Enhancing cognition before clinical symptoms of dementia.

As the title of the special issue indicates, controversy surrounds augmentation of brain cognition in humans. Lacking efficacious drugs for Alzheimer's disease (AD) and with many AD patients recruited for clinical trials that unfortunately do not provide the expected results, one wonders whether to test cognition enhancement strategies in individuals without symptoms of cognition decline. This opinion article presents the view that safe drugs and or dietary supplements should be tested worldwide in aged individuals under the control of a non-for-profit organization

On the Mechanistic Perceptions of Consciousness: From Quantum Mechanics to Consciousness and Free Will and from David Bohm to Benjamin Libet

Biologists and biochemists have been reluctant to en-ter the realm of consciousness with real scientific meth-ods. One approach by Nobel laureate Francis Crick in hisbook "Astonishing Hypothesis: The Scientific Search for the Soul" [1] was to look at scientific papers that, eventu-ally, could give insight into consciousness. The problem, in my opinion, is that the author took data obtained from experiments in nonhuman animals. The question that imme- diately arises is whether studies using animal models can be of interest to what only humans can have, be aware of and verbalize: consciousness. He focused on the visual system; this is puzzling because blindness is not incompatible with consciousness. In fact, we know that subjective events are noted as consciousness in individuals whose cortical primary visual areas are not functional [2]

Assessment of the cooling potential of an indoor living wall using different substrates in a warm climate

The use of vertical greenery systems in buildings is becoming very popular as they provide several benefits. In this work, the influence of an indoor living wall on the temperature and humidity in a hall inside the School of Agricultural Engineering (University of Seville) was studied. Four different substrates, Geotextile, Epiweb, Xaxim and coconut fibre, were used to grow the plants in order to assess their performance. Several parameters such as temperature, humidity, plant growth or water consumption were monitored and analyzed during a 4-month period. The cooling effect of the living wall was proven, with an average reduction of 4°C over the room temperature though maximum decrements of 6°C have been observed in warmer conditions. Higher air humidity levels were experienced near the living wall, increasing the overall humidity in the room. All the substrates tested were suitable for plant growing and their behaviour was similar. Geotextile showed the best cooling capacity but higher water consumption, coconut fibre presented degradation problems and Epiweb performance was the poorest. Therefore, these systems have been proven to be very useful and interesting for warm indoor environments due to the cooling effect observed in addition to their bio-filtration capacity and the aesthetic component

Suggesting a Way to Understand the Actual Potential of Anti-Alzheimer's Disease Drugs That Show Promise in Transgenic Mouse Models.

One conundrum in Alzheimer's disease (AD) research using transgenic mouse models is the high amount of successful memory-enhancing drugs. By contrast, very few drugs and of limited efficacy are available for humans having this pathology. As previously discussed (1), the advance in this field, i.e., to fulfill the translational facet of anti-AD research, requires deciphering why so many different drugs (or therapeutic interventions, such as exercise or training) have memory-enhancing properties in transgenic models of the disease. Transgenic animals do not accurately reflect the human disease, as they overexpress proteins with mutations that appear only in a reduced percentage of patients (2). The majority of patients have late-onset clinical symptoms due to multiple factors many of which may be circumstantial. On waiting for the development of novel animals models that may, eventually, shorten the distance between the lab bench and the bedside (3), we should take advantage of the huge amount of data showing promise of different drugs in transgenic models. [...

Successful therapies for Alzheimer's disease: why so many in animal models and none in humans?

Peering into the field of Alzheimer's disease (AD), the outsider realizes that many of the therapeutic strategies tested (in animal models) have been successful. One also may notice that there is a deficit in translational research, i.e., to take a successful drug in mice and translate it to the patient. Efforts are still focused on novel projects to expand the therapeutic arsenal to 'cure mice.' Scientific reasons behind so many successful strategies are not obvious. This article aims to review the current approaches to combat AD and to open a debate on common mechanisms of cognitive enhancement and neuroprotection. In short, either the rodent models are not good and should be discontinued, or we should extract the most useful information from those models. An example of a question that may be debated for the advancement in AD therapy is: In addition to reducing amyloid and tau pathologies, would it be necessary to boost synaptic strength and cognition? The debate could provide clues to turn around the current negative output in generating effective drugs for patients. Furthermore, discovery of biomarkers in human body fluids, and a clear distinction between cognitive enhancers and disease modifying strategies, should be instrumental for advancing in anti-AD drug discovery

Enzimas del catabolismo purínico en las fracciones soluble y microsomal de cerebro y cerebelo de rata

El término "microsomas", del que deriva el de "fracción microsomal", no representa un orgánulo subcelular concreto como ocurre con el término "mitocondrias" y su correspondiente "fracción mitocondrial". De Duve (1964) y, posteriormente, Reid (1967), definieron el término e hicieron corresponder los microsomas a la fracción que sedimenta al someter los homogeneizados de un tejido a fuerzas centrífugas superiores a 100.000 g. La estructura y propiedades biológicas de los microsomas dependen no solo de factores intrínsecos (especie, tipo o edad) sino también de las condiciones externas (dieta o estatus hormonal) (Tata 1972, Talwar et al 1962). Los microsomas de hígado, que han sido muy bien estudiados, consisten a menudo en una mezcla de elementos membranosos y de ribosomas (o polisomas), presentes en forma de unidades separadas o de complejos y que derivan casi exclusivamente del retículo endoplasmático (RE). Los microsomas no son, por tanto, estructuras estables y experimentan un recambio relativamente rápido en comparación con la vida de la célula (Omura et al 1967, Siekevitz et al 1967, Arias et al 1969, Hennaee y Horrocks 1978). Un gran número de actividades enzimáticas se asocian con las membranas del RE, mientras que los ribosomas unidos al RE intervienen muy activamente en la síntesis proteica (Tata 1967a y b; Andrews y Tata 1968, 1971; Campbell 1970; Bouchilloux et al 1973). Esta síntesis es muy evidente en tejidos secretores de proteínas, como el hígado (Manganiello y Phillips 1965; Sabatini et al 1966) y tiroides (Morais y Goldberg 1967; Buochilloux et al 1973), pero también se ha demostrado que ocurre en tejido pulmonar de conejo (Stenzel y Rubin 1966) y en corteza cerebral de rata (White et al 1972)

Qué es el estrés oxidativo y cómo afecta al envejecimiento

Cuando Rafael decidió pedir un plato de habas durante la cena de un congreso de trabajo, un compañero de profesión le comentó: ¡Hoy vas a hacer trabajar a tus eritrocitos (también llamados glóbulos rojos)! El comentario le sorprendió, dado que siempre había entendido que las habas tenían un carácter antioxidante que ayudaba a mejorar los procedimientos del estrés oxidativo. Este se desarrolla en el cuerpo con el paso de los años. Pero la realidad muestra que las habas también contienen oxidantes o pro oxidantes como la vicina o la convicina, por lo que su consumo produce un incremento del estrés oxidativo

Enzimas del catabolismo purínico en las fracciones soluble y microsomal de cerebro y cerebelo de rata

[spa] El término "microsomas", del que deriva el de "fracción microsomal", no representa un orgánulo subcelular concreto como ocurre con el término "mitocondrias" y su correspondiente "fracción mitocondrial". De Duve (1964) y, posteriormente, Reid (1967), definieron el término e hicieron corresponder los microsomas a la fracción que sedimenta al someter los homogeneizados de un tejido a fuerzas centrífugas superiores a 100.000 g. La estructura y propiedades biológicas de los microsomas dependen no solo de factores intrínsecos (especie, tipo o edad) sino también de las condiciones externas (dieta o estatus hormonal) (Tata 1972, Talwar et al 1962). Los microsomas de hígado, que han sido muy bien estudiados, consisten a menudo en una mezcla de elementos membranosos y de ribosomas (o polisomas), presentes en forma de unidades separadas o de complejos y que derivan casi exclusivamente del retículo endoplasmático (RE). Los microsomas no son, por tanto, estructuras estables y experimentan un recambio relativamente rápido en comparación con la vida de la célula (Omura et al 1967, Siekevitz et al 1967, Arias et al 1969, Hennaee y Horrocks 1978). Un gran número de actividades enzimáticas se asocian con las membranas del RE, mientras que los ribosomas unidos al RE intervienen muy activamente en la síntesis proteica (Tata 1967a y b; Andrews y Tata 1968, 1971; Campbell 1970; Bouchilloux et al 1973). Esta síntesis es muy evidente en tejidos secretores de proteínas, como el hígado (Manganiello y Phillips 1965; Sabatini et al 1966) y tiroides (Morais y Goldberg 1967; Buochilloux et al 1973), pero también se ha demostrado que ocurre en tejido pulmonar de conejo (Stenzel y Rubin 1966) y en corteza cerebral de rata (White et al 1972)

Naturación urbana y jardinería vertical: de las fachadas verdes a los muros vegetales

En las últimas décadas, las urbes están creciendo considerablemente, dedicándose un porcentaje cada vez más elevado a edificaciones. Se prevé que en el periodo entre 2000 y 2030, la población urbana del mundo habrá aumentado un 72%, mientras que la superficie de las zonas edificadas donde viven 100.000 o más personas podría aumentar en un 175%. En este difícil contexto, la aplicación de los principios de sostenibilidad en las áreas urbanas se erige como uno de los mayores retos de las políticas ambientales del siglo XXI. Su éxito dependerá en gran medida del modelo de ciudad a desarrollar, particularmente en lo que se refiere a la relación entre desarrollo urbano y consumo de recursos ambientales

The old and new visions of biased agonism through the prism of adenosine receptor signaling and receptor/receptor and receptor/protein interactions

Biased signaling is a concept that has arisen in the G protein-coupled receptor (GCPR) research field, and holds promise for the development of new drug development strategies. It consists of different signaling outputs depending on the agonist's chemical structure. Here we review the most accepted mechanisms for explaining biased agonism, namely the induced fit hypothesis and the key/lock hypothesis, but we also consider how bias can be produced by a given agonist. In fact, different signaling outputs may originate at a given receptor when activated by, for instance, the endogenous agonist. We take advantage of results obtained with adenosine receptors to explain how such mechanism of functional selectivity depends on the context, being receptor-receptor interactions (heteromerization) one of the most relevant and most studied mechanisms for mammalian homeostasis. Considering all the possible mechanisms underlying functional selectivity is essential to optimize the selection of biased agonists in the design of drugs targeting GPCRs