Yoshitaka Imoto

The University of Tokushima, Tokusima, Tokushima, Japan

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Publications (23)39.74 Total impact

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    ABSTRACT: A 30-year-old female was referred to our hospital for further examination of liver dysfunction. A huge, soft mass was noted in her left upper quadrant on physical examination. Abdominal ultrasonography and computed tomography revealed a huge cystic tumor of 20 cm in the hilus of the spleen. Serum CA19-9 was 491 U/ml, and splenectomy was performed under suspicion of a malignant cystic tumor. The inner surface of the cyst was lined by squamous epithelial cells that were immunohistochemically positive for CA19-9. Serum CA19-9 level was normalized after the surgery. Our case of a very rare, huge epidermoid cyst of the spleen suggests that measurement of the serum CA19-9 level is useful for evaluating therapeutic efficacy of a splenic epidermoid cyst. J. Med. Invest. 62: 89-92, February, 2015.
    Full-text · Article · Mar 2015 · The Journal of Medical Investigation
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    ABSTRACT: Human infection with the parasite Schistosoma japonicum is currently known to be endemic in China and South-east Asia, and infection with this parasite is rarely seen in Japan. However, we sometimes encounter unexpected and uncommon diseases as imported infectious diseases. We describe a rare case of Schistosomasis japonicum imported from a country in South-east Asia, presented with a complaint of dyspnea. The computed tomography and ultrasonography showed characteristic abnormality in the liver and serum antibody improved after administration of Praziquantel.
    No preview · Article · May 2014 · Kanzo

  • No preview · Article · Jan 2014 · Endoscopy
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    ABSTRACT: Background and study aims: Endoscopic submucosal dissection (ESD) in early gastric cancer has rapidly come into widespread use. However, since complications such as bleeding and perforation often occur, and the procedure time is longer for ESD than endoscopic mucosal resection (EMR), development of safer and more reliable technique is required. Patients and methods: The subjects comprised 45 patients with lesions diagnosed histologically as early gastric cancer. They were divided into three groups: cross-counter technique group (CC, n = 15), peroral traction-assisted ESD with suture material group (PT, n = 15), and no-traction group (NT, n = 15). ESD was carried out by two endoscopists who had experienced fewer than 30 cases of ESD. To compare safety and efficacy of a new traction method (CC group) for ESD in early gastric cancer with other methods (PT group and NT group), procedure time, dissected area per unit time, complete resection rate, perforation rate, and bleeding rate were evaluated. Results: There was no significant difference among these three groups in terms of complications, complete resection rate or procedure time. The dissection area per unit time was 22.4, 15.7, and 13.5 mm(2)/min in the CC, PT, and NT groups, respectively, and there was a significant difference between the CC and NT groups (p = 0.007). Conclusions: The cross-counter technique shortened the treatment time for endoscopists without abundant experience in gastric ESD, and it is considered a useful method to institute in order to introduce ESD.
    No preview · Article · Jun 2012 · Surgical Endoscopy

  • No preview · Article · May 2012 · Endoscopy

  • No preview · Article · May 2012 · Endoscopy
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    ABSTRACT: A 63-year-old female was referred to our hospital following the discovery of an abnormality in the upper GI tract during a medical examination. Endoscopic examination showed an elongated protrusion at the duodenal bulb, and an endoscopic polypectomy was performed. Histologically, the outer side was covered with normal duodenal mucosa and inner side consisted of proliferated Brunner's glands, loose connective tissue including dilated vessels and enlarged cystic glands of varying sizes. This case is considered to be identical with the concept of an intraluminal duodenal protrusion or an elongated non-neoplastic duodenal polyp as proposed by Inamoto et al. or Ezoe et al.
    No preview · Article · Feb 2012 · Gastroenterological Endoscopy
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    ABSTRACT: A 62-year-old man was referred to our hospital with enlargement of mucosa-associated lymphoid tissue (MALT) lymphoma of the rectum after the eradication of Helicobacter pylori. The patient was given a diagnosis of stage I MALT. Endoscopic observation revealed an enlarged rectal tumor with 3, 18 double trisomy. Rituximab monotherapy was given and complete remission was achieved. Rituximab monotherapy can be useful for MALT lymphoma of the rectum.
    No preview · Article · Apr 2010 · Nippon Shokakibyo Gakkai zasshi The Japanese journal of gastro-enterology
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    ABSTRACT: A 63-year-old man was admitted to a clinic because of vomiting and epigastic pain after eating bitter persimmons. Upper gastrointestinal endoscopy revealed a yellowish floating mass measuring 6cm in size. We diagnosed the mass as persimmon bezoar. We asked patient to drink Coca-Cola every day and performed a direct endoscopic dispersion of Coca-Cola using ERCP cannula. At repeated endoscopy, we could observe that the bezoar turned to be softened and finally disappeared. This form of dissolution of a persimmon bezoar proved to be rapidly effective, inexpensive, and safe in this case.
    No preview · Article · Jun 2008 · Gastroenterological Endoscopy
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    ABSTRACT: Indocyanine green (ICG) is a fluorescent marker that is excited by rays at a wavelength of 768 nm to emit fluorescence at a wavelength of 807 nm in the infrared (IR) range. We developed an IR fluorescence endoscope (IRFE) to observe superficial gastric tumors and assessed its clinical usefulness. To evaluate the clinical usefulness of an IRFE for the assessment of superficial gastric tumors. An observational study. University hospital. Newly developed IRFE. Thirty patients with gastric tumors were enrolled in this study, and their lesions were subjected to endoscopic submucosal dissection (ESD), or laparoscopic gastrectomy after observation with the IRFE. Gastric lesions were subjected to conventional observation, followed by IR fluorescence observation before and after intravenous ICG (0.01 mg/kg) injection. The relationship between the positive fluorescence and invasivity of each tumor. Fluorescence was positive in 8 of 10 gastric cancers with submucosal invasion (80%) and 1 of 20 adenomas or intramucosal gastric cancers (5%); the difference was statistically significant (P<.01). IRFE is a useful diagnostic tool for estimating the invasivity of gastric tumors.
    No preview · Article · Jul 2007 · Gastrointestinal Endoscopy
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    ABSTRACT: Humoral hypercalcemia of malignancy (HHM) in neoplastic syndrome has been most commonly reported in squamous cell carcinoma. Gallbladder carcinoma with HHM is uncommon. In this report, we describe a male case of gallbladder carcinoma with marked hypercalcemia and a high level of serum parathyroid hormone-related peptide (PTHrP). An immunohistochemical examination using PTHrP was also positive.
    No preview · Article · Apr 2007 · Nippon Shokakibyo Gakkai zasshi The Japanese journal of gastro-enterology
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    ABSTRACT: The present study evaluated correlations between preoperative bile juice cytology and mucin expression of surgical specimens in biliary tract carcinoma. Twenty-five patients with biliary tract carcinoma surgically treated at our hospital, whose bile juice cytology had been evaluated before operation, were allocated to this study. Biliary cytology was classified into three categories based on the Papanicolaou classification. Immunohistochemical staining of tissues was performed using MUC1 and MUC2 monoclonal antibodies. Lesions showing MUC1 expression of ++ or higher and MUC2 expression of - were classified as Group A, and the remaining lesions as Group B. According to the epithelial site, preoperative cytology was highly correlated in Group A, while it was negative in Group B (p<0.05). In the advanced site of carcinomas, preoperative cytology tended to highly be positive in Group A, while it tended to be negative in Group B (p<0.05). These results suggest that the bile juice cytology results are affected by characteristics of mucin expression in the tissue. Based on the possibility that mucin expression correlates with the prognosis of each carcinoma, a positive cytological result suggests a poor prognosis for the carcinoma, which may be informative for predicting the post-operative courses and choosing treatments.
    Full-text · Article · Feb 2007 · The Journal of Medical Investigation
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    ABSTRACT: In previous studies, we generated infrared ray fluorescence-labeled monoclonal antibodies and developed an infrared ray fluorescence endoscope capable of detecting the monoclonal antibodies to establish a novel diagnostic technique for gastrointestinal cancer. Although the whole IgG molecule has commonly been used for preparation of labeled antibodies, labeled IgG displays insufficient sensitivity and specificity, probably resulting from non-specific binding of the Fc fragment to target cells or interference between fluorochromes on the identical labeled antibody, which might be caused by molecular structure. In this in vitro study, we characterized an Fc-free fluorescence-labeled Fab fragment, which was expected to yield more specific binding to target cells than the whole IgG molecule.
    No preview · Article · Sep 2006 · Photodiagnosis and Photodynamic Therapy
  • N. Muguruma · Y. Imoto · T. Kimura · S. Okamura · S. Ito
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    ABSTRACT: Background: Adenomyomatosis of the gallbladder (ADM) is considered to be a type of benign proliferative gallbladder disease or tumorous lesion. However, in recent years, a large number of patients with ADM and gallbladder cancer have been reported. In this study we examined the possibility of carcinogenesis in patients with ADM. Methods: This study included 28 patients in whom various diagnostic imaging procedures suggested ADM. In 19 patients who underwent cholecystectomy and were histopathologically diagnosed as having ADM, immunohistochemical staining with p53 and bcl-2, was performed using paraffin sections. Expression of each protein was classified into 3 grades (+: focal, ++: partially aggregated, +++: diffuse). Grades ++ and +++ were regarded as showing overexpression. In 9 patients, symptoms and morphological changes were followed. Results: On immunohistochemical examination, p53 and bcl-2 were detected in 26.3% and 36.8% of the patients, respectively. Overexpression of p53 was observed in 5.3% of the patients. None of the patients showed excessive expression of bcl-2. During the follow-up period, there were no additional symptoms in any patient. None of the patients underwent cholecystectomy during the follow-up period. Cholecystolithiasis was detected in 63.2% of the patients undergoing resection and in 44.4% of the patients who were followed up. Conclusion: Neither immunohistochemical nor clinical examination strongly suggested that ADM is a precancerous lesion of gallbladder cancer. The association between cholecystolithiasis and gallbladder cancer has been indicated. The incidence of concurrent cholecystolithiasis was high in patients with ADM, suggesting that ADM is an indirect risk factor for gallbladder cancer.
    No preview · Article · Jun 2006

  • No preview · Article · Apr 2006 · Gastrointestinal Endoscopy
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    ABSTRACT: Since there is no infrared fluorescence materials in the living body, infrared fluorescence labeling materials are very useful for making a diagnosis of a micro cancer. We have developed an infrared fluorescence endoscope (IRFE) and indocyanin green (ICG)-derivative as infrared fluorescence labeling materials to evaluate gastrointestinal neoplastic lesions. The study aims were to apply an IRFE and to demonstrate its usefulness in detecting cancerous tissue using an antibody coupled with ICG-derivative. IRFE consisted of an infrared endoscope equipped with excitation (710-790 nm) and barrier (810-920 nm) filters and an intensified CCD camera. We have developed ICG N-hydroxy sulfo succinimide ester (ICG-sulfo-OSu) and 3-ICG-acyl-1, 3-thiazolidine-2-thione (ICG-ATT) as an infrared fluorescent-labeling reagent. ICG-derivative-labeled mouse anti-human carcinoembryonic antigen (CEA) antibody and MUC1 antibody were employed in this study. Moreover, we examined the ability of a reinforcement agent, octylglucoside, to intensity fluorescence from the labeled antibody. Biopsy specimens of gastric cancer were stained with anti-CEA antibody by the avidin-biotinylated peroxidase complex method. Among the positive specimens, freshly resected stomach from three cases were used for the infrared (IR) imaging analysis. The incubation of freshly resected stomach specimens with ICG-anti-CEA antibody-complex resulted in positive staining of the tumor sites by IRFE, and the IR fluorescent images correlated well with the tumor sites. The immunohistochemical studies suggested that the intensity of IR fluorescence of ICG-ATT-MUC1 was stronger than that of ICG-sulfo-OSu. In tumor sections, the reinforcement agent intensified fluorescence, ever at low antibody concentrations. Therefore, we conclude that an anti-CEA (and/or MUC1) antibody with affinity for cancerous lesions and labeled with ICG-derivative can be imaged with this IRFE. Specific antibodies tagged with ICG-derivative with the reinforcement agent can label cancer cells and generate a strong enough fluorescent signal to detect small cancers when examined with an IR fluorescence endoscope.
    Full-text · Article · Mar 2006 · The Journal of Medical Investigation
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    ABSTRACT: A 59-year-old man with situs inversus totalis presented obstructive jaundice due to a tumor of the pancreas head during the treatment of bladder cancer. A diagnosis of malignant obstruction of the common bile duct was made. First he was treated by PTBD to reduce jaundice, and then ERCP and endoscopic biliary stenting were successfully performed. With the patient in the right lateral decubitus position, the endoscope was shortened by twisting to the up-left to approach the papilla of the duodenum. We could perform demanding procedures successfully by paying attention to the left-right reversal.
    No preview · Article · Mar 2006
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    ABSTRACT: In recent years, labeled antibodies have been used for diagnostic imaging in many studies. In this study, we investigated the mode of binding in antibodies labeled with ICG derivatives newly developed for the diagnosis of microcarcinomas, and evaluated the optimal binding molar ratio between the labeling compounds and antibody. MUC 1 antibody and ICG derivatives (ICG-ATT and ICG-sulfo-OSu) were used. ICG derivatives non-covalently bound to the antibody were removed with ethyl acetate, and the ratio of ICG derivatives covalently bound to the labeled antibody was confirmed. During purification of the labeled antibody, the amount of each labeling compound reacting with 1 molecule of the antibody varied as follows: 4, 8, 16, and 32 molar equivalents. Subsequently, the intensity of fluorescence was evaluated by spectroscopy and infrared fluoroscopy. The ratio of residual ICG derivative labeling the antibody was 67.4% for ICG-ATT and 65.0% for ICG-sulfo-OSu. When fluorescent antibody labeled with ICG-ATT at an F/P ratio of 2.94 or 4.18 was used, specific and clear fluorescent images of the antigen were obtained. When ICG-ATT-labeled antibody at an F/P ratio of 6.50 or 6.75 was used, the fluorescence intensity decreased and the fluorescent images of antigen became unclear. It was found that the ICG-ATT-labeled antibody was a more specific and sensitive marker than ICG-sulfo-OSu-labeled antibody, and that lower binding molar ratios of ICG-ATT were more useful for labeling the antibody.
    Full-text · Article · Mar 2006 · The Journal of Medical Investigation
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    ABSTRACT: Mucin core proteins are known to be present in various organs and are specifically expressed with carcinogenesis and closely associated with the prognoses of various malignant tumors in the digestive tract such as colorectal cancer. The present study evaluated correlations between mucin and p53 expression and prognosis of gallbladder cancer using surgically resected tissue specimens from 26 patients with gallbladder carcinoma surgically treated at our hospital. Immunohistochemical staining was performed using MUC 1, MUC2, and p53 monoclonal antibody. The level of antigen expression in the lesion was classified into four stages: none(-), slight(+), moderate (++), and severe (+ + +). According to the UICC classification, histopathological grading, levels of T, N, and M factors, and tumor stages were compared with regard to the correlations with mucin and p53 expression. All cases were classified into two groups according to the results of mucin immunohistochemistry: group A (MUC1, > or = ++; and MUC2, < or = +) and group B (MUC1, < ++; or MUC2, > +). Postoperative survival periods were compared between the two groups and p53-positive and -negative groups. Neither histological grading nor T factor correlated with mucin or p53 expression, respectively. Moreover, neither N factor nor M factor correlated with mucin or p53 expression. Furthermore, stage grouping did not correlate with mucin or p53 expression. However, when the correlation between the postoperative survival period and mucin expression was evaluated, the mean postoperative surgical period was significantly shorter in Group A than in Group B (1.02 years in Group A vs 2.92 years in Group B; P = 0.016). There was no relationship between postoperative survival period and p53 positivity. Mucin expression was independent of various tumor growth factors and clearly reflected the prognosis of gallbladder cancer. Because the relative malignancy of gallbladder cancer could be evaluated by examining the level of glycoprotein expression in tumor tissue, mucin could be a more important marker than p53 for predicting prognosis in gallbladder carcinoma using surgically resected tissue specimens.
    No preview · Article · Aug 2005 · Digestive Diseases and Sciences
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    ABSTRACT: We have developed an infrared fluorescence endoscope to evaluate gastrointestinal vascular lesions. Infrared endoscopy (IRE) after intravenous administration of indocyanine green (ICG) is used at present to examine vascular lesions such as esophageal varices. However, no previous study has compared the sensitivity of infrared fluorescence endoscopy (IRFE) with that of IRE. In this study, we compared the usefulness of IRFE and IRE. For IRFE we used an infrared endoscope equipped with excitation and barrier filters and an intensified charge-coupled device camera. In preliminary experiments, the observable tissue depth was assessed by wrapping increasing numbers of layers of commercially available pork around a syringe containing a uniform concentration of ICG or by changing the concentration of ICG in a syringe covered by a piece of pork of uniform thickness. In the clinical part of the study, ICG was administered intravenously at different concentrations to patients with esophageal varices and the resulting infrared fluorescent images were evaluated. The preliminary experiments revealed that the depth of tissue that could be visualized was significantly greater in IRFE than it was in IRE (11.2 mm in IRFE vs. approximately 3.2 mm in IRE). Clear infrared fluorescence was obtained by IRFE at lower concentrations of ICG than the concentrations required to obtain clear images using IRE. In the clinical part of the study, clear infrared fluorescence was observed in a region where esophageal varices had been detected by conventional endoscopy when ICG was administered in doses of 0.005 mg/kg to 0.01 mg/kg, which was lower than the doses used in IRE. Compared with conventional IRE, IRFE facilitated the observation of deeper layers, and esophageal varices were observed by IRFE following the intravenous administration of a markedly reduced dose of ICG. IRFE, in combining the characteristics of reflected infrared light and fluorescence, may be a useful novel procedure in the diagnosis of vascular lesions in the gastrointestinal tract.
    No preview · Article · Feb 2005 · Endoscopy