Kazuhiro Kobayashi

Dr. Kazuhiro Kobayashi

orcid

Research Focus & Metrics

Academic Career Length

23Years (2004-Present)

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

Representative Publications

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27 August 2018 in Journal of Clinical Medicine
Verified
Journal Article
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KKKazuhiro Kobayashi
Kazuhiro Kobayashi
KHKenji Hisamatsu
Kenji Hisamatsu
ナすナツコ すずい
ナツコ すずい
AHAkira Hara
Akira Hara
HTHiroyuki Tomita
Hiroyuki Tomita
TMTatsuhiko Miyazaki
Tatsuhiko Miyazaki
Head and neck squamous cell carcinomas (HNSCCs) arise in the mucosal lining of the upper aerodigestive tract. Tobacco and alcohol use have been reported to be associated with HNSCC. Infection with high-risk human papillomaviruses (HPVs) has recently been implicated in the pathogenesis of HNSCCs. It is now widely accepted that high-risk HPV is a cause of almost all cervical cancers as well as some forms of HNSCCs. HPV-related HNSCCs are increasing. HPV-related HNSCCs and HPV-unrelated HNSCCs differ with respect to the molecular mechanisms underlying their oncogenic processes. HPV-related HNSCCs are known to have a better prognosis response to treatment as compared with HPV-unrelated HNSCCs. Therefore, in recent years, it has been required to accurately discriminate between HPV-related and HPV-unrelated HNSCCs. To diagnose the HPV-related HNSCCs, various methods including P16 immunohistochemistry, FISH, and genetic analyses of the HPV gene from histopathological and liquid biopsy specimens have been employed. Based on the results of the differential diagnosis, various treatments employing EGFR TKI and low-dose radiation have been employed. Here, we review the involvement of the HPV virus in HNSCCs as well as the molecular mechanism of carcinogenesis, classification, prognosis, diagnostic procedures, and therapy of the disease.

Verified
Journal Article
Open access
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KKKazuhiro Kobayashi
Kazuhiro Kobayashi
HTHiroyuki Tomita
Hiroyuki Tomita
Masahito ShimizuMasahito Shimizu
Masahito Shimizu
Takuji TanakaTakuji Tanaka
Takuji Tanaka
ナすナツコ すずい
ナツコ すずい
AHAkira Hara
Akira Hara
Ulcerative colitis (UC) is defined as an idiopathic inflammatory disorder primarily involving the mucosa and submucosa of the colon. UC-associated colon cancers (also known as colitic cancers) develop through the inflammation–dysplasia sequence, which is a major problem affecting the prognosis of patients with UC. It is therefore very important to detect malignancy from UC at an early stage. As precancerous lesions arising in UC, there are pathological adenomatous changes, basal cell changes, in situ anaplasia, clear cell changes, and pan-cellular change. It is considered that the mutation of the p53 gene plays a crucial role, and the protein expression of p53 in dysplastic crypts may serve as a good biomarker in the early stages of UC-associated colon carcinogenesis. Immunohistochemistry for p53 is a very valuable diagnostic tool in UC-associated colon cancers. However, protein expression of p53 is not always universal, and additional methods may be required to assess p53 status in UC-associated colon cancers.

3 October 2019 in Cancers
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Riuko OhashiRiuko Ohashi
Riuko Ohashi
PSPeter Schraml
Peter Schraml
SASilvia Angori
Silvia Angori
ABAashil Batavia
Aashil Batavia
NRNiels J. Rupp
Niels J. Rupp
HMHolger Moch
Holger Moch
Chromophobe renal cell carcinoma (chRCC) is a renal tumor subtype with a good prognosis, characterized by multiple chromosomal copy number variations (CNV). The World Health Organization (WHO) chRCC classification guidelines define a classic and an eosinophilic variant. Large cells with reticular cytoplasm and prominent cell membranes (pale cells) are characteristic for classic chRCC. Classic and eosinophilic variants were defined in 42 Swiss chRCCs, 119 Japanese chRCCs and in whole-slide digital images of 66 chRCCs from the Cancer Genome Atlas (TCGA) kidney chromophobe (KICH) dataset. 32 of 42 (76.2%) Swiss chRCCs, 90 of 119 (75.6%) Japanese chRCCs and 53 of 66 (80.3%) TCGA-KICH were classic chRCCs. There was no survival difference between eosinophilic and classic chRCC in all three cohorts. To identify a genotype/phenotype correlation, we performed a genome-wide CNV analysis using Affymetrix OncoScan® CNV Assay (Affymetrix/Thermo Fisher Scientific, Waltham, MA, USA) in 33 Swiss chRCCs. TCGA-KICH subtypes were compared with TCGA CNV data. In the combined Swiss and TCGA-KICH cohorts, losses of chromosome 1, 2, 6, 10, 13, and 17 were significantly more frequent in classic chRCC (p < 0.05, each), suggesting that classic chRCC are characterized by higher chromosomal instability. This molecular difference justifies the definition of two chRCC variants. Absence of pale cells could be used as main histological criterion to define the eosinophilic variant of chRCC.

2 October 2024 in Science Translational Medicine
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Journal Article
Closed access
LZLuping Zhou
Luping Zhou
MPMarc Torres Pereiro
Marc Torres Pereiro
YLYanqun Li
Yanqun Li
MDMarcus Derigs
Marcus Derigs
CKCarsten Kuenne
Carsten Kuenne
TWThomas Worzfeld
Thomas Worzfeld
Acute kidney injury (AKI) is a frequent and challenging clinical condition associated with high morbidity and mortality and represents a common complication in critically ill patients with COVID-19. In AKI, renal tubular epithelial cells (TECs) are a primary site of damage, and recovery from AKI depends on TEC plasticity. However, the molecular mechanisms underlying adaptation and maladaptation of TECs in AKI remain largely unclear. Here, our study of an autopsy cohort of patients with COVID-19 provided evidence that injury of TECs by myoglobin, released as a consequence of rhabdomyolysis, is a major pathophysiological mechanism for AKI in severe COVID-19. Analyses of human kidney biopsies, mouse models of myoglobinuric and gentamicin-induced AKI, and mouse kidney tubuloids showed that TEC injury resulted in activation of the glucocorticoid receptor by endogenous glucocorticoids, which aggravated tubular damage. The detrimental effect of endogenous glucocorticoids on injured TECs was exacerbated by the administration of a widely clinically used synthetic glucocorticoid, dexamethasone, as indicated by experiments in mouse models of myoglobinuric- and folic acid–induced AKI, human and mouse kidney tubuloids, and human kidney slice cultures. Mechanistically, studies in mouse models of AKI, mouse tubuloids, and human kidney slice cultures demonstrated that glucocorticoid receptor signaling in injured TECs orchestrated a maladaptive transcriptional program to hinder DNA repair, amplify injury-induced DNA double-strand break formation, and dampen mTOR activity and mitochondrial bioenergetics. This study identifies glucocorticoid receptor activation as a mechanism of epithelial maladaptation, which is functionally important for AKI.

1 January 2015 in World Journal of Surgical Oncology
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Manabu FutamuraManabu Futamura
Manabu Futamura
TATakahiko Asano
Takahiko Asano
KKKazuhiro Kobayashi
Kazuhiro Kobayashi
KMKasumi Morimitsu
Kasumi Morimitsu
MNMasahito Nawa
Masahito Nawa
KYKazuhiro Yoshida
Kazuhiro Yoshida
Axillary lymph node dissection (ALND) is important for improving the prognosis of patients with node-positive breast cancer. However, ALND can be avoided in select micrometastatic cases, preventing complications such as lymphedema or paresthesia of the upper limb. To appropriately omit ALND from treatment, evaluation of the axillary tumor burden is critical. The present study evaluated a method for preoperative quantification of axillary lymph node metastasis using positron emission tomography/computed tomography (PET/CT). The records of breast cancer patients who received radical surgery at the Gifu University Hospital (Gifu, Japan) between 2009 and 2014 were reviewed. The axillary lymph nodes were preoperatively evaluated by PET/CT. Lymph nodes were dissected by sentinel lymph node biopsy (SLNB) or ALND and were histologically diagnosed by experienced pathologists. The maximum standardized uptake value (SUVmax) was measured in both the axillary lymph node (SUV-LN) and primary tumor (SUV-T). The SUV-LN/T ratio (NT ratio) was calculated by dividing the SUV-LN by the SUV-T, and the efficacies of the NT ratio and SUV-LN were compared using receiver operating characteristic (ROC) curve analysis. The diagnostic performance was also compared between the techniques with the McNemar test. A total of 171 operable invasive breast cancer patients were enrolled, comprising 69 node-positive patients (macrometastasis (Mac): n = 55; micrometastasis (Mic): n = 14) and 102 node-negative patients (Neg). The NT ratio for node-positive patients was significantly higher than in node-negative patients (0.5 vs. 0.316, respectively, P = 0.041). The NT ratio for Mac patients (0.571) was significantly higher than in Mic (0.227) and Neg (0.316) patients (P <0.01 and P = 0.021, respectively). The areas under the curves (AUCs) by ROC analysis for the NT ratio and SUV-LN were 0.647 and 0.811, respectively (P <0.01). In patients with an SUV-T ≥2.5, the modified AUCs for the NT ratio and SUV-LV were 0.757 and 0.797 (not significant). The NT ratio and SUV-LN are significantly higher in patients with axillary macrometastasis than in those with micrometastasis or no metastasis. The NT ratio and SUV-LN can help quantify axillary lymph node metastasis and may assist in macrometastasis identification, particularly in patients with an SUV-T ≥2.5.

1 April 2009 in Legal Medicine
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Journal Article
Closed access
SNSayaka Nagasawa
Sayaka Nagasawa
TATakeshi Azuma
Takeshi Azuma
HMHisako Motani
Hisako Motani
YSYayoi Sato
Yayoi Sato
MHMutsumi Hayakawa
Mutsumi Hayakawa
HIHirotaro Iwase
Hirotaro Iwase