Publications by authors named "Tetsuhiko Yoshida"

41 Publications

Secretion of signal peptides via extracellular vesicles.

Biochem Biophys Res Commun 2021 Jun 5;560:21-26. Epub 2021 May 5.

Department of Brain Function, Division of Stress Adaptation and Protection, Research Institute of Environmental Medicine, Nagoya University, Nagoya, Aichi, 464-8601, Japan; Department of Molecular Pharmacokinetics, Nagoya University Graduate School of Medicine, Nagoya, Aichi, 464-8601, Japan.

Signal peptides (SPs) consist of short peptide sequences present at the N-terminal of newly synthesizing proteins and act as a zip code for the translocation of the proteins to the endoplasmic reticulum (ER). It was thought that the SPs are intracellularly degraded after translocation to the ER; however, recent studies showed cleaved SPs have diverse roles for controlling cell functions in auto- and/or intercellular manners. In addition, it still remains obscure how SP fragments translocate away from the site where they are produced. Extracellular vesicles (EV) are important for intercellular communication and can transport functional molecules to specific cells. In this study, we show that SPs are involved in EV from T-REx AspALP cells that were transfected with a human APP SP-inducible expression vector. There was no difference in the average particle size or particle concentration of EV collected from T-REx AspALP cells and T-REx Mock cells. When the SP content in the EV was examined by mass spectrometry, the C-terminal fragment of APP SP was identified in the exosomes (SEV) of T-REx AspALP cells. In our preparation of SEV fractions, no ER-specific proteins were detected; therefore, SPs may be included in SEV but not in the debris of degraded ER. This is the first indication that SPs are secreted from cells via EV.
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http://dx.doi.org/10.1016/j.bbrc.2021.04.073DOI Listing
June 2021

Environmental pH stress influences cellular secretion and uptake of extracellular vesicles.

FEBS Open Bio 2021 Mar 18;11(3):753-767. Epub 2021 Feb 18.

Keio University School of Medicine, Tsukuba, Japan.

Exosomes (extracellular vesicles/EVs) participate in cell-cell communication and contain bioactive molecules, such as microRNAs. However, the detailed characteristics of secreted EVs produced by cells grown under low pH conditions are still unknown. Here, we report that low pH in the cell culture medium significantly affected the secretion of EVs with increased protein content and zeta potential. The intracellular expression level and location of stably expressed GFP-fused CD63 (an EV tetraspanin) in HeLa cells were also significantly affected by environmental pH. In addition, increased cellular uptake of EVs was observed. Moreover, the uptake rate was influenced by the presence of serum in the cell culture medium. Our findings contribute to our understanding of the effect of environmental conditions on EV-based cell-cell communication.
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http://dx.doi.org/10.1002/2211-5463.13107DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7931216PMC
March 2021

[Hydromorphone in Cancer Patients-A Retrospective Study].

Gan To Kagaku Ryoho 2020 Dec;47(12):1687-1690

Dept. of Palliative Medicine, National Cancer Center Hospital.

We retrospectively investigated the use of oral hydromorphone for cancer pain. Nineteen patients treated for cancer pain with oral hydromorphone were reviewed in this study. Cancers had occurred in the gastrointestinal (n=4), lung(n=3), breast(n=2), bone and soft tissue(n=2), hematological(n=2), and others(n=6). The administered opioids before switching to hydromorphone were morphine, oxycodone, and tapentadol. The mean oral morphine equivalent daily dose (OMEDD)was 89.3 mg. The average dose of hydromorphone administered was 16.4 mg/day, and average NRS 10(numerical rating scale: 0-10)scores of cancer pain before and after switching were 4.1 and 3.8, respectively, showing no significant differences. In this study, switching from other opioids to oral hydromorphone was feasible with an approved conversion ratio, ie, an oral hydromorphone-to-oral morphine ratio of 1:5. No severe adverse effects were observed. The oral hydromorphone extended-release formulation was administered every 24 h, as a tiny tablet formulation that is preferable owing to easy administration and adherence.
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December 2020

Usefulness of carer-held records to support informal caregivers of patients with dementia who live at home.

Psychogeriatrics 2018 May 6;18(3):166-174. Epub 2018 Feb 6.

Department of Psychiatry, Osaka University Graduate School of Medicine, Suita, Japan.

Aim: It is unclear whether carer-held records (CHR) are useful for patients with dementia. In this study, we evaluated the usefulness of the CHR for patients with dementia at the municipal level.

Methods: Candidates for CHR use in this study were informal caregivers of patients with dementia who lived at home in Kawanishi, Japan. CHR users were those who are involved in the patient's care and treatment, such as informal caregivers, family physicians, dementia specialists, care professionals, and care service coordinators, known as ‛care managers' in Japan. Collaborative meetings were held every month mainly to help users, especially care managers, learn how to effectively use CHR. We surveyed informal caregivers before and 1.5 years after the start of CHR use to evaluate whether CHR improved collaboration and information provision. The Zarit Caregiver Burden Interview and Dementia Behaviour Disturbance Scale were also administered. We divided the informal caregivers who continued CHR use for 1.5 years into two subgroups based on whether their care manager attended the collaborative meetings at least twice. In addition, we divided informal caregivers into three subgroups depending on their relationship to the patient: spouse, child, or daughter-in-law.

Results: The study initially consisted of 201 informal caregivers. Among them, 74 informal caregivers continued CHR use for 1.5 years. The information provision score significantly improved after CHR use for all informal caregivers. The collaboration score significantly improved after CHR use only for informal caregivers whose care managers attended at least two collaborative meetings. The Zarit Caregiver Burden Interview score significantly improved after CHR use for daughter-in-law caregivers. The Dementia Behaviour Disturbance Scale scores did not significantly improve after CHR use.

Conclusions: CHR were useful for informal caregivers of patients with dementia. However, care managers need to teach informal caregivers how to properly use CHR.
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http://dx.doi.org/10.1111/psyg.12304DOI Listing
May 2018

BC-Box Motif-Mediated Neuronal Differentiation of Somatic Stem Cells.

Int J Mol Sci 2018 Feb 5;19(2). Epub 2018 Feb 5.

Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan.

Von Hippel-Lindau tumor suppressor protein (pVHL) functions to induce neuronal differentiation of neural stem/progenitor cells (NSCs) and skin-derived precursors (SKPs). Here we identified a neuronal differentiation domain (NDD) in pVHL. Neuronal differentiation of SKPs was induced by intracellular delivery of a peptide composed of the amino-acid sequences encoded by the NDD. Neuronal differentiation mediated by the NDD was caused by the binding between it and elongin C followed by Janus kinase-2 (JAK2) ubiquitination of JAK2 and inhibition of the JAK2/the signal transducer and activator of transcription-3(STAT)3 pathway. The NDD in pVHL contained the BC-box motif ((A,P,S,T)LXXX (A,C) XXX(A,I,L,V)) corresponding to the binding site of elongin C. Therefore, we proposed that other BC-box proteins might also contain an NDD; and subsequently also identified in them an NDD containing the amino-acid sequence encoded by the BC-box motif in BC-box proteins. Furthermore, we showed that different NDD peptide-delivered cells differentiated into different kinds of neuron-like cells. That is, dopaminergic neuron-like cells, cholinergic neuron-like cells, GABAnergic neuron-like cells or rhodopsin-positive neuron-like cells were induced by different NDD peptides. These novel findings might contribute to the development of a new method for promoting neuronal differentiation and shed further light on the mechanism of neuronal differentiation of somatic stem cells.
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http://dx.doi.org/10.3390/ijms19020466DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5855688PMC
February 2018

Active macropinocytosis induction by stimulation of epidermal growth factor receptor and oncogenic Ras expression potentiates cellular uptake efficacy of exosomes.

Sci Rep 2015 Jun 3;5:10300. Epub 2015 Jun 3.

1] Keio Advanced Research Centers (KARC), Keio University, Tsukuba, Ibaraki 300-2611, Japan [2] Institute for Advanced Sciences, Toagosei Co., Ltd., Tsukuba, Ibaraki 300-2611, Japan.

Exosomes are approximately 100-nm vesicles that consist of a lipid bilayer of cellular membranes secreted in large quantities from various types of normal and disease-related cells. Endocytosis has been reported as a major pathway for the cellular uptake of exosomes; however, the detailed mechanisms of their cellular uptake are still unknown. Here, we demonstrate the active induction of macropinocytosis (accompanied by actin reorganisation, ruffling of plasma membrane, and engulfment of large volumes of extracellular fluid) by stimulation of cancer-related receptors and show that the epidermal growth factor (EGF) receptor significantly enhances the cellular uptake of exosomes. We also demonstrate that oncogenic K-Ras-expressing MIA PaCa-2 cells exhibit intensive macropinocytosis that actively transports extracellular exosomes into the cells compared with wild-type K-Ras-expressing BxPC-3 cells. Furthermore, encapsulation of the ribosome-inactivating protein saporin with EGF in exosomes using our simple electroporation method produces superior cytotoxicity via the enhanced cellular uptake of exosomes. Our findings contribute to the biological, pharmaceutical, and medical research fields in terms of understanding the macropinocytosis-mediated cellular uptake of exosomes with applications for exosomal delivery systems.
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http://dx.doi.org/10.1038/srep10300DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4453128PMC
June 2015

Noninvasive prediction of shunt operation outcome in idiopathic normal pressure hydrocephalus.

Sci Rep 2015 Jan 14;5:7775. Epub 2015 Jan 14.

Department of Psychiatry, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871, Japan.

Idiopathic normal pressure hydrocephalus (iNPH) is a syndrome characterized by gait disturbance, cognitive deterioration and urinary incontinence in elderly individuals. These symptoms can be improved by shunt operation in some but not all patients. Therefore, discovering predictive factors for the surgical outcome is of great clinical importance. We used normalized power variance (NPV) of electroencephalography (EEG) waves, a sensitive measure of the instability of cortical electrical activity, and found significantly higher NPV in beta frequency band at the right fronto-temporo-occipital electrodes (Fp2, T4 and O2) in shunt responders compared to non-responders. By utilizing these differences, we were able to correctly identify responders and non-responders to shunt operation with a positive predictive value of 80% and a negative predictive value of 88%. Our findings indicate that NPV can be useful in noninvasively predicting the clinical outcome of shunt operation in patients with iNPH.
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http://dx.doi.org/10.1038/srep07775DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4293598PMC
January 2015

In vitro co-culture systems for studying molecular basis of cellular interaction between Aire-expressing medullary thymic epithelial cells and fresh thymocytes.

Biol Open 2014 Oct 17;3(11):1071-82. Epub 2014 Oct 17.

Advanced Research Center for Genome Super Power, Keio University, 2 Okubo, Tsukuba, Ibaraki 300-2611, Japan

We previously established three mouse cell lines (Aire(+)TEC1, Aire(+)TEC2 and Aire(+)DC) from the medullary thymic epithelial cells (mTECs) and dendritic cells (mDCs). These cells constitutively expressed "autoimmune regulator (Aire) gene" and they exhibited various features of self antigen-presenting cells (self-APCs) present in the thymic medullary region. Here, we confirmed our previous observation that Aire(+) thymic epithelial cells adhere to fresh thymocytes and kill them by inducing apoptosis, thus potentially reproducing in vitro some aspects of the negative selection of T cells in vivo. In this system, a single Aire(+) cell appeared able to kill ∼30 thymocytes within 24 hrs. Moreover, we observed that ectopic expression of peripheral tissue-specific antigens (TSAs), and expression of several surface markers involved in mTEC development, increased as Aire(+) cell density increases toward confluency. Thus, these Aire(+) cells appear to behave like differentiating mTECs as if they pass through the developmental stages from intermediate state toward mature state. Surprisingly, an in vitro co-culture system consisting of Aire(+) cells and fractionated sub-populations of fresh thymocytes implied the possible existence of two distinct subtypes of thymocytes (named as CD4(+) killer and CD4(-) rescuer) that may determine the fate (dead or alive) of the differentiating Aire(+)mTECs. Thus, our in vitro co-culture system appears to mimic a part of "in vivo thymic crosstalk".
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http://dx.doi.org/10.1242/bio.201410173DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4232765PMC
October 2014

Direct induction of ramified microglia-like cells from human monocytes: dynamic microglial dysfunction in Nasu-Hakola disease.

Sci Rep 2014 May 14;4:4957. Epub 2014 May 14.

Department of Neuropsychiatry, Graduate School of Medical Sciences, Kyushu University.

Microglia have been implicated in various neurological and psychiatric disorders in rodent and human postmortem studies. However, the dynamic actions of microglia in the living human brain have not been clarified due to a lack of studies dealing with in situ microglia. Herein, we present a novel technique for developing induced microglia-like (iMG) cells from human peripheral blood cells. An optimized cocktail of cytokines, GM-CSF and IL-34, converted human monocytes into iMG cells within 14 days. The iMG cells have microglial characterizations; expressing markers, forming a ramified morphology, and phagocytic activity with various cytokine releases. To confirm clinical utilities, we developed iMG cells from a patient of Nasu-Hakola disease (NHD), which is suggested to be directly caused by microglial dysfunction, and observed that these cells from NHD express delayed but stronger inflammatory responses compared with those from the healthy control. Altogether, the iMG-technique promises to elucidate unresolved aspects of human microglia in various brain disorders.
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http://dx.doi.org/10.1038/srep04957DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4019954PMC
May 2014

EEG and Neuronal Activity Topography analysis can predict effectiveness of shunt operation in idiopathic normal pressure hydrocephalus patients.

Neuroimage Clin 2013 19;3:522-30. Epub 2013 Oct 19.

Department of Psychiatry, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.

Idiopathic normal pressure hydrocephalus (iNPH) is a neuropsychiatric syndrome characterized by gait disturbance, cognitive impairment and urinary incontinence that affect elderly individuals. These symptoms can potentially be reversed by cerebrospinal fluid (CSF) drainage or shunt operation. Prior to shunt operation, drainage of a small amount of CSF or "CSF tapping" is usually performed to ascertain the effect of the operation. Unfortunately, conventional neuroimaging methods such as single photon emission computed tomography (SPECT) and functional magnetic resonance imaging (fMRI), as well as electroencephalogram (EEG) power analysis seem to have failed to detect the effect of CSF tapping on brain function. In this work, we propose the use of Neuronal Activity Topography (NAT) analysis, which calculates normalized power variance (NPV) of EEG waves, to detect cortical functional changes induced by CSF tapping in iNPH. Based on clinical improvement by CSF tapping and shunt operation, we classified 24 iNPH patients into responders (N = 11) and nonresponders (N = 13), and performed both EEG power analysis and NAT analysis. We also assessed correlations between changes in NPV and changes in functional scores on gait and cognition scales before and after CSF tapping. NAT analysis showed that after CSF tapping there was a significant decrease in alpha NPV at the medial frontal cortex (FC) (Fz) in responders, while nonresponders exhibited an increase in alpha NPV at the right dorsolateral prefrontal cortex (DLPFC) (F8). Furthermore, we found correlations between cortical functional changes and clinical symptoms. In particular, delta and alpha NPV changes in the left-dorsal FC (F3) correlated with changes in gait status, while alpha and beta NPV changes in the right anterior prefrontal cortex (PFC) (Fp2) and left DLPFC (F7) as well as alpha NPV changes in the medial FC (Fz) correlated with changes in gait velocity. In addition, alpha NPV changes in the right DLPFC (F8) correlated with changes in WMS-R Mental Control scores in iNPH patients. An additional analysis combining the changes in values of alpha NPV over the left-dorsal FC (∆alpha-F3-NPV) and the medial FC (∆alpha-Fz-NPV) induced by CSF tapping (cut-off value of ∆alpha-F3-NPV + ∆alpha-Fz-NPV = 0), could correctly identified "shunt responders" and "shunt nonresponders" with a positive predictive value of 100% (10/10) and a negative predictive value of 66% (2/3). In contrast, EEG power spectral analysis showed no function related changes in cortical activity at the frontal cortex before and after CSF tapping. These results indicate that the clinical changes in gait and response suppression induced by CSF tapping in iNPH patients manifest as NPV changes, particularly in the alpha band, rather than as EEG power changes. Our findings suggest that NAT analysis can detect CSF tapping-induced functional changes in cortical activity, in a way that no other neuroimaging methods have been able to do so far, and can predict clinical response to shunt operation in patients with iNPH.
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http://dx.doi.org/10.1016/j.nicl.2013.10.009DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3830071PMC
November 2013

Reversibility of brain morphology after shunt operations and preoperative clinical symptoms in patients with idiopathic normal pressure hydrocephalus.

Psychogeriatrics 2013 Mar;13(1):41-8

Department of Psychiatry, Osaka University Graduate School of Medicine, Suita, Japan.

Aim: Brain deformations might prevent clinical symptoms from worsening in patients with idiopathic normal pressure hydrocephalus (iNPH). We investigated the relationship between reversibility of brain morphology after shunt operations and preoperative clinical symptoms in iNPH patients.

Methods: Using head magnetic resonance images with voxel-based morphometry, we measured the cerebrospinal fluid volume in the combined areas of the lateral and third ventricles and Sylvian fissure (the volume of the ventricles and Sylvian fissure (vVS)) and the volume of the subarachnoid space at high convexity and midline areas (vHCM) before and 1 year after lumboperitoneal shunt operations in 12 patients with shunt-responsive iNPH. We used the ratio of normalized vVS to normalized vHCM (nvVS/nvHCM) as an index of the severity of the brain deformation. The degree of reversibility of the brain morphology after the shunt operation was defined as the change ratio of the preoperative nvVS/nvHCM to the postoperative nvVS/nvHCM (CR-nvVS/nvHCM). Higher CR-nvVS/nvHCM values indicated more improvement in the brain deformation. In addition, we rated the severity of the white matter lesions on the preoperative magnetic resonance images based on the Fazekas scale. Dependency in activities of daily living, gait and cognition were evaluated before and 1 year after the shunt operations.

Results: After the shunt operations, the nvVS/nvHCM and nvVS decreased significantly, and nvHCM increased significantly. The CR-nvVS/nvHCM negatively correlated with the preoperative severity of dependency in activities of daily living, gait and cognitive impairments. The CR-nvVS/nvHCM negatively correlated with the Fazekas scale, but not with age, duration of the disease and cerebrospinal fluid pressure.

Conclusions: Reversibility of brain morphology, which varied among iNPH patients, would prevent clinical symptoms from worsening in iNPH patients. The presence of white matter lesions reduced the degree of reversibility of the brain deformations in iNPH patients.
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http://dx.doi.org/10.1111/psyg.12001DOI Listing
March 2013

Recombinant human IgG antibodies recognizing distinct extracellular domains of EGF receptor exhibit different degrees of growth inhibitory effects on human A431 cancer cells.

Exp Cell Res 2013 May 13;319(8):1146-55. Epub 2013 Mar 13.

Advanced Research Center for Genome Super Power, Keio University, 2 Okubo, Tsukuba, Ibaraki 300-2611, Japan.

Recently, we isolated 4 distinct kinds of single chain antibody against human EGF receptor (EGFR) after screening the Keio phage display scFv library by using two methods of target-guided proximity labeling. In the current study, these monovalent scFv antibodies were converted to bivalent IgGs of humanized forms (hIgGs) by recombinant technology using the specially designed expression vectors followed by protein production in CHO cells. The resulting recombinant hIgGs were examined for their binding specificity using several different transformed human BJ cell lines that express deletion mutants of EGFR, each lacking one of 4 distinct extracellular domains (L1, L2, C1 and C2). Immuno-fluorescent microscopy and immuno-precipitation assay on these cells indicated that 4 distinct kinds of hIgGs bind to one of 3 different domains (L1, C1 and C2). Then, these hIgGs were further examined for biological effects on human A431 cancer cells, which overexpress EGFR. The results indicated that hIgG38 binding to L1 and hIgG45 binding to C2 substantially suppressed the EGF-induced phosphorylation of EGFR, resulting in the growth inhibition of A431 cancer cells. On the contrary, hIgG40 binding to C1 and hIgG42 binding to another site (epitope) of C2 exhibited no such inhibitory effects. Thus, the newly produced four recombinant hIgG antibodies recognize 4 different sites (epitopes) in 3 different extracellular domains of EGFR and exhibit different biological effects on cancer cells. These characteristics are somewhat different from the currently utilized therapeutic anti-EGFR antibodies. Hence, these hIgG antibodies will be invaluable as a research tool for the detailed molecular analysis of the EGFR-mediated signal transduction mechanism and more importantly a possible application as new therapeutic agents to treat certain types of cancers.
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http://dx.doi.org/10.1016/j.yexcr.2013.03.002DOI Listing
May 2013

Association between milder brain deformation before a shunt operation and improvement in cognition and gait in idiopathic normal pressure hydrocephalus.

Dement Geriatr Cogn Disord 2013 28;35(3-4):197-207. Epub 2013 Feb 28.

Department of Psychiatry, Osaka University Graduate School of Medicine, Suita, Japan.

We investigated the association between the degree of deformation of the brain before shunt operation and improvement of gait and cognitive impairment after shunt operation in 16 patients with idiopathic normal pressure hydrocephalus (iNPH). We evaluated gait and cognitive impairment and measured the cerebrospinal fluid volume in the ventricles/sylvian fissure (vVS) and the subarachnoid space at high convexity/midline areas (vHCM) using MR images with voxel-based morphometry before and 3 months after shunt operation. We used the ratio of vVS to vHCM (vVS/vHCM) as an index of the severity of brain deformation. After shunt operation, improvements were observed in gait, as shown by the Timed Up and Go (TUG) test and 10-meter reciprocating walking test (WT), and in cognitive function, as shown by the Mini-Mental State Examination, Alzheimer Disease Assessment Scale, Frontal Assessment battery (FAB), and Trail Making test A (TMT-A). The vVS/vHCM ratio was negatively correlated with improvement of the FAB, TMT-A and TUG. Preoperative vVS/vHCM was not significantly correlated with preoperative clinical assessments. The rate of change of vVS/vHCM was positively correlated with improvement in the WT. The improvements of gait and cognitive function were larger in iNPH patients with milder deformation of the brain before shunt operation.
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http://dx.doi.org/10.1159/000347147DOI Listing
October 2013

A novel big protein TPRBK possessing 25 units of TPR motif is essential for the progress of mitosis and cytokinesis.

Gene 2012 Dec 1;511(2):202-17. Epub 2012 Oct 1.

Advanced Research Center for Genome Super Power, Keio University, Tsukuba, Japan.

Through the comprehensive analysis of the genomic DNA sequence of human chromosome 22, we identified a novel gene of 702 kb encoding a big protein of 2481 amino acid residues, and named it as TPRBK (TPR containing big gene cloned at Keio). A novel protein TPRBK possesses 25 units of the TPR motif, which has been known to associate with a diverse range of biological functions. Orthologous genes of human TPRBK were found widely in animal species, from insecta to mammal, but not found in plants, fungi and nematoda. Northern blotting and RT-PCR analyses revealed that TPRBK gene is expressed ubiquitously in the human and mouse fetal tissues and various cell lines of human, monkey and mouse. Immunofluorescent staining of the synchronized monkey COS-7 cells with several relevant antibodies indicated that TPRBK changes its subcellular localization during the cell cycle: at interphase TPRBK locates on the centrosomes, during mitosis it translocates from spindle poles to mitotic spindles then to spindle midzone, and through a period of cytokinesis it stays on the midbody. Co-immunoprecipitation assay and immunofluorescent staining with adequate antibodies revealed that TPRBK binds to Aurora B, and those proteins together translocate throughout mitosis and cytokinesis. Treatments of cells with two drugs (Blebbistatin and Y-27632), that are known to inhibit the contractility of actin-myosin, disturbed the proper intracellular localization of TPRBK. Moreover, the knockdown of TPRBK expression by small interfering RNA (siRNA) suppressed the bundling of spindle midzone microtubules and disrupted the midbody formation, arresting the cells at G(2)+M phase. These observations indicated that a novel big protein TPRBK is essential for the formation and integrity of the midbody, hence we postulated that TPRBK plays a critical role in the progress of mitosis and cytokinesis during mammalian cell cycle.
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http://dx.doi.org/10.1016/j.gene.2012.09.061DOI Listing
December 2012

Different characteristics of cognitive impairment in elderly schizophrenia and Alzheimer's disease in the mild cognitive impairment stage.

Dement Geriatr Cogn Dis Extra 2011 Jan 6;1(1):20-30. Epub 2011 Jan 6.

Psychiatry, Department of Integrated Medicine, Division of Internal Medicine, Osaka University Graduate School of Medicine, Osaka, Japan.

We compared indices of the revised version of the Wechsler Memory Scale (WMS-R) and scaled scores of the five subtests of the revised version of the Wechsler Adult Intelligence Scale (WAIS-R) in 30 elderly schizophrenia (ES) patients and 25 Alzheimer's disease (AD) patients in the amnestic mild cognitive impairment (aMCI) stage (AD-aMCI). In the WMS-R, attention/concentration was rated lower and delayed recall was rated higher in ES than in AD-aMCI, although general memory was comparable in the two groups. In WAIS-R, digit symbol substitution, similarity, picture completion, and block design scores were significantly lower in ES than in AD-aMCI, but the information scores were comparable between the two groups. Delayed recall and forgetfulness were less impaired, and attention, working memory and executive function were more impaired in ES than in AD-aMCI. These results should help clinicians to distinguish ES combined with AD-aMCI from ES alone.
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http://dx.doi.org/10.1159/000323561DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3199876PMC
January 2011

The AKT1 gene is associated with attention and brain morphology in schizophrenia.

World J Biol Psychiatry 2013 Mar 12;14(2):100-13. Epub 2011 Dec 12.

Department of Psychiatry, Osaka University Graduate school of Medicine, Osaka, Japan.

Objectives: A meta-analysis of the associations between genetic variants in the AKT1 gene and schizophrenia found that a single nucleotide polymorphism (SNP5; rs2494732) was associated with schizophrenia in Asian populations.

Methods: In this study, we investigated the effects of this SNP on memory and attentional performance and brain structure using magnetic resonance imaging in a Japanese population (117 patients with schizophrenia and 189 healthy subjects).

Results: The memory performance, particularly attention/concentration score, measured by the Wechsler Memory Scale-Revised in A carriers of SNP5, which was found to be enriched in patients with schizophrenia, was lower than that in individuals with the G/G genotype. We confirmed the association of the SNP with attentional performance using the Continuous Performance Test, which assessed sustained attention and vigilance of attentional function. Patients with A allele demonstrated lower attentional performance than patients with the G/G genotype. Patients with the A allele had smaller gray matter volumes in the right inferior parietal lobule related to attentional processes and in the frontostriatal region related to different SNPs in AKT1 than patients with the G/G genotype.

Conclusions: Our results suggest that a genetic variant of AKT1 might be associated with attentional deficits and brain morphological vulnerability in patients with schizophrenia.
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http://dx.doi.org/10.3109/15622975.2011.591826DOI Listing
March 2013

Induced oscillatory responses during the Sternberg's visual memory task in patients with Alzheimer's disease and mild cognitive impairment.

Neuroimage 2012 Feb 25;59(4):4132-40. Epub 2011 Oct 25.

Department of Psychiatry, Osaka University Graduate School of Medicine, 2-2 D3, Yamadaoka, Suita, Osaka 565-0871, Japan.

In this study we used magnetoencephalography during a modified version of the Sternberg's memory recognition task performed by patients with early Alzheimer's disease (AD), mild cognitive impairment (MCI), and by age-matched healthy controls to identify differences in induced oscillatory responses. For analyses, we focused on the retention period of the working memory task. Multiple-source beamformer and Brain Voyager were used for localization of source-power changes across the cortex and for statistic group analyses, respectively. We found significant differences in oscillatory response during the task, specifically in beta and gamma frequency bands: patients with AD showed reduced beta event-related desynchronization (ERD) in the right central area compared to controls, and reduced gamma ERD in the left prefrontal and medial parietal cortex compared to patients with MCI. Our findings suggest that reduced oscillatory responses over certain brain regions in high frequency bands (i.e., beta, gamma), and especially in the beta band that was significantly different between AD patients and healthy subjects, may represent brain electromagnetic changes underlying visual-object working memory dysfunction in early AD, and a neurophysiological indicator of cognitive decline.
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http://dx.doi.org/10.1016/j.neuroimage.2011.10.061DOI Listing
February 2012

Screening of scFv-displaying phages recognizing distinct extracellular domains of EGF receptor by target-guided proximity labeling method.

J Immunol Methods 2011 Sep 18;372(1-2):127-36. Epub 2011 Jul 18.

Advanced Research Center for Genome Super Power, Keio University, 2 Okubo, Tsukuba, Ibaraki 300-2611, Japan.

We recently constructed the scFv-displaying phage library with extremely high repertoire and have successfully utilized for screening scFv antibodies against various proteins, polysaccharides and glyco-lipids. Here, we developed a new screening strategy to isolate scFv antibodies against cell surface EGF receptor (EGFR). For this, we applied two slightly different methods of "target-guided proximity labeling," such as Proximity selection (ProxiMol) method and a new sulfo-SBED labeling method with the aide of monoclonal anti-human EGFR antibody B4G7 as a guide molecule. ProxiMol method relies on the Biotin-labeling of scFv-displaying phages that bound to the target in a vicinity of 100Å from the guide molecule, whereas sulfo-SBED method transfers Biotin to scFv-displaying phages, which bound to the target in a distance of 20 Å. After two rounds of panning on the EGFR-overexpressing A431 cells starting from approx. 1 × 10¹² pfu, 47 each of Biotin-labeled scFv-displaying phages were recovered using Streptoavidin-coated magnetic beads, and among them total 11 scFv-phages were found to be definitely positive for binding to A431 cell surface by ELISA assay. Restriction mapping and sequencing analysis of these scFv-phage DNAs revealed that they encode 4 different scFv-nucleotide sequences in total. Immuno-fluorescent microscopy provided evidence that these 4 scFv antibodies bind specifically to EGFR on the A431 cells, showing slightly different staining patterns. Thus, "target-guided proximity labeling" methods were powerful for isolating scFv-displaying phages that recognize distinct extracellular domains of the target receptor. This novel screening strategy could be applicable to many other cell surface antigens and receptors.
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http://dx.doi.org/10.1016/j.jim.2011.07.003DOI Listing
September 2011

Protein synthesis in the posterior cingulate cortex in Alzheimer's disease.

Psychogeriatrics 2011 Mar;11(1):40-5

Division of Psychiatry, Course of Internal Medicine, Osaka University Graduate School of Medicine, Suita-city, Japan.

Background: Neuroimaging studies using (18) F-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) and single photon emission computed tomography (SPECT) have shown that the posterior cingulate cortex (PCC) is the primary and most prominent area of cerebral metabolic and perfusional decrement in early Alzheimer's disease (AD). We carried out the present preliminary study to investigate whether a decline of cerebral blood flow (CBF) in the PCC in early to moderate AD was accompanied with that of cerebral protein synthesis (CPS).

Methods: We carried out both N-isopropyl-p-[123I] iodoamphetamine SPECT (IMP-SPECT) and L-[methyl-11C] methionine positron emission tomography (MET-PET) in eight AD patients with apolipoprotein E epsilon 4 allele in the early to moderate stage. We also carried out IMP-SPECT in eight healthy controls (HC). We located 32 regions of interest (ROI), and values of regional MET or IMP uptakes were averaged in five regions; the frontal lobe (FL), the parietal lobe (PL), the medial temporal lobe (MTL), PCC and the occipital lobe. Furthermore, the values in the FL, PL, MTL and PCC were divided by values in the occipital areas, and normalized values of regional CBF (rCBF) and CPS (rCPS) were calculated. Then, the rCBF in the FL, PL, MTL and PCC were compared between AD and HC. In addition, the rCBF and rCPS were compared in the FL, PL, MTL and PCC of AD.

Results: The rCBF in the PCC, but not in the other three regions, was significantly lower in AD than in HC. The rCBF was significantly lower than rCPS in the PCC, but rCBF and rCPS were comparable in the other three regions in AD.

Conclusions: The CBF reduction in the PCC in AD was partly caused by neuronal loss in the PCC and partly supported the hypothesis that CBF reduction in the PCC was a result of functional deafferentation by neural degeneration in areas other than the PCC.
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http://dx.doi.org/10.1111/j.1479-8301.2010.00350.xDOI Listing
March 2011

Nucleolar localization signals of LIM kinase 2 function as a cell-penetrating peptide.

Protein Pept Lett 2010 Dec;17(12):1480-8

Institute for Advanced Sciences, Toagosei Co., Ltd., Tsukuba 300-2611, Japan.

LIM Kinase 2 (LIMK2) is a LIM domain-containing protein kinase which regulates actin polymerization thorough phosphorylation of the actin depolymerizing factor cofilin. It is also known to function as a shuttle between the cytoplasm and nucleus in endothelial cells. A basic amino acid-rich motif in LIMK2 was previously identified to be responsible for this shuttling function, as a nucleolar localization signal (NoLS). Here it is shown that this nucleolar localization signal sequence also has the characteristic function of a cell-penetrating peptide (CPP). We synthesized LIMK2 NoLS-conjugated peptides and a protein and analyzed their cell-penetrating abilities in various types of cells. The BC-box motif of the Von Hippel-Lindau (VHL) protein was used for the peptide. This motif previously has been reported to be involved in the neural differentiation of bone marrow stromal cells and skin-derived precursor cells. Green fluorescence protein (GFP) was used as a large biologically active biomolecule for the protein. The LIMK2 NoLS-conjugated peptides and protein translocated across the cell membranes of fibroblast cells, neural stem cells, and even iPS cells. These results suggest that LIMK2 NoLS acts as a cell-penetrating peptide and its cell-penetrating ability is not restricted by cell type. Moreover, from an in vivo assay using a mouse brain, it was confirmed that NoLS has potential for transporting biomolecules across the blood-brain barrier.
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http://dx.doi.org/10.2174/0929866511009011480DOI Listing
December 2010

KIBRA genetic polymorphism influences episodic memory in Alzheimer's disease, but does not show association with disease in a Japanese cohort.

Dement Geriatr Cogn Disord 2010 25;30(4):302-8. Epub 2010 Sep 25.

Department of Psychiatry, Osaka University Graduate School of Medicine, Japan.

Background/aims: A single-nucleotide polymorphism (SNP) in the KIBRA gene, rs17070145, was reported to be significantly associated with episodic memory in cognitively normal cohorts. This observation has expanded genetic studies on KIBRA to Alzheimer's disease (AD). Importantly, the association between KIBRA and episodic memory in AD has never been addressed. In this study, we investigated whether the KIBRA rs17070145 SNP influences AD episodic memory and the disease in a Japanese cohort.

Methods: Blood samples from 346 AD patients and 375 normal cognitive controls were collected and genotyped for rs17070145. Episodic memory was measured in 32 AD patients, diagnosed for the first time, by use of the Rivermead Behavioral Memory Test (RBMT).

Results: We found that KIBRA C allele carriers scored significantly lower than KIBRA non-C carriers on both RBMT total profile score (p = 0.042, effect size = 0.84) and RBMT total screening score (p < 0.001, effect size = 1.42). The KIBRA gene did not show association with AD in our Japanese cohort.

Conclusion: Our results evidence a strong association between the KIBRA gene and episodic memory impairment in AD, but show no influence on AD in our Japanese cohort. We propose that KIBRA might have an effect similar to cognitive reserve.
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http://dx.doi.org/10.1159/000320482DOI Listing
February 2011

Global cerebral hypoperfusion in preclinical stage of idiopathic normal pressure hydrocephalus.

J Neurol Sci 2010 Nov 22;298(1-2):35-41. Epub 2010 Sep 22.

Department of Psychiatry, Osaka University Graduate School of Medicine, National Hospital Organization Osaka National Hospital, Osaka, Japan.

In patients with idiopathic normal pressure hydrocephalus (iNPH), ventriculomegaly and narrowed subarachnoid spaces at the high convexity appear in magnetic resonance (MR) images before the occurrence of objective symptoms. In addition, quantitative regional cerebral blood flow (rCBF) has been reported to be reduced in iNPH patients with objective symptoms. To determine whether reduced rCBF is responsible for the appearance of symptoms, we compared rCBF in patients with suspected iNPH with no objective triad symptoms (NOS), iNPH patients with apparent objective triad symptoms (AOS) and normal control subjects (NC). Regional CBF was quantified in 35 Regions-of-interest (ROIs) by 123I-IMP single photon emission computed tomography (SPECT) using the autoradiography (ARG) method. Multiple comparisons showed that, in all brain regions examined except for in the frontal white matter, rCBF in the NOS group was significantly lower than that in the NC group, but in all brain regions, not significantly different from that of the AOS group. These results suggest that factors other than rCBF in the resting state are responsible for the occurrence of objective symptoms of iNPH.
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http://dx.doi.org/10.1016/j.jns.2010.09.001DOI Listing
November 2010

[Language and semantic memory impairment in a patient with motor neuron disease and semantic dementia: a case report].

Brain Nerve 2010 Jun;62(6):625-30

Psychiatry, Department of Integrated Medicine, Division of Internal Medicine, Osaka University Graduate School of Medicine, Suita-shi, Osaka, Japan.

We report the rare case of a 59-year-old man with motor neuron disease and semantic dementia (SD-MND); SD-MND was in a very early stage, and its clinical progression, especially with regard to language impairment, and abnormalities on neuroimages were evaluated for 3 years. The patient complained only of difficulties in recalling names of acquaintances and in writing kanji characters. After 1 year, he experienced difficulty in describing common objects. He developed two-way anomia only in some words, which varied from day to day. His anomia was not category-specific and was noted even with respect to words that describe color. In addition to experiencing difficulty in writing kanji characters, he experienced difficulty in writing kana characters. Muscle atrophy was observed, and he experienced weakness in his limbs, especially in the right upper limb; however, bulbar symptoms were not observed. At this point, he fulfilled the diagnostic criteria for MND. In the next year, semantic memory impairment became apparent, and he was subsequently diagnosed with SD. Deterioration in his ability to name objects in all categories, except body parts, was noted. Further, the ability of writing both kana and kanji characters was increasingly impaired. He developed bulbar symptoms and experienced increased muscle weakness. The characteristics of this patient differed from those of SD patients without MND with regard to the difficulty in writing kana characters and naming colors even though the SD-MND was in the early stage. Further, the pattern of brain hypoperfusion was different from that observed for SD patients without MND. In the case of this patient, brain hypoperfusion was found not only in the left anterior temporal lobe but also in the frontal lobe. The characteristics of his language symptoms might be related to the specific pattern of brain hypoperfusion, which might be commonly observed in patients with dementia and MND.
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June 2010

Association study of KIBRA gene with memory performance in a Japanese population.

World J Biol Psychiatry 2010 Oct;11(7):852-7

The Osaka-Hamamatsu Joint Research Center for Child Mental Development, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.

Objectives: Papassotiropoulos et al. (Science 314: p 475) discovered that a single nucleotide polymorphism (SNP) of the KIBRA gene (rs17070145) was associated with delayed recall performance in Caucasians. KIBRA is highly expressed in the brain and kidneys, and is reported to be involved in synaptic plasticity. Therefore, we first tried to replicate the association between the SNP and memory performance in a Japanese subjects.

Methods: We examined the association between the SNP and memory performance measured by the Wechsler Memory Scale-Revised (WMS-R) in 187 healthy Japanese people.

Results: The T allele carriers had significantly better verbal memory, attention/concentration and delayed recall performance than the C/C carriers (corrected P = 0.044, 0.047 and 0.0084, respectively). Furthermore, the C/T carriers and the T/T carriers had better delayed recall performance than the C/C carriers (post hoc P = 0.0017 and 0.0096).

Conclusions: This data suggest that the C/C genotype might have an impact on memory performance in Asian populations as well as in Caucasian populations. Further investigation to clarify the association of the KIBRA gene with memory in other ethnic groups is warranted.
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http://dx.doi.org/10.3109/15622971003797258DOI Listing
October 2010

Relationship between prepulse inhibition of acoustic startle response and schizotypy in healthy Japanese subjects.

Psychophysiology 2010 Sep 10;47(5):831-7. Epub 2010 Mar 10.

Department of Psychiatry, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.

Prepulse inhibition (PPI) of the acoustic startle reflex (ASR) is the most common psychophysiological index of sensorimotor gating. Several studies have investigated the relationship of PPI of ASR to schizotypy in Caucasians. However, little has been reported on this relationship in Asians. We investigated a possible relationship between PPI of ASR and schizotypy in 79 healthy Japanese subjects. Schizotypy was assessed by the Schizotypal personality Questionnaire (SPQ). PPI was evaluated at signal-to-noise ratios (SnRs: difference between background noise intensity and prepulse intensity) of +12, +16, and +20 dB. The total SPQ score, cognitive/perceptual score, and interpersonal score correlated negatively with PPI at SnR of +16 and +20 dB. We conclude that PPI is associated with the trait of schizotypy in healthy Asian subjects.
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http://dx.doi.org/10.1111/j.1469-8986.2010.01000.xDOI Listing
September 2010

Engrafted VHL peptide-delivered bone marrow stromal cells promote spinal cord repair in rats.

Neuroreport 2010 Mar;21(4):287-92

Department of Orthopaedic Surgery, Yokohama City University School of Medicine, Yokohama, Japan.

Stem cell-based therapy using bone marrow stromal cells (MSCs) has been expected to be a promising therapy for neuronal regeneration. To repair the injured spinal cord, neuronal differentiation of MSCs before transplantation has a more satisfactory effect. Recently, neuronal differentiation of neural progenitor/stem cells by an intracellular delivery of a pVHL-derived synthetic peptide (VHL peptide) has been shown. Here, we show that VHL peptide-delivered MSCs differentiated into neuron-like cells, and that engrafted VHL peptide-delivered MSCs more recovered the behaviors of the rats than that of nondelivered MSCs. Our result suggests that the use of VHL peptide-delivered MSCs would be a promising therapeutic strategy for repairing the injured spinal cord.
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http://dx.doi.org/10.1097/WNR.0b013e328336ee9aDOI Listing
March 2010

The chitinase 3-like 1 gene and schizophrenia: evidence from a multi-center case-control study and meta-analysis.

Schizophr Res 2010 Feb 3;116(2-3):126-32. Epub 2010 Jan 3.

Department of Psychiatry, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.

The chitinase 3-like 1 (CHI3L1) gene acts as a cellular survival factor in response to several environmental and psychosocial stresses. The expression level of CHI3L1 was increased in the hippocampus and prefrontal cortex regions of patients with schizophrenia. Genetic variants of the CHI3L1 gene have been significantly associated with schizophrenia in two distinct ethnic groups, the Chinese and Irish populations. The aims of this study are to confirm the association between the CHI3L1 gene and schizophrenia in a Japanese population using the largest sample size to date (1463 cases and 1795 controls) and perform a meta-analysis of the combined samples (3005 cases, 3825 controls and 601 trios). We found significant associations between single nucleotide polymorphism (SNP) 4/rs4950928 (p=0.009), which is located in the promoter region of the CHI3L1 gene, and haplotypes including this SNP and schizophrenia (the most significant global p<0.001). As the meta-analysis of the combined samples showed significant heterogeneity among studies of SNP3/rs10399805 (p=0.026) and SNP4 (p<0.001), we performed meta-analyses separately in the Japanese (2033 cases and 2365 controls) and Chinese populations (412 cases, 464 controls and 601 trios), the major groups analyzed in association studies of the CHI3L1 gene. The meta-analysis in Japanese populations showed stronger evidence for the association of schizophrenia with SNP4 (p=0.003), while the meta-analysis in Chinese populations showed an association with a different variant (SNP3) (p=0.003). We conclude that the genetic variants in the CHI3L1 gene have ethnic heterogeneity and confer a susceptibility to schizophrenia in Asian populations.
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http://dx.doi.org/10.1016/j.schres.2009.12.002DOI Listing
February 2010

Neuropsychiatric symptoms in patients with idiopathic normal pressure hydrocephalus.

Behav Neurol 2009 ;21(3):165-74

Psychiatry, Department of Integrated Medicine, Division of Internal Medicine, Osaka University Graduate School of Medicine, D3 2-2 Yamadaoka, Suita-city, Osaka, Japan.

Objective: To clarify the characteristics of neuropsychiatric symptoms in patients with idiopathic normal pressure hydrocephalus (iNPH).

Methods: Neuropsychiatric symptoms of 64 iNPH patients with mild triad symptoms from three kinds of hospitals were evaluated with the Neuropsychiatric Inventory (NPI) and compared with 126 patients with Alzheimer's disease (AD).

Results: The most frequently observed neuropsychiatric symptom in the iNPH patients was apathy followed by anxiety and aggression. No symptom was more prevalent or more severe in iNPH than in AD. The severity of cognitive impairment was correlated with both aberrant motor activity and apathy.

Conclusions: Neuropsychiatric symptoms were mild in patients with iNPH and apathy was the most prevalent symptom. The correlation between neuropsychiatric symptoms and cognitive impairment in iNPH appears to arise from a common pathology in the frontal lobe.
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http://dx.doi.org/10.3233/BEN-2009-0233DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5444276PMC
February 2010

[A case of unresectable advanced pancreatic cancer treated by gemcitabine-based chemotherapy following cancer pain alleviation by low-dose matrix-type transdermal fentanyl].

Gan To Kagaku Ryoho 2009 Aug;36(8):1351-3

Cancer Support Team, Osaka National Hospital, National Hospital Organization.

Cancer pain often makes patient's performance status worsen and is one of the difficulties in anti-cancer therapy. We report a case of unresectable advanced pancreatic cancer with cancer pain, which was treated by matrix-type transdermal fentanyl following slow-releasing oxycodone, which caused severe constipation. Rotation to matrix-type transdermal fentanyl (Durotep MT 2.1 mg) releaved severe constipation as well as cancer pain. The patient could take gemcitabine-based chemotherapy. Low-dose matrix-type transdermal fentanyl (Durotep MT 2.1 mg) is useful for opioid rotation from low-dose morphine or oxycodone with uncontrolled side effects, and it contributes to continuation of anti-cancer therapy.
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August 2009

Neuroimaging studies in patients with Charles Bonnet Syndrome.

Psychogeriatrics 2009 Jun;9(2):77-84

Psychiatry, Department of Integrated Medicine, Division of Internal Medicine, Osaka University Graduate School of Medicine, Osaka, Japan.

Charles Bonnet Syndrome (CBS) is characterized by complex formed and recurrent visual hallucinations in psychologically normal people, and is often associated with eye pathology. Many psychiatrists have taken an interest in CBS because this syndrome could provide clues to the mechanisms underlying visual hallucinations. In the present paper, we review previous neuroimaging studies in patients with CBS and summarize the results of these studies. There could be a fundamental dysfunction in the primary and secondary visual cortices in some patients with CBS, and transient cortical activation occurs in the inferior lateral temporal cortex during the appearance of visual hallucinations in CBS patients. External visual stimuli are perceived in the retina and are transmitted to the primary visual cortex (Brodmann area (BA) 17). The stimuli are transmitted from BA 17 to the secondary visual cortex (BA 18) and then to the visual association cortices (BA 19 and BA 37). In general, our perception of external visual stimuli normally has an inhibitory effect on the endogenous activation of the visual cortex. Visual loss due to certain conditions, of which eye pathology is the most commonly postulated in CBS patients, produces a state of sensory deprivation that releases the visual cortex from regulation by external stimuli, resulting in visual hallucinations (cortical release phenomenon). The results of previous neuroimaging studies suggest that the cortical release phenomenon hypothesis for the occurrence of visual hallucinations in patients with CBS is plausible. In addition, the results indicate that not only eye pathology, but also dysfunction in the primary and secondary visual cortices could result in deprivation of external visual stimuli.
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http://dx.doi.org/10.1111/j.1479-8301.2009.00288.xDOI Listing
June 2009