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Biomedical subjects

I Miyoshi

Publications and source records attributed to I Miyoshi.

At least 271 records · Page 15Linked to original sources
PubMed1984

Characterization of simian retrovirus genome related to human T-cell leukemia virus type I.

Human T-cell leukemia virus type I (HTLV-I) is exogenous for human transmission by viral infection and was shown to be a causative agent of adult T-cell leukemia (ATL) in man. Monkeys of several species were found to have antibodies reactive with HTLV-I antigens and thus infection with HTLV-I like retroviruses was suspected. The retroviruses in several species of monkeys were characterized by Southern hybridization, molecular cloning and sequencing. These monkey retroviruses, tentatively called simian T-cell leukemia viruses (STLV), have a genome structure of LTR-gag-pol-env-pX-LTR and are highly homologous with HTLV-I in all regions. A DNA clone of the STLV was isolated from a pig-tailed monkey and the nucleotide sequence was determined. The STLV showed 90% homology in the nucleotide sequence with that of HTLV-I in env-pX-LTR region. This highly homologous sequence indicates that the STLV is a member of the HTLV family but apparently different from HTLV-I. This result excluded the possibility of recent interspecies viral transmission from monkeys to humans, and suggested that STLV can be useful as an animal model in studies on HTLV-I transmission and leukemogenesis in humans. Supporting this suggestion, an African green monkey which was naturally infected with STLV was found to have developed T-cell leukemia that was very similar to human ATL.

Animals↗
PubMed1984

Infectious transmission of human T-cell leukemia virus to animals.

An human T-cell leukemia virus (HTLV)-producing cell line (Ra-1) was established from rabbit lymphocytes by co-cultivation with lethally irradiated MT-2 cells. Ra-1 cells were inoculated intravenously into a Japanese monkey and rabbits. All animals responded with the production of antibodies to HTLV. Lymphocytes from the seroconverted animals were grown in the presence of T-cell growth factor (TCGF) or co-cultured with lymphocytes from seronegative healthy persons. The TCGF-grown cells, which were chromosomally of the recipient type, expressed HTLV antigens and particles. The co-cultures gave rise to human T-cell lines which also harbored HTLV antigens and particles. Blood transfusion from the infected rabbits resulted in the seroconversion of the recipient rabbits. HTLV-producing lymphoid cell lines were established from some of the transfused rabbits. The recipient origin of these cell lines was determined by chromosome analysis. It was possible to serially transmit HTLV by blood transfusion in rabbits. Thus, these animals offer promise as a laboratory model for HTLV infection.

Animals↗
PubMed1984

Pseudotype viruses bearing envelope antigens of Japanese isolates of human T-cell leukemia viruses type I.

We tried to transmit human T-cell leukemia virus type I (HTLV-I) into non-lymphoid cells and found that S+L- CCC cat cells were permissive for HTLV-I. Using these HTLV-positive cat cells, vesicular stomatitis virus (VSV) pseudotypes bearing envelope antigens of Japanese isolates of HTLVs were prepared and their reactivities with human or rabbit serum were examined. Japanese HTLV2M, HTLV10Y, and HTLVMT-2 pseudotypes and American HTLVPL pseudotype were neutralized by sera of Japanese and American patients with adult T-cell leukemia/lymphoma (ATL) and rabbit antisera against HTLV. Each serum showed similar antibody titers against different pseudotypes. Thus, envelope antigens of four HTLVs that reacted with the human and rabbit sera were considered to belong to a single serotype.

Animals↗
PubMed1984

Establishment of a new peroxidase-positive human myeloid cell line, PL-21.

A myeloid cell line, designated PL-21, was established from the peripheral blood of a patient with acute promyelocytic leukemia. The PL-21 cell line grew in single-cell suspension, with a doubling time of 48-64 hr, and consisted of promyelocytes with fine immature nuclei and prominent azurophilic granules in the cytoplasm. PL-21 cells were positive for peroxidase, naphthol AS-D chloroacetate esterase, and Sudan Black B staining. Under the usual culture conditions, a small proportion of these cells differentiated into mature granulocytes, and this differentiation was enhanced by the addition of dimethyl sulfoxide in the culture medium. PL-21 cells had receptors for the Fc portion of IgG and complement, intracytoplasmic lysozyme and phagocytic activity, but lacked Epstein-Barr virus-associated nuclear antigen. Chromosome analysis of this cell line revealed a human male polyploid karyotype with 13q+ and double minute chromosomes. This new myeloid cell line may provide useful material for the study of proliferation and differentiation of human leukemia cells.

Adult↗
PubMed1983

Natural infection in non-human primates with adult T-cell leukemia virus or a closely related agent.

A total of 703 sera from 10 species of monkeys were examined for the presence of antibodies to adult T-cell leukemia (ATL)-associated antigens (ATLA). ATLA represent core protein(s) of ATL virus (ATLV) and ATLV-determined polypeptides. Anti-ATLA antibodies were found in all seven macaque species tested but not in three non-macaque species. The frequencies of seropositive macaques ranged from 10 to 50%. In three macaque species (Japanese monkeys, rhesus monkeys, and crab-eating monkeys) in which sufficient numbers of animals were studied, more females than males were anti-ATLA positive and the antibody-positive rate increased with age. In Japanese monkeys, over 70% were seropositive after the age of 10 years. A family study of Japanese monkeys suggested maternal transmission of ATLV or a closely related agent. These seroepidemiological features are consistent with those of Japanese in the ATL-endemic area. Three of 10 rhesus monkeys were found to be anti-ATLA-positive 13 days after arrival in Japan, suggesting that they had been infected with ATLV in Indonesia where they were captured. Thus, ATLV appears to be prevalent among several macaque species as well as in man, and its pathogenetic role in these non-human primates should be explored in relation to ATL in man.

Animals↗
PubMed1983

Bulimia nervosa complicated by deficiency of vitamin K-dependent coagulation factors.

A 28-year-old woman manifested a hemorrhagic tendency caused by a deficiency of vitamin K-dependent coagulation factors. Her condition was diagnosed as bulimia nervosa in view of a previous history of anorexia nervosa and episodes of self-induced vomiting and purging. There were no remarkable lesions in her alimentary system. In treatment of bulimia nervosa, attention should be given not only to the loss of body fluids and electrolytes, but also to the possibility of a deficiency of vitamin K-dependent coagulation factors.

Adult↗
PubMed1983

Establishment of a Ph1 chromosome-positive cell line from chronic myelogenous leukemia in blast crisis.

A new hematopoietic cell line, designated KCL-22, was established in vitro by cultivation of pleural effusion cells obtained from a woman with chronic myelogenous leukemia in blast crisis. KCL-22 grew in suspension culture with a doubling time of 24 h and consisted of immature undifferentiated cells which were positive for periodic acid-Schiff and acid phosphatase staining. Chromosome analysis of the KCL-22 line showed a female karyotype with double Ph1 chromosomes and additional chromosome abnormalities. Its representative karyotype was 52,XX, + 1p-,+6,+8,+8,+8, t(9q+;22q-), +22q-. This cell line possessed receptors for the Fc portion of IgG, but lacked lymphoid cell characteristics and the Epstein-Barr virus-associated nuclear antigen. These results indicate that the KCL-22 cells were derived from chronic myelogenous leukemia cells. This cell line should prove useful for research involving various aspects of chronic myelogenous leukemia.

Adult↗
PubMed1983

Immunoagglutination of type-C virus particles in a human T-cell line by serum supplementation from patients with adult T-cell leukemia.

A T-cell line, MT-2, derived from human cord blood lymphocytes by cocultivation with adult T-cell leukemia (ATL) cells is a continuous producer of type-C virus particles. Electron microscopy of MT-2 cells cultured for 1-3 weeks in medium containing 10% ATL patients' sera revealed agglutination of type-C virus particles within the electron-dense deposits in the extracellular spaces. No such agglutination occurred in control cultures supplemented with normal human or fetal calf serum. These results provide direct evidence for the specific reactivity of ATL patient's sera with type-C virus particles in the MT-2 cell line at the ultrastructural level.

Agglutination↗
PubMed1983

Detection of antibodies to adult T-cell leukemia (ATL)-associated virus in ATL patients' sera by immunoelectron microscopy.

In an attempt to demonstrate the presence of antibodies to ATL-associated type-C virus particles (ATLV), an indirect immunoferritin method of immunoelectron microscopy was performed on an ATLV-producing human cord T-cell line (MT-2) and short-term cultures of ATL cells. All five sera from ATL patients seropositive to ATL-associated antigens (ATLA) but not three sera from healthy adults were positive for the ferritin labeling of ATLV and plasma membranes in both MT-2 and short-term cultured ATL cells. Sera absorbed with sheep red blood cells or human T-cell acute lymphatic leukemia cells labeled ATLV much more intensely with ferritin than with plasma membranes. These results demonstrated at the ultrastructural level that anti-ATLA-positive sera contained antibodies to surface glycoproteins and/or structural proteins of ATLV and that they differed from anti-Forssman or anti-T-cell antibodies. It was also demonstrated that anti-ATLA-positive sera showed the same reactivity with ATLV from both MT-2 and short-term cultured ATL-cells by the immunoferritin method.

Antibodies, Viral↗
PubMed1983

Transformation of rabbit lymphocytes with T-cell leukemia virus.

Co-cultivation of rabbit lymphocytes with a human cell line carrying adult T-cell leukemia (ATL) virus (ATLV) resulted in the establishment of an ATLV-producer rabbit cell line. This cell line expressed ATL-associated antigens and reacted with antisera to the structural proteins of human T-cell leukemia virus which is identical or closely related to ATLV.

Animals↗
PubMed1983

Dimorphism of sister chromatid exchange in Bloom's syndrome B- and T-cell lines transformed with Epstein-Barr and adult T-cell leukemia viruses.

The present study describes the establishment of both B- and T-cell lines from the peripheral blood cells of two Bloom's syndrome (BS) patients and one healthy female by using Epstein-Barr (EBV) and adult T-cell leukemia viruses (ATLV). The cell lines from normal and BS subjects exhibited cell surface markers compatible with B- and T-cell origin; in addition, the BS B- and T-cell lines retained the original cytogenetic characteristics of the syndrome. Even though phytohemagglutinin-stimulated BS lymphocytes from the two BS patients studied all showed high levels of sister chromatid exchange (SCE), the established BS B-lines with EBV yielded two separate lines each, i.e., one with increased SCE and another with normal levels of SCE; also, one of the BS T-lines retained high SCE levels in 100% of the cells, whereas the other BS T-line contained two populations, one with high SCE (70%) and the other with normal SCE levels (30%), at a relatively constant frequency over a period of 6 months. Neither EBV nor ATLV caused a significant increase in chromosome instability in the established lines compared to fresh lymphocytes. Reinfection of the BS B- and T-cell lines with EBV or ATLV did not alter the SCE or karyotypes. These results strongly suggest that BS patients have two populations in vivo, one with high and another with normal levels of SCE, at least in the lymphoid cell system.

Adolescent↗