4,624 research outputs found

    Kinetics of CheY phosphorylation by small molecule phosphodonors

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    AbstractThe chemotaxis response regulator CheY can acquire phosphoryl groups either from its associated autophosphorylating protein kinase, CheA, or from small phosphodonor molecules such as acetyl phosphate. We report a stopped-flow kinetic analysis of CheY phosphorylation by acetyl phosphate. The results show that CheY has a very low affinity for this phosphodonor (Ks≫0.1 M), consistent with the conclusion that, whereas CheY provides catalytic functions for the phosphotransfer reaction, the CheA kinase may act simply to increase the effective phosphodonor concentration at the CheY active site

    The genesis of the Lombroso´s theory and its influence on the criminal law since the XIX century until our days

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    The aim of the present work is to analyze Lombroso´s criminal anthropology, one of the most notorious examples of the biological reductionism of evolutionist basis from the XIX century. Its main assumption is that there is a variety of criminals, the born criminals, who are cavemen that coexist in civilized societies. With this difference settled, they could be distinguished by the presence of some morphological stigmata of their atavist condition, constituting the criminal type. If it is true that, time ago, this theory fell into disuse its influence on the criminal law survives in the laws that allow suspended sentences. In order to fulfil our aim, we will split this writing in two main sections. In the first one we will treat the influences on Lombroso´s theory of the evolution and recapitulation (I). In the second part (II), we will treat the influence of Lombroso's theory upon the criminal law of the XIX century until our days.El objetivo del trabajo es analizar la antropología criminal de Lombroso, uno de los ejemplos más notorios del reduccionismo biológico de base evolutiva del siglo XIX. Su principal supuesto es que existe una variedad de criminales, los “criminales natos”, que son hombres de las cavernas que conviven en sociedades civilizadas, y que dada esta diferencia se los podría distinguir por presentar estigmas morfológicos de su condición atávica, constituyendo el “tipo criminal”. Si bien esta teoría cayó en desuso hace tiempo, su influencia en el derecho penal pervive en las leyes que permiten condenas por tiempo indeterminado. Para cumplir con el objetivo, dividimos este escrito en dos secciones principales. En la primera, tratamos las influencias sobre la teoría lombrosiana de la evolución y de la recapitulación (I). En la segunda parte (II), tratamos la influencia de la teoría de Lombroso sobre el derecho penal desde el siglo XIX hasta nuestros días.Fil: Da Re, Verónica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Maceri, Sandra Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Saavedra 15. Instituto Interdisciplinario de Economía Política de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Económicas. Instituto Interdisciplinario de Economía Política de Buenos Aires; Argentin

    Feasibility, drug safety, and effectiveness of etiological treatment programs for Chagas disease in Honduras, Guatemala, and Bolivia: 10-year experience of Médecins Sans Frontières

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    BACKGROUND: Chagas disease (American trypanosomiasis) is a zoonotic or anthropozoonotic disease caused by the parasite Trypanosoma cruzi. Predominantly affecting populations in poor areas of Latin America, medical care for this neglected disease is often lacking. Médecins Sans Frontières/Doctors Without Borders (MSF) has provided diagnostic and treatment services for Chagas disease since 1999. This report describes 10 years of field experience in four MSF programs in Honduras, Guatemala, and Bolivia, focusing on feasibility protocols, safety of drug therapy, and treatment effectiveness. METHODOLOGY: From 1999 to 2008, MSF provided free diagnosis, etiological treatment, and follow-up care for patients <18 years of age seropositive for T. cruzi in Yoro, Honduras (1999-2002); Olopa, Guatemala (2003-2006); Entre Ríos, Bolivia (2002-2006); and Sucre, Bolivia (2005-2008). Essential program components guaranteeing feasibility of implementation were information, education, and communication (IEC) at the community and family level; vector control; health staff training; screening and diagnosis; treatment and compliance, including family-based strategies for early detection of adverse events; and logistics. Chagas disease diagnosis was confirmed by testing blood samples using two different diagnostic tests. T. cruzi-positive patients were treated with benznidazole as first-line treatment, with appropriate counseling, consent, and active participation from parents or guardians for daily administration of the drug, early detection of adverse events, and treatment withdrawal, when necessary. Weekly follow-up was conducted, with adverse events recorded to assess drug safety. Evaluations of serological conversion were carried out to measure treatment effectiveness. Vector control, entomological surveillance, and health education activities were carried out in all projects with close interaction with national and regional programs. RESULTS: Total numbers of children and adolescents tested for T. cruzi in Yoro, Olopa, Entre Ríos, and Sucre were 24,471, 8,927, 7,613, and 19,400, respectively. Of these, 232 (0.9%), 124 (1.4%), 1,475 (19.4%), and 1,145 (5.9%) patients, respectively, were diagnosed as seropositive. Patients were treated with benznidazole, and early findings of seroconversion varied widely between the Central and South American programs: 87.1% and 58.1% at 18 months post-treatment in Yoro and Olopa, respectively; 5.4% by up to 60 months in Entre Ríos; and 0% at an average of 18 months in Sucre. Benznidazole-related adverse events were observed in 50.2% and 50.8% of all patients treated in Yoro and Olopa, respectively, and 25.6% and 37.9% of patients in Entre Ríos and Sucre, respectively. Most adverse events were mild and manageable. No deaths occurred in the treatment population. CONCLUSIONS: These results demonstrate the feasibility of implementing Chagas disease diagnosis and treatment programs in resource-limited settings, including remote rural areas, while addressing the limitations associated with drug-related adverse events. The variability in apparent treatment effectiveness may reflect differences in patient and parasite populations, and illustrates the limitations of current treatments and measures of efficacy. New treatments with improved safety profiles, pediatric formulations of existing and new drugs, and a faster, reliable test of cure are all urgently needed

    Prevalence of SOS-mediated control of integron integrase expression as an adaptive trait of chromosomal and mobile integrons

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    Background: Integrons are found in hundreds of environmental bacterial species, but are mainly known as the agents responsible for the capture and spread of antibiotic-resistance determinants between Gram-negative pathogens. The SOS response is a regulatory network under control of the repressor protein LexA targeted at addressing DNA damage, thus promoting genetic variation in times of stress. We recently reported a direct link between the SOS response and the expression of integron integrases in Vibrio cholerae and a plasmid-borne class 1 mobile integron. SOS regulation enhances cassette swapping and capture in stressful conditions, while freezing the integron in steady environments. We conducted a systematic study of available integron integrase promoter sequences to analyze the extent of this relationship across the Bacteria domain. Results: Our results showed that LexA controls the expression of a large fraction of integron integrases by binding to Escherichia coli-like LexA binding sites. In addition, the results provide experimental validation of LexA control of the integrase gene for another Vibrio chromosomal integron and for a multiresistance plasmid harboring two integrons. There was a significant correlation between lack of LexA control and predicted inactivation of integrase genes, even though experimental evidence also indicates that LexA regulation may be lost to enhance expression of integron cassettes. Conclusions: Ancestral-state reconstruction on an integron integrase phylogeny led us to conclude that the ancestral integron was already regulated by LexA. The data also indicated that SOS regulation has been actively preserved in mobile integrons and large chromosomal integrons, suggesting that unregulated integrase activity is selected against. Nonetheless, additional adaptations have probably arisen to cope with unregulated integrase activity. Identifying them may be fundamental in deciphering the uneven distribution of integrons in the Bacteria domain

    The SOS response controls integron recombination

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    Integrons are found in the genome of hundreds of environmental bacteria but are mainly known for their role in the capture and spread of antibiotic resistance determinants among Gram-negative pathogens. We report a direct link between this system and the ubiquitous SOS response. We found that LexA controlled expression of most integron integrases and consequently regulated cassette recombination. This regulatory coupling enhanced the potential for cassette swapping and capture in cells under stress, while minimizing cassette rearrangements or loss in constant environments. This finding exposes integrons as integrated adaptive systems and has implications for antibiotic treatment policie

    Effects of mycophenolate mofetil on key pattern of coronary restenosis: a cascade of in vitro and ex vivo models

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    BACKGROUND: Mycophenolate mofetil (MMF), the prodrug of mycophenolic acid (MPA), is a rationally designed immunosuppressive drug. The current study investigates the effect of MMF on key pattern of restenosis in a cascade of in vitro and ex vivo models. METHODS: Part I of the study investigated in northern blot and cytoflow studies the effect of MMF (50, 100, 150, 200, 250, and 300 μg/mL) on TNF-α induced expression of intercellular adhesion molecule 1 (ICAM-1) in human coronary endothelial cells (HCAEC) and human coronary medial smooth muscle cells (HCMSMC). Part II of the study applied a human coronary 3D model of leukocyte attack, the 3DLA-model. HCAEC and HCMSMC were cultured on both sides of a polycarbonate filters, mimicking the internal elastic membrane. Leukocyte attack (LA) was carried out by adding human monocytes (MC) on the endothelial side. The effect of MMF (50 μg/mL) on adhesion and chemotaxis (0.5, 1, 2, 3, 4, 6, and 24 h after LA) and the effect on proliferation of co-cultured HCMSMC (24 h after LA) was studied. In part III of the study a porcine coronary organ culture model of restenosis (POC-model) was used. After ex vivo ballooning MMF (50 μg/mL) was added to the cultures for a period of 1, 2, 3, 4, 5, 6, and 7 days. The effect on reactive cell proliferation and neointimal thickening was studied at day 7 and day 28 after ballooning. RESULTS: Expression of ICAM-1 in northern blot and cytoflow studies was neither clearly inhibited nor stimulated after administration of MMF in the clinical relevant concentration of 50 μg/mL. In the 3DLA-model 50 μg/mL of MMF caused a significant antiproliferative effect (p < 0.001) in co-cultured HCMSMC but had no effect on MC-adhesion and MC-chemotaxis. In the ex vivo POC-model neighter reactive cell proliferation at day 7 nor neointimal hyperplasia at day 28 were significantly inhibited by MMF (50 μg/mL). CONCLUSION: Thus, the data demonstrate a significant antiproliferative effect of clinical relevant levels of MMF (50 μg/mL) in the 3DLA-model. The antiproliferative effect was a direct antiproliferative effect that was not triggered via reduced expression of ICAM-1 or via an inhibition of MC-adhesion and chemotaxis. Probably due to technical limitations (as e.g. the missing of perfusion) the antiproliferative effect of MMF (50 μg/mL) could not be reproduced in the coronary organ culture model. A cascade of focused in vitro and ex vivo models may help to gather informations on drug effects before large experimental studies are initiated

    Methodological guide for ethnobotanical study of forest species in Amazonian and related communities

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    The ethnobotanical study is carried out due to the accelerated loss of traditional knowledge, forest degradation and natural habitats in Amazonian communities. This work proposes a methodological guide that facilitates accessibility for obtaining information in the ethnobotanical study of superior lignified and ruderal species for medicinal purposes and other uses. A survey was made that proposes the technique Interlocutor - Medium - Interlocutor for the dialogue, with a scientific character and the handling of the survey in three stages: application, validation and generalization, obtaining the ethnobotanical information that the Amazonian communities treasure in agreement with their ethnicity of origin. The results demonstrated the effectiveness in the application of the survey through the relationship established between the researcher and community leaders, ancestral healers, farmers, housewives, people of different ages and other members with interest in the subject, facilitating accessibility for the location and identification of superior lignified and ruderal species for medicinal purposes and other uses

    Quali strumenti giuridici statali e regionali per le comunit\ue0 patrimoniali?

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    The Framework Convention on the Value of Cultural Heritage for Society (Faro Convention, 2005) recognizes a central role to heritage communities in the process of identification, study, interpretation, protection, conservation and presentation of the cultural heritage. As a signatory State of the Convention (signed on 27th February 2013, still waiting for ratification), Italy has in any case to ensure its contribution to the safeguarding of the tangible and intangible cultural heritage by adequate policies. Currently, a State law providing a general regulation of the participation of civil society to the protection and the enhancement of cultural heritage in the Italian legal system has not been adopted yet. Nevertheless, communities, groups and individuals have a wide range of instruments available, which can be drawn by an accurate interpretation of the Constitution and of many State and regional laws. In the long run, the persistent lack of common rules on this subject may be a source of uncertainty, capable of weakening, instead of strengthening, the role of heritage communities, in contrast with the principles of the Faro Convention
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