Objective. This prospective open trial aimed to evaluate the efficacy and safety of isotretinoin (13-cis-retinoic acid) in patients with Cushing's disease (CD). Methods. Sixteen patients with CD and persistent or recurrent hypercortisolism after transsphenoidal surgery were given isotretinoin orally for 6–12 months. The drug was started on 20 mg daily and the dosage was increased up to 80 mg daily if needed and tolerated. Clinical, biochemical, and hormonal parameters were evaluated at baseline and monthly for 6–12 months. Results. Of the 16 subjects, 4% (25%) persisted with normal urinary free cortisol (UFC) levels at the end of the study. UFC reductions of up to 52.1% were found in the rest. Only patients with UFC levels below 2.5-fold of the upper limit of normal achieved sustained UFC normalization. Improvements of clinical and biochemical parameters were also noted mostly in responsive patients. Typical isotretinoin side-effects were experienced by 7 patients (43.7%), though they were mild and mostly transient. We also observed that the combination of isotretinoin with cabergoline, in relatively low doses, may occasionally be more effective than either drug alone. Conclusions. Isotretinoin may be an effective and safe therapy for some CD patients, particularly those with mild hypercortisolism.
RESUMOMacroprolactinemia caracteriza-se pelo predomínio no soro de uma prolactina (PRL) de alto peso molecular e baixa atividade biológica que não requer tratamento. A prevalência de macroprolactinemia foi avaliada em 115 pacientes consecutivos com hiperprolactinemia. Entre eles, 19 (16,5%) tinham exclusivamente macroprolactinemia, 4 (3,5%) síndrome dos ovários policísticos, 7 (6,1%) acromegalia, 8 (6,9%) hiperprolactinemia idiopática, 10 (8,7%) hipotiroidismo primário, 14 (12,2%) adenomas clinicamente não-funcionantes, 20 (17,4%) hiperprolactinemia farmacológica e 33 (28,7%) prolactinomas. O diagnóstico de macroprolactinemia foi estabelecido pela obtenção de uma recuperação da PRL < 30% após tratamento do soro com polietilenoglicol. Dentre os 19 pacientes com macroprolactinemia isolada, 16 (84,2%) eram mulheres e 12 (63,2%) eram assintomáticos, enquanto 4 (21%) tinham oligomenorréia e 3 (15,8%), galactorréia. Em contraste, apenas 11,5% dos indivíduos com outras causas de hiperprolactinemia eram assintomáticos (p< 0,001). Os níveis de PRL nos casos de macroprolactinemia variaram de 45,1 a 404 ng/mL (média de 113,3 ± 94,5), mas em 15 (78,9%) foram < 100 ng/mL. Nossos achados demonstram que macroprolactinemia é uma condição freqüente e, assim, sugerimos que seja rotineiramente pesquisada em pacientes com hiperprolactinemia. Macroprolactinemia is characterized by the predominance in the serum of macroprolactin, a prolactin (PRL) with high molecular mass and low biological activity that does not need treatment. The prevalence of macroprolactinemia was evaluated in 115 consecutive patients with hyperprolactinemia. Among them, 19 (16.5%) had solely macroprolactinemia, 4 (3.5%) polycystic ovary syndrome, 7 (6.1%) acromegaly, 8 (6.9%) idiopathic hyperprolactinemia, 10 (8.6%) primary hypothyroidism, 14 (12.2%) clinically non-functioning pituitary adenomas, 20 (17.4%) druginduced hyperprolactinemia and 33 (28.7%) prolactinomas. The diagnosis of macroprolactinemia was established by the demonstration of a PRL recovery < 30% after treatment of sera with polyethylene glycol. Among the 19 patients with isolated macroprolactinemia, 16 (84.2%) were female and 12 (63.2%) were asymptomatic, while 4 (21%) presented with oligomenorrhea and 3 (15.8%) with galactorrhea. In contrast, only 11.5% of individuals with other causes of hyperprolactinemia were asymptomatic (p< 0.001). Prolactin levels in cases of macroprolactin ranged from 45.1 to 404 ng/mL (mean 113.3 ± 94.5) but in 15 (78.9%) were < 100 ng/mL. Our findings demonstrate that macroprolactinemia is a common condition and, therefore, we suggest that it should be routinely screened in patients with hyperprolactinemia.
Artificial Neural Networks (ANNs) constitute a technology that has recently become the focus of great attention. The reason for this is due mainly to its capacity to treat complex and nonlinear problems. This work consists of the identification and control of a fluid cracking catalytic unit (FCCU) using techniques based on multilayered ANNs. The FCC unit is a typical example of a complex and nonlinear process, possessing great interaction among the operation variables and many operational constraints to be attended. Model Predictive Control is indicated in these occasions. The FCC model adopted was validated with plant data by Moro (1992); and was used in this work to replace the real process in the generation of data for the identification of the ANNs and to test the predictive control strategy. The results of the identification and control of the process through ANNs indicate the viability of the technique
We studied clinical and laboratorial features of 73 patients with endogenous Cushing's syndrome, subdivided as follows: 46 (63%) with Cushing's disease (CD), 21 (28.7%) with an adrenal tumor and 6 (8.2%) with ectopic ACTH secretion (EAS). The rate of typical manifestations of hypercortisolism was similar regardless its etiology. In 100% of cases of Cushing's syndrome we observed serum cortisol levels greater than 1.8 microg/dL in low-dose dexamethasone (DMS) suppression tests, as well as elevation of serum or salivary midnight cortisol. However, urinary free cortisol was normal in 11.5% of patients. ACTH levels were suppressed in patients with adrenal tumors, normal or high in CD and always high in EAS. In the 8-mg overnight DMS suppression test, serum cortisol suppression > 50% was observed in 78.2% of cases of CD and in 33.3% of subjects with EAS, while an 80% suppression was only seen in CD. After stimulation with CRH or DDAVP an ACTH increase > 35% occurred in 81% of individuals with CD and 16.6% of those with EAS, while an ACTH increase > 50 achieved 100% specificity. Moreover, the combination of serum cortisol suppression > 50% and an ACTH increase > 35% in both tests only occurred in Cushing's disease. Pituitary magnetic resonance imaging identified 100% of macroadenomas and 59.4% of microadenomas in patients with CD. Among 10 patients that underwent bilateral inferior petrosal sinus sampling, a central-to-peripheral ACTH gradient > 3 after CRH or DDAVP had 90% sensitivity and 100% specificity for Cushing's disease.
Dietary iron absorption regulation is one of the key steps for the maintenance of the body iron homeostasis. HFE gene expression undergoes a complex post-transcriptional alternative splicing mechanism through which two alternative transcripts are originated and translated to a soluble HFE protein isoform (sHFE). The first purpose of this study was to determine if sHFE transcript levels respond to different iron conditions in duodenal and macrophage cell models. In addition, we aimed to determine the functional effect of the sHFE protein on the expression of iron metabolism-related genes in a duodenal cell model as well as, in vivo, in duodenum biopsy samples. Levels of sHFE transcripts were measured in HuTu-80, Caco-2, HT-29 and activated THP1 cells, after holo-Tf stimulus, and in total RNA from duodenum biopsies of functional dyspepsia patients. Also, the expression of several iron metabolism-related genes was determined after endogenous and exogenous overexpression of sHFE protein in a duodenal cell model. sHFE endocytosis mechanism was studied using endocytosis inhibitors. Our results showed that sHFE transcript expression was up-regulated after holo-Tf stimuli. Hephaestin and duodenal cytochrome b expressions were down-regulated by both endogenous HFE and sHFE proteins in a duodenal cell model. Exogenous sHFE was able to down-regulate hephaestin mRNA levels by a clathrin-independent, dynamin-mediated, and RhoA-regulated endocytosis mechanism. Moreover, HEPH levels negatively correlated with sHFE levels in the duodenum of functional dyspepsia patients. Thus, sHFE seems to be an important iron metabolism regulator playing a role in the control of dietary iron absorption in the duodenum.
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