Masako Izawa
Boston Children's Hospital
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Featured researches published by Masako Izawa.
Clinical Pediatric Endocrinology | 2009
Keiko Aso; Masako Izawa; Asako Higuchi; Shinobu Kotoh; Yukihiro Hasegawa
Adrenal crises (ACs) sometimes progress rapidly and can be fatal. The aims of the present study were to reveal whether stress doses of glucocorticoids (SDGs) can prevent progression of severe ACs and to suggest a method of prevention, through analysis of its clinical features. We studied 24 severe ACs (nine patients) that occurred after diagnosis of primary or secondary adrenal insufficiency, retrospectively. The following information was analyzed: 1) whether SDGs were given orally and/or sc; 2) duration from the time when some symptoms started to the time when the patient came to the hospital; and 3) presence of hypoglycemia and electrolyte disturbance (hyponatremia, hyperkalemia). Eleven crises occurred after taking SDGs. Ten crises progressed within 3 h. Six of these ten crises progressed to severe ACs despite the fact that the patients took SDGs. Six crises were observed in association with hypoglycemia, and five of these six crises occurred in patients under 5 yr of age. Three of the six crises in association with hypoglycemia progressed to ACs within 3 h. Two of the three crises progressed to severe status within 3 h despite the fact that the patients took SDGs. Electrolyte disturbance was observed in only one crisis. In conclusion, SDGs cannot prevent progression of all ACs. Progression can be associated with hypoglycemia, particularly in patients under 5 yr of age. Patients should be given guidance on an ongoing basis on how to prevent ACs and hypoglycemia.
Clinical Pediatric Endocrinology | 2007
Masako Izawa; Keiko Aso; Asako Higuchi; Daisuke Ariyasu; Yukihiro Hasegawa
Auxological data is the gold standard index of the therapeutic condition in CYP21A2 deficiency over a long-range period, whereas urinary pregnanetriol for 24 h (PT) is variable for a shorter-range period. Ideal PT levels in comparison with auxological data have not been reported. The main purpose of this study was to analyze ideal PT values as an index of optimal control for CYP21A2 deficiency. First, inter-daily fluctuation of PT was analyzed in one participant. PT levels were distributed over a wide range of 0.44–14.7 mg/day (n=42) in this participant, suggesting that the therapeutic condition should be judged by multiple PT samples. Second, the therapeutic periods of 15 participants with CYP21A2 deficiency were classified using auxological data and Cushing-like symptoms, and the PT levels were analyzed in each period retrospectively. The 95% confidence intervals for the means of the PT levels in the excessive, good and poor control periods were 0.03–1.25 (n=26), 1.23–2.09 (n=116), and 5.35–8.37 (n=72) mg/m2/day, respectively. In conclusion, 1.2–2.1 mg/m2/day of PT values can be used as an index of optimal control in CYP21A2 deficiency.
Clinical Pediatric Endocrinology | 2009
Eri Suzuki; Makoto Yamada; Daisuke Ariyasu; Masako Izawa; Junko Miyamoto; Shinobu Koto; Yukihiro Hasegawa
The treatment for hypophosphatemic rickets in children includes phosphate and vitamin D preparations. In children, this regimen significantly improves symptoms, while a treatment for adult patients has not been established. We therefore investigated the clinical courses of 15 adult patients who discontinued therapy when final height was achieved in order to assess the necessity of treatment in adulthood. Thirteen patients developed symptomatic complications, including bone fractures. Among the 13, the 10 patients who restarted therapy all showed clinical improvement, and no side effects of treatment were observed. This study shows that there are some patients with hypophosphatemic osteomalacia who need continuous treatment during adulthood.
Endocrine Journal | 2017
Yukihiro Hasegawa; Daisuke Ariyasu; Masako Izawa; Junko Igaki-Miyamoto; Mami Fukuma; Megumi Hatano; Hiroko Yagi; Masahiro Goto
Estrogen replacement therapy in Turner syndrome should theoretically mimic the physiology of healthy girls. The objective of this study was to describe final height and bone mineral density (BMD) in a group of 17 Turner syndrome patients (group E) who started their ethinyl estradiol therapy with an ultra-low dosage (1-5 ng/kg/day) from 9.8-13.7 years. The subjects in group E had been treated with GH 0.35 mg/kg/week since the average age of 7.4 years. The 30 subjects in group L, one of the historical groups, were given comparable doses of GH, and conjugated estrogen 0.3125 mg/week ∼0.3125 mg/day was initiated at 12.2-18.7 years. The subjects in group S, the other historical group, were 21 patients who experienced breast development and menarche spontaneously. Final height (height gain < 2 cm/year) in group E was 152.4 ± 3.4 cm and the standard deviation (SD) was 2.02 ± 0.62 for Turner syndrome. The final height in group L was 148.5 ± 3.0 cm with a SD of 1.30 ± 0.55, which was significantly different from the values for group E. The volumetric BMD of group S (0.290 ± 0.026 g/cm3) was significantly different from that of group L or E (0.262 or 0.262 g/cm3 as a mean, respectively). This is the first study of patients with Turner syndrome where estrogen was administered initially in an ultra-low dose and then increased gradually. Our estrogen therapy in group E produced good final height but not ideal BMD.
Clinical Pediatric Endocrinology | 2008
Masako Izawa; Keiko Aso; Asako Higuchi; Daisuke Ariyasu; Yukihiro Hasegawa
Auxological data are the gold standard indexes of the therapeutic conditions in patients with CYP21 deficiency over long-term periods, whereas urinary pregnanetriol (PT) for 24 h has been used as an index for short-term periods. We previously reported that the range of 1.2–2.1 mg/m2/day of PT for 24 h (24-h PT) could be used as an index of optimal control in patients with CYP21 deficiency. The purpose of this study was to analyze the range of PT in the first morning urine samples (morning PT) as an index of optimal control in patients with CYP21 deficiency. First, the therapeutic periods of 15 participants (aged 2 yr and 5 mo to 17 yr and 4 mo) were classified into excessive, good or poor control periods using auxological data and Cushing-like symptoms, and 24-h PT levels were analyzed in each period, retrospectively. The 95% confidence intervals for the means of 24-h PT levels in the excessive, good and poor control periods were 0.24–2.24 (n=25), 2.88–4.92 (n=114) and 13.26–21.28 (n=72) mg/gCr, respectively. Subsequently, 24-h PT and morning PT levels collected on the same day were analyzed for 14 participants (aged 9 mo to 29 yr and 8 mo). There was a significant correlation between the above two PT levels (n=25, p<0.0001). When the 24-h PT range of the good control period, 2.88–4.92 mg/gCr, was adjusted by the correlation, the ideal morning PT range became 2.15–3.34 mg/gCr. In conclusion, a morning PT in the range of 2.2–3.3 mg/gCr can be used as an index of optimal control in patients with CYP21 deficiency.
Endocrine Journal | 2008
Uiko Kaku; Kaori Kameyama; Masako Izawa; Makoto Yamada; Junko Miyamoto; Takashi Suzuki; Hironobu Sasano; Yukihiro Hasegawa
Endocrine Journal | 2011
Junko Igaki; Makoto Yamada; Yuji Yamazaki; Shinobu Koto; Masako Izawa; Daisuke Ariyasu; Eri Suzuki; Hisashi Hasegawa; Yukihiro Hasegawa
Endocrine Journal | 2010
Keiko Aso; Shinobu Koto; Asako Higuchi; Daisuke Ariyasu; Masako Izawa; Junko Igaki; Yukihiro Hasegawa
Endocrine Journal | 2016
Ryusaku Matsumoto; Masako Izawa; Hidenori Fukuoka; Genzo Iguchi; Yukiko Odake; Kenichi Yoshida; Hironori Bando; Kentaro Suda; Hitoshi Nishizawa; Michiko Takahashi; Naoko Inoshita; Shozo Yamada; Wataru Ogawa; Yutaka Takahashi
54th Annual ESPE | 2015
Ryojun Takeda; Kentaro Miyai; Masaki Takagi; Masahiro Goto; Daisuke Ariyasu; Masako Izawa; Junko Igaki; Eri Suzuki; Yoshie Nakamura; Yukihiro Hasegawa