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Dive into the research topics where Ayako Nagai is active.

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Featured researches published by Ayako Nagai.


Pediatric Reports | 2010

Hyperuricemia in obese children and adolescents: the relationship with metabolic syndrome

Li Tang; Masaru Kubota; Ayako Nagai; Kimiyo Mamemoto; Masakuni Tokuda

The prevalence of hyperuricemia in obese children and adolescents and its association with metabolic syndrome are largely unknown. The objective of our study was to characterize hyperuricemia in relation to metabolic syndrome in Japanese children and adolescents with obesity. Between 2005 and 2008, we performed a cross-sectional study of 1,027 obese children and adolescents aged 6–14 years. Based on the reference value of serum uric acid we had established previously, hyperuricemia was defined as one standard deviation over the mean value at each age. The diagnosis of metabolic syndrome was made based on the Japanese criteria for children. A total of 213 children and adolescents (20.7%) was found to have hyperuricemia. The prevalence of hyperuricemia was significantly higher in the male gender and older age group. Sixty-five out of 213 subjects with hyperuricemia (30.5%) had metabolic syndrome, whereas 111 out of 814 subjects without hyperuricemia (13.6%) had metabolic syndrome. The most common abnormal component of metabolic syndrome was triglyceride, followed by diastolic blood pressure, systolic blood pressure, fasting blood glucose, and HDL-cholesterol. Such a tendency was almost identical between the two groups. We concluded that considering the association between hyperuricemia and metabolic syndrome in obese Japanese children and adolescents, the role of hyperuricemia in metabolic syndrome should receive more attention, beginning in early childhood.


Nucleosides, Nucleotides & Nucleic Acids | 2011

Investigation on Hyperuricemia in Children with Obesity or Various Pediatric Disorders

Masaru Kubota; Ayako Nagai; Li Tang; Masakuni Tokuda

The present study aims at investigating the frequency and characteristics of hyperuricemia in both obese and sick children. First, we established our own reference values for serum uric acid (UA), since UA values are highly dependent upon age. In the analysis of 328 samples consisting of six different age groups: <1, 1–3, 4–6, 7–9, 10–12, and 13–15 years, the mean values for UA were found to increase significantly with an increase of age. A significant sex difference was observed only in the age group of 13–15 years. Hyperuricemia was defined as the values over the mean value plus 2 standard deviations for each age group. Next, we examined the frequency of hyperuricemia in 1,687 obese children aged 6–15 years and its relation to metabolic syndrome (MetS). A total of 328 children (19.4%) were found to have hyperuricemia. Among them, 98 children (29.9%) had MetS, whereas 197 (14.5%) out of 1,359 children without hyperuricemia had MetS. Finally, the frequency of hyperuricemia in sick patients was investigated using 13,675 samples from 9,405 patients. Hyperuricemia was seen in 348 (3.7%) patients after excluding redundant samples. The number of patients with hyperuricemia was higher in males than in females. The most common disorder causing hyperuricemia was gastroenteritis, followed by respiratory tract infection and cardiac diseases. This first comprehensive study of childhood hyperuricemia is useful for considering its relationship with hyperuricemia and life-style-related disorders occurring in adulthood.


Asia Pacific Journal of Clinical Nutrition | 2013

Factors associated with exclusive breastfeeding in low birth weight infants at NICU discharge and the start of complementary feeding

Kimiyo Mamemoto; Masaru Kubota; Ayako Nagai; Yukihiro Takahashi; Tomoyuki Kamamoto; Hideki Minowa; Hajime Yasuhara

The aim of the present study was to clarify clinical factors in low birth weight infants and their mothers associated with exclusive breastfeeding at both neonatal intensive care unit (NICU) discharge and the start of complementary feeding. One hundred and fifteen low birth weight children and 98 mothers attending the follow-up clinic of two tertiary NICUs in Nara prefecture (Japan), between June and September, 2011, were enrolled. The relationship between the feeding categories at NICU discharge or the start of complementary feeding, and clinical factors of the mothers and low birth weight infants collected by either their charts or a face-to-face interview was analyzed. The prevalence of exclusive breastfeeding was 22.6% at NICU discharge, and 15.7% at the start of complementary feeding. In logistic analysis, exclusive breastfeeding at NICU discharge was associated with mothers younger age at delivery and an earlier start of oral nutrition. Among 26 exclusively breast-fed infants at NICU discharge, fifteen infants (57.7%) were still being exclusively breast-fed at the start of complementary feeding. In low birth weight infants, a shorter stay at NICU and an earlier start of oral nutrition were associated factors with exclusive breastfeeding at the start of complementary feeding. None of maternal factors were found to be associated with exclusive breastfeeding at the start of complementary feeding. Conclusively, starting of oral nutrition as early as possible is thought to be crucial for introducing exclusive breastfeeding in low birth weight infants both at NICU discharge and the start of complementary feeding.


Pediatrics International | 2013

Adipocytokines in childhood cancer survivors and correlation with metabolic syndrome components.

Chiaki Kojima; Masaru Kubota; Ayako Nagai; Souichi Adachi; Ken-ichiro Watanabe; Tatsutoshi Nakahata

Although there are several studies on the prevalence of metabolic syndrome (MetS) in childhood cancer survivors (CCS), the association between MetS components and serum adipocytokine level has not been elucidated.


Brain & Development | 2015

Carnitine in severely disabled patients: Relation to anthropometric, biochemical variables, and nutritional intake

Yoko Takeda; Masaru Kubota; Hinako Sato; Ayako Nagai; Yukie Higashiyama; Hajime Kin; Chiharu Kawaguchi; Kiyotaka Tomiwa

BACKGROUND Carnitine plays a pivotal role in a variety of cellular functions. Carnitine deficiency often occurs in severely disabled patients, especially under valproic acid administration. However, the possible causative factors underlying carnitine deficiency have not been fully identified. The present study aimed at clarifying the association of various anthropometric and biochemical variables, including dietary intake of carnitine, with carnitine levels in severely disabled patients. METHODS Twenty-six severely disabled patients (mean age: 14.1 years; s.d. 7.8) were enrolled. Plasma carnitine levels were evaluated by an enzyme cycling assay. Estimation of the dietary intake of carnitine was made based on dietary records over a 3-day period. RESULTS Plasma total and free carnitine levels in patients were significantly lower than those in controls obtained from the previous report. However, the ratios of free carnitine to total carnitine did not change significantly. Free carnitine levels were well correlated with a nutritional intake of carnitine. Administration of not only valproic acid but also other anti-epileptic drugs was found to cause a significant decrease of free carnitine levels after adjusting the nutritional intake of carnitine. Among various anthropometric or biochemical variables, albumin and uric acid showed a significant correlation with free carnitine levels. CONCLUSIONS Physicians should be aware of the fact that severely disabled patients are at risk for carnitine deficiency even in the absence of valproic acid administration, and pay more attention to the nutritional intake of carnitine.


International Journal of Pediatrics | 2010

Fatigue status in relation to lifestyle in healthy Japanese adolescents.

Ning Zou; Masaru Kubota; Eriko Kuruma; Chiaki Kojima; Ayako Nagai

In order to investigate the prevalence of physical, mental, and chronic fatigue syndrome-(CFS-) related fatigue and its relation to lifestyle, 1,225 adolescents (591 males, 634 females) aged 11 to 16 years were asked to complete a self-reported questionnaire on fatigue status and lifestyle in the past one month. There was no gender difference in physical and mental fatigue scores, but CFS-related scores were significantly higher in females than in males. These scores were found to increase with the increase of age. After adjusting for age and gender, multiple regression analysis showed that physical and mental fatigue scores were associated with sleeping hours, extracurricular sports activity, food balance, the frequencies of snacks between regular meals, intake of sugar-sweetened beverages, and visits to the nurses room. This paper is the first large cross-sectional study on fatigue in healthy adolescents in Japan, albeit there were numerous such studies in Western countries.


Pediatrics International | 2012

Fatigue in survivors of childhood acute lymphoblastic and myeloid leukemia in Japan

Ayako Nagai; Ning Zou; Masaru Kubota; Chiaki Kojima; Souichi Adachi; Ikuya Usami; Masayuki Okada; Akihiko Tanizawa; Keigo Hamahata; Kousaku Matsubara; Manryoku Higuchi; Masue Imaizumi

Background:  Fatigue in cancer survivors is a serious problem in pediatric oncology, but reports on this issue are limited, especially in Asian countries.


Nucleosides, Nucleotides & Nucleic Acids | 2011

Hyperuricemia in Pediatric Malignancies Before Treatment

Ayako Nagai; Masaru Kubota; Li Tang; Souichi Adachi; Ikuya Usami; Kousaku Matsubara

The objective of this study was to clarify the prevalence and characteristics of hyperuricemia in various pediatric malignancies before the initiation of treatment. We conducted a retrospective analysis of 119 children with various newly diagnosed malignancies between April 2000 and March 2010. On the basis of the reference values previously established in our laboratory, hyperuricemia was defined as uric acid (UA) levels above 2 standard deviations (s.d.) over the mean values at each age. Thirty-six patients (30.3%) showed hyperuricemia. Hyperuricemia was more common in male patients (36.8%) than in female patients (21.6%). The prevalence of hyperuricemia was highest in patients with lymphoma followed by those with acute lymphoblastic leukemia (ALL). When the study population was divided into hyperuricemia-negative and -positive populations, blood urea nitrogen, creatinine, and lactate dehydrogenase levels, and white blood cell counts (only in leukemia) were found to be significantly higher in the latter group by a univariate analysis. This study highlights useful information for identifying patients with malignancies at risk for tumor lysis syndrome (TLS) before starting chemotherapy.


Acta Paediatrica | 2014

Longitudinal study of thinness from birth to early childhood: the association with parental thinness.

Rena Kato; Masaru Kubota; Yukie Higashiyama; Ayako Nagai

Epidemiological research on thinness, particularly in early childhood, is limited. This study tracked thin children aged 5 years back to birth, compared them with normal‐weight children and investigated the relationship with parental thinness.


Asia Pacific Journal of Clinical Nutrition | 2014

Normal taste acuity and preference in female adolescents with impaired 6-n-propylthiouracil sensitivity

Ayako Nagai; Masaru Kubota; Midori Sakai; Yukie Higashiyama

This study was conducted to determine the relationship between 6-n-propylthiouracil sensitivity and taste characteristics in female students at Nara Womens University. Participants (n=135) were screened for 6-npropylthiouracil sensitivity using a taste test with 0.56 mM 6-n-propylthiouracil solution, and the sensitivity was confirmed by an assay for the bitter-taste receptor gene, TAS2R38. Based on the screening results, 33 6-npropylthiouracil tasters and 21 non-tasters were enrolled. The basic characteristics that are thought to influence taste acuity, including body mass index, saliva volume and serum micronutrient concentrations (iron, zinc and copper), were similar between the two groups. In an analysis using a filter-paper disc method, there were no differences in the acuity for four basic tastes (sweet, salty, sour and bitter) between 6-n-propylthiouracil tasters and non-tasters. In addition, the taste preference for the four basic tastes as measured by a visual analogue scale was also comparable between the two groups. This is the first study to demonstrate that 6-n-propylthiouracil nontasters have taste sensitivity for the four basic tastes similar to that in 6-n-propylthiouracil tasters, at least in female adolescents, as measured by the gustatory test using a filter-paper disc method.

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Yuka Yasui

Nara Women's University

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Li Tang

Nara Women's University

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Ning Zou

Nara Women's University

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