Publications by authors named "Pedro F Almaida-Pagan"

Purpose Of Review: Circadian rhythms impose daily rhythms a remarkable variety of metabolic and physiological functions, such as cell proliferation, inflammation, and DNA damage response. Accumulating epidemiological and genetic evidence indicates that circadian rhythms' disruption may be linked to cancer. The integration of circadian biology into cancer research may offer new options for increasing cancer treatment effectiveness and would encompass the prevention, diagnosis, and treatment of this disease.

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The longevity-homeoviscous adaptation (LHA) theory of ageing states that lipid composition of cell membranes is linked to metabolic rate and lifespan, which has been widely shown in mammals and birds but not sufficiently in fish. In this study, two species of the genus Amphiprion (Amphiprion percula and Amphiprion clarkii, with estimated maximum lifespan potentials [MLSP] of 30 and 9-16 years, respectively) and the damselfish Chromis viridis (estimated MLSP of 1-2 years) were chosen to test the LHA theory of ageing in a potential model of exceptional longevity. Brain, livers and samples of skeletal muscle were collected for lipid analyses and integral part in the computation of membrane peroxidation indexes (PIn) from phospholipid (PL) fractions and PL fatty acid composition.

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The lipid composition of cell membranes is linked to metabolic rate and lifespan in mammals and birds but very little information is available for fish. In this study, three fish species of the short-lived annual genus with different maximum lifespan potential (MLSP) and the longer-lived outgroup species were studied to test whether they conform to the predictions of the longevity-homeoviscous adaptation (LHA) theory of ageing. Lipid analyses were performed in whole-fish samples and the peroxidation index (PIn) for every phospholipid (PL) class and for the whole membrane was calculated.

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In order to develop objective indexes for chronotype identification by means of direct measurement of circadian rhythms, 159 undergraduate students were recruited as volunteers and instructed to wear ambulatory circadian monitoring (ACM) sensors that continuously gathered information on the individual's environmental light and temperature exposure, wrist temperature, body position, activity, and the integrated TAP (temperature, activity, and position) variable for 7 consecutive days under regular free-living conditions. Among all the proposed indexes, the night phase marker (NPM) of the TAP variable was the best suited to discriminate among chronotypes, due to its relationship with the Munich ChronoType Questionnaire (β = 0.531; < 0.

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Membrane compositions, particularly of mitochondria, could be critical factors in the mechanisms of growth and aging, especially during phases of high oxidative stress that result in molecular damage. Changes affecting lipid class or fatty acid (FA) compositions could affect phospholipid (PL) properties and alter mitochondrial function. In the present study, mitochondrial membrane PL compositions were analysed throughout the life-cycle of Nothobranchius furzeri, a species with explosive growth and one of the shortest-lived vertebrates.

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Several studies have been performed to identify age-related changes in the circadian system (CS) but the impairment of the CS and its chronodisruption at the end of an organism life have not been studied in depth. Aging commonly affects the input pathways into the biological clock or restraints their processing, therefore simplifying the system output, the overt rhythms. The purpose of this work was to do a complete characterization of changes that occurs in the CS in the last stage of a vertebrate organism life and to develop tools able to detect in which moment of the last days of life is the animal, using an overt rhythm, the rest-activity rhythm (RAR).

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In recent decades, the increase in human longevity has made it increasingly important to expand our knowledge on aging. To accomplish this, the use of animal models is essential, with the most common being mouse (phylogenetically similar to humans, and a model with a long life expectancy) and Caenorhabditis elegans (an invertebrate with a short life span, but quite removed from us in evolutionary terms). However, some sort of model is needed to bridge the differences between those mentioned above, achieving a balance between phylogenetic distance and life span.

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Considering membranes and membrane components as possible pacemakers of the main processes taking place inside mitochondria, changes in phospholipids or fatty acids could play a central role linking different mechanisms involved in cumulative damage to cell molecules and dysfunction during periods of high stress, such as rapid growth and aging. Changes affecting either lipid class or fatty acid compositions could affect phospholipid and membrane properties and alter mitochondrial function and cell viability. In the present study, mitochondrial oxidative status and mitochondrial membrane phospholipid compositions were analyzed throughout the life-cycle of zebrafish.

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Mitochondrial membrane composition may be a critical factor in the mechanisms of the aging process by influencing the propagation of reactions involved in mitochondrial function during periods of high stress. Changes affecting either lipid class or fatty acid compositions could affect phospholipid properties and alter mitochondrial function and cell viability. In the present study, mitochondrial membrane phospholipid compositions were analyzed throughout the life cycle of Nothobranchius rachovii.

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Adult (48-week-old) and senescent (72-week-old) individually-kept Nothobranchius korthausae were used as experimental subjects to characterise circadian system (CS) function and age-related changes in senescent fish. This species was specifically chosen because it has already shown potential for use as a model system in gerontological studies. The rest-activity rhythm (RAR) in fish can be easily monitored and used to characterise the state of the CS, and it has also been proposed as a reliable model to study sleep-like periods in fish.

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Membrane composition, particularly of mitochondria, could be a critical factor by determining the propagation of reactions involved in mitochondrial function during periods of high oxidative stress such as rapid growth and aging. Considering that phospholipids not only contribute to the structural and physical properties of biological membranes, but also participate actively in cell signaling and apoptosis, changes affecting either class or fatty acid compositions could affect phospholipid properties and, thus, alter mitochondrial function and cell viability. In the present study, heart and brain mitochondrial membrane phospholipid compositions were analyzed in rainbow trout during the four first years of life, a period characterized by rapid growth and a sustained high metabolic rate.

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Membrane compositions, particularly of mitochondria, could be critical factors in the mechanisms of growth and aging processes, especially during phases of high oxidative stress that result in molecular damage. In the present study, liver and mitochondrial membrane phospholipid (PL) compositions were analyzed in rainbow trout during its four first years of life, a period characterized by rapid growth and high oxidative stress. Specifically, farmed fish of three ages (1-, 2- and 4-years) were studied, and PL compositions of whole liver and liver mitochondria, and fatty acid compositions of individual PL classes were determined.

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