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Biomedical subjects

M Fukumoto

Publications and source records attributed to M Fukumoto.

At least 217 records · Page 12Linked to original sources
PubMed1989

Association of Ki-ras with amplified DNA sequences, detected in human ovarian carcinomas by a modified in-gel renaturation assay.

A modified in-gel DNA renaturation technique, which detects DNA sequences amplified greater than 7-fold in human DNA, was used to analyze gene amplification in surgical specimens of primary and metastatic ovarian carcinomas. Amplified DNA sequences were detected in two of eight tumors. Hybridization of these samples with different oncogene probes revealed that both tumors contained an amplified Ki-ras gene, which in one case was coamplified with c-myc. In one of the tumors, Ki-ras was found to be amplified in both the primary tumor and three different metastatic nodules. No mutations at codons 12 or 61 of Ki-ras were detected in these tumors. No additional cases of Ki-ras or c-myc amplification were detected by Southern hybridization in the tumors that were found to be amplification negative by modified in-gel renaturation assays. These results indicate that gene amplification in ovarian carcinomas is likely to involve the Ki-ras oncogene.

Base Sequence↗
PubMed1989

Phospholipases B from Japanese yellow hornet (Vespa xanthoptera) venom.

Two phospholipases B (Vx I and Vx II) were purified from the venom of the Japanese yellow hornet, Vespa xanthoptera, by sequential chromatography on Sephadex G-100, SP-Sephadex and Mono S columns. They are very similar to each other in molecular and enzymatic properties, though the specific activity of Vx I was one-fifth that of Vx II. They hydrolyze the acyl ester bonds at the 1-position of phosphatidylcholine and lysophosphatidylcholine, therefore, their enzymatic specificities were of the A1 and L1 types.

Amino Acids↗
PubMed1989

The interrelated effects of n-6/n-3 and polyunsaturated/saturated ratios of dietary fats on the regulation of lipid metabolism in rats.

The effects of various n-6/n-3 (0.45-9.31) and polyunsaturated/saturated (P/S; 0.25-6.08) ratios of dietary fatty acids on various lipid parameters were studied in rats using a combination of palm oil, safflower oil, soybean oil and perilla oil. When the n-6/n-3 ratio was changed while maintaining a constant P/S ratio (1.2), the concentration of serum cholesterol tended to increase linearly with the increasing n-6/n-3 ratio, whereas liver cholesterol tended to decrease. Serum triglyceride level increased linearly up to a n-6/n-3 ratio of approximately 5, whereas liver triglyceride was not influenced. When the n-6/n-3 ratio was kept relatively constant (5.6-6.4), serum and liver cholesterol levels decreased up to a P/S ratio of approximately 2, whereas serum triglyceride tended to be low below this value. The ratio of arachidonate to linoleate in tissue phosphatidylcholine (PC) was also influenced by the n-6/n-3 and P/S ratios; it increased up to a n-6/n-3 ratio of approximately 4, whereas it decreased up to a P/S ratio of approximately 2. The percentage of eicosapentaenoic and docosahexaenoic acid (n-3) in tissue phosphatidylcholine was positively related to dietary n-3 fatty acid levels. Prostacyclin (PGI2) production by thoracic aorta reached a plateau at a n-6/n-3 ratio approximately 5, whereas it tended to decrease with an increasing P/S ratio. Platelet production of thromboxane A2 exhibited a parabola-like pattern with a peak value at a n-6/n-3 ratio of approximately 2, whereas it was independent of the P/S ratio.(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue↗
PubMed1989

Human monoclonal antibodies against cytokeratin 18 generated from patients with gastric cancer.

By co-culturing regional lymph node B-cells and HAT-sensitive mutant cells obtained from RPMI-1788 cells, no less than 20,000 Epstein-Barr (EB)-transformed colonies were obtained from 32 patients with gastric cancer. From B-cell cultures generating antibodies reactive with gastric cancer tissues as well as cultured gastric cancer cells, two EB-transformed cell clones termed C418-59 and C1218-39 were isolated. Both of them produced human IgM-class antibodies, termed Mab418-59 and Mab1218-39, respectively. Both antibodies reacted with an antigen with a molecular weight of 45 kd existing in gastric cancer MKN-45, MKN-1, and Kato-III cells, and also with all of 4 adenocarcinomas of the stomach in paraffin sections. The antigen recognized by both antibodies was identified as a kind of cytoskeletal protein, cytokeratin 18. In this study, it was confirmed that B-cell clones generating autoantibodies against cytokeratin 18 were present in some patients with gastric cancer.

Adenocarcinoma↗
PubMed1989

[Histochemical study using lectin and anti-human von Willebrand factor antibody of oral hemangioma].

Twenty nine cases of oral hemangiomas composed of capillary hemangioma, cavernous hemangioma and pyogenic granuloma were examined with lectin histochemistry using ulex europaeus agglutinin I, ricinus communis agglutinin I, wheat germ agglutinin, concanavalin A, dolichos biflorus agglutinin, soybean agglutinin and peanut agglutinin, and immunohistochemistry using anti von Willebrand factor antibody in order to understand the nature of each endothelial cell. The following results were obtained; 1. UEA-I that specifically bound alpha-L-fucose was observed mainly in the endothelial cells of capillary hemangioma and hemangioma of granulation tissue type. 2. RCA-I which had specific affinity to beta-D-galactose was so identified in all endothelial cells of all type hemangiomas and normal blood vessels that it was supposed to be a useful marker of the cells. 3. WGA with specific affinity to N-acetyl-glucosamine was also found in various endothelial cells. 4. Con A which had specific affinity to alpha-D-mannose was not observed in various endothelial cells. 5. DBA, SBA and PNA that were specific bound up with N-acetyl-galactosamine were seen in the normal micro-vessels, especially in subepithelial regions. 6. Immunohistochemically, von Willbrand factor was identified chiefly in the endothelial cells of normal blood vessels and cavernous hemangioma, but it was not found in the cells of capillary hemangioma and pyogenic granuloma which had no differentiation in the functional point of view.

Antibodies↗
PubMed1989

Analysis of gene amplification in human tumor cells by in-gel DNA renaturation assay.

The incidence of gene amplification in leukemia/lymphoma is significantly lower than that in solid tumors. For understanding the biological characteristics of leukemia/lymphoma, it is necessary to clarify whether the incidence of gene amplification is actually lower or gene amplification specific to hemopoietic malignancies has not yet been found. We describe a new version of in-gel DNA renaturation technique for general screening of gene amplification that allows detection and cloning of amplified genes of unknown nature as few as 7- to 8-fold amplification.

DNA, Neoplasm↗
PubMed1988

Analysis of gene amplification in human tumor cell lines.

Oncogene amplification has been observed in various primary tumors and tumor-derived cell lines. In several types of cancer, amplification of specific oncogenes is correlated with the stage of tumor progression. To estimate the frequency of gene amplification in other tumor types and to determine whether the ability to grow in vivo is associated with gene amplification in tumor cell lines, we have developed a modified version of the in-gel renaturation assay that detects human DNA sequences of unknown nature amplified as little as 7- to 8-fold. This assay was used to screen 16 cell lines derived from various solid tumors and leukemias. Amplified DNA sequences were detected in only one cell line, Calu-3 lung adenocarcinoma. This cell line was found to contain coamplified NGL (formerly termed neu) and ERBA1 oncogenes. However, when one of the amplification-negative cell lines, PC-3 prostatic carcinoma, was selected for in vivo growth in nude mice, amplified DNA sequences became detectable in these cells. The amplified sequences included the MYC oncogene, which showed no amplification in the parental cell line but was amplified 10- to 12-fold in the in vivo-selected cells. MYC amplification may, therefore, provide tumor cells with a selective advantage specific for in vivo growth.

Cell Line↗
PubMed1988

Histologic study of homograft cartilages implanted in the middle ear.

We examined conditions of the micro-sliced homograft cartilages implanted in the middle ear, implanted cartilages removed at revision surgery or implanted cartilages removed at the second stage of staged tympanoplasty, both macroscopically and histologically. Macroscopically, the appearance and shape of the cartilages remained unchanged, with no evidence of erosion. There was no evidence of any foreign body reaction or rejection phenomenon. In general, no marked histologic changes of the matrix tissues were found, although chondrocytes showed degenerative changes. There was partial absorption of cartilage and replacement by fibrous connective tissue when inflammatory changes occurred in the middle ear. It is concluded that implanted homograft cartilage maintains its stiffness for more than 6 months in a healthy, aerated middle ear and appears to be clinically useful for tympanoplasty.

Cartilage↗
PubMed1986

Detection of amplified sequences in mammalian DNA by in-gel renaturation and SINE hybridization.

The presence of amplified sequences in mammalian DNA can be determined by in-gel renaturation of labeled restriction digests of total genomic DNA, provided that such sequences comprise at least 20-30 copies per haploid human or hamster genome or 40-50 copies per mouse genome. To detect amplified DNA in mouse cells at a lower level of amplification, a new procedure has been developed. This procedure combines in-gel DNA renaturation with Southern hybridization using a cloned probe containing a short interspersed repeated element (SINE). Using mouse cell lines containing amplified dihydrofolate reductase (DHFR) or c-Ki-ras genes as a model system, and the cloned B2 repeated sequence as a SINE probe, we have shown that this technique can detect gene amplification at a level as low as 10-15 copies of amplified DNA per haploid mouse genome. In-gel renaturation-SINE hybridization was used to assay for DNA amplification in different tissues and in different mouse strains. No tissue-specific DNA amplification has been detected, but comparison of B2-containing repeated fragments between three inbred mouse lines revealed strain-specific polymorphism.

Animals↗
PubMed1986

Effects of flavonoids on xanthine oxidation as well as on cytochrome c reduction by milk xanthine oxidase.

That flavonoids inhibit xanthine oxidase from cow milk was confirmed by measuring oxygen consumption with an oxygen electrode. In contrast, flavonoids did not inhibit glucose oxidase, another oxygen consuming enzyme. Among the flavonoids tested, quercetin, kaempferol, myricetin, chrysin, quercitrin, and morin were potent inhibitors of xanthine oxidase; their inhibition rates (%) were 80, 70, 69, 62, 59, and 51 at 100 microM (except chrysin at 50 microM), respectively. The xanthine oxidase-inhibiting activities of the flavonoids were not always well correlated with the suppressive activities of the flavonoids on cytochrome c reduction by a xanthine-xanthine oxidase system. The inhibition of xanthine oxidase by quercetin was not affected by cupric ion. The partition rates of the flavonoids between n-butanol and a buffer solution seemed to account for some of the inhibition.

Animals↗
PubMed1986

[Effect of PGF2 alpha on ovulation and collagenolytic activities in the rabbit treated by indomethacin].

To clarify a regulatory role of prostaglandins in collagenolytic enzyme activities of the follicular wall at ovulation, we studied whether the ovulation-blocking effect of indomethacin (IM) on hCG-stimulated rabbits could be reversed by an intravenous infusion of PGF2 alpha. The activities of BANA hydrolase and DNP peptidase were also measured by using synthetic substrates N-benzoyl-DL-arginine-2-naphthylamide HCl (BANA) and DNP-Pro-Gln-Gly-Ile-Ala-Gly-Gln-D-Arg-OH (DNP peptide), respectively, every hour during the specific preovulatory period. The ovulation-blocking effect of IM (4mg/kg) was reversed by an intravenous infusion of PGF2 alpha (1.5 mg/kg) starting at 3 hr after the hCG injection. In the control rabbits treated with hCG(100 iu) alone, these enzymatic activities were increased toward ovulation with the peak level 7-9 hr after a hCG injection and decreased significantly at 10 hr. The preovulatory increase in these enzymatic activities disappeared following the ovulation-blocking doses of indomethacin. By the addition of the PGF2 alpha infusion, the IM-induced changes in BANA hydrolase and DNP peptidase activities were returned close to the control. It is suggested that the preovulatory increases in BANA hydrolase and DNP peptidase are mandatory for ovulation and PGF2 alpha facilitates ovulation through its regulatory action on these enzymes.

Aminopeptidases↗