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Test Responses (test + response)
Kinds of Test Responses Selected AbstractsThe relative sensitivity of four benthic invertebrates to metals in spiked-sediment exposures and application to contaminated field sedimentENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 4 2003Danielle Milani Abstract The relative sensitivity of four benthic invertebrates (Hyalella azteca, Chironomus riparius, Hexagenia spp., and Tubifex tubifex) was determined for Cd, Cu, and Ni in water-only and in spiked-sediment exposures. Survival (median lethal concentrations [LC50s] and the concentrations estimated to be lethal to 25% of test organisms [LC25s]), and endpoints for growth and reproduction (mean inhibitory concentrations [IC25s]) were compared. The sensitivities differed depending on the species and metal, although some trends emerged. In water-only exposures, H. azteca is the most sensitive species to cadmium and nickel, with mean LC50s of 0.013 and 3.6 mg/L, respectively; C. riparius is the most sensitive species to copper, with a mean LC50 of 0.043 mg/L. In the spiked-sediment exposures, the order in decreasing sensitivity to copper is Hyalella = Hexagenia < Chironomus < Tubifex for survival and growth/reproduction. For cadmium, the order in decreasing sensitivity is Hyalella = Chironomus < Hexagenia < Tubifex, and for nickel is Hyalella , Hexagenia < Chironomus < Tubifex. Chironomus riparius and Hexagenia spp. survival can be used to distinguish between toxicity caused by different metals. Species test responses in field-collected sediment (Collingwood Harbour, ON, Canada) were examined in an attempt to determine the causative agent of toxicity throughout, using the established species sensitivities. Sediment toxicity was categorized first by comparing species responses to those established for a reference database. Test responses in the field-collected sediment do not support causality by Cu, a suspected toxicant based on comparison of sediment chemistry with sediment quality guidelines. [source] Predicting the development of early skin test sensitization in offspring of parents with asthmaEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 6 2007Y. Jin Abstract Background, The direct causal relationship between skin sensitization and asthma are controversial until now and remains to be further researched. Our aim is to analyse the role of parental asthma in the development of skin sensitization in offspring. Materials and methods, This study was performed among nuclear families (determined by index of asthma patients), and subjects included parents and offspring. Parents were subdivided into four phenotypes on the basis of skin sensitization (SPT+ or SPT,) and asthma status (AST+ or AST,) and offspring were subdivided into three age groups: 3,8, 9,14 and 15,20 years. The main tests included a standard questionnaire and skin prick tests. Results, Offspring's skin sensitization differed among parental phenotypes at all ages (P < 0·05). In the SPT+/AST,, SPT,/AST+ and SPT+/AST+ groups, offspring were significantly more likely to be allergic than the ones in SPT,/AST, group at 3,8 years. Offspring with at least one parent with asthma were significantly more likely to have positive skin prick test response than those with non-asthmatic parents at age 3,8 years and 9,14 years, but not at 15,20 years among offspring with allergic parents. Results were independent of asthma in the children and of the characteristics of atopy in the parents. Conclusion, Parent asthma history is an independent risk factor for allergic sensitization in their offspring in a Chinese population. [source] Predicting Recurrence of Vasovagal Syncope: A Simple Risk Score for the Clinical RoutineJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 4 2009MUHAMMET A. AYDIN M.D. Background: Predictors for recurrence of syncope are lacking in patients with vasovagal syncope. The aim of this study was to identify risk factors for recurrence of syncope and develop a simple prognostic risk score of clinical value. Methods: Two hundred seventy-six patients with a history of vasovagal syncope were prospectively followed for 2 years. Diagnosis of vasovagal syncope was based on clinical history and negative standard work-up. Inclusion in the study was independent from the result of the head-up tilt test, which was performed in all cases. Risk factors for syncope recurrence were evaluated by the Cox proportional hazards regression model and implemented in a risk score, which was validated with the log-rank test and an internal cross-validation. Results: The Cox-regression analysis identified the number of previous syncopal events, history of bronchial asthma, and female gender as predictors for syncope recurrence (all P < 0.05). In contrast, head-up tilt test response had no predictive value (P = 0.881). Developing a risk score, study patients were identified as having high (recurrence rate during 2 years of follow-up: 37.2%), intermediate (24.8%), and low (6.5%) risk for syncope recurrence (receiver operating characteristic [ROC] of score 0.83, P < 0.01; Log-rank test for event-free survival, P < 0.005). Conclusions: In patients with vasovagal syncope, risk of recurrence can be stratified and is predictable based on a simple risk score. [source] Single-Stage Adenosine Tilt Testing in Patients with Unexplained SyncopeJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 6 2004SUNEET MITTAL M.D. Introduction: We previously have shown that a 3-minute single-stage adenosine tilt test has a diagnostic yield comparable to a two-stage protocol consisting of a 30-minute drug-free tilt followed by a 15-minute isoproterenol tilt. In this study, we sought to further define the clinical utility of adenosine tilt testing in patients with unexplained syncope by prospectively evaluating test specificity and determining predictors of a positive test response. Methods and Results: The specificity of single-stage adenosine tilt testing was determined using 30 control subjects. To determine the diagnostic yield of this protocol, adenosine tilts were performed in 129 patients with unexplained syncope. The adenosine tilt test protocol had high specificity (100%) but a low overall diagnostic yield (18%). However, the yield was affected significantly by age. In patients ,40 years of age, the tilt test was positive in 15 (41%) of 37 patients, which was significantly greater than the yield in patients between the ages of 41 and 64 years (6/41 patients [15%], P = 0.012) and those ,65 years of age (2/41 patients [5%], P < 0.0001). Conclusion: These data support single-stage adenosine tilt testing in patients ,40 years of age because the diagnostic yield of the test is maximal in this group and the test can be completed in ,3 minutes. Conversely, the diagnostic yield of adenosine tilt testing in patients >40 years of age is low, suggesting that the clinical utility of this protocol is limited in these patients. (J Cardiovasc Electrophysiol, Vol. 15, pp. 1-4, June 2004) [source] Variability of Eustachian Tube Function: Comparison of Ears With Retraction Disease and Normal Middle Ears ,THE LARYNGOSCOPE, Issue 8 2000Marie Bunne MD Abstract Objective To explore the short-term and long-term variability of tubal opening and closing in ears with advanced retractions and in healthy ears. Study Design/Methods Twenty ears with retraction type middle ear disease (R-MED) and 20 normal ears underwent direct recording of the middle ear pressure during repeated forced openings, equalization of +100 daPa and ,100 daPa by swallowing, Valsalva inflation, and forceful sniffing. Tests were performed twice (separated by 30 min) on each of 2 days separated by 3 to 4 months. Results There was considerable intraindividual variability of the forced opening pressure and the closing pressure in both groups, within as well as between sessions and test days. Although the variability was 1.5 to 2 times higher in ears with retraction than in the normal group, mean Po and Pc did not differ between the groups. Compared with normal ears, ears with retraction changed more frequently from a positive to negative test response, or vice versa, when re-tested after 30 minutes. Rates of positive response in the equalization and Valsalva tests were significantly lower in diseased ears compared with normal ears. Conclusions Eustachian tube opening and closing functions vary more in ears with retraction disease than in normal ears, which is consistent with the variable clinical course of R-MED and implies that single tubal function tests have little prognostic value on the individual level. [source] Bacillus Calmette,Guérin-induced interleukin-12 did not additionally improve clinical and immunologic parameters in asthmatic children treated with sublingual immunotherapyCLINICAL & EXPERIMENTAL ALLERGY, Issue 3 2004C. Arikan Summary Objective To evaluate the effect of bacillus Calmette,Guérin (BCG) as an adjuvant to specific sublingual immunotherapy (SLIT) on the cytokine profile of peripheral blood mononuclear cells (PBMCs) and clinical outcome. Methods Thirty-two children with asthma and rhinitis allergic to house dust mite (HDM) with negative purified protein derivative (PPD) skin test response were enrolled. After a run-in period of 8 weeks, patients were randomized to receive either SLIT only (n=16) or one dose of BCG immunization before initiation of SLIT (n=16) with a standardized Dermatophagoides pteronyssinus (D. pteronyssinus)+D. farinea 50/50 extract. PPD-negative asthmatics (n=5) allergic to HDM receiving inhaled therapy only were included for comparison of cytokine levels in PBMC cultures. Efficacy was assessed both at the end of run-in and 6 months of treatment periods with criteria including symptom, medication and quality-of-life (QoL) scores, IgE levels, lung function, provocation concentration (PC20), eosinophil count and skin prick tests. IL-4, IL-5, IL-10, IL-12, IL-13 and IFN-, levels were determined in antigen specifically and polyclonally stimulated PBMC cultures. Results Both treatment groups showed significant improvement at the end of 6 months for asthma and rhinitis scores and QoL, number of asthma attacks, amount of ,2 -agonists, inhaled and intranasal steroids, blood eosinophil counts and PC20. Interestingly, phytohaemagglutinin (PHA)-stimulated IL-12 and D. pteronyssinus- stimulated IFN-, in PBMC were significantly higher in the treatment groups than controls. In addition, IL-12 levels in response to D. pteronyssinus and PHA stimulation were significantly higher in the SLIT+BCG group than the SLIT alone group and controls. Conclusion The present study demonstrates that successful SLIT is parallel to increased IFN-, production by PBMC. Although simultaneous BCG vaccination enhanced IL-12 production, it did not additionally improve the clinical outcome. [source] P45 Neomycine sulfate patch testsCONTACT DERMATITIS, Issue 3 2004Bolli Bjarnason Objective:, The purpose of this study is to investigate if patients with neomycin sulfate allergy may develop test responses that are unclassifiable by commonly used assessment scales but which should be considered positive. Materials:, 16 patients who tested positive to neomycin sulfate patch tests are retested with different dose levels and application times. Test areas are assessed visually up to 11 days. Results:, Three types of reactions were observed. The first type was characterized by erythema and diffuse infiltrate. Some of these had in addition either discrete papules or both papules and vesicles on their surface. The second type of reaction initially developed large perifollicular papules which later developed into coalescent erythema and diffuse infiltrate. The third type of reaction exhibited perifollicular papules only which declined over time. This type was unclassifiable by commonly used assessment scales. All types of reactions were of clinical significance. Conclusion:, The results support that universal assessment scales for patch-test responses due to different test agents may be inappropriate for assessment of neomycin sulfate patch tests. The clinician should only consider assessment scales as an aid in the assessment of test responses and be aware that morphology of test responses may differ between test agents and test techniques. [source] The relative sensitivity of four benthic invertebrates to metals in spiked-sediment exposures and application to contaminated field sedimentENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 4 2003Danielle Milani Abstract The relative sensitivity of four benthic invertebrates (Hyalella azteca, Chironomus riparius, Hexagenia spp., and Tubifex tubifex) was determined for Cd, Cu, and Ni in water-only and in spiked-sediment exposures. Survival (median lethal concentrations [LC50s] and the concentrations estimated to be lethal to 25% of test organisms [LC25s]), and endpoints for growth and reproduction (mean inhibitory concentrations [IC25s]) were compared. The sensitivities differed depending on the species and metal, although some trends emerged. In water-only exposures, H. azteca is the most sensitive species to cadmium and nickel, with mean LC50s of 0.013 and 3.6 mg/L, respectively; C. riparius is the most sensitive species to copper, with a mean LC50 of 0.043 mg/L. In the spiked-sediment exposures, the order in decreasing sensitivity to copper is Hyalella = Hexagenia < Chironomus < Tubifex for survival and growth/reproduction. For cadmium, the order in decreasing sensitivity is Hyalella = Chironomus < Hexagenia < Tubifex, and for nickel is Hyalella , Hexagenia < Chironomus < Tubifex. Chironomus riparius and Hexagenia spp. survival can be used to distinguish between toxicity caused by different metals. Species test responses in field-collected sediment (Collingwood Harbour, ON, Canada) were examined in an attempt to determine the causative agent of toxicity throughout, using the established species sensitivities. Sediment toxicity was categorized first by comparing species responses to those established for a reference database. Test responses in the field-collected sediment do not support causality by Cu, a suspected toxicant based on comparison of sediment chemistry with sediment quality guidelines. [source] Experimental study and constitutive modelling of elasto-plastic damage in heat-treated mortarINTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS, Issue 4 2010Xiao-Ting Chen Abstract This study investigates the effect of a heat-treatment upon the thermo-mechanical behaviour of a model cement-based material, i.e. a normalized mortar, with a (w/c) ratio of 0.5. First, a whole set of varied experimental results is provided, in order to either identify or validate a thermo-mechanical constitutive model, presented in the second paper part. Experimental responses of both hydraulic and mechanical behaviour are given after different heating/cooling cycling levels (105, 200, 300, 400,C). The reference state, used for comparison purposes, is taken after mass stabilization at 60,C. Typical uniaxial compression tests are provided, and original triaxial deviatoric compressive test responses are also given. Hydraulic behaviour is identified simultaneously to triaxial deviatoric compressive loading through gas permeability Kgas assessment. Kgas is well correlated with volumetric strain evolution: gas permeability increases hugely when ,v testifies of a dilatant material behaviour, instead of contractile from the test start. Finally, the thermo-mechanical model, based on a thermodynamics approach, is identified using the experimental results on uniaxial and triaxial deviatoric compression. It is also positively validated at residual state for triaxial deviatoric compression, but also by using a different stress path in lateral extension, which is at the origin of noticeable plasticity. Copyright © 2009 John Wiley & Sons, Ltd. [source] Is Home Orthostatic Self-Training Effective in Preventing Neurally Mediated Syncope?PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 5 2007Ph.D., YOUNG KEUN ON M.D. Background:Repeated orthostatic stress may prove to be of benefit in the regulation of neurally mediated syncope. But the role of home orthostatic self-training is not established to prevent symptoms in patients with neurally mediated syncope. We performed a prospective and randomized study to evaluate the effectiveness of repeated home orthostatic self-training in preventing tilt-induced neurally mediated syncope. Methods and Results:Fourty-two consecutive patients (24 males and 18 females, mean age 39 years, 16,68 years) with recurrent neurally mediated syncope were randomized into the tilt training and control groups. The home orthostatic self-training program consisted of daily sessions for 7 days a week for 4 weeks. In order to determine the effects of home orthostatic self-training, we repeated the head-up tilt test in both groups 4 weeks later. Among the tilt-training group, 9 of 16 patients (56%) had a positive response on follow-up head-up tilt test. Among the untreated control group, 9 of 17 patients (53%) had a positive response on follow-up head-up tilt test. In subgroup analyses according to the number of tilt-training sessions or the classified type, we found no differences in the follow-up head-up tilt test responses. Spontaneous syncope or presyncope over mean follow-up of 16.9 months were observed in 42.9% versus 47.1% in the tilt-training and control group, respectively. Conclusions:Home orthostatic self-training was ineffective in reducing the positive response rate of head-up tilt test in patients with recurrent neurally mediated syncope. [source] Endemically exposed asymptomatic individuals show no increase in the specific Leishmania (Viannia) panamensis -Th1 immune response in comparison to patients with localized cutaneous leishmaniasisPARASITE IMMUNOLOGY, Issue 9-10 2002C. M. Trujillo SUMMARY In Colombia, most cases of human cutaneous leishmaniasis are caused by Leishmania (Viannia) panamensis. Interestingly, up to 30% of the exposed population do not suffer from clinical leishmaniasis although it is likely that they are continuously infected with Leishmania parasites. Since it is believed that the induction of efficient Th1 immune responses protects against Leishmania infections both in humans and in animal models, we determined if endemically exposed asymptomatics showed stronger Leishmania -specific Th1 immune responses than patients with active localized cutaneous leishmaniasis (LCL). We found that Montenegro skin test responses were slightly higher among asymptomatic individuals compared to patients suffering from LCL. However, PBMC from patients with LCL showed similar Leishmania -specific proliferative responses compared to PBMC from asymptomatic individuals. Furthermore, PBMC from both groups also secreted similar amounts of IFN-,, IL-12p40 and IL-10 after in vitro exposure to L. panamensis. No IL-4 was detected in the supernatants. Taken together our results suggest that lack of LCL development in endemically exposed asymptomatics cannot be explained by stronger systemic anti- Leishmania Th1 immune responses or decreased Th2 responses in these individuals in comparison to individuals who develop LCL. It may be possible that other mechanisms are responsible for resistance to cutaneous leishmaniasis in Colombia in endemically exposed asymptomatics. [source] Seasonal variability in exercise test responses in GhanaPEDIATRIC ALLERGY AND IMMUNOLOGY, Issue 4 2002Emmanuel O. D. Addo-Yobo Exercise-induced bronchospasm (EIB) is widely used in epidemiological studies to investigate the prevalence of asthma. We aimed to determine seasonal variations in the prevalence of EIB in Ghanaian school children from urban-rich (UR), urban-poor (UP), and rural (R) schools. We have previously reported the prevalence of EIB in 9,16-year-old children to be 3.1% in the dry season, with UR children having a significantly higher prevalence of both EIB and atopy compared to UP or R children. In the current study, the prevalence of EIB was assessed in the same 1,095 children in the wet season (5 months following the initial study) using the same methodology. Exercise provocation consisted of free running outdoors for 6 min. In the wet season, 17/1,095 children [mean 1.55%, 95% confidence interval (CI): 0.91,2.47] had a positive response to exercise, compared to our previous report of 34 children (mean 3.1%, 95% CI: 2.15,4.32) with EIB in the dry season (dry vs. wet season, difference 1.55, 95% CI: 0.41,2.69). The proportion of children with a positive response to exercise in the UR school fell from 4.2% (25/599) to 1.3% (8/599) (difference 2.9, 95% CI: 1.2,4.5). In the wet season, there was no difference in the prevalence of EIB among the UR, UP, and R children. Only five of 1,095 subjects (mean 0.5%, 95% CI: 0.15,1.07) demonstrated EIB in both seasons. In conclusion, although exercise challenge remains a useful tool for determining asthma prevalence in epidemiological studies, seasonal variations in the pattern of responses may occur and the results should be interpreted with caution. [source] Respiratory morbidity and lung function in two Aboriginal communities in Western AustraliaRESPIROLOGY, Issue 3 2002Marieke W. VERHEIJDEN Objective: To examine differences in the rates of respiratory symptoms, asthma and levels of lung function in two remote Aboriginal communities. Methodology: Respiratory symptoms, smoking history, skin prick test responses to common allergens, serum IgE, lung function, airway responsiveness to methacholine and white blood cell counts were compared in two Aboriginal communities, one from the central desert (n = 84) and another from the tropical north (n = 209) of Western Australia. Results: Compared with the tropical community, chest tightness and dyspnoea were more frequent and forced expiratory volume in 1 s and forced vital capacity were lower in the desert community, despite similar levels of wheeze, doctor-diagnosed asthma and skin prick test responses and lower levels of airway responsiveness and smoking. The total white cell and neutrophil counts were greater in the desert community. Serum IgE was very high and similar in both communities. Conclusions: Our findings show a low prevalence of asthma in children, a high prevalence of respiratory symptoms and low levels of lung function in remote Aboriginal communities. The greater prevalence of respiratory morbidity in the desert community was not explained by diagnosed asthma, airway hyperresponsiveness or cigarette smoking. The role of infection requires further investigation. The results suggest that the lower lung function observed in Aboriginal communities (compared with non-Aboriginal communities) results at least partly from environmental factors. [source] Identification of Multivariable Delay Processes in Presence of Nonzero Initial Conditions and DisturbancesTHE CANADIAN JOURNAL OF CHEMICAL ENGINEERING, Issue 4 2007Qing-Guo Wang Abstract In this paper, a robust identification method is proposed for multiple-input and multiple-output (MIMO) continuous-time processes with multiple time delays. Suitable multiple integrations are constructed and regression equations linear in the aggregate parameters are derived with the use of the test responses and their multiple integrals. The multiple time delays are estimated by solving some algebraic equations without iteration and the other process model parameters are then recovered. Its effectiveness is demonstrated through simulation and real-time testing. On propose dans cet article une méthode d'identification robuste pour les procédés continus dans le temps à entrées et sorties multiples (MIMO) avec des retards multiples. Des intégrations multiples adéquates sont construites et des équations de régression linéaires par rapport aux paramètres regroupés sont établies à partir des réponses des tests et leurs intégrales multiples. Les retards sont estimés en résolvant certaines équations algébriques sans itération et les autres paramètres de modèles de procédés sont alors récupérés. L'efficacité de la méthode est démontrée par la simulation et l'expérimentation en temps réel. [source] Allergy to plant-derived fresh foods in a birch- and ragweed-free areaCLINICAL & EXPERIMENTAL ALLERGY, Issue 10 2000J. Cuesta-Herranz Background Allergy to plant-derived fresh foods has often been reported in geographical areas where birch or ragweed pollens are frequent and has been attributed to cross-reactivity to pollens. Objective The aim of this study has been to evaluate allergy to plant-derived fresh foods among pollen-allergic patients from a birch and ragweed-free area. Methods Ninety-five pollen-allergic patients took part in the study. The study consisted of a questionnaire, skin prick tests and challenge tests. Pollen skin tests to five grasses, eight trees and seven weeds were performed in duplicate. Prick tests (prick by prick) and challenge tests were carried out with the fresh foods. Results Most patients allergic to pollens were sensitized to grass (Lolium and Phleum; 97.9%), followed by tree (Olea; 82.1%) and weed pollens (Plantago; 64.2%). 35 of the 95 pollen-allergic patients had positive skin test responses to some plant-derived fresh foods, the highest percentage corresponding to several fruits in the Rosaceae family (peach and pear, 26.3%), followed by Cucurbitacea fruits (melon, 13.7%). The 21.05% of the pollen-allergic patients were allergic to some type of plant-derived fresh food. Peach was the plant-derived fresh food which most frequently elicited allergy symptoms (12.6%), followed by melon (7.36%). The cluster of positive responses to Rosaceae fruits was higher for skin testing than for challenge testing. Conclusion Peach was the most important allergy provoking fruit in a birch and ragweed free-area where apples were consumed at a rate of two times more than peaches and the patients allergic to pollen were principally sensitized to grass pollens. [source] Potato lectin activates basophils and mast cells of atopic subjects by its interaction with core chitobiose of cell-bound non-specific immunoglobulin ECLINICAL & EXPERIMENTAL IMMUNOLOGY, Issue 3 2007S. N. Pramod Summary A major factor in non-allergic food hypersensitivity could be the interaction of dietary lectins with mast cells and basophils. Because immunoglobulin E (IgE) contains 10,12% carbohydrates, lectins can activate and degranulate these cells by cross-linking the glycans of cell-bound IgE. The present objective focuses on the effect of potato lectin (Solanum tuberosum agglutinin; STA) for its ability to release histamine from basophils in vitro and mast cells in vivo from non-atopic and atopic subjects. In this study, subjects were selected randomly based on case history and skin prick test responses with food, pollen and house dust mite extracts. Skin prick test (SPT) was performed with STA at 100 µg/ml concentration. Histamine release was performed using leucocytes from non-atopic and atopic subjects and rat peritoneal exudate cells. SPT on 110 atopic subjects using STA showed 39 subjects positive (35%); however, none showed STA-specific IgE; among 20 non-atopic subjects, none were positive by SPT. Maximal histamine release was found to be 65% in atopic subjects (n = 7) compared to 28% in non-atopic subjects (n = 5); the release was inhibited specifically by oligomers of N -acetylglucosamine and correlates well with serum total IgE levels (R2 = 0·923). Binding of STA to N -linked glycoproteins (horseradish peroxidase, avidin and IgG) was positive by dot blot and binding assay. As potato lectin activates and degranulates both mast cells and basophils by interacting with the chitobiose core of IgE glycans, higher intake of potato may increase the clinical symptoms as a result of non-allergic food hypersensitivity in atopic subjects. [source] Interferon-, and skin test responses of schoolchildren in southeast England to purified protein derivatives from Mycobacterium tuberculosis and other species of mycobacteriaCLINICAL & EXPERIMENTAL IMMUNOLOGY, Issue 2 2003R. E. WEIR SUMMARY The immune responses of schoolchildren in southeast England to Mycobacterium tuberculosis and other species of mycobacteria were studied prior to vaccination with bacille Calmette-Guérin (BCG). Data are presented for tuberculin (Heaf) skin test and interferon- , (IFN- ,) responses to M. tuberculosis purified protein derivative (PPD), and IFN- , responses to PPDs from eight other environmental mycobacteria, measured in 424 schoolchildren (13,15 years of age). Responses to M. tuberculosis PPD were detected in 27% of schoolchildren by in vitro IFN- , response and in 20% by the Heaf test. IFN- , responses were more prevalent to PPDs from species of mycobacteria other than M. tuberculosis, predominantly those of the MAIS complex and M. marinum (45,60% responders). Heaf test and IFN- , responses were associated (P < 0·001) for M. tuberculosis, MAIS and M. marinum. These findings have implications for appropriate implementation of vaccination against tuberculosis. [source] | ||||||||||||||||||||||