Search results for "imulation"
showing 10 items of 7271 documents
Inverse correlation between baseline inhibin B and FSH after stimulation with GnRH: a study of serum levels of inhibin A and B, pro alpha-C and activ…
2000
OBJECTIVE: Interest has focused recently on the influences of the polypeptide factors inhibin and activin on the selective regulation of the pituitary secretion of gonadotropins. DESIGN: Measurement of the concentrations of inhibin-related proteins in relation to the changes in pituitary gonadotropin (FSH, LH) parameters, after GnRH stimulation with a bolus injection of 100 microg gonadorelin, in 19 women with ovulatory disturbances. METHODS: Serum levels of inhibin A and B, activin A, and pro alpha-C were measured using sensitive ELISA kits. RESULTS: Within 60 min after GnRH stimulation, FSH values doubled from 5 to 10 mU/ml (P < 0.001). LH increased 12-fold from 2 to 24 mU/ml (P < 0…
High-dose recombinant LH add-back strategy using high-dose GnRH antagonist is an innovative protocol compared with standard GnRH antagonist.
2011
High daily doses of gonadotrophin-releasing hormone (GnRH) antagonists during the follicular phase of ovarian stimulation were associated with low implantation rates. To test if this occurred because of profound pituitary suppression, the pituitary response was suppressed with a high-dose GnRH antagonist and recombinant LH (rLH) was added back to correct the implantation rate. An open-label, randomized, controlled, prospective clinical study in 60 patients undergoing IVF was performed. GnRH antagonist was initiated on day 6 of stimulation (2 mg/day) together with 375 IU rLH, and maintained until the day of HCG administration. Controls received 0.25 mg/day GnRH antagonist. Fluctuating LH con…
Timing of right parietal and frontal cortex activity in visuo-spatial perception: A TMS study in normal individuals
2001
In a recent study we showed that repetitive transcranial magnetic stimulation (rTMS) with train duration of 400 ms over right frontal and right posterior parietal cortices gives rise to transitory contralateral visuo-spatial neglect in normal subjects. In the present experiment we investigated whether using single-pulse TMS it is possible to obtain information about the timing of cortical activity related to spatial cognition. Nine healthy subjects performed in baseline condition and during TMS a tachistoscopic task, requiring a forced-choice estimation of the length of the two segments of prebisected horizontal lines. Single-pulse TMS was triggered at various time intervals (150 ms, 225 ms…
Neural specialization to human faces at the age of 7 months.
2021
AbstractSensitivity to human faces has been suggested to be an early emerging capacity that promotes social interaction. However, the developmental processes that lead to cortical specialization to faces has remained unclear. The current study investigated both cortical sensitivity and categorical specificity through event-related potentials (ERPs) previously implicated in face processing in 7-month-old infants (N290) and adults (N170). Using a category-specific repetition/adaptation paradigm, cortical specificity to human faces, or control stimuli (cat faces), was operationalized as changes in ERP amplitude between conditions where a face probe was alternated with categorically similar or …
[Velocity perception for curved motion].
1996
This study examined the effect of direction change of tangential velocity on speed perception using a dot in curved motion. The PSE values were measured for four standard stimuli of different motion curvature. In Experiment 1, semicircular motion was a comparison stimulus. The result showed that the PSE values increased with increasing motion curvature. This implies that direction change of tangential velocity can affect its speed perception. However, in Experiment 2, the effect of direction change of tangential velocity was not clear when a comparison stimulus was replaced with linear motion. In Experiment 3, the motion curvature as a comparison stimulus was set near the threshold level of…
Definition of discrete signals involved in human T-cell activation
1986
Abstract Mitogenic activities of monoclonal antibodies directed at denned receptor structures expressed on the surface of mature human T lymphocytes were employed to study, in detail, signals involved in primary T-cell activation. Based on differential requirements for stimulation, two discrete pathways of human T-cell activation can be defined: the antigen-induced mode of activation initiated through the Ti-T3 antigen-receptor complex and an alternative pathway which can be triggered by monoclonal antibodies directed at the T11 glycoprotein. Perhaps more importantly, the approach taken here allows the definition of stable intermediate cellular stages within the activation cascade and, thus…
Refractory Acne and 21-Hydroxylase Deficiency in a Selected Group of Female Patients.
2009
<i>Background:</i> Excessive androgen production, suspected in women when acne is accompanied by hirsutism and menstrual irregularities, may be due to congenital adrenal hyperplasia. This inherited disorder of cortisol biosynthesis is caused in more than 90–95% of all cases by 21-hydroxylase deficiency (21-OHD). The steroid 21-hydroxylase gene <i>(CYP21)</i> has a high degree of variability. <i>Objective:</i> This study was conducted to evaluate <i>CYP21 </i>gene mutations in a selected group of women with papulopustular and comedonal acne refractory to treatment, irregular menses and hirsutism. <i>Methods:</i> 30 out of 61 women e…
Is abdominal compression a useful stimulation test for analysis of lower esophageal sphincter function?
1984
The change in pressure of competent and incompetent lower esophageal sphincter (LES) due to abdominal compression is still a controversial subject. Therefore, we studied the effect of sustained (SAC) and intermittent (IAC) abdominal compression on lower esophageal sphincter pressure (LESP) in normals (N), patients with hiatus hernia (HH), and patients with scleroderma (S). When resting lower esophageal sphincter pressure exceeded 15 mm Hg, response to SAC and IAC was similar in patients with HH and in normals. On the other hand when basal LESP was below 15 mm Hg, stimulated sphincter pressure during IAC was significantly lower than during SAC. Values recorded during SAC were also falsely hi…
Implantation is apparently unaffected by the dopamine agonist Cabergoline when administered to prevent ovarian hyperstimulation syndrome in women und…
2007
Background Ovarian hyperstimulation syndrome (OHSS) is a result of ovarian overexpression of vascular endothelial growth factor (VEGF) and its receptor 2 (VEGFR2). VEGF/VEGFR2 binding disrupts cellular junctions and increases vascular permeability (VP), a characteristic of OHSS, but enhances angiogenesis, which is a fundamental step in implantation. In animals, the dopamine agonist Cabergoline (Cb2) prevents VP without affecting angiogenesis. In humans, Cb2 averts OHSS, but a possible detrimental effect on angiogenesis and implantation has not been explored. A pilot study was designed to analyze whether or not Cb2 administration, as a procedure for preventing OHSS, affects the outcome of as…
Association of a CB1 Cannabinoid Receptor Gene (CNR1) polymorphism with severe alcohol dependence
2002
Abstract Due to the involvement of the endogenous cannabinoid system in brain reward mechanisms a silent polymorphism (1359G/A; Thr453Thr) in the single coding exon of the CB1 human cannabinoid receptor gene ( CNR1 ) was analysed in 121 severely affected Caucasian alcoholics and 136 most likely non-alcoholic controls. The observed frequency of the A allele was 31.2% for controls and 42.1% for alcoholics with severe withdrawal syndromes ( P =0.010). Post-hoc exploration indicated that this allelic association resulted from an excess of the homozygous A/A genotype in patients with a history of alcohol delirium ( P =0.031, DF 2), suggesting s an increased risk of delirium (OR=2.45, 95% CI 1.14…