Search PubMed⌕ Search

Biomedical subjects

S Poppema

Publications and source records attributed to S Poppema.

At least 73 records · Page 4Linked to original sources
PubMed1995

Effects of monoclonal antibody against CD45RB on peripheral blood mononuclear cell proliferation and on HLA-DR and adhesion molecule expression on thyrocytes of patients with autoimmune thyroid disease.

To evaluate the role of CD45 (especially that of the ectodomain region B) on immunocyte-thyrocyte signaling in patients with autoimmune thyroid disease (AITD), we have examined the in vitro and in vivo effects of a monoclonal antibody (mAb) against with CD45RB, termed MT3. MT3 was added to cultured peripheral blood mononuclear cells (PBMC) from patients with AITD and was additionally injected into severe combined immunodeficient (SCID) mice to which Graves' thyroid cells and intrathyroidal lymphocytes were engrafted. MT3 stimulated proliferation of PBMC when cultured for 2 to 3 days in patients with Hashimoto's thyroiditis (HT) and Graves' disease (GD) and in normal controls (NC). However, when cultured for 7 days, the stimulation index [SI: counts per minute (cpm) with mAb/cpm without mAb] was lowered by MT3 in NC and GD patients. However, the mean SI was not lowered in patients with HT. In SCID mice, the concentrations of human immunoglobulin G, antithyroglobulin and antithyroperoxidase antibodies in sera were not significantly changed by injecting MT3. The expression of human leukocyte antigen (HLA)-DR and intercellular adhesion molecule (ICAM)-1 on engrafted human thyrocytes decreased after the tissues were engrafted into the control mice to which vehicle alone was injected. However, in the mice injected with MT3, HLA-DR and ICAM-1 expression remained high or up-regulated by the injection.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

Binding of cardiolipin to polystyrene beads: evidence for a lamellar phase orientation.

The association of cardiolipin with polystyrene beads was studied using 31P-NMR and electron microscopy. In the presence and absence of fetal calf serum, cardiolipin appeared to bind to the polystyrene beads in lamellar phase as assessed by 31P-NMR imaging. Electron microscopic analysis revealed an even coating of phospholipid about the beads with extensive micelle binding. Cardiolipin-coated beads challenged with ACA-positive sera followed by immunogold indicated antibody bound to micelles associated with the bead. Studies conducted with ACA IgG purified from patient sera indicated that some ACA bound to CL beads in the absence of a source of ACA cofactor (i.e. gelatin-blocked beads), some ACA required beta 2-GPI for binding (i.e. no binding in the presence of beta 2-GPI-depleted plasma), whereas other ACA which showed negligible binding with gelatin-blocked beads, showed enhanced binding in the presence of beta 2-GPI-depleted plasma. The data indicate that: (1) cardiolipin binds to polystyrene beads in lamellar phase, (2) ACA bind to phospholipid micelles bound directly to the polystyrene beads, and (3) ACA differ between individuals displaying varying phospholipid and phospholipid/cofactor substrate specificities.

Antibodies, Anticardiolipin↗
PubMed1994

Immunogold labelling of leukemic hairy cells with the B-ly7 monoclonal antibody: an SEM and TEM study.

Two cases of hairy cell leukemia have been studied by immuno-TEM and immuno-SEM after immunogold labelling of the cell surface antigen recognized by the B-ly7 monoclonal antibody. Most hairy cells appeared significantly labeled, although the density of the expression of the antigen, as demonstrated by immunogold labelling, seems variable from cell to cell. Moreover, some cells with the morphology of hairy cells and which could not be identified as monocytes were not labeled. Labelling for the antigen identified by the B-ly7 mAb does not seem to correlate with the presence of ribosome lamellae complexes which were present only in one of the two cases studied. Rare lymphocytes of unidentified lineage were labeled. Monocytes were significantly absent from the samples of peripheral blood of the two patients studied. In one normal control sample, monocytes were observed unlabelled. The results are discussed in reference to the pathogenesis of hairy cell leukemia, its surprisingly low mitotic rate, and its distinct response to chemotherapy.

Adult↗
PubMed1994

Epstein-Barr virus positivity in Hodgkin's disease does not correlate with an HLA A2-negative phenotype.

BACKGROUND: Epstein-Barr virus- (EBV) related DNA and RNA can be found in tissues involved with Hodgkin's disease, specifically in the Reed-Sternberg cells. These cells also express the membrane antigens LMP1 and LMP 2A and 2B. Studies in normal individuals indicate that cellular immunity against LMP2 was frequently mediated through human leukocyte antigen (HLA) A2, whereas responses to LMP1 appeared to be relatively infrequent. Assuming that LMP2-positive Reed-Sternberg cells would be sensitive to a CD8-positive cellular immune response, the hypothesis can be made that EBV-positive Hodgkin's disease should be more common in individuals not expressing HLA A2. To test this hypothesis, the authors have studied the frequency of HLA A2 in EBV-positive versus EBV-negative patients with Hodgkin's disease. METHODS: All 72 patients diagnosed with Hodgkin's disease in Northern and Central Alberta, Canada, during 1990 and 1991 were studied. A nonisotopic in situ hybridization method with an oligonucleotide probe specific for EBER 1 and 2 was used. In addition, sections were stained for the EBV-latent protein LMP1, HLA A2, and a monomorphic HLA class I determinant and beta 2-microglobulin. RESULTS: EBER-positive Reed-Sternberg cells were found in 26% of the patients. The percentage of positive patients was 86% in mixed cellularity, 13% in nodular sclerosis, and 0% in lymphocyte predominance. The number of those who were HLA-A2 positive was approximately 50% in the EBV-positive and -negative patients. CONCLUSIONS: Therefore, no correlation between HLA A2 expression and presence or absence of EBV in the R-S cells of Hodgkin's disease was identified.

Base Sequence↗
PubMed1994

Postnatal changes of CD45 expression in peripheral blood T and B cells.

One known postnatal change of CD45 expression is the decline of the CD45RAhigh CD45ROlow T subsets and the reciprocal increase of the CD45RAlow CD45ROhigh T subsets in the peripheral blood. Using a panel of monoclonal antibodies reactive with either protein or carbohydrate epitopes on the variable regions of CD45, we were able to detect more postnatal changes of CD45 expression. These changes are largely caused by modulation of the CD45 glycosylation, including: (1) lesser sialylation of the CD45RA region on T cells, and (2) differential sialylation of the CD45RB region leading to the distinction of CD45RBhigh and CD45RBlow T and B subsets. In addition, the existence of the CD45RAdim CD45ROdim labelled as transitional T cells is only found during the postnatal life. These changes may reflect the maturation of the immune system.

Adolescent↗
PubMed1994

CD45 isoform expression on human haemopoietic cells at different stages of development.

Alternate splicing and glycosylation produce multiple CD45 isoforms which are selectively expressed on the surface of cells of the haemopoietic system. The expression of CD45RA, CD45RB and CD45RO on CD34+ and CD34- haemopoietic cells from umbilical cord blood, bone marrow and fetal liver were studied by flow cytometry. CD34+ subpopulations defined by CD45 isoform expression were sorted from bone marrow and tested in long-term culture assays. By combining results of functional studies with phenotypic data and previously published information, the following pattern of CD45 isoform expression on early haemopoietic cells was established. The most primitive CD34+ cells are CD45RO+ CD45RB+ and express low or undetectable levels of CD45RA. Upon erythroid differentiation, CD34+ cells remain CD45RO+ CD45RB+, whereas commitment into the myeloid and lymphoid lineages coincides with down-regulation of CD45RO and up-regulation of CD45RA. As a result, the majority of CD34+ cells can be divided into two mutually exclusive populations of cells which express either CD45RO or CD45RA. This notion was confirmed in this study by three-colour immunofluorescence. The alternative expression of various CD45 isoforms on functionally distinct haemopoietic cells suggests an important role for these molecules in the proliferation and differentiation of haemopoietic cells.

Alternative Splicing↗
PubMed1994

Clinical significance of bcl-2-MBR gene rearrangement and protein expression in diffuse large-cell non-Hodgkin's lymphoma: an analysis of 83 cases.

PURPOSE: The goal of this study was to assess the prognostic significance of a rearrangement of the major breakpoint region of the bcl-2 gene and/or expression of bcl-2 protein in diffuse large-cell lymphomas of B-cell origin. PATIENTS AND METHODS: All 83 patients diagnosed at the Cross Cancer Institute between 1987 and 1992 with malignant lymphoma (ML), diffuse large-cell ML non-cleaved-cell ML or cleaved-cell ML, or with diffuse large-cell immunoblastic ML were studied. bcl-2 rearrangement was identified by a polymerase chain reaction technique. This technique detects the approximately 60% of rearrangements involving the major breakpoint region bcl-2 gene (bcl-2-MBR). bcl-2 protein expression was studied by immunohistochemistry. RESULTS: More than 66% of the cases expressed bcl-2 protein, whereas 18% had a detectable bcl-2-MBR gene rearrangement. Overall, cases with bcl-2-MBR rearrangement had shorter disease-free periods. Cases with nodal and extranodal presentation had a similar frequencies of bcl-2-MBR rearrangement; however, the disease-free period of patients with extranodal presentation and bcl-2-MBR rearrangement was significantly shorter than that of those without rearrangement. CONCLUSION: bcl-2 protein is frequently expressed in diffuse large-cell lymphomas, but does not influence prognosis. The bcl-2-MBR gene rearrangement may possibly be associated with a shorter disease-free period, particularly in the specific setting of a lymphoma with extranodal presentation.

Adolescent↗
PubMed1994

Absence of HLA class I expression by Reed-Sternberg cells.

The reactive cell population in Hodgkin's disease consists of predominantly CD4+ helper T cells and lacks CD8+ cytotoxic T cells and natural killer cells. This lack of a CD8+ response is surprising in view of the expression of the latent Epstein-Barr viral protein LMP by Reed-Sternberg cells in many cases of Hodgkin's disease, Deficient HLA class I expression would be one possible mechanism to avoid a CD8+ cytotoxic immune response. To test this possibility we studied the expression of HLA class I and II determinants on Reed-Sternberg cells in tissue sections and cell suspensions of Hodgkin's disease. Frozen tissue sections of 40 cases and cytocentrifuge preparations from cell suspensions of 10 lymph nodes involved by Hodgkin's disease were studied with monoclonal antibodies reactive with HLA determinants. As a control frozen tissue sections of two cases of infectious mononucleosis were studied. Careful examination of the tissue sections and subsequently of cytospins of cell suspensions showed that the Reed-Sternberg cells frequently lacked HLA class I but showed strong staining for HLA class II. Absence of HLA class I expression on Reed-Sternberg cells and their variants provides an explanation for the lack of a CD8+ cytotoxic immune response against antigens expressed on Reed-Sternberg cells.

Epitopes↗
PubMed1994

Immunocytology of body cavity fluids. MOC-31, a monoclonal antibody discriminating between mesothelial and epithelial cells.

This study was designed to assess whether monoclonal antibody MOC-31, which recognizes a membrane glycoprotein of 40-kd molecular weight present on epithelial cells and not on mesothelial cells, is a useful adjunct in the differential diagnosis of reactive pleural or ascitic fluids and adenocarcinoma. A panel of antibodies against carcinoembryonic antigen, epithelial membrane antigen, vimentin (antivimentin), keratin 18 (RGE-53), and cytokeratins of several molecular weights (AE1/AE3) was employed for comparison. Ninety-eight cases were selected based on the availability of pleural and peritoneal biopsy specimens for histologic confirmation. All cases with adenocarcinoma stained MOC-31 positive, including three cases that had not been identified by morphologic criteria. All cases of reactive mesothelial hyperplasia were negative, as well as five cases of malignant mesothelioma. One case of squamous cell carcinoma was also negative. Anti-carcinoembryonic antigen only identified half of the carcinoma cases, and anti-epithelial membrane antigen and both anticytokeratin antibodies were positive in the majority of tumor cells as well as in the mesothelial cells. This study indicates that monoclonal antibody MOC-31 is a highly sensitive and reliable reagent in the differential diagnosis between mesothelial and epithelial cells.

Adenocarcinoma↗
PubMed1993

Patterns of leucocyte common antigen expression in peripheral blood T cell populations.

The restricted forms of CD45 are differentially expressed on lymphocyte subsets in different maturation stages and with different functional activities. The best-known examples are the expression of CD45RA on naive and CD45RO on memory T cells. Multicolor flow cytometry allows for the analysis of lymphocyte subsets with respect to the expression of the various CD45R isoforms (RA, RB, RO). Here we report on the distribution of these isoforms in normal peripheral blood T cells, including the CD4, CD8, and CD56 subsets. The results indicate the presence of a number of consistent patterns within these subsets, which can be linked to populations with well-defined functional activities, and also identify several transitional stages and hitherto undefined subsets.

Antigens, CD↗
PubMed1993

Diagnostic application of two-color flow cytometry in 161 cases of hairy cell leukemia.

Recent immunophenotypic studies of hairy cell leukemia (HCL) have suggested specific patterns of immunoreactivity that may aid in diagnosis. We studied peripheral blood (PB) from 161 cases of HCL using two-color direct immunofluorescence flow cytometry and an extended panel of antibody combinations. Circulating hairy cells were identified by immunophenotypic features in 92% of the cases and could be detected even when representing < or = 1% of circulating lymphocytes. The 133 cases with > or = 2% detectable hairy cells were analyzed in detail. HCL showed a uniform and unique B-cell phenotype, with each of the following features identified in 99% to 100% of cases: (1) positive staining for B-ly7, coexpressed with CD19; (2) very intense, uniform expression of CD11c, with CD19; (3) moderately intense staining for CD25, with CD19; (4) very intense staining for CD22; (5) moderate to very intense staining for CD20; and (6) moderately intense monoclonal surface Ig. Phenotypic variability existed in expression of CD10 (26%) and CD5 (4%). Based on these features, HCL was easily distinguished from 50 cases of chronic lymphocytic leukemia (CLL). Although CLL exhibited frequent expression of CD11c (74%) and CD25 (68%), the intensity of staining was significantly less than HCL. Furthermore, CLL was uniformly positive for CD5 and showed weak staining for CD20, CD22, and surface Ig. B-ly7 proved to be the most specific marker, reacting with 100% of HCL cases, but absent in all cases of CLL. We conclude that two-color flow cytometry with specific antibody combinations is an efficacious method for characterization and sensitive detection of hairy cells in PB. Application of the phenotypic criteria described should help to increase accuracy in diagnosis of HCL.

Antigens, CD↗
PubMed1993

Expression and function of a receptor for hyaluronan-mediated motility on normal and malignant B lymphocytes.

Migration through extracellular matrix is fundamental to malignant invasion. A receptor for hyaluronan-mediated motility (RHAMM) has previously been shown to play a fundamental role in locomotion of ras-transformed cells as well as functioning in signal transduction. Expression of RHAMM was characterized on B lymphocytes from normal and malignant lymphoid tissues using multiparameter phenotypic immunofluorescence analysis as well as functional analysis of its role in locomotion of malignant hairy cell leukemia B cells. RHAMM is not detectable on most normal B cells located in blood, spleen, or lymph node, but it is detectable on bone marrow and thymic B cells. Among B-cell malignancies, it is expressed on most terminally differentiated B cells from multiple myeloma bone marrows, is present on a subset of non-Hodgkin's lymphomas, and is absent on B chronic lymphocytic leukemia. Activation of peripheral blood B cells by Staphylococcus A cowan (SAC), but not by pokeweed mitogen, induced transient expression of RHAMM at day 3 of culture, suggesting RHAMM may be used by antigen-activated normal B cells. For malignant cells, expression of RHAMM increased on long-term culture of bone marrow plasma cells from multiple myeloma patients, indicating prolonged expression in contrast to the transient expression on SAC-activated normal B cells. Intriguingly, RHAMM was expressed on hairy leukemia cells located in spleen but absent from those in peripheral blood of the same patient. RHAMM, as expressed on splenic hairy cells, was a 58-Kd molecule that binds hyaluronan, is encoded by a 5.2-kb messenger RNA, and participates in locomotion by these cells. Hairy cells locomoted in response to hyaluronan at 4 mu per minute. Monoclonal antibody to RHAMM inhibited this locomotion almost completely as detected using video time-lapse cinemicrography. These observations are consistent with a role for RHAMM in malignant invasion and metastatic growth.

B-Lymphocytes↗
PubMed1993

Chronic lymphocytic leukemia with CNS involvement.

Direct involvement of the brain by chronic lymphocytic leukemia (CLL) is extremely rare. This is the second documented case. A 63 year-old-man presented with motor deficits. Conventional radiographic imaging showed no abnormalities but an MRI scan of the head showed a high signal intensity lesion in the left cerebellum. Biopsy of this area showed a perivascular infiltrate of small B lymphocytes consistent with CLL involvement. The patient was treated with radiotherapy and had some improvement in symptoms. Three years later he remains alive with some neurologic deficit. This case confirms that CLL can be complicated by direct brain involvement.

Brain↗
PubMed1993

DNA analysis (ploidy) of molar pregnancies with image analysis on paraffin tissue sections.

Hydatidiform moles can be subclassified based on their ploidy. In general, complete moles are diploid, and partial moles are triploid. The standard method for the determination of DNA content is flow cytometric analysis. In this study, the authors investigated whether static cytometric analysis with the CAS 200 Image Analyzer (Cell Analysis Systems, Inc., Elmhurst, IL) with a software program designed for quantitation of nuclear DNA content in tissue sections can be used to classify moles. Tissue sections from 17 moles were analyzed with this system, and the results were compared with those obtained with flow cytometric analysis. It was found that cell selection was an important factor. A high proportion of the hyperplastic trophoblast was in G2M. Exclusion of these areas and measurement of the trophoblast lining the villi only led to reliable results, and complete agreement between the results of the two methods was obtained. The findings indicate that cytometric analysis on tissue sections is a reliable alternative to flow cytometric analysis for the designation of moles as diploid or triploid.

DNA↗
PubMed1993

Characterization of the alkaline phosphatase expressed on the surface of a Hodgkin's lymphoma cell line.

Alkaline phosphatase solubilized from a human Hodgkin's lymphoma cell line (L428) was compared with purified amphiphilic and hydrophilic forms of the enzyme from human liver, and with the enzyme solubilized from a cultured osteosarcoma cell line (Saos-2). Purified hydrophilic alkaline phosphatases from human placenta and intestine were also compared in some experiments. Alkaline phosphatase was released from the plasma membrane of intact lymphocytes by phosphatidylinositol phospholipase C and thus is anchored to the outside of the plasma membrane by covalently attached phosphatidylinositol. Enzyme released in this way was hydrophilic and that solubilized with Triton X-100 was amphiphilic, as assessed by adsorption to octyl-Sepharose. Lymphocyte alkaline phosphatase, when released from the membrane by phosphatidylinositol phospholipase C or solubilized by Triton X-100, had apparent M(r) values on gradient gel electrophoresis of 227 and 494 kDa, respectively. These values were consistently higher than equivalent ones obtained with enzymes purified from human liver, but were similar to those of cultured osteosarcoma cells. Isoenzyme-specific inhibitors of alkaline phosphatase showed similar patterns of inhibition between the enzyme from L428 cells and the tissue-nonspecific (liver/kidney/bone) isoenzyme from human liver. Heat stabilities were similar for the enzymes from L428 and Saos-2 (bone isoform) cell lines, but differed significantly from those of liver, intestine and placenta. We conclude that the alkaline phosphatase expressed in this lymphoma cell line (L428) has properties that most closely resemble those of the tissue-nonspecific isoenzyme found normally in osteoblasts of bone (bone isoform).

Alkaline Phosphatase↗
PubMed1992

Chromosomal abnormalities in patients with Hodgkin's disease: evidence for frequent involvement of the 14q chromosomal region but infrequent bcl-2 gene rearrangement in Reed-Sternberg cells.

BACKGROUND: Rearrangements of the bcl-2 gene (also known as BCL2) have been detected in up to 40% of cases of Hodgkin's disease, and it has been speculated that such rearrangements may have a role in the pathogenesis of Hodgkin's disease. PURPOSE: The purposes of this study were (a) to assess the frequency of clonal chromosomal abnormalities in Hodgkin's disease, (b) to identify recurrent changes, (c) to determine whether the bcl-2 gene rearrangement was present in Reed-Sternberg cells (the neoplastic cells of Hodgkin's disease) and their variants, and (d) to analyze whether the presence of t(14;18) translocations in Reed-Sternberg cells explains the observed bcl-2 gene rearrangements in Hodgkin's disease. METHODS: A cytogenetic study was performed on biopsy specimens from 28 consecutive untreated patients with Hodgkin's disease. The same patients were analyzed for bcl-2 gene rearrangement by a polymerase chain reaction (PCR) technique. To ascertain whether the abnormal karyotypes were present in and restricted to Reed-Sternberg cells, we also performed in situ hybridization with chromosome-specific probes. RESULTS: Abnormal metaphases were identified in 23 of the 28 patients. In 11 patients, the chromosome 14q region was abnormal; in six of these patients, there was involvement of the 14q32 region that comprises the gene encoding for heavy-chain immunoglobulin. Only one patient had a t(14;18) translocation, whereas almost 40% of these 28 patients showed bcl-2 gene rearrangements by a PCR method. The in situ hybridization method showed that the abnormal karyotype was present in and restricted to Reed-Sternberg cells. CONCLUSIONS: We conclude that the majority of cases of Hodgkin's disease contain a clonal population with an abnormal karyotype, comprising the Reed-Sternberg cells. The q32 region of chromosome 14 is frequently involved, but a t(14;18) translocation is extremely infrequent. The occurrence of a bcl-2 gene rearrangement in Hodgkin's disease most likely results from the presence of sporadic, small bystander B lymphocytes that carry the translocation and that also can be frequently detected in reactive lymphoid tissue such as tonsils. Also, a range of different chromosomal translocations may provide growth or survival advantages to Reed-Sternberg cells.

Chromosomes, Human, Pair 14↗
PubMed1992

Significance of c-erbB-2 amplification and DNA aneuploidy. Analysis in 78 patients with node-negative breast cancer.

BACKGROUND: Amplification of the c-erbB-2 protooncogene and DNA aneuploidy have been reported to correlate with poor patient prognosis in human breast cancer. Several studies have investigated the prognostic value of these two factors in heterogeneous populations of patients with node-positive and node-negative disease. This study evaluated, on a series of patients with node-negative disease, whether c-erbB-2 proto-oncogene amplification and cellular DNA content could identify a subset of patients who, without adjuvant therapy, are destined to experience a relapse. METHODS: Paraffin-embedded tissues of 78 patients were evaluated for cellular DNA content using flow cytometric analysis. Amplification of c-erbB-2 was determined on the same group of patients using slot-blot hybridization. The majority of patients were matched with control subjects for the following five clinicopathologic criteria: size of primary tumor, menopausal status, estrogen receptor, anniversary year of initial treatment, and age at treatment. Long-term follow-up (5-16 years) was available for each patient, none of whom received any form of adjuvant therapy. RESULTS: The presence of an abnormal DNA stemline was found in 47% (37 of 78) of the tissue specimens, whereas only 10% (8 of 78) of the tumors expressed from 3-fold to 22-fold c-erbB-2 amplification. Combined c-erbB-2 amplification and DNA aneuploidy occurred in a small group of patients (n = 4), all of whom experienced relapse. The four remaining tumors having excessive gene copy numbers had a diploid DNA distribution. CONCLUSIONS: The results indicate that tumors that overexpress the c-erbB-2 proto-oncogene have variable amounts of DNA and that c-erbB-2 amplification and DNA ploidy analysis provide limited predictive information of relapse in patients with node-negative breast cancer. Although the combination of c-erbB-2 amplification and DNA aneuploidy may be a predictor of poor prognosis in a small number of patients, neither measurement alone is effective in identifying patients at increased risk of recurrence of disease.

Aneuploidy↗