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Biomedical subjects

I Takano

Publications and source records attributed to I Takano.

At least 19 recordsLinked to original sources
PubMed2001

[Survey of pesticide residues in baby foods (1996.4-1998.6)].

Between April 1996 to June 1998, 133 samples of 9 food commodities were analyzed for pesticide residues. In 8 samples of 5 commodities, 5 kinds of pesticides residues were detected. The baby foods in which the pesticides were detected were produced from vegetables and fruits. In our investigations, pesticide residues have been frequently detected in the raw materials. For the baby foods containing pesticides, intake amounts of the pesticides calculated from the daily feeding volume and the ADI were compared. Residual pesticide levels in baby food commodities are low, and it was concluded that they are not likely to present any problem in normal usage.

Humans↗
PubMed1999

Suppressive effects of Hochu-ekki-to, a traditional Chinese medicine, on IgE production and histamine release in mice immunized with ovalbumin.

We examined the effects of Bu-Zhong-Yi-Qi-Tang (Japanese name: Hochu-ekki-to, HET), a traditional Chinese medicine, on IgE production and histamine release in mice immunized intraperitoneally with a mixture of ovalbumin (OA) and aluminum hydroxide (alum adjuvant). Three groups of mice were orally administered 0, 1.7 or 17 mg of HET on day 13 after the first immunization with a mixture of 1 microg OA and 1 mg alum adjuvant. They were again immunized with the same dose of OA plus alum adjuvant on day 14. The immunological changes in mice treated with OA alone or OA plus HET were examined, and the following findings were obtained. In the HET-treated mice, the elevation of anti-OA IgE in serum, and histamine release from basophils in blood, were significantly suppressed. A significant suppression of interleukin-4 (IL-4) secretion and proliferation of splenic lymphocytes in primary culture was also observed. A tendency to suppress the elevation of anti-OA IgG1 in serum and interleukin-2 (IL-2) secretion from splenic lymphocytes was observed in the HET-treated mice. These findings suggest that oral administration of HET suppresses IgE antibody production and histamine release in type I allergic reaction in mice immunized with OA plus alum adjuvant; this shows the efficacy of HET in treating type I allergic diseases, such as asthma.

Animals↗
PubMed1997

Ester-type cephalotaxus alkaloids from Cephalotaxus harringtonia var. drupacea.

Three alkaloids, neoharringtonine, homoneoharringtonine and 3'S-hydroxyneoharringtonine, were isolated from the leaves and stems of Cephalotaxus harringtonia var. drupacea. Their structures were established by spectroscopic methods, including two-dimensional NMR and CD spectra, and their antileukaemic activity was evaluated using P-388 leukaemia cells.

Alkaloids↗
PubMed1997

[Detection of human papilloma virus DNA and expression of p53 protein in patients with head and neck cancer].

We investigated the p53 expression and the presence of HPV DNA in 90 patients with squamous cell carcinomas (SCCs) of the head and neck and the relation to clinicopathological parameters and patients' prognosis. Immunohistochemical analysis of p53 protein was conducted by using monoclonal anti-p53 antibody, clone 1801 and clone 240. The relationship between the overexpression of p53 and the duration of survival of patients was analyzed. The polymerase chain reaction (PCR) was carried out with consensus primers capable of detecting HPV16, 18, 31, 33, 52b and 58. In situ hybridization was performed in the mesopharyngeal carcinoma to confirm the presence of HPV genomes in cancer cells with a wide-spectrum cDNA probe capable of detecting HPV6, 11, 16, 18, 30, 31, 33, 35, 45, 51, 52. Forty-five tissue samples (50%) were immunohistochemically positive for p53. T-category, N-category, primary site of tumor, clinical stage and tumor differentiation did not correlate with p53 expression. Our finding that p53 overexpression occurred in 50% of head and neck tumor samples is similar to the frequency of p53 overexpression reported for both lung and esophageal cancer. The common risk factor is the same in these neoplasms, and therefore it is not surprising to find a similar percentage of p53 overexpression. The prevalence of metastasis was higher in the patients with p53-positive staining than in those with p53-negative staining (p < 0.10). Analysis of cumulative survival rates of patients by the Kaplan-Meier method showed a close correlation between p53 expression and survival time. The survival differences according to p53 immunostaining were significant (p 0.05). Our results indicate that p53 immunohistochemical evaluation may be useful as one of the new prognostic parameters in head and neck cancer patients. The HPV genomes were detected in 9 of 90 patients (10.0%); 8 of 9 patients with mesopharyngeal cancer and one with maxillary cancer, namely, 29.6% of mesopharyngeal cancers and 6.7% of maxillary cancer contained HPV DNA sequences. Seven of 8 patients had SCCs of tonsil origin. Almost all of the HPV infections in our study occurred in patients with mesopharyngeal cancer, and it has been suggested that this anatomic subsite may be more frequently infected by HPV than other sites within the head and neck region. Among the 27 patients with mesopharyngeal cancer, HPV DNA-positive patients experienced a higher incidence of complete remission than HPV DNA-negative patients (87.5% vs. 26.3%, p < 0.05).

Aged↗
PubMed1996

[Two cases of lethal midline granuloma thought to be of natural killer cell origin].

So called lethal midline granuloma is of great clinical and theoretical interest. Recent evidence has shown that most lethal midline granulomas are associated with a T-cell phenotype and they are therefore referred to as nasal T-cell lymphomas (NTCL). Immunohistochemical studies, however, have shown peculiar phenotypic features such as expression of natural killer (NK)-cell-related markers and extensive T-cell antigen loss including absence of expression of alpha beta T-cell receptor (TCR). In this study, we reported genotypic and immunohistochemical features in two cases of lethal midline granuloma. The histopathological diagnosis of the biopsy specimens was polymorphic reticulosis/midline malignant reticulosis. Both cases displayed a CD2+, CD3-, CD3 epsilon+, CD4-, CD8-, CD16-, CD56+ phenotype, suggesting that these tumors may be peripheral T-cell lymphomas with extensive loss of T-cell antigens and expression of NK cell antigen (CD56), or, alternatively, NK cell neoplasias. No TCR beta gene rearrangement was detected in these cases. Monoclonal Epstein-Barr virus (EBV) genome was detected in each specimen by Southern blot hybridization. The tumor cells in one of the two cases expressed latent membrane protein (LMP). These findings support the concept that lethal midline granuloma constitutes a distinct group of lymphomas that, in addition to their peculiar clinical features, exhibits the phenotype of extensive loss of T-cell antigens and expression of the NK cell antigen, as well as harbors the EBV. In view of the LMP-transforming potential, these data suggest that EBV may play a role in the pathogenesis of lethal midline granuloma.

Aged↗
PubMed1993

Analysis of viral infection in patients with IgA nephropathy.

We investigated viral infections in the tonsils, pharynx and renal tissues of patients with IgA nephropathy using cell culture, polymerase chain reaction (PCR) and immuno-fluorescent techniques, and measured antibody titers against numerous types of viruses. Neutralization tests found no significant inhibition of growth of adenovirus-1, 2, 3, 4, 5, 6, 7, 11 or 19, Coxsackie virus-A7, A9, A16, B1, B2, B3, B4, B5 or B6, or RS virus. Swabs of the oral cavity of patients with IgA nephropathy were cultured with Hel cells, MDCK cells, FL cells, BHK-21 cells and RD-18S cells. No cytopathic effect was detected in any of these cell cultures. We failed to detect the presence of herpes simplex virus-1 and -2, varicella-zoster virus, cytomegalovirus and Epstein-Barr virus (EBV)-1 and -2 in tonsils, renal tissues and mouthwashings from patients with IgA nephropathy. On the other hand, EBV alone was detected with the PCR technique, in mouthwashings from 6 out of 14 patients with IgA nephropathy (42%). Immunohistological and serological analyses were done to examine the relationship between EBV and IgA nephropathy. No evidence was obtained that EBV-infected B lymphocytes were producing IgA. It seems unlikely that the viral infections examined in this study play a significant role in the pathogenesis of IgA nephropathy.

Adult↗
PubMed1982

Expression in Escherichia coli of chemically synthesized gene for a novel opiate peptide alpha-neo-endorphin.

Chemically synthesized alpha-neo-endorphin gene was fused to the Escherichia coli beta-galactosidase gene on the plasmid pKO13. The resulting recombinant DNA was used to transform E. coli cells. Radioimmunoassay for alpha-neo-endorphin in CNBr-treated bacterial cells showed that alpha-neo-endorphin was synthesized at approximately 5 x 10(5) molecules per single E. coli cell. One of the transformants, WA802/p alpha NE2, was used for alpha-neo-endorphin purification. From 10.9 g of wet cells, we isolated 4 mg of chemically pure and biologically active alpha-neo-endorphin.

Amino Acid Sequence↗
PubMed1982

Expression in Escherichia coli of chemically synthesized gene for a human immune interferon.

A 450 base pair fragment of double stranded DNA consisting of a gene for a human immune interferon (146 amino acid residues), initiation and termination signals plus appropriate restriction endonuclease sites was totally synthesized. The synthesis involved preparation of 62 oligodeoxyribonucleotides by rapid, solid phase procedures, and enzymatic ligation of the oligonucleotides. This synthetic gene was expressed in E. coli under the control of the lac UV5 promoter. Molecular weight of IFN-gamma produced by E. coli was estimated to be about 32,000 and 17,000 dalton by gel filtration and SDS-polyacrylamide gel electrophoresis respectively, suggesting that a dimer-form molecule was expressed in E. coli.

Amino Acid Sequence↗
PubMed1980

Duplicated genes producing transposable controlling elements for the mating-type differentiation in Saccharomyces cerevisiae.

Mutation of the two homothallic genes, HML alpha/HMLa and HMRa/HMR alpha, in homothallic strains of Saccharomyces cerevisiae was studied. Of 11 mutants of the HML alpha gene, eight were due to a phenotypic mutation from HML alpha to HMLa, i.e., a mutation causing a change in function of the original HML allele to that of the other HML allele (functional mutation), and three were due to a defective mutation at the HML alpha gene, i.e., a mutation causing a nonfunctional allele (nonfunctional mutation). All 14 mutants of the HMRa gene, on the other hand, were due to a phenotypic mutation from HMRa to HMR alpha i.e., a functional mutation. Phenotypic reverse mutations, i.e., HMLa to HML alpha and HMR alpha to HMRa, were also observed in the cultivation of EMS (ethyl methanesulfonate) treated spores having the HO HMR alpha HMLa genotype. Mutation from heterothallic cells to homothallism was observed in a nonfunctional mutant of the HML alpha gene, by mutagenesis with EMS, but not in the functional mutants of the HML alpha and HMRa genes or in the authentic strains having the alpha HO HMR alpha HML alpha (alpha Hp) and a HO HMRa HMLa (a Hq) genotypes. These observations suggest that the functional mutation is not caused by the direct mutation from a homothallic allele to the opposite, but by replacement of a transposable genic element produced from a homothallic locus with a region of a different homothallic locus. These observations also support the controlling-element model and the cassette model, which have been proposed to explain the mating-type differentiation by the homothallic genes.

DNA Transposable Elements↗
PubMed1979

Multiple fusion of protoplasts in Saccharomyces yeasts.

Fusion of protoplasts prepared from haploid strains of Saccharomyces yeasts having identical mating type was induced with the aid of polyethylene glycol. Stable fusion products were isolated by complementation of the auxotrophic markers. Of 64 isolates derived by protoplast fusion between two different haploid strains having alpha mating type, 35 fusion products were estimated from their cell volumes to be diploid, 13 to be triploid and 16 to be tetraploid. The isolates showing tetraploid cell size were thought to have resulted from fusion of three protoplasts of one strain and one protoplast of the other (three-to-one fusion) or from two-to-two fusion. In protoplast fusion of three different haploid strains having alpha mating type, all four possible phenotypes of fusion product were recovered. Fusion products of three different protoplasts were obtained in much lower frequency (2.1 x 10(-6)) than those of two different protoplasts (1.2 x 10(-5) to 1.4 x 10(-4)) in the three other combinations. Genetic analyses revealed that triploid fusion products were formed by protoplast fusion of two different strains as well as of three different strains.

Cell Fusion↗
PubMed1974

Independent regulation of the nuclear RNA polymerases I and II during the yeast cell cycle.

The activities of the nuclear RNA polymerases I and II have been investigated in cells of Sacharomyces cerevisiae at G(1), S, early G(2), and late G(2) stages of the cell cycle. The results show that the ratio of the activities of the two enzymes is different at these four stages, indicating that the two RNA polymerases are regulated independently during the cell cycle. The specific activity of the RNA polymerase I remains constant but that of RNA polymerase II increases sharply in cells at the beginning of the G(2) phase. These results are compatible with a pattern of continuous synthesis of the RNA polymerase I and step-wise synthesis of the RNA polymerase II during the yeast cell cycle.

Cell Division↗