899 resultados para Paper of the adult


Relevância:

100.00% 100.00%

Publicador:

Resumo:

Aims: The goal of the current study was to evaluate the impact of maternal sodium intake during gestation on the systemic and renal renin-angiotensin-aldosterone-system (RAAS) of the adult offspring. Main methods: Female Wistar rats were fed high- (HSD-8.0% NaCl) or normal-sodium diets (NSD-1.3% NaCl) from 8 weeks of age until the delivery of their first litter. After birth, the offspring received NSD. Tail-cuff blood pressure (TcBP) was measured in the offspring between 6 and 12 weeks of age. At 12 weeks of age, the offspring were subjected to either one week of HSD or low sodium diet (LSD-0.1 6%NaCl) feeding to evaluate RAAS responsiveness or to acute saline overload to examine sodium excretory function. Plasma (PRA) and renal renin content (RRC), serum aldosterone (ALDO) levels, and renal cortical and medullary renin mRNA expression levels were evaluated at the end of the study. Key findings: TcBP was higher among dams fed HSD, but no TcBP differences were observed among the offspring. Male offspring, however, exhibited increased TcBP after one week of HSD feeding, and this effect was independent of maternal diet. Increased RAAS responsiveness to the HSD and LSD was also observed in male offspring. The baseline levels of PRA. ALDO, and cortical and medullary renin gene expression were lower but the RRC levels were higher among HSD-fed male offspring (HSDoff). Conversely, female HSDoff showed reduced sodium excretion 4 h after saline overload compared with female NSDoff. Significance: High maternal sodium intake is associated with gender-specific changes in RAAS responsiveness among adult offspring. (C) 2012 Elsevier Inc. All rights reserved.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

OBJECTIVE: Understanding of articular cartilage physiology, remodelling mechanisms, and evaluation of tissue engineering repair methods requires reference information regarding normal structural organization. Our goals were to examine the variation of cartilage cell and matrix morphology in different topographical areas of the adult human knee joint. METHODS: Osteochondral explants were acquired from seven distinct anatomical locations of the knee joints of deceased persons aged 20-40 years and prepared for analysis of cell, matrix and tissue morphology using confocal microscopy and unbiased stereological methods. Differences between locations were identified by statistical analysis. RESULTS: Medial femoral condyle cartilage had relatively high cell surface area per unit tissue volume in the superficial zone. In the transitional zone, meniscus-covered lateral tibia cartilage showed elevated chondrocyte densities compared to the rest of the knee while lateral femoral condyle cartilage exhibited particularly large chondrocytes. Statistical analyses indicated highly uniform morphology throughout the radial zone (lower 80% of cartilage thickness) in the knee, and strong similarities in cell and matrix morphologies among cartilage from the femoral condyles and also in the mediocentral tibial plateau. Throughout the adult human knee, the mean matrix volume per chondron was remarkably constant at approximately 224,000 microm(3), corresponding to approximately 4.6 x 10(6) chondrons per cm(3). CONCLUSIONS: The uniformity of matrix volume per chondron throughout the adult human knee suggests that cell-scale biophysical and metabolic constraints may place limitations on cartilage thickness, mechanical properties, and remodelling mechanisms. Data may also aid the evaluation of cartilage tissue engineering treatments in a site-specific manner. Results indicate that joint locations which perform similar biomechanical functions have similar cell and matrix morphologies; findings may therefore also provide clues to understanding conditions under which focal lesions leading to osteoarthritis may occur.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Biologic agents (also termed biologicals or biologics) are therapeutics that are synthesized by living organisms and directed against a specific determinant, for example, a cytokine or receptor. In inflammatory and autoimmune diseases, biologicals have revolutionized the treatment of several immune-mediated disorders. Biologicals have also been tested in allergic disorders. These include agents targeting IgE; T helper 2 (Th2)-type and Th2-promoting cytokines, including interleukin-4 (IL-4), IL-5, IL-9, IL-13, IL-31, and thymic stromal lymphopoietin (TSLP); pro-inflammatory cytokines, such as IL-1β, IL-12, IL-17A, IL-17F, IL-23, and tumor necrosis factor (TNF); chemokine receptor CCR4; and lymphocyte surface and adhesion molecules, including CD2, CD11a, CD20, CD25, CD52, and OX40 ligand. In this task force paper of the Interest Group on Biologicals of the European Academy of Allergy and Clinical Immunology, we review biologicals that are currently available or tested for the use in various allergic and urticarial pathologies, by providing an overview on their state of development, area of use, adverse events, and future research directions.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

To investigate the evolution of globin genes in the genus Xenopus, we have determined the primary structure of the related adult alpha I- and alpha II-globin genes of X. laevis and of the adult alpha-globin gene of X. tropicalis, including their 5'-flanking regions. All three genes are comprised of three exons and two introns at homologous positions. The exons are highly conserved and code for 141 amino acids. By contrast, the corresponding introns vary in length and show considerable divergence. Comparison of 900 bp of the 5'-flanking region revealed that the X. tropicalis gene contains a conserved proximal 310-bp promoter sequence, comprised of the canonical TATA and CCAAT motifs at homologous positions, and five conserved elements in the same order and at similar positions as previously shown for the corresponding genes of X. laevis. We therefore conclude that these conserved upstream elements may represent regulatory sequences for cell-specific regulation of the adult Xenopus globin genes.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Fine finger and hand movements in humans, monkeys, and rats are under the direct control of the corticospinal tract (CST). CST lesions lead to severe, long-term deficits of precision movements. We transected completely both CSTs in adult rats and treated the animals for 2 weeks with an antibody that neutralized the central nervous system neurite growth inhibitory protein Nogo-A (mAb IN-1). Anatomical studies of the rubrospinal tracts showed that the number of collaterals innervating the cervical spinal cord doubled in the mAb IN-1- but not in the control antibody-treated animals. Precision movements of the forelimb and fingers were severely impaired in the controls, but almost completely recovered in the mAb IN-1-treated rats. Low threshold microstimulation of the motor cortex induced a rapid forelimb electromyography response that was mediated by the red nucleus in the mAb IN-1 animals but not in the controls. These findings demonstrate an unexpectedly high capacity of the adult central nervous system motor system to sprout and reorganize in a targeted and functionally meaningful way.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The dentate gyrus of the hippocampus is one of the few areas of the adult brain that undergoes neurogenesis. In the present study, cells capable of proliferation and neurogenesis were isolated and cultured from the adult rat hippocampus. In defined medium containing basic fibroblast growth factor (FGF-2), cells can survive, proliferate, and express neuronal and glial markers. Cells have been maintained in culture for 1 year through multiple passages. These cultured adult cells were labeled in vitro with bromodeoxyuridine and adenovirus expressing beta-galactosidase and were transplanted to the adult rat hippocampus. Surviving cells were evident through 3 months postimplantation with no evidence of tumor formation. Within 2 months postgrafting, labeled cells were found in the dentate gyrus, where they differentiated into neurons only in the intact region of the granule cell layer. Our results indicate that FGF-2 responsive progenitors can be isolated from the adult hippocampus and that these cells retain the capacity to generate mature neurons when grafted into the adult rat brain.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Group-size effects, as changes in the adult language when speaking to individual or multiple children in two- and three-year-olds' Australian childcare centre classrooms were investigated. The language addressed to children by 21 staff members was coded for social (e.g., non-verbal, inferential and pragmatic), and linguistic (e.g., morphological, lexical, syntactic and referential) features. In the two-year-olds' classrooms, minimal differences were found between the language used in dyads (addressed to a single child) and polyads (addressed to more than one child). More extensive group-size effects, particularly in syntactic complexity, were found in the three-year-olds' classrooms. Explanations for the constancy of the adult language input in the younger classrooms, and the changes noted in the older rooms will be discussed in terms of plurality (i.e., more than one listener), methodology, and group-size effects that may be specific to the early childhood educational setting.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The National Center for Family Literacy (2003a) and the National Even Start Association (2005) have stated that the single most effective and influential factor in increasing student academic achievement is parental involvement. The purpose of this qualitative study was to determine how participation in adult literacy courses influences parent-child interaction in various educationally related activities known as Interactive Literacy Activities (ILAs). This study investigated ILAs from the mothers? perspective, and examines the changes that occur in parental involvement or ILAs when immigrant parents of a limited educational background participate in an adult education program. The principal method of data collection was key informant interviews (Gall, Borg, & Gall, 1996). Other methods of data collection included observations of parent-child interactions and field observations. Data analysis methods included Memo-ing (Miles & Huberman, 1994), within case analysis and cross-case analysis. ^ Findings demonstrate that changes occurred in the parent-child relationship when mothers of a limited educational background participated in an adult literacy course. When participating in ILAs or English literacy activities related to second language acquisition (including reading and speaking for comprehension and pronunciation), the children of these mothers took on the role of the adult. Participation in literacy activities was often initiated by the child and the children were frequently concerned with their mother's literacy acquisition. Mothers reported that their children were more confident, worked harder on school related activities and were more open to communication. ^ It can be concluded from this study that, in the case of these immigrant families, a mother's participation in adult literacy classes is influential in the relationship between mother and child. These children participated in ILAs for the benefit of their mothers and initiated literacy activities more frequently. The children responded better to their parents during literacy activities because there was a positive change in the relationship between mother and child. The relationship between mother and child appeared to be strengthened by greater trust, a sense of pride and more communication. ^

Relevância:

100.00% 100.00%

Publicador:

Resumo:

ENGLISH:The gill rakers of both juvenile and adult anchovetas are long and numerous, with many fine processes which make a very efficient straining apparatus. The stomach is modified into a gizzard. The intestine undergoes heteronomous growth, and attains about eight times the standard length in adults. The stomach contents of 39 samples of juvenile fish and 120 adult fish were examined. Diatoms were the principal food of all the sizes of fish examined, from 29 to 153 millimeters. Silicoflagellates, dinoflagellates, pollen grains, formaniferans, rotifer shells, crustaceans, and eggs, probably of crustaceans, were also found in small amounts. Coscinodiscus, a diatom, was the most important item found in the stomachs of the juvenile fish. No strong differences were observed in the feeding habits of different sizes of juveniles. Even taking into account their smaller size, the juveniles had smaller volumes of material and lesser numbers of organisms in their stomachs than did the adults. The stomachs of the adult fish, unlike those of the juveniles, usually contained considerable quantities of mud. Melosira, Coscinodiscus, and Thalassionema, all diatoms, were the most important organisms found in the stomachs of the adults. The incidence of Melosira was much higher in the stomachs of fish from the areas to the east of the entrance of the Panama Canal than from those to the west. No seasonal differences in the food were observed. The volume of material in the stomachs ranged from almost none to nearly 1.0 milliliter, with an average of a little more than 0.2 milliliter. Twenty-six bottom samples were examined; the organisms found corresponded very closely to those encountered in the stomachs of the adult fish. It is concluded that the juvenile anchovetas are chiefly or entirely filter feeders of the pelagic zone. The adults, however, are mostly iliophagous feeders, but possibly do some feeding upon plankton as well. SPANISH:Las branquispinas de las anchovetas, tanto en las juveniles como en las adultas, son largas y numerosas, can varias protuberancias finas que hacen de ellas un aparato filtrador muy eficiente. El estómago está modificado en una molleja. El intestino está sometido a un crecimiento heterónomo, llega a alcanzar unas oeho veces la longitud estandar en las adultas. Fué examinado el contenido estomacal de 39 ,muestras de peces juveniles y de 120 adultos. Las diatomeas fueron el alimento principal de todos los peces que fueron examinados cuyo tamaño varió entre los 29 y 153 milimetros. Se encontraron también en cantidades silicoflagelados, dinoflagelados, granos de polen, foraminíferos, conchas de rotiferos, crustáceos y huevos, probablemente de crustáceos. Coscinodiscus, una diatomea, fué el alimento más importante encontrado en los estómagos de los peces juveniles. No se observaron mayores diferencias en los hábitos de alimentación en los juveniles de diferentes tamaños. Aún tomando en cuenta su tamaño menor, los juveniles tenian volúmenes más pequeños de material y un número menor de organismos en sus estómagos que los adultos. Los estómagos de los peces adultos, diferentes a los de los juveniles, contenían por lo general considerables cantidades de fango. Melosira, Coscinodiscus, y Thalassionema, todas ellas diatomeas, fueron los organismos más importantes encontrados en los estómagos de los adultos. La contribuciónde Melosira fué mucho más alta en los estómagos de los peces procedentes de las áreas al este de la entrada del Canal de Panamá que la de aquellos provenientes del oeste. No se observaron diferencias estacionales en la alimentacion. El volúmen de material en los estómagos varió de casi cero a cerca de 1.0 mililitros, con un promedio de un poco mas de 0.2 mili1itros. Se examinaron 26 muestras de fonda; los organismos encontrados correspondieron muy cercanamente a los hallados en los estómagos de los peces adultos. Se ha llegado a la conclusión de que las anchovetas juveniles son principalmente ó enteramente filtradoras de alimentos de la zona pelágica. Las adultas, sin embargo, son en su mayoria iliófagas, pero posiblemente se alimentan también de plancton.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The Drosophila compound eye has provided a genetic approach to understanding the specification of cell fates during differentiation. The eye is made up of some 750 repeated units or ommatidia, arranged in a lattice. The cellular composition of each ommatidium is identical. The arrangement of the lattice and the specification of cell fates in each ommatidium are thought to occur in development through cellular interactions with the local environment. Many mutations have been studied that disrupt the proper patterning and cell fating in the eye. The eyes absent (eya) mutation, the subject of this thesis, was chosen because of its eyeless phenotype. In eya mutants, eye progenitor cells undergo programmed cell death before the onset of patterning has occurred. The molecular genetic analysis of the gene is presented.

The eye arises from the larval eye-antennal imaginal disc. During the third larval instar, a wave of differentiation progresses across the disc, marked by a furrow. Anterior to the furrow, proliferating cells are found in apparent disarray. Posterior to the furrow, clusters of differentiating cells can be discerned, that correspond to the ommatidia of the adult eye. Analysis of an allelic series of eya mutants in comparison to wild type revealed the presence of a selection point: a wave of programmed cell death that normally precedes the furrow. In eya mutants, an excessive number of eye progenitor cells die at this selection point, suggesting the eya gene influences the distribution of cells between fates of death and differentiation.

In addition to its role in the eye, the eya gene has an embryonic function. The eye function is autonomous to the eye progenitor cells. Molecular maps of the eye and embryonic phenotypes are different. Therefore, the function of eya in the eye can be treated independently of the embryonic function. Cloning of the gene reveals two cDNA's that are identical except for the use of an alternatively-spliced 5' exon. The predicted protein products differ only at the N-termini. Sequence analysis shows these two proteins to be the first of their kind to be isolated. Trangenic studies using the two cDNA's show that either gene product is able to rescue the eye phenotype of eya mutants.

The eya gene exhibits interallelic complementation. This interaction is an example of an "allelic position effect": an interaction that depends on the relative position in the genome of the two alleles, which is thought to be mediated by chromosomal pairing. The interaction at eya is essentially identical to a phenomenon known as transvection, which is an allelic position effect that is sensitive to certain kinds of chromosomal rearrangements. A current model for the mechanism of transvection is the trans action of gene regulatory regions. The eya locus is particularly well suited for the study of transvection because the mutant phenotypes can be quantified by scoring the size of the eye.

The molecular genetic analysis of eya provides a system for uncovering mechanisms underlying differentiation, developmentally regulated programmed cell death, and gene regulation.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The seminal bag, or seminal receptacle, forms a characteristic organ of cyclopids, serving for retention of the sperms discharged from the spermatophores. The structure of the seminal receptacle, more precisely its form, is fairly widely used in diagnosis and undoubtedly can be more widely applied in the systematics of the group. Within the limits of the family Cyclopidae it is possible to distinguish crustaceans with three basic types of seminal bag. The differences consist of the position which this organ occupies in the genital segment. of one species, we carried out a series of observations on its formation in ontogenesis and during the life of the adult stage. As material for observation the study used laboratory cultures of three species; Acanthocyclops americanus (Marsh) from the plankton of the Moscow River, Cyclops vicinus Uljan and Mesocyclops leuckarti Glaus from the plankton of the channel section of the upper part of the Gorkovsk reservoir. The author concluded that the irreversibility of the changes in the seminal receptacle presents the possibility of utilising this structure as one of the indicators of the growth of the individual.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The stock assessment task group report (1991) mentions that fish counters could play a key role in providing data on the size of the adult stock, and in particular the migratory salmonid stock. This report assesses the performance of the 'logie' fish counter at Forge Weir on the River Lune. Using video surveillance, a total of 1137 hours time lapse and 15 hours real time were used for validation purposes. This report looks at materials and methods, counting accuracy, sizing ability and environmental conditions, performance across the electrode array and salmonid swimming speed.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Most Copepoda pass through, first, a series of nauplius stages, and then through a series of copepodid stages (or cyclops stages), in which the general form of the adult is assumed. ... In the first place, the differentiation between the larvae of the various copepod species to be found in the plankton, both marine and fresh water, greatly augments the value and accuracy of quantitative and qualitative plankton analyses, because many species spend a large portion of their life span in an immature condition. In the second place, the taxonomy of the Copepoda is admittedly not completely satisfactory ...

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The Mediterranean Sea is located in a crossroad of mid-latitude and subtropical climatic modes that enhance contrasting environmental conditions over both latitudinal and longitudinal ranges. Here, we show that the large-scale environmental forcing is reflected in the basin scale trends of the adult population of the calanoid copepod Centropages typicus. The species is distributed over the whole Mediterranean basin, and maximal abundances were found in the north-western basin associated to oceanic fronts, and in the Adriatic Sea associated to shallow and semi enclosed waters. The peak of main abundances of C. typicus correlates with the latitudinal temperature gradient and the highest seasonal abundances occurred in spring within the 14–18°C temperature window. Such thermal cline may define the latitudinal geographic region where C. typicus seasonally dominates the >200 μm-sized spring copepod community in the Mediterranean Sea. The approach used here is generally applicable to investigate the large-scale spatial patterns of other planktonic organisms and to identify favourable environmental windows for population development.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Functional genomics have not been reported for Opisthorchis viverrini or the related fish-borne fluke, Clonorchis sinensis. Here we describe the introduction by square wave electroporation of Cy3-labeled small RNA into adult O. viverrini worms. Adult flukes were subjected to square wave electroporation employing a single pulse for 20 ms of 125V in the presence of 50 µg/ml of Cy3-siRNA. The parasites tolerated this manipulation and, at 24 and 48 h after electroporation, fluorescence from the Cy3-siRNA was evident throughout the parenchyma of the worms, with strong fluorescence evident in the guts and reproductive organs of the adult worms. Second, other worms were treated using the same electroporation settings with double stranded RNA targeting an endogenous papain-like cysteine protease, cathepsin B. This manipulation resulted in a significant reduction in specific mRNA levels encoding cathepsin B, and a significant reduction in cathepsin B activity against the diagnostic peptide, Z-Arg-Arg-AMC. This appears to be the first report of introduction of reporter genes into O. viverrini and the first report of experimental RNA interference (RNAi) in this fluke. The findings indicated the presence of an intact RNAi pathway in these parasites which, in turn, provides an opportunity to probe gene functions in this neglected tropical disease pathogen.