Publications by authors named "Beresford G"

Background: Educational portfolios have been used across a variety of disciplines in university education as means of encouraging reflective practice in students and as a form of assessment by which a cumulative record of the student's experience can be substantiated. More recently, the development of ePortfolios has provided the potential to transform portfolio learning for students in the 21st century.

Aim: Development of a pilot ePortfolio for the Bachelor of Midwifery at the University of South Australia (UniSA).

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GM-CSF stimulates the growth and differentiation of hematopoietic progenitors and also affects mature cell function. These effects have led to the use of GM-CSF as a vaccine adjuvant with promising results; however, the mechanisms underlying GM-CSF-mediated immune potentiation are incompletely understood. In this study, we investigated the hypothesis that the immune stimulatory role of GM-CSF is in part due to effects on class II MHC Ag presentation.

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The induction of the monocyte chemoattractant protein 1 gene (MCP-1) by TNF occurs through an NF-kappaB-dependent distal regulatory region and an Sp1-dependent proximal regulatory region that are separated by 2.2 kb of sequence. To investigate how these regions coordinate activation of MCP-1 in response to TNF, experiments were performed to examine the role of coactivators, changes in local chromatin structure, and the acetylation of histones at the MCP-1 regulatory regions.

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Murine Ag-specific CD8(+) T cells express various NK markers and NK inhibitory receptors that have been proposed to modulate immune responses. Following acute infection of C57BL/6 and BALB/cJ mice with lymphocytic choriomeningitis virus (LCMV), we observed that Ag-specific CD8(+) T cells expressed CD94/NKG2. Only slight expression of Ly49A and Ly49C receptors was observed on NP396-specific T cells, while all NP396-specific T cells expressed the NKT cell marker U5A2-13 Ag.

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Chromatin immunoprecipitation assays were employed to assess the kinetics of transcription factor assembly and histone modifications that occur during gamma interferon (IFN-gamma) induction of CIITA gene expression. CIITA is the master regulator of major histocompatibility complex class II transcription. Promoter IV (PIV), the major IFN-gamma responsive promoter for CIITA expression, requires both STAT1 and IFN regulatory factor 1 (IRF-1) for induction by IFN-gamma.

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HLA-DO, encoded by the HLA-DOA and HLA-DOB genes, has been shown to function as a modulator of Ag presentation. DNA microarray comparisons between B cells wild-type and mutant for the master regulator of MHC class II transcription, class II transactivator (CIITA), identified HLA-DOA and HLA-DOB as being up-regulated by CIITA. Although HLA-DOA had been shown previously to be regulated by CIITA, HLA-DOB expression was suggested to be independent of CIITA.

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We present here an in vivo view of major histocompatibility complex (MHC) class II promoter assembly, nucleosome modifications and gene expression mediated by the class II transactivator (CIITA). Acetylation and deacetylation of histones H3 and H4 at the HLA-DRA promoter were found to occur during a time-course that depended on CIITA expression and binding. Expression of a CIITA mutant, which lacked the activation domain, induced H4 but not H3 histone acetylation.

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Single-chain variable fragments (scFvs) are tumor-recognition units that hold enormous potential in antibody-based therapeutics. Their clinical applications, however, require the large scale production and purification of biologically active recombinant scFvs. In the present study, we engineered and expressed divalent non-covalent [(scFv)(2)-His(6)] and covalent [sc(Fv)(2)-His(6)] scFvs of a tumor-associated monoclonal antibody (MAb) CC49 in Pichia pastoris.

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Unlabelled: Monoclonal antibodies (MAbs) have been proven useful in clinical studies for both diagnostic and therapeutic applications. The single-chain Fv (scFv) construct made from MAbs has potential applications for improved cancer diagnosis and therapy. A new CC49 scFv construct recognizing a tumor-associated mucin, TAG-72, was engineered and evaluated by immunological, pharmacokinetic and biodistribution analysis.

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Monoclonal antibodies (MAbs) may be considered 'magic bullets' due to their ability to recognize and eradicate malignant cells. MAbs, however, have practical limitations for their rapid application in the clinics. The structure of antibody molecules can be engineered to modify functional domains such as antigen-binding sites and/or effector functions.

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Pancreatic cancer is a therapeutic challenge for surgical and medical oncology. Development of specific molecular tracers for the diagnosis and treatment of this lethal cancer has been one of our major goals. Monoclonal antibodies (MAbs) have been successfully used as selective carriers for delivering radionuclides, toxins or cytotoxic drugs to malignant cell populations; therefore, monoclonal antibody technology has led to a significant amount of research into optimizing targeted therapy.

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Multivalency is a recognized means of increasing the functional affinity of single-chain Fvs (scFvs) for optimizing tumor uptake. A unique divalent single-chain Fv protein [sc(Fv)2], based on the variable regions of the monoclonal antibody (MAb) CC49, has been generated that differs from other dimeric single-chain constructs in that a linker sequence (L) is encoded between the repeated V(L) and V(H) domains (V(L)-L-V(H)-L-V(L)-L-V(H)). This construct was expressed in soluble form in Escherichia coli and purified by ion-exchange and gel-filtration chromatography.

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A novel strategy was developed in which an antibody scFv fragment of the monoclonal antibody (MAb) CC49 was modified by engineering DNA coding sequences to lower its isoelectric point. Negatively charged amino acids were added to the carboxy terminus of the CC49 VH region by adding nucleotide sequences in a polymerase chain reaction (PCR) amplification of the coding sequence of CC49 scFv. Two new DNA constructs coding for CC49 scFv with lower isoelectric points of 5.

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The X2 box of MHC class II promoters is homologous to TRE/CRE elements and is required for expression of MHC class II genes. The X2 box-specific DNA binding activity, X2BP, was purified to homogeneity, sequenced, and identified as CREB. Transient transactivation experiments showed that CREB can cooperate with CIITA to enhance activation of transcription from MHC class II promoters in a dose-dependent manner.

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Monoclonal antibodies (MAbs), because of their inherent specificity, are ideal targeting agents. They can be used to deliver radionuclides, toxins or cytotoxic drugs to a specific tissue or malignant cell populations. Intact immunoglobulin (IgG) molecules have several practical limitations of their pharmacology; their relatively large size of approximately 150,000 daltons leads to a slow clearance from the blood pool and the body resulting in significant exposure to normal organs with limited quantities delivered to tumors.

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The conversion of glucose to glycogen by direct and indirect pathways was determined from the incorporation of [6-3H,U-14C]glucose into glycogen in hepatocyte cultures isolated from fed, fasted or fasted-refed rats. Mercaptopicolinate, an inhibitor of phosphoenolpyruvate carboxykinase (PEPCK) was used to determine the extent by which 6-tritium is lost by mechanisms not involving flux through PEPCK. Glucose conversion to glycogen was lower in hepatocytes from fasted and higher in hepatocytes from fasted-refed rats than in hepatocytes from rats fed ad libitum.

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The microfilament cytoskeleton is postulated to have a role in the localization, transport and anchorage of certain specific mRNAs. We investigated the effects of cytochalasin D, a fungal metabolite that binds to actin and disrupts the microfilament structure, on insulin-induced expression of glucokinase mRNA in rat hepatocyte cultures. Cytochalasin-D significantly potentiates insulin-induced glucokinase mRNA expression at 100 nM concentration but counteracts glucokinase expression at 2-20 microM.

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Hepatic glucokinase is induced by insulin and repressed by glucagon. The effects of epidermal growth factor (EGF) on glucokinase expression were investigated in rat hepatocytes. EGF does not affect the decline in glucokinase activity in hepatocytes cultured for 48h in the absence of insulin, but it counteracts the increase in activity induced by insulin.

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