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Biomedical subjects

S Tsutsui

Publications and source records attributed to S Tsutsui.

At least 55 records · Page 3Linked to original sources
PubMed1997

Age-related changes in susceptibility of mice to low-virulent mouse hepatitis virus (MHV-2-CC) infection.

This study was performed to examine mouse age-dependent changes in susceptibility to MHV-2-CC-infection and participation of macrophages in such changes in BALB/c mice. One-week-old mice were fully susceptible (mortality, 100%), 2-week-old semi-susceptible (36%), and 3- and 4-week-old fully resistant (0%) to MHV-2-CC, respectively. Such age-dependent differences corresponded well with the differences in the virus titers in the liver, spleen and blood and in the severity of liver lesions. In 1-week-old mice with peritoneal exudate cells (PEC) transferred from 4-week-old mice and infected with MHV-2-CC, a slight prolongation of survival time was recorded, although there was no difference in mortality. In 3-week-old mice infected with MHV-2-CC after silica-treatment to suppress macrophages, there was no significant change in susceptibility. In macrophages infected with MHV-2-CC in vitro, the virus replicated better in macrophages obtained from younger mice. These results suggest that macrophages may play a small role in the age-related development of resistance to MHV-2-CC infection in BALB/c mice.

Aging↗
PubMed1997

The protein metabolite hypothesis, a model for the progression of renal failure: an oral adsorbent lowers indoxyl sulfate levels in undialyzed uremic patients.

We have recently demonstrated that indoxyl sulfate promotes the progression of glomerular sclerosis in uremic rats. In the present study, we determined whether an oral adsorbent (AST-120) could reduce the serum and urine levels of indoxyl sulfate and suppress the progression of chronic renal failure (CRF) in undialyzed uremic patients. Twenty-five undialyzed uremic patients were given AST-120 at a dose of 6 g/day for 6 months, while 10 undialyzed uremic patients were not given AST-120. The effects of the oral adsorbent on the slope of the 1/serum creatinine (Scr)-time plot, and the serum and urine levels of indoxyl sulfate were evaluated. Administration of AST-120 significantly decreased the serum and urine levels of indoxyl sulfate, and tended to improve the slope of the 1/SCr-time plot in the CRF patients. Among the patients in whom urinary excretion of indoxyl sulfate was reduced by AST-120, the oral adsorbent significantly improved the slope of the 1/SCr-time plot. The change in the slope of the 1/SCr-time plot showed a significant negative correlation with the change in the urine level of indoxyl sulfate. Thus, patients who showed a greater decrease of urinary indoxyl sulfate also showed more marked suppression of the progression of CRF. These results support the notion that indoxyl sulfate, a protein metabolite, is involved in the progression of CRF, and that an oral adsorbent can delay progression at least partly by reducing the serum and urine levels of indoxyl sulfate.

Administration, Oral↗
PubMed1996

Oxidative stress increases gene expression of heparin-binding EGF-like growth factor and amphiregulin in cultured rat gastric epithelial cells.

We investigated the effects of oxidative stress on mRNA levels of heparin-binding epidermal growth factor-like growth factor (HB-EGF) and amphiregulin (AR) in rat gastric epithelial RGM1 cells. In response to stimulation with hydrogen peroxide (100-400 microM), gene expression of HB-EGF and AR increased in a dose-dependent manner, peaked at 3 h, and returned to the base line at 7 h. Hydrogen peroxide-induced HB-EGF and AR gene expression was blocked by pretreatment with an antioxidant N-acetyl-cysteine. In addition, it was significantly inhibited by pretreatment with EGF receptor-specific tyrphostin AG1478, but not by depletion of protein kinase C. These data indicate that oxidative stress upregulates expression of EGF-related polypeptides and the possible involvement of EGF receptor in this process.

Acetylcysteine↗
PubMed1996

Heparin-binding EGF-like growth factor is an autocrine growth factor for rat gastric epithelial cells.

We examined the biological action and expression of heparin-binding EGF-like growth factor (HB-EGF) in a rat gastric mucosal cell line, RGM1. HB-EGF stimulated DNA synthesis of RGM1 cells in a dose-dependent manner. Mitogenic effect of HB-EGF was as potent as that of other known mitogens for gastric epithelial cells, such as hepatocyte growth factor (HGF) and transforming growth factor (TGF)-alpha. Northern blot analysis showed that RGM1 cells as well as rat gastric mucosal tissue expressed a 2.5-kilobase transcript of HB-EGF. Not only HB-EGF and TGF-alpha but also HGF caused a rapid induction of HB-EGF mRNA in the cells. Treatment with heparitinase which destroys heparan sulfate proteoglycan (HSPG) or with chlorate which inhibits sulfation of HSPG diminished [3H]thymidine incorporation of RGM1 cells in serum-free medium. In addition, a synthetic peptide corresponding to the heparin-binding domain of HB-EGF inhibits the DNA synthesis of RGM1 cells in serum-free medium in a dose-dependent manner. These results suggest that HB-EGF is an autocrine and paracrine growth factor for gastric epithelial cells and may play significant roles in mucosal repair of the stomach in cooperation with other growth factors.

Amino Acid Sequence↗
PubMed1996

What is the earliest malignant lesion in the esophagus?

BACKGROUND: The incidence of early esophageal cancer is definitely increasing due to recent advances in diagnostics. When we discuss early carcinoma of the esophagus, however, there is still controversy as to whether dysplasia is either benign or the earliest malignant lesion. METHODS: Nineteen resected esophaguses with both cancer and dysplasia (including 19 cancers concomitant with 26 dysplastic lesions) were studied for expression of p53 protein. RESULTS: Immunohistochemical overexpression of p53 protein in esophageal dysplasia is almost the same as that in cancer. CONCLUSIONS: Esophageal dysplasia should be recognized as the earliest malignant lesion which already demonstrates cancerous features although it is not immediately critical. A routine endoscopic Lugol's solution test is very useful for both detection and following-up of the early nests in the esophagus. These lesions are good candidates for endoscopic mucosal resection for the purpose of accurate diagnosis or curative treatment.

Esophageal Neoplasms↗
PubMed1996

Development of postoperative delirium in relation to a room change in the general surgical unit.

To analyze the relationship between the development of postoperative delirium and a change of the patient's room, 1,006 cases of patients who had undergone surgery with general anesthesia were reviewed. Postoperative delirium developed in 84 (8.3%) cases. On the basis of symptomatic features, postoperative delirium was divided into four types: (1) excitement type, (2) excitement-hallucination type, (3) hallucination type, and (4) disorientation type. Of the 31 excitement-type cases, 21 developed within the 2nd postoperative day (POD) while 27 of 29 hallucination types developed after POD 2. Of 29 hallucination types, 22 developed after a room change while 20 of these 22 cases were transferred to a single room before POD 2. A quiet, dark, and isolated environment in a single room is suggest to contribute to the development of hallucinations. The development of postoperative delirium with hallucinations alone should thus be taken into consideration whenever a room change is decided.

Adult↗
PubMed1996

Depletion of Mac1-positive macrophages protects DBA/2 mice from encephalomyocarditis virus-induced myocarditis and diabetes.

DBA/2 mice treated with anti-Mac1 monoclonal antibody (MAb) failed to develop encephalomyocarditis virus (EMCV)-induced diabetes and myocarditis. Virus concentrations and the number of viral RNA-positive cells in the pancreas and heart were significantly reduced in mice treated with anti-Mac1 MAb. Mac1-positive macrophages seem to be involved in EMCV-induced disease and to affect the replication of EMCV in target organs.

Animals↗
PubMed1995

Inhibition of gastrin-stimulated enterochromaffin-like cell proliferation and mucosal histamine production in the rat stomach by the somatostatin analogue octreotide.

The effect of octreotide, a potent and long-acting analogue of somatostatin, on gastrin-stimulated proliferation and function of enterochromaffin-like (ECL) cells were examined in rats. Animals were divided into four groups and each group was continuously infused with saline, octreotide alone (40 micrograms/kg per day), gastrin alone (60 nmol/kg per day), or octreotide (40 micrograms/kg per day) plus gastrin (60 nmol/kg per day) respectively for 9 days via osmotic minipumps. Gastrin induced the increase of the bromodeoxyuridine labeling index and density of oxyntic mucosal ECL cells as well as oxyntic mucosal histidine decarboxylase activity. Octreotide completely abolished the gastrin-induced increases in the labeling index and density of ECL cells and oxyntic mucosal histidine decarboxylase activity. These results indicate that octreotide inhibits gastrin-stimulated proliferation of ECL cells and histamine production by these cells.

Animals↗
PubMed1995

Carcinogenesis and histogenesis of esophageal carcinoma.

Dysplasia is one of the most important subjects regarding carcinogenesis of the esophagus, because there is continuing controversy as to whether esophageal dysplasia is a cancerous lesion or a noncancerous lesion. In this study, it is histopathologically shown that dysplasia has a close correlation with cancer itself and that there is no substantial difference in the cell proliferative activity of dysplasia and intraepithelial carcinoma. These findings thus show that dysplasia has as high a potential for malignancy, thus it should be treated as an extremely early cancerous lesion of the esophagus to substantially improve the long term results of this disease. Conversely, esophageal carcinoma with glandular and/or mucus-secreting components is commonly found in addition to the ordinary component of squamous cell carcinoma, which indicates that this type of esophageal tumor originates not only from the squamous epithelium but also from the esophageal mucus gland or the ductal epithelium. These findings support the concept of field carcinogenesis in esophageal carcinoma.

Carcinoma↗
PubMed1995

Lesser sac herniation through the greater omentum and gastro-pancreatic ligament: report of a case.

We report herein the case of a woman who developed a lesser sac hernia which was especially unusual in that the small bowel prolapsed through a defect in the greater omentum and was thereafter strangulated by a hole in the gastro-pancreatic ligament. The gastro-pancreatic ligament has never before been documented as causing an internal hernia. In our patient, a plain abdominal X-ray demonstrated as soft-tissue mass displacing the stomach to the left while abdominal computed tomography and ultrasonography showed a sac-like encapsulation of the small bowel loops between the liver and stomach. Careful evaluation of these radiographic findings allowed for the preoperative diagnosis of a lesser sac hernia to be made.

Adult↗
PubMed1995

No effect of RU 486 (mifepristone) on hepatocellular tumorigenesis in orchiectomized male mice induced by 3'-methyl-4-dimethylaminoazobenzene.

Effects of RU 486 (mifepristone) on hepatocellular tumorigenesis in orchiectomized male mice induced by 3'-methyl-4-dimethylaminoazobenzene (3'-Me-DAB) were investigated. Male mice that had been treated with 3'-Me-DAB neonatally were orchiectomized at one month of age, and injected daily with vehicle only or RU 486 at 0.2 or 0.4 mg/day thereafter. In the liver of orchiectomized males injected with vehicle only, adenomatous nodules developed at incidences of 16.2 and 38.5% at 9 and 12 months of age, respectively, but no carcinomas developed at these ages. Injections of RU 486 at 0.2 or 0.4 mg/day neither affect incidences of adenomatous nodules in the liver, their numbers per mouse, and their areas, nor promote the development of carcinomas. The present results suggest that the long term administration of RU 486 has no effects on hepatocellular tumorigenesis.

Animals↗
PubMed1995

Resection margin for squamous cell carcinoma of the esophagus.

OBJECTIVE: The safe resection margin in esophagectomy for esophageal squamous cell carcinoma (SCC) was determined based on the extent of epithelial and subepithelial accessory lesions from the main lesions of esophageal SCC. BACKGROUND: There have been many reports on the high incidence of a positive resection margin for esophageal cancer. Although there were some studies on the relationships of the proximal clearance to postoperative local recurrence, no pathologic study on the resection margin has been reported. METHODS: Four hundred twenty specimens of a whole resected esophagus were examined histopathologically and the longitudinal length from the main lesion to the five types of accessory lesions was measured on microscopic slides. RESULTS: Contiguous intraepithelial carcinoma existed in 69 (46%) of 150 sites of main lesions restricted to the mucosa or submucosa and subepithelial lesions existed in 131 (54%) of 245 sites and 82 (55%) of 150 sites of main lesions invading an adventitia and into neighboring structures, respectively. The risk of a positive resection margin due to subepithelial lesions was below 5% at 10 mm in the main lesion, restricted to the submucosa or the muscularis propria, and at 30 mm in the main lesion, invading the adventitia in the potentially curative operation cases. CONCLUSION: These clearances of the resection margin, in which the risk of a positive resection margin is below 5%, are acceptable, although these clearances should only be accepted after the extent of epithelial accessory lesions is accurately determined by the Lugol's stain method.

Adult↗
PubMed1995

Efficient removal of albumin-bound furancarboxylic acid by protein-leaking hemodialysis.

Furancarboxylic acid (3-carboxy-4-methyl-5-propyl-2-furanpropionic acid, CMPF), an inhibitor of erythropoiesis, cannot be removed by conventional hemodialysis due to its strong albumin binding, resulting in its accumulation in uremic serum. We used protein-leaking hemodialysis with BK-F dialyzers in 8 uremic patients for 4 months to determine its effect on the serum levels of CMPF. Pre-hemodialysis serum levels of CMPF significantly decreased to about 50% after 4 months by protein-leaking hemodialysis, while those of BUN and serum creatinine did not change significantly. Pre-hemodialysis hematocrit and hemoglobin levels significantly increased by protein-leaking hemodialysis. These results indicate that protein-leaking hemodialysis reduces serum levels of albumin-bound CMPF and improves anemia.

Adult↗
PubMed1995

Extensive spreading carcinoma of the esophagus with invasion restricted to the submucosa.

OBJECTIVES: The aim of this study was to examine the clinicopathological features of extensive spreading type of squamous cell carcinoma (SCC) of the esophagus with invasion restricted to the submucosa. METHODS: Thirty-eight submucosal SCC were studied histopathologically, and five of these 38 submucosal SCC, which demonstrated an extensive spreading-type SCC in which the size of the SCC was over 5 cm in longitudinal length while extending entirely across the esophageal lumen in a circumferential spread, are described in detail. RESULTS: The extent of SCC depended mainly on the extent of intraepithelial carcinoma (IEC) and ranged from 50 to 135 mm in longitudinal length. IEC existed continuously in four cases, and multiple IEC existed separately in one case. An epithelium showing dysplasia was present in all cases, and the involvement of the glands and ducts by IEC was present in two cases. There was only one invasive part of SCC observed in one case, and three to 10 invasive parts of SCC were observed in the other four cases; various features of invasion, including an invasive SCC from the esophageal glands and ducts, were also present. CONCLUSIONS: The extensive spreading-type SCC of the esophagus, which was considered to result from the widespread or multiple carcinomatous changes of the esophageal epithelium, was found to not be as rare as generally thought. The multiple and various features of the invasive parts of SCC suggested the simultaneous development of a downward invasion of SCC at different areas in extensive IEC.

Adult↗
PubMed1994

[Depression in the field of internal medicine].

Masked depression is a common case of depression observed in the field of internal medicine. Masked depression redeems the organic disease alone, and so is often detected in the case of unidentified complaints. Symptomatic depression associated with the underlying disease is another type of depression that is commonly observed. In addition, there is the so-called "premonitory depression", which must be regarded as clinically important. This report describes our experience in the treatment of premonitory depression, with discussion on the consequence of manifestation of depression as the primary symptom of malignant tumor.

Aged↗