Expert proposal to analyze the combination of aortic and mitral regurgitation in multiple valvular heart disease by comprehensive echocardiography.

The assessment of valvular pathologies in multiple valvular heart disease by echocardiography remains challenging. Data on echocardiographic assessment-especially in patients with combined aortic and mitral regurgitation-are rare in the literature. The proposed integrative approach using semi-quantitative parameters to grade the severity of regurgitation often yields inconsistent findings and results in misinterpretation. Therefore, this proposal aims to focus on a practical systematic echocardiographic analysis to understand the pathophysiology and hemodynamics in patients with combined aortic and mitral regurgitation. The quantitative approach of grading the regurgitant severity of each compound might be helpful in elucidating the scenario in combined aortic and mitral regurgitation. To this end, both the individual regurgitant fraction of each valve and the total regurgitant fraction of both valves must be determined. This work also outlines the methodological issues and limitations of the quantitative approach by echocardiography. Finally, we present a proposal that enables verifiable assessment of regurgitant fractions. The overall interpretation of echocardiographic results includes the symptomatology of patients with combined aortic and mitral regurgitation and the individual treatment options with respect to their individual risk. In summary, a reproducible, verifiable, and transparent in-depth echocardiographic investigation might ensure consistent hemodynamic plausibility of the quantitative results in patients with combined aortic and mitral regurgitation.

Oxidation of myofibrillar proteins induced by peroxyl radicals: Role of oxidizable amino acids.

During storage and processing of foods, myofibrillar proteins (MP), the most abundant proteins of meats, are exposed to peroxyl radicals (ROO). The present work shows that ROO induce oxidation of MP leading to a widespread of MP aggregation. In spite of the extent of such process, only partial consumption of the more oxidizable amino acids was determined. MP were exposed to ROO derived from thermolysis of AAPH (2,2'-azobis(2-methylpropionamidine) dihydrochloride), and samples studied through SDS-PAGE, western blotting, light scattering, time-resolved fluorescence, and high performance liquid chromatography. Together with MP aggregation, consumption of methionine (the most consumed residue), cysteine, tyrosine, and tryptophan were determined. These results are associated with conformational changes of MP affecting the accessibility of tryptophan residues to the solvent, as evidenced by a decreasing of its fluorescence lifetime. Lysine residues, which are not reactive towards ROO, were also consumed, suggesting participation of Schiff bases in the MP aggregation process.

α- and ß-casein aggregation induced by riboflavin-sensitized photo-oxidation occurs via di-tyrosine cross-links and is oxygen concentration dependent.

Type I photo-oxidation generates Trp-(TrpN) and Tyr-derived (TyrO) radicals in proteins which can dimerize producing cross-links, or alternatively react with O2. It was therefore hypothesized that the O2 concentration may have a significant effect on dye-photosensitized reactions. We studied photo-oxidation of α- and ß-caseins induced by riboflavin (RF), a photosensitizing vitamin present in milk, under aerobic and anaerobic conditions. Triplet-state RF induced oxidative modifications on both caseins, and significant levels of cross-links. The extent of damage, and the yield of cross-links versus oxidized products, was dependent on the O2 concentration. In the absence of O2, the overall extent of damage was decreased, but the yield of cross-linked products was significantly elevated. These cross-links are consistent with inter- and intra-molecular di-Tyr or di-Trp bridges. Alternative cross-links were detected in the presence of O2, consistent with pathways involving the reaction of protein radicals with O2 or O2-.

Controversial alkoxyl and peroxyl radical scavenging activity of the tryptophan metabolite 3-hydroxy-anthranilic acid.

3-Hydroxy-anthranilic acid (3-OHAA), a tryptophan metabolite produced in the kynurenine pathway, is an efficient antioxidant towards peroxyl radicals (ROO) derived from the AAPH (2,2'-azobis(2-amidinopropane) dihydrochloride) thermolysis. However, self-reactions of ROO can give rise to alkoxyl radicals (RO), which could strongly affect the fate of scavenging reactions. In the present work, we studied the influence of RO in the scavenging activity of 3-OHAA in three different systems: i) Monitoring of the direct reaction between 3-OHAA and AAPH-derived free radicals (kinetic studies); ii) Evaluation of the protective effect of 3-OHAA on the AAPH-induced consumption of fluorescein; and, iii) Inhibition, given by 3-OHAA, of the AAPH-initiated lipid peroxidation of both, rat brain synaptosomes and homogenate preparations (assessed by chemiluminescence). For such purposes, the fraction of free radicals (f) trapped per 3-OHAA molecule was determined in each system. Kinetic results show that the oxidation of 3-OHAA follows a process dominated by ROO with a zero order kinetic limit in 3-OHAA, and a fraction (fri) equal to 0.88. From the induction times, elicited by 3-OHAA in the kinetic profiles of fluorescein consumption, a fraction (fT) of 0.28 was determined. 3-OHAA also generated induction times in the kinetic profiles of light emission during the AAPH-initiated lipid peroxidation of rat brain synaptosomes and homogenates. From such induction times, fractions of 0.61 and 0.63 were determined for rat brain synaptosomes (fsyn) and homogenates (fhom), respectively. These results show that during the incubation of 3-OHAA and AAPH, a low fraction of ROO self-reacts to generate RO. Nevertheless, when 3-OHAA is employed to protect particular targets, such as fluorescein, rat brain synaptosomes and homogenates, reactions of ROO and/or RO should be considered.

Reaction of tetracycline with biologically relevant chloramines.

Helicobacter pylori (H. pylori) infection triggers inflammatory processes with the consequent production of hypochlorous acid (HOCl), monochloramine (NH2Cl), and protein-derived chloramines. As the therapy for eradicating H. pylori is partially based on the use of tetracycline, we studied the kinetic of its consumption elicited by HOCl, NH2Cl, N-chloro-n-butylamine (NHCl-But, used as a lysine-derived chloramine model), and lysozyme-derived chloramines. In the micromolar concentration range, tetracycline reacted rapidly with HOCl, generating in the first few seconds intermediates of short half-life. In contrast, a slow tetracycline consumption was observed in the presence of high NH2Cl and NHCl-But concentrations (millimolar range). Similar chlorinated products of tetracycline were identified by mass spectrometry, in the presence of HOCl and NH2Cl. These results evidenced that tautomers of tetracycline are pivotal intermediates in all reactions. In spite of the low reactivity of chloramines towards tetracycline, it is evident that, in the concentration range where they are produced in a H. pylori infection (millimolar range), the reactions lead to oxidation and/or chlorination of tetracycline. This kind of reactions, which were also observed triggered by lysozyme-derived chloramines, could limit the efficiency of the tetracycline-based therapy.

Antifungal activity of mango peel and seed extracts against clinically pathogenic and food spoilage yeasts.

The antioxidant and antifungal (antiyeast) properties of mango (Mangifera indica) peel and seed by-products were investigated. Nine extracts were obtained using three cultivars and two extraction methods. Significant differences between cultivars and extraction methods were detected in their bioactive compounds and antioxidant activity. The antifungal property was determined using agar diffusion and broth micro-dilution assays against 18 yeast species of the genera Candida, Dekkera, Hanseniaspora, Lodderomyces, Metschnikowia, Pichia, Schizosaccharomyces, Saccharomycodes and Zygosaccharomyces. All mango extracts showed antifungal activity. The minimum inhibitory concentration (MIC) and the minimum fungicidal concentration (MFC) values were lower for seed than for peel extracts. MICs and MFCs ranged from values <0.1 to 5 and 5 to >30 mgGAE/mL, respectively. The multivariate analysis showed a relationship between antifungal activity, the capacity to inhibit lipid peroxidation and total phenol content. These properties were associated with high levels of proanthocyanidins, gallates and gallotannins in the extracts.

Role of alkoxyl radicals on the fluorescein-based ORAC (Oxygen Radical Absorbance Capacity) assay.

During the last decades the ORAC (Oxygen Radical Absorbance Capacity) assay has been widely employed to evaluate the in vitro antioxidant capacity of polyphenol-rich fruits, vegetables and beverages. The method employs fluorescein (FLH) as target molecule and AAPH (2,2'-azo-bis(2-amidinopropane)dihydrochloride) as the source of peroxyl radicals (ROO•). The protection of FLH, afforded by antioxidants (XH), is often characterized by kinetic profiles with clear lag times (LT), which are directly associated with the stoichiometry (n) of the XH-ROO• reaction. However, even for simple phenolic compounds, the LT measured imply large n values (defined as the number of ROO• moles trapped by each antioxidant molecule) which cannot be explained by a simple reaction mechanism. Nonetheless, they can be explained when considering the formation of alkoxyl radicals (RO•) from the recombination of two AAPH-derived ROO•. In the present work, we provide kinetic data showing that, in the zero order kinetic limit of FLH consumption, there is a low reaction rate incompatible with total trapping of ROO•. Thus, the consumption of FLH should be mostly related to its reaction with RO•. In addition, we present data regarding the assumption that in competitive measurements, the LT is due to efficient trapping of the ROO• by the added phenols, leading to high n values (1.7 to 23) for mono and polyphenols. These values are not in agreement with kinetic studies of the antioxidant consumption mediated by the presence of AAPH carried out by HPLC-DAD technique, which imply a competition by RO•. The results suggest that the use of FLH as probe at low concentrations give, for several antioxidants, ORAC values mainly related to their reaction towards RO• radicals instead of primary ROO•radicals.

Furoplocamioids A-C, novel polyhalogenated furanoid monoterpenes from Plocamium cartilagineum.

Three new tetrahydrofuran derivatives, marine monoterpenes, with an unusual chlorobromo vinyl functional group, have been isolated from the red alga Plocamium cartilagineum. The structure and relative stereochemistry of these compounds were determined on the basis of spectroscopic evidence and molecular mechanics (MM2) calculations. These compounds are related to pantofuranoids isolated from the antarctic Pantoneura plocamioides, which strongly suggests a close relationship between these species.

Gestación adolescente y su repercusión en el recién nacido. Estudio de casos y controles / Adolescent pregnancy and its repercussion on the neonate. A case control study

Objetivo: Conocer las principales características del embarazo en la adolescencia y valorarlo como posible factor de riesgo para el bajo peso al nacer. Materiales y métodos: Estudio de casos y controles de 6 meses de duración. Los casos se seleccionaron a partir de nulíparas, de edades comprendidas entre los 14 y los 19 años, que iban ingresando en el servicio de obstetricia por trabajo de parto. Los controles, nulíparas de 20 años o más, que ingresaron en el mismo centro y en el mismo período, se escogieron de forma aleatoria del libro de admisiones. Se procedió a la codificación y al posterior procesamiento de los datos con el programa SPSS v. 11.0. Se llevaron a cabo un análisis descriptivo de los datos, y un cálculo de la odds ratio como medida de asociación, con un intervalo de confianza del 95 por ciento y un test de la 2 como contraste de hipótesis, asumiendo como diferencias estadísticamente significativas las que tenían un valor de p < 0,05. Asimismo, se realizó análisis multivariante mediante un modelo de regresión logística múltiple. Resultados: Doscientos cuarenta y dos casos y 484 controles. Los factores de riesgo asociados al bajo peso al nacer identificados en el análisis fueron: edad de la madre < 19 años (odds ratio = 2,12; intervalo de confianza del 95 por ciento, 1,30-3,44) y control prenatal < 5 consultas (odds ratio = 5,15 intervalo de confianza del 95 por ciento, 2,81-9,41). De forma general, las madres adolescentes están fuera del sistema educativo, en su mayoría dedicadas a las labores del hogar, y en ellas existe una mayor prevalencia de bajo peso y de prematuridad. Conclusiones: Existe asociación entre la edad de la madre y el bajo peso del neonato, que se incrementa entre quienes asisten de forma irregular al control prenatal (AU)

Infecciones posthisterectomía: estudio prospectivo de 3 años en Gran Canaria, España / Post hysterectomy infections: a three year prospective study in the hospital of Gran Canaria, Spain

Objetivos: Determinar la incidencia de las infecciones nosocomiales tras la realización de una histerectomía y la frecuencia del uso de la profilaxis quirúrgica. Sujetos y métodos: Estudio prospectivo, entre junio de 1999 y mayo de 2003. De forma sistemática se revisaron las historias clínicas para determinar quiénes presentaban una infección nosocomial. La incidencia de infección en la zona quirúrgica se calculó de acuerdo con el sistema nacional de vigilancia de infecciones nosocomiales. Resultados: De un total de 998 casos, 193 (19,3 por ciento) cumplían los criterios de infección postoperatoria (un 18,8 por ciento abdominal y un 20,7 por ciento vaginal), la mayoría urinaria. La incidencia de infecciones de localización quirúrgica puede considerarse adecuada (5,3 por ciento), y el NNISS ha demostrado que las pacientes con riesgo moderado tienen, con mayor frecuencia, infecciones, comparadas con aquellas clasificadas como de bajo riesgo (p = 0,01). Más del 84 por ciento recibió profilaxis antibiótica; las pacientes a las que ésta se administró de una forma inadecuada presentaron un riesgo 2,7 veces superior de experimentar una infección quirúrgica que aquellas que la recibieron de manera adecuada (intervalo de confianza del 95 por ciento, 1,54-4,95; p < 0,001). Conclusiones: La incidencia de infecciones postoperatorias fue alta. Consideramos que la estrategia más efectiva para conseguir un control de las infecciones en este tipo de procedimientos es la comunicación frecuente de los resultados de nuestra vigilancia a los profesionales implicados (AU)