Recent Submissions

  • The Effect of Preexisting Immunity on Virus Detection and Immune Responses in a Phase II, Randomized Trial of a Russian-Backbone, Live, Attenuated Influenza Vaccine in Bangladeshi Children

    Brickley, E.B.; Neuzil, K.M.; Ortiz, J.R. (Oxford University Press, 2018)
    Background: In a 2012 Phase II clinical trial, 300 Bangladeshi children aged 24 to 59 months with no prior influenza vaccine exposure were randomized to receive a single intranasally-administered dose of either trivalent, Russian-backbone, live, attenuated influenza vaccine (LAIV) or placebo. Protocol-defined analyses, presented in the companion manuscript, demonstrate decreased viral detection and immunogenicity for A/H1N1pdm09, relative to the A/H3N2 and B strains. This post hoc analysis of the trial data aims to investigate the LAIV strain differences by testing the hypothesis that preexisting humoral and mucosal immunity may influence viral recovery and immune responses after LAIV receipt. Methods: We used logistic regressions to evaluate the relations between markers of preexisting immunity (ie, hemagglutination inhibition [HAI], microneutralization, and immunoglobulin G and immunoglobulin A (both serum and mucosal antibodies) and LAIV viral recovery in the week post-vaccination. We then tested for potential effect modification by baseline HAI titers (ie, <10 versus ≥10) and week 1 viral recovery on the LAIV-induced serum and mucosal immune responses, measured between days 0 and 21 post-vaccination. Results: Higher levels of preexisting immunity to influenza A/H3N2 and B were strongly associated with strain-specific prevention of viral shedding upon LAIV receipt. While evidence of LAIV immunogenicity was observed for all 3 strains, the magnitudes of immune responses were most pronounced in children with no evidence of preexisting HAI and in those with detectable virus. Conclusions: The results provide evidence for a bidirectional association between viral replication and immunity, and underscore the importance of accounting for preexisting immunity when evaluating virologic and immunologic responses to LAIVs. Clinical Trials Registration: NCT01625689. Copyright 2018 The Author(s) 2018.
  • Angiogenic and osteogenic regeneration in rats via calcium phosphate scaffold and endothelial cell co-culture with human bone marrow mesenchymal stem cells (MSCs), human umbilical cord MSCs, human induced pluripotent stem cell-derived MSCs and human embryonic stem cell-derived MSCs

    Chen, W.; Liu, X.; Chen, Q. (John Wiley and Sons Ltd, 2018)
    Angiogenesis is a limiting factor in regenerating large bone defects. The objective of this study was to investigate angiogenic and osteogenic effects of coculture on calcium phosphate cement (CPC) scaffold using human umbilical vein endothelial cells (hUVECs) and mesenchymal stem cells (MSCs) from different origins for the first time. hUVECs were cocultured with four types of cells: human umbilical cord MSCs (hUCMSCs), human bone marrow MSCs (hBMSCs), and MSCs from induced pluripotent stem cells (hiPSC-MSCs) and embryonic stem cells (hESC-MSCs). Constructs were implanted in 8-mm cranial defects of rats for 12 weeks. CPC without cells served as control 1. CPC with hBMSCs served as control 2. Microcapillary-like structures were successfully formed on CPC in vitro in all four cocultured groups. Microcapillary lengths increased with time (p<0.05). Osteogenic and angiogenic gene expressions were highly elevated, and mineralization by cocultured cells increased with time (p<0.05). New bone amount and blood vessel density of cocultured groups were much greater than controls (p<0.05) in an animal study. hUVEC coculture with hUCMSCs, hiPSC-MSCs and hESC-MSCs achieved new bone and vessel density similar to hUVEC coculture with hBMSCs (p>0.1). Therefore, hUCMSCs, hiPSC-MSCs and hESC-MSCs could serve as alternative cell sources to hBMSCs which require an invasive procedure to harvest. In conclusion, this study showed for the first time that cocultures of hUVECs with hUCMSCs, hiPSC-MSCs, hESC-MSCs and hBMSCs delivered via CPC scaffold achieved excellent osteogenic and angiogenic capabilities in vivo. The novel coculture constructs are promising for bone reconstruction with improved angiogenesis for craniofacial/orthopedic applications. Copyright 2017 John Wiley & Sons, Ltd.
  • Pharmacist and pediatrician knowledge of codeine use in children

    He, T.; Lardieri, A.B.; Morgan, J.A. (Pediatric Pharmacy Advocacy Group, Inc., 2018)
    OBJECTIVES In 2011, approximately 1.7 million pediatric patients had a codeine-containing prescription filled at a US retail pharmacy. Numerous cases involving serious adverse effects or fatalities have been reported in children who have been prescribed codeine. In 2013, the US Food and Drug Administration added a boxed warning to avoid codeine in children after a tonsillectomy. The purpose of this study is to determine pharmacists' and pediatricians' knowledge of the boxed warning for codeine in children. METHODS Two separate surveys were administered to community pharmacists in Maryland, pediatricians, and pediatric residents at a single institution in Maryland. Both surveys consisted of questions regarding knowledge of the boxed warning for codeine in children. RESULTS There was no difference in the awareness of the boxed warning between pharmacists (48.9%, n = 43) and pediatricians (51.3%, n = 41, p = 0.88). More pharmacists knew that ultrarapid metabolizers have the risk for increased adverse events from codeine (39.5% pharmacists vs. 20% pediatricians, p = 0.01). In addition, 36% of pharmacists and 33% of pediatricians noted that it was never appropriate to use codeine in a child (p = 0.73). CONCLUSIONS Only half of pharmacists and pediatricians surveyed were aware of the boxed warning for codeine. One third of pharmacists and pediatricians in this study would never use codeine in a child. Therefore, more education is needed for pharmacists and pediatricians regarding the dangers of using codeine in children. Copyright Published by the Pediatric Pharmacy Advocacy Group. All rights reserved.
  • SUR1-TRPM4 and AQP4 form a heteromultimeric complex that amplifies ion/water osmotic coupling and drives astrocyte swelling

    Stokum, J.A.; Kwon, M.S.; Woo, S.K. (John Wiley and Sons Inc., 2018)
    Astrocyte swelling occurs after CNS injury and contributes to brain swelling, which can increase mortality. Mechanisms proffered to explain astrocyte swelling emphasize the importance of either aquaporin-4 (AQP4), an astrocyte water channel, or of Na+-permeable channels, which mediate cellular osmolyte influx. However, the spatio-temporal functional interactions between AQP4 and Na+-permeable channels that drive swelling are poorly understood. We hypothesized that astrocyte swelling after injury is linked to an interaction between AQP4 and Na+-permeable channels that are newly upregulated. Here, using co-immunoprecipitation and Förster resonance energy transfer, we report that AQP4 physically co-assembles with the sulfonylurea receptor 1 – transient receptor potential melastatin 4 (SUR1-TRPM4) monovalent cation channel to form a novel heteromultimeric water/ion channel complex. In vitro cell-swelling studies using calcein fluorescence imaging of COS-7 cells expressing various combinations of AQP4, SUR1 and TRPM4 showed that the full tripartite complex, comprised of SUR1-TRPM4-AQP4, was required for fast, high-capacity transmembrane water transport that drives cell swelling, with these findings corroborated in cultured primary astrocytes. In a murine model of brain edema involving cold-injury to the cerebellum, we found that astrocytes newly upregulate SUR1-TRPM4, that AQP4 co-associates with SUR1-TRPM4, and that genetic inactivation of the solute pore of the SUR1-TRPM4-AQP4 complex blocked in vivo astrocyte swelling measured by diolistic labeling, thereby corroborating our in vitro functional studies. Together, these findings demonstrate a novel molecular mechanism involving the SUR1-TRPM4-AQP4 complex to account for bulk water influx during astrocyte swelling. These findings have broad implications for the understanding and treatment of AQP4-mediated pathological conditions. Copyright 2017 Wiley Periodicals, Inc.
  • Nanoparticle-Based Fluoroionophore for Analysis of Potassium Ion Dynamics in 3D Tissue Models and In Vivo

    Zhdanov, A.V.; Borisov, S.M.; Mueller, B.J. (Wiley-VCH Verlag, 2018)
    The imaging of real-time fluxes of K+ ions in live cell with high dynamic range (5-150 mM) is of paramount importance for neuroscience and physiology of the gastrointestinal tract, kidney and other tissues. In particular, the research on high-performance deep-red fluorescent nanoparticle-based biosensors is highly anticipated. We found that BODIPY-based FI3 K+-sensitive fluoroionophore encapsulated in cationic polymer RL100 nanoparticles displays unusually strong efficiency in staining of broad spectrum of cell models, such as primary neurons and intestinal organoids. Using comparison of brightness, photostability and fluorescence lifetime imaging microscopy (FLIM) we confirmed that FI3 nanoparticles display distinctively superior intracellular staining compared to the free dye. We evaluated FI3 nanoparticles in real-time live cell imaging and found that it is highly useful for monitoring intra- and extracellular K+ dynamics in cultured neurons. Proof-of-concept in vivo brain imaging confirmed applicability of the biosensor for visualization of epileptic seizures. Collectively, this data makes fluoroionophore FI3 a versatile cross-platform fluorescent biosensor, broadly compatible with diverse experimental models and that crown ether-based polymer nanoparticles can provide a new venue for design of efficient fluorescent probes. Copyright 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
  • Imaging stem cell distribution, growth, migration, and differentiation in 3-D scaffolds for bone tissue engineering using mesoscopic fluorescence tomography

    Tang, Q.; Piard, C.; Lin, J. (John Wiley and Sons Inc., 2018)
    Regenerative medicine has emerged as an important discipline that aims to repair injury or replace damaged tissues or organs by introducing living cells or functioning tissues. Successful regenerative medicine strategies will likely depend upon a simultaneous optimization strategy for the design of biomaterials, cell-seeding methods, cell-biomaterial interactions and molecular signaling within the engineered tissues. It remains a challenge to image three-dimensional (3-D) structures and functions of the cell-seeded scaffold in mesoscopic scale (>2~3 mm). In this study, we utilized angled fluorescence laminar optical tomography (aFLOT), which allows depth-resolved molecular characterization of engineered tissues in 3-D to investigate cell viability, migration and bone mineralization within bone tissue engineering scaffolds in situ. Copyright 2017 Wiley Periodicals, Inc.
  • Stem cell therapy for hypoplastic left heart syndrome mechanism, clinical application, and future directions

    Bittle, G.J.; Morales, D.; Deatrick, K.B. (Lippincott Williams and Wilkins, 2018)
    Hypoplastic left heart syndrome is a type of congenital heart disease characterized by underdevelopment of the left ventricle, outflow tract, and aorta. The condition is fatal if aggressive palliative operations are not undertaken, but even after the complete 3-staged surgical palliation, there is significant morbidity because of progressive and ultimately intractable right ventricular failure. For this reason, there is interest in developing novel therapies for the management of right ventricular dysfunction in patients with hypoplastic left heart syndrome. Stem cell therapy may represent one such innovative approach. The field has identified numerous stem cell populations from different tissues (cardiac or bone marrow or umbilical cord blood), different age groups (adult versus neonate-derived), and different donors (autologous versus allogeneic), with preclinical and clinical experience demonstrating the potential utility of each cell type. Preclinical trials in small and large animal models have elucidated several mechanisms by which stem cells affect the injured myocardium. Our current understanding of stem cell activity is undergoing a shift from a paradigm based on cellular engraftment and differentiation to one recognizing a primarily paracrine effect. Recent studies have comprehensively evaluated the individual components of the stem cells' secretomes, shedding new light on the intracellular and extracellular pathways at the center of their therapeutic effects. This research has laid the groundwork for clinical application, and there are now several trials of stem cell therapies in pediatric populations that will provide important insights into the value of this therapeutic strategy in the management of hypoplastic left heart syndrome and other forms of congenital heart disease. This article reviews the many stem cell types applied to congenital heart disease, their preclinical investigation and the mechanisms by which they might affect right ventricular dysfunction in patients with hypoplastic left heart syndrome, and finally, the completed and ongoing clinical trials of stem cell therapy in patients with congenital heart disease. Copyright 2018 American Heart Association, Inc.
  • Clinical Reasoning: An unusual cause of adult cryptogenic ischemic stroke

    Leekoff, M.L.; Masur, J.E.; Burke, A.P. (Lippincott Williams and Wilkins, 2018)
  • Brain gray matter alterations in Chinese patients with chronic knee osteoarthritis pain based on voxel-based morphometry

    Liao, Xia; Mao, Cuiping; Seminowicz, David A. (Lippincott Williams and Wilkins, 2018-03-01)
    Altered cerebral gray matter volume (GMV) is commonly found in patients with chronic pain. Chronic pain is the prominent characteristic of knee osteoarthritis (KOA), yet little is known about its morphological changes in the brain. Here an MRI study was performed to examine the structural brain abnormalities in 30 KOA patients with knee pain and age-matched healthy subjects. We detected that the patients exhibited significant almost 2-fold age-related decreases of GMV compared to healthy controls. Moreover, KOA patients also had significant loss of regional GMV including in the bilateral orbital frontal cortex (OFC), the right lateral prefrontal cortex (lPFC), and precentral and postcentral cortices. In addition, a high proportion of KOA patients exerted abnormal scores of Hamilton Depression Rating Scale (HAMD), Hamilton Anxiety Scale (HAMA), Mini Mental State examination (MMSE), and Montreal Cognitive Assessment (MoCA) compare to controls. Our results imply that chronic pain conditions which preferentially involve PFC might consider as a "cognitive state." And emotion and cognitive function about chronic pain should be highly regarded. Copyright © 2018 the Author(s).
  • Evaluation of a booster dose of pentavalent rotavirus vaccine coadministered with measles, yellow fever, and meningitis a Vaccines in 9-Month-old malian infants

    Tapia, Milagritos D.; Sow, Samba O.; Fitzpatrick, Meagan; Neuzil, Kathleen M.; Kotloff, Karen L. (Oxford University Press, 2018-07-13)
    Background Rotavirus vaccines given to infants are safe and efficacious. A booster dose of rotavirus vaccine could extend protection into the second year of life in low-resource countries. Methods We conducted an open-label, individual-randomized trial in Bamako, Mali. We assigned 600 infants aged 9-11 months to receive measles vaccine (MV), yellow fever vaccine (YFV), and meningococcal A conjugate vaccine (MenAV) with or without pentavalent rotavirus vaccine (PRV). We assessed the noninferiority (defined as a difference of ≤10%) of seroconversion and seroresponse rates to MV, YFV, and MenAV. We compared the seroresponse to PRV. Results Seroconversion to MV occurred in 255 of 261 PRV recipients (97.7%) and 246 of 252 control infants (97.6%; difference, 0.1% [95% confidence interval {CI}, -4.0%-4.2%]). Seroresponse to YFV occurred in 48.1% of PRV recipients (141 of 293), compared with 52.2% of controls (153 of 293; difference, -4.1% [95% CI, -12.2%-4.0%]). A 4-fold rise in meningococcus A bactericidal titer was observed in 273 of 292 PRV recipients (93.5%) and 276 of 293 controls (94.2%; difference, -0.7% [95% CI, -5.2%-3.8%]). Rises in geometric mean concentrations of immunoglobulin A and immunoglobulin G antibodies to rotavirus were higher among PRV recipients (118 [95% CI, 91-154] and 364 [95% CI, 294-450], respectively), compared with controls (68 [95% CI, 50-92] and 153 [95% CI, 114-207], respectively). Conclusions PRV did not interfere with MV and MenAV; this study could not rule out interference with YFV. PRV increased serum rotavirus antibody levels. Clinical Trials Registration NCT02286895. © The Author(s) 2018.
  • Immunogenicity and Induction of Functional Antibodies in Rabbits Immunized with a Trivalent Typhoid-Invasive Nontyphoidal Salmonella Glycoconjugate Formulation

    Baliban, Scott M.; Allen, Jessica C.; Curtis, Brittany; Amin, Mohammed N.; Levine, Myron M.; Simon, Raphael (MDPI, 2018-07-17)
    Typhoid fever due to Salmonella Typhi and invasive nontyphoidal Salmonella (iNTS) infections caused by serovars Enteritidis (SE) and Typhimurium (STm) are major pediatric health problems in sub-Saharan Africa. Typhoid has high complication rates, and iNTS infections have high case fatality rates; moreover, emerging antimicrobial resistance is diminishing treatment options. Vi capsule-based typhoid conjugate vaccine (Typbar-TCV™), licensed in India and pre-qualified by the World Health Organization, elicits durable immunity when administered to infants, but no iNTS vaccines are licensed or imminent. We have developed monovalent SE and STm glycoconjugate vaccines based on coupling lipopolysaccharide-derived core-O polysaccharide (COPS) to phase 1 flagellin protein (FliC) from the homologous serovar. Herein, we report the immunogenicity of multivalent formulations of iNTS COPS:FliC conjugates with Typbar-TCV™. Rabbits immunized with the trivalent typhoid-iNTS glycoconjugate vaccine generated high titers of serum IgG antibody to all three polysaccharide antigens for which anti-COPS IgG antibodies were directed primarily against serogroup-specific OPS epitopes. Responses to SE and STm FliC were lower relative to anti-COPS titers. Post-vaccination rabbit sera mediated bactericidal activity in-vitro, and protected mice after passive transfer against challenge with virulent SE or STm Malian blood isolates. These results support accelerated progression to clinical trials.
  • The role of HIV infection in the etiology and epidemiology of diarrheal disease among children aged 0–59 months in Manhiça District, Rural Mozambique

    Farag, Tamer; Dilruba, Nasrin; Levine, Myron M.; Kotloff, Karen L. (Elsevier B.V., 2018-08-01)
    Background: Diarrhea is an important health problem among HIV-infected patients. This study evaluated the role of HIV in the epidemiology, etiology, and severity of diarrheal disease among children. Methods: The Global Enteric Multicenter Study enrolled children with moderate-to-severe diarrhea (MSD) and less-severe diarrhea (LSD) between December 2007 and November 2012. One to three controls for MSD cases and one per LSD case were enrolled and matched by age, sex, and neighborhood. All children were tested for HIV. Clinical data, anthropometric data, and stool samples were collected. Follow-up was performed at 60 days. Results: Two hundred and fourteen MSD cases and 418 controls, together with 349 LSD cases and 214 controls were tested. HIV prevalence was 25% among MSD cases (4% for matched controls) and 6% among LSD cases (6% among matched controls). HIV-infected children were more likely to have MSD (odds ratio 5.6, p < 0.0001). Mortality rates were higher among HIV-infected children than among the uninfected (34 vs. 5 per 1000 child-weeks at risk; p = 0.0039). Cryptosporidium, Giardia, and enteroaggregative Escherichia coli (aatA only) were more prevalent among HIV-infected MSD cases than among uninfected ones. Conclusion: HIV is an important risk factor for MSD. The high mortality rate implies that children with MSD should be screened for HIV and managed accordingly. © 2018 The Author(s)
  • Identification and characterization of human monoclonal antibodies for immunoprophylaxis against enterotoxigenic Escherichia coli infection

    Giuntini, Serena; Stoppato, Matteo; Barry, Eileen M. (American Society for Microbiology, 2018-08-01)
    Enterotoxigenic Escherichia coli (ETEC) causes diarrheal illness in infants in the developing world and travelers to countries where the disease is endemic, including military personnel. ETEC infection of the host involves colonization of the small intestinal epithelium and toxin secretion, leading to watery diarrhea. There is currently no vaccine licensed to prevent ETEC infection. CFA/I is one of the most common colonization factor antigens (CFAs). The CFA/I adhesin subunit, CfaE, is required for ETEC adhesion to host intestinal cells. Human antibodies against CfaE have the potential to block colonization of ETEC and serve as an immunoprophylactic against ETEC-related diarrhea. Mice transgenic for human immunoglobulin genes were immunized with CfaE to generate a panel of human monoclonal IgG1 antibodies (HuMAbs). The most potent IgG1 antibodies identified in the in vitro functional assays were selected and isotype switched to secretory IgA (sIgA) and tested in animal colonization assays via oral administration. Over 300 unique anti-CfaE IgG1 HuMAbs were identified. The lead IgG1 anti-CfaE HuMAbs completely inhibited hemagglutination and blocked adhesion of ETEC to Caco-2 cells. Epitope mapping studies revealed that HuMAbs recognized epitopes in the N-terminal domain of CfaE near the putative receptor binding site. Oral administration of anti-CfaE antibodies in either IgG or sIgA isotypes inhibited intestinal colonization in mice challenged with ETEC. A 2- to 4-log decrease in CFU was observed in comparison to mice challenged with irrelevant isotype controls. We identified fully human monoclonal antibodies against the CfaE adhesion domain that can be potentially employed as an immunoprophylactic to prevent ETEC-related diarrhea.
  • A Novel Shigella Proteome Microarray Discriminates Targets of Human Antibody Reactivity following Oral Vaccination and Experimental Challenge

    Ndungo, Esther; Hazen, Tracy H.; Kania, Dane A.; Barry, Eileen M.; Kotloff, Karen L.; Rasko, David A.; Pasetti, Marcela F. (2018-08-01)
    Shigella spp. are a major cause of diarrhea and dysentery in children under 5 years old in the developing world. The development of an effective vaccine remains a public health priority, necessitating improved understanding of immune responses to Shigella and identification of protective antigens. We report the development of a core Shigella proteome microarray consisting of 2,133 antigen targets common to all Shigella species. We evaluated the microarray with serum samples from volunteers immunized with either an inactivated whole-cell S. flexneri serotype 2a (Sf2aWC) vaccine or a live attenuated S. flexneri 2a vaccine strain (CVD 1204) or challenged with wild-type S. flexneri 2a (Sf2a challenge). Baseline reactivities to most antigens were detected postintervention in all three groups. Similar immune profiles were observed after CVD 1204 vaccination and Sf2a challenge. Antigens with the largest increases in mean reactivity postintervention were members of the type three secretion system (T3SS), some of which are regarded as promising vaccine targets: these are the invasion plasmid antigens (Ipas) IpaB, IpaC, and IpaD. In addition, new immunogenic targets (IpaA, IpaH, and SepA) were identified. Importantly, immunoreactivities to antigens in the microarray correlated well with antibody titers determined by enzyme-linked immunosorbent assay (ELISA), validating the use of the microarray platform. Finally, our analysis uncovered an immune signature consisting of three conserved proteins (IpaA, IpaB, and IpaC) that was predictive of protection against shigellosis. In conclusion, the Shigella proteome microarray is a robust platform for interrogating serological reactivity to multiple antigens at once and identifying novel targets for the development of broadly protective vaccines.IMPORTANCE Each year, more than 180 million cases of severe diarrhea caused by Shigella occur globally. Those affected (mostly children in poor regions) experience long-term sequelae that severely impair quality of life. Without a licensed vaccine, the burden of disease represents a daunting challenge. An improved understanding of immune responses to Shigella is necessary to support ongoing efforts to identify a safe and effective vaccine. We developed a microarray containing >2,000 proteins common to all Shigella species. Using sera from human adults who received a killed whole-cell or live attenuated vaccine or were experimentally challenged with virulent organisms, we identified new immune-reactive antigens and defined a T3SS protein signature associated with clinical protection. Copyright © 2018 Ndungo et al.
  • Dynamics of antimicrobial resistance in intestinal Escherichia coli from children in community settings in South Asia and sub-Saharan Africa

    Ingle, Danielle J.; Levine, Myron M.; Kotloff, Karen L. (Nature Publishing Group, 2018-09-01)
    The dynamics of antimicrobial resistance (AMR) in developing countries are poorly understood, especially in community settings, due to a sparsity of data on AMR prevalence and genetics. We used a combination of phenotyping, genomics and antimicrobial usage data to investigate patterns of AMR amongst atypical enteropathogenic Escherichia coli (aEPEC) strains isolated from children younger than five years old in seven developing countries (four in sub-Saharan Africa and three in South Asia) over a three-year period. We detected high rates of AMR, with 65% of isolates displaying resistance to three or more drug classes. Whole-genome sequencing revealed a diversity of known genetic mechanisms for AMR that accounted for >95% of phenotypic resistance, with comparable rates amongst aEPEC strains associated with diarrhoea or asymptomatic carriage. Genetic determinants of AMR were associated with the geographic location of isolates, not E. coli lineage, and AMR genes were frequently co-located, potentially enabling the acquisition of multi-drug resistance in a single step. Comparison of AMR with antimicrobial usage data showed that the prevalence of resistance to fluoroquinolones and third-generation cephalosporins was correlated with usage, which was higher in South Asia than in Africa. This study provides much-needed insights into the frequency and mechanisms of AMR in intestinal E. coli in children living in community settings in developing countries. © 2018, The Author(s).
  • Dengue illness index-A tool to characterize the subjective dengue illness experience

    Thomas, Stephen J.; Agulto, Liane; Edelman, Robert (PLOS One, 2018-10-01)
    Dengue virus infections are a major cause of febrile illness that significantly affects individual and societal productivity and drives up health care costs principally in the developing world. Two dengue vaccine candidates are in advanced clinical efficacy trials in Latin America and Asia, and another has been licensed in more than fifteen countries but its uptake has been limited. Despite these advances, standardized metrics for comparability of protective efficacy between dengue vaccines remain poorly defined. The Dengue Illness Index (DII) is a tool that we developed thru refinement of previous similar iterations in an attempt to improve and standardize the measurement of vaccine and drug efficacy in reducing moderate dengue illness. The tool is designed to capture an individual's overall disease experience based on how the totality of their symptoms impacts their general wellness and daily functionality. We applied the DII to a diary card, the Dengue Illness Card (DIC), which was examined and further developed by a working group. The card was then refined with feedback garnered from a Delphi methodology-based query that addressed the adequacy and applicability of the tool in clinical dengue research. There was overall agreement that the tool would generate useful data and provide an alternative perspective to the assessment of drug or vaccine candidates, which in the case of vaccines, are assessed by their reduction in any virologically confirmed dengue of any severity with a focus on the more severe. The DIC needs to be evaluated in the field in the context of vaccine or drug trials, prospective cohort studies, or during experimental human infection studies. Here, we present the final DIC resulting from the Delphi process and offer its further development or use to the dengue research community.
  • Coli surface antigen 26 acts as an adherence determinant of enterotoxigenic Escherichia coli and is cross-recognized by anti-CS20 antibodies

    Cádiz, Leandro; Levine, Myron M.; Rasko, David A. (Frontiers Media S.A., 2018-10-16)
    The coli surface antigen 26 (CS26) of enterotoxigenic Escherichia coli (ETEC) had been described as a putative adhesive pilus based on the partial sequence of the crsH gene, detected in isolates from children with diarrhea in Egypt. However, its production and activity as adherence determinant has not been experimentally addressed. The crsH was identified as a homolog of genes encoding structural subunits of ETEC colonization factors (CFs) CS12, CS18, and CS20. These CFs, along with the recently discovered CS30, belong to the γ2 family of pili assembled by the chaperone-usher pathway (CU pili). Further, the complete CS26 locus, crsHBCDEFG, was described in an O141 ETEC strain (ETEC 100664) obtained from a diarrhea case in The Gambia, during the Global Enterics Multicenter Study. Here, we report that CS26 is a pilus of ~10 nm in diameter, with the capacity to increase the cell adherence of the non-pathogenic strain E. coli DH10B. As for other related pili, production of CS26 seems to be regulated by phase variation. Deletion of crsHBCDEFG in ETEC 100664 significantly decreased its adherence capacity, which was recovered by in trans complementation. Furthermore, CrsH was cross-recognized by polyclonal antibodies directed against the major structural subunit of CS20, CsnA, as determined by Western blotting and immunogold labeling. ETEC CS26+ strains were found to harbor the heat-labile enterotoxin only, within three different sequence types of phylogroups A and B1, the latter suggesting acquisition through independent events of horizontal transfer. Overall, our results demonstrate that CS26 is an adhesive pilus of human ETEC. In addition, cross-reactivity with anti-CsnA antibodies indicate presence of common epitopes in γ2-CFs. Copyright © 2018 Cádiz, Torres, Valdés, Vera, Gutiérrez, Levine, Montero, O'Ryan, Rasko, Stine, Vidal and Del Canto.
  • Measuring progress from 1990 to 2017 and projecting attainment to 2030 of the health-related Sustainable Development Goals for 195 countries and territories: a systematic analysis for the Global Burden of Disease Study 2017

    Ortiz, Justin R.; Lozano, R; GBD 2017 SDG Collaborators (Lancet Publishing Group, 2018-11-10)
    Background: Efforts to establish the 2015 baseline and monitor early implementation of the UN Sustainable Development Goals (SDGs) highlight both great potential for and threats to improving health by 2030. To fully deliver on the SDG aim of “leaving no one behind”, it is increasingly important to examine the health-related SDGs beyond national-level estimates. As part of the Global Burden of Diseases, Injuries, and Risk Factors Study 2017 (GBD 2017), we measured progress on 41 of 52 health-related SDG indicators and estimated the health-related SDG index for 195 countries and territories for the period 1990–2017, projected indicators to 2030, and analysed global attainment. Methods: We measured progress on 41 health-related SDG indicators from 1990 to 2017, an increase of four indicators since GBD 2016 (new indicators were health worker density, sexual violence by non-intimate partners, population census status, and prevalence of physical and sexual violence [reported separately]). We also improved the measurement of several previously reported indicators. We constructed national-level estimates and, for a subset of health-related SDGs, examined indicator-level differences by sex and Socio-demographic Index (SDI) quintile. We also did subnational assessments of performance for selected countries. To construct the health-related SDG index, we transformed the value for each indicator on a scale of 0–100, with 0 as the 2·5th percentile and 100 as the 97·5th percentile of 1000 draws calculated from 1990 to 2030, and took the geometric mean of the scaled indicators by target. To generate projections through 2030, we used a forecasting framework that drew estimates from the broader GBD study and used weighted averages of indicator-specific and country-specific annualised rates of change from 1990 to 2017 to inform future estimates. We assessed attainment of indicators with defined targets in two ways: first, using mean values projected for 2030, and then using the probability of attainment in 2030 calculated from 1000 draws. We also did a global attainment analysis of the feasibility of attaining SDG targets on the basis of past trends. Using 2015 global averages of indicators with defined SDG targets, we calculated the global annualised rates of change required from 2015 to 2030 to meet these targets, and then identified in what percentiles the required global annualised rates of change fell in the distribution of country-level rates of change from 1990 to 2015. We took the mean of these global percentile values across indicators and applied the past rate of change at this mean global percentile to all health-related SDG indicators, irrespective of target definition, to estimate the equivalent 2030 global average value and percentage change from 2015 to 2030 for each indicator. Findings: The global median health-related SDG index in 2017 was 59·4 (IQR 35·4–67·3), ranging from a low of 11·6 (95% uncertainty interval 9·6–14·0) to a high of 84·9 (83·1–86·7). SDG index values in countries assessed at the subnational level varied substantially, particularly in China and India, although scores in Japan and the UK were more homogeneous. Indicators also varied by SDI quintile and sex, with males having worse outcomes than females for non-communicable disease (NCD) mortality, alcohol use, and smoking, among others. Most countries were projected to have a higher health-related SDG index in 2030 than in 2017, while country-level probabilities of attainment by 2030 varied widely by indicator. Under-5 mortality, neonatal mortality, maternal mortality ratio, and malaria indicators had the most countries with at least 95% probability of target attainment. Other indicators, including NCD mortality and suicide mortality, had no countries projected to meet corresponding SDG targets on the basis of projected mean values for 2030 but showed some probability of attainment by 2030. For some indicators, including child malnutrition, several infectious diseases, and most violence measures, the annualised rates of change required to meet SDG targets far exceeded the pace of progress achieved by any country in the recent past. We found that applying the mean global annualised rate of change to indicators without defined targets would equate to about 19% and 22% reductions in global smoking and alcohol consumption, respectively; a 47% decline in adolescent birth rates; and a more than 85% increase in health worker density per 1000 population by 2030. Interpretation: The GBD study offers a unique, robust platform for monitoring the health-related SDGs across demographic and geographic dimensions. Our findings underscore the importance of increased collection and analysis of disaggregated data and highlight where more deliberate design or targeting of interventions could accelerate progress in attaining the SDGs. Current projections show that many health-related SDG indicators, NCDs, NCD-related risks, and violence-related indicators will require a concerted shift away from what might have driven past gains—curative interventions in the case of NCDs—towards multisectoral, prevention-oriented policy action and investments to achieve SDG aims. Notably, several targets, if they are to be met by 2030, demand a pace of progress that no country has achieved in the recent past. The future is fundamentally uncertain, and no model can fully predict what breakthroughs or events might alter the course of the SDGs. What is clear is that our actions—or inaction—today will ultimately dictate how close the world, collectively, can get to leaving no one behind by 2030. Funding: Bill & Melinda Gates Foundation. © 2018 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license
  • Emerging Southeast Asian PfCRT mutations confer Plasmodium falciparum resistance to the first-line antimalarial piperaquine

    Ross, Leila S.; Dhingra, Satish K.; Takala-Harrison, Shannon (Nature Publishing Group, 2018-12-01)
    The widely used antimalarial combination therapy dihydroartemisinin + piperaquine (DHA + PPQ) has failed in Cambodia. Here, we perform a genomic analysis that reveals a rapid increase in the prevalence of novel mutations in the Plasmodium falciparum chloroquine resistance transporter PfCRT following DHA + PPQ implementation. These mutations occur in parasites harboring the K13 C580Y artemisinin resistance marker. By introducing PfCRT mutations into sensitive Dd2 parasites or removing them from resistant Cambodian isolates, we show that the H97Y, F145I, M343L, or G353V mutations each confer resistance to PPQ, albeit with fitness costs for all but M343L. These mutations sensitize Dd2 parasites to chloroquine, amodiaquine, and quinine. In Dd2 parasites, multicopy plasmepsin 2, a candidate molecular marker, is not necessary for PPQ resistance. Distended digestive vacuoles were observed in pfcrt-edited Dd2 parasites but not in Cambodian isolates. Our findings provide compelling evidence that emerging mutations in PfCRT can serve as a molecular marker and mediator of PPQ resistance. © 2018, The Author(s).
  • Immunogenicity and Induction of Functional Antibodies in Rabbits Immunized with a Trivalent Typhoid-Invasive Nontyphoidal Salmonella Glycoconjugate Formulation

    Baliban, Scott M.; Allen, Jessica C.; Curtis, Brittany; Amin, Mohammed N.; Levine, Myron M.; Simon, Raphael (Molecular Diversity Preservation International, 2018-07-17)
    Typhoid fever due to Salmonella Typhi and invasive nontyphoidal Salmonella (iNTS) infections caused by serovars Enteritidis (SE) and Typhimurium (STm) are major pediatric health problems in sub-Saharan Africa. Typhoid has high complication rates, and iNTS infections have high case fatality rates; moreover, emerging antimicrobial resistance is diminishing treatment options. Vi capsule-based typhoid conjugate vaccine (Typbar-TCV™), licensed in India and pre-qualified by the World Health Organization, elicits durable immunity when administered to infants, but no iNTS vaccines are licensed or imminent. We have developed monovalent SE and STm glycoconjugate vaccines based on coupling lipopolysaccharide-derived core-O polysaccharide (COPS) to phase 1 flagellin protein (FliC) from the homologous serovar. Herein, we report the immunogenicity of multivalent formulations of iNTS COPS:FliC conjugates with Typbar-TCV™. Rabbits immunized with the trivalent typhoid-iNTS glycoconjugate vaccine generated high titers of serum IgG antibody to all three polysaccharide antigens for which anti-COPS IgG antibodies were directed primarily against serogroup-specific OPS epitopes. Responses to SE and STm FliC were lower relative to anti-COPS titers. Post-vaccination rabbit sera mediated bactericidal activity in-vitro, and protected mice after passive transfer against challenge with virulent SE or STm Malian blood isolates. These results support accelerated progression to clinical trials.

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