Enhanced levels and enhanced clonogenic capacity of blood progenitor cells following administration of stem cell factor plus granulocyte colony-stimulating factor to humans.

Administration of hematopoietic growth factors is being used increasingly to obtain populations of blood progenitor/stem cells (PBPC) for clinical transplantation. Here we examined the effect of combining stem cell factor (SCF ) and granulocyte colony-stimulating factor (G-CSF ) versus G-CSF alone in a randomized clinical study involving 62 women with early-stage breast cancer. In the first patient cohorts, escalating doses of SCF were administered for 7 days with concurrent G-CSF administration.

The Charlotte Friend Memorial Lecture. The role of hematopoietic growth factors in the development and suppression of myeloid leukemias.

The transformation of normal hematopoietic cells to leukemic cells requires cells to acquire two intrinsic changes. These are the acquisition by some method of autocrine growth stimulation and a perturbation of differentiation commitment leading to abnormal levels of self-generation. Hematopoietic regulator action can be involved to produce or facilitate both these changes but the same regulators can also suppress some leukemic populations by enforced differentiation commitment.

Interferon regulatory factor 1 is induced by interferon-gamma equally in neurons and glial cells.

Class I MHC protein is induced in glia but not mature neurons by IFN-gamma. We have compared IFN-gamma signal transduction in these populations. There were identical levels of STAT1 homodimers and IRF-1 by gel-shift and IRF-1 mRNA was induced equally.

Kinetic analysis of the interaction between the monoclonal antibody A33 and its colonic epithelial antigen by the use of an optical biosensor. A comparison of immobilisation strategies.

The interaction between the humanised A33 monoclonal antibody and the corresponding F(ab)'2 or Fab' fragments with the colonic epithelial A33 antigen, purified by micropreparative HPLC from membrane extracts of the colonic carcinoma cell line LIM 1215, has been studied with the BIAcore 2000 biosensor using surface plasmon resonance detection. The surface orientation of immobilised antibody and the Fab' fragment onto the biosensor surface was controlled using alternative immobilisation chemistries. This resulted in significantly higher molar binding activities compared with the conventional N-hydroxysuccinimide (NHS)/N-ethyl-N'-dimethylaminopropylcarbodiimide (EDC) chemistry.

Clinical studies with megakaryocyte growth and development factor (Mpl-ligand).

The haemopoietic growth factor mpl-ligand (also known as thrombopoietin, and Megakaryocyte Growth and Development Factor [MGDF] is a recently cloned and characterized megakaryocyte-active factor. Administration of MGDF to humans was associated with a dose-related increase in the platelet count with maximum levels observed between days 12-18. Platelets had normal appearance and functioned normally in assays of platelet aggregation and ATP-release.

The GTPase and Rho GAP domains of p190, a tumor suppressor protein that binds the M(r) 120,000 Ras GAP, independently function as anti-Ras tumor suppressors.

p190 is a Tyr-phosphorylatable G protein of M(r) 190,000 that binds NH2-terminal SH2 domains of GAP1, a Ras GAP of M(r) 120,000. p190 contains at least two functional domains: a GTPase domain at the NH2 terminus and a GAP domain at the COOH terminus that can attenuate signal-transducing activity of three distinct G proteins (Rac, Rho, and CDC42). Here, we demonstrate that overexpression of either an antisense p190 RNA or a dominant negative mutant (Asn36) of p190 GTPase domain (residues 1-251) but not the wild-type p190 GTPase domain is able to transform normal NIH/3T3 fibroblasts.

The extent of affinity maturation differs between the memory and antibody-forming cell compartments in the primary immune response.

Immunization with protein-containing antigens results in two types of antigen-specific B cell: antibody forming cells (AFCs) producing antibody of progressively higher affinity and memory lymphocytes capable of producing high affinity antibody upon re-exposure to antigen. The issue of the inter-relationship between affinity maturation of memory B cells and AFCs was addressed through analysis of single, antigen-specific B cells from the memory and AFC compartments during the primary response to a model antigen. Only 65% of splenic memory B cells were found capable of producing high affinity antibody, meaning that low affinity cells persist into this compartment.

Microsatellite deletions in the c-myb transcriptional attenuator region associated with over-expression in colon tumour cell lines.

In the hemopoietic system c-myb expression is required for proliferation of immature cells and its down-regulation is required for differentiation. In colonic mucosa c-myb expression occurs at levels comparable to immature hemopoietic cells. Inhibition of c-myb expression in colon cell lines, using anti-sense oligonucleotides, indicates that c-myb expression is required for proliferation.

Deregulation of cell survival in lymphomagenesis.

Because normal lymphoid tissue homeostasis depends on a balance between cell proliferation and cell death, lymphomas can arise from mutations that interfere with the normal cell death process. We here discuss some circumstances in which lymphoid cell overexpression of a cell death antagonist, the Bcl2 protein, in E mu-bcl2 transgenic mice can contribute to the development of lymphomas and plasmacytomas.

Cytoplasmic domains of the common beta-chain of the GM-CSF/IL-3/IL-5 receptors that are required for inducing differentiation or clonal suppression in myeloid leukaemic cell lines.

Granulocyte-macrophage colony stimulating factor (GM-CSF) is a cytokine that controls the production and function of myeloid cells by interaction with a cell surface receptor composed of a specific ligand-binding alpha-chain (hGMRalpha) and a shared signal-transducing beta-chain (beta c). Co-expression of human GMR alpha-chain and wild-type human beta c in two murine leukaemic cell lines (M1 and WEHI-3B D+) conferred the ability to terminally differentiate into macrophages when stimulated with human GM-CSF. Analysis of cytoplasmic truncation mutants of beta c showed that residues to amino acid 783 (numbering from the first amino acid of the leader sequence) were sufficient for the GM-CSF-dependent induction of all aspects of differentiation in both cell types.

Aren't health services already promoting health?

Smoke-free health care environments are now the norm in Australia and exemplify the way in which environments for health care can become more health promoting. Community health services that assist people with chronic illnesses and disabilities to increase control over their lives, hospitals that provide nutritious food choices for staff and patients, and general practices that encourage routine preventive care throughout the life span are other examples of health-promoting environments. In their roles as providers of services, employers, community corporations and citizens, health care organisations have a wide range of opportunities for developing their capacity for health promotion.

Temporal discontinuities in progression of NOD autoimmune diabetes.

Consideration of the pathophysiology of insulin-dependent diabetes mellitus in the nonobese diabetic (NOD) mouse can be viewed from a temporal perspective. We argue that there are discontinuous phases and each phase may reflect a phenotype educed by a particular set of genetic and epigenetic events. Therefore, temporal dissection may be a useful platform for causal dissection and we have set out this article as follows: 1.

The cell death inhibitor Bcl-2 and its homologues influence control of cell cycle entry.

The effect of the cell death inhibitor Bcl-2 and its homologues on cell cycle regulation was explored in lymphocytes and cell lines. Expression of a bcl-2 transgene reduced proliferation of thymocytes and delayed cell cycle entry of mitogen-stimulated B and T lymphocytes. Overexpression of Bcl-2, Bcl-xL or adenovirus E1B19kD substantially delayed serum stimulation-induced S phase entry of quiescent NIH 3T3 fibroblasts.

Effects of viral inhibitors of apoptosis in models of mammalian cell death.

Apoptotic cell death is used as a defence against infection by viruses. To counter this protective mechanism, some viruses carry genes whose products can inhibit progression of the apoptotic process in the host cell. As it is clear that the core cell death mechanisms have been conserved through evolution, viral genes from various sources can be used to unravel these mechanisms in mammalian cells.

Lessons from bcl-2 transgenic mice for immunology, cancer biology and cell death research.

The protein product of the proto-oncogene bcl-2, originally discovered by virtue of its chromosomal translocation in human follicular centre B cell lymphoma, is a physiological inhibitor of programmed cell death, apoptosis. Initial studies in transgenic mice overexpressing Bcl-2 in B or T lymphocytes demonstrated that Bcl-2 can potently antagonise cell death induced by multiple independent signal transduction routes and can contribute to oncogenesis, particularly in combination with other oncogenes, like c-myc, that promote cell proliferation. Further investigations using crosses between bcl-2 transgenic mice and T cell receptor or immunoglobulin transgenic mice or mutant mice deficient in proper antigen receptor gene rearrangement demonstrated that Bcl-2 can only block death of cells that failed to receive a positive stimulus, "death by neglect', but not activation induced apoptosis.

bcl-w, a novel member of the bcl-2 family, promotes cell survival.

The prototypic mammalian regulator of cell death is bcl-2, the oncogene implicated in the development of human follicular lymphoma. Several homologues of bcl-2 are now known. Using a PCR-based strategy we cloned a novel member of this gene family, denoted bcl-w.

Progenitor tumours from Emu-bcl-2-myc transgenic mice have lymphomyeloid differentiation potential and reveal developmental differences in cell survival.

Mice expressing both a bcl-2 and a myc transgene within the B lymphoid cell compartment invariably develop novel immature haemopoietic tumours. The likely cell of origin of these tumours was identified by a common pattern of cell surface marker expression on a subset of cells comprising approximately 1% of normal mouse bone marrow. The bcl-2-myc tumour cells could be induced to differentiate into either B lymphocytes or macrophages in culture with certain cytokines and feeder cells.

Effects of excess GM-CSF levels on hematopoiesis and leukemia development in GM-CSF/max 41 double transgenic mice.

Double transgenic mice were produced by mating granulocyte-macrophage colony-stimulation factor (GM-CSF) transgenic mice with max 41 transgenic mice that exhibit excess granulopoiesis and a predisposition to thymic lymphoma development. Although only two-thirds of the double transgenic mice had elevated circulating GM-CSF levels, double transgenic mice maintained significantly higher blood granulocytes and monocytes and more extreme granulopoietic hypercellularity in the marrow and spleen than max 41 transgenic mice. In double transgenic mice, early death occurred from the GM-CSF transgenic syndrome.

Regulation of c-Myb through protein phosphorylation and leucine zipper interactions.

c-Myb function is modulated in part by a negative regulation domain which encompasses a leucine zipper (LZ). When E. coli-expressed c-Myb with wild type or mutated LZ proteins are assessed for DNA binding activity, the mutant form is substantially better at DNA binding than the wild type (WT) form.

Production of hematopoietic regulatory factors in cultures of adult and fetal mouse organs: measurement by specific bioassays.

Factor-specific cell line bioassays were used to monitor the production in vitro by adult and fetal mouse organs of GM-CSF, G-CSF, M-CSF, Multi-CSF (IL-3), IL-6 and leukemia inhibitory factor (LIF). No tissue was observed to produce Multi-CSF. Highest producers of the other regulators were lung, muscle, thymus, heart and bone shaft and all tissues producing detectable growth factors produced all five with the same rank order of activity.

A YAC contig map of Plasmodium falciparum chromosome 4: characterization of a DNA amplification between two recently separated isolates.

We have generated a physical map of Plasmodium falciparum chromosome 4 using yeast artificial chromosomes (YACs). The map is defined by a YAC contig spanning approximately 1.05 Mb, which has been restriction mapped to a resolution of 30 kb and is punctuated by 22 sequence-tagged sites.