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T Hanafusa

Publications and source records attributed to T Hanafusa.

7 recordsLinked to original sources
PubMed1992

Integration of SCP1, a giant linear plasmid, into the Streptomyces coelicolor chromosome.

SCP1, coding for the methylenomycin biosynthetic genes in Streptomyces coelicolor, is a giant linear plasmid of 350 kb. Extensive physical characterization revealed that SCP1 has unusually long terminal inverted repeats (TIR) of about 80 kb on both ends and an insertion sequence, IS466, at the end of the right TIR (TIR-R), and the 5'-ends are attached to a terminal protein. In the NF strain S. coelicolor 2612, SCP1 is integrated into the chromosome at the 9-o'clock position. Analysis of the two junctions between the SCP1 DNA and the chromosomal DNA revealed that the left junction had an almost intact left terminus of SCP1, while the right junction was composed of IS466, completely deleting TIR-R. Based on these results, we presented a possible formation mechanism of the NF strain, which is characterized by integration of SCP1 into the chromosome via an interaction of the target site and the combined ends of the racket-frame structure of SCP1 followed by deletion of TIR-R. We also hypothesized that this type of integration of a giant linear plasmid might be involved in the origin and distribution of the chromosomal antibiotic biosynthetic gene clusters in microorganisms.

Base Sequence↗
PubMed1992

The structure of an integrated copy of the giant linear plasmid SCP1 in the chromosome of Streptomyces coelicolor 2612.

In NF strain 2612 of Streptomyces coelicolor, a giant linear plasmid SCP1 is integrated into the chromosome at the 9 o'clock position. To characterize the integrated structure of SCP1, cloning and sequence analysis of the two junctions between the SCP1 DNA and the chromosomal DNA was carried out. The left junction was revealed to retain an almost intact left terminus of SCP1. On the other hand, the right junction was composed of IS466, deleting completely the right terminal inverted repeat of SCP1. This junction might have been formed by recombination of two IS466 elements, one present at the end of the right terminal inverted repeat of SCP1 and one on the chromosome. Based on these results, we have proposed a model for the integration of SCP1 into the chromosome. The unique conjugal transfer of NF strains and the origin of the chromosomal antibiotic biosynthetic genes in Streptomyces species are also discussed in relation to this model.

Base Sequence↗
PubMed1992

Treatment of hepatocellular carcinoma by transcatheter hepatic arterial injection of radioactive iodized oil solution.

After 12 days of culture, VX2 carcinoma cells were inoculated into the liver of 16 rabbits; 14 days later, 131I-labeled iodized oil ([131I]-Lp) suspended in lipiodol was injected into the hepatic artery. Selective accumulation of the contrast material in the tumor for an extended time was evident on X-rays and hepatic scintiphotographs. The antitumor effect was remarkable. [131I]-Lp agents warrant further examination for their clinical usefulness. Internal radiation therapy by transcatheter hepatic arterial injection of [131I]-Lp (group A) was evaluated in 9 patients with hepatocellular carcinoma (HCC, tumor stage III or IV) associated with liver cirrhosis (LC) and compared with combination therapy of Lp-TAE (group B) in 18 patients with HCC (tumor stage III or IV) associated with LC. In group A, serum AFP levels dropped rapidly in eight of the nine patients who had an elevated initial level of more than 500 ng/ml. The average reduction in tumor size was 50% in eight cases as determined by computed tomography. Histological examination of one resected liver specimen at 3 months after the third injection of [131I]-Lp revealed microscopic features highly suggestive of a radiation effect in the [131I]-Lp-containing area. The 1-year survival value for patients with HCC was estimated at 49.0% using the Kaplan-Meier method. The survival of patients treated with internal radiation therapy tended to be better than that of those treated with Lp-TAE (P = 0.119).

Aged↗
PubMed1992

Detection by western blotting of an antibody to the hepatitis C virus E1 envelope protein in sera of patients with chronic liver disease.

We detected an antibody to HCV envelope protein (E1) in sera of patients with HCV-related chronic liver diseases (20 patients with chronic hepatitis and 5 patients with liver cirrhosis) by Western blotting using the fusion protein of E1 envelope protein and beta-galactosidase as an antigen. The antibody to HCV E1 (anti-HCV E1) was detected in 8 (42%) of 19 patients positive for HCV-RNA (16 were positive and 3 were negative for antibody to C100-3) and in 1 (17%) of 6 patients negative for HCV-RNA but positive for antibody to C100-3. HCV-RNA was detected in 8 (89%) of 9 anti-HCV E1 positive sera. The value of alanine aminotransferase was significantly higher in patients positive for anti-HCV E1 than in patients negative for the antibody. Although an antibody to the envelope protein of HCV is suspected to be one of the candidates of virus-neutralizing antibodies, our results suggest this hypothesis appears to be unlikely.

Adolescent↗
PubMed1976

Pheasant virus: new class of ribodeoxyvirus.

Cocultivation of cells derived from embryos of golden pheasants or Amherst pheasants with chicken embryo cells infected with Bryan strain of Rous sarcoma virus resulted in the detection of viruses which appear to be endogenous in these pheasant cells. The pheasant viruses (PV) were similar to avian leukosis-sarcoma viruses (ALSV) in their gross morphology, in the size of their RNA, in the presence of a virion-associated RNA-dependent DNA polymerase (DNA nucleotidyltransferase; deoxynucleoside triphosphate: DNA deoxynucleotidyltransferase; EC 2.7.7.7), and in their growth characteristics. PV also serves as a helper for the glycoprotein-defective Rous sarcoma virus. However, PV was shown to be different from both ALSV and reticuloendotheliosis virus in the following properties: (i) PV does not have ALSV group specific antigens; (ii) the protein composition of PV is different from those of the other two groups of viruses; (iii) PV fails to complement the defective polymerase of alpha type Rous sarcoma virus; and (iv) PV RNA shows no detectable homology with nucleic acids of the other two groups of viruses. Thus, PV appears to be a new class of RNA viruses which contain RNA-dependent DNA polymerase.

Alpharetrovirus↗
PubMed1975

Quantitation of avian RNA tumor virus reverse transcriptase by radioimmunoassay.

A radioimmunoassay was developed that can detect and quantitate 3 ng or more of the avian RNA tumor virus reverse transcriptase. The assay detected no antigenic sites in Rous sarcoma virus alpha virions or in virions of a murine RNA tumor virus. About 70 molecules of reverse transcriptase were found per virion of avian myleloblastosis virus with this assay or with an assay based on antibody inhibition of enzymatic activity. The assay detected about 270 ng of enzyme per mg of cell protein in virus-producing cells; uninfected cells had much less antigenic material but contained some determinants able to displace radioactive antigen. No additional antigenic determinants on reverse transcriptase could be detected that were not found on the separated alpha subunit of the enzyme. Although sevenfold less sensitive than enzymatic activity as a measure of reverse transcriptase, the radioimmunoassay can detect antigen using small amounts of protein and in the presence of inhibtors.

Animals↗