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Biomedical subjects

M Tagawa

Publications and source records attributed to M Tagawa.

At least 253 records · Page 14Linked to original sources

Cytochemistry of acute promyelocytic leukemia (M3): leukemic promyelocytes exhibit heterogeneous patterns in cellular differentiation.

Cytochemical investigation of leukemic promyelocytes from 25 cases of acute promyelocytic leukemia (M3) disclosed two major cellular differentiation categories: (1) the pure neutrophilic (N) type (16 cases) with strong myeloperoxidase (MPO) and naphthol-ASD chloroacetate esterase (Es-chl), but lacking the monocytic enzyme NaF-sensitive alpha-naphthyl butyrate esterase (Es-b), and (2) the mixed neutrophilic/monocytoid (N/M) type (seven cases) with strong Es-b as well as strong MPO, all cases exhibiting Es-dual (Es-b + Es-chl) positive cells. Two more cases with unusual phenotypes were noted: one with intense lysozyme activity but without Es-b and the other with toluidine blue-methachromasia and negative MPO. Promyelocytes from the control group, consisting of nine cases of t(8;21) M2 AML and ten cases with normal bone marrow, lacked such cytochemical heterogeneity. HL-60, an M3 cell line that can be induced to differentiate toward monocytic lineage in vitro, was almost negative for Es-b in the uninduced condition. Cytogenetically, eight cases of N type and five of N/M type had the t(15;17) abnormality. Thus at least two differentiation patterns were observed in M3 leukemia with fidelity (N type) and infidelity (N/M type) for normal granulocytic differentiation. In this series, there was no statistically significant difference in clinical features (remission rate and survival) between the two types. Our study suggests that the development of M3 leukemia is not exclusively restricted to the neutrophilic pathway, but more heterogeneously related to myelomonocytic differentiation.

Adolescent↗

Preleukemic state of adult T cell leukemia: abnormal T lymphocytosis induced by human adult T cell leukemia-lymphoma virus.

We report the clinical, hematologic, and immunologic features of 18 preleukemic adult T cell leukemia (pre-ATL) cases with abnormal T lymphocytosis induced by human adult T cell leukemia-lymphoma virus (HTLV/ATLV). The patients were from the Nagasaki district, which is one of the most endemic areas of ATL in Japan. Pre-ATL is a subclinical T cell abnormality differing from ATL. It is characterized by an insidious onset and appearance of abnormal T lymphocytes (10% to 40%) in the peripheral blood without clinical symptoms except for a few cases transiently presenting fever, skin eruptions, and slight lymphadenopathies. Most abnormal T lymphocytes were small and mature with incised or lobulated nuclei and formed E rosettes with sheep RBCs. Virologic and biomolecular analysis revealed that all cases were infected with HTLV, and proviral DNA was integrated in host lymphocytes from 12 of the 14 cases examined. Furthermore, the lymphocyte populations, including abnormal T lymphocytes, were monoclonal with respect to the site of the provirus integration. Abnormal T lymphocytosis persisted from one to more than seven years in six cases, three of which developed ATL after a one- to five-year pre-ATL stage, whereas abnormal T lymphocytes spontaneously decreased in the other seven patients. However, HTLV-infected monoclonal lymphocytes were detected in four cases examined, even after most of the abnormal T lymphocytes had disappeared. Moreover, the same clonally provirus-integrated lymphocytes persisted in two of four cases not only during the course of abnormal lymphocytosis, but also in the subsequent almost-normal blood. These results indicate that the majority of the cases were in a pre-ATL state with a potential to develop ATL.

Adult↗

Early events in duck hepatitis B virus infection. Sequential appearance of viral deoxyribonucleic acid in the liver, pancreas, kidney, and spleen.

Early events in duck hepatitis B virus infection were studied in 1-day-old ducklings following inoculation. Group A ducklings (n = 26) were inoculated intraperitoneally with 10 microliter of infective serum, and group B ducklings (n = 29) were inoculated with 50 microliter. Samples of the serum, liver, pancreas, kidney, and spleen were taken, starting 3 h after inoculation and continuing through the 14th day. In group A, relaxed circular double-stranded deoxyribonucleic acid (DNA) did not appear in serum until day 10, whereas single-stranded DNA, indicative of active replication of the virus, was already demonstrable in the liver on day 6. In group B, single-stranded DNA was first detected in the liver on day 3, and relaxed circular double-stranded DNA became detectable in the liver and serum on day 6. The pancreas started to have single-stranded DNA on day 10 in group A and on day 6 in group B, suggesting active viral replication in this organ soon after it occurred in the liver. In the spleen, relaxed circular double-stranded DNA was detectable when serum became positive for viral DNA, probably due to contamination by serum DNA. However, single-stranded DNA became detectable on day 14 in group A and on day 6 in group B, suggesting a delayed but active viral replication in the constituent tissues of the spleen. These results have demonstrated that active replication of duck hepatitis B virus starts in the liver after infection, and is followed by the pancreas, the kidney, and the spleen. The incubation period is shortened when larger amounts of virus are inoculated, but the sequential occurrence of viral replication in these organs remains the same.

Animals↗

Epitope-specific regulation. IV. In vitro studies with suppressor T cells induced by carrier/hapten-carrier immunization.

Sequential immunization with a carrier molecule and a new epitope (hapten) conjugated to the carrier (carrier/hapten-carrier immunization) induces specific suppression for IgG antibody production to the new epitope (hapten) on the carrier. Once induced, this "epitope-specific" suppression persists and specifically suppresses subsequent in vivo IgG antibody responses to the hapten presented on the same or on an unrelated carrier molecule. In vitro studies presented here characterize the surface markers and specificity of suppressor T cells generated in carrier/hapten-carrier-immunized animals. Thus we show (1) that spleen cells from these donors suppress in vitro IgG anti-hapten antibody production by cocultured hapten-primed spleen cells; (2) that some but not all of the suppressor cells carry surface Lyt-2; (3) that at least some of the suppressor cells have receptors for the inducing hapten (DNP); and (4) that, unlike the suppression obtained in vivo, the in vitro suppression extends to IgG responses to unrelated carrier protein epitopes presented in association with the inducing hapten.

Animals↗

Erythrocyte glutathione reductase activity and acquired trisomy #8 in various hematologic disorders.

The gene for erythrocyte glutathione reductase (E-GR) activity has been assigned to chromosome #8. In the present series, we examined the E-GR activity in 14 cases with chronic myelodysplastic syndrome (CMS, preleukemia), atypical acute myelogenous leukemia (AML), or chronic myelogenous leukemia (CML), with and without acquired trisomy #8. No difference in the incidence of high levels of this enzyme was found between two groups, i.e., those with and without trisomy #8 suggesting the existence of a complex regulatory system in addition to chromosome #8.

Chromosomes, Human, 6-12 and X↗

Hereditary analysis of the strain difference of methylmercury distribution in mice.

Hereditary analyses of strain differences in the distribution of methylmercury (MeHg) were carried out with various strains of mice. First, dose-response relationships were examined with 6-week-old male mice of four strains at seven dose levels from 0.25 to 6.0 mg CH3HgCl/kg. Significant strain differences in dose-response were found for both blood and brain. Second, the frequency distribution of blood mercury concentration was examined with two inbred strains, C3H and C57BL, their hybrid (F1), F2 generation, and back-cross mice. The F1 generation showed an intermediate value between their parents, and characteristic hereditary segregations were found in the frequency of blood mercury concentration in F2 and back-cross mice. Third, the relationship between blood mercury concentration and the molecular structure of mouse hemoglobins (Hb) was examined with 14 strains of inbred mice and a single wild mouse strain. Five strains with Hb-beta d and one strain with Hb-beta p showed blood mercury concentrations twice as high as the other Hb-beta strains. Through these experiments, Hb structure, especially the number and position of cysteinyl residue in the molecule, was found to play a primary role in binding with MeHg and in determining blood mercury concentration.

Animals↗

A study on the biochemical and biological behavior of methylmercury.

The biochemical and biological behavior of methylmercury (MeHg) was investigated by measurement of MeHg release rate from erythrocytes (RBC) of selected animal strains and species, by measurement of the intracellular distribution of MeHg in RBC, and by measurement of the binding affinity of hemoglobin (Hb) for MeHg. Methylmercury chloride was used throughout the experiments. Significant strain and species differences were found in the release rate of MeHg from RBC of mice, rats, and man and in the distribution of MeHg in RBC. Significant correlations were found between the above two indexes and the brain/blood ratio of mercury concentration 24 hr after MeHg injection, ip. The affinity of Hb for MeHg was examined by ultrafiltration techniques and Scatchard plots. There were Hbs with only one type of binding site and others with two types of binding sites. Both sites were considered to be cysteinyl residues. Primary sites involved cysteinyl residues oriented externally at the outside of the alpha 1 beta 1 contact junction and cysteinyl residues in the junction, while secondary sites involved only cysteinyl residues in the junction.

Alleles↗