Simultaneous Measurement of IgM and IgG Antibodies to SARS-CoV-2 Spike, RBD, and Nucleocapsid Multiplexed in a Single Assay on the xMAP INTELLIFLEX DR-SE Flow Analyzer.

The multiplex capabilities of the new xMAP INTELLIFLEX DR-SE flow analyzer were explored by modifying a serological assay previously used to characterize the IgG antibody to infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The goal was to examine the instrument's performance and to simultaneously measure IgM and IgG antibody responses against multiple SARS-CoV-2 antigens in a single assay. Specific antibodies against the SARS-CoV-2 spike (S), receptor binding domain (RBD), and nucleocapsid (N) proteins were investigated in 310 symptomatic case patients using a fluorescent microsphere immunoassay and simultaneous detection of IgM and IgG. Neutralization potential was studied using the addition of soluble angiotensin-converting enzyme 2 (ACE2) to block antibody binding. A profile extending to 180 days from symptom onset (DFSO) was described for antibodies specific to each viral antigen. Generally, IgM levels peaked and declined rapidly ∼3-4 weeks following infection, whereas S- and RBD-specific IgG plateaued at 80 DFSO. ACE2 more effectively prevented IgM and IgG binding in convalescent cases > 30 DFSO, suggesting those antibodies had greater neutralization potential. This work highlighted the multiplex and multi-analyte potential of the xMAP INTELLIFLEX DR-SE, and provided further evidence for antigen-specific IgM and IgG trajectories in acute and convalescent cases. IMPORTANCE The xMAP INTELLIFLEX DR-SE enabled simultaneous and semi-quantitative detection of both IgM and IgG to three different SARS-CoV-2 antigens in a single assay. The assay format is advantageous for rapid and medium-throughput profiling using a small volume of specimen. The xMAP INTELLIFLEX DR-SE technology demonstrated the potential to include numerous SARS-CoV-2 antigens; future work could incorporate multiple spike protein variants in a single assay. This could be an important feature for assessing the serological response to emerging variants of SARS-CoV-2.

Detection of CTX-M-27 ß-Lactamase Genes on Two Distinct Plasmid Types in ST38 Escherichia coli from Three U.S. States.

Infections caused by extended-spectrum-ß-lactamase (ESBL)-producing Escherichia coli are a significant cause of morbidity and health care costs. Globally, the prevailing clonal type is ST131 in association with the blaCTX-M-15 ß-lactamase gene. However, other ESBLs, such as blaCTX-M-14 and blaCTX-M-27, can also be prevalent in some regions. We identified ST38 ESBL-producing E. coli from different regions in the United States which carry blaCTX-M-27 embedded on two distinct plasmid types, suggesting the potential emergence of new ESBL lineages.

Recurrent Fevers in a Triathlete.

Human granulocytic anaplasmosis (HGA) is a tick-borne illness that typically causes a self-limited febrile illness. We describe herein a healthy triathlete who had recurrent fevers for six weeks as a result of HGA and discuss the impact of this patient's HGA on his metabolic fitness during training over a three month time period. We also review the literature for other cases of Ehrlichia and Anaplasma with prolonged courses.

Induced abortion and contraception use: among immigrant and Canadian-born women in Calgary, Alta.

OBJECTIVE: To determine what proportion of women seeking induced abortion in the Calgary census metropolitan area were immigrants. DESIGN: For 2 months, eligible women were asked to complete a questionnaire. Women who refused were asked to provide their country of birth (COB) to assess for selection bias. SETTING: Two abortion clinics in Calgary, Alta. PARTICIPANTS: Women presenting at or less than 15 weeks' gestational age for induced abortion for maternal indications. MAIN OUTCOME MEASURES: The primary outcome was the proportion of women seeking induced abortion services who were immigrants. Secondary outcomes compared socioeconomic characteristics and contraception use between immigrant and Canadian-born women. RESULTS: A total of 752 women either completed a questionnaire (78.6%) or provided their COB (21.4%). Overall, 28.9% of women living in the Calgary census metropolitan area who completed the questionnaire were immigrants, less than the 31.2% background proportion of immigrant women of childbearing age. However, 46.0% of women who provided only COB were immigrants. When these data were combined, 34.2% of women presenting for induced abortion identified as immigrant, a proportion not significantly different from the background proportion (P = .127). Immigrant women presenting for induced abortion tended to be older, more educated, married with children, and have increased parity. They were similar to Canadian-born women in number of previous abortions, income status, and employment status. CONCLUSION: This study suggests that immigrant women in Calgary are not presenting for induced abortion in disproportionately higher numbers, which differs from existing European literature. This is likely owing to differing socioeconomic characteristics among the immigrant women in our study from what have been previously described in the literature (typically lower socioeconomic status). Much still needs to be explored with regard to factors influencing the use of abortion services by immigrant women.

Investigation of the in vitro therapeutic efficacy of nilotinib in immortalized human NF2-null vestibular schwannoma cells.

Vestibular schwannomas (VS) are a common posterior fossa brain tumor, and though benign can cause significant morbidity, particularly loss of hearing, tinnitus, vertigo and facial paralysis. The current treatment options for VS include microsurgical resection, stereotactic radiosurgery or close surveillance monitoring, with each treatment option carrying associated complications and morbidities. Most importantly, none of these options can definitively reverse hearing loss or tinnitus. Identification of a novel medical therapy, through the use of targeted molecular inhibition, is therefore a highly desirable treatment strategy that may minimize complications arising from both tumor and treatment and more importantly be suitable for patients whose options are limited with respect to surgical or radiosurgical interventions. In this study we chose to examine the effect of Nilotinib on VS. Nilotinib (Tasigna®) is a second-generation receptor tyrosine kinase (RTK) inhibitor with a target profile similar to that of imatinib (Gleevec®), but increased potency, decreased toxicity and greater cellular and tissue penetration. Nilotinib targets not only the BCR-ABL oncoprotein, but also platelet-derived growth factor (PDGF) receptor signalling. In this preclinical study, the human NF2-null schwannoma cell line HEI-193 subjected to nilotinib inhibition demonstrated decreased viability, proliferation and anchorage-independent growth, and increased apoptosis. A daily dose of nilotinib for 5 days inhibited HEI-I93 proliferation at a clinically-relevant concentration in a dose-dependent manner (IC(50) 3-5 µmol/L) in PDGF-stimulated cells. These anti-tumorigenic effects of nilotinib were correlated to inhibited activation of PDGFR-α and PDGFR-ß and major downstream signalling pathways. These experiments support a therapeutic potential for Nilotinib in VS.