938 resultados para PITUITARY ADENOMA
Resumo:
La sindrome di Cushing (SC) è una delle endocrinopatie più comuni nel cane. La diagnosi richiede l'integrazione di anamnesi, segnalamento, segni clinici, esami ematobiochimici, test endocrini specifici e diagnostica per immagini . Nel corso degli anni diversi sono i principi attivi testati per la terapia della SC del cane. In passato, il mitotane è stato il farmaco più utilizzato, sebbene il suo uso risulti complicato e non privo di potenziali effetti collaterali. Recentemente, il trilostano ha dimostrato di essere un trattamento efficace per il controllo dei sintomi ed è stato approvato per tale uso nel cane. Al fine di testare metodiche non invasive per la diagnosi di SC nel cane abbiamo valutato le concentrazioni di cortisolo nel pelo (HCC) .Queste risultavano significativamente più elevate nei cani con SC rispetto ai cani sani e malati. Questo test può essere quindi considerato una procedura diagnostica non invasiva in cani con un elevato sospetto di SC. Inoltre, a causa della difficile reperibilità dell’ACTH esogeno sono state valutate le concentrazioni di cortisolo basale come strumento di monitoraggio in cani con SC trattati con trilostano. Tuttavia la singola valutazione del cortisolo basale non rappresenta un parametro efficace ed accurato per il monitoraggio della terapia con trilostano. Sono stati inoltre valutati i fattori prognostici in cani con SC alla diagnosi. L' iperfosfatemia è risultata un riscontro comune nei cani SC, rappresentando un fattore prognostico negativo. La terapia chirurgica non è una procedura di routine nella SC del cane, tuttavia abbiamo descritto l'approccio di ipofisectomia transsfenoidale in un Galgo spagnolo di 8 anni con SC . Il cane è stato sottoposto per due volte ad ipofisectomia transsfenoidale che ha permesso di rimuovere completamente il macroadenoma ipofisario. In conclusione, questi studi ci hanno permesso di indagare alcuni aspetti patogenetici, clinici e diagnostici della SC del cane.
Resumo:
The thesis aims to expose the advances achieved in the practices of captive breeding of the European eel (Anguilla anguilla). Aspects investigated concern both approaches livestock (breeding selection, response to hormonal stimulation, reproductive performance, incubation of eggs) and physiological aspects (endocrine plasma profiles of players), as well as engineering aspects. Studies conducted on various populations of wild eel have shown that the main determining factor in the selection of wild females destined to captive breeding must be the Silver Index which may determine the stage of pubertal development. The hormonal induction protocol adopted, with increasing doses of carp pituitary extract, it has proven useful to ovarian development, with a synchronization effect that is positively reflected on egg production. The studies on the effects of photoperiod show how the condition of total darkness can positively influence practices of reproductions in captivity. The effects of photoperiod were also investigated at the physiological level, observing the plasma levels of steroids ( E2, T) and thyroid hormones (T3 and T4) and the expression in the liver of vitellogenin (vtg1 and vtg2) and estradiol membrane receptor (ESR1). From the comparison between spontaneous deposition and insemination techniques through the stripping is inferred as the first ports to a better qualitative and quantitative yield in the production of eggs capable of being fertilized, also the presence of a percentage of oocytes completely transparent can be used to obtain eggs at a good rate of fertility. Finally, the design and implementation of a system for recirculating aquaculture suited to meet the needs of species-specific eel showed how to improve the reproductive results, it would be preferable to adopt low-flow and low density incubation.
Resumo:
L’approccio chirurgico agli adenomi ipofisari ACTH secernenti è la terapia d’elezione nell’uomo. L’ipofisectomia transfenoidale è invece una tecnica poco diffusa in ambito veterinario. La terapia più diffusa nel cane con ipercortisolismo ipofisi dipendente (PDH) è di tipo medico e prevede la somministrazione di farmaci inibitori della sintesi del cortisolo. Gli adenomi ipofisari possono aumentare di volume e determinare una conseguente sintomatologia neurologica; in questi casi le uniche opzioni terapeutiche sono rappresentate dall’asportazione chirurgica della neoplasia e dalla radioterapia. Nella presente tesi vengono descritti 8 interventi di ipofisectomia transfenoidale effettuati su 7 cani con macroadenoma ipofisario presso il Dipartimento di Scienze Mediche Veterinarie dell’Università di Bologna. La difficoltà maggiore per il chirurgo è rappresentata dalla localizzazione della fossa ipofisaria rispetto ai punti di repere visibile in tomografia computerizzata o in risonanza magnetica nucleare, oltre ai problemi di sanguinamento durante la rimozione della neoplasia. Nel periodo post-operatorio maggiori complicazioni si riscontrano in soggetti con adenomi ipofisari di maggiori dimensioni. Al contrario, in presenza di adenomi di dimensioni più contenute, la ripresa post-operatoria risulta più rapida e il tasso di successo maggiore. Al fine di poter eseguire nel cane l’exeresi mirata della sola neoplasia ipofisaria, al pari di quanto avviene nell’uomo, è stato condotto uno studio sulla tomografia computerizzata (TC) in 86 cani con PDH. Il protocollo TC non ha tuttavia permesso di individuare con precisione la posizione della neoplasia per guidare il chirurgo nella sua rimozione. In due casi riportati nel presente lavoro si è verificata una recidiva della neoplasia ipofisaria. In un soggetto si è optato per il reintervento, mentre nell’altro caso per la radioterapia. Entrambe le opzioni hanno garantito una buona qualità di vita per più di un anno dall’intervento terapeutico. Questi casi clinici dimostrano come il reintervento e la radioterapia possano essere considerate valide opzioni in caso di recidiva.
Resumo:
Zur Detektion von neuen potentiellen Biomarkerkandidaten für das KRK sowie dessen Vorstufen wurde Blutplasma von gesunden Kontrollen und von Patienten mit kolorektalen Adenomen und Karzinomen untersucht. Mit Hilfe immunoaffinitäts-basierter Chromatographiesäulen wurde das Blutplasma mit einer automatisierten Methode von hoch und moderat abundanten Proteinen entfernt und daraufhin massenspektrometrisch analysiert. Hierfür wurde eine labelfreie quantitative und datenunabhängige Methode angewendet. Nach Auswertung der Daten kristallisierten sich mehrere potentielle Biomarkerkandidaten heraus, wobei das Augenmerk auf solchen Proteinen lag, die sowohl bei Adenompatienten als auch bei Karzinompatienten vermehrt im Plasma vorlagen. Nach Western Blot Experimenten und einer weiteren Validierung mittels eines ELISAs an einem größeren Patientenset zeigte sich, dass die beiden Proteine AMBP und CRP als potentielle Biomarker zur Detektion von Adenomen und Karzinomen herangezogen werden konnten. Receiver Operating Charakteristik (ROC)-Analysen ergaben einen AUC-Wert von 0,79 für AMBP und 0,77 für CRP für das Erkennen von Adenomen und Karzinomen. Dies resultierte in einer Sensitivität von 72,5% für AMBP bzw. 60% für CRP bei einer Spezifität von 80%. Durch die Kombination beider Markerproteine erhielt man sogar eine noch höhere Sensitivität von 80% bei 80% Spezifität für das Aufdecken kolorektaler Neoplasien. Ebenso zeigte sich in der histochemischen Analyse, dass AMBP direkt von intestinalen Epithelzellen exprimiert wird.
Resumo:
The hypothalamus-pituitary-interrenal axis is involved in stress response regulation. In addition, arginine vasotocin (AVT) and isotocin (IT) are also considered as important players in this stress regulation. The present study assessed, using the teleost gilthead sea bream (Sparus aurata) as a biological model, hypothalamic mRNA expression changes of AVT and IT and their receptors at hepatic level after an acute stress situation. Specimens were submitted to air for 3 min and place back in their respective tanks after that, being sampled at different times (15 min, 30 min, 1, 2, 4 and 8 hours post-stress) in order to study the time course response. Plasma cortisol values increased after few minutes post-exposure, decreasing during the experimental time while a metabolic reorganization occurred in both plasmatic and hepatic levels. At hypothalamic level, acute stress affects mRNA expression of AVT and IT precursors, as well as hepatic expression of their receptors, suggesting the involvement of both vasotocinergic and isotocinergic systems in the acute stress response. Our results demonstrate the activation and involvement of both endocrine pathways in the regulation of metabolic and stress systems of Sparus aurata, which is stated, at least, through changes in mRNA expression levels of these genes analysed.
Resumo:
Increasing knowledge on the endocrine mechanisms that regulate feeding and growth in cultured fish can contribute to make improvement in fish holding conditions and feeding strategies, supporting the development of new techniques that could ameliorate feeding, food conversion efficiency and growth in aquaculture practice. The main objective of this study was to investigate how daily mRNA expression of three specific anorexigenic hormones, i.e. the corticotropin-releasing hormone (CRH) and the paralogues α- and β- proopiomelanocortin (POMC), is modulated by different photoperiods, light spectra and feeding regimes, in both adult and larvae of Solea senegalensis. In addition, as Senegalese sole exhibits a shift from diurnal to nocturnal in locomotor activity and feeding habits during metamorphic process, we tried to elucidate if this shift is accompanied by relevant daily variations in the expression of these anorexigenic hormones before, during and after the completion of metamorphosis. In order to reach this main objective, three main experiments were developed. In a first experiment, adults were reared under LD (12 h light: 12h dark) cycle and fed at mid-light (ML), mid-dark (MD) and at random (RND). In a second experiment, adult specimens were reared in constant darkness (DD) and fed at subjective mid-light (sML) or at RND. Larvae of Senegalese sole were reared under LD cycle with white, blue or red light for 40 days. Our results show an independence of crh mRNA expression from the feeding time and suggest an endogenous control of crh expression in sole. Both pomc paralogues showed significant daily rhythms under LD conditions. The rhythms were maintained or were even more robust under DD conditions for pomc_a, but were completely abolished for pomc_b. Our results indicate an endogenous control of pomc_a expression by the molecular clock in telencephalon and diencephalon, but not in the pituitary gland. Our findings confirm for the first time the significant influence that ambient lighting has on larval growth and development in Senegalese sole, revealing an important effect of light spectra upon functional elements of this species. Our results also emphasize the importance of maintaining cycling light-dark conditions of the adequate wavelengths in aquaculture practices during early development of sole.
Resumo:
Chronic posttraumatic stress disorder (PTSD) has been associated with perturbed hypothalamic-pituitary-adrenal (HPA) axis function and a hyperadrenergic state. We hypothesized that patients with PTSD attributable to myocardial infarction (MI) would show peripheral hypocortisolemia and increased norepinephrine levels, whereby taking into account that depressive symptoms would affect this relationship.
Resumo:
An autosomal dominant form of isolated GH deficiency (IGHD II) can result from heterozygous splice site mutations that weaken recognition of exon 3 leading to aberrant splicing of GH-1 transcripts and production of a dominant-negative 17.5-kDa GH isoform. Previous studies suggested that the extent of missplicing varies with different mutations and the level of GH expression and/or secretion. To study this, wt-hGH and/or different hGH-splice site mutants (GH-IVS+2, GH-IVS+6, GH-ISE+28) were transfected in rat pituitary cells expressing human GHRH receptor (GC-GHRHR). Upon GHRH stimulation, GC-GHRHR cells coexpressing wt-hGH and each of the mutants displayed reduced hGH secretion and intracellular GH content when compared with cells expressing only wt-hGH, confirming the dominant-negative effect of 17.5-kDa isoform on the secretion of 22-kDa GH. Furthermore, increased amount of 17.5-kDa isoform produced after GHRH stimulation in cells expressing GH-splice site mutants reduced production of endogenous rat GH, which was not observed after GHRH-induced increase in wt-hGH. In conclusion, our results support the hypothesis that after GHRH stimulation, the severity of IGHD II depends on the position of splice site mutation leading to the production of increasing amounts of 17.5-kDa protein, which reduces the storage and secretion of wt-GH in the most severely affected cases. Due to the absence of GH and IGF-I-negative feedback in IGHD II, a chronic up-regulation of GHRH would lead to an increased stimulatory drive to somatotrophs to produce more 17.5-kDa GH from the severest mutant alleles, thereby accelerating autodestruction of somatotrophs in a vicious cycle.
Resumo:
The measurement of inflammation by biomarkers not only documents clinically relevant infections but also offers an important tool to pin point potentially harmful effects of chronic psychosocial stressors. This article focuses firstly on basic biology of inflammation and lists main biomarkers currently used in psycho-physiologic research. In the second part, the effects of the hypothalamic-pituitary-adrenal (HPA) axis and the autonomic nervous system as pathways modulating stress-related inflammation are discussed. Furthermore, current evidence of how chronic psychosocial stressors are related to alterations in inflammatory activity is presented. In summary, job stress, low socioeconomic status, childhood adversities as well as life events, caregiver stress, and loneliness were all shown to exert effects on immunologic activity.
Resumo:
A differentiation towards myoepithelial cells has been demonstrated in several types of lesions in the breast. These include multifocal myoepitheliomatosis, the rare mixed tumor or pleomorphic adenoma, adenoid cystic carcinoma, adenomyoepithelioma and myoepithelial carcinoma (malignant myoepithelioma). Myoepithelial carcinoma is the only lesion purely composed of myoepithelial cells. All these tumors are benign and/or of low-grade malignancy, with the exception of malignant myoepithelioma. In contrast to the statement of the current World Health Organization (WHO), recent studies have reported that regional and distant metastases may occur in about 50% of pure myoepithelial carcinomas. The presented case of a breast carcinoma with dominant myoepithelial/spindle cell differentiation in a 58-year-old woman is an excellent example to document the highly aggressive biological behavior of this tumor phenotype. Despite an extensive chemotherapy and radiotherapy, the tumor was rapidly progressive, forming a finally exulcerating local tumor relapse and widespread metastases to the myocardium, lungs, liver, kidneys and skin. Similarities in morphology and biological behavior compared to patients with "triple-negative" (hormone receptor and Her2) monophasic sarcomatoid carcinomas and pure spindle cell sarcomas are discussed.
Resumo:
The factors that influence Leydig cell activity currently include peptides such as neuropeptide Y (NPY). In this work we investigated the ability of this compound, injected directly into the testes of adult male rats, to alter testosterone (T) release into the general circulation. At a 5μg/kg dose administered 1h prior to challenge with human chorionic gonadotropin (hCG, 1.0 U/kg, iv), NPY significantly (P<0.01) blunted the T response to this gonadotropin. The inhibitory effect of NPY was observed in animals pretreated with an antagonist to gonadotropin-releasing hormone or not, indicating that the decrease in plasma T found was most likely independent of pituitary luteinizing hormone. However, testicular levels of steroidogenic acute regulatory (STAR) protein or translocator protein (TSPO) in the Leydig cells did not exhibit consistent changes, which suggested that other mechanisms mediated the blunted T response to hCG. We therefore used autoradiography and immunohistochemistry methodologies to identify NPY receptors in the testes, and found them primarily located on blood vessels. Competition studies further identified these receptors as being Y(1), a subtype previously reported to modulate the vasoconstrictor effect of NPY. The absence of significant changes in STAR and TSPO levels, as well as the absence of Y(1) receptors on Leydig cells, suggest that NPY-induced decreases in T release is unlikely to represent a direct effect of NPY on these cells. Rather, the very high expression levels of Y(1) found in testicular vessels supports the concept that NPY may alter gonadal activity, at least in part, through local vascular impairment of gonadotropin delivery to, and/or blunted T secretion from, Leydig cells.
Resumo:
Chemokines have been proposed to contribute to tumour growth and metastatic spread of several cancer entities. Here, we examined the relative levels of CXCL12/CXCR4 in resection specimens from patients with different malignant and non-malignant colorectal diseases as well as colorectal liver metastases (CRLM). CXCL12/CXCR4 mRNA and protein expression profiles were assessed by quantitative real-time PCR, Western blot analysis, enzyme-linked immunosorbent assay (ELISA) and immunohistochemistry in resection specimens from patients with ulcerative colitis (UC; n = 15), colorectal adenoma (CRA; n = 15), colorectal adenocarcinoma (CRC; n = 47) and CRLM (n = 16). Corresponding non-affected tissues served as control. In contrast to UC tissues, CXCL12 showed a distinct down-regulation in CRA, CRC and CRLM specimens, whereas the corresponding receptor CXCR4 demonstrated a significant up-regulation in CRC and CRLM related to corresponding non-affected tissues (p < 0.05, respectively). Our results strongly suggest an association between CXCL12/CXCR4 expression and the induction of CRA, CRC and the development of CRLM. Therefore, CXCR4 may be a potential target for specific therapeutic interventions.
Resumo:
This study was to evaluate the treatment dosimetry, efficacy and toxicity of intensity modulated radiation therapy (IMRT) and fractionated stereotactic radiotherapy (FSRT) in the management of infratentorial ependymoma. Between 1999 and 2007, seven children (median age, 3.1 years) with infratentorial ependymoma were planned with either IMRT (3 patients) or SFRT (4 patients), the latter after conventional posterior fossa irradiation. Two children underwent gross total resection. Median prescribed dose was 59.4 Gy (range, 55.8-60). The median follow-up for surviving patients was 4.8 years (range, 1.3-8). IMRT (median dose, 59.4 Gy) and FSRT (median dose, 55.8 Gy) achieved similar optimal target coverage. Percentages of maximum doses delivered to the cochleae (59.5 vs 85.0% Gy; P = 0.05) were significantly inferior with IMRT, when compared to FSRT planning. Percentages of maximum doses administered to the pituitary gland (38.2 vs 20.1%; P = 0.05) and optic chiasm (38.1 vs 14.1%; P = 0.001) were, however, significantly higher with IMRT, when compared to FSRT planning. No recurrences were observed at the last follow-up. The estimated 3-year progression-free survival and overall survival were 87.5 and 100%, respectively. No grade >1 acute toxicity was observed. Two patients presented late adverse events (grade 2 hypoacousia) during follow-up, without cognitive impairment. IMRT or FSRT for infratentorial ependymomas is effective and associated with a tolerable toxicity level. Both treatment techniques were able to capitalize their intrinsic conformal ability to deliver high-dose radiation. Larger series of patients treated with these two modalities will be necessary to more fully evaluate these delivery techniques.
Resumo:
?Glucocorticoids (GCs) are often used for the treatment of rheumatic disorders. However, doses are prescribed, which may suppress the hypothalamic-pituitary-adrenal (HPA) axis. After GC withdrawal, recovery of the HPA axis may be delayed putting the patient at risk for adrenal insufficiency. We assessed adrenal function and factors influencing adrenal responsiveness after termination of GC therapy in paediatric patients with rheumatic diseases.
Resumo:
Although stress is implicated in the pathophysiology of mood and anxiety disorders, not all individuals who suffer stressful life events develop psychopathology. Differential susceptibility to stress may be influenced by genetically mediated differences in hypothalamic-pituitary-adrenal (HPA) axis activity and moderation of the stress response by the opioid peptide beta-endorphin (beta-E). The present study investigated genetic contributions to coping behavior by examining anxious behavior of transgenic mice with varying capacities to synthesize beta-E [B6.129S2-Pomc(tm1Low)/J; regulated by insertion of a premature stop codon into one or both copies of the proopiomelanocortin (POMC) gene], both under normal conditions and following 3 min of forced swim (FS). Ten minutes after this stress exposure or a control manipulation, acutely food-deprived female and male transgenic mice were subjected to a novelty-suppressed feeding (NSF) test, during which their interaction with an almond slice located in the center of an open field box was measured. There was an interaction between genotype and stress for latency to approach the almond and whether or not the almond was approached, such that mice with low or absent beta-E displayed a stronger aversion to novelty-feeding after stress exposure than did mice with normal levels. These data provide evidence for a moderating effect of beta-E on the behavioral response to stress. Genotypic differences in anxious behavior emerged when mice were stressed prior to behavioral assessment, suggesting that beta-E plays a role in coping behavior. These findings indicate that genetic variability in sensitivity of the beta-E system to stress may contribute, at least in part, to heritable differences in stress reactivity as well as vulnerability to stress-related psychopathology.