1,589 research outputs found

    Cytotoxic antibody in acute myeloblastic leukaemia during immunotherapy: lack of tumour specificity.

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    Cytotoxic antibodies to antigens specific for leukaemic myeloblasts have been sought in the serum of patients with acute myeloblastic leukaemia treated by immunotherapy with irradiated allogeneic myeloblasts and BCG. Assays of complement- and K-cell-mediated activity were used. Cytotoxicity to allogeneic myeloblasts was detected in both assays. When sera from 15 patients, taken at various times during immunotherapy, were systematically tested against a panel of 5 myeloblasts, the following patterns emerged: 1. No antibody was cytotoxic against all myeloblasts of the panel in either the K-cell or complement-dependent assay. However, all myeloblasts of the panel were lysed by a number of sera. 2. Cytotoxic antibody was detected as often against a panel of lymphocytes from healthy donors as against the panel of allogeneic myeloblasts. 3. Fresh and cryopreserved myeloblasts were equally susceptible to lysis in both assays. 4. Experiments failed to demonstrate any deterioration of cytotoxic antibody on storage. 5. The number of K-cell-revealed cytotoxic antisera increased with length of immunotherapy. This pattern was not apparent for antibodies revealed by complement. 6. No instance of cytotoxicity in either assay was seen when serum was tested against 12 autologous myeloblasts. It is considered that cytotoxic antibody detected with allogeneic myeloblasts is probably directed against HLA antigens common to immunizing and test target myeloblasts and target lymphocytes

    Latitude dependence of co-rotating shock acceleration

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    Energetic particle observations in the outer heliosphere (approx 12 A. U.) by the LECP instruments on the Voyager 1 and Voyager 2 spacecraft are discussed that show a definite latitude dependence of the number and intensity of particle enhancements produced by corotating interplanetary regions during an interval when no solar energetic particle events were observed. The particle enhancements are fewer in number and less intense at higher (approx 20 deg.) heliolatitudes. However, the similar spectral shapes of the accelerated particles at the two spacecraft indicate that the acceleration process is the same at the two latitudes, but less intense at the higher latitude

    Solar cycle variations of the energetic H/He intensity ratio at high heliolatitudes and in the ecliptic plane

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    International audienceWe study the variability of the heliospheric energetic proton-to-helium abundance ratios during different phases of the solar cycle. We use energetic particle, solar wind, and magnetic field data from the Ulysses, ACE and IMP-8 spacecraft to compare the H/He intensity ratio at high heliographic latitudes and in the ecliptic plane. During the first out-of-ecliptic excursion of Ulysses (1992?1996), the HI-SCALE instrument measured corotating energetic particle intensity enhancements characterized by low values ( 10) of the 0.5?1.0 MeV nucleon-1 H/He intensity ratio. During the second out-of-ecliptic excursion of Ulysses (1999?2002), the more frequent occurrence of solar energetic particle events resulted in almost continuously high ( 20) values of the H/He ratio, even at the highest heliolatitudes reached by Ulysses. Comparison with in-ecliptic measurements from an identical instrument on the ACE spacecraft showed similar H/He values at ACE and Ulysses, suggesting a remarkable uniformity of energetic particle intensities in the solar maximum heliosphere at high heliolatitudes and in the ecliptic plane. In-ecliptic observations of the H/He intensity ratio from the IMP-8 spacecraft show variations between solar maximum and solar minimum similar to those observed by Ulysses at high heliographic latitudes. We suggest that the variation of the H/He intensity ratio throughout the solar cycle is due to the different level of transient solar activity, as well as the different structure and duration that corotating solar wind structures have under solar maximum and solar minimum conditions. During solar minimum, the interactions between the two different types of solar wind streams (slow vs. fast) are strong and long-lasting, allowing for a continuous and efficient acceleration of interstellar pickup He +. During solar maximum, transient events of solar origin (characterized by high values of the H/He ratio) are able to globally fill the heliosphere. In addition, during solar maximum, the lack of strong recurrent high-speed solar wind streams, together with the dynamic character of the Sun, lead to weak and short-lived solar wind stream interactions. This results in a less efficient acceleration of pickup He +, and thus a higher value of the H/He intensity ratio

    Solar Energetic Particle Spectral Breaks

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    The five large solar particle events during October–November 2003 presented an opportunity to test shock acceleration models with in-situ observations. We use solar particle spectra of H to Fe ions, measured by instruments on ACE, SAMPEX, and GOES-11, to investigate the Q/M-dependence of spectral breaks in the 28 October 2003 event. We find that the break energies scale as (Q/M)^b with b ≈ 1.56 to 1.75, somewhat less than predicted. We also conclude that SEP spectra >100 MeV/nucleon are best fit by a double power-law shape. ©2005 American Institute of Physic

    Neurotropic viruses and cerebral palsy: population based case-control study

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    Objective: To investigate the association between cerebral palsy and direct evidence for perinatal exposure to neurotropic viruses. Design: Population based case-control study. Setting: Adelaide Women's and Children's Hospital Research Laboratory. Participants and main outcome measures: Newborn screening cards of 443 white case patients with cerebral palsy and 883 white controls were tested for viral nucleic acids from enteroviruses and herpes viruses by using polymerase chain reaction. Herpes group A viruses included herpes simplex viruses 1 and 2 (HSV-1 and HSV-2), Epstein-Barr virus (EBV), cytomegalovirus (CMV), and human herpes virus 8 (HHV-8), and herpes group B viruses included varicella zoster virus (VZV) and human herpes viruses 6 and 7 (HHV-6 and HHV-7). Results: The prevalence of viral nucleic acids in the control population was high: 39.8% of controls tested positive, and the prevalence was highest in preterm babies. The detection of herpes group B viral nucleic acids increased the risk of developing cerebral palsy (odds ratio 1.68, 95% confidence interval 1.09 to 2.59). Conclusions: Perinatal exposure to neurotropic viruses is associated with preterm delivery and cerebral palsy.Catherine S. Gibson, Alastair H. MacLennan, Paul N. Goldwater, Eric A. Haan, Kevin Priest and Gustaaf A. Dekker

    Charged particle composition in the inner heliosphere during the rise to maximum of Solar Cycle 23

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    Flux distributions and abundances relative to oxygen of interplanetary ions (Z>1)(Z>1) are statistically studied and compared for measurements made at 1 and at ∼5 AU on the ACE and the Ulysses spacecraft near the ecliptic plane. Over the nearly two year interval studied, the distributions of the relative abundances and the fluxes of particles at the two locations are found to be approximately log normal. The statistical distributions of the relative abundances are found to be similar at the two helioradii. On a statistical basis, the fluxes at Ulysses times the distance of the measurements appear to be proportional to the fluxes at ACE. This radial dependence of the fluxes is consistent with the interpretation that, statistically, the ion parallel diffusion coefficient is large. © 2000 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87340/2/169_1.pd

    Mesh inlay, mesh kit or native tissue repair for women having repeat anterior or posterior prolapse surgery: randomised controlled trial (PROSPECT)

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    Funding The project was funded by the National Institute for Health Research Health Technology Assessment Programme (Project Number 07/60/18). The Health Services Research Unit and the Health Economics Research Unit are funded by the Chief Scientist Office of the Scottish Government Health and Social Care Directorates. Acknowledgements The authors wish to thank the women who participated in the PROSPECT study. We also thank Margaret MacNeil for her secretarial support and data management; Dawn McRae and Lynda Constable for their trial management support; the programming team in CHaRT, led by Gladys McPherson; members of the Project Management Group for their ongoing advice and support of the study; and the staff at the recruitment sites who facilitated the recruitment, treatment and follow up of study participants.Peer reviewedPublisher PD
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