医学部 内分泌・代謝・糖尿病内科学

fujisawa haruki

  (藤沢 治樹)

Profile Information

Affiliation
School of Medicine Faculty of Medicine, Fujita Health University
Degree
医学博士(名古屋大学)

J-GLOBAL ID
201801006704331319
researchmap Member ID
7000023604

Research History

 1

Education

 2

Papers

 32
  • Athanasia Stoupa, Monica Malheiros Franca, Maha Abdulhadi-Atwan, Haruki Fujisawa, Manassawee Korwutthikulrangsri, Isis Marchand, Gabrielle Polak, Jacques Beltrand, Michel Polak, Dulanjalee Kariyawasam, Xiao-Hui Liao, Chantalle Raimondi, Connolly Steigerwald, Nicolas J Abreu, Andrew J Bauer, Aurore Carré, Charit Taneja, Allison Bauman Mekhoubad, Alexandra M Dumitrescu
    Genetics in medicine : official journal of the American College of Medical Genetics, 101280-101280, Sep 21, 2024  
    PURPOSE: Defects in the gene encoding selenocysteine insertion sequence binding protein 2, SECISBP2, result in global impaired selenoprotein synthesis manifesting a complex syndrome with characteristic serum thyroid function tests due to impaired thyroid hormone metabolism. Knowledge about this multisystemic defect remains limited. METHODS: Genetic and laboratory investigations were performed in affected members from six families presenting with short stature, failure to thrive. RESULTS: Four probands presented a complex neurodevelopmental profile, including absent speech, autistic features, and seizures. Pediatric neurological evaluation prompted genetic investigations leading to the identification of SECISBP2 variants before knowing the characteristic thyroid tests in two cases. Thyroid hormone treatment improved motor development, while speech and intellectual impairments persisted. This defect poses great diagnostic and treatment challenges for clinicians, as illustrated by a case that escaped detection for 20years, as SECISBP2 was not included in the neurodevelopmental genetic panel, and his complex thyroid status prompted anti-thyroid treatment instead. CONCLUSION: This syndrome uncovers the role of selenoproteins in humans. The severe neurodevelopmental disabilities manifested in four patients with SECISBP2 deficiency highlight an additional phenotype in this multisystem disorder. Early diagnosis and treatment are required, and long-term evaluation will determine the full spectrum of manifestations and the impact of therapy.
  • Yuka Natsuki, Yuki Nagata, Toshiki Nagasaki, Mari Morimoto, Norikazu Toi, Masafumi Kurajoh, Tomoaki Morioka, Tetsuo Shoji, Yasuo Imanishi, Naoko Iwata, Haruki Fujisawa, Atsushi Suzuki, Yoshihisa Sugimura, Masanori Emoto
    Endocrine journal, Aug 27, 2024  
    Coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2, and various complications have been reported. Furthermore, there have been increasing reports of endocrinopathy related to COVID-19 following the pandemic. We report a 49-year-old healthy woman who developed rapid onset of polydipsia and polyuria three weeks after COVID-19. Laboratory tests indicated low urine osmolarity and increased serum osmolarity, and antidiuretic hormone (ADH) was undetectable. Urine osmolality remained low with water deprivation. Similarly, plasma ADH responses to hypertonic-saline infusion were blunted and urine osmolality increased in response to desmopressin. There was no clear evidence of anterior pituitary dysfunction. T1-weighted magnetic resonance imaging (MRI) showed pituitary stalk thickening and absence of posterior pituitary bright signal spots, suggesting the presence of hypophysitis. Based on these results, we made a probable diagnosis of lymphocytic infundibulo-neurohypophysitis (LINH) which have caused central diabetes insipidus. Positive findings for serum anti-rabphilin-3A antibodies, reported as a potential diagnostic marker for LINH, were also noted. Following oral desmopressin administration, polydipsia and polyuria were quickly improved, though treatment with desmopressin was still required over four months. This is the first report of a patient with a probable diagnosis of LINH after COVID-19 who tested positive for anti-rabphilin-3A antibodies. Positive findings for those antibodies suggest that pituitary dysfunction associated with COVID-19 is hypophysitis involving an abnormal immune mechanism. The presence of anti-rabphilin-3A antibodies may be useful as a non-invasive diagnostic marker of LINH and potentially serve as a valuable diagnostic aid in cases of LINH associated with COVID-19.
  • Haruki Fujisawa, Takashi Watanabe, Okiru Komine, Sachiho Fuse, Momoka Masaki, Naoko Iwata, Naoya Murao, Yusuke Seino, Hideyuki Takeuchi, Koji Yamanaka, Makoto Sawada, Atsushi Suzuki, Yoshihisa Sugimura
    Free radical biology & medicine, Aug 16, 2024  
    Hyponatremia is the most common clinical electrolyte disorder. Chronic hyponatremia has been recently reported to be associated with falls, fracture, osteoporosis, neurocognitive impairment, and mental manifestations. In the treatment of chronic hyponatremia, overly rapid correction of hyponatremia can cause osmotic demyelination syndrome (ODS), a central demyelinating disease that is also associated with neurological morbidity and mortality. Using a rat model, we have previously shown that microglia play a critical role in the pathogenesis of ODS. However, the direct effect of rapid correction of hyponatremia on microglia is unknown. Furthermore, the effect of chronic hyponatremia on microglia remains elusive. Using microglial cell lines BV-2 and 6-3, we show here that low extracellular sodium concentrations (36 mmol/L decrease; LS) suppress Nos2 mRNA expression and nitric oxide (NO) production of microglia. On rapid correction of low sodium concentrations, NO production was significantly increased in both cells, suggesting that acute correction of hyponatremia partly directly contributes to increased Nos2 mRNA expression and NO release in ODS pathophysiology. LS also suppressed expression and nuclear translocation of nuclear factor of activated T cells-5 (NFAT5), a transcription factor that regulates the expression of genes involved in osmotic stress. Furthermore, overexpression of NFAT5 significantly increased Nos2 mRNA expression and NO production in BV-2 cells. Expressions of Nos2 and Nfat5 mRNA were also modulated in microglia isolated from cerebral cortex in chronic hyponatremia model mice. These data indicate that LS modulates microglial NO production dependent on NFAT5 and suggest that microglia contribute to hyponatremia-induced neuronal dysfunctions.
  • Hiroki Takizawa, Hiromasa Goto, Toyoyoshi Uchida, Shuhei Aoyama, Haruki Fujisawa, Naoko Iwata, Atsushi Suzuki, Yoshihisa Sugimura, Hirotaka Watada
    BMC endocrine disorders, 24(1) 143-143, Aug 6, 2024  
    BACKGROUND: Arginine vasopressin deficiency (AVP-D) can occur due to various conditions, so clarifying its cause is important for deciding treatment strategy. Although several cases of AVP-D following coronavirus disease 2019(COVID-19) infection or COVID-19 vaccination have been reported, the diagnosis of the underlying disease has not been reported in most cases. CASE PRESENTATION: A 75-year-old woman who presented with polydipsia and polyuria 9 weeks after contracting COVID-19 and 5 weeks after receiving the SARS-CoV-2 vaccination, leading to the final diagnosis of AVP-D 8 months after the first appearance of symptoms. Interestingly, pituitary magnetic resonance imaging (MRI) still revealed stalk enlargement frequently observed in patients with SARS-CoV-2 vaccination-induced AVP-D. Although this finding could not rule out any malignancies, we additionally measured anti-rabphilin-3A antibodies, a known marker for lymphocytic infundibulo-neurohypophysitis (LINH), and found that the results were positive, strongly suggesting LINH as the cause of this disease. Thus, we avoided pituitary biopsy. At the follow-up MRI conducted 12 months after the initial consultation, enlargement of the pituitary stalk was still observed. CONCLUSION: We experienced a case with LINH probably induced by SARS-CoV-2 vaccination. In SARS-CoV-2 vaccination-related LINH, unlike typical LINH, there is a possibility of persistent pituitary stalk enlargement on MRI images for an extended period, posing challenges in differential diagnosis from other conditions. Pituitary stalk enlargement and positive anti-rabphilin-3A antibodies may help in the diagnosis of AVP-D induced by SARS-CoV-2 vaccination.
  • Koki Nishida, Shinji Ueno, Yusuke Seino, Shihomi Hidaka, Naoya Murao, Yuki Asano, Haruki Fujisawa, Megumi Shibata, Takeshi Takayanagi, Kento Ohbayashi, Yusaku Iwasaki, Katsumi Iizuka, Shoei Okuda, Mamoru Tanaka, Tadashi Fujii, Takumi Tochio, Daisuke Yabe, Yuuichiro Yamada, Yoshihisa Sugimura, Yoshiki Hirooka, Yoshitaka Hayashi, Atsushi Suzuki
    Nutrients, 16(14) 2270-2270, Jul 14, 2024  
    (1) Background: Proglucagon-derived peptides (PDGPs) including glucagon (Gcg), GLP-1, and GLP-2 regulate lipid metabolism in the liver, adipocytes, and intestine. However, the mechanism by which PGDPs participate in alterations in lipid metabolism induced by high-fat diet (HFD) feeding has not been elucidated. (2) Methods: Mice deficient in PGDP (GCGKO) and control mice were fed HFD for 7 days and analyzed, and differences in lipid metabolism in the liver, adipose tissue, and duodenum were investigated. (3) Results: GCGKO mice under HFD showed lower expression levels of the genes involved in free fatty acid (FFA) oxidation such as Hsl, Atgl, Cpt1a, Acox1 (p < 0.05), and Pparα (p = 0.05) mRNA in the liver than in control mice, and both FFA and triglycerides content in liver and adipose tissue weight were lower in the GCGKO mice. On the other hand, phosphorylation of hormone-sensitive lipase (HSL) in white adipose tissue did not differ between the two groups. GCGKO mice under HFD exhibited lower expression levels of Pparα and Cd36 mRNA in the duodenum as well as increased fecal cholesterol contents compared to HFD-controls. (4) Conclusions: GCGKO mice fed HFD exhibit a lesser increase in hepatic FFA and triglyceride contents and adipose tissue weight, despite reduced β-oxidation in the liver, than in control mice. Thus, the absence of PGDP prevents dietary-induced fatty liver development due to decreased lipid uptake in the intestinal tract.

Misc.

 110
  • 平塚 いづみ, 小出 晴香, 角沖 寛聡, 中島 優華, 布施 裟智穂, 公文 尚子, 田中 知香, 藤沢 治樹, 垣田 彩子, 鈴木 敦詞
    日本老年医学会雑誌, 60(4) 463-463, Oct, 2023  
  • 有馬 寛, 大月 道夫, 蔭山 和則, 高橋 裕, 田原 重志, 西山 充, 槙田 紀子, 水野 晴夫, 山田 正信, 有安 宏之, 井下 尚子, 井野元 智恵, 内田 信一, 菅原 明, 杉野 法広, 椙村 益久, 高野 幸路, 伊達木 澄人, 中里 雅光, 西岡 宏, 堀川 玲子, 松野 彰, 山下 美保, 横山 徹爾, 浜中 奈美, 曽根田 瞬, 青山 幸平, 浅利 ゆう子, 安藤 史顕, 井口 元三, 池谷 章, 石坂 栄太郎, 磯島 豪, 岩間 信太郎, 浦木 進丞, 大山 健一, 岡田 満夫, 尾上 剛史, 柿沢 圭亮, カロリナブゼン, 川口 頌平, 鞁嶋 有紀, 工藤 正孝, 小杉 理英子, 小林 朋子, 近藤 友里, 佐藤 潤一郎, 澤部 史一, 須賀 英隆, 菅原 大輔, 杉山 摩利子, 鈴木 敦詞, 鈴木 幸二, 蘇原 映誠, 高木 博史, 高見澤 哲也, 高安 忍, 竹下 章, 竹島 健, 辰島 啓太, 田村 功, 中野 依莉子, 祢津 昌広, 萩原 大輔, 服部 裕次郎, 坂東 弘教, 引間 雄介, 福岡 秀規, 福原 紀章, 藤沢 治樹, 藤本 正伸, 堀口 和彦, 前川 亮, 間中 勝則, 萬代 新太郎, 光井 悠人, 宮田 崇, 三善 陽子, 向井 康祐, 虫本 雄一, 村澤 真吾, 森 崇寧, 安田 康紀, 八ツ賀 秀一, 山田 早耶香, 山本 雅昭, 吉井 啓介, 綿貫 裕, 小川 佳宏, 柴田 洋孝, 下村 伊一郎, 間脳下垂体機能障害と先天性腎性尿崩症および関連疾患の診療ガイドライン作成委員会, 厚生労働科学研究費補助金難治性疾患政策研究事業「間脳下垂体機能障害に関する調査研究」班, 一般社団法人日本内分泌学会
    日本内分泌学会雑誌, 99(Suppl.) i-171, Jul, 2023  
  • 藤沢 治樹, 渡辺 崇, 竹内 英之, 鈴木 敦詞, 椙村 益久
    日本内分泌学会雑誌, 99(1) 297-297, May, 2023  
  • 森嶌 早紀, 岩崎 文菜, 綿引 基, 林 千雅, 柏原 裕美子, 佐々木 茂和, 大村 晋一郎, 藤沢 治樹, 鈴木 敦詞, 椙村 益久
    日本内分泌学会雑誌, 99(1) 354-354, May, 2023  

Books and Other Publications

 2

Research Projects

 12

Industrial Property Rights

 2