Masakazu Miyajima

Prof. Dr. Masakazu Miyajima


Research Focus & Metrics

Academic Career Length

16Years (2011-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
1 December 2016 in Journal of Neurosurgery
Verified
Journal Article
Closed access
MMMasakazu Miyajima
Masakazu Miyajima
HKHiroaki Kazui
Hiroaki Kazui
EMEtsuro Mori
Etsuro Mori
MIMasatsune Ishikawa
Masatsune Ishikawa
OBJECTIVE: Idiopathic normal pressure hydrocephalus (iNPH) is treated with cerebrospinal fluid shunting, and implantation of a ventriculoperitoneal shunt (VPS) is the current standard treatment. The objective of this study was to compare the efficacy and safety of VPSs and lumboperitoneal shunts (LPSs) for patients with iNPH. METHODS: The authors conducted a prospective multicenter study of LPS use for patients with iNPH. Eighty-three patients with iNPH (age 60 to 85 years) who presented with ventriculomegaly and high-convexity and medial subarachnoid space tightness on MR images were recruited from 20 neurological or neurosurgical centers in Japan between March 1, 2010, and October 19, 2011. The primary outcome was the modified Rankin Scale (mRS) score 1 year after surgery, and the secondary outcome included scores on the iNPH grading scale (iNPHGS). A previously conducted VPS cohort study with the same inclusion criteria and primary and secondary end points was used as a historical control. RESULTS: The proportion of patients who achieved a favorable outcome (i.e., improvement of at least 1 point in their mRS score) was 63% (95% CI 51%–73%) and was comparable to values reported with VPS implantation (69%, 95% CI 59%–78%). Using the iNPHGS, the 1-year improvement rate was 75% (95% CI 64%–84%) and was comparable to the rate found in the VPS study (77%, 95% CI 68%–84%). The proportion of patients experiencing serious adverse events (SAEs) and non-SAEs did not differ significantly between the groups at 1 year after surgery (SAEs: 19 [22%] of 87 LPS patients vs 15 [15%] of 100 VPS patients, p = 0.226; non-SAEs: 24 [27.6%] LPS patients vs 20 [20%] VPS patients, p = 0.223). However, shunt revisions were more common in LPS-treated patients than in VPS-treated patients (6 [7%] vs 1 [1%]). CONCLUSIONS: The efficacy and safety rates for LPSs with programmable valves are comparable to those for VPSs for the treatment of patients with iNPH. Despite the relatively high shunt failure rate, an LPS can be the treatment of choice because of its minimal invasiveness and avoidance of brain injury.

4 June 2012 in European Journal of Neurology
Verified
Journal Article
Closed access
PDF file
MMMasakazu Miyajima
Masakazu Miyajima
MNM. Nakajima
M. Nakajima
IOI. Ogino
I. Ogino
HMH. Miyata
H. Miyata
YMY. Motoi
Y. Motoi
HAH. Arai
H. Arai

1 January 2015 in Neurologia medico-chirurgica
Verified
Journal Article
Open access
PDF file
MMMasakazu Miyajima
Masakazu Miyajima
HAHajime Arai
Hajime Arai
Japan's largest platform for academic e-journals: J-STAGE is a full text database for reviewed academic papers published by Japanese societies

18 September 2013 in PLOS ONE
Verified
Journal Article
Open access
PDF file
MMMasakazu Miyajima
Masakazu Miyajima
MNMadoka Nakajima
Madoka Nakajima
YMYumiko Motoi
Yumiko Motoi
MMMasao Moriya
Masao Moriya
HSHidenori Sugano
Hidenori Sugano
HAHajime Arai
Hajime Arai
Leucine-rich α2-glycoprotein (LRG) is a protein induced by inflammation. It contains a leucine-rich repeat (LRR) structure and easily binds with other molecules. However, the function of LRG in the brain during aging and neurodegenerative diseases has not been investigated. Here, we measured human LRG (hLRG) concentration in the cerebrospinal fluid (CSF) and observed hLRG expression in post-mortem human cerebral cortex. We then generated transgenic (Tg) mice that over-expressed mouse LRG (mLRG) in the brain to examine the effects of mLRG accumulation. Finally, we examined protein-protein interactions using a protein microarray method to screen proteins with a high affinity for hLRG. The CSF concentration of hLRG increases with age and is significantly higher in patients with Parkinson’s disease with dementia (PDD) and progressive supranuclear palsy (PSP) than in healthy elderly people, idiopathic normal pressure hydrocephalus (iNPH) patients, and individuals with Alzheimer’s disease (AD). Tg mice exhibited neuronal degeneration and neuronal decline. Accumulation of LRG in the brains of PDD and PSP patients is not a primary etiological factor, but it is thought to be one of the causes of neurodegeneration. It is anticipated that hLRG CSF levels will be a useful biomarker for the early diagnosis of PDD and PSP.

1 October 2015 in Journal of the Neurological Sciences
Verified
Journal Article
Open access
MNMadoka Nakajima
Madoka Nakajima
MMMasakazu Miyajima
Masakazu Miyajima
IOIkuko Ogino
Ikuko Ogino
CAChihiro Akiba
Chihiro Akiba
HSHidenori Sugano
Hidenori Sugano
HAHajime Arai
Hajime Arai
The prognosis of cognitive improvement after cerebrospinal fluid (CSF) shunting in idiopathic normal pressure hydrocephalus (iNPH) remains uncertain, with no reports on CSF biomarkers related to long-term cognitive prognosis. We performed a preliminary study of CSF biomarker protein levels for cognitive outcome prognostication of two-year outcomes after shunt treated iNPH in 36 patients (13 women) with a median age of 75years (IQR 69-78). CSF biomarkers included soluble amyloid precursor proteins (sAPP, sAPPα, sAPPβ), amyloid β (Aβ)1-38, Aβ1-42 and phosphorylated tau (p-tau), lipocalin-type prostaglandin D synthase (L-PGDS)/β-trace, and cystatin C. The results clearly showed that p-tau levels (sensitivity of 71.4%, specificity of 77.8%, cut-off value of 22.0pg/mL), Aβ1-38/Aβ1-42 ratio (77.8%, 81%, 3.58), and the Aβ1-42/p-tau ratio (76%, 72.7%, 14.6) in preoperative CSF have the potential to determine postoperative prognosis. Improved cognition may be associated with the improvement in CSF circulation after LPS, which likely induces cystatin C and L-PGDS and switches synthesis from Aβ1-42 to Aβ1-38.

10 September 2021 in Metabolites
Verified
Journal Article
Open access
PDF file
KHKyoka Hoshi
Kyoka Hoshi
HIHiromi Ito
Hiromi Ito
EAEriko Abe
Eriko Abe
TFTakashi J. Fuwa
Takashi J. Fuwa
MKMayumi Kanno
Mayumi Kanno
YHYasuhiro Hashimoto
Yasuhiro Hashimoto
Glycosylation is a cell type-specific post-translational modification that can be used for biomarker identification in various diseases. Aim of this study is to explore glycan-biomarkers on transferrin (Tf) for Alzheimer’s disease (AD) in cerebrospinal fluid (CSF). Glycan structures of CSF Tf were analyzed by ultra-performance liquid chromatography followed by mass spectrometry. We found that a unique mannosylated-glycan is carried by a Tf isoform in CSF (Man-Tf). The cerebral cortex contained Man-Tf as a major isofom, suggesting that CSF Man-Tf is, at least partly, derived from the cortex. Man-Tf levels were analyzed in CSF of patients with neurological diseases. Concentrations of Man-Tf were significantly increased in AD and mild cognitive impairment (MCI) comparing with other neurological diseases, and the levels correlated well with those of phosphorylated-tau (p-tau), a representative AD marker. Consistent with the observation, p-tau and Tf were co-expressed in hippocampal neurons of AD, leading to the notion that a combined p-tau and Man-Tf measure could be a biomarker for AD. Indeed, levels of p-tau x Man-Tf showed high diagnostic accuracy for MCI and AD; 84% sensitivities and 90% specificities for MCI and 94% sensitivities and 89% specificities for AD. Thus Man-Tf could be a new biomarker for AD.