Search results for "imulation"
showing 10 items of 7271 documents
Circadian rhythm and effects of light on cAMP content of the dwarf hamster suprachiasmatic nucleus
1998
The present study was conducted in the dwarf hamster (Phodopus sungorus) to investigate whether a circadian rhythm is present in the content of the second messenger cyclic adenosine 3',5'-monophosphate (cAMP) in the suprachiasmatic nucleus (SCN), the endogenous clock in mammals. In animals held under light/dark conditions (LD), we observed high levels at the end of the light phase and low levels during the night in frozen SCN punches. In animals held in continuous dark, a similar rhythm was seen although a second peak was present in the subjective day. In senile hamsters under LD, the decrease of cAMP levels at the light transition was not seen. These data, obtained for the first time from …
Pituitary resistance to thyroid hormone action with preserved circadian rhythm of thyrotropin in a postmenopausal woman.
1992
We assessed the 24-h behavior of circulating TSH and the dopaminergic control on TSH release in a postmenopausal woman, who had elevated levels of serum thyroid hormones and an inappropriately high concentration of serum TSH, indicating pituitary resistance to thyroid hormone action. The patient was found to have a daily profile of serum TSH similar to that of normal subjects, except for the persistently elevated 24 h levels, suggesting that alterations in thyroid hormone negative feedback control did not affect substantially circadian TSH rhythm. The acute administration of a dopamine antagonist drug (metoclopramide) resulted in a markedly elevated peak of serum TSH, similar both in the mo…
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 …
HGH secretion after oral application of l-Dopa and l-Carbiodopa
1976
The stimulatory effect of L-Dopa and L-Carbidopa (Nacom) on HGH secretion was determined in 12 children of normal height aged from 6 to 14 years. Each child received a standard dose of 250 mg L-Dopa and 25 mg L-Carbidopa p.o. HGH concentration in the serum was determined at standard intervals. All subjects showed a sufficient increase of HGH. The mean value was 19.6 ng/ml. According to the maximum values of the HGH concentration the sample can be divided into two groups; the first group reached the highest values after 20--40 min, the second one after 60--90 min. On evaluation of the curve of the mean values it appears that 2 blood samples taken 40 and 90 min after the ingestion of L-Dopa a…
Endokrinologische Vorhersage der Therapieansprechbarkeit depressiver Patienten auf Lofepramin
1979
In a pilot study of 15 depressive patients of the neurotic and endogenous type we could show that some neuroendocrinological parameters are apt to predict the thymoleptic efficacy of lofepramine. These parameters, which were measured with a simple global stimulation test (insulin hypoglycaemia combined with injection of TRH and LHRH), were as follows: high basal blood glucose; high hypoglycaemic blood glucose; high decrease of blood glucose in comparison to the basal level; low basal TSH; low increase of HGH and low increase of cortisol after hypoglycemia. A synopsis of these parameters allowed a correct classification of 14 out of 15 patients according to therapy response and therapy resis…
Simultaneous stimulation of growth hormone, adrenocorticotropin and cortisol with L‐dopa/L‐carbidopa and propranolol in children of short stature
2000
In 59 otherwise healthy children of short stature, the simultaneous response of growth hormone, cortisol and plasma adrenocorticotropin (ACTH) to L-dopa/L-carbidopa and propranolol at 45 and 90 min after administration were investigated. A growth hormone response of 10 microg/l or higher was considered positive. The definition of a positive cortisol response included either a hormone increase of at least 193 nmol/l or a peak hormone level of at least 497 nmol/l. The ACTH increase had to be fourfold above 11 pmol/l to be considered positive. In the 59 investigated children, the median basal growth hormone levels increased from 1.35 microg/l to 18.05 microg/l and 10.15 microg/l at 45 and 90 m…
Hypothalamic-Pituitary-Adrenal Dysfunction in the Polycystic Ovary Syndrome
2007
Between 20 and 30% of patients with polycystic ovary syndrome (PCOS) demonstrate adrenal androgen (AA) excess, detectable primarily by elevated dehydroepiandrosterone sulfate (DHEAS) levels. Generalized adrenocortical hyperresponsivity to adrenocorticotropic hormone (ACTH) stimulation is also observed and may be the principal mechanism determining AA excess in PCOS. The causes of this abnormality are unclear, but increased peripheral metabolism of cortisol, altered factors regulating glucose-mediated glucose disposal, and perhaps ovarian sex steroids may in different ways contribute to the AA excess in PCOS. Additionally, DHEAS levels and the response of AAs to ACTH are relatively constant …
Inhibition of TSH/IGF-1 Receptor Crosstalk by Teprotumumab as a Treatment Modality of Thyroid Eye Disease
2021
Abstract Context We previously presented evidence that TSH receptor (TSHR)-stimulating autoantibodies (TSAbs) bind to and activate TSHRs but do not bind to IGF1 receptors (IGF1Rs). Nevertheless, we showed that IGF1Rs were involved in thyroid eye disease (TED) pathogenesis because TSAbs activated crosstalk between TSHR and IGF1R. Teprotumumab, originally generated to inhibit IGF1 binding to IGF1R, was recently approved for the treatment of TED (Tepezza). Objective To investigate the role of TSHR/IGF1R crosstalk in teprotumumab treatment of TED. Design We used orbital fibroblasts from patients with TED (TEDOFs) and measured stimulated hyaluronan (HA) secretion as a measure of orbital fibrobla…
Zeitlicher Ablauf der ACTH-induzierten Stimulierung der Corticosteroidbiosynthese
1969
The time course of ACTH action was studied during incubation of quartered rat adrenals by estimation of corticosterone production and secretion rates. The results suggest a two step action of ACTH during the acute stimulation of corticosteroid biosynthesis: A modest initial stimulation was observed within the first 30 min of exposure to ACTH which was overlapped by a marked secondary stimulation between 30 and 60 min.
A Simplified LCA Tool for Solar Heating and Cooling Systems
2016
Abstract This paper presents a user-friendly Life Cycle Assessment tool, which aims to support researchers, designers and decision-makers in evaluating the life cycle energy and environmental advantages related to the use of solar heating and cooling (SHC) systems in substitution of conventional ones, considering specific climatic conditions and building loads. The tool was developed within the Task 48 “Quality Assurance & Support Measures for Solar Cooling Systems”, promoted by the International Energy Agency in the framework of the SHC Programme.