Analysis of the EGFR mutation status in head and neck squamous cell carcinoma before treatment with Gefitinib

BACKGROUND: The efficacy of chemotherapy in metastatic and recurrent squamous cell carcinomas of the head and neck (HNSCC) remains unsatisfactory. Gefitinib offers a new therapeutic option with comparable results and better tolerability than chemotherapy. We conducted this study to see if mutations in the epidermal growth factor receptor (EGFR) might predict the therapeutic benefit in HNSCC patients. PATIENTS AND METHODS: In a pilot trial, 8 patients with metastatic or recurrent HNSCC were treated palliatively with gefitinib (500 mg/day orally). Forceps biopsies were taken to confirm tumor recurrence and to perform an EGFR mutation analysis. RESULTS: The EGFR status could be determined in 6 of the 8 patients. 5 patients had no EGFR gene mutation, and 1 patient showed a silent guanine-to-adenosine mutation in position 2607. Even without any relevant mutation in the EGFR, we observed partial remission in 3 of 6 patients treated with gefitinib. We also observed that an additional 4 patients had stable disease for at least 10 weeks. The median progression-free survival was 6.25 months, and the median overall survival was 7.39 months. CONCLUSION: In HNSCC, there are tumor responses to gefitinib without protein-altering mutations in the EGFR gene

Magnetic Vortex Core Reversal by Excitation of Spin Waves

Micron-sized magnetic platelets in the flux closed vortex state are characterized by an in-plane curling magnetization and a nanometer-sized perpendicularly magnetized vortex core. Having the simplest non-trivial configuration, these objects are of general interest to micromagnetics and may offer new routes for spintronics applications. Essential progress in the understanding of nonlinear vortex dynamics was achieved when low-field core toggling by excitation of the gyrotropic eigenmode at sub-GHz frequencies was established. At frequencies more than an order of magnitude higher vortex state structures possess spin wave eigenmodes arising from the magneto-static interaction. Here we demonstrate experimentally that the unidirectional vortex core reversal process also occurs when such azimuthal modes are excited. These results are confirmed by micromagnetic simulations which clearly show the selection rules for this novel reversal mechanism. Our analysis reveals that for spin wave excitation the concept of a critical velocity as the switching condition has to be modified.Comment: Minor corrections and polishing of previous versio

Caractérisations chimiques des ustensiles de cuisine artisanale en aluminium fabriqués au Burkina Faso : cas de Ouagadougou

Dans le cadre de la valorisation des matériaux d’origine artisanale du Burkina Faso, deux (02) types d’échantillons d’ustensiles de cuisine (marmites artisanales) en aluminium prélevés dans les différentes zones de la ville de Ouagadougou, ont subi une série d’analyses chimiques. L'artisanat pose le problème de la qualité des produits finis du pays surtout quand on sait qu'ils sont utilisés pour la cuisine de tous les jours. Ainsi, aucun de ces alliages ne devrait être utilisé pour la fabrication d'ustensiles de cuisine, si nous nous référons à la norme française EN 601 en juillet 2004. Ce travail est une contribution à la caractérisation physique et chimique des marmites artisanales au centre du Burkina Faso. L’analyse à la fluorescence X (XRF) indique que la majeure partie des échantillons étudiés, contiennent environ 87,3% d’aluminium. La diffraction aux rayons X (DRX), la spectrométrie de photoélectrons (XPS), la microscopie optique (MO) montrent que les éléments constitutifs essentiels des échantillons d’ustensiles de cuisine sont : Aluminium, Silicium, cuivre, Magnésium et de Zinc. Enfin, une mesure par colorimétrie permet de mettre en évidence la présence de l’aluminium en solution.Mots clés : Alliages d’aluminium, analyses chimiques, DRX, MO, XPS, colorimétrie

Harmonic long shears further reduce operation time in transanal endoscopic microsurgery

Background: Previous research indicates that application of 5-mm harmonic shears rather than diathermia significantly reduces operation time in transanal endoscopic microsurgery (TEM). Frequently, however, additional instruments were required to complete resection. We investigated whether the new 5-mm harmonic long shears (H-LS) are better equipped for TEM compared with regular harmonic shears (HS). Methods: Between 2001 and 2006, 162 tumors (117 adenomas, 42 carcinomas, and 3 other tumors; mean distance 6.6 cm, mean area 40 cm2) were excised in 161 patients (82 men, 79 women; mean age 66 years). Results: Eighty-eight resections were performed with HS and 74 with H-LS. Tumor and patient characteristics were similar except for specimen area. Tumors resected by H-LS were on average smaller than those resected by HS (34.4 versus 44.1 cm2; Mann-Whitney U-test: p = 0.027). Mean operation time was 48 min and proportional to area in both groups (univariate analysis of variance p<0.001). Mean operation time was 54 min using HS and 41 min using H-LS (t-test: p<0.001). After correction for area, operation time for H-LS was reduced by 14% compared with HS (t-test: p<0.001). H-LS is singly capable of completing resection in 88% compared with 26% for HS (Mann- Whitney U-test: p<0.001). Mean blood loss was 16 cc for HS and 3 cc for H-LS (p<0.001). Morbidity (11%) and mortality (0.6%) were not different between the two groups (Fisher's exact test). Conclusion: Performing transanal endoscopic microsurgery with 5-mm harmonic long shears reduces operation time compared with regular shears, and completing resection seldom requires other instruments

Urinary iodine concentration during pregnancy in an area of unstable dietary iodine intake in Switzerland

We prospectively investigated urinary iodine concentration (UIC) in pregnant women and in female, non-pregnant controls in the canton of Berne, Switzerland, in 1992. Mean UIC of pregnant women [205±151 μg iodine/g creatinine (μg I/g Cr); no.=153] steadily decreased from the first (236±180 μg I/g Cr; no.=31) to the third trimester (183±111 μg I/g Cr, p<0.0001; no.=66) and differed significantly from that of the control group (91±37 μg I/g Cr, p<0.0001; no.=119). UIC increased 2.6-fold from levels indicating mild iodine deficiency in controls to the first trimester, demonstrating that high UIC during early gestation does not necessarily reflect a sufficient iodine supply to the overall population. Pregnancy is accompanied by important alterations in the regulation of thyroid function and iodine metabolism. Increased renal iodine clearance during pregnancy may explain increased UIC during early gestation, whereas increased thyroidal iodine clearance as well as the iodine shift from the maternal circulation to the growing fetal-placental unit, which both tend to lower the circulating serum levels of inorganic iodide, probably are the causes of the continuous decrease of UIC over the course of pregnancy. Mean UIC in our control group, as well as in one parallel and several consecutive investigations in the same region in the 1990s, was found to be below the actually recommended threshold, indicating a new tendency towards mild to moderate iodine deficiency. As salt is the main source of dietary iodine in Switzerland, its iodine concentration was therefore increased nationwide in 1998 for the fourth time, following increases in 1922, 1965 and 198

Soliton pair dynamics in patterned ferromagnetic ellipses

Confinement alters the energy landscape of nanoscale magnets, leading to the appearance of unusual magnetic states, such as vortices, for example. Many basic questions concerning dynamical and interaction effects remain unanswered, and nanomagnets are convenient model systems for studying these fundamental physical phenomena. A single vortex in restricted geometry, also known as a non-localized soliton, possesses a characteristic translational excitation mode that corresponds to spiral-like motion of the vortex core around its equilibrium position. Here, we investigate, by a microwave reflection technique, the dynamics of magnetic soliton pairs confined in lithographically defined, ferromagnetic Permalloy ellipses. Through a comparison with micromagnetic simulations, the observed strong resonances in the subgigahertz frequency range can be assigned to the translational modes of vortex pairs with parallel or antiparallel core polarizations. Vortex polarizations play a negligible role in the static interaction between two vortices, but their effect dominates the dynamics.Comment: supplemental movies on http://www.nature.com/nphys/journal/v1/n3/suppinfo/nphys173_S1.htm