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Medical Science & Innovation Volume 71 Issue 1-2 pp. 35 - 43
published_at 2024-06
This study investigated the potential of adalimumab (ADA), a monoclonal antibody targeting TNF-alfa, to protect the inner ear from intense sound exposure, given that inflammatory cytokines, including TNF-alfa, are linked to hearing loss in acoustic disorders. In this study, adalimumab was administered to mice, and its effect on the inner ear was assessed. We examined the translocation of ADA to the inner ear and its ototoxicity and impact on acoustic exposure. The results showed that adalimumab partially reached the cochlea after administration but increased the susceptibility to acoustic exposure, resulting in higher hair cell loss in the inner ear. While TNF-alfa had been considered a potential therapeutic target, the results suggested that excessive TNF-alfa suppression could harm the inner ear. We acknowledged some limitations, such as the use of adalimumab instead of an anti-mouse TNF-alfa antibody and the need to explore the suppression of other cytokines for better inner ear protection. In conclusion, adalimumab administration was found to increase the inner earʼs susceptibility to acoustic exposure, potentially leading to more significant hair cell damage, possibly due to excessive TNF-alfa suppression
Creators : 山本 陽平 | Sugahara Kazuma | Tsuda Junko | Hashimoto Makoto | Yamashita Hiroshi Publishers : Yamaguchi University School of Medicine Updated At : 2024-06-21 11:54:58
Medical Science & Innovation Volume 71 Issue 1-2 pp. 21 - 33
published_at 2024-06
Vestibular hair cells are susceptible to damage from various stimuli such as infections, ischemia, and certain therapeutic drugs, including aminoglycoside antibiotics and the antineoplastic agent cisplatin. In mammals, damage to the vestibular hair cells is permanent. This study aimed to evaluate the protective effects of nobiletin (NOB) against aminoglycoside-induced hair cell death using utricles collected from adult mice. The utricles removed from CBA/N mice were assigned to eight groups according to the dose of NOB and the administration or not of neomycin. Hair cells in the utricles were counted by double labeling with calmodulin and calbindin. NOB inhibited hair cell death in utricles exposed to neomycin. The protective effect of NOB on hair cells in the utricles was also suggested to have resulted from the inhibition of the production and accumulation of 4-hydroxy-2-nonenal, the final product of lipid peroxide aldehyde. NOB suppressed neomycin-induced hair cell death. The principle of hair cell protection from aminoglycoside-induced hair cell death suggests that NOB inhibits reactive oxygen species formation in the utricles exposed to neomycin.
Creators : Masaki Tatsuya | Sugahara Kazuma | Hashimoto Makoto | Yamashita Hiroshi Publishers : Yamaguchi University School of Medicine Updated At : 2024-06-21 11:51:30
Medical Science & Innovation Volume 71 Issue 1-2 pp. 9 - 20
published_at 2024-06
Objective: The objective was to explore the potential existence and nature of the relationship between serum of uric acid (SUA) and serum uric acid to serum creatinine ratio (SUA/SCr) with reduced estimated glomerular filtration rate (eGFR) in patients with non-alcoholic fatty liver disease (NAFLD). Methods: A cross-sectional study was conducted among apparently healthy subjects with NAFLD (n=485). The association between tertiles of SUA and SUA/SCr with reduced eGFR (n=56) were investigated after adjustments for potentially relevant confounders. Also, the diagnostic performances of SUA and SUA/SCr were evaluated with the receiver operating characteristic (ROC) curve analysis. Results: In the adjusted models, SUA showed a significant positive association with reduced eGFR in the highest tertile (OR 5.65, 95% CI 2.48-12.86, p<0.001), and SUA/SCr, in the lowest tertile (4.21, 95% CI 1.76-10.07, p=0.001). The ROC curve analysis did not reveal any significant difference between the corresponding values of area under the curve for SUA and SUA/SCr (0.70 and 0.67, respectively; p=0.521). Conclusions: We revealed significant and independent associations of elevated SUA and reduced SUA/SCr with kidney function decline in NAFLD. However, the clinical utility of these two biomarkers seemed to be limited for the mentioned purpose and needs further investigations.
Creators : Shimokawa Junki | Mahbub MH | Yamaguchi Natsu | Hase Ryosuke | Wada Sunao | Saito Hiroyuki | Watanabe Rie | Matsumoto Shoko | Nakagami Yuki | Kurokawa Fumie | Tanabe Tsuyoshi Publishers : Yamaguchi University School of Medicine Updated At : 2024-06-21 11:36:34
Medical Science & Innovation Volume 71 Issue 1-2 pp. 1 - 8
published_at 2024-06
Benign paroxysmal positional vertigo (BPPV) is the most common vertigo disease and is more likely to occur in perimenopausal women, suggesting an association with osteoporosis. Since otoconia are primarily composed of calcium carbonate, abnormal calcium metabolism may lead to otoconia dislocation. However, the detailed mechanism is currently unknown. In this study, we investigated the effects of drugs (cadmium and dexamethasone) that cause abnormal calcium metabolism on otolith formation in zebrafish larvae. Here, otolith size was clearly reduced in the cadmium group, and the calcium content of the larvae was also markedly reduced. In contrast, in the dexamethasone group, which also had a lower calcium content than the control group, otolith size increased. Our results suggest that, as in bone, calcium metabolism influences the repeated dissolution and recrystallization of otoliths and maintains homeostasis in response to calcium concentrations in the endolymphatic fluid.
Creators : Iwamoto Aya | Sugahara Kazuma | Hashimoto Makoto | Yamashita Hiroshi Publishers : Yamaguchi University School of Medicine Updated At : 2024-06-21 11:27:58
Creators : Kambayashi Yoshinori Updated At : 2024-06-05 13:11:50
Creators : Masaki Tatsuya Updated At : 2024-06-05 13:12:19
In Japan, China, and Singapore, several studies have reported increased incidences of peripheral venous catheter-related bloodstream infection by Bacillus cereus during the summer. Therefore, we hypothesized that bed bathing with a B. cereus-contaminated “clean” towels increases B. cereus contact with the catheter and increases the odds of contaminating the peripheral parenteral nutrition (PPN). We found that 1) professionally laundered “clean” towels used in hospitals have B. cereus (3.3×10^4 colony forming units (CFUs) / 25cm^2), 2) B. cereus is transferable onto the forearms of volunteers by wiping with the towels (n=9), and 3) B. cereus remain detectable (80∼660 CFUs /50cm^2) on the forearms of volunteers even with subsequent efforts of disinfection using alcohol wipes. We further confirmed that B. cereus grow robustly (10^2 CFUs /mL to more than 10^6 CFUs /mL) within 24hours at 30°C in PPN. Altogether we find that bed bathing with a towel contaminated with B. cereus leads to spore attachments to the skin, and that B. cereus can proliferate at an accelerated rate at 30°C compared to 20°C in PPN. We therefore highly recommend ensuring the use of sterile bed bath towels prior to PPN administration with catheter in patients requiring bed bathing.
Creators : Hino Chieko Updated At : 2024-06-05 13:12:30