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Shinji Yamamoto

Publications and source records attributed to Shinji Yamamoto.

At least 19 recordsLinked to original sources
PubMed2006

DNA methylation regulates long-range gene silencing of an X-linked homeobox gene cluster in a lineage-specific manner.

DNA methylation is a major epigenetic mechanism that has been suggested to control developmental gene regulation during embryogenesis, but its regulatory mechanisms remain unclear. In this report, we show that CpG islands associated with the X-linked homeobox gene cluster Rhox, which is highly expressed in the extraembryonic trophectoderm, are differentially methylated in a stage- and lineage-specific manner during the post-implantation development of mice. Inactivation of both Dnmt3a and Dnmt3b, DNA methyltransferases essential for the initiation of de novo DNA methylation, abolished the establishment of DNA methylation and the silencing of Rhox cluster genes in the embryo proper. The Dnmt3-dependent CpG-island methylation at the Rhox locus extended for a large genomic region ( approximately 1 Mb) containing the Rhox cluster and surrounding genes. Complementation experiments using embryonic stem (ES) cells deficient in the DNA methyltransferases suggested that the CpG-island methylation by Dnmt3a and Dnmt3b was restricted within this large genomic region, and did not affect the neighboring genes outside it, implicating the existence of region-specific boundaries. Our results suggest that DNA methylation plays important roles in both long-range gene silencing and lineage-specific silencing in embryogenesis.

Animals↗
PubMed2006

Hepatoma-derived growth factor is a novel prognostic factor for hepatocellular carcinoma.

BACKGROUND: Hepatoma-derived growth factor (HDGF) is involved in hepatocarcinogenesis, as well as in liver development and regeneration. This study investigated the correlation of HDGF expression with differentiation and prognosis of hepatocellular carcinoma (HCC). METHODS: HDGF expression in 100 patients with HCC (81 men and 19 women) with ages ranging from 34 to 81 years (median, 61 years) receiving surgical treatment was analyzed by immunohistochemistry. HDGF messenger RNA expression was evaluated in 10 cases by reverse transcription-polymerase chain reaction. The immunostaining pattern in HCCs was categorized as a positive HDGF index (showing positive staining in >90% of tumor cells in both nucleus and cytoplasm) or a negative HDGF index (all others). RESULTS: Twenty-seven cases (27%) showed a positive and 73 (73%) showed a negative HDGF index. HDGF messenger RNA expression was significantly higher in four cases with a positive HDGF index than in six with a negative index. Cases with well-differentiated histological characteristics showed a higher rate of positive HDGF index than those with a poorly differentiated subtype. Univariate and multivariate analysis revealed significantly poorer disease-free and overall survivals in patients with a positive HDGF index compared with patients with a negative index. CONCLUSIONS: These findings suggest the potential utility of HDGF immunohistochemistry in determining the prognosis of HCC.

Adult↗
PubMed2006

Expression of hepatoma-derived growth factor is correlated with lymph node metastasis and prognosis of gastric carcinoma.

PURPOSE: Hepatoma-derived growth factor (HDGF) is a unique nuclear/growth factor and might play an important role in the development and progression of carcinomas. In the present study, association of HDGF expression with recurrence and prognosis of gastric carcinoma was examined. PATIENTS AND METHODS: HDGF expression in 317 patients with gastric carcinoma (233 males and 84 females) with ages ranging from 26 to 81 years (median, 60 years) was analyzed by immunohistochemistry. Samples with >90% of tumor cells to express positive immunoreactivity similar to or stronger than that in endothelial cells both for nucleus and cytoplasm were regarded as HDGF index level 2, and others as HDGF index level 1. RESULTS: One hundred and eighty-two cases showed level 1 HDGF expression, whereas 135 cases showed level 2 HDGF expression. Patients with level 2 expression showed higher rates of proximal tumor location (P < 0.0001), large tumor size (P < 0.0001), infiltrative tumor growth (P < 0.0001), presence of vascular and lymphatic invasion (P < 0.0001 for both), presence of lymph node metastasis (P < 0.0001), deep tumor invasion (P < 0.0001), and poorer disease-free and overall survival (P < 0.0001 for both) compared to those with level 1 expression. Multivariate analysis revealed HDGF expression level as an independent prognosticator for disease-free and overall survival. CONCLUSION: HDGF expression level was shown to be a prognostic factor for gastric carcinoma.

Adult↗
PubMed2006

Successful stenting seven days after atherothrombotic occlusion of the intracranial internal carotid artery.

PURPOSE: To report a case of successful stenting after a subacute stroke. CASE REPORT: A 75-year-old man presented with sudden onset of right-sided weakness and difficulty speaking. Imaging revealed an occlusion of the left petrous to lacerum internal carotid artery (ICA) segment and slightly decreased cerebral blood flow in the left hemisphere; there were stenoses of the ostial and cavernous ICA segments on the right. On the seventh day after the stroke, he underwent protected carotid angioplasty of the left intracranial ICA occlusion to reduce the high risk of ischemic stroke owing to bilateral disease. An external arteriovenous shunt was established with an occluding balloon in the proximal ICA and a filter in the femoral vein. After protected balloon dilation of the ICA occlusion, a 3.5 x 18-mm balloon-expandable coronary stent was deployed across the residual stenotic segment. An intraluminal filling defect of the petrous ICA segment suggested an arterial dissection or intraluminal thrombus, so another 2 coronary stents were deployed. Macroscopically visible materials were captured in the filter. The patient had a good clinical course and was discharged without neurological deficits on the twelfth day after the stroke. Angiography at 3 months confirmed no restenosis of the stented vessel. CONCLUSION: This experience suggests that short atherothrombotic intracranial ICA occlusions can be opened in the subacute stroke stage without distal migration of thrombi under proximal protection and flow reversal.

Aged↗
PubMed2006

[Ischemic stroke in a young patient with methylephedrine addiction: a case report].

We report a case of a young patient who had an ischemic stroke due to methylephedrine addiction. A 39-year-old man was admitted to our hospital because of right hemiplegia and persistent numbness. Brain diffusion-weighted magnetic resonance images demonstrated multiple hyperintensity spots in the deep and superficial borderzone area of the left hemisphere. The patient had no obvious diseases that might have caused ischemic stroke, including potential cardiac sources of embolism, vasculopathy of the cerebral artery, or abnormalities of blood coagulation. However, we found that the patient had started to abuse methylephedrine at the age of 20 years old, and we suspected that drug abuse might have caused his ischemic stroke. Although previous reports have associated ischemic stroke with ephedrine, no reports have related this condition to methylephedrine. However, our case suggests that methylephedrine abuse may cause ischemic stroke.

Adult↗
PubMed2005

Tead proteins activate the Foxa2 enhancer in the node in cooperation with a second factor.

The cell population and the activity of the organizer change during the course of development. We addressed the mechanism of mouse node development via an analysis of the node/notochord enhancer (NE) of Foxa2. We first identified the core element (CE) of the enhancer, which in multimeric form drives gene expression in the node. The CE was activated in Wnt/beta-catenin-treated P19 cells with a time lag, and this activation was dependent on two separate sequence motifs within the CE. These same motifs were also required for enhancer activity in transgenic embryos. We identified the Tead family of transcription factors as binding proteins for the 3' motif. Teads and their co-factor YAP65 activated the CE in P19 cells, and binding of Tead to CE was essential for enhancer activity. Inhibition of Tead activity by repressor-modified Tead compromised NE enhancer activation and notochord development in transgenic mouse embryos. Furthermore, manipulation of Tead activity in zebrafish embryos led to altered expression of foxa2 in the embryonic shield. These results suggest that Tead activates the Foxa2 enhancer core element in the mouse node in cooperation with a second factor that binds to the 5' element, and that a similar mechanism also operates in the zebrafish shield.

Animals↗
PubMed2005

Increased expression of valosin-containing protein (p97) is correlated with disease recurrence in follicular thyroid cancer.

BACKGROUND: Valosin-containing protein (VCP) is involved in the ubiquitin/proteasome-degradation pathway, which works in proliferation and antiapoptosis in human cancer cells. Our previous study showed that VCP expression levels correlated with the recurrence and prognosis of several human cancers, such as hepatocellular carcinoma, gastric carcinoma, and colorectal carcinoma. In this study, the correlation of VCP expression with the prognosis of differentiated thyroid carcinoma was examined. METHODS: VCP expression in 332 patients who underwent operation for differentiated thyroid carcinoma--257 with papillary thyroid carcinoma and 75 with follicular thyroid carcinoma (FTC)--was analyzed by immunohistochemistry. The staining intensity in tumor cells was categorized as weaker than (low expression), equal to (intermediate expression), or stronger than (high expression) that in endothelial cells in noncancerous tissue. RESULTS: One hundred ten (33.5%) cases showed low VCP expression, 117 (28.0%) showed intermediate expression, and 101 (30.8%) showed high expression. VCP expression significantly correlated with histological subtype (P < .05) and lymph node metastasis (P < .01). However, it correlated with neither any clinicopathologic factor nor prognosis in papillary thyroid carcinoma. VCP expression correlated with extrathyroidal extension (P < .05), pT classification (P < .05), and lymph node metastasis (P < .01) in FTC. Patients with low VCP expressing FTC showed better disease-free and overall survival rates than those with intermediate or high expression (P < .01 and P < .05, respectively). Multivariate analysis revealed VCP expression and extracapsular extension to be independent prognostic factors for disease-free survival in cases of FTC. CONCLUSIONS: The prognostic utility of VCP expression in FTC was demonstrated.

Adenocarcinoma, Follicular↗
PubMed2005

Portal venous reconstruction in a living liver donor with an anomalous hepatic arterial and portal venous anatomy.

Hepatic arterial and portal venous anomalies in living liver donors are not uncommon. Modified surgical techniques may be required in such circumstances, although the safety of the living donor must always be given top priority. We describe here a successful portal venous reconstruction in a living donor with an anomalous hepatic arterial and portal venous anatomy in which the right anterior and posterior hepatic arteries encircled the main portal vein. Although such an anomaly of hepatic vessels was not frequently encountered, we should be able to alter the surgical strategy to deal with it. This case illustrates the importance of preoperative hepatic artery and portal venous evaluation in all living donors to identify the feasibility of modifying vessel anastomoses in living donors, as well as recipients, before living donor liver transplantation.

Adult↗
PubMed2005

Immunohistochemical and ultrastructural detection of intestinal spirochetes in Thoroughbred horses.

Studies of equine intestinal spirochetes have long focused on intestinal contents alone, but intestinal spirochetosis has been reported recently in a 21-month-old Thoroughbred colt in Japan. To define the clinical and pathological significances of intestinal spirochetosis in several horses, an epizootiologic survey with histologic, immunohistochemical, and ultrastructural methods was conducted for Brachyspira antigen-containing intestinal spirochetes in 12 diseased or injured Thoroughbred horses, aged from 35 days to 17 years. Brachyspira antigen-containing spirochetes were found in 7 of 12 horses (58.3%) and were more frequent in the cecum than in other parts of the bowel. It was not clear whether the infection was clinically related to diarrhea or dysentery, but histopathology revealed a close association between the bacterial infection and epithelial hyperplasia. Crypt epithelium consisted mainly of goblet cells and showed frequent mitosis throughout its length. Inflammatory cells and congestion were also present. There were numerous spirochetes in the crypts, and some invaded the cecal and colonic epithelia and underlying lamina propria. Ultrastructurally, the spirochetes were divided into 4 types. Three types were identified in degenerative epithelial cells or intracellularly. Brachyspira antigen-containing intestinal spirochetes invading the mucosa were capable of causing epithelial hyperplasia in the cecum and colon in the horses. The findings in this study will increase awareness of the importance of intestinal spirochetosis and may also be helpful for diagnosis and treatment of this condition.

Animals↗
PubMed2004

Group IIA secretory phospholipase A2 is a unique 12/15-lipoxygenase-regulated gene in cytokine-stimulated rat fibroblastic 3Y1 cells.

We have proposed previously that the expression of group IIA secretory phospholipase A(2) (sPLA(2)-IIA), an enzyme implicated in inflammation, is under the control of group IVA cytosolic phospholipase A(2) (cPLA(2)) and 12/15-lipoxygense (12/15-LOX) in cytokine-stimulated rat fibroblastic 3Y1 cells. Here, we show that the reduction of cytokine-stimulated sPLA(2)-IIA induction by the cPLA(2) inhibitor arachidonyl trifluoromethyl ketone (AACOCF(3)) is partially overcome by the addition of various lysophospholipids, such as lysophosphatidylcholine (LysoPC). Furthermore, this lysophospholipid effect was enhanced by further addition of 12/15-LOX products, such as 12(S)- or 15(S)-hydroxyeicosatetraenoic acid (HETE) and 13(S)-hydroxyoctadecadienoic acid (HODE), thus substantiating the hypothesis that the expression of sPLA(2)-IIA is selectively regulated by lipid products of the cPLA(2)-12/15-LOX pathway. In an attempt to identify a set of 12/15-LOX-regulated genes, the cDNA subtraction technique, followed by Northern blotting, was performed to screen particular clones, the expression of which was suppressed by the LOX inhibitor nordihydroguaiaretic acid (NDGA). NDGA-sensitive clones identified thus far included sPLA(2)-IIA, cytoplasmic signaling intermediates, several oxygenases, extracellular matrices, secretory proteins, and other cellular proteins. Of these genes, however, only the expression of sPLA(2)-IIA and 14-3-3eta was enhanced by 12/15-LOX expression. Taken together, our data suggest that sPLA(2)-IIA represents a particular group of genes, the transcription of which is up-regulated by 12/15-LOX metabolites.

Animals↗
PubMed2004

Expression level of valosin-containing protein (p97) is associated with prognosis of esophageal carcinoma.

PURPOSE: Esophageal squamous cell carcinoma (ESCC) frequently shows a poor prognosis because of the occurrence of systemic metastasis, mainly via lymphatic vessels. Valosin-containing protein (VCP) has been shown to be associated with antiapoptotic function and metastasis via activation of the nuclear factor-kappaB signaling pathway. In the present study, we examined the association of VCP with the recurrence and prognosis of ESCC. EXPERIMENTAL DESIGN: VCP expression in 156 ESCC patients [139 males and 17 females; age range, 38-82 (median, 60) years] was analyzed by immunohistochemistry. Staining intensity in tumor cells was categorized as weaker (level 1) or equal to or stronger (level 2) than that in endothelial cells. The correlation of VCP expression between the mRNA and protein levels was examined in 12 patients. RESULTS: Fifty-seven (37.3%) cases showed level 1 and 96 (62.7%) level 2 VCP expression. Quantitative reverse transcription-PCR analysis revealed greater VCP mRNA expression in level 2 (n = 6) than level 1 cases (n = 6; P < 0.05). ESCC with level 2 expression showed higher rates of lymph node metastasis (P < 0.01) and deep tumor invasion (P < 0.01), and poorer disease-free and overall survival rates (P < 0.001 for both analyses) than ESCC with level 1 expression. Multivariate analysis revealed that VCP expression level is an independent prognosticator for disease-free and overall survival. Furthermore, VCP level was an indicator for disease-free survival in the early (pT1) and the advanced (pT2-pT4) stage groups. CONCLUSION: This study demonstrated the prognostic significance of VCP expression in ESCC.

Adenosine Triphosphatases↗
PubMed2004

Elevated expression of valosin-containing protein (p97) is associated with poor prognosis of prostate cancer.

PURPOSE: Valosin-containing protein (VCP) has been shown to be associated with metastasis and prognosis in human cancers. In the present study, the correlation of VCP with recurrence and prognosis in patients with prostate cancer (PCA) receiving conservative therapy was examined. EXPERIMENTAL DESIGN: VCP expression was analyzed immunohistochemically in 136 patients ranging from 46 to 92 years (median, 72 years), who received conservative therapy, including androgen deprivation, radiotherapy, or watchful waiting. Staining intensity of tumor cells was categorized as weaker (level 1) or equal to or stronger (level 2) than that in endothelial cells. The correlation of VCP expression between the mRNA and protein levels was examined in 10 patients. RESULTS: Thirty-two cases (23.5%) showed level 1 and 100 (76.5%) level 2 VCP expression. Quantitative reverse transcription-PCR analysis revealed greater VCPmRNA expression in level 2 (n = 5) than level 1 cases (n = 5; P < 0.05). A significant difference was observed between VCP level 1 and 2 patients in the positive rate for the digital rectal examination (P < 0.01), serum prostate-specific antigen level (P < 0.0001), cancer volume (P < 0.0001), Gleason score (P < 0.0001), stage (P < 0.0001), and progression-free and overall survival (P < 0.0001 for both). Multivariate analysis revealed VCP expression level, serum prostate-specific antigen level, and Gleason score to be independent prognosticators for progression-free and overall survival. Progression of PCA was found in 9.4% of level 1 but in 64% of level 2 patients. CONCLUSIONS: PCA with level 1 VCP expression could be treated conservatively.

Adenosine Triphosphatases↗
PubMed2004

Prognostic significance of activated Akt expression in pancreatic ductal adenocarcinoma.

PURPOSE: Akt is a serine/threonine kinase that plays a central role in tumorigenesis. Among the members of Akt family, Akt2 is associated with the development of human cancers. The present study was designed to clarify the prognostic significance of Akt2 and activated Akt expression in pancreatic ductal adenocarcinoma (PDAC). In addition, activated extracellular signal-regulated kinase 1 and 2 (ERK1/2) and the proliferation activity of tumor cells detected by Ki-67 immunohistochemistry were examined. EXPERIMENTAL DESIGN: Immunohistochemical analysis was performed on paraffin-embedded specimens from 65 patients with PDAC; 36 males and 29 females with ages ranging from 48 to 79 years (median, 66 years) of age. Expression levels of Akt2, phosphorylated Akt (p-Akt), and phosphorylated ERK 1/2 (p-ERK 1/2) were categorized as either weaker (low intensity) or equal to stronger (high intensity) compared with those in the endothelial cells of the same specimens. For Ki-67 immunohistochemistry, cases were divided into two groups: level 1, Ki-67 labeling index (LI), <20%; level 2, Ki-67 LI, > or = 20%. RESULTS: Twenty-six (42.6%), 28 (45.9%), 39 (63.9%), and 46 (75.4%) of the tumors showed high intensity of Akt2, p-Akt, and p-ERK 1/2 expression, and Ki-67 LI level 2, respectively. A significant positive correlation was observed between Akt2 and p-Akt expression (P < 0.01). Multivariate analysis revealed that p-Akt expression, Ki-67 LI, and histological differentiation are independent prognosticators for PDAC. CONCLUSIONS: p-Akt expression is a significant prognostic indicator for PDAC. Inhibition of Akt is a possible molecular approach for treatment of PDAC.

Adenocarcinoma↗
PubMed2004

Expression of valosin-containing protein in colorectal carcinomas as a predictor for disease recurrence and prognosis.

PURPOSE: Valosin-containing protein (VCP or p97) is associated with antiapoptotic function and metastasis via activation of the nuclear factor-kappaB signaling pathway. The present study was designed to investigate the prognostic significance of VCP expression in colorectal adenocarcinoma. EXPERIMENTAL DESIGN: We analyzed VCP expression immunohistochemically in 129 patients with colorectal carcinoma ages 35-84 years. The staining intensity of tumor cells was categorized as either weaker-to-equal (low VCP expression) or stronger (high expression) than that in noncancerous colonic mucosa. We also analyzed 8 colorectal adenomas and 10 metastatic foci. RESULTS: Low VCP expression was noted in 41 (31.8%) cases and high expression in 88 (68.2%) cases. A low level of VCP expression was noted in all adenomas, whereas a high level was seen in all metastatic tumors. A significant difference was observed in depth of invasion (T(1-2) versus T(3-4), P < 0.05), presence or absence of venous invasion (P < 0.05), and tumor stage (I and II versus III and IV; P < 0.05) between adenocarcinomas with low and high VCP expression. Patients with high VCP-expressing tumors had a higher recurrence rate (P < 0.001) and poorer disease-free and overall survival (P < 0.01 and P < 0.05, respectively) compared with the low expression group. Multivariate analysis revealed VCP expression level to be an independent prognosticator for both disease-free and overall survival. VCP level was an indicator of disease-free survival in both stage II and III (pathological Tumor-Node-Metastasis classification, P < 0.05 and <0.01, respectively). CONCLUSIONS: A high expression level of VCP in tumors is a poor prognostic marker in patients with colorectal carcinomas.

Adenoma↗