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Biomedical subjects

M Fujishiro

Publications and source records attributed to M Fujishiro.

At least 19 recordsLinked to original sources

The useful combination of a higher frequency miniprobe and endoscopic submucosal dissection for the treatment of T1 esophageal cancer.

BACKGROUND: There are few published data on the discrimination ability of endoscopic ultrasonography (EUS) among each subdivision of T1 cancer, and overdiagnosis is an unsolved problem that eventually causes overtreatment. The purpose of this study was to verify whether our treatment strategy incorporating EUS realizes a tailored patient management of T1 esophageal cancer. METHODS: This study comprised 20 esophageal cancer patients undergoing 12- to 20-MHz miniprobes for T staging and a 7.5-MHz dedicated echoendoscope for N staging. Initial therapy constituted endoscopic submucosal dissection (ESD) for endosonographically node-negative, mucosal, or slight submucosal cancers and a primary esophagectomy with three-field lymphadenectomy for deeper cancers. If the ESD specimen revealed no cancer involvement of the muscularis mucosa, the patients entered a follow-up program; otherwise, they were advised to undergo a subsequent esophagectomy and three-field lymphadenectomy. RESULTS: Perfect discrimination accuracy was achieved among T1, T2, and T3 cancers. Whether cancer depth was up to the slight submucosal layer or deeper was correctly differentiated in 12 of 14 T1 cancers (86%). EUS categorized all patients correctly into candidates for either ESD or surgery. The pathological cancer depth of the resected specimens revealed that no patients experienced unnecessary overtreatment. CONCLUSIONS: A higher frequency miniprobe is useful for the detailed evaluation of cancer depth, contributing to decision making for treatment options of T1 esophageal cancer. A miniprobe and echoendoscope in combination with ESD provide an appropriately tailored management plan on an individual basis, avoiding unnecessary treatment or indicating radical surgery.

Adenocarcinoma↗

Efficacy and safety of endoscopic submucosal dissection for tumors of the esophagogastric junction.

BACKGROUND AND STUDY AIMS: The esophagogastric junction (EGJ) has been considered a difficult location for endoscopic treatment of tumors, due to its narrow lumen and sharp angle. Endoscopic submucosal dissection (ESD) is a method of endoscopic resection, capable of removing large tumors in an en bloc fashion. The aim of this study was to evaluate the efficacy and safety of ESD for EGJ tumors. PATIENTS AND METHODS: For 30 lesions of EGJ tumors treated by ESD, the size of the lesions and resected specimens, the en bloc resection rate, complications, and local recurrence were assessed. RESULTS: The average maximum diameters of the lesions and resected specimens were 22.4 mm and 40.6 mm respectively. The complete en bloc resection (R0) rate was 97% (29/30). Histological evaluation of the resected specimens revealed five cases of angiolymphatic invasion and five cases of submucosal invasion deeper than 500 microm. Perforation occurred in one case but was safely managed by rotatable clips and administration of antibiotics for 3 days. Local recurrence was not observed in any patient during follow-up (mean 14.6 months, range 6-31 months). CONCLUSIONS: ESD can be safely performed for EGJ tumors, with a high en bloc resection rate. For lesions with no apparent submucosal invasion findings, ESD is a curative and diagnostic treatment option that may be considered before open surgery.

Adenocarcinoma↗

Histopathologic characteristics of gastric ulcers created by endoscopic submucosal dissection.

BACKGROUND AND STUDY AIM: We have previously reported that gastric ulcers artificially created by endoscopic submucosal dissection (ESD) would heal within 8 weeks regardless of size and location. The details of the healing process remain unclear, and we aimed to clarify the mechanism by histopathological investigation. PATIENTS AND METHODS: 21 post-ESD ulcers were examined histopathologically, using surgically resected specimens from patients who had subsequently undergone gastrectomy due to submucosal invasion and/or lymphovascular infiltration by the tumor. The grade of ulcer, appearance of regenerative mucosa, scar formation, and extent of fibrosis were evaluated. RESULTS: Fibrosis and wall thickening were observed from 2 weeks after ESD, but regenerative mucosa was not observed until 5 weeks. Among 12 patients who underwent gastrectomy later than 8 weeks after ESD, a mucosal defect was still observed in two patients. In these two patients the lesion was associated with severe fibrosis due to previous peptic ulcer or submucosal invasion by the lesion. CONCLUSION: Size reduction in these ulcers occurs by contraction in the early phase, then regenerative mucosa covers the remaining mucosal defect within 8 weeks. If there is fibrosis under the lesion before ESD, there is a possibility that the artificially created ulcer will not heal within 8 weeks.

Aged↗

Endoscopic submucosal dissection for rectal epithelial neoplasia.

BACKGROUND AND STUDY AIMS: The technique of endoscopic submucosal dissection (ESD) has recently been developed for en-bloc resection of gastric tumors. For oncological reasons and in order to improve the patients' quality of life, it may be desirable to use the same technique for rectal neoplasia. PATIENTS AND METHODS: Thirty-five consecutive patients with rectal neoplasia who had a preoperative diagnosis of large intraepithelial neoplasias with submucosal fibrosis or located on the rectal folds were enrolled. ESD was carried out with the same technique previously described for the stomach, with some modifications. The efficacy, complications, and follow-up results of the treatment were assessed. RESULTS: The rates of en-bloc resection and en-bloc plus R0 resection were 88.6 % (31 of 35) and 62.9 % (22 of 35), respectively. Hemoglobin levels did not drop by more than 2 g/dl in any of the patients after ESD. None of the patients had to receive blood transfusions or undergo emergency colonoscopy due to bleeding during ESD or hematochezia after ESD. Perforation during ESD occurred in two patients (5.7 %), who were managed with conservative medical treatment after endoscopic closure of the perforation. Excluding three patients in whom additional surgery was carried out, all but one of 32 patients were free of recurrence during a mean follow-up period of 36 months (range 12 - 60 months). The exception was a patient in whom a multiple-piece resection was required; the recurrent (residual) tumor, found 2 months after ESD, was a small adenoma that was again treated endoscopically. CONCLUSIONS: ESD is applicable in the rectum with promising results, but the technique is still at a developmental stage and patients should be informed of the potential risks.

Chi-Square Distribution↗

Successful nonsurgical management of perforation complicating endoscopic submucosal dissection of gastrointestinal epithelial neoplasms.

BACKGROUND AND STUDY AIMS: Endoscopic submucosal dissection (ESD) is a novel technique used for the treatment of gastrointestinal neoplasia. One of its major limitations, however, is the complication of perforation. PATIENTS AND METHODS: We included in our study all the cases of perforation that occurred during ESD procedures for gastrointestinal epithelial neoplasia between February 2000 and February 2005. Clinical outcomes after perforation were investigated. RESULTS: Perforation was experienced at 27 lesions in 27 patients (four in the esophagus, fourteen in the stomach, seven in the colon, and two in the rectum). Fibrosis under the lesions was confirmed histologically in seven patients (26 %). Immediate closure using endoclips was performed in all patients except for three asymptomatic patients in whom a stomach perforation was first noticed when free air was noticed on a radiograph the morning after the ESD procedure. Air accumulation was detected radiographically in 21 patients (78 %). The mean duration of antibiotic treatment was 6.7 days and the patients were fasted for a mean period of 5.3 days. The mean maximum body temperature was 37.3 degrees C, the mean white blood cell count was 9733/mm3, and the mean C-reactive protein level was 5.0 mg/dl. All the patients were discharged well from the ward after a mean time of 12.1 days after ESD, and no recurrence caused by tumor spread from the perforation occurred in any patient after a median follow-up period of 36 months (range 9 - 52 months). CONCLUSION: Successful nonsurgical management after ESD complicated by perforation is a highly feasible option if intensive conservative treatments are used following immediate endoscopic closure of the perforation.

Aged↗

A learning curve for endoscopic submucosal dissection of gastric epithelial neoplasms.

BACKGROUND AND STUDY AIMS: Endoscopic submucosal dissection (ESD) has become a widely accepted method for treating gastrointestinal neoplasms. The objective of our study was to assess the learning curve for ESD of gastric epithelial neoplasms. PATIENTS AND METHODS: Clinicopathological data were retrospectively collected from 383 ESD procedures for gastric epithelial neoplasms that were performed over a 5-year period. Thirteen endoscopists were involved as operators during this period. In study 1, the performance of the two principal operators was assessed every 25 patients. In study 2, the performance of all 13 operators was assessed according to their experience. RESULTS: In study 1, the caseloads of the two principal operators were 188 and 118 ESD procedures. There were no significant differences found between successive groups of 25 patients with regard to en-bloc resection rate and bleeding and perforation complication rates. The size of the lesions and the resected specimen diameter increased significantly as the number of treated cases increased, whereas the average procedure time decreased significantly. In study 2, the operators' caseloads ranged from 1 to 188 cases, with 11/13 operators having experience of fewer than 30 cases. There was no significant difference in treatment efficacy and complication rates between the operators throughout the study period. The lesions were mainly located in the lower part of the stomach in the procedures performed by the 11 less experienced endoscopists. The procedure times shortened as experience in the method increased. CONCLUSIONS: Constant rates of both treatment efficacy and complications were achieved over a 5-year period of experience with ESD. A decrease in procedure time was found to be a marker of proficiency in this technique.

Clinical Competence↗

Ex-vivo study of high-magnification chromoendoscopy in the gastrointestinal tract to determine the optimal staining conditions for endocytoscopy.

BACKGROUND AND STUDY AIMS: Endocytoscopy allows the observation of living cells in the gastrointestinal tract. Consistently clear views are essential for clinical application of the technique, but these are not always obtained. The aim of this study was to determine an appropriate staining regimen for endocytoscopy. MATERIALS AND METHODS: This was an ex-vivo animal study in which we stained freshly resected porcine esophagus, stomach, and colon with different concentrations of three dyes (1%, 0.5%, and 0.25% crystal violet; 5%, 2.5%, and 1% methylene blue; and 1%, 0.5%, and 0.25% toluidine blue) and assessed them after different exposure times (10 seconds, 30 seconds, 60 seconds, and 90 seconds). The images obtained were evaluated according to the staining status of the cytoplasm and the nucleus, and the contrast between the cytoplasm and the nuclei, and the optimal staining conditions for each organ were determined. Additionally, freshly resected human esophagus, stomach, and colon tissues were tested under the dye/exposure conditions that were found to be the most appropriate in the animal study. RESULTS: After intensive mucus removal, high-quality images were obtained using methylene blue and toluidine blue. The optimum conditions for endocytoscopic observation were obtained after staining with 1% methylene blue in the esophagus and with 0.25% toluidine blue in the stomach and the colon, after 60 seconds of exposure to the dye. This was confirmed in the human specimens. CONCLUSIONS: This study provides important information on appropriate staining conditions for endocytoscopy. Further ex-vivo and in-vivo studies are necessary before this technique comes into standard use, however.

Animals↗

Effect of fructose-rich high-fat diet on glucose sensitivity and atherosclerosis in nonhuman primate.

The present study examined a new model of impaired glucose tolerance (IGT) in a nonhuman primate fed with a high-fructose and high-fat (HFF) diet that contained 15% lard, 31% fructose, and 1% cholesterol. Female cynomolgus monkeys (age, 3-4 years) were divided into two groups: 1) those fed with normal control diet (N = 5) and 2) those fed with HFF diet (N = 5). In the HFF diet group, total cholesterol and low-density lipoprotein cholesterol in blood were significantly increased four- to fivefold when compared with the normal control diet group. No difference in the blood glucose, insulin, hemoglobin A1c, and triglyceride levels was detected between the two groups. Plasma levels of adiponectin, but not of resistin, were significantly higher in HFF diet at 20 weeks after HFF diet feeding. Oral glucose tolerance test was performed before HFF diet feeding and at 12 and 24 weeks after HFF diet feeding, but no significant changes in glucose sensitivity were observed even 24 weeks after HFF diet feeding. Twenty-four weeks after HFF diet feeding, accumulated foam cells and infiltrated macrophages were histologically detected in the thoracic aorta, in addition to a fatty liver. Interestingly, the pancreatic beta cells appeared normal in the HFF diet group. These results show that a chronic HFF diet does not induce IGT but can cause atherosclerotic lesions in conjunction with the generation of a fatty liver phenotype in cynomolgus monkey; however, the present results are very preliminary and they need to be validated in larger-scale studies in the future.

Adiponectin↗

Correlation of serum pepsinogens and gross appearances combined with histology in early gastric cancer.

The correlation between serum pepsinogen (PG) levels and the gross types was investigated in 128 consecutive patients with early gastric cancer. Although there was no significant difference in age, gender, cancer location, or cancer depth among gross appearances, the distribution of histological type was significantly different between polypoid and depressed cancers: all polypoid cancers except one were intestinal type, whereas nearly a third of depressed cancers were diffuse type. All the patients in whom Helicobacter pylori status was investigated had Helicobacterpylori infection. Combination of gross appearances and histology (polypoid cancer with intestinal type, depressed cancer with intestinal type and depressed cancer with diffuse type) showed a clear difference in distribution of serum PG levels and a ratio between levels of PG I and PG II (I/II ratio). In polypoid cancer with intestinal type, a PG I level and a I/II ratio were significantly lower than those of the others. In depressed cancer with diffuse type, PG I and PG II levels were significantly higher. These findings revealed that backgrounds such as intragastric acidity and extent of gastric atrophy might differ among early gastric cancers with different morphology and histology.

Adult↗

Serum concentrations of resistin-like molecules beta and gamma are elevated in high-fat-fed and obese db/db mice, with increased production in the intestinal tract and bone marrow.

AIMS/HYPOTHESIS: Resistin and the resistin-like molecules (RELMs) comprise a novel class of cysteine-rich proteins. Among the RELMs, RELMbeta and RELMgamma are produced in non-adipocyte tissues, but the regulation of their expression and their physiological roles are largely unknown. We investigated in mice the tissue distribution and dimer formation of RELMbeta and RELMgamma and then examined whether their serum concentrations and tissue expression levels are related to insulin resistance. METHODS: Specific antibodies against RELMbeta and RELMgamma were generated. Dimer formation was examined using COS cells and the colon. RELMbeta and RELMgamma tissue localisation and expression levels were analysed by an RNase protection assay, immunoblotting and immunohistochemical study. Serum concentrations in high-fat-fed and db/db mice were also measured using the specific antibodies. RESULTS: The intestinal tract produces RELMbeta and RELMgamma, and colonic epithelial cells in particular express both RELMbeta and RELMgamma. In addition, RELMbeta and RELMgamma were shown to form a homodimer and a heterodimer with each other, in an overexpression system using cultured cells, and in mouse colon and serum. Serum RELMbeta and RELMgamma levels in high-fat-fed mice were markedly higher than those in mice fed normal chow. Serum RELMbeta and RELMgamma concentrations were also clearly higher in db/db mice than in lean littermates. Tissue expression levels revealed that elevated serum concentrations of RELMbeta and RELMgamma are attributable to increased production in the colon and bone marrow. CONCLUSIONS/INTERPRETATION: RELMbeta and RELMgamma form homo/heterodimers, which are secreted into the circulation. Serum concentrations of RELMbeta and RELMgamma may be a novel intestinal-tract-mediating regulator of insulin sensitivity, possibly involved in insulin resistance induced by obesity and a high-fat diet.

Animals↗

Oxidative stress induces insulin resistance by activating the nuclear factor-kappa B pathway and disrupting normal subcellular distribution of phosphatidylinositol 3-kinase.

AIMS/HYPOTHESIS: Oxidative stress is associated with diabetes, hypertension and atherosclerosis. Insulin resistance is implicated in the development of these disorders. We tested the hypothesis that oxidative stress induces insulin resistance in rats, and endeavoured to identify mechanisms linking the two. METHODS: Buthionine sulfoximine (BSO), an inhibitor of glutathione synthase, was administered to Sprague-Dawley rats and 3T3-L1 adipocytes. Glucose metabolism and insulin signalling both in vivo and in 3T3-L1 adipocytes were examined. In 3T3-L1 adipocytes, the effects of overexpression of a dominant negative mutant of inhibitory kappa B (I kappa B), one role of which is to block oxidative-stress-induced nuclear factor (NF)-kappa B activation, were investigated. RESULTS: In rats given BSO for 2 weeks, the plasma lipid hydroperoxide level doubled, indicating increased oxidative stress. A hyperinsulinaemic-euglycaemic clamp study and a glucose transport assay using isolated muscle and adipocytes revealed insulin resistance in BSO-treated rats. BSO treatment also impaired insulin-induced glucose uptake and GLUT4 translocation in 3T3-L1 adipocytes. In BSO-treated rat muscle, adipose tissue and 3T3-L1 adipocytes, insulin-induced IRS-1 phosphorylation in the low-density microsome (LDM) fraction was specifically decreased, while that in whole cell lysates was not altered, and subsequent translocation of phosphatidylinositol (PI) 3-kinase from the cytosol and the LDM fraction was disrupted. BSO-induced impairments of insulin action and insulin signalling were reversed by overexpressing the dominant negative mutant of I kappa B, thereby suppressing NF-kappa B activation. CONCLUSIONS/INTERPRETATION: Oxidative stress induces insulin resistance by impairing IRS-1 phosphorylation and PI 3-kinase activation in the LDM fraction, and NF-kappa B activation is likely to be involved in this process.

3T3 Cells↗

Comparison of various submucosal injection solutions for maintaining mucosal elevation during endoscopic mucosal resection.

BACKGROUND AND STUDY AIMS: One of the major complications of endoscopic mucosal resection (EMR) for gastrointestinal tumors is perforation, and the most effective way of preventing perforation is to elevate the lesion sufficiently by endoscopic injection of fluid into the submucosa. MATERIALS AND METHODS: In order to compare the lesion-lifting properties of several different solutions, 1 ml of each of the following solutions was injected into the submucosa of the resected porcine stomach: normal saline, 3.75 % NaCl, 20 % dextrose water, 10 % glycerin with 0.9 % NaCl plus 5 % fructose, and two sodium hyaluronate (SH) solutions. RESULTS: Significantly higher initial elevation was produced by both SH solutions, and it remained higher than that achieved by the other solutions at all times. Hypertonic solutions, especially 10 % glycerin with 0.9 % NaCl plus 5 % fructose, tended to produce and maintain greater mucosal elevation than normal saline, but the difference was not significant. CONCLUSIONS: SH solutions were the most suitable ones for producing and maintaining long-term mucosal elevation, while the superiority of hypertonic solutions over normal saline was not clearly demonstrated.

Animals↗

Different mixtures of sodium hyaluronate and their ability to create submucosal fluid cushions for endoscopic mucosal resection.

BACKGROUND AND STUDY AIMS: Sodium hyaluronate (SH) is a promising submucosal injection solution during endoscopic mucosal resection, but its high cost is an obstacle to more widespread use. The aim of this study was to identify an appropriate low-cost SH solution by varying the molecular weight of SH and mixing various solutions with it. MATERIALS AND METHODS: The viscoelasticity of various SH solutions was first measured. The concentrations of two 1 % SH preparations with different molecular weights (800 kDa and 1900 kDa) were adjusted to 0.5 %, 0.25 %, and 0.125 %, using 0.9 %/3.75 % normal saline (NS), 5 %/20 % dextrose water (DW), and a glycerin solution (Glyceol): 10 % glycerin with 0.9 % normal saline plus 5 % fructose. The ability of these SH solutions to create submucosal fluid cushions (SFCs) was then investigated in the stomachs of two live minipigs. RESULTS: The 0.25 % 1900 kDa SH/NS solution and the 0.125 % 1900 kDa SH/20 % DW solution created a similar viscoelasticity to that of the 0.5 % 800 kDa SH/NS solution. The ability of these solutions to create SFCs was also similar. In addition, the 0.125 % 1900 kDa SH/Glyceol solution created similar SFCs, with a synergistic effect of increased viscoelasticity and the hypertonic nature of glycerin. CONCLUSIONS: A mixture of higher molecular weight sodium hyaluronate with a sugar solution (particularly 20 % dextrose), with or without glycerin, should be regarded as a cost-effective option for creating SFCs instead of the conventional SH solution made with the same amount of a 1 % 800 kDa SH preparation and normal saline.

Animals↗

Effects of p27Kip1 on cell cycle status and viability in A549 lung adenocarcinoma cells.

p27Kip1 is a cyclin-dependent kinase inhibitor, it negatively regulates G1 progression and is reported to modulate apoptosis. Phosphorylation of this protein is thought to regulate its intracellular localisation and affect its stability. The aim of this study was to regulate p27Kip1 expression levels, and to examine how this protein affects cell cycle status and modulates viability in A549 lung adenocarcinoma cells. In addition, the association between phosphorylation status of p27Kip1 and its intracellular localisation was investigated, using expression vectors with cDNA of p27Kip1 or mutants in which the phosphorylation sites had been mutated. Although overexpression of p27Kip1 reduced cell cycle progression, its removal did not change cell cycle status. Modest induction of p27Kip1 rescued adenovector-induced apoptosis and its removal with short interfering RNA increased spontaneous cell death. It was also observed that p27Kip1 localised mainly in the cytoplasm, and forced expression of p27Kip1 cDNA with the substitution of serine (S) 10, threonine (T) 157 and T198 to glutamate (phosphor-mimetic) induced its cytoplasmic localisation. In conclusion, p27Kip1, when expressed physiologically, exists mainly in the cytoplasm, has little effect on cell cycle status and contributes viability in A549 lung adenocarcinoma cells. It was also surmised that intracellular localisation of p27Kip1 dominates its function and that its localisation was partly determined by its phosphorylation.

Adenocarcinoma↗