A Strong Protective Action of Guttiferone-A, a Naturally Occurring Prenylated Benzophenone, Against Iron-Induced Neuronal Cell Damage

Guttiferone-A (GA) is a natural occurring polyisoprenylated benzophenone with several reported pharmacological actions. We have assessed the protective action of GA on iron-induced neuronal cell damage by employing the PC12 cell line and primary culture of rat cortical neurons (PCRCN). A strong protection by GA, assessed by the 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carbox-anilide (XTT) assay, was revealed, with IC(50) values <1 mu M. GA also inhibited Fe(3+)-ascorbate reduction, iron-induced oxidative degradation of 2-deoxiribose, and iron-induced lipid peroxidation in rat brain homogenate, as well as stimulated oxygen consumption by Fe(2+) autoxidation. Absorption spectra and cyclic voltammograms of GA Fe(2+)/Fe(3+) complexes suggest the formation of a transient charge transfer complex between Fe(2+) and GA, accelerating Fe(2+) oxidation. The more stable Fe(3+) complex with GA would be unable to participate in Fenton-Haber Weiss-type reactions and the propagation phase of lipid peroxidation. The results show a potential of GA against neuronal diseases associated with iron-induced oxidative stress.

Formation Of The Maritime Labor Force In Brazil: Culture And Daily Life, Tradition And Resistance (1808-1850).

Formation Of The Maritime Labor Force In Brazil: Culture And Daily Life, Tradition And Resistance (1808-1850). Since the 16(th) Century, Brazil has played a major role in the rise of a new economical and social order, in which ships represented a space of struggle and contradictions among rulers, captains and sailors. This article will study the proletarization process that transformed Indians, small farmers, free and slave black people in maritime labor force in Brazil during the first half of 19(th) century.

Comparisons of the release of vasodilator substances from left and right cardiac chambers of the isolated perfused rabbit heart: Implications for intraventricular thrombus formation

Prostacyclin (PgI(2)) and endothelium-derived nitric oxide (EDNO) are produced by the arterial and venous endothelium. In addition to their vasodilator action on vascular smooth muscle, both act together to inhibit platelet aggregation and promote platelet disaggregation. EDNO also inhibits platelet adhesion to the endothelium. EDNO and PgI(2) have been shown to be released from the cultured endocardial cells. In this study, we examined the release of vasoactive substances from the intact endocardium by using isolated rabbit hearts perfused with physiological salt solution (95% O(2)/5% CO(2), T = 37 degrees C). The right and left cardiac chambers were perfused through separate constant-flow perfusion loops (physiological salt solution, 8 ml min(-1)). Effluent from left and right cardiac, separately, was bioassayed on canine coronary artery smooth muscle, which had been contracted with prostaglandin F(2 alpha_)(2 x 10(-6) M) and no change in tension was exhibit. However, addition of calcium ionophore A23187 (10(-6) M) to the cardiac chambers` perfusion line induced vasodilation of the bioassay coronary ring, 61.4 +/- 7.4% versus 70.49 +/- 6.1% of initial prostaglandin F(2 alpha) contraction for the left and right cardiac chambers perfusate, respectively (mean +/- SEM, n = 10, p > 0.05). Production of vasodilator was blocked totally in the left heart but, only partially blocked in the right heart by adding indomethacin (10(-5) M) to the perfusate, respectively, 95.2 +/- 2.2% versus 41.5 +/- 4.8% (mean +/- SEM, n = 10, p < 0.05). 6-Keto prostaglandin F(1 alpha), measured in the endocardial superfusion effluent was also higher for the left cardiac chambers than for the right at the time of stimulation with the A23187, respectively, 25385.88 +/- 5495 pg/ml (n = 8) versus 13,132.45 +/- 1839.82 pg/ml (n = 8), (p < 0.05). These results showed that cyclooxygenase pathway plays major role in generating vasoactive substances for the left cardiac chamber endocardium; while it is not the main pathway for the right ventricular endocardium at which EDNO and PgI(2) Could act together and potentiate their antithrombogenic activities in isolated perfused rabbit heart. This may be an explanation for the intraventricular thrombus mostly seen in left ventricle rather than in right ventricle as a complication of myocardial infarction. (C) 2009 Elsevier Inc. All rights reserved.

Early dental plaque formation on toothbrushed titanium implant surfaces

Purpose: To evaluate the qualitative and quantitative differences on dental plaque formation on two different roughness titanium implant surfaces, i.e. machined and titanium plasma sprayed, as well as the amount of plaque removal by regular toothbrushing after 72-hour plaque accumulation. Methods: Eight systemically healthy subjects were recruited from the patient pool of a private dental practice. All patients underwent oral hygiene instruction and full mouth prophylaxis. Subsequently, maxillary casts from all patients were obtained and removable 0.7 mm-thick acetate stents without occlusal contact points were fabricated to support four titanium specimens of 4x2x2 mm divided into two groups (machined and plasma sprayed). Subjects were instructed to wear the stents for 72 hours, full time, removing them only during regular oral hygiene. Subsequently, the appliances were immediately repositioned and then the test side was brushed for 20 seconds. At the end of the 72-hour period, the stents were removed and prepared for microbiological analysis. Results: Both machined and plasma sprayed brushed surfaces presented statistically significant fewer bacteria than non-brushed surfaces. Similarly, regarding surface roughness, machined surfaces presented a total number of bacteria significantly smaller than those presented by plasma sprayed surfaces (P< 0.05). Statistically, the non-brushed machined turned surfaces presented a greater amount of Streptoccocus sp. when compared to the brushed machined surfaces. It was concluded that rough surfaces accumulated more dental plaque than polished surfaces. Both brushed surfaces presented less plaque accumulation, however, implant brushing was more effective on machined surfaces. (Am J Dent 2008;21:318-322).

A possible mechanism of low molecular weight protein tyrosine phosphatase (LMW-PTP) activity modulation by glutathione action during human osteoblast differentiation

Objective: Low molecular weight protein tyrosine phosphatases (LMW-PTPs) are a family of enzymes strongly involved in the regulation of cell growth and differentiation. Since there is no information concerning the relationship between osteoblastic differentiation and LMW-PTP expression/activity, we investigated its involvement during human osteoblast-like cells (hFOB 1.19) differentiation. It is known that LMW-PTP is regulated by an elegant redox mechanism, so we also observed how the osteoblastic differentiation affected the reduced glutathione levels. Design: hFOB 1.19 cells were cultured in DMEM/F12 up to 35 days. The osteoblast phenotype acquisition was monitored by measuring alkaline phosphatase activity and mineralized nodule formation by Von Kossa staining. LMW-PTP activity and expression were measured using the p-nitrophenylphosphate as substrate and Western blotting respectively. Crystal violet assay determined the cell number in each experimental point. Glutathione level was determined by both HPLC and DNTB assays. Results: LMW-PTP modulation was coincident with the osteoblastic differentiation biomarkers, such as alkaline phosphatase activity and presence of nodules of mineralization in Vitro. Likewise LMW-PTP, the reduced glutathione-dependent microenvironment was modulated during osteoblastic differentiation. During this process, LMW-PTP expression/activity, as well as alkaline phosphatase and glutathione increased progressively up to the 21st day (p < 0.001) of culturing, decreasing thereafter. Conclusions: Our results clearly suggest that LMW-PTP expression/activity was rigorously modulated during osteoblastic differentiation, possibly in response to the redox status of the cells, since it seems to depend on suitable levels of reduced glutathione. in this way, we pointed out LMW-PTP as an important signaling molecule in osteoblast biology and bone formation. (C) 2009 Elsevier Ltd. All rights reserved.

Qualified intervention/qualifying formation

An education promoting scientific literacy (SL) that prepares the citizens to a responsible citizenship has persisted as an argument across discussions on curricula design. The ubiquity of science and technology on contemporary societies and the ideological requirement of informed democratic participation led to the identification of relevant categories that drive curriculum reforms towards a humanistic approach of school science. The category ‘Science as culture’ acquires in the current work a major importance: it enlightens the meaning of scientific literacy. Looking closely to the French term, culture scientifique et tecnologique, turns science simultaneously into a cultural object and product that can be both received and worked at different levels and within several approaches by the individuals and the communities. On the other hand, nonformal and informal education spaces gain greater importance. Together with the formal school environment these spaces allow for an enrichment and diversification of learning experiences. Examples of nonformal spaces where animators can develop their work may be science museums or botanical gardens; television and internet can be regarded as informal education spaces. Due to the above mentioned impossibility of setting apart the individual or community-based experiences from Science and Technology (S&T), the work in nonformal and informal spaces sets an additional challenge to the preparation of socio-cultural animators. Socio-scientific issues take, at times, heavily relevance within the communities. Pollution, high tension lines, spreading of diseases, food contamination or natural resources conservation are among the socio-scientific issues that often call upon arguments and emotions. In the context of qualifying programmes on socio-cultural animation (social education and community development) within European Higher Education Area (EHEA) the present study describes the Portuguese framework. The comparison of programmes within Portugal aims to contribute to the discussion on the curriculum design for a socio-cultural animator degree (1st cycle of Bologna process). In particular, this study intends to assess how the formation given complies with enabling animators to work, within multiple scenarios, with communities in situations of socio-scientific relevance. A set of themes, issues and both current and potential fields of action, not described or insufficiently described in literature, is identified and analysed in the perspective of a qualified intervention of animators. One of these examples is thoroughly discussed. Finally, suggestions are made about curriculum reforms in order, if possible, to strongly link the desired qualified intervention with a qualifying formation.

Política(s) de saúde no trabalho : um inquérito sociológico às empresas portuguesas

Resumo Política(s) de saúde no trabalho: um inquérito sociológico às empresas portuguesas A literatura portuguesa sobre políticas, programas e actividades de Segurança, Higiene e Saúde no Trabalho (abreviadamente, SH&ST) é ainda escassa. Com este projecto de investigação pretende-se (i) colmatar essa lacuna, (ii) melhorar o conhecimento dos sistemas de gestão da saúde e segurança no trabalho e (iii) contribuir para a protecção e a promoção da saúde dos trabalhadores. Foi construída uma tipologia com cinco grupos principais de políticas, programas e actividades: A (Higiene & Segurança no Trabalho / Melhoria do ambiente físico de trabalho); B (Avaliação de saúde / Vigilância médica / Prestação de cuidados de saúde); C (Prevenção de comportamentos de risco/ Promoção de estilos de vida saudáveis); D (Intervenções a nível organizacional / Melhoria do ambiente psicossocial de trabalho); E (Actividades e programas sociais e de bem-estar). Havia uma lista de mais de 60 actividades possíveis, correspondendo a um índice de realização de 100%. Foi concebido e desenhado, para ser auto-administrado, um questionário sobre Política de Saúde no Local de Trabalho. Foram efectuados dois mailings, e um follow-up telefónico. O trabalho de campo decorreu entre a primavera de 1997 e o verão de 1998. A amostra (n=259) é considerada representativa das duas mil maiores empresas do país. Uma em cada quatro é uma multinacional. A taxa de sindicalização rondava os 30% da população trabalhadora, mas apenas 16% dos respondentes assinalou a existência de representantes dos trabalhadores eleitos para a SH&ST. A hipótese de investigação principal era a de que as empresas com um sistema integrado de gestão da SH&ST seriam também as empresas com um (i) maior número de políticas, programas e actividades de saúde; (ii) maior índice de saúde; (iii) maior índice de realização; e (iv) maior percentagem dos encargos com a SH&ST no total da massa salarial. As actividades de tipo A e B, tradicionalmente associadas à SH&ST, representavam, só por si, mais de 57% do total. Os resultados, correspondentes às respostas da Secção C do questionário, apontam, para (i) a hipervalorização dos exames de medicina do trabalho; e por outro para (ii) o subaproveitamento de um vasto conjunto de actividades (nomeadamente as de tipo D e E), que são correntemente levadas a cabo pelas empresas e que nunca ou raramente são pensadas em termos de protecção e promoção da saúde dos trabalhadores. As actividades e os programas de tipo C (Prevenção de comportamentos de risco/Promoção de estilos de vida saudáveis), ainda eram as menos frequentes entre nós, a seguir aos Programas sociais e de bem-estar (E). É a existência de sistemas de gestão integrados de SH&ST, e não o tamanho da empresa ou outra característica sociodemográfica ou técnico-organizacional, que permite predizer a frequência de políticas de saúde mais activas e mais inovadores. Os três principais motivos ou razões que levam as empresas portuguesas a investir na protecção e promoção da saúde dos seus trabalhadores eram, por ordem de frequência, (i) o absentismo em geral; (ii) a produtividade, qualidade e/ou competitividade, e (iii) a filosofia de gestão ou cultura organizacional. Quanto aos três principais benefícios que são reportados, surge em primeiro lugar (i) a melhoria da saúde dos trabalhadores, seguida da (ii) melhoria do ambiente do ambiente de trabalho e, por fim, (iii) a melhoria da produtividade, qualidade e/ou competitividade.Quanto aos três principais obstáculos que se põem, em geral, ao desenvolvimento das iniciativas de saúde, eles seriam os seguintes, na percepção dos respondentes: (i) a falta de empenho dos trabalhadores; (ii) a falta de tempo; e (iii) os problemas de articulação/ comunicação a nível interno. Por fim, (i) o empenho das estruturas hierárquicas; (ii) a cultura organizacional propícia; e (iii) o sentido de responsabilidade social surgem, destacadamente, como os três principais factores facilitadores do desenvolvimento da política de saúde no trabalho. Tantos estes factores como os obstáculos são de natureza endógena, susceptíveis portanto de controlo por parte dos gestores. Na sua generalidade, os resultados deste trabalho põem em evidência a fraqueza teóricometodológica de grande parte das iniciativas de saúde, realizadas na década de 1990. Muitas delas seriam medidas avulsas, que se inserem na gestão corrente das nossas empresas, e que dificilmente poderão ser tomadas como expressão de uma política de saúde no local de trabalho, (i) definida e assumida pela gestão de topo, (ii) socialmente concertada, (iii) coerente, (iv) baseada na avaliação de necessidades e expectativas de saúde dos trabalhadores, (v) divulgada, conhecida e partilhada por todos, (vi) contingencial, flexível e integrada, e, por fim, (vii) orientada por custos e resultados. Segundo a Declaração do Luxemburgo (1997), a promoção da saúde engloba o esforço conjunto dos empregadores, dos trabalhadores, do Estado e da sociedade civil para melhorar a segurança, a saúde e o bem-estar no trabalho, objectivo isso que pode ser conseguido através da (i) melhoria da organização e das demais condições de trabalho, da (ii) participação efectiva e concreta dos trabalhadores bem como do seu (iii) desenvolvimento pessoal. Abstract Health at work policies: a sociological inquiry into Portuguese corporations Portuguese literature on workplace health policies, programs and activities is still scarce. With this research project the author intends (i) to improve knowledge on the Occupational Health and Safety (shortly thereafter, OSH) management systems and (ii) contribute to the development of health promotion initiatives at a corporate level. Five categories of workplace health initiatives have been identified: (i) Occupational Hygiene and Safety / Improvement of Physical Working Environment (type A programs); (ii) Health Screening, Medical Surveillance and Other Occupational Health Care Provision (type B programs); (iii) Preventing Risk Behaviours / Promoting Healthy Life Styles (type C programs); (iv) Organisational Change / Improvement of Psycho-Social Working Environment (type D programs); and (v) Industrial and Social Welfare (type E programs). A mail questionnaire was sent to the Chief Executive Officer of the 1500 largest Portuguese companies, operating in the primary and secondary sectors (≥ 100 employees) or tertiary sector (≥ 75 employees). Response rate has reached about 20% (259 respondents, representing about 300 companies). Carried out between Spring 1997 and Summer 1998, the fieldwork has encompassed two direct mailings and one phone follow-up. Sample is considered to be representative of the two thousand largest companies. One in four is a multinational. Union membership rate is about 30%, but only 16% has reported the existence of a workers’ health and safety representative. The most frequent workplace health initiatives were those under the traditional scope of the OSH field (type A and B programs) (57% of total) (e.g., Periodical Medical Examinations; Individual Protective Equipment; Assessment of Working Ability). In SMEs (< 250) it was less likely to find out some time-consuming and expensive activities (e.g., Training on OSH knowledge and skills, Improvement of environmental parameters as ventilation, lighting, heating).There were significant differences in SMEs, when compared with the larger ones (≥ 250) concerning type B programs such as Periodical medical examinations, GP consultation, Nursing care, Other medical and non-medical specialities (e.g., psychiatrist, psychologist, ergonomist, physiotherapist, occupational social worker). With regard to type C programs, there were a greater percentage of programs centred on Substance abuse (tobacco, alcohol, and drug) than on Other health risk behaviours. SMEs representatives reported very few prevention- oriented programs in the field of Drug abuse, Nutrition, Physical activity, Off- job accidents, Blood pressure or Weight control. Frequency of type D programs included Training on Human Resources Management, Training on Organisational Behaviour, Total Quality Management, Job Design/Ergonomics, and Workplace rehabilitation. In general, implementation of this type of programs (Organisational Change / Improvement of Psychosocial Working Environment) is not largely driven by health considerations. Concerning Industrial and Social Welfare (Type E programs), the larger employers are in a better position than SMEs to offer to their employees a large spectrum of health resources and facilities (e.g., Restaurant, Canteen, Resting room, Transport, Infra-structures for physical activity, Surgery, Complementary social protection, Support to recreational and cultural activities, Magazine or newsletter, Intranet). Other workplace health promotion programs like Training on Stress Management, Employee Assistance Programs, or Self-help groups are uncommon in the Portuguese worksites. The existence of integrated OSH management systems, not the company size, is the main variable explaining the implementation of more active and innovative workplace health policies in Portugal. The three main prompting factors reported by employers for health protection and promotion initiatives are: (i) Employee absenteeism; (ii) Productivity, quality and/or competitiveness; and (iii) Corporate culture/management philosophy. On the other hand, (i) Improved staff’s health, (ii) Improved working environment and (iii) Improved productivity, quality and/or competitiveness were the three main benefits reported by companies’ representatives, as a result of successful implementation of workplace health initiatives. (i) Lack of staff commitment; (ii) Lack of time; and (iii) Problems of co-operation and communication within company or establishment (iii) are perceived to be the main barriers companies must cope with. Asked about the main facilitating factors, these companies have pointed out the following ones: (i) Top management commitment; (ii) Corporate culture; and (iii) Sense of social responsibility. This sociological research report shows the methodological weaknesses of workplace health initiatives, carried out by Portuguese companies during the last ‘90s. In many cases, these programs and actions were not part of a corporate health strategy and policy, (i) based on the assessment of workers’ health needs and expectancies, (ii) advocated by the employer or the chief executive officer, (ii) planned and implemented with the staff consultation and participation or (iv) evaluated according to a cost-benefit analysis. In short, corporate health policy and action were still rather based on more traditional OSH approaches and should be reoriented towards Workplace Health Promotion (WHP) approach. According to the Luxembourg Declaration of Workplace Health Promotion in the European Union (1997), WHP is “a combination of: (i) improving the work organisation and environment; (ii) promoting active participation; (iii) encouraging personal development”.Résumée Politique(s) de santé au travail: une enquête sociologique aux entreprises portugaises Au Portugal on ne sait presque rien des politiques de santé au travail, adoptés par les entreprises. Avec ce projet de recherche, on veut (i) améliorer la connaissance sur les systèmes de gestion de la santé et de la sécurité au travail et, au même temps, (ii) contribuer au développement de la promotion de la santé des travailleurs. Une typologie a été usée pour identifier les politiques, programmes et actions de santé au travail: A. Amélioration des conditions de travail / Sécurité au travail; B. Médecine du travail /Santé au travail; C. Prévention des comportements de risque / Promotion de styles de vie sains; D. Interventions organisationnelles / Amélioration des facteurs psychosociaux au travail; E. Gestion de personnel et bien-être social. Un questionnaire postal a été envoyé au représentant maximum des grandes entreprises portugaises, industrielles (≥ 100 employés) ou des services (≥ 75 employés). Le taux de réponse a été environ 20% (259 répondants, concernant trois centaines d’entreprises et d’établissements). La recherche de champ, conduite du printemps 1997 à l’été 1998, a compris deux enquêtes postales et un follow-up téléphonique. L´échantillon est représentatif de la population des deux miles plus grandes entreprises. Un quart sont des multinationales. Le taux de syndicalisation est d’environ 30%. Toutefois, il y a seulement 16% de lieux de travail avec des représentants du personnel pour la santé et sécurité au travail. Les initiatives de santé au travail les plus communes sont celles concernant le domaine plus traditionnel (types A et B) (57% du total): par exemple, les examens de médecine du travail, l’équipement de protection individuelle, les tests d’aptitude au travail. En ce qui concerne les programmes de type C, les plus fréquents sont le contrôle et la prévention des addictions (tabac, alcool, drogue). Les interventions dans le domaine de du système technique et organisationnelle du travail peuvent comprendre les courses de formation en gestion de ressources humaines ou en psychosociologie des organisations, l’ergonomie, le travail posté ou la gestion de la qualité totale. En général, la protection et la promotion de la santé des travailleurs ne sont pas prises en considération dans l’implémentation des initiatives de type D. Il y a des différences quand on compare les grandes entreprises et les moyennes en matière de politique de gestion du personnel e du bien-être (programmes de type E, y compris l’allocation de ressources humaines ou logistiques comme, par exemple, restaurant, journal d’entreprise, transports, installations et équipements sportifs). D’autres activités de promotion de la santé au travail comme la formation en gestion du stress, les programmes d’ assistance aux employés, ou les groupes de soutien et d’auto-aide sont encore très peu fréquents dans les entreprises portugaises. C’est le système intégré de gestion de la santé et de la sécurité au travail, et non pas la taille de l’entreprise, qui aide à prédire l’existence de politiques actives et innovatrices dans ce domaine. Les trois facteurs principaux qui encouragent les actions de santé (prompting factors, en anglais) sont (i) l’absentéisme (y compris la maladie), (ii) les problèmes liés à la productivité, qualité et/ou la compétitivité, et aussi (iii) la culture de l’entreprise/philosophie de gestion. Du coté des bénéfices, on a obtenu surtout l’amélioration (i) de la santé du personnel, (ii) des conditions de travail, et (iii) de la productivité, qualité et/ou compétitivité.Les facteurs qui facilitent les actions de santé au travail sont (i) l’engagement de la direction, (ii) la culture de l’entreprise, et (iii) le sens de responsabilité sociale. Par contre, les obstacles à surmonter, selon les organisations qui ont répondu au questionnaire, seraient surtout (i) le manque d’engagement des travailleurs et de leur représentants, (ii) le temps insuffisant, et (iii) les problèmes de articulation/communication au niveau interne de l’entreprise/établissement. Ce travail de recherche sociologique montre la faiblesse méthodologique des services et activités de santé et sécurité au travail, mis en place par les entreprises portugaises dans les années de 1990, à la suite des accords de concertation sociale de 1991. Dans beaucoup de cas, (i) ces politiques de santé ne font pas partie encore d’un système intégré de gestion, (ii) il n’a pas d’évaluation des besoins et des expectatives des travailleurs, (iii) c’est très bas ou inexistant le niveau de participation du personnel, (iv) on ne fait pas d’analyse coût-bénéfice. On peut conclure que les politiques de santé au travail sont plus proches de la médecine du travail et de la sécurité au travail que de la promotion de la santé des travailleurs. Selon la Déclaration du Luxembourg sur la Promotion de la Santé au Lieu de Travail dans la Communauté Européenne (1997), celle-ci « comprend toutes les mesures des employeurs, des employés et de la société pour améliorer l'état de santé et le bien être des travailleurs » e « ceci peut être obtenu par la concentration des efforts dans les domaines suivants: (i) amélioration de l'organisation du travail et des conditions de travail ; (ii) promotion d'une participation active des collaborateurs ; (iii) renforcement des compétences personnelles ».

Porto Polytechnical Engineering School sustainable development action plan

Porto Polytechnical Engineering School (ISEP), a Global Reporting Initiative training partner in Portugal, has just presented its Sustainable Development Action Plan (PASUS), which main objective is the formation of a new kind of engineers, with a Sustainable Development (SD) philosophy in the core of their academic curricula courses.

Une vision systémique de la formation continue universitaire

Res-Systemica, Volume N°5, Numéro Spécial

Antibacterial, anti-swarming and anti-biofilm formation activities of Chamaemelum nobile against Pseudomonas aeruginosa

AbstractINTRODUCTION:Chamomile ( Chamaemelum nobile ) is widely used throughout the world, and has anti-inflammatory, deodorant, bacteriostatic, antimicrobial, carminative, sedative, antiseptic, anti-catarrhal, and spasmolytic properties. Because of the increasing incidence of drug-resistant bacteria, the development of natural antibacterial sources such as medical herbs for the treatment of infectious diseases is necessary. Extracts from different plant parts such as the leaves, flowers, fruit, and bark of Combretum albiflorum, Laurus nobilis , and Sonchus oleraceus were found to possess anti-quorum sensing (QS) activities. In this study, we evaluated the effect of C. nobile against Pseudomonas aeruginosa biofilm formationMETHODS:The P. aeruginosa samples were isolated from patients with different types of infection, including wound infection, septicemia, and urinary tract infection. The flowers of C. nobile were dried and the extract was removed using a rotary device and then dissolved in dimethyl sulfoxide at pH 7.4. The microdilution method was used to evaluate the minimum inhibitory concentration (MIC) of this extract on P. aeruginosa , and biofilm inhibition was assayed.RESULTS:Eighty percent of the isolated samples (16/20) could form a biofilm, and most of these were isolated from wound infections. The biofilm inhibitory concentration of the C. nobile extract was 6.25-25mg/ml, whereas the MIC was 12.5-50mg/ml.CONCLUSIONS:The anti-QS property of C. nobile may play an important role in its antibacterial activity, thus offering an additional strategy in the fight against bacterial infections. However, molecular investigation is required to explore the exact mechanisms of the antibacterial action and functions of this phytocompound.

Action of growth regulators on flowering and pod production of soybean cultivar Davis

This research deals with the effects of growth regulators on flowering and pod formation in soybean plant (Glycine max cv. Davis). Under greenhouse conditions, soybean plants were sprayed with 2,3,5-triiodobenzoic acid (TIBA) 20 ppm, Agrostemmin (1g/10 ml/3 l) gibberellic acid (GA) 100 ppm, and (2-chloroethyl) trimethylammonium chloride (CCC) 2,000 ppm. Application of TIBA increased number of flowers. 'Davis' soybean treated with CCC and TIBA presented a tendency to produce a lower number of pods.

Formation continue dans les services publics en Suisse : quelles stratégies des acteurs dans un environnement managérialisé ?

Dans l'environnement actuel fortement évolutif, les questions relatives à la formation continue sont plus que jamais essentielles. Nombre de publications les abordent toutefois uniquement sous un angle prescriptif, sans considérer le comportement réel du personnel en matière de formation continue. La recherche dont il est question dans cet article vise à mettre en évidence les stratégies que les agents publics suisses mettent en oeuvre, au sein d'organisations soumises à une managérialisation croissante, pour atteindre leurs propres objectifs de formation. Sur la base des analyses effectuées, la conclusion esquisse certains enjeux plus fondamentaux relatifs à l'avenir de la formation continue dans les services publics suisses, enjeux à notre sens largement transposables au sein d'autres pays de l'OCDE (Organisation de coopération et de développement économiques).

Dirigent domain-containing protein is part of the machinery required for formation of the lignin-based Casparian strip in the root.

The endodermis acts as a "second skin" in plant roots by providing the cellular control necessary for the selective entry of water and solutes into the vascular system. To enable such control, Casparian strips span the cell wall of adjacent endodermal cells to form a tight junction that blocks extracellular diffusion across the endodermis. This junction is composed of lignin that is polymerized by oxidative coupling of monolignols through the action of a NADPH oxidase and peroxidases. Casparian strip domain proteins (CASPs) correctly position this biosynthetic machinery by forming a protein scaffold in the plasma membrane at the site where the Casparian strip forms. Here, we show that the dirigent-domain containing protein, enhanced suberin1 (ESB1), is part of this machinery, playing an essential role in the correct formation of Casparian strips. ESB1 is localized to Casparian strips in a CASP-dependent manner, and in the absence of ESB1, disordered and defective Casparian strips are formed. In addition, loss of ESB1 disrupts the localization of the CASP1 protein at the casparian strip domain, suggesting a reciprocal requirement for both ESB1 and CASPs in forming the casparian strip domain.

Mechanism of action of Bacillus thuringiensis toxins

The selectivity of Bacillus thuringiensis toxins is determined both by the toxin structure and by factors inherent to the insect. These toxins contain distinct domains that appear to be functionally important in toxin binding to protein receptors in the midgut of susceptible insects, and the subsequent formation of a pore in the insect midgut epithelium. In this article features necessary for the insecticidal activity of these toxins are discussed. These include toxin structure, toxin processing in the insect midgut, the identification of toxin receptors in susceptible insects, and toxin pore formation in midgut cells. In addition a number of B. thuringiensis toxins act synergistically to exert their full insecticidal activity. This synergistic action is critical not only for expressing the insecticidal activity of these toxins, but could also play a role in delaying the onset of insect resistance.

Experimental approaches in the targeting of photodynamic therapeutics

RÉSUMÉ : Chez l'homme, le manque de sélectivité des agents thérapeutiques représente souvent une limitation pour le traitement des maladies. Le ciblage de ces agents pour un tissu défini pourrait augmenter leur sélectivité et ainsi diminuer les effets secondaires en comparaison d'agents qui s'accumuleraient dans tout le corps. Cela pourrait aussi améliorer l'efficacité des traitements en permettant d'avoir une concentration localisée plus importante. Le ciblage d'agents thérapeutiques est un champ de recherche très actif. Les stratégies sont généralement basées sur les différences entre cellules normales et malades. Ces différences peuvent porter soit sur l'expression des molécules à leurs surfaces comme des récepteurs ou des transporteurs, soit sur les activités enzymatiques exprimées. Le traitement thérapeutique choisi ici est la thérapie photodynamique et est déjà utilisé pour le traitement de certains cancers. Cette thérapie repose sur l'utilisation de molécules qui réagissent à la lumière, les photosensibilisants. Elles absorbent l'énergie lumineuse et réagissent avec l'oxygène pour former des radicaux toxiques pour les cellules. Les photosensibilisants utilisés ici sont de deux natures : (i) soit ils sont tétrapyroliques (comme les porphyrines et chlorines), c'est à dire qu'ils sont directement activables par la lumière ; (ii) soit ce sont des prodrogues de photosensibilisants comme l'acide 5aminolévulinique (ALA) qui est transformé dans la cellule en protoporphyrine IX photosensibilisante. Dans le but d'augmenter la sélectivité des photosensibilisants, nous avons utilisé deux stratégies différentes : (i) le photosensibilisant est modifié par le greffage d'un agent de ciblage ; (ii) le photosensibilisant est incorporé dans des structures moléculaires de quelques centaines de nanomètres. Les sucres et l'acide folique sont des agents de ciblage largement établis et ont été utilisés ici car leurs récepteurs sont surexprimés à la surface de nombreuses cellules malades. Ainsi, des dérivés sucres ou acide folique de l'ALA ont été synthétisés et évalués in vitro sur de nombreuses lignées cellulaires cancéreuses. La stratégie utilisant l'acide folique est apparue incompatible avec l'utilisation de l'ALA puisque aucune photosensibilité n'a été induite par le composé. La stratégie utilisant les sucres a, par ailleurs, provoquée de bonnes photosensibilités mais pas d'augmentation de sélectivité. En parallèle, la combinaison entre les propriétés anticancéreuses des complexes métalliques au ruthénium avec les propriétés photosensibilisantes des porphyrines, a été évaluée. En effet, les thérapies combinées ont émergé il y a une dizaine d'années et représentent aujourd'hui de bonnes alternatives aux monothérapies classiques. Des ruthenium(I1)-arènes complexés avec la tetrapyridylporphyrine ont ainsi présenté de bonnes cytotoxicités et de bonnes phototoxicités pour des cellules de mélanomes. Des porphyrines ont aussi été compléxées avec des noyaux de diruthénium et ce type de dérivé a présenté de bonnes phototoxicités et une bonne sélectivité pour les cellules cancéreuses de l'appareil reproducteur féminin. L'incorporation de photosensibilisants tétrapyroliques a finalement été effectuée en utilisant des nanoparticules (NP) biocompatibles composées de chitosan et de hyaluronate. L'effet de ces NP a été évalué pour le traitement de la polyarthrite rhumatoïde (PR). Les NP ont d'abord été testées in vitro avec des macrophages de souris et les résultats ont mis en évidence de bonnes sélectivités et photosensibilités pour ces cellules. In vivo chez un modèle marin de la PR, l'utilisation de ces NP a révélé un plus grand temps de résidence des NP dans le genou de la souris en comparaison du temps obtenu avec le photosensibilisant seul. Le traitement par PDT a aussi démontré une bonne efficacité par ailleurs égale à celle obtenue avec les corticoïdes utilisés en clinique. Pour finir, les NP ont aussi démontré une bonne efficacité sur les myelomonocytes phagocytaires humains et sur les cellules contenues dans le liquide synovial de patients présentant une PR. Tous ces résultats suggèrent que les deux stratégies de ciblage peuvent être efficaces pour les agents thérapeutiques. Afm d'obtenir de bons résultats, il est toutefois nécessaire de réaliser une analyse minutieuse de la cible et du mode d'action de l'agent thérapeutique. Concernant les perspectives, la combinaison des deux stratégies c'est à dire incorporer des agents thérapeutiques dans des nanostructures porteuses d'agents de ciblage, représente probablement une solution très prometteuse. SUMMARY : In humans, the lack of selectivity of drugs and their high effective concentrations often represent limitations for the treatment of diseases. Targeting the therapeutical agents to a defined tissue could enhance their selectivity and then diminish their side effects when compared to drugs that accumulate in the entire body and could also improve treatment efûciency by allowing a localized high concentration of the agents. Targeting therapeutics to defined cells in human pathologies is a main challenge and a very active field of research. Strategies are generally based on the different behaviors and patterns of expression of diseased cells compared to normal cells such as receptors, proteases or trans-membrane carriers. The therapeutic treatment chosen here is the photodynamic therapy and is already used in the treatment of many cancers. This therapy relies on the administration of a photosensitizer (PS) which will under light, react with oxygen and induce formation of reactive oxygen species which are toxic for cells. The PSs used here are either tetrapyrolic (i. e. porphyries and chlorins) or prodrugs of PS (5-aminolevulinic acid precursor of the endogenous protoporphyrin Imo. In order to improve PS internalization and selectivity, we have used two different strategies: the modification of the PSs with diseased cell-targeting agents as well as their encapsulation into nanostructures. Sugars and folic acid are well established as targeting entities for diseased cells and were used here since their transporters are overexpressed on the surface of many cancer cells. Therefore sugar- and folic acid-derivatives of 5-aminolevulinic acid (ALA) were synthesized and evaluated in vitro in several cancer cell lines. The folic acid strategy appeared to be incompatible with ALA since no photosensitivity was induced while the strategy with sugars induced good photosensitivites but no increase of selectivity. Alternatively, the feasibility of combining the antineoplastic properties of ruthenium complexes with the porphyrin's photosensitizing properties, was evaluated since combined therapies have emerged as good alternatives to classical treatments. Tetrapyridylporphyrins complexed to ruthenium (I17 arenes presented good cytotoxicities and good phototoxicities toward melanoma cells. Porphyries were also complexed to diruthenium cores and this type of compound presented good phototoxicities and good selectivity for female reproductive cancer cells. The encapsulation of tetrapyrolic PSs was finally investigated using biocompatible nanogels composed of chitosan and hyaluronate. The behavior of these nanoparticles was evaluated for the treatment of rheumatoid arthritis (RA). They were first tested in vitro in mouse macrophages and results revealed good selectivities and phototoxicities toward these cells. In vivo in mice model of RA, the use of such nanoparticles instead of free PS showed longer time of residence in mice knees. Photodynamic protocols also demonstrated good efficiency of the treatment comparable to the corticoid injection used in the clinic. Finally our system was also efficient in human cells using phagocytic myelomonocytes or using cells of synovial fluids taken from patients with RA. Altogether, these results revealed that both strategies of modification or encapsulation of drugs can be successful in the targeting of diseased cells. However, a careful analysis of the target and of the mode of action of the drug, are needed in order to obtain good results. Looking ahead to the future, the combination of the two strategies (i.e. drugs loaded into nanostructures bearing the targeting agents) would represent probably the best solution.