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Biomedical subjects

S Yanase

Publications and source records attributed to S Yanase.

At least 19 recordsLinked to original sources

A case of thrombosis mimicking a buccal tumour: usefulness of MRI.

A rare case of thrombosis mimicking a tumour in the buccal region is reported. Since the entire round mass was located deeply, it was difficult to diagnose. Contrast computed tomography, magnetic resonance imaging (MRI) and ultrasound examinations may be useful, but MRI was most useful in this case because it allowed prediction of different kinds of histological structures in the soft tissue. The findings of T1 weighted imaging, T2 weighted imaging and examination with Gd-DTPA on T1 weighted imaging are useful for predicting the character of deeper soft tissue masses, and can differentiate thrombosis from lymphadenopathy, lipoma and other lesions.

Aged↗

Expression of glucose transporter 4 mRNA in adipose tissue and skeletal muscle of ovariectomized rats treated with sex steroid hormones.

The effects of 17beta-estradiol (E) and/or progesterone (P) on glucose transporter 4 (GLUT4) expression in the adipose tissue and skeletal muscle of ovariectomized female rats were studied. The Sprague-Dawley rats received daily subcutaneous injections of various doses of E and/or P for 7 days (n=5-6 per dose). The expression of GLUT4 mRNA was assessed by performing ribonuclease protection assays. GLUT4 protein levels were assessed by Western blotting assays. The adipose tissue levels of GLUT4 mRNA were reduced by the administration of 50 microg E, which resulted in unphysiologically high serum E concentrations. Although the GLUT4 mRNA levels did not change after the administration of 10 microg E or 5 mg P, they were reduced significantly to approximately half the control group level by the administration of both hormones (p <0.01). The skeletal muscle GLUT4 mRNA levels were not changed significantly by hormone treatment. These findings suggest that E and P may be involved in the regulation of GLUT4 mRNA expression in adipose tissue.

Adipose Tissue↗

Oxidative stress pretreatment increases the X-radiation resistance of the nematode Caenorhabditis elegans.

Pre-exposure of wild-type Caenorhabditis elegans to oxygen conferred a protective effect against the lethality imposed by subsequent X-irradiation. In contrast, two mutants (rad-1 and rad-2) that are UV and ionizing radiation hypersensitive but not oxygen sensitive, did not exhibit this adaptive response. To explore the molecular basis of protection, the expression of several key genes was examined using Northern blot analyses to measure mRNA levels. In the wild-type, expression of the heat shock protein genes, hsp16-1 and hsp16-48, increased dramatically after incubation under high oxygen. Expression of two superoxide dismutase genes (sod-1 and sod-3) was relatively unaffected. Unlike the wild-type, the basal levels of these four genes were significantly lower in the rad-1 and rad-2 mutants under atmospheric conditions. These genes were partially induced in response to oxidative stress. These data suggest that at least a portion of the hypersensitive phenotype of rad-1 and rad-2 may be attributed to inappropriate gene expression.

Adaptation, Physiological↗

Glucose transporter 4 (GLUT4) mRNA abundance in the adipose tissue and skeletal-muscle tissue of ovariectomized rats treated with 17 beta-estradiol or progesterone.

OBJECTIVE: To investigate the effects of 17 beta-estradiol and progesterone on the expression of glucose transporter 4 (GLUT4) in the adipose tissue and skeletal-muscle tissue of ovariectomized rats. METHODS: Female Sprague-Dawley rats (n = 63) received a daily subcutaneous injection of 10 micrograms, 50 micrograms, or 250 micrograms of 17 beta-estradiol (Group E) or of 1 mg, 5 mg or 25 mg of progesterone (Group P) for 3 days, 7 days, or 10 days (n = 3, at each dose). The expression of GLUT4 mRNA was assessed by performing ribonuclease protection assays. RESULTS: The levels of GLUT4 mRNA in adipose tissue was significantly reduced by treatment with estradiol, 50 micrograms or 250 micrograms, relative to findings in control rats (p < 0.01). No such reductions were seen regarding the progesterone treatment. The level of GLUT4 mRNA in skeletal-muscle tissue did not change, regardless of treatment. CONCLUSION: In ovariectomized rats, higher than physiologic dosages of 17 beta-estradiol can suppress the expression of GLUT4 mRNA in adipose tissue.

Adipose Tissue↗

Cloning of the oxidative stress-responsive genes in Caenorhabditis elegans.

Defense systems against free radicals and reactive oxygen species minimize the lethal and mutagenic consequences of these destructive agents. To investigate the genetic response to oxidative stress in a eukaryote, we cloned and characterized oxidative stress-responsive genes by comparing gene expression in the free-living nematode Caenorhabditis elegans under atmospheric conditions and high oxygen concentrations using a method of RNA arbitrarily primed polymerase chain reaction method (RAP-PCR). We identified four genes whose expression levels increase under high oxygen. These encoded 18 s, 5.8 s and 26 s rRNAs, 16 kDa heat shock proteins (hsp16-1 and 16-48) and a vacuolar ATPase G subunit. In addition, we also established that oxi-1, an oxidative stress-responsive gene we previously cloned, encodes a family of proteins related to human E6-AP ubiquitin-protein ligase. The similarity between human and nematode was 54% in one conserved amino acid region.

Amino Acid Sequence↗

A mutation in succinate dehydrogenase cytochrome b causes oxidative stress and ageing in nematodes.

Much attention has focused on the aetiology of oxidative damage in cellular and organismal ageing. Especially toxic are the reactive oxygen byproducts of respiration and other biological processes. A mev-1(kn1) mutant of Caenorhabditis elegans has been found to be hypersensitive to raised oxygen concentrations. Unlike the wild type, its lifespan decreases dramatically as oxygen concentrations are increased from 1 to 60%. Strains bearing this mutation accumulate markers of ageing (such as fluorescent materials and protein carbonyls) faster than the wild type. We show here that mev-1 encodes a subunit of the enzyme succinate dehydrogenase cytochrome b, which is a component of complex II of the mitochondrial electron transport chain. We found that the ability of complex II to catalyse electron transport from succinate to ubiquinone is compromised in mev-1 animals. This may cause an indirect increase in superoxide levels, which in turn leads to oxygen hypersensitivity and premature ageing. Our results indicate that mev-1 governs the rate of ageing by modulating the cellular response to oxidative stress.

Aging↗

Hexokinase II activity and messenger ribonucleic acid abundance in adipose tissue and skeletal muscle during pregnancy and lactation in rats.

OBJECTIVE: Our purpose was to investigate the influence of pregnancy and lactation on hexokinase II activity and gene expression in adipose tissue and skeletal muscle of rats. STUDY DESIGN: Intraabdominal adipose tissue and femoral quadriceps muscle were removed from Sprague-Dawley rats at various times (6 to 10 animals per group) during pregnancy and lactation. Hexokinase II messenger ribonucleic acid was assayed by quantitative ribonuclease protection analysis, and hexokinase activity was measured with the glucose-6-phosphate-coupled assay. RESULTS: The amount of hexokinase II messenger ribonucleic acid in adipose tissue on day 20 of pregnancy was 55.4% +/- 8.4% (p < 0.01, unpaired Student t test) of the value for nonpregnant control rats; hexokinase II activity was also decreased in this tissue at this time (39.34 +/- 3.05 vs 27.81 +/- 3.61 mU x min(-1) x mg protein(-1), p < 0.05). Hexokinase II activity and messenger ribonucleic acid abundance in skeletal muscle were unaffected by pregnancy and lactation. CONCLUSION: Both hexokinase II messenger ribonucleic acid abundance and enzyme activity are reduced in adipose tissue of pregnant rats near term, possibly contributing to the insulin resistance associated with late pregnancy.

Adipose Tissue↗

[A report on the hygienic status of sacred "temizu" water in shrines].

The quality of the sacred "temizu" water in shrines in Kyoto was surveyed. It was found that the sources of "temizu" were the municipal water supply or domestic wells and that the "temizu" was usually used for washing the hands and mouth, while in certain shrines it was drunk as well. Of 50 visitors responding to questions, 26 persons said that they drank "temizu". In some shrines using the municipal water supply as "temizu", the free residual chlorine concentration was lower than that in the municipal water supply itself. Contamination of "temizu" by Escherichia coli or Aeromonas hydrophila was observed in some shrines.

Hand Disinfection↗

[Histological study on localized scleroderma].

To define stage-specific and type-specific histological findings in morphea, 21 (14 plaque, 2 linear, and 5 en coup de sabre type) patients were examined. A) Fibrotic changes; 1) Every case had the fibrotic change of various degrees. 2) Nodular sclerotic fibrosis was found in 7 cases with morphea, namely in 5 of 11 cases with a plaque type and 2 of 4 en coup de sabre type morphea. And the above mentioned 7 cases were within two years since the onset, and no nodular fibrosis was found in the morphea with the longer duration than two years in history. Nodular fibrosis was located in the middle or lower dermis adjacent to the typical sclerotic dermis. It was strongly suggested that this nodular fibrosis is as an initial change of localized scleroderma. 3) Nodular fibrosis expanded to the neighboring area and made a typical histological feature of morphea which is completely different from that of diffuse scleroderma. B) Inflammatory findings; 1) Inflammatory changes were divided into, a perivascular, a diffuse or non-perivascular, and a mixed type. 2) The pure perivascular type was found in 10, the pure diffuse type only in one, the mixed type in 6 cases, and the other 4 cases had no inflammation. 3) Marked or moderate inflammation was found in cases with short history of the disease except for one case. 4) Inflammatory cells in the morphea were mainly composed of lymphocytes and histiocytes, but occasionally of plasma cells in 11 of 17 cases. C) Pigmentary changes; Incontinentia pigmenti was found in 18 of 21 cases.

Adolescent↗

Inhibition of chemical Epstein-Barr virus induction by dimethyl sulfoxide and related polar compounds.

Dimethyl sulfoxide and twelve related polar compounds, capable of inducing differentiation of murine erythroleukemia cells, markedly inhibited induction of Epstein-Barr virus antigens in virus producer and nonproducer lymphoblastoid cells exposed to 12-O-tetradecanoylphorbol-13-acetate, n-butyric acid, 5-iodo-2'-deoxyuridine, and a combination of 12-O-tetradecanoylphorbol-13-acetate and n-butyric acid. The concentration at which these compounds caused 90% inhibition of antigen induction corresponded to that optimal for induction of differentiation. At the same concentrations, polar compounds did not affect cell viability or virus induction by superinfection with Epstein-Barr virus recovered from P3HR-1 cells. The inhibitory activity was reversible. Three nonpolar differentiating compounds revealed no inhibitory activity.

Acetamides↗

Heat durability of Epstein-Barr virus-activating substances of plant origin: 12-O-tetradecanoylphorbol-13-acetate, 12-O-hexadecanoyl-16-hydrophorbol-13-acetate, croton oil, tung oil and Croton megalocarpus extract.

12-O-Tetradecanoyl-phorbol-13-acetate (TPA), 12-O-hexadecanoyl-16-hydrophorbol-13-acetate (HHPA), croton oil, tung oil and Croton megalocarpus ether extract, all of which are known to possess Epstein-Barr virus-activating potency, retained their capacity to induce Epstein-Barr virus early antigen complex in the viral genome-carrying human lymphoblastoid cells (Raji) even after heat treatment at 120 degrees C for 2 h or at 100 degrees C for 12 h. Such unusual heat resistance of the agents tested may contribute to the persistence and accumulation of the active principle(s) in soil under the plants which contain such substances, as we have previously reported.

Antigens, Viral↗