Genetic variants for head size share genes and pathways with cancer

The size of the human head is highly heritable, but genetic drivers of its variation within the general population remain unmapped. We perform a genome-wide association study on head size (N = 80,890) and identify 67 genetic loci, of which 50 are novel. Neuroimaging studies show that 17 variants affect specific brain areas, but most have widespread effects. Gene set enrichment is observed for various cancers and the p53, Wnt, and ErbB signaling pathways. Genes harboring lead variants are enriched for macrocephaly syndrome genes (37-fold) and high-fidelity cancer genes (9-fold), which is not seen for human height variants. Head size variants are also near genes preferentially expressed in intermediate progenitor cells, neural cells linked to evolutionary brain expansion. Our results indicate that genes regulating early brain and cranial growth incline to neoplasia later in life, irrespective of height. This warrants investigation of clinical implications of the link between head size and cancer

Action prediction in younger versus older adults: Neural correlates of motor familiarity

Contains fulltext : 116607.pdf (publisher's version ) (Open Access)Generating predictions during action observation is essential for efficient navigation through our social environment. With age, the sensitivity in action prediction declines. In younger adults, the action observation network (AON), consisting of premotor, parietal and occipitotemporal cortices, has been implicated in transforming executed and observed actions into a common code. Much less is known about age-related changes in the neural representation of observed actions. Using fMRI, the present study measured brain activity in younger and older adults during the prediction of temporarily occluded actions (figure skating elements and simple movement exercises). All participants were highly familiar with the movement exercises whereas only some participants were experienced figure skaters. With respect to the AON, the results confirm that this network was preferentially engaged for the more familiar movement exercises. Compared to younger adults, older adults recruited visual regions to perform the task and, additionally, the hippocampus and caudate when the observed actions were familiar to them. Thus, instead of effectively exploiting the sensorimotor matching properties of the AON, older adults seemed to rely predominantly on the visual dynamics of the observed actions to perform the task. Our data further suggest that the caudate played an important role during the prediction of the less familiar figure skating elements in better-performing groups. Together, these findings show that action prediction engages a distributed network in the brain, which is modulated by the content of the observed actions and the age and experience of the observer.15 p

novel Gd 3+ -doped silica-based optical fiber material for dosimetry in proton therapy

International audienceOptical fibers hold promise for accurate dosimetry in small field proton therapy due to their superior spatial resolution and the lack of significant Cerenkov contamination in proton beams. One known drawback for most scintillation detectors is signal quenching in areas of high linear energy transfer, as is the case in the Bragg peak region of a proton beam. In this study, we investigated the potential of innovative optical fiber bulk materials using the sol-gel technique for dosimetry in proton therapy. This type of glass is made of amorphous silica (SiO 2) and is doped with Gd 3+ ions and possesses very interesting light emission properties with a luminescence band around 314 nm when exposed to protons. The fibers were manufactured at the University of Lille and tested at the TRIUMF Proton Therapy facility with 8.2-62.9 MeV protons and 2-6 nA of extracted beam current. Dose-rate dependence and quenching were measured and compared to other silica-based fibers also made by sol-gel techniques and doped with Ce 3+ and cu +. The three fibers present strong luminescence in the UV (Gd) or visible (Cu,Ce) under irradiation, with the emission intensities related directly to the proton flux. In addition, the 0.5 mm diameter Gd 3+-doped fiber shows superior resolution of the Bragg peak, indicating significantly reduced quenching in comparison to the Ce 3+ and cu + fibers with a Birks' constant, k B , of (0.0162 ± 0.0003) cm/MeV in comparison to (0.0333 ± 0.0006) cm/MeV and (0.0352 ± 0.0003) cm/MeV, respectively. To our knowledge, this is the first report of such an interesting k B for a silica-based optical fiber material, showing clearly that this fiber presents lower quenching than common plastic scintillators. This result demonstrates the high potential of this inorganic fiber material for proton therapy dosimetry

Different Recurrence Pattern After Neoadjuvant Chemoradiotherapy Compared to Surgery Alone in Esophageal Cancer Patients

<p>To evaluate the rate and pattern of recurrences after neoadjuvant chemoradiotherapy (CRT) in esophageal cancer patients.</p><p>We described survival and differences in recurrences from a single center between neoadjuvant CRT (carboplatin/paclitaxel and 41.4 Gy) and surgery alone for the period 2000-2011. To reduce bias, we performed a propensity score matched analysis.</p><p>A total of 204 patients were analyzed, 75 treated with neoadjuvant CRT and 129 with surgery alone. The pathologic response to neoadjuvant CRT was 69 % with a complete response rate of 25 %. After matching, baseline characteristics between the groups (both n = 75) were equally distributed. The 3- and 5-year disease-free survival was 53 and 42 % in the neoadjuvant CRT group compared with 24 and 18 % in the surgery-alone group (P = 0.011). After 3 and 5 years' CRT, patients had an estimated locoregional recurrence-free survival of 83 and 73 % compared with 52 and 49 % in the surgery-alone group (P = 0.015). The distant recurrence-free survival was comparable in both groups. Locoregional recurrences were located less in the paraesophageal lymph nodes in the CRT group than in the surgery-alone group, 9 versus 21 %, respectively (P = 0.041). With respect to differences in distant recurrences, we observed more skeletal recurrences in the surgery-alone group compared to CRT, 12 versus 1 % (P = 0.009).</p><p>The neoadjuvant CRT regimen we used offers a significant improvement in outcome, with a different recurrence pattern compared with surgery alone. This effect is probably due to both the pathologic complete response and eradication of micrometastases in CRT group.</p>