Biomedical subjects

Chie Furihata

Publications and source records attributed to Chie Furihata.

6 recordsLinked to original sources

PubMed2006

Fluorescence-suppressed Raman technique for quantitative analysis of protein solution using a micro-Raman probe, the shifted excitation method, and partial least squares regression analysis.

A practical Raman analyzing technique with suppression of the strong fluorescent background in order to obtain quantitative information is proposed in the present study. The technique is based on the shifted excitation method and partial least squares regression (PLSR) analysis. The Raman system consists of a single Raman spectrometer, a background-free electrically tunable Ti:Sapphire laser (BF-ETL), and a micro-Raman probe (MRP). The system allows one to obtain reliable shifted excitation Raman spectra with a simple operation. The PLSR analysis successfully provides quantitative information from the obtained spectra with the suppression of random noise including photon shot noise. The present study demonstrates that the technique is effective for extracting quantitative information concealed behind a fluorescent background that is more than 200 times stronger than the Raman signal.

Animals↗

PubMed2003

Overexpression of NP95 mRNA by tumor promoters in the promotion phase of a two-stage BALB/3T3 cell transformation assay.

We studied altered gene expressions in BALB/3T3 cells treated by different tumor promoters in the promotion phase of a transformation assay, an in vitro model of a two-stage carcinogenicity test, using fluorescent mRNA differential display analysis. Expression of the NP95 gene, which was previously found to be the gene of a murine nuclear protein associated with cell proliferation, was increased in the cultures treated by 12-O-tetradecanoylphorbol-13-acetate (TPA), okadaic acid, and orthovanadate. The upregulation of NP95 mRNA was confirmed by reverse transcription-PCR, and Northern blot. TPA, okadaic acid, and orthovanadate enhanced cell proliferation as measured by a 5-bromo-2'-deoxyuridine incorporation assay. The expression level of NP95 mRNA was not affected by the treatment with typical carcinogens benzo[a]pyrene and 3-methylcholanthrene at concentrations at which they act as initiators of cell transformation. These facts may imply that the enhancement of cell transformation by these tumor promoters is due, at least in part, to the acceleration of cell proliferation. NP95 mRNA was also increased in the transformed BALB/3T3 cells. Overexpression of NP95 may also participate in the maintenance of the transformed phenotype.

Animals↗

PubMed2002

Osteonectin-expressing cells in human stomach cancer and their possible clinical significance.

The clinical significance of osteonectin in human stomach cancer was examined immunohistochemically and molecular biologically in 31 differentiated and eight undifferentiated stomach adenocarcinomas and 19 non-cancer stomach tissues. Osteonectin-mAb-stained cells were observed in stroma of 90% differentiated and 63% undifferentiated adenocarcinomas, and of 26% non-cancer stomach tissues. Competitive reverse transcriptase polymerase chain reaction results generally coincided with immunohistochemical data. The present results suggest that osteonectin is highly expressed in reactive stroma associated with invasive differentiated adenocarcinomas and that it may serve as a useful clinical diagnostic marker for stomach cancer.

Adenocarcinoma↗

PubMed2002

Independent variation in susceptibilities of six different mouse strains to induction of pepsinogen-altered pyloric glands and gastric tumor intestinalization by N-methyl-N-nitrosourea.

Strain differences in susceptibility regarding stomach carcinogenesis due to N-methyl-N-nitrosourea were examined in males of six strains of mice: BALB/cA (BALB), C57BL/6N (C57BL6), CBA/JN (CBA), C3H/HeN (C3H), DBA/2N (DBA/2), and CD-1 (ICR). The frequency of pepsinogen-altered pyloric glands (PAPGs), putative precancerous lesions, was highest (19.6+/-9.9%) in the BALB and lowest in the ICR (12.3+/-5.7%) mice (P<0.05). Incidences of adenocarcinomas at week 52 were 59.3% (16 of 27) and 18.5% (5 of 27), respectively (P<0.005). Invasion also tended to be deepest in BALB compared with the other strains. Intestinal alkaline phosphatase-positive intestinal type cells were observed heterogeneously in some hyperplasias, adenomas and adenocarcinomas consisting of gastric type cells. Thus, intestinalization appeared to occur at random in both non-neoplastic and monoclonal neoplastic lesions, making it unlikely that IAP-positive cells could be precursors of gastric tumors. In contrast, the data suggest a direct histogenetic role for the PAPG, a useful preneoplastic marker lesion in mouse strains.

Adenocarcinoma↗

PubMed2002

Dendritic cell appearance and differentiation during early and late stages of rat stomach carcinogenesis.

Dendritic cell appearance and differentiation during early and late stages of rat stomach carcinogenesis were studied in the pyloric mucosa. Young male rats were given drinking water with or without N-methyl-N'-nitro-N-nitrosoguanidine (MNNG; 100 mg/liter) for 14 days. Use of competitive RT-PCR and northern blotting showed that MNNG exposure induced 3- to 4-fold greater expression of the genes for integrin beta7 and integrin alphaE2 (identical with antigen OX-62, a dendritic cell marker), as well as three cytokines, IL-4, GM-CSF and TNFalpha, in the stomach pyloric mucosa of resistant Buffalo rats compared to sensitive ACI rats. These genes were minimally expressed in control animals. The results confirm the appearance of dendritic cells in the target pyloric mucosa and suggest the possibility that dendritic cell differentiation and maturation are induced by various cytokines, at least in Buffalo rats. Competitive RT-PCR showed expression of integrin alphaE2 and beta7, MHC class II-associated invariant chain (Ii), MHC class II, B7-1, CD28, GM-CSF and TNFalpha genes in all 12 examined stomach adenocarcinomas and adenomas induced in male Lewis and WKY rats with 30 weeks' MNNG exposure, suggesting the presence of dendritic cells in tumors. OX-62 staining and western blotting for OX-62 also confirmed the presence of dendritic cells in tumors. However, the population of dendritic cells in tumors was less than that in the pyloric mucosa after 14 days' MNNG exposure. The present results suggest that immune defense involving dendritic cells is marshaled from the very early initiation stage during rat stomach cancer development, but is downgraded in developed tumors.

Animals↗

PubMed2002

Appearance of osteonectin-expressing fibroblastic cells in early rat stomach carcinogenesis and stomach tumors induced with N-methyl-N'-nitro-N-nitrosoguanidine.

The present study was designed to define molecular alterations in the initiation stage of rat stomach carcinogenesis. Groups of male Lewis rats, 6 weeks old, were given drinking water with or without N-methyl-N'-nitro-N-nitrosoguanidine (MNNG; 100 mg/liter). Total RNA was isolated from the stomach pyloric mucosa, and fluorescent differential display analysis was performed. A cDNA fragment of 125 bp encoding an extracellular matrix-associated matricellular glycoprotein, osteonectin, was identified after 14 days of MNNG exposure. A severalfold increase in expression was observed after 14 and 27 days of MNNG exposure, as determined by northern blot and RT-PCR. Immunohistochemistry revealed that osteonectin-mAb-stained fibroblastic cells appeared in interstitial tissue of pyloric mucosa. Additionally the gene expression of other extracellular matrix proteins, viz., collagen type III, fibronectin, osteopontin, proteoglycan NG2, laminin gamma1 and S-laminin, was also markedly increased, as determined by competitive RT-PCR after 14 days of MNNG exposure. The gene expression of osteonectin and the six other extracellular matrix proteins was elevated in twelve stomach adenocarcinomas and adenomas induced by MNNG in Lewis and WKY rats. Osteonectin-mAb-stained fibroblastic cells were evident in interstitial tissue of stomach tumor. These results suggest that osteonectin-expressing fibroblastic cells appear in the interstitial tissue of pyloric mucosa from the early initiation stage of rat stomach chemical carcinogenesis, and that this phenomenon probably plays a role in cancer development.

Animals↗