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Biomedical subjects

M Hayami

Publications and source records attributed to M Hayami.

At least 199 records · Page 11Linked to original sources
PubMed1984

Detection and characterization of simian retroviruses homologous to human T-cell leukemia virus type I.

Lymphoid cell lines were established from five different species of monkeys which were positive in antibodies cross-reactive with human T-cell leukemia virus type I (HTLV-I) and were shown to contain provirus sequences homologous to HTLV-I. Gene-specific probes of HTLV-I, gag, pol, env, pX, and LTR, hybridized efficiently with monkey DNAs from these cell lines under stringent conditions, indicating that the proviruses are very similar to HTLV-I along with whole viral genomes. However, the preliminary restriction mapping turned out the difference between simian retroviruses and HTLV-I and also among simian retroviruses. These findings suggest a common ancestor of simian and human retroviruses, but exclude the recent interspecies transmission between monkeys and humans.

Animals↗
PubMed1984

Prevalence of antibody to adult T-cell leukemia virus-associated antigens (ATLA) in Japanese monkeys and other non-human primates.

The prevalence of adult T-cell-leukemia virus (ATLV) infection was examined in Japanese monkeys living naturally in various parts of Japan and in other species of non-human primates imported into and kept in Japan. Sera of 2,650 Japanese monkeys from 41 troops throughout Japan were tested. High incidences of anti-ATLV-associated antigen (ATLA)-positive monkeys were found in most troops, not only in the endemic area of human ATL(Southwestern Japan), but also in non-endemic areas. The incidence of sero-positive individuals increased gradually with age, reaching a maximum when the animals became adult, indicating age dependency, like that found by epidemiological studies on humans. Anti-ATLA antibodies were also detected in 90 of 815 sera of imported non-human primates of 33 species other than Japanese monkeys. All the anti-ATLA sero-positive monkeys were Catarrhines (Old World monkeys), mainly macaques of Asian origin. Some sero-positive monkeys were also found among animals of African origin, but no antibody was detected in Prosimians and Platyrrhines (New World monkeys). The clear-cut difference between the geographical distribution of sero-positive simians and that of humans indicates the improbability of direct transmission of ATLV from simians to humans.

Age Factors↗
PubMed1984

Experimental infection of cynomolgus monkeys with a human retrovirus, adult T-cell leukemia virus.

The experimental infection of six cynomolgus monkeys with adult T-cell leukemia virus (ATLV) was attempted. Three animals were inoculated with living MT-2 cells and three with cell-free ATLV. All animals developed an antibody response to virus-specific glycopolypeptides and viral core polypeptides. ATLV-specific antigens appeared in peripheral lymphocytes from all six animals. Virus expression persisted in all animals. Up to 40 weeks after inoculation no animal developed any symptom of leukemia.

Animals↗
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↗
PubMed1983

Characterization of small plaque mutants of mouse hepatitis virus, JHM strain.

Two small plaque mutants designated as 1a and 2c were isolated from DBT cells persistently infected with the JHM strain of mouse hepatitis virus. Unlike the wild type JHM, these two mutant viruses grew more slowly with no prominent cell fusion. The buoyant densities of the mutants were slightly lower and 2c was revealed to have fewer peplomers than JHM by electron microscopy. The purified JHM contained five polypeptides with molecular weights (M.W.) of 260,000, 105,000 (GP105), 65,000, 60,000 (P60), and 23,000 (GP23). In addition to two polypeptides, P60 and GP23, which were common to JHM and the mutants, 1a was found to contain three other specific polypeptides with M.W. of 180,000 (GP180), 110,000, and 95,000 (GP95), while 2c had GP180, GP105, GP95, and one with a M.W. of 175,000. All of these polypeptides were shown to be glycosylated except for P60. After bromelain treatment, all these viruses lost the peplomers and contained P60 and another new 18,000 dalton polypeptide.

Animals↗
PubMed1983

Suppression of natural killer cell activity by chicken alpha-fetoprotein in Japanese quails.

Spleen cells taken from quails treated with chicken alpha-fetoprotein (Ch-AFP) showed reduced natural killer (NK) activity as did spleen cells taken from quails treated with chicken amniotic fluid (ChAmF) in which the presence of Ch-AFP was demonstrated by a gel precipitation test. The Ch-AFP-induced reduction of NK activity was shown to be mediated by suppressor cells. In addition, Ch-AFP-treated quails developed tumors with shorter latent periods than those of the tumors that developed in untreated quails after inoculation with Rous sarcoma virus, as was true for ChAmF-treated quails.

Animals↗
PubMed1982

Heterologous response of antiserum-treated cell clones from a persistently infected DBT cell line to mouse hepatitis virus.

From DBT cells persistently infected with mouse hepatitis virus JHM strain (JHM-CC), a cell line producing neither infectious virus nor intracellular viral antigen was obtained after two passages in the presence of antiserum. In addition, 11 cell clones were manipulated from JHM-CC and found to be also free from the virus. These newly obtained cell line and 4 of 11 cell clones were shown to be resistant to JHM and the virus recovered from JHM-CC (JHM-CCV), while the other 7 cell clones were susceptible to both JHM and JHM-CCV as well as vesicular stomatitis virus. The susceptibility of all the cell clones and the newly obtained cell line to JHM and JHM-CCV became higher with passages. The observations were discussed in relation to the viral persistency in JHM-CC.

Animals↗
PubMed1982

Preliminary chemical and X-ray studies on the interactions of E. coli DNA with putrescine.

The interactions of E.coli DNA with putrescine in aqueous solution and fiber were studied by melting temperature analysis, equilibrium dialysis and X-ray diffraction. The equilibrium binding of putrescine to DNA is shown, of which association constant is in the order of 10(3) 1/mol. The binding of putrescine stabilizes the B-form of DNA fiber and the crossbridge of putrescine in the intra-double helix is suggested by precipitate formation experiments of various polyamines with DNA.

Chemical Phenomena↗
PubMed1981

The role of NK cells in tumor growth assessed by induction of their suppressor cells in Japanese quails.

In Japanese quails treated with chicken amniotic fluid (ChAmF) which had been previously shown to induce suppressor cells to natural killer (NK) cells, tumors appeared with shortened incubation periods after inoculation with Schmidt-Ruppin strain of Rous sarcoma virus (SR-RSV) compared with untreated quails. The tumors in ChAmF-treated quails subsequently grew in a similar pattern to those in untreated quails, whereas by challenging with a lower dose of the virus, enhanced tumor growth was observed as well as earlier onset of tumors in ChAmF-treated quails than in untreated ones. This enhancing effect on tumor growth due to suppression of NK-cell activity was transferred to normal quails with spleen cells obtained from ChAmF-treated quails, since RSV-induced tumors appeared earlier in the recipients of ChAmF-treated spleen cells than in those of untreated spleen cells. These findings show that suppression of NK-cell activity by ChAmF administration rendered quails higher susceptibility to tumor induction by SR-RSV challenge. In other words, NK-cell activity was strongly suggested to contribute to the early protection against tumor growth in the system of Rous sarcoma in Japanese quails.

Amniotic Fluid↗
PubMed1981

Analysis of structural proteins of measles, canine distemper, and rinderpest viruses.

Serological relationships among measles virus (MV), canine distemper virus (CDV), and rinderpest virus (RV), which constitute morbillivirus subgroup of paramyxoviridae, were investigated by immunoprecipitation and SDS-polyacrylamide gel electrophoresis for their major structural proteins, i.e., hemagglutinin (H), nucleocapsid (NC), fusion (F), and matrix (M) proteins. The molecular weights of the four structural proteins of MV and CDV were confirmed to correspond to those previously reported by several investigators. Structural proteins of RV were analyzed for the first time in the present study and found to have molecular weights of 74,000, 62,000, 44,000, and 40,000 for H, HC, F, and M proteins, respectively. By labeling with glucosamine, the presence of carbohydrate moiety was found in H protein for all the three viruses and in F protein of CDV. The serums from the convalescent animals infected with respective virus disclosed one-way cross pattern depending on the combinations of virus and antiserums, but failed to show the reciprocal cross reactivity. On the other hand, hyperimmune serums to respective virus showed the reciprocal cross-reactivity with the four structural proteins indicating that each of the major structural proteins possesses the antigen common to all three morbilliviruses.

Antigens, Viral↗
PubMed1981

Antibody response to structural proteins of measles virus in patients with natural measles and subacute sclerosing panencephalitis.

By immunoprecipitation and SDS-polyacrylamide gel electrophoresis, antibody responses to the structural proteins of measles virus were examined on patients with various forms of natural measles, atypical measles, and subacute sclerosing panencephalitis (SSPE). The serum of atypical measles most strongly reacted with four structural proteins, i.e., hemagglutinin (H), nucleocapsid (NC), fusion (F), and matrix (M) proteins. In natural measles, antibodies to the four structural proteins were detected at such an early convalescent stage as one month after the onset of disease. In late convalescent serums taken 9 years after natural measles, however, only low level antibody to M protein was present, whereas antibodies to H, NC and F proteins persisted. The serums and cerebrospinal fluid of SSPE patients showed patterns similar with those of the late convalescent serums. In Vero cells infected with cell-associated SSPE viruses (Niigata-1, ZH, and SI strains), M protein was not clearly demonstrated with serum of either atypical measles or SSPE patients, whereas H protein was demonstrated.

Adult↗