Controlled Synthesis of Gold Nanoparticles in Copolymers Nanomolds by X-ray Radiolysis.

We show by X-ray and neutron small-angle scattering that gold nanoparticles with controlled sizes and morphologies can be obtained by the metallic reduction of AuCl4- ions trapped in 3D organic molds by X-ray radiolysis. The molds are spherical frozen micelles of polystyrene-b-poly(dimethylaminoethyl methacrylate) (PS-b-PDMAEMA) block copolymer in acidic aqueous solution with a PS spherical core surrounded by a corona of PDMAEMA chains in good solvent. The behavior of micelles is controlled by the [AuCl4-]/[DMAEMA] ratio RAuCl4-/DMAEMA. At low gold concentration, AuCl4- ions condense on the positively charged DMAEMA moieties without changing the behavior of the PDMAEMA chains. At intermediate gold concentration, the ions induce a progressive contraction of the corona's chains and dehydration of micelles. At large gold concentration, the corona becomes a fully dry phase loaded with gold ions, which induces micelle aggregation. Radiolysis of the solution by an intense X-ray beam produces different types of gold nanoparticles with respect to RAuCl4-/DMAEMA and irradiation time. At RAuCl4-/DMAEMA = 0.033, irradiation produces in the first step gold clusters in the micelle corona which in the second step merge to form nanoparticles of a similar size to that of the micelle. Conversely, at RAuCl4-/DMAEMA = 0.33, micelles do not operate as templates but only as nucleation zones and large nanoparticles grow outside the micelles.

Risk for Thyroid Cancer Recurrence Is Higher in Men Than in Women Independent of Disease Stage at Presentation.

Background: Well-differentiated thyroid cancer (DTC) presents at a more advanced stage in men than in women, and the mortality in men is higher than that in women. However, it is not clear whether DTC recurrence is affected by sex independent of stage at presentation. The objective of the present study was to assess if male sex is an independent risk factor for recurrence of DTC. Methods: The Canadian Collaborative Network for Cancer of the Thyroid (CANNECT) is a collaborative registry to describe patterns of care for thyroid cancer. We included patients from the CANNECT registry with DTC diagnosed at age 18 or older between 2000 and 2010. We compared men and women with respect to presentation, management, and recurrence risk, stratified for American Joint Committee on Cancer (AJCC) stage. Results: We included 2595 patients, 2067 (79.7%) women and 528 (20.3%) men. Men presented with more advanced AJCC stage (p < 0.001), T stage (p < 0.001), N stage (p < 0.001), and M stage (p = 0.002) There was no difference in follow-up duration between women (7.7 ± 4.0 [mean ± standard deviation] years) and men (7.7 ± 4.0 years, p = 0.985). Overall recurrence was 2.2% (n = 46) for women and 8.5% (n = 45) for men (p < 0.001). In multivariate analysis adjusted for AJCC stage, men were at significantly greater risk for DTC recurrence than women (adjusted hazard ratio 2.72 [95% confidence interval [CI] 1.78-4.20]; p < 0.001). In multivariate analysis adjusted for tumor-node-metastasis (TNM) stage, men were at significantly greater risk for DTC recurrence than women (adjusted hazard ratio 2.31 [CI 1.48-3.60]; p < 0.001). Conclusions: Our study confirms that the risk for recurrence of DTC is higher in men than in women. Although men tend to present with more advanced-stage disease, the difference in recurrence risk persists when adjusted for stage of presentation. It needs to be determined whether sex should influence follow-up intensity and/or duration.

Coexistence of Myelolipoma and Primary Bilateral Macronodular Adrenal Hyperplasia With GIP-Dependent Cushing's Syndrome.

Introduction: Adrenal myelolipomas are usually isolated benign adrenal lesions, but can be adjacent to steroid-secreting adrenocortical tumors. We studied the aberrant regulation of cortisol secretion in a 61 year-old woman with combined bilateral myelolipomas and primary bilateral macronodular adrenal hyperplasia (BMAH) causing Cushing's syndrome. Materials and Methods: Cortisol response was measured during in vivo tests that transiently modulated the levels of ligands for potential aberrant receptors, including GIP. Response to medical therapies decreasing GIP was monitored. Expression of ACTH and of GIP receptors were examined in resected adrenal tissues by immunohistochemistry and reverse transcription polymerase chain reaction (RT-PCR). Results: In vivo, cortisol increased in response to mixed meals (+353%), oral 75 g glucose (+71%), GIP infusion (+416%), and hLH IV (+243%). Suppression of GIP by pasireotide improved cortisol secretion but produced hyperglycemia. The left adrenal was predominantly composed of myelolipoma and strands of BMAH, while the right was mainly composed of BMAH with some foci of myelolipoma on pathology. No ACTH was detectable by immunohistochemistry in BMAH or myelolipomas tissue. Ectopic GIP receptor was confirmed by RT-PCR and immunohistochemistry in BMAH tissues but not in the myelolipomas. No germline mutations were identified in the ARMC5 gene of the patient's leucocyte DNA. Conclusion: This is the first report of interspersed myelolipoma and BMAH with GIP-dependent Cushing's syndrome. In contrast with the BMAH tissues, myelolipoma tissue did not express specific GIP receptors. The potential mechanisms responsible for the interspersed growth of those two lesions remain to be identified.