Impacto del ejercicio físico en variables relacionadas con el bienestar emocional y funcional en adultos mayores

Background and aimThe benefits of the physical exercise in aging, and specially in frailty, have been associated with reduced risk of mortality, chronic disease, and cognitive and functional impairments. Multi-component training, which combines strength, endurance, balance, and gait training, represents the most beneficial kind of physical exercise in older adults.MethodsGiven the effectiveness of the multi-component training, a physical exercise program «Actívate» (based on the methodology Vivifrail), with the focus on «active aging», was conducted in the present study. Forty-nine older adults over 60 years participated in this program.ResultsThe physical exercise intervention led to a reduction in diastolic blood pressure, pain threshold and sleep disturbances (e. g. hypersomnia) (t ≥ 2.72, p < 0.01), as well as an increase of walking speed (t = 7.84, p ≤ 0.001). Further, quality of life factors (GENCAT scale), like emotional well-being, personal development, physical well-being, self-determination, and social inclusion, were greater after intervention (t ≥ ?2.06, p < 0.05).ConclusionsThese findings underline the benefits of multi-component training in functionality of older adults, and further, provide relevant aspects about the modulation of pain perception, sleep disturbances, social factors and physical and emotional well-being. Physical exercise programs such as «Actívate» should be promoted, in order to encourage healthy lifestyle habits, in the older adults’ population.     

Antioxidant and antiplatelet effects of the alpha-tocopherol-aspirin combination in type 1-like diabetic rats

We analyze the effect of the combination of acetylsalicylic acid (2 mg/kg/day p.o.) and alpha-tocopherol (25 mg/kg/day p.o.) in a type-1-like experimental model of diabetes mellitus on platelet factors, endothelial antithrombotic factors and tissue oxidative stress. In diabetic rats, the combination of drugs had a greater inhibitory effect on platelet aggregation than in untreated control animals with diabetes (88.87%). The combination of drugs had little effect on the inhibition of thromboxane production (-90.81%) in comparison to acetylsalicylic acid alone (-84.66%), potentiated prostacyclin production (+162%) in comparison to alpha-tocopherol alone (+30.55%), and potentiated nitric oxide production (+241%) in comparison to either drug alone (acetylsalicylic acid +125%, alpha-tocopherol +142%). The combination of the two drugs improved the thromboxane/prostacyclin balance (0.145+/-0.009) in comparison to untreated diabetic animals (4.221+/-0.264) and in untreated healthy animals (0.651+/-0.045). It did not potentiate the antioxidant effect of either drug alone, but did increase tissue concentrations of reduced glutathione, especially in vascular tissue (+90.09% in comparison to untreated animals). In conclusion, in the experimental model of diabetes tested here, the combination of acetylsalicylic acid and alpha-tocopherol led to beneficial changes that can help protect tissues from thrombotic and ischemic phenomena.     

62-kb Plasmids Harboring <Emphasis Type="Italic">rulAB</Emphasis> Homologues Confer UV-tolerance and Epiphytic Fitness to <Emphasis Type="Italic">Pseudomonas syringae</Emphasis> pv. <Emphasis Type="Italic">syringae</Emphasis> Mango Isolates

The presence of genetic determinants homologous to rulAB genes for ultraviolet (UV) radiation resistance was determined in a collection of Pseudomonas syringae pv. syringae strains isolated from mango. The potential role of these plasmids in UV tolerance and ecological fitness in the mango phyllosphere was also evaluated. Nearly all of the 62-kb plasmids present in the P. syringae pv. syringae strains hybridized with a rulAB probe, but these 62-kb plasmids showed differences in restriction patterns. In vitro assays of tolerance to UV radiation of P. syringae pv. syringae strains showed a higher survival of the strains harboring the 62-kb plasmids compared to strains lacking plasmids when exposed to UVC or UVA+B fractions. Similar results were observed when transconjugants harboring the 62-kb plasmid were tested. Survival assays were carried out under field conditions, and a higher survival of P. syringae pv. syringae strains harboring 62-kb plasmids under direct solar radiation on the adaxial surface of leaves was also observed. When the assays were carried out in shady areas or on the abaxial surface of leaves, survival time was comparable for all the assayed strains, whether or not they contained a 62-kb plasmid hybridizing to rulAB. Our results indicate that P. syringae pv. syringae strains harboring 62-kb plasmids show an increase in ecological fitness when colonizing the mango phyllosphere.     

Changes in intracellular sodium, chlorine, and potassium concentrations in staurosporine-induced apoptosis

Ion gradients across the plasma membrane, fundamentally K(+), play a pivotal role in the execution phase of apoptosis. However, little is known about other monovalent anions (Cl(-)) or cations (Na(+)) in apoptosis. In addition, the relationship between changes in total ion composition and morphological and biochemical events are poorly understood. We investigated simultaneous changes in sodium (Na), chlorine (Cl), and potassium (K) concentrations in stauroporine-induced apoptosis by quantitative electron probe X-ray microanalysis (EPXMA) in single cells. Apoptotic cells identified unequivocally from the presence of chromatin condensation in backscattered electron images were characterized by an increase in intracellular Na, a decrease in intracellular Cl and K concentrations, and a decrease in K/Na ratio. The ouabain-sensitive Rb-uptake assay demonstrated a net decrease in Na(+)/K(+)-ATPase activity, suggesting that increases in Na and decreases in K and the K/Na ratio in apoptotic cells were related with inhibition of the Na(+)/K(+)-ATPase pump. These changes in diffusible elements were associated with externalization of phosphatidyl serine and oligonucleosomal fragmentation of DNA. This alteration in ion homeostasis and morphological hallmarks of apoptosis occur in cells that have lost their inner mitochondrial transmembrane potential and before the plasma membrane becomes permeable.     

Co-existence of circular and multiple linear amplicons in methotrexate-resistant Leishmania.

Circular and linear amplicons were analyzed in detail in Leishmania tropica cells resistant to methotrexate (MTX). Both types of elements presented sequences related to the H locus and coexisted in resistant cells. The linear amplicons appeared first during the selection process (at 10 microM MTX) and varied with regard to size and structure in cells exposed to increasing concentrations of drug. The circular element was evident at higher concentrations (50 microMs) but was the major amplified DNA in cells resistant to 1000 microM MTX while the level of amplification of the linear elements remained low. The extrachromosomal DNAs were unstable in the absence of drug and their disappearance coincided with an increase in sensitivity to MTX. Mapping of the minichromosomes and the circular element showed that they were all constituted by inverted duplications. The circular amplicon contained an inverted repeat derived from the H locus that encompassed the pteridine reductase gene (PTR1) responsible for MTX resistance. The amplified segment in the linear amplicons was longer and included the pgpB and pgpC genes that encode P-glycoproteins of unknown function previously characterized in different Leishmania species.     

Biphasic behavior of changes in elemental composition during staurosporine-induced apoptosis

Although the identification of events that occur during apoptosis is a fundamental goal of apoptotic cell death research, little is know about the precise sequence of changes in total elemental composition during apoptosis. We evaluated total elemental composition (Na, Mg, P, Cl, S, and K) in relation to molecular and morphological features in human U937 cells induced to undergo apoptosis with staurosporine, an intrinsic pathway activator. To evaluate total elemental content we used electron probe X-ray microanalysis to measure simultaneously all elements from single, individual cells. We observed two phases in the changes in elemental composition (mainly Na, Cl and K). The early phase was characterized by a decrease in intracellular K (P < 0.001) and Cl (P < 0.001) content concomitant with cell shrinkage, and preceded the increase in proteolytic activity associated with the activation of caspase-3. The later phase started with caspase-3 activation, and was characterized by a decrease in the K/Na ratio (P < 0.001) as a consequence of a significant decrease in K and increase in Na content. The inversion of intracellular K and Na content was related with the inhibition of Na⁺/K⁺ ATPase. This later phase was also characterized by a significant increase (P < 0.001) in intracellular Cl with respect to the early phase. In addition, we found a decrease in S content and an increase in the P/S ratio. These distinctive changes coincided with chromatin condensation and DNA fragmentation. Together, these findings support the concept that changes in total elemental composition take place in two phases related with molecular and morphological features during staurosporine-induced apoptosis.     

Micropropagation of Isoplexis canariensis (l.) G. Don

Isoplexis canariensis is a source of compounds related to the Digitalis cardenolides and anthraquinones. It is a protected endemic plant, but even so, it is rapidly disappearing from nature. An optimal micropropagation procedure was achieved using nodal segments with two axillary buds as explants. A concentration of 0.5 μM kinetin in Murashige and Skoog liquid basal medium was found to be optimal for micropropagation. Rooting in vitro was unnecessary for ex vitro survival. This revised version was published online in June 2006 with corrections to the Cover Date.     

Iturin A is the principal inhibitor in the biocontrol activity of Bacillus amyloliquefaciens PPCB004 against postharvest fungal pathogens

Aims: A Bacillus amyloliquefaciens strain, surviving epiphytically on the surface of fruit, was isolated while searching for naturally occurring biological control agents. This bacterial strain was characterized for its antifungal activity against seven selected fungal postharvest pathogens of citrus. Methods and Results: To understand the antifungal activity, seven postharvest fungal pathogens were screened for growth inhibition by B. amyloliquefaciens strain. Assays using B. amyloliquefaciens lipopeptide extracts showed a strong inhibitive activity. The inhibitory effect was observed in abnormal conidial germination and germ tube development when conidia were treated with different lipopeptide extract concentrations. Further analysis using PCR and chromatography confirmed the presence of fengycin, iturin and surfactine, of which iturin A showed the strongest and most common inhibitory effect. The results are supported by site‐directed mutagenesis analysis, targeted to suppress the biosynthesis of iturin A production. Fruit trials confirmed disease development inhibition when the antagonist was applied 1 day prior to or 1 day after fungal application. Conclusions: We conclude that the iturin family of lipopeptides are vital in the antagonism of B. amyloliquefaciens against the seven citrus postharvest pathogenic fungi tested. Significance and Impact of the Study: We elucidated the principal mechanism used by B. amyloliquefaciens PPCB004 to suppress postharvest disease development on stored fruits.     

Bioinformatics Analysis of the Complete Genome Sequence of the Mango Tree Pathogen Pseudomonas syringae pv. syringae UMAF0158 Reveals Traits Relevant to Virulence and Epiphytic Lifestyle

The genome sequence of more than 100 Pseudomonas syringae strains has been sequenced to date; however only few of them have been fully assembled, including P. syringae pv. syringae B728a. Different strains of pv. syringae cause different diseases and have different host specificities; so, UMAF0158 is a P. syringae pv. syringae strain related to B728a but instead of being a bean pathogen it causes apical necrosis of mango trees, and the two strains belong to different phylotypes of pv.syringae and clades of P. syringae. In this study we report the complete sequence and annotation of P. syringae pv. syringae UMAF0158 chromosome and plasmid pPSS158. A comparative analysis with the available sequenced genomes of other 25 P. syringae strains, both closed (the reference genomes DC3000, 1448A and B728a) and draft genomes was performed. The 5.8 Mb UMAF0158 chromosome has 59.3% GC content and comprises 5017 predicted protein-coding genes. Bioinformatics analysis revealed the presence of genes potentially implicated in the virulence and epiphytic fitness of this strain. We identified several genetic features, which are absent in B728a, that may explain the ability of UMAF0158 to colonize and infect mango trees: the mangotoxin biosynthetic operon mbo, a gene cluster for cellulose production, two different type III and two type VI secretion systems, and a particular T3SS effector repertoire. A mutant strain defective in the rhizobial-like T3SS Rhc showed no differences compared to wild-type during its interaction with host and non-host plants and worms. Here we report the first complete sequence of the chromosome of a pv. syringae strain pathogenic to a woody plant host. Our data also shed light on the genetic factors that possibly determine the pathogenic and epiphytic lifestyle of UMAF0158. This work provides the basis for further analysis on specific mechanisms that enable this strain to infect woody plants and for the functional analysis of host specificity in the P. syringae complex.