483 research outputs found
Aluminofluoride action on G-proteins of the adenylate cyclase system is not different from that on transducin
Prognostic factors in stage III-IV adrenocortical carcinomas (ACC): an European Network for the Study of Adrenal Tumor (ENSAT) study.
BACKGROUND:
The clinical course of advanced adrenocortical carcinoma (ACC) is heterogeneous. Our study aimed primarily to refine and make headway in the prognostic stratification of advanced ACC.
PATIENTS AND METHODS:
Patients with advanced ENSAT ACC (stage III or stage IV) at diagnosis registered between 2000 and 2009 in the ENSAT database were enrolled. The primary end point was overall survival (OS). Parameters of potential prognostic relevance were selected. Univariate and multivariate analyses were carried out: model 1 'before surgery'; model 2 'post-surgery'.
RESULTS:
Four hundred and forty-four patients with advanced ENSAT ACC (stage III: 210; stage IV: 234) were analyzed. After a median follow-up of 55.2 months, the median OS was 24 months. A modified ENSAT (mENSAT) classification was validated: stage III (invasion of surrounding tissues/organs or the vena renalis/cava) and stage IVa, IVb, IVc (2, 3 or >3 metastatic organs, including N, respectively). Two- or 5-year OS was 73%, 46%, 26% and 15% or 50%, 15%, 14% and 2% for stages III, IVa, IVb and IVc, respectively. In the multivariate analysis, mENSAT stages (stages IVa, IVb, or IVc, respectively) were significantly correlated with OS (P 6 and/or Ki67 ≥20%, P = 0.06) in model 2.
CONCLUSION:
The mENSAT classification and GRAS parameters (Grade, R status, Age and Symptoms) were found to best stratify the prognosis of patients with advanced ACC
High prevalence of venous thrombotic events in Cushing’s syndrome:data from ERCUSYN and details in relation to surgery
Objective: The aim of this study was to evaluate the prevalence of venous thromboembolism (VTE) in patients included in the European Registry on Cushing's syndrome (ERCUSYN), compare their clinical characteristics with those who did not develop VTE and identify risk factors for VTE. Design: A retrospective observational cohort study. Methods: Data extraction from the registry was taken on February, 7, 2022. At the time there were 2174 patients diagnosed with Cushing's syndrome (CS) and 95 VTEs were reported in the database. Results: Of 95 VTE events 70 (74%) were in pituitary-dependent CS patients, 12 (12.5%) in adrenal-dependant CS, 10 (10.5%) in ectopic CS, and 3 (3%) in CS due to other causes. Sex, 24-hour urinary free cortisol (UFC) value at diagnosis, as well as the number of operations remained statistically significant predictors of VTE. Of patients who were treated with at least one surgery, 12 (13%) VTE occurred before and 80 (87%) after the surgery. Nearly half of these VTEs occurred within six months since the operation (36; 45%). Over half of the centers that reported VTE did not routinely anticoagulate CS patients. Anticoagulation schemes varied widely. Conclusion: Patients with CS have an elevated risk of developing VTE for an extended period of time. From ERCUSYN cohort patients have higher risk for VTE if they need multiple surgeries to treat CS, are males and have high UFC values at the diagnosis of CS. Since there is no agreement on thromboprohpylaxis, a protocol for VTE prevention that is widely adopted appears to be necessary for patients with CS.</p
Regulation of GIP and GLP1 Receptor Cell Surface Expression by N-Glycosylation and Receptor Heteromerization
In response to a meal, Glucose-dependent Insulinotropic Polypeptide (GIP) and Glucagon-like Peptide-1 (GLP-1) are released from gut endocrine cells into the circulation and interact with their cognate G-protein coupled receptors (GPCRs). Receptor activation results in tissue-selective pleiotropic responses that include augmentation of glucose-induced insulin secretion from pancreatic beta cells. N-glycosylation and receptor oligomerization are co-translational processes that are thought to regulate the exit of functional GPCRs from the ER and their maintenance at the plasma membrane. Despite the importance of these regulatory processes, their impact on functional expression of GIP and GLP-1 receptors has not been well studied. Like many family B GPCRs, both the GIP and GLP-1 receptors possess a large extracellular N-terminus with multiple consensus sites for Asn-linked (N)-glycosylation. Here, we show that each of these Asn residues is glycosylated when either human receptor is expressed in Chinese hamster ovary cells. N-glycosylation enhances cell surface expression and function in parallel but exerts stronger control over the GIP receptor than the GLP-1 receptor. N-glycosylation mainly lengthens receptor half-life by reducing degradation in the endoplasmic reticulum. N-glycosylation is also required for expression of the GIP receptor at the plasma membrane and efficient GIP potentiation of glucose-induced insulin secretion from the INS-1 pancreatic beta cell line. Functional expression of a GIP receptor mutant lacking N-glycosylation is rescued by co-expressed wild type GLP1 receptor, which, together with data obtained using Bioluminescence Resonance Energy Transfer, suggests formation of a GIP-GLP1 receptor heteromer
Super-resolution imaging as a method to study GPCR dimers and higher-order oligomers
The study of G protein-coupled receptor (GPCR) dimers and higher-order oligomers has unveiled mechanisms for receptors to diversify signaling and potentially uncover novel therapeutic targets. The functional and clinical significance of these receptor–receptor associations has been facilitated by the development of techniques and protocols, enabling researchers to unpick their function from the molecular interfaces, to demonstrating functional significance in vivo, in both health and disease. Here we describe our methodology to study GPCR oligomerization at the single-molecule level via super-resolution imaging. Specifically, we have employed photoactivated localization microscopy, with photoactivatable dyes (PD-PALM) to visualize the spatial organization of these complexes to <10 nm resolution, and the quantitation of GPCR monomer, dimer, and oligomer in both homomeric and heteromeric forms. We provide guidelines on optimal sample preparation, imaging parameters, and necessary controls for resolving and quantifying single-molecule data. Finally, we discuss advantages and limitations of this imaging technique and its potential future applications to the study of GPCR function
Adjuvant mitotane versus surveillance in low-grade, localised adrenocortical carcinoma (ADIUVO): an international, multicentre, open-label, randomised, phase 3 trial and observational study
BACKGROUND: Adjuvant treatment with mitotane is commonly used after resection of adrenocortical carcinoma; however, treatment remains controversial, particularly if risk of recurrence is not high. We aimed to assess the efficacy and safety of adjuvant mitotane compared with surveillance alone following complete tumour resection in patients with adrenocortical carcinoma considered to be at low to intermediate risk of recurrence. METHODS: ADIUVO was a multicentre, open-label, parallel, randomised, phase 3 trial done in 23 centres across seven countries. Patients aged 18 years or older with adrenocortical carcinoma and low to intermediate risk of recurrence (R0, stage I-III, and Ki67 ≤10%) were randomly assigned to adjuvant oral mitotane two or three times daily (the dose was adjusted by the local investigator with the target of reaching and maintaining plasma mitotane concentrations of 14-20 mg/L) for 2 years or surveillance alone. All consecutive patients at 14 study centres fulfilling the eligibility criteria of the ADIUVO trial who refused randomisation and agreed on data collection via the European Network for the Study of Adrenal Tumors adrenocortical carcinoma registry were included prospectively in the ADIUVO Observational study. The primary endpoint was recurrence-free survival, defined as the time from randomisation to the first radiological evidence of recurrence or death from any cause (whichever occurred first), assessed in all randomly assigned patients by intention to treat. Overall survival, defined as time from the date of randomisation to the date of death from any cause, was a secondary endpoint analysed by intention to treat in all randomly assigned patients. Safety was assessed in all patients who adhered to the assigned regimen, which was defined by taking at least one tablet of mitotane in the mitotane group and no mitotane at all in the surveillance group. The ADIUVO trial is registered with ClinicalTrials.gov, NCT00777244, and is now complete. FINDINGS: Between Oct 23, 2008, and Dec 27, 2018, 45 patients were randomly assigned to mitotane and 46 to surveillance alone. Because the study was discontinued prematurely, 5-year recurrence-free and overall survival are reported instead of recurrence-free and overall survival as defined in the protocol. 5-year recurrence-free survival was 79% (95% CI 67-94) in the mitotane group and 75% (63-90) in the surveillance group (hazard ratio 0·74 [95% CI 0·30-1·85]). Two people in the mitotane group and five people in the surveillance group died, and 5-year overall survival was not significantly different (95% [95% CI 89-100] in the mitotane group and 86% [74-100] in the surveillance group). All 42 patients who received mitotane had adverse events, and eight (19%) discontinued treatment. There were no grade 4 adverse events or treatment-related deaths. INTERPRETATION: Adjuvant mitotane might not be indicated in patients with low-grade, localised adrenocortical carcinoma considering the relatively good prognosis of these patients, and no significant improvement in recurrence-free survival and treatment-associated toxicity in the mitotane group. However, the study was discontinued prematurely due to slow recruitment and cannot rule out an efficacy of treatment. FUNDING: AIFA, ENSAT Cancer Health F2-2010-259735 programme, Deutsche Forschungsgemeinschaft, Cancer Research UK, and the French Ministry of Health
Aberrant GPCR expression is a sufficient genetic event to trigger adrenocortical tumorigenesis
Evaluation and diagnostic potential of circulating extracellular vesicle-associated microRNAs in adrenocortical tumors
There is no available blood marker for the preoperative diagnosis of adrenocortical malignancy. The objective of this study was to investigate the expression of extracellular vesicle-associated microRNAs and their diagnostic potential in plasma samples of patients suffering from adrenocortical tumors. Extracellular vesicles were isolated either by using Total Exosome Isolation Kit or by differential centrifugation/ultracentrifugation. Preoperative plasma extracellular vesicle samples of 6 adrenocortical adenomas (ACA) and 6 histologically verified adrenocortical cancer (ACC) were first screened by Taqman Human Microarray A-cards. Based on the results of screening, two miRNAs were selected and validated by targeted quantitative real-time PCR. The validation cohort included 18 ACAs and 16 ACCs. Beside RNA analysis, extracellular vesicle preparations were also assessed by transmission electron microscopy, flow cytometry and dynamic light scattering. Significant overexpression of hsa-miR-101 and hsa-miR-483-5p in ACC relative to ACA samples has been validated. Receiver operator characteristics of data revealed dCT hsa-miR-483-5p normalized to cel-miR-39 to have the highest diagnostic accuracy (area under curve 0.965), the sensitivity and the specifity were 87.5 and 94.44, respectively. Extracellular vesicle-associated hsa-miR-483-5p thus appears to be a promising minimally invasive biomarker in the preoperative diagnosis of ACC but needs further validation in larger cohorts of patients
Peptide-induced immune regulation by a promiscuous and immunodominant CD4T-cell epitope of Timothy grass pollen: a role of Cbl-b and Itch in regulation
Subtropical grass pollen allergens are important for allergic respiratory diseases in subtropical regions
Background: Grass pollen allergens are a major cause of allergic respiratory disease but traditionally prescribing practice for grass pollen allergen-specific immunotherapy has favoured pollen extracts of temperate grasses. Here we aim to compare allergy to subtropical and temperate grass pollens in patients with allergic rhinitis from a subtropical region of Australia. Methods. Sensitization to pollen extracts of the subtropical Bahia grass (Paspalum notatum), Johnson grass (Sorghum halepense) and Bermuda grass (Cynodon dactylon) as well as the temperate Ryegrass (Lolium perenne) were measured by skin prick in 233 subjects from Brisbane. Grass pollen-specific IgE reactivity was tested by ELISA and cross-inhibition ELISA. Results: Patients with grass pollen allergy from a subtropical region showed higher skin prick diameters with subtropical Bahia grass and Bermuda grass pollens than with Johnson grass and Ryegrass pollens. IgE reactivity was higher with pollen of Bahia grass than Bermuda grass, Johnson grass and Ryegrass. Patients showed asymmetric cross-inhibition of IgE reactivity with subtropical grass pollens that was not blocked by temperate grass pollen allergens indicating the presence of species-specific IgE binding sites of subtropical grass pollen allergens that are not represented in temperate grass pollens. Conclusions: Subtropical grass pollens are more important allergen sources than temperate grass pollens for patients from a subtropical region. Targeting allergen-specific immunotherapy to subtropical grass pollen allergens in patients with allergic rhinitis in subtropical regions could improve treatment efficacy thereby reducing the burden of allergic rhinitis and asthma
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