845 research outputs found

    Cowden syndrome - Diagnostic skin signs

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    Cowden syndrome is a rare autosomal dominant familial cancer syndrome with a high risk of breast cancer. The most important clinical features include carcinomas of the breast and thyroid, and hamartomatous polyps of the gastrointestinal tract. There are characteristic mucocutaneous features which allow early recognition of the disease and are generally present before internal malignancies develop. We report on a woman in whom the diagnosis of Cowden syndrome was first made after she had been treated for both breast cancer and melanoma. Copyright (C) 2001 S. KargerAG, Basel

    Muir-Torre syndrome - Treatment with isotretinoin and interferon alpha-2a can prevent tumour development

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    Muir-Torre syndrome is a genodermatosis in which multiple internal malignancies are associated with cutaneous sebaceous tumours and kerato-acanthomas. A 57-year-old man presented with multiple sebaceous tumours, kerato-acanthomas, verrucous carcinoma of the nose, renal cell and transitional cell carcinomas of the left kidney, adenoma of the colon and a positive family history of colon carcinoma. He was treated with interferon (IFN-alpha Pa) s.c. 3 x 10(6) U three times a week along with 50 mg isotretinoin daily as well as topical isotretinoin gel. During a follow-up of 29 months, only 1 sebaceous skin tumour developed and was removed, whereas more than 30 such skin tumours had been surgically removed during the last 3 years. No evidence of internal tumour development or recurrence was found. The combination of IFN with retinoids seems to be of promise to prevent tumour development in Muir-Torre syndrome. Copyright (C) 2000 S. Karger AG, Basel

    Dowling-Degos Disease: Case Report and Review of the Literature

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    Dowling-Degos disease (DDD) is an unusual pigmentary disorder usually caused by mutations in keratin 5. A 44-year-old woman in good general health presented due to the recent appearance of numerous pigmented macules on her axillary and anogenital skin. A biopsy showed lacy, finger-like epidermal extensions into the dermis which were heavily pigmented and associated with tiny cysts or dilated follicles. We view DDD as part of a spectrum of disorders which are morphologically related but vary in location and time of expression. In addition, both the clinical and histological differential diagnostic considerations are extensive. Copyright (C) 2010 S. Karger AG, Base

    Identification of human papillomavirus DNA in cutaneous lesions of Cowden syndrome

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    Background: Cowden syndrome (CS) or multiple hamartoma syndrome is a cancer-associated genodermatosis inherited in an autosomal dominant pattern. One of the diagnostic criteria is facial papules which are felt to be trichilemmomas, benign hair follicle tumors, which some consider to be induced by human papillomavirus (HPV). Objective: To search for HPV in skin tumors, especially trichilemmomas, from patients with CS. Methods: Skin lesions from patients with CS were classified histologically. Each tumor was then analyzed for HPV DNA by polymerase chain reaction with different primer sets; positive amplicons were typed by direct sequencing. Results: Twenty-nine biopsies from 7 patients with CS were investigated. Only 2 of 29 tumors clinically suspected of being trichilemmomas were confirmed histologically. In addition, 3 sclerotic fibromas, also typical of CS, were found, as well as 1 sebaceous hyperplasia. The other 23 lesions showed histological features of HPV-induced tumors in various stages of development. HPV DNA was found in 19 of 29 cutaneous lesions. Tumors without any histological signs of HPV induction were negative for HPV DNA. Two tumors which were histologically classified as common warts contained HPV types 27 and 28. All the 17 other HPV types belong to the group of epidermodysplasia-verruciformis-associated types. Conclusions: The majority of cutaneous lesions in CS contain HPV DNA. They may have a variety of histological patterns. Trichilemmomas are not clinically distinctive and can be difficult to identify in CS patients. Copyright (C) 2003 S. Karger AG, Basel

    An analysis tool for collision avoidance manoeuvres using aerodynamic drag

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    Aerodynamic collision avoidance manoeuvres provide an opportunity for satellites in Low Earth Orbits to reduce the risk during close encounters. With rising numbers of satellites and objects in orbit, satellites experience close encounters more frequently. Especially those satellites without thrusting capabilities face the problem of not being able to performimpulsive evasive manoeuvres. For satellites in Low Earth Orbits, though, perturbing forces due to aerodynamic drag may be used to influence their trajectories, thus offering a possibility to avoid collisions. This work introduces a tool for the analysis of aerodynamic collision avoidance manoeuvres. Current space-weather data are employed to estimate the density the satellite encounters. Achievable in-track separation distances following a variation of the ballistic coefficient through a change in attitude are then derived by evaluating an analytical equation from literature. Considering additional constraints for the attitude, e.g., charging phases, and uncertainties in the used parameters, the influence of a manoeuvre on the conjunction geometry and the collision probability is examined. The university satellite Flying Laptop of the University of Stuttgart is used as an exemplary satellite for analysis, which show the general effectiveness of evasive manoeuvres employing aerodynamic drag. First manoeuvring strategies can be deducted and the influence of parameter uncertainties is assessed.Comment: 18 pages, 13 figure

    The Automatic Real-Time GRB Pipeline of the 2-m Liverpool Telescope

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    The 2-m Liverpool Telescope (LT), owned by Liverpool John Moores University, is located in La Palma (Canary Islands) and operates in fully robotic mode. In 2005, the LT began conducting an automatic GRB follow-up program. On receiving an automatic GRB alert from a Gamma-Ray Observatory (Swift, INTEGRAL, HETE-II, IPN) the LT initiates a special override mode that conducts follow-up observations within 2-3 min of the GRB onset. This follow-up procedure begins with an initial sequence of short (10-s) exposures acquired through an r' band filter. These images are reduced, analyzed and interpreted automatically using pipeline software developed by our team called "LT-TRAP" (Liverpool Telescope Transient Rapid Analysis Pipeline); the automatic detection and successful identification of an unknown and potentially fading optical transient triggers a subsequent multi-color imaging sequence. In the case of a candidate brighter than r'=15, either a polarimetric (from 2006) or a spectroscopic observation (from 2007) will be triggered on the LT. If no candidate is identified, the telescope continues to obtain z', r' and i' band imaging with increasingly longer exposure times. Here we present a detailed description of the LT-TRAP and briefly discuss the illustrative case of the afterglow of GRB 050502a, whose automatic identification by the LT just 3 min after the GRB, led to the acquisition of the first early-time (< 1 hr) multi-color light curve of a GRB afterglow.Comment: PASP, accepted (8 pages, 3 figures

    ISOCAM observations of the L1551 star formation region

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    The results of a deep mid-IR ISOCAM survey of the L1551 dark molecular cloud are presented. The aim of this survey is a search for new YSO (Young Stellar Object) candidates, using two broad-band filters centred at 6.7 and 14.3 micron. Although two regions close to the centre of L1551 had to be avoided due to saturation problems, 96 sources were detected in total (76 sources at 6.7 micron and 44 sources at 14.3 micron). Using the 24 sources detected in both filters, 14 were found to have intrinsic mid-IR excess at 14.3 micron and were therefore classified as YSO candidates. Using additional observations in B, V, I, J, H and K obtained from the ground, most candidates detected at these wavelengths were confirmed to have mid-IR excess at 6.7 micron as well, and three additional YSO candidates were found. Prior to this survey only three YSOs were known in the observed region (avoiding L1551 IRS5/NE and HL/XZ Tau). This survey reveals 15 new YSO candidates, although several of these are uncertain due to their extended nature either in the mid-IR or in the optical/near-IR observations. Two of the sources with mid-IR excess are previously known YSOs, one is a brown dwarf MHO 5 and the other is the well known T Tauri star HH30, consisting of an outflow and an optically thick disk seen edge on.Comment: 14 Pages, 8 Figure

    IGFBP2 Produces Rapid-Acting and Long-Lasting Effects in Rat Models of Posttraumatic Stress Disorder Via a Novel Mechanism Associated with Structural Plasticity

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    Background: Posttraumatic stress disorder is an anxiety disorder characterized by deficits in the extinction of aversive memories. Insulin-like growth factor 1 (IGF1) is the only growth factor that has shown anxiolytic and antidepressant properties in human clinical trials. In animal studies, insulin-like growth factor binding protein 2 (IGFBP2) shows both IGF1-dependent and IGF1-independent pharmacological effects, and IGFBP2 expression is upregulated by rough-and-tumble play that induces resilience to stress. Methods: IGFBP2 was evaluated in Porsolt, contextual fear conditioning, and chronic unpredictable stress models of posttraumatic stress disorder. The dependence of IGFBP2 effects on IGF1- and AMPA-receptor activation was tested using selective receptor antagonists. Dendritic spine morphology was measured in the dentate gyrus and the medial prefrontal cortex 24 hours after in vivo dosing. Results: IGFBP2 was 100 times more potent than IGF1 in the Porsolt test. Unlike IGF1, effects of IGFBP2 were not blocked by the IGF1-receptor antagonist JB1, or by the AMPA-receptor antagonist 2,3-Dioxo-6-nitro-1,2,3,4 tetrahydrobenzo[f]quinoxaline-7-sulfonamide (NBQX) in the Porsolt test. IGFBP2 (1 microg/kg) and IGF1 (100 microg/kg i.v.) each facilitated contextual fear extinction and consolidation. Using a chronic unpredictable stress paradigm, IGFBP2 reversed stress-induced effects in the Porsolt, novelty-induced hypophagia, sucrose preference, and ultrasonic vocalization assays. IGFBP2 also increased mature dendritic spine densities in the medial prefrontal cortex and hippocampus 24 hours postdosing. Conclusions: These data suggest that IGFBP2 has therapeutic-like effects in multiple rat models of posttraumatic stress disorder via a novel IGF1 receptor-independent mechanism. These data also suggest that the long-lasting effects of IGFBP2 may be due to facilitation of structural plasticity at the dendritic spine level. IGFBP2 and mimetics may have therapeutic potential for the treatment of posttraumatic stress disorder

    Inferring statistics of planet populations by means of automated microlensing searches

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    (abridged) The study of other worlds is key to understanding our own, and not only provides clues to the origin of our civilization, but also looks into its future. Rather than in identifying nearby systems and learning about their individual properties, the main value of the technique of gravitational microlensing is in obtaining the statistics of planetary populations within the Milky Way and beyond. Only the complementarity of different techniques currently employed promises to yield a complete picture of planet formation that has sufficient predictive power to let us understand how habitable worlds like ours evolve, and how abundant such systems are in the Universe. A cooperative three-step strategy of survey, follow-up, and anomaly monitoring of microlensing targets, realized by means of an automated expert system and a network of ground-based telescopes is ready right now to be used to obtain a first census of cool planets with masses reaching even below that of Earth orbiting K and M dwarfs in two distinct stellar populations, namely the Galactic bulge and disk. The hunt for extra-solar planets acts as a principal science driver for time-domain astronomy with robotic-telescope networks adopting fully-automated strategies. Several initiatives, both into facilities as well as into advanced software and strategies, are supposed to see the capabilities of gravitational microlensing programmes step-wise increasing over the next 10 years. New opportunities will show up with high-precision astrometry becoming available and studying the abundance of planets around stars in neighbouring galaxies becoming possible. Finally, we should not miss out on sharing the vision with the general public, and make its realization to profit not only the scientists but all the wider society.Comment: 10 pages in PDF format. White paper submitted to ESA's Exo-Planet Roadmap Advisory Team (EPR-AT); typos corrected. The embedded figures are available from the author on request. See also "Towards A Census of Earth-mass Exo-planets with Gravitational Microlensing" by J.P. Beaulieu, E. Kerins, S. Mao et al. (arXiv:0808.0005
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