Investigation of novel malaria parasite enzyme (DHODH) inhibitors based on 4-amino-3-benzylcoumarin and 4-amino-8-azacoumarin scaffolds

Popular summery Malaria is a parasitic disease caused by five species of the genus Plasmodium (P. falciparum, P. vivax, P. ovale, P. malariae and P. knowlesi) that affect humans. The most deadly form of Malaria is due to Plasmodium Falciparum and it is mostly spread in African areas. Almost half of the world population is at risk to contract the infection and every year malaria causes around half million deaths. Since an effective vaccine is still not available, malaria treatment relies on chemotherapeutics. It is important to find new targets and new drugs to fight the parasite because it has an inherent ability to develop resistance. Biological background and discussion Dihydroorotate dehydrogenase (DHODH) is the enzyme which catalyzes the fourth and rate limiting step of de novo pyrimidine biosynthesis. It is an interesting target because the parasites rely on this pathway to get pyrimidines, while mammalian cells can also get them from salvage of “used pyrimidines”; if DHODH is inhibited in the parasite (PfDHODH), it will not be able to synthesize DNA so its growth will be impeded. Furthermore, dissimilarities between the human and the parasite enzyme in the primary structure allow the design of species-specific inhibitors. Some 4-aminocoumarin derivatives earlier showed micro molar IC50. In this study we have synthesized new 4-amino-3-benzylcoumarin and 4-amino-8-azacoumarin derivatives, after calculations with molecular modeling, trying to optimize the interactions with the protein. Conclusion In the end we got nine derivatives which will be tested on the purified recombinant pfDHODH. These results will aid us towards further optimization of the coumarin scaffold.Abstract Plasmodium falciparum is the causative agent of the most serious and fatal malarial infections, and it has developed resistance to commonly employed chemotherapeutics. The de novo pyrimidine biosynthesis enzymes offer potential as targets for drug design, because, unlike the host, the parasite lacks pyrimidine salvage pathway.In search for new Plasmodium falciparum dihydroorotate dehydrogenase (pfDHODH) inhibitors as antimalarials, modifications of original 4-aminocoumarin scaffold were synthesized. 4-Amino-3-benzylcoumarin derivatives are inactive against the recombinant enzyme, while results for the 4-Amino-8-azacoumarin derivatives are still not available. These results demonstrate that position-3 in the coumarin scaffold cannot be expanse most likely due to the steric hindrance in the hydrophobic subsite of the binding site

Standardization of concentrated antibodies for use in automated immunohistochemistry

Background: Immunohistochemistry (IHC) is a method of identifying proteins in cells or tissues that is useful for diagnosis and research. In modern pathology, it has assumed an important supporting role in the molecular diagnosis of certain neoplasia, with an exponential contribution in personalized medicine. Automation in immunohistochemistry contributes to reduced test variability through standardization. The transition to automation is a process, and for a laboratory that already has a collection of stockconcentrated primary antibodies, ideally, these antibodies will be compatible with the chosen automated method, as antibodies are of high value to be discarded as a consequence of migration to automated immunohistochemistry. Methods: 78 concentrated antibodies were tested for use in Ventana Medical Systems’ Benchmark XT automation platform. Thirty-one human tissue samples containing the antigens of interest were used as positive control. Results: All antibodies tested showed good performance, indicating the feasibility of using these antibodies concentrated in the automation platform in question. The protocol most frequently used was the one with antigenic retrieval with Cell Conditioning 1 for 60 minutes and incubation in the primary antibody for 32 minutes at 42ºC. The dilutions of the primary antibodies in automation ranged from 1:20 to 1:4000. Conclusion: Under the aforementioned conditions, it was possible to take advantage of the portfolio of concentrated antibodies present in the laboratory at the time of transition from manual to automated immunohistochemistry

Designing Health Structure in Emergency Contexts. Natural Ventilation as Response to COVID-19 Pandemic.

The importance of ventilation as response to pandemic emergency is a concept that trace its roots back in the history of human pandemic and it remains valid up to the current covid-19 emergency. Yet, extreme climates, scarcity of resources, and poverty might impinge heavily on the ability of designing a built environment fit for the purpose of guarantee environmental conditions appropriate to respond to pandemic. Often, in contexts of scarcity and hot climates, safety parameters of ventilation in buildings are achieved as ersatz, rather than by design, due to the difficulties of managing economic resources, thermal characteristic, and ventilation requirements. Keep buildings cool and well ventilated seems to be still a challenge. This work presents a study carried out to design health structures - both permanent and temporary - in response to covid-19, in the Global South. Specifically, the study focused on: 1) the design of a Severe Acute Respiratory Infection (SARI) Treatment Center (hospital for airborne diseases) in the city of Dori in Burkina Faso, and 2) the design and test of High Performance Tents. Natural ventilation is studied by mean of transient dynamic simulations, using Energy+ software, and the probability of contagion are evaluated applying the Gammaitoni-Nucci model, based on the original Wells and Riley approach. The yearly dynamic simulations are supported by specific 3D airflows analysis by mean of CFD (Computational Fluid Dynamic), with the intent to underline the effects of different internal partitions configuration. CFD is also used to evaluate pressure coefficient at the openings. Through this ventilation study and morphological design proposal, this work provides compositional, technological and environmental solutions to overcome limits due to the need of coexistence of ventilation and thermal control, and socio-economic limitations. The significance of this work is the ability to show the importance of the balance between passive ventilation, architectural design and behavioral organization by design. Such approach can play a critical factor to achieve healthy and resilient environment, and offer a feasible solution to the need for health buildings in hot climates and poor contexts

Natural ventilation as sustainable response to Covid-19: Designing an airborne disease treatment centre in Burkina Faso

Climate, pandemic and energy have often shaped and characterised the transformations of our built environment. Today, under the current pandemic conditions, we are witnessing the ability (or not) of the built environment in responding to such emergency through changes and adaptation. Among many approaches to such changes and emergencies, we are presenting the idea of relying on passive design as a medium to manage and prevent pandemic events. In particular, this paper will focus on the tight relation between natural ventilation and architectural design as a sustainable response to Covid-19. To do so, the work focus on the design of a Severe Acute Respiratory Infection (SARI) Treatment Centre in Dori, Burkina Faso, in collaboration with an International humanitarian Institution. This experience shows the ability of passive design and natural ventilation to deliver a sustainable and resilient health facility able to engage the local community and optimise resources in a context of scarcity. The importance of this work is to inform design guidelines for further health facilities in the same climatic area, as well as to set the example of passive design support the prevention of the spread of air borne diseases

Fe-Allocation in Liver during Early Stages of Endotoxemia in Fe Overload Rats

The hypothesis of this study was that alterations in Fe distribution triggered by lipopolysaccharide (LPS) administration were affected in vivo by Fe overload. Lipopolysaccharide treatment by itself significantly decreased Fe content in serum and increased the blood NO-hemoglobin (NO-Hb) EPR signal and nitrotyrosine protein content in liver, as compared to values in control animals. Fe overload (produced by Fe-dextran ip administration) caused an increase, as compared to values in control animals, in Fe content in serum, and a significant enhancement in ferritin (Ft) content, Fe content in Ft, the labile Fe pool (LIP), and the protein carbonyl content in the liver. The simultaneous administration of LPS and Fe-dextran lead to a significant increase in the Fe content in serum, blood NO-Hb EPR signal, the content of Fe, Fe in Ft, LIP, protein carbonyl, and nitrotyrosine protein in liver, as compared to values in control animals. The data reported here indicate that the protective strategy against endotoxemia of sequestering serum Fe content is not fully operative under Fe overload conditions. However, the oxidative condition of the liver does not seem to be being affected, since endogenous mechanisms were able to regulate the amount of catalytically active Fe to the same levels observed after Fe-dextran administration, even in the presence of LPS, over the initial six-hour period.Fil: Rousseau, Iván. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Programa de Radicales Libres; ArgentinaFil: Galleano, Mónica Liliana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Bioquímica y Medicina Molecular. Universidad de Buenos Aires. Facultad Medicina. Instituto de Bioquímica y Medicina Molecular; ArgentinaFil: Puntarulo, Susana Ángela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Bioquímica y Medicina Molecular. Universidad de Buenos Aires. Facultad Medicina. Instituto de Bioquímica y Medicina Molecular; Argentin

Linking biomarkers of oxidative stress and disease with flavonoid consumption: From experimental models to humans

Identification of the links among flavonoid consumption, mitigation of oxidative stress and improvement of disease in humans has significantly advanced in the last decades. This review used (−)-epicatechin (EC) as an example of dietary flavonoids, and inflammation, endothelial dysfunction/hypertension and insulin resistance/diabetes as paradigms of human disease. In these pathologies, oxidative stress is part of their development and/or their perpetuation. Evidence from both, rodent studies and characterization of mechanisms in cell cultures are encouraging and mostly support indirect antioxidant actions of EC and EC metabolites in endothelial dysfunction and insulin resistance. Human studies also show beneficial effects of EC on these pathologies based on biomarkers of disease. However, there is limited available information on oxidative stress biomarkers and flavonoid consumption to allow establishing conclusive associations. The evolving discovery of metabolites that could serve as reliable markers of intake of specific flavonoids constitutes a powerful tool to link flavonoid consumption to disease and prevention of oxidative stress in human populations.Fil: Oteiza, Patricia Isabel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. University of California at Davis; Estados UnidosFil: Fraga, César Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Bioquímica y Medicina Molecular. Universidad de Buenos Aires. Facultad Medicina. Instituto de Bioquímica y Medicina Molecular; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Química Analitica y Fisicoquímica. Cátedra de Fisicoquímica; ArgentinaFil: Galleano, Mónica Liliana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Bioquímica y Medicina Molecular. Universidad de Buenos Aires. Facultad Medicina. Instituto de Bioquímica y Medicina Molecular; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Química Analitica y Fisicoquímica. Cátedra de Fisicoquímica; Argentin

Grama Rhodes, ¿una opción para mejorar suelos bajos alcalinos?

Grama Rhodes, ¿una opción para mejorar suelos bajos alcalinos?Fil: ´Martín, Beatriz. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias; Argenti

Alerta de gatilho : atualizações da cultura do estupro nas redes sociais

Pesquisar sobre a cultura do estupro é um pesquisar feminista a partir do acompanhamento de movimentos nas redes sociais que possibilitam ser tanto espaços de resistência como de silenciamento de violência sexual. As produções de gênero que insistem em marcar nossos corpos como binários, a pornografia como parte dos processos de subjetivação violentos, e a normalização da violência sexual são eixos importantes desta escrita, ocorrendo a partir das atualizações e virtualizações da cultura do estupro nas redes sociais. O movimento #MeToo foi um dos primeiros movimentos nas redes sociais que incentivou o uso da linguagem como potência subversiva às lógicas violentas. Assim, é através do compartilhamento de relatos que podemos perceber a existência da cultura do estupro nas redes sociais, que muitas vêm atreladas ao termo trigger warning. Uso a cartografia como método ao passo que a pesquisa foi acontecendo e se transformando, se criando mapas ilimitados, que mudam, que se transformam. Como questões norteadoras propus pensar nas relações de poder em que estamos atravessadas, a fim de subverter a discursos misóginos, sexistas e opressores. Como resultados, a produção de gênero e a pornografia surgem enquanto produção de subjetividades violentas, que contribuem para a manutenção da cultura do estupro e à normalização da violência sexual. A figura do Ciborgue também foi uma ferramenta que possibilitou entender relações binárias entre natureza e tecnologia, e da potência existente nas transformações políticas e sociais para subversão das lógicas que nos produz e nos dividem.The Research about the rape culture is a feminist research based on the monitoring of movements on social networks, that make it possible to be spaces for resistance and silencing of sexual violence. Gender productions that insist on marking our bodies as binary, pornography as part of violent subjectivation processes, and the normalization of sexual violence are important axes of this writing, occurring from updates and virtualizations of rape culture on social media. The #MeToo movement was one of the first movements on social media that encouraged the use of language as a subversive power to violent logics. Thus, it is through the sharing of reports that we can perceive the existence of the rape culture on social networks, which many posts are linked to the term trigger warning. I use cartography as a method while the research has been happening and transforming itself, creating unlimited, changing and transforming maps. As guiding questions, I proposed thinking about the power relations in which we are crossed, in order to subvert misogynistic, sexist and oppressive discourses. As a result, the production of gender and pornography emerge as the production of violent subjectivities, which contribute to the maintenance of the rape culture and the normalization of sexual violence. The figure of Cyborg was also a tool that made it possible to understand binary relationships between nature and technology, and the power that exists in political and social transformations to subvert the logics that produce and divide us.Investigar la cultura de la violación es una investigación feminista basada en el seguimiento de los movimientos en las redes sociales que permiten ser tanto espacios de resistencia como de silencio frente a la violencia sexual. Las producciones de género que insisten en marcar nuestros cuerpos como binarios, la pornografía como parte de procesos de subjetivación violenta y la normalización de la violencia sexual son ejes importantes de este escrito, que se dan a partir de las actualizaciones y virtualizaciones de la cultura de la violación en las redes sociales. El movimiento #MeToo fue uno de los primeros movimientos en las redes sociales que fomentó el uso del lenguaje como un poder subversivo para las lógicas violentas. Así, es a través del intercambio de denuncias que podemos percibir la existencia de la cultura de la violación en las redes sociales, muchas de las cuales están vinculadas al término alerta de activación. Utilizo la cartografía como método mientras la investigación continúa, transformándose, creando mapas ilimitados, cambiantes y transformadores. Como preguntas orientadoras, propuse pensar en las relaciones de poder en las que nos atravesamos, para subvertir los discursos misóginos, sexistas y opresivos. Como resultado, la producción de género y pornografía surge como producción de subjetividades violentas, que contribuyen al mantenimiento de la cultura de la violación y la normalización de la violencia sexual. La figura de Cyborg fue también una herramienta que permitió comprender las relaciones binarias entre naturaleza y tecnología, y el poder que existe en las transformaciones políticas y sociales para subvertir las lógicas que nos producen y nos dividen

Plant bioactives and redox signaling: (–)-Epicatechin as a paradigm

Polyphenols are bioactives claimed to be responsible for some of the health benefits provided by fruit and vegetables. It is currently accepted that the bioactivities of polyphenols can be mostly ascribed to their interactions with proteins and lipids. Such interactions can affect cell oxidant production and cell signaling, and explain in part the ability of polyphenols to promote health. EC can modulate redox sensitive signaling by: i) defining the extent of oxidant levels that can modify cell signaling, function, and fate, e.g. regulating enzymes that generate superoxide, hydrogen peroxide and nitric oxide; or ii) regulating the activation of transcription factors sensible to oxidants. The latter includes the regulation of the nuclear factor E2-related factor 2 (Nfr2) pathway, which in turn can promote the synthesis of antioxidant defenses, and of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kB) pathway, which mediates the expression of oxidants generating enzymes, as well as proteins not involved in redox reactions. In summary, a significant amount of data vindicates the participation of EC in redox regulated signaling pathways. Progress in the understanding of the molecular mechanisms involved in EC biological actions will help to define recommendations in terms of which fruit and vegetables are healthier and the amounts necessary to provide health effects.Fil: Fraga, César Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Bioquímica y Medicina Molecular. Universidad de Buenos Aires. Facultad Medicina. Instituto de Bioquímica y Medicina Molecular; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Química Analitica y Fisicoquímica. Cátedra de Fisicoquímica; ArgentinaFil: Oteiza, Patricia Isabel. University of California. Department of Nutrition and Department of Environmental Toxicology; Estados UnidosFil: Galleano, Mónica Liliana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Bioquímica y Medicina Molecular. Universidad de Buenos Aires. Facultad Medicina. Instituto de Bioquímica y Medicina Molecular; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Química Analitica y Fisicoquímica. Cátedra de Fisicoquímica; Argentin