33 research outputs found

    Accumulation of hydrogen in titanium under irradiation with neutrons

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    The course of the nuclear reaction in titanium under neutron irradiation with formation of hydrogen was experimentally confirmed. Additional hydrogen and gamma quanta with an energy of 889 and 1120 keV are observed. The gamma-field effect should be taken into account when creating neutron protection based on titanium borides. The irradiation of titanium leads to a change in the thermoelectric power to 20%

    Local tumour control and radiation side effects for fractionated stereotactic photon beam radiotherapy compared to proton beam radiotherapy in uveal melanoma

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    Purpose: To compare the adverse side effects of fractionated stereotactic photon beam radiotherapy (fSRT) with proton beam radiotherapy (PBR) in patients with uveal melanoma (UM). Methods: A retrospective study investigating 306 UM patients treated with fSRT (N=153) by the Rotterdam Ocular Melanoma Study group (ROMS), The Netherlands, between 1999–2014 or with PBR (N=153) at the Royal Liverpool University Hospital and the Clatterbridge Cancer Centre, Bebington, United Kingdom, between 1993–2014. The tumours treated with fSRT were matched with tumours treated with PBR based on sex, left or right eye, TNM classification, posterior margin ≤ or > 3mm of the fovea and of the optic disc. Results: The five-year actuarial rates of tumour recurrence were 4.5% for fSRT and 6.1% for PBR. For fSRT and PBR, the five-year actuarial rates of maculopathy were 14.9% and 12.4%, and for vitreous haemorrhage were 29.4% and 4.7%, respectively. Only vitreous haemorrhage (HR: 0.19, 95% CI: 0.07–0.56) was more common after fSRT compared to PBR. Overall, larger tumours were risk factors for maculopathy and secondary enucleation. Conclusions: Both treatments have excellent local tumour control. In matched groups, vitreous haemorrhage was the only adverse side effect showing a significant difference between groups

    Multicenter external validation of the liverpool uveal melanoma prognosticator online: An OOG collaborative study

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    Uveal melanoma (UM) is fatal in ~50% of patients as a result of disseminated disease. This study aims to externally validate the Liverpool Uveal Melanoma Prognosticator Online V3 (LUMPO3) to determine its reliability in predicting survival after treatment for choroidal melanoma when utilizing external data from other ocular oncology centers. Anonymized data of 1836 UM patients from seven international ocular oncology centers were analyzed with LUMPO3 to predict the 10-year survival for each patient in each external dataset. The analysts were masked to the patient outcomes. Model predictions were sent to an independent statistician to evaluate LUMPO3’s performance using discrimination and calibration methods. LUMPO3’s ability to discriminate between UM patients who died of metastatic UM and those who were still alive was fair-to-good, with C-statistics ranging from 0.64 to 0.85 at year 1. The pooled estimate for all external centers was 0.72 (95% confidence interval: 0.68 to 0.75). Agreement between observed and predicted survival probabilities was generally good given differences in case mix and survival rates between different centers. Despite the differences between the international cohorts of patients with primary UM, LUMPO3 is a valuable tool for predicting all-cause mortality in this disease when using data from external centers

    Mitochondrial Dysfunction Links Ceramide Activated HRK Expression and Cell Death

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    Cell death is an essential process in normal development and homeostasis. In eyes, corneal epithelial injury leads to the death of cells in underlying stroma, an event believed to initiate corneal wound healing. The molecular basis of wound induced corneal stromal cell death is not understood in detail. Studies of others have indicated that ceramide may play significant role in stromal cell death following LASIK surgery. We have undertaken the present study to investigate the mechanism of death induced by C6 ceramide in cultures of human corneal stromal (HCSF) fibroblasts.Cultures of HCSF were established from freshly excised corneas. Cell death was induced in low passage (p<4) cultures of HCSF by treating the cells with C6 ceramide or C6 dihydroceramide as a control. Cell death was assessed by Live/Dead cell staining with calcein AM and ethidium homodimer-1 as well as Annexin V staining, caspase activation and TUNEL staining Mitochondrial dysfunction was assessed by Mito Sox Red, JC-1 and cytochrome C release Gene expression was examined by qPCR and western blotting.Our data demonstrate ceramide caused mitochondrial dysfunction as evident from reduced MTT staining, cyto c release from mitochondria, enhanced generation of ROS, and loss in mitochondrial membrane potential (ΔΨm). Cell death was evident from Live -Dead Cell staining and the inability to reestablish cultures from detached cells. Ceramide induced the expression of the harikari gene(HRK) and up-regulated JNK phosphorylation. In ceramide treated cells HRK was translocated to mitochondria, where it was found to interact with mitochondrial protein p32. The data also demonstrated HRK, p32 and BAD interaction. Ceramide-induced expression of HRK, mitochondrial dysfunction and cell death were reduced by HRK knockdown with HRK siRNA.Our data document that ceramide is capable of inducing death of corneal stromal fibroblasts through the induction of HRK mediated mitochondria dysfunction

    The Pediatric Choroidal and Ciliary Body Melanoma Study A Survey by the European Ophthalmic Oncology Group

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    Purpose: To collect comprehensive data on choroidal and ciliary body melanoma (CCBM) in children and to validate hypotheses regarding pediatric CCBM: children younger than 18 years, males, and those without ciliary body involvement (CBI) have more favorable survival prognosis than young adults 18 to 24 years of age, females, and those with CBI. Design: Retrospective, multicenter observational study. Participants: Two hundred ninety-nine patients from 24 ocular oncology centers, of whom 114 were children (median age, 15.1 years; range, 2.7-17.9 years) and 185 were young adults. Methods: Data were entered through a secure website and were reviewed centrally. Survival was analyzed using Kaplan-Meier analysis and Cox proportional hazards regression. Main Outcome Measures: Proportion of females, tumor-node-metastasis (TNM) stage, cell type, and melanoma-related mortality. Results: Cumulative frequency of having CCBM diagnosed increased steadily by 0.8% per year of age between 5 and 10 years of age and, after a 6-year transition period, by 8.8% per year from age 17 years onward. Of children and young adults, 57% and 63% were female, respectively, which exceeded the expected 51% among young adults. Cell type, known for 35% of tumors, and TNM stage (I in 22% and 21%, II in 49% and 52%, III in 30% and 28%, respectively) were comparable for children and young adults. Melanoma-related survival was 97% and 90% at 5 years and 92% and 80% at 10 years for children compared with young adults, respectively (P = 0.013). Males tended to have a more favorable survival than females among children (100% vs. 85% at 10 years; P = 0.058). Increasing TNM stage was associated with poorer survival (stages I, II, and III: 100% vs. 86% vs. 76%, respectively; P = 0.0011). By multivariate analysis, being a young adult (adjusted hazard rate [HR], 2.57), a higher TNM stage (HR, 2.88 and 8.38 for stages II and III, respectively), and female gender (HR, 2.38) independently predicted less favorable survival. Ciliary body involvement and cell type were not associated with survival. Conclusions: This study confirms that children with CCBM have a more favorable survival than young adults 18 to 25 years of age, adjusting for TNM stage and gender. The association between gender and survival varies between age groups. (C) 2016 by the American Academy of Ophthalmology.Peer reviewe

    The effects of neuroleptics on facial action in schizophrenic patients

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    This paper describes the influence of neuroleptic therapy on facial action in drug-naive schizophrenics. In a comparative study of medicated and unmedicated schizophrenic patients, the coordinates of 12 small light-reflecting points, attached to subjects' faces, were computer-recorded and analyzed automatically during a semistandardized clinical interview. In addition, facial activity in videotaped interviews was coded using the Facial Action Coding System (FACS). Each sample group comprised of eight patients with the DSMIII- R diagnostic criteria "schizophrenia" or "schizophreniform disorder". Subjects were studied on two occasions, one shortly after admission to the hospital, the other three weeks later. Group I was unmedicated during the first session, whereas group2 was medicated throughout the study. Three weeks after the start of medication, at the second interview, both recording methods showed a reduction in facial activity and facial expression across all subjects in group 1. The facial action of patients in group2, however, remained unchanged.Ziel der vorliegenden Arbeit war die Untersuchung des Einflusses von Neuroleptika auf die Mimik von unmedizierten schizophrenen Patienten. Wiihrend eines halbstandardisierten klinischen Interviews worde die Beweglichkeit von zwolf kleinen, licht-reflektierenden Punkten, die in das Gesicht von medizierten und unmedizierten schizophrenen Patienten geklebt worden, automatisch im Zeitverlauf gemessen. Erganzend wurde der mirnische Ausdruck mit dem Facial Action Coding System (FACS) kodiert, wofiir die Patienten gleichzeitig mit Video aufgenommen worden. Jede der beiden Gruppen bestand aus acht Patienten mit den DSM-IIIR- Diagnosen "Schizophrenie" oder "Schizophrenieforme Storung". Die Patienten worden einmal direkt nach der stationaren Aufnahme und ein zweites Mal nach drei Wochen untersucht. Die Patienten der ersten Gruppe waren zum ersten Zeitpunkt nicht mit Neuroleptika mediziert, wiihrend die der zweiten Gruppe schon zu diesem Zeitpunkt entsprechende Medikamente einnahmen. Es konnte eine Reduktion der mimischen Beweglichkeit des gesamten Gesichtes im Sinne einer neuroleptisch bedingten Hypornimie der primiir Neuroleptika-unbehandelten Patienten bei der zweiten Untersuchung beobachtet werden. Die andere Gruppe Schizophrener, die zu beiden Zeitpunkten mit Neuroleptika behandelt waren, zeigte keine Veriinderung in ihrer mimischen Beweglichkeit
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