Oita University
  • Ōita, Japan
Recent publications
A 67-year-old woman was diagnosed with chronic bronchitis after an abnormality on chest radiography. Two years later, proteinuria was noted, and she was diagnosed with nephrosis the following year. Membranous nephropathy associated with Mycobacterium intracellurare was confirmed and clarithromycin, ethambutol and rifampicin were administered. She recovered from nephrosis after two years of anti-mycobacterial treatment. Successful treatment of the underlying cause of secondary membranous nephropathy may result in a cure. Membranous nephropathy due to mycobacteria is a rare condition. To our knowledge, this is the first report of membranous nephropathy associated with M. intracellurare.
Our aim in this note is to deal with Trudinger-type inequalities for variable Riesz potentials of functions in Musielak–Orlicz spaces over bounded metric measure spaces as an extension of the previous paper by Hurri-Syrjänen and the authors ( Complex Var. Elliptic Equ. 68 (2023), no. 10, 1694–1714). As an application, we prove Trudinger-type inequalities for double phase functionals.
Background Rotavirus infections are a major cause of severe gastroenteritis in children. Human rotavirus strains with the unconventional G8P[14] genotype have sporadically been detected in diarrheic patients in different parts of the world. However, full genomes of only two human G8P[14] strains from Africa (North Africa) have been sequenced, and the origin and evolutionary patterns of African G8P[14] strains remain to be elucidated. Methods In this study, we sequenced the full genome of an African G8P[14] strain (RVA/Human-wt/KEN/A75/2000/G8P[14]) identified in archival stool samples from a diarrheic child in Kenya. Results Full genome-based analysis of strain A75 revealed a unique genogroup constellation, G8-P[14]-I2-R2-C2-M2-A11-N2-T6-E2-H3, with the I2-R2-C2-M2-A11-N2-T6-E2-H3 part being common among rotavirus strains from artiodactyls such as cattle. Phylogenetic analysis showed that all the 11 genomic segments of strain A75 are closely related to segments found in artiodactyl rotavirus strains, and likely strain A75 derived from spillover transmission of an artiodactyl rotavirus strain to humans. Conclusion This is the first report on a full genome-based characterization of a human G8P[14] strain from East Africa. This study demonstrates the diversity of human G8P[14] strains in Africa and contributes to the elucidation of their spreading and evolution, which includes zoonotic transmission from artiodactyls.
This case report describes a 56-year-old woman with autosomal dominant polycystic kidney disease and chronic renal failure who underwent transcatheter arterial embolization with N-butyl-2-cyanoacrylate-Lipiodol before renal transplantation. Both kidneys were significantly enlarged, necessitating transcatheter arterial embolization to reduce renal volume and create space for transplantation. The right kidney volume decreased from 2520 to 1150 mL within 9 months after transcatheter arterial embolization, enabling successful transplantation. Long-term (37 months) follow-up demonstrated continued shrinkage of the transcatheter arterial embolization-treated right kidney and a spontaneous reduction in the non-transcatheter arterial embolization-treated left kidney. The reduction in renal volume achieved with transcatheter arterial embolization exceeded that reported for conventional methods using metal coils or ethanol. This case highlights the potential of as an effective embolizing agent for patients with autosomal dominant polycystic kidney undergoing renal transplantation. Fullsize Image
Diagnosis of uterine mesenchymal tumors continues to be challenging because of their nonspecific clinicopathological presentation. Several studies have focused on the underdiagnosis/undertreatment of hidden uterine sarcomas. However, few have examined the overdiagnosis/overtreatment of benign uterine mesenchymal tumors that masquerade as uterine sarcomas. We report 4 cases of benign uterine mesenchymal tumors that were preoperatively diagnosed as having malignant potential and underwent extensive surgery. The patients had cotyledonoid-dissecting leiomyomas, uterine tumors resembling ovarian sex-cord tumors, metastasizing leiomyomas, and torsion of a subserosal uterine leiomyoma. The patients’ ages ranged from 42 to 59 years (median 51.5). All 4 cases were suspected of having a malignant tumor based on preoperative clinical imaging, and 1 case was suspected of having a malignant tumor based on preoperative imaging and pathological evaluations of biopsy. All patients underwent surgery, including a hysterectomy. One of the 4 patients (25%) underwent lymphadenectomy, and 1 (25%) underwent partial lung resection. All patients survived without evidence of disease. Overall, detailed pre- and intraoperative clinical and pathological evaluations may be insufficient for diagnosis. Physicians should be aware of the diversity of uterine mesenchymal tumors, the difficulty in diagnosing them, and how to avoid these pitfalls.
A cluster of coronavirus disease (COVID-19) cases occurred in a 40-bed private hospital in Oita City, Japan. This study examined the effect of heat and moisture exchangers (HMEs) with electrostatic filters on infection control. The study included 32 hospitalized patients, including four patients with normal breathing (non-tracheostomized patients), two tracheostomized patients with spontaneous breathing, and 26 tracheostomized patients on ventilators. HMEs without filters were used for airway management in the two tracheostomized patients with spontaneous breathing and one tracheostomized patient on ventilator, and HMEs with electrostatic filters were used in 25 tracheostomized patients on ventilators. All patients with negative test results for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antigen were further tested by reverse transcription polymerase chain reaction to confirm the absence of infection. All non-tracheostomized patients and tracheostomized patients with spontaneous breathing (100%) and two of the 26 (7.6%) tracheostomized patients on ventilators were confirmed to have SARS-CoV-2 infection. Both patients (100%) who used HMEs without filters were infected, whereas only one of the 25 patients (4%) using HMEs with electrostatic filters was infected, showing a significantly lower rate of infection in the latter group. The present results suggest that in situations where the level of virus contamination in the environment is high, such as during a large-scale COVID-19 outbreak, use of HMEs with electrostatic filters would be effective for controlling infection.
Placental transmogrification of the lung (PTL) is a rare cystic lesion characterized by a distinctive microscopic architecture resembling placental villi. Although its etiology remains unclear, PTL is frequently observed with emphysema, suggesting a potential association between these conditions. However, the precise nature of this relationship remains ambiguous, and whether PTL causes or results from emphysema remains unclear. This report presents an incidental finding of PTL without macroscopic emphysematous changes with detailed immunohistochemical and ultrastructural analysis. A 58‐year‐old man died from aspiration pneumonia due to methanol poisoning. Autopsy revealed pyothorax in the right lung cavity and hemorrhage in the bilateral putamen. Although the left lung showed no severe inflammatory changes, a white‐yellowish granular lesion was observed. Histopathologically, the lesion demonstrated villi‐like structures with interstitial adipocyte infiltration, without evidence of hamartomatous component, such as cartilage or smooth muscle. Thus, the lesion was diagnosed as PTL with lipomatous change. PTL is typically associated with emphysematous/cystic lesions and is often considered reactive due to these. Herein, the lesion was surrounded by microscopic emphysema, suggesting an early‐stage PTL that may have contributed to the development of emphysematous changes. This report describes the PTL with detailed immunohistochemical analysis.
The elimination of bosentan (BOSE) is involved in several metabolic enzymes and transporters, including CYP3A4 and OATP1B1/3. Clarithromycin (CAM) has the potential to inhibit these activities, leading to an approximately threefold increase in BOSE exposure when combined. Hepatic impairment, a common adverse effect of BOSE, is reportedly induced in a dose-dependent manner. This study comprehensively evaluated the adverse events of BOSE in combination with CAM. A total of 12 patients who received BOSE and CAM for more than 7 days at Oita University Hospital between June 2005 and December 2022 were included. The adverse events documented in the BOSE clinical trial were not observed within the 2-week period following the initiation of combination therapy. None of the patients exhibited an increase exceeding threefold the institutional reference threshold, which serves as the standard for BOSE suspension or discontinuation. No patient experienced a rise in liver function parameters necessitating the suspension or discontinuation of BOSE within 180 days of initiating the combination therapy. The findings suggest that concurrent use of BOSE and CAM does not increase the incidence of adverse events, including liver impairment. However, given that the daily dose in this study was approximately half the usual dose, caution is necessary when administering BOSE at the usual maintenance dose.
Background Helicobacter pylori (H. pylori) is a lifelong infection, often acquired in childhood and persisting throughout life, that can lead to serious gastric diseases, including gastric cancer in adults. While asymptomatic in most children, it may cause extraintestinal manifestations affecting growth, necessitating distinct pediatric management strategies—particularly in countries with a high risk of gastric cancer. Accurate diagnosis is critical in high-risk populations. The stool antigen test is a reliable, non-invasive method for young children. Despite Bhutan’s high H. pylori burden, diagnostic tools remain scarce. This study aimed to determine the prevalence and risk factors of H. pylori infection in Bhutanese children and validate a new in-house immunochromatography test (the A-ICT) kits. Methods A cross-sectional study was conducted in 2023 among children under 64 months of age at three immunization clinics in Thimphu. H. pylori antigen in stool was detected using an ICT kit. After obtaining informed consent, parents completed questionnaires. Data were analyzed using STATA version 14.2 and R version 4.4.1. Results A total of 226 children (mean age 33.28 months) participated in the study. The A-ICT kit showed high concordance with the commercial kit (Kappa 0.84 [95% CI: 0.78–0.89]) and excellent sensitivity (0.96) and specificity (0.95). The prevalence of H. pylori was 19.54% (95% CI:14.95–24.83). Risk factors included increasing age, having two or more siblings, and fathers who were farmers/wagers, and who worked in government/private sector. Children who were fed with or who ate using a spoon had a significantly lower risk of H. pylori infection than those who were fed or ate with fingers (p < 0.05). Conclusions The A-ICT kit demonstrated remarkable sensitivity and specificity. Improvements in hygiene and sanitation related to child feeding practices are essential. Awareness programs should target large families and individuals employed in the formal sector, including both household and workplace settings. The validation of the A-ICT is a significant step toward a gastric cancer prevention program that facilitates early diagnosis and H. pylori eradication. The test kit is highly recommended for H. pylori screening and the confirmation of eradication post-treatment given its accuracy, rapidity, and simplicity in execution.
Alpha-1-microglobulin (A1M), metabolized in renal tubules, plays an important role as a potent antioxidant in human cells. The majority of A1M is present in the blood in free form and in a bound form with IgA dimers, with the free form thought to have antioxidant capacity. However, the dynamics of A1M in chronic kidney disease patients being susceptible to oxidative stress remain unclear. The present study aimed to determine the profile and changes in A1M resulting from blood purification in patients undergoing maintenance hemodialysis (HD) (including hemodiafiltration). Eighteen patients on stable maintenance HD were included in the study. For analysis, residual serum samples were collected from these patients during routine blood tests. A1M was measured using a latex agglutination immunoassay. The abundance of the free and bound forms of A1M was determined by native PAGE. The A1M concentration was 91.58 ± 26.34 mg/L, the percentage of free A1M was 72.62 ± 20.02%. The pre- and postdialysis mean concentration of free A1M were 68.74 ± 29.78 and 52.13 ± 22.48 mg/L, respectively. The mean reduction rate in free A1M after blood purification treatment was 20.49 ± 20.91%, showing the significant difference between pre- and postdialysis concentrations. The predialysis mean concentration of protein-bound A1M was 22.85 ± 15.16 mg/L, with a postdialysis concentration of 24.73 ± 12.82 mg/L. The novel finding of this study is that A1M in patients on maintenance HD exists pre-dominantly in the free form and can be effectively removed by hemodialysis.
Background It is unclear to what extent silent atrial fibrillation (AF) is present in subjects previously undiagnosed with AF. The recently popular 7‐day patch electrocardiography (ECG) monitoring may help answer this question. Methods In the Kitsuki and Usuki cities in Oita Prefecture, Japan, a study was conducted among subjects who underwent 7‐day patch ECG monitoring (Heartnote) for silent AF screening during the national insurance health checkup between June and November 2023. Subjects were (1) 65–74 years old and have ≥ 1 of the following risk factors: hypertension, diabetes mellitus, stroke, transient ischemic attack, and underlying heart disease (heart failure and/or previous myocardial infarction) and (2) 75 years and older. Results A total of 571 subjects (307 females and 264 males, mean age 75.3 ± 5.4 years) were analyzed. Silent AF was detected in 16 out of 571 subjects (2.8%). Among those aged 75 years or older, silent AF was detected in 15 out of 291 subjects (5.2%). In multivariate analysis, among age, body mass index (BMI), hypertension, diabetes, stroke, and underlying heart disease, only age was the independent predictor of silent AF detection (odds ratio: 1.16, 95% confidence interval: 1.06–1.28, p < 0.01). Conclusions Seven‐day patch ECG monitoring during the national insurance health checkup efficiently detected silent AF in individuals aged 75 years and older.
Background Valvular injuries in chest trauma mostly affect the aortic and mitral valves, but traumatic tricuspid regurgitation (TR) remains rare. This report describes the successful repair of traumatic TR secondary to papillary muscle rupture complicated with right ventricular (RV) free wall injury and atrial septal perforation. Case presentation A 50-year-old male suffered blunt chest trauma from a tree fall, leading to multiple fractures, mediastinal hematoma, and hemoperitoneum caused by splenic bleeding. Given that heart failure worsened eventually, echocardiography was conducted on day 7, showing significant TR resulting from leaflet prolapse caused by papillary muscle rupture with concomitant 4.8 mm atrial septal perforation and focal RV free wall thinning. Nonetheless, the heart failure was responsive to medical treatment. The patient was then scheduled for surgery 1 month later. The atrial septal defect was closed via direct suture closure. The RV free wall injury presented with scarring and did not require repair. The tricuspid valve repair included suturing the ruptured medial papillary muscle to the RV wall, reconstructing the ruptured posterior leaflet chordae with prosthetic chordae, and securing an annuloplasty ring. Consequently, TR was completely controlled. Conclusions Traumatic tricuspid valve injuries are rare. The optimal timing of surgery for traumatic TR remains controversial. However, early diagnosis and intervention are recommended to prevent progressive RV dysfunction and improve the success of tricuspid valve repair.
Patients with ovarian high-grade serous carcinoma (OHGSC) gradually acquire resistance to standard chemotherapy following recurrence. In our previous study on OHGSC, histone deacetylase (HDAC) 6 upregulation led to a poor prognosis, and programmed death ligand-1 (PD-L1) expression was positively correlated with HDAC6 expression. We analyzed HDAC6 and PD-L1 expression before and after chemotherapy to investigate their association with chemotherapy resistance and patient survival. PD-L1 and HDAC6 expression were immunohistochemically analyzed using clinical samples from 54 patients with OHGSC before and after standard chemotherapy. High PD-L1 expression (≥ 5%) was detected in five and nine patients before and after chemotherapy, respectively. The mean PD-L1-positive rate after chemotherapy was 3.88%, which was significantly higher than the rate before chemotherapy (0.68%). The high HDAC6 expression frequency significantly increased from four patients before chemotherapy to 13 patients after. High PD-L1 expression after chemotherapy was significantly correlated with a chemotherapy response score of three, signifying a good chemo-response. High PD-L1 expression after chemotherapy was associated with poor progression-free survival and overall survival in patients who underwent complete surgical resection. In OHGSC, residual tumors after chemotherapy show enhanced HDAC6 and PD-L1 expression. Upregulated PD-L1 after neoadjuvant chemotherapy (NAC) has contradictory characteristics, indicating a good response to chemotherapy but unfavorable survival. It is a wolf in sheep’s clothing, and physicians should not make an optimistic prognosis even if the patient shows a good response to NAC. HDAC6 and PD-L1 may be therapeutic targets and prognostic factors for residual tumors after chemotherapy in OHGSC.
Background The global prevalence of obesity has risen significantly, thereby resulting in a consequential increase in the use of bariatric surgical procedures. Optical trocars are extensively utilized for identifying laparoscopic access in patients with morbid obesity. However, their efficacy and safety are dependent on the surgeon’s capability to accurately identify anatomical structures during insertion. The current study investigated the influence of anatomical structure recognition and insertion time on successful optical trocar insertion, which can offer insights that are applicable to various surgical specialties. Methods This retrospective study was conducted on 143 patients who underwent laparoscopic sleeve gastrectomy. Data on demographic characteristics, comorbidities, anatomical structure recognition, and trocar insertion time were collected. To evaluate the associations between these factors, a statistical analysis using the univariate and multivariate models was performed. Results The recognition of anatomical structures such as the rectus abdominis and peritoneum during the procedure was significantly related to shorter insertion times (p < 0.01). Multivariate analysis revealed that an accurate identification of these structures independently contributed to an efficient trocar placement. The risk of complications increased in cases where the peritoneum could not be clearly identified. However, there were no cases of major vascular or organ injuries, and all complications were managed with conservative treatment. Conclusions Successful trocar insertion in patients with morbid obesity is dependent on the precise recognition of anatomical structures, particularly the rectus abdominis and peritoneum. This approach enhances both procedural safety and efficiency, and the findings may have broader applicability to laparoscopic techniques.
Objective To confirm noninferiority of laparoscopic (LAP) to open surgery (OP) for progression-free survival (PFS) of patients with non-curable stage IV colorectal cancer (CRC). Background Benefits of LAP versus OP are suggested, but long-term survival following LAP for symptomatic, noncurable CRC remains unclear. Methods In this open-label, multicenter, randomized controlled trial, only accredited surgeons from 42 Japanese institutions participated. Eligibility criteria included pathologically proven adenocarcinoma or adenosquamous carcinoma; primary tumor anywhere in the colon causing bowel stenosis and/or bleeding; and at least 1 to 3 noncurable factors. Patients received mFOLFOX6+bevacizumab or CapeOX+bevacizumab postoperatively and were randomly assigned 1:1 to the OP or LAP group. The primary endpoint was PFS, with noninferiority margin for the hazard ratio (HR) set at 1.38. Results Between January 2013 and January 2021, 195 patients were randomized (OP, n = 95, LAP, n = 100). Ninety-two patients received OP and 98 LAP, with 82 OP and 86 LAP patients receiving postoperative chemotherapy. Median PFS was 9.7 months (95% CI = 8.7–11.3) for OP and 10.4 months (9.1–12.4) for LAP. Noninferiority of LAP was confirmed [HR = 1.02; 91.4% CI = 0.79–1.32 (<1.38), P for noninferiority = 0.021]. Median overall survival was 23.9 months (95% CI = 18.6–29.4) for OP and 25.4 months (19.4–29.0) for LAP (HR = 0.99; 95% CI, 0.72–1.36). In-hospital mortality was 1.1% (OP) and 0% (LAP). Postoperative complications (Grade 2–4) included ileus (OP = 12.0%; LAP = 5.1%), wound infection (OP = 2.2%; LAP = 2.0%), and anastomotic leakage (OP = 0%; LAP = 2.0%). Conclusions LAP appears to be an acceptable standard treatment for symptomatic, noncurable stage IV CRC. Trial registration UMIN-CTR, number UMIN000009715.
Helicobacter pylori is considered to contribute to gastric cancer and is also used as a marker to trace human migration due to its co-evolution with humans. To understand the recently proposed tripartite model suggesting three ancestral origins for the Japanese population and address the enigma of the high incidence of gastric cancer in Northeast Hondo (Hondo is mainland Japan), we conducted a fine-scale population structure analysis using a large Japanese H. pylori dataset, including 438 strains from 9 regions based on whole-genome sequences. As a result of fineSTRUCTURE analysis, it was found that H. pylori in Northeast Hondo is genetically distinct from hspEAsia subgroup 7 (sg7), which is widely distributed elsewhere in Hondo. We named this new subgroup hspEAsia-sg8 (Northeast Hondo). Ancestry analysis using ChromoPainter revealed that, while a large proportion of the genomes of hspEAsia-sg8 strains were painted by donors from their own population, the ancestry components of hspEAsia-sg7 showed a high proportion of Chinese and Korean components, suggesting that they were formed through admixture with continental hspEAsia subgroups. These results align with human genome studies, which indicate an original ancestry component in Northeast Hondo and a higher proportion of East Asian components in West Hondo, supporting the tripartite model. This also suggests novel potential for biogeographic ancestry inference in forensic science, as the H. pylori genome can distinguish Hondo populations. Furthermore, fixation index analysis comparing the genome of hspEAsia-sg8 with other Japanese hspEAsia subgroups revealed a high number of nonsynonymous mutations in hp0378 ( ccsBA ) and hp0377 ( dsbC / ccmG ). Because these genes are involved in cytochrome c maturation and disulphide bond formation, the detected mutations may affect bacterial survival, growth or pathogenicity. This study supports the tripartite model for the formation of modern Japanese people and suggests that the strain of H. pylori prevalent in the Northeast Hondo region may contribute to the high incidence of gastric cancer there.
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581 members
Hidekatsu Iha
  • Department of Microbiology
Masato Tanigawa
  • Faculty of Medicine
Toshiya Takami
  • Department of Computer Science and Intelligent Systems
Atsushi Kondo
  • Department of Applied Chemistry
Tadasuke Ando
  • Department of Urology
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Ōita, Japan