Publications by authors named "Masanori Kurihara"

17 Publications

  • Page 1 of 1

Enhancement of leukemia-like phenotypes in Drosophila mxc mutant larvae due to activation of the RAS-MAP kinase cascade possibly via down-regulation of DE-cadherin.

Genes Cells 2020 Dec 18;25(12):757-769. Epub 2020 Nov 18.

Department of Insect Biomedical Research, Center for Advanced Insect Research Promotion, Kyoto Institute of Technology, Matsugasaki, Kyoto, Japan.

Loss of mxc gene function in mature hemocytes of Drosophila mxc mutant results in malignant hyperplasia in larval hematopoietic tissues termed lymph glands (LGs) owing to over-proliferation of immature cells. This is a useful model for genetic analyses of leukemia progression. To identify other mutations that deteriorate the hyperplasia, we aimed to investigate whether hyper-activation of common signaling cascade enabled to enhance the phenotypes. Ectopic expression of the constitutively active forms of MAPK signaling factors in the mutant increased the hyperplasia and the number of circulating hemocytes, resulting in the production of LG fragments. The LG phenotype was related to the reduced DE-cadherin level in the mutants. Depletion of Drosophila MCRIP, involved in MAPK-induced silencing of cadherin gene expression, exhibited a similar enhancement of the mxc phenotypes. Furthermore, expression of MMP1 proteinase that cleaves the extracellular matrix proteins increased in the mutant larvae harboring MAPK cascade activation. Depletion of Mmp1 and that of pnt (required for Mmp1 expression) suppressed the LG hyperplasia. Hence, we speculated that reduction in DE-cadherin level by either down-regulation of MCRIP or up-regulation of MMP1 was involved in the progression of the tumor phenotype. Our findings can contribute to understanding the mechanism underlying human leukemia progression.
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http://dx.doi.org/10.1111/gtc.12811DOI Listing
December 2020

Dorsal type letter-by-letter reading accompanying alexia with agraphia due to a lesion of the lateral occipital gyri.

Neurocase 2020 10 17;26(5):285-292. Epub 2020 Aug 17.

Department of Neurology, Mitsui Memorial Hospital , Tokyo, Japan.

We report a patient with alexia with agraphia accompanied by letter-by-letter reading after hemorrhage in the left middle and inferior occipital gyri that spared the angular gyrus and the fusiform gyrus. Kanji (Japanese morphograms) and kana (Japanese phonetic writing) reading and writing tests revealed that alexia with agraphia was characterized by kana-predominant alexia and kanji-predominant agraphia. This type of "dorsal" letter-by-letter reading is discernable from conventional letter-by-letter reading that is observed in pure alexia in that (1) kinesthetic reading is less effective, (2) kana or literal agraphia coexists, and (3) fundamental visual discrimination is nearly normal.
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http://dx.doi.org/10.1080/13554794.2020.1803922DOI Listing
October 2020

[Factors Influencing Brain Interstitial Fluid Concentrations of Amyloid β and Tau].

Brain Nerve 2020 May;72(5):525-531

Department of Neurology, Graduate School of Medicine, The University of Tokyo.

In patients with Alzheimer's disease, the brain interstitial space is an important place where amyloid-β oligomers and aggregates exist. Although tau aggregates are observed inside neurons, extracellular brain interstitial fluid tau has drawn attention because of increasing understanding of cell-to-cell propagation of tau aggregation. In this review, we summarize our current understanding of factors influencing brain interstitial fluid concentrations of amyloid-β and tau, mainly focusing on known epidemiological risk factors for Alzheimer's disease.
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http://dx.doi.org/10.11477/mf.1416201557DOI Listing
May 2020

Loss of Histone Locus Bodies in the Mature Hemocytes of Larval Lymph Gland Result in Hyperplasia of the Tissue in Mutants of .

Int J Mol Sci 2020 Feb 26;21(5). Epub 2020 Feb 26.

Department of Insect Biomedical Research, Center for Advanced Insect Research Promotion, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-0962, Japan.

Mutations in the () gene in results in malignant hyperplasia in larval hematopoietic tissues, called lymph glands (LG). encodes a component of the histone locus body (HLB) that is essential for cell cycle-dependent transcription and processing of histone mRNAs. The mammalian () gene, encoded by the responsible gene for ataxia telangiectasia, is a functional Mxc orthologue. However, their roles in tumorigenesis are unclear. Genetic analyses of the mutants and larvae having LG-specific depletion revealed that a reduced activity of the gene resulted in the hyperplasia, which is caused by hyper-proliferation of immature LG cells. The depletion of in mature hemocytes of the LG resulted in the hyperplasia. Furthermore, the inhibition of HLB formation was required for LG hyperplasia. In the mutant larvae, the total mRNA levels of the five canonical histones decreased, and abnormal forms of polyadenylated histone mRNAs, detected rarely in normal larvae, were generated. The ectopic expression of the polyadenylated mRNAs was sufficient for the reproduction of the hyperplasia. The loss of HLB function, especially 3-end processing of histone mRNAs, is critical for malignant LG hyperplasia in this leukemia model in . We propose that is involved in the activation to induce adenosine deaminase-related growth factor A (Adgf-A), which suppresses immature cell proliferation in LG.
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http://dx.doi.org/10.3390/ijms21051586DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7084650PMC
February 2020

Colocalization of BRCA1 with Tau Aggregates in Human Tauopathies.

Brain Sci 2019 Dec 20;10(1). Epub 2019 Dec 20.

Department of Neurology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan.

The mechanism of neuronal dysfunction via tau aggregation in tauopathy patients is controversial. In Alzheimer's disease (AD), we previously reported mislocalization of the DNA repair nuclear protein BRCA1, its coaggregation with tau, and the possible importance of the subsequent DNA repair dysfunction. However, whether this dysfunction in BRCA1 also occurs in other tauopathies is unknown. The aim of this study was to evaluate whether BRCA1 colocalizes with tau aggregates in the cytoplasm in the brains of the patients with tauopathy. We evaluated four AD, two Pick's disease (PiD), three progressive supranuclear palsy (PSP), three corticobasal degeneration (CBD), four normal control, and four disease control autopsy brains. Immunohistochemistry was performed using antibodies against BRCA1 and phosphorylated tau (AT8). Colocalization was confirmed by immunofluorescence double staining. Colocalization of BRCA1 with tau aggregates was observed in neurofibrillary tangles and neuropil threads in AD, pick bodies in PiD, and globose neurofibrillary tangles and glial coiled bodies in PSP. However, only partial colocalization was observed in tuft-shaped astrocytes in PSP, and no colocalization was observed in CBD. Mislocalization of BRCA1 was not observed in disease controls. BRCA1 was mislocalized to the cytoplasm and colocalized with tau aggregates in not only AD but also in PiD and PSP. Mislocalization of BRCA1 by tau aggregates may be involved in the pathogenesis of PiD and PSP.
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http://dx.doi.org/10.3390/brainsci10010007DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7016802PMC
December 2019

A Novel de novo KIF1A Mutation in a Patient with Autism, Hyperactivity, Epilepsy, Sensory Disturbance, and Spastic Paraplegia.

Intern Med 2020 Mar 6;59(6):839-842. Epub 2019 Dec 6.

Department of Neurology, Graduate School of Medicine, The University of Tokyo, Japan.

Heterozygous mutations in KIF1A have been reported to cause syndromic intellectual disability or pure spastic paraplegia. However, their genotype-phenotype correlations have not been fully elucidated. We herein report a man with autism and hyperactivity along with sensory disturbance and spastic paraplegia, carrying a novel de novo mutation in KIF1A [c.37C>T (p.R13C)]. Autism and hyperactivity have only previously been reported in a patient with c.38 G>A (R13H) mutation. This case suggests that alterations in this arginine at codon 13 might lead to a common clinical spectrum and further expand the genetic and clinical spectra associated with KIF1A mutations.
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http://dx.doi.org/10.2169/internalmedicine.3661-19DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7118386PMC
March 2020

Estimating acceleration time point of respiratory decline in ALS patients: A novel metric.

J Neurol Sci 2019 Aug 30;403:7-12. Epub 2019 May 30.

Department of Neurology, Graduate School of Medicine, University of Tokyo, Japan.

Objective: We aimed to derive and assess a novel metric for respiratory decline: the timing of acceleration of respiratory functional decline during the course of the disease in patients with amyotrophic lateral sclerosis (ALS).

Methods: In this single-center retrospective study, we reviewed consecutive definite/probable ALS patients, diagnosed and followed up at our hospital. We recorded serial slow vital capacity (percentage of predicted slow vital capacity; %VC) since diagnosis for all patients. These serial %VC data were fitted with logistic function of the time since diagnosis, and 'acceleration point' was calculated as the week in which the second derivative of the fitted logistic function had the minimum value.

Results: We included 62 patients with ALS, whose serial %VC data had been recorded for a median of 8 times over a median of 94.3 weeks. The calculated acceleration time-point was the time-point at which the %VC is becoming 0.789 times of maximum %VC, and had a strong association with the period since diagnosis to the administration of nutritional/respiratory support (p < 0.001). Bulbar-type ALS or lower Body Mass Index at diagnosis, both are well-known ALS prognostic factors, were also associated with more rapid arrival of the acceleration time-point.

Conclusions: We introduced the time-point of acceleration in the vital capacity decline during disease progression as a novel metric for ALS respiratory decline. Although we could not build a practically-available clinical model that directly predicts acceleration time-point due to the limited sample size, our metric may be used as one of the helpful indicators in the management during earlier disease course of ALS, such as to be careful for the potentially approaching acceleration time-point when the %VC is decreasing to approximately 0.789 times of initial %VC.
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http://dx.doi.org/10.1016/j.jns.2019.05.031DOI Listing
August 2019

Rapidly progressive miliary brain metastasis of lung cancer after EGFR tyrosine kinase inhibitor discontinuation: An autopsy report.

Neuropathology 2019 Apr 13;39(2):147-155. Epub 2019 Mar 13.

Department of Pathology, Mitsui Memorial Hospital, Tokyo, Japan.

Miliary brain metastasis is a rare type of brain metastasis, in which carcinoma cells disseminate to numerous foci confined to Virchow-Robin/subpial spaces. Symptoms usually progress within several months, and magnetic resonance imaging (MRI) shows multiple small contrast-enhancing lesions. We report an autopsy case of a patient who rapidly deteriorated within a week due to miliary brain metastasis after epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) discontinuation, without contrast-enhancing lesions on MRI. A 74-year-old woman was diagnosed with stage IV lung adenocarcinoma with EGFR L868R mutation 2 years before presentation. Gefitinib, an EGFR-TKI was started. After 7 months, multiple new punctate contrast-enhancing lesions in the cerebral cortex appeared. After switching to another EGFR-TKI, erlotinib, these lesions disappeared. One year later, erlotinib was discontinued because of disease progression in the lung and docetaxel was initiated. Sixteen days later, cognitive decline appeared which rapidly progressed to bedridden state in 4 days. MRI showed multiple cortical small fluid-attenuated inversion recovery high intensity lesions which lacked contrast enhancement. The patient exhibited a state of akinetic mutism within a few days, and died 52 days after the appearance of neurological symptoms. The rapid progression indicated disease flare after EGFR-TKI discontinuation. Autopsy revealed numerous foci of metastasis in the cerebral cortex, basal ganglia, thalamus, and cerebellum, in which cancer cells were mostly confined to the Virchow-Robin/subpial spaces. These pathological findings were compatible with previous reports of miliary brain metastasis. Recent reports suggest that early disseminated cancer cells can survive for a long time and even remain after chemotherapy in supportive niches, and Virchow-Robin spaces are the niches in the brain. Our case suggests that these cancer cells may rapidly proliferate as a withdrawal burst after discontinuation of molecular targeted drugs, and show pathological findings of miliary brain metastasis.
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http://dx.doi.org/10.1111/neup.12542DOI Listing
April 2019

Aphasic status epilepticus preceding tumefactive left hemisphere lesion in anti-MOG antibody associated disease.

Mult Scler Relat Disord 2019 Jan 15;27:91-94. Epub 2018 Oct 15.

Department of Neurology, The University of Tokyo, Tokyo, Japan.

Introduction: Anti-myelin oligodendrocyte glycoprotein (MOG) antibodies have recently been associated with epilepsy with FLAIR hyperintense cortical lesions on MRI. Association between anti-MOG antibodies and epilepsy without detectable structural brain lesion on MRI is unknown.

Case Report: A 48-year-old right-handed man with a four-and-a-half year history of anti-MOG antibody associated demyelinating disease presented with persistent global aphasia. Brain MRI showed no new lesion or cortical lesion in the left hemisphere. Electroencephalogram, magnetoencephalography, and brain perfusion single-photon emission computed tomography suggested epileptic foci in the left temporal and parietal lobes, and the patient's aphasia transiently responded to intravenous diazepam, compatible with aphasic status epilepticus. Cerebrospinal fluid showed mildly elevated cell count and positive oligoclonal bands. The patient only partially responded to antiepileptic drugs but responded to steroid pulse therapy. Six months later, the patient again exhibited global aphasia. Brain MRI showed tumefactive white matter lesion in the left temporo-parietal lobes.

Conclusion: Autoimmune epilepsy without obvious causative lesion on MRI can be seen in the course of anti-MOG antibody associated demyelinating disease. The subsequent emergence of tumefactive lesion closely located to the epileptic foci may suggest some association between autoimmune epilepsy and demyelinating lesions.
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http://dx.doi.org/10.1016/j.msard.2018.10.012DOI Listing
January 2019

Optic neuropathy and decorticate-like posture as presenting symptoms of Bickerstaff's brainstem encephalitis: A case report and literature review.

Clin Neurol Neurosurg 2018 10 16;173:159-162. Epub 2018 Aug 16.

Department of Neurology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.

A 72-year-old woman with a 10-day history of bilateral visual impairment after respiratory tract infection showed decorticate-like posture and progressive deterioration of consciousness leading to coma. Ophthalmoplegia was also noted and anti-GQ1b antibodies were positive, consistent with Bickerstaff's brainstem encephalitis. After intravenous immunoglobulin and steroid pulse therapy, her consciousness gradually improved. However, severe visual impairment at the level of hand motion was noticed, which gradually normalized after second steroid pulse therapy. Atypical findings including optic neuropathy and decorticate-like posture can be seen in patients with Bickerstaff's brainstem encephalitis, and early diagnosis is essential for adequate management.
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http://dx.doi.org/10.1016/j.clineuro.2018.08.019DOI Listing
October 2018

HIV Dementia with a Decreased Cardiac I-metaiodobenzylguanidine Uptake Masquerading as Dementia with Lewy Bodies.

Intern Med 2018 Oct 18;57(20):3007-3010. Epub 2018 May 18.

Department of Neurology, Graduate School of Medicine, The University of Tokyo, Japan.

Cardiac I-metaiodobenzylguanidine (MIBG) scintigraphy is a promising biomarker for dementia with Lewy bodies (DLB). However, we experienced a patient with cognitive decline, parkinsonism, and a decreased MIBG uptake who turned out to have HIV dementia. Normal dopamine transporter single-photon emission computed tomography reduced the possibility of comorbid Lewy body pathology causing the patient' s parkinsonism. The decreased MIBG uptake was most likely due to postganglionic sympathetic nerve denervation, which can also be caused by HIV. This case further emphasizes the importance of excluding other causes of autonomic neuropathy, including HIV infection, before interpreting MIBG scans.
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http://dx.doi.org/10.2169/internalmedicine.0876-18DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6232034PMC
October 2018

Repetitive Discharge in a Case of Isaacs Syndrome with Burning Sensation.

Intern Med 2018 09 27;57(17):2597. Epub 2018 Apr 27.

Department of Neurology, Mitsui Memorial Hospital, Japan.

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http://dx.doi.org/10.2169/internalmedicine.0392-17DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6172557PMC
September 2018

Frontal Phonological Agraphia and Acalculia with Impaired Verbal Short-Term Memory due to Left Inferior Precentral Gyrus Lesion.

Case Rep Neurol 2018 Jan-Apr;10(1):72-82. Epub 2018 Mar 14.

Department of Neurology, Mitsui Memorial Hospital, Tokyo, Japan.

We report a patient with phonological agraphia (selective impairment of kana [Japanese phonetic writing] nonwords) and acalculia (mental arithmetic difficulties) with impaired verbal short-term memory after a cerebral hemorrhage in the opercular part of the left precentral gyrus (Brodmann area 6) and the adjacent postcentral gyrus. The patient showed phonemic paragraphia in five-character kana nonword writing, minimal acalculia, and reduced digit and letter span. Mental arithmetic normalized after 8 months and agraphia recovered to the normal range at 1 year after onset, in parallel with an improvement of the auditory letter span score from 4 to 6 over a period of 14 months and in the digit span score from 6 to 7 over 24 months. These results suggest a close relationship between the recovery of agraphia and acalculia and the improvement of verbal short-term memory. The present case also suggests that the opercular part of the precentral gyrus constitutes the phonological route in writing that conveys phonological information of syllable sequences, and its damage causes phonological agraphia and acalculia with reduced verbal short-term memory.
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http://dx.doi.org/10.1159/000487849DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5903121PMC
March 2018

Novel De Novo KCND3 Mutation in a Japanese Patient with Intellectual Disability, Cerebellar Ataxia, Myoclonus, and Dystonia.

Cerebellum 2018 Apr;17(2):237-242

Department of Neurology, Graduate School of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan.

Spinocerebellar ataxia 19/22 (SCA19/22) is a rare type of autosomal dominant SCA that was previously described in 11 families. We report the case of a 30-year-old Japanese man presenting with intellectual disability, early onset cerebellar ataxia, myoclonus, and dystonia without a family history. MRI showed cerebellar atrophy, and electroencephalograms showed paroxysmal sharp waves during hyperventilation and photic stimulation. Trio whole-exome sequencing analysis of DNA samples from the patient and his parents revealed a de novo novel missense mutation (c.1150G>A, p.G384S) in KCND3, the causative gene of SCA19/22, substituting for evolutionally conserved glycine. The mutation was predicted to be functionally deleterious by bioinformatic analysis. Although pure cerebellar ataxia is the most common clinical feature in SCA19/22 families, extracerebellar symptoms including intellectual disability and myoclonus are reported in a limited number of families, suggesting a genotype-phenotype correlation for particular mutations. Although autosomal recessive diseases are more common in patients with early onset sporadic cerebellar ataxia, the present study emphasizes that such a possibility of de novo mutation should be considered.
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http://dx.doi.org/10.1007/s12311-017-0883-4DOI Listing
April 2018

High PR3-ANCA positivity in a patient with chronic inflammatory demyelinating polyneuropathy.

eNeurologicalSci 2017 Mar 5;6:4-5. Epub 2016 Oct 5.

Department of Neurology, Mitsui Memorial Hospital, Tokyo, Japan.

Proteinase 3 anti-neutrophil cytoplasmic antibody (PR3-ANCA) is reported to be highly specific to vasculitis compared to myeloperoxidase (MPO)-ANCA. We report a case of a 19-year-old woman with chronic inflammatory demyelinating polyneuropathy (CIDP) with high PR3-ANCA positivity. The patient responded well to intravenous immunoglobulin plus oral steroid, and showed no signs of systemic vasculitis during the subsequent 10 months of follow-up. Our present case suggests that CIDP may accompany high PR3-ANCA levels, which should be differentiated from axonal neuropathy due to vasculitis.
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http://dx.doi.org/10.1016/j.ensci.2016.10.001DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5721574PMC
March 2017