Dentro del creciente interés por el medio acontecido, en el contexto norteamericano de finales de... more Dentro del creciente interés por el medio acontecido, en el contexto norteamericano de finales de los años sesenta, el programa Center for Advanced Visual Studies (CAVS), iniciado por György Kepes en el Instituto Tecnológico de Massachusetts (MIT) en 1967, sirvió de plataforma para vincular artistas, arquitectos y científicos en el diseño de entornos sostenibles. El aporte de esta investigación reside en detectar las estrategias de diseño medioambiental de las iniciativas artísticas y científicas desarrolladas por parte de la dirección y el estudiantado de dicho centro, en especial a través de unas propuestas que aunaban, por un lado, ciudad y naturaleza y, por otro, ciudad e información. El CAVS operó como una plataforma que amplió los discursos tradicionales de la arquitectura mediante la interacción directa y transversal con las artes, las ciencias y las coyunturas del momento histórico.Ante las urgencias sociales y ecológicas actuales, de alcance similar a aquellas que cincuenta...
DFT/MRCI quantum chemical studies suggest five excited electronic states to be involved in the pr... more DFT/MRCI quantum chemical studies suggest five excited electronic states to be involved in the prompt and delayed fluorescence emission of TpAT-tFFO.
Recent patents in allergy and immunology: New pyrazinones for the diagnosis of allergies to aminocephalosporins
Allergy, 2020
Cephalosporins are, after penicillins, the most important β-lactam inductors of immediate allergi... more Cephalosporins are, after penicillins, the most important β-lactam inductors of immediate allergic reactions. Their antigenic determinants are not completely identified due to difficulties for studying the structure of cephalosporin-protein conjugates, hampering the existence of in vitro tests with enough sensitivity to detect cephalosporin allergy.1 Therefore, the only diagnostic standardised options are skin tests and drug provocation tests, which are risky, especially in cases of severe reactions. This forces physicians to select alternative β-lactams that, although safe for penicillin/cephalosporin-allergic patients, could be less effective and pose problems related to costs and antibacterial-resistance.
Current gold standard for absolute quantitation of a specific DNA sequence is droplet digital PCR... more Current gold standard for absolute quantitation of a specific DNA sequence is droplet digital PCR (ddPCR), which has been applied to gene copy number variation (CNV) detection. However, the number of quantitation modules in ddPCR has been limited by fluorescence channels, which thus limits the CNV sensitivity due to sampling error following Poisson distribution. Here we develop a PCR-based molecular barcoding NGS approach, quantitative amplicon sequencing (QASeq), for accurate absolute quantitation which is compatible with high multiplexing to include over 200 quantitation modules. By attaching barcodes to individual target molecules with high efficiency, 2-plex QASeq exhibits higher and more consistent conversion yield than ddPCR in absolute molecule count quantitation. Multiplexed QASeq improves CNV sensitivity to allow confident distinguishment of 2.05 ploidy from normal 2.00 ploidy. We applied multiplexed QASeq to serial longitudinal plasma cfDNA samples from patients with metas...
Multireference quantum chemical calculations were performed in order to investigate the (reverse)... more Multireference quantum chemical calculations were performed in order to investigate the (reverse) intersystem crossing ((R)ISC) mechanisms of 4,5-di(9H-carbazol-9-yl)-phthalonitrile (2CzPN).
This study reports the antioxidant activity against singlet oxygen (1 O 2) of five newly synthesi... more This study reports the antioxidant activity against singlet oxygen (1 O 2) of five newly synthesized furanyl chalcones (FCs) (E)-3-(5-(4-chlorophenyl)furan-2-yl)-1-arylprop-2-en-1-ones (3a-e). Their structural difference is based on the aryl substituent as follows (Ar): 3a ¼ eC 6 H 4 eOCH 3 , 3b ¼ eC 6 H 3-(1,2-OCH 3), 3c ¼ eC 6 H 4 OC 6 H 4 , 3d ¼ eC 10 H 6-(OCH 3) and 3e ¼ eC 4 H 3 O. We used a Claisen-Schmidt condensation involving a 5-(4-chlorophenyl)furan-2-carbaldehyde and the corresponding ketones under ultrasonic irradiation. Their property to 1 O 2 quenching was analyzed in terms of the rate constant for the process (k Q at 25 C) determined by the SterneVolmer model in ethanol. For the compounds 3c, 3d and 3e, the k Q values are slightly larger respect to 3a and 3b. The FCs 3c behaves as the best quencher (k Q of 8.44 (±0.09) x 10 7 M À1 s À1). Geometry analysis and electronic structure calculations have been performed in the framework of Density Functional Theory (DFT) and DFT/Multi-Reference Configuration Interaction (DFT/MRCI) methods. According to DFT/MRCI, a physical quenching of 1 O 2 from the ground states of the FCs may not likely induce a spontaneous energy transfer processes but a chemical quenching mechanism may dominate the kinetics.
This article considers how financial mechanisms shape political and economic power around farmlan... more This article considers how financial mechanisms shape political and economic power around farmland. It draws on political ecology around the financialization of agriculture, and perspectives from Science and Technology Studies about performativity and topology to study how financial mechanisms in agriculture reconfigure networks of access to farmland for farmers, investors, workers and consumers. The article focuses on the case of Farmland Real Estate Investment Trusts (REITs) in the United States and shows REITS as sociotechnical assemblages of economic theories mobilized by investors and their representatives. Building on topologic ideas, the article highlights how financial mechanisms, such as REITs, shift networks of access to land. These mechanisms can profoundly shape landscapes and livelihoods by creating a market for farmland that transforms the connections of different actors with land, distancing workers and consumers from decision making processes while producing fluid and smooth access for investors. By studying REITs from the perspectives of economization and topology this article identifies key actors and mechanisms through which financialization is reconfiguring access to farmland and identifies limitations and opportunities for increased access to decisions about land for farmers, workers and consumers.
Environment and Planning E: Nature and Space, 2019
Work on global food systems has focused on the livelihoods of farmers directly affected as grower... more Work on global food systems has focused on the livelihoods of farmers directly affected as growers of agricultural export goods and has paid less attention to those who are left behind by new patterns of production and consumption. The connections between pre-existing agricultural livelihoods and the new systems of provision associated with fashionable products are poorly understood. Global trends in food culture have wide ranging local impacts. In this paper, we argue that researchers need to look beyond linear commodity chains and the goods that travel from producers in one country to consumers in another and expand global food systems analysis to understand what regional livelihoods are modified or displaced by globalized agriculture. Avocados are a popular health food among millennials. Colombia is experiencing a boom in exports. Avocados have long been grown in the Santander region, but global demand has turned them into a politically important crop. Using food systems analysis...
How do sexual difference and gender identity play out in interpersonal relationships within a mil... more How do sexual difference and gender identity play out in interpersonal relationships within a military context such as national service training, where participants are part-time soldiers and parttime civilians, as it were? These questions are explored in this autobiographical narrative non-fiction essay. The author reflects on the way military service training was romanticized as a calling, where the organization, the work and study, and the relationships between soldiers in training, were endowed with emotional significance; it was not merely a matter of technical up-skilling. This work will be useful for scholars, writers, and artists interested in embodiment in everyday military spaces, young women officers, performativity, feminist and queer approaches to military studies.
Nanomedicine: Nanotechnology, Biology and Medicine, 2019
We acknowledge the Rhône-Alpes Auvergne region for the financial support CLARA-Oncostarter (CVPPR... more We acknowledge the Rhône-Alpes Auvergne region for the financial support CLARA-Oncostarter (CVPPRCAN000162), Plan Cancer (C18038CS), ARC (RAC17012CCA and R17157CC) for their financial support.
The ethanolic extract of Syzygium cumini fruits was characterized and evaluated in the photogener... more The ethanolic extract of Syzygium cumini fruits was characterized and evaluated in the photogeneration of singlet oxygen (1 O 2) under visible light radiation. This process was studied from a theoretical approach by the survey of the generated electronic excited states, after photoexcitation of the most abundant anthocyanin of the extract, i.e. delphinidin-3,5-diglucoside. It was determinated that the adiabatic energy of the optimized T 1 (π H-1 →π L *) state was 1.55 eV and that the overall energy transfer releases ~0.58 eV in an exothermic process. Therefore, this state is the responsible of promoting electron transfer reactions and subsequent formation of 1 O 2 through illumination.
The possibility of dye charge recombination in DSSCs remains a challenge for the field. This cons... more The possibility of dye charge recombination in DSSCs remains a challenge for the field. This consists of: (a) back-transfer from the TiO to the oxidized dye and (b) intermolecular electron transfer between dyes. The latter is attributed to dye aggregation due to dimeric conformations. This leads to poor electron injection which decreases the photocurrent conversion efficiency. Most organic sensitizers are characterized by an Acceptor-Bridge-Donor (A-Bridge-D) arrangement that is commonly employed to provide charge separation and, therefore, lowering the unwanted back-transfer. Here, we address the intermolecular electron transfer by studying the dimerization and photovoltaic performance of a group of A-Bridge-D structured dyes. Specifically, eight famous sulfur containing π-bridges were analyzed (A and D remained fixed). Through quantum mechanical and molecular dynamics approaches, it was found that the formation of weakly stabilized dimers is allowed. The dyes with covalently bonde...
Dendrimeric Antigens (DeAns) consist of dendrimers decorated with multiple units of drug antigeni... more Dendrimeric Antigens (DeAns) consist of dendrimers decorated with multiple units of drug antigenic determinants. These conjugates have been shown to be a powerful tool for diagnosing penicillin allergy using in vitro immunoassays, in which they are recognized by specific IgE from allergic patients. Here we propose a new diagnostic approach using DeAns in cellular tests, in which recognition occurs through IgE bound to the basophil surface. Both IgE molecular recognition and subsequent cell activation may be influenced by the tridimensional architecture and size of the immunogens. Structural features of benzylpenicilloyl-DeAn and amoxicilloyl-DeAn (G2 and G4 PAMAM) were studied by diffusion Nuclear Magnetic Resonance (NMR) experiments and are discussed in relation to molecular dynamics simulation (MDS) observations. IgE recognition was clinically evaluated using the basophil activation test (BAT) for allergic patients and tolerant subjects. Diffusion NMR experiments, MDS and cellular...
Understanding how ultra-small gold nanoparticles (metal core ~ 1-1.5 nm), so-called gold nanoclus... more Understanding how ultra-small gold nanoparticles (metal core ~ 1-1.5 nm), so-called gold nanoclusters (Au NCs), interact with biological barriers has become highly important for their future bioapplications. The properties of Au NCs with tunable hydrophobicity were extensively characterized in different biological situations: i) interaction with serum in solution, ii) interaction with synthetic free-standing lipid bilayers integrated in a microfluidic device, and iii) cell studies with two different cell types (U87MG human primary glioblastoma and A375 melanoma cell lines). Our results indicate a significant impact of the precise tailoring of the hydrophilicity/hydrophobicity balance on the Au NC surfaces, which could prevent the formation of biomolecular absorption while maintaining excellent colloidal stability in solutions with high serum contents. Increasing the surface hydrophobicity of the Au NCs enabled more efficient lipid bilayer membrane insertion and induced faster cellular uptake. We showed the existence of a hydrophobicity threshold, which resulted in colloidal instability, lipid bilayer damage, and acute cytotoxicity. We also demonstrated a significant influence of metal-ligand shell hydrophobicity on the fluorescence signal of the Au NCs, increasing it in the near-infrared region. A twofold signal enhancement was achieved by simple replacement of methyl groups with ethyl groups.
Anaphylaxis is an acute, life-threatening, multisystem syndrome resulting from the sudden release... more Anaphylaxis is an acute, life-threatening, multisystem syndrome resulting from the sudden release of mediators by mast cells and basophils. Although anaphylaxis is often under-communicated and thus underestimated, its incidence appears to have risen over recent decades. Drugs are among the most common triggers in adults, being analgesics and antibiotics the most common causal agents. Anaphylaxis can be caused by immunologic or non-immunologic mechanisms. Immunologic anaphylaxis can be mediated by IgE-dependent or -independent pathways. The former involves activation of Th2 cells and the cross-linking of two or more specific IgE (sIgE) antibodies on the surface of mast cells or basophils. The IgE-independent mechanism can be mediated by IgG, involving the release of platelet-activating factor, and/or complement activation. Non-immunological anaphylaxis can occur through the direct stimulation of mast cell degranulation by some drugs, inducing histamine release and leading to anaphyla...
RATIONALE: Clavulanic acid (CLV) is a betalactam which inhibits betalactamases activity and is fr... more RATIONALE: Clavulanic acid (CLV) is a betalactam which inhibits betalactamases activity and is frequently administered combined with amoxicillin. Lately, immediate allergic reactions to CLV have been reported in 30% of patients allergic to Amoxicillin-CLV. Since protein haptenation with betalactams is known to be necessary to activate the immune system, the objective was to study haptenation and develop tools to identify CLV target proteins. METHODS: Human serum albumin (HSA) was incubated with increasing concentrations of CLV. Conjugates were purified by filtration and characterized by MALDI-TOF-MS. Biotinylated CLV (CLV-B) was synthesized introducing an oxygenated linker between CLV and a biotin moiety, for studying haptenation of human serum proteins. HSA and serum were incubated with increasing concentrations of CLV-B. The grade of biotinylation was determined by electrophoresis using biotinylated BSA as calibrator. Modified serum proteins were separated by SDS-PAGE and detected using HRP-streptavidin. 2D-electrophoresis was carried out for analysis of serum modification. RESULTS: Both CLV and CLV-B modified HSA (Dm5279.8 and Dm5543.0 respectively, compared with HSA control). Modification was proportional to the amount of CLVor CLV-B used during incubation. CLV-B was used as a sensitive tool to find out serum proteins target of haptenation. HSA, transferrin and heavy and light chains of immunoglobulins were identified as modified proteins. CONCLUSIONS: Our results show that CLV-B is a valuable tool for the identification of CLV targets with high sensitivity. The elucidation and comparison of CLV and CLV-B reactivity during conjugation deserve further study to finally understand the activation of the immune system by CLV.
RATIONALE: Clavulanic acid (CLV) is a betalactam which inhibits betalactamases activity and is fr... more RATIONALE: Clavulanic acid (CLV) is a betalactam which inhibits betalactamases activity and is frequently administered combined with amoxicillin. Lately, immediate allergic reactions to CLV have been reported in 30% of patients allergic to Amoxicillin-CLV. Since protein haptenation with betalactams is known to be necessary to activate the immune system, the objective was to study haptenation and develop tools to identify CLV target proteins. METHODS: Human serum albumin (HSA) was incubated with increasing concentrations of CLV. Conjugates were purified by filtration and characterized by MALDI-TOF-MS. Biotinylated CLV (CLV-B) was synthesized introducing an oxygenated linker between CLV and a biotin moiety, for studying haptenation of human serum proteins. HSA and serum were incubated with increasing concentrations of CLV-B. The grade of biotinylation was determined by electrophoresis using biotinylated BSA as calibrator. Modified serum proteins were separated by SDS-PAGE and detected using HRP-streptavidin. 2D-electrophoresis was carried out for analysis of serum modification. RESULTS: Both CLV and CLV-B modified HSA (Dm5279.8 and Dm5543.0 respectively, compared with HSA control). Modification was proportional to the amount of CLVor CLV-B used during incubation. CLV-B was used as a sensitive tool to find out serum proteins target of haptenation. HSA, transferrin and heavy and light chains of immunoglobulins were identified as modified proteins. CONCLUSIONS: Our results show that CLV-B is a valuable tool for the identification of CLV targets with high sensitivity. The elucidation and comparison of CLV and CLV-B reactivity during conjugation deserve further study to finally understand the activation of the immune system by CLV.
Dentro del creciente interés por el medio acontecido, en el contexto norteamericano de finales de... more Dentro del creciente interés por el medio acontecido, en el contexto norteamericano de finales de los años sesenta, el programa Center for Advanced Visual Studies (CAVS), iniciado por György Kepes en el Instituto Tecnológico de Massachusetts (MIT) en 1967, sirvió de plataforma para vincular artistas, arquitectos y científicos en el diseño de entornos sostenibles. El aporte de esta investigación reside en detectar las estrategias de diseño medioambiental de las iniciativas artísticas y científicas desarrolladas por parte de la dirección y el estudiantado de dicho centro, en especial a través de unas propuestas que aunaban, por un lado, ciudad y naturaleza y, por otro, ciudad e información. El CAVS operó como una plataforma que amplió los discursos tradicionales de la arquitectura mediante la interacción directa y transversal con las artes, las ciencias y las coyunturas del momento histórico.Ante las urgencias sociales y ecológicas actuales, de alcance similar a aquellas que cincuenta...
DFT/MRCI quantum chemical studies suggest five excited electronic states to be involved in the pr... more DFT/MRCI quantum chemical studies suggest five excited electronic states to be involved in the prompt and delayed fluorescence emission of TpAT-tFFO.
Recent patents in allergy and immunology: New pyrazinones for the diagnosis of allergies to aminocephalosporins
Allergy, 2020
Cephalosporins are, after penicillins, the most important β-lactam inductors of immediate allergi... more Cephalosporins are, after penicillins, the most important β-lactam inductors of immediate allergic reactions. Their antigenic determinants are not completely identified due to difficulties for studying the structure of cephalosporin-protein conjugates, hampering the existence of in vitro tests with enough sensitivity to detect cephalosporin allergy.1 Therefore, the only diagnostic standardised options are skin tests and drug provocation tests, which are risky, especially in cases of severe reactions. This forces physicians to select alternative β-lactams that, although safe for penicillin/cephalosporin-allergic patients, could be less effective and pose problems related to costs and antibacterial-resistance.
Current gold standard for absolute quantitation of a specific DNA sequence is droplet digital PCR... more Current gold standard for absolute quantitation of a specific DNA sequence is droplet digital PCR (ddPCR), which has been applied to gene copy number variation (CNV) detection. However, the number of quantitation modules in ddPCR has been limited by fluorescence channels, which thus limits the CNV sensitivity due to sampling error following Poisson distribution. Here we develop a PCR-based molecular barcoding NGS approach, quantitative amplicon sequencing (QASeq), for accurate absolute quantitation which is compatible with high multiplexing to include over 200 quantitation modules. By attaching barcodes to individual target molecules with high efficiency, 2-plex QASeq exhibits higher and more consistent conversion yield than ddPCR in absolute molecule count quantitation. Multiplexed QASeq improves CNV sensitivity to allow confident distinguishment of 2.05 ploidy from normal 2.00 ploidy. We applied multiplexed QASeq to serial longitudinal plasma cfDNA samples from patients with metas...
Multireference quantum chemical calculations were performed in order to investigate the (reverse)... more Multireference quantum chemical calculations were performed in order to investigate the (reverse) intersystem crossing ((R)ISC) mechanisms of 4,5-di(9H-carbazol-9-yl)-phthalonitrile (2CzPN).
This study reports the antioxidant activity against singlet oxygen (1 O 2) of five newly synthesi... more This study reports the antioxidant activity against singlet oxygen (1 O 2) of five newly synthesized furanyl chalcones (FCs) (E)-3-(5-(4-chlorophenyl)furan-2-yl)-1-arylprop-2-en-1-ones (3a-e). Their structural difference is based on the aryl substituent as follows (Ar): 3a ¼ eC 6 H 4 eOCH 3 , 3b ¼ eC 6 H 3-(1,2-OCH 3), 3c ¼ eC 6 H 4 OC 6 H 4 , 3d ¼ eC 10 H 6-(OCH 3) and 3e ¼ eC 4 H 3 O. We used a Claisen-Schmidt condensation involving a 5-(4-chlorophenyl)furan-2-carbaldehyde and the corresponding ketones under ultrasonic irradiation. Their property to 1 O 2 quenching was analyzed in terms of the rate constant for the process (k Q at 25 C) determined by the SterneVolmer model in ethanol. For the compounds 3c, 3d and 3e, the k Q values are slightly larger respect to 3a and 3b. The FCs 3c behaves as the best quencher (k Q of 8.44 (±0.09) x 10 7 M À1 s À1). Geometry analysis and electronic structure calculations have been performed in the framework of Density Functional Theory (DFT) and DFT/Multi-Reference Configuration Interaction (DFT/MRCI) methods. According to DFT/MRCI, a physical quenching of 1 O 2 from the ground states of the FCs may not likely induce a spontaneous energy transfer processes but a chemical quenching mechanism may dominate the kinetics.
This article considers how financial mechanisms shape political and economic power around farmlan... more This article considers how financial mechanisms shape political and economic power around farmland. It draws on political ecology around the financialization of agriculture, and perspectives from Science and Technology Studies about performativity and topology to study how financial mechanisms in agriculture reconfigure networks of access to farmland for farmers, investors, workers and consumers. The article focuses on the case of Farmland Real Estate Investment Trusts (REITs) in the United States and shows REITS as sociotechnical assemblages of economic theories mobilized by investors and their representatives. Building on topologic ideas, the article highlights how financial mechanisms, such as REITs, shift networks of access to land. These mechanisms can profoundly shape landscapes and livelihoods by creating a market for farmland that transforms the connections of different actors with land, distancing workers and consumers from decision making processes while producing fluid and smooth access for investors. By studying REITs from the perspectives of economization and topology this article identifies key actors and mechanisms through which financialization is reconfiguring access to farmland and identifies limitations and opportunities for increased access to decisions about land for farmers, workers and consumers.
Environment and Planning E: Nature and Space, 2019
Work on global food systems has focused on the livelihoods of farmers directly affected as grower... more Work on global food systems has focused on the livelihoods of farmers directly affected as growers of agricultural export goods and has paid less attention to those who are left behind by new patterns of production and consumption. The connections between pre-existing agricultural livelihoods and the new systems of provision associated with fashionable products are poorly understood. Global trends in food culture have wide ranging local impacts. In this paper, we argue that researchers need to look beyond linear commodity chains and the goods that travel from producers in one country to consumers in another and expand global food systems analysis to understand what regional livelihoods are modified or displaced by globalized agriculture. Avocados are a popular health food among millennials. Colombia is experiencing a boom in exports. Avocados have long been grown in the Santander region, but global demand has turned them into a politically important crop. Using food systems analysis...
How do sexual difference and gender identity play out in interpersonal relationships within a mil... more How do sexual difference and gender identity play out in interpersonal relationships within a military context such as national service training, where participants are part-time soldiers and parttime civilians, as it were? These questions are explored in this autobiographical narrative non-fiction essay. The author reflects on the way military service training was romanticized as a calling, where the organization, the work and study, and the relationships between soldiers in training, were endowed with emotional significance; it was not merely a matter of technical up-skilling. This work will be useful for scholars, writers, and artists interested in embodiment in everyday military spaces, young women officers, performativity, feminist and queer approaches to military studies.
Nanomedicine: Nanotechnology, Biology and Medicine, 2019
We acknowledge the Rhône-Alpes Auvergne region for the financial support CLARA-Oncostarter (CVPPR... more We acknowledge the Rhône-Alpes Auvergne region for the financial support CLARA-Oncostarter (CVPPRCAN000162), Plan Cancer (C18038CS), ARC (RAC17012CCA and R17157CC) for their financial support.
The ethanolic extract of Syzygium cumini fruits was characterized and evaluated in the photogener... more The ethanolic extract of Syzygium cumini fruits was characterized and evaluated in the photogeneration of singlet oxygen (1 O 2) under visible light radiation. This process was studied from a theoretical approach by the survey of the generated electronic excited states, after photoexcitation of the most abundant anthocyanin of the extract, i.e. delphinidin-3,5-diglucoside. It was determinated that the adiabatic energy of the optimized T 1 (π H-1 →π L *) state was 1.55 eV and that the overall energy transfer releases ~0.58 eV in an exothermic process. Therefore, this state is the responsible of promoting electron transfer reactions and subsequent formation of 1 O 2 through illumination.
The possibility of dye charge recombination in DSSCs remains a challenge for the field. This cons... more The possibility of dye charge recombination in DSSCs remains a challenge for the field. This consists of: (a) back-transfer from the TiO to the oxidized dye and (b) intermolecular electron transfer between dyes. The latter is attributed to dye aggregation due to dimeric conformations. This leads to poor electron injection which decreases the photocurrent conversion efficiency. Most organic sensitizers are characterized by an Acceptor-Bridge-Donor (A-Bridge-D) arrangement that is commonly employed to provide charge separation and, therefore, lowering the unwanted back-transfer. Here, we address the intermolecular electron transfer by studying the dimerization and photovoltaic performance of a group of A-Bridge-D structured dyes. Specifically, eight famous sulfur containing π-bridges were analyzed (A and D remained fixed). Through quantum mechanical and molecular dynamics approaches, it was found that the formation of weakly stabilized dimers is allowed. The dyes with covalently bonde...
Dendrimeric Antigens (DeAns) consist of dendrimers decorated with multiple units of drug antigeni... more Dendrimeric Antigens (DeAns) consist of dendrimers decorated with multiple units of drug antigenic determinants. These conjugates have been shown to be a powerful tool for diagnosing penicillin allergy using in vitro immunoassays, in which they are recognized by specific IgE from allergic patients. Here we propose a new diagnostic approach using DeAns in cellular tests, in which recognition occurs through IgE bound to the basophil surface. Both IgE molecular recognition and subsequent cell activation may be influenced by the tridimensional architecture and size of the immunogens. Structural features of benzylpenicilloyl-DeAn and amoxicilloyl-DeAn (G2 and G4 PAMAM) were studied by diffusion Nuclear Magnetic Resonance (NMR) experiments and are discussed in relation to molecular dynamics simulation (MDS) observations. IgE recognition was clinically evaluated using the basophil activation test (BAT) for allergic patients and tolerant subjects. Diffusion NMR experiments, MDS and cellular...
Understanding how ultra-small gold nanoparticles (metal core ~ 1-1.5 nm), so-called gold nanoclus... more Understanding how ultra-small gold nanoparticles (metal core ~ 1-1.5 nm), so-called gold nanoclusters (Au NCs), interact with biological barriers has become highly important for their future bioapplications. The properties of Au NCs with tunable hydrophobicity were extensively characterized in different biological situations: i) interaction with serum in solution, ii) interaction with synthetic free-standing lipid bilayers integrated in a microfluidic device, and iii) cell studies with two different cell types (U87MG human primary glioblastoma and A375 melanoma cell lines). Our results indicate a significant impact of the precise tailoring of the hydrophilicity/hydrophobicity balance on the Au NC surfaces, which could prevent the formation of biomolecular absorption while maintaining excellent colloidal stability in solutions with high serum contents. Increasing the surface hydrophobicity of the Au NCs enabled more efficient lipid bilayer membrane insertion and induced faster cellular uptake. We showed the existence of a hydrophobicity threshold, which resulted in colloidal instability, lipid bilayer damage, and acute cytotoxicity. We also demonstrated a significant influence of metal-ligand shell hydrophobicity on the fluorescence signal of the Au NCs, increasing it in the near-infrared region. A twofold signal enhancement was achieved by simple replacement of methyl groups with ethyl groups.
Anaphylaxis is an acute, life-threatening, multisystem syndrome resulting from the sudden release... more Anaphylaxis is an acute, life-threatening, multisystem syndrome resulting from the sudden release of mediators by mast cells and basophils. Although anaphylaxis is often under-communicated and thus underestimated, its incidence appears to have risen over recent decades. Drugs are among the most common triggers in adults, being analgesics and antibiotics the most common causal agents. Anaphylaxis can be caused by immunologic or non-immunologic mechanisms. Immunologic anaphylaxis can be mediated by IgE-dependent or -independent pathways. The former involves activation of Th2 cells and the cross-linking of two or more specific IgE (sIgE) antibodies on the surface of mast cells or basophils. The IgE-independent mechanism can be mediated by IgG, involving the release of platelet-activating factor, and/or complement activation. Non-immunological anaphylaxis can occur through the direct stimulation of mast cell degranulation by some drugs, inducing histamine release and leading to anaphyla...
RATIONALE: Clavulanic acid (CLV) is a betalactam which inhibits betalactamases activity and is fr... more RATIONALE: Clavulanic acid (CLV) is a betalactam which inhibits betalactamases activity and is frequently administered combined with amoxicillin. Lately, immediate allergic reactions to CLV have been reported in 30% of patients allergic to Amoxicillin-CLV. Since protein haptenation with betalactams is known to be necessary to activate the immune system, the objective was to study haptenation and develop tools to identify CLV target proteins. METHODS: Human serum albumin (HSA) was incubated with increasing concentrations of CLV. Conjugates were purified by filtration and characterized by MALDI-TOF-MS. Biotinylated CLV (CLV-B) was synthesized introducing an oxygenated linker between CLV and a biotin moiety, for studying haptenation of human serum proteins. HSA and serum were incubated with increasing concentrations of CLV-B. The grade of biotinylation was determined by electrophoresis using biotinylated BSA as calibrator. Modified serum proteins were separated by SDS-PAGE and detected using HRP-streptavidin. 2D-electrophoresis was carried out for analysis of serum modification. RESULTS: Both CLV and CLV-B modified HSA (Dm5279.8 and Dm5543.0 respectively, compared with HSA control). Modification was proportional to the amount of CLVor CLV-B used during incubation. CLV-B was used as a sensitive tool to find out serum proteins target of haptenation. HSA, transferrin and heavy and light chains of immunoglobulins were identified as modified proteins. CONCLUSIONS: Our results show that CLV-B is a valuable tool for the identification of CLV targets with high sensitivity. The elucidation and comparison of CLV and CLV-B reactivity during conjugation deserve further study to finally understand the activation of the immune system by CLV.
RATIONALE: Clavulanic acid (CLV) is a betalactam which inhibits betalactamases activity and is fr... more RATIONALE: Clavulanic acid (CLV) is a betalactam which inhibits betalactamases activity and is frequently administered combined with amoxicillin. Lately, immediate allergic reactions to CLV have been reported in 30% of patients allergic to Amoxicillin-CLV. Since protein haptenation with betalactams is known to be necessary to activate the immune system, the objective was to study haptenation and develop tools to identify CLV target proteins. METHODS: Human serum albumin (HSA) was incubated with increasing concentrations of CLV. Conjugates were purified by filtration and characterized by MALDI-TOF-MS. Biotinylated CLV (CLV-B) was synthesized introducing an oxygenated linker between CLV and a biotin moiety, for studying haptenation of human serum proteins. HSA and serum were incubated with increasing concentrations of CLV-B. The grade of biotinylation was determined by electrophoresis using biotinylated BSA as calibrator. Modified serum proteins were separated by SDS-PAGE and detected using HRP-streptavidin. 2D-electrophoresis was carried out for analysis of serum modification. RESULTS: Both CLV and CLV-B modified HSA (Dm5279.8 and Dm5543.0 respectively, compared with HSA control). Modification was proportional to the amount of CLVor CLV-B used during incubation. CLV-B was used as a sensitive tool to find out serum proteins target of haptenation. HSA, transferrin and heavy and light chains of immunoglobulins were identified as modified proteins. CONCLUSIONS: Our results show that CLV-B is a valuable tool for the identification of CLV targets with high sensitivity. The elucidation and comparison of CLV and CLV-B reactivity during conjugation deserve further study to finally understand the activation of the immune system by CLV.
Uploads
Papers by Angela Serrano