758 resultados para ROV


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This study analysed the outcome of 563 Aplastic Anaemia (AA) children aged 0-12 years reported to the Severe Aplastic Anaemia Working Party database of the European Society for Blood and Marrow Transplantation, according to treatment received. Overall survival (OS) after upfront human leucocyte antigen-matched family donor (MFD) haematopoietic stem cell transplantation (HSCT) or immunosuppressive treatment (IST) was 91% vs. 87% (P 0·18). Event-free survival (EFS) after upfront MFD HSCT or IST was 87% vs. 33% (P 0·001). Ninety-one of 167 patients (55%) failed front-line IST and underwent rescue HSCT. The OS of this rescue group was 83% compared with 91% for upfront MFD HSCT patients and 97% for those who did not fail IST up-front (P 0·017). Rejection was 2% for MFD HSCT and HSCT post-IST failure (P 0·73). Acute graft-versus-host disease (GVHD) grade II-IV was 8% in MFD graft vs. 25% for HSCT post-IST failure (P < 0·0001). Chronic GVHD was 6% in MFD HSCT vs. 20% in HSCT post-IST failure (P < 0·0001). MFD HSCT is an excellent therapy for children with AA. IST has a high failure rate, but remains a reasonable first-line choice if MFD HSCT is not available because high OS enables access to HSCT, which is a very good rescue option.

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Abstract We explored the feasibility of unrelated donor haematopoietic stem cell transplant (HSCT) upfront without prior immunosuppressive therapy (IST) in paediatric idiopathic severe aplastic anaemia (SAA). This cohort was then compared to matched historical controls who had undergone first-line therapy with a matched sibling/family donor (MSD) HSCT (n = 87) or IST with horse antithymocyte globulin and ciclosporin (n = 58) or second-line therapy with unrelated donor HSCT post-failed IST (n = 24). The 2-year overall survival in the upfront cohort was 96 ± 4% compared to 91 ± 3% in the MSD controls (P = 0·30) and 94 ± 3% in the IST controls (P = 0·68) and 74 ± 9% in the unrelated donor HSCT post-IST failure controls (P = 0·02).The 2-year event-free survival in the upfront cohort was 92 ± 5% compared to 87 ± 4% in MSD controls (P = 0·37), 40 ± 7% in IST controls (P = 0·0001) and 74 ± 9% in the unrelated donor HSCT post-IST failure controls (n = 24) (P = 0·02). Outcomes for upfront-unrelated donor HSCT in paediatric idiopathic SAA were similar to MSD HSCT and superior to IST and unrelated donor HSCT post-IST failure. Front-line therapy with matched unrelated donor HSCT is a novel treatment approach and could be considered as first-line therapy in selected paediatric patients who lack a MSD. © 2015 John Wiley & Sons Ltd.

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Multidrug-resistant (MDR) cytomegalovirus (CMV) emerged after transient responses to ganciclovir, foscarnet, and cidofovir in a CMV-seropositive recipient who underwent allogeneic hematopoietic stem cell transplantation from a CMV-seronegative donor. Experimental treatments using leflunomide and artesunate failed. Re-transplantation from a CMV-seropositive donor supported by adoptive transfer of pp65-specific T cells and maribavir was followed by lasting suppression. This case illustrates that successful MDR CMV therapy may require individualized multidisciplinary approaches. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

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OBJECTIVES The aetiology of hyposalivation in haematopoietic stem cell transplantation (HSCT) recipients is not fully understood. This study examined the effects of treatment-related aetiological factors, particularly medications, on stimulated salivary flow in HSCT recipients. SUBJECTS AND METHODS Adult HSCT recipients (N = 118, 66 males, 27 autologous and 91 allogeneic transplants) were examined. Stimulated whole salivary flow rates (SWSFR) were measured before HSCT and at 6 and 12 months post-HSCT. Linear regression models were used to analyse the associations of medications and transplant-related factors with salivary flow rates, which were compared to salivary flow rates of generally healthy controls (N = 247). RESULTS The SWSFR of recipients were lower pre-HSCT (mean ± standard deviation, 0.88 ± 0.56 ml/min; P < 0.001), 6 months post-HSCT (0.84 ± 0.61; P < 0.001) and 12 months post-HSCT (1.08 ± 0.67; P = 0.005) than the SWSFR of controls (1.31 ± 0.65). In addition, hyposalivation (<0.7 ml/min) was more frequent among HSCT recipients pre-HSCT (P < 0.001), 6 months post-HSCT (P < 0.001) and 12 months post-HSCT (P = 0.01) than among controls. The SWSFR was observed to improve over time being significantly higher 12 months post-HSCT compared to pre-HSCT (P < 0.001). The observed decrease of salivary flow could not be explained by the examined transplant-related factors and medications. CONCLUSIONS Decreased stimulated salivary flow rates could not be explained by the examined factors alone; these findings indicate that hyposalivation in HSCT recipients exhibits a multifactorial aetiology. CLINICAL RELEVANCE All HSCT recipients should be considered to be at high risk of hyposalivation and consequent oral diseases, and they should be treated accordingly.

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Hematopoietic stem cell transplantation (HSCT) plays a central role in patients with malignant and, increasingly, nonmalignant conditions. As the number of transplants increases and the survival rate improves, long-term complications are important to recognize and treat to maintain quality of life. Sexual dysfunction is a commonly described but relatively often underestimated complication after HSCT. Conditioning regimens, generalized or genital graft-versus-host disease, medications, and cardiovascular complications as well as psychosocial problems are known to contribute significantly to physical and psychological sexual dysfunction. Moreover, it is often a difficult topic for patients, their significant others, and health care providers to discuss. Early recognition and management of sexual dysfunction after HSCT can lead to improved quality of life and outcomes for patients and their partners. This review focuses on the risk factors for and treatment of sexual dysfunction after transplantation and provides guidance concerning how to approach and manage a patient with sexual dysfunction after HSCT.

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The ice cover of the Arctic Ocean has been changing dramatically in the last decades and the consequences for the sea-ice associated ecosystem remain difficult to assess. Algal aggregates underneath sea ice have been described sporadically but the frequency and distribution of their occurrence is not well quantified. We used upward looking images obtained by a remotely operated vehicle (ROV) to derive estimates of ice algal aggregate biomass and to investigate their spatial distribution. During the IceArc expedition (ARK-XXVII/3) of RV Polarstern in late summer 2012, different types of algal aggregates were observed floating underneath various ice types in the Central Arctic basins. Our results show that the floe scale distribution of algal aggregates in late summer is very patchy and determined by the topography of the ice underside, with aggregates collecting in dome shaped structures and at the edges of pressure ridges. The buoyancy of the aggregates was also evident from analysis of the aggregate size distribution. Different approaches used to estimate aggregate biomass yield a wide range of results. This highlights that special care must be taken when upscaling observations and comparing results from surveys conducted using different methods or on different spatial scales.

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In order to reveal the structure of the sparsely known deeper sublittoral hard bottom communities of glacial Kongsfjorden, the macroepibenthos from six depth zones (30-200 m) was analysed. A total of 180 still images derived from 6-h video recorded at the Kongsfjordneset remotely operated vehicle station were assessed quantitatively. Overall 27 mainly suspension-feeding species/taxa were observed. Of these, two-thirds have an arcto-boreal distribution, while the remainder are cosmopolitan. The overall mean epibenthos abundance was 33 ind./m**2 with maximum values at 150 m depth (97.9 ind./m**2). The majority of the taxa inhabited the entire depth range. Encrusting red algae, an unidentified sponge and the sea anemone Urticina eques, characterized the assemblage of the shallow zone. The sea anemones Hormathia spp. were important below 30 m, the Serpulid polychaete Protula tubularia was characteristic for the community below 50 m and the demosponge Haliclona sp. was a key taxon between 100 and 200 m depth. Cluster analysis and non-metrical multidimensional scaling based on abundance data showed differences between the assemblages along the bathymetric gradient, but only in the shallower depths in relation to the substratum surface incline. As surface and tidal current impacts attenuate with increasing depth, there is a gradual trend from robust key species towards more fragile ones (i.e. P. tubularia), in line with the 'Physical control hypothesis'.

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The study compiles the controlling factors for organic matter sedimentation patterns from a suite of organogeochemical parameters in surface sediments off Spitsbergen and direct seabed observations using a Remotely Operated Vehicle (ROV). In addition we assess its storage rates as well as the potential of carbon sinks on the northwestern margin of the Barents Sea with short sediment cores from a selected fjord environment (Storfjord). While sedimentation in the fjords is mainly controlled by river/meltwater discharge and coastal erosion by sea ice/glaciers resulting in high supply of terrigenous organic matter, Atlantic water inflow, and thus enhanced marine organic matter supply, characterizes the environment on the outer shelf and slope. Local deviations from this pattern, particularly on the shelf, are due to erosion and out washing of fine-grained material by bottom currents. Spots dominated by marine productivity close to the island have been found at the outer Isfjord and west off Prins Karls Forland as well as off the Kongsfjord/Krossfjord area and probably reflect local upwelling of nutrient-rich Atlantic water-derived water masses. Accumulation rates of marine organic carbon as well as reconstructed primary productivities decreased since the middle of the last century. Negative correlation of the Isfjord temperature record with reconstructed productivities in the Storfjord could be explained by a reduced annual duration of the marginal ice zone in the area due to global warming. Extremely high accumulation rates of marine organic carbon between 5.4 and 17.2 g/m**2/yr mark the Storfjord area, and probably high-latitude fjord environments in general, as a sink for carbon dioxide.

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The lipid and organic nitrogen isotopic (delta15N) compositions of two common deep-water corals (Lophelia pertusa and Madrepora oculata) collected from selected locations of the NE Atlantic are compared to the composition of suspended particulate organic matter, in order to determine their principle food source. Initial results suggest that they may feed primarily on zooplankton. This is based on the increased abundances of mono-unsaturated fatty acids and alcohols and the different ratios of the polyunsaturated fatty acids, 22:6/20:5 of the corals when compared to those of the suspended particulate organic matter. There is enrichment in L. pertusa of mono-unsaturated fatty acids and of delta15N relative to M. oculata. It is unclear whether this reflects different feeding strategies or assimilation/storage efficiencies of zooplankton tissue or different metabolism in the two coral species.

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Two active chemoherm build-ups growing freely up into the oceanic water column, the Pinnacle and the South East-Knoll Chemoherms, have been discovered at Hydrate Ridge on the Cascadia continental margin. These microbially-mediated carbonate formations rise above the seafloor by several tens of meters and display a pinnacle-shaped morphology with steep flanks. The recovered rocks are pure carbonates dominated by aragonite. Based on fabric and mineralogic composition different varieties of authigenic aragonite can be distinguished. Detailed visual and petrographic investigations unambiguously reveal the involvement of microbes during the formation of the carbonates. The fabric of the cryptocrystalline and fibrous aragonite can be described as thrombolitic. Fossilized microbial filaments in the microcrystalline aragonite indicate the intimate relationship between microbes and carbonates. The strongly 13C-depleted carbon isotope values of the samples (as low as -48.1 per mill PDB) are characteristic of methane as the major carbon source for the carbonate formation. The methane-rich fluids from which the carbonates are precipitated originate most probably from a gas reservoir below the bottom-simulating reflector (BSR) and rise through fault systems. The d18O values of the aragonitic chemoherm carbonates are substantially higher (as high as 5.0 per mill PDB) than the expected equilibrium value for an aragonite forming from ambient seawater (3.5 per mill PDB). As a first approximation this indicates formation from glacial ocean water but other factors are considered as well. A conceptual model is presented for the precipitation of these chemoherm carbonates based on in situ observations and the detailed petrographic investigation of the carbonates. This model explains the function of the consortium of archaea and sulfate-reducing bacteria that grows on the carbonates performing anaerobic oxidation of methane (AOM) and enabling the precipitation of the chemoherms above the seafloor surrounded by oxic seawater. Beggiatoa mats growing on the surface of the chemoherms oxidize the sulfide provided by sulfate-dependent anaerobic oxidation of methane within an oxic environment. The contact between Beggiatoa and the underlying microbial consortium represents the interface between the overlying oxic water column and an anoxic micro-environment where carbonate formation takes place.

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Uranium (U) concentrations and activity ratios (d234U) of authigenic carbonates are sensitive recorders of different fluid compositions at submarine seeps of hydrocarbon-rich fluids ("cold seeps") at Hydrate Ridge, off the coast of Oregon, USA. The low U concentrations (mean: 1.3 ± 0.4 µg/g) and high 234U values (165-317 per mil) of gas hydrate carbonates reflect the influence of sedimentary pore water indicating that these carbonates were formed under reducing conditions below or at the seafloor. Their 230Th/234U ages span a time interval from 0.8 to 6.4 ka and cluster around 1.2 and 4.7 ka. In contrast, chemoherm carbonates precipitate from marine bottom water marked by relatively high U concentrations (mean: 5.2 ± 0.8 µg/g) and a mean d234U ratio of 166 ± 3 per mil. Their U isotopes reflect the d234U ratios of the bottom water being enriched in 234U relative to normal seawater. Simple mass balance calculations based on U concentrations and their corresponding d234U ratios reveal a contribution of about 11% of sedimentary pore water to the bottom water. From the U pore water flux and the reconstructed U pore water concentration a mean flow rate of about 147 ± 68 cm/a can be estimated. 230Th/234U ages of chemoherm carbonates range from 7.3 to 267.6 ka. 230Th/234U ages of two chemoherms (Alvin and SE-Knoll chemoherm) correspond to time intervals of low sealevel stands in marine isotope stages (MIS) 2, 4, 5, 6, 7 and 8. This observation indicates that fluid flow at cold seep sites sensitively reflects pressure changes of the hydraulic head in the sediments. The d18OPDB ratios of the chemoherm carbonates support the hypothesis of precipitation during glacial times. Deviations of the chemoherm d18O values from the marine d18O record can be interpreted as to reflect temporally and spatially varying bottom water and/or vent fluid temperatures during carbonate precipitation between 2.6 and 8.6°C.