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Biomedical subjects

T Miyamura

Publications and source records attributed to T Miyamura.

At least 199 records · Page 11Linked to original sources
PubMed1989

[The influence of ferric metabolism on Ga-67 distribution in the human body].

This investigation was undertaken to make clear the influence of ferric metabolism on Ga-67 distribution in human body. Count ratios for each organ to femoral soft tissue (i.e. relative Ga-67 uptake) were calculated in 125 scintigrams obtained 48 hours following injection, and the relation between the relative Ga-67 uptake in each organ and serum Fe, or UIBC were investigated. The relative Ga-67 uptake in the liver and the lumbar vertebra had negative correlation to serum Fe, and had positive correlation to UIBC. However, there was no significant difference in the relative Ga-67 uptake in the lumbar vertebra between normal and high serum Fe group. Only in group with exceedingly low serum Fe, each vertebral body was visualized separately in posterior view of the abdomen. These findings indicated that in group with exceedingly low serum Fe, Ga-67 accumulated mainly in the bone marrow, and in group with high serum Fe, Ga-67 accumulated mainly in the bone. The urinary bladder was visualized only in group with high serum Fe, which suggested that the excretion of Ga-67 to the urine was continued yet at 48 hours after injection. Ferric metabolism affected remarkably on the relative Ga-67 uptake in the liver, the bone marrow and the bone, and also the excretion of Ga-67 to the urine.

Adolescent↗
PubMed1988

Analysis of integrated hepatitis B virus DNA and cellular flanking sequences cloned from a hepatocellular carcinoma.

By digestion with HindIII restriction enzyme, a human hepatocellular carcinoma was shown to contain only 2 hepatitis B virus (HBV) DNA inserts. Both HindIII fragments (8 and 16 kb) were molecularly cloned and the structures of HBV DNA and adjacent host sequences were analyzed. One clone (lambda YH 8) contained part of pre-S(I) through the entire S gene and the other (lambda YH 16) had the middle section of the S to the end of X gene of HBV DNA. No gross rearrangements were observed in either HBV or cellular DNA sequences in lambda YH 16 clone. However, the 8 kb HindIII fragment was considered to be amplified together with flanking cellular sequences. Furthermore, the HBV DNA was integrated into cellular genome at the Alu repeated sequences in lambda YH 8.

Bacteriophage lambda↗
PubMed1988

Characterization of hepatitis B virus X gene: in vitro translation of mRNA from COS-1 cells transfected with the X gene.

To elucidate the biological role of the X region of HBV DNA, we constructed an expression plasmid pSV2HBx by inserting the StuI/BglII fragment of HBV DNA into the pSV2 vector. Although X region products were not identified in vivo in transfected COS-1 cells, transcripts were translated in vitro and a 17-k Da protein was immunoprecipitated with an antibody raised against a synthetic peptide corresponding to the carboxy terminus of the X region open reading frame. Among 68 HBV carrier sera tested, two were found to contain antibodies reactive to the in vitro translation product. These results suggest that the X region is a gene which can be actually expressed at some stage of HBV infection.

Animals↗
PubMed1988

Stable expression of the hepatitis B virus surface antigen containing pre-S2 protein in mouse cells using a bovine papillomavirus vector.

The large BglII fragment (2.8 kilobases) of hepatitis B virus DNA including the transcription unit for the hepatitis B surface antigen (HBsAg) was inserted into a bovine papillomavirus vector containing the neomycin resistance gene. The recombinant DNA was transfected into mouse C127 cells. A stable transformed cell line (MS128) secreting a large amount of 22 nm HBsAg particles containing pre-S2 protein was established. The secreted HBsAg particles had the receptor for polymerized human serum albumin. Immunoprecipitation and Western blot analyses showed that HBsAg particles consisted of two major proteins of 22K and 26K encoded by the S gene and a minor protein of 35K encoded by the pre-S2 and S genes. Southern blot analysis revealed that the transfected plasmid was integrated into the host chromosomal DNA and that most of the plasmid sequences were present. These results suggest that the stable expression of the HBsAg in MS128 cells is related to the integrated state of the recombinant DNA.

Animals↗
PubMed1985

DNA rearrangement in the control region for early transcription in a human polyomavirus JC host range mutant capable of growing in human embryonic kidney cells.

A human polyomavirus JC virus (JCV) host range mutant (JC-HEK) can grow in human embryonic kidney cells, whereas the brain cell-tropic wild-type JCV strain (Mad-1) cannot; JC-HEK contains two complementing defective DNAs, JC-HEK-A and JC-HEK-B. We determined the nucleotide sequence of the putative transcriptional control region of JC-HEK-A DNA that can induce T-antigen synthesis in human embryonic kidney cells and compared it with the sequence of JCV Mad-1 DNA. The JC-HEK-A control region was found to have a complex DNA rearrangement, namely, a partial local duplication of a noncoding region generating two extra replication origins and translocation of segments from the large-T-antigen gene (415 base pairs) and the VP-1 gene (78 base pairs). In the rearranged segment, JC-HEK-A had seven sets of the sequence 5'TGGA(T)A(T)A(T)3', which is found in the simian virus 40 enhancer core, whereas JCV Mad-1 had only one set in its control region. JC-HEK-A also had a 5'TGGAAGTGTAA3' sequence resembling the adenovirus early region 1A enhancer core sequence 5'AGGAAGTGAA3'. Because the viral enhancer is host discriminatory and because another human polyomavirus, BK virus, that grows well in human embryonic kidney cells has these signals in its control region, it is likely that some of the newly acquired signals in JC-HEK play an important role in the altered host range of JCV.

Base Sequence↗
PubMed1985

[Clinical usefulness of integrated images of the radionuclide liver angiogram to evaluate diffuse hepatic disease].

New imaging method that was integrated image of radionuclide liver angiogram was proposed. Patients were placed supine beneath gamma camera, so that the liver, spleen, heart, and lung were included in an anterior image. Integrated image was recorded for 100 s, following injection of 111-222 MBq (3-6 mCi) of 99mTc tin-colloid. 595 cases were examined, and classified into 3 groups as follows. Group I: Cases without hepatic dysfunction Group II: Cases with hepatic dysfunction Group III: Liver cirrhosis. Numbers of each group were 208 (35%), 305 (51%), and 82 (14%) respectively. Integrated images were qualitatively determined by macroscopic inspection. Comparing liver intensity and lung intensity, 3 patterns of integrated image were classified. Pattern I: Liver intensity was greater than lung intensity Pattern II: Liver intensity was equal to lung intensity Pattern III: Liver intensity was less than lung intensity Numbers of each pattern were 412 (69%), 125 (21%), and 58 (10%) respectively. Numbers of group III distributed into each pattern were 8 (10%) in pattern I, 29 (35%) in pattern II, and 45 (55%) in pattern III. The correct diagnosis of liver cirrhosis as follows. In a case of choosing pattern III as diagnostic criterion, sensitivity was 55%, and specificity was 97%. The positive predictive value was 78%, and the negative predictive value was 93%. Total accuracy was 92%. This new method seems useful in evaluating diffuse hepatic disease.

Heart↗
PubMed1984

Monkey B-lymphotropic papovavirus DNA: nucleotide sequence of the region around the origin of replication.

We have determined the nucleotide sequence of the HindIII-B DNA segment of African green monkey B-lymphotropic papovavirus (LPV), which shows a highly restricted host range and whose genome is a 5.1-kilobase-long circular DNA. The segment, consisting of 1,123 base pairs, contained the origin of DNA replication, the putative control region for early transcription, and the region probably coding for the amino-terminal portion of T antigens. The symmetrical region at the center of replication origin, 5'-GAGGC CA GGGGCCCC TA GCCTC-3' (on the L strand), has diverged in the central portion from the corresponding regions of primate polyomaviruses simian virus 40, BK virus, and JC virus, but resembles that of mouse polyomavirus. The structure of the control region upstream of the replication origin was unique to LPV and contained several repeated sequences, the longest of which were two 60-base-pair tandem repeats. The amino-terminal region common to LPV small T and large T antigens showed some homology (41%) in the deduced amino acid sequence to that of both simian virus 40 and the mouse polyomavirus. Like other polyomaviruses, the probable carboxyl-terminal region unique to LPV small T antigen contained two sets of the Cys-x-Cys-x-x-Cys structure. These data show that, despite the unique structures in the control region, LPV is evolutionally related to the mouse polyomavirus and to simian virus 40.

Amino Acid Sequence↗
PubMed1983

High-titer SV40 replication in human fibroblast cell lines derived from patients with Wiskott-Aldrich syndrome.

Human fibroblast cell lines established from skin biopsies of patients with Wiskott-Aldrich syndrome (WAS), a sex-linked immunodeficiency disorder, were found to have unusually high sensitivity to SV40 infection. When examined by immunofluorescence, two of the cell lines showed almost 100% positive staining for tumor and viral antigens 4 days after infection, while the third cell line showed 75% positive cells for both antigens. Marked cytopathic changes were seen in infected cultures and viral yields of 10(8) pfu/ml were obtained. After six serial passages in WAS cells, the viral DNA was examined by restriction endonuclease analysis and found to have HindIII cleavage pattern similar to that of DNA from SV40 grown in monkey cells.

Antigens, Viral↗
PubMed1983

Genomic structure of human polyoma virus JC: nucleotide sequence of the region containing replication origin and small-T-antigen gene.

The nucleotide sequence of the region of human polyoma virus JC DNA between 0.5 and 0.7 map units from a unique EcoRI cleavage site was determined and compared with those of the corresponding regions of another human polyoma virus, BK, and simian virus 40 DNAs. Within this region consisting of 945 base pairs, we located the origin of DNA replication near 0.7 map units, the entire coding region for small T antigen, and the splice junctions for large-T-antigen mRNA. The deduced amino acid sequences for small T antigen and the part of large T antigen markedly resembled those of polyoma virus BK and simian virus 40. The results strongly suggest that polyoma virus JC has the same organization of early genome as polyoma virus BK and simian virus 40 on the physical map, with the EcoRI site as a reference point.

Amino Acid Sequence↗
PubMed1982

Prevalence rate and age of acquisition of antibodies against JC virus and BK virus in human sera.

A total of 480 serum samples from donors including 384 children up to 10 years of age were examined by the hemagglutination-inhibition (HI) test for the rates of prevalence and age of acquisition of HI antibodies against JC virus and BK virus. Among 136 serum samples from various age groups, there were five (4%) with no detectable antibodies against BK or JC virus, 75 (55%) with antibodies against both viruses, 41 (30.1%) with antibodies against only BK virus and 26 (19%) with antibodies against only JC virus. The prevalence of antibodies against JC and BK viruses was 70.5% and 80.8%, respectively, and the mean HI titers (4 x 2n,n greater than or equal to 1) were 4.90 and 4.30. About 50% of the children had acquired antibodies against BK virus by 3 years of age and against JC virus by 6 years of age. These results indicate that dual latent infections with both viruses are common, although independent infections with either virus are predominant in the human population.

Adolescent↗
PubMed1982

Two defective DNAs of human polyomavirus JC adapted to growth in human embryonic kidney cells.

Human polyomavirus JC (JCV) adapted to growth in human embryonic kidney (HEK) cells contains two or more species of shorter-length viral DNA even after two cycles of plaque purification in HEK cells. We have molecularly cloned JCV DNA from one plaque isolate and determined the physical map of its DNA. Using gel electrophoresis and electron microscopy, we found that the cloned DNA consisted of two classes of JCV DNA. One class of DNA had a deletion of 30% (between 0.7 and 1.0 map units from the EcoRI site) and an insertion of 1% at the same site in the late region. The other had a deletion of 35% (0.18 to 0.53 map units) and an insertion of 12% at the same site in the early region of the JCV genome. Both DNAs had added sequences near the origin of DNA replication. From their structure, the two DNAs appear to complement each other. These results indicate that the HEK-adapted JCV may be replicating by complementation between two defective mutants.

Cell Line↗