Kenji Kato

Kenji Kato

orcid

Research Focus & Metrics

Academic Career Length

6Years (2021-Present)

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

Representative Publications

View All Publications
16 January 2023 in Journal of Clinical Medicine
Verified
Journal Article
Open access
PDF file
MKMotoya Kobayashi
Motoya Kobayashi
Noriaki YokogawaNoriaki Yokogawa
Noriaki Yokogawa
Satoshi KatoSatoshi Kato
Satoshi Kato
TSTakeshi Sasagawa
Takeshi Sasagawa
HTHiroyuki Tsuchiya
Hiroyuki Tsuchiya
KWKota Watanabe
Kota Watanabe
For older patients with decreased reserve function, traumatic cervical spine injuries frequently lead to early mortality. However, the prognostic factors for early mortality remain unclear. This study included patients aged ≥65 years and hospitalized for treatment of traumatic cervical spine injuries in 78 hospitals between 2010 and 2020. Early mortality was defined as death within 90 days after injury. We evaluated the relationship between early mortality and the following factors: age, sex, body mass index, history of drinking and smoking, injury mechanisms, presence of a cervical spine fracture and dislocation, cervical ossification of the posterior longitudinal ligament, diffuse idiopathic skeletal hyperostosis, American Spinal Injury Association Impairment Scale, concomitant injury, pre-existing comorbidities, steroid administration, and treatment plan. Overall, 1512 patients (mean age, 75.8 ± 6.9 years) were included in the study. The early mortality rate was 4.0%. Multivariate analysis identified older age (OR = 1.1, p < 0.001), male sex (OR = 3.7, p = 0.009), cervical spine fracture (OR = 4.2, p < 0.001), complete motor paralysis (OR = 8.4, p < 0.001), and chronic kidney disease (OR = 5.3, p < 0.001) as risk factors for early mortality. Older age, male sex, cervical spine fracture, complete motor paralysis, and chronic kidney disease are prognostic factors for early mortality in older patients with traumatic cervical spine injuries.

20 August 2022 in BMC Musculoskeletal Disorders
Verified
Journal Article
Open access
PDF file
TSTakeshi Sasagawa
Takeshi Sasagawa
Noriaki YokogawaNoriaki Yokogawa
Noriaki Yokogawa
HHHiroyuki Hayashi
Hiroyuki Hayashi
HTHiroyuki Tsuchiya
Hiroyuki Tsuchiya
KAKei Ando
Kei Ando
Satoshi KatoSatoshi Kato
Satoshi Kato
Background: The 1-year mortality and functional prognoses of patients who received surgery for cervical trauma in the elderly remains unclear. The aim of this study is to investigate the rates of, and factors associated with mortality and the deterioration in walking capacity occurring 1 year after spinal fusion surgery for cervical fractures in patients 65 years of age or older. Methods: Three hundred thirteen patients aged 65 years or more with a traumatic cervical fracture who received spinal fusion surgery were enrolled. The patients were divided into a survival group and a mortality group, or a maintained walking capacity group and a deteriorated walking capacity group. We compared patients’ backgrounds, trauma, and surgical parameters between the two groups. To identify factors associated with mortality or a deteriorated walking capacity 1 year postoperatively, a multivariate logistic regression analysis was conducted. Results: One year postoperatively, the rate of mortality was 8%. A higher Charlson comorbidity index (CCI) score, a more severe the American Spinal Cord Injury Association impairment scale (AIS), and longer surgical time were identified as independent factors associated with an increase in 1-year mortality. The rate of deterioration in walking capacity between pre-trauma and 1 year postoperatively was 33%. A more severe AIS, lower albumin (Alb) and hemoglobin (Hb) values, and a larger number of fused segments were identified as independent factors associated with the increased risk of deteriorated walking capacity 1 year postoperatively. Conclusions: The 1-year rate of mortality after spinal fusion surgery for cervical fracture in patients 65 years of age or older was 8%, and its associated factors were a higher CCI score, a more severe AIS, and a longer surgical time. The rate of deterioration in walking capacity was 33%, and its associated factors were a more severe AIS, lower Alb, lower Hb values, and a larger number of fused segments.

20 March 2023 in Journal of Clinical Medicine
Verified
Journal Article
Open access
PDF file
KTKoji Tamai
Koji Tamai
HTHidetomi Terai
Hidetomi Terai
HNHiroaki Nakamura
Hiroaki Nakamura
Noriaki YokogawaNoriaki Yokogawa
Noriaki Yokogawa
TSTakeshi Sasagawa
Takeshi Sasagawa
Satoshi KatoSatoshi Kato
Satoshi Kato
The number of elderly patients with cervical trauma is increasing. Such patients are considered to be at high risk for delirium, which is an acute neuropsychological disorder that reduces the patient’s capacity to interact with their environment due to impairments in cognition. This study aimed to establish a risk score that predicts delirium in elderly patients with cervical SCI and/or cervical fracture regardless of treatment type. This retrospective cohort study included 1512 patients aged ≥65 years with cervical SCI and/or cervical fracture. The risk factors for delirium according to treatment type (surgical or conservative) were calculated using multivariate logistic regression. A delirium risk score was established as the simple arithmetic sum of points assigned to variables that were significant in the multivariate analyses. Based on the statistical results, the delirium risk score was defined using six factors: old age (≥80 years), hypoalbuminemia, cervical fracture, major organ injury, dependence on pre-injury mobility, and comorbid diabetes. The score’s area under the curve for the prediction of delirium was 0.66 (p < 0.001). Although the current scoring system must be validated with an independent dataset, the system remains beneficial because it can be used after screening examinations upon hospitalization and before deciding the treatment strategy.

27 February 2023 in Journal of Clinical Medicine
Verified
Journal Article
Open access
PDF file
YYYohei Yamada
Yohei Yamada
Noriaki YokogawaNoriaki Yokogawa
Noriaki Yokogawa
Satoshi KatoSatoshi Kato
Satoshi Kato
TSTakeshi Sasagawa
Takeshi Sasagawa
HTHiroyuki Tsuchiya
Hiroyuki Tsuchiya
KWKota Watanabe
Kota Watanabe
We aimed to retrospectively investigate the demographic characteristics and short-term outcomes of traumatic cervical spine injuries in patients with dementia. We enrolled 1512 patients aged ≥ 65 years with traumatic cervical injuries registered in a multicenter study database. Patients were divided into two groups according to the presence of dementia, and 95 patients (6.3%) had dementia. Univariate analysis revealed that the dementia group comprised patients who were older and predominantly female and had lower body mass index, higher modified 5-item frailty index (mFI-5), lower pre-injury activities of daily living (ADLs), and a larger number of comorbidities than patients without dementia. Furthermore, 61 patient pairs were selected through propensity score matching with adjustments for age, sex, pre-injury ADLs, American Spinal Injury Association Impairment Scale score at the time of injury, and the administration of surgical treatment. In the univariate analysis of the matched groups, patients with dementia had significantly lower ADLs at 6 months and a higher incidence of dysphagia up to 6 months than patients without dementia. Kaplan–Meier analysis revealed that patients with dementia had a higher mortality than those without dementia until the last follow-up. Dementia was associated with poor ADLs and higher mortality rates after traumatic cervical spine injuries in elderly patients.

31 December 2021 in Asian Spine Journal
Verified
Journal Article
Open access
PDF file
KYKiyoshi Yagi
Kiyoshi Yagi
YGYuta Goto
Yuta Goto
KKKenji Kato
Kenji Kato
NSNobuyuki Suzuki
Nobuyuki Suzuki
AKAkira Kondo
Akira Kondo
HMHideki Murakami
Hideki Murakami
Study Design: Human ligamentum flavum-derived cells (HFCs) were obtained from surgical samples for a basic experimental study. Purpose: We sought to evaluate the inflammatory response of human ligamentum flavum cells to investigate hypertrophic changes occurring in the ligamentum flavum. Overview of Literature: Lumbar spinal stenosis (LSS) is a disease commonly observed in the elderly. The number of patients with LSS has increased over time, yet the pathomechanisms of LSS still have not been fully elucidated. One of the clinical features of LSS is hypertrophy of the ligamentum flavum, which results in narrowing of the lumbar spinal canal. Some reports have suggested that ligamentum flavum hypertrophy is associated with inflammation and fibrosis; meanwhile, the p38 mitogen-activated protein (MAP) kinase is involved in the hypertrophy of human ligamentum flavum cells. Methods: HFCs were obtained from patients with LSS who underwent surgery. HFCs were stimulated by tumor necrosis factor-alpha (TNF-alpha) and a p38 MAP kinase inhibitor, SB203580. Phosphorylation of the p38 MAP kinase was analyzed by western blotting. The concentration of interleukin-6 ( IL-6) in the conditioned medium was measured by enzyme-linked immunoassay and IL-6 messenger RNA expression levels were determined by real-time polymerase chain reaction. Results: TNF-alpha induced the phosphorylation of p38 MAP kinase in a time-dependent manner, which was suppressed by the p38 MAP kinase inhibitor, SB203580. TNF-alpha also stimulated IL-6 release in both a time- and dose-dependent manner. On its own, SB203580 did not stimulate IL-6 secretion from HFCs; however, it dramatically suppressed the degree of IL-6 release stimulated by TNF-alpha from HFCs. Conclusions: This is the first report suggesting that TNF-alpha stimulates the gene expression and protein secretion of IL-6 via p38 MAP kinase in HFCs. A noted association between tissue hypertrophy and inflammation suggests that the p38 MAP kinase inflammatory pathway may be a therapeutic molecular target for LSS.

31 December 2023 in Asian Spine Journal
Verified
Journal Article
Open access
PDF file
YGYuta Goto
Yuta Goto
KKKenji Kato
Kenji Kato
KYKiyoshi Yagi
Kiyoshi Yagi
YKYohei Kawaguchi
Yohei Kawaguchi
HYHiroki Yonezu
Hiroki Yonezu
NSNobuyuki Suzuki
Nobuyuki Suzuki
Study Design: This experimental study was performed using human ligamentum flavum–derived cells (HFCs).Purpose: To investigate the intracellular signaling mechanism of interleukin-6 (IL-6) secretion in transforming growth factor-β (TGF- β)-stimulated HFCs.Overview of Literature: Lumbar spinal stenosis (LSS) is a prevalent disease among the elderly, characterized by debilitating pain in the lower extremities. Although the number of patients with LSS has increased in recent years, the underlying pathomechanism remains unclear. Clinical examinations typically rely on magnetic resonance imaging to diagnose patients, revealing ligamentum flavum hypertrophy. Some studies have suggested an association between ligamentum flavum hypertrophy and inflammation/fibrosis, and expression of TGF-β and IL-6 has been observed in surgically obtained ligamentum flavum samples. However, direct evidence linking TGF-β and IL-6 expression in HFCs is lacking.Methods: HFCs were obtained from patients with LSS who had undergone decompression surgery. The cells were stimulated with TGF-β and pretreated with either the p38 mitogen-activated protein (MAP) kinase inhibitor SB203580 or the p44/42 MAP kinase inhibitor FR180204. IL-6 secretion in the cell culture medium and IL-6 messenger RNA (mRNA) expression levels were analyzed using an enzyme-linked immunoassay and real-time polymerase chain reaction, respectively.Results: TGF-β administration resulted in a dose- and time-dependent stimulation of IL-6 release. Treatment with SB203580 and FR180204 markedly suppressed TGF-β–induced IL-6 secretion from HFCs. Moreover, these inhibitors suppressed IL-6 mRNA expression in response to TGF-β stimulation.Conclusions: Our findings indicate that TGF-β induces IL-6 protein secretion and gene expression in HFCs through the activation of p38 or p44/42 MAP kinases. These results suggest a potential association between IL-6–mediated inflammatory response and tissue hypertrophy in LSS, and we provide insights into molecular targets for therapeutic interventions targeting LSS-related inflammation through our analysis of the MAP kinase pathway using HFCs.