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2.
Proc Natl Acad Sci U S A ; 111(7): 2644-9, 2014 Feb 18.
Article in English | MEDLINE | ID: mdl-24550291

ABSTRACT

Antibody class switch recombination (CSR) in B lymphocytes joins two DNA double-strand breaks (DSBs) lying 100-200 kb apart within switch (S) regions in the immunoglobulin heavy-chain locus (IgH). CSR-activated B lymphocytes generate multiple S-region DSBs in the donor Sµ and in a downstream acceptor S region, with a DSB in Sµ being joined to a DSB in the acceptor S region at sufficient frequency to drive CSR in a large fraction of activated B cells. Such frequent joining of widely separated CSR DSBs could be promoted by IgH-specific or B-cell-specific processes or by general aspects of chromosome architecture and DSB repair. Previously, we found that B cells with two yeast I-SceI endonuclease targets in place of Sγ1 undergo I-SceI-dependent class switching from IgM to IgG1 at 5-10% of normal levels. Now, we report that B cells in which Sγ1 is replaced with a 28 I-SceI target array, designed to increase I-SceI DSB frequency, undergo I-SceI-dependent class switching at almost normal levels. High-throughput genome-wide translocation sequencing revealed that I-SceI-generated DSBs introduced in cis at Sµ and Sγ1 sites are joined together in T cells at levels similar to those of B cells. Such high joining levels also occurred between I-SceI-generated DSBs within c-myc and I-SceI- or CRISPR/Cas9-generated DSBs 100 kb downstream within Pvt1 in B cells or fibroblasts, respectively. We suggest that CSR exploits a general propensity of intrachromosomal DSBs separated by several hundred kilobases to be frequently joined together and discuss the relevance of this finding for recurrent interstitial deletions in cancer.


Subject(s)
B-Lymphocytes/immunology , DNA Breaks, Double-Stranded , DNA Repair/physiology , Immunoglobulin Class Switching/genetics , Immunoglobulin Heavy Chains/genetics , Neoplasms/genetics , Recombination, Genetic/genetics , DNA Primers/genetics , DNA Repair/genetics , Deoxyribonucleases, Type II Site-Specific/metabolism , Enzyme-Linked Immunosorbent Assay , Flow Cytometry , Neoplasms/immunology , Polymerase Chain Reaction , Saccharomyces cerevisiae Proteins/metabolism
3.
J Am Soc Echocardiogr ; 37(3): 276-284.e3, 2024 Mar.
Article in English | MEDLINE | ID: mdl-37879379

ABSTRACT

OBJECTIVES: Prior data indicate a very rare risk of serious adverse drug reaction (ADR) to ultrasound enhancement agents (UEAs). We sought to evaluate the frequency of ADR to UEA administration in contemporary practice. METHODS: We retrospectively reviewed 4 US health systems to characterize the frequency and severity of ADR to UEA. Adverse drug reactions were considered severe when cardiopulmonary involvement was present and critical when there was loss of consciousness, loss of pulse, or ST-segment elevation. Rates of isolated back pain and headache were derived from the Mayo Clinic Rochester stress echocardiography database where systematic prospective reporting of ADR was performed. RESULTS: Among 26,539 Definity and 11,579 Lumason administrations in the Mayo Clinic Rochester stress echocardiography database, isolated back pain or headache was more frequent with Definity (0.49% vs 0.04%, P < .0001) but less common with Definity infusion versus bolus (0.08% vs 0.53%, P = .007). Among all sites there were 201,834 Definity and 84,943 Lumason administrations. Severe and critical ADR were more frequent with Lumason than with Definity (0.0848% vs 0.0114% and 0.0330% vs 0.0010%, respectively; P < .001 for each). Among the 3 health systems with >2,000 Lumason administrations, the frequency of severe ADR with Lumason ranged from 0.0755% to 0.1093% and the frequency of critical ADR ranged from 0.0293% to 0.0525%. Severe ADR rates with Definity were stable over time but increased in more recent years with Lumason (P = .02). Patients with an ADR to Lumason since the beginning of 2021 were more likely to have received a COVID-19 vaccination compared with matched controls (88% vs 75%; P = .05) and more likely to have received Moderna than Pfizer-Biotech (71% vs 26%, P < .001). CONCLUSION: Severe and critical ADR, while rare, were more frequent with Lumason, and the frequency has increased in more recent years. Additional work is needed to better understand factors, including associations with recently developed mRNA vaccines, which may be contributing to the increased rates of ADR to UEA since 2021.


Subject(s)
COVID-19 Vaccines , Drug-Related Side Effects and Adverse Reactions , Fluorocarbons , Humans , Retrospective Studies , Prospective Studies , Incidence , Echocardiography , Drug-Related Side Effects and Adverse Reactions/diagnosis , Drug-Related Side Effects and Adverse Reactions/epidemiology , Headache , Back Pain
4.
Elife ; 102021 03 15.
Article in English | MEDLINE | ID: mdl-33720008

ABSTRACT

Atherosclerosis is a disease of chronic inflammation. We investigated the roles of the cytokines IL-4 and IL-13, the classical activators of STAT6, in the resolution of atherosclerosis inflammation. Using Il4-/-Il13-/- mice, resolution was impaired, and in control mice, in both progressing and resolving plaques, levels of IL-4 were stably low and IL-13 was undetectable. This suggested that IL-4 is required for atherosclerosis resolution, but collaborates with other factors. We had observed increased Wnt signaling in macrophages in resolving plaques, and human genetic data from others showed that a loss-of-function Wnt mutation was associated with premature atherosclerosis. We now find an inverse association between activation of Wnt signaling and disease severity in mice and humans. Wnt enhanced the expression of inflammation resolving factors after treatment with plaque-relevant low concentrations of IL-4. Mechanistically, activation of the Wnt pathway following lipid lowering potentiates IL-4 responsiveness in macrophages via a PGE2/STAT3 axis.


Subject(s)
Atherosclerosis/therapy , Interleukin-4/administration & dosage , Macrophages/metabolism , Wnt Signaling Pathway , Animals , Dose-Response Relationship, Drug , Female , Humans , Interleukin-4/metabolism , Male , Mice
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