A Novel Peptide ELISA for Universal Detection of Antibodies to Human H5N1 Influenza Viruses

BACKGROUND: Active serologic surveillance of H5N1 highly pathogenic avian influenza (HPAI) virus in humans and poultry is critical to control this disease. However, the need for a robust, sensitive and specific serologic test for the rapid detection of antibodies to H5N1 viruses has not been met. METHODOLOGY/PRINCIPAL FINDINGS: Previously, we reported a universal epitope (CNTKCQTP) in H5 hemagglutinin (HA) that is 100% conserved in H5N1 human isolates and 96.9% in avian isolates. Here, we describe a peptide ELISA to detect antibodies to H5N1 virus by using synthetic peptide that comprises the amino acid sequence of this highly conserved and antigenic epitope as the capture antigen. The sensitivity and specificity of the peptide ELISA were evaluated using experimental chicken antisera to H5N1 viruses from divergent clades and other subtype influenza viruses, as well as human serum samples from patients infected with H5N1 or seasonal influenza viruses. The peptide ELISA results were compared with hemagglutinin inhibition (HI), and immunofluorescence assay and immunodot blot that utilize recombinant HA1 as the capture antigen. The peptide ELISA detected antibodies to H5N1 in immunized animals or convalescent human sera whereas some degree of cross-reactivity was observed in HI, immunofluorescence assay and immunodot blot. Antibodies to other influenza subtypes tested negative in the peptide-ELISA. CONCLUSION/SIGNIFICANCE: The peptide-ELISA based on the highly conserved and antigenic H5 epitope (CNTKCQTP) provides sensitive and highly specific detection of antibodies to H5N1 influenza viruses. This study highlighted the use of synthetic peptide as a capture antigen in rapid detection of antibodies to H5N1 in human and animal sera that is robust, simple and cost effective and is particularly beneficial for developing countries and rural areas

Development of Epitope-Blocking ELISA for Universal Detection of Antibodies to Human H5N1 Influenza Viruses

10.1371/journal.pone.0004566PLoS ONE4

A randomised control trial of TeleClinical Care – a smartphone-app based model of care for heart failure and acute coronary syndromes

Abstract Background Acute coronary syndrome (ACS) and heart failure (HF) are frequent causes of hospitalisation and readmissions. A novel smartphone app-based model of care (TeleClinical Care – TCC) was developed to support patients after ACS or HF admission. Purpose This randomised control trial aimed to characterise both the intervention and clinical outcomes. The primary endpoint was the incidence of 30-day readmissions. Secondary endpoints included six-month cardiac and all-cause readmissions, mortality, major adverse cardiovascular events (MACE), cardiac rehabilitation (CR) completion, medication adherence, serum low-density lipoprotein (LDL-C), quality of life, blood pressure, body mass index, waist circumference and six-minute walk distance. Additionally, cost-effectiveness and user satisfaction were evaluated. Methods Patients were randomised 1:1 to either TCC plus usual care or usual care alone and were followed-up at six months. Intervention arm participants received the TCC app and were asked to use Bluetooth-enabled devices for measuring weight, heart rate, blood pressure and physical activity daily. Readings were automatically transmitted to the patient's smartphone and a secure web-server (KIOLA). Customisable thresholds for each parameter were defined at discharge. Abnormal readings were flagged by email to a monitoring team, who discussed management with the patient's usual healthcare providers. The app also provided educational push notifications. Results 164 patients from two hospitals in Sydney, Australia were enrolled between February 2019 and March 2020 (TCC n=81, control n=83). Recruitment ceased during the COVID-19 pandemic. The mean age was 61.5 years. 79% of patients were male. The per-patient mean percentage of days with data transmission was 64.2±27.5%. 565 alerts were received, 16% of which resulted in additional investigations, healthcare consultation or a change in management. There was no difference in 30-day readmission rate (11 readmissions in each arm). There was a significant difference in six-month readmissions, favouring the intervention (21 vs. 41 readmissions, HR=0.40, 95% CI 0.16–0.95, P=0.03), driven by a reduction in cardiac readmissions (11 vs. 25, HR=0.51, 95% CI 0.27–0.94, P=0.03). Use of TCC was associated with improved CR completion (39% vs. 18%, P=0.025) and medication adherence (75% vs. 50%, P=0.002). There was no significant difference in mortality, MACE, LDL-C, quality of life or any of the physical parameters. The average user rating was 4.56 out of 5. The study cost EUR 4015 per readmission saved. Upon modelling, it was calculated that if the number of enrolled patients exceeds 243, total expenditure will be overcome by cost savings from reducing readmissions. Conclusion The TCC model of care was feasible and safe. In this study, clinical benefits were demonstrated including a reduction in six-month readmissions, improved CR completion and improved medication adherence. Funding Acknowledgement Type of funding sources: Public hospital(s). Main funding source(s): Department of Cardiology, Prince of Wales HospitalPrince of Wales Hospital Foundation Figure 1. TCC interfaceFigure 2. Cumulative readmissions over the course of the trial </jats:sec

Data from: O father where art thou? Paternity analyses in a natural population of the haploid-diploid seaweed Chrondrus crispus

The link between life history traits and mating systems in diploid organisms has been extensively addressed in the literature, whereas the degree of selfing and/or inbreeding in natural populations of haploid–diploid organisms, in which haploid gametophytes alternate with diploid sporophytes, has been rarely measured. Dioecy has often been used as a proxy for the mating system in these organisms. Yet, dioecy does not prevent the fusion of gametes from male and female gametophytes originating from the same sporophyte. This is likely a common occurrence when spores from the same parent are dispersed in clumps and recruit together. This pattern of clumped spore dispersal has been hypothesized to explain significant heterozygote deficiency in the dioecious haploid–diploid seaweed Chondrus crispus. Fronds and cystocarps (structures in which zygotes are mitotically amplified) were sampled in two 25 m2 plots located within a high and a low intertidal zone and genotyped at 5 polymorphic microsatellite loci in order to explore the mating system directly using paternity analyses. Multiple males sired cystocarps on each female, but only one of the 423 paternal genotypes corresponded to a field-sampled gametophyte. Nevertheless, larger kinship coefficients were detected between males siring cystocarps on the same female in comparison with males in the entire population, confirming restricted spermatial and clumped spore dispersal. Such dispersal mechanisms may be a mode of reproductive assurance due to nonmotile gametes associated with putatively reduced effects of inbreeding depression because of the free-living haploid stage in C. crispus