232 research outputs found
Book Reviews
Emi Hamana, Shakespeare Performances in Japan: Intercultural-Multi-cultural-Translingual. Yokohama: Shumpusha, 2019. Pp. 188.Li Jun, Popular Shakespeare in China: 1993-2008. Beijing: University of International Business and Economics Press, 2016. Pp. 199.Soji Iwasaki’s Japanese Translation of Shakespeare, The Sonnets and A Lover’s Complaint. Revised edition. Tokyo: Kokubunsha, 2019. Pp. 242.
The role of glucocorticoid receptors in the induction and prevention of hippocampal abnormalities in an animal model of posttraumatic stress disorder
Rationale: Since the precise mechanisms of posttraumatic stress disorder (PTSD) remain unknown, effective treatment interventions have not yet been established. Numerous clinical studies have led to the hypothesis that elevated glucocorticoid levels in response to extreme stress might trigger a pathophysiological cascade which consequently leads to functional and morphological changes in the hippocampus.
Objectives: To elucidate the pathophysiology of PTSD, we examined the alteration of hippocampal gene expression through the glucocorticoid receptor (GR) in the single prolonged stress (SPS) paradigm, a rat model of PTSD.
Methods: We measured nuclear GRs by western blot, and the binding of GR to the promoter of Bcl-2 and Bax genes by chromatin immunoprecipitation-qPCR as well as the expression of these 2 genes by RT-PCR in the hippocampus of SPS rats. In addition, we examined the preventive effects of a GR antagonist on SPS-induced molecular, morphological, and behavioral alterations (hippocampal gene expression of Bcl-2 and Bax, hippocampal apoptosis using TUNEL staining, impaired fear memory extinction (FME) using the contextual fear conditioning paradigm).
Results: Exposure to SPS increased nuclear GR expression and GR binding to Bcl-2 gene, and decreased Bcl-2 mRNA expression. Administration of GR antagonist immediately after SPS prevented activation of the glucocorticoid cascade, hippocampal apoptosis, and impairment FME in SPS rats.
Conclusion: The activation of GRs in response to severe stress may trigger the pathophysiological cascade leading to impaired FME and hippocampal apoptosis. In contrast, administration of GR antagonist could be useful for preventing the development of PTSD.This work was supported by the Japan Society for the Promotion of Science (JSPS) KAKENHI (a grant-in aid for Scientific Research, C) Grant Number JP18K07562, and Takeda Science Foundation
Field-Induced gap due to four-spin exchange in a spin ladder
The effect of the four-spin cyclic exchange interaction at each plaquette in
the two-leg spin ladder is investigated at T=0, especially focusing on
the field-induced gap. The strong rung coupling approximation suggests that it
yields a plateau at half of the saturation moment () in the
magnetization curve, which corresponds to a field-induced spin gap with a
spontaneous breaking of the translational symmetry. A precise phase diagram at
is also presented based on the level spectroscopy analysis of the
numerical data obtained by Lanczos method. The boundary between the gapless and
plateau phases is confirmed to be of the Kosterlitz-Thouless (KT) universality
class.Comment: 10 pages, 3 eps figures (embedded), to be published in J. Phys.:
Cond. Matte
Psychosocial functioning in patients with treatment-resistant depression after group cognitive behavioral therapy
<p>Abstract</p> <p>Background</p> <p>Although patients with Treatment Resistant Depression (TRD) often have impaired social functioning, few studies have investigated the effectiveness of psychosocial treatment for these patients. We examined whether adding group cognitive behavioral therapy (group-CBT) to medication would improve both the depressive symptoms and the social functioning of patient with mild TRD, and whether any improvements would be maintained over one year.</p> <p>Methods</p> <p>Forty-three patients with TRD were treated with 12 weekly sessions of group-CBT. Patients were assessed with the Global Assessment of Functioning scale (GAF), the 36-item Short-Form Health Survey (SF-36), the Hamilton Rating Scale for Depression (HRSD), the Dysfunctional Attitudes Scale (DAS), and the Automatic Thought Questionnaire-Revised (ATQ-R) at baseline, at the termination of treatment, and at the 12-month follow-up.</p> <p>Results</p> <p>Thirty-eight patients completed treatment; five dropped out. For the patients who completed treatment, post-treatment scores on the GAF and SF-36 were significantly higher than baseline scores. Scores on the HRSD, DAS, and ATQ-R were significantly lower after the treatment. Thus patients improved on all measurements of psychosocial functioning and mood symptoms. Twenty patients participated in the 12-month follow-up. Their improvements for psychosocial functioning, depressive symptoms, and dysfunctional cognitions were sustained at 12 months following the completion of group-CBT.</p> <p>Conclusions</p> <p>These findings suggest a positive effect that the addition of cognitive behavioural group therapy to medication on depressive symptoms and social functioning of mildly depressed patients, showing treatment resistance.</p
Resting-state functional connectivity-based biomarkers and functional MRI-based neurofeedback for psychiatric disorders: a challenge for developing theranostic biomarkers
Psychiatric research has been hampered by an explanatory gap between
psychiatric symptoms and their neural underpinnings, which has resulted in poor
treatment outcomes. This situation has prompted us to shift from symptom-based
diagnosis to data-driven diagnosis, aiming to redefine psychiatric disorders as
disorders of neural circuitry. Promising candidates for data-driven diagnosis
include resting-state functional connectivity MRI (rs-fcMRI)-based biomarkers.
Although biomarkers have been developed with the aim of diagnosing patients and
predicting the efficacy of therapy, the focus has shifted to the identification
of biomarkers that represent therapeutic targets, which would allow for more
personalized treatment approaches. This type of biomarker (i.e., theranostic
biomarker) is expected to elucidate the disease mechanism of psychiatric
conditions and to offer an individualized neural circuit-based therapeutic
target based on the neural cause of a condition. To this end, researchers have
developed rs-fcMRI-based biomarkers and investigated a causal relationship
between potential biomarkers and disease-specific behavior using functional MRI
(fMRI)-based neurofeedback on functional connectivity. In this review, we
introduce recent approach for creating a theranostic biomarker, which consists
mainly of two parts: (i) developing an rs-fcMRI-based biomarker that can
predict diagnosis and/or symptoms with high accuracy, and (ii) the introduction
of a proof-of-concept study investigating the relationship between normalizing
the biomarker and symptom changes using fMRI-based neurofeedback. In parallel
with the introduction of recent studies, we review rs-fcMRI-based biomarker and
fMRI-based neurofeedback, focusing on the technological improvements and
limitations associated with clinical use.Comment: 46 pages, 5 figure
Impaired bone quality characterized by apatite orientation under stress shielding following fixing of a fracture of the radius with a 3D printed Ti-6Al-4V custom-made bone plate in dogs
Custom-made implants have recently gained attention in veterinary medicine because of their ability to properly fit animal bones having a wide variety of shapes and sizes. The effect of custom-made implants on bone soundness and the regeneration process is not yet clear. We fabricated a 3D printed Ti-6Al-4V custom-made bone plate that fits the shape of the dog radius, and placed it into the radius where an osteotomy had been made. The preferential orientation of the apatite c-axis contributes to the mechanical integrity of the bone and is a reliable measure of bone quality. We determined this parameter as well as the bone shape and bone mineral density (BMD). The bone portion which lies parallel to the bone plate exhibited bone resorption, decreased BMD, and significant degradation of apatite orientation, relative to the portion outside the plate, at 7 months after the operation. This demonstrates the presence of stress shielding in which applied stress is not transmitted to bone due to the insertion of a stiff bone plate. This reduced stress condition clearly influences the bone regeneration process. The apatite orientation in the regenerated site remained different even after 7 months of regeneration, indicating insufficient mechanical function in the regenerated portion. This is the first study in which the apatite orientation and BMD of the radius were evaluated under conditions of stress shielding in dogs. Our results suggest that assessment of bone repair by radiography can indicate the degree of restoration of BMD, but not the apatite orientation.Impaired bone quality characterized by apatite orientation under stress shielding following fixing of a fracture of the radius with a 3D printed Ti-6Al-4V custom-made bone plate in dogs. Keiichiro Mie et al. PLOS ONE. 2020. 9(2) doi.org/10.1371/journal.pone.023767
DLPFC and KYN in MDD treatment response
Aim: To establish treatment response biomarkers that reflect the pathophysiology of depression, it is important to use an integrated set of features. This study aimed to determine the relationship between regional brain activity at rest and blood metabolites related to treatment response to escitalopram to identify the characteristics of depression that respond to treatment.
Methods: Blood metabolite levels and resting-state brain activity were measured in patients with moderate to severe depression (n = 65) before and after 6–8 weeks of treatment with escitalopram, and these were compared between Responders and Nonresponders to treatment. We then examined the relationship between blood metabolites and brain activity related to treatment responsiveness in patients and healthy controls (n = 36).
Results: Thirty-two patients (49.2%) showed a clinical response (>50% reduction in the Hamilton Rating Scale for Depression score) and were classified as Responders, and the remaining 33 patients were classified as Nonresponders. The pretreatment fractional amplitude of low-frequency fluctuation (fALFF) value of the left dorsolateral prefrontal cortex (DLPFC) and plasma kynurenine levels were lower in Responders, and the rate of increase of both after treatment was correlated with an improvement in symptoms. Moreover, the fALFF value of the left DLPFC was significantly correlated with plasma kynurenine levels in pretreatment patients with depression and healthy controls.
Conclusion: Decreased resting-state regional activity of the left DLPFC and decreased plasma kynurenine levels may predict treatment response to escitalopram, suggesting that it may be involved in the pathophysiology of major depressive disorder in response to escitalopram treatment
Altered Gamma-Band Activity in Recovered Depression
Background: The neurophysiological mechanisms of cognitive reactivity, the primary vulnerability factor of major depressive disorder (MDD) recurrence, remain unclear in individuals with recovered MDD (rMDD). Because gamma-band responses (GBRs) can be used to measure cognitive processing, they may also be useful for elucidating the mechanisms underlying cognitive reactivity. Identifying these mechanisms may permit the development of an index for predicting and preempting MDD recurrence. Here, to identify the neurophysiological mechanisms of cognitive reactivity, we examined the characteristics of the GBRs evoked/induced by emotional words in participants with and without rMDD after inducing a negative mood.
Methods: Thirty-three healthy control participants and 18 participants with rMDD completed a lexical emotion identification task during electroencephalography along with assessments of cognitive reactivity after negative mood induction.
Results: No between-group differences were identified for the task reaction times; however, the rMDD group had significantly higher cognitive reactivity scores than did the control group. Furthermore, the power of late GBRs to positive words was significantly greater in the rMDD group, with the greater power of late GBRs being related to higher cognitive reactivity.
Limitations: Considering the population studied, our findings cannot be completely generalized to populations other than adolescents, people with rMDD, and those without a history of co-morbid disorders and early life stress.
Conclusions: Our findings indicate that the dysfunction of neural circuits related to higher-order processes like memory and attention might underlie cognitive reactivity. Altered late GBRs to positive information may be persistent biomarkers of the depression recurrence risk
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