Kosuke Kojo

Dr. Kosuke Kojo

orcid

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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27 April 2020 in Journal of Human Genetics
Verified
Journal Article
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YSYouichi Sato
Youichi Sato
Atsushi TajimaAtsushi Tajima
Atsushi Tajima
MKMisaki Kiguchi
Misaki Kiguchi
SKSuzu Kogusuri
Suzu Kogusuri
AFAki Fujii
Aki Fujii
TITeruaki Iwamoto
Teruaki Iwamoto

23 December 2024 in Journal of Clinical Laboratory Analysis
Verified
Journal Article
Open access
KKKosuke Kojo
Kosuke Kojo
TOTomoko Oguri
Tomoko Oguri
TTTakazo Tanaka
Takazo Tanaka
AIAtsushi Ikeda
Atsushi Ikeda
TSTakuya Shimizu
Takuya Shimizu
HNHiroyuki Nishiyama
Hiroyuki Nishiyama
Background: Inductively coupled plasma mass spectrometry (ICP‐MS) is widely used for the accurate measurement of minerals. However, its application to serum essential mineral measurement has not been fully evaluated. The present study aimed to assess the performance of ICP‐MS for serum minerals by comparing its measurements to those obtained using standard quantification methods.Methods: Cross‐sectional data were collected from 282 participants from a single facility in Japan. Serum concentrations of eight key minerals, namely sodium, potassium, calcium, phosphorus, magnesium, iron, zinc, and copper, measured via ICP‐MS and standard methods were compared using Passing–Bablok regression and Bland–Altman plots.Results: All minerals, except phosphorus, exhibited good agreement with standard methods, with more stable regression coefficients observed for minerals with greater interindividual variability. After systematically filtering outliers, the mean relative errors were approximately −3% for sodium, potassium, calcium, and magnesium; +5% for iron; 0% for zinc; and −19% for copper. The outliers for iron were primarily due to mild hemolysis, whereas those for zinc were largely attributed to nonhemolysis factors. For phosphorus, the serum total phosphorus concentration measured using ICP‐MS was approximately 3.5 times higher than the serum inorganic phosphorus concentration measured using standard methods, with a weak correlation observed between the two methods.Conclusion: This study provides a practical foundation for future research. Understanding ICP‐MS characteristics will facilitate the development of new approaches in clinical diagnostics.

1 January 2021 in Journal of Medical Education and Curricular Development
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Journal Article
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TKTomokazu Kimura
Tomokazu Kimura
KKKosuke Kojo
Kosuke Kojo
MSMasanobu Shiga
Masanobu Shiga
ICIchiro Chihara
Ichiro Chihara
AIAtsushi Ikeda
Atsushi Ikeda
HNHiroyuki Nishiyama
Hiroyuki Nishiyama
Urological education is as important as surgical training for undergraduates. However, students in undergraduate medical schools have less exposure to urology as their curriculum focuses more on clinical skills, particularly community-based healthcare for a super-aging society. This study aimed to evaluate whether urology-related hands-on training could increase the interest of undergraduate medical students in urology. A 1-day elective program in urological surgery at the University of Tsukuba, particularly in robotic, laparoscopic, and endoscopic surgeries, was offered to 85 fourth-year medical students from 2018 to 2020, prior to their clinical clerkship. The average age of the participants was 22 (range: 21-25) years. We used a scoring system that comprised 1-5 Likert-type items to assess training activity, interest in surgery, and interest in urology before and after the course. Before attending the program, the average scores of interest in urology were 3.53 in 2018, 3.15 in 2019, and 3.00 in 2020. The scores in surgery increased after the program; however, this was not significantly different from scores prior to the program. However, the average interest scores in urology were significantly increased to 3.91 ± 0.63 (P < .05), 3.88 ± 0.58 (P < .01), and 4.00 ± 0.61 (P < 0.01) in 2018, 2019, and 2020, respectively. Total likely scores of this program in 2018, 2019, and 2020 were 4.59, 4.76, and 4.88, respectively, indicating a motivation to study surgery and urology during clinical clerkship. Urological hands-on training facilitated interest in urology in medical students prior to their clinical clerkship.

19 July 2021 in International Journal of Urology
Verified
Journal Article
Open access
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SYShinichi Yamashita
Shinichi Yamashita
KKKenichi Kakimoto
Kenichi Kakimoto
MUMotohide Uemura
Motohide Uemura
TKTakeshi Kishida
Takeshi Kishida
KKKoji Kawai
Koji Kawai
YAYoichi Arai
Yoichi Arai
Objective To evaluate fertility and use of reproductive technology of testicular cancer survivors in a multi-institutional, cross-sectional study. Methods This study recruited testicular cancer survivors who were followed after treatment for testicular cancer at eight high-volume institutions between 2018 and 2019. The participants completed the questionnaires on marital status, fertility and use of reproductive technology. Results A total of 567 testicular cancer survivors, with a median age of 43 years, responded to the questionnaire. Chemotherapy was given to 398 survivors, including three cycles of cisplatin-based chemotherapy in 106 patients and four cycles in 147 patients. Among 153 survivors who attempted sperm cryopreservation, 133 (87%) could preserve sperm. Of the 28 survivors whose cryopreserved sperm was used, 17 (61%) fathered children. Of the 72 survivors who fathered children without the use of cryopreserved sperm, 59 (82%) fathered naturally. Whereas 33 (20%) of 169 survivors treated without chemotherapy fathered children without using cryopreserved sperm, 39 (10%) of 398 treated with chemotherapy fathered children (P < 0.05). Furthermore, the paternity rate was 12% and 5% in testicular cancer survivors with three and four cycles of cisplatin-based chemotherapy, respectively (P < 0.05). However, of 121 survivors who wanted to have children, 14 (12%) received counseling about infertility treatment. Conclusions Testicular cancer survivors preserving their sperm have a higher paternity rate after chemotherapy, especially after four cycles, than those not using cryopreserved sperm. Physicians who give chemotherapy for testicular cancer need to take particular care not only with respect to recurrence of testicular cancer, but also to post-treatment fertility.

19 May 2021 in International Journal of Urology
Verified
Journal Article
Closed access
PDF file
MSMasanobu Shiga
Masanobu Shiga
YNYoshiyuki Nagumo
Yoshiyuki Nagumo
ICIchiro Chihara
Ichiro Chihara
SNSatoshi Nitta
Satoshi Nitta
KKKosuke Kojo
Kosuke Kojo
HNHiroyuki Nishiyama
Hiroyuki Nishiyama

6 July 2020 in Japanese Journal of Clinical Oncology
Verified
Journal Article
Closed access
KKKosuke Kojo
Kosuke Kojo
KKKoji Kawai
Koji Kawai
TKTakashi Kawahara
Takashi Kawahara
TKTomokazu Kimura
Tomokazu Kimura
SKShuya Kandori
Shuya Kandori
HNHiroyuki Nishiyama
Hiroyuki Nishiyama
Objective: Japan’s national database of hospital-based cancer registries is estimated to cover ~67% of all new cancer cases. Using this database, we analyzed the characteristics of the recently diagnosed testicular malignancy. Methods: We obtained data for 6510 adult testicular malignancy patients diagnosed in 2012–2015. The distributions of patient ages, histological diagnoses and testicular germ cell tumor hospital care volumes were determined. Results: The most common histology was seminoma (60.3% of all testicular malignancies), followed by non-seminoma (24.1%) and diffuse large B-cell lymphoma (13.1%). The median and mean ages of the testicular germ cell tumor patients were high at 38 and 39.8 years, respectively. The age distribution peaked at 30–40 years, followed by 40–50 years. Approximately 18% of testicular germ cell tumor patients were ≥50 years. The ages of the diffuse large B-cell lymphoma patients peaked at 70–80 years (mean 67.7 years). When the analysis was limited to the testicular germ cell tumor patients who received first-course cancer treatment at the participating hospitals, the number of high-volume hospitals with ≥20 testicular germ cell tumor care volume was limited to 61 (10.0% of the 605 hospitals that treated ≥1 testicular germ cell tumor patient). However, when the patients who changed hospitals during treatment or relapsed after treatment completion were analyzed together, the number of high-volume hospitals increased to 104 (17.0% of 612 hospitals). Conclusion: The testicular germ cell tumor patients’ mean age was nearly 40 years. The proportions of older testicular germ cell tumor patients and diffuse large B-cell lymphoma patients were higher than previously thought. The reasons for this trend are unknown, but it is important to address the trend identified herein in a country with a super-aging population.