Expression of Circadian Clock and Melatonin Receptors within Cultured Rat Cardiomyocytes

Melatonin, the pineal gland hormone, provides entrainment of many circadian rhythms to the ambient light/dark cycle. Recently, cardiovascular studies have demostrated melatonin interactions with many physiological processes and diseases, such as hypertension and cardiopathologies. Although membrane melatonin receptors (MT1, MT2) and the transcriptional factor ROR alpha have been reported to be expressed in the heart, there is no evidence of the cell-type expressing receptors as well as the possible role of melatonin on the expression of the circadian clock of cardiomyocytes, which play an important role in cardiac metabolism and function. Therefore, the aim of this study was to evaluate the mRNA and protein expressions of MT1, MT2, and ROR alpha and to determine whether melatonin directly influences expression of circadian clocks within cultured rat cardiomyocytes. Adult rat cardiomyocyte cultures were created, and the cells were stimulated with 1 nM melatonin or vehicle. Gene expressions were assayed by real-time polymerase chain reaction (PCR). The mRNA and protein expressions of membrane melatonin receptors and RORa were established within adult rat cardiomyocytes. Two hours of melatonin stimulation did not alter the expression pattern of the analyzed genes. However, given at the proper time, melatonin kept Rev-erb alpha expression chronically high, specifically 12 h after melatonin treatment, avoiding the rhythmic decline of Rev-erb alpha mRNA. The blockage of MT1 and MT2 by luzindole did not alter the observed melatonin-induced expression of Rev-erb alpha mRNA, suggesting the nonparticipation of MT1 and MT2 on the melatonin effect within cardiomyocytes. It is possible to speculate that melatonin, in adult rat cardiomyocytes, may play an important role in the light signal transduction to peripheral organs, such as the heart, modulating its intrinsic rhythmicity. (Author correspondence: cipolla@icb.usp.br)

Melatonin and the circadian entrainment of metabolic and hormonal activities in primary isolated adipocytes

The aim of this work was to investigate the effect of the in vitro circadian-like exposure to melatonin [in the presence or absence of insulin (Ins)] on the metabolism and clock gene expression in adipocytes. To simulate the cyclic characteristics of the daily melatonin profile, isolated rat adipocytes were exposed in a circadian-like pattern to melatonin added to the incubating medium for 12 hr (mimicking the night), followed by an equal period without melatonin (mimicking the day) combined or not with Ins. This intermittent incubation was interrupted when four and a half 24-hr cycles were fulfilled. At the end, either during the induced night (melatonin present) or the induced day (melatonin absent), the rates of lipolysis and D-[U-(14)C]-glucose incorporation into lipids were estimated, in addition to the determination of lipogenic [glucose-6-phosphate dehydrogenase and fatty acid synthase (FAS)] and lipolytic (hormone sensitive lipase) enzymes and clock gene (Bmal-1b, Clock, Per-1 and Cry-1) mRNA expression. The leptin release was also measured. During the induced night, the following effects were observed: an increase in the mRNA expression of Clock, Per-1 and FAS; a rise in lipogenic response and leptin secretion; and a decrease in the lipolytic activity. The intermittent exposure of adipocytes to melatonin temporally and rhythmically synchronized their metabolic and hormonal function in a circadian fashion, mimicking what is observed in vivo in animals during the daily light-dark cycle. Therefore, this work helps to clarify the physiological relevance of the circadian pattern of melatonin secretion and its interactions with Ins, contributing to a better understanding of the adipocyte biology.

Pars pro toto: Experimental exhibition design and curatorial paradigms

'Pars pro toto: Experimental Exhibition Design and Curatorial Paradigms' is situated within the ongoing debate over the conflation of art and curating, and the subsequent tension between artistic autonomy and curatorial intervention. This practice-led research project acclimates these polarities using a collaborative and discursive curatorial methodology in the creation of two exhibitions. Both exhibitions, one digital and one primarily physical, investigated how the temporary exhibition can operate as a site for provocation, how the suggested methodology facilitates the relationship between artist and curator within this paradigm, and outlines factors that assist in expanding the definition of the contemporary curatorial role.

Conspectus florae Fennicae vol. VII Dicotyledoneae: pars VI Compositae.

Kielet ruotsi, latina ja suomi. Typis impr. 1924-1926.

Argentina. Crisis de pagos y sinergia entre programas del FMI y Club de París. 1956-2009

Desde 1956, en ocho ocasiones la Argentina refinanció deudas oficiales en el ámbito del Club de París. Estas refinanciaciones implicaron implementar programas de ajuste, acompañados en seis oportunidades por acuerdos contingentes con el FMI. Pero la apreciación subsiguiente de la moneda doméstica y los compromisos de facilitar importaciones pactados en tales acuerdos, desencadenan un ciclo de auge y deterioro de la cuenta corriente del balance de pagos que finaliza con una nueva crisis y una deuda externa incrementada, agravando la restricción de divisas originante de tal situación, en un contexto de salida masiva de capitales, inflación y recesión.

Copia de una carta remitida desde París a los sacerdotes vascos presos en Dueñas.

Fecha: 31-5-1939 (>1970 copia) / Unidad de instalación: Carpeta 45 - Expediente 2-33 / Nº de pág.: 3 (mecanografiadas)

De la Viena "Fin-de-Siècle" al París "Rive-Gauche": Reigen/La Ronde

Eguíluz, Federico; Merino, Raquel; Olsen, Vickie; Pajares, Eterio; Santamaría, José Miguel (eds.)

Justificante de la Delegación de Hacienda del Gobierno de Euzkadi en París, 1939

1 carta (mecanografiada) ; 210x270mm. Ubicación: Caja 1 - Carpeta 16

Exploring the role of the substantia nigra pars reticulata in eye movements.

Experiments that demonstrated a role for the substantia nigra in eye movements have played an important role in our understanding of the function of the basal ganglia in behavior more broadly. In this review we explore more recent experiments that extend the role of the substantia nigra pars reticulata from a simple gate for eye movements to include a role in cognitive processes for eye movements. We review recent evidence suggesting that basal ganglia nuclei beyond the substantia nigra may also play a role in eye movements and the cognitive events leading up to the production of eye movements. We close by pointing out some unresolved questions in our understanding of the relationship of basal ganglia nuclei and eye movements.

Emergencias de la mediación intelectual. "La Revista de América" (París, 1912-1914) y la red de escritores latinoamericanos en Europa a comienzos del siglo XX

Este trabajo estudia el proyecto editorial de la Revista de América (1912-1914), fundada en París y dirigida por Francisco García Calderón. Mi propósito es analizar el modo en que muchos de los vínculos entre los escritores latinoamericanos radicados en París entre fines del siglo XIX y la Primera Guerra Mundial se materializaron en la edición de revistas. Propongo examinar las estrategias de difusión de las producciones latinoamericanas en el Viejo Continente, como así también algunos aspectos ideológicos y de intervención intelectual que la revista llegó a articular. En un primer momento, me detengo en los rasgos materiales tanto del proyecto editorial de la revista como de los vínculos entre los latinoamericanos desterrados. Luego indago las distintas formas de mediación crítica, por un lado, y cultural, por otro, que la revista escenificó y, en algunos casos, desarrolló activamente. En efecto, la revista de García Calderón vuelve visible una dimensión mediadora en varios sentidos: mediación crítica entre productores y lectores, pues se propuso como instancia de difusión, al convocar a “a los mejores escritores latinoamericanos”. Al mismo tiempo, propuso otras dos mediaciones: entre pares, al funcionar como consagradora, seleccionando y agrupando simbólicamente a los escritores de cada país latinoamericano. Finalmente, una mediación intercontinental entre culturas en la contemporaneidad, que intentó acercar dos gestos en la acción de la revista: una legitimación del pensamiento y el arte “de ultramar” y una valoración de los desarrollos artísticos europeos del presente.

Palaeoclimate change recorded in Upper Cretaceous (Albian-Cenomanian) Kazhdumi Formation Borehole spectral Gamma-Ray Logs, South Pars Gas field, Persian Gulf

Th/U and Th/K data from spectral gamma-ray logs obtained from outcrop successions have been used as a rapid and inexpensive proxy for determining possible episodes of humid-arid palaeoclimate change. Such outcrop-based measurements have never been tested using spectral gamma-ray data obtained from wireline logs in subsurface boreholes. Th/K and Th/U ratios have traditionally been used to decipher sequence stratigraphic patterns, at outcrop and in borehole. The possible influence of palaeoclimate on such ratio changes has yet to be proven, especially from borehole data. In this work, we compare borehole-derived Th/K (and to a lesser extent Th/U) to palaeoenvironmental changes inferred from palynology and deduce that both sea level and changing hinterland weathering regimes caused discrete fluctuations observed in the spectral gamma-ray logs. This is the first time such subsurface information has been used in this way. Interpretation of wireline logs in terms of palaeoclimate as well as sea level may now be considered, and the use of such logs in palaeoclimate reconstruction is strengthened.