Nagoya Journal of Medical Science

Fixation of tissues and cells is an essential step in histological analysis; however, structural deformation and fluorescence signal attenuation caused by fixatives often pose challenges. This study aimed to evaluate the performance of a newly developed fixative, the FM Fix, by comparing it with conventional fixation methods in tissue staining, optical clearing, and flow cytometry analysis. FM Fix demonstrated staining properties comparable to those of standard fixatives and showed superiority with respect to tissue structure retention. Optical clearing allowed the visualization of fluorescent signals at greater depths. In flow cytometry using green fluorescent protein (GFP)-expressing cells, FM Fix minimized the loss of GFP fluorescence, preserved cell membrane integrity, and maintained cell size. Furthermore, the staining quality of human renal biopsy samples was equivalent to that of 10% neutral buffered formalin (NBF). These findings suggest that FM Fix has excellent structural preservation, fluorescence retention, and antigen preservation properties, making it broadly applicable for histological evaluation and quantitative cellular analysis.

The aim of this study was to examine the associations between components of subjective sleep quality and parasympathetic nervous activity, as assessed by heart rate variability, in intensive care unit nurses during work hours. Sleep quality was assessed using the Pittsburgh Sleep Quality Index, which comprises seven components: subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbances, use of sleeping medications, and daytime dysfunction. Heart rate variability was measured using a Holter monitor, with high-frequency power used as an index of parasympathetic activity. Age, energy expenditure, and step count were included as covariates. Associations between each Pittsburgh Sleep Quality Index component and both raw and adjusted high-frequency power data were analyzed using Kruskal–Wallis tests followed by Bonferroni-adjusted post hoc comparisons. Twenty-four full-time intensive care unit nurses participated. Significant differences in high-frequency adjusted for age and step count were found for sleep duration, with post hoc comparisons revealing significantly lower high-frequency in those with short sleep durations than in those with moderate sleep durations. Significant differences in both raw and all high-frequency residuals were observed for habitual sleep efficiency, with lower high-frequency power in participants with moderate sleep efficiency than in those with optimal efficiency. Poor sleep efficiency and short sleep duration were associated with reduced parasympathetic nervous activity during work hours among intensive care unit nurses.

The study was a cross-sectional study of 377 male Japanese workers to investigate the relationship between lifestyle habits and body composition components, such as body mass index (BMI), grip strength, skeletal muscle mass, and skeletal muscle index (SMI), to promote the prevention of sarcopenic obesity and sarcopenia. Their sleep quality was evaluated using the Athens Insomnia Scale (AIS), and their exercise habits were assessed using the Japanese version of the International Physical Activity Questionnaire. Body composition components, including body fat mass and skeletal muscle mass, were measured using a body composition impedance analyzer, InBody470. Handgrip strength and SMI were evaluated based on the standard values set in the Asian Working Group for Sarcopenia 2019 (AWGS 2019) guidelines. Of the 377 participants, 119 (31.6%) had a BMI of ≥25.0 kg/m². According to the AWGS 2019 guidelines, these participants did not meet the criteria for sarcopenic obesity. Participants with a higher BMI had higher age and handgrip strength (trend, P < 0.001). Additionally, they had higher skeletal muscle mass and SMI (trend, P < 0.001). Multiple regression analysis was performed using skeletal muscle mass and SMI as dependent variables, which revealed that skeletal muscle mass and SMI were associated with age, BMI, breakfast intake, and waist circumference. Furthermore, skeletal muscle mass was associated with heavy physical activity. From the perspective of disease prevention, our findings highlight the importance of prioritizing breakfast intake and physical activity to maintain muscle mass.

Patients with hypertension are recommended to decrease their salt intake. However, some patients do not follow this recommendation. It is possible that some of these individuals cannot restrict their salt intake due to a genetic preference for salt. Thus, we attempted to identify genetic factors related to salt restriction behavior. The subjects were 817 patients with hypertension. Salt restriction status was determined by self-reported answers (yes/no) to the question “Do you restrict your salt intake in everyday meals?” We focused on 21 single-nucleotide polymorphisms related to genes involved in the regulation of blood pressure, salt metabolism, or neurotransmission, and analyzed the associations of the single-nucleotide polymorphisms with salt restriction behavior. Of the 817 subjects, 568 (69.5%) reported that they restricted their salt intake. Two single-nucleotide polymorphisms (rs1167998 and rs2970847) were found to be correlated with salt restriction behavior. Among the 21 single-nucleotide polymorphisms, rs1167998 in the intron region of the dedicator of cytokinesis 7 gene, which encodes a guanine nucleotide exchange factor that plays a role in axon formation and neuronal polarization, showed the strongest association (odds ratio per allele, 1.48; 95% confidence interval, 1.11 to 1.95). In conclusion, rs1167998, a single-nucleotide polymorphism in the dedicator of cytokinesis 7 gene that is associated with blood lipid levels and cardiovascular disease risk was associated with salt restriction behavior in a population of Japanese patients with hypertension. Further confirmatory studies are warranted.

B-cell acute lymphoblastic leukemia (B-ALL) is the most common malignancy occurring in children and a leading cause of cancer-related mortality, thus there is an urgent need for development of novel therapeutic strategies for high risk B-ALL patients. The significance of IKZF1 gene alterations in B-ALL cases is controversial, as some studies have shown those to be associated with poor prognosis, while others have reported that deletion of exons 4–7 of the IKZF1 gene, which results in generation of IKAROS isoform 6, is related favorable prognosis. For the present study, clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 was employed for knockout of the IKZF1 gene and various IKAROS knockout lines were established, which allowed for investigation of precise functions of the gene by comparing four lines with different IKAROS isoform 1 and 6 statuses. The results clearly showed induction of significant differentiation and cell cycle progression in IKAROS isoform 6 knockout clones. Furthermore, knockout of IKAROS isoform 6 resulted in significant upregulation of the expression of IKAROS isoform 1 as well as signal transducer and activator of transcription 5 (STAT5) activity, which are considered to be related to the observed features. Further investigations are warranted to provide greater mechanistic insight regarding IKAROS-mediating pathways, which will lead to development of novel therapy for human B-ALL.

There are limited reports on the effectiveness of promoting pharmacist-led management of candidemia in tertiary care hospitals without a full-time infectious disease specialist. We aimed to assess the effectiveness of promoting pharmacist-led management of candidemia in a tertiary care hospital without a full-time infectious disease specialist and to determine the type of support provided by pharmacists in the antimicrobial stewardship team. This retrospective cohort study evaluated patients with Candida spp. detected in blood cultures between April 2013 and March 2024 at our hospital. To compare the effect of bundled intervention on patients with candidemia, patients enrolled during the periods from April 2013 to March 2018 and April 2018 to March 2024 were classified in the pre- and post-antimicrobial stewardship team pharmacist intervention groups, respectively. There were no significant differences in the baseline clinical characteristics or Candida spp. distribution between the two groups. Compliance to the candidemia treatment bundle significantly improved in the post-antimicrobial stewardship team pharmacist intervention group (4.5% vs 39.6%); however, there was no difference between the two groups in 30-day mortality. The antimicrobial stewardship team pharmacist primarily contributed by recommending treatment initiation, drug selection, and checking for bundle compliance. Pharmacist-led management of candidemia did not improve outcomes for patients with candidemia in a tertiary care hospital with no full-time infectious disease specialist. However, this management may have helped improve the quality of antifungal therapy in terms of drug selection, dosing, and drug interactions, thus contributing to improved candidemia treatment bundle compliance.

Diabetic orthostatic hypotension, associated with cardiovascular autonomic neuropathy, can be assessed using the coefficient of variation of the R-R interval (CVRR). We investigated whether CVRR during deep breathing could serve as a risk indicator for orthostatic blood pressure decline in patients with type 2 diabetes. This study included 88 hospitalized patients aged 51.5–71.4 years with type 2 diabetes undergoing diabetes education or glycemic control. Blood pressure changes during postural transitions were measured using a non-invasive beat-to-beat blood pressure monitoring device. Participants were divided into two groups based on CVRR values measured at rest and during deep breathing, using a cutoff of 2%. Blood pressure changes during postural transitions were compared. At rest, no significant differences in systolic or diastolic blood pressure changes were observed between the autonomic dysfunction group (CVRR ≤ 2%, n = 42) and the non-autonomic dysfunction group (CVRR >2%, n = 46; p > 0.05). However, during deep breathing, patients with CVRR ≤ 2% (n = 20) exhibited significantly greater decreases in systolic blood pressure at 0–30, 31–60, 61–90, 91–120, and 151–180 seconds after standing (p < 0.05). These findings suggest that a CVRR below 2% during deep breathing serves as a risk indicator for orthostatic systolic blood pressure decline in patients with type 2 diabetes.

Patients with severe aortic stenosis undergoing transcatheter aortic valve implantation are usually older adults with multiple comorbidities and often frail. Frailty reflects increased vulnerability to adverse outcomes and is an important factor in this population; however, its impact on postoperative complications and healthcare resource utilization remains uncertain. We investigated the association between preoperative frailty and postoperative outcomes using a nationwide electronic medical records database in Japan. We included patients aged 65 years or older who underwent transcatheter aortic valve implantation between April 2013 and December 2021. Frailty was assessed with the Hospital Frailty Risk Score, with a score of 5 or higher indicating frailty. The primary outcome was acute kidney injury within seven days. Secondary outcomes included major adverse kidney events, blood transfusion within 30 days, and hospital length of stay. Among 781 patients, 237 (30.3%) were classified as frail. Acute kidney injury occurred in 8.8% of non-frail and 12.7% of frail patients. After adjustment for age, sex, comorbidities, baseline estimated glomerular filtration rate, surgical approach, anesthesia type, and hospital size, the odds ratio for acute kidney injury in frail patients was 1.42 (95% confidence interval, 0.83–2.45; P = 0.20). Hospital stay was significantly longer in frail patients, with an adjusted mean difference of 3.45 days. Preoperative frailty was not significantly associated with acute kidney injury or other complications but was associated with prolonged hospitalization. Frailty screening before transcatheter aortic valve implantation may help identify patients at risk of extended hospital stay and guide perioperative care.

Teachers’ instructional strategies and students’ learning styles are key determinants of learning effectiveness. This study examined whether the World Cafe teaching strategy and the Four-Topic Approach to ethical decision-making could enhance outcomes in nursing ethics education. A total of 250 nursing students participated in this study. Two instructional strategies were implemented during the semester: (1) the World Cafe teaching strategy and (2) the Four-Topic Approach. Pretests and post-tests were administered. Learning-style classifications included visual (n = 106), auditory (n = 96), and kinesthetic (n = 124). Additionally, 50 students demonstrated a single learning style, 54 demonstrated two learning styles (eg, visual–auditory, auditory–kinesthetic, or kinesthetic–visual), and 56 demonstrated all three learning styles (visual, auditory, kinesthetic). Eighty-eight students could not be assigned to any learning-style category. Overall, 110 students (44%) exhibited two learning styles. Significant correlations were observed between the use of multiple teaching strategies and nursing students’ learning styles (r = 0.352, p = .01), as well as between teaching strategies and moral sensitivity (r = 0.329, p = .01). Both learning styles and instructional strategies were associated with improved moral sensitivity scores. The findings suggest that integrating diverse teaching strategies―such as the World Cafe and structured ethical decision-making―can effectively enhance nursing ethics education. Tailoring instruction to accommodate students’ learning styles may contribute to improved moral sensitivity among nursing students.

Age-related hearing loss (ARHL) is closely linked to mitochondrial dysfunction in cochlear hair cells; however, its molecular regulation remains unclear. Sestrin2 (SESN2), a stress-inducible protein crucial for regulating energy metabolism, has not been comprehensively studied in the context of ARHL. To investigate SESN2’s role, cochlea-specific SESN2 overexpression and knockout mouse models were established via adeno-associated virus 9 (AAV9) delivery through posterior semicircular canal injection. These models, combined with an H₂O₂-induced accelerated-aging paradigm and H₂O₂-treated House Ear Institute-organ of Corti 1 (HEI-OC1) cellular oxidative injury system, were systematically evaluated using auditory brainstem response (ABR), immunofluorescence (IF), mitochondrial membrane potential assays, western blotting, and other methods. Analysis of ARHL mouse cochleae revealed downregulation of SESN2 in hair cells, accompanied by mitochondrial membrane disruption and increased apoptosis. In aged mice, SESN2 overexpression significantly improved low-frequency hearing thresholds (p < 0.01). Mechanistically, SESN2 reduced oxidative stress, restored mitochondrial function, and suppressed excessive PTEN-induced putative kinase 1 (PINK1)-Parkin-mediated mitophagy, thereby maintaining mitochondrial quality control. This study is the first to show that SESN2 protects against ARHL through a tripartite cascade: antioxidant defense, mitochondrial functional restoration, and dynamic mitophagy regulation. These findings highlight SESN2's pivotal role in auditory preservation and identify it as a promising new therapeutic target for age-related hearing deterioration.

Distraction osteogenesis (DO) is a surgical technique used to repair skeletal defects by promoting bone and soft tissue regeneration. However, prolonged use of external fixators often causes complications such as infections and joint contractures. Neurotrophin-3 (NT-3) enhances osteoblast differentiation via bone morphogenetic protein-2 (BMP-2) and Akt signaling and may also modulate the Wnt/β-catenin pathway. In this study, we investigated the role of NT-3 in bone regeneration during DO. A DO model was established in 9-week-old male ICR mice, in which tibiae were osteotomized and stabilized with external fixators under anesthesia. After a 5-day latency period, distraction was performed at 0.2 mm every 12 hours for 8 days. RNA was extracted at defined time points post-osteotomy for quantitative polymerase chain reaction (qPCR) analysis, and NT-3 was administered post-distraction. Bone regeneration was evaluated by radiographic, histological, and biomechanical analyses. The effects of NT-3 and Dickkopf-1 were further examined in ST2 bone marrow–derived mesenchymal stem cells. NT-3 significantly enhanced bone formation, increased bone mineral density within the DO gap, and improved the mechanical stiffness of regenerated bone. Histological examination revealed earlier bone continuity and greater callus formation in the NT-3 group. Gene expression analysis demonstrated upregulation of Wnt/β‑catenin pathway components, including Wnt10b, β‑catenin, and low-density lipoprotein receptor-related protein 5 (LRP5). In ST2 cells, NT‑3 increased the expression of LRP5, LRP6, β‑catenin, and Runx2, while co‑treatment with Dickkopf‑1 abolished these effects. These findings suggest that NT-3 promotes bone regeneration during DO by activating the Wnt/β-catenin signaling pathway, highlighting its therapeutic potential to improve DO outcomes.

Atherosclerosis, which leads to cardiovascular disease (CVD), can progress without any symptoms. To prevent CVD, it is important to detect atherosclerotic lesions early and assess their severity. Atherosclerosis evaluation for primary prevention is a preferable non-invasive diagnostic tool. In this study, a new device was developed to measure arterial stiffness. This new device measures the pressure–volume relationship during avascularization and the upper arm release process, similar to an automatic blood pressure monitor. The proportionality coefficient between pressure and volume was calculated from this curve; the larger the proportionality coefficient, the greater the arterial stiffness. Using this device, the arterial stiffness index (ASI), standard arteriosclerosis indices, cardio-ankle vascular index (CAVI), ankle-brachial pressure index (ABI), and pulse wave velocity (PWV) were measured in 97 patients with chronic kidney disease and investigated the associations between ASI and these arteriosclerosis indices, as well as CVD history. A positive correlation was observed between ASI and PWV (P = 0.04); however, ABI and CAVI showed no correlation with ASI when analyzed using multiple regression, adjusting for age, sex, smoking, diastolic pressure, and serum creatinine. Furthermore, ASI was related to CVD history by an odds ratio of 1.03 (95% CI, 1.01–1.06) using logistic regression analysis adjusted for age, sex, smoking, and diastolic pressure, whereas CAVI, PWV, and ABI showed no relation to CVD history. ASI measured by our device is easier to measure than indices by devices in everyday use and was the only index to identify actual atherosclerotic disease events.

This study investigated the clinical characteristics of red blood cell distribution width (RDW) in rheumatoid arthritis (RA) and the impact of treatment, including longitudinal dose changes. Among 691 RA patients enrolled in 2025, 591 with RDW recorded in both 2024 and 2025 were analyzed. Based on 2024 data, patients were classified into normal RDW (≤14.5%, n = 436) and high RDW (>14.5%, n = 155) groups. Logistic regression identified factors associated with high RDW. Associations with methotrexate (MTX) and glucocorticoid (GC) dose were examined, and one-year changes in RDW (ΔRDW, 2024–2025) were evaluated according to dose modifications. Patients with high RDW were older (70.6 vs 68.0 years), frequently used MTX (71.0% vs 57.6%) and GCs (41.3% vs 18.8%), had higher Disease Activity Score in 28 joints based on erythrocyte sedimentation rate (DAS28-ESR, 2.92 vs 2.68) and Health Assessment Questionnaire Disability Index (HAQ-DI, 0.64 vs 0.40), and lower hemoglobin (11.8 vs 12.9 g/dL). Multivariable analysis revealed that low hemoglobin (odds ratio [OR], 0.56), MTX use (OR, 2.47), and GC use (OR, 2.21) were independently associated with high RDW. The prevalence of high RDW increased with higher MTX (14.0%, 18.3%, 28.6%) and GC (14.0%, 20.7%, 43.2%) doses. Longitudinally, ΔRDW rose with MTX initiation or escalation (0.43 ± 0.91 vs −0.08 ± 1.06 or −0.26 ± 1.18), whereas GC changes were not significant. These findings indicate that RDW in RA is influenced more by treatment—particularly MTX use and dose escalation—than by inflammation. GC use also showed cross-sectional associations, though longitudinal effects were less evident. RDW should be interpreted in light of treatment rather than as a simple marker of disease activity.

Isolated bone marrow involvement in sarcoidosis is a rare condition, mostly manifested by cytopenia, hypercalcemia and/or hypercalciuria. We present the case of a 48-year-old man with a prolonged fever meeting the criteria for fever of unknown origin, in whom a suspicion of sarcoidosis only emerged after non-necrotizing granulomas were identified in the bone marrow, one year after the onset of the disease. The patient exhibited only mild anemia, moderate leukocytosis, thrombocytosis, and increased erythrocyte sedimentation rate, C-reactive protein levels. Other potential causes of fever of unknown origin and bone marrow non-necrotizing granulomas were ruled out. Although serum angiotensin-converting enzyme levels were elevated, they did not reach diagnostic thresholds. The diagnosis of sarcoidosis was confirmed by newly detected intra-abdominal lymphadenopathy on computed tomography and whole-body 18F-fluorodeoxyglucose positron emission tomography with computed tomography, along with the presence of multiple sarcoid-type non-necrotizing granulomas in the intra-abdominal lymph nodes. Treatment with prednisolone normalized the patient’s body temperature, improved laboratory-inflammatory profile, and enhanced the patient’s quality of life. In cases where fever of unknown origin is present and sarcoidosis is suspected, a bone marrow biopsy may be considered, even in the absence of cytopenia, hypercalcemia, or hypercalciuria.

There were no reports of chronic extensor digitorum communis (EDC) III tendon rupture in zone 5. We report a case of chronic EDC III tendon rupture in zone 5 reconstructed with a bridge tendon graft using palmaris longus tendon. End-to-end tendon repair seemed difficult for chronic EDC tendon rupture, and it was feared that direct repair would result in residual extension contracture of the finger. A 47-year-old right-handed male underwent a bridge tendon graft using the palmaris longus tendon for a chronic EDC III tendon rupture in zone 5 six weeks after the injury. Six months after the surgery, the middle finger extension was almost full, and the flexion range of motion was full.

Clazosentan, a selective endothelin-A (ET-A) receptor antagonist, is used to prevent cerebral vasospasm after aneurysmal subarachnoid hemorrhage (SAH). Although pulmonary edema and fluid retention are recognized adverse effects, hypoxemia associated with atelectasis has not been described. Endothelin-1 contributes to hypoxic pulmonary vasoconstriction (HPV), which preserves ventilation–perfusion (V/Q) matching by diverting blood flow from poorly ventilated regions; pharmacologic ET-A blockade may attenuate HPV, increasing intrapulmonary shunt and impairing oxygenation. We report a man in his 60s with aneurysmal SAH (World Federation of Neurosurgical Societies [WFNS] I, Fisher 3) who underwent clipping surgery and postoperative clazosentan infusion (10 mg/h, standard Japanese dosage). On day 7 of infusion, hypoxemia (SpO₂ < 90% room air) developed; on day 8, arterial blood gas showed PaO₂ 62.5 mmHg with a PaO₂/FiO₂ (P/F) ratio of 109. Chest computed tomography (CT) demonstrated right lower-lobe atelectasis without pulmonary edema or pleural effusion, and echocardiography showed normal cardiac function. Clazosentan was discontinued and corticosteroid therapy initiated, after which oxygenation improved and the atelectasis resolved. The patient was extubated on day 18 and discharged with good neurological recovery. This case illustrates a plausible mechanism whereby ET-A receptor blockade suppresses HPV, exacerbating V/Q mismatch in the presence of segmental atelectasis. Improvement after drug withdrawal supports this association. Clinicians should recognize that hypoxemia during clazosentan therapy may occur independently of fluid overload and warrants early respiratory evaluation.

Classic deficiency of interleukin-36 (IL-36) receptor antagonist (DITRA) is characterized by severe, recurrent generalized pustular psoriasis (GPP) with systemic inflammation and is typically caused by biallelic IL36RN variants. However, monoallelic c.115+6T>C and c.28C>T variants of IL36RN have also been reported to underlie DITRA. To the best of our knowledge, no cases of a heterozygous IL36RN c.28C>T variant presenting with the unilateral localization of symptoms have been reported. Our present case emphasize that IL36RN-related disease should be considered even with the atypical skin symptoms, thereby broadening the spectrum of DITRA.