Natsuki Ohkawa
Juntendo University
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Featured researches published by Natsuki Ohkawa.
Brain & Development | 2009
Kyoko Tanaka; N. Kon; Natsuki Ohkawa; Naomi Yoshikawa; Toshiaki Shimizu
AIM Breast milk is rich in docosahexaenoic acid (DHA), which is selectively concentrated in neuronal membranes and is thought to be necessary for optimal neurodevelopment. This study evaluated the relationship between breastfeeding, especially the resultant DHA level in the red blood cell (RBC) membranes of infants, and the cognitive function of very-low-birth-weight infants at 5 years of age. METHODS Eighteen patients were classified into groups that were breastfed or formula-fed or both. We measured the DHA concentration in the RBC membranes of 18 preterm infants at 4 weeks of age. To evaluate cognitive function at the age of 5 years, we asked the children to perform five tests: the Kaufman Assessment Battery for Children, Day-Night Test, Kansas Reflection Impulsivity Scale for Preschoolers (KRISP), Motor Planning Test, and Strengths and Difficulties Questionnaire. RESULTS The DHA level at 4 weeks after birth was significantly higher in the breastfed infants than in the formula-fed infants. The scores for the Day-Night Test, KRISP, and Motor Planning Test were significantly higher in the breastfed group. There were significant correlations between the scores for the Day-Night Test and for the KRISP and the level of DHA at 4 weeks of age. CONCLUSION Breastfeeding in the neonatal periods increases the DHA level in preterm infants and may have an important influence on brain development not only during early infancy but also during the preschool years, especially in terms of cognitive function.
Acta Paediatrica | 2009
Natsuki Ohkawa; Hiromichi Shoji; Tomohiro Kitamura; Hiroki Suganuma; Naomi Yoshikawa; Mitsuyoshi Suzuki; Tsubasa Lee; Ken Hisata; Toshiaki Shimizu
Aim: We investigated the relationship between plasma insulin‐like growth factor I (IGF‐I), leptin, active ghrelin levels, and postnatal growth in very low birth weight (VLBW) infants.
Pediatrics International | 2009
Tomohiro Kitamura; Toshiaki Shimizu; Natsuki Ohkawa; Hisayuki Oda; Masahiro Ohtsuki; Masahiko Kishiro
Background: Ghrelin has effects on appetite and growth. Recent reports suggest effects on cardiac function, but no study has evaluated the ghrelin levels of congenital heart disease (CHD) infants with heart failure. The purpose of the present study was therefore to investigate the relationship between ghrelin level and growth and cardiac function in CHD infants.
Pediatrics International | 2014
Hiromichi Shoji; Naho Ikeda; Mariko Hosozawa; Natsuki Ohkawa; Nobuaki Matsunaga; Hiroki Suganuma; Ken Hisata; Kyoko Tanaka; Toshiaki Shimizu
Reactive oxygen species may be involved in serious diseases in premature infants. The objective of this study was to assess the relationship between neurodevelopmental outcome and oxidative stress marker level in the urine of very low‐birthweight (VLBW) infants.
Acta Paediatrica | 2014
Hiromichi Shoji; Yayoi Murano; Mari Mori; Nobuaki Matsunaga; Natsuki Ohkawa; Hiroki Suganuma; Mitsuru Ikeno; Ken Hisata; Satoshi Hirayama; Tsuyoshi Ueno; Takashi Miida; Toshiaki Shimizu
The intra‐uterine environment affects the risk of development of cardiovascular disease in adulthood. The aim of this study was to determine the influence of prematurity and foetal growth restriction on lipid metabolism, by assessing atherogenic indices soon after birth in preterm infants.
Acta Paediatrica | 2011
Hiromichi Shoji; Ken Hisata; Mitsuyoshi Suzuki; Naomi Yoshikawa; Hiroki Suganuma; Natsuki Ohkawa; Toshiaki Shimizu
Aim: Conventional soybean lipid emulsions contain no docosahexaenoic acid (DHA) or arachidonic acid (AA). We investigated the relationship between blood DHA and AA status in 27 very‐low‐birth‐weight (VLBW) infants with or without parenteral lipid emulsion.
Pediatrics International | 2016
Naho Ikeda; Hiromichi Shoji; Hiroki Suganuma; Natsuki Ohkawa; Masato Kantake; Yayoi Murano; Koji Sakuraya; Toshiaki Shimizu
Insulin‐like growth factor‐I (IGF‐I) is essential for perinatal growth and development; low serum IGF‐I has been observed during intrauterine growth restriction (IUGR). We investigated the effects of recombinant human (rh) IGF‐I in IUGR rats during the early postnatal period.
Thrombosis Research | 2015
Kyoko Hatta; Shinji Kunishima; Hiroki Suganuma; Noboru Tanaka; Natsuki Ohkawa; Toshiaki Shimizu
Type 2B von Willebrand disease (VWD) is frequently associated with distinct platelet morphology. Here we present a familial case of type 2B VWD with a novel VWF mutation (p.R1308S), which caused neonatal thrombocytopenia. The mother had been treated for refractory immune thrombocytopenia (ITP) for more than 20years. The most important hematological features of this case were large platelets and platelet aggregates detected on peripheral blood smears. Hemostatic tests showed enhanced ristocetin-induced platelet agglutination at low-ristocetin concentrations, absence of high-molecular weight von Willebrand factor (VWF) multimers, and low VWF cofactor activity/antigen ratio. In patients with intractable ITP, family history of ITP and consecutive neonatal thrombocytopenia, the differential diagnosis of congenital thrombocytopenia is mandatory. For this purpose, the identification of large platelets and platelet aggregates on peripheral blood smears is the key aspect of type 2B VWD diagnosis.
Pediatrics International | 2014
Naho Ikeda; Hiroki Suganuma; Natsuki Ohkawa; Satoru Nagata; Hiromichi Shoji; Toshiaki Shimizu
Enterococcus faecalis is rarely involved in neonatal meningitis. Several studies have indicated that the cytokines related to bacterial infection may induce nerve cell damage; therefore, the cytokine levels in cerebrospinal fluid (CSF) could represent a valuable hallmark for rapid recognition of the disease and evaluation of the degree of neurological involvement. We analyzed cytokine levels in the CSF of a neonate with E. faecalis meningitis over time. Tumor necrosis factor‐α (TNF‐α) tended to be elevated during the acute phase of infection, and then decreased during the convalescent stage after treatment. CSF inflammatory cytokine measurement may provide important clues for predicting the development of complications in the host because some of these cytokines, such as TNF‐α, can injure neurons.
Pediatric Neurology | 2014
Natsuki Ohkawa; Akihisa Okumura; Rie Miyata; Naoyuki Tanuma; Masaharu Hayashi; Hiroaki Sato; Toshiaki Shimizu
BACKGROUND Some children with incontinentia pigmenti exhibit encephalopathic features with severe seizures and disturbed consciousness, from the neonatal through the early infantile period. However, the pathological mechanism of brain lesion development is not fully understood. METHODS We measured the cerebrospinal fluid levels of cytokines and oxidative stress markers (8-hydroxy-2-deoxyguanosine and the hexanoyl-lysine adduct) in a young girl with incontinentia pigmenti complicated by an encephalopathic event that occurred on her first day of life. Magnetic resonance imaging revealed widespread reduction of water diffusion in the basal ganglia, the periventricular and subcortical white matter, and the corpus callosum. RESULTS Oxidative stress markers were elevated at 4 days of age but decreased mildly by 25 days of age. Elevated levels of soluble tumor necrosis factor receptor 1 were observed at both 4 and 25 days of age, although tumor necrosis factor-α levels were below the limit of detection. No other cytokine levels were elevated, except for those of interleukin-10 at 25 days of age. CONCLUSIONS Tumor necrosis factor-α expression and oxidative stress are involved in the pathogenesis of brain lesions in children with incontinentia pigmenti, and elevated cerebrospinal fluid cytokine levels may not be apparent during encephalopathic events.