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This study aimed to examine the effect of Japanese policies for appropriate hypnotics use and novel hypnotics (e.g., melatonin receptor agonist [MRA] and orexin receptor antagonist [ORA]) on long-term prescriptions of hypnotics.This retrospective study was conducted using a large-scale health insurance claims database. Among subscribers prescribed hypnotics at least once between April 2005 and March 2021, those prescribed hypnotics for the first time after being included in the database in three periods (period 1, April 2012-March 2013; period 2, April 2016-March 2017; and period 3, April 2018-March 2019) were eligible. These were set considering the timing of the 2014 and 2018 medical fee revisions (2014 for polypharmacy of three or more hypnotics, 2018 for long-term prescription of benzodiazepine receptor agonists for12 months). The duration of consecutive prescriptions of hypnotics over 12 months was evaluated. Factors associated with short-term prescriptions of hypnotics were also investigated.In total, 186,535 participants were newly prescribed hypnotics. The mean duration of prescriptions was 2.9 months, and 9.3% of participants were prescribed hypnotics for 12 months. Prescription periods were not associated with short-term prescriptions of hypnotics. ORA use was associated with short-term prescriptions of hypnotics (adjusted hazard ratio, 1.077; 95% confidence interval, 1.035-1.120; p0.001), but MRA use was not.Japanese policies had no statistically significant effect on long-term prescriptions of hypnotics. Although this study suggests initiating ORA for insomniacs as a candidate strategy to prevent long-term prescriptions of hypnotics, further research is necessary to draw conclusions. This article is protected by copyright. All rights reserved.

Masaya Ogasawara,1 Masahiro Takeshima,1 Shumpei Kosaka,2 Aya Imanishi,1 Yu Itoh,1 Dai Fujiwara,1 Kazuhisa Yoshizawa,1 Norio Ozaki,3 Kazuyuki Nakagome,4 Kazuo Mishima1 1Department of Neuropsychiatry, Akita University Graduate School of Medicine, Akita, Japan; 2Department of Psychiatry, Akita Prefectural Center for Rehabilitation and Psychiatric Medicine, Daisen, Japan; 3Department of Pathophysiology of Mental Disorders, Nagoya University Graduate School of Medicine, Nagoya, Japan; 4Department of Psychiatry, National Center of Neurology and Psychiatry, Tokyo, JapanCorrespondence: Kazuo Mishima, Department of Neuropsychiatry, Akita University Graduate School of Medicine, 1-1-1 Hondo, Akita, 010-8543, Japan, Tel +81-18-884-6122, Fax +81-18-884-6445, Email clocksclub@gmail.comPurpose: Sleep-tracking devices have performed well in recent studies that evaluated their use in healthy adults by comparing them with the gold standard sleep assessment technique, polysomnography (PSG). These devices have not been validated for use in patients with psychiatric disorders. Therefore, we tested the performance of three sleep-tracking devices against PSG in patients with psychiatric disorders.Patients and methods: In total, 52 patients (32 women; 48.1 ± 17.2 years, mean ± SD; 18 patients diagnosed with schizophrenia, 19 with depressive disorder, 3 with bipolar disorder, and 12 with sleep disorder cases) were tested in a sleep laboratory with PSG, along with portable electroencephalography (EEG) device (Sleepgraph), actigraphy (MTN-220/221) and consumer sleep-tracking device (Fitbit Sense).Results: Epoch-by-epoch sensitivity (for sleep) and specificity (for wake), respectively, were as follows: Sleepgraph (0.95, 0.76), Fitbit Sense (0.95, 0.45) and MTN-220/221 (0.93, 0.40). Portable EEG (Sleepgraph) had the best sleep stage-tracking performance. Sleep-wake summary metrics demonstrated lower performance on poor sleep (ice, shorter total sleep time, lower sleep efficiency, longer sleep latency, longer wake after sleep onset).Conclusion: Devices demonstrated similar sleep-wake detecting performance as compared with previous studies that evaluated sleep in healthy adults. Consumer sleep device may exhibit poor sleep stage-tracking performance in patients with psychiatric disorders due to factors that affect the sleep determination algorithm, such as changes in autonomic nervous system activity. However, Sleepgraph, a portable EEG device, demonstrated higher performance in mental disorders than the Fitbit Sense and actigraphy.Keywords: polysomnography, actigraphy, portable EEG, consumer sleep technologies, psychiatric patients

An RNA aptamer that induces suitable conformational changes upon binding to a user-defined ligand allows us to artificially construct a riboswitch, a ligand-dependent and

Kazuhisa Yoshizawa,1 Masahiro Takeshima,2 Sayaka Ishino,3 Masaya Ogasawara,2 Dai Fujiwara,2 Yu Itoh,2 Aya Imanishi,2 Hidenobu Ohta,2 Kazuo Mishima2 1Department of Psychiatry, Akita Prefectural Center for Rehabilitation and Psychiatric Medicine, Daisen City, Akita, 019-2492, Japan; 2Department of Neuropsychiatry, Akita University Graduate School of Medicine, Akita City, Akita, 010-8543, Japan; 3Department of Neuropsychiatry, Sugawara Hospital, Yurihonjo City, Akita, 015-0012, JapanCorrespondence: Masahiro TakeshimaDepartment of Neuropsychiatry, Akita University Graduate School of Medicine, 1-1-1, Hondo, Akita City, Akita, 010-8543, JapanTel +81-18-884-6122Fax +81-18-884-6445Email m.takeshima@med.akita-u.ac.jpPurpose: A major depressive episode is a risk factor for venous thromboembolism (VTE) in psychiatric inpatients. However, it is unclear whether the severity of depressive symptoms or duration of the current depressive episode is associated with VTE. Further, the VTE prevalence among hospitalized patients with a major depressive episode receiving electroconvulsive therapy is unknown. This retrospective study examined factors associated with VTE among hospitalized patients with a major depressive episode and estimated the prevalence of VTE in such patients who underwent electroconvulsive therapy.Patients and Methods: Patients with a major depressive episode hospitalized in the Department of Neuropsychiatry at Akita University Hospital between January 2018 and December 2020 were included. Data from the first week of hospitalization were extracted from medical records. VTE was diagnosed based on the findings of computed tomography. To evaluate whether the severity of depressive symptoms or duration of the current depressive episode was associated with VTE, logistic regression analysis was conducted after adjusting for covariates with known VTE risk factors (antidepressants, antipsychotics, and physical comorbidities).Results: We analyzed 133 patients; of these, 14 were diagnosed with asymptomatic VTE. The severity of depressive symptoms (odds ratio: 1.220, 95% confidence interval: 1.081– 1.377, p = 0.001) was significantly associated with VTE. The prevalence of VTE among those receiving electroconvulsive therapy was 35% (7/20).Conclusion: The prevalence of VTE was 35% among patients receiving in-hospital electroconvulsive therapy for a major depressive episode. VTE should be considered for hospitalized patients with severe depressive symptoms and patients receiving in-hospital electroconvulsive therapy for a major depressive episode.Keywords: bipolar depression, depressive symptoms, electroconvulsive therapy, unipolar depression, venous thromboembolism

Masahiro Takeshima,1 Hiroyasu Ishikawa,1 Masaya Ogasawara,1 Munehiro Komatsu,2 Dai Fujiwara,1 Yu Itoh,2 Yuki Wada,3 Yuki Omori,4 Hidenobu Ohta,1 Kazuo Mishima1 1Department of Neuropsychiatry, Akita University Graduate School of Medicine, Akita, Japan; 2Department of Neuropsychiatry, Akita City Hospital, Akita, Japan; 3Department of Radiology, Akita University Graduate School of Medicine, Akita, Japan; 4Department of Neuropsychiatry, Tokyo Metropolitan Geriatric Hospital, Tokyo, JapanCorrespondence: Masahiro TakeshimaDepartment of Neuropsychiatry, Akita University Graduate School of Medicine, 1-1-1, Hondo, Akita City, Akita, 010-8543, JapanTel +81-18-884-6122Fax +81-18-884-6445Email m.takeshima@med.akita-u.ac.jpPurpose: D-dimer has the advantage of excluding venous thromboembolism (VTE) due to its high sensitivity but is disadvantageous for diagnosing VTE due to its low specificity. A method to increase the usefulness of D-dimer in the diagnosis of VTE is warranted. This study aimed to investigate the usefulness of the combination of D-dimer and soluble fibrin monomer complex (SFMC), which has been suggested as a new candidate marker for VTE, in VTE diagnosis.Patients and Methods: This prospective study in 109 subjects was performed at a psychiatric department between August 1, 2017 and December 31, 2019. Subjects’ levels of D-dimer and SFMC were measured simultaneously. Plasma levels of D-dimer and SFMC were measured using NANOPIA® D-dimer and NANOPIA® SF. Subjects with positive D-dimer (≥ 1.0 μg/mL) results underwent contrast computed tomography for confirmation of VTE within 12 hours of D-dimer measurement. A receiver operating characteristic curve analysis was performed to examine the usefulness of SFMC for the diagnosis of VTE.Results: Only 109 of the 783 subjects without symptoms suggestive of VTE participated in the study. Out of 41 subjects with positive D-dimer results, 17 subjects were diagnosed with VTE. A receiver operating characteristic curve analysis was performed to determine cutoff values. The area under the curves was 0.848 for SFMC (p< 0.001, 95% CI 0.722 to 0.974), and the optimal cutoff value was 10.0 μg/mL (sensitivity 58.8%, specificity 100%, positive predictive value 100%, negative predictive value 77.4%).Conclusion: SFMC was useful for diagnosing VTE in the psychiatric patients with positive D-dimer results.Keywords: computed tomography, D-dimer, psychiatric patients, soluble fibrin monomer complex, venous thromboembolism

We here designed an in vitro selection scheme for obtaining an aptamer with which to rationally construct an artificial riboswitch as its component part. In fact, a nanosized DNA-binding aptamer obtained through this scheme allowed us to easily and successfully create eukaryotic riboswitches that upregulate internal ribosome entry site-mediated translation in response to the ligand (nanosized DNA) in wheat germ extract, a eukaryotic cell-free expression system. The induction ratio of the best riboswitch ligand-dose-dependently increased to 21 at 300 μM ligand. This switching efficiency is much higher than that of the same type of riboswitch with a widely used theophylline-binding aptamer, which was in vitro selected without considering its utility for constructing riboswitches. The selection scheme described here would facilitate obtaining various ligand/aptamer pairs suitable for constructing artificial riboswitches, which could serve as elements of synthetic gene circuits in synthetic biology.

Yu Itoh,1 Masahiro Takeshima,1 Yoshitaka Kaneita,2 Naohisa Uchimura,3 Yuichi Inoue,4 Makoto Honda,5 Wataru Yamadera,6 Norio Watanabe,7 Shingo Kitamura,8 Isa Okajima,9 Naoko Ayabe,10 Kyoko Nomura,11 Kazuo Mishima1 1Department of Neuropsychiatry, Akita University Graduate School of Medicine, Akita, Japan; 2Division of Public Health, Department of Social Medicine, Nihon University School of Medicine, Tokyo, Japan; 3Department of Neuropsychiatry, Kurume University, Fukuoka, Japan; 4Department of Somnology, Tokyo Medical University, Tokyo, Japan; 5Sleep Disorders Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan; 6Division of Bioregulatory Medicine, Department of Katsushika Medical Center, The Jikei University, Tokyo, Japan; 7Health Promotion and Human Behavior, School of Public Health, Kyoto University Graduate School of Medicine, Kyoto, Japan; 8Department of Sleep-Wake Disorders, National Institute of Mental Health, National Center of Neurology and Psychiatry, Tokyo, Japan; 9Department of Psychological Counseling, Faculty of Humanities, Tokyo Kasei University, Tokyo, Japan; 10Department of Regional Studies and Humanities, Faculty of Education and Human Studies, Akita University, Akita, Japan; 11Department of Environmental Health Science and Public Health, Akita University Graduate School of Medicine, Akita, JapanCorrespondence: Kazuo MishimaDepartment of Neuropsychiatry, Akita University Graduate School of Medicine, Hondo 1-1-1, Akita, 010-8543, JapanTel +81-18-884-6122Fax +81-18-884-6445Email mishima@med.akita-u.ac.jpPurpose: Large-scale natural disasters have an enormous physical and mental impact, immediately after they occur, on people living near the central disaster areas. It is known that, in the early stages, a seismic disaster triggers high rates of symptoms for insomnia, depression, and anxiety. However, little information is available about their medium- to long-term clinical outcomes. In this study, we conducted a repeated cross-sectional nationwide questionnaire survey to clarify changes in the prevalence of insomnia and its background factors after the Great East Japan Earthquake, a huge earthquake with a moment magnitude of 9.0 that occurred on March 11, 2011.Methods: We conducted a repeated cross-sectional survey in November 2009 (pre-earthquake, 1224 participants), July 2011 (4 months post-earthquake, 1259 participants), and August 2012 (18 months post-earthquake, 1289 participants) using stratified random sampling from 157 Japanese sites.Results: Compared to 2009, the prevalence of insomnia statistically increased nationwide immediately post-disaster (11.7% vs 21.2%; p < 0.001) but significantly decreased in 2012 compared to immediately after the earthquake (10.6% vs 21.2%; p < 0.001). In 2011, insomnia was most frequent in the central disaster area. Multivariable logistic regression models demonstrated the association between the following factors and increased risk of insomnia: being a woman (odds ratio [OR] 1.48, 95% confidence interval [CI]: 1.00– 2.19), being employed in 2009 (OR 1.74, 95% CI: 1.15– 2.62), and being of younger age group (20– 64 years) in 2011 (OR 1.64, 95% CI: 1.12– 2.42) and 2012 (OR 2.50 95% CI: 1.47– 4.23). Post-earthquake, the prevalence of insomnia symptoms in men increased, while the gender difference decreased and was no longer statistically significant. Additionally, insomnia was associated with psychological distress (scores ≥ 5 on the Kessler Psychological Distress Scale) in 2011 and 2012.Conclusion: This study demonstrated that the prevalence of insomnia was significantly higher after the earthquake. Moreover, individuals with insomnia were more likely to experience psychological distress after the earthquake that continued until 2012.Keywords: disaster, earthquakes, insomnia, psychological stress

The Cre-loxP system is invaluable for spatial and temporal control of gene knockout, knockin, and reporter expression in the mouse nervous system. However, we report varying probabilities of unexpected germline recombination in distinct Cre driver lines designed for nervous system-specific recombination. Selective maternal or paternal germline recombination is showcased with sample Cre lines. Collated data reveal germline recombination in over half of 64 commonly used Cre driver lines, in most cases with a parental sex bias related to Cre expression in sperm or oocytes. Slight differences among Cre driver lines utilizing common transcriptional control elements affect germline recombination rates. Specific target loci demonstrated differential recombination; thus, reporters are not reliable proxies for another locus of interest. Similar principles apply to other recombinase systems and other genetically targeted organisms. We hereby draw attention to the prevalence of germline recombination and provide guidelines to inform future research for the neuroscience and broader molecular genetics communities.

A hippocampal mossy fiber synapse has a complex structure in which presynaptic boutons attach to the dendritic trunk by puncta adherentia junctions (PAJs) and wrap multiply-branched spines, forming synaptic junctions. It was previously shown that afadin regulates the formation of the PAJs cooperatively with nectin-1, nectin-3, and N-cadherin. Afadin is a nectin-binding protein with two splice variants, l-afadin and s-afadin: l-afadin has an actin filament-binding domain, whereas s-afadin lacks it. It remains unknown which variant is involved in the formation of the PAJs or how afadin regulates it. We showed here that re-expression of l-afadin, but not s-afadin, in the afadin-deficient cultured hippocampal neurons in which the PAJ-like structure was disrupted, restored this structure as estimated by the accumulation of N-cadherin and αΝ-catenin. The l-afadin mutant, in which the actin filament-binding domain was deleted, or the l-afadin mutant, in which the αΝ-catenin-binding domain was deleted, did not restore the PAJ-like structure. These results indicate that l-afadin, but not s-afadin, regulates the formation of the hippocampal synapse PAJ-like structure through the binding to actin filaments and αN-catenin. We further found here that l-afadin bound αN-catenin, but not γ-catenin, whereas s-afadin bound γ-catenin, but hardly αN-catenin. These results suggest that the inability of s-afadin to form the hippocampal synapse PAJ-like structure is due to its inability to efficiently bind αN-catenin.

The medial habenula (MHb), implicated in stress, depression, memory, and nicotine withdrawal syndromes, receives septal inputs and sends efferents to the interpeduncular nucleus. We previously showed that the immunoglobulin‐like cell adhesion molecules (CAMs) nectin‐2α and nectin‐2δ are expressed in astrocytes in the brain, but their expression in neurons remains unknown. We showed here by immunofluorescence microscopy that nectin‐2α, but not nectin‐2δ, was prominently expressed in the cholinergic neurons in the developing and adult MHbs and localized at the boundary between the adjacent somata of the clustered cholinergic neurons where the voltage‐gated A‐type K+ channel Kv4.2 was localized. Analysis by immunoelectron microscopy on this boundary revealed that Kv4.2 was localized at the membrane specializations (MSs) with plasma membrane darkening in an asymmetrical manner, whereas nectin‐2α was localized on the apposed plasma membranes mostly at the outside of these MSs, but occasionally localized at their edges and insides. Nectin‐2α at this boundary was not colocalized with the nectin‐2α‐binding protein afadin, other CAMs, or their interacting peripheral membrane proteins, suggesting that nectin‐2α forms a cell adhesion apparatus different from the Kv4.2‐associated MSs. Genetic ablation of nectin‐2 delayed the localization of Kv4.2 at the boundary between the adjacent somata of the clustered cholinergic neurons in the developing MHb. These results revealed the unique localization of nectin‐2α and its regulatory role in the localization of Kv4.2 at the MSs in the MHb.

A hippocampal mossy fiber synapse, which is implicated in learning and memory, has a complex structure in which mossy fiber boutons attach to the dendritic shaft by puncta adherentia junctions (PAJs) and wrap around a multiply-branched spine, forming synaptic junctions. Here, we electron microscopically analyzed the ultrastructure of this synapse in afadin-deficient mice. Transmission electron microscopy analysis revealed that typical PAJs with prominent symmetrical plasma membrane darkening undercoated with the thick filamentous cytoskeleton were observed in the control synapse, whereas in the afadin-deficient synapse, atypical PAJs with the symmetrical plasma membrane darkening, which was much less in thickness and darkness than those of the control typical PAJs, were observed. Immunoelectron microscopy analysis revealed that nectin-1, nectin-3, and N-cadherin were localized at the control typical PAJs, whereas nectin-1 and nectin-3 were localized at the afadin-deficient atypical PAJs to extents lower than those in the control synapse and N-cadherin was localized at their non-junctional flanking regions. These results indicate that the atypical PAJs are formed by nectin-1 and nectin-3 independently of afadin and N-cadherin and that the typical PAJs are formed by afadin and N-cadherin cooperatively with nectin-1 and nectin-3. Serial block face-scanning electron microscopy analysis revealed that the complexity of postsynaptic spines and mossy fiber boutons, the number of spine heads, the area of postsynaptic densities, and the density of synaptic vesicles docked to active zones were decreased in the afadin-deficient synapse. These results indicate that afadin plays multiple roles in the complex ultrastructural morphogenesis of hippocampal mossy fiber synapses. This article is protected by copyright. All rights reserved.

Mitral cells project lateral dendrites that contact the lateral and primary dendrites of other mitral cells and granule cell dendrites in the external plexiform layer (EPL) of the olfactory bulb. These dendritic structures are critical for odor information processing, but it remains unknown how they are formed. In immunofluorescence microscopy, the immunofluorescence signal for the cell adhesion molecule nectin-1 was concentrated on mitral cell lateral dendrites in the EPL of the developing mouse olfactory bulb. In electron microscopy, the immunogold particles for nectin-1 were symmetrically localized on the plasma membranes at the contacts between mitral cell lateral dendrites, which showed bilateral darkening without dense cytoskeletal undercoats characteristic of puncta adherentia junctions. We named the contacts where the immunogold particles for nectin-1 were symmetrically accumulated "nectin-1 spots." The nectin-1 spots were 0.21 μm in length on average and the distance between the plasma membranes was 20.8 nm on average. In 3D reconstruction of serial sections, clusters of the nectin-1 spots formed a disc-like structure. In the mitral cell lateral dendrites of nectin-1-knockout mice, the immunogold particles for nectin-1 were undetectable and the plasma membrane darkening was electron-microscopically normalized, but the plasma membranes were partly separated from each other. The nectin-1 spots were further identified between mitral cell lateral and primary dendrites and between mitral cell lateral dendrites and granule cell dendritic spine necks. These results indicate that the nectin-1 spots constitute a novel adhesion apparatus that tethers mitral cell dendrites in a dendritic meshwork structure of the developing mouse olfactory bulb.

A hippocampal mossy fiber synapse, which is implicated in learning and memory, has a complex structure. We have previously shown using afadin-deficient mice that afadin plays multiple roles in the structural and functional differentiations of this synapse. We investigated here using a co-culture system with cultured hippocampal neurons and non-neuronal COS-7 cells expressing synaptogenic cell adhesion molecules (CAMs) whether afadin is involved in the presynaptic differentiation of hippocampal synapses. Postsynaptic CAMs NGL-3 (alias, a Lrrc4b gene product) and neuroligin induced presynaptic differentiation by trans-interacting with their respective presynaptic binding CAMs LAR (alias, a Ptprf gene product) and neurexin. This activity of NGL-3, but not neuroligin, was dependent on afadin, but not the afadin-binding presynaptic CAM nectin-1. The afadin-binding postsynaptic CAM nectin-3 did not induce presynaptic differentiation. Immunofluorescence and immunoelectron microscopy analyses showed that afadin was localized mainly at puncta adherentia junctions, but partly at synaptic junctions, of the mossy fiber synapse. β-Catenin and γ-catenin known to bind to LAR were co-immunoprecipitated with afadin from the lysate of mouse brain. These results suggest that afadin is involved in the NGL-3-LAR system-induced presynaptic differentiation of hippocampal neurons cooperatively with β-catenin and γ-catenin in a nectin-1-independent manner.

Afadin interacts with the cytoplasmic region of nectins, which are immunoglobulin-like cell adhesion molecules at adherens junctions, and links them to the actin cytoskeleton. Afadin regulates activities of cells in culture such as directional motility, proliferation and survival. We used Cre-loxP technology to generate mice conditionally lacking afadin specifically in the intestinal epithelia after birth. The loss of afadin caused increased paracellular permeability in the intestinal mucosa and enhanced susceptibility to the tissue destruction induced by dextran sulfate sodium. The junctional architecture of the intestinal epithelia appeared to be preserved, whereas the deficiency of afadin caused the mislocalization of nectin-2 and nectin-3 from adherens junctions to basolateral membrane domains but not that of other components of apical junctions. By contrast, such phenotypic changes were undetected in mice lacking nectin-2, nectin-3 or both. These findings suggest that afadin plays crucial roles, independently of the role as the nectin–afadin module, in barrier function and homeostasis of the intestinal epithelia once the epithelial structure has been established.

LIM-domain only protein 7 (LMO7) has been suggested to act as a tumor suppressor for murine lung adenocarcinoma, while its splice variant p100 LMO7/#16 is associated with invasion and metastasis of rat AH130W1 cells. However, the importance of LMO7 in human lung cancer is unknown. We investigated LMO7 protein expression by immunohistochemistry in tumor tissues obtained from 57 patients with adenocarcinoma of the lung using a rabbit anti-LMO7 antibody. Signals for LMO7 were localized to the apical surface of the bronchial epithelium and to the cell membranes of pneumocytes in non-cancerous pulmonary tissues, but were noted circumferentially around the plasma membrane of cancer cells in all 57 patients with adenocarcinoma. The LMO7-positive group (24 patients, 42%) showed equivocal to strong expression of LMO7 in more than 50% cancer cells, while the remaining 33 patients (58%) showed LMO7 expression in less than 50% of their cancer cells. The latter group had significantly more advanced disease than the LMO7-positive group with regard to T factor (p=0.011), nodal involvement (p=0.026) and p-stage (p=0.010; χ(2) test). Multivariate analysis using a logistic regression model showed that LMO7 expression was independently associated with the T factor (p=0.041). Kaplan-Meier analysis showed that a poor prognosis was associated with low expression of LMO7 (p=0.036; log-rank test). Our findings are consistent with earlier observations and demonstrate that LMO7 is inversely correlated with the development and prognosis of human lung adenocarcinoma.

This paper deals with an analysis of a crack-tip field of particulate-reinforced composites which can describe the evolution of debonding damage, matrix plasticity and particle size effect on deformation and damage. Numerical analyses were carried out on a crack-tip field in elastic-plastic matrix composites reinforced with elastic particles by using a finite element method developed based on an incremental damage theory. The particle size effect on damage is described by a critical energy criterion for particle-matrix interfacial debonding. The effect of debonding damage on a crack-tip field is discussed based on numerical results. The debonding damage initiates and progresses ahead of a crack-tip. The stress distribution shifts downward in the debonding damage area. It is concluded that a crack-tip field is strongly affected by debonding damage.

This paper deals with a constitutive model of particulate-reinforced composites which can describe the evolution of debonding damage, matrix plasticity and particle size effects on deformation and damage. An incremental damage model of particulate-reinforced composites based on the Mori–Tanaka’s mean field concept has been extended to consider the particle size effects by using the Nan–Clarke’s simple method. The particle size effect on deformation is realized by introducing dislocation plasticity for stress–strain relation of in situ matrix in composites, and the particle size effect on damage is described by a critical energy criterion for particle–matrix interfacial debonding. For composites containing particles of various sizes, the effects of particle size distribution is incorporated into the model. Influence of debonding damage, particle size and particle volume fraction on overall stress–strain response of composites is discussed based on numerical results.

This paper deals with a micromechanics model of particle-reinforced composites which can describe debonding damage of particles-matrix interface, matrix plasticity and particle size effect on deformation and damage. The Tohgo-Chou-Weng's incremental damage theory of particle-reinforced composites based on the Eshelby's equivalent inclusion method and Mori-Tanaka's mean field concept has been extended to consider the particle size effect by using the Nan-Clarke's simple method. The particle size effect on deformation is realized by introducing dislocation plasticity for stress-strain relation of in-situ matrix in composites, and the particle size effect on damage is described by a strain energy release rate criterion for particle-matrix interfacial debonding. Furthermore, for the composites containing particles of various sizes, the effect of a particle size distribution is incorporated into the model. Influence of the debonding damage and particle size on the stress-strain response of composites is discussed based on numerical results by the proposed model.

Nectins are Ca2+-independent immunoglobulin-like cell-cell adhesion molecules. In the nervous system, among four members (nectin-1, -2, -3, and -4), nectin-1 and -3 are asymmetrically localized at puncta adherentia junctions formed between the mossy fiber terminals and the dendrites of CA3 pyramidal neurons in the mouse hippocampus and heterophilic trans-interactions between nectin-1 and nectin-3 are involved in the selective interaction of axons and dendrites of cultured neurons. By contrast, nectin-2, which has two splicing variants, nectin-2α and -2δ, has not been well characterized in the brain. We showed here that nectin-2α was expressed in both cultured mouse neurons and astrocytes whereas nectin-2δ was selectively expressed in the astrocytes. Nectin-2δ was localized at the adhesion sites between adjacent cultured astrocytes, but in the brain it was localized on the plasma membranes of astrocytic perivascular endfoot processes facing the basement membrane of blood vessels. Genetic ablation of nectin-2 caused degeneration of astrocytic perivascular endfoot processes and neurons in the cerebral cortex. These results uncovered for the first time the localization and critical functions of nectin-2 in the brain.

Intestinal epithelial cells possess apical-basal polarity, which governs the exchange of nutrients and waste. Perturbation of cell polarity appears to be a general feature of cancers, although most colorectal cancers are differentiated adenocarcinomas, in which polarity is maintained to some extent. Little is known about the role of dysregulated polarity in cancer. The cancer tissue-originated spheroid method was applied to the preparation and culture of spheroids. Spheroids were cultured in suspension or in type I collagen gel. Polarity was assessed by IHC of apical markers and electron microscopy. Two types of polarity status in spheroids were observed: apical-in, with apical membrane located at cavities inside the spheroids in type I collagen gel; and apical-out, with apical membrane located at the outermost layer of spheroids in suspension. These polarities were highly interchangeable. Inhibitors of Src and dynamin attenuated the polarity switch. In patients, clusters of cancer cells that invaded vessels had both apical-in and apical-out morphologic features, whereas primary and metastatic tumors had apical-in features. In a mouse liver metastasis model, apical-out spheroids injected into the portal vein became apical-in spheroids in the liver within a few days. Inhibitors of Src and dynamin significantly decreased liver metastasis. Polarity switching was observed in spheroids and human cancer. The polarity switch was critical in an experimental liver metastasis model.

Olfactory mitral cells extend lateral secondary dendrites that contact the lateral secondary and apical primary dendrites of other mitral cells in the external plexiform layer (EPL) of the olfactory bulb. The lateral dendrites further contact granule cell dendrites, forming dendrodendritic reciprocal synapses in the EPL. These dendritic structures are critical for odor information processing, but it remains unknown how they are formed. We recently showed that the immunoglobulin-like cell adhesion molecule nectin-1 constitutes a novel adhesion apparatus at the contacts between mitral cell lateral dendrites, between mitral cell lateral and apical dendrites, and between mitral cell lateral dendrites and granule cell dendritic spine necks in the deep sub-lamina of the EPL of the developing mouse olfactory bulb and named them nectin-1 spots. We investigated here the role of the nectin-1 spots in the formation of dendritic structures in the EPL of the mouse olfactory bulb. We showed that in cultured nectin-1-knockout mitral cells, the number of branching points of mitral cell dendrites was reduced compared to that in the control cells. In the deep sub-lamina of the EPL in the nectin-1-knockout olfactory bulb, the number of branching points of mitral cell lateral dendrites and the number of dendrodendritic reciprocal synapses were reduced compared to those in the control olfactory bulb. These results indicate that the nectin-1 spots regulate the branching of mitral cell dendrites in the deep sub-lamina of the EPL and suggest that the nectin-1 spots are required for odor information processing in the olfactory bulb.

We have previously shown that transforming growth factor-beta1 (TGF-beta1) markedly stimulates the invasive capacity of rat ascites hepatoma AH130 W1 cells in vitro and in vivo. A differential hybridization procedure was used to isolate genes that were specifically up-regulated in TGF-beta1 treated W1 cells. Among ten independent cDNA clones, we focused on LMO7 and a variant isoform, LMO7S, that was generated by alternative splicing. LMO7 had PDZ and LIM domains, while LMO7S had only PDZ domain. TGF-beta1 up-regulated expression levels of LMO7 and LMO7S. LMO7 expression was up-regulated in the highly metastatic clone MM1.

Interacting population models often exhibit sustained stochastic oscillations, while the corresponding deterministic models present damped oscillations toward stable equilibrium. We study stochastic oscillation using the Langevin equation. We calculate several indicators that correspond to frequency. We find that their values are different.

Ecosystem dynamics can be studied using model populations. Perturbation experiments have often been applied to simulated populations in order to study the uncertainty in ecosystem dynamics. Most of these studies have predicted a stationary state. We report on the uncertainty in the dynamics near extinction. In particular, we explore fluctuation enhancements, i.e., enhanced variability in dynamics of paths to extinction. We examine two dynamic models on a two-dimensional lattice of finite size: (1) the contact process (CP) in which interactions are restricted to occur between adjacent lattice points, and (2) mean-field simulation (MFS), where interactions occur globally, between any pair of lattice points. Computer simulation reveals that, for both CP and MFS, the random drift of density about a stationary state increases with the decrease of steady-state density. Drift is much more pronounced in the vicinity of the critical mortality rate, at the transition to extinction. Simulation demonstrates that MFS shows greater variability when relative mortality rate is low whereas CP shows much more pronounced variability when mortality is near the critical threshold. The CP process shows wider fluctuations while the MFS process shows minimal increases following perturbations that lead to extinction. Because interactions are local for CP, there are a variety of different paths to extinction.

The extinction process in model ecosystems is studied on two-dimensional lattice. Simulations are carried out by two different methods: lattice model (LM) and mean-field simulation (MFS). In the former case interaction occurs between adjacent lattice points, whereas in the latter case interaction globally occurs between any pair of lattice points. Computer simulation reveals the occurrence of fluctuation enhancement which means that there are a variety of paths to the extinction. It is found that the enhancement for LM is stronger, compared to MFS. The critical behavior of extinct species may play an important role for the enhancement.

There has been much literature on ecological model of Prisoner's Dilemma (PD) game. This game illustrates that cooperation can evolve in situations where individuals tend to look after themselves. In order to explain some behaviors of altruism in animal societies, the strategy All Cooperate (AC), often called the Golden Rule, is more appropriate than other strategies. However, very little is known about the superiority of AC. In the present article, we study patch dynamics based on non-iterated PD game, applying two different methods: island and lattice models. Each patch is assumed to be either vacant or composed of a population of AC or All Defect (AD), where AD means a selfish strategy. Both models exhibit a phase transition between a phase where both AC and AD survive, and a phase where AD is extinct. The latter phase means that AC beats AD completely. In the case of lattice model, the extinction of AD easily occurs and the abundance of AC takes a larger value, compared with the island model. Our models can be also extended to general iterated PD game; we describe the reason why AC can outperform any other strategy.

Mitral cells project lateral dendrites that contact the lateral and primary dendrites of other mitral cells and granule cell dendrites in the external plexiform layer (EPL) of the olfactory bulb. These dendritic structures are critical for odor information processing, but it remains unknown how they are formed. In immunofluorescence microscopy, the immunofluorescence signal for the cell adhesion molecule nectin-1 was concentrated on mitral cell lateral dendrites in the EPL of the developing mouse olfactory bulb. In electron microscopy, the immunogold particles for nectin-1 were symmetrically localized on the plasma membranes at the contacts between mitral cell lateral dendrites, which showed bilateral darkening without dense cytoskeletal undercoats characteristic of puncta adherentia junctions. We named the contacts where the immunogold particles for nectin-1 were symmetrically accumulated "nectin-1 spots." The nectin-1 spots were 0.21 μm in length on average and the distance between the plasma membranes was 20.8 nm on average. In 3D reconstruction of serial sections, clusters of the nectin-1 spots formed a disc-like structure. In the mitral cell lateral dendrites of nectin-1-knockout mice, the immunogold particles for nectin-1 were undetectable and the plasma membrane darkening was electron-microscopically normalized, but the plasma membranes were partly separated from each other. The nectin-1 spots were further identified between mitral cell lateral and primary dendrites and between mitral cell lateral dendrites and granule cell dendritic spine necks. These results indicate that the nectin-1 spots constitute a novel adhesion apparatus that tethers mitral cell dendrites in a dendritic meshwork structure of the developing mouse olfactory bulb.

Afadin is an actin filament-binding protein that acts cooperatively in cell adhesion with the cell adhesion molecule nectin, and in directional cell movement with the small G protein Rap1 in a nectin-independent manner. We studied the role of afadin in the organization of the small intestinal epithelium using afadin conditional gene knockout (cKO) mice. Afadin was localized at adherens junctions of all types of epithelial cells throughout the crypt-villus axis. Paneth cells were localized at the base of the crypt in control mice, but not confined there, and migrated into the villi in afadin-cKO mice. The distribution of other types of epithelial cells did not change significantly in the mutant mice. The Paneth cells remaining in the crypt exhibited abnormal shapes, were buried between adjacent cells, and did not face the lumen. In these cells, the formation of adherens junctions and tight junctions was impaired. Rap1 and EphB3 were highly expressed in control Paneth cells but markedly down-regulated in the afadin-deficient Paneth cells. Taken together, the results indicate that afadin plays a role in the restricted localization of Paneth cells at the base of the crypt by maintaining their adhesion to adjacent crypt cells and inhibiting their movement toward the top of villi.

With the aim of voice restoration after repair of a total defect or obstruction of the cervical trachea, we developed a new method of total cervical tracheal reconstruction with a free forearm flap. The forearm flap is inverted to form a tube and then interposed between the subglottic trachea and an adjacent cutaneous fistula created at the upper portion of the tracheostoma. A permanent tracheostoma is preserved, and an L-shaped silicone tube is inserted in the reconstructed cervical trachea and the tracheostoma as a stent. In two patients, both became able to speak.

The authors have been carrying out a preliminary study on the design of microgrid. Designing microgrid includes selection and capacity determination of power supply devices according to their response characteristics, efficiency and initial cost, and development of methods for integrated control to maintain power quality and efficiency. Both design and control methods depend on conditions of loads, for which microgrid is installed. In this paper, design methods of microgrid, such as power demand analysis, response characteristics measurement of power sources and fuel efficiency measurement of engine-generators, and integrated control methods for power sources are proposed, along with experimental results for a prototype of microgrid.

Coexistence of competing species is extremely common in nature. If competing species live separately, then they can coexist easily. In the present article, we present a lattice version of Lotka–Volterra competition model. This system contains two competing species. They can coexist, when intraspecific competition is stronger than interspecific competition. We find a self-organized isolation of microhabitat: when the densities of both species approach zero, living regions of both species are naturally and completely separated from each other. Previously, co-workers in our laboratory presented a model of habitat segregation. In this case, however, a specific interaction was assumed: the rock-paper-scissors relation was assumed among three species. In contrast, the model presented here may be applicable to many ecosystems, since we only assume competition which is very common in real systems. Our model composed of two species X and Y is defined by j! E ðrate: mjÞ ð1aÞ jþ E! 2j ðrate: rjÞ ð1bÞ jþ j! jþ E ðrate: cjÞ ð1cÞ Here j is the lattice site occupied by species j ( j 1⁄4 X, Y), and E is the empty site. The pair of reactions (1a) and (1b) are called the contact process, where (1a) and (1b) represent death and birth processes, respectively. The last reaction means the intraspecific competition. An example is the direct competition between a pair of plants; neighboring plants are competing to take sunlight or resources. The parameters mj, rj and cj respectively denote mortality, reproduction and competition rates. Besides the direct competition (1c), our model contains a tacit (indirect) competition: according to reaction (1b), any pair of individuals compete to get the empty space E. Simulations are performed by the method of lattice Lotka–Volterra model: 1) Initially, we distribute X and Y on the square lattice. 2) The lattice is updated as follows: (i) we perform two-body reactions (1b) and (1c). Choose one lattice site randomly, and then randomly specify one of four neighboring sites. Let the pair react; for example, if the pair of sites are (X, E), then E is changed into X with the rate rx. (ii) we perform one-body reactions (1a). Choose one lattice point randomly; if the site is X (or Y), it will become E by the rate mx (or my). 3) Repeat step 2) until the system reaches a stationary state. If the global interaction is allowed between any pair of lattice sites, the population dynamics of our system (1) is given by the mean-field theory (rate equation)