337 research outputs found
Testicular Adrenal Rest Tumours in Congenital Adrenal Hyperplasia
In adult patients with congenital adrenal hyperplasia (CAH), the presence
of testicular adrenal rest tumours (TART) is an important complication leading to
gonadal dysfunction and infertility. These tumours can be already found in childhood and puberty. In this paper, we review the embryological, histological, biochemical,
and clinical features of TART and discuss treatment options
Physical, social and societal functioning of children with congenital adrenal hyperplasia (CAH) and their parents, in a Dutch population
<p>Abstract</p> <p>Background</p> <p>Most research concerning congenital adrenal hyperplasia (CAH) and related conditions caused by primary adrenal insufficiency, such as Addison's or Cushing's disease, has focused on medical aspects rather than on patients' quality of life. Therefore, our objective was to investigate the physical, social and societal functioning of children with CAH and their parents in a Dutch population.</p> <p>Methods</p> <p>The study is descriptive and cross-sectional. Self-designed questionnaires, based on questionnaires developed in the Netherlands for different patient groups, were sent to parents of children with CAH between 0 and 18 years old. Participants were recruited through the Dutch patient group for Adrenal Disease (NVACP) and six hospitals in the Netherlands. Three different questionnaires were designed for parents: for children aged 0 - 4, aged 4 - 12 and aged 12 - 18. Additionally, a fourth questionnaire was sent to adolescents with CAH aged 12 - 18. Main outcome measures were experienced burden of the condition, self-management and participation in several areas, such as school and leisure time.</p> <p>Results</p> <p>A total of 106 parents returned the questionnaire, 12 regarding pre-school children (0-4 years), 63 regarding primary school children (4-12 years), and 32 regarding secondary school children (12-18 years), combined response rate 69.7%. Also, 24 adolescents returned the questionnaire. Children and adolescents with CAH appear to be capable of self-management at a young age. Experienced burden of the condition is low, although children experience several health related problems on a daily basis. Children participate well in school and leisure time. Few children carry a crisis card or emergency injection with them.</p> <p>Conclusions</p> <p>Overall, our research shows that, according to their parents, children with CAH experience few negative effects of the condition and that they participate well in several areas such as school and leisure time. However, improvements can be made concerning the measures parents and children must take to prevent an adrenal crisis.</p
Geometric-phase-induced false electric dipole moment signals for particles in traps
Theories are developed to evaluate Larmor frequency shifts, derived from geometric phases, in experiments to measure electric dipole moments (EDMs) of trapped, atoms, molecules and neutrons. A part of these shifts is proportional to the applied electric field and can be interpreted falsely as an electric dipole moment. A comparison is made between our theoretical predictions for these shifts and some results from our recent experiments, which shows agreement to within the experimental errors of 15 %. The comparison also demonstrates that some trapped particle EDM experiments have reached the sensitivity where stringent precautions are needed to minimise and control such false EDMs. Computer simulations of these processes are also described. They give good agreement with the analytical results and they extend the study by investigating the influence of varying surface reflection laws in the hard walled traps considered. They also explore the possibility to suppress such false EDMs by introducing collisions with buffer gas particles. Some analytic results for frequency shifts proportional to the square of the E-field are also given and there are results for the averaging of the B-field in the absence of an E-field
Comparing the Sensitivity of Algal, Cyanobacterial and Bacterial Bioassays to Different Groups of Antibiotics
Comparing the sensitivity of algal, cyanobacterial and bacterial bioassays to different groups of antibiotics van der Grinten, E.; Pikkemaat, M.G.; van den Brandhof, E.J.; Stroomberg, G.J.; Kraak, M.H.S. Published in: Chemosphere DOI: 10.1016/j.chemosphere.2010.04.011 Link to publication Citation for published version (APA): van der Grinten, E., Pikkemaat, M. G., van den Brandhof, E. J., Stroomberg, G. J., & Kraak, M. H. S. (2010). Comparing the sensitivity of algal, cyanobacterial and bacterial bioassays to different groups of antibiotics. Chemosphere, 80(1), 1-6. https://doi.org/10.1016/j.chemosphere.2010.04.011 General rights It is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s) and/or copyright holder(s), other than for strictly personal, individual use, unless the work is under an open content license (like Creative Commons). Disclaimer/Complaints regulations If you believe that digital publication of certain material infringes any of your rights or (privacy) interests, please let the Library know, stating your reasons. In case of a legitimate complaint, the Library will make the material inaccessible and/or remove it from the website. Please Ask the Library: https://uba.uva.nl/en/contact, or a letter to: Library of the University of Amsterdam, Secretariat, Singel 425, 1012 WP Amsterdam, The Netherlands. You will be contacted as soon as possible. a b s t r a c t Antibiotics may affect both primary producers and decomposers, potentially disrupting ecosystem processes. Hence, it is essential to assess the impact of antibiotics on aquatic ecosystems. The aim of the present study was therefore to evaluate the potential of a recently developed test for detecting antibiotics in animal tissue, the Nouws Antibiotic Test (NAT), as a sensitive bioassay to assess the effects of antibiotics in water. To this purpose, we determined the toxicity of sulphamethoxazole, trimethoprim, flumequine, tylosin, streptomycin, and oxytetracycline, using the NAT adapted for water exposure. The sensitivity of the NAT was compared to that of bioassays with bacteria (Microtox), cyanobacteria and green algae. In the Microtox test with Vibrio fischeri as test organism, no effects were observed for any of the test compounds. For three of the six antibiotics tested, the cyanobacteria were more vulnerable than the green algae when using photosynthetic efficiency as an endpoint. The lowest EC50 values for four out of six tested antibiotics were obtained using the NAT bacterial bioassay. The bacterial plate system responded to antibiotics at concentrations in the lg L Ă1 and lower mg L Ă1 range and, moreover, each plate proved to be specifically sensitive to the antibiotics group it was designed for. It is concluded that the NAT bioassay adapted for water exposure is a sensitive test to determine the presence of antibiotics in water. The ability of this test to distinguish five major antibiotic groups is a very strong additional value
An Improved Experimental Limit on the Electric Dipole Moment of the Neutron
An experimental search for an electric-dipole moment (EDM) of the neutron has
been carried out at the Institut Laue-Langevin (ILL), Grenoble. Spurious
signals from magnetic-field fluctuations were reduced to insignificance by the
use of a cohabiting atomic-mercury magnetometer. Systematic uncertainties,
including geometric-phase-induced false EDMs, have been carefully studied. Two
independent approaches to the analysis have been adopted. The overall results
may be interpreted as an upper limit on the absolute value of the neutron EDM
of |d_n| < 2.9 x 10^{-26} e cm (90% CL).Comment: 5 pages, 2 figures. The published PRL is slightly more terse (e.g. no
section headings) than this version, due to space constraints. Note a small
correction-to-a-correction led to an adjustment of the final limit from 3.0
to 2.9 E-26 e.cm compared to the first version of this preprin
Androgen receptor expression is required to ensure development of adult leydig cells and to prevent development of steroidogenic cells with adrenal characteristics in the mouse testis
Background:
The interstitium of the mouse testis contains Leydig cells and a small number of steroidogenic cells with adrenal characteristics which may be derived from the fetal adrenal during development or may be a normal subset of the developing fetal Leydig cells. Currently it is not known what regulates development and/or proliferation of this sub-population of steroidogenic cells in the mouse testis. Androgen receptors (AR) are essential for normal testicular function and in this study we have examined the role of the AR in regulating interstitial cell development.
Results:
Using a mouse model which lacks gonadotropins and AR (hpg.ARKO), stimulation of luteinising hormone receptors in vivo with human chorionic gonadotropin (hCG) caused a marked increase in adrenal cell transcripts/protein in a group of testicular interstitial cells. hCG also induced testicular transcripts associated with basic steroidogenic function in these mice but had no effect on adult Leydig cell-specific transcript levels. In hpg mice with functional AR, treatment with hCG induced Leydig cell-specific function and had no effect on adrenal transcript levels. Examination of mice with cell-specific AR deletion and knockdown of AR in a mouse Leydig cell line suggests that AR in the Leydig cells are likely to regulate these effects.
Conclusions:
This study shows that in the mouse the androgen receptor is required both to prevent development of testicular cells with adrenal characteristics and to ensure development of an adult Leydig cell phenotype
Optimizing the Timing of Highest Hydrocortisone Dose in Children and Adolescents With 21-Hydroxylase Deficiency
CONTEXT: Hydrocortisone treatment of young patients with 21-hydroxylase deficiency (21OHD) is given thrice daily, but there is debate about the optimal timing of the highest hydrocortisone dose, either mimicking the physiological diurnal rhythm (morning), or optimally suppressing androgen activity (evening). OBJECTIVE: We aimed to compare 2 standard hydrocortisone timing strategies, either highest dosage in the morning or evening, with respect to hormonal status throughout the day, nocturnal blood pressure (BP), and sleep and activity scores. METHODS: This 6-week crossover study included 39 patients (aged 4-19 years) with 21OHD. Patients were treated for 3 weeks with the highest hydrocortisone dose in the morning, followed by 3 weeks with the highest dose in the evening (nâ
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21), or vice versa (nâ
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18). Androstenedione (A4) and 17-hydroxyprogesterone (17OHP) levels were quantified in saliva collected at 5 am; 7 am; 3 pm; and 11 pm during the last 2 days of each treatment period. The main outcome measure was comparison of saliva 17OHP and A4 levels between the 2 treatment strategies. RESULTS: Administration of the highest dose in the evening resulted in significantly lower 17OHP levels at 5 am, whereas the highest dose in the morning resulted in significantly lower 17OHP and A4 levels in the afternoon. The 2 treatment dose regimens were comparable with respect to averaged daily hormone levels, nocturnal BP, and activity and sleep scores. CONCLUSION: No clear benefit for either treatment schedule was established. Given the variation in individual responses, we recommend individually optimizing dose distribution and monitoring disease control at multiple time points
Body mass index at diagnosis of a childhood brain tumor; a reflection of hypothalamic-pituitary dysfunction or lifestyle?
Purpose: Childhood brain tumor survivors (CBTS) are at risk of becoming overweight, which has been shown to be associated with hypothalamic-pituitary (HP) dysfunction during follow-up. Body mass index (BMI) at diagnosis is related to BMI at follow-up. It is uncertain, however, whether aberrant BMI at brain tumor diagnosis reflects early hypothalamic dysfunction or rather reflects genetic and sociodemographic characteristics. We aimed to examine whether BMI at childhood brain tumor diagnosis is associated with HP dysfunction at diagnosis or its development during follow-up. Methods: The association of BMI at diagnosis of a childhood brain tumor to HP dysfunction at diagnosis or during follow-up was examined in a Dutch cohort of 685 CBTS, excluding children with craniopharyngioma or a pituitary tumor. Individual patient data were retrospectively extracted from patient charts. Results: Of 685 CTBS, 4.7% were underweight, 14.2% were overweight, and 3.8% were obese at diagnosis. Being overweight or obese at diagnosis was not associated with anterior pituitary deficiency or diabetes insipidus at diagnosis or during follow-up. In children with suprasellar tumors, being obese at diagnosis was associated with central precocious puberty. Conclusion: Overweight or obesity at diagnosis of a childhood brain tumor seems not to be associated with pituitary deficiencies. These results suggest that genetics and lifestyle may be more important etiologic factors for higher BMI at diagnosis in these children than hypothalamic dysfunction. To improve the long-term outcome of CBTS with regards to overweight and obesity, more attention should be given to lifestyle already at the time of brain tumor treatment
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