Background: The Sl(a) (Knops system) located on complement receptor 1 (CR1) has been associated with malarial rosetting, a process associated with severe malarial infections. Moreover, the long homologous repeats (LHRs) B and C of CR1 were implicated in rosette formation. As a step toward mapping the location of Knops system antigens, truncated CR1 proteins have been expressed and their ability to inhibit antibodies to the high-incidence Knops system antigens was assessed.
Study Design And Methods: Individual LHRs (A, B, C, and D) of CR1 of the common CR1*1 (F) allotype were expressed as secreted forms in 293T cells. Their abilities to specifically neutralize Knops system antibodies were tested by both hemagglutination and flow cytometry.
Results: Three examples of anti-Kn(a) (n = 6) were almost completely inhibited by LHR-C and three by LHR-D. Two examples of anti-McC(a) (n = 2) and seven examples of anti-Sl(a) (n = 8) were inhibited by LHR-D. Both examples of anti-Yk(a) (n = 2) were partially inhibited by LHR-D.
Conclusion: The high-incidence Knops system antigens reside within LHR-D and to a lesser extent within LHR-C. Because of the role of Sl(a) antigen in malaria rosetting, these results indicate that LHR-D may represent an additional malaria interaction region in CR1.
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http://dx.doi.org/10.1046/j.1537-2995.2001.41111397.x | DOI Listing |
Int J Cardiol Heart Vasc
February 2025
Dept. of Cardiology, Erasmus University Medical Center, Rotterdam, the Netherlands.
Background: Areas of conduction disorders play an important role in both initiation and perpetuation of AF and can be recognized by specific changes in unipolar potential morphology. For example, EGM fractionation may be caused by asynchronous activation of adjacent cardiomyocytes because of structural barriers such as fibrotic strands. However, it is unknown whether there are sex differences in unipolar potential morphology.
View Article and Find Full Text PDFEur J Endocrinol
January 2025
Department of Pediatric Oncology, Princess Máxima Center for Pediatric Oncology, 3584 CS Utrecht, The Netherlands.
Objective: Survivors of pediatric head and neck rhabdomyosarcoma (HNRMS) are at risk of developing endocrinopathies following local treatment, resulting from radiation damage to the pituitary gland, hypothalamus, or thyroid gland, often at a young age. Our aim was to determine the prevalence of endocrine dysfunction in long-term HNRMS survivors and compare the prevalence of anterior pituitary insufficiency (API) among different local treatment strategies: external beam radiation with photons, external beam radiation with protons, microscopically radical surgery combined with external irradiation, and macroscopic radical surgery combined with brachytherapy.
Design And Methods: Head and neck rhabdomyosarcoma survivors treated between 1993 and 2017, with ≥2 years of follow-up, without recurrent disease or secondary malignancy were eligible for this study.
Clin Appl Thromb Hemost
December 2024
Department of Blood Transfusion, The Central Hospital of Shaoyang, Shaoyang, China.
The Knops blood group system is an independent blood group system recognized by International Society of Blood Transfusion (ISBT) in 1992, and latest time consisting of 13 antigens carried on a glycoprotein of 2489 amino acids and called the Complement C3b/C4b Receptor 1 (CR1). Erythrocyte KN antigen was first reported in 1970, and CR1 is a protein coding gene that is a member of the receptors of complement activation (RCA) family and is located in the "cluster RCA" region of chromosome 1. CR1 is an important participant in the erythrocyte immune machinery and plays an major role in inhibiting complement activation, and polymorphisms in its expression have been closely associated with a variety of diseases, including systemic lupus erythematosus (SLE), malaria, Plasmodium falciparum malaria, Alzheimer's disease (AD) and leprosy.
View Article and Find Full Text PDFEcology
January 2025
Department of Environmental Science, Policy, and Management, University of California Berkeley, Berkeley, California, USA.
Plants display a range of temporal patterns of inter-annual reproduction, from relatively constant seed production to "mast seeding," the synchronized and highly variable interannual seed production of plants within a population. Previous efforts have compiled global records of seed production in long-lived plants to gain insight into seed production, forest and animal population dynamics, and the effects of global change on masting. Existing datasets focus on seed production dynamics at the population scale but are limited in their ability to examine community-level mast seeding dynamics across different plant species at the continental scale.
View Article and Find Full Text PDFTranspl Int
December 2024
Translational Cardiothoracic Surgery Research Lab, Department of Cardiothoracic Surgery, Erasmus University Medical Center, Rotterdam, Netherlands.
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