11 research outputs found

    The GIP/GIPR axis is functionally linked to GH-secretion increase in a significant proportion of gsp(-) somatotropinomas

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    Glucose-dependent insulinotropic polypeptide receptor (GIPR) overexpression has been recently described in a proportion of gsp(-) somatotropinomas and suggested to be associated with the paradoxical increase of GH (GH-PI) during an oral glucose load

    A Combined Nucleic Acid and Protein Analysis in Friedreich Ataxia: Implications for Diagnosis, Pathogenesis and Clinical Trial Design

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    BACKGROUND: Friedreich's ataxia (FRDA) is the most common hereditary ataxia among caucasians. The molecular defect in FRDA is the trinucleotide GAA expansion in the first intron of the FXN gene, which encodes frataxin. No studies have yet reported frataxin protein and mRNA levels in a large cohort of FRDA patients, carriers and controls. METHODOLOGY/PRINCIPAL FINDINGS: We enrolled 24 patients with classic FRDA phenotype (cFA), 6 late onset FRDA (LOFA), all homozygous for GAA expansion, 5 pFA cases who harbored the GAA expansion in compound heterozygosis with FXN point mutations (namely, p.I154F, c.482+3delA, p.R165P), 33 healthy expansion carriers, and 29 healthy controls. DNA was genotyped for GAA expansion, mRNA/FXN was quantified in real-time, and frataxin protein was measured using lateral-flow immunoassay in peripheral blood mononuclear cells (PBMCs). Mean residual levels of frataxin, compared to controls, were 35.8%, 65.6%, 33%, and 68.7% in cFA, LOFA, pFA and healthy carriers, respectively. Comparison of both cFA and pFA with controls resulted in 100% sensitivity and specificity, but there was overlap between LOFA, carriers and controls. Frataxin levels correlated inversely with GAA1 and GAA2 expansions, and directly with age at onset. Messenger RNA expression was reduced to 19.4% in cFA, 50.4% in LOFA, 52.7% in pFA, 53.0% in carriers, as compared to controls (p<0.0001). mRNA levels proved to be diagnostic when comparing cFA with controls resulting in 100% sensitivity and specificity. In cFA and LOFA patients mRNA levels correlated directly with protein levels and age at onset, and inversely with GAA1 and GAA2. CONCLUSION/SIGNIFICANCE: We report the first explorative study on combined frataxin and mRNA levels in PBMCs from a cohort of FRDA patients, carriers and healthy individuals. Lateral-flow immunoassay differentiated cFA and pFA patients from controls, whereas determination of mRNA in q-PCR was sensitive and specific only in cFA

    Perioperative thromboprophylaxis in Cushing's disease: What we did and what we are doing?

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    Purpose: Cushing\u2019s disease (CD) is associated with an increased risk of thrombotic events, particularly after surgery. No guidelines are available on the management of patients with CD undergoing pituitary transsphenoidal surgery (TSS). We aimed to compare the effectiveness of different prophylactic procedures on the prevention of thrombotic events after surgery in CD. Methods: We retrospectively collected data on 78 consecutive patients who underwent TSS for CD between 2001 and 2012 at Padova\u2019s Neurosurgical Unit, recording their hemostatic, hormonal and anthropometric parameters. Patients were divided into two groups according to their perioperative management. Group A (34 patients) received fractionated heparin for a maximum of 14 days after surgery. Patients in group B (44 patients) were given no early glucocorticoid replacement therapy, and treated with subcutaneous enoxaparin 4,000\u20138,000 U/daily (depending on their weight) for 30 days plus graduated elastic stockings until mobilization, and early ambulation. Results: The whole cohort of patients had clotting and anticoagulant factors significantly higher than the normal range. The two groups were comparable for age, BMI, ACTH, urinary free cortisol levels, outcome of surgery, and main clotting parameters. The surgical procedure did not change during the study period. Three venous thrombotic events [venous thromboembolic events (VTE), 2 associated with pulmonary embolism] were recorded in group A, none in group B (p = 0.079). No hemorrhagic events were reported. Conclusions: Provoked thrombotic events pose a major problem in the management of CD patients after surgery, regardless of the procedure\u2019s outcome. The prophylactic regimen proposed in this paper afforded an efficacy prophylaxis against postoperative VTE in patients with CD. Due to the rarity of CD, a multicenter study on a larger sample of cases would be warranted in order to collect more thrombotic events

    Temozolomide and pasireotide treatment for aggressive pituitary adenoma: expertise at a tertiary care center.

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    Aggressive pituitary adenomas (PAs) are clinically challenging for endocrinologists and neurosurgeons due to their locally invasive nature and resistance to standard treatment (surgery, medical or radiotherapy). Two pituitary-directed drugs have recently been proposed: temozolomide (TMZ) for aggressive PA, and pasireotide for ACTH-secreting PA. We describe the experience of our multidisciplinary team of endocrinologists, neurosurgeons, neuroradiologists, oncologists, otolaryngologists and pathologists with TMZ and pasireotide treatment for aggressive PAs in terms of their radiological shrinkage and genetic features. We considered five patients with aggressive PA, three of them non-secreting (two ACTH-silent and one becoming ACTH secreting), and two secreting (one GH and one ACTH). TMZ was administrated orally at 150-200 mg/m(2) daily for 5 days every 28 days to all 5 patients, and 2 of them also received pasireotide 600-900 mu g bid sc. We assessed the MRI at the baseline and during TMZ or pasireotide treatment. We also checked for MGMT promoter methylation and IDH, BRAF and kRAS mutations. Considering TMZ, two patients showed PA progression, one stable disease and two achieved radiological and clinical response. Pasireotide was effective in reducing hypercortisolism and mass volume, combined with TMZ in one case. Both treatments were generally well tolerated; one patient developed a grade 2 TMZ-induced thrombocytopenia. None of patients developed hypopituitarism while taking TMZ or pasireotide treatment. No genetic anomalies were identified in the adenoma tissue. TMZ and pasireotide may be important therapies for aggressive PA, alone or in combination

    Activation of the dopamine receptor type-2 (DRD2) promoter by 9-cis retinoic acid in a cellular model of Cushing's disease mediates the inhibition of cell proliferation and ACTH secretion without a complete corticotroph-to-melanotroph transdifferentiation

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    Cushing\u2019s disease (CD) is a rare condition in which hypercortisolemia is secondary to excessive ACTH release from a pituitary corticotroph adenoma. CD is associated with significant morbidity and mortality, and a safe therapy that effectively targets the pituitary tumor is still lacking. Retinoic acid (RA) and dopamine agonists (DAs) have recently been considered as monotherapy in CD patients, and satisfactory results have been reported, albeit in a limited number of patients. Given the permissive role of RA on the dopamine receptor type-2 (DRD2), the aim of present study was to see whether a combination of 9-cis RA and the DA bromocriptine (Br) might represent a possible treatment for CD. Here we show that 9-cis RA induces a functional DRD2 in the pituitary corticotroph cell line AtT20, and increases cell sensitivity to Br via a mechanism only partially related to corticotroph-to-melanotroph transdifferentiation. In addition, 9-cis RA and Br act synergistically to modulate cell viability, with favorable implications for clinical use. In nearly 45% of corticotropinoma-derived primary cultures, the combined administration of 9-cis RA and Br lowered the steady-state level of the ACTH precursor proopiomelanocortin (POMC) more efficiently than either of the drugs alone. In conclusion, the effects of a combination of 9-cis RA and Br on ACTH synthesis/secretion and cell viability in AtT20, and on POMC transcriptional activity in human corticotropinomas might represent a suitable starting point for assessing the potential of this treatment regimen for ACTH-secreting pituitary adenomas. This study thus has potentially important implications for novel therapeutic approaches to Cushing\u2019s disease

    SParC-LES: Enabling large eddy simulations with parallel sparse matrix computation tools

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    We discuss the design and development of a parallel code for Large Eddy Simulation (LES) by exploiting libraries for sparse matrix computations. We formulate a numerical procedure for the LES of turbulent channel flows, based on an approximate projection method, in terms of linear algebra operators involving sparse matrices and vectors. Then we implement the procedure using general-purpose linear algebra libraries as building blocks. This approach allows to pursue goals such as modularity, accuracy and robustness, as well as easy and fast exploitation of parallelism, with a relatively low coding effort. The parallel LES code developed in this work, named SParC-LES (Sparse Parallel Computation-based LES), exploits two parallel libraries: PSBLAS, providing basic sparse matrix operators and Krylov solvers, and MLD2P4, providing a suite of algebraic multilevel Schwarz preconditioners. Numerical experiments, concerning the simulation by SParC-LES of a turbulent flow in a plane channel, confirm that the LES code can achieve a satisfactory parallel performance. This supports our opinion that the software design methodology used to build SParC-LES yields a very good tradeoff between the exploitation of the computational power of parallel computers and the amount of coding effort

    A Survey on Pituitary Surgery in Italy

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    Pituitary tumors are a heterogeneous group of lesions that are usually benign. Therefore, a proper understanding of the anatomy, physiology, and pathology is mandatory to achieve favorable outcomes. Accordingly, diagnostic tests and treatment guidelines should be determined and implemented. Thus, we decided to perform a multicenter study among Italian neurosurgical centers performing pituitary surgery to provide an actual depiction from the neurosurgical standpoint

    Initial invasive or conservative strategy for stable coronary disease

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    BACKGROUND Among patients with stable coronary disease and moderate or severe ischemia, whether clinical outcomes are better in those who receive an invasive intervention plus medical therapy than in those who receive medical therapy alone is uncertain. METHODS We randomly assigned 5179 patients with moderate or severe ischemia to an initial invasive strategy (angiography and revascularization when feasible) and medical therapy or to an initial conservative strategy of medical therapy alone and angiography if medical therapy failed. The primary outcome was a composite of death from cardiovascular causes, myocardial infarction, or hospitalization for unstable angina, heart failure, or resuscitated cardiac arrest. A key secondary outcome was death from cardiovascular causes or myocardial infarction. RESULTS Over a median of 3.2 years, 318 primary outcome events occurred in the invasive-strategy group and 352 occurred in the conservative-strategy group. At 6 months, the cumulative event rate was 5.3% in the invasive-strategy group and 3.4% in the conservative-strategy group (difference, 1.9 percentage points; 95% confidence interval [CI], 0.8 to 3.0); at 5 years, the cumulative event rate was 16.4% and 18.2%, respectively (difference, 121.8 percentage points; 95% CI, 124.7 to 1.0). Results were similar with respect to the key secondary outcome. The incidence of the primary outcome was sensitive to the definition of myocardial infarction; a secondary analysis yielded more procedural myocardial infarctions of uncertain clinical importance. There were 145 deaths in the invasive-strategy group and 144 deaths in the conservative-strategy group (hazard ratio, 1.05; 95% CI, 0.83 to 1.32). CONCLUSIONS Among patients with stable coronary disease and moderate or severe ischemia, we did not find evidence that an initial invasive strategy, as compared with an initial conservative strategy, reduced the risk of ischemic cardiovascular events or death from any cause over a median of 3.2 years. The trial findings were sensitive to the definition of myocardial infarction that was used
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