School of Molecular and Biomedical Science
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Comprising the disciplines of biochemistry, genetics, physiology, microbiology and immunology.
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Item Metadata only Carbohydrates in hepatitis B antigen(Nature Publishing Group, 1973) Burrell, C.J.; Proudfoot, E.; Keen, G.A.; Marmion, B.P.Abstract not availableItem Metadata only Antibody to hepatitis B antigen in haemophiliacs and their household contacts(BMJ Publishing Group, 1974) Burrell, C.J.; Parker, A.C.; Ramsay, D.M.; Proudfoot, E.The prevalence of antibody to hepatitis B antigen, detectable by radioimmunoassay, was found to be no higher among 58 long-term household contacts of multiply transfused haemophiliacs than among 100 randomly chosen blood donors. This suggested that such contacts do not have greater exposure to serum hepatitis virus than that occurring through natural means. Among those persons possessing antibody, the multiply transfused haemophiliacs showed a marked tendency for higher antibody titres than their contacts, implying differences in pathogenesis between infection acquired through multiple transfusion and infection acquired naturally.Item Metadata only Host components in hepatitis B antigen(Society for General Microbiology, 1975) Burrell, C.J.Purified [125I]-labelled 20 to 25 nm hepatitis B antigen particles were found to give low affinity immunoprecipitation reactions with antisera to several normal serum components, which were immunologically distinct from the reaction due to the classical hepatitis B antigen surface determinant. These additional antigenic determinants were acid-stable and tightly bound to the particles; they could not be released by treatment with Tween 80 or ether, but were removed by protease digestion with the preservation of particle integrity. It was not possible to distinguish whether they were due to the presence of trace amounts of partly denatured serum components, or to a weak cross-reaction with antigens present in normal serum. The implications of this finding for hepatitis B antigen and antibody detection in sensititive assays are discussed. No evidence was found for native antigenic material, present in normal serum or normal liver cells, being integral to the structure of these particles.Item Metadata only Increased and decreased sensitivity to carbon catabolite repression of enzymes of acetate metabolism in mutants of Aspergillus nidulans(Springer-Verlag, 1977) Kelly, J.M.; Hynes, M.J.The creA204, creB15 and creC27 mutations have been shown to cause carbon catabolite derepression of acetyl CoA synthase and isocitrate lyase in Aspergillus nidulans. A recessive mutation, cre-34, which is linked to the creC gene, results in these enzymes being more sensitive than cre or wildtype strains to catabolite repression. The acetamidase levels of strains containing cre mutations have been investigated and provide support for the hypothesis that an acetate metabolite, rather than acetamide, induces this enzyme.Item Metadata only Pleiotropic mutants of Aspergillus nidulans altered in carbon metabolism(Springer-Verlag, 1977) Hynes, M.J.; Kelly, J.M.Mutants altered in carbon catabolite regulation have been isolated by selecting for mutants of theareA217 strain capable of using acetamide as the sole nitrogen source in the presence of sucrose. In addition tocreA mutants described previously by Arst and Cove, strains with mutations in two new genes,creB andcreC, have been found. ThecreB andcreC mutants grow poorly on some sole carbon sources and have low levels of some enzymes of carbon catabolism e.g. β-galactosidase and D-quinate dehydrogenase. ThecreB andcreC mutants are hypersitive to fluoroacetate, fluoroacetamide and allyl alcohol in the presence of glucose or sucrose but not glycerol; and the enzymes, acetamidase, and alcohol dehydrogenase, are less sensitive to carbon catabolite repression than the wild-type strain. Extracellular protease and α-glucosidase enzyme activities are elevated increB andcreC mutants, while L-proline and L-glutamate uptake capacities are lower in both the presence and absence of glucose. Interactions betweencreA, B and C mutations have been investigated in double mutants, and the dominance properties ofcreB andcreC mutants determined. The results indicate that thecreB andcreC genes may have a regulatory role in the control of carbon catabolism.Item Metadata only Membrane phospholipid asymmetry in Bacillus amyloliquefaciens(American Society for Microbiology, 1978) Paton, J.; May, B.; Elliott, W.The phospholipid distribution in the membrane of Bacillus amyloliquefaciens was studied by using phospholipase C (B. cereus), phospholipase A2 (Crotalus), and the nonpenetrating chemical probe trinitrobenzenesulfonic acid. After treatment of intact protoplasts of B. amyloliquefaciens with either phospholipase, about 70% of total membrane phospholipid was hydrolyzed; specifically, about 90, 90, and 30% of phosphatidylethanolamine, phosphatidylglycerol, and cardiolipin, respectively. Under these conditions, protoplasts remained intact and sealed. However, when protoplasts that were permeabilized by cold-shock treatment were incubated with either of the phospholipases, up to 80% of cardiolipin was hydrolyzed and phosphatidylglycerol and phosphatidylethanolamine were hydrolyzed virtually to completion. In intact cells, 92% of the phosphatidylethanolamine could be labeled with trinitrobenzenesulfonic acid under conditions in which the reagent did not penetrate the membrane to any significant extent. These results indicate that 70% of total phospholipid of this bacillus exists in the outer half of the bilayer. The distribution of phosphatidylethanolamine in this bilayer is highly asymmetric with it being located predominantly in the outer half. The results with phospholipases suggest that the distributions of cardiolipin and phosphatidylglycerol are also asymmetric but independent confirmation of this is required.Item Metadata only Effect of growth temperature on membrane fatty acid composition and susceptibility to cold shock of Bacillus amyloliquefaciens(American Society for Microbiology, 1978) Paton, J.C.; McMurchie, E.J.; May, B.K.; Elliott, W.H.We investigated the fatty acid composition of the membrane of Bacillus amyloliquefaciens grown at different temperatures. A decrease in growth temperature was accompanied by an increase in the ratio of branched- to straight-chain fatty acids and a marked increase in the level of unsaturation of branched-chain fatty acids. When cells of this organism grown at 30 degrees C were cold shocked, viability and ability to secrete extracellular protease were lost. Growth of this organism at lower temperatures or addition of Tween 80 to cells caused the critical temperature zone for cold shocking to be lowered significantly. These results suggest a direct correlation between membrane fluidity and the susceptibility to cold shock.Item Metadata only Detection of hepatitis B virus DNA sequences in infected hepatocytes by in situ cytohybridisation(Wiley-Liss, 1981) Gowans, E.J.; Burrell, C.J.; Jilbert, A.R.; Marmion, B.P.Plasmid pHBV 114 DNA, which contains 73% of the genome of hepatitis B virus (HBV), was radiolabelled with tritium to 1-2 X 10(8) dpm/microgram by nick translation and used as a radioactive probe to detect HBV DNA present in sections of infected liver tissue by in situ hybridisation followed by autoradiography. Factors affecting the sensitivity of the reaction were examined, including different methods of fixation, hybridisation time, temperature, and buffers. The specificity of the reaction for detecting viral DNA was carefully established by the use of unrelated DNA probes, pretreatment of sections with DNAase, and comparing the stability of the binding of DNA probe at different temperatures, with the melting curve of double-stranded DNA in solution. In the one liver studied in detail, cells containing large amounts of viral DNA were distributed in foci corresponding to areas containing morphologically damaged hepatocytes. This observation suggested a relationship between active viral replication and cell damage. Viral DNA was found mainly in the cytoplasm, although a minority of nuclei in these foci were also positive.Item Metadata only Ash from rice stubble inactivates thiobencarb and molinate(Wiley, 1981) Toth, J.; Milham, P.J.; Raison, J.M.The vegetative growth of Japanese millet (Echinochloa utilis Ohwi et Yabuno) was much lens reduced by pre-emergent treatments of thiobencarb (S-eithyl hexahydro-1,4-azepine-l-thiolcarbamate) and molinate (S-(4-chlorobenzyl)-N.N-diethylithiolcarbamate] when the herbicides were applied at <4 l a.i. ha−1 over rice stubble ash. The effcct was caused by adsorption of the herbicides onto activated carbon in the ash and occurred alike in field and pot experiments. The reduction in herbicide activity was quantified in the pot experiment. There the ash rendered at least 60% of the applied herbicide biologically unavailable. = Les cendres de chaume de riz inactivent le thiobencarb et le malinate La croissance végétative du millet japonais (Echinochloa utilis Ohwi et Yabuno) a été beaucoup moins réduite par des traitements en prélevée avec du thiobencarb (hexahydro-1, 4-uzépine-l-thiol carbamate de S-éthyle) et de molinate [N.N-dièthylthiolcarbamate de S-(4-chlorobenzyle)]. lorsque ces herbicides ont été appliqués à moins de 4 l/ha, m.a. sur des cendres de chaumes de riz. Ce phénomène est provoqué par l'adsorption des herbicides sur le carbone activé de la cendre et il se manifeste dans les expériences aussi bien au champ qu'en pots. La réduction de l'activité herbicide a été mesurée dans l'expérience en pots. Dans ce cas, la cendre a rendu biologiquement indisponible au moins 60% de l'herbicide appliqué. = Asche aus Reisstoppeln inaktiviert Thiobencarb und Molinat Das Wachstum von Echinocloa utilis (Ohwi et Yabuno) wurde durch Vorauflaufbebandlungen mit Thiobencarb (S-Äthyl-hexanydro-1,4-azepin-l-thiolcarbamat) und Molinat [S–(4-Chlorbenzyl>-N,N-diathylthiolcarbamat] bei Aufwandmengcn von <4 l/ ha deutlich weniger vermindert, wenn die Herbizide auf die Asche der Reisstoppel appliziert wurden. Die Ursache bierfür lag in der Sorption der Herbizide an die Aktivkohle in der Asche und war in Feld- wie auch in Gefässvcrsuchen zu beobachten. Die verminderte Herbizid Wirkung wurde in Gefasversuch quantifiziert, und es zeigte tuen, dass durch die Asche mindestens 60% des applizierten Herbizids biologisch nicht mehr verfügbar waren.Item Metadata only Quantitation of Clostridium botulinum organisms and toxin in the feces of an infant with botulism(American Society for Microbiology, 1982) Paton, J.; Lawrence, A.; Manson, J.A 4-month-old boy presented with symptoms and signs characteristic of infant botulism. Examination of feces revealed Clostridium botulinum type B and type B toxin. The numbers of C. botulinum and the amount of toxin in feces were measured throughout the 4-week period in hospital. The maximum numbers and amounts were detected in a fecal specimen collected 16 days after admission: this contained 8.4 X 10(6) C. botulinum type B colony-forming units and 61,440 mouse 100% lethal doses of type B toxin per g (wet weight) of feces. This latter figure is the highest fecal toxin titer reported yet for a case of infant botulism. By day 16, however, substantial improvement in the patient's clinical condition had occurred. This suggests that initiation of recovery from infant botulism is not necessarily preceded by a reduction in the numbers of C. botulinum organisms and the quantity of toxin in the gut.Item Metadata only The regulation of NADP-linked isocitrate dehydrogenase in Aspergillus nidulans(Society for General Microbiology, 1982) Kelly, J.M.; Hynes, M.J.The regulation of NADP-linked isocitrate dehydrogenase (NADP-IDH) has been studied in wild-type and mutant strains of Aspergillus nidulans. In the wild-type strain studied, the levels of NADP-IDH vary in a similar way to those of acetamidase, acetyl-CoA synthase, isocitrate lyase and malate synthase under all growth conditions used. Similarly,foc mutants, which are altered in the regulation of these enzymes of acetate utilization, are affected in NADP-IDH levels in a parallel fashion, as are cre mutants, which show altered carbon catabolite repression of this group of enzymes. Possible functions of the NADP-IDH enzyme are considered.Item Metadata only Effect of immunization with pneumolysin on survival time of mice challenged with Streptococcus pneumoniae(American Society for Microbiology, 1983) Paton, J.; Lock, R.; Hansman, D.The role of the cytolytic toxin pneumolysin in the pathogenicity of Streptococcus pneumoniae was investigated. Pneumolysin was purified to homogeneity and used to immunize mice. When these mice were subsequently challenged via the nasal route with virulent S. pneumoniae, they survived significantly longer than control mice. The mean survival times were 5.52 and 2.48 days for immunized and control mice, respectively. This work provides direct evidence for the involvement of pneumolysin in pneumococcal pathogenicity.Item Metadata only Inhibition of human polymorphonuclear leukocyte respiratory burst, bactericidal activity, and migration by pneumolysin(American Society for Microbiology, 1983) Paton, J.; Ferrante, A.The in vitro effects of pneumolysin, a sulfhydryl-activated toxin produced by Streptococcus pneumoniae, on various functions of human polymorphonuclear leukocytes (PMNLs) was investigated. Treatment of PMNLs with highly purified toxin significantly inhibited respiratory burst (in response to stimulation), ability to kill opsonized pneumococci, chemotaxis, and random migration. These inhibitions were observed at very low toxin doses (less than or equal to 1 hemolytic unit (2 ng) per 10(6) PMNLs), which had no effect on PMNL viability. These results suggest that pneumolysin could function in pathogenicity by interfering with the ability of PMNLs to migrate toward and kill pneumococci.Item Metadata only Effect of sterol structure on the physical-properties and function of plasma-membranes from yeast(Federation of American Societies for Experimental Biology, 1983) BOTTEMA, C.; PARKS, L.Abstract not availableItem Metadata only Quantities of Clostridium botulinum organisms and toxin in feces and presence of Clostridium botulinum toxin in the serum of an infant with botulism(American Society for Microbiology, 1983) Paton, J.; Lawrence, A.; Steven, I.A 7-week-old boy presented with symptoms and signs characteristic of infant botulism, and the diagnosis was confirmed by the detection of Clostridium botulinum type A organisms and toxin in the feces. The levels of organisms and toxin in the feces were measured throughout the 81-day period in hospital. The maximum levels detected were 2.46 x 10(8) C. botulinum type A colony-forming units and 64,000 mouse 100% lethal doses of type A toxin per g (wet weight) of feces. C. botulinum toxin was also detected in two samples of the patient's serum, collected 3 and 10 days after admission. Improvement in the patient's clinical condition occurred before the levels of organisms and toxin in the feces reached their maxima. A slight improvement may also have occurred while toxin was still present in the serum.Item Metadata only Antibody response of young children to pneumococcal vaccination(Carfax, 1983) Douglas, R.M.; Paton, J.C.; Miles, H.; Duncan, S.J.; Hansman, D.; Combined Meeting of the Royal College of Pathologists of Australasia and the New Zealand Society of Pathologists (Aug 1982 - Aug 1982 : Dunedin, New Zealand)Item Metadata only Antibody response to pneumococcal vaccination in children younger than five years of age(Oxford University Press, 1983) Douglas, R.M.; Paton, J.C.; Duncan, S.J.; Hansman, D.J.Sera were analyzed by radioimmunoassay for type-specific pneumococcal antibody in 249 children aged six to 54 months, who were participating in a controlled trial of a 14-valent pneumococcal vaccine. Levels of serum antibody to all serotypes increased after immunization in all age groups tested. For all serotypes, the antibody response increased progressively with age whether response was viewed as antibody doubling, relative increase in geometric mean, or final antibody level. Responses were poor up to the age of five years for the important pediatric serotypes 6A, 14, 19F, and 23F. Seventeen children under the age of two years at the time of primary immunization received booster doses of vaccine six months later. There was no significant increase in antibody to any serotype, and the geometric mean antibody levels fell for most types. Immune response to the pediatric serotypes was poor until the age of 4.5 years.Item Metadata only An analysis of the moisture content of soil cores in a designed experiment(International Biometric Society, 1983) Roberts, E.A.; Raison, J.M.An analysis of the moisture content of 10 segments of soil cores in a designed experiment is presented. Difficulties arise in the analysis of such data, as the observations at successive depths are usually correlated and have different variances. From the data, treatment contrasts at each depth were calculated, and a polynomial regression analysis of these contrasts was carried out. Polynomials up to third degree adequately describe the variation, with depth, in the treatment contrasts. The variance of all polynomials is estimated more efficiently by including higher-order coefficients as covariates and this is particularly so for zero-degree polynomials for which the residual variance is reduced from 3.86 to 1.57 by using the first-order coefficient as a covariate, and to 1.13 by using the first- and ninth-order coefficients.Item Metadata only Expression of Plasmodium falciparum blood-stage antigens in Escherichia coli: detection with antibodies from immune humans(National Academy of Sciences, 1983) Kemp, D.J.; Coppel, R.L.; Cowman, A.F.; Saint, R.B.; Brown, G.V.; Anders, R.F.Many proteins produced by blood stages of the malaria parasite Plasmodium falciparum are natural immunogens in man. As an approach to determining which of these are relevant to protective immunity we have constructed an expression library of P. falciparum cDNA sequences, cloned in Escherichia coli. The cDNA sequences were inserted into the beta-galactosidase gene of an ampicillin-resistant derivative of the temperature-sensitive lysogenic bacteriophage lambda gt11. About 5% of the resulting clones expressed P. falciparum sequences as polypeptides fused to beta-galactosidase. We have identified many clones that express P. falciparum antigens by immunological screening in situ with antibodies from immune human sera that inhibit P. falciparum growth in vitro. The antigen-positive clones contain P. falciparum cDNA sequences, as determined by hybridization. Some express polypeptides that are larger than beta-galactosidase and react both with antibodies to beta-galactosidase and with antibodies from humans immune to P. falciparum. The cloned P. falciparum antigens should facilitate new approaches to the identification of potential vaccine molecules.Item Metadata only Immune sera recognize on erythrocytes a Plasmodium falciparum antigen composed of repeated amino acid sequences(Nature Publishing Group, 1984) Coppel, R.L.; Cowman, A.F.; Anders, R.F.; Bianco, A.E.; Saint, R.B.; Lingelbach, K.R.; Kemp, D.J.; Brown, G.V.Abstract not available