1.Current Status and Issues of Education on Radiation Health Risk Science
Naoki MATSUDA ; Yoshishige URATA ; Masanobu KITAGAWA ; Masahiko AOKI ; Yoshio HOSOI ; Kenji NEMOTO ; Akira OHTSURU ; Tomonori ISOBE ; Hideyuki SAKURAI ; Kiyoshi MIYAKAWA ; Ryoichi YOSHIMURA ; Reiko KANDA ; Takashi KONDO ; Shunichi TAKEDA ; Takeshi TOUDO ; Kazuo AWAI ; Teruhisa TSUZUKI ; Takeshi NAGAYASU
Medical Education 2019;50(6):581-587
In accordance with the new model-core-curriculum for medical education, the current status of education about the science of radiation health was surveyed in all medical schools in Japan. Among the four learning points related to the “Biological effects of radiation and radiation hazards” , about half of the schools covered issues on “radiation and human body” and the “effect of medical radiation exposure” in one, or less than one, 60-minutes class, but did not touch on “radiation risk communication” and “radiological disaster medicine” . A significant deviation of human resources was also observed between schools. Learning tools such as presentation files and video content were preferred as education support materials. Therefore, development and distribution of the learning tools, especially in “radiation risk communication” and “radiological disaster medicine” , may be a first step to promoting high-quality education on the science of radiation health risk in each school’s curriculum.
2.Unsintered Hydroxyapatite and Poly-L-Lactide Composite Screws/Plates for Stabilizing β-Tricalcium Phosphate Bone Implants.
Akio SAKAMOTO ; Takeshi OKAMOTO ; Shuichi MATSUDA
Clinics in Orthopedic Surgery 2018;10(2):253-259
Unsintered hydroxyapatite (u-HA) and poly-L-lactide (PLLA) composites (u-HA/PLLA) are osteoconductive and biodegradable. Screw (Super-Fixsorb MX30) and plate (Super-Fixsorb MX40 Mesh) systems made of u-HA/PLLA are typically used in small bones in maxillofacial surgeries. After the resection of bone tumors in larger bones, reconstructions with β-tricalcium phosphate (β-TCP) implants of strong compression resistance have been reported. After a resection, when the cavity is hemispheric- or concave-shaped, stabilization of the implanted β-TCP block is necessary. In the current series, u-HA/PLLA were used to stabilize the mechanically strong implanted low-porous β-TCP blocks in six bone tumor cases, including three giant cell tumors of bone, and one case each of chondroblastoma, chondrosarcoma, and parosteal osteosarcoma. The mean age of patients at the time of surgery was 31.3 years (range, 19 to 48 years). The bones involved were two ilia (posterior), a femur (diaphysis to distal metaphysis), and three tibias (proximal epiphysis, proximal metaphysis to epiphysis, and distal metaphysis to epiphysis). Neither displacement of the implanted β-TCP block nor any u-HA/PLLA-related complications were observed. The radiolucent character of the u-HA/PLLA did not hinder radiological examinations for potential signs of tumor recurrence. The method of using u-HA/PLLA components for the stabilization of β-TCP blocks makes the procedure easy to perform and reliable. It can extend the application of β-TCP blocks in reconstruction surgery.
Bone Neoplasms
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Chondroblastoma
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Chondrosarcoma
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Durapatite*
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Epiphyses
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Femur
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Giant Cell Tumors
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Humans
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Hydroxyapatites
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Methods
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Osteosarcoma
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Reconstructive Surgical Procedures
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Recurrence
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Tibia
3.Repeatedly Recurrent Colon Cancer Involving the Appendiceal Orifice after Endoscopic Piecemeal Mucosal Resection: A Case Report.
Masau SEKIGUCHI ; Takahisa MATSUDA ; Shigeki SEKINE ; Taku SAKAMOTO ; Takeshi NAKAJIMA ; Ryoji KUSHIMA ; Takayuki AKASU ; Yutaka SAITO
The Korean Journal of Gastroenterology 2013;61(5):286-289
Local recurrence after endoscopic piecemeal mucosal resection (EPMR) for colorectal tumors is a crucial issue. However, such recurrence is usually detected within one year and cured with additional endoscopic treatment, which makes EPMR acceptable. Herein, we report a rare case of repeatedly recurrent colon cancer involving the appendiceal orifice after EPMR, which was not cured with additional endoscopic treatments. A 67-year-old man was referred to us for endoscopic treatment of a 25 mm cecal tumor spreading to the appendiceal orifice in May 2002. The tumor was resected with EPMR, showing well differentiated intramucosal adenocarcinoma with a positive lateral cut margin of tubular adenoma. Endoscopic surveillance was conducted and the first local recurrence was detected in August 2006. Although we resected it endoscopically, the second local recurrence was found in September 2007 and we removed it with endoscopic resection again. However, the third local recurrence was detected in March 2008. Although endoscopic resection was performed also for the third recurrence, curative resection was not achieved. In February 2009, laparoscopic assisted colectomy was performed and histopathological examination showed well differentiated adenocarcinoma with deep submucosal invasion. This case is important in considering indication for endoscopic resection in colorectal tumors involving the appendiceal orifice.
Adenocarcinoma/*diagnosis/pathology/surgery
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Aged
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Appendiceal Neoplasms/complications
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Colectomy
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Colonic Neoplasms/*diagnosis/pathology/surgery
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Colonoscopy
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Humans
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Intestinal Mucosa/pathology
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Male
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Neoplasm Recurrence, Local
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Recurrence
4.Indications for and Technical Aspects of Colorectal Endoscopic Submucosal Dissection.
Yutaka SAITO ; Yosuke OTAKE ; Taku SAKAMOTO ; Takeshi NAKAJIMA ; Masayoshi YAMADA ; Shin HARUYAMA ; Eriko SO ; Seiichiro ABE ; Takahisa MATSUDA
Gut and Liver 2013;7(3):263-269
Due to the widespread acceptance of gastric and esophageal endoscopic submucosal dissections (ESDs), the number of medical facilities that perform colorectal ESDs has grown and the effectiveness of colorectal ESD has been increasingly reported in recent years. The clinical indications for colorectal ESD at the National Cancer Center Hospital, Tokyo, Japan include laterally spreading tumor (LST) nongranular type lesions >20 mm and LST granular type lesions >30 mm. In addition, 0-IIc lesions >20 mm, intramucosal tumors with nonlifting signs and large sessile lesions, all of which are difficult to resect en bloc by conventional endoscopic mucosal resection (EMR), represent potential candidates for colorectal ESD. Rectal carcinoid tumors less than 1 cm in diameter can be treated simply, safely, and effectively by endoscopic submucosal resection using a ligation device and are therefore not indications for ESD. The en bloc resection rate was 90%, and the curative resection rate was 87% for 806 ESDs. The median procedure time was 60 minutes, and the mean size for resected specimens was 40 mm (range, 15 to 150 mm). Perforations occurred in 23 (2.8%) cases, and postoperative bleeding occurred in 15 (1.9%) cases, but only two perforation cases required emergency surgery (0.25%). ESD was an effective procedure for treating colorectal tumors that are difficult to resect en bloc by conventional EMR. ESD resulted in a higher en bloc resection rate as well as decreased invasiveness in comparison to surgery. Based on the excellent clinical results of colorectal ESDs in Japan, the Japanese healthcare insurance system has approved colorectal ESD for coverage.
Asian Continental Ancestry Group
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Carcinoid Tumor
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Colorectal Neoplasms
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Delivery of Health Care
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Emergencies
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Hemorrhage
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Humans
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Insurance
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Japan
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Ligation
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Tokyo
5.Influence of Signal Intensity Non-Uniformity on Brain Volumetry Using an Atlas-Based Method.
Masami GOTO ; Osamu ABE ; Tosiaki MIYATI ; Hiroyuki KABASAWA ; Hidemasa TAKAO ; Naoto HAYASHI ; Tomomi KUROSU ; Takeshi IWATSUBO ; Fumio YAMASHITA ; Hiroshi MATSUDA ; Harushi MORI ; Akira KUNIMATSU ; Shigeki AOKI ; Kenji INO ; Keiichi YANO ; Kuni OHTOMO
Korean Journal of Radiology 2012;13(4):391-402
OBJECTIVE: Many studies have reported pre-processing effects for brain volumetry; however, no study has investigated whether non-parametric non-uniform intensity normalization (N3) correction processing results in reduced system dependency when using an atlas-based method. To address this shortcoming, the present study assessed whether N3 correction processing provides reduced system dependency in atlas-based volumetry. MATERIALS AND METHODS: Contiguous sagittal T1-weighted images of the brain were obtained from 21 healthy participants, by using five magnetic resonance protocols. After image preprocessing using the Statistical Parametric Mapping 5 software, we measured the structural volume of the segmented images with the WFU-PickAtlas software. We applied six different bias-correction levels (Regularization 10, Regularization 0.0001, Regularization 0, Regularization 10 with N3, Regularization 0.0001 with N3, and Regularization 0 with N3) to each set of images. The structural volume change ratio (%) was defined as the change ratio (%) = (100 x [measured volume - mean volume of five magnetic resonance protocols] / mean volume of five magnetic resonance protocols) for each bias-correction level. RESULTS: A low change ratio was synonymous with lower system dependency. The results showed that the images with the N3 correction had a lower change ratio compared with those without the N3 correction. CONCLUSION: The present study is the first atlas-based volumetry study to show that the precision of atlas-based volumetry improves when using N3-corrected images. Therefore, correction for signal intensity non-uniformity is strongly advised for multi-scanner or multi-site imaging trials.
Adult
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Atlases as Topic
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Brain Mapping/*methods
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Female
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Humans
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Image Enhancement/methods
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Image Processing, Computer-Assisted/*methods
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Magnetic Resonance Imaging/*methods
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Male
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Middle Aged
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Software
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Statistics, Nonparametric
6.Ciguatera Fish Poisoning on Kakeroma Island, Kagoshima Prefecture, Japan
Naomasa Oshiro ; Toshiaki Matsuo ; Satsuki Sakugawa ; Kentaro Yogi ; Seiko Matsuda ; Takeshi Yasumoto ; Yasuo Inafuku
Tropical Medicine and Health 2011;39(2):53-57
In this paper we report two incidents of ciguatera fish poisoning (CFP) that occurred in 2008 on Kakeroma Island in Kagoshima Prefecture, Japan. A family consisting of father (42 y.o.), mother (39 y.o.), daughter (11 y.o.) and son (6 y.o.), as well as a friend of the family (male, 78 y.o.) consumed sliced flesh (sashimi) and developed typical symptoms of CPF 4-5 h later: diarrhea, vomiting, and paresthesia of the extremities. Additionally, the two male adults (42 and 78 y.o.) developed mild hypotention (84/48 and 94/40 mmHg, respectively) and bradycardia (36 and 50 bpm, respectively) and were rushed to the ER of the nearest hospital, located on an adjacent island. The implicated fish were caught together off the west coast of the island and were identified as Variola louti and Lutjanus monostigma based on analysis of 16S rRNA gene coded on mtDNA. Remnants of the implicated fish and other fish caught on the same occasion were examined by the official mouse bioassay method (MBA), which defines the minimum amount of CFP toxin needed to kill a male mouse of ddY strain of 20 g body weight within 24 h as one mouse unit (MU). A significantly high toxicity was detected in the V. louti (0.2 MU/g) eaten by the family and the L. monostigma (0.8 MU/g) eaten by the elderly man. Other specimens of Lethrinus nebulosus, Variola albimarginata, Lutjanus gibbus (2 specimens), Aphareus rutilans, and Sphyraena forsteri (2 specimens) were found to be nontoxic (< 0.025 MU/g).
The medical records regarding island inhabitants (ca. 1,500) kept at Kakeroma Tokushukai Clinic, the only medical facility on the Island, and also at Setouchi Tokushukai Hospital, a nearest hospital on an adjacent island (Amami) revealed 6 CFP outbreaks involving 13 cases between 2005 and 2008. The estimated frequency of CFP was 10.0 incidents/10,000 persons/year and the morbidity rate was 21.7 cases/10,000 persons/year. The symptoms and signs observed in the patients and the implicated fish species, L. monostigma and V. louti, were typical of CFP in this region.
7.Successful Surgical Treatment of Isolated Iliac Aneurysm with Arterio-enteric Fistula
Shuji Setozaki ; Mitsuhiko Matsuda ; Takeshi Soeda ; Sadatoshi Yuasa ; Kazuteru Shimizu
Japanese Journal of Cardiovascular Surgery 2009;38(4):270-272
A 76-year-old male was admitted to our hospital because of melena. However, no remarkable findings of rupture were shown by enhanced CT scan and angiography. On the 9th day of admission, he fell into a state of shock because of sudden massive bloody intestinal discharge. Colonofiberscopic findings revealed a primary arterio-enteric fistula. Therefore, an emergency operation was undertaken. Following aneurysmectomy, colostomy was performed in the descending colon. Right axillo-femoral artery bypass was finally performed as an extra-anatomical bypass to secure the right leg blood flow.
8.THE EFFECTS OF DAILY PHYSICAL ACTIVITY ON THE AGE-RELATED CAROTID ARTERIA STIFFENING IN MIDDLE-AGED AND ELDERLY PEOPLE
JUN SUGAWARA ; TAKESHI OTSUKU ; TAKUMI TANABE ; KOICHIRO HAYASHI ; SEIJI MAEDA ; SHINYA KUNO ; RYUICHI AJISAKA ; MITSUO MATSUDA
Japanese Journal of Physical Fitness and Sports Medicine 2006;55(Supplement):S11-S14
The engaging>30 minutes of physical activity (PA) at 4-6 METs has been recommended for the prevention of cardiovascular disease. We determined whether relatively low intensity (i. e., 3-5 METs) PA inhibits the age-related central arterial stiffening, a risk of cardiovascular disease. In the cross-sectional study, the association between carotid arterial properties (via ultrasound system) and daily PA (via electric accelerometer) were studied in 172 normotensive people (41-82 yrs). People engaging>30 min/day of PA corresponding to 3-5 METs had a significantly lower beta-stiffness index than sedentary peers after adjusting for covariates (i. e., age and PA time at more than 6 METs). In the interventional study, beta-stiffness index of nine normotensive postmenopausal women was significantly decreased after the 12-week aerobic training (cycling at 80% of ventiratory threshold, ≈4 METs, 30 min/day, 5 days/week). These results suggest that the increase in daily PA at 3-5 METs inhibits the age-related carotid arterial stiffening.
9.SAFETY OF LOWER EXTREMITY EXERCISE IN MIDDLE-AGED OR ELDERLY PATIENTS WITH HYPERTENSION AND USEFULNESS OF RESPIRATORY GUIDANCE
YASUFUMI SUZUKI ; RYUICHI AJISAKA ; TAKUMI TANABE ; TAKESHI OOTSUKI ; JUN SUGAWARA ; SHINYA KUNO ; MITSUO MATSUDA
Japanese Journal of Physical Fitness and Sports Medicine 2003;52(Supplement):185-192
Resistance exercise in the elderly and patients with a cardiovascular disorder has been thought to have a high cardiovascular risk, because it has the tendency to cause an excessive rise in blood pressure and induce serious arrhythmia. But recently, resistance exercise has been introduced into physical therapy because the safety of such exercise has been confirmed in subjects without a cardiovascular disorder.
The purpose of this study was to investigate the safety of lower extremity resistance exercise in middle-aged or elderly subjects with hypertension and receiving medical treatment (n=24), and those without hypertension (n=40), by measuring cardiovascular response during resistance exercise of different loads (40% and 60% 1 RM), and usefulness of respiratory guidance during such exercise.
As a result, there was no difference in diastolic blood pressure between those with and without hypertension ; but systolic blood pressure and rate pressure product both at rest and during exercise were significantly greater in patients with hypertension. However, neither group showed symptoms of angina, ischemic signs in ECG, or serious arrhythmia ; and there was no difference in the frequency of excessive rise in blood pressure between the groups (2 subjects with hypertension and 1 subject without hypertension) . Blood pressure during exercise was significantly lowered by respiratory guidance.
These results show that it is important to measure blood pressure during exercise before resistance exercise training regardless of the presence of hypertension, although an excessive rise in blood pressure occurred in only a few subjects. Furthermore, it is important to exhale slowly and not hold one's breath during exercise.
10.EFFECT OF PHYSICL ACTIVITY ON SYSTOLIC BLOOD PRESSURE IN ELDERLY HUMANS
TAKUMI TANABE ; SEIJI MAEDA ; JUN SUGAWARA ; TAKESHI OTSUKI ; TAKASHI MIYAUCHI ; SHINYA KUNO ; RYUICHI AJISAKA ; MITSUO MATSUDA
Japanese Journal of Physical Fitness and Sports Medicine 2003;52(Supplement):167-176
Arterial compliance progressively decreases with aging. This aging-induced reduction of arterial compliance causes an increase of systolic blood pressure (SBP), whereas regular exercise increases arterial compliance. We hypothesized that an increase in daily physical activity (DPA) produces a beneficial effect on systemic arterial compliance (SAC ; an index of central arterial compliance) and this phenomenon could decrease SBP in the elderly. We investigated the relationship among DPA, SAC, SBP, diastolic blood pressure (DBP), and some other risk factors for cardiovascular and/or cerebrovascular events (total cholesterol, HDL-cholesterol, and HOMA-R) cross-sectionally in 127 elderly persons (42 male, 85 female : aged 74±4 years) . The DPA was estimated by expended calories using an accelerometer. The SAC was calculated from a finger pulse pressure waveform recorded by using PORTAPRES ; and stroke volume obtained from the same pressure waveform based on the volume-clump method. The analyses demonstrated that SBP was directly and decreasingly affected by SAC, and that DPA had an increasing effect on SAC. Furthermore, SBP was directly and increasingly affected by DBP, and DBP was directly and decreasingly affected by both SAC and DPA. Therefore, it is considered that DPA may have suppressive effects on the rise of SBP through the indirect effects of changing SAC and DBP. These findings suggest that an increase in DPA could improve the age-induced reduction of arterial compliance and rise of SBP in elderly humans.


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