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Biomedical subjects

Y Tokumine

Publications and source records attributed to Y Tokumine.

24 records · Page 2Linked to original sources

Leu 11+ T gamma cell chronic lymphocytic leukemia with partially activated natural killer function and its further activation by recombinant IL2 in vitro.

A patient with T gamma cell chronic lymphocytic leukemia with the Leu 11+ phenotype and novel function of activated natural killer cells is reported. The peripheral blood mononuclear cells of this patient showed large granular lymphocytes by May-Giemsa staining and lamellipodia by scanning electron micrography. Tests on reactivity with monoclonal antibodies showed that most cells were Leu 11+, OKT3-/Leu 1-, OKT4-, OKT8-, Leu 7-, OKM1-, and Tac-. Freshly collected cells lysed not only K562, which is highly sensitive to natural killer cells, but also Raji cells and Daudi cells, which are not. Leu 11+ cells were triggered by recombinant interleukin 2 (rIL2) to proliferate, produce gamma-interferon (gamma IFN), and show enhanced HLA-DR antigen expression, and 30% of the Leu 11+ cells became positive for IL2 receptor antigen (Tac). The spectrum of cytotoxic activity of these cells against target cells was extended by rIL2; after treatment with rIL2, the cells also lysed HeLa cells and even fresh cancer cells. This stimulation also increased the activities of acid phosphatase and tartrate-resistant acid phosphatase of the cells and resulted in the appearance of nonspecific esterase activity. The expanded cell population may represent a neoplasm, but these findings provide information on a novel differentiation stage of activated NK cells.

Aged↗

Association of specific tyrosine phosphorylation with stages of B-cell differentiation in human lymphoid leukemias.

In vitro protein phosphorylation in various types of human fresh lymphoid leukemic cells (C-ALL, B-CLL, HCL and PCL: B-cell lineage and T-ALL, ATL and T-CLL: T-cell lineage) were studied. In cases of B-CLL and HCL, tyrosine protein kinase (TPK) activity was at least 5-fold higher than that in other cases of B- and T-cell lineages. B-cell leukemic cells at various differentiation stages had different endogenous substrates in tyrosine phosphorylation as well as distinct TPK activity. The P-tyr-containing proteins of 68K, 59K and 56K were detected commonly in all the cases of B-cell lineage. The phosphorylated protein of 32K was present only in cases of PCL. On the other hand, in T-ALL and ATL, the major substrate in tyrosine phosphorylation was 58K. These results suggest that the characterization of in vitro tyrosine phosphorylation provides a new means not only to distinguish T- and B-lymphoid leukemia, but also to differentiate stages of lymphoid development.

B-Lymphocytes↗

Serum immunosuppressive acidic protein in adult T-cell leukaemia (ATL).

The availability of serum immunosuppressive acidic protein (IAP) as a marker of subtypes of adult T-cell leukaemia (ATL) was examined. Serum IAP levels were measured in 34 patients with ATL (18 typical, 9 atypical and 7 smoldering), 7 healthy carriers of ATLA antibody and 53 healthy controls. The mean value of serum IAP was significantly higher in patients with typical ATL (897.8 +/- 502.4 micrograms/ml) than in those with atypical ATL (426.7 +/- 106.6 micrograms/l), smoldering ATL (310.0 +/- 51.3 micrograms/ml), healthy carriers of ATLA antibody (302.9 +/- 39.5 micrograms/ml) and normal controls (350.5 +/- 73.2 micrograms/ml). Serial determinations of IAP revealed that the level was correlated with the clinical course in patients with ATL; there was a difference in the prognosis of patients with high and normal levels of IAP (P less than 0.05). Thus, routine measurement of serum IAP seems useful in differentiating typical, atypical and smoldering ATL and also in evaluating the prognosis of patients.

Adult↗

Phenotypical heterogeneity of Japanese adult T-cell leukaemia.

The leukaemic cells of 11 patients with Japanese adult T-cell leukaemia (ATL) were characterized in terms of phenotype employing various monoclonal antibodies against T-cell surface antigens. The leukaemic cells of all ATL patients except patient no. 11 displayed the phenotype OKT4+/OKT8-. However, the % of OKT3+ cells varied from 3 to 98. In 1 case, cells with phenotype OKT4+/OKT8+, which is characteristic of T-cells at an early stage of differentiation, were found. These results suggest that some ATL cells may be in an immature differentiation stage. Among the 11 patients, 2 with unusual ATL cell phenotypes (1 case with OKT3- cells and 1 case with Ia+/EAC+ cells) showed spontaneous regression of leukaemic cells. Characterization of leukaemic cells from a larger number of ATL patients may demonstrate a significant relationship between cell phenotype and prognosis.

Aged↗

A unique variant of hairy cell leukemia in Japan.

We studied 25 Japanese patients with hairy cell leukemia (HCL) and found a manner in which HCL can be divided into two subtypes. In each patient, hairy cells (HC) showed striking surface hairs and reacted with HC-specific antibodies (alpha Leu-M5 and alpha HC-M). Twenty of the 25 patients had HC characterized by round nuclei with dense nuclear chromatin, weak tartrate-resistant acid phosphatase (TRAP) activity and the phenotype of low density surface immunoglobulin (SIg)+, Tac-. In this group of 20 patients, the male to female ratio was low, and there was frequent leukocytosis. On the other hand, the remaining 5 patients showed a high male to female ratio and a normal or decreased leukocyte count. HC had folded nuclei, strong TRAP activity and the phenotype of high density SIg+, Tac+. The features of the latter patients are consistent with those of HCL in Western countries, while those of the former group appear to indicate a unique variant of HCL.

Adult↗