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Papers by Ana Maria Moreno H

Research paper thumbnail of Antibodies against synthetic deamidated gliadin peptides as predictors of celiac disease: prospective assessment in an adult population with a high pretest probability

Clinical …, 2007

Background: Noninvasive serologic tests have shown high diagnostic accuracy for celiac disease (C... more Background: Noninvasive serologic tests have shown high diagnostic accuracy for celiac disease (CD) in selected populations. Our aim was to determine prospectively the performance of CD-related serology in individuals undergoing intestinal biopsy because of clinical suspicion of small-bowel disorders. Methods: We enrolled 141 unselected consecutive adult patients attending a small-bowel disease clinic. Patients underwent endoscopy and biopsy; serum samples were obtained at that time for measurements of anti-tissue transglutaminase (a-tTG), IgA and IgG anti-deamidated gliadin-related peptide (a-DGP), and IgA antiactin antibodies (AAAs). Characterization of patients was based on histological criteria (Marsh type II lesion or greater). Results: The prevalence of CD was 42.5%. Sensitivity, specificity, and positive and negative predictive values were >90% for most assays. Diagnostic accuracy based on ROC curve analysis was similar for all assays [area under the curve (95% CI): 0.996 (0.967-0.998) for a-tTG, 0.995 (0.964 -0.998) for IgA a-DGP, 0.989 (0.954 -0.999) for IgG a-DGP, 0.996 (0.966 -0.998) for blended conjugated of IgA ؉ IgG a-DGP in a single assay, and 0.967 (0.922-0.990) for AAA]. The combinations of 2 tests, IgG a-DGP plus IgA a-tTG or the single blended conjugate detecting IgA ؉ IgG a-DGP plus IgA a-tTG had 100% positive and negative predictive values if concentrations of both tests in either combination were above or below the cutoff.

Research paper thumbnail of Oxidative stress in arterial hypertension role of NAD (P) H oxidase

…, 2001

Increased vascular reactive oxygen species production, especially superoxide anion, contributes s... more Increased vascular reactive oxygen species production, especially superoxide anion, contributes significantly in the functional and structural alterations present in hypertension. An enhanced superoxide production causes a diminished NO bioavailability by an oxidative reaction that inactivates NO. Exaggerated superoxide levels and a low NO bioavailability lead to endothelial dysfunction and hypertrophy of vascular cells. It has been shown that the enzyme NAD(P)H oxidase plays a major role as the most important source of superoxide anion in vascular cells. Several experimental observations have shown an enhanced superoxide generation as a result of the activation of vascular NAD(P)H oxidase in hypertension. Although this enzyme responds to stimuli such as vasoactive factors, growth factors, and cytokines, some recent data suggest the existence of a genetic background modulating the expression of its different components. New polymorphisms have been identified in the promoter of the p22 phox gene, an essential subunit of NAD(P)H oxidase, influencing the activity of this enzyme. Genetic investigations of these polymorphisms will provide novel markers for determination of genetic susceptibility to oxidative stress in hypertension. (Hypertension. 2001;38: 1395-1399.)

Research paper thumbnail of The Trichoplax genome and the nature of placozoans

Nature, 2008

As arguably the simplest free-living animals, placozoans may represent a primitive metazoan form,... more As arguably the simplest free-living animals, placozoans may represent a primitive metazoan form, yet their biology is poorly understood. Here we report the sequencing and analysis of the ,98 million base pair nuclear genome of the placozoan Trichoplax adhaerens. Whole-genome phylogenetic analysis suggests that placozoans belong to a 'eumetazoan' clade that includes cnidarians and bilaterians, with sponges as the earliest diverging animals. The compact genome shows conserved gene content, gene structure and synteny in relation to the human and other complex eumetazoan genomes. Despite the apparent cellular and organismal simplicity of Trichoplax, its genome encodes a rich array of transcription factor and signalling pathway genes that are typically associated with diverse cell types and developmental processes in eumetazoans, motivating further searches for cryptic cellular complexity and/or as yet unobserved life history stages. ARTICLES 959

Research paper thumbnail of Accuracy of testing for antibodies to synthetic gliadin-related peptides in celiac disease

… and hepatology: the …, 2006

Our aim was to explore the diagnostic value of a newly developed synthetic peptide antibody assay... more Our aim was to explore the diagnostic value of a newly developed synthetic peptide antibody assay addressing specific synthetic gliadin-derived deamidated peptides (AGA II) for the diagnosis of celiac disease (CD).

Research paper thumbnail of Biofilm formation and phenotypic variation enhance predation-driven persistence of Vibrio cholerae

Proceedings of the …, 2005

Persistence of the opportunistic bacterial pathogen Vibrio cholerae in aquatic environments is th... more Persistence of the opportunistic bacterial pathogen Vibrio cholerae in aquatic environments is the principal cause for seasonal occurrence of cholera epidemics. This causality has been explained by postulating that V. cholerae forms biofilms in association with animate and inanimate surfaces. Alternatively, it has been proposed that bacterial pathogens are an integral part of the natural microbial food web and thus their survival is constrained by protozoan predation. Here, we report that both explanations are interrelated. Our data show that biofilms are the protective agent enabling V. cholerae to survive protozoan grazing while their planktonic counterparts are eliminated. Grazing on planktonic V. cholerae was found to select for the biofilm-enhancing rugose phase variant, which is adapted to the surface-associated niche by the production of exopolymers. Interestingly, grazing resistance in V. cholerae biofilms was not attained by exopolymer production alone but was accomplished by the secretion of an antiprotozoal factor that inhibits protozoan feeding activity. We identified that the cell density-dependent regulator hapR controls the production of this factor in biofilms. The inhibitory effect of V. cholerae biofilms was found to be widespread among toxigenic and nontoxigenic isolates. Our results provide a mechanistic explanation for the adaptive advantage of surface-associated growth in the environmental persistence of V. cholerae and suggest an important contribution of protozoan predation in the selective enrichment of biofilm-forming strains in the out-of-host environment.

Research paper thumbnail of Antibodies against synthetic deamidated gliadin peptides as predictors of celiac disease: prospective assessment in an adult population with a high pretest probability

Clinical …, 2007

Background: Noninvasive serologic tests have shown high diagnostic accuracy for celiac disease (C... more Background: Noninvasive serologic tests have shown high diagnostic accuracy for celiac disease (CD) in selected populations. Our aim was to determine prospectively the performance of CD-related serology in individuals undergoing intestinal biopsy because of clinical suspicion of small-bowel disorders. Methods: We enrolled 141 unselected consecutive adult patients attending a small-bowel disease clinic. Patients underwent endoscopy and biopsy; serum samples were obtained at that time for measurements of anti-tissue transglutaminase (a-tTG), IgA and IgG anti-deamidated gliadin-related peptide (a-DGP), and IgA antiactin antibodies (AAAs). Characterization of patients was based on histological criteria (Marsh type II lesion or greater). Results: The prevalence of CD was 42.5%. Sensitivity, specificity, and positive and negative predictive values were >90% for most assays. Diagnostic accuracy based on ROC curve analysis was similar for all assays [area under the curve (95% CI): 0.996 (0.967-0.998) for a-tTG, 0.995 (0.964 -0.998) for IgA a-DGP, 0.989 (0.954 -0.999) for IgG a-DGP, 0.996 (0.966 -0.998) for blended conjugated of IgA ؉ IgG a-DGP in a single assay, and 0.967 (0.922-0.990) for AAA]. The combinations of 2 tests, IgG a-DGP plus IgA a-tTG or the single blended conjugate detecting IgA ؉ IgG a-DGP plus IgA a-tTG had 100% positive and negative predictive values if concentrations of both tests in either combination were above or below the cutoff.

Research paper thumbnail of Oxidative stress in arterial hypertension role of NAD (P) H oxidase

…, 2001

Increased vascular reactive oxygen species production, especially superoxide anion, contributes s... more Increased vascular reactive oxygen species production, especially superoxide anion, contributes significantly in the functional and structural alterations present in hypertension. An enhanced superoxide production causes a diminished NO bioavailability by an oxidative reaction that inactivates NO. Exaggerated superoxide levels and a low NO bioavailability lead to endothelial dysfunction and hypertrophy of vascular cells. It has been shown that the enzyme NAD(P)H oxidase plays a major role as the most important source of superoxide anion in vascular cells. Several experimental observations have shown an enhanced superoxide generation as a result of the activation of vascular NAD(P)H oxidase in hypertension. Although this enzyme responds to stimuli such as vasoactive factors, growth factors, and cytokines, some recent data suggest the existence of a genetic background modulating the expression of its different components. New polymorphisms have been identified in the promoter of the p22 phox gene, an essential subunit of NAD(P)H oxidase, influencing the activity of this enzyme. Genetic investigations of these polymorphisms will provide novel markers for determination of genetic susceptibility to oxidative stress in hypertension. (Hypertension. 2001;38: 1395-1399.)

Research paper thumbnail of The Trichoplax genome and the nature of placozoans

Nature, 2008

As arguably the simplest free-living animals, placozoans may represent a primitive metazoan form,... more As arguably the simplest free-living animals, placozoans may represent a primitive metazoan form, yet their biology is poorly understood. Here we report the sequencing and analysis of the ,98 million base pair nuclear genome of the placozoan Trichoplax adhaerens. Whole-genome phylogenetic analysis suggests that placozoans belong to a 'eumetazoan' clade that includes cnidarians and bilaterians, with sponges as the earliest diverging animals. The compact genome shows conserved gene content, gene structure and synteny in relation to the human and other complex eumetazoan genomes. Despite the apparent cellular and organismal simplicity of Trichoplax, its genome encodes a rich array of transcription factor and signalling pathway genes that are typically associated with diverse cell types and developmental processes in eumetazoans, motivating further searches for cryptic cellular complexity and/or as yet unobserved life history stages. ARTICLES 959

Research paper thumbnail of Accuracy of testing for antibodies to synthetic gliadin-related peptides in celiac disease

… and hepatology: the …, 2006

Our aim was to explore the diagnostic value of a newly developed synthetic peptide antibody assay... more Our aim was to explore the diagnostic value of a newly developed synthetic peptide antibody assay addressing specific synthetic gliadin-derived deamidated peptides (AGA II) for the diagnosis of celiac disease (CD).

Research paper thumbnail of Biofilm formation and phenotypic variation enhance predation-driven persistence of Vibrio cholerae

Proceedings of the …, 2005

Persistence of the opportunistic bacterial pathogen Vibrio cholerae in aquatic environments is th... more Persistence of the opportunistic bacterial pathogen Vibrio cholerae in aquatic environments is the principal cause for seasonal occurrence of cholera epidemics. This causality has been explained by postulating that V. cholerae forms biofilms in association with animate and inanimate surfaces. Alternatively, it has been proposed that bacterial pathogens are an integral part of the natural microbial food web and thus their survival is constrained by protozoan predation. Here, we report that both explanations are interrelated. Our data show that biofilms are the protective agent enabling V. cholerae to survive protozoan grazing while their planktonic counterparts are eliminated. Grazing on planktonic V. cholerae was found to select for the biofilm-enhancing rugose phase variant, which is adapted to the surface-associated niche by the production of exopolymers. Interestingly, grazing resistance in V. cholerae biofilms was not attained by exopolymer production alone but was accomplished by the secretion of an antiprotozoal factor that inhibits protozoan feeding activity. We identified that the cell density-dependent regulator hapR controls the production of this factor in biofilms. The inhibitory effect of V. cholerae biofilms was found to be widespread among toxigenic and nontoxigenic isolates. Our results provide a mechanistic explanation for the adaptive advantage of surface-associated growth in the environmental persistence of V. cholerae and suggest an important contribution of protozoan predation in the selective enrichment of biofilm-forming strains in the out-of-host environment.