Search PubMed⌕ Search

Biomedical subjects

T Fujimori

Publications and source records attributed to T Fujimori.

At least 109 records · Page 6Linked to original sources
PubMed1994

p53 mutations in flat- and polypoid-type colorectal tumors detected by temperature-gradient gel electrophoresis.

Reports of cases of flat-type colorectal tumors are increasing in Japan, but almost nothing has been elucidated about the genetic abnormalities of these tumors. In this study, we have examined p53 mutations in six cases of colon cancer cell lines, 22 cases of flat-type colorectal tumors, and 27 cases of polypoid-type colorectal tumors using the polymerase chain reaction (PCR) and temperature-gradient gel electrophoresis (TGGE); the latter has recently been developed as a screening method for gene mutations. p53 mutations were observed in four colon cancer cell lines, six flat-type colorectal tumors, and three polypoid-type colorectal tumors, all of which were analyzed by direct sequencing. These mutations were observed only in adenomas with high-grade dysplasia and in colorectal cancers but not in adenomas with low-grade dysplasia. These observations suggest that p53 gene mutations are involved in flat-type as well as polypoid-type colorectal tumors at relatively later stages of carcinogenesis and that TGGE seems to be useful as one of the rapid screening methods.

Adenoma↗
PubMed1994

Effect of the acyl-CoA:cholesterol acyltransferase inhibitor, E5324, on experimental atherosclerosis in rabbits.

E5324, n-butyl-N'-[2-[3-(5-ethyl-4-phenyl-1H-imidazol-1-yl)propoxy]-6- methylphenyl]urea, a novel and orally absorbable acyl-CoA:cholesterol acyltransferase (ACAT) inhibitor, was evaluated for its antiatherosclerotic and antihyperlipidemic effects in cholesterol-fed hypercholesterolemic rabbits. When administered concurrently with a high-cholesterol (0.5% cholesterol) diet for 12 weeks, E5324 (0.0025%, 0.005% and 0.01% in diet) lowered plasma total cholesterol levels dose-dependently (by about 55%-87% at the end of the experiment compared with the control) and also reduced atherosclerotic plaque formation (about 90% reduction at the highest dose; P < 0.01). In pre-established hypercholesterolemic rabbits, which had been pre-fed a high-cholesterol diet for 8 weeks, E5324 administered in the same diet at a dose of 0.005%, 0.01% or 0.02% for 4 weeks significantly reduced plasma cholesterol levels dose-dependently. Cholesterol content and ACAT activity in the aortic arch were also decreased (by about 72% and 58% at the highest dose, respectively) compared with the control. Another ACAT inhibitor, CI-976, had a similar action, but cholestyramine and probucol (2% and 1% in diet, respectively) lacked anti-atherosclerotic activity in this model. Furthermore, when pre-established hypercholesterolemic rabbits were fed normal rabbit chow diet with or without 0.02% E5324 for 4 weeks, changes in plasma cholesterol levels were similar in both E5324-treated and control groups. On the other hand, E5324 significantly reduced cholesterol content and ACAT activity in the aortic arch (by about 52% and 50%, respectively) compared with the control group. These results indicate that E5324 not only has hypocholesterolemic activity, but also may have a direct effect on the arterial wall in experimental atherosclerosis.

Anilides↗
PubMed1994

The anthocyanin responsible for purplish blue flower colour of Aconitum chinense.

The anthocyanin in the purplish blue flowers of Aconitum chinense was identified as delphinidin 3-rutinoside-7-O-(6-O-(4-(6-O-(4-hydroxybenzoyl)-beta-D-glucosyl)oxyb enzoyl- beta-D-glucoside), violdelphin by means of chromatography, FAB-MS including MS-MS, 1H and 13C NMR. The anthocyanin is stable in neutral or slightly acidic aqueous solution and the absorption spectra in the pH range of 4.0-6.2 exhibited three characteristic bands at 534, 569 and 620 nm, which are practically identical with those of purplish blue petals of A. chinense. Thus the purplish blue flower colour is manifested by intramolecular co-pigmentation of the anthocyanin.

Anthocyanins↗
PubMed1994

Comparative clinicopathological and immunohistochemical study of ras and p53 in flat and polypoid type colorectal tumours.

Mutations in oncogenes and tumour suppressor genes may have an important oncogenic role. Although flat type tumours have been frequently detected in recent years, ras and p53 expressions have not been studied in these tumours. Using a monoclonal and polyclonal antibody to the ras p21 and p53 product, paraffin wax embedded sections of 98 colorectal tumours (43 cases of the flat type colorectal tumour and 55 cases of polypoid type tumour) were stained using the immunoperoxidase technique. Staining was evaluated by light microscopic examination. Positive staining rate of ras p21 for the flat type was 0%; for the polypoid type, it was 60% in cancer with submucosal invasion, 82% in adenoma with high grade dysplasia, and 0% in adenoma with low grade dysplasia. The positive staining rate of p53 for the flat type was 50% in submucosal cancer, 9% in adenoma with high grade dysplasia, and 0% in adenoma with low grade dysplasia. For the polypoid type, it was 40% in submucosal cancer, 12% in adenoma with high grade dysplasia, and 0% in adenoma with low grade dysplasia. The intermediate staining rate of p53 in the polypoid type was 20% in submucosal cancer and 41% in adenoma with high grade dysplasia. It was seen that p53 was commonly expressed in both flat and polypoid lesions, p21 was not expressed in flat lesions, whereas it was commonly expressed in polypoid neoplasms. In the flat type cancer, a genetic change different from that of the polypoid type cancer is suggested.

Adenoma↗
PubMed1994

[Expression of the p53 protein in human osteosarcoma].

The expression of the p53 tumor suppressor gene protein was analyzed in 35 resected osteosarcomas, 5 resected osteochondromas, and in 2 human osteosarcoma cell lines by immunohistochemistry and flow cytometry. An abnormality in the expression of the p53 protein was found in 10(29%) of the 35 osteosarcomas. An overexpression of the p53 protein showed no correlation with the clinicopathological features, but the p53 protein staining pattern showed a tendency to be correlated with aggressive growth and the metastatic potential. Diffusely-stained tumors had a worse prognosis than those focally-stained. The relationship between the expression of p53 protein and the cell cycle was examined by flow cytometry. The maximum overexpression of p53 protein was detected in the cells at the S phase. These results indicated that the nuclear accumulation of the p53 protein, especially the staining pattern, was a potentially useful prognostic factor for osteosarcoma. However our study did not show any clear correlation between either the growth pattern or the morphological type of osteosarcoma and the immunohistochemical results for the p53 protein.

Adolescent↗
PubMed1994

A case of Behçet's disease with multiple longitudinal ulcers all over the colon.

We experienced a rare case of intestinal Behçet's disease simulating Crohn's colitis. A 70-yr-old female presented oral and genital ulcers, erythema nodosum, arthralgias, and abdominal pain. Regardless of our efforts, she died of septic shock. Autopsy showed punched-out ulcers in the terminal ileum and multiple longitudinal ulcers with inflammatory polyposis spreading from the ascending to the descending colon. The differential diagnosis of intestinal Behçet's disease versus Crohn's disease was difficult. However, microscopic findings showed nonspecific ulceration, and no evidence of Crohn's disease could be found. Clinically, the patient met the criteria of Behçet's disease, and punched-out ulcers in the ileocecal region, which is characteristic of intestinal Behçet's disease, confirmed the diagnosis of Behçet's colitis. Although rarely encountered, multiple longitudinal ulcers can involve all of the colon in Behçet's disease, like Crohn's disease.

Aged↗
PubMed1993

Parathyroid hormone-related protein in gastric cancers with heterotopic ossification.

BACKGROUND: Parathyroid hormone-related protein (PTHrP) has been regarded as one of the substances causing humoral hypercalcemia of malignancy. METHODS: The immunohistochemical localization of PTHrP was investigated in 33 cases of gastric cancer (4 with heterotopic ossification and 29 without heterotopic ossification) to clarify the role of PTHrP in heterotopic ossification by using the anti-PTHrP monoclonal antibody, 4B3. RESULTS: The four cases with heterotopic ossification showed positive staining at primary or metastatic sites, and in one case fibroblasts in the stroma surrounding the heterotopic ossifying foci also showed positive. On the other hand, of the 29 cases without heterotopic ossification, only 5 showed positive staining. CONCLUSIONS: The presence of PTHrP in ossifying gastric carcinomas at a relatively high rate indicates that PTHrP also might be related to heterotopic ossification associated with malignancies. It is speculated that PTHrP would contribute to heterotopic ossification by facilitating the process of mineralization.

Adenocarcinoma↗
PubMed1993

Structure-activity relationship of N-[2-(dimethylamino)-6-[3-(5-methyl-4-phenyl-1H-imidazol-1-yl)propoxy] phenyl]-N'-pentylurea and analogues. Novel potent inhibitors of acyl-CoA:cholesterol O-acyltransferase with antiatherosclerotic activity.

We have discovered N-butyl-N'-[2-(dimethylamino)-6-[3-(4-phenyl-1H- imidazol-1-yl)propoxy]phenyl]urea (4), a novel, potent, and systemically bioavailable inhibitor of ACAT (acylCoA:cholesterol O-acyltransferase). The structure-activity relationships (SARs) of this lead compound 4 were investigated by systematic modification of four regions in the molecule. The compounds prepared in this study were tested for in vitro inhibitory activity toward both aortic and intestinal ACATs, and selected compounds were further tested for in vivo hypocholesterolemic activity. The studies not only resulted in the discovery of N-[2-(dimethylamino)-6-[3-(5-methyl-4-phenyl-1H-imidazol-1-yl) propoxy]phenyl]-N'-pentylurea (24), with potent activity and moderate plasma level after oral administration, but also revealed the SAR in each modified region. Four compounds (4, 13, 14, 24) were further selected for testing of in vivo antiatherosclerotic activity; 4, 13, and 24 reduced atherosclerotic plaque development to 38-45% of the control value in terms of area, while 14 did not have a significant antiatherosclerotic effect.

Animals↗
PubMed1993

Common expression of parathyroid hormone-related protein and no correlation of calcium level in renal cell carcinomas.

BACKGROUND: Parathyroid hormone-related protein (PTHrP) is the predominant cause of humoral hypercalcemia of malignancy (HHM). METHODS: Using a PTHrP-specific monoclonal antibody (MoAb), 4B3, the authors investigated the immunohistochemical localization of PTHrP in formalin-fixed and paraffin-embedded sections of normal human kidney tissues and tissues from 42 human renal cell carcinomas obtained at operation or autopsy. RESULTS: In normal renal tissues, the distal tubules and collecting ducts showed positive immunostaining. PTHrP was detected in 40 of 42 renal cell carcinoma tissues (95%). Histopathologically, the granular cell subtypes of renal cell carcinomas tended to be more strongly positive than the clear cell subtypes. There was no significant correlation between the level of immunostaining and each patient's serum calcium level. CONCLUSION: PTHrP was commonly observed in renal cell carcinomas, and no significant correlation was seen between the intensity of PTHrP staining and the serum calcium level.

Antibodies, Monoclonal↗
PubMed1993

The role of Ras mutation in pancreatic cancer, precancerous lesions, and chronic pancreatitis.

Point mutations in K-ras codon 12 were detected in 7 of 10 specimens (70%) of frozen tissues. To determine when point mutations appear in the oncogenic stage, paraffin-embedded tissues of pancreatic cancer, hyperplastic ductal lesions in pancreatic cancer and in chronic pancreatitis were used. DNA extracted from the paraffin-embedded tissues classified as cancer, atypical and nonatypical hyperplasia of the pancreatic duct epithelium, and normal tissue from pancreatic cancer patients and those classified as atypical hyperplasia of the pancreatic duct epithelium and normal tissue from chronic pancreatitis patients were amplified by the polymerase chain reaction (PCR) method. Point mutations were detected in 8 of 17 cancer cases (47.0%). In 5 of 8 point mutation positive cases, atypical hyperplasias were found in the surrounding tissues. In all 5 of these atypical hyperplasia, point mutations, that is, GGT-GTT (Gly-Val) and GGT-GAT (Gly-Asp), were detected. The same transitions were observed in the cancer of these 5 cases. These results suggest a strong relationship between cancer and atypical hyperplasia surrounding cancer. Although atypical hyperplasia around cancer was histologically very similar to that found in chronic pancreatitis, all 5 atypical and 5 nonatypical hyperplasias in chronic pancreatitis were negative for ras point mutation. Thus, the result argues against an association between chronic pancreatitis and pancreatic cancer.

Adult↗
PubMed1993

Expression of oncogene products and growth factors in early gallbladder cancer, advanced gallbladder cancer, and chronic cholecystitis.

The expression of oncogene products and growth factors (epidermal growth factor, transforming growth factor-beta, erbB-2, ras p 21, and c-myc) in gallbladder cancer and chronic cholecystitis was measured by immunohistochemical staining on paraffin-embedded serial sections. Expression of these products was graded according to staining intensity in an area of positively stained cells. This study reports the detection of oncogene products and growth factors in cholecystitis as well as in early and late gallbladder cancer. The multiexpression of oncogene products and growth factors was greater for both gallbladder cancer groups as compared with the cholecystitis group. The percentage of epidermal growth factor positivity diminished with increased proportion of interstitial tissue and, conversely, the percentage of transforming growth factor positivity increased with increased proportion of interstitial tissue. The proportion of ras positivity was significantly greater in both early and advanced cholecystic cancer as compared with cholecystitis, but also was considerable even for cholecystitis. These results suggest that various oncogenes may have significant roles in gallbladder cancer and that collagen synthesis is reduced by epidermal growth factor and enhanced by transforming growth factor-beta.

Cholecystitis↗
PubMed1993

Disruption of epithelial cell-cell adhesion by exogenous expression of a mutated nonfunctional N-cadherin.

Cadherins, a family of transmembrane cell-cell adhesion receptors, require interactions with the cytoskeleton for normal function. To assess the mechanisms of these interactions, we studied the effect of exogenous expression of a mutant N-cadherin, cN390 delta; on epithelial cell-cell adhesion. The intracellular domain of cN390 delta was intact but its extracellular domain was largely deleted so that this molecule was not functional for cell adhesion. cDNA of cN390 delta was attached to the metallothionein promoter, and introduced into the keratinocyte line PAM212 expressing endogenous E- and P-cadherin. When the expression of cN390 delta was induced by Zn2+, cadherin-dependent adhesion of the transfected cells was inhibited, resulting in the dispersion of cell colonies, although their contacts were maintained under high cell density conditions. In these cultures, cN390 delta was expressed not only on the free surfaces of the cells but also at cell-cell junctions. The endogenous cadherins were concentrated at cell-cell junctions under normal conditions. As a result of cN390 delta expression, however, the endogenous cadherins localizing at the cell-cell junctions were largely diminished, suggesting that these molecules were replaced by the mutant molecules at these sites. As a control, we transfected the same cell line with cDNA of a truncated form of N-cadherin cadherin whose intracellular C terminus had been deleted leaving the extracellular domain intact. This molecule had no effect on cell-cell adhesion, nor did it localize to cell-cell contact sites. We also found that the association of the endogenous cadherins with alpha- and beta-catenins and plakoglobin was not affected by the expression of cN390 delta, which also formed a complex with these molecules, suggesting that no competition occurred between the endogenous and exogenous cadherins for these cytoplasmic proteins. These and other additional results suggest that the nonfunctional cadherins whose intracellular domain is intact occupy the sites where the endogenous cadherins should localize, through interactions with the cytoskeleton, and inhibit the cadherin adhesion system.

Amino Acid Sequence↗
PubMed1993

Inhibitory effects of a novel antiplatelet agent, E5510, on collagen-induced platelet-derived growth factor release and aggregation of human platelets in vitro.

E5510, 4-cyano-5,5-bis(4-methoxyphenyl)-4-pentenoic acid, is a new anti-platelet-aggregation agent under development. We examined the inhibitory efficacy of E5510 on PDGF-release from washed human platelets. E5510 concentration-dependently inhibited collagen-induced PDGF release from human platelets. PDGF release was reduced to below the detection limit (0.47 ng/ml) by preincubation of platelets with 0.04 microM or higher concentrations of E5510. Total growth factor release from platelets was also measured by a bioassay with cultured smooth muscle cells. E5510 almost completely abolished the mitogenic effect of collagen-induced platelet releasates at concentrations of 0.04 microM or higher. Our data suggest that the release of PDGF and other growth factors was inhibited by E5510 at the same concentration that inhibited platelet aggregation.

Animals↗
PubMed1993

In situ hybridization using bromodeoxyuridine labelled DNA probe and RNase H.

We developed a modified in situ DNA-RNA hybridization technique and demonstrated c-myc proto-oncogene transcripts in nodular sclerosis type Hodgkin's disease (HD-NS). A hybridization probe was prepared by metabolic labelling of bromodeoxyuridine (BrdU). The hybridized probe was detected with anti-BrdU monoclonal antibody after incubation with ribonuclease H (RNase H), which specifically degrades RNA from DNA-RNA hybrids. In HD-NS, c-myc protooncogene transcripts were demonstrated in the cytoplasm of lacuna cells and a few surrounding lymphoid cells. This modified hybridization method was sensitive and applicable to the study of oncogene expression at a single cell level.

Adult↗
PubMed1993

In situ hybridization at the electron microscopic level using a bromodeoxyuridine labeled DNA probe.

A bromodeoxyuridine (BrdU) labeled DNA probe was used for in situ hybridization at the electron microscopic (EM) level. A BrdU labeled DNA probe was hybridized in situ to cryostat sections of paraformaldehyde fixed OCT compound embedded cultured HL-60 cells. After hybridization, some sections were incubated with FITC-conjugated anti-BrdU monoclonal antibody for fluorescence microscopy (FM), and others were embedded in Quetol for electron microscopy (EM). The ultrathin sections of Quetol-embedded specimens were incubated with the anti-BrdU monoclonal antibody and the immunoglobulin: gold colloid. In both FM and EM studies, the signals were concentrated in the rough endoplasmic reticulum. Moreover, some label was arranged from the nucleus to the cytoplasm at the EM level. Relatively simple methods using the BrdU labeled DNA probe for the detection of the defined nucleic acid sequence with reasonable tissue preservation and high resolution are described here. This method may be useful for developmental and disease related studies of specific mRNA in cells and tissues.

Antibodies, Monoclonal↗