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Biomedical subjects

T Fujimori

Publications and source records attributed to T Fujimori.

At least 55 records · Page 3Linked to original sources
PubMed2000

Establishment of the anti-Klotho monoclonal antibodies and detection of Klotho protein in kidneys.

A novel gene, klotho (kl), which is involved in the development of a syndrome resembling human aging in mice, was recently identified. The kl gene encodes a single-pass membrane protein whose extracellular domain carries homology to beta-glucosidases. There also exists a splice variant of kl mRNA which encodes a putative secreted protein in both human and mouse. In this study, to characterize the physiological roles of Klotho protein, we established three monoclonal antibodies (mAbs) against the recombinant human Klotho protein. The mAbs are named KM2076 (rat IgG(2)a), KM2119 (rat IgG(2)b), and KM2365 (mouse IgG(1)). In Western blots, KM2076 and KM2119 specifically recognized a 130 kDa Klotho protein in the mouse and human kidney membrane fractions. To detect the human Klotho protein, the sandwich-type ELISA system with KM2076 and KM2365 was established. Using the ELISA system, we detected the human Klotho protein as low as 20 ng/ml in the supernatant of Chinese hamster ovary cells (CHO cells), introduced the human klotho gene. KM2076 and KM2119 specifically gave a positive staining by immunohistochemical staining in paraffin or frozen sections of the kidneys from wild-type mice but not in those from kl mice. Strong staining was observed especially in cortical renal tubules of the mouse kidney, where expression of klotho transcripts overlaps. KM2076 also showed a similar reaction pattern in the paraffin sections of rat and human kidneys. The mAbs established in this paper will serve as useful analytical, pathological, and diagnostic tools to disclose the role of Klotho protein in the suppression of a syndrome resembling human aging.

Aging↗
PubMed2000

Immunohistochemical localization of cathepsin D in colorectal tumors.

PURPOSE: Although it has been suggested that cathepsin D, a lysosomal protease, is involved in tumor invasion and metastasis in human colorectal cancers, conflicting studies have also been reported recently. In addition, this issue has been only rarely studied in human colorectal tumors by use of immunohistochemical methods. The aim of the study presented here was to clarify not only the correlation between cathepsin D expression and tumor invasion or metastasis but also the correlation between the intracellular immunostaining pattern of cathepsin D and tumor invasion and metastasis in human colorectal tumors. METHODS: Thirty-four primary colorectal adenocarcinomas and 24 adenomas were immunostained by use of an anticathepsin D antibody. Both the incidence and the immunostaining patterns of cathepsin D were investigated in all tissue samples. RESULTS: Three different immunostaining patterns, i.e., supranuclear, basal, and diffuse, were observed in samples containing cathepsin D. Although the incidence of cathepsin D-positive carcinomas was not correlated with tumor progression, invasion, or metastasis, the immunostaining pattern was significantly correlated with lymphatic invasion. CONCLUSIONS: The results of this study suggest that abnormal cathepsin D immunostaining patterns (basal or diffuse) can be used to predict a potential for lymphatic invasion in colorectal carcinoma.

Adenocarcinoma↗
PubMed2000

Clinicopathologic evaluation of the trend toward histologically poor differentiation with submucosal invasion in superficial early colorectal adenocarcinomas.

We examined differences in the degree of differentiation in intramucosal and submucosal areas of involvement in early colorectal adenocarcinomas of 131 patients and compared these findings with tumor morphology. In addition, K-ras and p53 protein expression was determined in cases where poorly differentiated adenocarcinoma was detected in the submucosa. We identified 6 patients with both intramucosal differentiated (well-to-moderately differentiated) adenocarcinoma and submucosal poorly differentiated adenocarcinoma (MwSp). The morphological tumor type was superficial in all MwSp cases. The observed MwSp adenocarcinomas had a significantly higher frequency of lymphatic invasion than the more common superficial type of adenocarcinoma. Genetic analysis of these MwSp lesions was carried out using the polymerase chain reaction-restriction fragment-length polymorphism (PCR-RFLP) method to detect the presence of K-ras codon 12 point mutations, and an immunologic staining technique was used to identify the presence of p53 protein overexpression. The K-ras mutation rate was 33.3%, and the p53 overexpression rate was 66.7% for the MwSp adenocarcinomas. Our findings suggest that the rapidly reduced histologic differentiation observed in some of these superficial colorectal adenocarcinomas may play a role in their higher degree of invasiveness.

Adenocarcinoma↗
PubMed2000

Molecular cloning and expression analyses of mouse betaklotho, which encodes a novel Klotho family protein.

We report here the identification of mouse betaklotho (betakl), which encodes a type I membrane protein with high resemblance to Klotho (KL). Both betaKL and KL consist of two internal repeats with homology to family 1 glycosidases, while these essential glutamates for the enzymatic activities were not conserved. The identical pattern of substitution and variation in the substituted amino acids between these two proteins indicate that they likely to form a unique family within the glycosidase family 1 superfamily. During mouse embryonic development, strong betakl expression was detected in the yolk sac, gut, brown and white adipose tissues, liver and pancreas, and in the adult, predominantly in the liver and pancreas. Despite the high structural similarity between betaKL and KL, their expression profiles were considerably different and betakl expression was not induced in kl-deficient mouse mutants.

Amino Acid Sequence↗
PubMed2000

Analysis of K-ras codon 12 mutations and p53 overexpression in colorectal nodule-aggregating tumors.

BACKGROUND AND AIMS: Morphologically, colorectal nodule-aggregating tumors are quite different from polypoid-type colorectal tumors that develop via the adenoma-carcinoma sequence. Although polypoid-type colorectal tumors are well known to have a high incidence of K-ras gene mutation and p53 overexpression, colorectal nodule-aggregating tumors have not been examined in terms of genetic changes and clinicopathological features. In the present study, therefore, we analysed the clinicopathological features, genetic changes in K-ras codon 12, and p53 overexpression in colorectal nodule-aggregating tumors. METHODS: A total of 18 colorectal nodule-aggregating tumors were surgically resected and then analysed clinicopathologically. Immunohistochemistry and polymerase chain reaction-single stranded conformational polymorphism were performed to analyse p53 abnormalities in the tumors. K-ras codon 12 mutations were screened out by the polymerase chain reaction-restriction fragment length polymorphism method and analysed by fluorescence direct sequencing. RESULTS: p53 overexpression was observed in six lesions (33%). p53-overexpressing cells were observed in parts of carcinoma or adenoma showing high-grade atypia. Four of the 10 (40%) samples had a p53 gene mutation. Nine of the 18 (50%) samples had a K-ras codon 12 point mutation. In eight cases (89%), the mutations of the K-ras codon 12 were of the same type: GGT (glycine) to GTT (valine). CONCLUSIONS: The colorectal nodule-aggregating tumor has distinctive characteristics showing a morphological phenotype of the superficial-type tumors and genotype of the polypoid tumors in terms of K-ras gene mutation and p53 overexpression.

Adenoma↗
PubMed2000

Incidence of P53 and K-ras alterations in ovarian mucinous and serous tumors.

Clarification of the pathogenic relationships existing among ovarian cystadenomas, tumors of low malignant potential (LMP) and various adenocarcinoma types, a series of 29 mucinous and 19 serous ovarian tumors including adenomas, LMP tumors and adenocarcinomas were examined. P53 protein was detected by the streptavidin-biotin method and point mutation of K-ras codon 12 was detected by polymerase chain reaction-restriction fragment length polymorphism analysis. P53 overexpression was observed more frequently in serous adenocarcinomas (5/8, 63%) than in mucinous adenocarcinomas (2/9, 22%) and was correlated with the malignant potential of serous tumors. Furthermore, the proportion of P53-positive cells was significantly higher in serous adenocarcinomas than in mucinous adenocarcinomas. P53 overexpression may therefore be closely related to the early events of carcinogenesis in serous tumors. Although mutation of the K-ras oncogene appears to be an important event in the early tumorigenesis of mucinous tumors, mutation of the K-ras oncogene in serous tumors may be dependent on morphology. Different complex pathways of oncogene and/or tumor suppressor gene abnormalities may be involved in the development of mucinous and serous adenocarcinomas.

Cell Transformation, Neoplastic↗
PubMed2000

Shape-memory alloy loop snare for endoscopic photodynamic therapy of early gastric cancer.

BACKGROUND AND STUDY AIMS: Photodynamic therapy (PDT) has proved effective in the treatment of gastric cancer, but there is room for improvement. To achieve the technical goal of carrying out endoscopic PDT, endoscopists need to determine the precise area for laser irradiation at adequate dosages. This report describes the use of a shapememory alloy (SMA) loop snare as a useful tool in endoscopic PDT. PATIENTS AND METHODS: Eleven patients with biopsy-proved early gastric cancer were treated with endoscopic PDT after intravenous injection of Photofrin II (2 mg/kg b.w.). Five patients underwent PDT using the SMA loop snare, and six underwent PDT without the use of the device. Cancer lesions smaller than 2 cm in diameter were irradiated with an excimer-dye laser (4 mJ, 80 Hz, 630 nm) for 20 min. RESULTS: All five patients (100%) treated with PDT using the SMA loop snare, and four of the six patients (67%) treated with PDT without use of the SMA loop snare, showed complete remission. CONCLUSIONS: The SMA loop snare routinely forms a circle 2 cm in diameter, covering an area of 3.14 cm2, and makes it possible to mark and calculate the precise area of cancerous lesions for irradiation at appropriate dosages. The findings of this study suggest that the SMA loop snare is an effective tool for PDT in early gastric cancer.

Aged↗
PubMed2000

[Smoking behaviors among medical doctors in Fukui, Japan].

This study was conducted in order to identify the smoking prevalence among all doctors (N = 874) belonging to the medical associations in Fukui Prefecture and factors that might possibly indicate causal smoking habits. A survey was conducted from December of 1996 to February of 1997, using a self-administered questionnaire, and the response rate for the survey was 91%. The main results of this survey were as follows: The prevalence of smoking among male and female medical doctors was 28% and 8% respectively, which was lower than that of adults in the general population, but higher than that of doctors in the developed countries. The prevalence of smoking among doctors was almost highest when they were 20 to 29 years old, and that among medical practitioners with their own institution was higher than doctors employed by an institution. In particular, medical practitioners who did not smoke were more likely to restrict or ban smoking in their hospitals or clinics.

Adult↗
PubMed2000

Biosynthesis of depudecin, a metabolite of Nimbya scirpicola.

Feeding experiments of labeled acetates to Nimbya scirpicola proved the carbon origin of the straight-chain polyketide, depudecin. Differential hydrogen exchange of the 2H label originating from 2H labeled acetate along the polyketide chain occurred. In particular, the deuterium of an epoxide methine at C-3 was lost to a substantial extent in the formation of depudecin.

Alkadienes↗
PubMed2000

Calcium antagonist inhibits glomerular cell apoptosis and injuries of L-NAME exacerbated nephrosclerosis in SHR.

Increased apoptosis of glomerular cells, with progression of glomerulosclerosis, overactivity of the renin-angiotensin system and elevation of glomerular pressure, follows chronic nitric oxide synthase (NOS) inhibition in spontaneously hypertensive rats (SHR). To gain insight into the regulation of glomerular cell apoptosis in severe nephrosclerosis, we investigated apoptosis, the expression of proliferative cell nuclear antigen (PCNA) in glomeruli, and glomerular morphometric changes in 20-week-old SHR, SHR treated with NOS inhibitor, NG-nitro-L-arginine methyl ester (L-NAME; 80 mg/l in drinking water), and SHR treated with L-NAME and the calcium antagonist, efonidipine (20 mg/kg per day), for 3 weeks. Apoptosis in non-sclerotic glomeruli was quantified by terminal deoxynucleotide transferase-mediated dUTP nick-end labeling. The increase in systolic blood pressure and the severe proteinuria with severe nephrosclerosis induced by chronic NOS inhibition were completely prevented by efonidipine. Furthermore, the glomerular area and capillary tuft area were markedly increased in rats treated with efonidipine compared with both control rats (+30 and +42%, respectively, p<0.01) and rats treated with L-NAME (+35 and +56%, respectively, p<0.01)-treated rats. This calcium antagonist also significantly inhibited the both increases of the glomerular cell apoptosis index (-72%) and the PCNA index (+44%), therefore the alteration between apoptosis and proliferation slightly increased the number of glomerular cells (subcapsular, +22%, p<0.01; juxtamedullary, +2%, not significant). Thus, the calcium antagonist efonidipine seems to play an important role in the regulation of apoptosis and proliferation of glomerular cells and may be effective in preventing nephrosclerosis exacerbated by NOS inhibition.

Animals↗
PubMed2000

[Histopathological diagnosis in reflux esophagitis].

We reviewed the histopathological features for the diagnosis of reflux esophagitis and gastroesophageal reflux disease(GERD) including carcinogenesis of the esophagus. Histologically, the presence of capillary dilatation, elongation of papillary, hyperplasia of basal layer, inflammatory cells-infiltration, balloon cells in the epithelium, and ulceration were evaluated in GERD cases. Although, histopathological changes were not clear in endoscopic-negative GERD cases, immunohistochemical examination with cell cycle protein(PCNA, p21, and p27) revealed the same abnormalities with GERD cases. In Japan, the majority cases of GERD are evaluated in grade according to Los Angeles system, therefore the prevalence of Barrett's esophagus and cancer is very low. We hypothesize that esophageal squamous cell carcinoma arising from GERD different from Barrett's cancer sequence, and clinicopathological long-term follow up will be required to assess the carcinogenesis including gene analysis.

Barrett Esophagus↗
PubMed2000

Relationship between cyclooxygenase-2 expression and K-ras gene mutation in colorectal adenomas.

BACKGROUND AND AIMS: Cyclooxygenase (COX)-2 has a trophic effect on gastrointestinal epithelial cells and is associated with the progression of colorectal adenomas. Mutation of the K-ras gene is also associated with the progression of colorectal adenomas and has recently been suggested to play an important role in the induction of COX-2. In the present study, we investigated the relationship between COX-2 expression and K-ras mutation in colorectal adenomas. METHODS: Twenty-nine colorectal adenomas were obtained from specimens resected by the use of surgery or endoscopic mucosal resection and analyzed clinicopathologically. Immunohistochemistry was performed to analyze COX-2 expression in the adenoma specimens. The K-ras codon 12 mutations were detected by using the polymerase chain reaction-restriction fragment length polymorphism method. RESULTS: An increase of COX-2-positive cells in adenoma was observed in 11 (37.9%) lesions, 10 (90.9%) of which had a K-ras gene mutation, suggesting a significant correlation between COX-2 expression and K-ras gene mutation in colorectal adenomas. Morphologically, COX-2-positive adenomas (13.8 +/- 2.6 mm) were significantly larger than COX-2-negative ones (5.8 +/- 0.9 mm). In addition, the increase of COX-2-positive cells in the lesion was observed more frequently in tubulovillous (63.6%) than in tubular (36.4%) adenoma. CONCLUSIONS: Cycloxygenase-2 expression in colorectal adenoma cells is strongly correlated with K-ras gene mutation, suggesting that COX-2 and mutated K-ras are connectively associated with the progression of colorectal adenoma.

Adenoma↗
PubMed1999

Effects of opioids on neuronal survival in culture of embryonic chick dorsal root ganglion neurons.

We studied the effects of endogenous and synthetic opioids on survival of primary-cultured dorsal root ganglion neurons of 8-day chick embryos. In the basal growth medium containing nerve growth factor (NGF), [Leu5]enkephalin, [Met5]enkephalin or selective mu-agonist, [D-Ala2, N-Me-Phe4, Gly5-ol]enkephalin (DAMGO) produced significant increase of neuronal survival in a naloxone-reversible manner. On the other hand, dynorphin A (1-13), [D-Pen2, L-Pen5] enkephalin (DPLPE) (a delta-agonist) and U-50,488 (a kappa-agonist) showed no such effect. No viable neurons were observed in the absence of NGF in spite of the presence of any opioid peptides. These results suggest that [Leu5]enkephalin and [Met5]enkephalin might increase neuronal survival by stimulating mu-opioid receptors, and that these opioid peptides are working with other growth factors but, in and by themselves, do not promote survival.

Animals↗
PubMed1999

Cyclooxygenase (COX)-2 immunoreactivity and relationship to p53 and Ki-67 expression in colorectal cancer.

The tumor-suppressive effects of nonsteroidal antiinflammatory drugs (NSAIDs) have been suggested to be due to a reduction in cyclooxygenase (COX)-2 activity, although the effects of COX-2 in the colonic mucosa and in colorectal cancer have not been determined. Ki-67 immunoreactivity in cancers is also attracting attention, as Ki-67 reflects cell proliferation, while p53 immunoreactivity is also of interest, as it reflects the malignancy of colorectal lesions. Accordingly, to determine these correlation, we investigated the distribution and intensity of COX-2, p53 and Ki-67 expression in both cancerous and non-cancerous tissues from patients with sporadic and ulcerative colitis (UC)-associated colorectal cancer. We selected 21 colorectal cancer specimens, obtained by surgical resection or colonoscopic biopsy, from 21 patients, including 3 with UC (13 men and 8 women; aged 42-78 years). Histological examination of hematoxylin and eosin-stained specimens revealed that 9 were well differentiated; 11. moderately differentiated: and 1 was a poorly differentiated adenocarcinoma. We used anti-COX-2, p53, and Ki-67 antisera to perform immunohistochemical staining by the labelled streptavidin biotin method and then assessed and graded the staining intensity and distribution. COX-2 staining was more intense in cancer tissue than in non-cancerous areas. Colorectal cancers associated with UC were not stained intensely. COX-2, p53, and Ki-67 positivity rates in were 38.1%, 38.1%, and 47.6%, respectively. There were no relationships among the distributions or intensities of COX-2, p53, and Ki-67 expression. Our results indicate that colorectal cancer tissues overexpress COX-2, but that there are no relationships between COX-2, p53, and Ki-67 expression, suggesting that COX-2 expression may not be related to cell proliferation or to the grade of malignancy. However, it is necessary to determine whether COX-2 in cancer tissue is involved in carcinogenesis or whether it is simply a product of cancer.

Adult↗
PubMed1999

Expression of heregulin alpha, erbB2, and erbB3 and their influences on proliferation of gastric epithelial cells.

BACKGROUND & AIMS: Heregulins (HRGs) regulate the proliferation and differentiation of various cell types. However, very little is known about their function in the gastrointestinal tract. The aim of this study was to investigate the role of HRGs on gastrointestinal cells. METHODS: We examined the expression of erbB receptors and HRG-alpha in human gastric cancer cell lines, rat gastrointestinal epithelial cells, and human gastric fibroblasts by Western blot analysis or reverse-transcription polymerase chain reaction. Receptor phosphorylation and heterodimerization induced by HRG-alpha were detected by Western blot analysis. We also evaluated the in vitro effects of HRG-alpha on cell proliferation and restitution. RESULTS: Cancer cell lines and rat epithelial cells expressed erbB2 and erbB3, but protein expression of erbB4 was not detected. HRG-alpha was detected only in gastric fibroblasts. HRG-alpha activated tyrosine phosphorylation of epidermal growth factor receptor (EGFR), erbB2, and erbB3 and induced not only erbB3/erbB2 but also erbB3/EGFR and erbB2/EGFR heterodimer formation in MKN-28 cancer cells. Simultaneous cultivation of MKN-28 cells with gastric fibroblasts resulted in tyrosine phosphorylation of erbB3 in MKN-28 cells. HRG-alpha also stimulated proliferation of MKN-28 cells and gastric epithelial cells. CONCLUSIONS: The data suggest that HRG-alpha may affect epithelial cell proliferation through mesenchymal-epithelial interaction in the gastric mucosa.

Animals↗