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Affiliation |
Graduate School of Medicine Doctorial Course in Medicine Organ Function-Oriented Medicine Department of Pediatrics |
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Date of Birth |
1966 |
ARAI Hirokazu
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Graduating School 【 display / non-display 】
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-1992.03
Akita University Faculty of Medicine Graduated
Graduate School 【 display / non-display 】
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-1997.03
Akita University Graduate School, Division of Medicine Doctor's Course Completed
Campus Career 【 display / non-display 】
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2025.10-Now
Akita University Graduate School of Medicine Doctorial Course in Medicine Organ Function-Oriented Medicine Department of Pediatrics Professor
Research Areas 【 display / non-display 】
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Life Science / Embryonic medicine and pediatrics
Research Achievements 【 display / non-display 】
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The relationship between free T4 levels and postnatal steroid therapy in preterm infants
Arai H， Goto R， Matsuda T， Takahashi T
Pediatr Int 51 800 - 803 2009.01 [Refereed]
Research paper (journal) Domestic Co-author
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Increased numbers of macrophages in tracheal aspirates in premature infants with funisitis
Arai H， Matsuda T， Goto R， Takada G
Pediatr Int 50 84 - 88 2008.01 [Refereed]
Research paper (journal) Domestic Co-author
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Dexamethasone-induced prenatal alveolar wall thinning is associated with a decrease in EIIIA+ fibronectin isoform in the fetal rat lung
Arai H， Kikuchi W， Ishida A， Takada G
Biol. Neonate 87 113 - 120 2005.01 [Refereed]
Research paper (journal) Domestic Co-author
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Distal pulmonary cell proliferation is associated with the expression of EIIIA+ fibronectin in the developing rat lung. Exp
Kikuchi W， Arai H， Ishida A， Takahashi Y， Takada G
Lung Res 29 135 - 147 2003.01 [Refereed]
Research paper (journal) Domestic Co-author
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Immunohistochemical study on transforming growth factor-beta 1 expression in liver fibrosis of Down’s syndrome with transient abnormal myelopoiesis
Arai H， Ishida A， Nakajima W， Nishinomiya F， Yamazoe A， Takada G
Hum .Pathol 30 474 - 476 1999.01 [Refereed]
Research paper (journal) Domestic Co-author
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Seki Koshi, Maruya Jun, Arai Hirokazu, Nishiyama Kenichi, Nishimaki Keiichi, Fujii Yukihiko
Nervous System in Children ( The Japanese Society for Pediatric Neurosurgery ) 49 ( 1 ) 46 - 51 2024
<p>Complications of ventriculo-peritoneal shunts (VP shunts) in children are not rare. A few of these complications include infection, malfunction, excessive spinal fluid drainage, intraperitoneal cysts, and skin abnormalities. Herein, we report a case in which a patient with hydrocele due to peritoneal malabsorption following repeated VP shunt procedures was successfully weaned off the shunt via endoscopic third ventriculostomy (ETV).</p><p>He was born at 22 weeks 6 days gestation as one of the twins, weighing 614 grams. He was in a state of shock due to sepsis from the time of his birth, and intensive care procedures like intubation and ventilation was immediately started. Bilateral intraventricular hemorrhage was observed at 1 day of age. Simultaneously, he developed severe necrotizing enterocolitis, requiring long-term central intravenous feeding and antimicrobial therapy. When his condition was stable, a cerebrospinal fluid reservoir (CSF reservoir) was placed, and intermittent CSF elimination was started at the age of 179 days. Results of ventriculography confirmed that there was an obstruction of the midbrain aqueduct, and a VP shunt was performed at 209 days of age. Moreover, the patient required 7 shunt reconstructions (1 ventricular catheter occlusion, 1 extension by growth, 3 abdominal catheter malfunctions, and 2 shunt valve occlusions) till the age of 16 years. A shunt with siphon guard was used but slit like ventricle persisted. Adhesions after necrotizing enterocolitis caused peritoneal pseudocyst and caused a dysfunction on the peritoneal side. He had psychomotor retardation, eye movement disorder, visual impairment, and gait disorder due to spasticity in both the lower limbs. He also had a hydrocele at around 10 years of age, but the amount was small, and was considered acceptable to follow-up.</p><p>At the age of 16, he presented headache and vomiting. Head CT revealed the enlargement of the slit like ventricle. Shunt tube contrast examination showed that the ventricular catheter was patent. A post-contrast CT scan showed a large cyst formation from the abdominal cavity to the right scrotum and contrast medium inflow into the cyst. The shunt was not obstructed, and it was concluded that the hydrocephalus was aggravated due to intraperitoneal malabsorption. On the third day, the catheter was replaced with an external drainage, and the symptoms improved. MRI showed obstruction of the midbrain aqueduct and ballooning of the third ventricular floor. Based on the history, the risk of shunt occlusion was considered high. ETV was selected due to its high success rate. The first ETV was performed without complications, but the stoma was closed nine days after operation. The second operation was performed after 20 days, where we perforated two stomas on the tuber cinereum, and connected them, made a large stoma, and opened the Lilliquist's membrane, which ensured that there was no deterioration in his condition for the next ten years. His hydrocele was caused by extension of a peritoneal pseudocyst into the scrotum, which is not previously reported. Additionally, ETV should be considered for weaning from shunt dependence.</p>
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Ota Shozo, Noguchi Atsuko, Kondo Daiki, Nakajima Yoko, Ito Tetsuya, Arai Hirokazu, Takahashi Tsutomu
The Tohoku Journal of Experimental Medicine ( 東北ジャーナル刊行会 ) 250 ( 1 ) 5 - 11 2020
<p>Acid sphingomyelinase (ASM) is a lysosomal hydrolase that degrades sphingomyelin into ceramide and phosphocholine. Recent crystallographic studies revealed the functional role of the N-terminal ASM saposin domain. ASM deficiency due to mutations in the ASM-encoding <i>sphingomyelin phosphodiesterase 1 (SMPD1)</i> gene causes an autosomal recessive sphingolipid-storage disorder, known as Niemann-Pick disease Type A (NPA) or Type B (NPB). NPA is an early-onset neuronopathic disorder, while NPB is a late-onset non-neuronopathic disorder. A homozygous one-base substitution (c.398G>A) of the <i>SMPD1</i> gene was identified in an infant with NPA, diagnosed with complete loss of ASM activity in the patient’s fibroblasts. This mutation is predicted to substitute tyrosine for cysteine at amino acid residue 133, abbreviated as p.C133Y. The patient showed developmental delay, hepatosplenomegaly and rapid neurological deterioration leading to death at the age of 3 years. To characterize p.C133Y, which may disrupt one of the three disulfide bonds of the N-terminal ASM saposin domain, we performed immunoblotting analysis to explore the expression of a mutant ASM protein in the patient’s fibroblasts, showing that the protein was detected as a 70-kDa protein, similar to the wild-type ASM protein. Furthermore, transient expression of p.C133Y ASM protein in COS-7 cells indicated complete loss of ASM enzyme activity, despite that the p.C133Y ASM protein was properly localized to the lysosomes. These results suggest that the proper three-dimensional structure of saposin domain may be essential for ASM catalytic activity. Thus, p.C133Y is associated with complete loss of ASM activity even with stable protein expression and proper subcellular localization.</p>