Maternal Tissues (maternal + tissue)

Distribution by Scientific Domains

Selected Abstracts

Gross Morphometry of the Bovine Placentome during Gestation

RA Laven
Forty-seven pregnant uteri were collected from an abattoir at eight chronological stages of gestation. Assessments were made of placentome number, weight, length shape and ratio of foetal to maternal tissue by weight. The study showed that there was a great variation in number, size, weight and shape of placentomes. There was no significant change in the total number of placentomes during gestation. Both mean weight and length increased significantly during gestation, but there was a significant change in the relationship between the two as gestation progressed. There was no correlation between the number of placentomes and the mean weight or length of the placentomes. The development of the placenta in the non-pregnant horn was significantly different from that of the pregnant horn, with fewer, smaller, lighter placentomes. However, there was no evidence that placentome development in the non-pregnant horn was affected by placentome development in the pregnant horn. The proportion of the placentome that was maternal tissue increased during gestation, but there was no significant effect of placentome number, or individual placentome weight or length on this proportion. Two placentome shapes were identified, but no effect on foeto-maternal proportion or relationship between shape and total placentome number or weight was identified. [source]

Effects of excessive glucocorticoid receptor stimulation during early gestation on psychomotor and social behavior in the rat ,

Karine Kleinhaus
Abstract Severe psychological stress in the first trimester of pregnancy increases the risk of schizophrenia in the offspring. To begin to investigate the role of glucocorticoid receptors in this association, we determined the effects of the glucocorticoid dexamethasone (2,mg/kg), administered to pregnant rats on gestation days 6,8, on maternal behaviors and schizophrenia-relevant behaviors in the offspring. Dams receiving dexamethasone exhibited increased milk ejection bouts during nursing. Offspring of dexamethasone-treated dams (DEX) showed decreased juvenile social play and a blunted acoustic startle reflex in adolescence and adulthood, effects that were predicted by frequency of milk ejections in the dams. DEX offspring also showed increased prepulse inhibition of startle and reduced amphetamine-induced motor activity, effects not correlated with maternal behavior. It is postulated that over-stimulation of receptors targeted by glucocorticoids in the placenta or other maternal tissues during early gestation can lead to psychomotor and social behavioral deficits in the offspring. Moreover, some of these deficits may be mediated by alterations in postnatal maternal behavior and physiology produced by early gestational exposure to excess glucocorticoids. 2010 Wiley Periodicals, Inc. Dev Psychobiol 52:121,132, 2010 [source]

Maternal and fetal microvasculature in sheep placenta at several stages of gestation

Shireen A. Hafez
Abstract Maternal and fetal microvasculature was studied in ewes at days 50, 90 and 130 of gestation using microvascular corrosion casting and scanning electron microscopy. Microvascular corrosion casts of caruncles at day 50 were cup-shaped with a centrally located cavity. Branches of radial arteries entered the caruncle from its base and ramified on the maternal surface of the caruncle. Stem arteries broke into an extensive mesh of capillaries forming crypts on the fetal surface. The architecture of the caruncle at day 90 was similar to what was found at day 50 but the vascularity and the depth of the crypts increased in correspondence to increased branching of fetal villi. The substance of the caruncle was thicker at day 130 compared with day 50, with no remarkable difference compared with day 90. Capillary sinusoids of irregular form and diameter were observed on the fetal surface of the caruncle at all stages. These sinusoids may reduce blood flow resistance and subsequently increase transplacental exchange capacity. A microvascular corrosion cast of the cotyledon was cup-shaped with wide and narrow sides. Cotyledonary vessels entered and left the cotyledon from the narrow side. A cotyledonary artery gave proximal collateral branches immediately after entering the cotyledon and then further branched to supply the remaining portion of the cotyledon. Vessel branches broke into a mesh of capillaries forming the fetal vascular villi. Fetal villi that were nearest to the center of the cotyledon were the longest. Capillaries forming villi were in the form of a web-like mesh, were irregular in size and had sinusoidal dilations. The architecture of the cotyledon at day 90 was similar to day 50, but the vascularity increased. Branching of the fetal villi became more abundant. This extensive branching presumably allows a higher degree of invasion and surface contact to maternal tissues. At day 130, the distal portions of the fetal villi showed low ridges and troughs to increase the surface area for diffusion. Branching of fetal villi appears to influence the elaboration of maternal crypts in all stages of gestation. However, correspondence between crypts and villi is restricted to distal portions of fetal villi. [source]

Nitrogen balance and ,15N: why you're not what you eat during pregnancy

Benjamin T. Fuller
Carbon (13C/12C) and nitrogen (15N/14N) stable isotope ratios were longitudinally measured in human hair that reflected the period from pre-conception to delivery in 10 pregnant women. There was no significant change in the ,13C results, but all subjects showed a decrease in ,15N values (,0.3 to ,1.1,) during gestation. The mechanisms causing this decrease in hair ,15N have not been fully elucidated. However, since the ,15N values of dietary nitrogen and urea nitrogen are significantly lower compared to maternal tissues, it is hypothesized that the increased utilization of dietary and urea nitrogen for tissue synthesis during pregnancy resulted in a reduction of the steady state diet to a body trophic level effect by approximately 0.5,1,. An inverse correlation (R2,=,0.67) between hair ,15N and weight gain was also found, suggesting that positive nitrogen balance results in a reduction of ,15N values independent of diet. These results indicate that ,15N measurements have the ability to monitor not only dietary inputs, but also the nitrogen balance of an organism. A potential application of this technique is the detection of fertility patterns in modern and ancient species that have tissues that linearly record stable isotope ratios through time. Copyright 2004 John Wiley & Sons, Ltd. [source]

Infant Intersubjectivity: Research, Theory, and Clinical Applications

Colwyn Trevarthen
We review research evidence on the emergence and development of active " self-and-other " awareness in infancy, and examine the importance of its motives and emotions to mental health practice with children. This relates to how communication begins and develops in infancy, how it influences the individual subject's movement, perception, and learning, and how the infant's biologically grounded self-regulation of internal state and self-conscious purposefulness is sustained through active engagement with sympathetic others. Mutual selfother- consciousness is found to play the lead role in developing a child's cooperative intelligence for cultural learning and language. A variety of preconceptions have animated rival research traditions investigating infant communication and cognition. We distinguish the concept of " intersubjectivity ", and outline the history of its use in developmental research. The transforming body and brain of ahumanindividual grows in active engagement with an environment of human factors-organic at first, then psychological or inter-mental. Adaptive, human-responsive processes are generated first by interneuronal activity within the developing brain as formation of the human embryo is regulated in a support-system of maternal tissues. Neural structures are further elaborated with the benefit of intra-uterine stimuli in the foetus, then supported in the rapidly growing forebrain and cerebellum of the young child by experience of the intuitive responses of parents and other human companions. We focus particularly on intrinsic patterns and processes in pre-natal and post-natal brain maturation that anticipate psychosocial support in infancy. The operation of an intrinsic motive formation (IMF) that developed in the core of the brain before birth is evident in the tightly integrated intermodal sensory-motor coordination of a newborn infant's orienting to stimuli and preferential learning of human signals, by the temporal coherence and intrinsic rhythms of infant behaviour, especially in communication, and neonates' extraordinary capacities for reactive and evocative imitation. The correct functioning of this integrated neural motivating system is found to be essential to the development of both the infant's purposeful consciousness and his or her ability to cooperate with other persons' actions and interests, and to learn from them. The relevance of infants' inherent intersubjectivity to major child mental health issues is highlighted by examining selected areas of clinical concern. We review recent findings on postnatal depression, prematurity, autism, ADHD, specific language impairments, and central auditory processing deficits, and comment on the effcacy of interventions that aim to support intrinsic motives for intersubjective communication when these are not developing normally. [source]

In vitro culture of Arabidopsis embryos within their ovules

Michael Sauer
Summary Embryogenesis of flowering plants establishes a basic body plan with apical,basal, radial and bilateral patterns from the single-celled zygote. Arabidopsis embryogenesis exhibits a nearly invariant cell division pattern and therefore is an ideal system for studies of early plant development. However, plant embryos are difficult to access for experimental manipulation, as they develop deeply inside maternal tissues. Here we present a method for the culture of zygotic Arabidopsis embryos in vitro. The technique omits excision of the embryo by culturing the entire ovule, thus greatly facilitating the time and effort involved. It enables external manipulation of embryo development and culture from the earliest developmental stages up to maturity. Administration of various chemical treatments as well as the use of different molecular markers is demonstrated together with standard techniques for visualizing gene expression and protein localization in in vitro cultivated embryos. The presented set of techniques allows for so far unavailable molecular physiology approaches in the study of early plant development. [source]