1.Relationship between force level and exertion strategy in rapid isometric contractions.
SEIJI ONO ; MORIHIKO OKADA ; TOMOHIRO KIZUKA ; KATSUNORI TANII
Japanese Journal of Physical Fitness and Sports Medicine 1997;46(3):289-295
The relationships were examined between the relative force level and exertion strategy during rapid isometric contractions. Thirteen subjects exerted isometric pinchings as fast as possible at various force levels. Force curves and surface EMGs from the first dorsal interosseous muscle were obtained during the contractions. While the single-peaked force curves remained analogous up to a certain force level, they changed to multi-peaked ones at higher force levels. The critical force level, which could be determined in all subjects as relative force level to MVC, was positively correlated with the %MVC EMG magnitude for unit time, obtained below the critical level. EMG durations were significantly shorter blow than above the critical level. These results suggest that different exertion strategies are utilized in rapid contractions at different force levels, and that individual differences in the critical force level are related to difference in the manner of motor unit activation.
2.Clinical Influence of Cervical Spinal Canal Stenosis on Neurological Outcome after Traumatic Cervical Spinal Cord Injury without Major Fracture or Dislocation.
Tsuneaki TAKAO ; Seiji OKADA ; Yuichiro MORISHITA ; Takeshi MAEDA ; Kensuke KUBOTA ; Ryosuke IDETA ; Eiji MORI ; Itaru YUGUE ; Osamu KAWANO ; Hiroaki SAKAI ; Takayoshi UETA ; Keiichiro SHIBA
Asian Spine Journal 2016;10(3):536-542
STUDY DESIGN: Retrospective case series. PURPOSE: To clarify the influence of cervical spinal canal stenosis (CSCS) on neurological functional recovery after traumatic cervical spinal cord injury (CSCI) without major fracture or dislocation. OVERVIEW OF LITERATURE: The biomechanical etiology of traumatic CSCI remains under discussion and its relationship with CSCS is one of the most controversial issues in the clinical management of traumatic CSCI. METHODS: To obtain a relatively uniform background, patients non-surgically treated for an acute C3-4 level CSCI without major fracture or dislocation were selected. We analyzed 58 subjects with traumatic CSCI using T2-weighted mid-sagittal magnetic resonance imaging. The sagittal diameter of the cerebrospinal fluid (CSF) column, degree of canal stenosis, and neurologic outcomes in motor function, including improvement rate, were assessed. RESULTS: There were no significant relationships between sagittal diameter of the CSF column at the C3-4 segment and their American Spinal Injury Association motor scores at both admission and discharge. Moreover, no significant relationships were observed between the sagittal diameter of the CSF column at the C3-4 segment and their neurological recovery during the following period. CONCLUSIONS: No relationships between pre-existing CSCS and neurological outcomes were evident after traumatic CSCI. These results suggest that decompression surgery might not be recommended for traumatic CSCI without major fracture or dislocation despite pre-existing CSCS.
Cerebrospinal Fluid
;
Cervical Cord*
;
Constriction, Pathologic*
;
Decompression
;
Dislocations*
;
Humans
;
Magnetic Resonance Imaging
;
Retrospective Studies
;
Spinal Canal*
;
Spinal Injuries
3.Does Helicobacter pylori Exacerbate Gastric Mucosal Injury in Users of Nonsteroidal Anti-Inflammatory Drugs? A Multicenter, Retrospective, Case-Control Study.
Yoshiyasu KONO ; Hiroyuki OKADA ; Ryuta TAKENAKA ; Ko MIURA ; Hiromitsu KANZAKI ; Keisuke HORI ; Masahide KITA ; Takao TSUZUKI ; Seiji KAWANO ; Yoshiro KAWAHARA ; Kazuhide YAMAMOTO
Gut and Liver 2016;10(1):69-75
BACKGROUND/AIMS: The interaction between nonsteroidal anti-inflammatory drugs (NSAIDs) and Helicobacter pylori remains controversial. We retrospectively investigated whether H. pylori infection exacerbates severe gastric mucosal injury among chronic NSAID users. METHODS: From January 2010 to December 2013, a total of 245 long-term NSAID (including low-dose aspirin) users who had undergone an esophagogastroduodenoscopy and had been evaluated for H. pylori infection were enrolled at Okayama University Hospital and Tsuyama Chuo Hospital. The degree of gastric mucosal injury was assessed according to the modified Lanza score (MLS). Severe gastric mucosal injury was defined as an MLS > or =4. Univariate and multivariate logistic regression analyses were performed. RESULTS: In the univariate analysis, age > or =75 years (odds ratio [OR], 2.4; 95% confidence interval [CI], 1.3 to 4.2), H. pylori-positivity (OR, 2.0; 95% CI, 1.2 to 3.5), and the concomitant use of proton pump inhibitors (PPIs) (OR, 0.48; 95% CI, 0.26 to 0.86) were significantly associated with severe gastric mucosal injury. The multivariate analysis was adjusted by age and sex and demonstrated that H. pylori-positivity (OR, 1.8; 95% CI, 1.0 to 3.3) and the concomitant use of PPIs (OR, 0.53; 95% CI, 0.28 to 0.99) significantly contributed to severe gastric mucosal injury. CONCLUSIONS: H. pylori infection exacerbates severe gastric mucosal injury among chronic NSAID users.
Aged
;
Anti-Inflammatory Agents, Non-Steroidal/*adverse effects
;
Case-Control Studies
;
*Disease Progression
;
Endoscopy, Digestive System
;
Female
;
Gastric Mucosa/*drug effects/*microbiology
;
Helicobacter Infections/*complications/microbiology/pathology
;
*Helicobacter pylori/drug effects
;
Humans
;
Logistic Models
;
Male
;
Middle Aged
;
Odds Ratio
;
Proton Pump Inhibitors/adverse effects
;
Retrospective Studies
4.Establishment of an Allo-Transplantable Hamster Cholangiocarcinoma Cell Line and Its Application for In Vivo Screening of Anti-Cancer Drugs.
Nattapong PUTHDEE ; Kulthida VAETEEWOOTTACHARN ; Wunchana SEUBWAI ; Orasa WONKCHALEE ; Worasak KAEWKONG ; Amornrat JUASOOK ; Somchai PINLAOR ; Chawalit PAIROJKUL ; Chaisiri WONGKHAM ; Seiji OKADA ; Thidarut BOONMARS ; Sopit WONGKHAM
The Korean Journal of Parasitology 2013;51(6):711-717
Opisthorchis viverrini (O. viverrini) is a well-known causative agent of cholangiocarcinoma (CCA) in humans. CCA is very resistant to chemotherapy and is frequently fatal. To understand the pathogenesis of CCA in humans, a rodent model was developed. However, the development of CCA in rodents is time-consuming and the xenograft-transplantation model of human CCA in immunodeficient mice is costly. Therefore, the establishment of an in vivo screening model for O. viverrini-associated CCA treatment was of interest. We developed a hamster CCA cell line, Ham-1, derived from the CCA tissue of O. viverrini-infected and N-nitrosodimethylamine-treated Syrian golden hamsters. Ham-1 has been maintained in Dulbecco's Modified Essential Medium supplemented with 10% fetal bovine serum for more than 30 subcultures. These cells are mostly diploid (2n=44) with some being polyploid. Tumorigenic properties of Ham-1 were demonstrated by allograft transplantation in hamsters. The transplanted tissues were highly proliferative and exhibited a glandular-like structure retaining a bile duct marker, cytokeratin 19. The usefulness of this for in vivo model was demonstrated by berberine treatment, a traditional medicine that is active against various cancers. Growth inhibitory effects of berberine, mainly by an induction of G1 cell cycle arrest, were observed in vitro and in vivo. In summary, we developed the allo-transplantable hamster CCA cell line, which can be used for chemotherapeutic drug testing in vitro and in vivo.
Allografts
;
Animals
;
Antineoplastic Agents/*isolation & purification/therapeutic use
;
Berberine/therapeutic use
;
Cell Culture Techniques
;
*Cell Line, Tumor
;
Cell Transplantation/methods
;
Cholangiocarcinoma/*drug therapy/pathology
;
Cricetinae
;
Culture Media/chemistry
;
Disease Models, Animal
;
Drug Evaluation, Preclinical/*methods
;
Male
;
Mesocricetus
5.Postoperative Bleeding Risk after Gastric Endoscopic Submucosal Dissection in Patients Receiving a P2Y12 Receptor Antagonist
Ryosuke HIRAI ; Seiji KAWANO ; Shoko INOO ; Sakiko KURAOKA ; Shotaro OKANOUE ; Takuya SATOMI ; Kenta HAMADA ; Yoshiyasu KONO ; Hiromitsu KANZAKI ; Masaya IWAMURO ; Yoshiro KAWAHARA ; Hiroyuki OKADA
Gut and Liver 2023;17(3):404-411
Background/Aims:
The safety of gastric endoscopic submucosal dissection (ESD) in users of a P2Y12 receptor antagonist (P2Y12RA) under current guidelines has not been verified.
Methods:
Patients treated by gastric ESD at Okayama University Hospital between January 2013 and December 2020 were registered. The postoperative bleeding rates of patients (group A) who did not receive any antithrombotic drugs; patients (group B) receiving aspirin or cilostazol monotherapy; and P2Y12RA users (group C) those on including monotherapy or dual antiplatelet therapy were compared. The risk factors for post-ESD bleeding were examined in a multivariate analysis of patient background, tumor factors, and antithrombotic drug management.
Results:
Ultimately, 1,036 lesions (847 patients) were enrolled. The bleeding rates of group B and C were significantly higher than that of group A (p=0.012 and p<0.001, respectively), but there was no significant difference between group B and C (p=0.11). The postoperative bleeding rate was significantly higher in dual antiplatelet therapy than in P2Y12RA monotherapy (p=0.014). In multivariate analysis, tumor diameter ≥12 mm (odds ratio [OR], 4.30; 95% confidence interval [CI], 1.99 to 9.31), anticoagulant use (OR, 4.03; 95% CI, 1.64 to 9.86), and P2Y12RA use (OR, 3.40; 95% CI, 1.07 to 10.70) were significant risk factors for postoperative bleeding.
Conclusions
P2Y12RA use is a risk factor for postoperative bleeding in patients who undergo ESD even if receiving drug management according to guidelines. Dual antiplatelet therapy carries a higher risk of bleeding than monotherapy.
6.Interspinous Ligament Lidocaine and Steroid Injections for the Management of Baastrup's Disease: A Case Series.
Kentaro OKADA ; Seiji OHTORI ; Gen INOUE ; Sumihisa ORITA ; Yawara EGUCHI ; Junichi NAKAMURA ; Yasuchika AOKI ; Tetsuhiro ISHIKAWA ; Masayuki MIYAGI ; Hiroto KAMODA ; Miyako SUZUKI ; Gou KUBOTA ; Yoshihiro SAKUMA ; Yasuhiro OIKAWA ; Kazuhide INAGE ; Takeshi SAINOH ; Tomoaki TOYONE ; Kazuyo YAMAUCHI ; Kazuhisa TAKAHASHI
Asian Spine Journal 2014;8(3):260-266
STUDY DESIGN: Prospective study. PURPOSE: To examine the long-term effects of interspinous ligament injections of local anesthetics and steroids for the treatment of Baastrup's diseases. OVERVIEW OF LITERATURE: Baastrup's disease is associated with axial low back pains. Baastrup's disease has been more recently described as the "kissing spinous processes" disease. Several authors have reported methods for the diagnosis and treatment of the disease. However, there has been only one report of patients receiving interspinous ligament injections of agents for the treatment of Baastrup's disease. METHODS: Seventeen patients showed severe low back pains between spinous processes at L3-L4 or L4-L5. X-ray imaging, computed tomography, and magnetic resonance imaging revealed kissing spinous processes, consolidation of spinous process, or inflammation of an interspinous ligament. Pain reliefs after lidocaine and dexamethasone administration into interspinous ligament as therapy for low back pains were being examined and followed up. RESULTS: Low back pain scores significantly improved immediately after injection of the agents into interspinous ligaments. At final follow-up (1.4 year), low back pain scores significantly improved as compared with before the treatment. CONCLUSIONS: Findings from the current study indicate that lidocaine and dexamethasone administration into interspinous ligament in patients diagnosed with Baastrup's disease is effective for managing the pain associated with this disease.
Anesthetics, Local
;
Dexamethasone
;
Diagnosis
;
Follow-Up Studies
;
Humans
;
Inflammation
;
Lidocaine*
;
Ligaments*
;
Low Back Pain
;
Magnetic Resonance Imaging
;
Prospective Studies
;
Steroids
7.Assessing the utility of osteoporosis self-assessment tool for Asians in patients undergoing hip surgery
Keisuke UEMURA ; Kazuma TAKASHIMA ; Ryo HIGUCHI ; Sotaro KONO ; Hirokazu MAE ; Makoto IWASA ; Hirohito ABE ; Yuki MAEDA ; Takayuki KYO ; Takashi IMAGAMA ; Wataru ANDO ; Takashi SAKAI ; Seiji OKADA ; Hidetoshi HAMADA
Osteoporosis and Sarcopenia 2024;10(1):16-21
Objectives:
Diagnosis and treatment of osteoporosis are instrumental in obtaining good outcomes of hip surgery.Measuring bone mineral density (BMD) using dual-energy X-ray absorptiometry (DXA) is the gold standard for diagnosing osteoporosis. However, due to limited access to DXA, there is a need for a screening tool to identify patients at a higher risk of osteoporosis. We analyzed the potential utility of the Osteoporosis Self-assessment Tool for Asians (OSTA) as a screening tool for osteoporosis.
Methods:
A total of 1378 female patients who underwent hip surgery at 8 institutions were analyzed. For each patient, the BMD of the proximal femoral region was measured by DXA (DXA-BMD), and the correlation with OSTA score (as a continuous variable) was assessed. Receiver operating characteristic (ROC) curve analysis was performed to assess the ability of OSTA score to predict osteoporosis. Lastly, the OSTA score was truncated to yield an integer (OSTA index) to clarify the percentage of patients with osteoporosis for each index.
Results:
DXA-BMD showed a strong correlation with OSTA (r = 0.683; P < 0.001). On ROC curve analysis, the optimal OSTA score cut-off value of − 5.4 was associated with 73.8% sensitivity and 80.9% specificity for diagnosis of osteoporosis (area under the curve: 0.842). A decrease in the OSTA index by 1 unit was associated with a 7.3% increase in the probability of osteoporosis.
Conclusions
OSTA is a potentially useful tool for screening osteoporosis in patients undergoing hip surgery. Our findings may help identify high-risk patients who require further investigation using DXA.
8.Ongoing rubella epidemic in Osaka, Japan, in 2018–2019
Daiki Kanbayashi ; Takako Kurata ; Hideyuki Kubo ; Seiji Yamamoto ; Kazutaka Egawa ; Yuki Hirai ; Kazuma Okada ; Ryo Ikemori ; Takahiro Yumisashi ; Akira Yamamoto ; Hideki Yoshida ; Takanori Hirayama ; Kazuyoshi Ikuta ; Kazushi Motomura ; Atsushi Kaida
Western Pacific Surveillance and Response 2020;11(2):48-50
Abstract
A large rubella epidemic is currently ongoing since 2018 in Osaka, Japan. The detected rubella viruses were classified into genotypes 1E lineage 2 and 2B lineage 1. These strains may have been imported from endemic countries, and these viruses spread within the susceptible population.