148 research outputs found
Mineralocorticoid Deficiency and Treatment in Congenital Adrenal Hyperplasia
Approximately 75%–80% of patients with Congenital Adrenal Hyperplasia (CAH) fail to synthesize sufficient mineralocorticoids to maintain salt and water balance. In most instances genotype can predict mineralocorticoid deficiency in CAH. Early recognition and replacement with 9α-fludrocortisone and salt supplements will prevent development of potentially lethal salt losing crises. In infancy a relative state of aldosterone resistance exists and replacement dose of 9α-fludrocortisone based on body surface area is higher during infancy compared to childhood and adults. Salt supplementation is generally not required after weaning is started. Regular monitoring of blood pressure and measurements of plasma electrolytes and renin are required to prevent complications of under or over dosage
Transport of flexible chiral objects in a uniform shear flow
The transport of slightly deformable chiral objects in a uniform shear flow
is investigated. Depending on the equilibrium configuration one finds up to
four different asymptotic states that can be distinguished by a lateral drift
velocity of their center of mass, a rotational motion about the center of mass
and deformations of the object. These deformations influence the magnitudes of
the principal axes of the second moment tensor of the considered object and
also modify a scalar index characterizing its chirality. Moreover, the
deformations induced by the shear flow are essential for the phenomenon of
dynamical symmetry breaking: Objects that are achiral under equilibrium
conditions may dynamically acquire chirality and consequently experience a
drift in the lateral direction.Comment: 25 pages, 16 figure
Repetitive Stimulation of the Pituitary with Growth-Hormone-Releasing Hormone Alters the Proportion of 22 and 20 Kilodalton Human-Growth Hormone Released
Background/Aims. 20 Kilodalton-hGH (20 K-hGH) is the second most abundant pituitary GH variant after 22 K-hGH. In the steady state the proportion of 20 : 22 K-hGH appears constant; does this proportion change with repetitive somatotroph stimulation? Methods. Forty adult males were randomised to receive a GHRH(1–29)NH2 bolus (0.5 μg/kg (n = 20) or 1.0 μg/kg (n = 20)), preceded or followed by a saline bolus, 1 week apart. Four to six weeks later, 10 subjects received 0.5 μg/kg GHRH(1–29)NH2 at 0, 60, 120, and 180 minutes. Clearance rate of 22 and 20 K-hGH was measured in 10 subjects. Results. Total amount/proportion of 22 K-hGH/20 K-hGH secreted was similar for both GHRH(1–29)NH2 doses. Repetitive stimulation reduced the amount of 22 K-hGH released whereas the amount of 20 K-hGH did not change significantly leading to an increase in the proportion of 20 K-hGH (P = .05). Half-life of 20 and 22 K-hGH were not significantly different (P = .55). Conclusions. Repetitive stimulation of the somatotroph may alter the proportion of GH variant released
Effect of oxandrolone and timing of pubertal induction on final height in Turner’s syndrome: randomised, double blind, placebo controlled trial
Objective To examine the effect of oxandrolone and the timing of pubertal induction on final height in girls with Turner’s syndrome receiving a standard dose of growth hormone
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Increased Cross-Gender Identification Independent of Gender Role Behavior in Girls with Congenital Adrenal Hyperplasia: Results from a Standardized Assessment of 4- to 11-Year-Old Children.
While reports showing a link between prenatal androgen exposure and human gender role behavior are consistent and the effects are robust, associations to gender identity or cross-gender identification are less clear. The aim of the current study was to investigate potential cross-gender identification in girls exposed prenatally to high concentrations of androgens due to classical congenital adrenal hyperplasia (CAH). Assessment included two standardized measures and a short parent interview assessing frequency of behavioral features of cross-gender identification as conceptualized in Part A of the diagnostic criteria for gender identity disorder (GID) in the DSM-IV-TR. Next, because existing measures may have conflated gender role behavior with gender identity and because the distinction is potentially informative, we factor analyzed items from the measures which included both gender identity and gender role items to establish the independence of the two constructs. Participants were 43 girls and 38 boys with CAH and 41 unaffected female and 31 unaffected male relatives, aged 4- to 11-years. Girls with CAH had more cross-gender responses than female controls on all three measures of cross-gender identification as well as on a composite measure of gender identity independent of gender role behavior. Furthermore, parent report indicated that 5/39 (12.8 %) of the girls with CAH exhibited cross-gender behavior in all five behavioral domains which comprise the cross-gender identification component of GID compared to 0/105 (0.0 %) of the children in the other three groups combined. These data suggest that girls exposed to high concentrations of androgens prenatally are more likely to show cross-gender identification than girls without CAH or boys with and without CAH. Our findings suggest that prenatal androgen exposure could play a role in gender identity development in healthy children, and may be relevant to gender assignment in cases of prenatal hormone disruption, including, in particular, cases of severely virilized 46, XX CAH.The study was supported by USPHS grant HD24542 to Melissa Hines and by funds from Cambridge University, Cambridge, UK.This is the accepted manuscript version. The final version is available from Springer at http://link.springer.com/article/10.1007%2Fs10508-014-0385-0
Prenatal androgen exposure alters girls' responses to information indicating gender-appropriate behaviour.
Individual variability in human gender-related behaviour is influenced by many factors, including androgen exposure prenatally, as well as self-socialization and socialization by others postnatally. Many studies have looked at these types of influences in isolation, but little is known about how they work together. Here, we report that girls exposed to high concentrations of androgens prenatally, because they have the genetic condition congenital adrenal hyperplasia, show changes in processes related to self-socialization of gender-related behaviour. Specifically, they are less responsive than other girls to information that particular objects are for girls and they show reduced imitation of female models choosing particular objects. These findings suggest that prenatal androgen exposure may influence subsequent gender-related behaviours, including object (toy) choices, in part by changing processes involved in the self-socialization of gendered behaviour, rather than only by inducing permanent changes in the brain during early development. In addition, the findings suggest that some of the behavioural effects of prenatal androgen exposure might be subject to alteration by postnatal socialization processes. The findings also suggest a previously unknown influence of early androgen exposure on later processes involved in self-socialization of gender-related behaviour, and thus expand understanding of the developmental systems regulating human gender development.This is the author accepted manuscript. The final version is available from Royal Society Publishing via http://dx.doi.org/10.1098/rstb.2015.012
Gender, smoking during pregnancy and gestational age influence cord leptin concentrations in newborn infants
Emotional and behavioral adjustment in 4 to 11-year-old boys and girls with classic congenital adrenal hyperplasia and unaffected siblings.
It has been suggested that atypical hormone environments during early development may contribute to subsequent development of psychopathology. Also, it has been suggested that individuals with the autosomal recessive genetic variant, classic congenital adrenal hyperplasia (CAH), might be at increased risk of psychopathology. The present study examined emotional and behavioral adjustment in young children with CAH and their unaffected siblings in the United Kingdom. The parent-reported version of the Strengths and Difficulties Questionnaire (SDQ) was employed to assess adjustment in children aged 4 to 11 years. There were 38 boys with CAH, 43 girls with CAH, 23 unaffected brothers, and 31 unaffected sisters. No differences in emotional or behavioral problems were found between boys or girls with CAH and unaffected same-sex siblings. In addition, affected and unaffected boys in the current sample generally did not differ from boys in the general population. However, compared with girls in the general population, girls with CAH had more difficulties related to conduct problems, hyperactivity/ inattention, and prosocial behavior, and unaffected sisters had more difficulties related to peer problems, conduct problems, and prosocial behavior. These findings suggest that both girls with CAH and unaffected sisters of girls or boys with CAH may be at increased risk of developing behavioral problems. Potential influences related to the early hormone environment, familial process, and social stigma are considered.USPHS National Institutes of Health grant numbers [HD24542
Encoding via conjugate symmetries of slow oscillations for globally coupled oscillators
Peter Ashwin and Jon Borresen, Physical Review E, Vol. 70, p. 026203 (2004). "Copyright © 2004 by the American Physical Society."We study properties of the dynamics underlying slow cluster oscillations in two systems of five globally coupled oscillators. These slow oscillations are due to the appearance of structurally stable heteroclinic connections between cluster states in the noise-free dynamics. In the presence of low levels of noise they give rise to long periods of residence near cluster states interspersed with sudden transitions between them. Moreover, these transitions may occur between cluster states of the same symmetry, or between cluster states with conjugate symmetries given by some rearrangement of the oscillators. We consider the system of coupled phase oscillators studied by Hansel et al. [Phys. Rev. E 48, 3470 (1993)] in which one can observe slow, noise-driven oscillations that occur between two families of two cluster periodic states; in the noise-free case there is a robust attracting heteroclinic cycle connecting these families. The two families consist of symmetric images of two inequivalent periodic orbits that have the same symmetry. For N=5 oscillators, one of the periodic orbits has one unstable direction and the other has two unstable directions. Examining the behavior on the unstable manifold for the two unstable directions, we observe that the dimensionality of the manifold can give rise to switching between conjugate symmetry orbits. By applying small perturbations to the system we can easily steer it between a number of different marginally stable attractors. Finally, we show that similar behavior occurs in a system of phase-energy oscillators that are a natural extension of the phase model to two dimensional oscillators. We suggest that switching between conjugate symmetries is a very efficient method of encoding information into a globally coupled system of oscillators and may therefore be a good and simple model for the neural encoding of information
Fermionic massive modes along cosmic strings
The influence on cosmic string dynamics of fermionic massive bound states
propagating in the vortex, and getting their mass only from coupling to the
string forming Higgs field, is studied. Such massive fermionic currents are
numerically found to exist for a wide range of model parameters and seen to
modify drastically the usual string dynamics coming from the zero mode currents
alone. In particular, by means of a quantization procedure, a new equation of
state describing cosmic strings with any kind of fermionic current, massive or
massless, is derived and found to involve, at least, one state parameter per
trapped fermion species. This equation of state exhibits transitions from
subsonic to supersonic regimes while the massive modes are filled.Comment: 27 pages, 15 figures, uses ReVTeX. Shortened version, accepted for
publication in Phys. Rev.
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