Yukimasa Matsuzawa

Mr. Yukimasa Matsuzawa

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Research Focus & Metrics

Academic Career Length

12Years (2015-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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14 May 2020 in Vaccines
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Journal Article
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YMYukimasa Matsuzawa
Yukimasa Matsuzawa
TKTadaichi Kitamura
Tadaichi Kitamura
MSMotofumi Suzuki
Motofumi Suzuki
YKYasuhiro Koyama
Yasuhiro Koyama
KSKazuyoshi Shigehara
Kazuyoshi Shigehara
Objectives: Epidemiological reports of sexual life and human papilloma virus (HPV) infection among Japanese men are scarce, and the necessity of HPV vaccines for males is regarded as a controversial topic in Japan. The objective of this study is to determine the prevalence, genotype distribution, and risk factors against HPV infections targeted by bivalent (2v), quadrivalent (4v), and 9-valent (9v) HPV vaccines among Japanese male patients who visited our urological clinics. Material and Methods: The study population consisted of 798 males aged 20 to 95 years (mean ± standard deviation, 55.4 ± 19.5 years). We collected scraping samples from the glans penis using cotton swabs from all patients for genotyping of HPVs. We compared patients’ characteristics and detected HPV genotypes in order to determine the risk factors against HPV infections. Results: Of 798 participants, 198 participants (198/798; 24.8%) had at least one genotype of any HPV infection. The total number of detected HPV genotypes was 328. Of 328 genotypes, 30% (n = 99; 99/328) were 9v HPV genotypes. Most frequently detected types of high-risk HPV infection were type 52 (n = 40; 40/328; 12.2%). Number of lifetime sex partners (≥21) and present or history of sexually transmitted infections were found to be predictors of any HPV infection with adjusted odds ratios of 3.106 (95% confidence interval (CI), 1.593–6.509) and 1.894 (95% CI, 1.185–3.026), respectively. Age of sex initiation was a predictor of 2v and 4v HPV infections with adjusted odds ratios of 100 (95% CI, 1.013–25.673) and 2.676 (95% CI, 1.037–6.905), respectively. Number of lifetime sex partners (≥21) was a predictor of 9v HPVs with adjusted odds ratios of 2.397 (95% CI, 1.060–5.424). Conclusions: Approximately, a quarter of Japanese male patients who visited urological clinics were exposed to HPV. Moreover, from the perspective of our multivariate logistic regression analysis, some kinds of sexual behavior aggravate the risk of typical HPV genotypes infections.

15 July 2019 in Internal Medicine
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YMYukimasa Matsuzawa
Yukimasa Matsuzawa
EAEisuke Adachi
Eisuke Adachi
ATAtsuko Takahashi
Atsuko Takahashi
HSHidenori Sato
Hidenori Sato
LLLay Ahyoung Lim
Lay Ahyoung Lim
HYHiroshi Yotsuyanagi
Hiroshi Yotsuyanagi
We herein describe a case of Sweet's syndrome (SS) in a patient being treated for pulmonary toxoplasmosis complicated with myelodysplastic syndrome (MDS). The patient's SS developed after the pulmonary toxoplasmosis improved following treatment. We searched his cytokine profiles comprehensively using a bead-based immunoassay. The results showed no elevation of IL-2, IFN-γ or IL-17A, and IL-6 was only observed to have increased at the onset of SS, suggesting that the pulmonary toxoplasmosis had been well controlled and that chronic inflammation may have been the cause of SS. Pulmonary toxoplasmosis is an extremely rare occurrence. The cytokine profile can help to clarify the pathological condition of SS and MDS complicated with severely invasive infectious diseases.

23 October 2019 in Viruses
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YMYukimasa Matsuzawa
Yukimasa Matsuzawa
KIKiyoko Iwatsuki-Horimoto
Kiyoko Iwatsuki-Horimoto
YNYoshinori Nishimoto
Yoshinori Nishimoto
YAYukiko Abe
Yukiko Abe
SFSatoshi Fukuyama
Satoshi Fukuyama
YKYoshihiro Kawaoka
Yoshihiro Kawaoka
Human influenza A(H2N2) viruses emerged in 1957 and were replaced by A(H3N2) viruses in 1968. The antigenicity of human H2N2 viruses has been tested by using ferret antisera or mouse and human monoclonal antibodies. Here, we examined the antigenicity of human H2N2 viruses by using human plasma samples obtained from 50 aged individuals who were born between 1928 and 1933 and from 33 younger adult individuals who were born after 1962. The aged individuals possessed higher neutralization titers against H2N2 viruses isolated in 1957 and 1963 than those against H2N2 viruses isolated in 1968, whereas the younger adults who were born between 1962 and 1968 possessed higher neutralization titers against H2N2 viruses isolated in 1963 than those against other H2N2 viruses. Antigenic cartography revealed the antigenic changes that occurred in human H2N2 viruses during circulation in humans for 11 years, as detected by ferret antisera. These results show that even though aged individuals were likely exposed to more recent H2N2 viruses that are antigenically distinct from the earlier H2N2 viruses, they did not possess high neutralizing antibody titers to the more recent viruses, suggesting immunological imprinting of these individuals with the first H2N2 viruses they encountered and that this immunological imprinting lasts for over 50 years.

1 January 2015 in The Japanese Journal of Urology
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Journal Article
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YMYukimasa Matsuzawa
Yukimasa Matsuzawa
SMShigekatsu Maekawa
Shigekatsu Maekawa
HNHiroaki Nishimatsu
Hiroaki Nishimatsu
KTKatsutoshi Takahashi
Katsutoshi Takahashi
ANAya Niimi
Aya Niimi
YHYukio Homma
Yukio Homma
(目的) 副腎出血は保存的に経過観察できるものから致死的なものまで様々である一方,治療の基準や方法は明確に確立されていない.今回我々は自験例および文献例にて副腎出血の治療法,そしてその適応について検討する. (対象と方法) 2004年11月から2013年9月までに東京大学医学部附属病院および同愛記念病院に来院した副腎出血6例と医中誌にて検索し得た57例について後向きに調査した. (結果) 今回の自験例6例と既報告57例の計63例において,悪性腫瘍の転移による副腎出血は重篤化する可能性が高い傾向があった.治療では保存的治療が13例(23%),TAEを行ったのが5例(8%),緊急手術が3例(5%)であり,残りの症例は状態が安定した後に診断を兼ねて待機的に副腎摘除術を施行していた.また,Hb 10 g/dl以下かつ血腫径が10 cm以上の症例は5例あり,そのうち1例を除いて,緊急止血術が行われた. (結論) 悪性腫瘍の副腎転移による出血,Hb 10 g/dl以下かつ血腫径が10 cmを超えるものは緊急で止血術を考慮すべきであり,止血術後も再出血や全身状態の悪化を起こす可能性があり厳重な観察を要すると考えられた.治療法としては,手術と比べ侵襲も少ないことからTAEを第一選択とすることが勧められる.

4 August 2020 in IJU Case Reports
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Journal Article
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MNMichio Noda
Michio Noda
YMYukimasa Matsuzawa
Yukimasa Matsuzawa
HNHiroaki Nishimatsu
Hiroaki Nishimatsu
SMShinichiro Murayama
Shinichiro Murayama
HKHirohisa Kishi
Hirohisa Kishi
HKHaruki Kume
Haruki Kume
Introduction The development of secondary tumors is a well‐known late adverse event after urinary diversion. However, the frequency of secondary tumors after an ileal conduit is the lowest compared to other methods used for urinary diversion. We observed a rare case of a gastrointestinal stromal tumor in an ileal conduit detected by recurrent massive bleeding from the stoma. Case presentation An 87‐year‐old female was hospitalized at our hospital due to recurrent bleeding from a stoma 22 years after radical cystectomy. Contrast‐enhanced computed tomography revealed a 5‐cm mass in her ileal conduit. She underwent a complete resection of the tumor, a histological examination of which revealed it to be a gastrointestinal stromal tumor. The condition of the patient has been good showing no recurrence or metastases 4 years after surgery. Conclusion We report a rare secondary tumor, a gastrointestinal stromal tumor, arising from an ileal conduit.