Biomedical subjects

M Furusawa

Publications and source records attributed to M Furusawa.

At least 37 records · Page 2Linked to original sources

PubMed1997

Post-column enzyme reactors for chemiluminometric detection of glucose, 1,5-anhydroglucitol and 3-hydroxybutyrate in an anion-exchange chromatographic system.

A liquid chromatographic system consisting of a co-immobilized 3-hydroxybutyrate dehydrogenase-NADH oxidase reactor and an immobilized pyranose oxidase reactor in series and a chemiluminometer was developed for the simultaneous determination of glucose, 1,5-anhydroglucitol and 3-hydroxybutyrate in plasma. The enzymes were immobilized on toresylated poly(vinyl alcohol) beads. Separation was achieved on a TSK gel SAX column (40 x 4 mm I.D.) with an eluent of 50 mM NaOH containing 30 mM sodium butyrate. The hydrogen peroxide produced was detected by measuring the chemiluminescence emitted on admixing with luminol and potassium hexacyanoferrate(III). The calibration curves were linear from 0.8 to 500 microM (7 ng-4 micrograms) for glucose, from 0.8 to 400 microM (7 ng-3 micrograms) for 1,5-anhydroglucitol and from 1 to 700 microM (5 ng-4 micrograms in a 50-microliter injection) for 3-hydroxybutyrate. The sample throughput was four per hour. The reactors were stable for at least ten days.

3-Hydroxybutyric Acid↗

PubMed1997

Insulin stimulates production of glycoconjugate layers on the cell surface of gastric surface mucous cell line GSM06.

The mechanism of regulation of mucus production in the gastric mucosa remains unclear. Recently, we established a gastric surface mucous cell line GSM06, which produces periodic acid-Shiff (PAS)-positive glycoconjugate (mucus) layers on the cell surface, from transgenic mice harboring a temperature-sensitive simian virus 40 large T-antigen gene. In this study, GSM06 cells were examined for its production of PAS-positive glycoconjugate layers to acid secretagogues and growth factors. The cells were cultured at nonpermissive temperature (39 degrees C) for 3-18 days and stained with PAS. Insulin (1-30 microg/ml; 0.29-8.6 microM) time- and dose-dependently increased production of glycoconjugates on the cell surface. When glycoconjugate layers produced by stimulation of insulin (3-30 microg/ml; 0.86-8.6 microM) were removed from the cell surface of GSM06 cells by a mild trypsin treatment, PAS-positive materials were remarkably decreased (day 18). In addition, morphological findings indicate that a high concentration of insulin (30 microg/ml; 8.6 microM) produced thick PAS-positive glycoconjugate layers just like normal gastric surface mucosa on the cell surface on day 18. In contrast, histamine (0.1-100 microM), carbachol (0.1-100 microM), gastrin-17 (0.1-100 nM), epidermal growth factor (0.01-10 ng/ ml; 1.7-1,700 pM), transforming growth factor-alpha (0.01-10 ng/ml; 1.8-1,800 pM), and fetal bovine serum (1-10%) did not increase glycoconjugate production. These findings suggest that insulin is a stimulator of glycoconjugate production, and stimulates production of glycoconjugate layers on the cell surface in the gastric surface mucous cell line GSM06.

Animals↗

PubMed1997

CT and MR findings of denervated tongue after radical neck dissection.

PURPOSE: To describe the CT and MR findings in the denervated tongue after a radical neck dissection. METHODS: We retrospectively evaluated the radiologic findings in seven patients who had hypoglossal paralysis following radical neck dissection. None of the patients had clinical or radiologic evidence of tumor recurrence. RESULTS: The side of the tongue operated on showed low density on CT scans. At MR imaging, denervated tongues were clearly seen as hyperintense relative to muscle on T2-weighted images; on T1-weighted images, the signal was hypointense to hyperintense, representing increased extracellular water or fatty degeneration. CONCLUSION: In patients who have undergone a neck dissection for a malignant process, abnormal imaging findings in the tongue not only might indicate a recurrence of tumor involving the hypoglossal nerve but also suggest the possibility of postoperative change. Our findings emphasize the importance of the denervated tongue in differentiating inflammatory from neoplastic diseases of the the tongue.

Adult↗

PubMed1996

Preferential replication-dependent mutagenesis in the lagging DNA strand in Escherichia coli.

The mutation frequencies attributable to -1 frameshift or one-base substitution in the structural genes coding for resistance to chloramphenicol (Cm) and tetracycline (Tc) were followed over several cycles of DNA replication, and found to differ several-fold, depending on the orientation of the gene on the plasmid with respect to the direction of (unidirectional ColE1-type) replication. The mutation frequency was higher when the reporter gene was present in the plasmid in the same orientation as the direction of the origin, i.e., when the transcription template is the lagging daughter strand, than when the gene was inserted in the opposite orientation. This significant difference in reversion frequencies of genes with different polarities was demonstrated only for a brief period of cell growth (several cycles of replication) after induction of the dnaQ49 mutator, but was not observed when an increased number of replication cycles, was permitted, most probably due to fixation of the mutation into both strands. The mutated intermediate DNA which possesses a misaligned basepair in the Cm gene was demonstrated to be replicated into two progeny DNA molecules; one is the chloramphenicol-resistant (CmR) DNA synthesized from the template strand having the mutation and the other is the CmS DNA from the template strand without mutation. Our results suggest that replication-dependent mutagenesis may occur preferentially in the lagging strand.

Bacteriocin Plasmids↗

PubMed1996

Postcolumn co-immobilized leucine dehydrogenase-NADH oxidase reactor for the determination of branched-chain amino acids by high-performance liquid chromatography with chemiluminescence detection.

A liquid chromatographic system with a co-immobilized leucine dehydrogenase-NADH oxidase reactor is described for the determination of branched-chain amino acids such as I-leucine, I-isoleucine and I-valine. The enzymes were simultaneously immobilized on tresylate-containing poly(vinyl alcohol) beads. The separation was achieved by means of an ODS column with elution with phosphate buffer (pH 7.5). The hydrogen peroxide produced was detected chemiluminometrically via a luminol-hexacyanoferrate(III) reaction. The system gave a linear response from 0.3 to 300 mu M for each amino acid and the detection limit was 0.1 mu M.

Amino Acid Oxidoreductases↗

PubMed1996

Chondrocytes synthesize type I collagen and accumulate the protein in the matrix during development of rat tibial articular cartilage.

The present study was designed to investigate whether or not chondrocytes in articular cartilage express type I collagen in vivo under physiological conditions. Expressions of the gene and the phenotype of type I collagen were examined in rat tibial articular cartilage in the knee joint during development. Knee joints of Wistar rats at 1, 5, and 11 weeks postnatal were fixed in 4% paraformaldehyde with or without 0.5% glutaraldehyde and decalcified in 10% EDTA. After the specimens were embedded in paraffin and serial sections made, adjacent sections were processed for immunohistochemistry and in situ hybridization for type I collagen. The epiphysis of the tibia was composed of cartilage in week- 1 rats. Formation of articular cartilage was in progress in week 5 as endochondral ossification proceeded and was completed in week 11. Anti-type I collagen antibody stained only the superficial area of the epiphysis in week 1, but the immunoreactivity was expanded into the deeper region of the articular cartilage with development in weeks 5 and 11. Hybridization signals for pro-alpha 1 (I) collagen were seen in some of chondrocytes in the epiphysis of the week-1 tibia. The most intense signals were identified in chondrocytes in week 5 and the signals appeared weaker in week 11. The present study demonstrated that chondrocytes synthesize type I collagen and accumulate the protein in the matrix during development of the articular cartilage.

Age Factors↗

PubMed1996

A clinicopathological study of asymptomatic gastric cancer.

The clinicopathological profiles of 419 patients with asymptomatic gastric cancer (AGC) first detected by gastric screening, were reviewed and compared with those of the 1727 patients with symptomatic gastric cancer (SGC). The incidence of AGC increased gradually and has amounted to 30% of the total resected cases in recent years. About 75% of AGC cases were of early cancer and 84% were negative for lymph node metastases. In contrast, only 33% of SGC cases were of early cancer and 57% were node positive. Curative resection was done in 97% of AGC and 75% of SGC. The cumulative 5 and 10 year survival rates of patients with curatively resected AGC were 85.2% and 72.2%, respectively, while those for patients with SGC were 66.8% and 55.4%. These data demonstrated that most patients with asymptomatic gastric cancers could expect a curative resection, i.e. have a better clinical outcome, than those with symptomatic cancer.

Adult↗

PubMed1996

Specific arrest of spermatogenesis caused by apoptotic cell death in transgenic mice.

BACKGROUND: The c-myc protooncogene has been implicated in the control of cell proliferation, differentiation and/or apoptosis in various cellular systems. However, the role of c-myc in germ cell lineage is largely unknown. RESULTS: We have produced transgenic mouse lines carrying the rat c-myc protooncogene under the control of human metallothionein promoter (hMT-c-myc). It was found that the male transgenic mice were sterile. In contrast, all of the female transgenic mice were completely fertile and transmitted the transgene to the next generation. However, male transgenic mice from the female transgenic founders were also found to be sterile. This sterility was due to a defect in spermatogenic cell differentiation, since virtually no sperm were seen within the seminiferous tubules or the cauda epididymis. Histological examination revealed that germ cell death occurred approximately 7 days after birth and, consequently, spermatogenesis was arrested at an early stage in meiotic division in the transgenic mice. Moreover, this germ cell death was found to be caused by apoptosis. CONCLUSION: We conclude that an excess level of c-myc expression in differentiating spermatogenic cells is responsible for the apoptotic death of germ cell, and that a decrease in c-myc level would be an obligatory step for the completion of normal spermatogenesis.

Animals↗

PubMed1996

Biological characterization of gastric surface mucous cell line GSM06 from transgenic mice harboring temperature-sensitive simian virus 40 large T-antigen gene.

We investigated the biological features of gastric surface mucous cell line GSM06, established from transgenic mice harboring the temperature-sensitive simian virus 40 large T-antigen gene. GSM06 cells grew until confluent monolayers were formed at the permissive temperature (33 degrees C), showing that the cessation of cell growth may be due to contact inhibition. Moreover, the cells did not grow in a soft agar gel. However, chromosome numbers of the cells were not normal. When GSM06 cells were cultured in Daigo's T medium supplemented with growth factors and 10% fetal bovine serum at 33 degrees C for 1, 3 or 9 days, the cells gradually grew to confluent monolayers (day 9). Morphological observations revealed that the cells time-dependently formed microvilli-like structures and yielded periodic acid-Schiff-positive glycoproteins on the cell surface with the growth of the structures. When GSM06 cells were cultured on a membrane filter for 1-9 days, elevated transepithelial resistance was noted in a culture period-dependent fashion. On day 9, junctional complexes such as tight junctions and desmosomes were observed between the cells. In addition, prostaglandin E2 production was evoked from the cells from day 1. In order to determine cell viability, GSM06 cells were labeled with the fluorescence dye 2',7'-bis(carboxyethyl)-carboxyfluorescein. Exposure of GSM06 cells to ethanol (7.5-17.5%) elicited cell injuries in a concentration-related manner on day 1, whereas these cytotoxic effects were attenuated on days 3 and 9, suggesting that this protection may be, at least in part, related to the increased glycoproteins and transepithelial resistance. GSM06 cells possessing these unique characteristics should be highly useful as an in vitro model of gastric epithelium.

Animals↗

PubMed1996

Lingual carcinoma. Correlation of MR imaging with histopathological findings.

PURPOSE: To determine the utility of MR imaging in the evaluation of lingual carcinomas. MATERIAL AND METHODS: Eleven patients with lingual carcinoma were evaluated with MR imaging including dynamic study within one week before surgery. Nine patients underwent preoperative chemotherapy or irradiation, and 2 patients had no preoperative treatment. Delineation of the tumor, the contrast between tumor and surrounding tissue, and extent of the tumor were evaluated in a blinded manner. After glossectomy, MR images were correlated with pathological findings. Statistical analysis was performed on the visual assessment ratings. RESULTS: Blinded evaluation suggested that dynamic and T2-weighted images (T2WI) were significantly superior to postcontrast T1WI in demonstrating the lesion. There were no significant differences between dynamic MR images and T2WIs. However, histopathological correlation showed that in patients with preoperative treatment, dynamic MR imaging demonstrated more accurately the size and extent of the residual tumor than did T2WI and postcontrast T1WI, which tended to demonstrate an area of signal abnormality that was more extensive than the true size of the residual lesion. In patients without preoperative treatment, dynamic MR imaging, T2WI, and postcontrast T1WI gave an equivalent depiction of the extent of the carcinoma. CONCLUSION: In patients with no preoperative treatment, dynamic MR imaging does not appear to offer any advantage over T2WI. However, in patients with preoperative treatment, dynamic MR imaging provides a more accurate assessment of the residual tumor than do T2WI and postcontrast T1WI.

Aged↗

PubMed1996

Short communication: the value of embolization therapy in painful osseous metastases from hepatocellular carcinomas; comparative study with radiation therapy.

We evaluated the therapeutic effect of transcatheter arterial embolization therapy (TAE) for painful osseous metastases from hepatocellular carcinoma (HCC) in comparison with radiation therapy (RT). TAE using gelatin sponge particles was performed for seven lesions in seven patients. Selective catheterization and embolization were successfully performed in all lesions. Within 10 days after TAE, complete pain relief (CR), partial relief (PR) and no relief (NR) were attained in 57%, 29% and 14%, respectively. RT was used to treat 34 lesions in 22 patients. The dose fractionation schedules were in the range 28.0-50.4 Gy, with 1.8-4.0 Gy per fraction. CR, PR and NR were attained in 47%, 47% and 6%, respectively. There were no serious complications related to these treatments. Both TAE and RT are effective and the treatment of choice should be selected on an individual basis.

Bone Neoplasms↗

PubMed1995

Ebselen, a seleno-organic compound, protects against ethanol-induced murine gastric mucosal injury in both in vivo and in vitro systems.

The inhibitory effect of the seleno-organic compound ebselen on ethanol-induced murine gastric mucosal injury was examined. In an in vivo study, absolute ethanol (50 microliters/mouse, oral) produced marked gastric mucosal necrosis along with hemorrhage or edema and elevations in both lipid peroxide and peptidoleukotriene levels in the fundic mucosa. Pretreatment with ebselen (30 and 100 mg/kg, oral) significantly prevented this gastric mucosal injury and, further, remarkably decreased the elevated lipid peroxide and peptidoleukotriene levels. In an in vitro study using a murine gastric surface mucous cell line GSM06, exposure to ethanol concentration dependently elicited cell damage (7.5-17.5% ethanol) and an increase in lipid peroxides without alterations in peptidoleukotrienes (15% ethanol). Addition of ebselen (10 and 100 microM) to this system (15% ethanol) significantly inhibited the cell damage and completely prevented the increase in lipid peroxide level. These results indicate that ebselen protects against murine gastric mucosal injury both in vivo and in vitro, and that this protection may be related at least in part to its inhibitory action on lipid peroxides.

Animals↗

PubMed1995

Correlation between sialyl Tn antigen and lymphatic metastasis in patients with Borrmann type IV gastric carcinoma.

The expression of sialyl Tn (STn) antigen in 180 patients with Borrmann type IV gastric carcinomas was examined immunohistochemically. The rate of positive STn staining was 32% (57/180) for the primary tumours, and this positive staining correlated well with tumour extension, lymph node metastasis (P < 0.05) and peritoneal dissemination (P < 0.01). One-third (5/15) of patients with positive STn-staining cancer cells had a high level of serum STn. Lesions with positive STn staining were related to a lower survival rate for the patients (P < 0.05). Proliferative activity of the tumour, as measured by proliferating nuclear antigen (PCNA) labelling percentage and argyrophilic nucleolar organiser region (AgNOR) count, was significantly higher (41.5 +/- 13.0%, 3.78 +/- 0.98) in the STn-positive group than in the STn-negative group (34.2 +/- 13.2%, 3.48 +/- 0.85) (P < 0.01, P < 0.05 respectively). Estimating STn antigen may be useful for predicting the likelihood of lymph node metastasis or peritoneal dissemination and the clinical prognosis for patients with Borrmann type IV gastric carcinoma.

Adult↗

PubMed1995

[Analysis of DNA content in primary colorectal carcinoma and lung metastasis].

We analyzed DNA content of resected primary colorectal carcinoma and lung metastasis by flow cytometry. Of the 14 primary lesions, 5 cases showed diploid pattern, 9 cases aneuploid pattern. In contrast, 12 metastatic lung lesions of 19 showed diploid pattern and 7 lesions aneuploid pattern. DNA index of primary and metastatic lesions was 1.4 +/- 0.4 and 1.2 +/- 0.2, respectively (p = 0.08). In combination of DNA ploidy pattern between primary and metastatic lesions, there were 11 in which ploidy pattern was identical, 1 in which metastasis was aneuploid and primary was diploid, 7 in which metastasis was diploid and primary was aneuploid. Four year, survival rate from operation of metastasis was better in diploid pattern than in aneuploid pattern, but it was not significant. These results indicate that patients who have operative indication of metastasis from colorectal carcinoma have metastatic tumor which shows relatively good biological behavior (diploid tumors) and that there are heterogeneity of ploidy pattern between primary and metastatic lesions.

Adult↗

PubMed1995

Structure of translation initiation region of c-myc mRNA and thermostability of the c-myc mRNA/antisense ODN complex.

We enzymatically synthesized c-myc mRNA fragment containing the translation initiation (TI) region (36mer) and examined the structure by CD, 1H-NMR and RNaseV1 digestion. These study demonstrated that the c-myc mRNA fragment forms a hairpin structure at 37 degrees C. Six 15-mer antisense oligodeoxynucleotides(ODNs), which hybridize to the c-myc mRNA fragment were designed, and synhesized. Thermostabilities of the antisense ODNs-mRNA fragment complexes were examined. Antisense A (complementary to the c-myc mRNA from -9 to +6)-c-myc mRNA fragment complex had the highest melting temperature(Tm), and Antisense D (complementary to the c-myc mRNA from +1 to +15)-c-myc mRNA fragment complex had the most different Tm from a predicted Tm. Furthermore, Antisense D exhibited high inhibitory effect on HL60 cell proliferation, whereas Antisense A did not. The results suggest that the difference in the antisense effect is not simply due to the complex thermostability.

Cell Line↗

PubMed1994

Isolation of a DEAD-family protein gene that encodes a murine homolog of Drosophila vasa and its specific expression in germ cell lineage.

In an effort to study the molecular basis of the determination processes of the mammalian germ cell lineage, we have tried to isolate a mouse gene homolog to vasa, which plays an essential role as a maternal determining factor for the formation of Drosophila germ cell precursors. By reverse transcriptase PCRs of mouse primordial germ cell cDNAs using family-specific primers, we obtained a gene (Mvh) encoding a DEAD-family protein that showed a much higher degree of similarity with the product of the Drosophila vasa gene (vas) than previously reported mouse genes. In adult tissues, Mvh transcripts were exclusively detected in testicular germ cells, in which Mvh protein was found to be localized in cytoplasm of spermatocytes and round spermatids including a perinuclear granule. The protein was also expressed in germ cells colonized in embryonic gonads but was not detected in pluripotential embryonic cells such as stem cells and germ cells. These results suggest the possibility that the Mvh protein may play an important role in the determination events of mouse germ cells as in the case of Drosophila vasa.

Amino Acid Sequence↗

PubMed1994

The multicentric occurrence of squamous epithelial dysplasia and squamous cell carcinoma in the esophagus.

BACKGROUND: The biologic significance of esophageal dysplasia has not yet been completely elucidated, especially regarding the process of multiple occurrences of squamous cell carcinoma. METHODS: The multiplicity of dysplasia in 73 patients with solitary carcinoma of the esophagus (Group I) and 21 with multiple carcinomas (Group II) was compared in surgically resected specimens. RESULTS: Thirty-nine second carcinomas were identified in 13 patients of Group II, and all were superficial. The incidences of five or more isolated dysplasias in cases without continuity to a carcinomatous lesion, was 6.8% and 66.7% in Groups I and II, respectively (P < 0.01). In a case with three or more carcinomas, the incidence increased to 84.6%. The coexistence of all grades of isolated dysplasias was observed in 10 patients (47.6%) in Group II but in only 6 patients (8.2%) in Group I (P < 0.01). CONCLUSIONS: These findings suggest that various degrees of evolving biologically related lesions, such as dysplasia and carcinoma, can occur multicentrically in the same esophagus.

Carcinoma in Situ↗

PubMed1994

Multiple occurrence of carcinoma in the upper aerodigestive tract associated with esophageal cancer: reference to smoking, drinking and family history.

Smoking and drinking habits as well as family history were examined in 143 men with esophageal cancer, including 30 who had associated second cancers of the upper aerodigestive tract (UADT) and 113 who did not. The risk of second cancers of UADT associated with the main lesions of the esophagus was evaluated, using odds ratios (ORs). As a result, the ORs of second cancers for current smoking and drinking were 5.3 and 7.6 respectively. The ORs significantly increased to 12.7 and 14.7 in heavy smokers and in heavy drinkers respectively. Furthermore, the risk of second cancer also significantly increased (8-fold) in patients who had close relatives with UADT cancer, compared to those without family history of any cancer. However, there were no differences in smoking or drinking habits regardless of family history. Our data thus suggest that a family history of UADT cancer as well as heavy smoking and drinking are clearly associated with multiple occurrence of UADT cancer. Therefore, careful and frequent examination for appearance of any second lesions are required for patients in these high-risk groups.

Aged↗