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Metamaterials made of periodic collections of dielectric nanorods are considered theoretically. When quantum resonators are embedded within the nanorods, one obtains a quantum metamaterial, whose electromagnetic properties depend upon the state of the quantum resonators. The theoretical model predicts that when the resonators are pumped and reach the inversion regime, the quantum metamaterial exhibits an all-optical switchable conduction band. The phenomenon can be described by considering the pole stucture of the scattering matrix of the metamaterial. [ABSTRACT FROM AUTHOR]

E. Rousseau, M.-M. Ruchoux, F. Scaravilli, F. Chapon, M. Vinchon, C. De Smet, C. Godfraind and M. Vikkula (2003) Neuropathology and Applied Neurobiology, doi: 10.1046/j.1365-2990.2003.0505.x CDKN2A, CDKN2B and p14 ARF are frequently and differentially methylated in ependymal tumours Ependymal tumours are histologically and clinically varied lesions. Numerical abnormalities of chromosome 9 are frequently associated with these tumours. Nevertheless, the three important tumour suppressor genes located in this chromosome, CDKN2A, CDKN2B and p14 ARF, have not been reported to be commonly altered in them. We studied promoter methylation of these genes, an important mechanism associated with gene silencing in a series of 152 ependymal tumours of WHO grades I to III. Methylation status of the CDKN2A, CDKN2B and p14 ARF promoters was assessed by methylation-specific polymerase chain reaction and the genetic results were correlated to clinicopathological features. We observed promoter methylation for CDKN2A in 21% (26/123) of tumours, for CDKN2B in 32% (23/71) and p14 ARF in 21% (23/108). For all three genes, posterior fossa ependymomas were less frequently methylated in paediatric patients than in adults. For CDKN2B, extracranial tumours were more frequently methylated than intracranial ones. For CDKN2B and p14 ARF, methylation was more frequent in low-grade tumours; the reverse was observed for CDKN2A. CDKN2A, CDKN2B and p14 ARF promoters were methylated in 21–32% of the tumours. Frequencies of methylation varied according to clinicopathological features. This suggests a role for these genes in ependymoma tumorigenesis. [ABSTRACT FROM AUTHOR]

A subset of oligodendrogliomas and oligoastrocytomas has been associated with 1p /19q deletion. Subsequently, this genetic alteration was linked to chemosensitivity and classic histology of oligodendrogliomas. Tumoural progression includes deletions of 9p , 10q and alterations of CDKN2A . However, these (epi)genetic changes have not been associated with specific histological features. In a series of 45 gliomas including oligodendrogliomas, oligoastrocytomas and astrocytomas, deletions of chromosomal regions implied in these tumours (1p , 9p , 10 , 17p13 , 19q and 22 ) were looked for by microsatellite analysis. Tumours that were deleted for 1p and 19q were selected. Subsequently, presence of deletions in the other studied regions, (epi)genetic changes in p14 [sup ARF ] , CDKN2A and CDKN2B , as well as histological features, were associated to these tumours. 1p/19q deletion was observed in 22 tumours. Twenty-one of them presented regions of classic histology of oligodendroglioma. A deletion of 9p was found in eight of them, always in association with tumour necrosis and/or microvascular proliferation. In addition, (epi)genetic alterations of CDKN2A were observed in 71% of these tumours. Presence of regions of classic histology of oligodendroglioma in a tumour sample is predictive of 1p/19q deletions. Necrosis and/or microvascular proliferation are signs of an additional 9p deletion. Finally, as CDKN2A (epi)genetic alterations were found in 71% of the 1p/19q/9p -deleted oligodendrogliomas, CDKN2A may have a role in oligodendroglioma-associated microvascular proliferation. [ABSTRACT FROM AUTHOR]

We report the observation of the biexciton in semiconducting single-wall carbon nanotubes by means of nonlinear optical spectroscopy. Our measurements reveal the universal asymmetric line shape of the Fano resonance intrinsic to the biexciton transition. For nanotubes of the (9,7) chirality, we find a biexciton binding energy of 106 meV. From the calculation of the X(3) nonlinear response, we provide a quantitative interpretation of our measurements, leading to an estimation of the characteristic Fano factor q of 7 ± 3. This value allows us to extract the first experimental information on the biexciton stability and we obtain a biexciton annihilation rate comparable to the exciton-exciton annihilation one. [ABSTRACT FROM AUTHOR]

Cyclic nucleotides are involved in the control of pulmonary vascular tone. In the present study, we measured the cyclic nucleotide specific phosphodiesterase (PDE) activity in the media of bovine isolated main pulmonary artery (MPA). Total cAMP- and cGMP-PDE activities were measured in microsomal and cytosolic fractions. Both cyclic nucleotides were hydrolysed in these subcellular fractions at consistently higher rate in the cytosolic than in the microsomal fraction. Using different classes of PDE modulator, at least four PDE isoforms (PDE1, 3, 4 and 5) were identified in these fractions. PDE3 (cilostamide-sensitive), PDE4 (rolipram-sensitive) and PDE5 (zaprinast- and DMPPO-sensitive) isoforms appeared as the main isozymes implicated in the cAMP and cGMP hydrolytic activities. Calcium–camodulin stimulated PDE activity (PDE1) was mainly present in the cytosolic fraction. PDE2, although present, had a lower hydrolytic activity since addition of its specific inhibitor, erythro-9-(2-hydroxy-3nonyl)adenine (EHNA), to a combination of inhibitors of PDE3, 4 and 5 produced no further significant reduction in the enzymatic activity. Resolution of PDE activities from the cytosolic fraction using anion exchange chromatography confirmed this finding. Functional experiments performed in endothelium-denuded rings of rat MPA revealed that all specific PDE inhibitors used relaxed precontracted vascular smooth muscle preparations in a concentration-dependent manner. The rank order of potency was cilostamide >zaprinast>rolipram>>EHNA. The present study demonstrates the presence in the smooth muscle cells-containing layer of MPA of PDE1, 3, 4 and 5 isoforms and suggests that PDE3, 4 and 5 are the main enzymes involved in the control of vascular tone. [Copyright &y& Elsevier]

We addressed the carrier dynamics in so-called G-centers in silicon (consisting of substitutional-interstitial carbon pairs interacting with interstitial silicons) obtained via ion implantation into a silicon-on-insulator wafer. We performed detailed photoluminescence experiments as a function of excitation energy, incident power, irradiation fluence, and temperature in order to study the impact of radiative and nonradiative recombination channels on the spectrum, yield, and lifetime of G-centers. In the framework of the Huang-Rhys theory with nonperturbative calculations of the acoustic phonon sidebands, we reach an estimation of 1.6 ± 0.1 Å for the spatial extension of the electronic wave function in the G-center. The radiative recombination time measured at low temperature lies in the 6 ns range. The estimation of both radiative and nonradiative recombination rates as a function of temperature further demonstrates a constant radiative lifetime. [ABSTRACT FROM AUTHOR]

Résumé Objectifs Le cancer du sein chez l’homme est une affection rare, de ce fait mal connue. Il ne représente que 0,6 % de tous les cancers mammaires, et moins de 1 % de la pathologie cancéreuse chez l’homme. Les objectifs de l’étude étaient d’analyser les caractéristiques cliniques, histologiques et thérapeutiques de 95 hommes pris en charge pour un cancer du sein entre 2000 et 2010 dans 4 centres hospitaliers, et déterminer des facteurs prédictifs de mauvais pronostic, afin d’améliorer la prise en charge. Méthodes Il s’agit d’une étude multicentrique et rétrospective. L’analyse des dossiers cliniques de cette série s’est effectuée sur différentes structures hospitalières, regroupant le groupe hospitalier Sud Réunion (GHSR), le centre hospitalier de Dax, l’institut Bergonié (centre de lutte contre le cancer de Bordeaux et du Sud-Ouest) et le centre René-Gauducheau (institut de cancérologie de l’Ouest). Tous les carcinomes in situ ou infiltrants du sein, survenus chez des patients de sexe masculin, ont été inclus. Une analyse des caractéristiques cliniques, histologiques et thérapeutiques a été réalisée. Les analyses statistiques de notre étude ont porté sur les survies globale et spécifique des patients selon la méthode de Kaplan-Meier, permettant ainsi de rechercher des facteurs prédictifs de mauvais pronostic. Résultats L’âge moyen était de 65 ans. Trente-sept pourcent des patients présentaient un surpoids ou une obésité. La maladie s’est révélée, dans 88 % des cas, sous forme d’une tumeur palpable, avec une taille clinique moyenne de 26,29 mm. Sur 90 patients, aucun ne présentait une lésion non palpable T0, 44 % une tumeur T1, 38 % une tumeur T2, 3 % une tumeur T3, et enfin 10 % une tumeur T4. Le type histologique le plus fréquent était le carcinome canalaire infiltrant 87 %. Une proportion identique de patients avec ou sans envahissement ganglionnaire était retrouvée. Chez les patients N+, une rupture capsulaire était observée dans 29 % des cas. Une positivité des récepteurs avait été constatée, aux œstrogènes dans 95 % des cas et à la progestérone dans 83 % des cas. Sur l’ensemble des patients, 93 soit 98 % avaient bénéficié d’une mastectomie. Sur l’ensemble des mastectomies, 83 étaient associées à un curage axillaire. L’irradiation complémentaire était pratiquée chez 75 % des patients et la chimiothérapie chez 37 % des patients. La survie globale était de 79,2 % à cinq ans et 70,8 % à dix ans. L’âge, la taille histologique tumorale et la rupture capsulaire sont des facteurs qui influencent de manière significative les survies globales et spécifiques. Conclusion Le cancer du sein chez l’homme est une pathologie différente du cancer du sein chez la femme. La majorité des recommandations suggère de traiter les hommes qui sont diagnostiqués avec le cancer du sein en utilisant les lignes directrices appliquées aux femmes ménopausées. Il n’y a aucune étude basée sur la population masculine qui a évalué ces modalités de traitement en termes d’impact sur la survie. Le diagnostic est en général fait à des stades plus avancés, et la taille tumorale est souvent supérieure. Les caractéristiques histologiques diffèrent également. Pourtant le traitement reste quasiment identique. Objectives The optimal treatment for male breast cancer is not known because male breast cancer is a rare disease. It represents as little as 0.6% of all breast cancers and less than 1% of human cancers. The aim was to analyze the clinical, histological and therapeutic characteristics of 95 men cared for breast cancer between 2000 and 2010 in four hospitals, and determine predictors of poor prognosis to improve care of male breast cancer. Methods This study is a multi-institutional survey, retrospective, involving four French institutions: Cancer Institute of the West (ICO), Reunion Island South hospital group, the hospital group of Dax, and the Bergonié Institute. All carcinomas in situ or invasive breast occurred in male patients were included. An analysis of clinical, histological and therapeutic features was performed. Statistical analysis of our study focused on the overall survival of patients and specific method of Kaplan-Meier, enabling search for predictors of poor prognosis. Results The mean age was 65 years. Thirty-seven percent of patients were overweight or obese. It was in 88% of cases of palpable tumor whose average size was 26.29 mm. Ninety patients, none had a lesion palpable T0, 44% T1 tumors, 38% T2 tumors, 3% had a T3 tumors, and finally 10% T4 tumors. The histological type was the most common invasive ductal carcinoma (87%). He found a similar proportion of patients with or without lymph node involvement. N+ patients, capsular rupture was observed in 29% of cases. Receptor positivity was found, estrogen in 95% of cases and progesterone in 83% of cases. Additional irradiation was performed in 75% of patients and chemotherapy in 37% of patients. Overall survival was 79.2% at five years and 70.8% at ten years. Age, tumor size and histological capsular rupture are factors that significantly influence the overall survival and specific. Conclusion Male breast cancer is a different pathology of breast cancer in women. The majority of recommendations suggest treating men who are diagnosed with breast cancer, using the guidelines applied to postmenopausal women treatments. There is no study based on male population that has evaluated these treatment modalities in terms of impact on survival. The diagnosis is usually made at later stages, and tumor size is often greater. Histological characteristics also differ. However, the treatment is almost identical. [ABSTRACT FROM AUTHOR]

We have synthesized 20-hydroxyeicosatetraenoic acid (20-HETE) following a new route and delineated its functional effects in human bronchi. Isometric tension measurements were performed, and they demonstrated that synthetic 20-HETE induced a concentration-dependent relaxant effect in ASM on resting tone and on bronchi pre-contracted with methacholine. [ABSTRACT FROM AUTHOR]

Abstract Objectives: We evaluated the long-term efficacy of continuous subcutaneous insulin infusion (CSII) for treating type 2 diabetes patients uncontrolled by multiple daily injections. Research Design and Methods: All 102 type 2 diabetes patients who began insulin pump therapy at Caen University Hospital (Caen, France) between January 1998 and August 2008 were included in a retrospective observational study. Ninety-three percent of the patients were previously treated by insulin with a mean duration of 5.6 years. Results: The median duration of follow-up with CSII was 24 months. A1c glycated hemoglobin (HbA1c) improved from baseline (9.3 ± 1.8%) to the 1-year evaluation (7.8 ± 1.4%) (P < 0.001). The magnitude of HbA1c improvement was highly dependent on (1) pretreatment HbA1c level, (2) degree of patient's autonomy, and (3) previous antidiabetes treatment. HbA1c decreased by 0.9 ± 1.6% (P = 0.002) in the group previously treated by a basal-bolus regimen. HbA1c decrease was maintained at follow-up until 6 years (P < 0.05). Mean body weight gain was 3.9 ± 8.6 kg at 1 year (P < 0.001) and remained stable at follow-up. No significant change in insulin requirement was observed. Conclusions: The use of CSII in patients with type 2 diabetes is safe and effective for improving glycemic control, particularly in those patients with baseline HbA1c above 8%. Such beneficial effect of CSII may persist until 6-year follow-up, suggesting the durability of CSII efficacy in our study population. [ABSTRACT FROM AUTHOR]

Invetigates the effect of sildenafil on cyclic nucleotide phosphodiesterase (PDE) activity, vascular tone and calcium signalling in rat pulmonary artery. Potent pulmonary vasodilator action of sildenafil; Measurement of PDE activity in cystolic and microsomal fractions.

Background Physical violence frequently brings victims to seek care in emergency departments, providing opportunity for prevention. Objective To describe physical aggression-related injuries in youth 5–19 years presenting to an urban emergency department and identify risk factors. Methods We used retrospective data from one paediatric tertiary centre affiliated with the Canadian Hospitals Injury Reporting and Prevention Program. Intentional injuries inflicted by other youth were examined from 1998 to 2007. Injuries were classified by age groups and characterised according to type, body part involved, place where they occurred, mechanism and disposition of the patient. Results Five hundred four visits for non-accidental physical injuries were identified. There were 395 (78%) males. Thirty-nine (8%) patients were 5–9 years-old, 251 (50%) were 10–14 years-old and 214 (42%) were 15–19 years-old. Injuries were superficial (23%), open wounds (21%), concussions (19%) and fractures (17%). The head and face were involved most frequently (63%). When information was available, 50% of injuries occurred at school (153 of 306), and 63% involved bodily force (190 of 300). Twenty-five (5%) were admitted to the hospital for more severe injuries. Conclusion In this study, most physical aggression-related injuries in youth occurred in 10–19 year-old boys, involved the head and face, occurred at school and resulted from bodily force. A small minority of patients were admitted. Youth that have been assaulted can be targeted for intervention and follow-up in order to manage the physical and psychological sequelae, as well as prevent their repeated victimisation, their possible evolution into perpetrators and enhance their empowerment. [ABSTRACT FROM PUBLISHER]