Maria Amaro - Academia.edu (original) (raw)
Papers by Maria Amaro
Saber, Sep 21, 2012
Se evaluó la actividad hemaglutinante y hemolítica de las esponjas Niphates erecta y Callyspongia... more Se evaluó la actividad hemaglutinante y hemolítica de las esponjas Niphates erecta y Callyspongia vaginalis (Porifera, Demospongiae), sobre eritrocitos humanos del sistema ABO(H). Los ejemplares fueron recolectados manualmente en la punta "El Toro", Parque Nacional Mochima, estado Sucre y sometidos a procesos de limpieza y liofilización. Del producto liofilizado de cada especie se preparó un extracto acuoso, al cual le fueron precipitadas, concentradas, separadas por exclusión molecular las proteínas activas y evaluada su pureza por la técnica electroforética (SDS-PAGE). Para la detección de aglutininas y hemolisinas se prepararon suspensiones sanguíneas al 5% de muestras de sangre humana de los tipos A, B y O, evidenciándose dichas actividades por la formación de grumos o las transformaciones físicas de viscosidad y color de cada una de las muestras, respectivamente. A los extractos acuosos se les determinó la presencia de compuestos de las familias químicas saponinas y polifenoles, arrojando resultados positivos solo para saponinas. Tanto la actividad hemaglutinante como la hemolítica fueron exhibidas por el extracto acuoso y el precipitado de proteínas de ambas esponjas, manteniéndose esta última actividad en el fraccionamiento de las mismas. Las proteínas líticas purificadas, arrojaron masas molares aproximadas de 45 kDa para N. erecta y de menos de 14,3 kDa para C. vaginalis. Estos resultados permiten inferir que la actividad hemaglutinante puede deberse a la presencia de proteínas aglutinantes y que la actividad hemolítica podría atribuirse tanto a las saponinas encontradas en los extractos acuosos, como a las proteínas líticas purificadas del precipitado de proteínas.
Bol. Inst. Oceanog. …, 2004
Coral Reefs, 2014
The first incidence of an alien soft coral of the family Xeniidae in the Caribbean, an invasion i... more The first incidence of an alien soft coral of the family Xeniidae in the Caribbean, an invasion in eastern Venezuelan coral communities Octocorals in family Xeniidae (Ehrenberg, 1828) constitute an abundant component of many Indo-Pacific coral reefs. Several xeniids are ephemeral pioneers, with rapid growth rates, high fecundity, and extensive vegetative reproduction (Benayahu and Loya 1985). There is increased evidence that opportunistic Xeniidae are taking over degraded reef substrata (Tilot et al. 2008) and have thus become highly relevant to ecological processes on coral reefs, affecting their colonization, restoration, and function. An invasive xeniid soft coral with close genetic affinities to Xenia membranacea Schenk 1896 from Indonesia (C.S. McFadden pers comm) was first found in 2007 on the coastal coral community of Valle Seco (northeast Venezuela, 10°14.6 N; 64°31.70 W). At that time, a single colony was found growing on a dead stony coral and subsequently found on coral rubble, sand, and debris. Since then, it has increased in abundance, spreading several km away to Conoma Bay and Mono Island, occupying~20 % of the substratum. Abundance fluctuates, with a decrease during the rainy season. This soft coral inhabits both soft and hard substrata, including introduced debris, in well-illuminated habitats (0.5-4 m). It overgrows scleractinian corals, such as Colpophyllia natans (Fig. 1a), Diploria strigosa (Fig. 1a), Orbicella annularis, Montastraea cavernosa, and the hydrocoral Millepora alcicornis (Fig. 1b), the latter being a principal component of the coral communities. Biodiversity at the sites has deteriorated, mainly due to the loss of living stony coral coverage. The current findings are the first report of an invasive soft coral of the Xeniidae and its expansion beyond the Indo-Pacific region. It appears to have been illegally introduced into Venezuela by commercial aquarists and intentionally seeded in the rocky substrate for propagation and farming purposes. There has been no attempt to remove the species. The ecological consequences of the invasion, and both spatial and temporal changes in its spread, should undoubtedly be carefully monitored.
Revista Portuguesa de Cardiologia, 2014
Studies in health technology and informatics, 2007
The use of communication technologies may overcome some of the difficulties of conventional, pape... more The use of communication technologies may overcome some of the difficulties of conventional, paper-based, self-management of chronic diseases. This paper aims to describe and evaluate the use of P'ASMA - a web based asthma self-management support tool regarding the opinion of patients and their adherence to monitoring in comparison to standard paper-based tools. P'ASMA allows the collection of asthma monitoring data and provides, to both patient and doctor, immediate feedback about patient's condition. For each patient a set of forms and scheduling options can be chosen. Twenty-one adults with previous medical diagnosis of asthma were included in an exploratory randomized crossover study. Patients used…
Journal of Medical Virology, 1997
Nitric oxide is a free radical gas molecule which may be implicated in antiviral defense. However... more Nitric oxide is a free radical gas molecule which may be implicated in antiviral defense. However, there is no information about its possible role in chronic viral hepatitis B and C. In this study we have analyzed the serum levels of NO2- (as an index of nitric oxide generation) from patients with chronic viral hepatitis B and C and relationship of same with the response to interferon therapy. Serum samples were analysed from 61 patients with chronic hepatitis B, 60 patients with chronic hepatitis C, 11 with chronic liver disease of nonviral origin, and 23 healthy controls. Levels of NO2- were statistically higher in healthy controls (P < 0.001) than in patients with chronic liver disease. No relation was found between NO2- and viremia or response to interferon therapy in patients with chronic hepatitis B. In contrast in chronic hepatitis C, responder patients had significantly higher NO2- than nonresponders (P < 0.01). With respect to the relation between NO2- levels and liver damage, patients with cirrhosis had lower NO2- levels than the rest of the patients (P < 0.001). In conclusion, patients with chronic viral hepatitis have low serum NO2- levels.
Intervirology, 1998
The nucleotide sequence of hepatitis GB virus type C (HGBV-C)/hepatitis G virus (HGV) NS3/helicas... more The nucleotide sequence of hepatitis GB virus type C (HGBV-C)/hepatitis G virus (HGV) NS3/helicase and 5'-untranslated regions from 23 Spanish patients were analyzed to assign the HGV isolates one of the proposed HGBV-C/HGV genotypes. The analysis of the evolutionary distance frequency showed that the distances among all sequences in NS3/helicase region were distributed around a single peak of 0.20, suggesting that all included sequences belonged to the same HGBV-C/HGV genotype. By contrast, in the 5'-untranslated region, all the distances corresponding to our sequences and those of the HGBV-C/HGV types 2 and 3 were distributed around a major peak of 0.03. The remaining distances corresponding to the HGBV-C/HGV type 1 sequences were distributed around a minor peak of 0.11. The phylogenetic tree and pairwise comparison of evolutionary distances among the 5'-untranslated region of the infected patients and each HGBV-C/HGV genotype demonstrated that our HGBV-C/HGV isolates belonged to subtype 2a (17/23; 78%) and 2b (5/23; 22%). No relation was found between HGBV-C/HGV subtype and hepatitis B or C virus infection.
Pharmaceutical Research, 2014
To formulate and investigate the physicochemical properties, physical stability and aerosolizatio... more To formulate and investigate the physicochemical properties, physical stability and aerosolization characteristics of nanoporous/nanoparticulate microparticles (NPMPs) prepared by co-spray drying the sugars raffinose pentahydrate (R) or trehalose dihydrate (T) with the cyclic oligosaccharide hydroxypropyl-β-cyclodextrin (HPβCD). Production of powders was carried out using a laboratory scale spray dryer. The resulting powders were characterised by X-ray powder diffraction (XRPD), scanning electron microscopy (SEM), laser diffraction particle sizing, specific surface area analysis (SSA), Fourier transform infrared (FTIR), differential scanning calorimetry (DSC), dynamic vapour sorption (DVS) and aerodynamic assessment using a Next Generation Impactor (NGI). Powders were amorphous and composed of spherical, porous microparticles with reduced particle size and high specific surface area (~100 m(2)/g). DSC scans showed a single glass transition temperature. FTIR was indicative of the existence of molecular interactions between the carbohydrates. DVS analysis showed an increase in the critical relative humidity (RH) of raffinose and trehalose and eventual crystallization inhibition with increasing concentration of HPβCD. The in vitro deposition showed powders formulated with HPβCD had higher recovered emitted dose and fine particle fraction (<5 μm) than raffinose and trehalose spray dried alone. The co-spray drying of raffinose or trehalose with HPβCD results in powders with improved physicochemical characteristics, physical stability and aerodynamic behaviour compared to spray-dried raffinose/trehalose particles, constituting improved potential drug-carrier systems for pulmonary delivery.
The present study investigated the effect of operating parameters of a laboratory spray dryer on ... more The present study investigated the effect of operating parameters of a laboratory spray dryer on powder characteristics, in order to optimise the production of trehalose and raffinose powders, intended to be used as carriers of biomolecules for inhalation.
Toxicology Letters, 1998
79 described in a case series. Future studies need to examine the role of HBOf in preventing PNS ... more 79 described in a case series. Future studies need to examine the role of HBOf in preventing PNS following chronic CO exposure.
Toxicology Letters, 1998
79 described in a case series. Future studies need to examine the role of HBOf in preventing PNS ... more 79 described in a case series. Future studies need to examine the role of HBOf in preventing PNS following chronic CO exposure.
Advanced Drug Delivery Reviews, 2014
Dry powder inhaler (DPI) products have traditionally comprised a simple formulation of micronised... more Dry powder inhaler (DPI) products have traditionally comprised a simple formulation of micronised drug mixed with a carrier excipient, typically lactose monohydrate. The presence of the carrier is aimed at overcoming issues of poor flowability and dispersibility, associated with the cohesive nature of small, micronised active pharmaceutical ingredient (API) particles. Both the powder blend and the DPI device must be carefully designed so as to ensure detachment of the micronised drug from the carrier excipient on inhalation. Over the last two decades there has been a significant body of research undertaken on the design of carrier-free formulations for DPI products. Many of these formulations are based on sophisticated particle engineering techniques; a common aim in formulation design of carrier-free products being to reduce the intrinsic cohesion of the particles, while maximising dispersion and delivery from the inhaler. In tandem with the development of alternative formulations has been the development of devices designed to ensure the efficient delivery and dispersion of carrier-free powder on inhalation. In this review we examine approaches to both the powder formulation and inhaler design for carrier-free DPI products.
Journal of Molecular Structure, 2006
... all (9h9k). Given that the LUMO is an empty orbital the first electron that enters the molec... more ... all (9h9k). Given that the LUMO is an empty orbital the first electron that enters the molecule will likely go to it. In the ... 4.575 debye, respectively. Inactive compounds have values that go from 2.30 to 2.57 debye. Partition coefficient ...
Food Research International, 2009
A great number of antioxidants are naturally present in citrus juice, being responsible for their... more A great number of antioxidants are naturally present in citrus juice, being responsible for their potentially protective action against inflammation. Naringin, a bitter compound, in citrus, is hydrolysed by naringinase into tasteless naringenin and to rhamnose and glucose. The aim of this study was to evaluate the anti-inflammatory activity of naringin and naringenin in an acute model of induced colitis in mice. Microstructured particles were used for naringinase immobilization. The influence of naringin and naringinase concentration on the bioconversion was evaluated through a central composite design.
Saber, Sep 21, 2012
Se evaluó la actividad hemaglutinante y hemolítica de las esponjas Niphates erecta y Callyspongia... more Se evaluó la actividad hemaglutinante y hemolítica de las esponjas Niphates erecta y Callyspongia vaginalis (Porifera, Demospongiae), sobre eritrocitos humanos del sistema ABO(H). Los ejemplares fueron recolectados manualmente en la punta "El Toro", Parque Nacional Mochima, estado Sucre y sometidos a procesos de limpieza y liofilización. Del producto liofilizado de cada especie se preparó un extracto acuoso, al cual le fueron precipitadas, concentradas, separadas por exclusión molecular las proteínas activas y evaluada su pureza por la técnica electroforética (SDS-PAGE). Para la detección de aglutininas y hemolisinas se prepararon suspensiones sanguíneas al 5% de muestras de sangre humana de los tipos A, B y O, evidenciándose dichas actividades por la formación de grumos o las transformaciones físicas de viscosidad y color de cada una de las muestras, respectivamente. A los extractos acuosos se les determinó la presencia de compuestos de las familias químicas saponinas y polifenoles, arrojando resultados positivos solo para saponinas. Tanto la actividad hemaglutinante como la hemolítica fueron exhibidas por el extracto acuoso y el precipitado de proteínas de ambas esponjas, manteniéndose esta última actividad en el fraccionamiento de las mismas. Las proteínas líticas purificadas, arrojaron masas molares aproximadas de 45 kDa para N. erecta y de menos de 14,3 kDa para C. vaginalis. Estos resultados permiten inferir que la actividad hemaglutinante puede deberse a la presencia de proteínas aglutinantes y que la actividad hemolítica podría atribuirse tanto a las saponinas encontradas en los extractos acuosos, como a las proteínas líticas purificadas del precipitado de proteínas.
Bol. Inst. Oceanog. …, 2004
Coral Reefs, 2014
The first incidence of an alien soft coral of the family Xeniidae in the Caribbean, an invasion i... more The first incidence of an alien soft coral of the family Xeniidae in the Caribbean, an invasion in eastern Venezuelan coral communities Octocorals in family Xeniidae (Ehrenberg, 1828) constitute an abundant component of many Indo-Pacific coral reefs. Several xeniids are ephemeral pioneers, with rapid growth rates, high fecundity, and extensive vegetative reproduction (Benayahu and Loya 1985). There is increased evidence that opportunistic Xeniidae are taking over degraded reef substrata (Tilot et al. 2008) and have thus become highly relevant to ecological processes on coral reefs, affecting their colonization, restoration, and function. An invasive xeniid soft coral with close genetic affinities to Xenia membranacea Schenk 1896 from Indonesia (C.S. McFadden pers comm) was first found in 2007 on the coastal coral community of Valle Seco (northeast Venezuela, 10°14.6 N; 64°31.70 W). At that time, a single colony was found growing on a dead stony coral and subsequently found on coral rubble, sand, and debris. Since then, it has increased in abundance, spreading several km away to Conoma Bay and Mono Island, occupying~20 % of the substratum. Abundance fluctuates, with a decrease during the rainy season. This soft coral inhabits both soft and hard substrata, including introduced debris, in well-illuminated habitats (0.5-4 m). It overgrows scleractinian corals, such as Colpophyllia natans (Fig. 1a), Diploria strigosa (Fig. 1a), Orbicella annularis, Montastraea cavernosa, and the hydrocoral Millepora alcicornis (Fig. 1b), the latter being a principal component of the coral communities. Biodiversity at the sites has deteriorated, mainly due to the loss of living stony coral coverage. The current findings are the first report of an invasive soft coral of the Xeniidae and its expansion beyond the Indo-Pacific region. It appears to have been illegally introduced into Venezuela by commercial aquarists and intentionally seeded in the rocky substrate for propagation and farming purposes. There has been no attempt to remove the species. The ecological consequences of the invasion, and both spatial and temporal changes in its spread, should undoubtedly be carefully monitored.
Revista Portuguesa de Cardiologia, 2014
Studies in health technology and informatics, 2007
The use of communication technologies may overcome some of the difficulties of conventional, pape... more The use of communication technologies may overcome some of the difficulties of conventional, paper-based, self-management of chronic diseases. This paper aims to describe and evaluate the use of P'ASMA - a web based asthma self-management support tool regarding the opinion of patients and their adherence to monitoring in comparison to standard paper-based tools. P'ASMA allows the collection of asthma monitoring data and provides, to both patient and doctor, immediate feedback about patient's condition. For each patient a set of forms and scheduling options can be chosen. Twenty-one adults with previous medical diagnosis of asthma were included in an exploratory randomized crossover study. Patients used…
Journal of Medical Virology, 1997
Nitric oxide is a free radical gas molecule which may be implicated in antiviral defense. However... more Nitric oxide is a free radical gas molecule which may be implicated in antiviral defense. However, there is no information about its possible role in chronic viral hepatitis B and C. In this study we have analyzed the serum levels of NO2- (as an index of nitric oxide generation) from patients with chronic viral hepatitis B and C and relationship of same with the response to interferon therapy. Serum samples were analysed from 61 patients with chronic hepatitis B, 60 patients with chronic hepatitis C, 11 with chronic liver disease of nonviral origin, and 23 healthy controls. Levels of NO2- were statistically higher in healthy controls (P < 0.001) than in patients with chronic liver disease. No relation was found between NO2- and viremia or response to interferon therapy in patients with chronic hepatitis B. In contrast in chronic hepatitis C, responder patients had significantly higher NO2- than nonresponders (P < 0.01). With respect to the relation between NO2- levels and liver damage, patients with cirrhosis had lower NO2- levels than the rest of the patients (P < 0.001). In conclusion, patients with chronic viral hepatitis have low serum NO2- levels.
Intervirology, 1998
The nucleotide sequence of hepatitis GB virus type C (HGBV-C)/hepatitis G virus (HGV) NS3/helicas... more The nucleotide sequence of hepatitis GB virus type C (HGBV-C)/hepatitis G virus (HGV) NS3/helicase and 5'-untranslated regions from 23 Spanish patients were analyzed to assign the HGV isolates one of the proposed HGBV-C/HGV genotypes. The analysis of the evolutionary distance frequency showed that the distances among all sequences in NS3/helicase region were distributed around a single peak of 0.20, suggesting that all included sequences belonged to the same HGBV-C/HGV genotype. By contrast, in the 5'-untranslated region, all the distances corresponding to our sequences and those of the HGBV-C/HGV types 2 and 3 were distributed around a major peak of 0.03. The remaining distances corresponding to the HGBV-C/HGV type 1 sequences were distributed around a minor peak of 0.11. The phylogenetic tree and pairwise comparison of evolutionary distances among the 5'-untranslated region of the infected patients and each HGBV-C/HGV genotype demonstrated that our HGBV-C/HGV isolates belonged to subtype 2a (17/23; 78%) and 2b (5/23; 22%). No relation was found between HGBV-C/HGV subtype and hepatitis B or C virus infection.
Pharmaceutical Research, 2014
To formulate and investigate the physicochemical properties, physical stability and aerosolizatio... more To formulate and investigate the physicochemical properties, physical stability and aerosolization characteristics of nanoporous/nanoparticulate microparticles (NPMPs) prepared by co-spray drying the sugars raffinose pentahydrate (R) or trehalose dihydrate (T) with the cyclic oligosaccharide hydroxypropyl-β-cyclodextrin (HPβCD). Production of powders was carried out using a laboratory scale spray dryer. The resulting powders were characterised by X-ray powder diffraction (XRPD), scanning electron microscopy (SEM), laser diffraction particle sizing, specific surface area analysis (SSA), Fourier transform infrared (FTIR), differential scanning calorimetry (DSC), dynamic vapour sorption (DVS) and aerodynamic assessment using a Next Generation Impactor (NGI). Powders were amorphous and composed of spherical, porous microparticles with reduced particle size and high specific surface area (~100 m(2)/g). DSC scans showed a single glass transition temperature. FTIR was indicative of the existence of molecular interactions between the carbohydrates. DVS analysis showed an increase in the critical relative humidity (RH) of raffinose and trehalose and eventual crystallization inhibition with increasing concentration of HPβCD. The in vitro deposition showed powders formulated with HPβCD had higher recovered emitted dose and fine particle fraction (<5 μm) than raffinose and trehalose spray dried alone. The co-spray drying of raffinose or trehalose with HPβCD results in powders with improved physicochemical characteristics, physical stability and aerodynamic behaviour compared to spray-dried raffinose/trehalose particles, constituting improved potential drug-carrier systems for pulmonary delivery.
The present study investigated the effect of operating parameters of a laboratory spray dryer on ... more The present study investigated the effect of operating parameters of a laboratory spray dryer on powder characteristics, in order to optimise the production of trehalose and raffinose powders, intended to be used as carriers of biomolecules for inhalation.
Toxicology Letters, 1998
79 described in a case series. Future studies need to examine the role of HBOf in preventing PNS ... more 79 described in a case series. Future studies need to examine the role of HBOf in preventing PNS following chronic CO exposure.
Toxicology Letters, 1998
79 described in a case series. Future studies need to examine the role of HBOf in preventing PNS ... more 79 described in a case series. Future studies need to examine the role of HBOf in preventing PNS following chronic CO exposure.
Advanced Drug Delivery Reviews, 2014
Dry powder inhaler (DPI) products have traditionally comprised a simple formulation of micronised... more Dry powder inhaler (DPI) products have traditionally comprised a simple formulation of micronised drug mixed with a carrier excipient, typically lactose monohydrate. The presence of the carrier is aimed at overcoming issues of poor flowability and dispersibility, associated with the cohesive nature of small, micronised active pharmaceutical ingredient (API) particles. Both the powder blend and the DPI device must be carefully designed so as to ensure detachment of the micronised drug from the carrier excipient on inhalation. Over the last two decades there has been a significant body of research undertaken on the design of carrier-free formulations for DPI products. Many of these formulations are based on sophisticated particle engineering techniques; a common aim in formulation design of carrier-free products being to reduce the intrinsic cohesion of the particles, while maximising dispersion and delivery from the inhaler. In tandem with the development of alternative formulations has been the development of devices designed to ensure the efficient delivery and dispersion of carrier-free powder on inhalation. In this review we examine approaches to both the powder formulation and inhaler design for carrier-free DPI products.
Journal of Molecular Structure, 2006
... all (9h9k). Given that the LUMO is an empty orbital the first electron that enters the molec... more ... all (9h9k). Given that the LUMO is an empty orbital the first electron that enters the molecule will likely go to it. In the ... 4.575 debye, respectively. Inactive compounds have values that go from 2.30 to 2.57 debye. Partition coefficient ...
Food Research International, 2009
A great number of antioxidants are naturally present in citrus juice, being responsible for their... more A great number of antioxidants are naturally present in citrus juice, being responsible for their potentially protective action against inflammation. Naringin, a bitter compound, in citrus, is hydrolysed by naringinase into tasteless naringenin and to rhamnose and glucose. The aim of this study was to evaluate the anti-inflammatory activity of naringin and naringenin in an acute model of induced colitis in mice. Microstructured particles were used for naringinase immobilization. The influence of naringin and naringinase concentration on the bioconversion was evaluated through a central composite design.