MAEKAWA Kazunari



Faculty of Medicine School of Medicine Department of Pathology, Pathophysiology


Assistant Professor

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Degree 【 display / non-display

  • (医学) ( 2004.3   防衛省 防衛医科大学校 )

Research Areas 【 display / non-display

  • Life Science / Human pathology


Papers 【 display / non-display

  • Adverse Local Tissue Reaction and Late-Onset Eosinophilic Gastroenteritis After Primary Total Hip Arthroplasty: A Case Report.

    Mihara M, Hirakawa K, Takayanagi S, Maekawa K, Kitagawa R, Sato T

    JBJS case connector   11 ( 4 )   2021.11

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:JBJS case connector  

    CASE: A 67-year-old woman suffered from chronic diarrhea at 10 years after right total hip arthroplasty. She also had a pseudotumor caused by an adverse local tissue reaction (ALTR) in her right pelvis. We performed revision arthroplasty, in part because we suspected the diarrhea may have been associated with the intrapelvic pseudotumor. She was later diagnosed with eosinophilic gastroenteritis (EGE). CONCLUSION: Although these two diseases were thought be be related through a similar immune reaction, our patient's clinical course suggests that the ALTR and EGE were independent events.

    DOI: 10.2106/JBJS.CC.21.00333



  • Association between fetal vascular malperfusion and gestational diabetes.

    Goto T, Sato Y, Kodama Y, Tomimori K, Sameshima H, Aman M, Maekawa K, Yamashita A, Asada Y

    The journal of obstetrics and gynaecology research   48 ( 1 )   80 - 86   2021.11

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:Journal of Obstetrics and Gynaecology Research  

    Aim: Diabetes mellitus (DM) is a major complication in pregnancy. Placental lesions with DM remain unclear and controversial. Recently, the terms of placental pathological findings, such as maternal and fetal vascular malperfusions (MVM and FVM, respectively) were introduced by the Amsterdam Placental Workshop Group Consensus Statement (APWGCS). FVM cases were classified as the partial obstruction type (global FVM) and the complete obstruction type (segmental FVM). The aim of this study was to clarify the pathological characteristics of the placenta with pregestational DM/gestational DM; GDM according to APWGCS. Methods: We studied the placentas of 182 DM women (27 pregestational DM and 155 GDM) and control placentas of 460 women without DM during 2011–2018. We excluded cases of intrauterine fetal death or multiple pregnancies. We reviewed microscopical findings including, MVM, FVM, chorioamnionitis with the slides according to the APWGCS. Results: Microscopically, the incidence of FVM was significantly higher in GDM patients than control (17% vs. 10%, p = 0.0138), but not significant in pregestational DM (11%, p = 0.7410). Segmental FVM (complete obstruction) was significantly more observed in GDM than control group (5% vs. 0.4%, p = 0.0013). Segmental FVM in GDM showed high incidence of light-for-dates infant (three of seven cases, 43%, p = 0.0288). In addition, several segmental FVM findings (villous stromal-vascular karyorrhexis and stem vessel occlusion) were frequently noted in 2 or 3 points positive of 75 g oral glucose tolerance test than 1 point positive GDM. Conclusion: Our placental findings suggest disorder of carbohydrate metabolism might affect the fetal vascular damage, especially complete fetal vascular obstruction.

    DOI: 10.1111/jog.15046



  • Upregulated Kynurenine Pathway Enzymes in Aortic Atherosclerotic Aneurysm: Macrophage Kynureninase Downregulates Inflammation.

    Masanori Nishimura, Atsushi Yamashita, Yunosuke Matsuura, Junichi Okutsu, Aiko Fukahori, Tsuyoshi Hirata, Tomohiro Nishizawa, Hirohito Ishii, Kazunari Maekawa, Eriko Nakamura, Kazuo Kitamura, Kunihide Nakamura, Yujiro Asada

    Journal of atherosclerosis and thrombosis   28 ( 11 )   1214 - 1240   2021.11

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:Japan Atherosclerosis Society  

    AIMS: Inflammation and hypertension contribute to the progression of atherosclerotic aneurysm in the aorta. Vascular cell metabolism is regarded to modulate atherogenesis, but the metabolic alterations that occur in atherosclerotic aneurysm remain unknown. The present study aimed to identify metabolic pathways and metabolites in aneurysmal walls and examine their roles in atherogenesis. METHODS: Gene expression using microarray and metabolite levels in the early atherosclerotic lesions and aneurysmal walls obtained from 42 patients undergoing aortic surgery were investigated (early lesion n=11, aneurysm n=35) and capillary electrophoresis-time-of-flight mass spectrometry (early lesion n=14, aneurysm n=38). Using immunohistochemistry, the protein expression and localization of the identified factors were examined (early lesion n=11, non-aneurysmal advanced lesion n=8, aneurysm n=11). The roles of the factors in atherogenesis were analyzed in macrophages derived from human peripheral blood mononuclear cells. RESULTS: Enrichment analysis using 35 significantly upregulated genes (log2 ratio, >3) revealed the alteration of the kynurenine pathway. Metabolite levels of tryptophan, kynurenine, and quinolinic acid and the kynurenine-to-tryptophan ratio were increased in the aneurysmal walls. Gene and protein expression of kynureninase and kynurenine 3-monooxygenase were upregulated and localized in macrophages in the aneurysmal walls. The silencing of kynureninase in the cultured macrophages enhanced the expression of interleukin-6 and indoleamine 2,3-dioxygenase 1. CONCLUSION: Our study suggests the upregulation of the kynurenine pathway in macrophages in aortic atherosclerotic aneurysm. Kynureninase may negatively regulate inflammation via the kynurenine pathway itself in macrophages.

    DOI: 10.5551/jat.58248



    CiNii Research


  • Translocator protein imaging with <sup>18</sup>F-FEDAC-positron emission tomography in rabbit atherosclerosis and its presence in human coronary vulnerable plaques

    Maekawa K., Tsuji A.B., Yamashita A., Sugyo A., Katoh C., Tang M., Nishihira K., Shibata Y., Koshimoto C., Zhang M.R., Nishii R., Yoshinaga K., Asada Y.

    Atherosclerosis   337   7 - 17   2021.11

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    Language:Japanese   Publishing type:Research paper (scientific journal)   Publisher:Atherosclerosis  

    Background and aims: This study aimed to investigate whether N-benzyl-N-methyl-2-[7,8-dihydro-7-(2-[18F]fluoroethyl)-8-oxo-2-phenyl-9H-purin-9-yl]acetamide (18F-FEDAC), a probe for translocator protein (TSPO), can visualize atherosclerotic lesions in rabbits and whether TSPO is localized in human coronary plaques. Methods: 18F-FEDAC-PET of a rabbit model of atherosclerosis induced by a 0.5% cholesterol diet and balloon injury of the left carotid artery (n = 7) was performed eight weeks after the injury. The autoradiography intensity of 18F-FEDAC in carotid artery tissue sections was measured, and TSPO expression was evaluated immunohistochemically. TSPO expression was examined in human coronary arteries obtained from autopsy cases (n = 16), and in human coronary plaques (n = 12) aspirated from patients with acute myocardial infarction (AMI). Results: 18F-FEDAC-PET visualized the atherosclerotic lesions in rabbits as high-uptake areas, and the standard uptake value was higher in injured arteries (0.574 ± 0.24) than in uninjured arteries (0.277 ± 0.13, p < 0.05) or myocardium (0.189 ± 0.07, p < 0.05). Immunostaining showed more macrophages and more TSPO expression in atherosclerotic lesions than in uninjured arteries. TSPO was localized in macrophages, and arterial autoradiography intensity was positively correlated with macrophage concentration (r = 0.64) and TSPO (r = 0.67). TSPO expression in human coronary arteries was higher in AMI cases than in non-cardiac death, or in the vulnerable plaques than in early or stable lesions, respectively. TSPO was localized in macrophages in all aspirated coronary plaques with thrombi. Conclusions: 18F-FEDAC-PET can visualize atherosclerotic lesions, and TSPO-expression may be a marker of high-risk coronary plaques.

    DOI: 10.1016/j.atherosclerosis.2021.10.003



  • Glioblastoma mimicking metastatic small cell carcinoma: A case report with ultrastructural findings. International journal

    Kazunari Maekawa, Takako Tokumitsu, Hiroshi Noguchi, Eriko Nakamura, Toshihiro Gi, Shoichi Horinouchi, Shinji Yamashita, Hideo Takeshima, Yujiro Asada, Yuichiro Sato

    Diagnostic cytopathology   49 ( 8 )   E291 - E296   2021.8

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    Language:Japanese   Publishing type:Research paper (scientific journal)  

    It is often straightforward to distinguish glioblastoma (GBM) from metastatic carcinoma by cytology; however, small cell variants of GBM or GBM with primitive neuronal component (GBMPNC) can mimic metastatic small cell carcinoma (SCC). Herein, we report a case of GBMPNC mimicking metastatic SCC and present cytological and ultrastructural findings. A 65-year-old man with memory disturbance was hospitalized. Magnetic resonance imaging revealed the presence of a 6 cm sized tumor in the right anterior temporal lobe. Intraoperative cytology slides indicated that the tumor consisted of small-sized cells with scant cytoplasm showing high cellularity. The initial intraoperative diagnosis was metastatic SCC; however, any primary visceral tumor was not detected clinically. Immunohistochemical and ultrastructural studies of postoperative histological sections revealed that the lesion was GBMPNC. This case shows that some GBMs may have the potential to closely mimic metastatic SCC, which expands the differential diagnosis and emphasizes the importance of clinical correlation.

    DOI: 10.1002/dc.24715




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Books 【 display / non-display

Presentations 【 display / non-display

  • Quantitative Susceptibility Mapping on Magnetic Resonance Imaging Distinguishes Intraplaque Hemorrhage and Iron Deposition from Calcification in Carotid Atherosclerosis International conference

    Kazunari Maekawa, Atsushi Yamashita, Minako Azuma, Masahiro Enzaki, Kiyotaka Yokogami, Hideo Takeshima, Ti Wang, Toshinori Hirai, Yujiro Asada

    Vascular Discovery: From Genes to Medicine Scientific Sessions 2019  (Boston Marriott Copley Place Hotel, Boston, Massachusetts)  American Heart Association

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    Event date: 2019.5.14 - 2019.5.16

    Language:English   Presentation type:Poster presentation  

    Venue:Boston Marriott Copley Place Hotel, Boston, Massachusetts  

  • Histology and quantitative susceptibility mapping of carotid atherosclerotic plaque

    Kazunari Maekawa, Minako Azuma, Atsushi Yamashita, Toshinori Hirai, Yujiro Asada

    The 108th Annual Meeting of the Japanese Society of Pathology  (Tokyo International Forum) 

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    Event date: 2019.5.9 - 2019.5.11

    Language:English   Presentation type:Poster presentation  

    Venue:Tokyo International Forum  

  • 頸部リンパ節穿刺吸引細胞診で卵巣Dysgerminomaの転移を推定し得た一例


    第34回臨床細胞学会九州連合会学会  (長崎市、長崎県)  臨床細胞学会九州連合会

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    Event date: 2018.7.21 - 2018.7.22

    Language:Japanese   Presentation type:Oral presentation (general)  


    【症例】20代、女性。8番染色体異常、ファロー四徴症(2歳時に手術)、てんかんのため当院小児科外来でフォローされていた。3か月前から下腹部腫瘤、1か月前から左鎖骨上の腫瘤を自覚。CTで子宮腹側に18cm超大の分葉状腫瘤がみられ、左頸部から鎖骨上に最大8㎝の数珠状・分葉状のリンパ節腫大がみられた。婦人科腫瘍、GIST、悪性リンパ腫を鑑別に、頸部リンパ節病変からの穿刺吸引細胞診が施行された。細胞学的には、リンパ球を背景に大型の異型細胞が緩い結合性を示す集塊あるいは孤在性に認められた。異型細胞はリンパ球の4倍程度の径を示す大型核を有し、クロマチンパターンは繊細で、大型好酸性核小体がみられ、淡明な細胞質を有していた。針洗浄液にて作製したセルブロックによる免疫染色で異型細胞はD2-40及びPlacental alkaline phosphatase陽性で、AE1/AE3、LCA、HMB-45、Myogenin及びSynaptophysin陰性であった。悪性と診断し、臨床像と併せて卵巣Dysgerminomaの頸部リンパ節転移が推定されるとした。その1週間後に子宮および両側附属器切除、大網切除術が施行され、病理組織学的に左卵巣原発のDysgerminomaと診断された。

  • Hypoxia augments macrophage tissue factor expression under inflammatory stimuli

    Maekawa Kazunari, Yamashita Atsushi, Nishihira Kensaku, Hatakeyama Kinta, Asada Yujiro

    JSTH2018  (Sapporo, Hokkaido, Japan)  Japanese Society of Thrombosis and Hemostasis

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    Event date: 2018.6.28 - 2018.6.30

    Language:English   Presentation type:Poster presentation  

    Venue:Sapporo, Hokkaido, Japan  

    Hypoxia and inflammatory stimuli augment tissue factor expression in macrophages but not in smooth muscle cells or in endothelial cells.

  • Hypoxia augments tissue factor expression in inflammatory stimulated macrophages but not in smooth muscle cells or in endothelial cells. International conference

    Kazunari Maekawa, Atsushi Yamashita, Kinta Hatakeyama, Kensaku Nishihira, Yujiro Asada

    ISTH2017  (Berlin)  International Society on Thrombosis and Haemostasis

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    Event date: 2017.7.8 - 2017.7.13

    Language:English   Presentation type:Poster presentation  


    Hypoxia may have synergetic effect on TF expression over inflammatory stimuli in macrophages, but not in smooth muscle cells (SMCs) or in endothelial cells (ECs).
    Aspirated plaques included macrophages with expression of tissue factor and hexokinase II, suggesting that exposure of highly thrombogenic macrophages into circulation contributes to coronary thrombus formation after plaque disruption.

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