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Dive into the research topics where Tetsuya Kunikata is active.

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Featured researches published by Tetsuya Kunikata.


Pediatric Research | 2000

Chemiluminescence because of the production of reactive oxygen species in the lungs of newborn piglets during resuscitation periods after asphyxiation load.

Masatoshi Kondo; Susumu Itoh; Kenichi Isobe; Mayumi Kondo; Tetsuya Kunikata; Tadashi Imai; Shoju Onishi

Reactive oxygen species are regarded as a possible cause of many diseases. However, there are few reports offering in vivo and in situ proof of the direct involvement of reactive oxygen species in the pathogenesis of disease. In the present study, the luciferin derivative 2-methyl-6-[4-methoxyphenyl]-3,7-dihydroimidazo [1,2-α] pyrazin-3-one (MCLA) was used to investigate the amount of reactive oxygen species produced during resuscitation after asphyxiation load in newborn piglets. The animals were first asphyxiated by stopping respiration for 4 min, and then resuscitated using 100% oxygen. When physiologic saline solution was administered, lung surface chemiluminescence had a mean value of 2, whereas with MCLA, a maximum luminescence of 580 was seen, demonstrating the possibility of measuring reactive oxygen species in vivo and in situ using MCLA. In a group in which resuscitation after acute asphyxiation was performed with 21% oxygen, the relative maximum lung surface chemiluminescence was 59.5 ± 39, whereas that for a group in which resuscitation was performed using 100% oxygen had a significantly higher value of 186.1 ± 72.5. Consequently, ventilation and especially resuscitation by 100% oxygen may represent a potential danger.


Neonatology | 2011

Changes in skin and subcutaneous perfusion in very-low-birth-weight infants during the transitional period.

Akio Ishiguro; Takashi Sekine; Keiji Suzuki; Clara Kurishima; Shoichi Ezaki; Tetsuya Kunikata; Hisanori Sobajima; Masanori Tamura

Background: Conventional parameters of circulation that are routinely used in neonatal intensive care units, including blood pressure, have been reported to be inadequate in improving prognosis of very-low-birth-weight (VLBW) infants. Recently, the importance of evaluating the blood flow to each organ, including both vital and nonvital organs, has been increasingly recognized. Objectives: To study the changes in peripheral perfusion occurring in VLBW infants of less than 32 weeks’ gestation during the extrauterine transitional period. Methods: In 32 VLBW infants of less than 32 weeks’ gestation, forehead blood flow (FBF) and lower-limb blood flow (LBF) were measured for 48 h after birth using a novel laser Doppler flowmeter, and the indices of vascular resistance were estimated. Superior vena cava (SVC) blood flow was measured by echocardiography. Changes in these variables of circulation as well as the correlations were evaluated. Results: Both FBF and LBF significantly increased at 24 h, while the SVC flow remained unchanged over the same period. Both forehead and lower-limb vascular resistance indices significantly decreased at 24 h. LBF was negatively and positively correlated with estimated upper body vascular resistance and SVC flow, respectively. Conclusions: The increase in the peripheral blood flow along with the decrease in the peripheral vascular resistance indices, without an increase in the systemic blood flow at 24 h of age, indicated vasodilation in skin and subcutaneous tissue during the transitional period in VLBW infants. FBF and LBF can be useful parameters as indicators of both peripheral and systemic circulation.


Allergology International | 2012

Prophylactic Probiotics Reduce Cow's Milk Protein Intolerance in Neonates after Small Intestine Surgery and Antibiotic Treatment Presenting Symptoms That Mimics Postoperative Infection

Shoichi Ezaki; Kanako Itoh; Tetsuya Kunikata; Keiji Suzuki; Hisanori Sobajima; Masanori Tamura

BACKGROUND To examine occurrence of cows milk protein intolerance (CMPI) in newborns that underwent small intestine surgery and the clinical profiles of those newborns with postoperative CMPI, and to evaluate the preventive effects of probiotics on CMPI. METHODS We retrospectively reviewed from 2000 to 2009, a total of 30 newborns required surgery on their small intestines. All of these patients had received antibiotics to prevent postoperative infection. Since 2005 we adopted a protocol of targeted probiotic therapy prophylaxis. RESULTS Eighteen patients received probiotic therapy, while twelve did not. One infant among those eighteen patients and eight patients among those twelve developed CMPI, a significantly lower rate for the group with probiotic therapy than that without it (p < 0.001). Patients with positive cultures for gram positive and gram negative organisms increased in number before and after surgery but then decreased after probiotics treatment. Poor weight gain, gastrointestinal symptoms, and rise in C reactive protein (CRP) levels were observed in all of those nine CMPI patients. Specific IgE antibodies were elevated in four of the nine subjects, and total IgE levels were elevated in seven of them. All CMPI patients had increased level of CRP without proven infections. CONCLUSIONS CMPI was induced in newborns after surgery on their small intestines and antibiotics treatment with presentation of symptoms that mimic postoperative infection. Development of CMPI in this population possibly involves disruption of intestinal flora. Administration of probiotics can reduce the incidence of CMPI after small intestine surgery. The elevated CRP level may be useful in the diagnosis of CMPI.


Pediatric Research | 2012

Effect of dopamine on peripheral perfusion in very-low-birth-weight infants during the transitional period

Akio Ishiguro; Keiji Suzuki; Takashi Sekine; Hidenori Kawasaki; Kanako Itoh; Masayo Kanai; Shoichi Ezaki; Tetsuya Kunikata; Hisanori Sobajima; Masanori Tamura

Introduction:Dopamine is one of the most frequently used inotropic drugs in neonatal intensive care units (NICUs); however, it does not seem to improve outcomes in premature infants. Given that the ultimate aim of cardiovascular management is to stabilize and maintain organ perfusion, an understanding of dopamine’s effects on organ blood flow will help in judging when to use dopamine and how to titrate the dosage. Such an approach can lead to improved outcomes. This study aimed to evaluate the effects of dopamine on peripheral perfusion in very-low-birth-weight (VLBW) infants within 72 h of birth.Methods:This prospective observational study identified and sampled 44 instances of initiation of dopamine treatment or increase in dopamine dose in 29 VLBW infants. Blood pressure, heart rate, and skin and subcutaneous blood flow were measured and compared before and after each instance.Results:Blood pressure and skin and subcutaneous blood flow in the lower limbs increased after initiation of dopamine treatment or after dose increase.Discussion:Dopamine increases blood pressure as well as skin and subcutaneous blood flow in VLBW infants despite its supposed vasoconstrictive action, indicating that it increases both perfusion pressure and blood flow and is devoid of overwhelming peripheral vasoconstrictive effects.


Journal of Pediatric Surgery | 2011

Rare case of disseminated neonatal zygomycosis mimicking necrotizing enterocolitis with necrotizing fasciitis.

Seiichiro Inoue; Akio Odaka; Daijo Hashimoto; Reiichi Hoshi; Clara Kurishima; Tetsuya Kunikata; Hisanori Sobajima; Masanori Tamura; Jun-ichi Tamaru

A set of monochorionic male twins presented with intestinal perforation. The smaller twin was diagnosed with necrotizing enterocolitis followed by sepsis, disseminated intravascular coagulation, and necrotizing fasciitis of the abdominal wall. The infant died on the fourth day after surgery, 16 days after birth. Surgical specimens and autopsy revealed a disseminated zygomycotic infection. Gastrointestinal zygomycosis followed by necrotizing fasciitis in premature infants is a rare condition and mimics necrotizing enterocolitis clinically. Necrotizing fasciitis after gastrointestinal zygomycosis in premature infants is considered a poor prognostic sign. Gastrointestinal zygomycosis should be considered in the differential diagnosis of necrotizing enterocolitis.


Pediatrics International | 2015

Current incidence of clinical kernicterus in preterm infants in Japan.

Ichiro Morioka; Hajime Nakamura; Tsubasa Koda; Tomoyuki Yokota; Hitoshi Okada; Yoshinori Katayama; Tetsuya Kunikata; Masatoshi Kondo; Makoto Nakamura; Shigeharu Hosono; Saneyuki Yasuda; Naoki Yokoyama; Hiroshi Wada; Susumu Itoh; Masahisa Funato; Yoshitada Yamauchi; Yong Kye Lee; Masahiko Yonetani

Clinical kernicterus in preterm infants has recently been reported in Japan, diagnosed on the basis of clinical findings during the neonatal and infancy periods. We investigated the incidence of clinical kernicterus in preterm infants <30 weeks gestational age (GA) based on a nationwide survey conducted in 233 certified educational facilities for neonatologists. The numbers of infants admitted and infants who died within 14 days after birth during 2011, and the number of infants who subsequently developed clinical kernicterus, were recorded. A total of 2720 infants were analyzed, representing 59% (2720/4623) of all preterm live births <30 weeks GA in Japan in 2011. Of these, 159 (5.8%) died within 14 days after birth, similar to the national rate. Five infants developed clinical kernicterus in infancy (5/2720, 0.18%). The current incidence of clinical kernicterus in Japan is therefore estimated at 1.8 per 1000 live births <30 weeks GA.


Neonatology | 2009

Levels of Catecholamines, Arginine Vasopressin and Atrial Natriuretic Peptide in Hypotensive Extremely Low Birth Weight Infants in the First 24 Hours after Birth

Shoichi Ezaki; Keiji Suzuki; Clara Kurishima; Masumi Miura; Koichi Moriwaki; Hiroshi Arakawa; Tetsuya Kunikata; Hisanori Sobajima; Masanori Tamura

Background: Extremely low birth weight infants (ELBWI) often suffer from severe hypotension in the early neonatal period. However, few previous studies have ever revealed plasma levels of vasoactive substances which regulate the cardiovascular system in ELBWI. Objective: To study plasma levels of vasoactive substances in ELBWI with hypotension during the first 24 h of life. Methods: 22 ELBWI with hypotension (gestational age 26.4 ± 1.9 weeks; birth weight 751 ± 135 g) were involved in the study. After initial volume therapy, the infants were arbitrarily divided into two groups depending on requirement of dopamine dosage: severe hypotension group (SH; dopamine >10 μg/kg/min, n = 9) and mild hypotension group (MH; dopamine ≤10 μg/kg/min, n = 13). Plasma levels of dopamine, norepinephrine, epinephrine, arginine vasopressin, and atrial natriuretic peptide were measured at admission and at 24 h after birth. Results: Infants in the SH group had higher plasma dopamine than infants in the MH group both at admission (median; range: 14,410; 224–46,770 vs. 7,900; 32–21,220 pg/ml, p < 0.05) and at 24 h (80,920; 494–146,100 vs. 25,680; 10,130–63,180 pg/ml; p < 0.05). The norepinephrine/dopamine ratio (median; range) was lower in the SH group than in the MH group at admission (0.3; 0.0–1.0 vs. 1.1; 0.1–25.1; p < 0.01). Plasma levels of atrial natriuretic peptide or arginine vasopressin were not different between the two groups. Conclusions: ELBWI with SH may have decreased conversion of dopamine to norepinephrine. We speculate that this mechanism may contribute to development of SH in ELBWI.


OA Autism | 2013

Socio-emotional development evaluated by Behaviour Output analysis for Quantitative Emotional State Translation (BOUQUET): Towards early diagnosis of individuals with developmental disorders

Mamiko Koshiba; Shun Nakamura; Koki Mimura; Aya Senoo; Genta Karino; S Amemiya; T Miyaji; Tetsuya Kunikata; Hideo Yamanouchi

For citation purposes: Koshiba M, Nakamura S, Mimura K, Senoo A, Karino G, Amemiya S, et al. Socio-emotional development evaluated by Behaviour Output analysis for Quantitative Emotional State Translation (BOUQUET): towards early diagnosis of individuals with developmental disorders. OA Autism 2013 Jul 21;1(2):18. Co m pe tin g in te re st s: n on e de cl ar ed . C on fli ct o f i nt er es ts : n on e de cl ar ed .


Pediatrics International | 2015

Survey of delivery room resuscitation practices at tertiary perinatal centers in Japan

Shigeharu Hosono; Masanori Tamura; Tetsuya Kunikata; Masaki Wada; Isao Kusakawa; Satoshi Ibara

The aim of this study was to determine the current neonatal resuscitation practices for term infants in Japan, immediately before the 2010 publication of the international neonatal resuscitation consensus.


Pediatrics International | 2000

Formation of propentdyopents and biliverdin, oxidized metabolites of bilirubin, in infants receiving oxygen therapy.

Tetsuya Kunikata; Susumu Itoh; Takashi Ozaki; Masatoshi Kondo; Kenichi Isobe; Shoju Onishi

Abstract Background: Bilirubin has antioxidative effects. When bilirubin reacts with reactive oxygen species, oxidized metabolites of bilirubin are formed, such as biliverdin and propentdyopents. A decrease in serum bilirubin concentration and an increase in serum and urinary oxidized metabolites of bilirubin may indicate the protective action of bilirubin against reactive oxygen species.

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Masanori Tamura

Saitama Medical University

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Genta Karino

Tokyo University of Agriculture and Technology

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Hideo Yamanouchi

Saitama Medical University

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Hisanori Sobajima

Saitama Medical University

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Mamiko Koshiba

Saitama Medical University

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Shun Nakamura

Tokyo University of Agriculture and Technology

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Susumu Itoh

Tokyo University of Science

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Koki Mimura

Tokyo University of Agriculture and Technology

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Masatoshi Kondo

Tokyo Institute of Technology

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