Quantitation of the Pap reaction on single cells by absorption cytophotometry

The reaction product of the unlabeled antibody enzyme method was quantitated at the single cell level by absorption microphotometry. Attempts were made to demonstrate that the amount of dye deposited on individual cells can be taken as a measure of the number of antibody molecules bound. In an experiment with prefixed sheep erythrocytes loaded in excess with amboceptor a close relationship was observed between cell size and the amount of dye measured. Furthermore, the known differences in A1 antigen density on human A1 and A2 erythrocytes were satisfactorily reproduced with this quantitative approach. As regards T antigen density on human lymphocytes of different origin, the results presented tally with data in the literature. It is therefore concluded that the method is suitable for quantitating antibody amounts bound to individual cells.

Expression of common acute lymphoblastic leukaemia antigen and terminal deoxynucleotidyl transferase in normal mononuclear blood cells during diffusion chamber culture

Peripheral mononuclear blood cells of 2 healthy individuals were cultured over a 13 d period in diffusion chambers. A high percentage of cALL antigen positive cells and later on TdT containing cells appeared during culture. The cALL+ cells could be clearly distinguished into 2 groups: a population with weak and diffuse fluorescence and a small number of ring-like brightly dyed cells. The first group develops into TdT+ cells and therefore resembles immature T-cells. The interpretation of the ring-like stained cells is still preliminary, but it cannot be excluded, that these cells represent a cell population with more than lymphatic differentiation capacity.

Appearance of B- or T-lymphocyte markers after diffusion chamber culture of acute lymphoblastic leukemia cells

Blast cells derived from blood and marrow samples of a patient with acute lymphoblastic leukemia (ALL), as well as from the Reh line originally established from an ALL patient, were cultured in diffusion chambers implanted i.p. into preirradiated CBA mice. At different intervals over a period of up to 20 days, surface immunoglobulins, ALL antigen, and T-cell antigen were investigated by using direct immunofluorescence. Rosette formation was tested with sheep and mouse erythrocytes. On day 0, the cells expressed only ALL antigen at the surface, and no rosette formation was observed. During culture the patient's lymphoblasts, which originally had cytoplasmic IgM in addition to ALL antigen, expressed surface immunoglobulins as well as mouse erythrocyte receptors. The Reh line cells were ambivalent in two experiments developing T-cell antigens and sheep erythrocyte receptors as well as mouse erythrocyte receptors. Our data suggest that the differentiation arrest in leukemic lymphoblasts can be overcome, thus entailing a surface pattern similar to mature T- or B-lymphocytes.

A simple test for the terminal deoxynucleotidyl transferase using the peroxidase-antiperoxidase technique

A technique has been worked out for an easy detection of terminal transferase in individual cells by means of the unlabeled antibody enzyme (PAP) method. Terminal transferase is an important enzyme marker for the classification of acute lymphoblastic leukemias that show a variable extent of differentiation into the T-cell series. The incubation procedure giving the best results is described.

Discrimination in immunofluorescence between labeled and unlabeled cells by quantitative microfluorometry and computer analysis

An automated procedure for discrimination in immunofluorescence between antibody-labeled and unlabeled cells has been developed on the basis of microfluorimetric determination of intensity distributions. After smoothing the raw data for irregularities caused by the scoring statistics optimum fit of the negative distribution to the corresponding positive one was achieved. The procedure was tested in a model system by mixing various known proportions of immunofluorescence-negative and -positive plastic beads. In addition, variable mixtures of T-negative CLL cells and normal mononuclear peripheral blood cells were labeled with FITC-conjugated anti-T-antiserum. The expected percentage of T-positive peripheral blood cells agreed satisfactorily with the data measured and computed. Finally, the measured percentage of Ig-positive mononuclear cells from normal peripheral blood was in agreement with the values obtained by other techniques.

Growth of the Reh cell line in diffusion chambers. Evidence for differentiation along the T- and B-cell pathway

Cells of the Reh line, originally derived from an ALL of the 'Non-T, Non-B' type were cultured in diffusion chambers implanted intraperitoneally into perirradiated CBA mice. At different intervals over a period of 20 d changes in surface characteristics were examined by labelling the cells with AcALLG, ATCG as well as with polyvalent AIg. The evaluation was performed by using direct immunofluorescence. In addition, the ability to form rosetts with SRBC, AET-treated sheep erythrocytes, mouse red blood cells and EoxAC was tested. On day 0 of the diffusion chamber culture the cells only carried cALLA, and no rosette formation was observed. In the course of the diffusion chamber culture the cells unequivocally developed T-cell antigen, and in 1 of 2 experiments they further acquired a receptor for forming AET- and E-rosettes. Conversely, in the other experiment a receptor for mouse red blood cells was detected in a considerable portion of the cells. Our data show that the rather undifferentiated Reh line cells in vitro are able to develop features of mature T-cells and attributes of early B-cells during the diffusion chamber culture. In vitro they apparently retain a bivalent potentiality of lymphatic maturation. The diffusion chamber system proves to be a suitable tool for promoting differentiation in these cells.

Myeloid membrane markers. I. Expression of marker antigens specific for murine granulocytes and their precursor cells

Bone marrow cells were investigated by immunoelectromicroscopy and by quantitative photometric immunoradioautography with a rabbit antiserum against murine bone marrow cells. The serum was absorbed with murine spleen, liver and thymus cells until it no longer reacted with thymocytes and lymph node cells in a quantitative complement fixation test. The antiserum stained granulopoietic but not erythropoietic or lymphopoietic cells. The density of the myeloid antigen on single cells increased with the differentiation from immature to mature granulopoietic cells. While the increase of label was statistically not significant at the level of differentiation from promyelocyte to myelocyte and metamyelocyte to band neutrophil, there was a remarkable gain of label from myeloblast to promyelocyte and from band neutrophil to segmented neutrophil. This was evident under the electron microscopy using peroxidase-labeled antibodies and could be measured quantitatively with photometric immunoradioautography using 125I-labeled antibodies.

[Clinico-endoscopic problems in malignant changes of the gastric stump]

The authors give a report on occasional difficulties concerning the radiological and endoscopic clarification of the malignant changes at the gastric stump after treatment of resection. Four relevant cases are stated and explained. The endoscopy (glass fibre gastroscopy) together with the biopsy is at present the most reliable method for the diagnosis of the pathological processes in the remaining part of the stomach. A regular endoscopic and radiological control of patients with gastric resection is desirable.

[Polyacrylic acid beads as a marker for B-lymphocytes (author's transl)]

B-lymphocytes can be characterized by the adherence of polyacrylic acid beads. The method was analyzed for specifity and reproducibility.

[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.