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Biomedical subjects

H Rodt

Publications and source records attributed to H Rodt.

At least 91 records · Page 5Linked to original sources
PubMed1977

Immunofluorescence study of lymphocytic infiltration in gliomas. Identification of T-lymphocytes.

Five human brain tumours (3 glioblastomas and 2 astrocytomas) and 5 rat brain tumours induced in Sprague--Dawley animals by systemic administration of N-methyl-N-nitrosourea (3 pleomorphic gliomas and 2 mixed gliomas) were studied. The human brain tumours were surgical specimens excised from patients with no cranial surgery prior to their disease. The experimental brain tumour had been adapted to tissue culture, propagated in vitro and then transplanted to immunocompetent and immunodeficient rats of the same stock. The above-described material was selected in consideration of the mononuclear cell infiltrates occurring in these tumours. Frozen sections of human and rat gliomas, the latter both primary and transplanted, were prepared and investigated as to the presence of T-lymphocytes within the mononuclear round cell infiltrates. This was done with the indirect immunofluorescence method using rabbit antisera against man and rat T-lymphocytes. With this technique a variable percentage of T-lymphocytes was demonstrated in the cell infiltrates of human and rat gliomas alike. The tumour transplanted in thymectomized rats showed only isolated, scattered, positive-reacting cells, i.e., cells recognizable as T-lymphocytes by the above method. The results can be interpreted as circumstantial evidence for the occurrence of tumour-specific and/or tumour-associated antigens in the parenchymal cells of spontaneous and chemically-induced gliomas.

Animals↗
PubMed1977

Immunohistochemical identification of T-and B-lymphocytes delineated by the unlabeled antibody enzyme method. II. Anatomical distribution of T- and B-cells in lymphoid organs of nude mice.

Tissue sections of the spleen, lymph nodes, and Peyer's patches were examined using an immunohistochemical demonstration of T- and B-lymphocytes in athymic homozygous nude mice possessing a known 1-5% of T-lymphocytes. Some of the few lymphocytes in the tyhmus-dependent periarteriolar zone of the spleen white pulp, the paracortex of lymph nodes and interfollicular area of Peyer's patches, were identified as T-lymphocytes. Also, singular T-lymphocytes occur in the thymus-independent marginal zone of the spleen white pulp, cortex and medulla of lymph nodes, as well as the follicular and subepithelial zones of Peyer's patches. These results indicate that the decreased numbers of T-cells in nude mice are found preferably in thymus-dependent regions, and to a smaller degree may recirculate in a similar way as in normal mice.

Animals↗
PubMed1977

Transplantation of syngeneic bone marrow incubated with leucocyte antibodies. I. Suppression of lymphatic leukemia of syngeneic donor mice.

"Antileukemic autotransplantation" an approach to eradicate by antibodies residual leukemia in the bone marrow taken during remission and regrafted in relapse is proposed and is the basis of investigations on the elimination of leukemic cells transferred to syngeneic mice. Rabbit antiserum against mouse T cells killed over 99% of cells when incubated with 10-5 lymphocytes of a T cell AKR/J leukemia transferred subsequently to syngeneic hosts. Seventy-five per cent of the recipients of antibody-coated and complement-treated leukemic cells survived the observation period of 80 days. Recipients conditioned with 800 R and given syngeneic bone marrow mixed with 10-5 leukemic cells died within 11 days, while 40% survived the observation period of 100 days without leukemia if the leukemic bone marrow had been preincubated with anti-T cell globulin (ATCG) and complement. A detrimental effect of ATCG on normal T cells could only be demonstrated in thymectomized, irradiated recipients of syngeneic ATCG-treated marrow. These mice did not reject H-2-incompatible skin grafts in contrast to the controls without ATCG or without thymectomy. ATCG thus inhibited leukemic lymphocytes while sparing stem cells for hemopoietic reconstitution. At the same time it did not interfere with the recovery of cellular immunity after bone marrow transplantation.

Animals↗
PubMed1977

Anatomical distribution of T and B lymphocytes identified by immunohistochemistry in the chicken spleen.

Antisera against chicken bursal and thymic lymphocytes were raised in rabbits. They were made specific for the target T or B cells by appropriat absorption and then used for immunohistochemical identification of T and B lymphocytes in tissue sections of chicken spleen, applying the unlabeled antibody enzyme method. Lymphocyte reacting with anti-chicken-thymus globulin predominated in the periarteriolar lymphatic sheaths and in the red-pulp cords. A few of these lymphocytes were localized between the periellipsoid lymphatic tissue and in germinal centers. The periellipsoid lymphocytes around the Schweigger-Seidel sheaths consisted of lymphocytes positive with anti-chicken-bursa-cell globulin. The majority of lymphocytes in the germinal centers were labeled also by anti-chicken bursa-cell globulin. Age-dependent changes in the anatomical localization of T and B lymphocytes are described between late embryonic development and an age of 2 years. The different conditions of avian and mammalian T and B cell distribution in the spleen were considered.

Aging↗
PubMed1977

Specific absorbed antithymocyte globulin for incubation treatment in human marrow transplantation.

The experimental data show that absorption of ATG with liver-kidney homogenate and CLL and LCL cells stepwise removed the hemopoietic toxicity, whereas the specific activity against T lymphocytes remained. Although the mode of action of absorbed ATG could not be tested in the first clinical case, the successful experiments in rodents together with the fact that the incubation treatment was tolerated by the patient may provide a new way of preventing fatal GVH reactions in man.

Animals↗
PubMed1977

Antilymphocytic antibodies and marrow transplantation. V. Suppression of secondary disease by host-versus-theta-graft reaction.

An approach to block secondary disease was investigated in mice sensitized against the Th-1.1 (theta-AKR) alloantigen on the marrow donor's T cells. To avoid a concomitant sensitization against the donor's histocompatibility antigens, prospective marrow recipients were sensitized against thymocytes of a third-party strain sharing the donor's Th-1 alloantigen but not his histocompatibility antigens. Advantage was taken of the fact that rats carry a Th-1.1-like theta-antigen which induces anti-Th-1.1 antibodies in Th-1.2 mice. CBA/J and (C57BL/6 x CBA)F1 Th-1.2 mice were sensitized against rat thymocytes and tranfused with spleen and bone marrow of AKR/J Th-1.1 after irradiation with 800 to 900 R. Although unsensitized recipients died within 3 weeks of acute secondary disease, sensitized mice survived the observation period of 50 days as chimaeras. Sensitized recipients were killed by the transplantation of spleen cells from congenic AKR/Cum carrying the Th-1.2 antigen. The host-versus-theta-graft approach suppressed secondary disease following H-2-compatible and -incompatible marrow grafts. Its hemopoietic and Tcell chimaeras tolerated skin grafts of the donor strain while rejecting third-party skin grafts.

Animals↗
PubMed1977

Effects of busulfan (BU) on hemopoiesis and immune reactivity in dogs.

Hematologic and immunosuppressive effects of BU were evaluated in 21 dogs. Twenty to 30 mg BU/kg produced severe but in most cases reversible myelotoxicity. All animals given 40 mg BU/kg died of marrow failure which was consistently reversed by the infusion of autologous marrow. Granulocytic progenitor cells (CFU-C) in the bone marrow of BU-treated dogs were severely depressed by day 7 after drug administration and in surviving animals showed only slow recovery to normal values. Cell-mediated immunity as determined by the in vitro reactivity of lymphocytes was normal after stimulation with T-cell mitogens (PHA, ConA), but impaired after stimulation with B-cell mitogens (PWM, SpA). Antibody formation against sheep red blood cells was not suppressed by BU-treatment.

Animals↗
PubMed1976

[Use of specific anti-T-lymphocyte globulin (sATG) for the diagnosis of lymphoproliferative diseases (author's transl)].

Difficulties in the production of specific antisera against T-lymphocytes could be overcome by a stepwise absorption and purification procedure of anti-human thymocyte serum. Specific anti-T lymphocyte globulin (sATG) reacted with thymocytes, thymus-derived lymphocytes and a lymphoblastoid cell line of T-cell type whereas no activity was found against lymphoblastoid cell lines of B-cell type. Five chronic and three acute lymphatic leukemias were characterized using sATG in the cytotoxic test, electron microscopy, complement fixation test and quantitative immunoautoradiography, and compared with lymphocyte populations of normal individuals. Three chronic lymphatic leukemias with low numbers of spontaneous rosettes and high percentages of membrane-Ig-positive lymphocytes showed only few T-cell-antigen-positive lymphocytes and were therefore classified as B-cell leukemias. The cells of two chronic lymphatic leukemias with high numbers of spontaneous rosettes carried T-cell-antigen. The T-cell-antigen concentration, however, was lower than that of normal peripheral blood T-lymphocytes. The T-cell nature of two acute lymphatic leukemias with high numbers of spontaneous rosettes was confirmed by a positive reaction of the cells with sATG. In one case of acute lymphatic leukemia most leukemic cells carried T-cell-antigen although these cells did not form spontaneous rosettes. In the first two cases the T-cell-antigen concentration on the cell surface exceeded that of normal blood-T-lymphocytes, in the latter case it was slightly below that. The advantages of the characterization of leukemias with sATG in comparison with the spontaneous rosette formation and the relevance for prognosis are discussed.

Antilymphocyte Serum↗
PubMed1976

Virus and trinitrophenol hapten-specific T-cell-mediated cytotoxicity against H-2 incompatible target cells.

Immune spleen cells from LCM virus-infected (CBA X C57BL/6)F1 radiation chimeras entirely repopulated with CBA-T6 lymphocytes were cytotoxic for allogeneic, LCM virus infected C57BL/6 mouse-derived target cells. Normal C57BL/6 targets were not lysed. CBA-T6 lymphocytes derived from (CBA X C57BL/6) radiation chimeras sensitized in vitro against TNP-conjugated C57BL/6 spleen cells lysed TNP-conjugated C57BL/6 targets. However normal C57BL/6 mouse-derived targets were not destroyed. The magnitude of virus-specific (or TNP-specific) cytotoxic responses against H-2 incompatible targets was lower compared to that against H-2 compatible targets. These data are considered to support and to extend the altered self concept, but are not consistent with the dual recognition concept.

Animals↗
PubMed1976

[Electronmicroscopic and immunohistochemical studies on human lymphocytes].

Lymphocytes from the blood of healthy individuals and of patients suffering from CLL were investigated by electron microscopy and peroxidase-immunohistochemistry. B-lymphocytes were labelled by heterologous, peroxidase-conjugated antisera directed against the Id-determinants of their membranes. T-lymphocytes were labelled by an indirect method: specific incubation with a specific anti-T-cell-globulin from the rabbit; labelling-incubation with a peroxidase-conjugated anti-rabbit-IgG-globulin from the sheep. In addition, T-lymphocytes were identified by their ability to form rosettes with sheep erythrocytes spontaneously. The quantitative results were: about 80% T-lymphocytes and about 24% B-lymphocytes in normal persons, the opposite results in CLL. T- and B-lymphocytes were photographed electron microscopically; the number of organelles in the single cells was evaluated: lysosomes in the average are more numerous in T-lymphocytes, ergastoplasm in B-lymphocytes, mitochondria are equally distributed in both groups of cells. There is so much overlapping, however, that the single cell only with the aid of immunochemistry or rosette formation can be identified as a B- or T-cell. In both, the T- and the B-cell-series, different forms of lymphocytes can be distinguished according to the degree of cell differentiation. Some further problems, as specificity of the antisera and labelling of the cells by means of their Fc-receptor are discussed.

B-Lymphocytes↗
PubMed1976

[T-cell leukemias of adulthood].

9 adult patients suffering from different forms of T-cell-malignancies were investigated: 4 patients with T-ALL; 1-T-ALL-CLL mixed form (prolymphocytic); 2 T-CLL; 2 Sézary-syndrome. The clinical peculiarities of the different forms of leukemias were compared: involvement of lymph nodes and spleen, of the central nervous system and the skin was frequent; in contrast to the findings in Sézary-syndrome, bone marrow infiltration was prominent. Light and electron microscopic morphology of the malignant cells are described. In all cases a strong activity of acid phosphatase was demonstrated, in one patient prominent deposits of glycogen. The T-cell-quality of the respective malignant cell population as well as the B-T-cell distribution of the remaining "normal" lymphocytes were shown by the following cell markers: demonstration of T-cell-antigen, resp. membrane immunoglobulins with the aid of specific heterologous antisera conjugated with peroxidase, 125iodine or fluoresceine; complement consumtion or cytotoxicity with such antisera; spontaneous rosette formation with sheep red cells or with acrylic acid beads. Usually, there was a good coincidence in results obtained with the different markers. In two patients, however, T-cells demonstrated by anti-T-globulin were not able to form T-rosettes. Responsiveness of the malignant T-cells and also of the remaining "normal" blood lymphocytes to different mitogens usually was depressed, immunoglobulin levels in the blood mostly were normal. Taking all findings into consideration, T-cell-leukemias of the adult represent a special group of hematological malignancies; the different subgroups show similarities; transitional forms occur.

Adult↗
PubMed1976

Immunohistochemical identification of T- and B-lymphocytes delineated by the unlabeled antibody enzyme method. I. Anatomical distribution of theta-positive and Ig-positive cells in lymphoid organs of mice.

The unlabeled antibody enzyme method was used to delineate the anatomical distribution of lymphocytes positive with a MBtheta and a-MIg in tissue sections of thymus, spleen, lymph nodes and Peyer's patches of mice. The known T- and B-cell areas were established. Moreover, individual B-cells are detected in T-cell regions, especially in the thymus medulla, and in the periarteriolar section of spleen white pulp. Similarly, individual T-cells occur in B-cell areas, namely in the marginal zone of spleen white pulp, in the medullar cores of lymph nodes, and in germinal centers.

Animals↗
PubMed1976

Decrease and altered distribution of human T antigen on chronic lymphatic leukemia cells of T type, suggesting a clonal origin.

B- and T-cell markers were studied in a patient with chronic lymphocytic leukemia and erythroderma. The absence of immunoglobulin, complement receptor, and Fc receptor, and the presence of sheep erythrocyte receptor and T-cell antigen on the membrane of the leukemic cells classified them as thymus derived. Using quantitative microphotometric immunoautoradiography, surface antigen densities were measured at the cellular level with the following results: (1) The density of T-antigenic sites was less on leukemic cells compared to normal T lymphocytes. (2) The T-antigen densities of leukemic lymphocytes varied less from cell to cell forming a homogeneous peak in histograms. (3) An Ig density of normal B lymphocytes was demonstrated on the residual T-antigen-negative cells. The results were qualitatively confirmed by direct immunofluorescence and electron microscopy with peroxidase-labeled antibodies. Furthermore, the surface antigens were quantitative microcomplement fixation test which revealed reduced binding of anti-T-cell antibodies and complement, and no antiglobulin fixation on the leukemic lymphocytes. Since lymphocytes with normal T-antigen concentration could not be found among the leukemic T lymphocytes, a lack of normal T cells was assumed. The findings that there was a decrease and altered distribution of surface markers on chronic lymphatic leukemia cells of the B- and T-cell type are discussed as further arguments referring to their clonal origin.

Aged↗
PubMed1975

Bone marrow transplantation in children with aplastic anemia and acute lymphatic leukemia.

A boy with severe Aplastic Anemia (AA) and a girl with Acute Lymphoblastic Leukemia (ALL) in relapse have been grafted with marrow from HL-A identical, mixed leukocyte culture (MLC) negative siblings after appropriate immunosuppressive and antileukemic therapy. Both of them are well 7 and 2 months after transplantation respectively. Bone marrow transplantation should be considered in children with AA and ALL in relapse, if HL-A identical, MLC negative siblings are available.

Anemia, Aplastic↗
PubMed1975

Quantitative immunoautoradiography at the cellular level. I. Design of a microphotometric method to quantitate membrane antigens on single cells using 125I-labeled antibodies.

Iodine-125 has become a commonly-used radioisotope, especially for immunoautoradiographic investigations. Microphotometry of grain density, a well-established method in autoradiography with tritium and carbon-14, was applied to nucleated cells with 125I-labeled membranes. Geometric and absorption factors of radiation were investigated in order to find suitable conditions for quantitative evaluation. A preparatory device is given and a set-up of appropriate measuring conditions is presented. With these prerequisites the reflected-light bright-field photometry of immunoautoradiographs permits to determine automatically the content of surface antigens of single cells. Measurement examples were demonstrated.

Animals↗