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Protein Derivative (protein + derivative)

Distribution by Scientific Domains
Medical Sciences92%
Distribution within Medical Sciences
Immunology50%
Dermatology16%

Kinds of Protein Derivative

  • purified protein derivative
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    Selected Abstracts

    TLR9 activation is a key event for the maintenance of a mycobacterial antigen-elicited pulmonary granulomatous response

    EUROPEAN JOURNAL OF IMMUNOLOGY, Issue 10 2007
    Toshihiro Ito
    Abstract Type 1 (Th1) granulomas can be studied in mice sensitized with mycobacterium antigens followed by challenge of agarose beads covalently coupled to purified protein derivative. TLR9 is known to play a role in the regulation of Th1 responses; thus, we investigated the role of TLR9 in granuloma formation during challenge with mycobacterium antigens and demonstrated that mice deficient in TLR9 had increased granuloma formation, but a dramatically altered cytokine phenotype. Th1 cytokine levels of IFN-, and IL-12 in the lungs were decreased in TLR9,/, mice when compared to wild-type mice. In contrast, Th2 cytokine levels of IL-4, IL-5, and IL-13 were increased in TLR9,/, mice. The migration of CD4+ T cells in the granuloma was impaired, while the number of F4/80+ macrophages was increased in TLR9,/, mice. Macrophages in the lungs of the TLR9-deficient animals with developing granulomas expressed significantly lower levels of the classically activated macrophage marker, nitric oxide synthase, but higher levels of the alternatively activated macrophage markers such as ,found in inflammatory zone-1, antigen and Arginase-1. These results suggest that TLR9 plays an important role in maintaining the appropriate phenotype in a Th1 granulomatous response. [source]

    Erythema induratum with pulmonary tuberculosis: histopathologic features resembling true vasculitis

    INTERNATIONAL JOURNAL OF DERMATOLOGY, Issue 3 2001
    Yong Suk Lee MD
    A 22-year-old South Korean woman presented with a 4-month history of several nodules on both legs. She looked healthy, but suffered from tenderness and swelling of the legs. Physical examination showed multiple, nonulcerating, erythematous nodules occurring on the calves, knee joints, and thighs (Fig. 1). A biopsy specimen of the skin revealed necrotizing vasculitis of medium-sized arteries with fibrinoid necrosis at the border between the dermis and the subcutis. Dense cellular infiltrates, including numerous neutrophils and lymphocytes, presented within and around the vessel walls as in polyarteritis nodosa, with some eosinophils (Fig. 2A,B). There were no other generalized symptoms. She was diagnosed with cutaneous polyarteritis nodosa and was initially treated with systemic steroids. She was given an intravenous injection of Solu-Cortef, 60 mg/6 h for 7 days. This was replaced with oral prednisolone for 2 weeks. The skin lesions and symptoms improved. Figure 1. Small, nut-sized, erythematous, brown-colored nodules and patches on the lower extremities, even above the knee joints Figure 2. (A) Dense infiltration within and around artery (× 40). (B) Slightly expanded lobular panniculitis with vasculitis (× 100) Six months later, she complained of general weakness and recurrent skin lesions. Purified protein derivative (PPD) test gave a moderate positive reaction and chest X-ray examination showed the features of pulmonary tuberculosis: radio-opaque infiltrations in the right lower lung field. A repeated biopsy revealed mild vasculitis with more diffuse lobular infiltrations of the subcutaneous tissue compared with the former specimen. Polymerase chain reaction (PCR) and tissue culture for Mycobacterium tuberculosis were performed from a biopsy specimen. DNA was extracted from skin tissue with an AplisystemTM DNA/RNA detection kit using the resin-mediated boiling method (Stargene, Seoul, South Korea). The primers were designed on the basis of the M. tuberculosis gene IS6110 target (sense primer, 5,-CCA GAT GCA CCG TCG AAC GGC TGA T-3, antisense primer, 5,-CGC TCG CTG AAC CGG ATC GAT GTG T-3,). The amplification was performed with uracil- N -glycosylase (UNG), to prevent carry-over contamination, and internal control primers, to correct for false-negative reaction (Kox LF, Rhienthong D, Miranda AM et al. A more reliable PCR for detection of Mycobacterium tuberculosis in clinical samples. J Clin Microbiol 1994; 32: 672,678; Longo MC, Berninger MS, Hartley JL. Use of uracil DNA glycosylase to control carry-over contamination in polymerase chain reactions. Gene 1990; 93: 125,128). According to the manufacturer's instructions, amplification was carried out for 40 cycles with denaturation at 94 °C for 40 s, annealing at 70 °C for 1 min, and extension at 72 °C for 1 min in a thermal cycler (Perkin,Elmer Cetus, Norwalk, CT, USA). The results of PCR and tissue culture for M. tuberculosis using the biopsy specimen were all negative (Fig. 3). Figure 3. Negative result in PCR for M. tuberculosis (negative control is not shown; M, marker; P, positive control; I, internal control; S, specimen) The patient was finally diagnosed with erythema induratum with pulmonary tuberculosis and was started on antituberculosis medication (isoniazid 400 mg, rifampicin 600 mg, ethambutol 800 mg, and pyrazinamide 1500 mg daily). She showed prompt improvement after 2 weeks of medication. After 9 months of antituberculosis therapy, her skin lesions and chest X-ray had cleared. She was followed up for 4 months with no recurrence of skin and pulmonary lesions. [source]

    A clinical study evaluating the treatment of supra-alveolar-type defects with access flap surgery with and without an enamel matrix protein derivative: a pilot study

    JOURNAL OF CLINICAL PERIODONTOLOGY, Issue 8 2008
    Holger Jentsch
    Abstract Aim: There is evidence that regenerative treatment of intra-bony and mandibular class II furcation defects with access flap and an application of an enamel matrix protein derivative (EMD) can result in a clinical benefit compared with access flap alone. The aim of this pilot study was to check if the results of access flap surgery in suprabony defects are improved by additional application of EMD. Material and Methods: Thirty-nine adult subjects with supra-alveolar-type defects were randomly assigned to a test (n=25) and a control group (n=14). Seventy teeth were treated with EMD; 28 teeth were treated by access flap. Probing depth (PD), clinical attachment level and bleeding on probing were evaluated at baseline and after 12 months. Results: PD of the operated teeth was improved in both groups (p<0.001 to p=0.041) but always better in the test group. The attachment gain was 2.72±1.80 mm at sites with an initial PD 7 mm in the test group and 0.78±0.62 mm in the control group (p=0.004). In the test group the mean attachment gain was 0.97±0.92 mm (p<0.001); the mean reduction of PD was 1.55±0.90 mm (p<0.001). Conclusions: The data suggest a significant clinical benefit of supplementary application of EMD during surgical treatment of periodontitis of supra-alveolar pockets, especially in deeper pockets. [source]

    Effect of an enamel matrix protein derivative (Emdogain®) on ex vivo dental plaque vitality

    JOURNAL OF CLINICAL PERIODONTOLOGY, Issue 11 2001
    Anton Sculean
    Abstract Background: A common clinical observation following surgical periodontal therapy with an enamel matrix derivative (Emdogain®) is the improved healing of the soft tissues and the limited inflammation of the operated areas. These clinical observations are empirical and difficult to explain. One of the factors influencing the early wound healing might be a potential antimicrobial effect of Emdogain®. Aim: To investigate the effect of Emdogain® on the vitality of ex vivo supragingival dental plaque and to compare this effect to that of a standard 0.2% chlorhexidine solution. Materials and Methods: 24 patients suffering from adult periodontitis were included in the study. At the beginning of the experiment, all participants were given a professional tooth cleaning. For the following 4 days, they had to refrain from any kind of oral hygiene measures. At day 5, from each of the volunteers, a voluminous plaque biofilm sample was taken with a sterile curette from the vestibular surfaces of the 1st lower molars and divided into 5 equal parts. Each part was mounted with 5 ,l of the following solutions: (1) NaCl, (2) enamel matrix derivative dissolved in water (EMD), (3) enamel matrix derivative dissolved in the vehicle (Emdogain®), (4) vehicle (propylene glycol alginate, PGA), (5) 0.2% chlorhexidine digluconate (CHX). After a reaction time of 2 min the test solutions were sucked off, and subsequently the biofilm was stained with a fluorescence dye. The vitality of the plaque flora after the treatments was evaluated under the fluorescence microscope (VF%). Results: Plaque samples treated with NaCl showed a mean vitality of 76.8±8%. The EMD, Emdogain®, PGA and CHX showed VF values of 54.4±9.2, 21.4±10.6%, 19.6±11.6% and 32.3±11.8%, respectively. Emdogain®, PGA and CHX showed statistically highly significant reductions (p<0.0001) in terms of bacteria vitality when compared to water (negative control) and EMD. Both Emdogain® and PGA were found to be statistically significantly different compared to CHX (p<0.001) (positive control). Conclusion: The results of this study indicate that Emdogain® might have an antibacterial effect on the vitality of the ex vivo supragingival dental plaque flora. Zusammenfassung Hintergrund: Eine allgemeine klinische Beobachtung nach parodontalchirurgischer Therapie mit einem Schmelzmatrixderivat (Emdogain®) ist die verbesserte Heilung des Weichgewebes und die begrenzte Entzündung des operierten Gebietes: Diese klinischen Beobachtungen sind empirisch und schwierig zu erklären. Ein Faktor, der die frühe Wundheilung beeinflusst, könnte ein potentieller antimikrobieller Effekt von Emdogain® sein. Ziel: Untersuchung des Effektes von Emdogain® auf die Vitalität von ex vivo supragingivaler dentaler Plaque und Vergleich dieses Effektes zu demjenigen einer Standard 0.2%igen Chlorhexidinlösung. Material und Methoden: 24 Patienten, die an einer Erwachsenen-Parodontitis litten, wurden in diese Studie aufgenommen. Zu Beginn der Studie wurde bei allen Teilnehmern eine professionelle Zahnreinigung durchgeführt. An den folgenden 4 Tagen wurden keine oralen Hygienemaßnahmen erlaubt. Am Tag 5 wurde von jedem Teilnehmer eine voluminöse Plaquebiofilmprobe mit einer sterilen Kürette von der vestibulären Oberfläche des ersten unteren Molaren genommen und in 5 gleiche Teile aufgeteilt. Jeder Teil wurde mit 5 ,l der folgenden Lösungen gemischt: (1) NaCl, (2) Schmelzmatrixderivat in Wasser gelöst (EMD), (3) Schmelzmatrixderivat in einem Vehikel gelöst (Emdogain®), (4) Vehikel (Propylenglycolalginat, PGA), (5) 0.2%iges Chlorhexidindiglukonat (CHX). Nach einer Reaktionszeit von 2 Minuten wurden die Testlösungen aufgesaugt und folgend der Biofilm mit Fluoreszenzfarbstoff gefärbt. Die Vitalität der Plaqueflora nach den Behandlungen wurde unter dem Vitalfluoreszenzmikroskop (VF%) evaluiert. Ergebnisse: Die Plaqueproben, die mit NaCl behandelt wurden, zeigten eine mittlere Vitalität von 76.8±8%. Das EMD, Emdogain®, PGA und CHX zeigten VF Werte von 54.4±9.2%, 21.4±10.6%, 19.6±11.6% und 32.3±11.8%. Emdogain®, PGA und CHX zeigten statistisch signifikant höhere Reduktionen (p<0.0001) in Beziehung zur bakteriellen Vitalität, wenn zu Wasser (negative Kontrolle) und EMD verglichen wurde. Sowohl Emdogain® und PGA waren statistisch signifikant unterschiedlich zu CHX (p<0.0001) (positive Kontrolle). Schlussfolgerung: Die Ergebnisse dieser Studie zeigten, dass Emdogain® einen antibakteriellen Effekt auf die Vitalität von supragingivaler dentaler ex vivo Plaqueflora haben könnte. Résumé Origine: Une observation clinique courante durant un traitement parodontal chirurgical à l'aide de protéines de la matrice améllaire (Emdogain®) est une meilleure guérison des tissus mous et une inflammation moindre. Ces observations cliniques sont empiriques et difficiles à expliquer. Un des facteurs influençant la guérison précoce peut être un effet antimicrobien de l'EMD. But: Le but de cette étude a été d'évaluer l'effet de l'Emdogain® sur la vitalité de la plaque dentaire sus-gingivale ex vivo et de comparer cet effet avec une solution de chlorhexidine 2%. Matériaux et Méthodes: 24 patients souffrant de parodontite de l'adulte ont été inclus dans cette étude. Au début de l'expérience, tous les participants ont recu un nettoyage dentaire professionnel. Pendant les 4 journées suivantes, ils ont dû arrêté toute hygiène buccale. Au jour 5, une quantité de plaque dentaire volumineuse a étééchantillonné des surfaces vestibulaires des premières molaires inférieures de chaque volontaire à l'aide d'une curette stérile et divisée en 5 parts égales. Chaque partie a été montée avec 5 ,l des solutions suivantes: (1) NaCl, (2) EMD: dérivé de la matrice améllaire dissout dans l'eau (3) Emdogain®: dérivé de la matrice améllaire dissout dans son véhicule, (4) PGA: le véhicule propylène glycol alginate, (5) CHX: chlorhexidine 0.2%. Après un temps de réaction de 2 min, les solutions tests ont été aspirées et le biofilm dentaire a été imprégné d'un colorant de fluorescence. La vitalité de la flore de la plaque dentaire après ces traitements a étéévaluée sous microscopie à fluorescence (VF%). Résultats: Les échantillons de plaque traités avec NaCl possèdaient une vitalité moyenne de 76.8±8%. L'EMD, Emdogain®, PGA, et CHX avaient des valeurs VF respectives de 54.4±9.2%, 21.4±10.6%, 19.6±11.6% et 32.3±11.8%. Emdogain®, PGA, et CHX réduisaient la vitalité bactérienne de manière très hautement significative (p<0.0001) lorsque ces solutions étaient comparées aux contrôle négatif NaCl et à EMD. Tant Emdogain® que PGa étaient différents comparés au contrôle positif CHX (p<0.001). Conclusions: Les résultats de cette étude indiquent que Emdogain® pourrait avoir un effet antibactérien sur la vitalité de la flore se trouvant dant la plaque dentaire sus-gingivale ex vivo. [source]

    Bacillus Calmette,Guérin-induced interleukin-12 did not additionally improve clinical and immunologic parameters in asthmatic children treated with sublingual immunotherapy

    CLINICAL & EXPERIMENTAL ALLERGY, Issue 3 2004
    C. Arikan
    Summary Objective To evaluate the effect of bacillus Calmette,Guérin (BCG) as an adjuvant to specific sublingual immunotherapy (SLIT) on the cytokine profile of peripheral blood mononuclear cells (PBMCs) and clinical outcome. Methods Thirty-two children with asthma and rhinitis allergic to house dust mite (HDM) with negative purified protein derivative (PPD) skin test response were enrolled. After a run-in period of 8 weeks, patients were randomized to receive either SLIT only (n=16) or one dose of BCG immunization before initiation of SLIT (n=16) with a standardized Dermatophagoides pteronyssinus (D. pteronyssinus)+D. farinea 50/50 extract. PPD-negative asthmatics (n=5) allergic to HDM receiving inhaled therapy only were included for comparison of cytokine levels in PBMC cultures. Efficacy was assessed both at the end of run-in and 6 months of treatment periods with criteria including symptom, medication and quality-of-life (QoL) scores, IgE levels, lung function, provocation concentration (PC20), eosinophil count and skin prick tests. IL-4, IL-5, IL-10, IL-12, IL-13 and IFN-, levels were determined in antigen specifically and polyclonally stimulated PBMC cultures. Results Both treatment groups showed significant improvement at the end of 6 months for asthma and rhinitis scores and QoL, number of asthma attacks, amount of ,2 -agonists, inhaled and intranasal steroids, blood eosinophil counts and PC20. Interestingly, phytohaemagglutinin (PHA)-stimulated IL-12 and D. pteronyssinus- stimulated IFN-, in PBMC were significantly higher in the treatment groups than controls. In addition, IL-12 levels in response to D. pteronyssinus and PHA stimulation were significantly higher in the SLIT+BCG group than the SLIT alone group and controls. Conclusion The present study demonstrates that successful SLIT is parallel to increased IFN-, production by PBMC. Although simultaneous BCG vaccination enhanced IL-12 production, it did not additionally improve the clinical outcome. [source]

    A comparison of ex vivo cytokine production in venous and capillary blood

    CLINICAL & EXPERIMENTAL IMMUNOLOGY, Issue 3 2007
    M. Eriksson
    Summary We performed a randomized study of the immunological effects of an early measles vaccine given at 4·5 months of age and aimed to obtain venous samples from the infants at baseline and 6 weeks later. If this was not feasible, a capillary sample was obtained. We analysed baseline samples from the first 50 children enrolled in the study to investigate the potential differences in ex vivo cytokine production between venous blood and capillary blood. We also obtained paired venous and capillary blood samples from 11 adult volunteers. Whole blood was stimulated with lipopolysaccharide (LPS) [a Toll-like receptor (TLR)-4 ligand], (S)-(2, 3-bis (palmitoyloxy)-(2-RS)-propyl)-N-palmitoyl-(R)-Cys-(S)-Ser-(S)-Lys4-OH, trihydrochloride (PAM3Cys) (a TLR-2 ligand), phytohaemagglutinin (PHA) or purified protein derivative (PPD). Cytokine concentrations in the supernatants were assessed by a multiplexed assay and were compared between venous and capillary samples in both infants and adults. The production of both the pro- and the anti-inflammatory cytokines, tumour necrosis factor (TNF)-, and interleukin (IL)-10, was higher in cultures of capillary blood compared with venous blood. This was found in non-stimulated control samples as well as in blood stimulated with PAM3Cys and PPD. Adults produced more IL-5 in venous blood than in capillary blood upon PHA stimulation. We found no other difference in the levels of IL-5 or IFN-, between venous and capillary blood. In capillary blood we found sex differences in response to PHA but this was not the case in venous blood. We found significant differences in the production of cytokines between venous and capillary blood. Such differences should be taken into account when setting up immuno-epidemiological studies. [source]

    Interferon-, and skin test responses of schoolchildren in southeast England to purified protein derivatives from Mycobacterium tuberculosis and other species of mycobacteria

    CLINICAL & EXPERIMENTAL IMMUNOLOGY, Issue 2 2003
    R. E. WEIR
    SUMMARY The immune responses of schoolchildren in southeast England to Mycobacterium tuberculosis and other species of mycobacteria were studied prior to vaccination with bacille Calmette-Guérin (BCG). Data are presented for tuberculin (Heaf) skin test and interferon- , (IFN- ,) responses to M. tuberculosis purified protein derivative (PPD), and IFN- , responses to PPDs from eight other environmental mycobacteria, measured in 424 schoolchildren (13,15 years of age). Responses to M. tuberculosis PPD were detected in 27% of schoolchildren by in vitro IFN- , response and in 20% by the Heaf test. IFN- , responses were more prevalent to PPDs from species of mycobacteria other than M. tuberculosis, predominantly those of the MAIS complex and M. marinum (45,60% responders). Heaf test and IFN- , responses were associated (P < 0·001) for M. tuberculosis, MAIS and M. marinum. These findings have implications for appropriate implementation of vaccination against tuberculosis. [source]

    Plasmodium falciparum infection of the placenta affects newborn immune responses

    CLINICAL & EXPERIMENTAL IMMUNOLOGY, Issue 3 2003
    J. ISMAILI
    SUMMARY The effects of exposure to placental malaria infection on newborn immunological responses, in particular Th1/Th2 cytokines and antigen-presenting cell (APC) function, were compared between cord blood mononuclear cells (CBMC) from parasitized and non-parasitized placentas of Gambian women. Cells were analysed in vitro for their ability to respond to mitogens [phorbol myristate acetate (PMA)/ionomycin, phytohaemagglutinin (PHA)], a malaria-unrelated test antigen [purified protein derivative of Mycobacterium tuberculin[purified protein derivative (PPD)] and Plasmodium falciparum schizont extracts. Mitogens induced strong proliferation and secretion of high concentrations of both IL-13 and sCD30 in CBMC from both groups. Conversely, significantly lower amounts of IFN- , were induced in the parasitized group in response to low doses of PHA. Protein antigens induced very low amounts of all tested cytokines, in particular IFN- ,. However, a significantly higher release of sCD30 was observed in response to schizont extracts in the parasitized group. Addition of LPS to activate APC to low doses of PHA or schizont extracts increased the IFN- , production in both groups but levels remained lower in CBMC from the parasitized group. This result correlates with the lower production of IL-12 found following lipopolysaccharide (LPS) stimulation in this group. Taken together, these data show that placental infection with P. falciparum affects Th1 differentiation and sCD30 priming of neonatal lymphocytes and that the probable mode of action is via APC. [source]

    Differential CD4+ T-cell memory responses induced by two subsets of human monocyte-derived dendritic cells

    IMMUNOLOGY, Issue 3 2007
    Sandra Bajaña
    Summary Dendritic cells (DC) are powerful inducers of primary T-cell responses, but their role in secondary responses has not been extensively analysed. Here, we address the role of two DC subsets derived from human CD16+ (16+ mDC) or CD16, (16, mDC) monocytes on the reactivation of memory responses. CD4+ CD45RA, memory T cells were obtained from adult blood donors, and central (TCM) and effector (TEM) memory T cells were isolated by fluorescence-activated cell sorting with anti-CCR7 antibodies. The 16+ mDC and 16, mDC were cocultured with autologous lymphocytes, either unpulsed or loaded with purified protein derivatives of Mycobacterium tuberculosis (PPD) or tetanus toxoid (TT), and were analysed for up to 8 days. Over a range of doses, 16+ mDC drove stronger T-cell proliferative responses against both antigens. Overall, antigen-specific memory cells tended to acquire a phenotype of TEM at later time-points in the culture, whereas cells that had completed fewer cycles of division were similar to TCM. The 16+ mDC induced higher rates of proliferation on both TCM and TEM lymphocytes than 16, mDC. This phenomenon was not related to the ability of both DC to induce CD25 expression on T cells, to lower secretion of interleukin-2, or to raise production of interleukin-10 during T-cell/16, mDC cocultures. The induction of TCM effector capacity in terms of interferon-, production was faster and more pronounced with 16+ mDC, whereas both DC had similar abilities with TEM. In conclusion, these data might reveal new potentials in vaccination protocols with 16+ mDC aimed at inducing strong responses on central memory T cells. [source]

    Conditioning polymers in today's shampoo formulations , efficacy, mechanism and test methods

    INTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Issue 1 2000
    Hössel
    Synopsis Today's shampoo formulations are beyond the stage of pure cleansing of the hair. Additional benefits are expected, e.g. conditioning, smoothing of the hair surface, improvement of combability and lather creaminess. Cationic polymers play an important role in providing many of those features. Therefore, within the last few years their use in shampoos has increased greatly. In the only last two decades, shampoo designation has gradually changed from ,2-in-1' to ,3-in-1' and then to ,multifunctional', as at present. The consumer demands products which live up to their promises. Modern shampoos contain a wide variety of ingredients such as co-surfactants, vitamins and pro-vitamins, protein derivatives, silicones, natural-based plant extracts and other ,active ingredients', but there is still a need for conditioning polymers. The specific objective of this study is to assess the conditioning efficacy of cationic polymers and to investigate their mechanisms in a shampoo system. The investigations were carried out on formulations that contained sodium lauryl ether sulphate and different cationic polymers, e.g. Polyquaternium 7, 10, 11, cationic guar gum and Luviquat Care (Polyquaternium 44), a new branched copolymer of vinylpyrrolidone (VP) and quaternized vinylimidazolium salts (QVI). We used test methods relevant to the applications in question, such as combing force measurements, the feel of the hair and the creaminess of the lather, to assess the efficacy. Atomic force microscopy and electrokinetics (streaming potential) were used to detect polymer residues on treated hair. All the polymers under investigation improved the overall performance of the shampoo formulations. This was demonstrated by means of combing force measurements, sensorial tests and analytical methods, namely zeta potential measurement and atomic force microscopy. Polyquaternium 44 exhibited the best conditioning properties on wet hair without sacrificing removability or absence of build-up. The latter are the most striking weaknesses of cationic Guar Gum-based polymers. Polyquaternium 10 can also be removed from the hair after rinsing with anionic surfactant but it does not perform as well as Polyquaternium 44 in the fields of wet combability and sensorial criteria such as lather creaminess and feel of the hair. We postulate that the outstanding properties of Polyquaternium 44 as a conditioning agent for shampoos are due to its tailor-made ,branched' structure. There is a clear correlation between the molecular weight and the efficacy of the new copolymers of VP and QVI. Only cationic polymers with a very high molecular weight are effective as conditioners in shampoos based on anionic surfactants. Surprisingly, they do not have to have a high cationic charge. On the basis of all our results, our postulation is that the polymer residue which is responsible for conditioning does not form a flat layer on the hair. Rather, the polymer residue adsorbs with the few cationic moieties, while the uncharged part of the polymer forms loops, which are orientated away from the hair and which are responsible for the reduced friction between hairs. Résumé Les formulations actuelles de shampoing font plus qu'un simple nettoyage des cheveux. On en attend un intérêt supplémentaire, par exemple après-shampoing, lissage de la surface du cheveu, amélioration de la coiffabilité et aspect crémeux du savon. Les polymères cationiques jouent un rôle important dans l'apport de nombre de ces caractéristiques. Par conséquent, ces quelques dernières années leur utilisation a considérablement augmenté dans les shampoings. Dans les seules deux dernières décades, l'appellation du shampoing est progressivement passée de "2 en 1"à"3 en 1" puis ensuite à"multifonctionnel", comme actuellement. Le consommateur recherche des produits qui tiennent leurs promesses. Les shampoings modernes contiennent une grande diversité d'ingrédients tels que des co-tensioactifs, des vitamines et des provitamines, des dérivés de protéines, des silicones, des extraits à base de plantes naturelles et autres "ingrédients actifs", mais il existe toujours un besoin pour des polymères d'après shampoing. L'objectif spécifique de cette étude est d'évaluer l'efficacité comme après-shampoing de polymères cationiques et de rechercher leurs mécanismes dans le système de shampoing. Les recherches ont été menées sur des formulations qui contiennent du sulfate de lauryl éther sodium et différents polymères cationiques, par exemple du Polyquaternium 7, 10, 11, de la gomme de guar cationique et du Luviquat Care (Polyquaternium 44), un nouveau copolymère ramifié de vinylpyrrolidone (VP) et de sels quaternaires de vinylimidazolium (QVI). Nous avons utilisé les procédés de contrôle appropriées aux applications en question, tels que les mesures de force de coiffage, le toucher du cheveu et l'aspect crémeux du savon, pour évaluer l'efficacité. La microscopie atomique et l'électrocinétique (potentiel d'écoulement) ont été utilisées pour détecter les résidus de polymère sur le cheveu traité. Tous les polymères étudiés améliorent le comportement global des formulations de shampoing. Ceci est démontré au moyen des mesures de force de coiffage, des tests sensoriels et des méthodes analytiques, en l'occurrence la mesure du potentiel zêta et la microscopie atomique. Le Polyquaternium 44 présente les meilleures propriétés d'après-shampoing sur cheveu mouillé sans diminuer sa capacité d'élimination ou l'absence d'accumulation. Ces dernières sont les faiblesses les plus frappantes des polymères à base de gomme de guar cationique. Le Polyquaternium 10 peut aussi être éliminé du cheveu après rinçage avec un tensioactif anionique mais il ne se comporte pas aussi bien que le Polyquaternium 44 dans les domaines de la coiffabilitéà l'état mouillé et des critères sensoriels tels que l'aspect crémeux du savon et du toucher du cheveu. Nous supposons que les propriétés exceptionnelles du Polyquaternium 44 comme agent après-shampoing pour shampoings sont dues à sa structure "ramifiée" conçue sur mesure. Il existe une corrélation claire entre le poids moléculaire et l'efficacité des nouveaux copolymères de VP et QVI. Seuls les polymères cationiques avec un poids moléculaire très élevé sont efficaces comme après shampoings dans des shampoings à base de tensioactifs anioniques. Etonnamment, ils n'ont pas besoin d'avoir une charge cationique élevée. Sur la base de tous nos résultats, notre hypothèse est que le fragment de polymère qui est responsable du traitement ne forme pas une couche plate sur le cheveu. Le fragment de polymère adsorbe plutôt les quelques fragments cationiques, tandis que la partie non chargée du polymère forme des boucles, qui sont orientées à l'extérieur du cheveu et qui sont responsables de la friction réduite entre les cheveux. [source]

    Flk prevents premature secretion of the anti-, factor FlgM into the periplasm

    MOLECULAR MICROBIOLOGY, Issue 3 2006
    Phillip Aldridge
    Summary The flk locus of Salmonella typhimurium was identified as a regulator of flagellar gene expression in strains defective in P- and l -ring formation. Flk acts as a regulator of flagellar gene expression by modulating the protein levels of the anti-,28 factor FlgM. Evidence is presented which suggests that Flk is a cytoplasmic-facing protein anchored to the inner membrane by a single, C-terminal transmembrane-spanning domain (TMS). The specific amino acid sequence of the TMS is not essential for Flk activity, but membrane anchoring is essential. Membrane fractionation and visualization of protein fusions of green fluorescent protein derivatives to Flk suggested that the Flk protein is present in the membrane as punctate spots in number that are much greater than the number of flagellar basal structures. The turnover of the anti-,28 factor FlgM was increased in flk mutant strains. Using FlgM,,-lactamase fusions we show the increased turnover of FlgM in flk null mutations is due to FlgM secretion into the periplasm where it is degraded. Our data suggest that Flk inhibits FlgM secretion by acting as a braking system for the flagellar-associated type III secretion system. A model is presented to explain a role for Flk in flagellar assembly and gene regulatory processes. [source]

    Interferon-, and skin test responses of schoolchildren in southeast England to purified protein derivatives from Mycobacterium tuberculosis and other species of mycobacteria

    CLINICAL & EXPERIMENTAL IMMUNOLOGY, Issue 2 2003
    R. E. WEIR
    SUMMARY The immune responses of schoolchildren in southeast England to Mycobacterium tuberculosis and other species of mycobacteria were studied prior to vaccination with bacille Calmette-Guérin (BCG). Data are presented for tuberculin (Heaf) skin test and interferon- , (IFN- ,) responses to M. tuberculosis purified protein derivative (PPD), and IFN- , responses to PPDs from eight other environmental mycobacteria, measured in 424 schoolchildren (13,15 years of age). Responses to M. tuberculosis PPD were detected in 27% of schoolchildren by in vitro IFN- , response and in 20% by the Heaf test. IFN- , responses were more prevalent to PPDs from species of mycobacteria other than M. tuberculosis, predominantly those of the MAIS complex and M. marinum (45,60% responders). Heaf test and IFN- , responses were associated (P < 0·001) for M. tuberculosis, MAIS and M. marinum. These findings have implications for appropriate implementation of vaccination against tuberculosis. [source]