Thesis (M.Nurs.)--University of Hong Kong, 2004. / Also available in print.

Thesis (Master Diploma(Medical Technology) -- Cape Technikon, Cape Town, 1990 / Eighty six patients with acute l.eukaemia were studied using morphol.ogical., cytochemical. and immunol.ogical. techniques. The acute l.eukaemias were subdivided using the French-American-British (FAB) cl.assification. The immunophenotyping studies were compared with the morphological classification to assess their contribution to the diagnosis. Acute non-lymphoblastic leukaemia (ANLL) was diagnosed on the basis of morphol.ogy and cytochemical. criteria. In addition this group of patients was studied with antibodies directed against myel.omonocytic antigens. However, no further cl.inical.l.y useful. information was obtained. Patients whose bl.asts did not stain with Sudan black or myel.operoxidase were considered to have acute lymphoblastic leukaemia (ALL). After assessment with monocl.onal. antibodies directed against epitopes expressed on cel.l.s from the l.ymphoid lineage, these patients were subgrouped into non-T-ALL, common-ALL, B-ALL, T-ALL and l.ymphoblastic lymphoma categories. This study confirmed the val.ue of monocl.onal. antibodies for accurately assigning l.ineage to the acute l.eukaemias and particularly in those situations where conventional morphol.ogical. criteria and cytochemical. markers are inconclusive.

A cell surface protein from human acute myelogenous leukemia (AML) cells has been purified. (Al-Rammahy et al., Cancer Immunol. Immunother. 9:181, 1980; Malcolm et al., J. Immunol. 128:2599, 1982). This material was used to immunize rabbits. The resulting antiserum (anti-AML) showed myelogenous leukemia specificity in that it reacted with myelogenous leukemia cell extracts and did not react with cell extracts of normal individuals or patients with non-myelogenous leukemia or other malignant disorders in the enzyme-linked immunosorbent assay (ELISA). Bone marrow and peripheral blood leucocytes (PBL) from either patients with myelogenous leukemia, other disorders or normal individuals were analysed in the fluorescence-activated cell sorter (FACS IV) after labelling with anti-AML, normal rabbit serum (NRS), or antiserum raised to normal human membrane antigens. Of 40 cell samples from patients with AML, 39 reacted strongly with the anti-AML. Similarly, all of 15 specimens from patients with chronic myelogenous leukemia (CML) reacted with the anti-AML. When 42 bone marrow or PBL samples from patients with a variety of lymphoproliferative disorders were examined, only 2 specimens reacted with the antiserum, both from individuals with diagnoses of acute lymphocytic leukemia (ALL). None of the 14 normal bone marrow or PBL donor specimens tested reacted with the anti-AML. It was also found that essentially all samples from patients in clinical remission from AML had high numbers of cells reactive with the anti-AML. When cells from such individuals were labelled and sorted on the FACS IV, it was found that the cell population fluorescing strongly with the anti-AML contained cells of both myeloid and lymphoid origin. The AML antigen was used to produce AML specific monoclonal antibody. Spleens from AML-antigen immunized Balb/c mice were fused to NS-1 myeloma parental cells and a myelogenous leukemia specific monoclonal antibody was selected from the hybrid colonies produced. This monoclonal antibody (MAL-1) as well as the rabbit anti-AML has been used to identify myelogenous leukemia patient samples in the FACS IV. In addition, this monoclonal also demonstrates positive fluorescence binding to HL-60 (a promyelocytic leukemia cell line), while there is no binding to lymphocytic leukemia cell lines, CCRF-SB-ALL-B and CCRF-CEM-ALL-T. The MAL-1 monoclonal has been shown to be specific for myelogenous leukemia cell extracts in the ELISA and has been successfully used as an immunoadsorbent for the isolation of the AML antigen from cell extracts. No equivalent antigen was found when cell extracts from normal cells, lymphocytic leukemia cells and lymphoma cells were similarly absorbed. These findings indicate that both the rabbit anti-AML serum and MAL-1 monoclonal show specificity for an antigen associated with myelogenous leukemia cells. / Science, Faculty of / Microbiology and Immunology, Department of / Graduate

A dissertation submitted to the Faculty of Science University of the Witwatersrand, Johannesburg for the Degree of Masters of Science. Johannesburg 1995 / This study ~valuates the expression ofthe m1U\lAand protein products flfthebClw 2 prato-onCPllenein the.b1.lman myelooytlc THP~land.Hl',."60cell lines. The bcl..2 Pl'oto-llcogerle codes for a protein termerJ. nCL-2. that is able. to inhibit sO~1'le pa~hways tWprogrammed celt death, Both c;~lFlines are. capable of und~rgomg programmed cell death, as. is shown by the presence of some apoptosing cells in cell morphQlogy studies after 24 11our·stimulations with the protein synthesis inhibitor pummycin(1 n.g/ml). Some HL~60 cells, but no TlIP ..I. cells, undergo apo!ptosis upon 24 pout co-stinrulation with the phorbol ester PMA (16 nMrand the PKA activator dbcAMP (50 ~M). Stimulating with PMl\ or dhcAM.P alone ., does not induce detectable levels of. apoptosls in THP ..1 and lIL-60 cells. Bt.L-2 expression is inversely related to differentiation in myeloid cells, and mature tnonoc}'tes express no :aCt..2. Cell cycle analyses and [3HJthymidine uptake studies show that PMA (16 nM) decreases proliferation both in THP..1 cells and the less differentiated HL~60 cells, While dbcAMP (50. ",M) decreases proliferation markedlyin TI:W ...1 cells only e . Cell adhesion and cell morphology studies show that PMA, but not abeAM?, induces differentiation in both cell lines. Sthnulating cells witli PMA for 24 hours induces the expression Of IL-IB mRNA and protein in THP ..1 cells, but. not in the less differentiatt:.d· BLooO cells, ~ldicatingthat n.,.·Hl expression. is .related to differentiation itr~~~e .celllines. The expression of bc1-2 mRNA and BCL~21)r()tein ia.analyseQr'ant:1. compared itt . both •cell lines, both undet undifferentiated cQnditittms' andiafter induction,.of idlffere;nl;iation. bel-?, mRNA expression is eval~lated using reVCJtselransciption and polymerase. chain reaction amplification memods, and is sho~,.nto decrease upon PMA:-stimulation in both cell lines. bcl..Z mRNA exptes,~i()n :isshown to decreese to less than 5 % of contrpl values irt.TB:P~1 cells (n;::;2) and ,to1;)etweert10 % and 20. % of.cohttol values in HL-60 cells (11::;,3) after24 houtitof PlVtA stirnuiatiol1. be;..2 mRNA expression aite!' dbeAMP sti.umldion may·,d~teaseor may remain unchanged in both cell lines When C(tmp~rv' ( to unstimulfated cells. sIotblotting' methods is described qllantitatively. in HL~60 cells, hut only qua1itativ~ly in Tap..I cells where .low levels. 0'( BCL-2 ••e•xp]('essio~ made quantit.ation. technically difficult. :aCL~2 eJtpresston is shown to decrease. to 78 % of control values by 24 hours after PMA stimulation in HLh6() cells. The );}ICL..Z p.rotl~in"xpresslon is betvlleen 5 X and 15 X lower in THP-l cells than in HL-60 cells. The inverse relationship of myeloid cell differentiation'to bel..2 mRNA and BCL ..2 pl;otein expression is confirmed by these results. Stimulation with dbcAMP does not cause changes in BCL-2 protem ,.::xpressi(>n.in '7,.HP-l cells. Immunocytochemical detection of 'SCL-:2protein in w\v)le cells is describ~. The protein is shown to be located mtAultly in the cytoplnsm. Stronger positive staining is observed in HL ..60 cells .than in .THP ..1 cells, thus confirming the results obtained from protein slotblots. IThiS:!Rtudy confirms the inverse relationship of myeloid cell differentiation to bcl-2 ,,'m, RNA expression and to BCL·2 protein expression. MO!1(lcytes and tis~ue macrophages .have a high turnover rate' compared ti;) their, ,ha,ematopoietic stem· cells, and are 'c,msistently rep1aceJ by newly differentiated progeny cells. High BCL-Z expressi911 in the long.:;1ivedstem cells will help' pro«!ct them/ from cell, death, jDecreases in PCL~2 expressiQU during differentiation y,villlead to increased susceptibility to programmed cell death, and will allow for the high turnover rate observed in Ul0i10Cytes:and macropll~ges. Tissue homeostas~s is maintainoo by this balance between cell proliferation and cell death.

published_or_final_version / Physiology / Doctoral / Doctor of Philosophy

No description available.

We sought to understand whether giving patients additional consolidation chemotherapy prior to transplant might be an effective tool to reduce the risk of relapse after transplant through the use of a large retrospective database. A theoretical framework was developed based on previous publications to help guide the project. Potential confounding variables from the database were identified using this theoretical framework. Patients who received consolidation chemotherapy prior to transplant were compared to patients who did not receive consolidation chemotherapy. After multivariate analysis, there was no difference in overall survival between groups. This study suggests that clinicians should not routinely administer consolidation chemotherapy with the aim of reducing relapse rates and improving outcomes after transplant / October 2016

The Polycomb Repressive Complex 2 (PRC2) epigenetically regulates gene expression by methylating lysine 27 on histone 3 (H3K27me3). While the role of PRC2 core members during hematopoiesis has been elucidated, the role of PRC2 accessory protein, Mtf2, has not been well characterized outside of mouse embryonic stem cells. To investigate the role of Mtf2 in vivo, we created a gene-targeted knockout mouse model. Using this model, we discovered that Mtf2 was a critical regulator of hematopoiesis and its loss within the hematopoietic cells leads to loss of global H3K27me3 levels at the transcriptional start sites (TSS) therefore leading to the overexpression of multiple signalling networks. These findings presented in the first part of my thesis place Mtf2 as a critical regulator of hematopoiesis and expand the role of Mtf2 beyond a canonical accessory PcG protein. While our murine studies revealed that the loss of Mtf2 did not cause leukemia in mice, our studies of MTF2 in human cells demonstrated that MTF2 deficiency within human Hematopoietic Stem and Progenitor Cells (HSPCs) causes a myelo-proliferative phenotype that is reminiscent of pre-leukemia. Furthermore, when we screened MTF2 expression within leukemic stem cell (LSC) enriched CD34+ CD38- cells isolated from primary Acute Myeloid Leukemia (AML) patient samples at diagnosis, we observed that MTF2 is miss-regulated in AML and its loss predicted refractory AML. Using MTF2 knockdown (KD) transcriptomic and ChIP-seq data, we drafted MTF2-PRC2 Gene Regulatory Network (GRN) in human HSPCs and LSC enriched cells. Finally, using the MTF2-PRC2 GRN, we uncovered a direct mechanism by which MTF2 regulates chemoresistance in AML and show that targeting this mechanism via MDM2 inhibitors sensitizes refractory AML to standard induction therapy. These findings presented in second part of my thesis demonstrate MTF2 as a novel prognostic marker for refractory AML and provide a novel therapy that helps target MTF2 deficient refractory AML.

No description available.

Thesis (PH. D.)--Johns Hopkins university, 1914. / Vita. Pub. also as Johns Hopkins hospital reports, monographs, new ser. no. VIII. "Literature of leukæmia in the fowl": p. 32-33. Also available in digital form on the Internet Archive Web site.