Search results for "structures"
showing 10 items of 4815 documents
Associations between neonatal cry acoustics and visual attention during the first year
2019
It has been suggested that early cry parameters are connected to later cognitive abilities. The present study is the first to investigate whether the acoustic features of infant cry are associated with cognitive development already during the first year, as measured by oculomotor orienting and attention disengagement. Cry sounds for acoustic analyses (fundamental frequency; F0) were recorded in two neonatal cohorts at the age of 0–8 days (Tampere, Finland) or at 6 weeks (Cape Town, South Africa). Eye tracking was used to measure oculomotor orienting to peripheral visual stimuli and attention disengagement from central stimuli at 8 months (Tampere) or at 6 months (Cape Town) of age. Only a m…
Pharmacological Characterization of Melanocortin Receptors in Fish Suggests an Important Role for ACTH
2005
The melanocortin (MC) receptor subtypes have distinctive characteristic binding profiles. We found that the trout and Fugu MC4 receptors have similar affinity for alpha-MSH and beta-MSH and a much higher affinity for ACTH than does the human MC4 receptor. The Fugu MC1 and the trout and Fugu MC5 receptors also have higher affinity for ACTH-derived peptides than alpha-, beta-, or gamma-MSH. It is tempting to speculate that ACTH-derived peptides may have played an important role as "original" ligands at the MC receptors, while the specificity of the different subtypes for the alpha-, beta-, and gamma-MSH peptides may have appeared at later stages during vertebrate evolution.
Distribution of corticotropin-releasing factor-immunoreactive neurons in the central nervous system of the domestic chicken and Japanese quail
2004
In birds, as in mammals, corticotropin-releasing factor (CRF) is present in a number of extrahypothalamic brain regions, indicating that CRF may play a role in physiological and behavioral responses other than the control of adrenocorticotropin hormone release by the pituitary. To provide a foundation for investigation of the roles of CRF in the control of avian behavior, the distribution of CRF immunoreactivity was determined throughout the central nervous system of the domestic chicken (Gallus domesticus) and Japanese quail (Coturnix japonica). The distribution of CRF-immunoreactive (-ir) perikarya and fibers in the chicken and quail brain was found to be more extensive than previously re…
Role of glutathione in Thiobencarb resistance in the European eel Anguilla anguilla.
2000
Glutathione-dependent defense against xenobiotic toxicity is a multifaceted phenomenon that has been well characterized in mammals. In the present study, eels of species Anguilla anguilla were exposed to 15 ppm of the herbicide thiobencarb (S-4-chlorobenzyl diethylthiocarbamate) for 96 h. Eels exposed to the pesticide were grouped in 24-h intervals according to their time of death, while surviving intoxicated eels constituted another group (live animals). Glutathione content (GSx, GSH, GSSG) was determined in liver and muscle tissues of the dead and live (intoxicated) animals and compared to control values (nonexposed eels). The fish that died before 96 h of exposure were considered suscept…
Development of day-night rhythmicity in "synaptic" ribbon numbers in the pinealocytes of posthatch chicks kept under either natural photoperiodic con…
1991
: Pineal synaptic ribbons (SR) undergo characteristic changes over a period of 24 hr under natural photoperiodic conditions in various vertebrates, being low in number during daytime and elevated at night. During posthatch development of chicks, the rhythmicity of SR numbers is reported to appear at the age of about 2 weeks. Because the influence of external light during the growth phase of chicks on the development of day-night rhythmicity in SR numbers is unknown, we studied day-night differences in SR numbers in the pinealocytes of chicks at the posthatch ages of 15, 17, and 19 days; chicks had previously been kept under natural photoperiodic conditions or continuous illumination. Under …
Human Oviductal Gonadotropin-Releasing Hormone: Possible Implications in Fertilization, Early Embryonic Development, and Implantation1
2000
The oviduct is host to gametes and early embryos at a critical point in their lives. It is clear that the interactions of gametes/early embryo with the maternal oviduct in an autocrine and paracrine manner provide a microenvironment that enhances fertilization, early embryonic development, and implantation. Moreover, there is considerable evidence that an extrahypothalamic GnRH may play a substantial role as a molecular autocrine/paracrine regulator in these events. Gametes and preimplantation embryos express GnRH and GnRH receptor at both messenger ribonucleic acid (mRNA) and protein levels. However, whether GnRH is produced by the human oviduct has not yet been demonstrated. We used RT-PC…
Adjuvante dermatokosmetische Aknetherapie
2010
Adjuvant dermato-cosmetic therapy in acne is an essential part of the concept of treating acne after initiation and during maintenance therapy. Those are mechanical peeling, chemical peeling and its combination. It needs supervision by an experienced dermatologist.
Adamantiades-Behçet disease : an enigmatic process with oral manifestations
2006
La enfermedad de Adamantiades-Behçet es una vasculitis multisistémica crónica, potencialmente capaz de afectar a cualquier órgano o sistema del cuerpo humano y en la que la aparición repetida de úlceras orales es una de sus principales expresiones clínicas. La EAB es una patología de carácter universal, con una prevalencia variable en función de la población estudiada y que muestra una curiosa distribución geográfica. A pesar de ser un proceso conocido desde la antigüedad, su etiopatogenia en la que probablemente se hayan implicados factores genéticos, microbiológicos e inmunológicos, continua siendo enigmática. Su amplio espectro de manifestaciones clínicas orales, genitales, cutáneas, ocu…
Reconfigurable DNA Origami Nanocapsule for pH-Controlled Encapsulation and Display of Cargo
2019
DNA nanotechnology provides a toolbox for creating custom and precise nanostructures with nanometer-level accuracy. These nano-objects are often static by nature and serve as versatile templates for assembling various molecular components in a user-defined way. In addition to the static structures, the intrinsic programmability of DNA nanostructures allows the design of dynamic devices that can perform predefined tasks when triggered with external stimuli, such as drug delivery vehicles whose cargo display or release can be triggered with a specified physical or chemical cue in the biological environment. Here, we present a DNA origami nanocapsule that can be loaded with cargo and reversibl…
Caracterización de complejos enzimáticos histona acetiltransferasa en Saccharomyces cerevisiae mediante el uso de mutantes en genes implicados en la …
1999
En la cromatina de los organismos eucariotas el DNA se organiza alrededor de octámeros de histonas, dando lugar a la estructura nucleosomal. Las histonas sufren una serie de modificaciones postraduccionales entre las que se encuentra la acetilación de residuos de lisina, situados en los extremos N-terminales de estas proteínas. Esta modificación reversible, catalizada in vivo por las histona desacetilasas (HD) y las histona acetiltransferasas (HAT), ha sido implicada durante muchos años en la regulación de diversos procesos celulares de gran importancia. Recientemente, el papel de la acetilación de histonas en la regulación de la transcripción ha cobrado gran importancia con el descubrimien…