Publications by authors named "David J Price"

140 Publications

Functional brain defects in a mouse model of a chromosomal t(1;11) translocation that disrupts DISC1 and confers increased risk of psychiatric illness.

Transl Psychiatry 2021 Feb 19;11(1):135. Epub 2021 Feb 19.

Centre for Genomic and Experimental Medicine, MRC Institute of Genetics and Molecular Medicine at the University of Edinburgh, Edinburgh, UK.

A balanced t(1;11) translocation that directly disrupts DISC1 is linked to schizophrenia and affective disorders. We previously showed that a mutant mouse, named Der1, recapitulates the effect of the translocation upon DISC1 expression. Here, RNAseq analysis of Der1 mouse brain tissue found enrichment for dysregulation of the same genes and molecular pathways as in neuron cultures generated previously from human t(1;11) translocation carriers via the induced pluripotent stem cell route. DISC1 disruption therefore apparently accounts for a substantial proportion of the effects of the t(1;11) translocation. RNAseq and pathway analysis of the mutant mouse predicts multiple Der1-induced alterations converging upon synapse function and plasticity. Synaptosome proteomics confirmed that the Der1 mutation impacts synapse composition, and electrophysiology found reduced AMPA:NMDA ratio in hippocampal neurons, indicating changed excitatory signalling. Moreover, hippocampal parvalbumin-positive interneuron density is increased, suggesting that the Der1 mutation affects inhibitory control of neuronal circuits. These phenotypes predict that neurotransmission is impacted at many levels by DISC1 disruption in human t(1;11) translocation carriers. Notably, genes implicated in schizophrenia, depression and bipolar disorder by large-scale genetic studies are enriched among the Der1-dysregulated genes, just as we previously observed for the t(1;11) translocation carrier-derived neurons. Furthermore, RNAseq analysis predicts that the Der1 mutation primarily targets a subset of cell types, pyramidal neurons and interneurons, previously shown to be vulnerable to the effects of common schizophrenia-associated genetic variants. In conclusion, DISC1 disruption by the t(1;11) translocation may contribute to the psychiatric disorders of translocation carriers through commonly affected pathways and processes in neurotransmission.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41398-021-01256-3DOI Listing
February 2021

An experimental design tool to optimize inference precision in data-driven mathematical models of bacterial infections .

J R Soc Interface 2020 12 16;17(173):20200717. Epub 2020 Dec 16.

Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge CB3 0ES, UK.

The management of bacterial diseases calls for a detailed knowledge about the dynamic changes in host-bacteria interactions. Biological insights are gained by integrating experimental data with mechanistic mathematical models to infer experimentally unobservable quantities. This inter-disciplinary field would benefit from experiments with maximal information content yielding high-precision inference. Here, we present a computationally efficient tool for optimizing experimental design in terms of parameter inference in studies using isogenic-tagged strains. We study the effect of three experimental design factors: number of biological replicates, sampling timepoint selection and number of copies per tagged strain. We conduct a simulation study to establish the relationship between our optimality criterion and the size of parameter estimate confidence intervals, and showcase its application in a range of biological scenarios reflecting different dynamics patterns observed in experimental infections. We show that in low-variance systems with low killing and replication rates, predicting high-precision experimental designs is consistently achieved; higher replicate sizes and strategic timepoint selection yield more precise estimates. Finally, we address the question of resource allocation under constraints; given a fixed number of host animals and a constraint on total inoculum size per host, infections with fewer strains at higher copies per strain lead to higher-precision inference.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1098/rsif.2020.0717DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7811585PMC
December 2020

Influenza With and Without Fever: Clinical Predictors and Impact on Outcomes in Patients Requiring Hospitalization.

Open Forum Infect Dis 2020 Jul 3;7(7):ofaa268. Epub 2020 Jul 3.

Victorian Infectious Diseases Service, The Royal Melbourne Hospital, at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia.

Background: The Infectious Diseases Society of America influenza guidelines no longer require fever as part of their influenza case definition in patients requiring hospitalization. However, the impact of fever or lack of fever on clinical decision-making and patient outcomes has not been studied.

Methods: We conducted a retrospective review of adult patients admitted to our tertiary health service between April 2016 and June 2019 with laboratory-confirmed influenza, with and without fever (≥37.8ºC). Patient demographics, presenting features, and outcomes were analyzed using Pearson's chi-square test, the Wilcoxon rank-sum test, and logistic regression.

Results: Of 578 influenza inpatients, 219 (37.9%) had no fever at presentation. Fever was less likely in individuals with a nonrespiratory syndrome (adjusted odds ratio [aOR], 0.44; 95% CI, 0.26-0.77), symptoms for ≥3 days (aOR, 0.53; 95% CI, 0.36-0.78), influenza B infection (aOR, 0.45; 95% CI, 0.29-0.70), chronic lung disease (aOR, 0.55; 95% CI, 0.37-0.81), age ≥65 (aOR, 0.36; 95% CI, 0.23-0.54), and female sex (aOR, 0.69; 95% CI, 0.48-0.99). Patients without fever had lower rates of testing for influenza in the emergency department (64.8% vs 77.2%;  = .002) and longer inpatient stays (median, 2.4 vs 1.9 days;  = .015). These patients were less likely to receive antiviral treatment (55.7% vs 65.6%;  = .024) and more likely die in the hospital (3.2% vs 0.6%;  = .031), and these differences persisted after adjustment for potential confounders.

Conclusions: Absence of fever in influenza is associated with delayed diagnosis, longer length of stay, and higher mortality.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/ofid/ofaa268DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7580166PMC
July 2020

Estimation of the force of infection and infectious period of skin sores in remote Australian communities using interval-censored data.

PLoS Comput Biol 2020 10 5;16(10):e1007838. Epub 2020 Oct 5.

School of Mathematics and Statistics, The University of Melbourne, Melbourne, Australia.

Prevalence of impetigo (skin sores) remains high in remote Australian Aboriginal communities, Fiji, and other areas of socio-economic disadvantage. Skin sore infections, driven primarily in these settings by Group A Streptococcus (GAS) contribute substantially to the disease burden in these areas. Despite this, estimates for the force of infection, infectious period and basic reproductive ratio-all necessary for the construction of dynamic transmission models-have not been obtained. By utilising three datasets each containing longitudinal infection information on individuals, we estimate each of these epidemiologically important parameters. With an eye to future study design, we also quantify the optimal sampling intervals for obtaining information about these parameters. We verify the estimation method through a simulation estimation study, and test each dataset to ensure suitability to the estimation method. We find that the force of infection differs by population prevalence, and the infectious period is estimated to be between 12 and 20 days. We also find that optimal sampling interval depends on setting, with an optimal sampling interval between 9 and 11 days in a high prevalence setting, and 21 and 27 days for a lower prevalence setting. These estimates unlock future model-based investigations on the transmission dynamics of skin sores.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1371/journal.pcbi.1007838DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7561265PMC
October 2020

Early analysis of the Australian COVID-19 epidemic.

Elife 2020 08 13;9. Epub 2020 Aug 13.

Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, Australia.

As of 1 May 2020, there had been 6808 confirmed cases of COVID-19 in Australia. Of these, 98 had died from the disease. The epidemic had been in decline since mid-March, with 308 cases confirmed nationally since 14 April. This suggests that the collective actions of the Australian public and government authorities in response to COVID-19 were sufficiently early and assiduous to avert a public health crisis - for now. Analysing factors that contribute to individual country experiences of COVID-19, such as the intensity and timing of public health interventions, will assist in the next stage of response planning globally. We describe how the epidemic and public health response unfolded in Australia up to 13 April. We estimate that the effective reproduction number was likely below one in each Australian state since mid-March and forecast that clinical demand would remain below capacity thresholds over the forecast period (from mid-to-late April).
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.7554/eLife.58785DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7449695PMC
August 2020

Understanding the clinical manifestations of 16p11.2 deletion syndrome: a series of developmental case reports in children.

Psychiatr Genet 2020 10;30(5):136-140

Division of Psychiatry, Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, UK.

Background: Copy number variants (CNVs) are genetic rearrangements, such as deletions and duplications, which result in a deviation from the normal number of copies of a given gene segment. CNVs are implicated in many neuropsychiatric disorders. Deletions of the human chromosomal region 16p11.2 are one of the most common genetic linkages to autism spectrum disorders (ASD). However, ASD is not the only presenting feature, and many patients with 16p11.2 deletions present with a variable clinical spectrum.

Methods: To better understand the nature and presentation of the syndrome throughout development, we present three different, unrelated clinical cases of children with 16p11.2 deletion and provide a detailed description of their clinical manifestations.

Results: Cognitive and motor impairments were characteristic of all three patients with 16p11.2 deletion, despite the differences in the extent and clinical presentation of impairment. Two patients had a clinical diagnosis of ASD and one showed several ASD traits. In addition, two patients also had severe speech and language impairments, which is in line with previous reports on 16p11.2 phenotypes. Although epilepsy and obesity have been frequently associated with 16p11.2 deletion, only one patient had a diagnosis of epilepsy and none of the three cases were obese.

Conclusion: This variation in clinical phenotype renders correct clinical interpretation and diagnosis challenging. Therefore, it is critical to elucidate the variable clinical phenotypes of rare CNVs, including 16p11.2 deletions, to help guide clinical monitoring and counselling of patients and families.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1097/YPG.0000000000000259DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7497286PMC
October 2020

Cerebral organoids as tools to identify the developmental roots of autism.

Mol Autism 2020 07 13;11(1):58. Epub 2020 Jul 13.

Centre for Discovery Brain Sciences and Simons Initiative for the Developing Brain, University of Edinburgh, George Square, Edinburgh, EH8 9XD, UK.

Some autism spectrum disorders (ASD) likely arise as a result of abnormalities during early embryonic development of the brain. Studying human embryonic brain development directly is challenging, mainly due to ethical and practical constraints. However, the recent development of cerebral organoids provides a powerful tool for studying both normal human embryonic brain development and, potentially, the origins of neurodevelopmental disorders including ASD. Substantial evidence now indicates that cerebral organoids can mimic normal embryonic brain development and neural cells found in organoids closely resemble their in vivo counterparts. However, with prolonged culture, significant differences begin to arise. We suggest that cerebral organoids, in their current form, are most suitable to model earlier neurodevelopmental events and processes such as neurogenesis and cortical lamination. Processes implicated in ASDs which occur at later stages of development, such as synaptogenesis and neural circuit formation, may also be modeled using organoids. The accuracy of such models will benefit from continuous improvements to protocols for organoid differentiation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s13229-020-00360-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7359249PMC
July 2020

A data-based mathematical modelling study to quantify the effects of ciprofloxacin and ampicillin on the within-host dynamics of during treatment and relapse.

J R Soc Interface 2020 07 8;17(168):20200299. Epub 2020 Jul 8.

Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge CB3 0ES, UK.

Antibiotic therapy has drastically reduced the mortality and sequelae of bacterial infections. From naturally occurring to chemically synthesized, different classes of antibiotics have been successfully used without detailed knowledge of how they affect bacterial dynamics . However, a proportion of patients receiving antimicrobial therapy develop recrudescent infections post-treatment. Relapsing infections are attributable to incomplete clearance of bacterial populations following antibiotic administration; the metabolic profile of this antibiotic-recalcitrant bacterial subpopulation, the spatio-temporal context of its emergence and the variance of antibiotic-bacterial interactions remain unclear. Here, we develop and apply a mechanistic mathematical model to data from a study comparing the effects of ciprofloxacin and ampicillin on the within-host dynamics of serovar Typhimurium in murine infections. Using the inferential capacity of our model, we show that the antibiotic-recalcitrant bacteria following ampicillin, but not ciprofloxacin, treatment belong to a non-replicating phenotype. Aligning with previous studies, we independently estimate that the lymphoid tissues and spleen are important reservoirs of non-replicating bacteria. Finally, we predict that post-treatment, the progenitors of the non-growing and growing bacterial populations replicate and die at different rates. Ultimately, the liver, spleen and mesenteric lymph nodes are all repopulated by progenitors of the previously non-growing phenotype in ampicillin-treated mice.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1098/rsif.2020.0299DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7423434PMC
July 2020

The role of the diencephalon in the guidance of thalamocortical axons in mice.

Development 2020 06 26;147(12). Epub 2020 Jun 26.

Centre for Discovery Brain Sciences, Hugh Robson Building, George Square, Edinburgh EH8 9XD, UK.

Thalamocortical axons (TCAs) cross several tissues on their journey to the cortex. Mechanisms must be in place along the route to ensure they connect with their targets in an orderly fashion. The ventral telencephalon acts as an instructive tissue, but the importance of the diencephalon in TCA mapping is unknown. We report that disruption of diencephalic development by Pax6 deletion results in a thalamocortical projection containing mapping errors. We used conditional mutagenesis to test whether these errors are due to the disruption of pioneer projections from prethalamus to thalamus and found that, although this correlates with abnormal TCA fasciculation, it does not induce topographical errors. To test whether the thalamus contains navigational cues for TCAs, we used slice culture transplants and gene expression studies. We found the thalamic environment is instructive for TCA navigation and that the molecular cues netrin 1 and semaphorin 3a are likely to be involved. Our findings indicate that the correct topographic mapping of TCAs onto the cortex requires the order to be established from the earliest stages of their growth by molecular cues in the thalamus itself.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1242/dev.184523DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7327999PMC
June 2020

Quantification of glucose-6-phosphate dehydrogenase activity by spectrophotometry: A systematic review and meta-analysis.

PLoS Med 2020 05 14;17(5):e1003084. Epub 2020 May 14.

Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Australia.

Background: The radical cure of Plasmodium vivax and P. ovale requires treatment with primaquine or tafenoquine to clear dormant liver stages. Either drug can induce haemolysis in individuals with glucose-6-phosphate dehydrogenase (G6PD) deficiency, necessitating screening. The reference diagnostic method for G6PD activity is ultraviolet (UV) spectrophotometry; however, a universal G6PD activity threshold above which these drugs can be safely administered is not yet defined. Our study aimed to quantify assay-based variation in G6PD spectrophotometry and to explore the diagnostic implications of applying a universal threshold.

Methods And Findings: Individual-level data were pooled from studies that used G6PD spectrophotometry. Studies were identified via PubMed search (25 April 2018) and unpublished contributions from contacted authors (PROSPERO: CRD42019121414). Studies were excluded if they assessed only individuals with known haematological conditions, were family studies, or had insufficient details. Studies of malaria patients were included but analysed separately. Included studies were assessed for risk of bias using an adapted form of the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) tool. Repeatability and intra- and interlaboratory variability in G6PD activity measurements were compared between studies and pooled across the dataset. A universal threshold for G6PD deficiency was derived, and its diagnostic performance was compared to site-specific thresholds. Study participants (n = 15,811) were aged between 0 and 86 years, and 44.4% (7,083) were women. Median (range) activity of G6PD normal (G6PDn) control samples was 10.0 U/g Hb (6.3-14.0) for the Trinity assay and 8.3 U/g Hb (6.8-15.6) for the Randox assay. G6PD activity distributions varied significantly between studies. For the 13 studies that used the Trinity assay, the adjusted male median (AMM; a standardised metric of 100% G6PD activity) varied from 5.7 to 12.6 U/g Hb (p < 0.001). Assay precision varied between laboratories, as assessed by variance in control measurements (from 0.1 to 1.5 U/g Hb; p < 0.001) and study-wise mean coefficient of variation (CV) of replicate measures (from 1.6% to 14.9%; p < 0.001). A universal threshold of 100% G6PD activity was defined as 9.4 U/g Hb, yielding diagnostic thresholds of 6.6 U/g Hb (70% activity) and 2.8 U/g Hb (30% activity). These thresholds diagnosed individuals with less than 30% G6PD activity with study-wise sensitivity from 89% (95% CI: 81%-94%) to 100% (95% CI: 96%-100%) and specificity from 96% (95% CI: 89%-99%) to 100% (100%-100%). However, when considering intermediate deficiency (<70% G6PD activity), sensitivity fell to a minimum of 64% (95% CI: 52%-75%) and specificity to 35% (95% CI: 24%-46%). Our ability to identify underlying factors associated with study-level heterogeneity was limited by the lack of availability of covariate data and diverse study contexts and methodologies.

Conclusions: Our findings indicate that there is substantial variation in G6PD measurements by spectrophotometry between sites. This is likely due to variability in laboratory methods, with possible contribution of unmeasured population factors. While an assay-specific, universal quantitative threshold offers robust diagnosis at the 30% level, inter-study variability impedes performance of universal thresholds at the 70% level. Caution is advised in comparing findings based on absolute G6PD activity measurements across studies. Novel handheld quantitative G6PD diagnostics may allow greater standardisation in the future.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1371/journal.pmed.1003084DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7224463PMC
May 2020

Cost-Effectiveness Analysis of Sex-Stratified Treatment Strategies Using Available G6PD Diagnostics to Accelerate Access to Radical Cure.

Am J Trop Med Hyg 2020 07 30;103(1):394-403. Epub 2020 Apr 30.

Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.

Tafenoquine has been licensed for the single-dose radical cure of in adults; however, it is only recommended in patients with > 70% of normal glucose-6-phosphate dehydrogenase (G6PD) activity. Because this may hinder widespread use, we investigated sex-based treatment strategies in which all adult patients are tested with a qualitative G6PD rapid diagnostic test (RDT). Glucose-6-phosphate dehydrogenase normal males are prescribed tafenoquine in all three strategies, whereas G6PD normal females are prescribed either a low-dose 14-day primaquine regimen (PQ14, total dose 3.5 mg/kg) or a high-dose 7-day primaquine regimen (PQ7, total dose 7 mg/kg), or referred to a healthcare facility for quantitative G6PD testing before prescribing tafenoquine. Patients testing G6PD deficient are prescribed a weekly course of primaquine for 8 weeks. We compared the cost-effectiveness of these three strategies to usual care in four countries using a decision tree model. Usual care in Ethiopia does not include radical cure, whereas Afghanistan, Indonesia, and Vietnam prescribe PQ14 without G6PD screening. The cost per disability-adjusted life-year (DALY) averted was expressed through incremental cost-effectiveness ratios (ICERs). Compared with usual care, the ICERs for a sex-based treatment strategy with PQ7 for females from a healthcare provider perspective were $127 per DALY averted in Vietnam, $466 in Ethiopia, $1,089 in Afghanistan, and $4,443 in Indonesia. The PQ14 and referral options cost more while averting fewer DALYs than PQ7. This study provides an alternative cost-effective mode of rolling out tafenoquine in areas where initial testing with only a G6PD RDT is feasible.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.4269/ajtmh.19-0943DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7356471PMC
July 2020

Effect of Vancomycin or Daptomycin With vs Without an Antistaphylococcal β-Lactam on Mortality, Bacteremia, Relapse, or Treatment Failure in Patients With MRSA Bacteremia: A Randomized Clinical Trial.

JAMA 2020 02;323(6):527-537

Menzies School of Health Research, Charles Darwin University, Casuarina, Northern Territory, Australia.

Importance: Methicillin-resistant Staphylococcus aureus (MRSA) bacteremia is associated with mortality of more than 20%. Combining standard therapy with a β-lactam antibiotic has been associated with reduced mortality, although adequately powered randomized clinical trials of this intervention have not been conducted.

Objective: To determine whether combining an antistaphylococcal β-lactam with standard therapy is more effective than standard therapy alone in patients with MRSA bacteremia.

Design, Setting, And Participants: Open-label, randomized clinical trial conducted at 27 hospital sites in 4 countries from August 2015 to July 2018 among 352 hospitalized adults with MRSA bacteremia. Follow-up was complete on October 23, 2018.

Interventions: Participants were randomized to standard therapy (intravenous vancomycin or daptomycin) plus an antistaphylococcal β-lactam (intravenous flucloxacillin, cloxacillin, or cefazolin) (n = 174) or standard therapy alone (n = 178). Total duration of therapy was determined by treating clinicians and the β-lactam was administered for 7 days.

Main Outcomes And Measures: The primary end point was a 90-day composite of mortality, persistent bacteremia at day 5, microbiological relapse, and microbiological treatment failure. Secondary outcomes included mortality at days 14, 42, and 90; persistent bacteremia at days 2 and 5; acute kidney injury (AKI); microbiological relapse; microbiological treatment failure; and duration of intravenous antibiotics.

Results: The data and safety monitoring board recommended early termination of the study prior to enrollment of 440 patients because of safety. Among 352 patients randomized (mean age, 62.2 [SD, 17.7] years; 121 women [34.4%]), 345 (98%) completed the trial. The primary end point was met by 59 (35%) with combination therapy and 68 (39%) with standard therapy (absolute difference, -4.2%; 95% CI, -14.3% to 6.0%). Seven of 9 prespecified secondary end points showed no significant difference. For the combination therapy vs standard therapy groups, all-cause 90-day mortality occurred in 35 (21%) vs 28 (16%) (difference, 4.5%; 95% CI, -3.7% to 12.7%); persistent bacteremia at day 5 was observed in 19 of 166 (11%) vs 35 of 172 (20%) (difference, -8.9%; 95% CI, -16.6% to -1.2%); and, excluding patients receiving dialysis at baseline, AKI occurred in 34 of 145 (23%) vs 9 of 145 (6%) (difference, 17.2%; 95% CI, 9.3%-25.2%).

Conclusions And Relevance: Among patients with MRSA bacteremia, addition of an antistaphylococcal β-lactam to standard antibiotic therapy with vancomycin or daptomycin did not result in significant improvement in the primary composite end point of mortality, persistent bacteremia, relapse, or treatment failure. Early trial termination for safety concerns and the possibility that the study was underpowered to detect clinically important differences in favor of the intervention should be considered when interpreting the findings.

Trial Registration: ClinicalTrials.gov Identifier: NCT02365493.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1001/jama.2020.0103DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7042887PMC
February 2020

Vaccine-Specific Immune Responses against Mycobacterium ulcerans Infection in a Low-Dose Murine Challenge Model.

Infect Immun 2020 02 20;88(3). Epub 2020 Feb 20.

Department of Microbiology and Immunology, Doherty Institute, University of Melbourne, Melbourne, Victoria, Australia

The neglected tropical disease Buruli ulcer (BU) is an infection of subcutaneous tissue with There is no effective vaccine. Here, we assessed an experimental prime-boost vaccine in a low-dose murine tail infection model. We used the enoyl reductase (ER) domain of the mycolactone polyketide synthases electrostatically coupled with a previously described Toll-like receptor 2 (TLR-2) agonist-based lipopeptide adjuvant, RPamCys. Mice were vaccinated and then challenged via tail inoculation with 14 to 20 CFU of a bioluminescent strain of Mice receiving either the experimental ER vaccine or bacillus Calmette-Guérin (BCG) were equally protected, with both groups faring significantly better than nonvaccinated animals (0.05). To explore potential correlates of protection, a suite of 29 immune parameters were assessed in the mice at the end of the experimental period. Multivariate statistical approaches were used to interrogate the immune response data to develop disease-prognostic models. High levels of interleukin 2 (IL-2) and low gamma interferon (IFN-γ) produced in the spleen best predicted control of infection across all vaccine groups. Univariate logistic regression revealed vaccine-specific profiles of protection. High titers of ER-specific IgG serum antibodies together with IL-2 and IL-4 in the draining lymph node (DLN) were associated with protection induced by the ER vaccine. In contrast, high titers of IL-6, tumor necrosis factor alpha (TNF-α), IFN-γ, and IL-10 in the DLN and low IFN-γ titers in the spleen were associated with protection following BCG vaccination. This study suggests that an effective BU vaccine must induce localized, tissue-specific immune profiles with controlled inflammatory responses at the site of infection.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1128/IAI.00753-19DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7035934PMC
February 2020

A statistical model for restoration of serum potassium level disturbed by hemolysis.

Clin Chim Acta 2019 Oct 26;497:137-140. Epub 2019 Jul 26.

Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Victoria, Australia; The Peter Doherty Institute for Infection and Immunity, Royal Melbourne Hospital & The University of Melbourne, Victoria, Australia.

Background: Blood sample hemolysis affects pre-analytical quality and may cause pseudohyperkalemia. We established a statistical model to estimate the corrected potassium (K) in serum.

Methods: Serum K and H index were analyzed, and blood cell index was obtained from the examined Full Blood Examination (FBE) results. A linear-regression model was developed using hemolysis (H) index, K and covariates of blood cell index from 139 cell lysates of blood samples. The model was then validated against 26 in vitro physically hemolyzed serum samples.

Results: The final model selected H index, hemoglobin concentration (HGB), and hematocrit (HCT) as important predictors in estimating the K content. The model was validated against artificially hemolyzed serum samples, which returned a correlation of 0.942 between observed and predicted net K increase by hemolysis. The predictors H index, HCT, and HB contributed 93.7%, 3.5% and 2.8% to the model R, respectively.

Conclusion: In vitro hemolysis induced pseudohyperkalemia could be accurately predicted and restored by our model for clinical application.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.cca.2019.07.029DOI Listing
October 2019

Atlas of group A streptococcal vaccine candidates compiled using large-scale comparative genomics.

Nat Genet 2019 06 27;51(6):1035-1043. Epub 2019 May 27.

School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland, Australia.

Group A Streptococcus (GAS; Streptococcus pyogenes) is a bacterial pathogen for which a commercial vaccine for humans is not available. Employing the advantages of high-throughput DNA sequencing technology to vaccine design, we have analyzed 2,083 globally sampled GAS genomes. The global GAS population structure reveals extensive genomic heterogeneity driven by homologous recombination and overlaid with high levels of accessory gene plasticity. We identified the existence of more than 290 clinically associated genomic phylogroups across 22 countries, highlighting challenges in designing vaccines of global utility. To determine vaccine candidate coverage, we investigated all of the previously described GAS candidate antigens for gene carriage and gene sequence heterogeneity. Only 15 of 28 vaccine antigen candidates were found to have both low naturally occurring sequence variation and high (>99%) coverage across this diverse GAS population. This technological platform for vaccine coverage determination is equally applicable to prospective GAS vaccine antigens identified in future studies.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41588-019-0417-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6650292PMC
June 2019

Systematic Review of Group A Streptococcal Types Associated with Acute Post-Streptococcal Glomerulonephritis.

Am J Trop Med Hyg 2019 05;100(5):1066-1070

Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, University of Melbourne, Victoria, Australia.

Acute post-streptococcal glomerulonephritis (APSGN) is a postinfectious immune-mediated kidney disease associated with group A (GAS). The prevalence of APSGN varies within and between countries and is influenced by socioeconomic, host, and bacterial factors. The disease is more prevalent in developing countries and resource-poor settings of developed countries, such as the Indigenous populations residing in tropical Australia. The M-protein is a universally present GAS surface antigen that is the focus of molecular typing and vaccine research. Early reports suggested that some M-proteins ( types) are more likely to cause APSGN than others. Here, we present the first systematic review of the global distribution of APSGN-associated GAS types. There were 46 types among the 676 cases described in 15 reviewed articles. Only 43% APSGN cases would have had theoretical coverage from the experimental M protein-based GAS vaccine. Vaccine coverage was higher in regions such as North America (97%) and the United Kingdom (98%) than Africa (67%) and Australia (38%). Variable vaccine coverage against APSGN- associated types highlights the need for further research into this disease, particularly in settings of poverty, where APSGN prevalence is higher. Three GAS types (49, 60, and 55) consistently occur in APSGN cases around the world. Future studies would therefore benefit from examining the genomic epidemiology of these types to unravel potential markers of APSGN.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.4269/ajtmh.18-0827DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6493963PMC
May 2019

Loss of Causes Regional Changes in Expression in Developing Cerebral Cortex.

Front Cell Neurosci 2019 6;13:78. Epub 2019 Mar 6.

Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom.

The transcription factor Pax6 controls multiple aspects of forebrain development. Conditional deletion of in embryonic mouse cortex causes increased proliferation of cortical progenitor cells and a concomitant decrease in neural differentiation. Notch signaling regulates the balance between proliferation and differentiation of cortical progenitor cells, suggesting a possible connection between Pax6 and Notch signaling. We investigated how expression of the Notch ligand () is altered by loss of Pax6. Acute cortex-specific deletion of Pax6 resulted in a widespread decrease in the density of + cells at embryonic days 12.5 and 13.5 (E12.5 and E13.5). In constitutive loss-of-function mutants, decreases in the densities of + cells were more limited both spatially and temporally. Controlled over-expression of Pax6 had no detectable effect on expression. The proneural transcription factor Neurog2 is a target of Pax6 that can activate expression and we found clear co-expression of and in radial glial progenitors, suggesting that Pax6's effect on could be mediated through Neurog2. However, we found no change in + cells in cortex suggesting either that Neurog2 is not directly involved, or that its loss of function in embryonic cortex can be compensated for.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fncel.2019.00078DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6414449PMC
March 2019

Tissue-Specific Actions of Pax6 on Proliferation and Differentiation Balance in Developing Forebrain Are Foxg1 Dependent.

iScience 2018 Dec 22;10:171-191. Epub 2018 Nov 22.

Simons Initiative for the Developing Brain, Hugh Robson Building, George Square, Edinburgh EH8 9XD, UK.

Differences in the growth and maturation of diverse forebrain tissues depend on region-specific transcriptional regulation. Individual transcription factors act simultaneously in multiple regions that develop very differently, raising questions about the extent to which their actions vary regionally. We found that the transcription factor Pax6 affects the transcriptomes and the balance between proliferation and differentiation in opposite directions in the diencephalon versus cerebral cortex. We tested several possible mechanisms to explain Pax6's tissue-specific actions and found that the presence of the transcription factor Foxg1 in the cortex but not in the diencephalon was most influential. We found that Foxg1 is responsible for many of the differences in cell cycle gene expression between the diencephalon and cortex and, in cortex lacking Foxg1, Pax6's action on the balance of proliferation versus differentiation becomes diencephalon like. Our findings reveal a mechanism for generating regional forebrain diversity in which one transcription factor completely reverses the actions of another.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.isci.2018.11.031DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6287089PMC
December 2018

Pax6 Lengthens G1 Phase and Decreases Oscillating Cdk6 Levels in Murine Embryonic Cortical Progenitors.

Front Cell Neurosci 2018 15;12:419. Epub 2018 Nov 15.

Biomedical Sciences, The University of Edinburgh, Edinburgh, United Kingdom.

Pax6 is a key regulator of the rates of progenitor cell division in cerebral corticogenesis. Previous work has suggested that this action is mediated at least in part by regulation of the cell cycle gene , which acts largely on the transition from G1 to S phase. We began the present study by investigating whether, in addition to , other Pax6-regulated cell cycle genes are likely to be primary mediators of Pax6's actions on cortical progenitor cell cycles. Following acute cortex-specific deletion of Pax6, showed changes in expression a day earlier than any other Pax6-regulated cell cycle gene suggesting that it is the primary mediator of Pax6's actions. We then used flow cytometry to show that progenitors lacking Pax6 have a shortened G1 phase and that their Cdk6 levels are increased in all phases. We found that Cdk6 levels oscillate during the cell cycle, increasing from G1 to M phase. We propose a model in which loss of Pax6 shortens G1 phase by raising overall Cdk6 levels, thereby shortening the time taken for Cdk6 levels to cross a threshold triggering transition to S phase.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fncel.2018.00419DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6249377PMC
November 2018

-Lineage Cells Increase Their Contribution to Visual Thalamic Nuclei during Murine Embryogenesis If They Are Homozygous or Heterozygous for Loss of Function.

eNeuro 2018 Sep-Oct;5(5). Epub 2018 Oct 23.

Simons Initiative for the Developing Brain, Biomedical Sciences, The University of Edinburgh, Edinburgh EH8 9XD, United Kingdom.

Our aim was to study the mechanisms that contribute to the development of discrete thalamic nuclei during mouse embryogenesis (both sexes included). We characterized the expression of the transcription factor coding gene and the distribution of cells that expressed in their lineage. We used genetic fate mapping to show that -lineage cells mainly contribute to a subset of thalamic nuclei, in particular the lateral geniculate nuclei (LGNs), which are crucial components of the visual pathway. We observed that almost all -lineage diencephalic progenitors express the transcription factor Pax6 at variable location-dependent levels. We used conditional mutagenesis to delete either one or both copies of from -lineage cells. We found that -lineage cells carrying either homozygous or heterozygous loss of contributed in abnormally high numbers to one or both of the main lateral geniculate nuclei (LGNs). This could not be attributed to a change in cell production and was likely due to altered sorting of thalamic cells. Our results indicate that positional information encoded by the levels of Pax6 in diencephalic progenitors is an important determinant of the eventual locations of their daughter cells.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1523/ENEURO.0367-18.2018DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6220585PMC
April 2019

A conditional Pax6 depletion study with no morphological effect on the adult mouse corneal epithelium.

BMC Res Notes 2018 Oct 5;11(1):705. Epub 2018 Oct 5.

Centre for Integrative Physiology, Clinical Sciences, University of Edinburgh Medical School, Hugh Robson Building, George Square, Edinburgh, EH8 9XD, UK.

Objective: The corneas of heterozygous Pax6 mice develop abnormally and deteriorate further after birth but it is not known whether the postnatal deterioration is predetermined by abnormal development. Our objective was to identify whether depletion of Pax6 in adult mice caused any corneal abnormalities, similar to those in Pax6 mice, where Pax6 levels are low throughout development and adulthood. We used two tamoxifen-inducible, Cre-loxP experimental strategies to deplete Pax6 either ubiquitously or in a restricted range of cell types.

Results: In a preliminary study, ubiquitous depletion of Pax6 by tamoxifen treatment of E9.5 CAG-CreER;Pax6 embryos affected eye development. Tamoxifen treatment of 12-week old, adult CAG-CreER;Pax6 and CAG-CreER;Pax6 mice resulted in weak and/or patchy Pax6 immunostaining in the corneal epithelium but caused no corneal abnormalities. GFP staining in tamoxifen-treated CAG-CreER;RCE:loxP reporter mice was also patchy. We attribute patchy Pax6 staining to mosaic deletion of the Pax6 allele, probably caused by mosaic CAG-CreER expression. In a parallel study, we treated adult Krt19-CreER;Pax6 mice with tamoxifen to try to deplete Pax6 in limbal epithelial stem cells (LESCs) which replenish the corneal epithelium. However, Pax6 staining remained strong after a 12-week chase period so the Krt19-CreER transgene may have failed to target LESCs.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s13104-018-3812-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6173925PMC
October 2018

DISC1 regulates N-methyl-D-aspartate receptor dynamics: abnormalities induced by a Disc1 mutation modelling a translocation linked to major mental illness.

Transl Psychiatry 2018 09 6;8(1):184. Epub 2018 Sep 6.

Centre for Genomic and Experimental Medicine, MRC Institute of Genetics and Molecular Medicine at the University of Edinburgh, Edinburgh, UK.

The neuromodulatory gene DISC1 is disrupted by a t(1;11) translocation that is highly penetrant for schizophrenia and affective disorders, but how this translocation affects DISC1 function is incompletely understood. N-methyl-D-aspartate receptors (NMDAR) play a central role in synaptic plasticity and cognition, and are implicated in the pathophysiology of schizophrenia through genetic and functional studies. We show that the NMDAR subunit GluN2B complexes with DISC1-associated trafficking factor TRAK1, while DISC1 interacts with the GluN1 subunit and regulates dendritic NMDAR motility in cultured mouse neurons. Moreover, in the first mutant mouse that models DISC1 disruption by the translocation, the pool of NMDAR transport vesicles and surface/synaptic NMDAR expression are increased. Since NMDAR cell surface/synaptic expression is tightly regulated to ensure correct function, these changes in the mutant mouse are likely to affect NMDAR signalling and synaptic plasticity. Consistent with these observations, RNASeq analysis of the translocation carrier-derived human neurons indicates abnormalities of excitatory synapses and vesicle dynamics. RNASeq analysis of the human neurons also identifies many differentially expressed genes previously highlighted as putative schizophrenia and/or depression risk factors through large-scale genome-wide association and copy number variant studies, indicating that the translocation triggers common disease pathways that are shared with unrelated psychiatric patients. Altogether, our findings suggest that translocation-induced disease mechanisms are likely to be relevant to mental illness in general, and that such disease mechanisms include altered NMDAR dynamics and excitatory synapse function. This could contribute to the cognitive disorders displayed by translocation carriers.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41398-018-0228-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6127284PMC
September 2018

Gli3 controls the onset of cortical neurogenesis by regulating the radial glial cell cycle through expression.

Development 2018 08 20;145(17). Epub 2018 Aug 20.

Centre for Discovery Brain Sciences, Hugh Robson Building, University of Edinburgh, Edinburgh EH8 9XD, UK

The cerebral cortex contains an enormous number of neurons, allowing it to perform highly complex neural tasks. Understanding how these neurons develop at the correct time and place and in accurate numbers constitutes a major challenge. Here, we demonstrate a novel role for Gli3, a key regulator of cortical development, in cortical neurogenesis. We show that the onset of neuron formation is delayed in conditional mouse mutants. Gene expression profiling and cell cycle measurements indicate that shortening of the G1 and S phases in radial glial cells precedes this delay. Reduced G1 length correlates with an upregulation of the cyclin-dependent kinase gene , which is directly regulated by Gli3. Moreover, pharmacological interference with Cdk6 function rescues the delayed neurogenesis in mutant embryos. Overall, our data indicate that Gli3 controls the onset of cortical neurogenesis by determining the levels of expression, thereby regulating neuronal output and cortical size.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1242/dev.163147DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6141774PMC
August 2018

Designing group dose-response studies in the presence of transmission.

Math Biosci 2018 10 25;304:62-78. Epub 2018 Jul 25.

School of Mathematical Sciences, University of Adelaide, SA 5005, Australia; ARC Centre of Excellence for Mathematical & Statistical Frontiers, School of Mathematical Sciences, University of Adelaide, SA 5005, Australia.

Dose-response studies are used throughout pharmacology, toxicology and in clinical research to determine safe, effective, or hazardous doses of a substance. When involving animals, the subjects are often housed in groups; this is in fact mandatory in many countries for social animals, on ethical grounds. An issue that may consequently arise is that of unregulated between-subject dosing (transmission), where a subject may transmit the substance to another subject. Transmission will obviously impact the assessment of the dose-response relationship, and will lead to biases if not properly modelled. Here we present a method for determining the optimal design - pertaining to the size of groups, the doses, and the killing times - for such group dose-response experiments, in a Bayesian framework. Our results are of importance to minimising the number of animals required in order to accurately determine dose-response relationships. Furthermore, we additionally consider scenarios in which the estimation of the amount of transmission is also of interest. A particular motivating example is that of Campylobacter jejuni in chickens. Code is provided so that practitioners may determine the optimal design for their own studies.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.mbs.2018.07.007DOI Listing
October 2018

Variation in cell-associated unspliced HIV RNA on antiretroviral therapy is associated with the circadian regulator brain-and-muscle-ARNT-like-1.

AIDS 2018 09;32(15):2119-2128

Department of Infectious Diseases, Alfred Hospital and Monash University, Melbourne, Australia.

Objective(s): To determine whether variation in cell-associated unspliced (CA-US) HIV RNA in HIV-infected individuals on antiretroviral therapy (ART) has a circadian basis.

Methods: Prospective observational study of HIV-infected individuals on ART. Blood was collected on three occasions and CA-US HIV RNA and mRNA of the circadian-locomotor-output-cycles-kaput (CLOCK)-associated genes quantified by real time PCR. CLOCK-associated proteins were over-expressed in a cell line stably transfected with an HIV long-terminal repeat (LTR) luciferase reporter.

Results: Using a mixed effects model, there was a significant increase in log-CA-US RNA at the third visit compared with the first visit (effect size of 0.619 with standard error (SE) of 0.098, P < 0.001) and an independent effect of time of blood draw (effect size 0.051 (SE 0.025), P = 0.040). The CLOCK-associated gene, brain-and-muscle-ARNT-like-1 (BMAL-1) had a significant relationship with log CA-US HIV RNA (effect size 8.508 (SE 3.777), P = 0.028) and also with time (P = 0.045). Over expression of BMAL-1 and CLOCK in a cell line stably transfected with an HIV-LTR luciferase reporter resulted in an increase in luciferase expression and this was reduced following mutation of the second E-box in the HIV-LTR.

Conclusion: The basal level of HIV transcription on ART can vary significantly and is modulated by the circadian regulator BMAL-1, amongst other factors.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1097/QAD.0000000000001937DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6173794PMC
September 2018

Accounting for twin births in sample size calculations for randomised trials.

Paediatr Perinat Epidemiol 2018 07 4;32(4):380-387. Epub 2018 May 4.

Melbourne Children's Trials Centre, Murdoch Children's Research Institute, Melbourne, VIC, Australia.

Background: Including twins in randomised trials leads to non-independence or clustering in the data. Clustering has important implications for sample size calculations, yet few trials take this into account. Estimates of the intracluster correlation coefficient (ICC), or the correlation between outcomes of twins, are needed to assist with sample size planning. Our aims were to provide ICC estimates for infant outcomes, describe the information that must be specified in order to account for clustering due to twins in sample size calculations, and develop a simple tool for performing sample size calculations for trials including twins.

Methods: ICCs were estimated for infant outcomes collected in four randomised trials that included twins. The information required to account for clustering due to twins in sample size calculations is described. A tool that calculates the sample size based on this information was developed in Microsoft Excel and in R as a Shiny web app.

Results: ICC estimates ranged between -0.12, indicating a weak negative relationship, and 0.98, indicating a strong positive relationship between outcomes of twins. Example calculations illustrate how the ICC estimates and sample size calculator can be used to determine the target sample size for trials including twins.

Conclusions: Clustering among outcomes measured on twins should be taken into account in sample size calculations to obtain the desired power. Our ICC estimates and sample size calculator will be useful for designing future trials that include twins. Publication of additional ICCs is needed to further assist with sample size planning for future trials.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/ppe.12471DOI Listing
July 2018

SP8 Transcriptional Regulation of During Mouse Early Corticogenesis.

Front Neurosci 2018 2;12:119. Epub 2018 Mar 2.

Université de Lyon, Université Claude Bernard Lyon 1, Inserm, Stem Cell and Brain Research Institute U1208, Bron, France.

Multiple signals control the balance between proliferation and differentiation of neural progenitor cells during corticogenesis. A key point of this regulation is the control of G1 phase length, which is regulated by the Cyclin/Cdks complexes. Using genome-wide chromatin immunoprecipitation assay and mouse genetics, we have explored the transcriptional regulation of () during the early developmental stages of the mouse cerebral cortex. We found evidence that SP8 binds to the locus on exon regions. experiments show SP8 binding activity on gene 3'-end, and point to a putative role for SP8 in modulating PAX6-mediated repression of along the dorso-ventral axis of the developing pallium, creating a medial-lateral gradient of neuronal differentiation. Activation of through the promoter/5'-end of the gene does not depend on SP8, but on βcatenin (CTNNB1). Importantly, alteration of the level of expression affects expression during early corticogenesis. Our results indicate that regulation is the result of multiple signals and that SP8 is a player in this regulation, revealing an unexpected and potentially novel mechanism of transcriptional activation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fnins.2018.00119DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5863514PMC
March 2018

Early emergence of cortical interneuron diversity in the mouse embryo.

Science 2018 04 22;360(6384):81-85. Epub 2018 Feb 22.

Centre for Developmental Neurobiology, Institute of Psychiatry, Psychology, and Neuroscience, King's College London, London SE1 1UL, UK.

GABAergic interneurons (GABA, γ-aminobutyric acid) regulate neural-circuit activity in the mammalian cerebral cortex. These cortical interneurons are structurally and functionally diverse. Here, we use single-cell transcriptomics to study the origins of this diversity in the mouse. We identify distinct types of progenitor cells and newborn neurons in the ganglionic eminences, the embryonic proliferative regions that give rise to cortical interneurons. These embryonic precursors show temporally and spatially restricted transcriptional patterns that lead to different classes of interneurons in the adult cerebral cortex. Our findings suggest that shortly after the interneurons become postmitotic, their diversity is already patent in their diverse transcriptional programs, which subsequently guide further differentiation in the developing cortex.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1126/science.aar6821DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6195193PMC
April 2018