Glycosylation is the most abundant post-translational polypeptide chain modification in nature. Although carbohydrate modification of protein antigens from many microbial pathogens constitutes important components of B cell epitopes, the role in T cell immunity is not completely understood. Here, using ELISPOT and polychromatic flow cytometry, we show that O-mannosylation of the adhesin, Apa, of Mycobacterium tuberculosis (Mtb) is crucial for its T cell antigenicity in humans and mice after infection. However, subunit vaccination with both mannosylated and non-mannosylated Apa induced a comparable magnitude and quality of T cell response and imparted similar levels of protection against Mtb challenge in mice. Both forms equally improved waning BCG vaccine-induced protection in elderly mice after subunit boosting. Thus, O-mannosylation of Apa is required for antigenicity but appears to be dispensable for its immunogenicity and protective efficacy in mice. These results have implications for the development of subunit vaccines using post-translationally modified proteins such as glycoproteins against infectious diseases like tuberculosis.
Mycobacterium tuberculosis (Mtb) is the most devastating bacterial pathogen of all time that kills approximately 1.4 million people each year. Mtb modifies several of its proteins with sugar residues that influence many biological events. However, the significance of such sugar decorations and resulting carbohydrate and glycopeptide epitopes in shaping the T cell response during infection or after vaccination is insufficiently understood. Here, we show that the carbohydrate modifications of the Mtb Apa protein strikingly influence the magnitude of specific T cell responses in humans and mice after infection, but have only minor effect on the polyfunctionality and quality of T cell responses. The glycosylation of Apa was, however, expendable for T cell immunogenicity and protective efficacy when used either as a subunit vaccine or as a BCG-booster vaccine in dimethyl-dioctadecyl ammonium bromide (DDA)-monophosphoryl lipid A (MPL) adjuvant against virulent Mtb infection in mice. Our results suggest that the carbohydrate modification of microbial protein antigens may not always be critical for protection as our unmodified recombinant protein was sufficient for subunit vaccination. Together, our data underline the need to understand the role of heightened Apa glycoprotein-specific T cell responses in infection processes.
The mechanisms that maintain sterility in the urinary tract are incompletely understood; however, recent studies stress the importance of antimicrobial peptides in protecting the urinary tract from infection. Ribonuclease 7 (RNase 7), a potent antimicrobial peptide contributing to urinary tract sterility, is expressed by intercalated cells in the renal collecting tubules and is present in the urine at levels sufficient to kill bacteria at baseline. Here, we characterize the expression and function of RNase 7 in the human urinary tract during infection. Both quantitative real-time PCR and ELISA assays demonstrated increases in RNASE7 expression in the kidney along with kidney and urinary RNase 7 peptide concentrations with infection. While immunostaining localized RNase 7 production to the intercalated cells of the collecting tubule during sterility, its expression during pyelonephritis was found to increase throughout the nephron but not in glomeruli or the interstitium. Recombinant RNase 7 exhibited antimicrobial activity against uropathogens at low micromolar concentrations by disrupting the microbial membrane as determined by atomic force microscopy. Thus, RNase 7 expression is increased in the urinary tract with infection, and has antibacterial activity against uropathogens at micromolar concentrations.
Ribonuclease 7; Antimicrobial Peptide; Pyelonephritis; Urinary Tract Infection; Intercalated Cells; Innate Immunity; Immunology
What motivates children to radically transform themselves during early development? We addressed this question in the domain of infant visual exploration. Over the first year, infants' exploration shifts from familiarity to novelty seeking. This shift is delayed in preterm relative to term infants and is stable within individuals over the course of the first year. Laboratory tasks have shed light on the nature of this familiarity-to-novelty shift, but it is not clear what motivates the infant to change her exploratory style. We probed this by letting a Dynamic Neural Field (DNF) model of visual exploration develop itself via accumulating experience in a virtual world. We then situated it in a canonical laboratory task. Much like infants, the model exhibited a familiarity-to-novelty shift. When we manipulated the initial conditions of the model, the model's performance was developmentally delayed much like preterm infants. This delay was overcome by enhancing the model's experience during development. We also found that the model's performance was stable at the level of the individual. Our simulations indicate that novelty seeking emerges with no explicit motivational source via the accumulation of visual experience within a complex, dynamical exploratory system.
visual exploration; dynamic systems; dynamic neural fields; intrinsic motivation
A 75-year-old woman presented with a presumed urothelial carcinoma of the right renal pelvis. A radical nephroureterectomy was carried out and histological analysis of the specimen revealed lymphoepithelioma-like carcinoma. This is the seventh reported case of this normally nasopharyngeal tumour found in the renal pelvis. These tumours have a distinct histological appearance comprising sheets of undifferentiated syncytial cells on a background of lymphoid stroma. We review the pathological features of lymphoepithelioma-like carcinoma and make arguments for managing these tumours in a similar way to urothelial carcinoma.
The relationship between health services and population outcomes is an important area of public health research that requires bringing together data on outcomes and the relevant service environment. Linking independent, existing datasets geographically is potentially an efficient approach; however, it raises a number of methodological issues which have not been extensively explored. This sensitivity analysis explores the potential misclassification error introduced when a sample rather than a census of health facilities is used and when household survey clusters are geographically displaced for confidentiality.
Using the 2007 Rwanda Service Provision Assessment (RSPA) of all public health facilities and the 2007–2008 Rwanda Interim Demographic and Health Survey (RIDHS), five health facility samples and five household cluster displacements were created to simulate typical SPA samples and household cluster datasets. Facility datasets were matched with cluster datasets to create 36 paired datasets. Four geographic techniques were employed to link clusters with facilities in each paired dataset. The links between clusters and facilities were operationalized by creating health service variables from the RSPA and attaching them to linked RIDHS clusters. Comparisons between the original facility census and undisplaced clusters dataset with the multiple samples and displaced clusters datasets enabled measurement of error due to sampling and displacement.
Facility sampling produced larger misclassification errors than cluster displacement, underestimating access to services. Distance to the nearest facility was misclassified for over 50% of the clusters when directly linked, while linking to all facilities within an administrative boundary produced the lowest misclassification error. Measuring relative service environment produced equally poor results with over half of the clusters assigned to the incorrect quintile when linked with a sample of facilities and more than one-third misclassified due to displacement.
At low levels of geographic disaggregation, linking independent facility samples and household clusters is not recommended. Linking facility census data with population data at the cluster level is possible, but misclassification errors associated with geographic displacement of clusters will bias estimates of relationships between service environment and health outcomes. The potential need to link facility and population-based data requires consideration when designing a facility survey.
Spatial linkage; DHS; SPA; Misclassification error
Ribonuclease 7 (RNase 7) is a 14.5-kDa peptide that possesses potent antimicrobial properties against Gram-negative and Gram-positive bacteria and is expressed in a variety of epithelial tissues. Little is known about its mechanisms of action and the determinants of its antimicrobial properties. The objective of this study was to identify the intrinsic functional domains of RNase 7 that influence its activity against uropathogenic bacteria. A series of RNase 7 fragments were generated that contained different components of its secondary motifs starting from both the N terminus and the C terminus of RNase 7. We determined the antimicrobial properties of each fragment against both Gram-positive Staphylococcus saprophyticus and Gram-negative Escherichia coli and Proteus mirabilis. RNase 7 fragments displayed significant differences in their antimicrobial activity profiles. Compared to N-terminal fragments, C-terminal fragments showed uniformly decreased activity against Gram-negative E. coli and P. mirabilis and Gram-positive S. saprophyticus. Fragments that lack β-sheets 1, 3, and 4 also demonstrated significantly decreased activities. We have also identified one fragment with at least 4-fold increased potency against both E. coli and Staphylococcus compared to full-length peptide. We identified distinct regions of the peptide that are independently responsible for Gram-negative and Gram-positive activity. Our results suggest that distinct mechanisms are responsible for RNase 7's antimicrobial activity against various uropathogens.
The cell-mediated immunity (CMI)-based in vitro gamma interferon release assay (IGRA) of Mycobacterium leprae-specific antigens has potential as a promising diagnostic means to detect those individuals in the early stages of M. leprae infection. Diagnosis of leprosy is a major obstacle toward ultimate disease control and has been compromised in the past by the lack of specific markers. Comparative bioinformatic analysis among mycobacterial genomes identified potential M. leprae-specific proteins called “hypothetical unknowns.” Due to massive gene decay and the prevalence of pseudogenes, it is unclear whether any of these proteins are expressed or are immunologically relevant. In this study, we performed cDNA-based quantitative real-time PCR to investigate the expression status of 131 putative open reading frames (ORFs) encoding hypothetical unknowns. Twenty-six of the M. leprae-specific antigen candidates showed significant levels of gene expression compared to that of ESAT-6 (ML0049), which is an important T cell antigen of low abundance in M. leprae. Fifteen of 26 selected antigen candidates were expressed and purified in Escherichia coli. The seroreactivity to these proteins of pooled sera from lepromatous leprosy patients and cavitary tuberculosis patients revealed that 9 of 15 recombinant hypothetical unknowns elicited M. leprae-specific immune responses. These nine proteins may be good diagnostic reagents to improve both the sensitivity and specificity of detection of individuals with asymptomatic leprosy.
Leprosy reversal reactions type 1 (T1R) are acute immune episodes that affect a subset of leprosy patients and remain a major cause of nerve damage. Little is known about the relative importance of innate versus environmental factors in the pathogenesis of T1R. In a retrospective design, we evaluated innate differences in response to Mycobacterium leprae between healthy individuals and former leprosy patients affected or free of T1R by analyzing the transcriptome response of whole blood to M. leprae sonicate. Validation of results was conducted in a subsequent prospective study. We observed the differential expression of 581 genes upon exposure of whole blood to M. leprae sonicate in the retrospective study. We defined a 44 T1R gene set signature of differentially regulated genes. The majority of the T1R set genes were represented by three functional groups: i) pro-inflammatory regulators; ii) arachidonic acid metabolism mediators; and iii) regulators of anti-inflammation. The validity of the T1R gene set signature was replicated in the prospective arm of the study. The T1R genetic signature encompasses genes encoding pro- and anti-inflammatory mediators of innate immunity. This suggests an innate defect in the regulation of the inflammatory response to M. leprae antigens. The identified T1R gene set represents a critical first step towards a genetic profile of leprosy patients who are at increased risk of T1R and concomitant nerve damage.
Leprosy type 1 reversal reactions (T1R) are an important cause of nerve damage in leprosy patients and accurate prediction of patients at increased risk of T1R is a major challenge of current leprosy control. The incidence of T1R differs widely from 6% to 67% of leprosy patients in different leprosy endemic settings. Whether or not this reflects the impact of unknown environmental triggers or differences in the genetic background across ethnicities is not known. We performed a comparative transcriptome analysis between leprosy patients affected and free of T1R in response to M. leprae antigens. As the discovery sample we enrolled cured leprosy patients who had been diagnosed with T1R at the time of leprosy diagnosis and leprosy patients who had never undergone T1R (retrospective arm). Whole genome transcriptome analysis after stimulation of blood with M. leprae antigen resulted in the definition of a T1R signature gene set. We validated the T1R gene set in RNA samples obtained from T1R-free patients at the time of leprosy diagnosis and followed for 3 years for development of T1R (prospective arm). These results confirm the role of innate factors in T1R and are a first step towards a predictive genetic T1R signature.
Visual working memory (VWM) capacity has been studied extensively in adults, and methodological advances have enabled researchers to probe capacity limits in infancy using a preferential looking paradigm. Evidence suggests that capacity increases rapidly between 6 and 10 months of age. To understand how the VWM system develops, we must understand the relationship between the looking behavior used to study VWM and underlying cognitive processes. We present a dynamic neural field model that captures both real-time and developmental processes underlying performance. Three simulation experiments show how looking is linked to VWM processes during infancy and how developmental changes in performance could arise through increasing neural connectivity. These results provide insight into the sources of capacity limits and VWM development more generally.
Leprosy is not eradicable with currently available diagnostics or interventions as evidenced by its stable incidence. Early diagnosis of Mycobacterium leprae infection should therefore be emphasized in leprosy-research. It remains challenging to develop tests based on immunological biomarkers that distinguish individuals controlling bacterial replication from those developing disease.
To identify biomarkers for field-applicable diagnostics, we determined cytokines/chemokines induced by M. leprae proteins in blood of leprosy patients and controls (EC) from high leprosy-prevalence areas (Bangladesh, Brazil, Ethiopia) and from South Korea where leprosy is not endemic anymore.
M. leprae- sonicate induced IFN-γ was similar for all groups, excluding M. leprae/IFN-γ as a diagnostic read-out. By contrast, ML2478 and ML0840 induced high IFN-γ concentrations in Bangladeshi EC, which were completely absent for South Korean controls. Importantly, ML2478/IFN-γ could indicate distinct degrees of M. leprae exposure, and thereby the risk of infection and transmission, in different parts of Brazilian and Ethiopian cities.
Notwithstanding these discriminatory responses, M. leprae proteins did not distinguish patients from EC in one leprosy endemic area based on IFN-γ. Analyses of additional cytokines/chemokines showed that M. leprae and ML2478 induced significantly higher concentrations of MCP-1, MIP-1β and IL-1β in patients compared to EC, whereas IP-10, like IFN-γ, differed between EC from areas with dissimilar leprosy prevalence.
This study identifies M. leprae-unique antigens, particularly ML2478, as biomarker tools to measure M. leprae exposure using IFN-γ or IP-10, and also shows that MCP-1, MIP-1β and IL-1β can potentially distinguish pathogenic immune responses from those induced during asymptomatic exposure to M. leprae.
Mycobacterium leprae (M. leprae); biomarkers; leprosy; multiplex analysis
The p53 cancer mutant Y220C is an excellent paradigm for rescuing the function of conformationally unstable p53 mutants because it has a unique surface crevice that can be targeted by small-molecule stabilizers. Here, we have identified a compound, PK7088, which is active in vitro: PK7088 bound to the mutant with a dissociation constant of 140 μM and raised its melting temperature, and we have determined the binding mode of a close structural analogue by X-ray crystallography. We showed that PK7088 is biologically active in cancer cells carrying the Y220C mutant by a battery of tests. PK7088 increased the amount of folded mutant protein with wild-type conformation, as monitored by immunofluorescence, and restored its transcriptional functions. It induced p53-Y220C-dependent growth inhibition, cell-cycle arrest and apoptosis. Most notably, PK7088 increased the expression levels of p21 and the proapoptotic NOXA protein. PK7088 worked synergistically with Nutlin-3 on up-regulating p21 expression, whereas Nutlin-3 on its own had no effect, consistent with its mechanism of action. PK7088 also restored non-transcriptional apoptotic functions of p53 by triggering nuclear export of BAX to the mitochondria. We suggest a set of criteria for assigning activation of p53.
The Dimensional Change Card Sort (DCCS) task requires children to switch from sorting cards based on shape or color to sorting based on the other dimension. Typically, 3-year-olds perseverate, while 4-year-olds flexibly sort by different dimensions. Zelazo et al. (1996) asked children questions about the post-switch rules and found an apparent dissociation between rule-knowledge and rule-use: 3-year-olds demonstrate accurate knowledge of the post-switch rules despite sorting cards incorrectly. Here, we show that children’s success with these questions is grounded in their use of available visual cues: children who fail sorting use the target cards to correctly answer questions; when the cards are unavailable, they guess. This suggests that there may not be a dissociation between children’s rule-knowledge and rule-use in the DCCS.
There is evidence that graduates of different medical schools vary in their preparedness for their first post. In 2003 Goldacre et al. reported that over 40% of UK medical graduates did not feel prepared and found large differences between graduates of different schools. A follow-up survey showed that levels of preparedness had increased yet there was still wide variation. This study aimed to examine whether medical graduates from three diverse UK medical schools were prepared for practice.
This was a qualitative study using a constructivist grounded theory approach. Prospective and cross-sectional data were collected from the three medical schools.
A sample of 60 medical graduates (20 from each school) was targeted. They were interviewed three times: at the end of medical school (n = 65) and after four (n = 55) and 12 months (n = 46) as a Year 1 Foundation Programme doctor. Triangulated data were collected from clinicians via interviews across the three sites (n = 92). In addition three focus groups were conducted with senior clinicians who assess learning portfolios. The focus was on identifying areas of preparedness for practice and any areas of lack of preparedness.
Although selected for being diverse, we did not find substantial differences between the schools. The same themes were identified at each site. Junior doctors felt prepared in terms of communication skills, clinical and practical skills and team working. They felt less prepared for areas of practice that are based on experiential learning in clinical practice: ward work, being on call, management of acute clinical situations, prescribing, clinical prioritisation and time management and dealing with paperwork.
Our data highlighted the importance of students learning on the job, having a role in the team in supervised practice to enable them to learn about the duties and responsibilities of a new doctor in advance of starting work.
Leprosy is a persistent infectious disease caused by Mycobacterium leprae that still affects over 200,000 new patients annually. The host genetic background is an important risk factor for leprosy susceptibility and the PARK2 gene is a replicated leprosy susceptibility candidate gene. The protein product of PARK2, Parkin, is an E3 ubiquitin ligase that is involved in the development of various forms of Parkinsonism. The human macrophage is both a natural host cell of M. leprae as well as a primary mediator of natural immune defenses, in part by secreting important pro-inflammatory cytokines and chemokines. Here, we report that down-regulation of Parkin in THP-1 macrophages, human monocyte-derived macrophages and human Schwann cells resulted in a consistent and specific decrease in interleukin-6 (IL-6) and monocyte chemoattractant protein 1 (MCP-1/CCL2) production in response to mycobacteria or LPS. Interestingly, production of IL-6 at 6 hours by THP-1 cells stimulated with live M. leprae and M. bovis BCG was dependent on pretreatment with 1,25-dihydroxyvitamin D3 (VD). Parkin knockdown in VD-treated cells blocked IL-6 induction by mycobacteria. However, IκB-α phosphorylation and levels of IκB-ξ, a nuclear protein required for IL-6 expression, were not affected by Parkin silencing. Phosphorylation of MAPK ERK1/2 and p38 was unaffected by Parkin silencing while JNK activation was promoted but did not explain the altered cytokine production. In a final set of experiments we found that genetic risk factors of leprosy located in the PARK2 promoter region were significantly correlated with M. leprae sonicate triggered CCL2 and IL6 transcript levels in whole blood assays. These results associated genetically controlled changes in the production of MCP-1/CCL2 and IL-6 with known leprosy susceptibility factors.
Leprosy is an infectious disease with a strong host genetic component. The identification of host genetic lesions predisposing to disease is a powerful approach for mapping key junctions in the host pathogen interplay. Genetic variants located in the promoter region of the PARK2 gene are replicated leprosy susceptibility factors. To better understand a possible contribution of PARK2 to host effector mechanisms in leprosy patients, we developed a cellular model to test the contribution of the PARK2 encoded parkin protein to host responses to mycobacterial antigens. We observed that parkin was a mediator of IL-6 production in response to mycobacterial antigen in both THP-1 macrophages and human Schwann cells while human monocyte-derived macrophages needed to be pre-activated with VitD to show the same impact. Parkin also impacted on the constitutive production of MCP-1. The regulatory activity of parkin on cytokine production was found to be independent of the canonical TLR-NFκB signalling pathway. We also tested association of IL6 and CCL2 gene expression levels in whole blood assays with PARK2 polymorphisms. For both cytokines, we found significant associations with those PARK2 variants that were established leprosy susceptibility factors. Hence, our results show that genetic PARK2 variants that are correlated with leprosy susceptibility are also correlated with production of these cytokines following stimulation with M. leprae sonicate.
This article reviews the major contributions of dynamic systems theory in advancing thinking about development, the empirical insights the theory has generated, and the key challenges for the theory on the horizon. The first section discusses the emergence of dynamic systems theory in developmental science, the core concepts of the theory, and the resonance it has with other approaches that adopt a systems metatheory. The second section reviews the work of Esther Thelen and colleagues, who revolutionized how researchers think about the field of motor development. It also reviews recent extensions of this work to the domain of cognitive development. Here, the focus is on dynamic field theory, a formal, neurally grounded approach that has yielded novel insights into the embodied nature of cognition. The final section proposes that the key challenge on the horizon is to formally specify how interactions among multiple levels of analysis interact across multiple time scales to create developmental change.
The development of a cytokine detection assay suitable for detection of multiple biomarkers for improved diagnosis of mycobacterial diseases.
Design and Methods
A lateral flow (LF) assay to detect IL-10 was developed utilizing the up-converting phosphor (UCP) reporter-technology. The assay was evaluated using blood samples of leprosy patients. Multiplex applications were explored targeting: 1) IL-10 and IFN-γ in assay buffer; 2) IL-10 and anti-phenolic glycolipid (PGL-I) antibodies in serum from leprosy patients.
Detection of IL-10 below the targeted level of 100 pg/mL in serum was shown. Comparison with ELISA showed a quantitative correlation with R2 value of 0.92. Multiplexing of cytokines and simultaneous detection of cytokine and antibody was demonstrated.
The UCP-LF IL-10 assay is a user-friendly, rapid alternative for IL-10 ELISAs, suitable for multiplex detection of different cytokines and can be merged with antibody-detection assays to simultaneously detect cellular- and humoral immunity.
cytokine; diagnostic test; IL-10; IFN-γ; lateral flow; leprosy; multiplex analysis; mycobacteria; anti-PGL-I; up-converting phosphor
Neoconstructivism is a new approach in developmental science that sheds light on the processes underlying change over time. The present commentary evaluates this new approach in the context of existing theories of development and nine central tenets of neoconstructivism proposed by Newcombe (2011). For inspiration, Hull’s evaluation of psychological theory in 1935 is discussed. Hull noted a proliferation of theories that he attributed to poorly specified concepts and a lack of rigorous theoretical work. Noting a similar proliferation of “isms” in developmental science, the commentary concludes that existing theories have much to offer and suggests that what is needed is not a new “ism” but a rigorous evaluation and integration of modern developmental concepts.
MHC class I-restricted CD8+ T-cells play an important role in protective immunity against mycobacteria. Previously, we showed that p113-121, derived from Mycobacterium leprae protein ML1419c, induced significant IFN-γ-production by CD8+ T-cells in 90% of paucibacillary leprosy patients and 80% of multibacillary patients' contacts, demonstrating induction of M. leprae-specific CD8+ T-cell immunity. Here, we studied the in vivo role and functional profile of ML1419c p113-121-induced T-cells in HLA-A*0201-transgenic mice. Immunization with 9- or 30mer covering p113-121 sequence combined with TLR9 agonist CpG induced HLA-A*0201-trestricted, M. leprae-specific CD8+ T-cells as visualized by p113-121/HLA-A*0201 tetramers. Most CD8+ T-cells produced IFN-γ, but distinct IFN-γ+/TNF-α+ populations were detected simultaneously with significant secretion of CXCL10/IP-10, CXCL9/MIG and VEGF. Strikingly, peptide immunization also induced high ML1419c-specific IgG levels, strongly suggesting that peptide-specific CD8+ T-cells provide help to B-cells in vivo as CD4+ T-cells were undetectable. An additional important characteristic of p113-121-specific CD8+ T-cells was their capacity for in vivo killing of p113-121-labeled, HLA-A*0201+ splenocytes. The cytotoxic function of p113-121/ HLA-A*0201 specific CD8+ T-cells extended into direct killing of splenocytes infected with live M. smegmatis expressing ML1419c: both 9- and 30mer induced CD8+ T-cells that reduced the number of ML1419c-expressing mycobacteria with 95% while no reduction occurred using wild-type M. smegmatis.
These data, combined with previous observations in Brazilian cohorts, show that ML1419c p113-121 induces potent CD8+ T-cells that provide protective immunity against M. leprae and B-cell help for induction of specific IgG, suggesting its potential use in diagnostics and as subunit(vaccine) for M. leprae infection.
Mycobacterium leprae (M. leprae); diagnostics; vaccines; in vivo cytotoxicity; CD8+ T-cells; HLA-A*0201
This study seeks to determine if implementing a culturally-appropriate early childhood caries (ECC) intervention reduces dental disease burden and oral health inequalities among Indigenous children living in South Australia, Australia.
This paper describes the study protocol for a randomised controlled trial conducted among Indigenous children living in South Australia with an anticipated sample of 400. The ECC intervention consists of four components: (1) provision of dental care; (2) fluoride varnish application to the teeth of children; (3) motivational interviewing and (4) anticipatory guidance. Participants are randomly assigned to two intervention groups, immediate (n = 200) or delayed (n = 200). Provision of dental care (1) occurs during pregnancy in the immediate intervention group or when children are 24-months in the delayed intervention group. Interventions (2), (3) and (4) occur when children are 6-, 12- and 18-months in the immediate intervention group or 24-, 30- and 36-months in the delayed intervention group. Hence, all participants receive the ECC intervention, though it is delayed 24 months for participants who are randomised to the control-delayed arm. In both groups, self-reported data will be collected at baseline (pregnancy) and when children are 24- and 36-months; and child clinical oral health status will be determined during standardised examinations conducted at 24- and 36-months by two calibrated dental professionals.
Expected outcomes will address whether exposure to a culturally-appropriate ECC intervention is effective in reducing dental disease burden and oral health inequalities among Indigenous children living in South Australia.
During recent years, comparative genomic analysis has allowed the identification of Mycobacterium leprae-specific genes with potential application for the diagnosis of leprosy. In a previous study, 58 synthetic peptides derived from these sequences were tested for their ability to induce production of IFN-γ in PBMC from endemic controls (EC) with unknown exposure to M. leprae, household contacts of leprosy patients and patients, indicating the potential of these synthetic peptides for the diagnosis of sub- or preclinical forms of leprosy. In the present study, the patterns of IFN-γ release of the individuals exposed or non-exposed to M. leprae were compared using an Artificial Neural Network algorithm, and the most promising M. leprae peptides for the identification of exposed people were selected. This subset of M. leprae-specific peptides allowed the differentiation of groups of individuals from sites hyperendemic for leprosy versus those from areas with lower level detection rates. A progressive reduction in the IFN-γ levels in response to the peptides was seen when contacts of multibacillary (MB) patients were compared to other less exposed groups, suggesting a down modulation of IFN-γ production with an increase in bacillary load or exposure to M. leprae. The data generated indicate that an IFN-γ assay based on these peptides applied individually or as a pool can be used as a new tool for predicting the magnitude of M. leprae transmission in a given population.
Despite the efforts to treat registered leprosy patients, the number of new cases reported globally remains stable and high (about 200,000/year). As the treatment of multibacillary leprosy patients, the major recognized source for new infections, did not allow the expected reduction in new leprosy cases, additional sources must be considered. Following exposure to M. leprae infection, the evolution to active disease is estimated to take from 2 to 10 years, and it is conceivable that some of these asymptomatic individuals could be a yet unrecognized source of infection. Previously, the use of computational tools allowed us to select M. leprae-specific genes or gene regions, and derive M. leprae-specific synthetic peptides from the M. leprae genome. Ex vivo stimulation of the blood leukocytes with a subset of these peptides induced IFN-γ production that allowed the differentiation of individuals exposed to M. leprae from unexposed ones. Individuals with no known history of exposure to M. leprae, but living in an area with high frequency of leprosy cases had high-level positive responses to the peptides. This last observation raised the possibility of using this test as a tool for evaluating the level of transmission of M. leprae infection in areas of interest.
A major debate in the study of word learning centers on the extension of categories to new items. The rational approach assumes that learners make structured inferences about category membership, whereas the mechanistic approach emphasizes the attentional and memorial processes upon which generalization behaviors are based. Recent support for the rational view comes from a phenomenon called the “suspicious coincidence”: people generalize category membership narrowly when presented with three subordinate examples that share the same label and broadly when presented with one example. Across three experiments, we examine the mechanistic basis of the suspicious coincidence. Results show that the presentation of multiple subordinate examples only leads to narrow generalization when the exemplars are presented simultaneously, even when the number of examples is increased from three to six. These data demonstrate that the suspicious coincidence is firmly grounded in the general cognitive processes of attention, memory, and visual comparison.
The re-emergence of tuberculosis (TB) as a global public health threat highlights the necessity of rapid, simple and inexpensive point-of-care detection of the disease. Early diagnosis of TB is vital not only for preventing the spread of the disease but also for timely initiation of treatment. The later in turn will reduce the possible emergence of multi-drug resistant strains of Mycobacterium tuberculosis. Lipoarabinomannan (LAM) is an important non-protein antigen of the bacterial cell wall, which is found to be present in different body fluids of infected patients including blood, urine and sputum. We have developed a bispecific monoclonal antibody with predetermined specificities towards the LAM antigen and a reporter molecule horseradish peroxidase (HRPO). The developed antibody was subsequently used to design a simple low cost immunoswab based assay to detect LAM antigen. The limit of detection for spiked synthetic LAM was found to be 5.0 ng/ml (bovine urine), 0.5 ng/ml (rabbit serum) and 0.005 ng/ml (saline) and that for bacterial LAM from M. tuberculosis H37Rv was found to be 0.5 ng/ml (rabbit serum). The assay was evaluated with 21 stored clinical serum samples (14 were positive and 7 were negative in terms of anti-LAM titer). In addition, all 14 positive samples were culture positive. The assay showed 100% specificity and 64% sensitivity (95% confidence interval). In addition to good specificity, the end point could be read visually within two hours of sample collection. The reported assay might be used as a rapid tool for detecting TB in resource constrained laboratory settings.
The mechanisms that maintain sterility in the urinary tract are incompletely understood. Recent studies have implicated the importance of antimicrobial peptides (AMP) in protecting the urinary tract from infection. Here, we characterize the expression and relevance of the AMP human alpha-defensin 5 (HD5) in the human kidney and urinary tract in normal and infected subjects.
Using RNA isolated from human kidney, ureter, and bladder tissue, we performed quantitative real-time PCR to show that DEFA5, the gene encoding HD5, is constitutively expressed throughout the urinary tract. With pyelonephritis, DEFA5 expression significantly increased in the kidney. Using immunoblot analysis, HD5 production also increased with pyelonephritis. Immunostaining localized HD5 to the urothelium of the bladder and ureter. In the kidney, HD5 was primarily produced in the distal nephron and collecting tubules. Using immunoblot and ELISA assays, HD5 was not routinely detected in non-infected human urine samples while mean urinary HD5 production increased with E.coli urinary tract infection.
DEFA5 is expressed throughout the urinary tract in non-infected subjects. Specifically, HD5 is expressed throughout the urothelium of the lower urinary tract and in the collecting tubules of the kidney. With infection, HD5 expression increases in the kidney and levels become detectable in the urine. To our knowledge, our findings represent the first to quantitate HD5 expression and production in the human kidney. Moreover, this is the first report to detect the presence of HD5 in infected urine samples. Our results suggest that HD5 may have an important role in maintaining urinary tract sterility.
Humans and objects, and thus social interactions about objects, exist within space. Words direct listeners' attention to specific regions of space. Thus, a strong correspondence exists between where one looks, one's bodily orientation, and what one sees. This leads to further correspondence with what one remembers. Here, we present data suggesting that children use associations between space and objects and space and words to link words and objects—space binds labels to their referents. We tested this claim in four experiments, showing that the spatial consistency of where objects are presented affects children's word learning. Next, we demonstrate that a process model that grounds word learning in the known neural dynamics of spatial attention, spatial memory, and associative learning can capture the suite of results reported here. This model also predicts that space is special, a prediction supported in a fifth experiment that shows children do not use color as a cue to bind words and objects. In a final experiment, we ask whether spatial consistency affects word learning in naturalistic word learning contexts. Children of parents who spontaneously keep objects in a consistent spatial location during naming interactions learn words more effectively. Together, the model and data show that space is a powerful tool that can effectively ground word learning in social contexts.