• Antimicrobial agents and biofilms

      Brown, Michael R. W.; Smith, Anthony W. (Cambridge University Press, 2003)
      Interest in biofilms has increased dramatically in recent years. New microscopic and molecular techniques have revolutionized our understanding of biofilm structure, composition, organization, and activities. This book brings advances in the prevention and treatment of biofilm-related diseases to the attention of clinicians and medical researchers. Human tissues often support complex microbial communities growing as biofilms that can cause infections. As microbes in biofilms exhibit increased tolerance toward anti-microbial agents and decreased susceptibility to host defense systems, biofilm-associated diseases have become increasingly difficult to treat. (Cambridge University Press)
    • Antioxidants and AP-1 activation: a brief overview.

      Gómez del Arco, Pablo; Martínez-Martínez, Sara; Calvo, Victor; Armesilla, Angel Luis; Redondo, Juan Miguel (Elsevier BV, 1997)
      Activity of the transcription factor AP-1 is controlled by different MAPK cascades that regulate the different AP-1 components at the transcriptional and posttranscriptional level. Recently, AP-1 has been shown to behave as a redox-sensitive transcription factor that can be induced under both pro-oxidative and antioxidative conditions. In this overview we summarize the signaling pathways that converge on the activation of AP-1 and the components of these pathways that have been shown to be targets of antioxidants. The activation of AP-1 by antioxidants may account for the expression of a number of genes that mediate important functions under physiological conditions.
    • Antisolvent crystallisation is a potential technique to prepare engineered lactose with promising aerosolisation properties: effect of saturation degree.

      Kaialy, Waseem; Nokhodchi, Ali (Elsevier, 2012-11-01)
      Engineered lactose particles were prepared by anti-solvent crystallisation technique using lactose solutions with different saturation degrees. In comparison to commercial lactose, engineered lactose particles exhibited less elongated and more irregular shape (large aggregates composed of smaller sub-units), rougher surface texture, higher specific surface area, and different anomer form. Engineered lactose powders demonstrated smaller bulk density, smaller tap density, and higher porosity than commercial lactose powder. Dry powder inhaler (DPI) formulations containing engineered lactose and salbutamol sulphate as a model drug demonstrated improved drug content homogeneity and higher amounts of drug delivered to lower airway regions. Higher fine particle fraction of drug was obtained in the case of lactose powders with higher porosity, higher specific surface area and higher fine particle content (<5 μm). The results indicated that the higher the saturation degree of lactose solution used during crystallisation the smaller the specific surface area, the higher the amorphous lactose content, and the higher the β-lactose content of engineered lactose particles. Also, lactose powders obtained from lactose solution with higher degree of saturation showed higher bulk and tap densities and smaller porosity. Engineered lactose powders crystallized from lower saturation degree (20% and 30% w/v) deposited higher amounts of drug on lower airway regions. In conclusion, this study demonstrated that it is possible to prepare engineered lactose particles with favourable properties (e.g. higher fine particle fraction and better drug content homogeneity) for DPI formulations by using lactose solutions with lower degree of saturation during crystallisation process.
    • Apoptosis of malignant cells in Hodgkin's disease is related to expression of the cdk inhibitor p27KIP1.

      Kolar, Zdenek; Flavell, Joanne R.; Ehrmann, Jiri; Rihakova, Petra; Macak, Jirka; Lowe, Derek; Crocker, John; Vojtesek, Borivoj; Young, Lawrence S.; Murray, Paul G. (John Wiley And Sons, 2000)
      Previous results from B-cell chronic lymphocytic leukaemia suggest that expression of p27KIP1 might be important in protection from apoptosis. Given the relevance of apoptosis to the pathogenesis of Hodgkin's disease (HD), it was decided to examine the expression of p27KIP1 in relation to apoptosis in these lesions. Paraffin-wax sections from a total of 65 histologically confirmed HD tumours were used to derive apoptotic index (AI) and DNA fragmentation index (DFI) scores, which were compared with the expression of various cell-cycle-regulating proteins, including p27KIP1 (p27), p21WAF1/CIP1 (p21) and cyclin D1, and with Epstein-Barr virus (EBV) status. The DFI was measured by TdT-mediated dUTP-FITC nick end-labelling (TUNEL), and the AI by conventional morphology. Cells showing the typical morphology of apoptosis, together with those resembling so-called 'mummified' Hodgkin/Reed-Sternberg (HRS) cells, were included in AI measurements. Increasing numbers of p27-positive HRS cells were associated with lower levels of apoptosis in these cells, as indicated by significantly lower AI and DFI scores. There was a trend towards poorer survival in those patients with the highest numbers of p27-positive HRS cells and with lower AI and DFI scores, but these differences were not statistically significant. p21-positive HRS cells were significantly more frequent in those cases with lower AI scores. A similar trend was observed for p21 and DFI, although this relationship was not statistically significant. There was also a trend towards higher levels of cyclin D1 protein in HD cases with high AI and DFI values. A tendency for increasing numbers of p27-positive and p21-positive HRS cells in EBV-positive cases was noted, but this relationship was not statistically significant. EBV status did not correlate with either AI or DFI scores. The results of this study suggest that p27, and possibly also p21, may be involved in protection from apoptosis in HD.
    • Applications of cell-penetrating peptides as signal transduction modulators.

      Jones, Sarah; Howl, John D. (Washington, D.C.: CRC Press, 2006)
      THIS BOOK: Since the first Handbook of Cell-Penetrating Peptides was prepared in 2001, the wealth of new information on the use of these peptides as transport systems has in fact served to confound the field. The constant internal change in the field of cell-penetrating peptides (CPPs) is due to recent research uncovering apparent ambiguities in cellular uptake. There is still neither a common terminology nor a uniform explanation for the penetrative mechanism of cell-penetrating peptides. In this second edition of the Handbook of Cell-Penetrating Peptides, the authors summarize the current state of the field including recent reevaluations of earlier studies of CPP mechanisms. Beginning with an overview of the classes of peptides and their individual uptake mechanisms, from the earlier lipid models to the more recent endocytotic pathways, the book demonstrates the diversity and the opportunity for these biologically active proteins to serve as future drug leads. The text then covers the use of CPPs in gene modulation, addressing the application of antisense and decoy oligonucleotides, as well as the new avenue of research targeting specific tumors and other tissues-questions that had barely been asked when the first edition was published. (CRC Press)
    • Aristolochic acids detected in some raw Chinese medicinal herbs and manufactured herbal products--a consequence of inappropriate nomenclature and imprecise labelling?

      Cheung, Thomas P.; Xue, Charlie; Leung, Kelvin Sze-Yin; Chan, Kelvin C.; Li, Chun G. (Taylor & Francis, 2006)
      BACKGROUND: Certain frequently used Chinese herbal medicines commonly used for weight control, may contain toxic Aristolochia species, which have been associated with severe nephropathy and urothelial cancer in humans and animals. The toxic entities in Aristolochia species are aristolochic acid-I (AA-I) and aristolochic acid-II (AA-II). There is a lack of systematic information about the aristolochic acid content of Aristolochia species and related genera, including those in Chinese materia medica that are used in the treatment of overweight individuals. OBJECTIVES: To determine the content of AA-I and AA-II of commonly used Chinese herbal medicines (raw herbs and manufactured products) including species of Aristolochia and related genera. METHODS: Twenty-one raw herbs and seven manufactured herbal products were purchased from herbal wholesalers and traditional Chinese medicinal herb retailers in Melbourne, Australia in September 2003, after the supply of known aristolochic acid-containing herbs and products had been banned in Australia. Six additional raw herbs were sourced from a herbal teaching museum. These were purchased in 2001, before the prohibition. The contents of aristolochic acids of each was determined by high pressure liquid chromatography (HPLC), and confirmed by liquid chromatography-mass spectrometry (LC-MS). RESULTS: Of the samples tested, four of the raw herbs purchased before the ban and two manufactured products purchased after the ban, were found to contain aristolochic acids (16-1002 ppm). CONCLUSIONS: Several Chinese raw herbs and some commercially available manufactured herbal products contain aristolochic acids. The confusion in Chinese nomenclature for related raw herbs, and imprecise labelling of manufactured products may contribute to the inadvertent use of toxic herbal species in Chinese medicine practice. Additional measures are needed to ensure the safety of consumers of Chinese herbal medicines.
    • Assay of free ferulic acid and total ferulic acid for quality assessment of Angelica sinensis.

      Lu, Guang-Hua; Chan, Kelvin C.; Leung, Kelvin Sze-Yin; Chan, Chi-Leung; Zhao, Zhong-Zhen; Jiang, Zhi-Hong (2005)
      Activity of Chinese Danggui (DG), the processed root of Angelica sinensis (Oliv.) Diels, is linked to the ferulic acid content but the stability of ferulic acid during extraction for medicinal use is not known. The stabilities of ferulic acid and coniferyl ferulate were evaluated in the extracts of DG using a variety of extraction solvents. These included various combinations and proportions of methanol, water, formic acid, 1 M aqueous hydrochloric acid and 2% sodium hydrogen carbonate (NaHCO3) in water. Coniferyl ferulate was found liable to hydrolyze into ferulic acid in neutral, strongly acidic and basic solvents, where heat and water could facilitate this hydrolysis. However, the hydrolysis was relatively resisted in weakly organic acid. Based on the stability evaluation, two new terms, namely: free ferulic acid and total ferulic acid, were suggested and defined. Free ferulic acid refers to the natural content of ferulic acid in herbs. Total ferulic acid means the sum of free ferulic acid plus the amount of related hydrolyzed components. Meanwhile, the high-performance liquid chromatographic (HPLC) method was developed to assay free ferulic acid and total ferulic acid in DG using methanol-formic acid (95:5) and methanol-2% NaHCO3 in water (95:5) as extraction solvents, respectively. Ten DG samples were investigated on their contents of free and total ferulic acid. The results indicated that the amount variety of free ferulic acid was larger than that of their counterparts, and the ratio of total ferulic acid to free ferulic acid was 4.07 +/- 2.73 (mean +/- SD, n = 10). The chemical assay of DG using total ferulic acid content would be a better choice to assess the herbal quality and was recommended.
    • Astragalus saponins induce growth inhibition and apoptosis in human colon cancer cells and tumor xenograft.

      Tin, Mandy; Cho, Chi-Hin; Chan, Kelvin C.; James, Anthony; Ko, Joshua (Oxford Journals, 2007)
      Astragalus memebranaceus is used as immunomodulating agent in treating immunodeficiency diseases and to alleviate the adverse effects of chemotherapeutic drugs. In recent years, it has been proposed that Astragalus may possess anti-tumorigenic potential in certain cancer cell types. In this study, the anti-carcinogenic effects of Astragalus saponin extract were investigated in HT-29 human colon cancer cells and tumor xenograft. Our findings have shown that Astragalus saponins (AST) inhibit cell proliferation through accumulation in S phase and G2/M arrest, with concomitant suppression of p21 expression and inhibition of cyclin-dependent kinase activity. Besides, AST promotes apoptosis in HT-29 cells through caspase 3 activation and poly(ADP-ribose) polymerase cleavage, which is indicated by DNA fragmentation and nuclear chromatin condensation. Nevertheless, we also demonstrate the anti-tumorigenic effects of AST in vivo, of which the reduction of tumor volume as well as pro-apoptotic and anti-proliferative effects in HT-29 nude mice xenograft are comparable with that produced by the conventional chemotherapeutic drug 5-fluorouracil (5-FU). In addition, the side effects (body weight drop and mortality) associated with the drug combo 5-FU and oxaliplatin are not induced by AST. These results indicate that AST could be an effective chemotherapeutic agent in colon cancer treatment, which might also be used as an adjuvant in combination with other orthodox chemotherapeutic drugs to reduce the side effects of the latter compounds.
    • B-type natriuretic peptide in reversible myocardial ischaemia.

      Chatha, K.; Alsoud, M.; Griffiths, M.J.; Elfatih, A.; Abozguia, K.; Horton, R.C.; Dunmore, Simon J.; Gama, R. (BMJ Publishing, 2006)
      BACKGROUND: Coronary heart disease is associated with increased B-type natriuretic peptides (BNPs), and, although controversial, may cause exaggerated exercise-induced BNP secretion. We investigated BNP in relation to reversible myocardial ischaemia. Materials and methods: Serum N-terminal proBNP (NT-proBNP) was measured before and after an exercise electrocardiogram test (ETT) in 14 patients with and 45 patients without exercise-induced myocardial ischaemia. Statistical analysis was carried out on logarithmically transformed data. Results, however, are pre-transformed data. RESULTS: NT-proBNP increased with exercise both in ETT-positive patients (mean (SD) 71.4 (41.2) v 76.8 (44.0) ng/l; p<0.001) and ETT-negative patients (54.0 (61.2) v 60.1 (69.0) ng/l; p<0.001). Pre-exercise and post-exercise NT-proBNP were higher (p<0.05) in ETT-positive than in ETT-negative patients. Incremental NT-proBNP was similar in ETT-positive (4.7 (4.2) ng/l) and ETT-negative (6.2 (8.6) ng/l) patients. CONCLUSION: Serum NT-proBNP concentrations are higher in patients with exercise-induced myocardial ischaemia than in those without. Exercise-induced electrocardiographic myocardial ischaemia, however, is not associated with exaggerated BNP secretion.
    • Biofilms and protozoa: a ubiquitous health hazard

      Smith, Anthony W.; Brown, Michael R. W. (IWA Publishing, 2003)
      This timely book will introduce its readers to the structure and function of biofilms at a fundamental level as determined during the past decade of research, including: Extracellular polymers as the biofilm matrix; Biofilm phenotype (differential gene expression, interspecies signalling); Biofilm ecology; Biofilm monitoring; Resistance of biofilms to antimicrobial agents and Biofilm abatement. (IWA Publishing)
    • Biofilms, dormancy and resistance

      Smith, Anthony W.; Brown, Michael R. W. (Cambridge University Press, 2003)
      All cellular life-forms can exist in replicating and non-replicating states. Organisms replicate only when the conditions are beneficial, and when not replicating they concentrate on survival of these environmental stresses. Many bacteria, harmful to humans, survive the period of infection in a low growth state. This book addresses the basic science of microbial dormancy and low growth states, putting this in the context of human medicine. Such fundamental topics as bacterial growth and non-growth, culturability and viability are covered, as well as survival of the host’s immune response, and inter-bacterial signalling. Following this introduction, more medically-focused topics are discussed, namely antibiotic resistance arising during stationary phase, biofilms, the bacteria which cause gastric ulcers and tuberculosis as the classic persistent bacterial infection. This book will be of interest to graduate students and researchers in medical microbiology, immunology and infectious disease medicine who are interested in bacterial dormancy in relation to disease. (Cambridge University Press)
    • Biological applications of the receptor mimetic peptide mastoparan.

      Jones, Sarah; Howl, John D. (Betham Science Publishers, 2006)
      The receptor mimetic and mast cell degranulating peptide mastoparan (MP) translocates cell membranes as an amphipathic alpha-helix, a feature that is undoubtedly a major determinant of bioactivity through the activation of heterotrimeric G proteins. Chimeric combinations of MP with G protein-coupled receptor (GPCR) ligands has produced peptides that exhibit biological activities distinct from their composite components. Thus, chimeric peptides such as galparan and M391 differentially modulate GTPase activity, display altered binding affinities for appropriate GPCRs and possess disparate secretory properties. MP and MP-containing chimerae also bind and modulate the activities of various other intracellular protein targets and are valuable tools to manipulate and study enzymatic activity, calcium homeostasis and apoptotic signalling pathways. In addition, charge delocalisation within the hydrophilic face of MP has produced analogues, including [Lys5, Lys8,Aib10]MP, that differentially regulate mast cell secretion and/or cytotoxicity. Finally, the identification of cell penetrant variants of MP chimerae has enabled the effective intracellular delivery of non-permeable biomolecules and presents an opportunity to target novel intracellular therapeutic loci.
    • Blockade of T-cell activation by dithiocarbamates involves novel mechanisms of inhibition of nuclear factor of activated T cells.

      Martínez-Martínez, Sara; Gómez del Arco, Pablo; Armesilla, Angel Luis; Aramburu, Jose; Luo, Chun; Rao, Anjana; Redondo, Juan Miguel (American Society for Microbiology, 1997)
      Dithiocarbamates (DTCs) have recently been reported as powerful inhibitors of NF-kappaB activation in a number of cell types. Given the role of this transcription factor in the regulation of gene expression in the inflammatory response, NF-kappaB inhibitors have been suggested as potential therapeutic drugs for inflammatory diseases. We show here that DTCs inhibited both interleukin 2 (IL-2) synthesis and membrane expression of antigens which are induced during T-cell activation. This inhibition, which occurred with a parallel activation of c-Jun transactivating functions and expression, was reflected by transfection experiments at the IL-2 promoter level, and involved not only the inhibition of NF-kappaB-driven reporter activation but also that of nuclear factor of activated T cells (NFAT). Accordingly, electrophoretic mobility shift assays (EMSAs) indicated that pyrrolidine DTC (PDTC) prevented NF-kappaB, and NFAT DNA-binding activity in T cells stimulated with either phorbol myristate acetate plus ionophore or antibodies against the CD3-T-cell receptor complex and simultaneously activated the binding of AP-1. Furthermore, PDTC differentially targeted both NFATp and NFATc family members, inhibiting the transactivation functions of NFATp and mRNA induction of NFATc. Strikingly, Western blotting and immunocytochemical experiments indicated that PDTC promoted a transient and rapid shuttling of NFATp and NFATc, leading to their accelerated export from the nucleus of activated T cells. We propose that the activation of an NFAT kinase by PDTC could be responsible for the rapid shuttling of the NFAT, therefore transiently converting the sustained transactivation of this transcription factor that occurs during lymphocyte activation, and show that c-Jun NH2-terminal kinase (JNK) can act by directly phosphorylating NFATp. In addition, the combined inhibitory effects on NFAT and NF-KB support a potential use of DTCs as immunosuppressants.
    • Bovine enterovirus as an oncolytic virus: foetal calf serum facilitates its infection of human cells.

      Smyth, M.S.; Symonds, A.; Brazinova, S.; Martin, Jan H. (University of Crete, 2002)
      Many viruses have been investigated for their oncolytic properties and potential use as therapeutic agents for cancer treatment. Most of these replication-competent viruses are human pathogens. We investigated the oncolytic properties of an animal virus which is non pathogenic for both its natural host and humans. Bovine enterovirus has previously been shown to exhibit a very wide tissue tropism for cell types in vitro. We compare the ability of bovine enterovirus to replicate in and to cause cytopathic effect in freshly isolated human monocytes and monocyte derived macrophages with the monocyte-like U937 tumour cell line. We also include the adherent ZR-75-1 human breast cancer cell line. We have also carried out infections of bovine enterovirus in the presence and in the absence of serum of bovine origin. Our study shows that the virus will replicate in and produce cytopathic effect in the U937 and ZR-75-1 cell types to the same extent as the cells (BHK-21) in which the virus is routinely propagated. We believe bovine enterovirus to be a worthwhile candidate for further study as an anti-tumour agent.
    • Bradykinin receptors as a therapeutic target

      Howl, John D.; Payne, Sarah J. (London: Informa Healthcare, 2003)
      Biologically-active kinins, including bradykinin (BK) and Lys(0)-BK (kallidin), are short-lived peptide mediators predominantly generated by the enzymatic action of kallikreins on kininogen precursors. A diverse spectrum of physiological and pathological actions attributed to local kinin production is a consequence of the activation of G-protein-coupled receptors (GPCRs). Currently, two major subtypes of kinin receptor, designated B(1) and B(2), are recognised, although there is much evidence for pharmacological heterogeneity, particularly within the B(2) receptors. Considering these facts and the widespread distribution of kinin receptors in many human tissues, it is no surprise that the therapeutic potential of kinins and kinin receptor antagonists remains the focus of numerous investigations. Studies in animals and animal tissues, instrumental in elucidating the biological roles of kinins, are well-documented in numerous excellent reviews. Unfortunately, and despite the enormous potential illustrated by animal studies, attempts to develop kinin analogues as therapeutic agents to combat human disease have largely proven disappointing. Consequently, this review selectively focuses upon studies that are directly relevant to the targeting of human BK receptors as a therapeutic intervention. In addition to providing a succinct review of well-documented pathological conditions to which kinin receptors contribute, the authors have also included more recent data that illustrate new avenues for the therapeutic application of kinin analogues.
    • Cannabinoid receptor systems: therapeutic targets for tumour intervention.

      Jones, Sarah; Howl, John D. (Taylor & Francis (Informa Healthcare), 2003)
      The past decade has witnessed a rapid expansion of our understanding of the biological roles of cannabinoids and their cognate receptors. It is now certain that Delta9-tetrahydrocannabinol, the principle psychoactive component of the Cannabis sativa plant, binds and activates membrane receptors of the 7-transmembrane domain, G-protein-coupled superfamily. Several putative endocannabinoids have since been identified, including anandamide, 2-arachidonyl glycerol and noladin ether. Synthesis of numerous cannabinomimetics has also greatly expanded the repertoire of cannabinoid receptor ligands with the pharmacodynamic properties of agonists, antagonists and inverse agonists. Collectively, these ligands have proven to be powerful tools both for the molecular characterisation of cannabinoid receptors and the delineation of their intrinsic signalling pathways. Much of our understanding of the signalling mechanisms activated by cannabinoids is derived from studies of receptors expressed by tumour cells; hence, this review provides a succinct summary of the molecular pharmacology of cannabinoid receptors and their roles in tumour cell biology. Moreover, there is now a genuine expectation that the manipulation of cannabinoid receptor systems may have therapeutic potential for a diverse range of human diseases. Thus, this review also summarises the demonstrated antitumour actions of cannabinoids and indicates possible avenues for the future development of cannabinoids as antitumour agents.
    • Case study of Felty’s Syndrome

      Nelson, Paul N.; Bowman, S.J. (Oxford: Blackwell Publishing, 2001)
      This book: is an introductory level text on the biological principles of human disease. The book is aimed at medical students in degree courses in biomedical science. The book fuses the biological (physiological and biochemical) processes which underlie the clinical manifestations of disease. As such, it brings together material which is conventionally dealt with by several books. The authors have covered the fundamentals of each topic in a readable manner, which should encourage students to develop a fuller understanding, where necessary, by reference to more comprehensive texts.
    • CEL1: a novel cellulose binding protein secreted by Agaricus bisporus during growth on crystalline cellulose.

      Armesilla, Angel Luis; Thurston, Christopher F.; Yague, Ernesto (Blackwell Publishing, 1994)
      The cel1 gene of Agaricus bisporus encodes a protein (CEL1) that has an architecture resembling the multi-domain fungal cellulases, although the sequence of its putative catalytic core is not matched by any other in the protein and nucleic acid data bases. The N-terminal half of the putative catalytic domain of CEL1 was expressed in Escherichia coli as a fusion protein with glutathione-S-transferase. The fusion protein was used to raise a CEL1-specific antibody. CEL1 was detected as an extracellular 49.8 kDa protein in A. bisporus cellulose-grown cultures, where it bound strongly to cellulose. CEL1 was neither an endoglucanase, a cellobiohydrolase able to hydrolyze fluorogenic cellobiosides, a beta-glucosidase, a xylanase, nor a cellobiose: quinone oxidoreductase. CEL1 was present in some fractions of culture fluid separated by electrophoresis which released soluble sugars from crystalline cellulose.
    • Cell penetrating peptides as signal transduction modulators

      Jones, Sarah; Howl, John D. (CRC Press (Taylor & Francis), 2007)
      THIS BOOK: Since the first Handbook of Cell-Penetrating Peptides was prepared in 2001, the wealth of new information on the use of these peptides as transport systems has in fact served to confound the field. The constant internal change in the field of cell-penetrating peptides (CPPs) is due to recent research uncovering apparent ambiguities in cellular uptake. There is still neither a common terminology nor a uniform explanation for the penetrative mechanism of cell-penetrating peptides. In this second edition of the Handbook of Cell-Penetrating Peptides, the authors summarize the current state of the field including recent reevaluations of earlier studies of CPP mechanisms. Beginning with an overview of the classes of peptides and their individual uptake mechanisms, from the earlier lipid models to the more recent endocytotic pathways, the book demonstrates the diversity and the opportunity for these biologically active proteins to serve as future drug leads. The text then covers the use of CPPs in gene modulation, addressing the application of antisense and decoy oligonucleotides, as well as the new avenue of research targeting specific tumors and other tissues-questions that had barely been asked when the first edition was published. By summarizing the diffuse information regarding CPPs, including the ambiguities and variety of mechanisms, the Handbook of Cell-Penetrating Peptides provides the most solid foundation available from which to expand the potential of this rapidly growing field of medicine. (CRC Press)