Feasibility of wastewater-based detection of emergent pandemics through a global network of airports.

Wastewater-based surveillance has been put into practice during the pandemic. Persistence of SARS-CoV-2 in faeces of infected individuals, and high volume of passengers travelling by air, make it possible to detect virus from aircraft wastewater, lending itself to the potential identification of a novel pathogen prior to clinical diagnosis. In this study, we estimated the likelihood of detecting the virus through aircraft wastewater from the probabilities of air travel, viral shedding, defecation, testing sensitivity, and sampling. We considered various hypothetical scenarios, with diverse sampling proportions of inbound flights, surveillance airports, and sources of outbreaks. Our calculations showed that the probability of detecting SARS-CoV-2 would increase exponentially against time in the early phase of the pandemic, and would be much higher if the 20 major airports in Asia, Europe, and North America cooperated to perform aircraft wastewater surveillance. We also found other contributors to early detection, including high sampling proportion of inbound flight at destination airports, small population size of the epicentre relative to the travel volume, and large volume of outbound travelers to major airports around the globe. We concluded that routine aircraft wastewater monitoring could be a feasible approach for early identification and tracking of an emerging pathogen with high faecal shedding rates, particularly when implemented through a global surveillance network of major airports.

Application of emerging technologies for gut microbiome research.

Microbiome is associated with a wide range of diseases. The gut microbiome is also a dynamic reflection of health status, which can be modified, thus representing great potential to exploit the mechanisms that influence human physiology. Recent years have seen a dramatic rise in gut microbiome studies, which has been enabled by the rapidly evolving high-throughput sequencing methods (i.e. 16S rRNA sequencing and shotgun sequencing). As the emerging technologies for microbiome research continue to evolve (i.e. metatranscriptomics, metabolomics, culturomics, synthetic biology), microbiome research has moved beyond phylogenetic descriptions and towards mechanistic analyses. In this review, we highlight different approaches to study the microbiome, in particular, the current limitations and future promise of these techniques. This review aims to provide clinicians with a framework for studying the microbiome, as well as to accelerate the adoption of these techniques in clinical practice.

A case report of improvement on ADHD symptoms after fecal microbiota transplantation with gut microbiome profiling pre- and post-procedure.

BACKGROUND: Recent studies demonstrate the association of the gut microbiome in regulating interactions between the central nervous system and intestinal function. Individuals with attention-deficit hyperactivity disorder (ADHD) have been shown to have unique gut microbial signature, with depletion of beneficial commensal microbes. Fecal microbiota transplant (FMT) restores the imbalanced gut microbiome and may replete missing microbes to increase production of hormones and neurotransmitters regulating human behavior and cognition. RESEARCH DESIGN & METHODS: Here, we present an interesting case of a 22-year-old woman treated with FMT primarily to treat recurrent Clostridioides difficile infection, which coincidentally alleviated her ADHD symptoms. We also present the pre- and post-FMT gut microbiota profiles conducted using shotgun metagenomic sequencing on the patient's fecal samples to thereby highlight potential microbial-associated mechanisms associated with the relief of ADHD symptoms. RESULTS & CONCLUSIONS: Our case report provides preliminary evidence regarding the use of FMT in a patient with C. difficile and ADHD. We speculate that gut microbiome modulation, in particular the gain or loss of specific microbial species and pathways involving the metabolism of SCFAs, tryptophan and GABA, may merit further exploration as a potential therapeutic strategy for ADHD.

Patient perspectives of the Self-management and Educational Technology tool for Atrial Fibrillation (SETAF): A mixed-methods study in Singapore.

BACKGROUND: Atrial fibrillation (AF) is the most common arrythmia and is associated with costly morbidity such as stroke and heart failure. Mobile health (mHealth) has potential to help bridge the gaps of traditional healthcare models that may be poorly suited to the sporadic nature of AF. The Self-management and Educational technology support Tool for AF patients (SETAF) was designed based on the preferences and needs of AF patients but more study is required to assess the acceptance of this novel tool. OBJECTIVE: Explore the usability and acceptance of SETAF among AF patients in Singapore. METHODS: A mixed methods study was conducted with AF patients who were purposively sampled from an outpatient cardiology clinic in Singapore. After 6 weeks of using SETAF, semi-structured interviews were performed, and data were analyzed inductively following a thematic analysis approach. Results from a short 4-item survey and application usage data were also analyzed descriptively. Both qualitative and quantitative results were organized and presented following the Technology Acceptance Model (TAM) framework. RESULTS: A total of 37 patients participated in the study and 19 were interviewed. Participants perceived SETAF as useful for improving AF knowledge, self-management and access to healthcare providers and was easy to use due to the guided tutorial and user-friendly interface. They also identified the need for better personalization of content, psychosocial support features and reduction of language barriers. Application usage data revealed preference for AF related content and decreased interaction with the motivational message component of SETAF over time. Overall, most of the participants would continue using SETAF and were willing to pay for it. CONCLUSIONS: AF patients in Singapore found SETAF useful and acceptable as a tool for AF management. The insights from this study not only support the potential of mHealth but may also inform the design and implementation of future mHealth tools for AF patients.

Understanding the Attitudes of Clinicians and Patients Toward a Self-Management eHealth Tool for Atrial Fibrillation: Qualitative Study.

BACKGROUND: Atrial fibrillation (AF) is the most common heart rhythm disorder and poses a growing disease burden worldwide because of an aging population. A multidisciplinary approach with an emphasis on patient education and self-management has been demonstrated to improve outcomes for AF through the engagement of patients in their own care. Although electronic tools (e-tools) such as apps have been proposed to provide patient education and facilitate self-management, there have been few studies to guide the development of these tools for patients with AF. OBJECTIVE: This study aims to explore the perceptions of patients and health care providers (HCPs) and their attitudes toward the use of e-tools for the self-management of AF. It also seeks to elicit the factors that contribute to these attitudes. METHODS: Semistructured qualitative interviews with HCPs and patients were conducted to understand the interpretations and expectations of an e-tool that would be used for the self-management of AF. Interview data were analyzed using an exploratory thematic analysis approach to uncover emergent themes and infer ideas of preferred features in a device. A modified technology acceptance model was developed as a framework to help interpret these findings. Data from the HCPs and patients were compared and contrasted. RESULTS: Both patients and HCPs thought that an e-tool would be useful in the self-management of AF. Although both groups favored educational content and monitoring of blood pressure, patients expressed more passivity toward self-care and an ambivalence toward the use of technology to monitor their medical condition. This appears to be related to factors such as a patient's age, social support, and their attitudes toward technology. Instead, they favored using the app to contact their HCPs. CONCLUSIONS: This study provides insights into significant differences in the attitudes of patients and HCPs toward the use of e-tools for self-care against their priorities. Understanding patients' motivations and their needs are key to ensuring higher acceptance of such tools.

Real-world data for health technology assessment for reimbursement decisions in Asia: current landscape and a way forward.

There is growing interest globally in using real-world data (RWD) and real-world evidence (RWE) for health technology assessment (HTA). Optimal collection, analysis, and use of RWD/RWE to inform HTA requires a conceptual framework to standardize processes and ensure consistency. However, such framework is currently lacking in Asia, a region that is likely to benefit from RWD/RWE for at least two reasons. First, there is often limited Asian representation in clinical trials unless specifically conducted in Asian populations, and RWD may help to fill the evidence gap. Second, in a few Asian health systems, reimbursement decisions are not made at market entry; thus, allowing RWD/RWE to be collected to give more certainty about the effectiveness of technologies in the local setting and inform their appropriate use. Furthermore, an alignment of RWD/RWE policies across Asia would equip decision makers with context-relevant evidence, and improve timely patient access to new technologies. Using data collected from eleven health systems in Asia, this paper provides a review of the current landscape of RWD/RWE in Asia to inform HTA and explores a way forward to align policies within the region. This paper concludes with a proposal to establish an international collaboration among academics and HTA agencies in the region: the REAL World Data In ASia for HEalth Technology Assessment in Reimbursement (REALISE) working group, which seeks to develop a non-binding guidance document on the use of RWD/RWE to inform HTA for decision making in Asia.

Landscape analysis of health technology assessment (HTA): systems and practices in Asia.

This paper explores the characteristics of health technology assessment (HTA) systems and practices in Asia. Representatives from nine countries were surveyed to understand each step of the HTA pathway. The analysis finds that although there are similarities in the processes of HTA and its application to inform decision making, there is variation in the number of topics assessed and the stakeholders involved in each step of the process. There is limited availability of resources and technical capacity and countries adopt different means to overcome these challenges by accepting industry submissions or adapting findings from other regions. Inclusion of stakeholders in the process of selecting topics, generating evidence, and making funding recommendations is critical to ensure relevance of HTA to country priorities. Lessons from this analysis may be instructive to other countries implementing HTA processes and inform future research on the feasibility of implementing a harmonized HTA system in the region.

Isolation of a recombinant antibody specific for a surface marker of the corneal endothelium by phage display.

Cell surface antigens are important targets for monoclonal antibodies, but they are often difficult to work with due to their association with the cell membrane. Phage display is a versatile technique that can be applied to generate binders against difficult targets. Here we used antibody phage display to isolate a binder for a rare and specialized cell, the human corneal endothelial cell. The human corneal endothelium is a medically important cell layer; defects in this layer account for about half of all corneal transplants. Despite its importance, no specific antigens have been found to mark this cell type. By panning a phage library directly on human corneal endothelial cells, we isolated an antibody that bound to these cells and not the other types of corneal cells. Subsequently, we identified the antibody's putative target to be CD166 by immunoprecipitation and mass spectrometry. This approach can be used to isolate antibodies against other poorly-characterized cell types, such as stem cells or cancer cells, without any prior knowledge of their discriminating markers.

Identification of new susceptibility loci for IgA nephropathy in Han Chinese.

IgA nephropathy (IgAN) is one of the most common primary glomerulonephritis. Previously identified genome-wide association study (GWAS) loci explain only a fraction of disease risk. To identify novel susceptibility loci in Han Chinese, we conduct a four-stage GWAS comprising 8,313 cases and 19,680 controls. Here, we show novel associations at ST6GAL1 on 3q27.3 (rs7634389, odds ratio (OR)=1.13, P=7.27 × 10(-10)), ACCS on 11p11.2 (rs2074038, OR=1.14, P=3.93 × 10(-9)) and ODF1-KLF10 on 8q22.3 (rs2033562, OR=1.13, P=1.41 × 10(-9)), validate a recently reported association at ITGAX-ITGAM on 16p11.2 (rs7190997, OR=1.22, P=2.26 × 10(-19)), and identify three independent signals within the DEFA locus (rs2738058, P=1.15 × 10(-19); rs12716641, P=9.53 × 10(-9); rs9314614, P=4.25 × 10(-9), multivariate association). The risk variants on 3q27.3 and 11p11.2 show strong association with mRNA expression levels in blood cells while allele frequencies of the risk variants within ST6GAL1, ACCS and DEFA correlate with geographical variation in IgAN prevalence. Our findings expand our understanding on IgAN genetic susceptibility and provide novel biological insights into molecular mechanisms underlying IgAN.

Conditional ligands for Asian HLA variants facilitate the definition of CD8+ T-cell responses in acute and chronic viral diseases.

Conditional ligands have enabled the high-throughput production of human leukocyte antigen (HLA) libraries that present defined peptides. Immunomonitoring platforms typically concentrate on restriction elements associated with European ancestry, and such tools are scarce for Asian HLA variants. We report 30 novel irradiation-sensitive ligands, specifically targeting South East Asian populations, which provide 93, 63, and 79% coverage for HLA-A, -B, and -C, respectively. Unique ligands for all 16 HLA types were constructed to provide the desired soluble HLA product in sufficient yield. Peptide exchange was accomplished for all variants as demonstrated by an ELISA-based MHC stability assay. HLA tetramers with redirected specificity could detect antigen-specific CD8(+) T-cell responses against human cytomegalovirus, hepatitis B (HBV), dengue virus (DENV), and Epstein-Barr virus (EBV) infections. The potential of this population-centric HLA library was demonstrated with the characterization of seven novel T-cell epitopes from severe acute respiratory syndrome coronavirus, HBV, and DENV. Posthoc analysis revealed that the majority of responses would be more readily identified by our unbiased discovery approach than through the application of state-of-the-art epitope prediction. This flow cytometry-based technology therefore holds considerable promise for monitoring clinically relevant antigen-specific T-cell responses in populations of distinct ethnicity.

CISH and susceptibility to infectious diseases.

BACKGROUND: The interleukin-2-mediated immune response is critical for host defense against infectious pathogens. Cytokine-inducible SRC homology 2 (SH2) domain protein (CISH), a suppressor of cytokine signaling, controls interleukin-2 signaling. METHODS: Using a case-control design, we tested for an association between CISH polymorphisms and susceptibility to major infectious diseases (bacteremia, tuberculosis, and severe malaria) in blood samples from 8402 persons in Gambia, Hong Kong, Kenya, Malawi, and Vietnam. We had previously tested 20 other immune-related genes in one or more of these sample collections. RESULTS: We observed associations between variant alleles of multiple CISH polymorphisms and increased susceptibility to each infectious disease in each of the study populations. When all five single-nucleotide polymorphisms (SNPs) (at positions -639, -292, -163, +1320, and +3415 [all relative to CISH]) within the CISH-associated locus were considered together in a multiple-SNP score, we found an association between CISH genetic variants and susceptibility to bacteremia, malaria, and tuberculosis (P=3.8x10(-11) for all comparisons), with -292 accounting for most of the association signal (P=4.58x10(-7)). Peripheral-blood mononuclear cells obtained from adult subjects carrying the -292 variant, as compared with wild-type cells, showed a muted response to the stimulation of interleukin-2 production--that is, 25 to 40% less CISH expression. CONCLUSIONS: Variants of CISH are associated with susceptibility to diseases caused by diverse infectious pathogens, suggesting that negative regulators of cytokine signaling have a role in immunity against various infectious diseases. The overall risk of one of these infectious diseases was increased by at least 18% among persons carrying the variant CISH alleles.

cMET and refractive error progression in children.

OBJECTIVE: To assess whether genetic variation in cMET is associated with refractive error or change in refractive error over time. DESIGN: Cohort study. PARTICIPANTS AND CONTROLS: Discovery set (Set 1: N = 579 children; 403 cases, 176 controls). Confirmatory set (Set 2: N = 547 children; 338 cases, 209 controls). METHODS: Children in the discovery set were genotyped for a panel of genetic markers within cMET. Markers that were found to be significantly associated with the presence of refractive error or more rapid change in refractive error were then genotyped in the confirmatory set. MAIN OUTCOME MEASURES: Presence or absence of myopia and the rate of change in refractive error over a 3-year follow-up period. RESULTS: Carriage of the variant cMET +110703 A allele was found to associate with increased susceptibility to myopia. The variant was also found to associate with a faster rate of change in refractive error in both the discovery set and the confirmatory cohort regardless of the initial refractory ability (School 1; chi(2) for trend P = 0.014) (Schools 2 and 3; chi(2) for trend = 5.42, P = 0.020) (combined N = 1126, overall chi(2) for trend = 10.90, P = 9.6 x 10(-4)). Carriage of the variant allele was also found to be significantly overrepresented in children within the fastest changing quartile (Q4: mean change of -3.01 D over 3 years) compared with the slowest (Q1: mean change of -0.28 D over 3 years) (P(Set1) = 0.004, P(Set2) = 0.02, Combined N = 559, P = 3.0 x 10(-4)). CONCLUSIONS: Our data implicate the involvement of cMET in the pathogenesis of myopia in general, as well as more rapid progression in refractive error regardless of the initial refractory ability. These results underline the importance of eye growth genes in the development of common myopia.

Identification and molecular characterization of a novel PDE4D11 cAMP-specific phosphodiesterase isoform.

Here we report the cloning and characterization of a novel PDE4D isoform (PDE4D11) identified in mouse brain cDNA. This novel isoform has a unique isoform-specific 5'-UTR and N-terminal sequence, whereas, downstream regulatory N-terminal and catalytic C-terminal regions are homologous to other long PDE4D isoforms (Ex2-15). In silico analysis of PDE4D11 cDNA transcript identified the predicted translational start site and the use of a different transcriptional start site compared to other PDE4D isoforms. This isoform is ubiquitously expressed in different mouse tissues, particularly in the brain, liver and spleen. In the brain, PDE4D11 expression levels increased in the cerebellum, but decreased in the hippocampus with progressive age, highlighting a potential role for this isoform in the development of the brain. When transfected in vitro into murine neuroblastoma cells PDE4D11_EGFP expression is cytosolic, consistent with other long PDE4D isoforms. The appearance of cytosolic protein aggregates in discrete microdomains with this isoform, however, may represent a method of compartmentalizing PDE4D11 activity. The novel 5'-sequence of PDE4D11 is conserved among higher vertebrates including human, monkey, dog, horse and rat. Identification of this new isoform highlights the mutliplicity of unique PDE4D isoforms and their potential importance in regulating cAMP levels through compartmentalization and cell-specific expression and underscores the importance of understanding the functional role of each isoform in the development of specific drugs for the treatment of memory disorders.

Identification and characterization of novel mouse PDE4D isoforms: molecular cloning, subcellular distribution and detection of isoform-specific intracellular localization signals.

We report here the cloning and characterization of short and supershort mouse PDE4D isoforms. PDE4D is one of the phosphodiesterase enzyme families with multiple promoters and splice variants. PDE4 isoforms present in humans, rats and mice share considerable homology in their catalytic and regulatory domains. In this study, we have identified the novel PDE4D2 variant3 (PDE4D2v3) and PDE4D10 isoforms and the mouse orthologs of PDE4D1, PDE4D2 variant1 (PDE4D2v1), PDE4D2 variant2 (PDE4D2v2) and PDE4D6 isoforms. These isoforms have many different lengths of 5'UTR, signifying the use of different transcription start sites. Our data indicate that many novel PDE4D isoforms exist as a result of alternative mRNA splicing, each isoform having unique N-terminal regions and multiple transcription start sites. Subcellular distribution study showed that the PDE4D1 short isoforms are localized to the nucleus while the supershort isoforms (PDE4D2v1, PDE4D2v2, PDE4D2v3, PDE4D6 and PDE4D10) are restricted to the cytoplasm. Deletion study confirmed that the N-terminus of PDE4D1 is necessary for nuclear targeting. In addition, we showed that the unique N-terminus contains nuclear localization signal sequence. Identifying novel tissue-specific PDE4D isoforms with unique N-terminal regions may aid in the development of selective phosphodiesterase inhibitors.