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Biomedical subjects

K Nasu

Publications and source records attributed to K Nasu.

At least 163 records · Page 9Linked to original sources

Significance of extra 18q- chromosome in Japanese t(14;18)-positive lymphoma.

Karyotype evolution of t(14;18)-positive lymphoma was studied in 13 Japanese patients. The extra 18q- chromosome, found in six of ten patients with complex karyotypes, was the most common change subsequent to a t(14;18)(q32;q21) chromosome translocation. The additional change was interpreted as being a duplication of an 18q- derived from a t(14;18). The six patients had transformed histology of follicular small cleaved cell lymphoma or diffuse large cell lymphoma, and five of them had extranodal expansion associated with a poor prognosis. These findings indicate that the extra 18q-, together with other chromosome abnormalities, is closely associated with the advanced grade disease of t(14;18)-positive lymphoma, and the extra chromosome is evolutionally comparable with the second Philadelphia (Ph1) chromosome often found in the blastic phase of chronic myelocytic leukemia carrying a t(9;22)(q34;q11). In addition, since the extra 18q- is rarely found in American patients with t(14;18)-positive lymphoma, there appears to be a difference in the karyotype evolution between Japanese and American patients.

Chromosome Aberrations↗

Recurrent chromosome abnormalities in adult T-cell lymphomas of peripheral T-cell origin.

Cytogenetic studies were performed on 11 Japanese patients with adult T-cell lymphoma of peripheral T-cell origin. All patients had a histologic diagnosis of diffuse lymphoma, and were treated with intensive combination chemotherapy; their median survival was 6 months. Lymphomas were categorized on the basis of the classification proposed by the Lymphoma Study Group of Japan: 5 patients had the features of pleomorphic lymphoma; 3, mixed lymphoma; 2, large-cell lymphoma; and 1, medium-sized-cell lymphoma. The modal chromosome number of abnormal cells was near-diploid in 7, and hypotetraploid in 4 including 3 patients with pleomorphic lymphoma. Abnormalities of the clonal chromosomes were observed in all 11 patients. A translocation of the short arm of 19 at band 19p13 was found in 2 patients with pleomorphic lymphoma and in one patient each with mixed lymphoma and medium-sized-cell lymphoma. A translocation of the short arm of 14, with a break at band 14p12, occurred in 4 patients with pleomorphic lymphoma. In one patient each with mixed lymphoma and large-cell lymphoma, an extra chromosome 3 was found. The numerical change was unique because their lymphomas were further categorized as "angioimmunoblastic lymphadenopathy with dysproteinemia" and "large-cell immunoblastic lymphoma", respectively. Our findings suggest that characteristic chromosome abnormalities occur in adult T-cell lymphoma, and dividing cells in the tetraploid range tend to be predominant in pleomorphic lymphoma.

Adult↗

Lymphomatoid papulosis. A cutaneous proliferation of activated helper T cells expressing Hodgkin's disease-associated antigens.

A distinctive immunologic phenotype was demonstrated for the characteristic large atypical cells in skin lesions of 9 patients with lymphomatoid papulosis (LP). Coexpression of Hodgkin's disease (HD)-associated antigen(s) Ki-1, and often Leu-M1, with helper T-cell antigens T11, T4, and T3 and cellular activation antigens Tac, Ia, and T9 was the most common phenotype, observed in 6 of 9 cases. In 2 cases T-cell-specific antigens were not detected, and the phenotype was indistinguishable from Reed-Sternberg (RS) cells of HD. Numerous Ki-1 positive cells and infrequent expression of Leu-1 antigen by large atypical cells in LP cases facilitated the differential diagnosis between LP and mycosis fungoides. A possible transition between small, medium, and large cells expressing only T-cell antigens and large transformed RS-like cells expressing both T-cell and HD-associated antigens was shown by immunoelectron microscopy. These immunologic findings should prove useful for the diagnosis of LP and may help to explain the unexpectedly frequent clinical associations of LP, mycosis fungoides, and HD.

Antigens, Neoplasm↗

Phenotypic analysis of acute lymphoblastic leukemia (ALL) cells which are classified as non-T non-B and negative for common ALL antigen.

When phenotypic marker analysis of acute lymphoblastic leukemia (ALL) cells (102 cases) was performed, a group of ALL cells (15 cases) classified as non-T non-B, and negative for common-ALL antigen (CALLA) was characterized in a focused manner. "Non-T non-B" was defined as negative for T cell properties such as E-rosetting or reactivity with anti-human T-cell monoclonal antibodies (T101, WT1), and absence of any B-cell characteristics (cell surface and/or cytoplasmic immunoglobulin and reactivity with B1 monoclonal antibody). Despite their marked heterogeneity, CALLA(-) non-T non-B ALL cells revealed three different phenotypic patterns in terms of presence of terminal deoxynucleotidyl transferase (TdT) and of reactivity with antimyeloid (MCS1) or myelomonocyte (MCS2 and OKM1) monoclonal antibodies. Four of 15 cases reacted with some myeloid-specific antibodies, but were negative for TdT. Six cases had both MCS2 antigen and TdT. The remaining five cases expressed no myeloid antigens, but were positive for TdT with some exceptions. These findings showed that acute leukemias with myeloid antigens might be involved in CALLA(-) non-T non-B ALL having no relationship to the presence of TdT, and, furthermore, that the blasts with simultaneous expression of TdT and myeloid-specific antigen (MCS2) might represent an immature stage in hematopoietic differentiation closely corresponding with the bifurcation of the lymphocyte/myeloid pathway. Alternatively, only five cases remained "unclassified leukemia." We therefore think that the detailed examination of CALLA(-) non-T non-B ALL cells using myeloid specific antibodies is helpful in clarifying the characteristics of myeloid precursors and the common bipotential stem cell of lymphoid and myeloid progenitors.

Adult↗

Immunopathology of cutaneous T-cell lymphomas.

In this study the authors attempted to establish immunopathologic criteria for the distinction of various T-cell lymphomas affecting the skin. We studied skin specimens from 27 patients with mycosis fungoides (MF) (n = 12), the Sézary syndrome (SS) (n = 6), adult T-cell leukemia (ATL) (n = 4), and nonepidermotropic T-cell lymphoma of large cell (n = 4) and lymphoblastic (n = 1) types. Identification of tumor cells in mixed cell populations and detection of weak expression of surface antigens by tumor cells was facilitated by immunoelectron microscopy. The mature helper T-cell phenotype (T11+ T3+ T4+) was found in 14 of 18 cases of MF/SS. One case of MF had a cytotoxic/suppressor (T4- T8+ 3A1+) phenotype; one with frequent blastic cells showed only weak expression of T4 antigen; 2 cases of SS were T11-. Tumor cells infiltrating the skin expressed 3Al antigen in 44% and cellular activation antigens Ia and/or Tac in 78% of patients with MF/SS. No consistent phenotypic differences were found between ATL cells from ATLV (HTLV) antibody-positive patients and tumor cells of patients with MF/SS who lacked this antibody. In contrast, a group of nonepidermotropic T-cell lymphomas showed phenotypic differences from MF/SS and ATL in all but 1 case. These cases were distinguished by the frequent absence of T3, T4, and Leu 1 antigens in 3 large-cell lymphomas; frequent expression of Ki-1 antigen, a Hodgkin's disease-associated antigen, in 2 cases with RS-like cells; and an immature thymocyte phenotype in lymphoblastic lymphoma. These findings demonstrate that tumor-cell phenotypes can be useful in distinguishing different histologic types of cutaneous T-cell lymphoma.

Adult↗