Dietetics, Nutrition and Biological Sciences

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Aeromonas salmonicida extracellular virulence factors: The common components [Project Report]
(International Council for the Exploration of the Sea. Maritime Committee, 1986) Coleman, G.; Fyfe, Lorna
A comparison of the distribution of extracellular proteins produced by the protease-secreting organism Aeromonas salmonicida during aerobic and anaerobic growth
(1986) Fyfe, Lorna; Coleman, G.; Munro, A. L.
Aeromonas salmonicida was grown aerobically and anaerobically in supplemented 3% (w/v) tryptone soya broth medium for 24 h at 25 degrees C. Although the bacterial density achieved was 4.9 times higher in the aerobic culture, the exoprotein produced per unit of bacterial dry weight was only 1.9 times higher than in the anaerobic culture. However, the protease activity of the exoprotein showed a marked reduction anaerobically, being only one-tenth of that of the exoprotein produced aerobically. This finding was consistent with the differing SDS-PAGE patterns of the extracellular proteins from the two cultures, which also showed marked loss and reinforcement of other, as yet unidentified extracellular products.
A study of the pathological effect of isolated Aeromonas salmonicida extracellular protease on Atlantic salmon, Salmo salar
(Wiley, 1986-09) Fyfe, Lorna; Finley, A.; Coleman, G.; Munro, A. L. S.
A comparison was made between the effects of Aeromonas salmonidda extracellular protease and total extracellular products (ECP) following intramuscular injection into juvenile Atlantic salmon, Salmo salar L. Thus, 20, 10, 5, 2.5 and 1.5 units of salt-free protease in 0.2 ml water were compared with ECP preparations with the same levels of proteolytic activity. The highest concentration of ECP produced a gross pathology with a large furuncular lesion 36 h after injection. The corresponding protease preparation had a lesser effect, although a furuncle was formed and tissue liquefaction was produced. These effects were less marked with reduced concentrations. At the lowest level studied, no significant effect was observed with protease alone but ECP (0.8 _g of protein) produced a small, characteristic lesion similar to that achieved with 5 units of isolated protease.
A comparison of the characteristics of extracellular protein secretion by a Gram positive and a Gram negative bacterium
(Plenum Press, 1987) Coleman, G.; Abbas, A.; Sutherland, J.; Fyfe, Lorna; Finley, A.; Chaloipka, J.; Krumphanzi, V.
Some properties of a 56 kilodalton haemolysin specific for fish erythrocytes in the supernatant fraction of cultures of Aeromonas salmonicida [Project Report]
(International Council for Exploration of the Sea. Maritime Committee, 1987) Fyfe, Lorna
A comparative study of the formation of extracellular proteins by Aeromonas salmonicida at two different temperatures
(Wiley, 1987-04) Fyfe, Lorna; Coleman, G.; Munro, A. L.
Aeromonas salmonicida was grown in a supplemented 3% (w/v) tryptone soya broth medium at 10 degrees C, a temperature at the lower end of the range over which furunculosis has been observed to occur in the field, and 25 degrees C, the optimum temperature for growth. Similar bacterial densities in the range 2.35 +/- 0.05 mg dry wt/ml were achieved in the two cultures at the beginning of the stationary phase of the growth cycle, after 125 h at 10 degrees C and 18 h at 25 degrees C. At this point, at the higher temperature 1.5 times more exoprotein was formed, 80 +/- 2.8 micrograms/ml compared with 54 +/- 1.7 micrograms/ml. Exoprotein contained the same proportion of haemolysin at both temperatures and twice as much protease at the higher temperature. The most marked difference was in an unidentified 100 kD protein which was formed in a 10-fold greater amount at 10 degrees C.
Identification of major common extracellular proteins secreted by Aeromonas salmonicida strains isolated from diseased fish
(1987-04-01) Fyfe, Lorna; Coleman, G.; Munro, A. L.
Ten different strains of Aeromonas salmonicida that were isolated from diseased fish were grown under identical conditions (24 h at 25 degree C) in 3% (wt/vol) tryptone soya broth medium supplemented with vitamins and inorganic ions. In each case the extracellular proteins that were formed were compared by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and it was found that there were two significant common components, one with a molecular weight of 70,000 and the other with a weight of 56,000. Application of enzyme purification techniques to the supernatant fraction proteins of a culture of one of the strains resulted in the isolation of a 70-kilodalton (kDa) component, which was found to be a serine protease, and a 56-kDa component, which was hemolytic to trout erythrocytes. Rocket immunoelectrophoresis with rabbit antibodies to the isolated protease and hemolysin showed the same antigenic components in the supernatant fractions of all the cultures. These activities were assayed, and protease activity was found to vary by a factor of three, from 59 to 195 U/ml, while the range of hemolytic activity was over a narrow band, from 28 to 43 U/ml. There was an inconsistency between the immunoelectrophoretic and direct assay data in only one case. This indicated the presence of additional hemolytic activity, in addition to the 56-kDa component. The detection of large amounts of the same protease and hemolysin, two potent degradative activities, in a random series of strains of A. salmonicida suggests that they may be obligatory virulence factors in the development of furunculosis.
The combined effect of isolated Aeromanas salmonicida protease and haemolysin on Atlantic salmon, Salmo salar L. compared with that of total extra-cellular products preparation
(Wiley, 1988-01) Fyfe, Lorna; Coleman, G.; Munro, A. L. S.
The molecular approaches to the therapy of HIV infection : the SCID-HU mouse as a model to study strategies for the treatment of HIV
(Queen Margaret University, 1991) Fyfe, Lorna
Murine immune response to recombinant HIV1 p24 core protein following subcutaneous, intraperitoneal and intravenous immunisation
(Wiley-Blackwell, 1991-11) Fyfe, Lorna; Maingay, J.; Robinson, A. C.; Howie, S. E.
The murine immune response to baculovirus-produced human immunodeficiency virus type-1 (HIV-1)p24 was examined after injection by three different routes: subcutaneously (s.c.), intraperitoneally (i.p.) and intravenously (i.v.). Both antigen-specific T-cell proliferation and serum antibody were induced by i.p. injection. In contrast, s.c. and i.v. injection of antigen resulted in specific antibody generation alone. Lympho-proliferative responses seen after i.p. injection were confined to splenocytes, and were greater after a low dose of antigen than after a high dose. p24-specific proliferation was not detected in lymph node cells. CD4:CD8 ratios were normal in lymph nodes and spleen at all times, irrespective of the dose or route of administration. p24-specific serum IgG antibodies were detected in all animals after the second injection of antigen. After s.c. and i.v. administration of high doses of antigen, the median antibody titres continued to rise after a third injection, but plateaued in animals injected by the i.p. route. In contrast, low doses of antigen given i.p. increased the median titre during and after the course of four injections. A low antigen dose given s.c. resulted in a plateau of median titre between the third and fourth injections. In i.v.-injected animals the median titre decreased between the third and fourth injections. IgG1 p24-specific antibodies were detected in all immunized mice, whereas IgM antibodies were detectable only following i.p. injection of antigen.
Growth factors and cutaneous wound repair.
(1992) Martin, P.; Hopkinson-Woolley, J.; McCluskey, Jane T.
The healing of an adult skin lesion is a well studied but complex affair of some considerable clinical interest. Endogenous growth factors, including the EGF, FGF, PDGF and TGF beta families, are released at the wound site and presumed to be a necessary part of the natural wound healing machinery. Moreover, members of each of these families have been shown to enhance healing if added exogenously to a wound site. In this review we shall briefly discuss what is known about the mechanics and cell biology of adult wound healing, describe the normal cellular source of growth factors during the healing process and, with reference to their known capacities in tissue culture, speculate as to how particular growth factors might be able to enhance healing.
A review on immunonutrition in parenteral and enteral nutrition
(1993) Fyfe, Lorna
Clinical implications of embryonic wound healing
(Mark Allen Group, 1993) Hopkinson-Woolley, J.; McCluskey, Jane T.; Lewis, J.; Martin, P.
An examination of research on the healing abilities of animal embryos and a consideration of its implications for human adult wound healing
Murine HIV p24 specific T lymphocyte activation by different antigen presenting cells: B lumphocytes from immunised mice present core protein to T-cells
(Elsevier, 1993-01) Fyfe, Lorna; Maingay, J P.; Howie, S. E. M.
Mice were injected with three doses of baculovirus-produced recombinant HIV-1 p24 core protein in alum adjuvant. CD4 positive T lymphocytes from immunized animals proliferated in vitro in the presence of antigen and peritoneal macrophages (Mps) or splenic dendritic cells (DCs) from non-immunized mice as antigen presenting cells (APCs). DCs were approximately three times more efficient than Mps on a cell for cell basis. No synergy was observed between Mps and DCs in this system. B lymphocytes from immunized animals also presented p24 antigen to the specific T cells. Mps did synergize with B cells to enhance the level of T lymphocyte proliferation. This may have implications for the induction of specific immune responses to pathogens after administration of single protein vaccines.
A study of wound healing in the E11.5 mouse embryo by light and electron microscopy
(Elsevier, 1993-04) McCluskey, Jane T.; Hopkinson-Woolley, James; Luke, Babara; Martin, Paul
In this paper we report our light and electron microscopic studies of the healing of a simple excisional lesion to the E11.5 mouse embryo hindlimb. The wounded living embryo is cultured in a roller bottle and under such conditions the lesion is completely re-covered with epithelium by 24 hr. We discuss how our studies of such a simple wound healing model may offer insight into the mechanisms of tissue repair generally.
Repair of excisional wounds in the embryo
(Nature Publishing Group, 1994) Martin, Paul; Nobes, Catherine; McCluskey, Jane T.; Lewis, Julian
Wound healing in the embryo, just as in the adult, comprises two tissue movements: re-epithelialisation and connective-tissue contraction. In this brief review we describe our recent studies of these two movements in both chick and rodent embryo model systems. In the chick we have evidence that the embryonic wound epidermis is drawn forwards by contraction of an actin pursestring extending around the circumference of the wound, rather than by lamellipodial crawling as in adult healing. Significant connective-tissue contraction also occurs. In the rat and mouse embryo we have examined expression of transcription factors and growth factors at the wound edge. We discuss our observations that the immediate-early gene c-fos and the growth factor transforming growth factor beta-1 are rapidly induced at the embryonic wound margin, and the possibility that these signals may trigger proliferation of wound edge cells and contraction of the exposed wound mesenchyme.
Identification and characterization of a putative serine protease expressed in vivo by Mycobacterium avium subsp. paratuberculosis
(Microbiology Society, 1994-08-01) Barron, Rona; Stevenson, Karen; Inglis, Neil F.; Klausen, Joan; Sharp, J. Michael
A putative serine protease expressed in vivo by Mycobacterium avium subsp. paratuberculosis was isolated from a lambda gt11 genomic expression library by screening with serum from a naturally infected sheep. The gene was contained in two overlapping clones, which were shown by antibody elution to encode a protein of 34 kDa in M. a. paratuberculosis. The clones were sequenced and database searches detected a motif identical to the active serine site in trypsin, and 30% homology to the putative serine proteases (HtrA proteins) of Escherichia coli, Salmonella typhimurium, Brucella abortus and Rochalimaea henselae.
The Centre for Food Research at Queen Margaret College in Edinburgh
(1995) Looy, Anne de; Turner, Pamela
A New Centre for Food Research was created in September 1993 at Queen Margaret College, Edinburgh. Its main purpose is to promote research into food choice, particularly factors influencing choice such as sensory, socio-cultural and nutritional aspects. Research undertaken involves a multi-disciplinary approach by bringing together expertise from various disciplines including consumer sciences, dietetics and nutrition, food science, social sciences and hospitality studies. A one-day symposium “Food research in Europe” was held in 1994 to mark the Centre's official launch. The symposium was well attended, with delegates representing a wide range of organizations in the UK and other EU countries. Presentations were given by eminent speakers and researchers – Dr David Lindsay, MAFF; Dr Ronan Gormley, The National Food Centre in Dublin; Dr David Kilcast, Leatherhead Food Research Association; Dr Wendy Brown and Dr Richard Shepherd, both from the Institute of Food Research, Reading. The centre's major research interests and activities are related to fruit and vegetable consumption (sensory qualities of apples; barriers to consumption); the relationship between snacking, body weight and physical activity; healthy eating award schemes in the UK
Analysis of the Tissue Movements of Embryonic Wound Healing-DiI Studies in the Limb Bud Stage Mouse Embryo
(Elsevier, 1995-07) McCluskey, Jane T.; Martin, Paul
The tissue movements of epithelial spreading and mesenchymal contraction play key roles in many aspects of embryonic morphogenesis. One way of studying these movements in a controlled manner is to make an excisional skin wound to an embryo and watch the wound heal. In this paper we report our studies of healing of a simple excisional lesion made to the limb bud stage mouse embryo. The wounded, living embryo is cultured in a roller bottle; under such conditions the wound heals with a highly reproducible time course and is completely closed by 24 hr. During the healing period the environment bathing the wound can be simply manipulated by adding drugs or factors to the culture medium. We have used DiI to label mesenchymal cells exposed at the margin of the initial wound and, by following their fate and measuring the area of mesenchyme remaining exposed at various time points during the healing process, we have quantified both the extent of mesenchymal contraction and the extent of reepithelialisation by movement of epidermis over mesenchyme. We show that the two types of tissue movement contribute almost equally (50:50) to the total wound closure rate. We have gone on to investigate the cell machinery underlying these processes. In adult wounds the epidermis migrates by means of lamellipodial crawling, but we show that reepithelialisation in the embryo is achieved instead by purse-string contraction of a cable of filamentous actin which assembles in the basal layer of cells at the free edge of the epidermis. Addition of cytochalasin D to the culture medium blocks formation of this actin cable and leads to failure of reepithelialisation. Contraction of adult wound connective tissue appears to be driven by conversion of dermal fibroblasts into a specialist smooth muscle-like fibroblast, the myofibroblast. However, using an antibody recognising the alpha-isoform of smooth muscle actin and specific for smooth muscle cells and myofibroblasts, we show that a similar conversion into myofibroblasts does not occur at any stage during the embryonic wound healing process. These observations indicate that both of the tissue movements of embryonic wound healing utilise cell machinery fundamentally different from that driving the analogous tissue movements of adult healing.
Perfect wound healing in the keratin 8 deficient mouse embryo.
(Wiley, 1996) Brock, J.; McCluskey, Jane T.; Baribault, H.; Martin, P.
It is generally believed that the strength and structural integrity of both adult and embryonic epithelia comes, at least in part, from their internal cytoskeletal network of keratin filaments and associated cell:cell junctions. Indeed, recent keratin depletion experiments in Xenopus suggest that the capacity of embryonic epithelia to undergo natural morphogenetic movements such as gastrulation, or artificially triggered epithelial movements such as wound closure, are severely compromised in the absence of the predominant embryonic keratin, K8 [Torpey et al., 1992: Nature 357:413-415; Klymkowsky et al., 1992: Proc. Natl. Acad. Sci. USA 89:8736-8740]. These experiments contrast with studies of genetically K8 deficient mouse embryos which undergo gastrulation quite normally and, dependent upon background strain, can survive until beyond birth [Baribault et al., 1993: Genes Dev. 7:1191-1202; Baribault et al., 1994: Genes Dev. 8:2964-2973], but to date no wound healing investigations have been carried out on mK8-mice. In this article, we report our studies of healing in embryonic day 11.5 mouse embryos, wounded by amputation of the hindlimb bud and then cultured in roller bottles. In wild-type embryos, wound closure puts severe strain on the embryonic epidermis since it is under tension and gapes immediately upon wounding; subsequently, epithelial cells tug on one another by means of an actin purse-string in order to close the defect. Even given these extremely challenging conditions, we show here that the mK8- epidermis performs no differently from wild-type epidermis, assembling an actin purse-string in the wound marginal cells and closing the wound with identical timecourse to its wild-type counterpart.