著者
友田 陽 関戸 信彰 徐 平光 川崎 卓郎 ハルヨ ステファヌス 田中 雅彦 篠原 武尚 蘇 玉華 谷山 明
出版者
一般社団法人 日本鉄鋼協会
雑誌
鉄と鋼 (ISSN:00211575)
巻号頁・発行日
vol.103, no.10, pp.570-578, 2017 (Released:2017-09-30)
参考文献数
31
被引用文献数
15 16

Various methods were employed to measure the austenite volume fraction in a 1.5Mn-1.5Si-0.2C steel. It has been confirmed that the volume fractions determined by transmission electron microscopy, scanning electron microscopy/electron back scatter diffraction, X-ray diffraction and neutron diffraction exhibit a general trend to become larger in this order, although the values obtained by X-ray and neutron diffraction are similar in the present steel because austenite is relatively stable. The austenite volume fractions determined by diffraction methods have been found to be affected by the measuring specimen direction, i.e., texture, even by applying the conventional correcting procedure. To avoid this influence, it is recommended to measure both of volume fraction and texture simultaneously using neutron diffraction. Although synchrotron X-ray shows higher angle resolution, its small incident beam size brings poor statistic reliability. The influence of texture cannot be avoided for transmission Bragg edge measurement, either, which must be overcome to realize 2D or 3D volume fraction mapping.
著者
田中 聡 山本 一徹 権藤 学司 渡辺 剛史 堀田 和子 田中 貴大 田中 雅彦
出版者
日本脊髄外科学会
雑誌
脊髄外科 (ISSN:09146024)
巻号頁・発行日
vol.35, no.3, pp.312-315, 2021 (Released:2021-12-28)
参考文献数
13

Calcification of ligamentum flavum (CLF) is a degenerative spinal disease in which calcium crystals deposit in the ligamentum flavum. The CLF may cause spinal cord compression, and the patient may need decompressive surgery. However, CLF can spontaneously regress with some medications as well as no treatment. Here, the authors reported a case in which small CLF remaining after cervical decompression surgery markedly enlarged during the follow-up period and spontaneously regressed after pregabalin administration. Therefore, pregabalin might be involved in the spontaneous regression of CLF.  A 66-year-old female complaining of right upper limb pain and numbness was diagnosed with CLF at C5/6 and C6/7 by computed tomography (CT) and magnetic resonance imaging (MRI). The symptoms improved after removal of the CLF at C5/6 with C5 laminectomy and C4, C6 laminoplasty. Postoperative CT showed small residual CLF at C6/7. Six years after surgery, she suffered pain and numbness in her right arm. Her cervical MRI showed a marked increase of CLF at C6/7. The pain disappeared after the administration of pregabalin. Six months later, a marked reduction of CLF was observed on MRI.  It has been reported that the administration of cimetidine or etidronate resulted in the regression of CLF. Cimetidine affects calcium metabolism via parathyroid hormone (PTH), and etidronate has an inhibitory effect on calcification. It was reported that the serum PTH was markedly reduced in a uremic patient after the administration of pregabalin. The efficacy of pregabalin was also reported for a case with refractory paroxysmal kinesigenic choreoathetosis whose parathyroid glands were removed. It is presumed that pregabalin was involved in calcification regression via PTH metabolism in this case.
著者
渡辺 剛史 権藤 学司 田中 雅彦 山本 一徹 堀田 和子 玉井 洋太郎 田中 聡
出版者
日本脊髄外科学会
雑誌
脊髄外科 (ISSN:09146024)
巻号頁・発行日
vol.33, no.2, pp.170-174, 2019 (Released:2019-09-10)
参考文献数
12

The purpose of this article is to analyze the characteristics of spinal magnetic resonance images (MRI) in multiple myeloma patients. Two hundred and eighteen patients were diagnosed with multiple myelomas at the Shonan Kamakura General Hospital from January 2009 to April 2018. Spinal MRIs were evaluated in 66 cases. Initial symptoms, spinal MRI findings, and blood sample test findings at the time of diagnosis were investigated. There were 37 males and 29 females analyzed. Mean age at the time of diagnosis was 70.1 years (42 to 87 years). Main initial symptoms were low back pain (n=23), back pain (n=15), neck pain (n=1), lower limb weakness (n=6), lower limb pain/paresthesia (n=4), cranial nerve palsy (n=2), respiratory symptoms (n=6), renal failure (n=4), anemia (n=3) and asymptomatic (n=6). Spinal MRI revealed vertebral fracture (n=42), intravertebral tumor (n=35), epidural tumor (n=9), diffuse spotty signal (n=13), and diffuse low signal (n=4). There were only five cases where no abnormality was observed beyond the vertebral body fracture. Dural sac compression was observed in 16 cases, of which 12 cases were co-localized with the tumor and 4 cases were by a fractured bony fragment. The results of the blood sampling were confirmed in 65 patients. Anemia, decreased albumin/globulin ratio, hyperproteinemia, hypercalcemia, and increased alkaline phosphatase were observed in 57, 44, 29, 13, and 12 patients, respectively. Only 9 cases showed normal blood test results. The most common symptom of multiple myeloma was lower back pain. As such, half of the patients had visited an orthopedic or spinal surgery clinic. Spinal MRI findings were classified as intervertebral focal lesion, epidural mass, diffuse spotty signal, or diffuse low signal. The presence of an abnormal finding was observed in 92% of patients by spinal MRI and in 86% by blood sampling. Spinal MRI and blood sampling examination should be considered in cases of vertebral fracture in order to prevent the misdiagnosis of multiple myeloma as an osteoporotic vertebral fracture.
著者
加藤 真由佳 田中 雅彦 松井 みどり 橋本 由徳 神谷 葉子 神谷 剛 渡邉 賢司
出版者
一般社団法人 日本臨床衛生検査技師会
雑誌
医学検査 (ISSN:09158669)
巻号頁・発行日
vol.63, no.4, pp.434-439, 2014-07-25 (Released:2014-09-10)
参考文献数
10
被引用文献数
1

異常ヘモグロビンとはグロビン鎖のアミノ酸配列異常を呈するヘモグロビンの総称である.鎌状赤血球貧血患者の研究に端を発し,Hb M-Iwateの発見により日本人においても異常ヘモグロビン症が証明された.異常ヘモグロビン症は等電点電気泳動法の応用や技術改良による検出頻度の拡大を経て,現在ではヘモグロビンA1cの測定に用いられる高速液体クロマトグラフィの異常クロマトグラムより発見される例が増えている.今回われわれは,非血縁2家系,4例の異常ヘモグロビン症を経験した.同疾患は遺伝性疾患であり人口移動の少ない地域では出現に注意する必要がある.異常クロマトグラムであってもヘモグロビンA1cが測定される場合があり,クロマトグラムのパターンに注意を要する.遺伝子解析には十分に配慮する必要があるが,不要な検査,治療を避けるためにも患者が自身の病態について理解しておくことは重要と考える.普段から臨床医とコミュニケーションを図り,適切な情報を臨床側に提供していく必要があると考えられる.
著者
野田 尚志 渡辺 剛史 田中 雅彦 山本 一徹 田中 聡 権藤 学司
出版者
日本脊髄外科学会
雑誌
脊髄外科 (ISSN:09146024)
巻号頁・発行日
vol.32, no.1, pp.69-72, 2018 (Released:2018-06-20)
参考文献数
14

A 55-year-old woman felt a left shoulder pain and then left upper weakness 3 days after the pain onset. The patient was introduced to our department because of suspected cervical spondylosis. Muscle weakness was detected in her left deltoid, biceps brachii, and radial flexor carpi muscles. Cervical magnetic resonance imaging demonstrated a significantly expanded left vertebral artery in the C4/5, C5/6, and C6/7 intervertebral foramina. A septum was found inside the dilated vertebral artery, and true and false lumens were confirmed. The septum, expanded false lumen, and shrunk true lumen were also observed on contrast-enhanced computed tomographic (CT) angiography. The nerve root compression symptoms were thought to be caused by the dissection of the left vertebral artery. The symptoms were spontaneously improved after 6 months. The false lumen was markedly reduced on contrast-enhanced CT. We report a case of extracranial vertebral artery dissection presenting with radiculopathy, along with a literature review.