PubMed Health⌕ Search

Biomedical subjects

Satoru Tamura

Publications and source records attributed to Satoru Tamura.

18 recordsLinked to original sources
PubMed2005

Primary gastric small cell carcinoma: report of a case and review of the literature.

A 52-year-old man suffering from a pure-type primary gastric small cell carcinoma was treated with surgery and combination chemotherapy. The small cell carcinoma, approximately 6.5 cm in diameter, was situated in the posterior wall of the antrum and there were no distant metastases. Total gastrectomy and regional lymph node dissection was carried out. Histological examination revealed a solid pattern of proliferation of small cells with hyperchromatic, round nuclei and scant cytoplasm. Neoplastic cells infiltrated into the subserosal layer with severe lymphatic and vascular invasion. Regional lymph node cells were mostly replaced by tumor cells that stained positive for Grimelius, neuron-specific enolase (NSE), and synaptophysin. Accumulations of electron-dense core granules in the small neoplastic cells were seen by electron microscopy. Following surgery, the patient was treated with adjuvant chemotherapy consisting of cisplatin and etoposide. The patient is alive and recurrence free 3 years after surgical operation. We review 107 published cases of primary gastric small cell carcinoma, an extremely rare disease first reported in 1976. Small cell carcinoma is an aggressive, malignant tumor. Intensive chemotherapy is essential for patient survival even when curative surgical resection is carried out.

Carcinoma, Small Cell↗
PubMed2004

New analogue of arenastatin A, a potent cytotoxic spongean depsipeptide, with anti-tumor activity.

Two analogues possessing steric hindered substituents on C-15 of arenastatin A (1), a potent cytotoxic spongean depsipeptide, were synthesized and shown to enhance stability in mouse serum. Notably, 15-tert-butylanalogue (6) with higher cytotoxicity exhibited in vivo anti-tumor activity through iv administration different from 1. Additionally, conformation analysis among the two analogues and arenastatin A (1) indicated that the torsion angle from C-14 to C-20 is a conclusive factor for the potent cytotoxicity of 1.

Animals↗
PubMed2004

Evaluation of tumor development from the viewpoint of the three-dimensional configuration of isolated crypts in colorectal adenomas with a type IIIL pit pattern.

BACKGROUND: The relationship between the three-dimensional configurations of superficial and protruded-type colon tumors with a type IIIL pit pattern was examined to evaluate their morphological development. METHODS: Forty-five isolated crypts of superficial-type adenomas and 65 isolated crypts of protruded-type adenomas were evaluated, all derived from segments of 12 colorectal lesions removed by surgery or endoscopic resection. For isolation of the crypts, an HCl-digestion method was used. Morphological features of the isolated crypts were observed by scanning electron microscopy (SEM). We investigated the configuration, length, and width of the isolated crypts in a comparison of the superficial and protruded-type tumors. The configuration and surface structure of the crypts were classified into three types (scores 1 to 3) by the shape and degree of branching and protuberances on their surface. RESULTS: The average lengths of the isolated crypts of the superficial and protruded types were 310.9 +/- 122.9 micro m ( n = 45) and 434.4 +/- 163.3 micro m ( n = 65), respectively ( P < 0.001), and the average widths of the superficial and protruded types were 140.4 +/- 68.2 micro m and 171.5 +/- 73.3 micro m, respectively ( P = 0.02). The average scores for the degree of branching and protruberances in the superficial and protruded types were 1.178 +/- 0.442 and 1.569 +/- 0.529, respectively ( P < 0.0001). In terms of configuration, in the isolated crypts, the superficial-type tumors exhibited a two-layer structure and the protruded type had the shape of a spindle with protuberances. CONCLUSIONS: In colorectal tumors with a type IIIL pit pattern, the isolated crypts of protruded-type tumors displayed more roughness on their surface structure and were longer than those of superficial-type tumors. This suggested that the three-dimensional configuration of the isolated crypt constitutes an important factor in the formation of the gross configuration of colorectal tumors. Colorectal superficial and protruded-type tumors may develop with different growth patterns.

Adenoma↗
PubMed2004

Non-multiple lymphomatous polyposis form of mantle cell lymphoma in the gastrointestinal tract.

Mantle cell lymphoma (MCL) comprises 2.5%-7% of all non-Hodgkin's lymphomas, and the gastrointestinal tract is involved in about 20% of cases. Multiple lymphomatous polyposis (MLP) is an uncommon disease that is regarded as the intestinal form of MCL. We present a rare case of gastrointestinal MCL without MLP, and demonstrate that rituximab was effective for the treatment of this patient. A 61-year-old man presented with continuous diarrhea and hematochezia for a period of 5 months. Superficial lymph nodes were not palpable, but both tonsilla were enlarged. The level of soluble interleukin (IL)2-receptor was 3480 U/ml (normal <500 U/ml). Colonoscopy showed diffuse redness with erosion, without observation of any venous capillary, with these findings continuing from the rectum to the ileum. Upper gastrointestinal endoscopy showed a slightly rough gastric mucosal surface, and chicken-skin like mucosa was observed in the second portion of the duodenum. Small-to-medium size lymphoma cells were seen histologically from the tonsilla to the rectum. The lymphoma cells were immunohistochemically positive for CD5, CD20, CD79a, and cyclin D1. Polymerase chain reaction analysis revealed a chromosomal translocation t(11;14)(q13;q32) in the bcl-1 gene. We diagnosed this as a case of MCL from these findings. For treatment, the patient received a total of ten courses of combination chemotherapy consisting of cyclophosphamide (1000 mg), doxorubicin (70 mg), vincristine (2 mg) and prednisolone (50 mg) (CHOP), which led to a partial remission. However, 2.5 years later, massive infiltrations of the lymphoma cells were found in the colon and stomach. As the infiltrating lymphoma cells expressed CD20 molecules on their surfaces, the patient was treated with a chimeric anti-CD20 monoclohal antibody, rituximab, which showed significant efficacy, and a second partial remission was achieved.

Antibodies, Monoclonal↗
PubMed2004

Co-existence of early esophageal carcinoma and leiomyoma: a case report.

There have been several reports of co-existing esophageal squamous cell carcinoma and esophageal submucosal tumor. However, there is no previous report describing a submucosal tumor located within an area of early esophageal cancer. This report presents the case of a 64-year-old man who developed early esophageal cancer with leiomyoma situated within the lesion in the upper third of the esophagus. Since leiomyoma existed within the area of the esophageal cancer, it was misdiagnosed as a component of esophageal cancer and the depth of esophageal cancer invasion was overdiagnosed by endoscopic ultrasonography. Therefore, surgery was chosen as treatment for esophageal cancer. If the leiomyoma had been diagnosed correctly as a submucosal tumor by endoscopy and endoscopic ultrasonography, an endoscopic mucosal resection would have been the therapeutic procedure of choice for an esophageal tumor.

Carcinoma, Squamous Cell↗
PubMed2003

New semisynthetic quassinoids with in vivo antimalarial activity.

On the basis of a comparative analysis for stability in mouse serum between 15-O-acetylbruceolide and bruceolide 15-methyl carbonate, several 3,15-dialkyl carbonates of bruceolide were synthesized and their in vitro antimalarial activity was assessed. Methyl, ethyl, and isopropyl carbonates with pronounced in vitro activity were further evaluated for in vivo antimalarial potency. Both the methyl and ethyl carbonates significantly increased the life span of mice as compared with 3,15-di-O-accetylbruceolide and chloroquine.

Animals↗
PubMed2003

Analysis of K-ras codon 12 mutation in flat and nodular variants of serrated adenoma in the colon.

PURPOSE: The developmental process of serrated adenomas is obscure, and the importance of genetic alterations has not been elucidated clearly. The possibility that the developmental process and genetic alterations of serrated adenomas could differ from those of ordinary tubular adenomas was explored in this work. METHODS: Serrated adenomas were obtained by endoscopic resection (n = 57) and divided into two groups: flat (n = 10) and nodular (n = 47). Mutation of the K-ras gene was analyzed by enriched polymerase chain reaction-enzyme-linked mini-sequence assay, which can detect not only the presence of a mutation but also the mutation type of K-ras codon 12 with high sensitivity. Methylation-specific polymerase chain reaction was performed with specific primers for the DNA repair gene O6-methylguanine-DNA methyltransferase. RESULTS: Serrated adenomas located in the rectum were more likely to have a K-ras mutation (9/12, 75 percent), whereas serrated adenomas of the flat type were less likely to have one (1/10, 10 percent). Furthermore, nodular serrated adenomas that occurred in the rectum possessed a high frequency of K-ras gene codon 12 point mutation (8/10, 80 percent) despite an overall frequency of 46.8 percent (22/47). A mutation of the K-ras codon 12 gene was detected in 23 (40.4 percent) of 57 serrated adenomas. Three types of point mutations of codon 12 were detected, with the mutation of GAT being observed most frequently. CONCLUSIONS: This study shows that development of nodular serrated adenomas may depend on the mutation of the K-ras codon 12 gene, whereas development of flat serrated adenomas may not. Additionally, serrated adenomas that occur in the rectum are closely related to the mutation of the K-ras codon 12 gene. K-ras mutations in serrated adenomas may be unaffected by the epigenetic silencing of O6-methylguanine-DNA methyltransferase by promoter hypermethylation.

Adenoma↗
PubMed2003

A rare case of idiopathic retroperitoneal fibrosis involving obstruction of the mesenteric arteries, duodenum, common bile duct, and inferior vena cava.

Idiopathic retroperitoneal fibrosis (IRF), usually affects the ureter, although the biliary tree, duodenum and vasculature may also be susceptible. This case report describes a 64-year-old man with IRF, who presented painless watery diarrhea, radiological features of obstructive jaundice and duodenal obstruction, and ultimately an obstruction of the inferior vena cava. We employed tamoxifen for his treatment, but the disease progressed and the patient died of multiple organ failure two years after the onset. While the cause of IRF in this patient was obscure, we suspected his painless watery diarrhea indicated chronic ischemia of the small bowel, and the findings of an abdominal CT scan were extremely valuable in indicating IRF.

Angiography↗
PubMed2002

Facilely accessible multidrug resistance modulator derived from sucrose.

Exploration for new MDR-modulators utilizing atractysucroses as scaffolds disclosed 2,3,4,3',4'-O-pentaisovalerylsucrose (9) as a readily accessible medicinal lead. This lead was prepared from sucrose in 65% total yield for three steps. In addition, compound 9 exhibited more potent MDR modulating activity than verapamil, a representative modulator of MDR mediated by P-gp.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2002

Pit pattern and three-dimensional configuration of isolated crypts from the patients with colorectal neoplasm.

BACKGROUND: This study examined the usefulness of magnifying videoscopic pit-pattern diagnosis in the differential diagnosis of colonic neoplasms. The relationship between pit patterns and the three-dimensional configuration of the neoplastic gland was evaluated for its contribution toward an understanding of pit patterns. METHODS: A total of 3005 colorectal lesions were examined endoscopically and histopathologically. Pit patterns were classified into six types. All materials used for crypt isolation were derived from segments of 21 colorectal lesions and one normal colonic mucosa. For the crypt isolation, the HCl-digestion method was used. RESULTS: The magnifying videoscopic diagnosis was comparable with the histological diagnosis in the 3005 colorectal lesions. Isolated crypts with the type-I pit pattern resembled a test-tube; the type-II pit pattern was also tubular, but had observed fissures at the bottom; the type-III l pit pattern was a reversed triangle or tongue-like in shape; and the type-III s pit pattern was columnar and either tapered off or meandered. Isolated crypts with the type-IV b pit pattern appeared as long reversed triangles with protuberances, and the type-IV v pit pattern was flat with slender tubules or finger-like processes. The isolated crypts with the type-V pit pattern were complicated and indistinct in shape. CONCLUSIONS: Evaluation of the three-dimensional configuration revealed that when the pit patterns, of each isolated crypt differed, their three-dimensional configurations also differed. Recognition of the differences in the three-dimensional configuration should contribute toward both an understanding of pit-pattern diagnosis and the further development of the endoscopic diagnosis of various colorectal lesions.

Adenoma↗
PubMed2002

Surface structure of single-gland adenoma in familial adenomatous polyposis.

Magnifying videoendoscopic observation of a minute lesion with a single IIIL type cryptal orifice was reported. This minute lesion was a single-gland adenoma accompanied histopathologically by a bud of adenomatous gland and was located in the upper part of the mucosa. This finding regarding a pit pattern should make possible the endoscopic diagnosis of a colonic single-gland adenoma.

Adenomatous Polyposis Coli↗