PubMed Health⌕ Search

Biomedical subjects

B D Clarkson

Publications and source records attributed to B D Clarkson.

At least 163 records · Page 9Linked to original sources
PubMed1975

A scanning electron microscopy and immunological study of 84 cases of lymphocytic leukaemia and related lymphoproliferative disorders.

The surface features of cells from 84 cases of lymphocytic leukaemia, and related lymphoproliferative disorders are described as seen by scanning electron microscopy (SEM). Most of the 46 cases of CLL were shown to be B-derived, but rare cases of mixed B and T cell leukaemia and leukaemia with cells bearing both B and T markers were also encountered. Despite the existence of a spectrum of cell surface morphology, it was possible in many cases to identify a dominant cell type. Cells from cases of B derived malignancies were most frequently of the 'predominantly villous' type while a smaller proportion of cases were of the predominantly 'smoother' or 'mixed villous and smooth' type. Variations in surface morphology also occurred with progression of the disease. In most cases of acute lymphoblastic leukaemia (ALL) 'smoother' cells predominated. However, more cases of ALL and T derived leukaemia need to be examined before definite conclusions can be drawn concerning the surface of these cell types. This study also illustrates the importance of examining large numbers of cases of leukaemia, before conclusions are drawn concerning their surface features and indicates that SEM cannot consistently distinguish between leukaemic B and T cells. It will be of interest to determine whether the surface architecture of the leukaemic cell is related to the degree of cell differentiation and eventual prognosis in these cases.

B-Lymphocytes↗
PubMed1975

Treatment of acute lymphoblastic leukemia in childreq with "prophylactic" intrathecal methotrexate and intensive systemic chemotherapy.

Sventy-five children under the age of 15 years, with acute lymphoblastic leukemia, were treated with a multiple drug chemotherapy regimen (L-2) and intrathecal methodtrexate. Remission was achieved in all except 1. Three died from infection early in remission and 1 was lost to follow-up. Of the remaining 70, relapse occurred in 19; in 3 children this was confined to the central nervous system (CNS) and in 1 was in both the CNS and bone marrow. Fifty-one children continue in complete remission from 14 to 54 months. Fourteen of these children have completed 3 years of chemotherapy and are disease free 2 to 18 months posttreatment. The results indicate that periodic administration on intrathecal methotrexate with no CNA irradiation, plus intensive systemic chemotherapy, can effectively control CNA leukemia and prolong the duration of complete remissions.

Adolescent↗
PubMed1973

Identification of human B and T lymphocytes by scanning electron microscopy.

In this study a variety of human lymphocytes of known B or T cell type, obtained from multiple sources, were prepared for scanning electron microscopy (SEM) by the critical point drying method. Distinction between normal B and T lymphocytes was relatively easy in most instances, on the basis of their surface architecture. Using immunological methods, between 20 and 30% of normal peripheral blood lymphocytes (PBL) were identified as B cells and from 69 to 82% as T cells. SEM results showed that 20% of the PBL had a complex villous surface and approximately 80% of cells were smaller and had a relatively smooth surface. Comparison of the above data and enrichment of B cells from PBL, by centrifugation after T cell rosettes had formed, indicated that the "villous" cells were B lymphocytes and the "relatively smooth" cells were T lymphocytes. T cells obtained from two human thymuses were also of the generally smooth cell type. Further evidence for the distinction of B and T lymphocytes, on the basis of surface morphology, was obtained from the examination of cultured lymphoid cell lines of known B or T cell derivation. Cells from cases of chronic lymphocytic leukemia also provided support for the above interpretations. Five of six untreated cases were clearly of B cell type by immunologic and SEM criteria. One unusual case showed the presence of T and B lymphocytes in almost equal numbers by SEM and a mixture of B and T cells by immunologic markers. An additional case that had received chemotherapy showed numerous atypical cells that were difficult to classify by SEM. Detailed examination of the smoother T cells showed that at least half of them had a moderate number of surface digitations and a small proportion had an intermediate surface morphology with a relatively large number of surface digitations. The latter presented difficulties in classification and may correspond to different stages of differentiation and represent subpopulations of lymphocytes. The distinction between human B and T lymphocytes on the basis of their surface architecture can be made by SEM of critical point dried samples, with relative ease in most but not all instances. The effects of stimulation, cell cycle, differentiation, intercellular contact, and density of cell population, on the surface architecture of lymphoid cells, remain to be determined.

B-Lymphocytes↗