Masato Hirabayashi

Kansai Medical University, Moriguchi, Ōsaka, Japan

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Publications (7)11.98 Total impact

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    ABSTRACT: Elective Cesarean section performed before 39 weeks of gestation may be associated with increased risk of neonatal complications. We retrospectively investigated differences in the neonatal complication rate between 684 newborns delivered by elective Cesarean section at 37 weeks of gestation (n = 390) and those delivered by the same procedure at 38 weeks (n = 294) between 2006 and 2012 at our hospital in order to ascertain whether adverse outcomes differ between the groups. Newborns delivered at 37 weeks had a significantly higher incidence of neonatal intensive care unit admission (p = 0.03), adverse respiratory complications (p < 0.01), low birth weight (p < 0.001), and hypoglycemia (p < 0.005) than those delivered at 38 weeks. Compared with normal weight neonates, low birth weight neonates were more likely to have hypoglycemia (p < 0.001). Multivariate logistic regression analysis revealed that an adverse respiratory outcome was independently associated with gestational age (p < 0.01; odds ratio [OR], 3.26; 95% confidence interval [CI], 1.36-7.81), while hypoglycemia was independently associated with birth weight (p < 0.01; OR, 16.34; 95% CI, 7.72-34.56). Respiratory disorders were significantly associated with gestational age even in normal birth weight newborns without any other complications such as hyperbirilubinemia, hypoglycemia or bacterial infections. In conclusion, the incidence of neonatal complications was higher in newborns delivered at 37 weeks of gestation than in those delivered at 38 weeks via elective Cesarean section. Thus, the procedure should be scheduled at 38 weeks to improve neonatal outcomes.
    The Tohoku Journal of Experimental Medicine 08/2014; 233(4):243-248. DOI:10.1620/tjem.233.243 · 1.35 Impact Factor
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    ABSTRACT: AimHaemodynamically significant patent ductus arteriosus (hsPDA) is frequently observed in premature infants. This study was conducted to explore whether the blood BNP can be a valuable biomarker to assess the necessity of treatment for hsPDA in premature infants.Methods Serial measurements of the blood BNP were performed during the first 5 days of life in premature infants with hsPDA (Group I) and those without hsPDA (Group N). The definition of the hsPDA was the PDA requiring treatment, such as indomethacin administration and/or surgical ligation.ResultsForty-six subjects were enrolled. Compared with Group N, Group I showed significantly higher level of blood BNP at postnatal 24-96 h and demonstrated the peak value at postnatal 24-48 h. With the ROC curve using the data at postnatal 24-48 h in Group I, we deduced the predictive value of 250 pg/mL of blood BNP for indomethacin treatment. Similarly, with the ROC curve using the maximal value of blood BNP within the first 5 days of life, the predictive value of 2000 pg/mL for surgical ligation was deduced.Conclusions Blood BNP during early postnatal period can be a useful biomarker to assess the necessity of treatment for hsPDA in premature infants.
    Acta Paediatrica 04/2013; 102(8). DOI:10.1111/apa.12273 · 1.67 Impact Factor
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    ABSTRACT: Hemolytic uremic syndrome (HUS) in infants is mainly caused by the Shiga toxin (Stx), which is produced by pathogenic Escherichia coli O157:H7. Infants are prone to develop HUS in comparison to older children and adults, but its underlying mechanism remains unknown. Recent observations suggest that reactive oxygen species (ROS) and reactive nitrogen species (RNS) including nitric oxide (NO) may be involved in the pathogenesis of HUS. We therefore measured NO production by neutrophils prepared from infants (6-27 months old), children (5.3-11 years old) or adults (25-47 years old). The NO production was measured by a flow cytometric analysis with a fluorescent indicator (expressed as mean fluorescence intensity), and mRNA expression of inducible NO synthase (iNOS) was analyzed by reverse transcription-polymerase chain reaction (RT-PCR). The amount of NO produced was significantly lower in Stx-stimulated neutrophils prepared from infants (45.8 ± 23.3) than that in those from children (120.5 ± 81.5) or adults (127.7 ± 45.8) (n = 10 each group, P < 0.05). The expression level of iNOS mRNA was lower in Stx-stimulated neutrophils of the infants than the level in those of children or adults. In conclusion, Stx increased NO production in neutrophils probably via iNOS. Importantly, the degree of the Stx-mediated increase in NO production was lower in neutrophils of infants compared to those of children or adults, which may explain the higher incidence of HUS in infants. These results suggest that NO may contribute to the cellular defense mechanisms against Stx.
    The Tohoku Journal of Experimental Medicine 10/2012; 228(3):247-52. DOI:10.1620/tjem.228.247 · 1.35 Impact Factor
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    ABSTRACT: The administration of ceftriaxone is known to be associated with biliary pseudolithiasis, although the development of urolithiasis has only rarely been reported. We treated a young male with bacterial meningitis complicated by urinary precipitates composed of ceftriaxone-calcium salt, which prompted us to study whether ceftriaxone administration predisposes children to the formation of urinary precipitates. The case-control study reported here included 83 children with bacterial pneumonia aged from 3 months to 8.9 years. The children were divided into one group of 43 children who received ceftriaxone (group A) and a second group of 40 children who received amoxicillin (group B). Paired samples of serum and urine before and after treatment were obtained from the patients in each group. There were no significant differences in demographic characteristics and blood biochemistry between the groups. However, the mean urinary calcium to creatinine ratio (uCa/Cr; mg/mg) was significantly higher in group A patients than in group B patients after treatment (0.19 vs. 0.09, respectively; p < 0.001), and analysis of the paired urine samples revealed that the uCa/Cr significantly increased after treatment only in group A patients(p < 0.001). There was a weak but non-significant relationship between the dose of ceftriaxone and the uCa/Cr in group A (p = 0.10, r = 0.24). Our results are the first to demonstrate that ceftriaxone has the potential to significantly increase urinary excretion of calcium, which may be linked to ceftriaxone-related urolithiasis or sludge. We therefore suggest that it is worthwhile monitoring the uCa/Cr levels in patients on ceftriaxone as they may be at greater risk for developing large stones and renal damage.
    Pediatric Nephrology 04/2012; 27(4):605-9. DOI:10.1007/s00467-011-2038-z · 2.86 Impact Factor
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    ABSTRACT: Hyponatremia frequently occurs in Kawasaki disease (KD). The aim of this study was to investigate the effect of Na content of the intravenous immunoglobulin (IVIG) preparation on serum Na levels in KD. Seventy-eight subjects, of whom 27 had hyponatremia, were split up into two groups: group A receiving IVIG preparations containing high Na (0.9%) and group B receiving IVIG preparations containing trace Na. While the data before IVIG therapy revealed no significant differences in the median serum Na between the groups, an administration of IVIG preparations increased the serum levels of Na in group A (P < 0.01) but not in group B (P > 0.05). Furthermore, the median serum Na level was significantly higher in group A than that in group B (139.0 vs 137.0 mEq/L, respectively, P < 0.01). No significant difference was found in the prevalence of coronary artery lesions between the groups. In conclusion, we should keep it in mind that the IVIG products without Na have an adverse affect on hyponatremia in KD though their efficacy seems to be equivalent to those containing high Na.
    European Journal of Pediatrics 02/2010; 169(8):957-60. DOI:10.1007/s00431-010-1155-1 · 1.89 Impact Factor
  • Pediatric Nephrology 02/2010; 25(10):2187-8. DOI:10.1007/s00467-010-1490-5 · 2.86 Impact Factor
  • Nihon Shoni Jinzobyo Gakkai Zasshi 01/2010; 23(2):150-153. DOI:10.3165/jjpn.23.150