Chemical and Biomolecular Engineering - Research Publications

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    Inheritance of chromosome 7 is associated with a drug-resistant phenotype in somatic cell hybrids
    deSilva, M ; Kantharidis, P ; Wall, DM ; Campbell, L ; Vrazas, V ; Nadalin, G ; Kaczmarczyk, SJ ; Hu, XF ; Parkin, JD ; Zalcberg, JR (STOCKTON PRESS, 1996-01)
    A major form of drug resistance in tumour cells known as classical multidrug resistance (MDR) is associated with the overexpression of the mdr1 gene product, the membrane protein P-glycoprotein (P-gp), which acts as an energy-dependent drug efflux pump. In this study the inheritance of P-gp expression was examined using hybrids formed after somatic cell fusion between a drug-sensitive human T-cell leukaemia cell line, CEM/CCRF, and a drug-resistant derivative, CEM/A7, which is characterized by a clonal chromosomal duplication dup(7)(q11.23q31.2). Fourteen hybrids, chosen at random, were analysed by reverse transcriptase-polymerase chain reaction (RT-PCR) and by binding studies involving the monoclonal antibody MRK16, which recognises an external P-gp epitope. Only two hybrids were positive for both MRK16 antibody labelling and mdr1 mRNA. Partial karyotypic analysis of all hybrids revealed that only the MRK16-positive hybrids contained the duplication in chromosome 7 seen in the CEM/A7 parental MDR line. Therefore, P-gp overexpression in the MRK16-positive hybrids may be linked to the inheritance of chromosome 7 from CEM/A7 and possibly associated with the chromosome 7 abnormality.
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    Enhanced osteoblast adhesion on nanostructured selenium compacts for anti-cancer orthopedic applications.
    Tran, P ; Webster, TJ (Informa UK Limited, 2008)
    Metallic bone implants possess numerous problems limiting their long-term efficacy, such as poor prolonged osseointegration, stress shielding, and corrosion under in vivo environments. Such problems are compounded for bone cancer patients since numerous patients receive orthopedic implants after cancerous bone resection. Unfortunately, current orthopedic materials were not originally developed to simultaneously increase healthy bone growth (as in traditional orthopedic implant applications) while inhibiting cancerous bone growth. The long-term objective of the present research is to investigate the use of nano-rough selenium to prevent bone cancer from re-occurring while promoting healthy bone growth for this select group of cancer patients. Selenium is a well known anti-cancer chemical. However, what is not known is how healthy bone cells interact with selenium. To determine this, selenium, spherical or semispherical shots, were pressed into cylindrical compacts and these compacts were then etched using 1N NaOH to obtain various surface structures ranging from the micron, submicron to nano scales. Changes in surface chemistry were also analyzed. Through these etching techniques, results of this study showed that biologically inspired surface roughness values were created on selenium compacts to match that of natural bone roughness. Moreover, results showed that healthy bone cell adhesion increased with greater nanometer selenium roughness (more closely matching that of titanium). In this manner, this study suggests that nano-rough selenium should be further tested for orthopedic applications involving bone cancer treatment.
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    A Model Analysis of Arterial Oxygen Desaturation during Apnea in Preterm Infants
    Sands, SA ; Edwards, BA ; Kelly, VJ ; Davidson, MR ; Wilkinson, MH ; Berger, PJ ; Prisk, K (PUBLIC LIBRARY SCIENCE, 2009-12)
    Rapid arterial O(2) desaturation during apnea in the preterm infant has obvious clinical implications but to date no adequate explanation for why it exists. Understanding the factors influencing the rate of arterial O(2) desaturation during apnea (Sa(O)₂) is complicated by the non-linear O(2) dissociation curve, falling pulmonary O(2) uptake, and by the fact that O(2) desaturation is biphasic, exhibiting a rapid phase (stage 1) followed by a slower phase when severe desaturation develops (stage 2). Using a mathematical model incorporating pulmonary uptake dynamics, we found that elevated metabolic O(2) consumption accelerates Sa(O)₂throughout the entire desaturation process. By contrast, the remaining factors have a restricted temporal influence: low pre-apneic alveolar P(O)₂causes an early onset of desaturation, but thereafter has little impact; reduced lung volume, hemoglobin content or cardiac output, accelerates Sa(O)₂during stage 1, and finally, total blood O(2) capacity (blood volume and hemoglobin content) alone determines Sa(O)₂during stage 2. Preterm infants with elevated metabolic rate, respiratory depression, low lung volume, impaired cardiac reserve, anemia, or hypovolemia, are at risk for rapid and profound apneic hypoxemia. Our insights provide a basic physiological framework that may guide clinical interpretation and design of interventions for preventing sudden apneic hypoxemia.
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    Control of viremia and prevention of AIDS following immunotherapy of SIV-infected macaques with peptide-pulsed blood
    De Rose, R ; Fernandez, CS ; Smith, MZ ; Batten, CJ ; Alcantara, S ; Peut, V ; Rollman, E ; Loh, L ; Mason, RD ; Wilson, K ; Law, MG ; Handley, AJ ; Kent, SJ ; Koup, RA (PUBLIC LIBRARY SCIENCE, 2008-05)
    Effective immunotherapies for HIV are needed. Drug therapies are life-long with significant toxicities. Dendritic-cell based immunotherapy approaches are promising but impractical for widespread use. A simple immunotherapy, reinfusing fresh autologous blood cells exposed to overlapping SIV peptides for 1 hour ex vivo, was assessed for the control of SIV(mac251) replication in 36 pigtail macaques. An initial set of four immunizations was administered under antiretroviral cover and a booster set of three immunizations administered 6 months later. Vaccinated animals were randomized to receive Gag peptides alone or peptides spanning all nine SIV proteins. High-level, SIV-specific CD4 and CD8 T-cell immunity was induced following immunization, both during antiretroviral cover and without. Virus levels were durably approximately 10-fold lower for 1 year in immunized animals compared to controls, and a significant delay in AIDS-related mortality resulted. Broader immunity resulted following immunizations with peptides spanning all nine SIV proteins, but the responses to Gag were weaker in comparison to animals only immunized with Gag. No difference in viral outcome occurred in animals immunized with all SIV proteins compared to animals immunized against Gag alone. Peptide-pulsed blood cells are an immunogenic and effective immunotherapy in SIV-infected macaques. Our results suggest Gag alone is an effective antigen for T-cell immunotherapy. Fresh blood cells pulsed with overlapping Gag peptides is proceeding into trials in HIV-infected humans.
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    Mechanisms for the ultrasonic enhancement of dairy whey ultrafiltration
    Muthukumaran, S ; Kentish, SE ; Ashokkumar, M ; Stevens, GW (ELSEVIER SCIENCE BV, 2005-08-01)
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    The use of ultrasonic cleaning for ultrafiltration membranes in the dairy industry
    Muthukumaran, S ; Yang, K ; Seuren, A ; Kentish, S ; Ashokkumar, M ; Stevens, GW ; Grieser, F (ELSEVIER SCIENCE BV, 2004-10)
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    INVESTIGATION OF IMMUNE-REACTIONS IN A FLOW-INJECTION SYSTEM USING SURFACE-PLASMON RESONANCE
    CARUSO, F ; VUKUSIC, PS ; MATSUURA, K ; URQUHART, RS ; FURLONG, DN ; OKAHATA, Y (ELSEVIER SCIENCE BV, 1995-10-10)
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    Formation of luminescent spherical core-shell particles by the consecutive adsorption of polyelectrolyte and CdTe(S) nanocrystals on latex colloids
    Susha, AS ; Caruso, F ; Rogach, AL ; Sukhorukov, GB ; Kornowski, A ; Möhwald, H ; Giersig, M ; Eychmüller, A ; Weller, H (ELSEVIER, 2000-03-31)
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    A quartz crystal microbalance study of the removal of solid organic soils from a hard surface in aqueous surfactant solution
    Weerawardena, A ; Drummond, CJ ; Caruso, F ; McCormick, M (ELSEVIER SCIENCE BV, 1999-01-15)