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Biomedical subjects

H Zola

Publications and source records attributed to H Zola.

At least 127 records · Page 7Linked to original sources
PubMed1986

RCH-ACV: a lymphoblastic leukemia cell line with chromosome translocation 1;19 and trisomy 8.

A cell line (RCH-ACV) was established from a bone marrow sample of a child with acute lymphoblastic leukemia (ALL). The cell line lacked Epstein-Barr virus nuclear antigen and exhibited a recently described nonrandom chromosome translocation, 1;19, thought to be associated with pre-B-ALL and poor prognosis. Banding studies confirm that the breakpoint of chromosome #19 occurs at p13.3. Cell surface marker analysis using a panel of monoclonal antibodies revealed markers consistent with common ALL phenotype. Although the cells did not show cytoplasmic immunoglobulin, studies of the immunoglobulin gene rearrangement confirmed the pre-B phenotype. This cell line could be of great value to studies of the role of the specific translocation 1;19 in the etiology of pre-B-ALL.

Cell Line↗
PubMed1986

Surface marker analysis in acute myeloid leukaemia and correlation with FAB classification.

The immunological phenotype of blast cells in 102 patients with acute myeloid leukaemia (AML) was analysed with a panel of 20 monoclonal antibodies and the enzyme terminal transferase, and correlated with the FAB classification. Although a partial correlation between these two approaches could be observed, almost every morphological group contained patients from more than one immunological phenotype. The M1 and M5a leukaemias showed the most undifferentiated phenotype, often lacking in specific myelomonocytic antigens. The M3 formed a uniform group defined as My7+, Ia-, FMC8+, a phenotype which was also observed in two cases of the microgranular variant. The granulocytic (CDw15) and monocytic (CDw14) antibodies crossreacted with some M5b and M2 leukaemias, respectively. Compared with M5a, the M5b leukaemias showed a large increase in the expression of CDw14 antigen, confirming the validity of the morphological differentiation. Glycophorin-A was present in four out of five M6 leukaemias. TdT activity was demonstrated in 10% of AML cases, with a higher incidence among the monocytic variants: M4 and M5-. Eleven AML were considered as unclassifiable according to the FAB criteria and in seven of them a megakaryoblastic cell population (GP IIb/IIIa+, GPIb+) was demonstrated; this confirms the need to include the subgroup of megakaryoblastic leukaemias within the AML. Finally, a possible immunological classification for AML is proposed.

Adult↗
PubMed1986

Immunological phenotype of neoplasms involving the B cell in the last step of differentiation.

The immunological phenotype of diseases involving the last step of B cell differentiation--multiple myeloma (MM, 38 patients) and Waldenström's macroglobulinaemia (WM, 12 patients)--was analysed with a panel of monoclonal antibodies (McAb) as well as conventional markers. Most of the bone marrow plasma cells (80%) from MM patients reacted with the McAb OKT10, FMC8 and FMC48. Plasma cells were consistently negative with FMC7, Leu-1 and mouse rosettes. Ia, B1 and SIg were expressed in a minority of plasma cells (less than 30%) in half of the cases. The circulating neoplastic cells from five MM patients showed a more immature phenotype, with a higher reactivity for OKIa, B1 and increased SIg and a lower expression of CIg, than bone marrow plasma cells. The malignant cells of WM patients differed from those of MM in the reactivity with FMC7, being positive in 10 out of 11 cases, and in their high expression of B1, Ia and SIg with a predominant mu+ phenotype. Mouse rosettes and Leu-1 were positive in one case; OKT10 was positive in three out of five WM patients studied. This phenotype indicates that WM cells correspond to an earlier stage of B cell differentiation than MM plasma cells. The McAb J5 was positive in three out of six MM and two out of four WM analysed. The antigenic differences observed in MM and WM patients support the notion that the cells of the neoplastic clone are able to undergo a certain degree of differentiation.

Antibodies, Monoclonal↗
PubMed1986

Standardization of monoclonal antibodies for use in autologous bone marrow transplantation for common acute lymphoblastic leukemia.

Two monoclonal antibodies suitable for leukemia cell purging of remission bone marrow from patients with common acute lymphoblastic leukemia (common-ALL) are described. WM-21, reacting with the gp 100 common-ALL associated antigen (CALLA), and FMC-8, reactive with a p24 surface antigen, both bind to the majority of leukemic blast cells from cases of common ALL, and promote complement-mediated lysis of CALLA+ leukemias and cell lines. After initial dye exclusion studies to standardize antibody and rabbit complement concentrations and incubation times, an in vitro plating assay using CALLA+ p24+ cell lines was used to investigate the lytic ability of monoclonal antibody treatment. Incubation with WM-21, FMC-8, and complement produced up to 5 logs inhibition of growth in this system. Under similar conditions, no inhibition of in vitro growth of normal bone marrow myeloid progenitor cells was seen. These antibodies therefore appear to be useful therapeutic reagents for removing residual common ALL blast cells from bone marrow prior to autologous marrow transplantation.

Antibodies, Monoclonal↗
PubMed1986

Responses of 'mature' human B lymphocyte lines to inducers of maturation and activation.

Four human B cell lines with a mature phenotype (immunoglobulin secretion and expression of membrane markers associated with maturation) were cultured in the presence of phorbol ester (PMA), dimethyl sulphoxide (DMSO) and two conditioned media. PMA and DMSO led to changes in phenotype which suggested the cells were being activated, whilst the conditioned media resulted in increased immunoglobulin secretion, accompanied by phenotypic changes more consistent with maturation towards the plasma cell stage. The four cell lines, which had different origins (EBV-transformed normal B cell, Burkitt's lymphoma, prolymphocytic leukaemia and multiple myeloma) responded differently to the culture stimuli. These differences suggest that the changes associated with transformation affect the way in which these cells respond to agents which stimulate activation and maturation.

B-Lymphocytes↗
PubMed1985

Purification and preliminary characterization of the glycoprotein Ib complex in the human platelet membrane.

Human platelet glycoprotein Ib (GP Ib) is a major integral membrane protein that has been identified as the platelet-binding site mediating the factor VIII/von Willebrand-factor-dependent adhesion of platelets to vascular subendothelium. Recent evidence suggests that GP Ib is normally complexed with another platelet membrane protein, GP IX. In this study, human platelet plasma membranes were selectively solubilized with a buffer containing 0.1% (v/v) Triton X-100. The GP Ib complex (GP Ib plus GP IX) was purified to homogeneity in approximately 30% yield by immunoaffinity chromatography of the membrane extract using the anti-(glycoprotein Ib complex) murine monoclonal antibody, WM 23, coupled to agarose. GP Ib and GP IX were subsequently isolated as purified components by immunoaffinity chromatography of the GP Ib complex using a second anti-(glycoprotein Ib complex) monoclonal antibody, FMC 25, coupled to agarose. As assessed by dodecyl sulphate/polyacrylamide gel electrophoresis, purified GP Ib was identical to the molecule on intact platelets and had an apparent relative molecular mass of 170 000 under nonreducing conditions and 135 000 (alpha subunit) and 25 000 (beta subunit) under reducing conditions. GP IX had an apparent Mr of 22 000 under both nonreducing and reducing conditions. Purified Gb Ib complex and GP Ib inhibited the ristocetin-mediated, human factor VIII/von Willebrand-factor-dependent and bovine factor VIII/von Willebrand-factor-dependent agglutination of washed human platelets suggesting the proteins had been isolated in functionally active form. GP Ib alpha had a similar amino acid composition to that previously reported for its proteolytic degradation product, glycocalicin. The amino acid compositions of GP Ib beta and GP IX were similar but showed marked differences in the levels of glutamic acid, alanine, histidine and arginine. The N-termini of GP Ib alpha and GP IX were blocked; GP Ib beta had the N-terminal sequence, Ile-Pro-Ala-Pro-. On crossed immunoelectrophoresis, both GP Ib and GP IX were found to occur in the same immunoprecipitin arc(s) whether the platelets had been solubilized in the absence or presence of the calcium-dependent protease inhibitor, leupeptin. Binding studies in platelet-rich plasma indicated a similar number of binding sites (means +/- SD) for three anti-(glycoprotein Ib complex) monoclonal antibodies: AN 51, epitope on GP Ib alpha (22 000 +/- 2700, n = 3), WM 23, epitope on GP Ib alpha (21 000 +/- 3400, n = 3), FMC 25, epitope on GP IX (20 100 +/- 2700, n = 3), and FMC 25 (Fab')2 (27 100 +/- 800, n = 2).(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1985

A simple technique for evaluation of methods of cell separation.

A simple method is described for labelling cells with fluorescein and using them in artificial mixtures to assess cell separation procedures. The method facilitates the examination of the variables in a separation procedure. It is thus possible to tailor a separation procedure (for example panning with monoclonal antibody) to suit the specific requirements of the experiment.

Antibodies, Monoclonal↗
PubMed1985

FMC-HU-1-B: a lymphoma B-cell line with unusual characteristics.

A cell line (FMC-Hu-1-B) was established from a biopsy of an abdominal mass of a child with non-Burkitt's lymphoma. The establishment of the cell line initially required the presence of normal bone marrow stromal cells and phytohaemagglutinin stimulated leucocyte conditioned medium. The cell line lacked Epstein-Barr virus nuclear antigen and exhibited numerous chromosomal abnormalities. Cell-surface marker analysis using a panel of monoclonal antibodies revealed only markers of the B lineage. Within the B-cell lineage FMC-Hu-1-B seemed to occupy a level of maturation equivalent to normal mature B-cells (surface membrane IgM, secretion of immunoglobulin and FMC-1 positive). However, the cells also weakly expressed the common acute lymphoblastic leukaemia antigen, normally found on early precursors of B-cells. The cells appear to secrete auto-stimulatory growth factor(s).

B-Lymphocytes↗
PubMed1985

Normal counterparts of hairy cells and B-prolymphocytes in the peripheral blood. An ultrastructural study with monoclonal antibodies and the immunogold method.

The morphological and membrane phenotypic characteristics of normal peripheral blood B-lymphocytes were studied at ultrastructural level by means of the immunogold method with the following McAb: anti-HLA-Dr (OKIa and FMC4), FMC7, OKT10, and alpha HC1 and alpha HC2, reactive with HCL cells. Five morphological subsets of B-lymphocytes were identified: (i) 40% had a high nuclear cytoplasmic ratio, well condensed chromatin and small pale granules localised in one area of the cytoplasm, these cells expressed HLA-Dr and did not react with any of the other McAb; (ii) 40% had a prominent nucleolus, variable amount of chromatin condensation and localised granules, these cells were HLA-Dr positive and some of them expressed FMC7 as do the cells of B-PLL; (iii) 10% had a villous outline and variable numbers of polyribosomes scattered throughout the cytoplasm, some of these cells resembled morphologically HCL cells and were HLA-Dr +, FMC7 +, alpha HC1 +, alpha HC2 + and OKT10 +/-. The remaining two types of B-cells (10%) had the morphology of antibody secreting cells with parallel arrays of endoplasmic reticulum and some displayed electron dense granules in the Golgi zone. These cells were: (iv) lymphoplasmacytoid, the more common type, which were HLA-Dr +/-, FMC7-, alpha HC1-, alpha HC2 + and OKT10 +/-, and (v) plasma cells which were positive only with OKT10. The similarities in morphology and membrane markers between two of the subsets defined in this study and the cells of B-PLL and HCL suggest that they may represent normal counterparts of these B-cell malignancies.

Adult↗
PubMed1985

Characterization of blast cells in chronic granulocytic leukaemia in transformation, acute myelofibrosis and undifferentiated leukaemia. II. Studies with monoclonal antibodies and terminal transferase.

A panel of 19 monoclonal antibodies (McAb) and the enzyme terminal transferase (TdT) have been applied to the characterization of poorly differentiated blasts from 50 patients with chronic granulocytic leukaemia (CGL) and myelofibrosis in blast crisis (BC), acute myelofibrosis and undifferentiated leukaemia. These cells were also extensively studied by transmission electron microscopy (TEM) (see Polli et al, 1985a). McAb against platelet glycoproteins (GP) showed a high specificity for megakaryoblasts, in particular those reactive with the GPIIb/IIIa complex (J15) and GPIIIa (C15 and C17), which were positive in a higher proportion of blasts than the McAb to GPIb (AN51 and FMC25). Findings with these anti-platelet McAb paralleled those of the platelet-peroxidase (PPO) reaction in 76% of cases studied simultaneously. The PPO reaction was always positive in cases in which two or more of the McAb were reactive with the blast cells. The differences observed suggest, nevertheless, that PPO is more sensitive for megakaryoblasts than the McAb and that this TEM technique should be reserved for cases which are negative with the platelet specific McAb. Of the McAb against myeloid antigens used in this series OKM1 was positive in 50% of cases but the others failed to demonstrate early features of differentiation in myeloblasts and monoblasts. In only three cases were erythroid precursors demonstrated by TEM and these were the only ones reactive with a McAb to glycophorin-A (LICR LON/R10). TdT and the McAb J5 helped in the identification of lymphoblasts which were seen as a 'pure' proliferation in 23% of CGL-BC and as part of blast cell mixtures in another 17% of cases. The McAb reactive to haemopoietic precursor cells (RFB1, FMC8 and OKIa), on the other hand, were of no practical value for the classification of blast cell types. The lineage specificity of several of the McAb used in this study, confirmed by TEM, suggest that these reagents are valuable tools for the characterization of immature blast cells.

Acute Disease↗
PubMed1985

The human leucocyte P30 antigen: properties and assessment of value as a clonal marker.

FMC3 and FMC29 are monoclonal antibodies which react with a 30,000 Dalton molecule expressed on the lymphocyte surface membrane. The molecule is a protein which does not appear to be N-glycosylated. The antigen, which is also expressed intracellularly, does not appear to be a marker of differentiation or maturation. Polyclonal cell populations, such as peripheral blood lymphocytes, show a bimodal distribution of surface antigen density, whilst monoclonal cell populations analysed quantitatively showed unimodal antigen density distributions. This suggests the antigen may be a clonal marker.

Antibodies, Monoclonal↗
PubMed1985

Speaking personally: monoclonal antibodies as diagnostic reagents.

It is 10 years since Kohler & Milstein published the first paper describing the laboratory production of a monoclonal antibody. In those 10 yr monoclonal antibodies have caused a revolution in Immunology and in some branches of Pathology. After a surprisingly slow initial reaction, the scientific community has embraced the new technique enthusiastically, indeed overenthusiastically. Inevitably, excessive enthusiasm was followed by disappointment. There can be no doubt that monoclonal antibodies provide opportunities for major improvements in diagnostic specificity and resolving power. It is equally clear that monoclonal antibodies do not solve all analytical problems, and have a few problems of their very own. This brief review presents one man's assessment of the place of monoclonal antibodies as diagnostic reagents and discusses the properties of the antibodies and the parameters of the assay which most influence the successful use of diagnostic tests based on monoclonal antibodies.

Antibodies, Monoclonal↗
PubMed1985

Preliminary functional characterization of a 24,000 dalton platelet surface protein involved in platelet activation.

We have recently investigated three monoclonal antibodies, FMC 8, FMC 48 and FMC 56, directed against a 24,000 dalton (24K) cell surface protein on human platelets and pre-B progenitor cells. These monoclonal antibodies (at 0.1-10 micrograms/ml) were found to be potent inducers of platelet aggregation with normal and with aspirin-treated platelets. FMC 8 Fab' and FMC 56 (Fab')2 fragments blocked aggregation induced by intact antibody. The Fab' and (Fab')2 fragments, however, were ineffective by themselves (at 100 micrograms/ml) as platelet agonists but augmented (at 10-25 micrograms/ml) the aggregation response of normal and aspirin-treated platelets to threshold concentrations of ADP. It has been suggested that the 24K cell surface protein may be identical to a 24K cAMP-dependent phosphoprotein involved in regulating transmembrane calcium flux. To examine this, 32P-phosphate-loaded platelets were treated with prostaglandin E1 to raise intracellular cAMP levels and then analysed on two-dimensional O'Farrell gels. No labelled phosphoprotein corresponded in mobility to the 24K cell surface protein. Further, FMC 56 failed to immunoprecipitate a 24K phosphoprotein. The combined results suggest that the three monoclonal antibodies activate platelets via a prostaglandin-independent and as yet undefined mechanism which requires the intact bivalent antibody for full platelet response. Fab' fragments (monovalent) and (Fab')2 fragments (altered Fab-Fab configuration) are ineffective as platelet agonists but can augment the response of other stimuli. Thus, further studies with this system should allow delineation of those intracellular events necessary for partial and full platelet responses.

Antibodies, Monoclonal↗
PubMed1985

Monoclonal antibody-defined B lymphocyte subpopulations in primary immunodeficiency disorders.

Peripheral blood from 23 patients with common variable immunodeficiency (CVI) and 5 with selective IgA deficiency (SIAD) was examined for the proportions of B lymphocytes defined with monoclonal antibodies FMC 1 and FMC 7. In healthy controls, FMC 1 monoclonal antibody reacts with antigen present on almost all surface Ig+ B lymphocytes; FMC 7 monoclonal antibody reacts with antigen present only a subset of surface Ig+ and FMC 1+ B cells. In 13 of 23 patients with CVI and all patients with SIAD, a relative increase in FMC 7+ B cells, resulting in proportions of FMC 7+ B cell comparable to surface Ig+ or FMC 1+ B cells was observed. These data suggest abnormality of the proportion of B cell subsets in patients with CVI and SIAD that could suggest an intrinsic defect of B cells in these disorders.

Adolescent↗
PubMed1985

Thrombocyte aggregates in renal allografts. Analysis with fine-needle aspiration biopsy and monoclonal antithrombocyte antibodies.

It has been demonstrated previously that thrombocytes have a role in renal allograft rejection. The purpose of the present studies was to use fine-needle aspiration biopsy techniques during the early postoperative period to determine whether the specific localization of thrombocytes was correlated with the ultimate outcome of renal transplantation. The thrombocyte morphology and location were evaluated using monoclonal antithrombocyte antibody techniques. The results show that loose aggregates, often in combination with granulocytes, are nearly invariably seen in acute blast-cell-dominated reversible rejections; these aggregates disappear from the graft when the inflammation is overcome. In irreversible rejections in which inflammation continues and increases in intensity, the early loose aggregates are followed and accompanied by aggregation of thrombocytes on the graft vascular endothelial cells. The result suggests that thrombocyte aggregation into the graft is a two-stage phenomenon, and that only thrombocyte-graft endothelial cell aggregates are an adverse prognostic sign indicating an unfavorable course of rejection.

Acute Disease↗
PubMed1985

Molecular characterization of quinine/quinidine drug-dependent antibody platelet interaction using monoclonal antibodies.

Two murine monoclonal antibodies, FMC 25 and AN 51, directed against distinct epitopes on the glycoprotein Ib complex, have been used to further define the mechanism of quinine/quinidine drug-dependent antibody interaction with platelets. FMC 25, directed against an epitope on glycoprotein IX, had no effect on platelet aggregation induced by collagen or adenosine diphosphate and little, if any, effect on ristocetin-induced platelet agglutination. FMC 25 and its (Fab)2 fragment, however, were potent inhibitors of drug-dependent antibody-induced platelet aggregation and blocked binding of drug-dependent antibody to platelets as assessed by indirect platelet immunofluorescence. In contrast, AN 51, directed against an epitope on the alpha-subunit of glycoprotein Ib, blocked ristocetin-induced, factor VIII/von Willebrand factor (FVIII/vWF)-dependent platelet agglutination but not drug-dependent antibody-induced platelet aggregation or binding of drug-dependent antibody to platelets. Selective proteolytic removal of the majority of the alpha-subunit of glycoprotein Ib (glycocalicin) from platelets by treatment with calcium-dependent protease did not affect binding of drug-dependent antibody. In addition, a quinidine-dependent antiplatelet antibody immunoprecipitated glycoprotein Ib complex from normal platelets and the membrane-associated proteolytic remnant of the glycoprotein Ib complex from calcium-dependent protease-treated platelets. Preincubation of drug-dependent antibody with purified glycoprotein Ib complex inhibited subsequent binding of antibody to platelets, but the separated components, glycoprotein Ib and glycoprotein IX, were both ineffective, suggesting that the normal interaction between glycoprotein Ib and glycoprotein IX in the intact complex was necessary for drug-dependent antibody recognition. The functional response of platelets to drug-dependent antibody was not mediated by way of platelet Fc receptor, since aggregation of washed platelets by acetone-aggregated IgG was not inhibited by FMC 25 (Fab)2. FVIII/vWF was not required for drug-dependent antibody-induced platelet aggregation. The combined evidence is consistent with quinine/quinidine-dependent antibody-platelet interaction occurring by way of a FVIII/vWF-independent, Fc receptor-independent mechanism that probably involves binding of antibody to glycoprotein IX or the beta-subunit of glycoprotein Ib or both.

Antibodies, Monoclonal↗
PubMed1984

Analysis of chemical and biochemical properties of membrane molecules in situ by analytical flow cytometry with monoclonal antibodies.

Methods are described for analysing chemical and biochemical properties of membrane antigens against which monoclonal antibodies are available. The methods are based on gentle manipulation of whole viable cells and quantitative flow cytometric fluorescence analysis of the effect of such treatment on monoclonal antibody binding. Proteolytic enzymes, glycosidases, inhibitors of biosynthesis and various mild chemical treatments have been used to derive information on the chemical nature of individual membrane antigens, their insertion in the membrane, and their turnover. The nature of the particular epitope detected by a monoclonal antibody may be probed in a similar way.

Antibodies, Monoclonal↗