420 research outputs found
LSHTM - February 2013 podcast - Cancer survival, mosquito repellent resistance, TB vaccination
No full textThe February 2013 podcast from the London School of Hygiene & Tropical Medicine.
Includes Michel Coleman discussing the CONCORD study into cancer survival rates, Nina Stanczyk on mosquitoes resistance to DEET, and Hazel Dockrell on the effectiveness of the BCG vaccination.
Look out for extended video interviews on the School website
Longitudinal patterns of behavioral, emotional, and social difficulties and self-concept in adolescents with a history of specific language impairment
No full textPurpose: This study explored the prevalence and stability of behavioral difficulties and self-concepts between 8 and 17 years in a sample of children with a history of specific language impairment (SLI). We investigated whether earlier behavioral, emotional and social difficulties (BESD), self-concepts, language, and literacy abilities predicted behavioral difficulties and self-concepts at 16/17 years.
Method: In this prospective longitudinal study, 65 students were followed up with teacher behavior ratings and individual assessments of language, literacy, and self-concepts at 8, 10, 12, 16, and 17 years.
Results: The students had consistently higher levels of five domains of BESD, which had different trajectories over time, and poorer scholastic competence, whose trajectory also varied over time. Earlier language ability did not predict later behavioral difficulties or self-concepts but the prediction of academic self-concept at 16 by literacy at 10 years approached significance.
Conclusions: We demonstrate the importance of distinguishing domains of behavioral difficulties and self-concept. Language, when measured at 8 or 10 years, was not a predictor of behavior or self-concepts at 16 years, or of self-concepts at 17 years. The study stresses the importance of practitioners addressing academic abilities and different social-behavioral domains in delivering support for adolescents with SLI
Variability between countries in cytokine responses to BCG vaccination: what impact might this have on protection?
No full textPopulation differences in immune responses to Bacille Calmette-Guérin vaccination in infancy.
No full textBacille Calmette-Guérin (BCG) vaccination induces a marked increase in the interferon (IFN)-gamma response to Mycobacterium tuberculosis purified protein derivative (Mtb PPD) in UK adolescents, but not in Malawian adolescents. We hypothesized that Mtb PPD-induced IFN-gamma after BCG vaccination would be similar in infants from these 2 countries. Infants were vaccinated with BCG during the first 3-13 weeks of life. Three months after BCG vaccination, 51 (100%) of 51 UK infants had an IFN-gamma response to Mtb PPD, compared to 41 (53%) of 78 of Malawian infants, in whom responses varied according to their season of birth. We conclude that population differences in immune responses after BCG vaccination are observed among infants, as well as among young adults
Antigen-coated latex particles as a model system for probing monocyte responses in leprosy
No full textTo study responses to Mycobacterium leprae antigens, we developed an in vitro model system in which latex particles coated with M. leprae sonic extract (MLSON) antigen were presented to monocytes. Uptake and oxidative response as measured by superoxide production to these antigens were investigated. Phagocytosis of MLSON-coated particles was greater than that of control particles in monocytes from both leprosy patients and controls from leprosy-endemic areas; uptake of MLSON-coated particles was higher in monocytes from lepromatous leprosy patients than in cells from tuberculoid leprosy patients and controls. In both patients and controls, uptake of latex particles coated with leprosy antigens triggered very little reduction of nitroblue tetrazolium although the cells were capable of mounting a respiratory burst. Antigen-coated latex particles can therefore be used as a tool to investigate monocyte responses to M. leprae and individual recombinant antigens.Peer reviewedfinal article publishe
Broad heparin-binding haemagglutinin-specific cytokine and chemokine response in infants following Mycobacterium bovis BCG vaccination.
No full text: Heparin-binding haemagglutinin (HBHA)-specific immune responses have been linked to protection against tuberculosis (TB). We investigated the hypothesis that BCG vaccination of human infants primes an HBHA-specific response, using multiplex to measure secreted cytokines and chemokines following HBHA and Mycobacterium tuberculosis purified protein derivative (PPD) stimulation of diluted whole blood samples from BCG-vaccinated or unvaccinated infants. Of 42 analytes measured, 24 and 32 significant, BCG-associated increases were detected in response to HBHA and PPD respectively. Both response profiles included Th-1, Th-2, Th-17 and inflammatory cytokines and chemokines (e.g. IFN-?, TNF-?, IL-5, IL-10, IL-13, IL-17, MIP-1? and MIP-1?). We also found that 6 of the 7 responses most closely correlated with IFN-? were common to both HBHA and PPD. Notably, all HBHA-specific secretion of cytokines and chemokines from infant samples was dependant on previous BCG vaccination. Also, long term persistence of HBHA-specific responses was found in adolescents with evidence of infant BCG vaccination. This study demonstrates for the first time, BCG priming of an HBHA-specific immune response in infants that is characterised by a broad cytokine and chemokine signature. It also suggests a number of BCG vaccination-associated, HBHA-induced responses that should be useful for future studies of biomarkers of protection against TB
The impact of sound field systems on learning and attention in elementary school classrooms
No full textPurpose: An evaluation of the installation and use of sound field systems (SFS) was carried out to investigate their impact on teaching and learning in elementary school classrooms. Methods: The evaluation included acoustic surveys of classrooms, questionnaire surveys of students and teachers and experimental testing of students with and without the use of SFS. Students ’ perceptions of classroom environments and objective data evaluating change in performance on cognitive and academic assessments with amplification over a six month period are reported. Results: Teachers were positive about the use of SFS in improving children’s listening and attention to verbal instructions. Over time students in amplified classrooms did not differ from those in nonamplified classrooms in their reports of listening conditions, nor did their performance differ in measures of numeracy, reading or spelling. Use of SFS in the classrooms resulted in significantly larger gains in performance in the number of correct items on the nonverbal measure of speed of processing and the measure of listening comprehension. Analysis controlling for classroom acoustics indicated that students ’ listening comprehension score
Mycobacterium tuberculosis PPD-induced immune biomarkers measurable in vitro following BCG vaccination of UK adolescents by multiplex bead array and intracellular cytokine staining.
No full textBACKGROUND: The vaccine efficacy reported following Mycobacterium bovis Bacillus Calmette Guerin (BCG) administration to UK adolescents is 77% and defining the cellular immune response in this group can inform us as to the nature of effective immunity against tuberculosis. The aim of this study was to identify which cytokines and lymphocyte populations characterise the peripheral blood cellular immune response following BCG vaccination. RESULTS: Diluted blood from before and after vaccination was stimulated with Mycobacterium tuberculosis purified protein derivative for 6 days, after which soluble biomarkers in supernatants were assayed by multiplex bead array. Ten out of twenty biomarkers measured were significantly increased (p < 0.0025) 1 month after BCG vaccination when compared to paired samples (n = 12) taken prior to vaccination (IFNgamma, TNFalpha, IL-1alpha, IL-2, IL-6, IL-10, IL-17, GM-CSF, MIP1alpha, IP-10). All of these remained detectable by multiplex bead array in samples taken 12 months after BCG vaccination of a partially overlapping adolescent group (n = 12). Intracellular cytokine staining after 24 hour Mycobacterium tuberculosis purified protein derivative stimulation of PBMC samples from the 12 month group revealed that IFNgamma expression was detectable in CD4 and CD8 T-cells and natural killer cells. Polyfunctional flow cytometry analysis demonstrated that cells expressing IFNgamma alone formed the majority in each subpopulation of cells. Only in CD4 T-cells and NK cells were there a notable proportion of responding cells of a different phenotype and these were single positive, TNFalpha producers. No significant expression of the cytokines IL-2, IL-17 or IL-10 was seen in any population of cells. CONCLUSIONS: The broad array of biomarker responses detected by multiplex bead array suggests that BCG vaccination is capable, in this setting, of inducing a complex immune phenotype. Although polyfunctional T-cells have been proposed to play a role in protective immunity, they were not present in vaccinated adolescents who, based on earlier epidemiological studies, should have developed protection against pulmonary tuberculosis. This may be due to the later sampling time point available for testing or on the kinetics of the assays used
Quantitation of IgM antibodies to the M. leprae synthetic dissacharide can predict early bacterial multiplication in leprosy
No full textQuantitative enzyme-linked immunosorbent assays detecting IgM to the soluble Mycobacterium leprae crude sonicate (CD75) and the synthetic disaccharide antigen coupled to bovine serum albumin (ND-BSA) were assessed for their ability to determine early infection in families/household contacts of leprosy patients and employees of a leprosy center working in close contact with leprosy patients. Although IgM to both antigens (CD75 and ND-BSA) correlated with the bacterial index (BI) assessed histologically on skin-biopsy samples, the level of IgM antibodies to ND-BSA was a much more sensitive indicator of low bacterial loads. A 4.4-fold difference in antibody levels was observed between the mean group levels of endemic controls (N = 116) and tuberculoid leprosy patients with a BI of 0 (N = 88), increasing to sevenfold in tuberculoid leprosy patients with a BI of 1 (N = 20). Using a statistical cut off with endemic controls (mean + 2 S.D.), household/family contacts showed 30% seropositivity (N = 180) as compared to staff contacts who showed 17% seropositivity (N = 55). Percent seropositivity in family contacts was not related to the type of leprosy of the index case (lepromatous vs. tuberculoid) or the duration of treatment of the index case. Age of the individual in the family contact group had a significant influence on seropositivity. These results support the hypothesis that, in this community, factors other than the viable bacterial load of the index case, such as genetic susceptibility, may be influencing the high rate of seropositivity in family contacts. IgM ND-BSA antibodies seem to provide a good indicator of low antigenic loads and could prove to be useful in detecting subclinical infection before the onset of dis-ease. Follow-up studies of these seropositive individuals are in progress to understand the relationship between seropositivity and the progress of clinical disease.Peer reviewedfinal article publishe
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