Biomedical subjects

Shin Ishizawa

Publications and source records attributed to Shin Ishizawa.

11 recordsLinked to original sources

PubMed2006

Cholangiocarcinoma at the cystic duct discovered by lymph node metastases with clear cell transformation.

We encountered a case with cholangiocarcinoma of the cystic duct, which was first manifested by multiple lymph node metastases with clear cell changes resembling clear cell adenocarcinoma (CCC). Because the clear cell changes were not prominent at the primary site, clear cell transformation might have occurred preferentially at the metastatic lesion in this case. Alternatively, tumor cells with clear cell transformation, found at the primary site, might have high metastatic potential. The patient showed thromboembolism and hypercalcemia as paraneoplastic syndromes at the terminal stage as reported in patients with CCC of the ovary. Those complications might be common biological features of CCC.

Adenocarcinoma, Clear Cell↗

PubMed2006

Absence of human herpesvirus-8 and Epstein-Barr virus in inflammatory myofibroblastic tumor with anaplastic large cell lymphoma kinase fusion gene.

Inflammatory myofibroblastic tumor (IMT) is clinically and histologically characterized by inflammation. Some populations of IMT have anaplastic large cell lymphoma kinase (ALK) gene rearrangements. Infection with Epstein-Barr virus (EBV) and human herpesvirus-8 (HHV-8) in tumor cells of IMT has been reported; these reports, however, have been limited to ALK-negative IMT. The purpose of the present paper was to evaluate 21 cases of IMT for the presence of EBV and HHV-8. Immunohistochemically, 15 cases were ALK positive and six were negative. Of eight cases analyzed using reverse transcription-polymerase chain reaction, tropomyosin 3 (TPM3)-ALK, TPM4-ALK and clathrin heavy chain-ALK fusion genes were detected in one, two and two cases, respectively. All 21 IMT, irrespective of ALK expression, were negative for EBV by in situ hybridization for EBV-encoded RNA and immunohistochemical stain for latent membrane antigen-1. HHV-8 was also negative in all IMT by PCR for HHV-8 DNA sequence (KS330/233) and immunohistochemical stain for latent nuclear antigen. These results suggest that IMT may be a heterogeneous group in terms of pathogenesis, and EBV and HHV-8 do not play a major role in the pathogenesis of ALK-positive tumor.

Adolescent↗

PubMed2006

Mouse brains deficient in neuronal PDGF receptor-beta develop normally but are vulnerable to injury.

Platelet-derived growth factors (PDGFs) and PDGF receptors (PDGFRs) are widely expressed in the mammalian CNS, though their functional significance remains unclear. The corresponding null-knockout mutations are lethal. Here, we developed novel mutant mice in which the gene encoding the beta subunit of PDGFR (PDGFR-beta) was genetically deleted in CNS neurons to elucidate the role of PDGFR-beta, particularly in the post-natal stage. Our mutant mice reached adulthood without apparent anatomical defects. In the mutant brain, immunohistochemical analyses showed that PDGFR-beta detected in neurons and in the cells in the subventricular zone of the lateral ventricle in wild-type mice was depleted, but PDGFR-beta detected in blood vessels remained unaffected. The cerebral damage after cryogenic injury was severely exacerbated in the mutants compared with controls. Furthermore, TdT-mediated dUTP-biotin nick end labeling (TUNEL)-positive neuronal cell death and lesion formation in the cerebral hemisphere were extensively exacerbated in our mutant mice after direct injection of NMDA without altered NMDA receptor expression. Our results clearly demonstrate that PDGFR-beta expressed in neurons protects them from cryogenic injury and NMDA-induced excitotoxicity.

Animals↗

PubMed2005

Suppression of Epstein-Barr nuclear antigen 1 (EBNA1) by RNA interference inhibits proliferation of EBV-positive Burkitt's lymphoma cells.

PURPOSE: Epstein-Barr virus (EBV) is associated with the development of several lymphoid and epithelial malignancies, including Burkitt's lymphoma. The EBV latent protein, EBV Nuclear Antigen 1 (EBNA1), is detectable in almost all types of EBV-associated tumors and is essential for replication and maintenance of the latent episome of EBV. We here examined whether the RNA interference (RNAi) technique could be employed to suppress expression of EBNA1 in EBV-positive Burkitt's lymphoma cells. METHODS: A Raji cell line expressing small hairpin RNAs (shRNAs) against EBNA1 was established and EBNA1 mRNA level was determined by real-time RT-PCR analysis. We investigated the effects of EBNA1 silence on lymphoma cell growth and cell cycle progression. RESULTS: Transfection of an EBNA1 RNAi plasmid resulted in substantial loss of EBNA1 mRNA and significantly inhibited proliferation of Raji cells relative to the control plasmid case. Suppression of EBNA1 was also associated with downregulation of EBV oncogene EBNA2, a decreased PCNA labeling index and increased G0/G1 fraction in cell cycle analysis. CONCLUSIONS: These findings point to potential therapeutic applications for vector-mediated siRNA delivery to control EBV-associated malignant disorders.

Apoptosis↗

PubMed2005

Cytoplasmic expression of c-erbB2 in non-small cell lung cancers.

The aim of this study was to investigate the expression of c-erbB2 in non-small cell lung cancers (NSCLCs) with attention both to membranous and cytoplasmic reaction, and to try to elucidate the meaning of cytoplasmic expression of c-erbB2 in NSCLCs. Immunohistochemical c-erbB2 expression and related clinico-pathological features were examined in 312 surgically resected patient tissues of NSCLCs, including 175 cases of adenocarcinoma and 137 cases of squamous cell carcinoma. Immunostaining of inner- and ecto-domain of c-erbB2, mRNA expression and the quantitation of soluble c-erbB2 in cultured media were performed in five NSCLC cell lines. Cytoplasmic expression of c-erbB2 was observed more frequently than membranous, both in patient tissues and cell lines. Neither membranous nor cytoplasmic expression of c-erbB2 was significantly correlated with short outcome in NSCLCs. Membranous c-erbB2 was expressed by both inner and ecto-domain, while cytoplasmic c-erbB2 was expressed by either or both inner and ecto-domain. c-erbB2 mRNA was produced in most cell lines; however, the soluble form was only detectable in a cell line that only presented a membranous c-erbB2. In conclusion, cytoplasmic c-erbB2 of NSCLCs was not a full-length protein only expressed in cellular membrane, but reflected degenerated c-erbB2 fragments with less functional ability.

Adult↗

PubMed2004

Deletion of the PDGFR-beta gene affects key fibroblast functions important for wound healing.

This study provides new perspectives of the unique aspects of platelet-derived growth factor beta-receptor (PDGFR-beta) signaling and biological responses through the establishment of a mutant mouse strain in which two loxP sequences were inserted into the introns of PDGFR-beta genome sequences. Isolation of skin fibroblasts from the mutant mice and Cre recombinase transfection in vitro induced PDGFR-beta gene deletion (PDGFR-betaDelta/Delta). The resultant depletion of the PDGFR-beta protein significantly attenuated platelet-derived growth factor (PDGF)-BB-induced cell migration, proliferation, and protection from H2O2-induced apoptosis of the cultured PDGFR-betaDelta/Delta dermal fibroblasts. PDGF-AA and fetal bovine serum were mitogenic and anti-apoptotic but were unable to induce the migration in PDGFR-beta Delta/Delta fibroblasts. Concerning the PDGF signaling, PDGF-BB-induced phosphorylation of Akt, ERK1/2, and JNK, but not p38, decreased in PDGFR-betaDelta/Delta fibroblasts, but PDGF-AA-induced signaling was not altered. Overexpression of the phospholipid phosphatases, SHIP2 and/or PTEN, inhibited PDGF-BB-induced phosphorylation of Akt and ERK1/2 in PDGFR-betaDelta/Delta fibroblasts but did not affect that of JNK and p38. These results indicate that disruption of distinct PDGFR-beta signaling pathways in PDGFR-betaDelta/Delta dermal fibroblasts impaired their proliferation and survival, but completely inhibits migratory response, and that PDGF-BB-induced phosphorylation of Akt and ERK1/2 possibly mediated by PDGFR-alpha is regulated, at least in part, by the lipid phosphatases SHIP2 and/or PTEN. Thus, the PDGFR-beta function on dermal fibroblasts appears to be critical in PDGF-BB action for skin wound healing and is clearly distinctive from that of PDGFR-alpha in the ligand-induced biological responses and the underlying properties of cellular signaling.

Animals↗

PubMed2004

Acute subdural hematoma due to arteriovenous malformation primarily in dura mater: a case report.

We report a 42-year-old female with alcohol addiction who suddenly died of subdural hematoma (SDH) caused by dural arteriovenous malformation (AVM). In autopsy, there was seen a massive SDH with a total weight of 181 g that covered an entire part of the left cerebral hemisphere, although either serious external injuries of the head or any visible internal injuries of the brain were observed. SDH subsequently resulted in the tonsillar, transtentorial and subfalcial herniations with a right-sided shift of the left-lateral and third ventricles, and the left thalamus as well. Histopathological examination on the serial sections cut from the falx cerebri revealed abnormal distribution of arteries and veins with various sizes, which were comprehensively highlighted by immunohistochemical stainings with alpha-SMA and CD31. Although a very point of bleeding was not identified even by careful histological observation, we concluded that dural AVM could be critical for acute SDH in the present case. The value of ethanol concentration examined in the samples from SDH supported that the lesion could be not chronic, but acute.

Adult↗

PubMed2004

Improved 1-h rapid immunostaining method using intermittent microwave irradiation: practicability based on 5 years application in Toyama Medical and Pharmaceutical University Hospital.

Immunostaining depending on antigen-antibody specificity is the commonest approach for determining the localization of specific antigens in tissue sections. This procedure is applicable not only with frozen or specially fixed samples, but also has proved reliable with formalin-fixed paraffin-embedded tissue sections through improvement of antigen-retrieval. Immunostaining is thus firmly established as a tool for diagnostic pathology and in our institute multiple antibodies are applied for 13-15% of the cases examined, as well as H and E staining. With the standard approach, approximately 3 h is necessary from the beginning of deparaffinization till covering sections with the Envision system. We utilized intermittent microwave irradiation for 10 min during hybridization with primary and secondary antibodies in a special moist-chamber, to achieve all immunostaining steps within 1 h in 178 primary antibodies frequently used for diagnostic pathology. According to our 5 years experience, such microwave irradiation not only obtained significant specific staining for enhancing the specificity of antigen-antibody reactions, but also inhibited nonspecific binding. We present herein the details of the methodology and recommendations for its application with particular primary antibodies. This method can contribute to savings in time and energy, allowing pathologists to rapidly obtain diagnostic information.

Antibodies, Monoclonal↗

PubMed2004

A case of small cell gastric carcinoma with an adenocarcinoma component operated curatively.

We present a case of a primary advanced gastric tumor that was composed of 2 different pathological components: small cell carcinoma and moderately-differentiated adenocarcinoma. The patient was still alive four years after the surgery was performed, without recurrence. A large part of the tumor consisted of a diffuse sheet of small cell carcinoma, which transitioned into another small portion consisting of moderately-differentiated tubular adenocarcinoma components. Therefore, this case raised the possibility that small cell gastric carcinoma may originate from totipotential stem cells of the stomach. Although small cell carcinoma progresses aggressively, and patients with it have an extremely poor prognosis, this patient recovered uneventfully after the surgical resection, and has remained in good health, without any recurrences.

Adenocarcinoma↗

PubMed2002

Clinicopathological studies of peripheral neuropathy in Churg-Strauss syndrome.

Clinicopathological studies were performed on the visceral organs and the sural nerve of a male patient with Churg-Strauss syndrome (CSS) in order to understand the mechanisms of peripheral nervous system damage. A 67-year-old man, with a 2-year history of bronchial asthma, developed acutely painful paraplegia and dyspnea. Laboratory data showed a leukocytosis, an elevated serum creatinine kinase (CK) and marked eosionophilia. Autoantibodies including p- and c-ANCA were negative. Electrophysiological studies revealed a severe sensory-motor neuropathy of multiple mononeuritis type. Steroid pulse therapy performed a day after biopsy of skin, muscle and sural nerve was effective in resolving his respiratory and neurological dysfunction but a perforation of an intestinal ulcer occurred which required surgical intervention. In the biopsied sural nerve and the surgically resected intestine and mesentery there was vasculitis with fibrinoid necrosis accompanied by numerous eosinophils and macrophages containing eosinophil cationic protein (ECP). These findings suggest that in addition to ischemic changes due to vasculitis some neurotoxic substances generated by the eosinophils may be involved in the development of neuropathy in CSS.

Aged↗

PubMed2002

Hepatocyte antigen as a marker of hepatocellular carcinoma: an immunohistochemical comparison to carcinoembryonic antigen, CD10, and alpha-fetoprotein.

Hepatocyte monoclonal antibody (Hep) (alternatively Hep Par 1 for Hep paraffin 1) has been reported to stain normal hepatic tissue and hepatocellular carcinoma (HCC) with high specificity. We have studied the Hepatocyte expression in 96 cases of HCC and 311 cases of nonhepatic epithelial tumors. All cases of HCC were also stained with CEA-Gold 5, CD10, and alpha-fetoprotein. Hep, CEA-Gold 5, CD10, and alpha-fetoprotein immunostains were performed on formalin-fixed, paraffin-embedded tissue sections. Hep immunoreactivity was detected in 88 of 96 cases of HCC (92%), with a cytoplasmic and granular pattern of staining. The level of Hep expression in HCC corresponded to the nuclear grade and growth pattern. All 50 cases of nuclear grade 1 and nuclear grade 2 HCC were positive (100%), whereas 37 of 44 nuclear grade 3 (84%) and 1 of 2 nuclear grade 4 (50%) were positive. Sixty-seven of 68 cases of HCC with a trabecular, pseudoglandular, or scirrhous growth pattern were positive (98%), whereas 22 of 27 cases of HCC with a compact growth pattern were positive (81%). CEA-Gold 5, CD10, and alpha-fetoprotein immunoreactivity was detected in 76% (73 of 96), 52% (50 of 96), and 31% (30 of 96) cases of HCC, respectively. The positive predictive value of the combination of all four antibodies was 97%. Three cases of HCC were negative for all four antibodies; these cases had a high nuclear grade or a sarcomatoid or compact growth pattern. Twenty of 311 cases of nonhepatic tumors were positive for Hep (6%): 15 were adenocarcinomas and five were neuroendocrine tumors. The negative predictive value of Hep in HCC was 94%. The Hep-positive nonhepatic epithelial tumors were easily distinguished from HCC by the expression of keratin 7 or keratin 20 for adenocarcinoma and chromogranin and synaptophysin for neuroendocrine tumors because HCC does usually not express these markers. With the exception of two cases of hepatoid gastric carcinoma, all Hep-positive nonhepatic epithelial tumors were negative for alpha-fetoprotein, CEA-Gold 5, and CD10. Our study demonstrates that Hep is a relatively specific marker for HCC. It is useful in differentiating HCC from primary hepatic cholangiocarcinoma and metastatic tumors when combined with other immunomarkers.

Antibodies, Monoclonal↗