1,720,996 research outputs found
Circannual rhythm of plasma thyrotropin in middle-aged and old euthyroid subjects
No full textThe circannual rhythm of plasma thyrotropin (TSH) was evaluated in 8,310 euthyroid, serially independent, young, middle-aged and old men and women. A statistically significant circannual rhythm of plasma TSH was validated, by the mean group-cosinor method, in the middle-aged and old men and women (p less than 0.05), with acrophase in December, whereas the young subjects did not show any rhythm. No significant correlation was found between TSH plasma levels and free thyroxine (fT4) or ambient temperature in any group. Moreover, plasma fT4 did not show seasonal variations
Crooke's hyalinization in silent corticotroph adenoma: Report of two cases
No full textCorticotroph adenomas rarely show Crooke's hyaline change in neoplastic cells, a feature similar to that of normal corticotroph cells exposed to excess cortisol. Crooke's cell adenomas are usually associated with Cushing's disease. Nonfunctioning examples are uncommon. We report two clinically silent corticotroph adenomas featuring extensive Crooke's hyalinization in neoplastic cells. The two patients were 49 and 59 yr of age and neither had Cushing's disease. Serum and urinary cortisol were normal. One patient had elevated serum adrenocorticotropic hormone. In our experience, the two patients accounted for 0.4% of pituitary adenomas operated on from January 1992 to December 2001 and 3.5% of all corticotroph adenomas. The two lesions had features of the subtype 1 silent corticotroph adenoma. Cytogenetic analysis performed on one lesion showed a normal karyotype (46;XY). Hyalinization in clinically silent Crooke's cell adenoma indicates that hyaline changes do not always relate to excess cortisol. It is known that neoplastic Crooke's cells show immunoreactivity for glucocorticoid receptors stronger than nontumorous Crooke's corticotrophs. This fact suggests that receptor overexpression or lack of receptor downregulation may result in hypersensitivity of neoplastic Crooke's cells to physiologic cortisol plasma levels
Thyrotropin secreting pituitary tumours: significance of “atypical adenomas” in a series of 10 patients and association with Hashimoto’s thyroiditis as a cause of delay in diagnosis.
No full textRitmo circadiano del testosterone, sex hormone binding globulin e proteine plasmatiche in giovani adulti ed anziani di sesso maschile.
No full textnot applicabl
Risposta dell'LH plasmatico immunoreattivo e biologicamente attivo all'LHRH test in pazienti con sindrome di Turner prima e dopo trattamento estrogenico.
No full textnot applicabl
Rare primary non-neuroendocrine tumours of the sella
No full textAbout 1% of primary tumour of the sellar region can be diagnostically challenging. The spectrum of these lesions includes lesions that have been codified in 4th edition of the WHO classification of tumours of the pituitary gland published in 2017 such as posterior lobe and neuronal and paraneuronal tumours as well as lesions that have not been included such as the sellar atypical teratoid rhabdoid tumour, salivary gland-like tumours and primary sellar melanocytic tumours. This review aims to provide the diagnostic criteria for these rare lesions and an overview of their essential clinical and neuroimaging features
Circadian rhythm of plasma testosterone in men with idiopathic hypogonatropic hypogonadism before and during pulsatile administration of gonadotropin-releasing hormone.
No full textOBJECTIVE: The aim was to investigate whether a pulsatile discharge of LH from the pituitary is necessary to achieve the circadian secretion of testosterone. DESIGN: The daily rhythm of the androgen has been studied in patients with idiopathic hypogonadotrophic hypogonadism (IHH) both in the absence of therapy and during pulsatile administration of gonadotrophin releasing hormone (GnRH). PATIENTS: Six patients with IHH and ten normal subjects were analysed. Blood sampling was performed at 2-hourly intervals, for 24 hours. The IHH patients then received synthetic GnRH i.v. at the rate of one pulse every 2 hours (10 micrograms/pulse). On day 11 of treatment, blood samples were taken for the rhythm analysis every 2 hours, for 24 hours. MEASUREMENTS: Plasma testosterone and LH were measured in the individual samples by radioimmunoassay. Evaluation of the rhythm was performed by cosinor analysis. RESULTS: A significant circadian rhythm of plasma testosterone was statistically validated in the normal subjects, whereas no rhythm was detected in the IHH patients in the absence of therapy. On day 11 of GnRH pulsatile administration the IHH patients showed normal testosterone levels and a statistically significant circadian rhythm of the androgen was evident, with acrophase between 0700 and 0800 h. Moreover, the amplitude, acrophase and mesor of testosterone rhythm in IHH patients in the course of treatment were statistically indistinguishable from the corresponding values in the normal subjects. Plasma LH did not show statistically significant circadian variations, either in the control group or in the IHH patients before or during therapy. CONCLUSIONS: We conclude that a physiological circadian rhythm of plasma testosterone can be obtained, in IHH men, by treatment with GnRH. Since the pulsatile administration of exogenous GnRH at constant doses induced a circadian rhythm in testosterone and no daily variations in LH were evident, we suggest that, although a pulsatile secretion of LH is probably necessary for the synchronization of the circadian rhythm with acrophase in the morning, the testosterone variations might be the results of a local testicular modulation of LH action
Endoscopic Endonasal Transplanum–Transtuberculum Approach for Pituitary Adenomas/PitNET: 25 Years of Experience
Full text linkThe role of the endoscopic transplanum–transtuberculum approach (ETTA) in the treatment of pituitary adenomas/PitNETs (PAs) is sparsely analyzed in the literature, and its use is still debated in the current practice. The aim of this study was to report our experience with this approach. Our institutional registry was retrospectively reviewed, and patients who underwent ETTA for a PA from 1998 to 2022 were included. Fifty-seven cases were enrolled over a time span of 25 years, corresponding to 2.4% of our entire PA caseload. Radical resection was achieved in 57.9% of cases, with re-do surgery (p = 0.033) and vessel encasement/engulfment (p < 0.001) as predictors of partial resection. CSF leak incidence stood at 8.8%, with higher BMI (p = 0.038) as its only significant predictor. Partial or full improvement of the visual field deficits was achieved in 73.5% of cases. No surgical mortality was observed. According to our results, ETTA for the treatment of PAs is characterized by a satisfactory surgical outcome but with greater morbidity than the conventional endoscopic approach. Therefore, it should be reserved for the few selected cases otherwise unsuitable for the endoscopic trans-sphenoidal route, representing a valid alternative and an effective complementary route for the transcranial approach for these challenging PAs
Late-onset Leber’s hereditary optic neuropathy and antiandrogens for prostate cancer: is there a causative link?
Full text linkIntroduction: Leber's hereditary optic neuropathy (LHON) is a maternally inherited condition due to mitochondrial DNA (mtDNA) mutations usually affecting young men within their thirties, while women seem protected by estrogens with a female-to-male ratio of 1:3. Late-onset cases (over 40 years of age) are usually associated to toxic exposure to tobacco smoke or drugs causing mitochondrial dysfunction. Results: We describe two cases of LHON remarkable for their late onset (> 60 years) in the absence of classic toxic factors. They were both affected by advanced prostate cancer and developed LHON after introduction of enzalutamide, an antagonist of androgens' receptor, in association with leuprolide, a gonadotropin-releasing hormone (GnRH) analogue, used in the context of Androgen deprivation therapy (ADT). Both patients presented very low serum levels of gonadotropin, estrogens and androgens compatible with hormonotherapy. MtDNA copy number in our probands resulted significantly reduced (like other LHON affected cases), compared to age-matched LHON unaffected mutation carriers and controls. Discussion: The role of hormones in LHON pathogenesis remains still debated. Recent evidence suggests a protective effect of estrogens in increasing mitochondrial biogenesis (and mtDNA copy number), partially explaining the gender bias of the disease, while the role of androgens is yet to be fully understood. Considering the effect of the ADT on circulating hormonal levels and their reciprocal interactions, we hypothesize that in a context of already low estrogens levels due to GnRH analogue, the block of androgens receptors by Leuprolide further imbalance the estrogens to androgens ratio and eventually trigger the disease
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