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Biomedical subjects

T Muto

Publications and source records attributed to T Muto.

At least 181 records · Page 10Linked to original sources
PubMed1998

Pancreatic mucin-producing adenocarcinoma associated with a pancreatic stone: report of a case.

We present an autopsy case of an 83-year-old Japanese man with a mucin-producing adenocarcinoma accompanied by pancreatolithiasis in the head of the pancreas. He suffered from obstructive jaundice and died of disseminated intravascular coagulation. He did not normally drink alcohol and had no history of chronic pancreatitis. The autopsy findings revealed a mucinous cystic tumor, composed of multiple dilatated branches, in the head of the pancreas. Histological examinations showed papillary adenocarcinoma, which scirrhously infiltrated the distal common bile duct with perineural invasion and lymph node involvement. He was thus diagnosed to have mucin-producing branch-type cancer in the head of the pancreas. The main pancreatic duct was dilated, and the residual pancreatic tissue showed moderate fibrosis and parenchymal atrophy. A stone was observed in a dilated branch of the primary lesion. To the best of our knowledge, there have only been five previously reported cases of mucin-producing tumor associated with pancreatolithiasis. Intraductal calcification is a major characteristic of chronic pancreatitis, but it is clinically important not to misdiagnose cancers associated with pancreatolithiasis such as chronic pancreatitis.

Adenocarcinoma, Mucinous↗
PubMed1998

Substance P containing nerve fibers in ulcerative colitis.

The distribution of and morphological changes in substance P containing nerve fibers were examined immunohistochemically in the colonic mucosa of ulcerative colitis (UC) patients. Quantitative and morphological changes in substance P fibers were analyzed by digitized morphometry. The linear density of substance P fibers was significantly greater in the UC group (19.4 +/- 1.2 microns/1000 micron 2) than in the Crohn's disease group (10.1 +/- 1.2 microns; P < 0.01) and the control group (8.4 +/- 0.8 microns; P < 0.01). Analysis of the UC group showed that the degree of inflammation affected the linear density of substance fibers, with "moderate" cases presenting the highest linear density and "severe" cases the lowest. Substance P fibers were thickened and coarse in UC; they were significantly wider in the UC group (2.5 +/- 0.5 microns) than in the Crohn's disease group (1.5 +/- 0.2 microns; P < 0.01) and the control group (1.2 +/- 0.1 microns; P < 0.01). In conclusion, alterations in substance P containing nerve fibers, as evidenced by both the linear density and morphology, may play some role in the pathogenesis of UC.

Adolescent↗
PubMed1998

Steroid complications and surgery in intractable ulcerative colitis.

The major operative indication for ulcerative colitis is intractability. Although steroid side effects appear to be closely associated with surgical indications for intractable ulcerative colitis, this relationship has yet to be analyzed in detail. To elucidate this relationship, we investigated 39 surgical patients with intractable ulcerative colitis, as defined by the Research Committee for Intractable Diseases of the Ministry of Health and welfare of Japan, and 66 conservatively treated patients with ulcerative colitis, of whom 6 had intractable disease. All patients with major steroid side effects and 17/24 (71%) patients with minor side effects underwent surgery. The median number of admissions was higher in patients with major side effects than in those with less severe or no side effects in the operative series, while this value was lower in the non-operative series than in the operative series. This tendency was similar for the total duration of hospitalization and the number of relapses. In the operative series, markedly higher steroid doses were administered to patients with side effects than to those without, and lower doses were given in the non-operative series. On multivariate regression analysis, the presence of steroid side effects, disease extent, and disease duration were significantly associated with surgery. Patients without side effects had a higher postoperative complication rate than those with minor side effects. We conclude that major side effects are a surgical indication for patients with intractable ulcerative colitis, and that even minor side effects should be taken as a surgical indication in view of the patient's quality of life.

Adolescent↗
PubMed1998

Inhibitory effects of n-3 polyunsaturated fatty acids on sigmoid colon cancer transformants.

Various types of polyunsaturated fatty acids (PUFAs) have been suggested to exert different effects on the colon in terms of promotion or inhibition of tumor development. Results of in vitro and in vivo studies are, however, inconsistent and it remains unclear whether or not the cellular effects of PUFAs change along with the malignant transformation of colonic cells. In this study, we used the NIH3T3 cell line and its SIC (sigmoid colon cancer) oncogene transformants to compare the effects of PUFAs on the proliferation of non-malignant and malignant cells. We also determined the cellular utilization of fatty acids in media by a high-performance liquid chromatography method. The addition of exogenous arachidonic acid (ARA, an n-6 fatty acid), eicosapentaenoic acid (EPA, n-3), and docosahexaenoic acid (DHA, n-3) exerted different effects on NIH3T3 cells, and on SIC transformants, in which selective inhibitory effects were observed at media concentrations ranging from 10 to 20 microg/ml. In cells cultured in media supplemented with EPA or DHA at a concentration of 2 microg/ml, which had no effect on cell proliferation, the cellular utilization of linoleic acid (n-6), a precursor of n-3 fatty acids, was inhibited. This inhibition was stronger in SIC transformants than in NIH3T3 cells (P < 0.05). There was no difference in the utilization of fatty acids between the two cell lines cultured in media supplemented with ARA. We conclude that the cellular response to exogenous long-chain PUFAs is modified during the course of malignant transformation, and that EPA and DHA (n-3 PUFAs) appear to have specific inhibitory effects on cancer cells and may thus enhance the host defense against colon cancer.

Animals↗
PubMed1998

A schwannoma of the cecum: case report and review of Japanese schwannomas in the large intestine.

A 66-year-old Japanese man had a positive fecal occult blood test at a regular check-up, and a large polypoid mass was detected in the cecum by barium enema study. Colonoscopy showed a submucosal tumor with ulcer protruding into the cecal lumen. A large-forceps biopsy specimen was taken from the bottom of the ulcer. With the tentative diagnosis of neurogenic tumor, ileocecal resection was performed. The tumor showed spindle-cell proliferation in a concentric or fascicular pattern. Immunohistochemically, the tumor cells were diffusely positive for S-100 protein, and they had intracytoplasmic periodic acid Schiff (PAS)-positive crystalloids. The mitosis count was low (about 1 per 20 high-power fields). The pathological diagnosis of this tumor was benign gastrointestinal schwannoma. A large number of schwannoma cases have been reported since 1910 when Verocay reported it as a true tumor that stemmed from Schwann cells and did not contain neuroganglion cells. However, gastrointestinal schwannomas are rare, and schwannomas of the large intestine are extremely rare. We reviewed 40 cases already reported in Japan and this present case in order to clarify the clinicopathological features of this tumor.

Aged↗
PubMed1998

Per anal suturing of a bleeding ulcer to achieve successful hemostasis of massive hemorrhage associated with ulcerative colitis: report of two cases.

We report herein the cases of two patients with ulcerative colitis complicated by massive hemorrhage who were successfully treated by per anal suturing of a bleeding ulcer. A 40-year-old woman and a 22-year-old man had suffered from extensive colitis for 8 and 2 years, respectively, and both followed a similar clinical course. They were admitted under emergency conditions and, despite treatment with intravenous high-dose prednisolone and thereafter with intraarterial injections of prednisolone, suffered several attacks of massive hemorrhage with hypovolemic shock. Emergency subtotal colectomy with ileostomy and rectal mucous fistula were performed, but recurrent massive hemorrhage occurred during the early postoperative period. Bleeding from a discrete ulcer in the rectum was subsequently located, and both patients underwent per anal suturing of the ulcer. No recurrent bleeding occurred thereafter, and an ileoanal anastomosis was performed several months later. Massive hemorrhage is a rare complication of ulcerative colitis which is most often resolved by subtotal colectomy without proctectomy. Although bleeding associated with ulcerative colitis usually occurs diffusely, these case reports serve to demonstrate that massive bleeding can also result from a discrete ulcer. We advocate that this condition be treated by an endoscopic or local hemostatic procedure.

Adult↗
PubMed1998

Complete dissection of the lymph nodes located along and at the roots of the left gastroepiploic vessels during distal gastrectomy.

Achieving complete dissection of the lymph nodes located at the roots of the left gastroepiploic vessels is difficult when distal gastrectomy is the surgical goal; firstly, because the short gastric vessels must be preserved to supply blood to the remnant stomach; and also, because the roots of the left gastroepiploic vessels at the splenic hilus are obscured intraoperatively by adipose tissues. We describe herein a technique which enables complete and easy dissection of the lymph nodes located along and at the roots of the left gastroepiploic vessels.

Gastrectomy↗
PubMed1998

Primary iliopsoas abscess successfully treated by ultrasonographically guided percutaneous drainage.

We report a case of primary iliopsoas abscess successfully treated by ultrasonographically guided percutaneous drainage. A 56-year-old man presented at our hospital with lumbago, right-sided back pain, fever (temperature 38.5 degrees C) and chills. On physical examination, we found dark red skin, swelling, and tenderness localized at the right side at the back of his waist. Laboratory examination showed leukocytosis (white blood cell count 9700/mm3) with a leftward shift and elevated C-reactive protein (5.2 mg/dl). Ultrasonography (US), computed tomography (CT), and magnetic resonance imaging revealed a hypodense lesion in the right iliopsoas muscle extending to the subcutaneous tissue. About 50 ml of thick yellow pus was obtained by ultrasonographically guided aspiration drainage. A drain catheter was inserted in the abscess cavity. Laboratory findings improved and clinical symptoms abated rapidly after drainage. On the twenty-first day after drainage, US and CT showed that the abscess was no longer present. The patient was discharged after 32 days of hospitalization. As possible primary diseases causing iliopsoas abscess, such as digestive tract disease, tuberculosis, and osteomyelitis, were not found, we diagnosed the disease as primary iliopsoas abscess. Although surgical drainage has been performed in most reported cases of iliopsoas abscess, this case report shows that ultrasonographically guided percutaneous drainage is also effective for treating primary iliopsoas abscess if it is diagnosed early enough.

C-Reactive Protein↗
PubMed1998

Surgical indications for small polypoid lesions of the gallbladder.

BACKGROUND: To determine which polyps of the gallbladder should be operated upon, we investigated the size and number of polyps in resected gallbladders, and studied changes in gallbladder polyps using ultrasonography (US). METHODS: We studied 74 resected gallbladders with small polypoid lesions less than 20 mm in diameter, and 60 patients with gallbladder polyps by US. The polyps in resected gallbladders were classified into four groups histologically, and clinical features, maximum diameter, and number of lesions were compared among the groups. In the followed-up cases with gallbladder polyps, the size and number of polyps were examined by US, and changes during the observation period were studied. RESULTS: The mean diameter of adenoma was 6.00 +/- 3.39 mm (mean +/- SD) and that of cancer 10.8 +/- 4.16 mm; 97% of cholesterol polyps were less than 10 mm in diameter (3.66 +/- 2.68 mm). Neoplastic polyps tended to be single (adenoma, n = 1.40 +/- 0.89; cancer, n = 1.16 +/- 0.40), whereas half of the cholesterol polyps were multiple (n = 3.09 +/- 3.31). However, when there were fewer than 3 lesions, the incidence of neoplasm was 37% among polyps 5 to 10 mm in diameter. A low incidence (6%) of neoplasm was also observed among polyps less than 5 mm in diameter. CONCLUSIONS: These data indicate that an aggressive surgical approach for small gallbladder polyps is warranted when there are fewer than 3 polyps, regardless of their size.

Adult↗
PubMed1998

Self-limited spontaneous dissection of the main trunk of the superior mesenteric artery.

Spontaneous dissection of the splanchnic arteries is rare and reportedly carries a high risk of mortality. Two cases with spontaneous dissection of the main trunk of the superior mesenteric artery followed by a self-limited clinical course are presented. Current management strategies, including bypass operation, patch angioplasty, and conservative treatments, are discussed. Emphasis is placed on the role of nonsurgical management with careful follow-up with the use of new technologies such as duplex and computed tomography scanning.

Aortic Dissection↗
PubMed1998

Development and histologic characteristics of synovitis induced by trauma in the rat temporomandibular joint.

Histopathological changes caused by trauma to the rat temporomandibular joint synovium were examined by light microscopy. The trauma was induced by forced hypermobility of the condyle. Pathological changes of the synovium were found primarily in the anterior pouch of the upper joint compartment. The main findings included surface cell proliferation, increased capillary hyperemia, fibrin deposits on the surfaces of inflamed synovial membranes, and fibrinous adhesion between closely opposed synovial membranes. A gradual change from fibrinous adhesion to fibrous adhesion was also seen.

Animals↗
PubMed1998

Histologic study of synovitis induced by trauma to the rat temporomandibular joint.

OBJECTIVE: The purpose of this study was to establish and histologically examine the time course of synovitis induced by trauma to the rat temporomandibular joint. STUDY DESIGN: Synovitis of the temporomandibular joints of 8-week-old male Wister rats was induced by forced condylar hypermobility, which was administered 10 times successively once a day for 10 days. Pathologic changes were observed microscopically at 2 and 5 days and 2, 4, 6, 8, 10, and 20 weeks after treatment. RESULTS: Histologic findings from the 5th day to the 6th week after treatment were characterized by multiple layers of synovial cells, an increase of dilated vasculature, fibrin deposits, and synovial adhesion. These findings were in good agreement with those reported for the human temporomandibular joint. The pathologic changes decreased with advancing time, and synovitis was not observed at 20 weeks after treatment. CONCLUSION: The present procedure for inducing synovitis of the temporomandibular joint in rats will be useful in understanding the pathogenesis of synovitis in human temporomandibular joints.

Animals↗
PubMed1998

Enhanced metastasis of B16 melanoma cells by unexpected elevated expression of the metastasis-associated TI-241 (LRF-1-, Jun-Fos-related) gene treated with antisense oligonucleotide.

B16-F10 is a B16 mouse melanoma subline that preferentially metastasizes to the lung following intravenous injection. Previously we isolated TI-241 (LRF-1 homologue related to Jun-Fos) gene that was expressed higher in the high metastatic clone B16-F10 than the low metastatic clone F1. Transfection of TI-241 into F1 converted it into a high-metastatic cell. We studied the effect of antisense oligonucleotide designed to reduce the expression of TI-241 in B16-F10 cells, and observed an unexpected increase in the TI-241 level. The increase in the expression was maximal at 30 h, then it decreased during further culture with or without TI-241 antisense oligonucleotide. This increased TI-241 expression by antisense oligonucleotide was also observed in B16-F1 cells whereas sense oligonucleotide did not affect the expression. B16-F10 cells cultured with TI-241 antisense oligonucleotide showed enhanced experimental metastatic potential to the mouse lungs compared with untreated B16-F10 and B16-F10 cultured with TI-241 sense oligonucleotide.

Activating Transcription Factor 3↗
PubMed1998

Screening for APC mutations based on detection of truncated APC proteins.

Mutation of the adenomatous polyposis coli (APC) gene is frequently found in colorectal tumors from both familial adenomatous polyposis (FAP) and non-FAP patients. Analysis of APC mutation is time-consuming and costly due to the large size of the APC gene. As the majority of APC mutations result in the truncation of gene products, the detection of truncated APC proteins may be used as a screening method for APC mutations. The aim of this study is to establish a practical method of detecting truncated APC proteins for the screening of APC mutations. APC proteins in human colorectal cancer cell lines were analyzed by western blotting. Truncated APC proteins were expressed in all of the colorectal cancer cell lines studied. Two species of truncated APC proteins were expressed in two cell lines. Western blotting is a rapid, reliable screening method for APC mutations and provides information on both alleles.

Antibodies, Monoclonal↗
PubMed1998

5-Fluorouracil induces apoptosis in human colon cancer cell lines with modulation of Bcl-2 family proteins.

Recently, apoptosis has been implicated as one of the end points of cells exposed to chemotherapeutic agents. The p53 and Bcl-2 family of proteins are involved in chemotherapy-induced apoptosis, but in a cell type-dependent manner. We sought to determine the roles played by the p53 and Bcl-2 family of proteins in 5-fluorouracil (5-FU)-induced apoptosis of human colon cancer cell lines. We first studied the p53 genetic and functional status, and then 5-FU, at inhibitory concentration of 50% (IC50) doses, was used to induce apoptosis, which was confirmed by morphological analysis and enzyme-linked immunosorbent assay (ELISA). Bcl-2, Bcl-X(L), Bax, Bad, Bak and p53 protein expression was analysed by Western blotting. Using five human colon cancer cell lines, we found that equitoxic (IC50) doses of 5-FU induced apoptosis in both wild-type p53 and mutant p53 cells. Analysis of the steady-state levels of Bcl-2 family proteins showed high expression of Bcl-X(L) in all of the cell lines except Colo320. Bcl-2 was expressed in two of them. Bax presented with the lowest basal expression and Bad showed homogeneous expression. On the other hand, Bak expression varied more than fivefold among these cells. In cells containing wild-type p53 (e.g. LoVo), 5-FU-induced apoptosis was accompanied by increased expression of Bax and Bak without consistent modulation of other bcl-2 family proteins. In contrast in cells containing mutant p53 (e.g. DLD1), Bak expression was remarkably increased. There was a significant correlation between chemosensitivity and Bcl-X(L) to Bax ratio, rather than Bcl-2 to Bax. In conclusion, these results suggest that some members of the Bcl-2 family of proteins, in human colon cancer cell lines, are modulated by 5-FU and that the ratio of Bcl-X(L) to Bax may be related to chemosensitivity to 5-FU.

Apoptosis↗