Pseudohypoparathyroidism type‐Ia (PHP‐Ia), characterized by renal proximal tubular resistance to parathyroid hormone (PTH), results from maternal mutations of GNAS that lead to loss of α‐subunit of the stimulatory G protein (Gαs) activity. Gαs expression is paternally silenced in the renal proximal tubule, and this genomic event is critical for the development of PTH resistance, as patients display impaired hormone action only if the mutation is inherited maternally. The primary clinical finding of PHP‐Ia is hypocalcemia, which can lead to various neuromuscular defects including seizures. PHP‐Ia patients frequently do not present with hypocalcemia until after infancy, but it has remained uncertain whether PTH resistance occurs in a delayed fashion. Analyzing reported cases of PHP‐Ia with documented GNAS mutations and mice heterozygous for disruption of Gnas, we herein determined that the manifestation of PTH resistance caused by the maternal loss of Gαs, ie, hypocalcemia and elevated serum PTH, occurs after early postnatal life. To investigate whether this delay could reflect gradual development of paternal Gαs silencing, we then analyzed renal proximal tubules isolated by laser capture microdissection from mice with either maternal or paternal disruption of Gnas. Our results revealed that, whereas expression of Gαs mRNA in this tissue is predominantly from the maternal Gnas allele at weaning (3 weeks postnatal) and in adulthood, the contributions of the maternal and paternal Gnas alleles to Gαs mRNA expression are equal at postnatal day 3. In contrast, we found that paternal Gαs expression is already markedly repressed in brown adipose tissue at birth. Thus, the mechanisms silencing the paternal Gαs allele in renal proximal tubules are not operational during early postnatal development, and this finding correlates well with the latency of PTH resistance in patients with PHP‐Ia. © 2014 American Society for Bone and Mineral Research.

Transactivation of epidermal growth factor receptor (EGFR) by α 1-adrenoceptor ( α 1-AR) is implicated in contraction and hypertrophy of vascular smooth muscle (VSM). We examine whether all α 1-AR subtypes transactivate EGFR and explore the mechanism of transactivation. Chinese hamster ovary (CHO) cells stably expressing one subtype of α 1-AR were transiently transfected with EGFR. The transactivation mechanism was examined both by coexpression of a chimeric erythropoietin (EPO)-EGFR with an extracellular EPO and intracellular EGFR domain, and by pharmacologic inhibition of external and internal signaling routes. All three α 1-AR subtypes transactivated EGFR, which was dependent on the increase in intracellular calcium. The EGFR kinase inhibitor AG1478 [4-(3′-chloroanilino)-6,7-dimethoxyquinazoline] abrogated α 1A-AR and α 1D-AR induced phosphorylation of EGFR, but both the inhibition of matrix metalloproteinases by GM6001 [( R )- N 4-hydroxy- N 1-[( S )-2-(1 H -indol-3-yl)-1-methylcarbamoyl-ethyl]-2-isobutyl-succinamide] or blockade of EGFR by cetuximab did not. Stimulation of α 1A-AR and α 1D-AR also induced phosphorylation of EPO-EGFR chimeric receptors. Moreover, α 1A-AR stimulation enhanced phosphorylation of extracellular signal regulated kinase (ERK) 1/2 and serine-threonine kinases (Akt), which were both unaffected by AG1478, indicating that ERK1/2 and Akt phosphorylation is independent of EGFR transactivation. Accordingly, inhibitors of ERK1/2 or Akt did not influence the α 1A-AR–mediated EGFR transactivation. Inhibition of calcium/calmodulin-dependent kinase II (CaMKII), phosphatidylinositol 3-kinase (PI3K), and Src, however, did block EGFR transactivation by α 1A-AR and α 1D-AR. These findings demonstrate that all α 1-AR subtypes transactivate EGFR, which is dependent on an intracellular signaling route involving an increase in calcium and activation of CaMKII, PI3K, and Src, but not the of ERK1/2 and Akt pathways.

Purpose: The electron energy characteristics of mobile intraoperative radiotherapy (IORT) accelerator LIAC^® differ from commonly used linear accelerators, thus some of the frequently used detectors can give less accurate results. The aim of this study is to evaluate the output factors (OFs) of several ionization chambers (IC) and solid state detectors (SS) for electron beam energies generated by LIAC^® and compare with the output factor of Monte Carlo model (MC) in order to determine the adequate detectors for LIAC^®.Methods: The OFs were measured for 6, 8, 10, and 12 MeV electron energies with PTW 23343 Markus, PTW 34045 Advanced Markus, PTW 34001 Roos, IBA PPC05, IBA PPC40, IBA NACP‐02, PTW 31010 Semiflex, PTW 31021 Semiflex 3D, PTW 31014 Pinpoint, PTW 60017 Diode E, PTW 60018 Diode SRS, SNC Diode EDGE, and PTW 60019 micro Diamond detectors. Ion recombination factors (k_sat) of IC were measured for all applicator sizes and OFs were corrected according to k_sat. The measured OFs were compared with Monte Carlo output factors (OF_MC).Results: The measured OFs of IBA PPC05, PTW Advanced Markus, PTW Pinpoint, PTW microDiamond, and PTW Diode E detectors are in good agreement with OF_MC. The maximum deviations of IBA PPC05 OFs to OF_MC are −1.6%, +1.5%, +1.5%, and +2.0%; for PTW Advanced Markus +1.0%, +1.5%, +2.0%, and +2.0%; for PTW Pinpoint +2.0%, +1.6%, +4.0%, and +2.0%; for PTW microDiamond −1.6%, +2%, +1.1%, and +1.0%; and for PTW Diode E −+1.7%, +1.7%, +1.3%, and +2.5% for 6, 8, 10, and 12 MeV, respectively. PTW Roos, PTW Markus, IBA PPC40, PTW Semiflex, PTW Semiflex 3D, SNC Diode Edge measured OFs with a maximum deviation of +5.6%, +4.5%, +5.6%, +8.1%, +4.8%, and +9.6% with respect to OF_MC, while PTW Diode SRS and IBA NACP‐02 were the least accurate (with highest deviations −37.1% and −18.0%, respectively).Conclusion: The OFs results of solid state detectors PTW microDiamond and PTW Diode E as well as the ICs with small electrode spacing distance such as IBA PPC05, PTW Advanced Markus and PTW Pinpoint are in excellent agreement with OF_MC. The measurements of the other detectors evaluated in this study are less accurate, thus they should be used with caution. Particularly, PTW Diode SRS and IBA NACP‐02 are not suitable and their use should be avoided in relative dosimetry measurements under high dose per pulsed (DPP) electron beams.

In this study, 683 patients with endometrial cancer (EC) after comprehensive surgical staging were classified into four risk groups as low (LR), intermediate (IR), high-intermediate (HIR) and high-risk (HR), according to the recent consensus risk grouping. Patients with disease confined to the uterus, ≥50% myometrial invasion (MI) and/or grade 3 histology were treated with vaginal brachytherapy (VBT). Patients with stage II disease, positive/close surgical margins or extra-uterine extension were treated with external beam radiotherapy (EBRT)±VBT. The median follow-up was 56 months. The overall survival (OS) was significantly different between LR and HR groups, and there was a trend between LR and HIR groups. Relapse-free survival (RFS) was significantly different between LR and HIR, LR and HR and IR and HR groups. There was no significant difference in OS and RFS rates between the HIR and HR groups. In HR patients, the OS and RFS rates were significantly higher in stage IB – grade 3 and stage II compared to stage III and non-endometrioid histology without any difference between the two uterine-confined stages and between stage III and non-endometrioid histology. The current risk grouping does not clearly discriminate the HIR and IR groups. In patients with comprehensive surgical staging, a further risk grouping is needed to distinguish the real HR group.