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A Perspective on Substorm Dynamics Using 10 Years of Auroral Kilometric Radiation Observations From Wind. JOURNAL OF GEOPHYSICAL RESEARCH. SPACE PHYSICS 2022; 127:e2022JA030449. [PMID: 36245707 PMCID: PMC9540659 DOI: 10.1029/2022ja030449] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Revised: 08/19/2022] [Accepted: 08/23/2022] [Indexed: 06/16/2023]
Abstract
We study 10 years (1995-2004 inclusive) of auroral kilometric radiation (AKR) radio emission data from the Wind spacecraft to examine the link between AKR and terrestrial substorms. We use substorm lists based on parameters including ground magnetometer signatures and geosynchronous particle injections as a basis for superposed epoch analyses of the AKR data. The results for each list show a similar, clear response of the AKR power around substorm onset. For nearly all event lists, the average response shows that the AKR power begins to increase around 20 min prior to expansion phase onset, as defined by the respective lists. The analysis of the spectral parameters of AKR bursts show that this increase in power is due to an extension of the source region to higher altitudes, which also precedes expansion phase onset by 20 min. Our observations show that the minimum frequency channel that observes AKR at this time, on average, is 60 kHz. AKR visibility is highly sensitive to observing spacecraft location, and the biggest radio response to substorm onset is seen in the 21:00-03:00 hr local time sector.
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Resolving Magnetopause Shadowing Using Multimission Measurements of Phase Space Density. JOURNAL OF GEOPHYSICAL RESEARCH. SPACE PHYSICS 2022; 127:e2021JA029298. [PMID: 35864842 PMCID: PMC9286781 DOI: 10.1029/2021ja029298] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 12/21/2021] [Accepted: 01/10/2022] [Indexed: 06/15/2023]
Abstract
Loss mechanisms act independently or in unison to drive rapid loss of electrons in the radiation belts. Electrons may be lost by precipitation into the Earth's atmosphere, or through the magnetopause into interplanetary space-a process known as magnetopause shadowing. While magnetopause shadowing is known to produce dropouts in electron flux, it is unclear if shadowing continues to remove particles in tandem with electron acceleration processes, limiting the overall flux increase. We investigated the contribution of shadowing to overall radiation belt fluxes throughout a geomagnetic storm starting on the 7 September 2017. We use new, multimission phase space density calculations to decipher electron dynamics during each storm phase and identify features of magnetopause shadowing during both the net-loss and the net-acceleration storm phases on sub-hour time scales. We also highlight two distinct types of shadowing; "direct," where electrons are lost as their orbit intersects the magnetopause, and "indirect," where electrons are lost through ULF wave driven radial transport toward the magnetopause boundary.
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A diagnosis of the plasma waves responsible for the explosive energy release of substorm onset. Nat Commun 2018; 9:4806. [PMID: 30442968 PMCID: PMC6237928 DOI: 10.1038/s41467-018-07086-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Accepted: 08/31/2018] [Indexed: 11/08/2022] Open
Abstract
During geomagnetic substorms, stored magnetic and plasma thermal energies are explosively converted into plasma kinetic energy. This rapid reconfiguration of Earth's nightside magnetosphere is manifest in the ionosphere as an auroral display that fills the sky. Progress in understanding of how substorms are initiated is hindered by a lack of quantitative analysis of the single consistent feature of onset; the rapid brightening and structuring of the most equatorward arc in the ionosphere. Here, we exploit state-of-the-art auroral measurements to construct an observational dispersion relation of waves during substorm onset. Further, we use kinetic theory of high-beta plasma to demonstrate that the shear Alfven wave dispersion relation bears remarkable similarity to the auroral dispersion relation. In contrast to prevailing theories of substorm initiation, we demonstrate that auroral beads seen during the majority of substorm onsets are likely the signature of kinetic Alfven waves driven unstable in the high-beta magnetotail.
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Energization of the Ring Current by Substorms. JOURNAL OF GEOPHYSICAL RESEARCH. SPACE PHYSICS 2018; 123:8131-8148. [PMID: 30775195 PMCID: PMC6360953 DOI: 10.1029/2018ja025766] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Revised: 08/10/2018] [Accepted: 09/12/2018] [Indexed: 06/01/2023]
Abstract
The substorm process releases large amounts of energy into the magnetospheric system, although where the energy is transferred to and how it is partitioned remains an open question. In this study, we address whether the substorm process contributes a significant amount of energy to the ring current. The ring current is a highly variable region, and understanding the energization processes provides valuable insight into how substorm-ring current coupling may contribute to the generation of storm conditions and provide a source of energy for wave driving. In order to quantify the energy input into the ring current during the substorm process, we analyze Radiation Belt Storm Probes Ion Composition Experiment and Helium Oxygen Proton Electron ion flux measurements for H+, O+, and He+. The energy content of the ring current is estimated and binned spatially for L and magnetic local time. The results are combined with an independently derived substorm event list to perform a statistical analysis of variations in the ring current energy content with substorm phase. We show that the ring current energy is significantly higher in the expansion phase compared to the growth phase, with the energy enhancement persisting into the substorm recovery phase. The characteristics of the energy enhancement suggest the injection of energized ions from the tail plasma sheet following substorm onset. The local time variations indicate a loss of energetic H+ ions in the afternoon sector, likely due to wave-particle interactions. Overall, we find that the average energy input into the ring current is ∼9% of the previously reported energy released during substorms.
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Indigenous cultural competence: A dental faculty curriculum review. EUROPEAN JOURNAL OF DENTAL EDUCATION : OFFICIAL JOURNAL OF THE ASSOCIATION FOR DENTAL EDUCATION IN EUROPE 2018; 22:e419-e426. [PMID: 29288521 DOI: 10.1111/eje.12320] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 12/05/2017] [Indexed: 06/07/2023]
Abstract
BACKGROUND Indigenous Australians have more than double the rate of poor oral health than their non-Indigenous counterparts. Cultural competence of dental and oral health practitioners is fundamental to health care and quality of life in addressing health disparities in minority cultural groups in Australia. Higher education curricula reviews have identified the need for institutions to incorporate Indigenous culture and knowledge more widely into the curricula to improve educational outcomes for Indigenous Australians and to increase cultural competence for all students. AIM The aim of this research was to provide a baseline analysis of Indigenous cultural competence curricula practices to ascertain changes required within Faculty of Dentistry programmes at the University of Sydney to enable students to become more culturally competent upon graduation. METHODS Staff and students of the Doctor of Dental Medicine and Bachelor of Oral Health programmes at the Faculty of Dentistry, University of Sydney participated in an online survey. Quantitative analysis of the survey data was conducted using integrated research electronic data capture survey tools, with open-ended questions being coded to common responses for those questions. RESULTS A total of 69 staff (71%) and 191 students (51%) participated in the online survey. The majority of participants perceived there was limited Indigenous content in the curriculum. Most participants reported that Indigenous curriculum was integrated into several units of study. The main pedagogical method for curriculum delivery was lectures, followed by case studies and group discussions. CONCLUSION Although some Indigenous content exists in dental faculty curriculum, in-depth investigation is required to develop a comprehensive, evidenced-based Indigenous cultural competence teaching framework, for integration into Doctor of Dental Medicine and Bachelor of Oral Health curricula.
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The Incidence of Incorrect Direct-Acting Oral Anticoagulant Dosing and Associated Iron Deficiency in Hospitalised Cardiac Patients. Heart Lung Circ 2018. [DOI: 10.1016/j.hlc.2018.06.688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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The Incidence of Iron Deficiency in Hospitalised Cardiac Patients and its Relationship to Anticoagulant and Antiplatelet Therapy. Heart Lung Circ 2018. [DOI: 10.1016/j.hlc.2018.06.689] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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What effect do substorms have on the content of the radiation belts? JOURNAL OF GEOPHYSICAL RESEARCH. SPACE PHYSICS 2016; 121:6292-6306. [PMID: 27656336 PMCID: PMC5014235 DOI: 10.1002/2016ja022620] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Revised: 06/06/2016] [Accepted: 06/08/2016] [Indexed: 06/01/2023]
Abstract
Substorms are fundamental and dynamic processes in the magnetosphere, converting captured solar wind magnetic energy into plasma energy. These substorms have been suggested to be a key driver of energetic electron enhancements in the outer radiation belts. Substorms inject a keV "seed" population into the inner magnetosphere which is subsequently energized through wave-particle interactions up to relativistic energies; however, the extent to which substorms enhance the radiation belts, either directly or indirectly, has never before been quantified. In this study, we examine increases and decreases in the total radiation belt electron content (TRBEC) following substorms and geomagnetically quiet intervals. Our results show that the radiation belts are inherently lossy, shown by a negative median change in TRBEC at all intervals following substorms and quiet intervals. However, there are up to 3 times as many increases in TRBEC following substorm intervals. There is a lag of 1-3 days between the substorm or quiet intervals and their greatest effect on radiation belt content, shown in the difference between the occurrence of increases and losses in TRBEC following substorms and quiet intervals, the mean change in TRBEC following substorms or quiet intervals, and the cross correlation between SuperMAG AL (SML) and TRBEC. However, there is a statistically significant effect on the occurrence of increases and decreases in TRBEC up to a lag of 6 days. Increases in radiation belt content show a significant correlation with SML and SYM-H, but decreases in the radiation belt show no apparent link with magnetospheric activity levels.
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Statistical characterization of the growth and spatial scales of the substorm onset arc. JOURNAL OF GEOPHYSICAL RESEARCH. SPACE PHYSICS 2015; 120:8503-8516. [PMID: 27867792 PMCID: PMC5111420 DOI: 10.1002/2015ja021470] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Revised: 09/14/2015] [Accepted: 09/19/2015] [Indexed: 06/02/2023]
Abstract
We present the first multievent study of the spatial and temporal structuring of the aurora to provide statistical evidence of the near-Earth plasma instability which causes the substorm onset arc. Using data from ground-based auroral imagers, we study repeatable signatures of along-arc auroral beads, which are thought to represent the ionospheric projection of magnetospheric instability in the near-Earth plasma sheet. We show that the growth and spatial scales of these wave-like fluctuations are similar across multiple events, indicating that each sudden auroral brightening has a common explanation. We find statistically that growth rates for auroral beads peak at low wave number with the most unstable spatial scales mapping to an azimuthal wavelength λ≈ 1700-2500 km in the equatorial magnetosphere at around 9-12 RE . We compare growth rates and spatial scales with a range of theoretical predictions of magnetotail instabilities, including the Cross-Field Current Instability and the Shear Flow Ballooning Instability. We conclude that, although the Cross-Field Current instability can generate similar magnitude of growth rates, the range of unstable wave numbers indicates that the Shear Flow Ballooning Instability is the most likely explanation for our observations.
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Book review: The smile revolution in eighteenth century Paris. Br Dent J 2015. [DOI: 10.1038/sj.bdj.2015.70] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Increases in plasma sheet temperature with solar wind driving during substorm growth phases. GEOPHYSICAL RESEARCH LETTERS 2014; 41:8713-8721. [PMID: 26074645 PMCID: PMC4459207 DOI: 10.1002/2014gl062400] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Accepted: 11/27/2014] [Indexed: 06/02/2023]
Abstract
During substorm growth phases, magnetic reconnection at the magnetopause extracts ∼1015 J from the solar wind which is then stored in the magnetotail lobes. Plasma sheet pressure increases to balance magnetic flux density increases in the lobes. Here we examine plasma sheet pressure, density, and temperature during substorm growth phases using 9 years of Cluster data (>316,000 data points). We show that plasma sheet pressure and temperature are higher during growth phases with higher solar wind driving, whereas the density is approximately constant. We also show a weak correlation between plasma sheet temperature before onset and the minimum SuperMAG AL (SML) auroral index in the subsequent substorm. We discuss how energization of the plasma sheet before onset may result from thermodynamically adiabatic processes; how hotter plasma sheets may result in magnetotail instabilities, and how this relates to the onset and size of the subsequent substorm expansion phase.
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In situ spatiotemporal measurements of the detailed azimuthal substructure of the substorm current wedge. JOURNAL OF GEOPHYSICAL RESEARCH. SPACE PHYSICS 2014; 119:927-946. [PMID: 26167439 PMCID: PMC4497475 DOI: 10.1002/2013ja019302] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2013] [Accepted: 01/13/2014] [Indexed: 06/01/2023]
Abstract
UNLABELLED The substorm current wedge (SCW) is a fundamental component of geomagnetic substorms. Models tend to describe the SCW as a simple line current flowing into the ionosphere toward dawn and out of the ionosphere toward dusk, linked by a westward electrojet. We use multispacecraft observations from perigee passes of the Cluster 1 and 4 spacecraft during a substorm on 15 January 2010, in conjunction with ground-based observations, to examine the spatial structuring and temporal variability of the SCW. At this time, the spacecraft traveled east-west azimuthally above the auroral region. We show that the SCW has significant azimuthal substructure on scales of 100 km at altitudes of 4000-7000 km. We identify 26 individual current sheets in the Cluster 4 data and 34 individual current sheets in the Cluster 1 data, with Cluster 1 passing through the SCW 120-240 s after Cluster 4 at 1300-2000 km higher altitude. Both spacecraft observed large-scale regions of net upward and downward field-aligned current, consistent with the large-scale characteristics of the SCW, although sheets of oppositely directed currents were observed within both regions. We show that the majority of these current sheets were closely aligned to a north-south direction, in contrast to the expected east-west orientation of the preonset aurora. Comparing our results with observations of the field-aligned current associated with bursty bulk flows (BBFs), we conclude that significant questions remain for the explanation of SCW structuring by BBF-driven "wedgelets." Our results therefore represent constraints on future modeling and theoretical frameworks on the generation of the SCW. KEY POINTS The substorm current wedge (SCW) has significant azimuthal structureCurrent sheets within the SCW are north-south alignedThe substructure of the SCW raises questions for the proposed wedgelet scenario.
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When should iron chelation therapy be considered in patients with myelodysplasia and other bone marrow failure syndromes with iron overload? Intern Med J 2013; 42:450-5. [PMID: 22498118 DOI: 10.1111/j.1445-5994.2012.02734.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Despite the absence of a robust evidence base, there is growing consensus that effective treatment of iron overload leads to decreased morbidity and premature mortality in patients with good prognosis myelodysplastic syndromes (MDSs). Furthermore, new treatment modalities, including disease-modifying therapies (lenalidamide and azacytidine) and reduced intensity conditioning therapies for allogeneic blood stem cell transplants, are offering the prospect of longer survival for patients with traditionally less favourable prognosis MDS, who might also benefit from iron chelation. This article proposes assessment of patients with MDS and related bone marrow failure syndromes to determine suitability for iron chelation. Iron chelation therapy options and monitoring are discussed.
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P-240 Haematopoietic improvement following iron chelation may result from deferasirox-induced restoration of T cell immune surveillance. Leuk Res 2013. [DOI: 10.1016/s0145-2126(13)70287-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Response re: 'Neutralizing human monoclonal antibodies binding multiple serotypes of botulinum neurotoxin' by Garcia-Rodriguez et al., PEDS, 2011;24:321-331. Protein Eng Des Sel 2011. [DOI: 10.1093/protein/gzr012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Neutralizing human monoclonal antibodies binding multiple serotypes of botulinum neurotoxin. Protein Eng Des Sel 2010; 24:321-31. [PMID: 21149386 DOI: 10.1093/protein/gzq111] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Botulism, a disease of humans characterized by prolonged paralysis, is caused by botulinum neurotoxins (BoNTs), the most poisonous substances known. There are seven serotypes of BoNT (A-G) which differ from each other by 34-64% at the amino acid level. Each serotype is uniquely recognized by polyclonal antibodies, which originally were used to classify serotypes. To determine if there existed monoclonal antibodies (mAbs) capable of binding two or more serotypes, we evaluated the ability of 35 yeast-displayed single-chain variable fragment antibodies generated from vaccinated humans or mice for their ability to bind multiple BoNT serotypes. Two such clonally related human mAbs (1B18 and 4E17) were identified that bound BoNT serotype A (BoNT/A) and B or BoNT/A, B, E and F, respectively, with high affinity. Using molecular evolution techniques, it proved possible to both increase affinity and maintain cross-serotype reactivity for the 4E17 mAb. Both 1B18 and 4E17 bound to a relatively conserved epitope at the tip of the BoNT translocation domain. Immunoglobulin G constructed from affinity matured variants of 1B18 and 4E17 were evaluated for their ability to neutralize BoNT/B and E, respectively, in vivo. Both antibodies potently neutralized BoNT in vivo demonstrating that this epitope is functionally important in the intoxication pathway. Such cross-serotype binding and neutralizing mAbs should simplify the development of antibody-based BoNT diagnostics and therapeutics.
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Poor English. Br Dent J 2008. [DOI: 10.1038/bdj.2008.64] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Preface. Curr Med Chem 2002. [DOI: 10.2174/0929867023368854] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Abnormal dicentric chromosome with co-amplification of sequences from chromosomes 11 and 19: a novel rearrangement in a patient with myelodysplastic syndrome transforming to acute myeloid leukemia. CANCER GENETICS AND CYTOGENETICS 2001; 130:29-32. [PMID: 11672770 DOI: 10.1016/s0165-4608(01)00463-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A 66-year-old man with a myelodysplastic syndrome transforming to acute myeloid leukemia showed a complex abnormal karyotype on bone marrow aspirate. An unbalanced dicentric translocation with a very long der(11) long arm-dic(11;19)(q25;p13.4)-was present. Fluorescence in situ hybridization studies utilised paints for chromosomes 11 and 19 as well as the locus specific probe MLL, localised to 11q23. The abnormal chromosome 11q contained 6 copies of intact MLL and 6 copies of chromosome 19 (unidentified) sequences. To our knowledge, gene co-amplification of chromosomes 11 and 19 sequences has not been reported before.
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Management of acute vascular graft thrombosis associated with HIT syndrome: a case report. THE AUSTRALIAN AND NEW ZEALAND JOURNAL OF SURGERY 1997; 67:302-3. [PMID: 9152167 DOI: 10.1111/j.1445-2197.1997.tb01973.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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Rapid quantitation of mixed red cell populations using flow cytometry. CLINICAL AND LABORATORY HAEMATOLOGY 1996; 18:207-13. [PMID: 8939392 DOI: 10.1046/j.1365-2257.1996.00165.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Methods are described for the identification and quantitation of mixed red cell populations using flow cytometry. Antibodies specific for a wide range of blood group antigens have been used and examples are given in which these analyses have proved to be of clinical use. These examples include monitoring of erythropoiesis following engraftment in allogeneic bone marrow transplant recipients and the detection of chimaeric states months or years after transplantation. The techniques involved are fast, simple and inexpensive.
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Autologous red cell recovery and relapse of multiple myeloma after bone marrow transplantation: is this a graft-versus-myeloma effect? Bone Marrow Transplant 1996; 17:457-9. [PMID: 8704707] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
We report a patient who, following an allogeneic bone marrow transplant for multiple myeloma, recovered autologous erythropoiesis which was rapidly followed by relapse of her multiple myeloma. We postulate that the loss of the graft (as demonstrated by loss of donor erythropoiesis) and subsequent relapse of the multiple myeloma may be support for the existence of a graft-versus-myeloma effect.
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Membrane-associated CD19-LYN complex is an endogenous p53-independent and Bc1-2-independent regulator of apoptosis in human B-lineage lymphoma cells. Proc Natl Acad Sci U S A 1995; 92:9575-9. [PMID: 7568175 PMCID: PMC40844 DOI: 10.1073/pnas.92.21.9575] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
CD19 receptor is expressed at high levels on human B-lineage lymphoid cells and is physically associated with the Src protooncogene family protein-tyrosine kinase Lyn. Recent studies indicate that the membrane-associated CD19-Lyn receptor-enzyme complex plays a pivotal role for survival and clonogenicity of immature B-cell precursors from acute lymphoblastic leukemia patients, but its significance for mature B-lineage lymphoid cells (e.g., B-lineage lymphoma cells) is unknown. CD19-associated Lyn kinase can be selectively targeted and inhibited with B43-Gen, a CD19 receptor-specific immunoconjugate containing the naturally occurring protein-tyrosine kinase inhibitor genistein (Gen). We now present experimental evidence that targeting the membrane-associated CD19-Lyn complex in vitro with B43-Gen triggers rapid apoptotic cell death in highly radiation-resistant p53-Bax- Ramos-BT B-lineage lymphoma cells expressing high levels of Bcl-2 protein without affecting the Bcl-2 expression level. The therapeutic potential of this membrane-directed apoptosis induction strategy was examined in a scid mouse xenograft model of radiation-resistant high-grade human B-lineage lymphoma. Remarkably, in vivo treatment of scid mice challenged with an invariably fatal number of Ramos-BT cells with B43-Gen at a dose level < 1/10 the maximum tolerated dose resulted in 70% long-term event-free survival. Taken together, these results provide unprecedented evidence that the membrane-associated anti-apoptotic CD19-Lyn complex may be at least as important as Bcl-2/Bax ratio for survival of lymphoma cells.
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First trimester antigen typing of fetal red cells using a flow cytometric technique. Aust N Z J Obstet Gynaecol 1995; 35:97-8. [PMID: 7772013 DOI: 10.1111/j.1479-828x.1995.tb01842.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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Quantifying the loss of ABO antigenicity in a patient with acute myeloid leukemia by flow cytometric analysis. Immunohematology 1995; 11:5-7. [PMID: 15447070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/30/2023]
Abstract
The loss of B antigenicity from the red blood cells of a patient with acute myeloid leukemia is reported. The patient had normal B transferase levels, but had reduced levels of H transferase. Flow cytometry was used to quantify the loss of B antigenicity and monitor the expression of the B antigen throughout the progression of the disease.
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Rapid detection of Rh(D)- or K-positive fetal red cells in chorion villus samples by a flow cytometric technique. Transfus Med 1994; 4:297-302. [PMID: 7889142 DOI: 10.1111/j.1365-3148.1994.tb00267.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Rh(D)- and K-negative women who have become severely isoimmunized by pregnancy are at risk of fetal loss or damage in subsequent pregnancies. A flow cytometric method is described whereby the presence of Rh(D) or K antigen on fetal erythrocytes may be determined using chorion villus samples taken during the first trimester. This method has the advantage of speed and sensitivity with results being available within 2 h. Decisions as to management of the pregnancy or termination may thus be made with minimal delay.
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Development of a flow cytometric test for the detection of D-positive fetal cells after fetomaternal hemorrhage and a survey of the prevalence in D-negative women. Immunohematology 1994; 10:55-9. [PMID: 15945791] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
A sensitive test for the presence of D-positive fetal red blood cells (RBCs) in the maternal circulation of D-negative women has been developed. It was used to investigate the possibility that the occasional failure in preventing alloimmunization might be due to the administration of inadequate amounts of prophylactic anti-D Rh immune globulin. The standard dose in Australia contains 125 microg of antibody, and can suppress immunization by an estimated 6 mL of packed D-positive RBCs. A fetomaternal hemorrhage (FMH) of this volume is detectable in the maternal circulation as approximately 0.25 percent of the total RBCs. Our test utilizes a commercially available human monoclonal IgG anti-D that has been biotinylated and used with a dye-conjugated streptavidin. Flow cytometry is used to quantitate fluorescing D-positive RBCs. To date, 2,288 tests have been performed on blood samples from D-negative women attending local antenatal clinics or at the time of delivery. Evidence for an FMH has been obtained in six cases (0.26%). In one case, the FMH was only 0.1 percent, and in another (confirmed by the Kleihauer-Betke method), fetal cells constituted only 0.2 percent. Additional Rh immune globulin was not given to these patients. In the other four cases, the D-positive fetal cells were estimated to be 0.7,0.5,0.5, and 0.4 percent, and additional prophylactic Rh immune globulin was administered. Although the prevalence of FMH is low, screening D- negative women at risk of alloimmunization has proved to be simple, fast, and inexpensive.
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Abstract
The range of neuropathology found in cases of prion disease is considerable. The pathology present in dendrites and axons is associated with a marked loss of spines and synaptic contacts. It is probable that this loss underlies the functional and neurological deficits in the disease. Immunocytochemical re-examination of 2 cases of inherited disease with a 144 bp prion gene insertion with no characteristic pathology (i.e. spongiform change, astrocytosis and gliosis), together with 3 typical cases of prion disease (CJD), with antibodies to synaptophysin and synaptic protein demonstrated the presence of synaptic "plaque-like" lesions throughout the temporal cortex and cerebellum. In addition, examining the tissue by image analysis demonstrated a greater than 30% reduction in the relative synaptic index in all the prior disease cases when compared with controls. Synaptic disorganization and/or loss is a fundamental and constant feature of prion disease, irrespective of the presence or absence of spongiform change, neuronal loss and severe gliosis. Assessment of the extent and location of synaptic deficits might produce a more accurate documentation of the degree of neuronal disorganisation occurring during the course of prion disease.
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The above letter was referred to the authors, who respond as follows:. Ann Oncol 1992. [DOI: 10.1093/oxfordjournals.annonc.a058341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Severe vascular adverse effects with thrombocytopenia and renal failure following emetogenic chemotherapy and ondansetron. Ann Oncol 1992; 3:719-22. [PMID: 1450061 DOI: 10.1093/oxfordjournals.annonc.a058326] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
During late 1991, a series of severe adverse events involving thrombocytopenia, renal insufficiency and thrombotic episodes was observed in patients receiving emetogenic chemotherapy. Two patients died, one of renal failure and one of cerebral haemorrhage in the presence of thrombocytopenia. Other severe side effects included thrombosis of the aorta causing paraplegia and multifocal cerebral infarctions. Common exposure features included the use of ondansetron and dexamethasone as antiemetics, and in most of the cases high dose (100 mg/M2 or more) cisplatin. Retrospective review of a series of patients treated with similar cytotoxic regimens for similar diseases before the use of ondansetron revealed no similar adverse effects, but no substantial differences were observed in renal function or haematologic toxicity in the two groups overall. Sporadic adverse vascular events have been observed before the use of ondansetron. The mechanism remains unknown, and it is not clear whether ondansetron was a factor in the unusual incidence of such events in the present series.
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Secretion of Active, Full– and Half–Length Human Secretory Leukocyte Protease Inhibitor by Sacchammyces Cerevisiae. Nat Biotechnol 1989. [DOI: 10.1038/nbt0189-55] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Abstract
We analyzed the charts and CT scans of 49 cases of civilian .22 caliber gunshot wounds of the brain admitted to the University of Alberta and Royal Alexandra Hospitals between 1975 and 1985. The average age of the patients was 30 years, 88% were males, 88% were suicide attempts. There were no deaths among patients with an initial coma score above 12 whereas the mortality rate was 85% for those admitted with a score of 7 or less. All those with fixed pupils on admission died. The overall mortality rate of 61% is comparable to that of other series of civilian gunshot wounds including those in which more aggressive surgical management was undertaken. We recommend that no treatment be given those cases with an admission coma score of 3 and/or fixed pupils and that simple scalp wound debridement be employed with those having a coma score of 7 or less. Tract exploration and retrieval of bullet fragments is not indicated, as retained fragments carry a very low incidence of complications (e.g. abscess formation). In patients in good condition (GCS greater than or equal to 12) the management of intracranial hematomas should be independent of their etiology and approached aggressively.
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Watch out for 'old' ipecac. Pediatrics 1984; 73:569. [PMID: 6143294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
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Orchestration. AMERICAN JOURNAL OF PSYCHOLOGY 1915. [DOI: 10.2307/1413240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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IMMEDIATE OPERATION IN APPENDICITIS. West J Med 1913. [DOI: 10.1136/bmj.1.2725.637-a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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