Biomedical subjects

A Porwit

Publications and source records attributed to A Porwit.

45 records · Page 3Linked to original sources

PubMed1987

B-cell chronic lymphocytic leukaemia with aberrant expression of CD8 antigen.

The monoclonal antibodies against CD8 (T suppressor/cytotoxic) antigen (Leu2/OKT8) were found to bind to leukaemic lymphocytes from a patient with chronic lymphocytic leukaemia. The cells also had an unusual type of rod-like cytoplasmic immunoglobulin of IgM/lambda type as seen by light, fluorescence and electron microscopy, and displayed several antigens characteristic for B lymphocytes. Gene rearrangement analysis showed rearrangement of mu heavy chain gene. In spite of an expression of CD8 antigen, T-cell receptor genes were not rearranged.

Aged↗

PubMed1987

Interleukin-2 can induce proliferation of leukemic B-cells in prolymphocytic leukemia.

In a case of prolymphocytic leukemia (PLL), receptors for interleukin-2 (IL-2R) were demonstrated by immunofluorescence with a monoclonal antibody against IL-2R. Highly purified leukemic B-cells, cultured in vitro with recombinant IL-2 (r-IL-2), responded to IL-2 with a marked increase of DNA-synthesis. Both spontaneous and r-IL-2-induced proliferation of leukemic cells were totally abrogated by the anti-IL-2R monoclonal antibody.

Aged↗

PubMed1987

Histopathology and immunohistology of HTLV-III/LAV related lymphadenopathy and AIDS.

Fifty-nine lymph node biopsies from homosexual men with serum antibodies to HTLV-III/LAV were the subject of a detailed histopathological and immunohistochemical study. The histological findings were correlated to the patients clinical status, and the T4/T8 ratios in blood and lymph nodes. Four histological patterns predominated and were defined as follicular hyperplasia (FH), follicular fragmentation (FF), follicular atrophy (FA), and follicular depletion (FD). Immunocytochemical studies indicated that destruction of follicular dendritic cells is related to the initiation of follicular involution from FH to FF, but the possible role of follicular infiltrating T-cells cannot be excluded. Marked individual variations in lymph node angiogenesis increasing during involution were observed, which suggests that the degree of angiogenic host response may predispose for evolution of Kaposi's sarcoma. The majority of the patients with the clinical diagnosis of persistent generalized lymphadenopathy (PGL) were morphologically staged as FH or FF (89%), whereas most of the AIDS patients showed lymph node changes compatible with FA and FD (89%). Patients with AIDS-related complex (ARC) had a wider spectrum of morphological lymph node changes but a majority of cases (62%) were also classified as FA or FD. Clinical follow-up showed progression from PGL to ARC in seven of 21 cases with the FF pattern and only in three of 19 cases with FH, indicating a possible prognostic value in differentiating between FH and FF. Three cases with FD and one with FA progressed to AIDS during the time of observation. T4/T8 ratios in blood and lymph nodes were significantly lower in patients with FD histology compared to patients of the other histological groups. At autopsy, all AIDS cases showed the FD pattern of lymphadenopathy. Autopsy findings in seven patients emphasized the importance of post-mortem studies in clarifying the spectrum of opportunistic diseases, including tumors which afflict the AIDS patients.

AIDS-Related Complex↗

PubMed1987

Quantification of CD8-positive lymphocytes in lymph node follicles from HIV-infected male homosexuals and controls.

The number of CD8-positive cells in follicular centres of hyperplastic lymph nodes from 20 Danish and Swedish homosexual men with persistent generalized lymphadenopathy and 43 control patients were enumerated in frozen tissue sections immunostained with monoclonal antibody reactive with the CD8-antigen ("cytotoxic-suppressor" T-cell antigen). All the homosexuals were seropositive for HIV and histology showed changes characteristic of the early stage of HIV lymphadenitis. A significant increase (p much less than 0.001) of CD8-positive cells was demonstrated (mean 1,307 per mm2 follicular centre, SD 639) in HIV-related lymphadenopathy compared with the controls (mean 161 CD8-positive cells per mm2 follicular centre, SD 169). The results of this study show that the immunohistological demonstration of a significant increase of CD8-positive cells in the follicles of hyperplastic lymph nodes is suggestive of HIV-related lymphadenopathy.

Acquired Immunodeficiency Syndrome↗

PubMed1986

Malignant B-cells have receptors for and respond to interleukin-2.

Interleukin-2 (IL-2) for a long time has been considered as a T-cell specific growth factor which acts through distinct surface receptors present on activated, but not on resting, T-lymphocytes. Recently it has been shown that activated murine and human B-cells also express IL-2 receptors and respond to IL-2 with an increase of DNA synthesis. Some human B-cell malignancies have been reported to react with anti-IL-2 receptor antibodies, but no response to IL-2 has been documented in these cases. Here, in five of 11 B-cell leukemia/lymphoma cases, we identified cells which not only express the IL-2 receptor, but also respond to IL-2 stimulation, as shown by a marked increase of 3H-thymidine incorporation and by differentiation of lymphoma cells. The IL-2-induced 3H-thymidine uptake was completely blocked by a monoclonal antibody to IL-2 receptor, which indicates that IL-2 acted directly through functional IL-2 receptors.

Antibodies, Monoclonal↗

PubMed1985

Leukemic myeloblasts expressing lymphoid markers.

Out of 60 patients with acute myeloid leukemia not preceded by chronic myelocytic leukemia or any preleukemic phase, 7 had both lymphoid and myeloid markers. All patients expressed common acute lymphatic leukemia antigen (CALLA) in 20% or more of their leukemic cells, which also showed positive peroxidase reaction. In addition, 4 patients had Auer rods. Two additional patients had morphologically clear acute monocytic leukemia (FAB M5b) and cells expressing CALLA. In 4 of the 7 patients the sum of the percentages of peroxidase or Leu M1 + and CALLA-positive blast cells exceeded 100%, suggesting that at least some of the cells had both myeloid and lymphoid markers. Moreover, out of 3 patients where double staining with the CALLA antibody J5 and the myeloid marker Leu M1 was performed, 2 had both markers on the same cells.

Adult↗

PubMedDate not supplied

Photodynamic therapy with topical 5-aminolevulinic acid for mycosis fungoides: clinical and histological response.

There is no curative treatment for mycosis fungoides (MF), the most common primary cutaneous T-cell lymphoma. The aim of this study was to investigate the response of single lesions to photodynamic therapy (PDT). The study included 10 plaque MF lesions and 2 tumour MF lesions from 10 patients. First, 20% 5-aminolevulinic acid was applied topically to the lesion and adjacent skin for 5-6 h. The lesion was then exposed to red light at around 630nm. Skin biopsies were taken before treatment, after clinical improvement and after clinical remission. The expression of CD3, CD4, CD7, CD8, CD1a, CD34, CD68, CD71, Ki-67, bcl-2 and p53 was studied immunohistochemically. There was complete clinical clearance in seven of nine plaque lesions. Neither tumour lesion responded to PDT. The biopsies confirmed a regression of the infiltrate after treatment. In the sparse remaining infiltrate a few CD4+ and CD8+ cells were found, most of which showed normal bcl-2. There were also fewer proliferating cells, illustrated by a decrease in Ki-67 and CD71. In conclusion, PDT has good clinical and histological effects in treating local plaque MF lesions.

Administration, Topical↗

PubMedDate not supplied

IFN-gamma is not the only mediator of suppressed myelopoiesis produced by mononuclear cells from aplastic anemia patients.

Peripheral blood mononuclear cells (PBMC) from patients with aplastic anemia (AA) and healthy donors were compared with regard to their ability to produce soluble factors with inhibitory activity on in vitro granulopoiesis (GM-CFC). Although PBMC from AA patients produced enhanced levels of IFN-gamma as compared to controls, this lymphokine was found not to be the main inhibitor of in vitro granulopoiesis. Other, non-IFN related factors were potent inhibitors of both the mature and the immature precursors for GM-CFC, could act across the species barrier and were of low molecular weight. Also PBMC from healthy donors produced a non-IFN mediated GM-CFC inhibitory factor, but to a lesser degree and acting only on one type of myeloid precursors. The possible implications of these findings in relation to the etiology of AA will be discussed.

Adult↗

PubMedDate not supplied

Immunocytochemical analysis and cytomorphologic diagnosis on fine needle aspirates of lymphoproliferative disease.

Fine needle aspirates were used for the cytologic and immunologic analysis of 21 cases of lymphoproliferative disorders. Immunocytochemical studies performed on Cytospin preparations confirmed the cytomorphologic diagnosis in 19 cases. In one case, the morphology of both aspirates and surgically obtained material showed a reactive pattern while immunologic analyses were inconclusive on both types of material. Immunocytochemistry on tumor material obtained by fine needle aspirations was in agreement with immunohistochemistry on surgical biopsies in 15 of 16 patients with malignant lymphomas. We conclude that immunocytochemical studies performed on Cytospin material in conjunction with the cytologic diagnosis will lead to an increase in diagnostic accuracy as well as providing a means for subclassification of neoplastic lymphoid cells. Moreover, this technique appears to give results comparable to those obtained by histopathologic and immunohistochemical analysis on surgically removed lymph nodes.

Adult↗