Search results for "pituitary"
showing 10 items of 238 documents
Autoimmune Hypophysitis
2014
Autoimmune hypophysitis is a chronic inflammation of the pituitary gland that can be classified according to anatomic location, histopathology, or cause. Location differentiates hypophysitis into adenohypophysitis, infundibulo-neurohypophysitis, or panhypophysitis depending on whether the clinical and radiological signs (and pathological findings if available) involve the anterior lobe, the posterior lobe and the stalk, or both structures. Histopathology identifies two main forms of hypophysitis, lymphocytic and granulomatous, as well as xanthomatous, IgG4 plasmacytic, and necrotizing variants. Etiology distinguishes primary and secondary hypophysitis. Primary hypophysitis refers to the cas…
Hypogonadotrophic Pituitary Insufficiency in Transfusional Hemochromatosis Complicating Thalassemia Major: MR Imaging
1999
To identify pituitary iron overload in patients with transfusion-dependent thalassemia major causing secondary hypogonadism, we prospectively evaluated signal intensity abnormalities of the anterior lobe of the pituitary gland of 30 patients comparing spin-echo, gradient-echo imaging and pituitary T2 relaxation times measurement. We found that pituitary iron overload can best be assessed by MR imaging using gradient-echo T2*-weighted technique to establish signal reduction in the anterior lobe of the pituitary gland. This finding is correlated to increasing serum ferritin level — a parameter that reflects the severity of iron overload, and is more evident in patients with secondary hypogon…
Inflammatory pituitary lesions
2021
Abstract Inflammatory pituitary lesions are rare but important differential diagnoses of nonfunctioning pituitary masses. Primary hypophysitis as an autoimmune disorder has received increasing attention over the past decades. In the last decade, immune checkpoint inhibitor–induced hypophysitis has emerged as a new type of secondary hypophysitis. Various pituitary tumors may also cause secondary hypophysitis. Systemic, noninfectious granulomatous diseases that can involve the pituitary region include sarcoidosis, granulomatosis with polyangiitis, Langerhans cell histiocytosis, Erdheim-Chester disease, and Rosai-Dorfman disease. Furthermore, infectious diseases can affect the pituitary gland.…
The Tuberohypophyseal Dopamine System: Dopaminergic Modulation of Vasopressin Release. Characterization of Release and Metabolism of3H-Dopamine
1986
Dopamine (DA) fibres originating in the arcuate nucleus project into the neural and intermediate lobes (N-IL) of the pituitary gland. It has been shown that DA and DA agonists decrease the electrically evoked vasopressin release from the isolated N-IL, an effect antagonized by D2 selective DA antagonists (see Holzbauer et al., 1983). However, there are also observations suggesting that there is an additional facilitation of the evoked vasopressin release via D1 receptors. Thus, SKF 82526 (6-chloro-7,8-drhydroxy-1-(p-hydroxyphenyl)-2,3,4,5-tetrahydro-1H-benzazepine mesylate) concentrationdependently decreased (max. 30 % at 30 nM) and increased (max. 40 % at 3 µM) the electrically evoked vaso…
Selektive Blutentnahme aus dem Sinus petrosus inferior: Vergleich von CRF- und TRH-Stimulation
1993
In 10 patients with hypophyseal Cushing microadenomas, selective bilateral sampling from the inferior petrosal sinuses was performed and the effect of stimulation by iv TRH and CRF was compared. On the side of the microadenoma. ACTH concentration rose from 650 +/- 242 pg/ml to 2712 +/- 843 pg/ml following injection of CRF and 2025 +/- 242 pg/ml after TRH. Contralateral values were 165 +/- 79 pg/ml, 490 +/- 200 pg/ml and 165 +/- 72 pg/ml respectively. Prolactin concentration on the side of the adenoma was 98 +/- 49 ng/ml before stimulation, 236 +/- 62 ng/ml after CRF and 747 +/- 168 ng/ml after TRH. Contralateral concentration was 22 +/- 10 ng/ml, 64 +/- 19 ng/ml respectively. Sampling local…
Presynaptic regulation of the electrically evoked release of endogenous dopamine from the isolated neurointermediate lobe or isolated neural lobe of …
1988
Isolated neurointermediate lobes (NILs) or isolated neural lobes (NLs) of the rat pituitary gland were incubated in Krebs-HEPES solution which contained pargyline and the dopamine uptake inhibitor GBR 12921. The release of endogenous dopamine was determined by HPLC with electrochemical detection. Electrical stimulation of the pituitary stalk induced a frequency-dependent release of dopamine. The release of dopamine from the combined NIL evoked by stimulation at 15 Hz was increased by 130% in the presence of the dopamine D2 receptor antagonist, (-)-sulpiride; the (+)-enantiomer of sulpiride had virtually no effect. When the stimulation frequency was 3 Hz (-)-sulpiride caused an increase in d…
The role of cytoplasmic (newly synthesized) dopamine for the spontaneous and electrically evoked release of dopamine and its metabolites from the iso…
1987
Isolated rat NILs were incubated in Krebs-HEPES solution. The release of dopamine and its metabolites (DOPAC, HVA and MOPET) was determined by HPLC with electrochemical detection. The spontaneous release of the sum of metabolites was about 40 times that of dopamine. The spontaneous outflow of dopamine metabolites was unaffected after inhibition of dopamine uptake (by GBR 12921) or after pretreatment with reserpine (5 mg/kg, 12 h before the experiments), but it was reduced by 50% after preincubation with the irreversible DOPA decarboxylase inhibitor, (MFMD, 10 microM, for 10 min). The combination of pretreatment with reserpine and preincubation with MFMD resulted in an 80% inhibition of the …
Pituitary Function and the Somatotrophic System in Patients with Idiopathic Parkinson’s Disease Under Chronic Dopaminergic Therapy
2007
Idiopathic Parkinson's disease and dopaminergic medication may influence pituitary hormone secretion. The present study aimed to reveal any abnormalities of the somatotrophic system induced by the disease itself and/or the dopaminergic therapy. Investigations of other pituitary hormones under basal and stimulated conditions, as well as an analysis of body composition, were also performed. This was a controlled diagnostic study in which luteinising hormone-releasing hormone, thyroid-releasing hormone, corticotrophin-releasing hormone and arginine hydrochloride were administered to ten patients with idiopathic Parkinson's disease under dopaminergic medication. Basal and stimulated hormone con…
Pasireotide versus pituitary surgery: a retrospective analysis of 12 months of treatment in patients with Cushing’s disease
2017
Pituitary surgery represents the first-line treatment for most patients with Cushing’s disease (CD). In the case of surgery failure, additional treatment options are required. Pasireotide has shown favourable results in the first-line treatment of patients with CD, who are not candidates for surgery or in the second-line when surgery has failed. The aim of the current study is to compare the effects of surgery and pasireotide treatment in a cohort of patients with CD, and to evaluate the differences in response rate in terms of hormonal and clinical control, and improvement of metabolic complications
Use of a clinicoradiological score to determine the presurgical diagnosis of autoimmune hypophysitis in a teenage girl.
2013
The distinction between autoimmune hypophysitis and other non–hormone secreting pituitary masses is often difficult to determine with certainty without pituitary biopsy and pathological examination. To aid in this distinction, the authors recently published a clinicoradiological scoring system, which they used in the case of a 15-year-old girl presented here. The patient presented with headache, visual field defects, polydipsia, and polyuria, and she was found to have secondary hypogonadism and hypoadrenalism. Magnetic resonance imaging showed a pituitary mass of approximately 2 cm in diameter. Application of the clinicoradiological parameters gave a score of −6, which favored a diagnosis o…