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Featured researches published by Masahide Yazaki.


American Journal of Transplantation | 2007

Progressive Wild‐Type Transthyretin Deposition after Liver Transplantation Preferentially Occurs onto Myocardium in FAP Patients

Masahide Yazaki; Shigeaki Mitsuhashi; Takahiko Tokuda; Fuyuki Kametani; Yo-ichi Takei; Jun Koyama; A. Kawamorita; Hiroyuki Kanno; Shu-ichi Ikeda

To elucidate whether progressive wild‐type transthyretin (TTR) deposition can actually occur after liver transplantation (LT), amyloid fibrils were investigated in two familial amyloid polyneuropathy patients with TTR Val30Leu variant, who died 1 year after LT. Amyloid fibrils were extracted from cardiac muscles, sciatic nerves and kidney, which were investigated by the immunoprecipitation‐mass spectrometry method and liquid chromatography‐ion trap mass spectrometry analysis. The ratio of wild‐type to variant TTR in cardiac muscle was approximately 5:5 before LT, but greatly increased to about 9:1 after transplantation. The ratios in sciatic nerves and kidney obtained at autopsy were approximately 5:5. Wild‐type TTR was undetectable in kidney amyloid obtained before LT. Our results indicate that paradoxical wild‐type TTR deposition after LT can preferentially occur in myocardium, leading to fatal cardiac dysfunction, but it is quite likely that this phenomenon can also occur in other visceral organs.


Journal of the Neurological Sciences | 2004

Anti-neuronal autoantibody in Hashimoto's encephalopathy: neuropathological, immunohistochemical, and biochemical analysis of two patients

Takashi Oide; Takahiko Tokuda; Masahide Yazaki; Megumi Watarai; Shigeaki Mitsuhashi; Kazuma Kaneko; Takao Hashimoto; Shinji Ohara; Shu-ichi Ikeda

Hashimotos encephalopathy (HE) is thought to be caused by disorders of immune mechanisms. Although immunologically mediated central nervous system vasculitis or unidentified anti-neuronal autoantibodies have been suspected of causing HE, its pathogenesis is still unclear. For the study presented here, two patients with typical clinical and laboratory/electrophysiological findings of HE were analyzed to clarify the role of anti-neuronal autoantibodies in the pathogenesis of HE. The autopsied brain of one of the patients was histopathologically examined. For Western blotting analysis and immunohistochemistry, serum and purified immunoglobulin G obtained from the other patient were used. Autopsy revealed no evidence of central nervous system vasculitis or other abnormal findings in the brain. The patients serum contained an anti-neuronal autoantibody that immunohistochemically labeled neurons of mouse and human cerebral cortices and reacted with the 36-kDa antigenic protein present in a soluble fraction obtained from human cerebral cortex. Our results indicate that anti-neuronal autoantibodies may be associated with the pathogenesis of HE.


Journal of Neurology, Neurosurgery, and Psychiatry | 2001

Type II (adult onset) citrullinaemia: clinical pictures and the therapeutic effect of liver transplantation

Shu-ichi Ikeda; Masahide Yazaki; Yo-ichi Takei; Toshihiko Ikegami; Yasuhiko Hashikura; Seiji Kawasaki; Masahide Iwai; Keiko Kobayashi; Takeyori Saheki

OBJECTIVE Adult onset type II citrullinemia is an inherited disorder of amino acid metabolism caused by a deficiency of liver specific argininosuccinate synthetase activity. Most of the patients with this disease were reported in Japan and therefore, this disease has not been well recognised outside this country. The detailed clinical pictures of the patients with type II citrullinaemia are reported and their outcomes after liver transplantation referred to. METHODS Ten patients with this disease were evaluated. Seven of them underwent liver transplants using a graft obtained from a healthy family member. RESULTS There were six men and four women; the age of onset of encephalopathy ranged from 17 to 51 years. The initial symptom in nine patients was sudden onset disturbance of consciousness, and one patient had long been regarded as having a chronic progressive psychotic illness. High concentrations of plasma citrulline and ammonia were commonly seen on admission. Although brain CT or MRI lacked any consistent findings, the EEG was abnormal in all patients, showing diffuse slow waves. Additionally, in five patients chronic pancreatitis preceded the onset of encephalopathy. After liver transplantation the metabolic abnormalities, including abnormal plasma concentrations of citrulline and ammonia, were immediately corrected and all neuropsychic symptoms soon disappeared, except for impaired cognitive function in one patient. Six out of these seven patients returned to their previous social lives, including work. CONCLUSIONS The clinical concept of adult onset type II citrullinaemia coincides well with the range of hepatic encephalopathy, and liver transplantation is a very promising therapeutic approach.


Medicine | 2012

Familial Mediterranean fever in Japan.

Kiyoshi Migita; Ritei Uehara; Yoshikazu Nakamura; Michio Yasunami; Ayako Tsuchiya-Suzuki; Masahide Yazaki; Akinori Nakamura; Junya Masumoto; Akihiro Yachie; Hiroshi Furukawa; Hiromi Ishibashi; Hiroaki Ida; Kazuko Yamazaki; Atsushi Kawakami; Kazunaga Agematsu

AbstractFamilial Mediterranean fever (FMF) is a hereditary autoinflammatory disease that is prevalent in Mediterranean populations. While it is considered a rare disease in the rest of world, a significant number of FMF patients have been reported in East Asia, including Japan. Our aim was to determine the prevalence of FMF in Japan and elucidate the clinical and genetic features of Japanese patients. A primary nationwide survey of FMF was conducted between January and December 2009. Hospitals specializing in pediatrics and hospitals with pediatric, internal medicine, and rheumatology/allergy departments were asked to report all patients with FMF during the survey year. The estimated total number of Japanese FMF patients was 292 (95% confidence interval, 187–398 people). We evaluated the clinical and genetic profiles of Japanese patients from the data obtained in a secondary survey of 134 FMF patients. High-grade fever was observed in 95.5%, chest pain (pleuritis symptoms) in 36.9%, abdominal pain (peritonitis symptoms) in 62.7%, and arthritis in 31.3%. Of the patients profiled, 25.4% of patients experienced their first attack before 10 years of age, 37.3% in their teens, and 37.3% after age 20 years. Colchicine was effective in 91.8% of patients at a relatively low dose (mean dose, 0.89 ± 0.45 mg/d). AA amyloidosis was confirmed in 5 patients (3.7%). Of the 126 patients studied, 109 (86.5%) were positive for 1 or more genetic mutations and 17 (13.5%) had no mutation detected. Common Mediterranean fever gene (MEFV) mutations were E148Q/M694I (19.8%) and M694I/normal (12.7%). The differences in the prevalence of peritonitis, pleuritis, and a family history of FMF were statistically significant between FMF patients with MEFV exon 10 mutations compared with those without exon 10 mutations.In conclusion, a significant number of patients with FMF exist in Japan. Although Japanese patients with FMF are clinically or genetically different from Mediterranean patients, the delay in diagnosis is an issue that should be resolved.


The Journal of Rheumatology | 2009

Clinical and Genetic Features of Familial Mediterranean Fever in Japan

Ayako Tsuchiya-Suzuki; Masahide Yazaki; Akinori Nakamura; Kazuko Yamazaki; Kazunaga Agematsu; Masayuki Matsuda; Shu-ichi Ikeda

Objective. Familial Mediterranean fever (FMF) is thought to be a rare disorder in Japan, and the clinical features of Japanese patients with FMF remain unclear. Our aim was to elucidate the clinical characteristics of FMF in Japanese patients. Methods. We analyzed clinical and genetic data of 80 patients based on the results of a nationwide questionnaire survey and review of the literature. Results. From clinical findings of 80 Japanese patients, high-grade fever was observed in 98.8%, chest attacks (pleuritis symptoms) in 61.2%, abdominal attacks (peritonitis symptoms) in 55.0%, and arthritis in 27.5%. Twenty-four percent of patients experienced their first attacks before 10 years of age, 40% in their teens, and 36% after age 20 years. Colchicine was effective in many patients at a relatively low dose (< 1.0 mg/day). AA amyloidosis was seen in only 1 patient. Common MEFV mutation patterns were E148Q/M694I (25.0%), M694I alone (17.5%), and L110P/E148Q/M694I (17.5%), and no patient carried the M694V mutation, the most common mutation in Mediterranean patients with FMF. Conclusion. A larger than expected number of patients with FMF exist in Japan, and the clinical presentation of Japanese FMF patients seems to be relatively milder than those of Mediterranean FMF patients. AA amyloidosis rarely occurs in Japanese patients, probably due to difference in patterns of the MEFV genotype between Japanese and Mediterranean patients.


Journal of Hepatology | 2008

Citrin deficiency as a cause of chronic liver disorder mimicking non-alcoholic fatty liver disease.

Michiharu Komatsu; Masahide Yazaki; Naoki Tanaka; Kenji Sano; Etsuko Hashimoto; Yo-ichi Takei; Yuan-Zong Song; Eiji Tanaka; Kendo Kiyosawa; Takeyori Saheki; Toshifumi Aoyama; Keiko Kobayashi

BACKGROUND/AIMS Citrin deficiency caused by SLC25A13 gene mutations develops into adult-onset type II citrullinemia (CTLN2) and may be accompanied with hepatic steatosis and steatohepatitis. As its clinical features remain unclear, we aimed to explore the characteristics of fatty liver disease associated with citrin deficiency. METHODS The prevalence of hepatic steatosis in 19 CTLN2 patients was examined, and clinical features were compared with those of non-alcoholic fatty liver disease (NAFLD) patients without known SLC25A13 gene mutations. RESULTS Seventeen (89%) CTLN2 patients had steatosis, and 4 (21%) had been diagnosed as having NAFLD before appearance of neuropsychological symptoms. One patient had steatohepatitis. Citrin deficiency-associated fatty livers showed a considerably lower prevalence of accompanying obesity and metabolic syndrome, higher prevalence of history of pancreatitis, and higher serum levels of pancreatic secretory trypsin inhibitor (PSTI) than fatty livers without the mutations. Receiver operating characteristic curve analyses revealed that a body mass index < 20kg/m(2) and serum PSTI>29ng/mL were associated with citrin deficiency. CONCLUSIONS Patients presenting with non-alcoholic fatty liver unrelated to obesity and metabolic syndrome might have citrin deficiency, and serum PSTI may be a useful indicator for distinguishing this from conventional NAFLD.


Journal of Clinical Neuroscience | 2008

Follow-up of three patients with a large in-frame deletion of exons 45–55 in the Duchenne muscular dystrophy (DMD) gene

Akinori Nakamura; Kunihiro Yoshida; Kazuhiro Fukushima; Hideho Ueda; Nobuyuki Urasawa; Jun Koyama; Yoshikazu Yazaki; Masahide Yazaki; Toshiaki Sakai; Seiichi Haruta; Shin'ichi Takeda; Shu-ichi Ikeda

We review the clinical status of skeletal involvement and cardiac function in three unrelated patients harboring an in-frame deletion of exons 45 to 55 in the DMD gene followed up for 2 to 7 years. Two younger patients diagnosed as having X-linked dilated cardiomyopathy (XLDCM) developed congestive heart failure without overt skeletal myopathy. Heart failure recurred after viral infection but responded well to diuretics and angiotensin-converting enzyme inhibitors. One older patient diagnosed with Becker muscular dystrophy showed limb-girdle muscular atrophy and weakness at the age of 50, but did not have any cardiac symptoms. Skeletal muscle involvement in each patient remained unchanged, and cardiac function did not worsen in any of the patients during the study. In a younger XLDCM patient, the amount and molecular weight of mutant dystrophin were equally slightly decreased in both skeletal and cardiac muscles. Immunostaining for dystrophin and dystrophin-associated proteins was slightly reduced in both skeletal and cardiac muscle, with no discernible difference between the two. The phenotype of this dystrophinopathy can manifest as XLDCM in younger patients; however, careful attention to cardiac management may result in a favorable prognosis.


Transplantation | 1996

Complete neurological recovery of an adult patient with type II citrullinemia after living related partial liver transplantation.

Masahide Yazaki; Shu-ichi Ikeda; Yo-ichi Takei; Nobuo Yanagisawa; Hidetoshi Matsunami; Yasuhiko Hashikura; Seiji Kawasaki; Masatoshi Makuuchi; Keiko Kobayashi; Takeyori Saheki

Type II citrullinemia is an adult-onset hepatocerebral disease caused by a deficiency of argininosuccinate synthetase in liver. A 25-year-old Japanese man suddenly developed encephalopathy, showing disorientation and flapping tremor. Plasma concentrations of ammonia and citrulline were extremely high, and hepatic argininosuccinate synthetase activity was deficient. The patients condition deteriorated rapidly in spite of intensive medications. Therefore, we performed a partial liver transplantation using a graft obtained from his healthy 61-year-old father. After surgery, his neurological symptoms soon disappeared and plasma levels of ammonia and citrulline were normalized within 3 months after operation. Type II citrullinemia is one fulminant form of various liver-based metabolic diseases, and immediate liver transplantation is necessary to rescue patients with this disease. As liver transplantation from cadaveric donor is still not possible in Japan, it seems justifiable to use living related partial liver transplantation for our patient.


Liver Transplantation | 2007

Transthyretin-derived amyloid deposition on the gastric mucosa in domino recipients of familial amyloid polyneuropathy liver

Yo-ichi Takei; Takahisa Gono; Masahide Yazaki; Shu-ichi Ikeda; Toshihiko Ikegami; Yasuhiko Hashikura; Shinichi Miyagawa; Yoshinobu Hoshii

Familial amyloid polyneuropathy (FAP) is a form of hereditary generalized amyloidosis. Liver tissue explanted from FAP patients has normal structure and function, except for the production of amyloidogenic variant transthyretin (TTR), and domino liver transplantation (DLT) using grafts from FAP patients was first performed in 1995. FAP symptoms usually develop in genetically determined individuals after the age of 20, but it is difficult to estimate when FAP symptoms will appear in domino recipients. Concerning this problem, histological findings showing amyloid deposition have recently been obtained in a few domino recipients of FAP livers. This study investigated the presence of de novo amyloid deposition in the gastroduodenal mucosa of domino recipients transplanted at our institution. Biopsy of gastroduodenal mucosa was carried out in 5 recipients of FAP livers and TTR‐derived amyloid deposits were detected in 2 patients, both of whom had undergone DLT 47 months previously. In FAP liver recipients, de novo systemic amyloid deposition may begin much sooner than previously supposed. Therefore, careful follow‐up of domino recipients of FAP livers is required. Liver Transpl, 2006.


Liver Transplantation | 2008

Marked regression of abdominal fat amyloid in patients with familial amyloid polyneuropathy during long-term follow-up after liver transplantation

Ayako Tsuchiya; Masahide Yazaki; Fuyuki Kametani; Yo-ichi Takei; Shu-ichi Ikeda

To elucidate whether the amount of tissue‐deposited amyloid in familial amyloid polyneuropathy (FAP) patients decreases or increases over the long‐term course after liver transplantation (LT), we examined changes in histopathological and biochemical characteristics of abdominal fat amyloid in the transplanted patients with a postoperative history of more than 10 years. Using a series of aspirated abdominal fat tissues from 6 FAP patients with transthyretin (TTR) Val30Met variant, the severity of amyloid deposits was examined and the composition ratio of wild type‐to‐variant TTR in fat amyloid was assayed by liquid chromatography‐ion trap mass spectrometry (LC‐MS/MS). Histopathological examination of abdominal fat tissues demonstrated a significant decrease or disappearance of amyloid deposits in all 6 patients. On LC‐MS/MS analysis, the contribution of wild‐type TTR to the composition ratio in amyloid fibrils was markedly increased in all patients after LT. This is the first report showing pathological evidence that deposited amyloid in FAP patients with long posttransplantation courses can gradually regress or disappear. Liver Transpl 14:563–570, 2008.

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Fuyuki Kametani

Tokyo Metropolitan University

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