Sodium Dodecyl Sulphate (sodium + dodecyl_sulphate)

Distribution by Scientific Domains
Distribution within Medical Sciences

Terms modified by Sodium Dodecyl Sulphate

  • sodium dodecyl sulphate polyacrylamide gel electrophoresis

  • Selected Abstracts


    Adsorbing colloid flotation for removal of metal ions in waters from base metal mines

    ENVIRONMENTAL PROGRESS & SUSTAINABLE ENERGY, Issue 1 2002
    H. Sabti
    Adsorbing Colloid Flotation (ACF) has been shown in laboratory experiments to be effective for the removal of heavy metals (Zn, Cu, Cd and Pb) from dilute solutions. Sodium dodecyl sulphate (SDS) and sodium oleate (NaOl) were used as surfactants in single or mixed form, with Fe(OH)3 as a flocculant for colloid formation. These reagents worked best for zinc and copper ions for a feed concentration of 50 parts per million (ppm). The removal of lead improved significantly by the use of Fe(OH)3 and NaLS (Sodium lauryl sulphate), while the best removal of cadmium was achieved by the use of Al(OH)3 and HTMABr (hexadecyltrimethylammonium bromide). Flotation experiments were conducted with feed concentrations of 50 and 500 parts per billion (ppb) and 50 ppm (parts per million). The experimental results showed that the residual concentration of metal ions decreased significantly with the decrease in the feed concentration. This could be the effect of excessive (much more than stoichiometric ratio) amounts of surfactant and flocculant, compared to the feed concentrations, required in the effective flotation of dilute feed solutions. The surfactant concentration and feed pH had the largest effects on the process, as observed in the case of cadmium removal. This can be attributed to the flocformation and flotation tendencies of the colloid-metal complexes at various solution pH and surfactant concentrations. The ACF method was applied to a number of natural drainage solutions from the metal mines at Te Aroha, New Zealand, and the experimental results demonstrate that significant removal is achieved for most of the heavy metals. [source]


    CHARACTERIZATION OF POLYPHENOL OXIDASE FROM ROOSTER POTATO (SOLANUM TUBEROSUM CV ROOSTER)

    JOURNAL OF FOOD BIOCHEMISTRY, Issue 1 2010
    D. NI EIDHIN
    ABSTRACT The isolation and purification of polyphenol oxidase from potatoes (Solanum tuberosum cv. Rooster) is described. A 64-fold purified preparation has been obtained with 10% yield by a procedure involving (NH4)2SO4 precipitation, phenyl sepharose chromatography, ion exchange chromatography and hydroxyapatite chromatography. The partially purified enzyme has both cresolase and catecholase activity. Activity was lower toward monophenols than diphenols. Enzyme activity was optimal at pH 6.0,6.5 and at 30C. Greater than 50% activity was retained during storage for 72 h at pH 6.0,7.5. Residual activity was greater than 50% after incubation at 20C for 72 h, 30C for 48 h, 40C for 24 h, 50C for 2 h and 60C for 15 min. The most effective inhibitors tested were sodium metabisulfite and ascorbic acid. Sodium dodecyl sulphate appeared to activate the enzyme. The enzyme was capable of cross-linking casein but did not increase gel-strengths in acidified milk gels. PRACTICAL APPLICATIONS Rooster is the most important potato cultivar grown in Ireland and data on its isolation and characterization has not been reported previously. This work describes a method to isolate polyphenol oxidase and characterization of the enzyme. Information on characterization of the enzyme could be valuable in relation to control of enzymatic browning during current processing and in minimum processing. There is potential for use of the enzyme in the emerging cross-linking area, as the results show some success and there may be potential of more cross-linking as the field develops and as interest in natural methods of cross-linking for food texture grows. This could lead to an important use for potato waste. Food product applications are given. [source]


    Airborne viable fungi in Riyadh and allergenic response of their extracts

    MYCOSES, Issue 9-10 2001
    A. S. Al-Suwaini
    Luftbürtige Pilze; Allergenität; Antigenität; Prick-Test; Saudi-Arabien. Summary. The allergenicity and antigenicity of various airborne fungi isolated from the atmosphere of Riyadh were studied. Protein nitrogen contents were estimated and found to range from 0.9 mg ml,1 for Cladosporium to 2.1 mg ml,1 for Aspergillus extracts. Sodium dodecyl sulphate,polyacrylamide gel electrophoresis analysis for those extracts exhibited a number of protein bands of higher molecular weight between 13 and 80 kDa for Alternaria, Ulocladium, Penicillium, Aspergillus and Cladosporium. Extracts in both aqueous and lyophilized forms were sterilized and tested for diagnostic skin prick test in 100 consecutive patients having bronchial asthma and allergic rhinitis. Overall, 13% of patients reacted positively to fungal extracts, revealing allergic sensitization to these fungi. These findings necessitate further investigation as regards the purification and characterization of these local extracts for better diagnostic use in patients in Saudi Arabia. Zusammenfassung. Es wurde die Allergenität und Antigenität mehrerer luftbürtiger Pilze untersucht, die aus der Luft von Riad isoliert worden waren. Hierzu wurden Pilzextrakte hergestellt, deren Proteinstickstoffgehalt zwischen 0.9 mg ml,1 bei Cladosporium und 2.1 mg ml,1 bei Aspergillus lag. Die SDS,PAGE-Analyse zeigte eine Anzahl von Proteinbanden höheren Molekulargewichts zwischen 13 und 80 kDa für Alternaria, Ulocladium, Penicillium, Aspergillus und Cladosporium. Die sowohl wässrigen wie lyophilisierten Extrakte wurden sterilisiert und an 100 unausgewählten Patienten mit Bronchialasthma und allergischer Rhinitis im Pricktest getestet. Ingesamt 13% der Patienten reagierten auf die Extrakte positiv, was für eine allergische Sensibilisierung gegen diese Pilze spricht. [source]


    Spin- and Spray-Deposited Single-Walled Carbon-Nanotube Electrodes for Organic Solar Cells

    ADVANCED FUNCTIONAL MATERIALS, Issue 14 2010
    Sungsoo Kim
    Abstract Organic bulk-heterojunction solar cells using thin-film single-walled carbon-nanotube (SWCNT) anodes deposited on glass are reported. Two types of SWCNT films are investigated: spin-coated films from dichloroethane (DCE), and spray-coated films from deionized water using sodium dodecyl sulphate (SDS) or sodium dodecyl benzene sulphonate (SDBS) as the surfactant. All of the films are found to be mechanically robust, with no tendency to delaminate from the underlying substrate during handling. Acid treatment with HNO3 yields high conductivities >1000,S,cm,1 for all of the films, with values of up to 7694,±,800,S,cm,1 being obtained when using SDS as the surfactant. Sheet resistances of around 100,,,sq,1 are obtained at reasonable transmission, for example, 128,±,2,,,sq,1 at 90% for DCE, 57,±,3,,,sq,1 at 65% for H2O:SDS, and 68,±,5,,,sq,1 at 70% for H2O:SDBS. Solar cells are fabricated by successively coating the SWCNT films with poly(3,4-ethylenedioxythiophene):poly(styrene sulphonate) (PEDOT:PSS), a blend of regioregular poly(3-hexylthiophene) (P3HT) and 1-(3-methoxy-carbonyl)-propyl-1-phenyl-(6,6)C61 (PCBM), and LiF/Al. The resultant devices have respective power conversions of 2.3, 2.2 and 1.2% for DCE, H2O:SDS and H2O:SDBS, with the first two being at a virtual parity with reference devices using ITO-coated glass as the anode (2.3%). [source]


    Absence of Gup1p in Saccharomyces cerevisiae results in defective cell wall composition, assembly, stability and morphology

    FEMS YEAST RESEARCH, Issue 7 2006
    Célia Ferreira
    Abstract Saccharomyces cerevisiae Gup1p and its homologue Gup2p, members of the superfamily of membrane-bound O -acyl transferases, were previously associated with glycerol-mediated salt-stress recovery and glycerol symporter activity. Several other phenotypes suggested Gup1p involvement in processes connected with cell structure organization and biogenesis. The gup1, mutant is also thermosensitive and exhibits an altered plasma membrane lipid composition. The present work shows that the thermosensitivity is independent of glycerol production and retention. Furthermore, the mutant grows poorly on salt, ethanol and weak carboxylic acids, suggestive of a malfunctioning membrane potential. Additionally, gup1, is sensitive to cell wall-perturbing agents, such as Calcofluor white, Zymolyase, lyticase and sodium dodecyl sulphate and exhibits a sedimentation/aggregation phenotype. Quantitative analysis of cell wall components yielded increased contents of chitin and ,-1,3-glucans and lower amounts of mannoproteins. Consistently, scanning electron microscopy showed a strikingly rough surface morphology of the mutant cells. These results suggest that the gup1, is affected in cell wall assembly and stability, although the Slt2p/MAP kinase from the PKC pathway was phosphorylated during hypo-osmotic shock to a normal extent. Results emphasize the pleiotropic nature of gup1,, and are consistent with a role of Gulp1p in connection with several pathways for cell maintenance and construction/remodelling. [source]


    The Rubino test for leprosy is a ,2 -glycoprotein 1-dependent antiphospholipid reaction

    IMMUNOLOGY, Issue 1 2000
    A. Panunto-Castelo
    Summary We describe the isolation and identification of three components required for the Rubino reaction (RR), which is the rapid sedimentation of formalinized sheep red-blood cells (SRBC) initiated by serum from leprosy patients with defective Mycobacterium leprae -specific cell immunity. The Rubino reaction factor (RRF) required for this phenomenon, previously identified as an immunoglobulin M (IgM), was purified from leprosy patient serum by adsorption to formalinized SRBC. Purified RRF IgM, when added to formalinized SRBC, did not produce a positive RR. However, when the contact was carried out in the presence of normal human serum (NHS), cells rapidly sedimented. The purified cofactor from NHS contained two components of 70 000 and 50 000 molecular weight (MW), as determined by sodium dodecyl sulphate,polyacrylamide gel electrophoresis (SDS,PAGE). The latter was recognized by the RRF IgM on immunoblot and its N-terminal sequence indicated that it was ,2 -glycoprotein 1 (,2 -GP1), an anionic phospholipid-binding protein. Methanol-treated formalinized SRBC did not support the RR. Thin-layer chromatography of an extract of membranes indicated that the SRBC ligand was a cell-surface phospholipid. Cardiolipin inhibited the RR. These data demonstrate that the RR involves a trimolecular interaction in which IgM, ,2 -GP1 and an SRBC phospholipid participate. By analogy with the antiphospholipid antibodies (anti-PL) that occur in autoimmune processes, serum samples from 29 systemic lupus erythematosus patients with high levels of anticardiolipin antibodies were submitted to the RR. A positive RR was obtained for 45% (13 of 29 patients). These results modify the paradigm of the absolute specificity of the RR for leprosy and demonstrate that RRF IgM is a ,2 -GP1-dependent anti-PL. [source]


    Angiopoietin-2 in experimental colitis

    INFLAMMATORY BOWEL DISEASES, Issue 6 2010
    Vijay C. Ganta PhD
    Abstract Background: The pathophysiology of inflammatory bowel disease (IBD) includes leukocyte infiltration, blood and lymphatic remodeling, weight loss and protein enteropathy. The roles of angiopoietin-2 (Ang-2) in initiating gut inflammation, leukocyte infiltration and angiogenesis are not well understood. Methods: Disease activity index, histopathological scoring, myeloperoxidase assay, immunohistochemistry and sodium dodecyl sulphate- polyacrylamide gel electrophoretic methods were employed in the present study to addess the roles of Ang-2 in experimental colitis. Results: Several important differences were seen in the development of experimental IBD in Ang-2,/, mice. Although weight change and disease activity differ only slightly in WT and Ang-2,/, + DSS treated mice, leukocyte infiltration, inflammation and blood and lymphatic vessel density is significantly attenuated compared to WT + DSS mice. Gut capillary fragility and water export (stool blood and form) appear significantly earlier in Ang-2,/, + DSS mice vs. WT. Colon lengths were also significantly reduced in Ang-2,/, and gut histopathology was less severe in Ang-2,/, compared to WT + DSS. Lastly, the decrease in serum protein content in WT + DSS was less severe in Ang-2,/, + DSS, thus protein losing enteropathy (PLE) a feature of IBD is relieved by Ang-2,/,. Conclusion: These data demonstrate that in DSS colitis, Ang-2 mediates inflammatory hemangiogenesis, lymphangiogenesis and neutrophil infiltration to reduce some, but not all clinical features of IBD. The implications for Ang-2 manipulation in the development of IBD and other inflammatory diseases and treatments involving Ang-2 are discussed. (Inflamm Bowel Dis 2009) [source]


    pH-induced alterations in stratum corneum properties

    INTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Issue 3 2003
    K. P. Ananthapadmanabhan
    Synopsis Skin-cleansing compositions based on alkyl carboxylates (soaps) have a higher irritation potential than those based on syndet surfactants such as alkyl isethionates or alkyl ether sulphates. Contributing factors include inherent differences in the irritation potential of soaps and syndet surfactants, pH-induced changes in surfactant solution chemistry, and the direct effects of pH on the physical properties of the stratum corneum (SC). Past work has not directly addressed the effect of solution pH on the SC itself and its potential role in cleanser-induced skin irritation. In the current work, alterations to SC properties induced by buffered pH solutions and two strongly ionizable surfactants, sodium dodecyl sulphate and sodium lauryl ether sulphate, at different pH values are measured. By utilizing optical coherence tomography (OCT) and infrared (IR) spectroscopy we have directly measured physical changes in SC proteins and lipids. Our results indicate that SC swelling, which reflects alterations to SC structural proteins, is increased significantly at pH 10, compared to pH 4 and 6.5. The transition temperature (Tm) of SC lipids is found to increase at pH 10, compared to pH 4 and 6.5, suggesting a more rigid SC lipid matrix. Surfactants cause a further increase in swelling and lipid rigidity. Some aspects of what these results mean for SC physical properties as well as their implications to potential mechanisms of surfactant-induced skin irritation are discussed. Résumé Les compositions nettoyantes pour la peau à base d'alkyl carboxylates (savons) ont un potentiel irritant supérieur à celles à base de syndet tensioactifs tels que les alkyl isothionates ou les alkyl ether sulfates. Les facteurs en cause comprennent les différences de potentiel irritant inhérentes aux savons et aux syndet tensioactifs, les modifications de la chimie de la solution de tensioactif dues aux pH, et les effets directs du pH sur les propriétés physiques de la couche cornée (CC). Les travaux antérieurs n'ont pas traité directement l'effet du pH de la solution sur la couche cornée elle-même et son rôle potentiel dans l'irritation de la peau due à la solution nettoyante. Dans la présente étude on a mesuré les altérations des propriétés de la CC causées par des solutions à pH tamponné et deux tensioactifs fortement ionisables, le dodecyl sulfate de sodium et le lauryl ether sulfate de sodium, à différentes valeurs de pH. En utilisant la tomographie optique (OCT) et la spectroscopie à infrarouge (IR) on a mesuré directement les modifications physiques des protéines et des lipides de la CC. Nos résultats montrent que le gonflement de la CC, qui traduit des altérations des protéines structurales de la CC, augmente significativement à pH 10, par comparaison au pH 4 et 6.5. On observe que la température de transition (Tm) des lipides de la CC augmente à pH 10, par comparaison au pH 4 et 6.5, suggérant une matrice lipidique de la CC plus rigide. Les tensioactifs provoquent une augmentation plus importante du gonflement et de la rigidité lipidique. On aborde certains aspects de la signification de ces résultats vis-à-vis des propriétés physiques de la couche cornée ainsi que leurs conséquences sur les mécanismes potentiels de l'irritation de la peau causée par les tensioactifs. [source]


    Effect of surfactants and liquid hydrocarbons on gas hydrate formation rate and storage capacity

    INTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 8 2003
    Zhigao Sun
    Abstract Hydrate formation rate plays an important role in making hydrates for the storage and transport of natural gas. Micellar surfactant solutions were found to increase gas hydrate formation rate and storage capacity. With the presence of surfactant, hydrate could form quickly in a quiescent system and the energy costs of hydrate formation reduced. Surfactants (an anionic surfactant, a non-ionic surfactant and their mixtures) and liquid hydrocarbons (cyclopentane and methylcyclohexane) were used to improve hydrate formation. The experiments of hydrate formation were carried out in the pressure range 3.69,6.82 MPa and the temperature range 274.05,277.55 K. The experimental pressures were kept constant during hydrate formation in each experimental run. The effect of anionic surfactant (sodium dodecyl sulphate (SDS)) on natural gas storage in hydrates is more pronounced compared to a non-ionic surfactant (dodecyl polysaccharide glycoside (DPG)). The induction time of hydrate formation was reduced with the presence of cyclopentane (CP). Cyclopentane and methylcyclohexane (MCH) could increase hydrate formation rate, but reduced hydrate storage capacity The higher methylcyclohexane concentration, the lower the hydrate storage capacity. Copyright © 2003 John Wiley & Sons, Ltd. [source]


    The emulsifying properties of a polysaccharide isolated from the fruit of Cordia abyssinica

    INTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 5 2004
    Mudadi Albert Nhamoiesu Benhura
    Summary Polysaccharide was isolated from Cordia abyssinica and its effect, at differing concentrations, on its emulsifying ability was determined. Emulsions of vegetable oil containing up to 1% of the polysaccharide in phosphate pH 7.4 buffer, were prepared by using a hand piston homogenizer. Emulsification was assessed by diluting samples of the emulsions in sodium dodecyl sulphate and measuring absorbance at 500 nm. Addition of increasing concentrations of the polysaccharide up to 1% enhanced emulsification and emulsion stability. Above 1% concentration the polysaccharide solutions were too viscous for making emulsions conveniently. At a constant concentration of the polysaccharide, addition of up to a 1% concentration of salt enhanced emulsion formation. Further addition of salt above 1% resulted in no further changes in emulsifying ability, but the stability of the emulsions formed decreased on increasing the concentration of salt above 1%. The effect of pH on emulsifying ability was investigated by preparing emulsions using buffers of different pH, from pH 3 to pH 13. The polysaccharide had poor emulsifying ability below pH 7. Emulsifying ability increased with pH between pH 7 and 11. At pH above 11 there was a decrease in emulsifying ability. [source]


    Intrinsic and acquired resistance to quaternary ammonium compounds in food-related Pseudomonas spp.

    JOURNAL OF APPLIED MICROBIOLOGY, Issue 4 2003
    S. Langsrud
    Abstract Aims: To determine the sensitivity of a strain used for disinfectants testing (Pseudomonas aeruginosa ATCC 15442) and food-associated isolates to benzalkonium chloride and didecyl dimethylammonium chloride (DDAC). To determine whether the increase in bacterial resistance after adaptation to DDAC can be associated with phenotypic changes. To test the activity of alternative disinfectants to eliminate resistant Pseudomonas spp. Methods and Results:Pseudomonas aeruginosa ATCC 15442 was among the most resistant strains tested using a bactericidal suspension test. Growth of a sensitive Ps. fluorescens in gradually higher concentrations of DDAC resulted in stable higher resistance and to some cross-resistance to several antibacterial agents, with the exception of disinfectants containing chloramine T, glutaraldehyde or peracetic acid. It was shown by microscopy that adaptation was followed by loss of flagella, and slime formation. Removal of the slime by sodium dodecyl sulphate resulted in partial loss of the acquired resistance. Conclusions:Pseudomonas spp. may adapt to survive against higher concentrations of quaternary ammonium compounds (QACs), but resistant strains can be eliminated with chemically unrelated disinfectants. Significance and Impact of the Study: The work supports the rotation of disinfectants in food processing environments for avoiding the development of bacterial resistance to QACs. The alternating disinfectants should be chosen carefully, because of possible cross-resistance. [source]


    Characterization and application of monoclonal antibodies against white spot syndrome virus

    JOURNAL OF FISH DISEASES, Issue 3 2001

    Three hybridoma clones secreting monoclonal antibodies (MAbs) were produced from mouse myeloma and spleen cells immunized with white spot syndrome virus (WSSV) isolated and purified from Penaeus monodon (Fabricius), collected from north-eastern Taiwan. By sodium dodecyl sulphate,polyacrylamide gel electrophoresis (SDS,PAGE), the protein profile of this isolate contained four major proteins with sizes of approximately 35 (VP35), 28 (VP28), 24 (VP24), and 19 kDa (VP19). Western blot analysis revealed that two MAbs (1D7 and 6E1) recognized epitopes on VP28 and one MAb (3E8) recognized an epitope on VP19. The MAb 6E1 isotyped to the IgG1 class was used in both an indirect immunofluorescence assay (IFA) and in an immunochemical staining protocol for successful identification and localization of WSSV in infected shrimp tissues. Antigenic similarity of isolates from Indonesia and Malaysia to the Taiwan isolate was illustrated by IFA with MAb 6E1. A MAb (2F6) which bound specifically to two shrimp proteins, 75 and 72 kDa, and reacted to the healthy and non-target tissues of WSSV in infected shrimp, such as hepatopancreas, is also described here and shows the necessity for specific identification of antibodies. [source]


    PRG4 exchange between the articular cartilage surface and synovial fluid

    JOURNAL OF ORTHOPAEDIC RESEARCH, Issue 10 2007
    G.E. Nugent-Derfus
    Abstract The boundary lubrication function of articular cartilage is mediated in part by proteoglycan 4 (PRG4) molecules, found both in synovial fluid (SF) and bound to the articular cartilage surface. Currently the mechanism by which PRG4 binds to the articular surface is not well understood. The objectives of this study were to determine (1) the effect of bathing fluid contents on PRG4 concentration at the articular surface ([PRG4]cart), and (2) whether native PRG4 can be removed from the surface and subsequently repleted with PRG4 from synovial fluid. In one experiment, cylindrical cartilage disks were stored in solutions of various PRG4 concentrations, either in phosphate-buffered saline (PBS) or SF as the carrier fluid. In a separate experiment, cartilage disks were stored in solutions expected to remove native PRG4 from the articular surface and allow subsequent repletion with PRG4 from SF. [PRG4]cart was independent of PRG4 concentration of the bathing fluid, and was similar for both carrier fluids. PRG4 was removed from cartilage by treatment with hyaluronidase, reduction/alkylation, and sodium dodecyl sulphate, and was repleted fully by subsequent bathing in SF. These results suggest that the articular surface is normally saturated with tightly bound PRG4, but this PRG4 can exchange with the PRG4 in SF under certain conditions. This finding suggests that all tissues surrounding the joint cavity that secrete PRG4 into the SF may help to maintain lubrication function at the articular surface. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 25:1269,1276, 2007 [source]


    Analysis of flunarizine in the presence of some of its degradation products using micellar liquid chromatography (MLC) or microemulsion liquid chromatography (MELC) , Application to dosage forms

    JOURNAL OF SEPARATION SCIENCE, JSS, Issue 2 2005
    Dina T. El-Sherbiny
    Abstract The separation of flunarizine hydrochloride (FLZ) and five of its degradation products , 1-[bis(4-fluorophenyl)methyl]-4-(3-phenyl-2-propenyl)piperazine, 4-oxide (A), bis(4-fluorophenyl)methanone (B), bis(4-fluorophenyl)methanol (C), 1-(3-phenyl-2-propenyl)piperazine (D), and 1-[bis-4-fluorophenyl) methyl] piperazine (E) , could be accomplished by reversed phase liquid chromatography using either micellar or microemulsion mobile phases. Cyanopropyl-bonded stationary phase has been used with UV detection at 254 nm. Microemulsion mobile phase consisting of 0.15 M SDS, 10% n -propanol, 1% n -octanol, and 0.3% triethylamine in 0.02 M phosphoric acid of pH 7.0, has been used for the separation of FLZ and its degradation products (B, C, D, and E). Micellar mobile phases consisting of 0.15 M sodium dodecyl sulphate (SDS), 10% n -propanol, 0.3% triethylamine (TEA) in 0.02 M phosphoric acid of pH values either 4.0 or 6.8 have been used for the separation of FLZ from its degradation products, i.e. either from (B, C, D, and E) or from (A, B, C, and D), respectively. Micellar liquid chromatography (MLC) was applied to the determination of FLZ in pure form as well as in dosage forms; the calibration graph was linear over the concentration range of 0.15,50 ,g/mL with detection limit of 0.02 ,g/mL (4.19×10,8M). [source]


    Phenotypes, serotypes and antibiotic susceptibility of Swedish Porphyromonas gingivalis isolates from periodontitis and periodontal abscesses

    MOLECULAR ORAL MICROBIOLOGY, Issue 2 2007
    G. Dahlén
    This study was conducted to reveal phenotypic, serological subtypes and antibiotic susceptibility among fresh isolates of Porphyromonas gingivalis in a Swedish population with periodontitis and periodontal abscess. Fifty-five subgingival strains were isolated and tentatively designated as P. gingivalis from 55 consecutive paper-point samples taken from 51 patients with periodontitis (at least one site with >6-mm pocket depth) in Sweden and were sent in for microbiological evaluation. Eight P. gingivalis strains from periodontal abscesses were also included. Four P. gingivalis strains served as reference and another four type strains were included. The strains were characterized by colony morphology, biochemical tests, enzyme profile, gas,liquid chromatography and antibiotic susceptibility. The strains were further characterized for whole cell protein profiles using sodium dodecyl sulphate,polyacrylamide gel electrophoresis (SDS,PAGE) and were identified to serotype by specific monoclonal antibodies. Among the 55 P. gingivalis strains 35 had smooth (S), 13 rough (R) and seven semi-rough colony morphologies. All strains were phenotypically homogeneous in biochemical tests, enzyme profile and antibiotic susceptibility. All strains produced phenylacetic acid and , -fucosidase. Almost all (96%) of the subgingival strains, but relatively fewer (62%) of the abscess strains, belonged to serotype A. Two subgingival and three abscess strains were classified as serotype B. No specific SDS,PAGE protein profiles were recorded for the two serotypes. The P. gingivalis strains from Swedish periodontitis cases showed homogeneity in terms of biochemical phenotypes and antibiotic susceptibility patterns. The strains fell into two serotypes, of which serotype A predominated in the periodontitis cases and serotype B was overrepresented in periodontal abscesses. [source]


    Phenotypic and genotypic characterization of reference strains of the genus Aspergillus

    MYCOSES, Issue 3-4 2001
    P.-M. Rath
    Aspergillus; Genotypisierung; Biotypisierung; SDS-PAGE; RAPD Summary. Twenty-five culture collection strains from four Aspergillus species (A. fumigatus n = 8, A. flavus n = 8, A. niger n= 4, A. nidulans n = 5) were characterized by four methods: (i) determination of patterns in an assimilation assay; (ii) protein pattern of whole mycelial cell lysates in the sodium dodecyl sulphate (SDS)-polyacrylamide gel electrophoresis (PAGE); (iii) reactivity of a pool serum obtained from cystic fibrosis patients with mycelial lysates in the immunoblot; and (iv) random amplification of polymorphic DNA (RAPD) with eight primers having arbitrary or repetitive sequences. In the assimilation assay the A. fumigatus strains showed identical patterns in contrast to the strains of the species A. flavus, A. niger, and A. nidulans, which each showed four patterns. In the SDS-PAGE no differences in the band patterns in the A. fumigatus strains were found, in contrast to the A. flavus (three patterns), A. nidulans (five patterns) and A. niger strains (two patterns). The immunoblot patterns were characteristic for each species with bands at 62 and 17/18 kDa in the A. fumigatus strains, at 51 and 18 kDa in the A. flavus strains, at 51 kDa in the A. niger strains, and at 51, 40 and 17/18 kDa in the A. nidulans strains allowing, however, no intraspecies typing. In the RAPD assay four out of eight primers gave interpretable patterns with 3,20 bands. None of the primers showed sufficient discriminatory power when used alone. However, when combining the results of two of the primers (5,-GTA TTG CCC T-3, and 5,-GAT AGA TAG ATA GAT A-3,) all strains except two A. fumigatus strains could be clearly separated from each other. It is concluded that the the RAPD assay showed the most discriminatory power in all Aspergillus species investigated. In contrast to the phenotypically similar A. fumigatus strains, the strains of the species A. flavus, A. nidulans and A. niger differed in their phenotypic characteristics. The presented data of strains from international culture collections may serve as basis for interlaboratory standardization of typing methods. Zusammenfassung. Fünfundzwanzig Aspergillus -Stämme aus internationalen Stammsammlungen (A. fumigatus n = 8, A. flavus n = 8, A. niger n = 4, A. nidulans n = 5) wurden mit vier Methoden charakterisiert: (1) Reaktionsmuster in einem Assimilationstest (2) Proteinmuster von Ganzzell-Lysaten in der SDS-PAGE (3) Reaktionsmuster eines Poolserums von Patienten mit Mukoviszidose mit Zellextrakten im Immunoblot und (4) random amplification of polymorphic DNA (RAPD) mit acht Primern zufälliger oder repetitiver Sequenz. Im Assimilationstest zeigten die A. fumigatus -Stämme identische Muster, während die Stämme der Spezies A.flavus, A. niger und A. nidulans je vier Reaktionsmuster aufwiesen. In der SDS-PAGE wiesen die A. fumigatus -Stämme identische Muster auf, während die A. flavus -Stämme drei, die A. niger -Stämme zwei, und die A. nidulans -Stämme fünf verschiedene Muster zeigten. Im Immunoblot waren die Muster für jede Spezies charakteristisch mit Banden bei 62 kDa und 17/18 kDa bei A. fumigatus, bei 51 kDa und 18 kDa bei A. flavus, bei 51 kDa bei A. niger und bei 51, 40 und 17/18 kDa bei A. nidulans. Eine Intraspezies-Typisierung gelang jedoch nicht. In der RAPD ergaben vier der acht Primer interpretierbare Muster mit 3 bis 20 Banden. Keiner der Primer alleine zeigte eine ausreichende Diskriminationskapazität. Wurden die Resultate von zwei Primern (5,-GTA TTG CCC T-3, and 5,-GAT AGA TAG ATA GAT A-3,) kombiniert, konnten mit Ausnahme von zwei A. fumigatus -Stämmen alle Isolate voneinander abgegrenzt werden. Die Ergebnisse zeigen, daß die RAPD die größte Diskriminationskapazität aufweist. Im Gegensatz zu den phänotypisch ähnlichen A. fumigatus -Stämmen unterschieden sich die Stämme der Spezies A. flavus, A. nidulans und A. niger voneinander. Die gezeigten Daten von Stämmen internationaler Stammsammlungen können als Grundlage für die Standardisierung von Typisierungsmethoden dienen. [source]


    Method optimisation for peptide profiling of microdissected breast carcinoma tissue by matrix-assisted laser desorption/ionisation-time of flight and matrix-assisted laser desorption/ionisation-time of flight/time of flight-mass spectrometry

    PROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 10 2005
    Arzu Umar
    Abstract Appropriate methods for the analysis of microdissected solid tumour tissues by matrix-assisted laser desorption/ionisation-time of flight-mass spectrometry (MALDI-TOF MS) are not yet well established. Optimisation of sample preparation was performed first on undissected tissue slices, representing ,200,000 cells, which were solubilised either in urea containing buffer, trifluoroethanol/NH4HCO3, 0.1% sodium dodecyl sulphate (SDS) or in 0.1% RapiGest solution, then trypsin digested and analysed by MALDI-TOF MS. Solubilisation in 0.1% SDS resulted in detection of the highest number of sample specific peak signals. Interestingly, there was little overlap in detectable peaks using the different buffers, implying that they can be used complementarily to each other. Additionally, we fractionated tryptic digests on a monolithic high-performance liquid chromatography column. Fractionation of tryptic digest from whole tissue sections resulted in a four-fold increase in the total number of peaks detected. To prove this principle, we used 0.1% SDS to generate peptide patterns from 2000 microdissected tumour and stromal cells from five different breast carcinoma tumours. The tumour and stroma specific peaks could be detected upon comparison of the peptide profiles. Identification of differentially expressed peaks by MALDI-TOF/TOF MS was performed on fractionated tryptic digests derived from a whole tissue slice. In conclusion, we describe a method that is suitable for direct peptide profiling on small amounts of microdissected cells obtained from breast cancer tissues. [source]


    Identification of Cytokeratins in Bovine Sperm Outer Dense Fibre Fractions

    REPRODUCTION IN DOMESTIC ANIMALS, Issue 2 2003
    E Hinsch
    Contents Outer dense fibres (ODF) are important substructures of mammalian sperm tails that are involved in the regulation of sperm motility. In this study, we investigated the identity of several sodium dodecyl sulphate (SDS)-insoluble ODF proteins. Bovine ODF were purified by separating sperm heads and tails using ultrasound and Percoll® density gradient centrifugation. Sperm flagella were treated with the detergent cetyltrimethylammonium bromide (CTAB). CTAB-insoluble material, which reportedly represents the ODF fraction, was collected, and electron microscopy confirmed a highly purified ODF fraction. We found after solubilization of this fraction with SDS that high amounts of insoluble material were retained after centrifugation. SDS-insoluble material was collected and quantitatively dissolved in 8 M urea. SDS-gel electrophoresis in the presence of urea revealed polypeptides with apparent molecular masses of approximately 25, 43, and 50 kDa. Subsequent immunoblotting with anti-cytokeratin antibodies detected two urea-soluble, SDS-insoluble proteins with apparent molecular masses of 45 and 66 kDa. The 45-kDa protein was identified as cytokeratin 19. An antibody reacting with a palette of cytokeratins (CK 1,18 and CK 20), KL1, was the only antibody that reacted with the 66-kDa polypeptide. We conclude that sperm ODF fractions contain at least one each of type I and type II intermediate filaments. As keratins and intermediate filaments are described as rope-like structures, we suggest that these intermediate filaments play an important structural or tension-bearing role in sperm flagella. [source]


    The effect of surfactants on deformation of falling non-Newtonian drops in a Newtonian liquid

    THE CANADIAN JOURNAL OF CHEMICAL ENGINEERING, Issue 1 2008
    Denis RodrigueArticle first published online: 4 MAR 200
    Abstract Deformation of settling non-Newtonian ellipsoidal drops in a Newtonian liquid was experimentally observed. Corn oil was used as the Newtonian phase and solutions of polyacrylamide in aqueous glycerine as the non-Newtonian phase. The shear-thinning behaviour of the drops fluid was controlled by the amount of polymer dissolved, while the effect of interfacial tension was examined using different concentrations of sodium dodecyl sulphate (SDS). In the range of 1,<,E,<,2.9, 0.2,<,Eo,,<,23, and 0,<,Ma,<,17.2, drop eccentricity increased linearly with a modified Eötvös number taking into account the effect of surfactants. For the range of experimental conditions tested, drop deformation was mainly controlled by viscous and interfacial tension forces, while shear-thinning and inertia effects were negligible. On a observé expérimentalement la déformation de gouttelettes ellipsödales non newtoniennes sédimentant dans un liquide newtonien. Del'huile de mäs a été utilisée comme phase newtonienne et des solutions de polyacrylamide dans de la glycérine aqueuse comme phase non newtonienne. Le comportement rhéofluidifant du fluide des gouttes est contrôlé par la quantité de polymères dissous, tandis que l'effet de la tension interfaciale est examiné avec différentes concentrations de sulfate de dodécyle de sodium. Dans la gamme de 1,<,E,<,2,9, 0,2,<,Eo 23 and 0,<,Ma,<,17,2, l'eccentricité des gouttelettes augmente linéairement avec le nombre d'Eötvös modifié en tenant compte de l'effet des surfactants. Pour la gamme des conditions expérimentales testées, la déformation des gouttelettes est principalement contrôlée par les forces de tension visqueuse et interfaciale, tandis que les effets de rhéofluidifiance et d'inertie sont négligeables. [source]


    Dietary intake of probiotics and maslinic acid in juvenile dentex (Dentex dentex L.): effects on growth performance, survival and liver proteolytic activities

    AQUACULTURE NUTRITION, Issue 4 2006
    M.C. HIDALGO
    Abstract Two feeding trials were carried out to evaluate the efficiency of probiotics and maslinic acid, on growth and survival of juvenile dentex; liver proteolytic activities were also investigated in the second trial. For experiment 1, triplicate groups were fed six diets with two probiotics (Bacillus toyoi, T, and B. cereus, E) at increasing levels (0.5, 1 and 2 g kg,1 diet) and a control diet. Growth and feed conversion were not significantly influenced by the probiotics. The diet T1 produced the lower mortality, whereas diet E1 rendered the higher mortality. It was concluded that no significant effects on growth and survival were found following the addition of two kinds of probiotics to dentex diets. However, the diet E0.5 showed a tendency to ameliorate the growth and feed utilization of the diet. In a second trial, triplicate groups were fed four diets with increasing levels of maslinic acid (0, 20, 40 and 80 mg kg,1 diet). Growth of fish given diets with the highest level of maslinic acid (D80) was slightly but not significantly lower than those from the other groups. Furthemore, mortality of fish fed diet D40 was the lowest. Changes in liver proteasome and endoprotease activities measured on sodium dodecyl sulphate (SDS)/gelatin gels were also detected in a dose-dependent manner. It was concluded that a dietary maslinic acid at a level of 80 mg kg,1 diet seems to be too high for juvenile dentex to maintain a maximal growth and survival rate. [source]


    Structural studies of wheat flour glutenin polymers by CD spectroscopy

    BIOPOLYMERS, Issue 4 2004
    S. Fisichella
    Abstract A dissolution procedure of unreduced glutenin polymers of three wheat flour varieties (WRU 6981, Alisei 1, and Alisei 2) by sonication in the presence of SDS (sodium dodecyl sulphate), after the elimination of albumins, globulins, and gliadins, was achieved, and the molecular weight distribution of glutenin polymers obtained by this method was measured by matrix assisted laser desorption ionization,time of flight (MALDI-TOF) mass spectrometry. A structural study by CD spectroscopy at different temperatures of WRU 6981 glutenin polymer and of 1Ax1 high- Mr (relative molecular mass) glutenin subunit, which is the only high- Mr subunit contained in WRU 6981 flour, was undertaken to understand if the information obtained from the single subunit were applicable to the total polymer. CD spectroscopy also has been employed to study the glutenin polymers obtained by Alisei 1 and Alisei 2 wheat flours; Alisei 1 biotype contained 1Bx7 and 1Dx2+1Dy12 high-Mr subunits, whereas the Alisei 2 biotype contained only 1Bx7 and 1Dy12 subunits. A conformational study was undertaken by CD spectroscopy at different temperatures and in the presence of some chemical denaturant agents, such as urea and sodium dodecyl sulphate, in order to obtain information about their intrinsic stability and to verify if the 1Dx2 subunit presence determined a different structural behavior between Alisei 1 and Alisei 2 polymers. MALDI-TOF mass spectrometric experiments showed that the glutenin polymers molecular weights were in the mass range of 500,000,5,000,000. CD spectra indicated that a single conformational state did not predominate in the temperature range studied but equilibrium between two distinct conformational states existed; moreover, all the changes induced by urea and by SDS followed a multistep transition process. © 2004 Wiley Periodicals, Inc. Biopolymers, 2004 [source]


    Novel function of DUSP14/MKP6 (dual specific phosphatase 14) as a nonspecific regulatory molecule for delayed-type hypersensitivity

    BRITISH JOURNAL OF DERMATOLOGY, Issue 5 2007
    Y. Nakano
    Summary Background, Nonspecific unresponsive states of delayed-type hypersensitivity (DTH) to unrelated antigens are induced in mice by a single administration of hapten. In these studies, we found a unique regulatory mechanism of contact hypersensitivity (CHS) mediated by nonspecific suppressor factor (NSF) induced by the intravenous injection of hapten-conjugated syngeneic spleen cells. NSF is a , 45-kDa protein released from the macrophage-like suppressor cells and binds selectively to dendritic cells (DCs). Moreover, NSF-treated DCs release a second , 20-kDa NSF (NSFint). Objectives, To try and identify NSF and characterize its function. Methods, The suppressor activity was evaluated by inhibition of the passive transfer of CHS by the effector cells sensitized with hapten and the antigen-presenting cell (APC) activity of hapten-primed draining lymph node cells (DLNCs) to induce CHS. NSF-containing supernatants obtained from the culture of spleen cells from mice that had been injected intravenously with oxazolone-conjugated syngeneic spleen cells 7 days before were prepared and purified with a Green A dye-affinity column, DEAE column and Sephacryl S-200 column. Then, samples of molecular mass of , 45 kDa were separated by native-PAGE (polyacrylamide gel electrophoresis) and nonreducing sodium dodecyl sulphate (SDS)-PAGE. After confirming the suppressor activity of proteins of , 45 kDa separated by native-PAGE, samples were separated by nonreducing SDS-PAGE, transferred onto polyvinylidene difluoride membranes and analysed using matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry. Results, Proteins of , 45 kDa eluted from a Sephacryl S-200 column and the slice of native-PAGE gel exhibited the strong suppressor activity. Analyses using MALDI-TOF mass spectrometry and MASCOT algorithm of the protein bands around 45 kDa separated by nonreducing SDS-PAGE identified NSF as a 22·5-kDa protein, dual specific phosphatase 14/MAP-kinase phophatase-6 (DUSP14/MKP6), which functions as a negative regulator of the MAP-kinase signalling. Western blot analyses revealed that recombinant DUSP14 (rDUSP14) exists as the mixture of 22·5-kDa monomer and 45-kDa dimer under nonreducing conditions, and monomers under reducing conditions. Treatment with rDUSP14 at 4 °C for 2 h suppressed the ability of effector cells to transfer CHS dose dependently and the APC function of DLNCs to induce CHS. Epicutaneous application of rDUSP14 immediately after challenge inhibited the subsequent CHS expression. rDUSP14 was bound specifically by major histocompatibility complex class II (Ia)-positive spleen cells (presumably DCs). The suppressor activity of NSF was neutralized by anti-DUSP14 monoclonal antibody. Expression of DUSP14 mRNA in the spleen was upregulated parallel to the unresponsive state induced by hapten-conjugated cells. NSF, NSFint and rDUSP14 exhibited the phosphatase activity towards p -nitrophenyl phosphate in vitro as alkaline phosphatase. Conclusions, These studies indicate for the first time that NSF is a dimer of DUSP14 secreted by macrophage-like suppressor cells by stimulation with hapten-conjugated cells and exerts a regulatory function on CHS through DCs as a secreted phosphatase. [source]


    Cross-linked envelopes in nail plate in lamellar ichthyosis

    BRITISH JOURNAL OF DERMATOLOGY, Issue 5 2003
    R.H. Rice
    Summary Background Corneocytes of the nail plate, like those of the stratum corneum, generate cornified envelopes (CEs) of cross-linked protein that can be visualized readily after removal of non-cross-linked protein by detergent extraction. Defective CE formation occurs in epidermal scale and hair in transglutaminase 1 (TGM1)-negative lamellar ichthyosis (LI) and has been proposed as a diagnostic aid for this syndrome. Objectives (i) To ascertain whether TGM1 is important for CE formation in nail; (ii) to characterize CE abnormalities occurring in LI that may be distinguished from other types of inherited ichthyosis when nail samples are subjected to detergent extraction; and (iii) to evaluate the utility of nails as a diagnostic aid for LI. Methods Nail samples were provided by nine patients previously classified as having TGM1-negative LI, four with other types of ichthyotic conditions and six normal controls. Samples were extracted extensively in sodium dodecyl sulphate under reducing conditions and examined by light and electron microscopy. Results After extraction, defective CE cross-linking was visualized in epidermal corneocytes from seven of nine patients exhibiting TGM1-negative LI, whereas nail samples from patients with the other syndromes were normal. The defects in CE structure resembled those recently reported for LI scale, although in some cases residual CE and CE-associated structures were present. Conclusions Despite the paucity of clinical nail symptoms in LI, TGM1 activity is important for generation of normal CE in nail plate, consistent with its importance in protein cross-linking in interfollicular epidermis and hair. Lack of this activity leads to a strikingly aberrant appearance of CE in LI nail after detergent extraction that is evident ultrastructurally in a large majority of cases. Nail envelopes therefore could provide a useful diagnostic tool in distinguishing LI from other ichthyoses with overlapping clinical features. [source]


    Epidermal proliferative response induced by sodium dodecyl sulphate varies with environmental humidity

    BRITISH JOURNAL OF DERMATOLOGY, Issue 2 2001
    M. Denda
    Background Previous studies have suggested that susceptibility of skin to external agents increases in the dry winter season. Objectives To test the hypothesis that environmental humidity affects skin sensitivity to irritants. Methods The epidermal hyperplasia induced by sodium dodecyl sulphate (SDS) under various humidity conditions was evaluated on the skin of hairless mice. Results Mice kept under low humidity for 2 days showed more obvious epidermal proliferation 24 h after topical application of SDS than those kept under high or normal humidity for 2 days. In contrast, mice kept under high humidity for 2 weeks showed more obvious epidermal proliferation 24 h after topical application of SDS than those kept under low or normal humidity. The transepidermal water loss was altered significantly in the animals kept under high humidity for 2 weeks, although it was not altered during the first 7 days under either low or high humidity. Conclusions These results suggest that environmental humidity influences the sensitivity of skin to topical application of SDS and that increased sensitivity is not always associated with alteration of the water impermeability of the stratum corneum. [source]


    Synthesis and secondary structure of loop 4 of myelin proteolipid protein: effect of a point mutation found in Pelizaeus-Merzbacher disease

    CHEMICAL BIOLOGY & DRUG DESIGN, Issue 3 2005
    E. Trifilieff
    Abstract:, To study the effects of a point mutation found in Pelizaeus-Merzbacher disease (PMD) on the physicochemical and structural properties of the extracellular loop 4 of the myelin proteolipid protein (PLP), we synthesized the peptide PLP(181,230)Pro215 and one mutant PLP(181,230)Ser215 with regioselective formation of the two disulphide bridges Cys200 -Cys219 and Cys183 -Cys227. As conventional amino acid building blocks failed to give crude peptides of good quality we had to optimize the synthesis by introducing pseudoproline dipeptide building blocks during the peptide elongation. In peptide Pro215 the first bridge Cys200,Cys219 was obtained after air oxidation, but in peptide Ser215 because of aggregation, dimethyl sulfoxide (DMSO) oxidation had to be used. The second bridge Cys183,Cys227 was obtained by iodine oxidation of both Cys (acetamidomethyl, Acm)-protected peptides. The secondary structures of the parent and mutant loops were analysed by circular dichroism (CD) in the presence of trifluoroethanol (TFE) and sodium dodecyl sulphate (SDS) as a membrane mimetic. Analysis of the spectra showed that the content of , -helix and , -sheet varied differently for both peptides in TFE and SDS solutions, demonstrating the sensitivity of their conformation to the environment and the differences in their secondary structure. The ability of both peptides to insert into the SDS micelles was assayed by intrinsic tryptophan fluorescence. [source]


    Surfactant Effects on Aeration Performance of Stirred Tank Reactors

    CHEMICAL ENGINEERING & TECHNOLOGY (CET), Issue 10 2008
    M. Martinov
    Abstract The effect of surfactants on aeration performance in stirred tank reactors (STR) at high rates of foaming is studied. The volumetric oxygen transfer coefficient (kLa) and foaming activity estimated as foaming height (Hf) were determined. Biotechnology of lipopeptide biosurfactants from aerobic organisms, e.g., Bacillus subtilis were addressed. Using model solutions of known foam-generating properties, high-molecular weight surfactin and low-molecular weight sodium dodecyl sulphate (SDS), as well as impellers of different types, with flat and fluid-foil blades, clues on the concentration dependence of STR oxygen transfer and foaming as well as options for foam reduction in the presence of biosurfactant were sought. In response to a two-fold decrease of surface tension by surfactin, kLa values decreased up to 30,% but remained within the range expected for the mixing system in water; the experiments with SDS showing stronger dependence on surfactant concentration and surface tension. Mixing of surfactant media by a standard six-blade disc turbine (RT) imposed rate limitations on gassing. A low-shear impeller Narcissus (NS) could be used to avoid bulk foam outflow, while preserving kLa values that remained unchanged. The ,power per unit volume' correlation of kLa in stirred tanks is tested in the presence of surfactin. [source]


    Production and characterization of monoclonal antibodies to serine proteinase allergens in Penicillium and Aspergillus species

    CLINICAL & EXPERIMENTAL ALLERGY, Issue 11 2000
    W.-L. Lin
    Background Alkaline and/or vacuolar serine proteinases are major allergens in prevalent airborne Penicillium and Aspergillus species. Objective The object of this study is to generate and characterize monoclonal antibodies against these serine proteinase allergens. Methods BALB/c mice were immunized individually with the Penicillium citrinum culture medium or the crude extract and culture medium preparations of Aspergillus fumigatus. Hybridoma cells that secrete monoclonal antibodies against serine proteinase allergens were selected by immunoblotting. Antigens in three different Penicillium (P. citrinum, P. notatum and P. oxalicum) and two different Aspergillus species (A. fumigatus, and A. flavus) recognized by these monoclonal antibodies were analysed by sodium dodecyl sulphate and two-dimensional polyacrylamide gel electrophoresis immunoblotting and N-terminal amino acid sequence analysis. Results Four (PCM8, PCM10, PCM16 and PCM39) and one (FUM20) monoclonal antibodies against serine proteinase allergens were generated after fusion of NS-1 cells with spleen cells obtained from BALB/c mice immunized with antigens from P. citrinum and A. fumigatus, respectively. Immunoblotting results showed that PCM8 reacted with an alkaline serine proteinase allergen in P. citrinum and P. notatum. PCM10 and PCM39 reacted with the alkaline serine proteinase in two Penicillium (P. citrinum, P. notatum) and two Aspergillus species (A. fumigatus, and A. flavus) tested. PCM16 reacted with the alkaline serine proteinase allergen in P. citrinum, A. fumigatus and A. flavus but not with that in P. notatum. MoAb FUM20 reacted with the alkaline serine proteinase allergen in two Aspergillus species (A. fumigatus and A. flavus) but not with that in two different Penicillium species (P. citrinum, P. notatum) tested. Among these five monoclonal antibodies generated, only PCM39 and FUM20 can react with the vacuolar serine proteinase allergen in P. notatum, P. oxalicum and in A. fumigatus. The 35 kDa P. citrinum component that reacted with FUM20 has an N-terminal amino acid sequence of DSPSVEKNAP. Conclusion Five monoclonal antibodies against different epitopes of the serine proteinase major allergens in prevalent Penicillium and Aspergillus species were generated in the present study. Antibodies obtained may be useful in the characterization and standardization of serine proteinase allergens in crude fungal extracts. [source]


    Autoantibodies against CD28 are associated with atopic diseases

    CLINICAL & EXPERIMENTAL IMMUNOLOGY, Issue 2 2006
    K. Neuber
    Summary The B7-1/B7-2-CD28/CTLA-4 pathway is crucial in regulating T cell activation and tolerance. Autoantibodies to surface molecules on lymphocytes have already been described in various immune conditions, such as autoimmune diseases, infections and blood transfusions. The objective of this study was to test sera from healthy individuals and from patients for association of CD28 autoantibodies with inflammatory and non-inflammatory diseases. First, CD28 was obtained by digestion of CD28-Ig fusion protein with trypsin. The cleavage products were separated by sodium dodecyl sulphate,page gel electrophoresis. Additionally, a CD28/GST fusion protein was expressed in Escherichia coli and was used to establish an enzyme-linked immunosorbent assay for detection of autoantibodies against CD28. Sera from healthy individuals (n = 72) and patients with different inflammatory and non-inflammatory skin diseases (n = 196) were tested for the presence of autoantibodies against CD28. Using mixed lymphocyte reaction (MLR), purified autoantibodies against CD28 were tested for their effects on CTLA-4-Ig-induced T cell anergy. In this study, for the first time, we describe the existence of autoantibodies against CD28 in humans which are associated with atopic diseases, e.g. allergic rhinitis and asthma. These antibodies stimulate T cells and overcome the CTLA-4-Ig-induced anergy of T cells in an MLR. The existence of autoantibodies against CD28, which may have a T cell-stimulating function, has been shown. The data indicate that autoantibodies against CD28 could be a new immunological mechanism in allergic inflammation. Additionally, autoantibodies against CD28 could be an important new marker to discriminate between atopic diseases and other inflammatory skin diseases. [source]