Publications by authors named "Schuit H"

We present the long-term outcome, at a median of 18 years (12.8 to 23.5) of open posterior bone block stabilisation for recurrent posterior instability of the shoulder in a heterogenous group of 11 patients previously reported on in 2001 at a median follow-up of six years.

View Article and Find Full Text PDF

Natural killer cells can phenotypically be identified as CD16 positive with a specific monoclonal antibody (B73.1 = Leu-11c) by either immunofluorescence microscopy or by flow cytometry. The standard procedure in flow cytometry is to set a window or gate around the so called lymphocytic population, based on scatter characteristics.

View Article and Find Full Text PDF

We studied natural killer (NK) cell subsets and NK function in young (25-35 years) and aged (75-84 years) persons by means of the single-cell assay. The subjects admitted to the study all fulfilled the SENIEUR health criteria in order to avoid confounding factors such as underlying disease or the influence of medication. We found no significant difference in the NK function between healthy young and aged persons on a per cell basis.

View Article and Find Full Text PDF

Analysis of the subpopulations of mononuclear cells in human blood in ageing has revealed a striking increase in the number of null cells, defined as non-T, non-B, non-monocyte cells, and a decrease in the number of T and B cells. By using recently developed monoclonal antibodies against natural killer cells in combination with T-cell markers in two-wavelength immunofluorescence, we were able to define 13 subpopulations of mononuclear cells and compare them in two groups of persons, respectively aged 25-34 and 75-84 years, all fulfilling the stringent admission criteria for immunogerontological studies described in the SENIEUR protocol, and thus all to be considered as optimally healthy and immunologically uncompromised. We found that the increased null cell population in the aged is a result of an increase in the numbers of NK cells, mostly the CD16+Leu7+ subset.

View Article and Find Full Text PDF

A patient with chronic B-cell leukemia in whom the malignant lymphocytes showed intracellular inclusions of immunoglobulin (Ig) G kappa molecules is described. Electron microscopy revealed filamentous material in the nuclear envelopes and in the cisternae of the rough endoplasmic reticulum. These in vivo surface Ig-negative, nonexcreting cells could be stimulated in vitro to excrete immunoglobulin-free light chain molecules into the supernatant, which were not found in the cytoplasm after stimulation.

View Article and Find Full Text PDF

Study of the immune system in ageing has yielded conflicting results. These controversies are mainly due to the selection of the subjects studied. We investigated the mononuclear cell subpopulations in the peripheral blood of subjects fulfilling strict admission criteria meant to exclude persons with diseases that influence the immune system.

View Article and Find Full Text PDF

To better understand the heterogeneity of chronic B-cell leukemias we correlated morphological and immunological features by studying the peripheral blood from 80 patients with a panel of anti-immunoglobulin and fourteen monoclonal antibodies, which hitherto were studied separately or with respect to one single morphological entity only. Of these the surface immunoglobulins (sIg) and monoclonal antibodies (McAb) BA-1, BA-2, FMC7, OKM1, and anti-T65 allowed a fair distinction between five cytological subtypes: chronic lymphocytic (CLL), "lymphoplasmacytoid" (LPL), centrocytic (CL), prolymphocytic (PLL), and hairy cell leukemia (HCL). In that order the sIg showed a decreasing number of cases of mu +/- delta class and an increase of alpha or gamma positivity.

View Article and Find Full Text PDF

Hairy cell leukemia is a chronic B cell leukemia. The presence of surface Ig (SIg) of gamma or multiple isotypes on the cells locates HCL at a rather mature stage of B cell differentiation. The reactivity of HC with McAb is in accordance with this concept (T65-, OKM1+, FMC7+, BA-1-).

View Article and Find Full Text PDF

Results of immunofluorescence observations in the study of normal and malignant blood lymphocytes are described. Data which support the proposition that most membrane bound immunoglobulin molecules are stable enough to remain intact during cytocentrifuge slide preparation are presented. Therefore not all positive cells in a fixed cytocentrifuge slide should be considered as containing cytoplasmic immunoglobulins.

View Article and Find Full Text PDF

Hairy cell leukemia (HCL) is a usually chronic B cell lymphoproliferative disorder. To evaluate the prognostic significance of the various heavy and light chain determinants of the surface immunoglobulins (slg), we analyzed the clinical data and immunologic phenotype of 64 patients with HCL. Sixty-two of the 64 patients showed slg, which was invariably of only one light chain type (kappa 33, lambda 29).

View Article and Find Full Text PDF

Most cases of hairy-cell leukaemia (HCL) involve proliferations of neoplastic B lymphocytes. In rare cases, M-proteins or osteolytic lesions have been documented in patients with HCL. In this study two patients with typical HCL are reported in whom both paraproteinaemia and osteolytic lesions of the femoral neck developed.

View Article and Find Full Text PDF

A case history of a patient with primary plasma cell leukaemia is presented. Analysis of serum showed an IgD lambda paraprotein, and lambda-light-chains were found in the urine. Immunofluorescence studies of a bone marrow aspirate revealed intracytoplasmatic IgD of lambda-type in plasma cells.

View Article and Find Full Text PDF

To determine the maturation arrest of the neoplastic cells of hairy-cell leukemia (HCL) and the spectrum of the surface markers on these cells, a series of 51 patients with this disease was studied. The cells of all but two of the patients showed monoclonal surface Ig with respect to light chains. In about one-third of the cases, only gamma heavy chain determinants were present on the cells; the majority carried multiple heavy chain determinants as documented by the application of different fluorochromes.

View Article and Find Full Text PDF

The activity and the specificity of 29 fluorochrome conjugated antisera against human immunoglobulin heavy and light chains were evaluated by performance testing with the direct technique of immunofluorescence using plasma cells and lymphocytes as biological substrates. Fifteen conjugates gave satisfactory results in the detection and classification of cytoplasmic and surface bound immunoglobulins and were therefore considered specific. Fourteen conjugates did not meet the required standards.

View Article and Find Full Text PDF

Small lymphocytes from adult human blood were examined for the presence of membrane-associated alpha, gamma, delta and mu Ig isotypes by means of a direct immunofluorescence technique. Since less than 10% of the small lymphocytes in blood are B cells as defined by positive reactivity with an anti-Fab conjugate, our experiments were performed on a T cell-depleted fraction in which about 80% of the small lymphocytes were B cells. With the two-wavelength immunofluorescence method, all of the double-isotype combinations were found.

View Article and Find Full Text PDF

The presence of surface-associated immunoglobulins and Fc receptors on mononuclear cells from normal human blood was investigated by the direct immunofluorescence technique combined with phase-contrast microscopy. Formaldehyde-fixed cells were compared to unfixed cells and to cells preincubated at 37 degrees C. In the unfixed samples a separate population which showed Fc receptors in an immunofluorescence technique using a labelled antigen--antibody complex was detected.

View Article and Find Full Text PDF

The technical details of a fixation procedure with formaldehyde which was applied in a direct membrane immunofluorescence technique to mononuclear cells from normal human blood are described. After separation of the cells with Ficoll--Isopaque according to Böyum (1963) they were washed and fixed with 0 . 04% formaldehyde in PBS for 10 min and washed again.

View Article and Find Full Text PDF

Formaldehyde-fixed small lymphocytes from human tonsils were investigated for the presence of the Ig heavy chain class isotypes alpha, gamma, delta and mu on their membranes by means of a direct immunofluorescence technique. About 50% of the small lymphocytes were defined as B cells with an anti-Fab antiserum. Most of the B lymphocytes carried more than one isotype on their membrane, and all combinations of two isotypes were observed.

View Article and Find Full Text PDF

Most cases of hairy cell leukemia represent malignancies of B cells. However, recent findings suggest that there is a spectrum of functional capacities within the entity hairy cell leukemia. Two patients with hairy cell leukemia, whose malignant cells in the peripheral blood showed both T- and B-cell features, are reported.

View Article and Find Full Text PDF

Fifteen cases of histologically proven hairy-cell leukaemia (HCL) were studied with immunofluorescence, rosette, and phagocytosis techniques. Unfixed hairy cells (HC) bound all kinds of labelled antiserum; but after fixation with formaldehyde a much more selective binding was observed. In two cases no surface-bound Ig was detected; four cases showed gamma and in nine cases two or three heavy chains were found, alpha and delta being the most frequent.

View Article and Find Full Text PDF

Transplantation experiments in the C57BL/KaLwRij mouse model of idiopathic paraproteinemia (IP) showed that an IP-producing clone can be further propagated in young, lethally irradiated mice and also equally as well in nonirradiated recipients by a bone marrow and/or spleen cell transfer. The latency period before the original paraprotein was detected in the sera of recipients varied in different experiments between 1 and 9 months after transplantation. With subsequent transplantations, the "take" frequency gradually decreased.

View Article and Find Full Text PDF

Fresh lymphocytes and frozen-stored lymphocytes were separated into E-RFC-enriched and E-RFC-depleted cell fractions by density gradient centrifugation of sheep red blood cell (SRBC) rosette-forming cells (E-RFC), since the ability to form rosettes is primarily a T cell characteristic. Subpopulations of lymphocytes were identified, demonstrating the presence of cell surface markers: T cell specific antigens (T+), receptors for SRBC on T cells (E-RFC), Fc-receptors (FcR) for IgG type antibodies, and surface Ig (sIg). Our results indicate that, although the E-RFC-depleted fraction contains virtually no cells capable of binding SRBC, there is still a considerable proportion of T cells present in that fraction, as detected with the anti-T cell antiserum.

View Article and Find Full Text PDF

The development of T- or B-membrane determinants on human foetal lymphoid cells was studied by the direct immunofluorescence technique, using a tetramethyl rhodamine isothiocyanate (TRITC) labelled horse antihuman T-cell conjugate (ATC) for the detection of T lymphocytes and a fluorescein isothiocyanate (FITC) labelled goat antihuman Fab conjugate for the demonstration of Ig-bearing B lymphocytes. Human foetal lymphocytes were also tested for spontaneous rosette formation with sheep red blood cells (SRBC). Cell suspensions of liver, spleen, thymus, bone marrow and blood of twenty-five human foetuses of 5·5–26 weeks of gestational age have been investigated.

View Article and Find Full Text PDF