering the special band structure of the MnGa alloy, we present a model explaining this transition by the spin-polarization reversal of Fe1-xCox alloys due to the rise of the Fermi level as the Co content increases. The effect of interfacial exchange coupling on the coercive force (Hc) and the spin-dependent tunneling effect in perpendicular magnetic tunnel junctions (pMTJs) based on the coupled composite were also studied. Changes from the normal spin valve to inverted magnetoresistance loops corresponding to the coupling transition were observed in pMTJs with MnGa/Fe1-xCox as an electrode.

Role of nerve growth factor-tyrosine kinase receptor A signaling in paclitaxel-induced peripheral neuropathy in rats

The mechanisms underlying paclitaxel-induced peripheral neuropathy remain unknown. Nerve growth factor (NGF) is a representative neurotrophic factor that maintains neuronal function, promotes survival, and mediates neuropathic pain. We investigated expression levels of NGF and its receptors in the dorsal root ganglia (DRG) and spinal dorsal horn (DH) following paclitaxel treatment. Intraperitoneal (I.P.) administration of paclitaxel induced significant mechanical hypersensitivity and cold allodynia in rats, significantly increased the expression of NGF and its receptor tyrosine kinase receptor A (trkA) in the DRG, and increased NGF expression in the DH. In contrast, paclitaxel treatment did not alter the mRNA levels of NGF or its receptors in the DRG, DH, sciatic nerve, or hindpaw skin. Moreover, expression of NEDD4-2, a negative regulator of trkA, was significantly increased in the DRG of paclitaxel-treated rats. Intrathecal (I.T.) administration of the tyrosine kinase receptor inhibitor k252a significantly alleviated mechanical hypersensitivity in paclitaxel-treated rats. Our results suggest that NGF-trkA signaling is involved in mechanical allodynia in paclitaxel-induced neuropathy.

Engineered antibody Fc variant with selectively enhanced FcγRIIb binding over both FcγRIIa(R131) and FcγRIIa(H131)

Engaging inhibitory FcγRIIb by Fc region has been recently reported to be an attractive approach for improving the efficacy of antibody therapeutics. However, the previously reported S267E/L328F variant with enhanced binding affinity to FcγRIIb, also enhances binding affinity to FcγRIIa(R131) allotype to a similar degree because FcγRIIb and FcγRIIa(R131) are structurally similar. In this study, we applied comprehensive mutagenesis and structure-guided design based on the crystal structure of the Fc/FcγRIIb complex to identify a novel Fc variant with selectively enhanced FcγRIIb binding over both FcγRIIa(R131) and FcγRIIa(H131). This novel variant has more than 200-fold stronger binding affinity to FcγRIIb than wild-type IgG1, while binding affinity to FcγRIIa(R131) and FcγRIIa(H131) is comparable with or lower than wild-type IgG1. This selectivity was achieved by conformational change of the C(H)2 domain by mutating Pro to Asp at position 238. Fc variant with increased binding to both FcγRIIb and FcγRIIa induced platelet aggregation and activation in an immune complex form in vitro while our novel variant did not. When applied to agonistic anti-CD137 IgG1 antibody, our variant greatly enhanced the agonistic activity. Thus, the selective enhancement of FcγRIIb binding achieved by our Fc variant provides a novel tool for improving the efficacy of antibody therapeutics.

Social isolation perturbs experience-driven synaptic glutamate receptor subunit 4 delivery in the developing rat barrel cortex

In neonates, the stress of social isolation can alter developing neural circuits and cause mental illness. However, the molecular and cellular bases for these effects are poorly understood. Experience-driven synaptic AMPA receptor delivery is crucial for circuit organisation during development. In the rat, whisker experience drives the delivery of glutamate receptor subunit 4 (GluA4) but not glutamate receptor subunit 1 (GluA1) to layer 4-2/3 pyramidal synapses in the barrel cortex during postnatal day (P)8-10, whereas GluA1 but not GluA4 is delivered to these synapses during P12-14. We recently reported that early social isolation disrupts experience-driven GluA1 delivery to layer 4-2/3 pyramidal synapses during P12-14. Here, we report that neonatal isolation affects even earlier stages of development by preventing experience-dependent synaptic GluA4 delivery. Thus, social isolation severely affects synaptic maturation throughout early postnatal development.

Medical emergency education using a robot patient in a dental setting

INTRODUCTION

In an ageing society, the frequency of medical emergencies in a dental setting appears to be increasing because of a growing number of medically compromised patients. However, we currently have no dental-specific simulation environment with advanced reproducibility for medical emergencies. Therefore, we used the robot patient in objective structured clinical examinations (OSCEs) for testing student competence in emergency management. This study aimed to evaluate student responses to medical emergencies in the dental setting.

MATERIAL AND METHODS

We used 98 fifth-grade dental students at Showa University as subjects and implemented the OSCE task entitled 'Management of medical emergency using a robot patient'. Candidates were asked to manage an emergency situation immediately after local anaesthesia, with one robot patient configured to develop vasovagal syncope and the other to experience adrenaline hypersensitivity. A questionnaire on the educational value of the robot patient was completed after the examination.

RESULTS

Thirty-two per cent of students could not accurately count her pulse because of an inappropriate method. Moreover, 78% could not correctly attach either the tonometer or pulse oximetry to the patient. Accurate diagnoses were given by only 22% of students, with vasovagal syncope diagnosed by 33% and adrenaline hypersensitivity by 8%. From a questionnaire, 78% of students recognised the usefulness of the robot patient in medical emergency training.

CONCLUSION

We found that student responses to the emergency situation were poor. The robot patient is useful in dental education for medical emergency training and assessment not only for situation management but also for differential diagnosis.

Low vitamin and carotenoid levels are related to cerebral white matter lesions

OBJECTIVES

PURPOSE

To determine the effects of vitamins and carotenoids on brain white matter lesions (WMLs), we examined the associations between WMLs with vitamin and carotenoid levels in Japanese middle-aged and elderly subjects.

SUBJECTS AND METHODS

Four-hundred and sixty-nine healthy participants (male = 317; female = 152) that underwent medical examinations were examined. Deep white matter lesions (DWLs) were detected via magnetic resonance imaging (MRI) in 39 subjects. We evaluated the effects of vitamin and carotenoid levels on DWLs via logistic regression analysis.

RESULTS

Lower gamma-tocopherol levels were significantly associated with DWLs in all subjects. While lower gamma-tocopherol and vitamin C levels were significantly associated with DWLs in males, lower delta-tocopherol levels were associated with DWLs in females. The associations between DWLs and lower gamma- and delta-tocopherol and vitamin C levels were independent of age, hypertension, or smoking. However, the associations between DWLs and lower alfa-tocopherol were not significant following adjustments for smoking.

CONCLUSION

Lower carotenoid and vitamin levels were independently associated with cerebral DWLs in Japanese subjects.

Identification of Hic-5 as a novel regulatory factor for integrin αIIbβ3 activation and platelet aggregation in mice

BACKGROUND

Integrin αIIbβ3 plays key roles in platelet aggregation and subsequent thrombus formation. Hydrogen peroxide-inducible clone-5 (Hic-5), a member of the paxillin family, serves as a focal adhesion adaptor protein associated with αIIbβ3 at its cytoplasmic strand.

OBJECTIVES

Hic-5 function in αIIbβ3 activation and subsequent platelet aggregation remains unknown. To address this question, platelets from Hic-5(-/-) mice were analyzed.

METHODS AND RESULTS

Hic-5(-/-) mice displayed a significant hemostatic defect and resistance to thromboembolism, which were explained in part by weaker thrombin-induced aggregation in Hic-5(-/-) platelets. Mechanistically, Hic-5(-/-) platelets showed limited activation of αIIbβ3 upon thrombin treatment. Morphological alteration in Hic-5(-/-) platelets after thrombin stimulation on fibrinogen plates was also limited. As a direct consequence, the quantity of actin co-immunoprecipitating with the activated αIIbβ3 was smaller in Hic-5(-/-) platelets than in wild-type platelets.

CONCLUSION

We identified Hic-5 as a novel and specific regulatory factor for thrombin-induced αIIbβ3 activation and subsequent platelet aggregation in mice.

[Perioperative management of esophageal cancer patients with endocrine or metabolic disease]

Many esophageal cancer patients have endocrine or metabolic diseases, and surgeons should therefore learn to manage these conditions in the perioperative period. Mortality and morbidity rates are higher in patients with diabetes mellitus( DM) than patients without DM, because DM is a risk factor for conditions such as ischemic heart disease, chronic renal failure, and cerebrovascular disease. Uncontrolled hyperglycemia also increases susceptibility to infection and delays wound healing. Preoperative assessment of blood glucose control and comorbidities is important in patients with DM. Rapid-acting insulin is useful for controlling blood glucose levels in the perioperative period. In patients with thyroid disease, surgery is safest at a time when thyroid hormone levels are normalized. Patients with adrenocortical insufficiency need appropriate perioperative steroid therapy. Surgery for esophageal cancer should be undertaken when endocrine and metabolic diseases are well controlled. Strict perioperative management is required to prevent complications.

Disrupted cortical function underlies behavior dysfunction due to social isolation

Stressful events during early childhood can have a profound lifelong influence on emotional and cognitive behaviors. However, the mechanisms by which stress affects neonatal brain circuit formation are poorly understood. Here, we show that neonatal social isolation disrupts molecular, cellular, and circuit developmental processes, leading to behavioral dysfunction. Neonatal isolation prevented long-term potentiation and experience-dependent synaptic trafficking of α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) receptors normally occurring during circuit formation in the rodent barrel cortex. This inhibition of AMPA receptor trafficking was mediated by an increase of the stress glucocorticoid hormone and was associated with reduced calcium/calmodulin-dependent protein kinase type II (CaMKII) signaling, resulting in attenuated whisker sensitivity at the cortex. These effects led to defects in whisker-dependent behavior in juvenile animals. These results indicate that neonatal social isolation alters neuronal plasticity mechanisms and perturbs the initial establishment of a normal cortical circuit, which potentially explains the long-lasting behavioral effects of neonatal stress.

Chronic atherosclerotic mesenteric ischemia that started to develop symptoms just after anaphylaxis

An 83-year-old woman was referred to our emergency department with acute urticaria and sudden shortness of breath approximately 30 min after taking rectal diclofenac potassium for lumbago. After treatment with adrenaline and corticosteroids, the patient became hemodynamically stable and left the hospital on the next day. She attended our hospital 1 week after the onset of anaphylaxis because of repeated postprandial epigastric pain. No abnormal lesions were found in endoscopy. Radiographic selective catheter angiography revealed chronic mesenteric ischemia caused by atherosclerosis and abundant collateral arteries between the celiac trunk, the superior mesenteric artery and the inferior mesenteric artery. Patients with chronic mesenteric ischemia usually present with a clinical syndrome characterized by painful abdominal cramps and colic occurring typically during the postprandial phase. Fear of eating resulted in malnutrition. She was prescribed proton pump inhibitor, digestants, anticholinergic agents, serine protease inhibitors, prokinetics, antiplatelet agents and transdermal nitroglycerin intermittently, but these had no beneficial effects. It was most probable that this patient with chronic atherosclerotic mesenteric ischemia was suffering from functional abdominal pain syndrome induced by anaphylaxis. Since psychiatric disorders were associated with alterations in the processing of visceral sensation, we facilitated the patient's understanding of functional abdominal pain syndrome with the psychologist. Postprandial abdominal pain gradually faded after administration of these drugs and the patient left the hospital. Developing a satisfactory patient-physician relationship was considered more effective for the management of persistent abdominal pain caused by complicated mechanisms.

O(N) methods in electronic structure calculations

Linear-scaling methods, or O(N) methods, have computational and memory requirements which scale linearly with the number of atoms in the system, N, in contrast to standard approaches which scale with the cube of the number of atoms. These methods, which rely on the short-ranged nature of electronic structure, will allow accurate, ab initio simulations of systems of unprecedented size. The theory behind the locality of electronic structure is described and related to physical properties of systems to be modelled, along with a survey of recent developments in real-space methods which are important for efficient use of high-performance computers. The linear-scaling methods proposed to date can be divided into seven different areas, and the applicability, efficiency and advantages of the methods proposed in these areas are then discussed. The applications of linear-scaling methods, as well as the implementations available as computer programs, are considered. Finally, the prospects for and the challenges facing linear-scaling methods are discussed.

CLIPR-59 regulates TNF-α-induced apoptosis by controlling ubiquitination of RIP1

Tumor necrosis factor-α (TNF-α) has important roles in several immunological events by regulating apoptosis and transcriptional activation of cytokine genes. Intracellular signaling mediated by TNF-receptor-type 1 (TNFR1) is constituted by two sequential protein complexes: Complex-I containing the receptor and Complex-II-containing Caspase-8. Protein modifications, particularly ubiquitination, are associated with the regulation of the formation of these complexes. However, the underlying mechanisms remain poorly defined. Here, we identified CLIP-170-related 59 kDa protein (CLIPR-59) as a novel adaptor protein for TNFR1. Experimental reduction of CLIPR-59 levels prevented induction of apoptosis and activation of caspases in the context of TNF-α signaling. CLIPR-59 binds TNFR1 but dissociates in response to TNF-α stimulation. However, CLIPR-59 is also involved in and needed for the formation of Complex-II. Moreover, CLIPR-59 regulates TNF-α-induced ubiquitination of receptor-interacting protein 1 (RIP1) by its association with CYLD, a de-ubiquitinating enzyme. These findings suggest that CLIPR-59 modulates ubiquitination of RIP1, resulting in the formation of Complex-II and thus promoting Caspase-8 activation to induce apoptosis by TNF-α.

Introduction of a robot patient into dental education

In recent years, with the increasing social awareness of safety in medical practice, improving clinical skills has become very important, especially for recently graduated dentists. Traditionally, mannequins have been used for clinical skill training, but a mannequin is quite different from a real patient because they have no autonomous movement or conversational ability. This indicates that pre-clinical simulation education is inadequate. We have, therefore, developed a robot patient that can reproduce an authentic clinical situation for dental clinical training. The robot patient, designed as a full-body model with a height of 157 cm, has eight degrees of freedom in the head and the ability to perform various autonomous movements. Moreover, saliva secretion and conversation with the trainee can be reproduced. We have introduced the robot patient into an objective structured clinical examination targeted at fifth-grade students in our dental school to evaluate their skills in cavity preparation, whilst considering the safety of the treatment. As a result, many of the students were able to deal appropriately with a patient's unexpected movement. Moreover, results of a questionnaire survey showed that almost all the students recognised the educational value of the robot patient especially for 'risk management', and they preferred the robot patient to traditional mannequins. Practical application of the robot patient in dental clinical education was evaluated through the experiences of the fifth-grade students, which showed the effectiveness of the robot patient in the dental field.

Acute liver dysfunction in the course of norovirus gastroenteritis

A 48-year-old female with abdominal pain and malaise who showed delayed symptom of acute gastroenteritis came to see us. Her illness was diagnosed as norovirus infection, but liver dysfunction accompanied this gastroenteritis. We investigated the pathogenesis of this hepatitis for all causes including drugs, but we could not detect norovirus infection. The liver damage improved shortly in course of the gastroenteritis. She recovered completely within 2 weeks without any damage left. Norovirus-induced liver dysfunction is not known, and there is no report in the literature. We report, for the first time, the case of liver dysfunction with norovirus gastroenteritis.

Quasiparticles and Fermi liquid behaviour in an organic metal

Many organic metals display exotic properties such as superconductivity, spin-charge separation and so on and have been described as quasi-one-dimensional Luttinger liquids. However, a genuine Fermi liquid behaviour with quasiparticles and Fermi surfaces have not been reported to date for any organic metal. Here, we report the experimental Fermi surface and band structure of an organic metal (BEDT-TTF)(3)Br(pBIB) obtained using angle-resolved photoelectron spectroscopy, and show its consistency with first-principles band structure calculations. Our results reveal a quasiparticle renormalization at low energy scales (effective mass m*=1.9 m(e)) and ω(2) dependence of the imaginary part of the self energy, limited by a kink at ~50 meV arising from coupling to molecular vibrations. The study unambiguously proves that (BEDT-TTF)(3)Br(pBIB) is a quasi-2D organic Fermi liquid with a Fermi surface consistent with Shubnikov-de Haas results.