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Featured researches published by Seiko Kitamura.


Hepatology Research | 2011

Characterization of hepatocellular adenoma based on the phenotypic classification: The Kanazawa experience

Motoko Sasaki; Norihide Yoneda; Seiko Kitamura; Yasunori Sato; Yasuni Nakanuma

Aim:  Hepatocellular adenoma (HCA) represents a heterogeneous entity, and recently four major subgroups were identified based on genotype and phenotype classification from Europe. HCA is rare in Asian countries including Japan and there has been no study regarding the subgroups of HCA in Japan.


The Journal of Pathology | 2012

Gene amplification of ESR1 in breast cancers-fact or fiction? A fluorescence in situ hybridization and multiplex ligation-dependent probe amplification study

Akishi Ooi; Masafumi Inokuchi; Shinichi Harada; Johji Inazawa; Ryousuke Tajiri; Seiko Kitamura; Hiroko Ikeda; Hiroko Kawashima; Yoh Dobashi

Oestrogen receptor‐alpha (ERα), encoded by the ESR1 gene located on 6q25, is a nuclear transcription factor. Since it was reported in 2007 that more than 20% of breast cancers show ESR1 gene amplification, there has been considerable controversy about its frequency and clinical significance. We set out to assess the frequency and levels of ESR1 amplification in breast cancers. In a total of 106 breast needle biopsy specimens examined by immunohistochemistry, 78 tumours contained more than 10% ERα‐positive cancer cells. In fluorescence in situ hybridization (FISH) analysis with an ESR1‐specific probe, variously extended ESR1 signals were found in ERα‐expressing cells. Some of these were indistinguishable from large clustered signals generally accepted to mean high‐level gene amplification in homogeneously staining regions (HSRs), and could be considered to represent gene amplification. However, with RNase treatment, the ‘HSR‐like’ signals changed to small compact signals, and are thus thought to represent concentrated RNA. FISH using two differently labelled probes corresponding to the non‐overlapping 5′‐ and 3′‐end portions of the ESR1 gene on touch smears showed a preserved spatial relationship of the 3′ to 5′ sequence of ESR1, therefore strongly suggesting that the RNA consisted of primary transcripts. Using touch smears obtained from 51 fresh tumours, precise enumeration of ESR1 signals with a correction by the number of centromere 6 on FISH after RNase A treatment revealed that three tumours (5.9%) had tumour cells with one to three additional copies of ESR1 as predominant subpopulations. This infrequent and low level of gene amplification of ESR1 was also detected as a ‘gain’ of the gene by analysis with multiplex ligation‐dependent probe amplification (MLPA). The consistent results from immunohistochemistry, FISH, and MLPA in the present study settle the long‐standing debate concerning gene amplification of ESR1 in breast carcinoma. Copyright


Liver International | 2015

Characteristics of hepatic fatty acid compositions in patients with nonalcoholic steatohepatitis

Kazutoshi Yamada; Eishiro Mizukoshi; Hajime Sunagozaka; Kuniaki Arai; Tatsuya Yamashita; Yumie Takeshita; Hirofumi Misu; Toshinari Takamura; Seiko Kitamura; Yoh Zen; Yasuni Nakanuma; Masao Honda; Shuichi Kaneko

Nonalcoholic fatty liver disease (NAFLD) is closely related to insulin resistance and lipid metabolism. Recent studies have suggested that the quality of fat accumulated in the liver is associated with the development of nonalcoholic steatohepatitis (NASH). In this study, we investigated the fatty acid composition in liver tissue and its association with the pathology in NAFLD patients.


Human Pathology | 2012

α-Fetoprotein–producing gastric carcinoma and combined hepatocellular and cholangiocarcinoma show similar morphology but different histogenesis with respect to SALL4 expression

Hiroko Ikeda; Yasunori Sato; Norihide Yoneda; Kenichi Harada; Motoko Sasaki; Seiko Kitamura; Yoshiko Sudo; Akishi Ooi; Yasuni Nakanuma

α-Fetoprotein is expressed in hepatocellular carcinoma, yolk sac tumor, and some gastric carcinomas. The α-fetoprotein-producing gastric carcinoma composed of hepatoid and common adenocarcinoma shows morphological similarities to combined hepatocellular and cholangiocarcinoma. In this study, the expression of putative hepatic stem/progenitor markers (EpCAM, OV-6, DLK-1, and NCAM/CD56), hepatocyte markers (HepParI, α-fetoprotein, glypican 3), and the germ cell marker SALL4 was examined in α-fetoprotein-producing gastric carcinoma (20 cases) and combined hepatocellular and cholangiocarcinoma (20 cases) for evaluation of pathologic differentiation and also the histogenesis of both tumors. The SALL4 protein was expressed in 95% of α-fetoprotein-producing gastric carcinoma, including the hepatoid component (hepatoid gastric carcinoma), but was absent in combined hepatocellular and cholangiocarcinoma. Glypican 3 and α-fetoprotein were detected in all hepatoid-type α-fetoprotein-producing gastric carcinoma but variably in combined hepatocellular and cholangiocarcinoma. NCAM/CD56 was expressed focally in combined hepatocellular and cholangiocarcinoma but was rare in hepatoid gastric carcinoma. EpCAM, DLK-1, and OV6 were variably expressed in hepatoid gastric carcinoma and combined hepatocellular and cholangiocarcinoma. SALL4 was a useful differential marker for combined hepatocellular and cholangiocarcinoma and hepatoid gastric carcinoma. The histogenesis of hepatoid gastric carcinoma expressing SALL4 seems to reflect fetal gut differentiation or involve the germ cell lineage and may be different from that of combined hepatocellular and cholangiocarcinoma involving the hepatic stem cell or progenitor cell lineages. In conclusion, hepatoid gastric carcinoma and combined hepatocellular and cholangiocarcinoma shared morphologies, whereas the distinction of hepatoid gastric carcinoma from combined hepatocellular and cholangiocarcinoma is possible by immunostaining for SALL4. These 2 tumors seem to differ in their histogenesis with respect to SALL4 expression.1.


American Journal of Clinical Pathology | 2013

Clinicopathologic significance of combined hepatocellular-cholangiocarcinoma with stem cell subtype components with reference to the expression of putative stem cell markers.

Hiroko Ikeda; Kenichi Harada; Yasunori Sato; Motoko Sasaki; Norihide Yoneda; Seiko Kitamura; Yoshiko Sudo; Akishi Ooi; Yasuni Nakanuma

OBJECTIVES To examine the clinicopathologic features of combined hepatocellular-cholangiocarcinoma (HC-CC), which the World Health Organization (WHO) proposed classifying into 2 types, and the expression of delta-like 1 homolog (DLK1), as well as putative stem cell markers, such as NCAM/CD56 and CD133. METHODS In this study we examined the expression of stem cell markers using immunohistochemistry. RESULTS Thirty-six cases of combined HC-CC were subclassified into 24 cases, with more than 5% stem cell features (group B) and 12 cases with less than 5% stem cell areas (group A). The postoperative overall survival rate was worse for group B than for group A. DLK1 was frequently expressed in group B cases compared with group A, hepatocellular carcinoma, and intrahepatic cholangiocarcinoma cases. CONCLUSIONS The 2010 WHO classification seems important for elucidating the pathogenesis of stem cell-related liver cancers.


Journal of Clinical Pathology | 2011

Participation of bile ductular cells in the pathological progression of non-alcoholic fatty liver disease

Mayumi Chiba; Motoko Sasaki; Seiko Kitamura; Hiroko Ikeda; Yasunori Sato; Yasuni Nakanuma

Aims Non-alcoholic fatty liver disease (NAFLD) represents a spectrum of pathological conditions, ranging from simple steatosis to hepatic fibrosis with progression to cirrhosis. While activated hepatic stellate cells (HSC) are known to be involved in intralobular, perisinuosidal fibrosis, the mechanisms of portal and bridging fibrosis remain speculative. This study investigated the roles of bile ductules in portal and septal fibrosis. Methods 48 liver biopsies were obtained from NAFLD patients. These cases were divided into four stages according to the Brunt classification. Results Bile ductules positive for CK19 were increased along with the progression of staging and fibrosis of NAFLD, and the increased bile ductules were associated with portal inflammation and fibrosis. The cellular senescence marker; p16INK4a and p21WAF1/Cip1-positive bile ductular cells were increased in stages 3 and 4. Such senescent bile ductules frequently express chemotactic protein, CCL2 (MCP-1), which may be responsible for chemoattraction of activated HSC around the bile ductules in portal and septal fibrosis and for portal inflammation. The migration of cultured mouse HSC was significantly facilitated in the presence of cultured senescent mouse biliary epithelial cells (BEC), and this migration was mediated by CCL2 secreted from senescent cultured BEC. Small spindle-like cells positive for CK7 alone in the hepatic parenchyma in the advanced stage seem to differentiate to periportal bile ductular cells positive for CK19 and CK7. Conclusions It seems possible that increased bile ductules expressing cellular senescence markers and chemokines are at least partly involved in the progressive portal and bridging fibrosis in NAFLD.


Modern Pathology | 2012

A serum amyloid A-positive hepatocellular neoplasm arising in alcoholic cirrhosis: a previously unrecognized type of inflammatory hepatocellular tumor

Motoko Sasaki; Norihide Yoneda; Seiko Kitamura; Yasunori Sato; Yasuni Nakanuma

Hepatocellular adenoma usually arises in the absence of significant fibrosis. Herein, we report seven patients with serum amyloid A-positive hepatocellular neoplasm, which shares features with inflammatory hepatocellular adenoma arising in alcoholic cirrhosis. Seven patients (two women and five men, age range 41–67 years) with hypervascular hepatocellular nodules associated with alcoholic cirrhosis were retrieved from our pathological files (1997–2011). The hepatocellular nodules were multiple (>3) in all patients and 17 nodules were histologically examined. We surveyed the immunoreactivity for serum amyloid A, glutamine synthetase, and glypican-3 in the hepatocellular nodules and control lesions, including 5 focal nodular hyperplasia, 18 dysplastic nodules, and 54 hepatocellular carcinomas in various background diseases. In all, 15 of 17 nodules showed strong and distinct immunoreactivity for serum amyloid A, sharing features with inflammatory hepatocellular adenoma. The serum amyloid A-positive hepatocellular neoplasms showed increased cellular density, inflammatory infiltrate, sinusoidal dilatation, and ductular reaction to various degrees. Although about a half of dysplastic nodules and hepatocellular carcinomas showed focal immunoreactivity for serum amyloid A, the extent of serum amyloid A expression was significantly higher in serum amyloid A-positive hepatocellular neoplasms, than in control nodules. The serum amyloid A-positive hepatocellular neoplasms did not show the overexpression of glutamine synthetase or immunoreactivity for glypican-3. In contrast, most hepatocellular carcinomas showed the overexpression of glutamine synthetase and immunoreactivity for glypican-3, irrespective of background diseases. In conclusion, this study highlights a characteristic group of hepatocellular neoplasms arising in alcoholic cirrhosis, which share features with inflammatory hepatocellular adenomas. These serum amyloid A-positive hepatocellular neoplasms may be a new type of inflammatory hepatocellular tumors in alcoholic patients.


Academic Radiology | 2011

Triple-negative Breast Cancer: Are the Imaging Findings Different Between Responders and Nonresponders to Neoadjuvant Chemotherapy?

Hiroko Kawashima; Masafumi Inokuchi; Hiroyuki Furukawa; Seiko Kitamura

RATIONALE AND OBJECTIVES The purpose of the present study was to evaluate the imaging findings of triple-negative breast cancer patients receiving neoadjuvant chemotherapy (NAC) and to investigate whether the findings are different between responders and nonresponders, enabling us to predict the final patient response. MATERIALS AND METHODS The subjects included 22 women ages 35-73 years (mean, 50.4 years) with 23 triple-negative breast cancers who underwent NAC. In all cases, a mammography, ultrasound, and magnetic resonance imaging (MRI) were performed a total of three times: before NAC, after the first half of NAC, and after NAC. The mass shape, mass margin, presence of clear intratumoral necrosis, and presence of intratumoral calcification were analyzed. The presence of clear intratumoral necrosis was evaluated on the MRI. If there was a very high signal intensity (similar to that of water) in the tumor on the fat-suppressed T2-weighted MRI scans, we judged it to be clear intratumoral necrosis. RESULTS An irregularly shaped mass (P = .018) and the presence of clear intratumoral necrosis (P = .044) were significantly associated with NAC nonresponse in triple-negative breast cancer patients. The mass margin and the presence of intratumoral calcification were not related to the effects after NAC. CONCLUSIONS In cases of triple-negative breast cancer involving clear intratumoral necrosis with an irregular mass shape, it is predicted that the effects of neoadjuvant chemotherapy will likely be poor, and therefore, the presence of such image findings may be useful for determining the optimal application of neoadjuvant chemotherapy.


Oncology Reports | 2013

Advantages of the rapid double-staining method for intraoperative detection of micrometastasis in sentinel lymph nodes

Toshihiko Ojima; Shinichi Kinami; Keishi Nakamura; Katsunobu Oyama; Inokuchi M; Hideto Fujita; Itasu Ninomiya; Sachio Fushida; Takashi Fujimura; Seiko Kitamura; Shinichi Harada; Tetsuo Ohta

For rapid intraoperative diagnosis of lymph node micrometastasis, we refined the rapid immunohistochemistry method by combining anti-cytokeratin antibody-labeled nanocrystal beads with rapid hematoxylin and eosin (H&E) staining on the same section, referred to as the rapid double staining (RDS) technique. Two frozen-section slices each were obtained from 372 lymph nodes of 100 breast cancer patients. We performed RDS for 1 slide and rapid H&E staining for the other. The results were compared with the corresponding final pathological data obtained from the permanent specimens. For specimens from patients with pN1(mi) as determined by final pathological examination, the false‑negative rate was 33.3% for rapid H&E staining and 16.7% for RDS. For specimens from patients with pN0(i+) as determined by final pathological examination, the false‑negative rate was 80% for rapid H&E staining and 0% for RDS. These results indicate that RDS is superior to conventional rapid H&E staining for intraoperative diagnosis of nodal micrometastasis and isolated tumor cells.


Case Reports in Oncology | 2014

Inflammatory myofibroblastic tumor of the urinary bladder with benign pelvic lymph node enlargement: a case report.

Kazuaki Machioka; Yasuhide Kitagawa; Kouji Izumi; Seiko Kitamura; Hiroko Ikeda; Mikio Namiki

Inflammatory myofibroblastic tumors (IMTs) rarely occur in the urinary bladder. It is apparently difficult to distinguish these tumors from other malignant spindle cell proliferations. Herein, we report a case of IMT of the urinary bladder with enlarged pelvic lymph nodes. The definitive pathological diagnosis could not be established by biopsy. Instead, the diagnosis of IMT of the urinary bladder was determined by a positive reaction to anaplastic lymphoma kinase by immunohistochemistry after radical cystectomy. No malignant findings were observed on histopathological evaluations of the enlarged lymph nodes.

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