Validación de la escala Short FES-I en población española mayor de 70 años / Validation of the short FES-I scale in Spanish population over 70 years

Introducción Las caídas deterioran la calidad de vida de los ancianos y el miedo a estas ha demostrado ser un factor de riesgo independiente para fragilidad, por lo que es prioritario disponer de herramientas para su evaluación. La escala ShortFalls Efficacy Scale-International (FES)-I, versión corta (siete ítems) de la escala FES-I (16 ítems), evalúa el miedo a caer (MC). El objetivo de este estudio es validar la escala Short FES-I en población española mayor de 70 años y analizar la relación entre el miedo a las caídas, el riesgo de las mismas y la fragilidad. Material y métodos Se trata de un estudio observacional transversal. La muestra consistió en 227 sujetos (50,7% varones; edad media 75,8 años). La ubicación fue en el norte de España. Las variables empleadas fueron sociodemográficas, clínicas, pruebas de ejecución Short Physical Performance Battery (SPPB) y Timed Up and Go Test (TUG), FES-I y Short FES-I. Se analizaron las propiedades psicométricas: validez y fiabilidad. Resultados La escala Short FES-I muestra excelentes consistencia interna (alfa de Cronbach = 0,90, coeficiente correlación intraclase = 0,89) y reproducibilidad test-retest (Rho Spearman = 0,76). Tiene una elevada validez de criterio concomitante analizada por su correlación con FES-I (Rho Spearman = 0,90). La validez de constructo discriminante ha sido confirmada tanto para SPPB como TUG. Short FES-I presenta buena capacidad de clasificación de fragilidad (definida por SPPB) con área bajo la curva [AUC] = 0,715; como punto de corte se propone un valor Short FES-I>8 para miedo moderado/alto de caídas. Conclusiones La escala Short FES-I es un buen instrumento para estudiar el miedo a las caídas en población española mayor de 70 años y es válida para su uso clínico y en investigación. (AU)

Introduction Falls deteriorate the quality of life of the elderly and the fear of falling has been shown to be an independent risk factor for frailty, so having tools for its evaluation is a priority. The short FES-I scale, short version (7 items) of the FES-I scale (16 items), assesses fear of falling. The objective of this study is to validate the short FES-I scale in the Spanish population over 70 years and to analyze the relationship between fear of falling, risk of falls and frailty. Material and methods Cross-sectional observational study. Sample: 227 subjects (50.7% male; mean age 75.8 years). Setting: northern Spain. Variables: sociodemographic, clinical, short physical performance battery (SPPB) and timed up and go test (TUG) execution tests, FES-I and short FES-I. Analysis of psychometric properties: validity and reliability. Results The short FES-I scale shows excellent internal consistency (Cronbach's alpha = 0.90, intraclass correlation coefficient = 0.89) and test–retest reliability (rho Spearman = 0.76). It has a high concomitant criterion validity analyzed by its correlation with FES-I (rho Spearman = 0.90). The discriminant construct validity has been confirmed for both SPPB and TUG. Short FES-I presents good capacity for frailty classification (defined by SPPB) with AUC = 0.715. As a cut-off point, a short FES-I value > 8 is proposed for moderate/high fear of falling. Conclusions The short FES-I scale is a good instrument to study fear of falling in the Spanish population over 70 years and is valid for clinical and research use. (AU)

Validación de la escala Short FES-I en población española mayor de 70 años / Validation of the short FES-I scale in Spanish population over 70 years

Introducción Las caídas deterioran la calidad de vida de los ancianos y el miedo a estas ha demostrado ser un factor de riesgo independiente para fragilidad, por lo que es prioritario disponer de herramientas para su evaluación. La escala ShortFalls Efficacy Scale-International (FES)-I, versión corta (siete ítems) de la escala FES-I (16 ítems), evalúa el miedo a caer (MC). El objetivo de este estudio es validar la escala Short FES-I en población española mayor de 70 años y analizar la relación entre el miedo a las caídas, el riesgo de las mismas y la fragilidad. Material y métodos Se trata de un estudio observacional transversal. La muestra consistió en 227 sujetos (50,7% varones; edad media 75,8 años). La ubicación fue en el norte de España. Las variables empleadas fueron sociodemográficas, clínicas, pruebas de ejecución Short Physical Performance Battery (SPPB) y Timed Up and Go Test (TUG), FES-I y Short FES-I. Se analizaron las propiedades psicométricas: validez y fiabilidad. Resultados La escala Short FES-I muestra excelentes consistencia interna (alfa de Cronbach = 0,90, coeficiente correlación intraclase = 0,89) y reproducibilidad test-retest (Rho Spearman = 0,76). Tiene una elevada validez de criterio concomitante analizada por su correlación con FES-I (Rho Spearman = 0,90). La validez de constructo discriminante ha sido confirmada tanto para SPPB como TUG. Short FES-I presenta buena capacidad de clasificación de fragilidad (definida por SPPB) con área bajo la curva [AUC] = 0,715; como punto de corte se propone un valor Short FES-I>8 para miedo moderado/alto de caídas. Conclusiones La escala Short FES-I es un buen instrumento para estudiar el miedo a las caídas en población española mayor de 70 años y es válida para su uso clínico y en investigación. (AU)

Introduction Falls deteriorate the quality of life of the elderly and the fear of falling has been shown to be an independent risk factor for frailty, so having tools for its evaluation is a priority. The short FES-I scale, short version (7 items) of the FES-I scale (16 items), assesses fear of falling. The objective of this study is to validate the short FES-I scale in the Spanish population over 70 years and to analyze the relationship between fear of falling, risk of falls and frailty. Material and methods Cross-sectional observational study. Sample: 227 subjects (50.7% male; mean age 75.8 years). Setting: northern Spain. Variables: sociodemographic, clinical, short physical performance battery (SPPB) and timed up and go test (TUG) execution tests, FES-I and short FES-I. Analysis of psychometric properties: validity and reliability. Results The short FES-I scale shows excellent internal consistency (Cronbach's alpha = 0.90, intraclass correlation coefficient = 0.89) and test–retest reliability (rho Spearman = 0.76). It has a high concomitant criterion validity analyzed by its correlation with FES-I (rho Spearman = 0.90). The discriminant construct validity has been confirmed for both SPPB and TUG. Short FES-I presents good capacity for frailty classification (defined by SPPB) with AUC = 0.715. As a cut-off point, a short FES-I value > 8 is proposed for moderate/high fear of falling. Conclusions The short FES-I scale is a good instrument to study fear of falling in the Spanish population over 70 years and is valid for clinical and research use. (AU)

[Validation of the short FES-I scale in Spanish population over 70 years]. / Validación de la escala Short FES-I en población española mayor de 70 años.

INTRODUCTION: Falls deteriorate the quality of life of the elderly and the fear of falling has been shown to be an independent risk factor for frailty, so having tools for its evaluation is a priority. The short FES-I scale, short version (7 items) of the FES-I scale (16 items), assesses fear of falling. The objective of this study is to validate the short FES-I scale in the Spanish population over 70 years and to analyze the relationship between fear of falling, risk of falls and frailty. MATERIAL AND METHODS: Cross-sectional observational study. SAMPLE: 227 subjects (50.7% male; mean age 75.8 years). SETTING: northern Spain. VARIABLES: sociodemographic, clinical, short physical performance battery (SPPB) and timed up and go test (TUG) execution tests, FES-I and short FES-I. Analysis of psychometric properties: validity and reliability. RESULTS: The short FES-I scale shows excellent internal consistency (Cronbach's alpha = 0.90, intraclass correlation coefficient = 0.89) and test-retest reliability (rho Spearman = 0.76). It has a high concomitant criterion validity analyzed by its correlation with FES-I (rho Spearman = 0.90). The discriminant construct validity has been confirmed for both SPPB and TUG. Short FES-I presents good capacity for frailty classification (defined by SPPB) with AUC = 0.715. As a cut-off point, a short FES-I value > 8 is proposed for moderate/high fear of falling. CONCLUSIONS: The short FES-I scale is a good instrument to study fear of falling in the Spanish population over 70 years and is valid for clinical and research use.

Preparation and Characterization of a Multicomponent Arthrospira platensis Biomass Hydrolysate with Superior Anti-Hypertensive, Anti-Hyperlipidemic and Antioxidant Activities via Selective Proteolysis.

Arthrospira platensis biomass is a sustainable source of bioactive products for the food, cosmetic, and medicine industries. As well as primary metabolites, different secondary metabolites can be obtained via distinct enzymatic degradation of biomass. In this work, different hydrophilic extracts were obtained after treating the biomass with: (i) a serine endo-peptidase (Alcalase®), (ii) a mixture of amino-, dipeptidyl-, and endo-peptidases (Flavourzyme®), (iii) a mixture of endo-1,3(4)-ß-glucanase and an endo-1,4-xylanase, and ß-glucanase (Ultraflo®), and (iv) an exo-1,3-glucanase (Vinoflow®) (all the enzymes from Novozymes A/S (bagsvaerd, Denmark)); with subsequent extraction of the biocomponents with an isopropanol/hexane mixture. The composition of each aqueous phase extract (in terms of amino acids, peptides, oligo-elements, carbohydrates, and phenols) and their in vitro functional properties were compared. The conditions described in this work using the enzyme Alcalase® permits the extraction of eight distinctive peptides. This extract is 7.3 times more anti-hypertensive, 106 times more anti-hypertriglyceridemic, 26 times more hypocholesterolemic, has 4.4 times more antioxidant activities, and has 2.3 times more phenols, than the extract obtained without any prior enzyme biomass digestion. Alcalase® extract is an advantageous product with potential application in functional food, pharmaceutics, and cosmetics.

Analysis of trait-performance-fitness relationships reveals pollinator-mediated selection on orchid pollination traits.

PREMISE: The role of pollinators in evolutionary floral divergence has spurred substantial effort into measuring pollinator-mediated phenotypic selection and its variation in space and time. For such estimates, the fitness consequences of pollination processes must be separated from other factors affecting fitness. METHODS: We built a fitness function linking phenotypic traits of food-deceptive orchids to female reproductive success by including pollinator visitation and pollen deposition as intermediate performance components and used the fitness function to estimate the strength of pollinator-mediated selection through female reproductive success. We also quantified male performance as pollinarium removal and assessed similarity in trait effects on male and female performance. RESULTS: The proportion of plants visited at least once by an effective pollinator was moderate to high, ranging from 53.7% to 85.1%. Tall, many-flowered plants were often more likely to be visited and pollinated. Given effective pollination, pollen deposition onto stigmas tended to be more likely for taller plants. Pollen deposition further depended on traits affecting the physical fit of pollinators to flowers (flower size, spur length), though the exact relationships varied in time and space. Using the fitness function to assess pollinator-mediated selection through female reproductive success acting on multiple traits, we found that selection varied detectably among taxa after accounting for sampling uncertainty. Across taxa, selection on most traits was stronger on average and more variable when pollination was less reliable. CONCLUSIONS: These results support pollination-related trait-performance-fitness relationships and thus pollinator-mediated selection on traits functionally involved in the pollination process.

Spirulina extract improves age-induced vascular dysfunction.

CONTEXT: Vascular dysfunction is considered a hallmark of ageing that has been associated with altered vasomotor responses, in which nitric oxide (NO) and reactive oxygen species participate. The consumption of Spirulina extracts, with antioxidant properties, increased recently. OBJECTIVE: This study investigates the effect of Spirulina aqueous extract (SAE) on the vascular function of the aorta from aged rats. MATERIALS AND METHODS: Aortic segments from aged male Sprague-Dawley rats (20-22 months old) were exposed to SAE (0.1% w/v, for 3 h) to analyse: (i) the vasodilator response induced by acetylcholine (ACh), by the NO donor sodium nitroprusside (SNP), by the carbon monoxide releasing molecule (CORM) and by the KATP channel opener, cromakalim (CK); (ii) the vasoconstrictor response induced by KCl and noradrenaline (NA); (iii) the production of NO and superoxide anion, and (iv) the expression of the p-eNOS and HO-1 proteins. RESULTS: Incubation with SAE increased the expression of p-eNOS (1.6-fold) and HO-1 (2.0-fold), enhanced NO release (1.4-fold in basal and 1.9-fold in ACh-stimulated conditions) while decreased the production of superoxide (0.7-fold). SAE also increased the sensitivity (measured as pEC50) to ACh (control: -7.06 ± 0.11; SAE: -8.16 ± 0.21), SNP (control: -7.96 ± 0.16; SAE: -9.11 ± 0.14) and CK (control: -7.05 ± 0.39; SAE: -8.29 ± 0.53), and potentiated the response to KCl (1.3-fold) and to NA (1.7-fold). CONCLUSION: The antioxidant properties of SAE improved the vasomotor responses of aorta from aged rats. These results may support the use of Spirulina as a protection against vascular dysfunction.

Beneficial Effects of Spirulina Aqueous Extract on Vasodilator Function of Arteries from Hypertensive Rats.

Hypertension is a multifactorial disorder considered one of the major causes of premature death worldwide. This pathology is associated with vascular functional/structural alterations in which nitric oxide (NO) and oxygen reactive species participate. On the other hand, the use of microalgae extracts in the treatment of cardiovascular diseases is increasing. Based on the antioxidant and antihypertensive properties of Spirulina, this study aims to investigate the effect of an aqueous extract of Spirulina on the vasodilator function of the aorta from spontaneously hypertensive rats (SHR), analyzing the functional role of NO. For this, aortic segments from male SHR were divided into two groups, one control and the other exposed to an Spirulina aqueous extract (0.1% w/v, for 3 hours), to analyze (i) the production of NO, superoxide anion, and hydrogen peroxide; (ii) the vasodilator response induced by acetylcholine (ACh), by the NO donor and sodium nitroprusside (SNP), and by the KATP channel opener and pinacidil; and (iii) the expression of the p-Akt, p-eNOS, and HO-1 proteins. The results showed that the aqueous Spirulina extract (i) increased the production of NO, did not significantly modify that of superoxide, while decreased that of hydrogen peroxide; (ii) increased the vasodilatory responses induced by ACh, NPS, and pinacidil; and (iii) increased the expression of p-Akt and HO-1. These results suggest that incubation with the aqueous Spirulina extract improves the vascular function of arteries from SHR by increasing the release/bioavailability/function of NO. Increased KATP channel activation and expression of pAkt and HO-1 appear to be participating in these actions.

Prolongation of secondary drying step of phospholipid lyophilization greatly improves acidolysis reactions catalyzed by immobilized lecitase ultra.

Conjugated linolenic acid (CLA) has important health effects, and their phospholipids forms (PL) are advantageous vehicles of this bioactive agent. Acidolysis of soybean phosphatidylcholine (PC) with conjugated linolenic acid (CLA) catalyzed by Lecitase® Ultra immobilized on Duolite A658 was studied. This reaction is typically limited by hydrolysis, producing 60-90 % of lyso- and glycero-PC and yielding low the process efficiency. Drying the amphiphilic PC material was found the key factor for maximal diacylglycerol phosphatidylcholines (PC) production and different drying approaches were studied to maximize the formation of PC rich in CLA in a solvent free process. PC lyophilization for 24 h getting dry solid appearance (PC; 783 ±â€¯11 mg water/Kg PC) or other standard protocols to reduce water content/activity of reaction medium, did not improve the reaction performance. However, adding 4 extra days to the second step of lyophilization at high vacuum (1 Pa) and moderate temperature (20 °C), followed by further PC dehydration with molecular sieves, drastically reduced the hydrolysis process by achieving a extensive PC dehydration (279 ±â€¯4 mg water/Kg PC), obtaining for the first time >99% molar yield of diacyl-PC product. After 24 h of reaction, a diacyl-PC product with 72.3% CLA content was obtained. PC molecules containing two CLA were the major species formed.

Rapid and high yield production of phospholipids enriched in CLA via acidolysis: The critical role of the enzyme immobilization protocol.

Phospholipids (PL) rich in conjugated linolenic acid (CLA) have important health effects. Yields of phosphatidylcholine (PC) acidolysis with CLA use to be limited to <30%, due to competitive side-hydrolysis. Duolite A658-Lecitase is a very suitable biocatalyst for this reaction. In this study, PC hydrolysis has been practically eliminated using extremely dried lyophilized PC (279 ±â€¯4 mg water/Kg PC), obtaining close to 100% molar yield of modified PC (72.3% CLA) with Duolite-Lecitase in 24 h, the highest yield reported in the literature for this reaction. It has been better improved by changing the immobilization support, using three food grade hydrophobic supports (Styrene, and two Octadecyl methacrylates (OM and OMC)). In only 2 h, with a 1/12 PC/CLA molar ratio at 50 °C, similar almost quantitative yields of PC with 74.4% CLA content has been obtained using OM-Lecitase. The fatty acid composition of modified PCs is not affected by the enzyme immobilization protocol.

Enfermedades auto-inmunes producidas por el estreptococo beta hemolítico del grupo a (streptocococus pyogenes) / Self-immune diseases produced by the beta hemolytic breast streptocco of group a (streptocococus pyogenes)

Streptococcus pyogenes o estreptococo beta-hemolítico del grupo A (EBHGA) es una bacteria que produce enfermedades de gran importancia médica debido a lasaltas tasas de incapacidad y mortalidad a nivel mundial. EBHGA produce reacciones autoinmunes que afectan a un sin número de órganos y tejidos de los pacientes, lo que está relacionado con mimetismos moleculares entre las células del hospedero y moléculas que se hallan en la bacteria. Esta revisión estuvo enfocada en las enfermedades autoinmunes desencadenadas por S. pyogenes. Se ofrece información sobre las manifestaciones clínicas y la reacción inmune desencadenada en los pacientes, además de la epidemiología de las enfermedades.

Streptococcus pyogenes or group A beta-hemolytic streptococcus (GABHS) is a bacterium that produces diseases of great medical importance due to the high rates of disability and mortality worldwide. EBHGA produces autoimmune reactions that affect a number of organs and tissues of patients, which is related to molecular mimicry between the cells of the host and molecules found in the bacteria. This review focused on the autoimmune diseases triggered by S. pyogenes. Information is offered on the clinical manifestations and the immune reaction triggered in patients, in addition to the epidemiology of the diseases.

Nuevos horizontes en el tratamiento de la enfermedad de Kawasaki / New horizonts in the treatment of Kawasaki disease

La enfermedad de Kawasaki, es una vasculitis auto limitada que afecta principalmente a niños pequeños; Es la segunda causa más común de vasculitis en menores de 5 años. La enfermedad se caracteriza por la presencia de un criterio mayor, el cual es la fiebre mayor o igual a 5 días y la presencia de ≥4 de las 5 características clínicas principales. Esta revisión está enfocada en la actualización sobre el manejo médico de la enfermedad, sin abordar el manejo quirúrgico de los aneurismas coronarios.

Kawasaki disease is a self-limited vasculitis that mainly affects young children; It is the second most common cause of vasculitis in children <5 years. The disease is characterized by the presence of a major criterion, which is a fever greater than or equal to 5 days and the presence of ≥4 of the 5 main clinical features. In this review, it focuses on the management update without addressing the surgical management of coronary aneurysms.

Selective synthesis of partial glycerides of conjugated linoleic acids via modulation of the catalytic properties of lipases by immobilization on different supports.

Lipases B from Candida antarctica (CALB), Rhizomucor miehei (RML) and Thermomyces lanuginosus (TLL) were immobilized on octadecyl methacylate (OM) or octadecyl methacrylate (OMC) beads. Their specific activity and regioselectivity were studied in the synthesis of conjugated linoleic acid (CLA) partial glycerides, which presented nutraceutical properties. TLL derivatives were poor catalysts. Novozym® 435 was much better than Lipozyme® RM IM. RML activity (a GRAS enzyme) was modulated via immobilization. After only 3 h, OM-RML gave the highest CLA conversion (54% at 40 °C with 1:3 M ratio of glycerol to CLA). OM-RML reduced by a factor of 3.12 and 1.16 the activation energy of the reaction with Lipozyme® RM IM and Novozym® 435, respectively. The new GRAS preparation OM-RML brings forth an optimal regioselective preparation of sn-1 mono and sn-1,3 diacylglycerols rich in CLA, with a ratio of sn-1,3/sn-1,2 regioisomers of 21.8, compared to 2.3 for Novozym® 435.

Improved stability of immobilized lipases via modification with polyethylenimine and glutaraldehyde.

Phospholipase Lecitase Ultra (LU) and lipase from Thermomyces lanuginosus (TLL) have been immobilized under conditions that favor either enzyme crowding or enzyme dispersion. Highly loaded LU was more stable than low loaded biocatalyst under all studied conditions. Using TLL, the results depended on the inactivation conditions, e.g., crowding was positive at pH 5 and negative at pH 7. Then, all preparations were treated with glutaraldehyde (Glu), polyethyleneimine (PEI) or sequentially with Glu and PEI. These treatments may permit to stabilize the physically immobilized lipases by avoiding enzyme desorption via intermolecular crosslinking. Moreover, immobilizing a second enzyme on the lipase-glutaraldehyde-PEI has been proposed as a strategy without risks of PEI desorption by incubation in high ion strength solutions. The treatments altered the enzyme activity slightly but produced significant enzyme stabilization. This enzyme stabilization was more significant when using the highly loaded preparations, where intermolecular crosslinking was easier to obtain. SDS-PAGE analyses confirmed that crowded enzyme preparations were intermolecular crosslinked using Glu plus PEI, but some molecules still remained non-crosslinked. In general, PEI treatment was the most effective in increasing enzyme stability, while glutaraldehyde had a milder stabilization effect.

Desorption of Lipases Immobilized on Octyl-Agarose Beads and Coated with Ionic Polymers after Thermal Inactivation. Stronger Adsorption of Polymers/Unfolded Protein Composites.

Lipases from Candida antarctica (isoform B) and Rhizomucor miehei (CALB and RML) have been immobilized on octyl-agarose (OC) and further coated with polyethylenimine (PEI) and dextran sulfate (DS). The enzymes just immobilized on OC supports could be easily released from the support using 2% SDS at pH 7, both intact or after thermal inactivation (in fact, after inactivation most enzyme molecules were already desorbed). The coating with PEI and DS greatly reduced the enzyme release during thermal inactivation and improved enzyme stability. However, using OC-CALB/RML-PEI-DS, the full release of the immobilized enzyme to reuse the support required more drastic conditions: a pH value of 3, a buffer concentration over 2 M, and temperatures above 45 °C. However, even these conditions were not able to fully release the thermally inactivated enzyme molecules from the support, being necessary to increase the buffer concentration to 4 M sodium phosphate and decrease the pH to 2.5. The formation of unfolded protein/polymers composites seems to be responsible for this strong interaction between the octyl and some anionic groups of OC supports. The support could be reused five cycles using these conditions with similar loading capacity of the support and stability of the immobilized enzyme.

Docosahexaenoic Acid Supplemented Diet Influences the Orchidectomy-Induced Vascular Dysfunction in Rat Mesenteric Arteries.

Over the past few decades, the cardiovascular benefits of a high dietary intake of long-chain polyunsaturated fatty acids (PUFAs), like docosahexaenoic acid (DHA), have been extensively studied. However, many of the molecular mechanisms and effects exerted by PUFAs have yet to be well explained. The lack of sex hormones alters vascular tone, and we have described that a DHA-supplemented diet to orchidectomized rats improve vascular function of the aorta. Based on these data and since the mesenteric artery importantly controls the systemic vascular resistance, the objective of this study was to analyze the effect of a DHA-supplemented diet on the mesenteric vascular function from orchidectomized rats. For this purpose mesenteric artery segments obtained from control, orchidectomized or orchidectomized plus DHA-supplemented diet were utilized to analyze: (1) the release of prostanoids, (2) formation of NO and ROS, (3) the vasodilator response to acetylcholine (ACh), as well as the involvement of prostanoids and NO in this response, and (4) the vasoconstrictor response to electrical field stimulation (EFS), analyzing also the effect of exogenous noradrenaline (NA), and the NO donor, sodium nitroprusside (SNP). The results demonstrate beneficial effects of DHA on the vascular function in orchidectomized rats, which include a decrease in the prostanoids release and superoxide formation that were previously augmented by orchidectomy. Additionally, there was an increase in endothelial NO formation and the response to ACh, in which NO involvement and the participation of vasodilator prostanoids were increased. DHA also reversed the decrease in EFS-induced response caused by orchidectomy. All of these findings suggest beneficial effects of DHA on vascular function by reversing the neurogenic response and the endothelial dysfunction caused by orchidectomy.

Operational stabilities of different chemical derivatives of Novozym 435 in an alcoholysis reaction.

Industrial use of Novozym 435 in synthesis of structured lipids and biodiesel via alcoholysis is limited by mass transfer effects of the glycerides through immobilized enzymes and its low operational stability under operation conditions. To better understand this, differently modified Novozym 435 preparations, differing in their surface nature and in their interactions with reactants, have been compared in the alcoholysis of Camelina sativa oil. The three modifications performed have been carried out under conditions where all exposed groups of the enzyme have been modified. These modifications were: 2,4,6-trinitrobenzensulfonic acid (Novo-TNBS), ethylendiamine (Novo-EDA) and polyethylenimine (Novo-PEI). Changes in their operational performance are analyzed in terms of changes detected by scan electron microscopy in the support morphology. The hydrophobic nature of the TNBS accelerates the reaction rate; t-ButOH co-solvent swells the macroporous acrylic particles of Lewatit VP OC 1600 in all biocatalysts, except in the case of Novo-PEI. This co-solvent only increases the maximal conversions obtained at 24h using the modified biocatalysts. t-ButOH reduces enzyme inactivation by alcohol and water. In a co-solvent system, these four biocatalysts remain fully active after 14 consecutive reaction cycles of 24h, but only Novo-TNBS yields maximal conversion before cycle 5. Some deposits on biocatalyst particles could be appreciated during reuses, and TNBS derivatization diminishes the accumulation of product deposits on the catalyst surface. Most particles of commercial Novozym(®) 435 are broken after operation for 14 reaction cycles. The broken particles are fully active, but they cause problems of blockage in filtration operations and column reactors. The three derivatizations studied make the matrix particles more resistant to rupture.

Effect of Dietary Docosahexaenoic Acid Supplementation on the Participation of Vasodilator Factors in Aorta from Orchidectomized Rats.

Benefits of n-3 polyunsaturated fatty acids (PUFAs) against cardiovascular diseases have been reported. Vascular tone regulation is largely mediated by endothelial factors whose release is modulated by sex hormones. Since the incidence of cardiovascular pathologies has been correlated with decreased levels of sex hormones, the aim of this study was to analyze whether a diet supplemented with the specific PUFA docosahexaenoic acid (DHA) could prevent vascular changes induced by an impaired gonadal function. For this purpose, control and orchidectomized rats were fed with a standard diet supplemented with 5% (w/w) sunflower oil or with 3% (w/w) sunflower oil plus 2% (w/w) DHA. The lipid profile, the blood pressure, the production of prostanoids and nitric oxide (NO), and the redox status of biological samples from control and orchidectomized rats, fed control or DHA-supplemented diet, were analyzed. The vasodilator response and the contribution of NO, prostanoids and hyperpolarizing mechanisms were also studied. The results showed that orchidectomy negatively affected the lipid profile, increased the production of prostanoids and reactive oxygen species (ROS), and decreased NO production and the antioxidant capacity, as well as the participation of hyperpolarizing mechanisms in the vasodilator responses. The DHA-supplemented diet of the orchidectomized rats decreased the release of prostanoids and ROS, while increasing NO production and the antioxidant capacity, and it also improved the lipid profile. Additionally, it restored the participation of hyperpolarizing mechanisms by activating potassium. Since the modifications induced by the DHA-supplemented diet were observed in the orchidectomized, but not in the healthy group, DHA seems to exert cardioprotective effects in physiopathological situations in which vascular dysfunction exists.

Enzymatic re-esterification of lower glycerides from soybean oil with conjugated linoleic acid (CLA).

New structured lipids essentially free of saturated fatty acids and rich in essential fatty acids and CLA were prepared from soybean oil using a selective enzymatic procedure of synthesis. Saturated fatty acids originally present in the oil were selectively removed in a selective alcoholysis step. Enzymatic re-esterification with conjugated linoleic acid (CLA) of lower glycerides (di- and monoglycerides) obtained from soybean oil was studied using several commercially available lipases. Higher maximum reaction conversions were obtained with the free acid form of CLA than with the corresponding ethyl ester. Reactions with Novozym 435 were fastest, producing 84% diacylglycerols (DAG) in 0.5 h of reaction at 60 degrees C. For Lipozyme RM IM the maximum yields of triacylglycerols (TAG) were achieved at 60 degrees C (43% in 4.5 h) and 25 degrees C (43% TAG in 7 h). The dominant species in DAG-rich products were LnL and LL. TAG-rich products obtained with Lipozyme RM IM had LLL and LLO/OLO as their predominant TAG. Quantitative conversions to DAG were obtained in 3-4.5 h with 10% (w/w) Lipase G 50 at 60 degrees C and a molar ratio of free CLA to hydroxyl groups of 5:1.

Different enzyme requirements for the synthesis of biodiesel: Novozym 435 and Lipozyme TL IM.

Enzymatic syntheses of biodiesel via alcoholysis of different vegetable oils (sunflower, borage, olive and soybean) have been studied. Loss of lipase activity induced by the nucleophile is greater with methanol than with ethanol, and is greater for Lipozyme TL IM than for Novozym 435. The optimum volume of ethanol depends on the loading of solid biocatalyst and is higher for preparations of Novozym 435 than for Lipozyme TL IM. Maximum rates were obtained with Lipozyme TL IM, for a molar ratio of alcohol to FA residues of 0.33. By contrast, Novozym 435 requires at least a 2:1 ratio. Alcoholysis of the vegetable oils is faster with Lipozyme TL IM than with Novozym 435. Use of a high loading of Novozym 435 (50% w/w) and a large molar excess of ethanol are required to obtain an initial rate similar to that obtained with Lipozyme TL IM at a lower enzyme loading (10% w/w) and an equimolar ratio of ethanol and FA residues. Novozym 435 produces quantitative conversions in only 7h at 25 degrees C, but complete conversions are not obtained with Lipozyme TL IM. Three stage stepwise addition of ethanol yields 84% conversion to ethyl esters for Lipozyme TL IM. Hence use of Novozym 435 is preferred. After nine cycles in a batch reactor Novozym 435 retained 85% of its initial activity.