| 11. |
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| 12. |
- Tait, Brian D, et al.
(författare)
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Consensus Guidelines on the Testing and Clinical Management Issues Associated With HLA and Non-HLA Antibodies in Transplantation.
- 2013
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Ingår i: Transplantation. - 1534-6080. ; 95:1, s. 19-47
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The introduction of solid-phase immunoassay (SPI) technology for the detection and characterization of human leukocyte antigen (HLA) antibodies in transplantation while providing greater sensitivity than was obtainable by complement-dependent lymphocytotoxicity (CDC) assays has resulted in a new paradigm with respect to the interpretation of donor-specific antibodies (DSA). Although the SPI assay performed on the Luminex instrument (hereafter referred to as the Luminex assay), in particular, has permitted the detection of antibodies not detectable by CDC, the clinical significance of these antibodies is incompletely understood. Nevertheless, the detection of these antibodies has led to changes in the clinical management of sensitized patients. In addition, SPI testing raises technical issues that require resolution and careful consideration when interpreting antibody results. METHODS: With this background, The Transplantation Society convened a group of laboratory and clinical experts in the field of transplantation to prepare a consensus report and make recommendations on the use of this new technology based on both published evidence and expert opinion. Three working groups were formed to address (a) the technical issues with respect to the use of this technology, (b) the interpretation of pretransplantation antibody testing in the context of various clinical settings and organ transplant types (kidney, heart, lung, liver, pancreas, intestinal, and islet cells), and (c) the application of antibody testing in the posttransplantation setting. The three groups were established in November 2011 and convened for a "Consensus Conference on Antibodies in Transplantation" in Rome, Italy, in May 2012. The deliberations of the three groups meeting independently and then together are the bases for this report. RESULTS: A comprehensive list of recommendations was prepared by each group. A summary of the key recommendations follows. Technical Group: (a) SPI must be used for the detection of pretransplantation HLA antibodies in solid organ transplant recipients and, in particular, the use of the single-antigen bead assay to detect antibodies to HLA loci, such as Cw, DQA, DPA, and DPB, which are not readily detected by other methods. (b) The use of SPI for antibody detection should be supplemented with cell-based assays to examine the correlations between the two types of assays and to establish the likelihood of a positive crossmatch (XM). (c) There must be an awareness of the technical factors that can influence the results and their clinical interpretation when using the Luminex bead technology, such as variation in antigen density and the presence of denatured antigen on the beads. Pretransplantation Group: (a) Risk categories should be established based on the antibody and the XM results obtained. (b) DSA detected by CDC and a positive XM should be avoided due to their strong association with antibody-mediated rejection and graft loss. (c) A renal transplantation can be performed in the absence of a prospective XM if single-antigen bead screening for antibodies to all class I and II HLA loci is negative. This decision, however, needs to be taken in agreement with local clinical programs and the relevant regulatory bodies. (d) The presence of DSA HLA antibodies should be avoided in heart and lung transplantation and considered a risk factor for liver, intestinal, and islet cell transplantation. Posttransplantation Group: (a) High-risk patients (i.e., desensitized or DSA positive/XM negative) should be monitored by measurement of DSA and protocol biopsies in the first 3 months after transplantation. (b) Intermediate-risk patients (history of DSA but currently negative) should be monitored for DSA within the first month. If DSA is present, a biopsy should be performed. (c) Low-risk patients (nonsensitized first transplantation) should be screened for DSA at least once 3 to 12 months after transplantation. If DSA is detected, a biopsy should be performed. In all three categories, the recommendations for subsequent treatment are based on the biopsy results. CONCLUSIONS: A comprehensive list of recommendations is provided covering the technical and pretransplantation and posttransplantation monitoring of HLA antibodies in solid organ transplantation. The recommendations are intended to provide state-of-the-art guidance in the use and clinical application of recently developed methods for HLA antibody detection when used in conjunction with traditional methods.
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| 13. |
- Bi, Zhaoxia, et al.
(författare)
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Self-assembled InN quantum dots on side facets of GaN nanowires
- 2018
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Ingår i: Journal of Applied Physics. - : AIP Publishing. - 0021-8979 .- 1089-7550. ; 123:16
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Tidskriftsartikel (refereegranskat)abstract
- Self-assembled, atomic diffusion controlled growth of InN quantum dots was realized on the side facets of dislocation-free and c-oriented GaN nanowires having a hexagonal cross-section. The nanowires were synthesized by selective area metal organic vapor phase epitaxy. A 3 Å thick InN wetting layer was observed after growth, on top of which the InN quantum dots formed, indicating self-assembly in the Stranski-Krastanow growth mode. We found that the InN quantum dots can be tuned to nucleate either preferentially at the edges between GaN nanowire side facets, or directly on the side facets by tuning the adatom migration by controlling the precursor supersaturation and growth temperature. Structural characterization by transmission electron microscopy and reciprocal space mapping show that the InN quantum dots are close to be fully relaxed (residual strain below 1%) and that the c-planes of the InN quantum dots are tilted with respect to the GaN core. The strain relaxes mainly by the formation of misfit dislocations, observed with a periodicity of 3.2 nm at the InN and GaN hetero-interface. The misfit dislocations introduce I1 type stacking faults (...ABABCBC...) in the InN quantum dots. Photoluminescence investigations of the InN quantum dots show that the emissions shift to higher energy with reduced quantum dot size, which we attribute to increased quantum confinement.
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| 14. |
- Colvin, B. T., et al.
(författare)
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European principles of haemophilia care
- 2008
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Ingår i: Haemophilia. - : Wiley. - 1351-8216 .- 1365-2516. ; 14:2, s. 361-374
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Tidskriftsartikel (refereegranskat)abstract
- As the management of haemophilia is complex, it is essential that those with the disorder should have ready access to a range of services provided by a multidisciplinary team of specialists. This document sets out the principles of comprehensive haemophilia care in Europe. Within each country there should be a national organization which oversees the provision of specialist Comprehensive Care Centres that provide the entire spectrum of clinical and laboratory services. Depending upon the size and geographical distribution of the population, a network of smaller haemophilia centres may also be necessary. There should be arrangements for the supply of safe clotting factor concentrates which can also be used in home treatment and prophylaxis programmes. A national register of patients is recommended along with collection of treatment statistics. As comprehensive haemophilia care is multidisciplinary by nature, the need for education and research programmes for all staff members is emphasized: Members of the Interdisciplinary Working Group not represented in the list of authors are mentioned in Section 4 of this document.
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| 15. |
- Colvin, Jovana, et al.
(författare)
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Local defect-enhanced anodic oxidation of reformed GaN nanowires
- 2020
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Ingår i: Physical Review Materials. - 2475-9953. ; 4:7
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Tidskriftsartikel (refereegranskat)abstract
- Understanding formation and distribution of defects in GaN substrates and device layers is needed to improve device performance in rf and power electronics. Here we utilize conductive atomic force microscopy (c-AFM) for studying defect-related leakage paths in an unintentionally doped GaN film formed by nanowire reformation. A nanoscopic Schottky contact is formed between the c-AFM probe and the GaN surface, which, under reverse-bias conditions, reveals local leakage currents at the positions of the nanowires. Cathodoluminescence shows these areas to be dominated by yellow-band luminescence, in contrast to the surrounding GaN matrix, which mainly shows near-band-gap luminescence. These results are attributed to a high density of native and residual defects, confined to the nanowires. In addition, we use anodic oxidation to map defect-related conductive paths through locally induced growth of gallium oxide. The oxide yield, which is known to depend on the local electric field strength between the AFM tip and the sample, correlates well with the level of reverse-bias leakage current. Local irregularities in oxide height reveal extended oxidation attributed to defect-related deep-level states. Thisis confirmed by controlled dissolution of the oxide in NaOH, showing that a deeper oxide film is grown over areas where defect-related conductive paths are formed. Finally, we demonstrate how this approach can be used as a quick and easy diagnostic tool for evaluating the influence of specific growth conditions and process steps on defect-induced leakage current levels and defect distribution in GaN structures, demonstrating its potential for accelerated test of leakage degradation at critical positions in GaN-based devices.
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| 16. |
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| 17. |
- Jackson, Debra J., et al.
(författare)
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Operational effectiveness and 36 week HIV-free survival in the South African programme to prevent mother-to-child transmission of HIV-1
- 2007
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Ingår i: AIDS. - 0269-9370 .- 1473-5571. ; 21:4, s. 509-516
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Previous studies on the operational effectiveness of programmes to reduce transmission of HIV from mother-to-child (PMTCT) in Africa have generally been hospital-based pilot studies with short follow-up periods. METHOD: Prospective cohort study to evaluate the routine operational effectiveness of the South African National PMTCT Programme, primarily measured by HIV-free survival at 36 weeks post-delivery. Three of eighteen pilot sites participating in the programme were selected as they reflected differences in circumstances, such as HIV prevalence, socioeconomic status and rural-urban location. A total of 665 HIV-positive mothers and their infants were followed. RESULTS: HIV-free survival at 36 weeks varied significantly across sites with 84% in Paarl, 74% in Umlazi and 65% in Rietvlei (P = 0.0003). Maternal viral load was the single most important factor associated with HIV transmission or death [hazard ratio (HR), 1.54; 95% confidence interval (CI), 1.21-1.95]. Adjusting for health system variables (fewer than four antenatal visits and no antenatal syphilis test) explained the difference between Rietvlei and Paarl (crude HR, 2.27; 95% CI, 1.36-3.77; adjusted HR, 1.81; 95% CI, 0.93-3.50). Exposure to breastmilk feeding explained the difference between Umlazi and Paarl (crude HR, 1.74; 95% CI, 1.06-2.84; adjusted HR, 1.41; 95% CI, 0.81-2.48). CONCLUSION: Ever breastfeeding and underlying inequities in healthcare quality within South Africa are predictors of PMTCT programme performance and will need to be addressed to optimize PMTCT effectiveness.
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| 18. |
- Jakobsen, Lasse H., et al.
(författare)
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Minimal relapse risk and early normalization of survival for patients with Burkitt lymphoma treated with intensive immunochemotherapy : an international study of 264 real-world patients
- 2020
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Ingår i: British Journal of Haematology. - : Wiley. - 0007-1048 .- 1365-2141. ; 189:4, s. 661-671
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Tidskriftsartikel (refereegranskat)abstract
- Non-endemic Burkitt lymphoma (BL) is a rare germinal centre B-cell-derived malignancy with the genetic hallmark of MYC gene translocation and with rapid tumour growth as a distinct clinical feature. To investigate treatment outcomes, loss of lifetime and relapse risk in adult BL patients treated with intensive immunochemotherapy, retrospective clinic-based and population-based lymphoma registries from six countries were used to identify 264 real-world patients. The median age was 47 years and the majority had advanced-stage disease and elevated LDH. Treatment protocols were R-CODOX-M/IVAC (47%), R-hyper-CVAD (16%), DA-EPOCH-R (11%), R-BFM/GMALL (25%) and other (2%) leading to an overall response rate of 89%. The two-year overall survival and event-free survival were 84% and 80% respectively. For patients in complete remission/unconfirmed, the two-year relapse risk was 6% but diminished to 0·6% for patients reaching 12 months of post-remission event-free survival (pEFS12). The loss of lifetime for pEFS12 patients was 0·4 (95% CI: −0·7 to 2) months. In conclusion, real-world outcomes of adult BL are excellent following intensive immunochemotherapy. For pEFS12 patients, the relapse risk was low and life expectancy similar to that of a general population, which is important information for developing meaningful follow-up strategies with increased focus on survivorship and less focus on routine disease surveillance.
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| 19. |
- Khalilian, Maryam, et al.
(författare)
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Coherently strained and dislocation-free architectured AlGaN/GaN submicron-sized structures
- 2021
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Ingår i: Nano Select. - : Wiley. - 2688-4011. ; n/a:n/a, s. 1-14
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Tidskriftsartikel (refereegranskat)abstract
- To improve the performance and efficiency of Al containing III-Nitride-based devices, a number of issues must be addressed, especially the presence and generation of dislocations and other structural defects. The main sources of the dislocations are growth on non-native substrates and heteroepitaxial growth of lattice-mismatched layers. We demonstrate the ability to completely avoid structural defects including dislocations in AlxGa1-xN layers with x up to 0.90 and thicknesses over 100 nm, grown directly on submicron-sized, flat-topped GaN platelets. These structures have an excellent homogeneity over an entire array. The GaN platelets were produced by epitaxial growth and reformation of GaN nanowires, effectively blocking the propagation of threading dislocations (TDs) from the underlying substrate. The platelets have a sufficiently small volume to elastically accommodate the strain built up in the architectured AlGaN/GaN heterostructures. Effectively, we have designed a sacrificial nano-scaled GaN seed, with the ability to be strained by the AlGaN layer grown on top of it. The conditions for the growth of the AlGaN are chosen to avoid the creation of misfit dislocations and other structural defects. These thick and structural defect-free, submicron-sized AlGaN/GaN structures may open up a new path for highly efficient electronic and optoelectronic devices. These structures can be used as substrates for light-emitting diodes and transistors, either as individual devices or arrays in parallel, depending on the need for light output or transistor current.
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| 20. |
- Yusuf, D, et al.
(författare)
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The transcription factor encyclopedia
- 2012
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Ingår i: Genome biology. - : Springer Science and Business Media LLC. - 1474-760X .- 1465-6906. ; 13:3, s. R24-
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Tidskriftsartikel (refereegranskat)
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