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Biomedical subjects

Z N Berneman

Publications and source records attributed to Z N Berneman.

At least 73 records · Page 4Linked to original sources
PubMed1992

cDNA sequencing confirms HTLV-I expression in adult T-cell leukemia/lymphoma and different sequence variations in vivo and in vitro.

Human T-lymphotropic virus type I (HTLV-I) is the etiological agent of adult T-cell leukemia/lymphoma (ATL) and of tropical spastic paraparesis/HTLV-I-associated myelopathy (TSP/HAM). In both diseases, expression of viral message can generally only be demonstrated by the reverse transcriptase-polymerase chain reaction (RT-PCR) technique. We have previously reported on the the expression of at least four types of alternatively spliced pX mRNAs in vitro and in vivo (1). The sequence variation between HTLV-I pX cDNAs cloned from two different HTLV-I-infected cell lines and from uncultured primary peripheral blood mononuclear cells (PBMC) from two ATL patients was examined. None of the cDNA clones from one of the ATL samples was completely identical to any of the previously cloned cell line messages, establishing that the demonstration of HTLV-I mRNA in ATL is not the result of PCR contamination. Sequence analysis showed that differences between samples can be clustered according to their geographic origin. Cell line cDNAs showed a more marked sequence drift than ATL cDNAs, especially in the long terminal repeat (LTR), demonstrating association of intrastrain variability with culture in vitro. Intrastrain cDNA variability in vivo also suggests ongoing viral replication in infected individuals. A premature stop codon in the pX-II open reading frame (orf) was a common finding, suggesting that the complete putative pX-II protein is not essential for T-cell immortalization or HTLV-I replication.

Base Sequence↗
PubMed1991

Flow-cytometric analysis of erythrocytic blood group A antigen density profile.

Blood group A antigen density on red blood cells (RBC) was studied using flow cytometry (FCM) and fluoresceinated polyclonal and monoclonal IgG anti-A antisera. Agglutination was a problem, which could only be solved by prefixation of the RBC with glutaraldehyde or formaldehyde. However, this treatment resulted in a significant reduction of the number of antigen sites as compared to the native (i.e. nonfixed) RBC. Two major new findings came out of this study: (1) A antigen density on native RBC seems to be higher than previously recognized, and (2) A antigen density distribution is probably non-Gaussian. The absolute number of A antigen sites was determined, using a human polyclonal IgG antiserum and commercially available absolute fluorescence standards. The site numbers on fixed RBC were comparable to those found by earlier radioimmunological studies (x 10(6)/RBC): A1, 1.07 +/- 0.28; A2, 0.21 +/- 0.09; A1B, 0.79 +/- 0.26 sites (mean +/- SD). The values found for native RBC were considerably higher (x 10(6)/RBC): A1, 2.86 +/- 0.95; A2, 0.47 +/- 0.29; A1B, 1.98 +/- 0.58 sites (mean +/- SD). With the 1 monoclonal and the 3 polyclonal antisera used in this study, and in contrast to Rh D, the erythrocytic A antigen density distribution of a given sample is highly asymmetrical. This non-Gaussian distribution profile does not seem to be affected by such factors as antibody heterogeneity, variability in antibody fluoresceination range, RBC density and reticulocyte content. This suggests that the asymmetrical A antigen distribution may be an intrinsic property of the RBC population.

ABO Blood-Group System↗
PubMed1991

Stromal populations and fibrosis in human long-term bone marrow cultures.

An immunofluorescence study of the adherent layer of human long-term bone marrow cultures (HLTBMC) revealed the following surface markers on the different stromal cell populations: stromal fibroblastic cells CD10+, FIB86.3+, CD13+, CD71+; adipocytes CD10+, FIB86.3-, CD13+, CD71-/+; and macrophages CD10-/+, FIB86.3+, CD13+, CD71-/+, CD14+, CD33+, CD25+, HLA-DR+, CD4+, CD19+, CD45+. The markers of the stromal fibroblastic cells in HLTBMC were similar to those of twice-passaged fibroblasts not only from bone marrow and spleen, but also from a hemopoietic non-supportive organ such as the skin. Some of the cultured human umbilical vein endothelial cells used as controls were found to be CD25+, demonstrating for the first time the interleukin-2 receptor p55 chain on normal non-hemopoietic cells. The stromal fibroblastic cells are overrepresented compared to the small non-macrophage hemopoietic cell population in the adherent layer of HLTBMC. In addition, silver staining revealed an increased reticulin content in most of the HLTBMC. An excessive growth of stromal fibroblastic cells and an excessive deposition of their product, the reticulin fibers, are the hallmark of myelofibrosis. The finding of equivalent observations in HLTBMC suggests that the hitherto unexplained, premature quenching of hemopoiesis in HLTBMC might at least partly be due to mechanisms similar to those operating in myelofibrosis in vivo.

Antigens, CD↗
PubMed1990

Morphological evidence for a motile behavior by plasma cells.

Immunofluorescence microscopy of the adherent layer of human long-term bone marrow cultures (HLTBMCs) consistently revealed motility-associated features in a part of the plasma cells. Not only were small surface blebs observed, but also long extensions whose morphology was reminiscent of neuronal axons. The observations were made in all HLTBMCs established with normal as well as myelomatous bone marrow (BM). Plasma cells with long extensions were also noticed on May-Grünwald-Giemsa smears of original uncultured BM from normal individuals and patients with myelomatous disorders. This suggests that the motility-associated morphological features occur in vivo as well as in vitro. The observations were most striking in the one case of plasma cell leukemia, both in culture as well as in the BM smear.

Bone Marrow Cells↗
PubMed1989

DNA fingerprints revealing common and divergent human DNA methylation patterns.

We compared DNA fingerprints of different cell populations from the same individuals, after separate digestion with the isoschizomers MboI and Sau3A. Methylation differences were observed within every individual when comparing fingerprints of Sau3A- with MboI-digested DNA, and of Sau3A-digested sperm with somatic DNA. In some cases, differences were also detected between fingerprints of Sau3A-digested somatic DNA originating from various cell sources. Methylation patterns common to all cell populations examined, including the germline, were observed with a higher frequency than divergent ones. These 'common methylations' are most likely to find their origin during early embryogenesis.

DNA↗
PubMed1989

A quantitative and dynamic study of endothelial cells and megakaryocytes in human long-term bone marrow cultures.

The quantitative evolution of endothelial cells (ECs) in Dexter-type human long-term bone marrow cultures (HLTBMCs) was investigated. Using monoclonal antibodies directed against von Willebrand factor (vWF) and against membrane antigens (EN-4 and PAL-E), a low percentage--usually less than 1% of stromal cells--of ECs was detected in all confluent cultures established from 11 different bone marrow samples. Generally these cells are not associated directly with the areas of myelopoiesis ("cobblestone areas"). ECs cannot be demonstrated in the adherent layer of most young, non-confluent, and of some old, HLTBMCs. In some instances, morphological features suggestive of dynamic behavior were seen (sprouting, canal formation). In addition, a very low proportion of vWF-positive megakaryocytic cells was found in 4 of 11 cultures, always in direct contact with the stromal fibroblastic cells.

Bone Marrow↗
PubMed1989

The nature of the adherent hemopoietic cells in human long-term bone marrow cultures (HLTBMCs): presence of lymphocytes and plasma cells next to the myelomonocytic population.

An immunological analysis of the nonmacrophage hemopoietic cells in the adherent layer of human long-term bone marrow cultures was performed in situ. It revealed not only the expected granulocytic and monocytic cells, but an important lymphoid population as well. The latter consisted of cells bearing the markers of mature T lymphocytes, B lymphocytes, and plasma cells. These cells were also present in the hemopoietic foci of the adherent layer, the so-called cobblestone areas. Although more CD8+ than CD4+ lymphocytes were generally present in the initial bone marrow inoculum, both the adherent layer and the nonadherent fraction disclosed a preponderance of CD4+ cells after a short period of culture. The majority of the lymphoid cells were present in the adherent layer, rather than in the nonadherent fraction of the cultures. The long-term presence of lymphoid elements in the adherent layer suggests their affinity for the bone marrow stroma and the possible enhancement of their persistence in vitro by contact with these cells.

Antibodies, Monoclonal↗
PubMed1989

Human long-term bone marrow cultures (HLTBMCs) in myelomatous disorders.

Human long-term bone marrow cultures (HLTBMCs) were established with bone marrow (BM) collected from five patients with myelomatous disorders (four with multiple myeloma, one with plasma cell leukemia). In all cases, up to at least 6 weeks of culture, there was a persistence of the monoclonal plasma cell population in the adherent layer of the culture. In some cultures proliferating plasma cells could be demonstrated by the Ki-67 monoclonal antibody. In all instances a paraprotein could be shown in the conditioned medium. This study demonstrates that malignant plasma cells, in analogy to their normal counterparts, have an affinity for the BM stroma and suggests that their long-term survival might be enhanced by their interaction with it.

Bone Marrow↗
PubMed1989

Comparison of human long-term bone marrow cultures (HLTBMCs) established from fresh and post-cryopreservation bone marrow samples from living and cadaver donors.

Human long-term bone marrow cultures (HLTBMCs) were established from thawed post-cryopreservation, as well as from cadaver donor bone marrow (BM) samples. The longevity was similar in the different series of HLTBMCs examined. CFU-GM could be cultured out of cadaver donor BM. This indicates that previously healthy people, under the conditions generally accepted as suitable for organ donation, could become suitable donors for allogeneic BM transplantation.

Bone Marrow Cells↗
PubMed1988

Karyotypic evidence for the leukemic involvement of the erythroblasts in erythroleukemia.

With the use of a monoclonal anti-glycophorin A antibody and flow cytometric cell sorting, an erythroleukemic bone marrow sample was separated in highly purified erythroblast and myeloblast fractions. Similar karyotypic anomalies were found in both cell populations as in the unseparated bone marrow. This study confirms that acute nonlymphocytic leukemia can originate at the level of a multipotential hemopoietic stem cell.

Antibodies, Monoclonal↗
PubMed1987

Flow cytometric analysis of T-lymphocyte subpopulations in B-cell chronic lymphocytic leukemia: correlation with clinical stage.

Several authors have studied the T-lymphocyte subpopulations in B-cell chronic lymphocytic leukemia (B-CLL), but previous studies were performed after preceding enrichment procedures, which are known to cause selective losses of certain subpopulations. To correct for this deficiency we used flow cytometric analysis, which enabled us to measure subpopulations directly on total blood samples. We studied T-lymphocyte subsets with OKT monoclonal antibodies in 45 patients with B-CLL. Serum levels of IgG, IgA and IgM were assayed simultaneously and findings were correlated with clinical stage (Rai classification). The absolute number of CD4-positive cells decreased in more advanced Rai stages, while the absolute number of CD8-positive cells increased, resulting in a progressive reduction in CD4/8 ratio. Results from patients in stages with equal prognosis (Rai I and II, Rai III and IV) were similar and when these results were grouped the observed differences were highly significant and clearly correlated with all prognostic groups.

Adult↗
PubMed1986

Flow cytometric analysis of hairy cell leukemia using right-angle light scatter.

We report on an easy and reliable method for the enumeration of the typical cells present in the blood, bone marrow, and spleen of patients with hairy cell leukemia. Samples of five patients were analyzed. In three patients, the hairy cells were very accurately followed during treatment with alpha-interferon, using right-angle light scatter to differentiate them from other leukocytes present in total blood. Excellent correlation was obtained with the microscopic hairy cell enumeration. Additional verification by cell sorting and immunofluorescence studies confirmed these findings.

Cell Count↗
PubMed1986

Treatment of hairy-cell leukemia with recombinant alpha 2-interferon.

Eleven patients with hairy-cell leukemia (eight with progressive and three with non-progressive disease) were treated with low dose recombinant human alpha 2-interferon. After a 3-month treatment period, nine patients showed an improvement and one patient a partial remission. By then, transfusions were not required any more and serious infections were no longer encountered. Four patients were further treated: three for a total period of 9 months and one for 6 months; all of them reached a partial or complete remission. The treatment was equally effective in patients with both progressive and non-progressive disease. Previous absence of response to splenectomy did not preclude a positive effect of IFN therapy. In two patients, IFN dose reduction was necessary due to unremitting flu-like symptoms.

Humans↗
PubMed1986

Flow cytometric analysis of erythrocytic D antigen density profile.

Red blood cells (RBC) were studied with flow cytometry (FCM) after staining with a directly fluoresceinated anti-D antiserum. The immunofluorescence distribution profiles were slightly asymmetrical, due to a significant, yet small skewness. This skewness was not associated specifically with D antigen positivity, making a homogeneous, normal D antigen distribution on the RBC very likely. With the exception of Du, D-positive RBC could always be distinguished from D-negative ones. FCM was successful in bringing the following phenomena to light: difference in mean fluorescence intensity between the different rhesus phenotypes, the D gene dosage effect, the depressing effect of C antigen on D antigenicity, the nonspecific attachment of IgG on (D-negative) RBC and rhesus mosaicism. The absolute number of D antigen sites could be calculated, using an absolute fluorescence standard.

Erythrocytes↗