Updated on 2025/08/19

写真a

 
浦田 晴生
 
Organization
Department of Comprehensive Technical Solutions Technical Expert staff
Position
Technical Expert staff
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Papers

  • A Novel Method for Detecting Lanthanum Phosphate Deposition in the Gastroduodenal Mucosa Using Fluorescence Microscopy. International journal

    Masaya Iwamuro, Haruo Urata, Satoshi Iwasa, Takehiro Tanaka, Yoshiro Kawahara, Horoyuki Okada

    Cureus   14 ( 10 )   e30729   2022.10

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    Diagnostic utility of fluorescence microscopy for lanthanum phosphate deposition in the gastrointestinal mucosa has not been reported previously. In this study, we comparatively assessed the light, electron, and fluorescence microscopy features of gastroduodenal lanthanum phosphate deposition in 10 patients with deposits in the stomach and 5 patients with deposits in the duodenum. During light microscopy, lanthanum deposits were observed as dark-brown, needle-shaped, or crystalloid structures and pale red amorphous materials. During electron microscopy, the deposited material appeared as bright aggregates. Fluorescence microscopy also revealed lanthanum deposits as bright areas under green, red, and blue filters. The deposits were more easily recognizable on electron and fluorescence microscopy than on light microscopy. Furthermore, during fluorescence microscopy, the green filter provided the most clear visualization of lanthanum phosphate. In conclusion, fluorescence microscopy with a green filter is useful in determining the degree and extent of lanthanum deposition in the gastroduodenal mucosa.

    DOI: 10.7759/cureus.30729

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  • Application of electron microscopy in gastroenterology. International journal

    Masaya Iwamuro, Haruo Urata, Takehiro Tanaka, Hiroyuki Okada

    World journal of gastrointestinal pathophysiology   13 ( 2 )   41 - 49   2022.3

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    Electron microscopy has long been used in research in the fields of life sciences and materials sciences. Transmission and scanning electron microscopy and energy-dispersive X-ray spectroscopy (EDX) analyses have also been performed in the field of gastroenterology. Electron microscopy and EDX enable (1) Observation of ultrastructural differences in esophageal epithelial cells in patients with gastroesophageal reflux and eosinophilic esophagitis; (2) Detection of lanthanum deposition in the stomach and duodenum; (3) Ultrastructural and elemental analyses of enteroliths and bezoars; (4) Detection and characterization of microorganisms in the gastrointestinal tract; (5) Diagnosis of gastrointestinal tumors with neuroendocrine differentiation; and (6) Analysis of gold nanoparticles potentially used in endoscopic photodynamic therapy. This review aims to foster a better understanding of electron microscopy applications by reviewing relevant clinical studies, basic research findings, and the state of current research carried out in gastroenterology science.

    DOI: 10.4291/wjgp.v13.i2.41

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  • Review of the diagnosis of gastrointestinal lanthanum deposition. International journal

    Masaya Iwamuro, Haruo Urata, Takehiro Tanaka, Hiroyuki Okada

    World journal of gastroenterology   26 ( 13 )   1439 - 1449   2020.4

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    Lanthanum carbonate is used for treatment of hyperphosphatemia mostly in patients with chronic renal failure. Although lanthanum carbonate is safe, recently, lanthanum deposition in the gastrointestinal mucosa of patients has been reported in the literature. This review provides an overview of gastroduodenal lanthanum deposition and focuses on disease's endoscopic, radiological, and histological features, prevalence, and outcome, by reviewing relevant clinical studies, case reports, and basic research findings, to better understand the endoscopic manifestation of gastrointestinal lanthanum deposition. The possible relationship between gastric lanthanum deposition pattern and gastric mucosal atrophy is also illustrated; in patients without gastric mucosal atrophy, gastric lanthanum deposition appears as diffuse white lesions in the posterior wall and lesser curvature of the gastric body. In the gastric mucosa with atrophy, lanthanum-related lesions likely appear as annular or granular whitish lesions. Moreover, these white lesions are probably more frequently observed in the lower part of the stomach, where intestinal metaplasia begins.

    DOI: 10.3748/wjg.v26.i13.1439

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  • Frequent Involvement of the Duodenum with Lanthanum Deposition: A Retrospective Observational Study.

    Masaya Iwamuro, Haruo Urata, Takehiro Tanaka, Seiji Kawano, Yoshiro Kawahara, Hiroyuki Okada

    Internal medicine (Tokyo, Japan)   58 ( 16 )   2283 - 2289   2019.8

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    Objective This study aimed to investigate the endoscopic features of lanthanum-associated duodenal lesions and the prevalence of duodenal involvement among patients with pathologically proven lanthanum deposition in the gastrointestinal tract. Methods We retrospectively reviewed 24 patients with pathologically proven lanthanum deposition in the gastrointestinal tract. Patients were subdivided into three groups: Group A, patients with pathologically-proven lanthanum deposition in the duodenum; Group B, patients without lanthanum deposition in the duodenum; and Group C, patients without a biopsy of the duodenum. Results A biopsy examination of the duodenum was performed in 19 patients, and lanthanum deposition was detected in 17 patients (17/19, 89.5%). In group A (n=17), whitish duodenal villi were detected in 15 patients during esophagogastroduodenoscopy (15/17, 88.2%). While the other two patients showed no whitish villi, a biopsy of the duodenal mucosa revealed lanthanum deposition. The deposition of a white substance showing a clear margin was visible within multiple villi under magnified observation in some patients of group A. Group B patients (n=2) also showed whitish villi. However, the whitish color was faint in one case and sparse in the other case. Conclusion Lanthanum deposits in the duodenum may resemble white villi. However, in some cases, these deposits may be unrecognizable during esophagogastroduodenoscopy due to the subtle degree of deposition. Endoscopists should biopsy the duodenum as well as the stomach, regardless of the presence or absence of white villi, for an accurate determination of lanthanum deposition in the gastrointestinal tract.

    DOI: 10.2169/internalmedicine.2398-18

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  • Gastric lanthanum phosphate deposition masquerading as white globe appearance. International journal

    Masaya Iwamuro, Haruo Urata, Takehiro Tanaka, Hiroyuki Okada

    Digestive and liver disease : official journal of the Italian Society of Gastroenterology and the Italian Association for the Study of the Liver   51 ( 1 )   168 - 168   2019.1

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    DOI: 10.1016/j.dld.2018.07.031

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  • A Bezoar Composed of Bilirubin Calcium, Calcium Carbonate, and Fatty Acid Calcium. International journal

    Masaya Iwamuro, Haruo Urata, Shoichiro Hirata, Toru Ueki, Tetsuro Hanabata, Sho Takeda, Akira Teraoka, Hiroyuki Okada

    Case reports in gastrointestinal medicine   2019   5742672 - 5742672   2019

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    A 68-year-old Japanese man was diagnosed with bezoar in the stomach, which was endoscopically retrieved. The bezoar was composed of bilirubin calcium, calcium carbonate, and fatty acid calcium. Due to the presence of bilirubin calcium in the bezoar, we performed imaging studies of the bile duct; gallstones and common bile duct stones were identified. Although bezoar with components similar to bile is infrequently encountered, our findings suggest that a bezoar originating from bile should be considered among the differential diagnoses in patients without a recent consumption history of persimmons who demonstrate a mass in the digestive tract. This case highlights the importance of component analysis of gastric bezoars because its findings may alter the treatment plan.

    DOI: 10.1155/2019/5742672

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  • A Magnesium Oxide Bezoar.

    Masaya Iwamuro, Shunsuke Saito, Masao Yoshioka, Haruo Urata, Kumiko Ueda, Kazuhide Yamamoto, Hiroyuki Okada

    Internal medicine (Tokyo, Japan)   57 ( 21 )   3087 - 3091   2018.11

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    A 75-year-old Japanese woman presented with nausea and appetite loss. Computed tomography showed a radiopaque substance in the stomach. Esophagogastroduodenoscopy revealed bezoars in the stomach, which were endoscopically retrieved. The bezoars were mainly composed of magnesium and oxide. Although bezoar formation associated with magnesium oxide consumption is infrequently encountered, the present case indicates that pharmacobezoar should be considered among the differential diagnoses in patients who demonstrate a radiopaque mass in the digestive tract and have a history of magnesium oxide use.

    DOI: 10.2169/internalmedicine.1124-18

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  • Lanthanum deposition corresponds to white lesions in the stomach. International journal

    Masaya Iwamuro, Haruo Urata, Takehiro Tanaka, Seiji Kawano, Yoshiro Kawahara, Katsuhiko Kimoto, Hiroyuki Okada

    Pathology, research and practice   214 ( 7 )   934 - 939   2018.7

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    OBJECTIVE: Although lanthanum deposition in the stomach has been most frequently reported to occur as white lesions, no study has investigated whether the white lesions observed during esophagogastroduodenoscopy are truly lanthanum-related. Here, we retrospectively investigated the amount of lanthanum in endoscopic biopsy specimens. METHODS: We reviewed four patients showing gastric white spots or annular whitish mucosa in the gastric white lesions (Bw) and peripheral mucosa where the white substance was not endoscopically observed (Bp) during biopsy. We also reviewed three patients with diffuse whitish mucosa and three patients with no whitish lesions. We performed scanning electron microscopy and energy dispersive X-ray spectrometry to quantify the lanthanum elements (wt%) in the biopsy specimens. RESULTS: The amount of lanthanum in the Bw ranged from 0.15-0.31 wt%, whereas that of Bp was 0.00-0.13 wt%. The difference was statistically significant (P < 0.05). The amount of lanthanum in the Bw, endoscopically presented with white spots or annular whitish mucosa, was significantly higher than that of no whitish lesions (0.05-0.14 wt%, P < 0.05). The amount of lanthanum was also higher in the diffuse whitish mucosa (0.21-0.23 wt%) compared with no whitish lesions (P < 0.01). CONCLUSIONS: This study is the first to reveal that pathological lanthanum deposition corresponds to the endoscopically observed white lesions in the gastric mucosa. Therefore, during esophagogastroduodenoscopy, physicians should pay attention to possible presence of white lesions in patients treated with oral lanthanum carbonate to ensure prompt identification of associated issues.

    DOI: 10.1016/j.prp.2018.05.024

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  • Lanthanum Deposition in the Stomach in the Absence of Helicobacter pylori Infection.

    Masaya Iwamuro, Haruo Urata, Takehiro Tanaka, Seiji Kawano, Yoshiro Kawahara, Katsuhiko Kimoto, Hiroyuki Okada

    Internal medicine (Tokyo, Japan)   57 ( 6 )   801 - 806   2018.3

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    In this case report, we describe two patients who showed a diffusely whitish mucosa in the posterior wall and the lesser curvature of the gastric body. The patients were serologically- and histopathologically-negative for Helicobacter pylori. Random biopsy specimens from the stomach revealed no regenerative changes, intestinal metaplasia, and/or foveolar hyperplasia in either of the patients. Although lanthanum deposition in the gastric mucosa has been reported to occur in close association with H. pylori-associated gastritis, our patients tested negative for H. pylori. These cases suggest that lanthanum deposition presents as whitish lesions in the gastric body in H. pylori-negative patients.

    DOI: 10.2169/internalmedicine.9665-17

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  • Ghost tablet in feces.

    Masaya Iwamuro, Yosuke Morishita, Haruo Urata, Hiroyuki Okada

    Journal of general and family medicine   18 ( 6 )   483 - 484   2017.12

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    Recently, we encountered a female patient who identified the presence of a ghost tablet in her fecal matter. Interestingly, although the patient was prescribed potassium chloride capsules, elemental composition analysis by energy-dispersive X-ray spectroscopy was unable to detect the presence of either potassium or chloride in the fecal tablet remnant.

    DOI: 10.1002/jgf2.134

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  • Relationship between gastric lanthanum deposition and Helicobacter pylori-associated chronic gastritis: is it rare or common? International journal

    Masaya Iwamuro, Haruo Urata, Hiroyuki Okada

    Pathology international   67 ( 12 )   649 - 649   2017.12

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    DOI: 10.1111/pin.12602

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  • Lanthanum phosphate deposition in the duodenum. International journal

    Masaya Iwamuro, Takehiro Tanaka, Haruo Urata, Katsuhiko Kimoto, Hiroyuki Okada

    Gastrointestinal endoscopy   85 ( 5 )   1103 - 1104   2017.5

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    DOI: 10.1016/j.gie.2016.06.012

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  • Lanthanum Deposition in the Stomach: Usefulness of Scanning Electron Microscopy for Its Detection.

    Masaya Iwamuro, Haruo Urata, Takehiro Tanaka, Akemi Ando, Takahiro Nada, Kosuke Kimura, Kenji Yamauchi, Chiaki Kusumoto, Fumio Otsuka, Hiroyuki Okada

    Acta medica Okayama   71 ( 1 )   73 - 78   2017.2

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    After having been treated with lanthanum carbonate administration for 4 years for hyperphosphatemia, a 75-year-old Japanese woman undergoing hemodialysis was diagnosed with lanthanum phosphate deposition in the stomach. The deposition, seen as white microgranules, was observed using esophagogastroduodenoscopy with magnifying observation. To the best of our knowledge, these are the minutest endoscopy images of lanthanum phosphate deposition in the gastric mucosa. Scanning electron microscopy (SEM) observation enabled easier identification of the deposited material, which was visible as bright areas. The present case suggests the usefulness of SEM observation in the detection of lanthanum phosphate deposition in the gastrointestinal tract.

    DOI: 10.18926/AMO/54828

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  • A Calcium Enterolith in a Patient with Crohn's Disease and Its In Vitro Dissolubility in Citric Acid. International journal

    Masaya Iwamuro, Haruo Urata, Sakiko Hiraoka, Masayasu Ohmori, Yoshitaka Kondo, Yoshiro Kawahara, Hiroyuki Okada

    Case reports in gastrointestinal medicine   2017   2951547 - 2951547   2017

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    The microstructure and dissolubility of a calcified enterolith and enterolith pieces removed from a 26-year-old Japanese woman with Crohn's disease were analyzed using scanning electron microscopy and energy dispersive X-ray spectroscopy. The enterolith showed a multilayered structure with fatty acid calcium and magnesium phosphate. The amount of calcium, magnesium, and phosphate decreased after they were immersed in a citric acid solution, suggesting a potential contribution of acidic aqueous solution to elute inorganic substances contained in calcified enteroliths. This is the first study to investigate the in vitro dissolubility of calcified enteroliths induced by citric acid solution.

    DOI: 10.1155/2017/2951547

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  • An Energy Dispersive X-ray Spectroscopy Analysis of Elemental Changes of a Persimmon Phytobezoar Dissolved in Coca-Cola.

    Masaya Iwamuro, Haruo Urata, Reiji Higashi, Masahiro Nakagawa, Shin Ishikawa, Hidenori Shiraha, Hiroyuki Okada

    Internal medicine (Tokyo, Japan)   55 ( 18 )   2611 - 5   2016

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    To investigate the mechanism of phytobezoar dissolution by Coca-Cola(®), persimmon phytobezoar pieces removed from a 60-year-old Japanese woman were analyzed by energy dispersive X-ray spectroscopy. The amount of calcium significantly decreased after dissolution treatment using Coca-Cola(®), suggesting a potential contribution of calcium to dissolution mechanisms. Moreover, immersion in Coca-Cola(®) for 120 hours on the exterior surface revealed that Coca-Cola(®) did not permeate persimmon phytobezoars. This is the first study to investigate the mechanisms of persimmon phytobezoar permeability and dissolution induced by Coca-Cola(®).

    DOI: 10.2169/internalmedicine.55.6985

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  • Ultrastructural analysis of an enterolith composed of deoxycholic acid.

    Masaya Iwamuro, Yuichi Miyashima, Takahiro Yoshioka, Toshihiro Murata, Yoshio Miyabe, Yoshinari Kawai, Haruo Urata, Hidenori Shiraha, Hiroyuki Okada, Kazuhide Yamamoto

    Acta medica Okayama   68 ( 6 )   369 - 74   2014.12

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    A 67-year-old Japanese man underwent enterotomy because of enterolith ileus. Component analysis by infrared spectroscopy revealed that the enterolith was composed of a high concentration of deoxycholic acid. We further analyzed and compared the ultrastructure of the enterolith and a commercially available powdered form of deoxycholic acid by means of scanning electron microscopy and energy dispersive X-ray spectroscopy. Energy dispersive X-ray spectroscopy analysis revealed that the ratios of carbon and oxygen in the enterolith were equal to those in the deoxycholic acid powder. Scanning electron microscopy analysis showed rectangular prism-shaped particles on the surface of the enterolith. This structure was similar to that of the deoxycholic acid powder. The surgically removed enterolith had a twisted and coiled appearance. Possible mechanisms underlying the formation of this unique form are discussed.

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  • Ultrastructural analysis of a gastric persimmon phytobezoar. International journal

    Masaya Iwamuro, Haruo Urata, Masumi Furutani, Yoshinari Kawai, Hidenori Shiraha, Akinobu Takaki, Hiroyuki Okada, Kazuhide Yamamoto

    Clinics and research in hepatology and gastroenterology   38 ( 4 )   e85-7   2014.9

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