Biomarkers for Clinical and Incipient Tuberculosis: Performance in a TB-Endemic Country

Simple biomarkers are required to identify TB in both HIV(-)TB(+) and HIV(+)TB(+) patients. Earlier studies have identified the M. tuberculosis Malate Synthase (MS) and MPT51 as immunodominant antigens in TB patients. One goal of these investigations was to evaluate the sensitivity and specificity of anti-MS and -MPT51 antibodies as biomarkers for TB in HIV(-)TB(+) and HIV(+)TB(+) patients from a TB-endemic setting. Earlier studies also demonstrated the presence of these biomarkers during incipient subclinical TB. If these biomarkers correlate with incipient TB, their prevalence should be higher in asymptomatic HIV(+) subjects who are at a high-risk for TB. The second goal was to compare the prevalence of these biomarkers in asymptomatic, CD4(+) T cell-matched HIV(+)TB(-) subjects from India who are at high-risk for TB with similar subjects from US who are at low-risk for TB.Anti-MS and -MPT51 antibodies were assessed in sera from 480 subjects including PPD(+) or PPD(-) healthy subjects, healthy community members, and HIV(-)TB(+) and HIV(+)TB(+) patients from India. Results demonstrate high sensitivity (approximately 80%) of detection of smear-positive HIV(-)TB(+) and HIV(+)TB(+) patients, and high specificity (>97%) with PPD(+) subjects and endemic controls. While approximately 45% of the asymptomatic HIV(+)TB(-) patients at high-risk for TB tested biomarker-positive, >97% of the HIV(+)TB(-) subjects at low risk for TB tested negative. Although the current studies are hampered by lack of knowledge of the outcome, these results provide strong support for the potential of these biomarkers to detect incipient, subclinical TB in HIV(+) subjects.These biomarkers provide high sensitivity and specificity for TB diagnosis in a TB endemic setting. Their performance is not compromised by concurrent HIV infection, site of TB and absence of pulmonary manifestations in HIV(+)TB(+) patients. Results also demonstrate the potential of these biomarkers for identifying incipient subclinical TB in HIV(+)TB(-) subjects at high-risk for TB

Mycobacterium tuberculosis Lipolytic Enzymes as Potential Biomarkers for the Diagnosis of Active Tuberculosis

BACKGROUND: New diagnosis tests are urgently needed to address the global tuberculosis (TB) burden and to improve control programs especially in resource-limited settings. An effective in vitro diagnostic of TB based on serological methods would be regarded as an attractive progress because immunoassays are simple, rapid, inexpensive, and may offer the possibility to detect cases missed by standard sputum smear microscopy. However, currently available serology tests for TB are highly variable in sensitivity and specificity. Lipolytic enzymes have recently emerged as key factors in lipid metabolization during dormancy and/or exit of the non-replicating growth phase, a prerequisite step of TB reactivation. The focus of this study was to analyze and compare the potential of four Mycobacterium tuberculosis lipolytic enzymes (LipY, Rv0183, Rv1984c and Rv3452) as new markers in the serodiagnosis of active TB. METHODS: Recombinant proteins were produced and used in optimized ELISA aimed to detect IgG and IgM serum antibodies against the four lipolytic enzymes. The capacity of the assays to identify infection was evaluated in patients with either active TB or latent TB and compared with two distinct control groups consisting of BCG-vaccinated blood donors and hospitalized non-TB individuals. RESULTS: A robust humoral response was detected in patients with active TB whereas antibodies against lipolytic enzymes were infrequently detected in either uninfected groups or in subjects with latent infection. High specifity levels, ranging from 93.9% to 97.5%, were obtained for all four antigens with sensitivity values ranging from 73.4% to 90.5%, with Rv3452 displaying the highest performances. Patients with active TB usually exhibited strong IgG responses but poor IgM responses. CONCLUSION: These results clearly indicate that the lipolytic enzymes tested are strongly immunogenic allowing to distinguish active from latent TB infections. They appear as potent biomarkers providing high sensitivity and specificity levels for the immunodiagnosis of active TB

Meta-ethnography of experiences of early discharge, with a focus on paediatric febrile neutropenia

PURPOSE (STATING THE MAIN PURPOSES AND RESEARCH QUESTION): Many children have no significant sequelae of febrile neutropenia. A systematic review of clinical studies demonstrated patients at low risk of septic complications can be safely treated as outpatients using oral antibiotics with low rates of treatment failure. Introducing earlier discharge may improve quality of life, reduce hospital acquired infection and reduce healthcare service pressures. However, the review raised concerns that this might not be acceptable to patients, families and healthcare professionals. METHODS: This qualitative synthesis explored experiences of early discharge in paediatric febrile neutropenia, including reports from studies of adult febrile neutropenia and from other paediatric conditions. Systematic literature searching preceded meta-ethnographic analysis, including reading the studies and determining relationships between studies, translation of studies and synthesis of these translations. RESULTS: Nine papers were included. The overarching experience of early discharge is that decision-making is complex and difficult and influenced by fear, timing and resources. From this background, we identified two distinct themes. First, participants struggled with practical consequences of treatment regimens, namely childcare, finances and follow-up. A second theme identified social and emotional issues, including isolation, relational and environmental challenges. Linking these, participants considered continuity of care and the need for information important. CONCLUSIONS: Trust and confidence appeared interdependent with resources available to families-both are required to manage early discharge. Socially informed resilience is relevant to facilitating successful discharge strategies. Interventions which foster resilience may mediate the ability and inclination of families to accept early discharge. Services have an important role in recognising and enhancing resilience

Whole genome identification of Mycobacterium tuberculosis vaccine candidates by comprehensive data mining and bioinformatic analyses

<p>Abstract</p> <p>Background</p> <p><it>Mycobacterium tuberculosis</it>, the causative agent of tuberculosis (TB), infects ~8 million annually culminating in ~2 million deaths. Moreover, about one third of the population is latently infected, 10% of which develop disease during lifetime. Current approved prophylactic TB vaccines (BCG and derivatives thereof) are of variable efficiency in adult protection against pulmonary TB (0%–80%), and directed essentially against early phase infection.</p> <p>Methods</p> <p>A genome-scale dataset was constructed by analyzing published data of: (1) global gene expression studies under conditions which simulate intra-macrophage stress, dormancy, persistence and/or reactivation; (2) cellular and humoral immunity, and vaccine potential. This information was compiled along with revised annotation/bioinformatic characterization of selected gene products and <it>in silico </it>mapping of T-cell epitopes. Protocols for scoring, ranking and prioritization of the antigens were developed and applied.</p> <p>Results</p> <p>Cross-matching of literature and <it>in silico</it>-derived data, in conjunction with the prioritization scheme and biological rationale, allowed for selection of 189 putative vaccine candidates from the entire genome. Within the 189 set, the relative distribution of antigens in 3 functional categories differs significantly from their distribution in the whole genome, with reduction in the Conserved hypothetical category (due to improved annotation) and enrichment in Lipid and in Virulence categories. Other prominent representatives in the 189 set are the PE/PPE proteins; iron sequestration, nitroreductases and proteases, all within the Intermediary metabolism and respiration category; ESX secretion systems, resuscitation promoting factors and lipoproteins, all within the Cell wall category. Application of a ranking scheme based on qualitative and quantitative scores, resulted in a list of 45 best-scoring antigens, of which: 74% belong to the dormancy/reactivation/resuscitation classes; 30% belong to the Cell wall category; 13% are classical vaccine candidates; 9% are categorized Conserved hypotheticals, all potentially very potent T-cell antigens.</p> <p>Conclusion</p> <p>The comprehensive literature and <it>in silico</it>-based analyses allowed for the selection of a repertoire of 189 vaccine candidates, out of the whole-genome 3989 ORF products. This repertoire, which was ranked to generate a list of 45 top-hits antigens, is a platform for selection of genes covering all stages of <it>M. tuberculosis </it>infection, to be incorporated in rBCG or subunit-based vaccines.</p

Digital Speech Compression Using Vector Quantization

Program year: 1983-1984Digitized from print original stored in HDRA vector quantization technique called hybrid vector quantization which uses both scalar DPCM as well as pyramid vector quantization is developed. A linear transformation is used to decorrelate the input vectors. It is demonstrated that this technique achieves performance better than can be obtained using comparable scalar techniques

Workplace bullying: Protective mechanisms between bullying and post-traumatic stress disorder

This quantitative replicated study was adapted from Nielson et al. (2008). It explored the relationship between exposure to bullying and symptoms of post-traumatic stress disorder as experienced by Licensed Professional Counselors (L PCs), who are themselves targets or have witnessed bullying in the workplace. The research questions probed (a) incidences of workplace bullying of LPCs, (b) the occurrence of post-traumatic stress disorder (PTSD) symptoms because of workplace bullying, and (c) the manner in which sense of coherence moderates PTSD-related symptoms for counselors experiencing bullying. Online surveys were sent to LPCs via email as a means of data gathering. LPC email addresses were obtained from Medical Solution links. The instruments chosen for the study were three validated surveys. The 54 LPC participants have provided their perceptions and personal experiences on workplace bullying, post-traumatic stress disorder, and a sense of coherence. The findings showed that the LPC respondents in this study were extensively exposed to workplace bullying. It was also established that there were no significant differences in the self-reported PTSD symptoms of LPCs who have experienced workplace bullying and those who did not. Lastly, the study concluded that high, moderate, or low sense of coherence (SOC) makes no significant differences in the development of PTSD-linked aftereffects to bullying. These findings add to the body of knowledge concerning bullying of licensed professional counselors, its aftermath, and any long-lasting effects of post-traumatic stress

Economic evaluation of an acute paediatric hospital at home clinical trial

Aims: To compare the privately borne and NHS costs of hospital at home (HAH) and conventional inpatient care for children with selected acute conditions. Methods: Prospective economic evaluation using cost minimisation analysis within a randomised controlled trial, in paediatric wards of a district general hospital, and private homes in the local catchment area in Wirral, Merseyside. Subjects were children who fulfilled the criteria for admission to HAH, suffering from breathing difficulties (n = 202), diarrhoea and vomiting (n = 125), or fever (n = 72). Results: Direct costs borne by families are reduced by 41% for HAH patients (£23.31 v £13.76, p = 0.001). There is no evidence that HAH transfers the burden of care to parents, and there is no difference in absence rates from paid employment. Patients and their carers expressed a strong preference for HAH. Comparison of NHS costs is equivocal, depending on how HAH is implemented alongside the conventional hospital service. Conclusion: Paediatric HAH schemes are unlikely to reduce NHS costs and do not increase privately borne costs. They will, however, significantly increase patient and carer satisfaction with care provision for sick children with appropriate conditions

Ion mobility mass spectrometry for the study of mycobacterial mycolic acids

Abstract Lipids are highly structurally diverse molecules involved in a wide variety of biological processes. The involvement of lipids is even more pronounced in mycobacteria, including the human pathogen Mycobacterium tuberculosis, which produces a highly complex and diverse set of lipids in the cell envelope. These lipids include mycolic acids, which are among the longest fatty acids in nature and can contain up to 90 carbon atoms. Mycolic acids are ubiquitously found in mycobacteria and are alpha branched and beta hydroxylated lipids. Discrete modifications, such as alpha, alpha’, epoxy, methoxy, keto, and carboxy, characterize mycolic acids at the species level. Here, we used high precision ion mobility-mass spectrometry to build a database including 206 mass-resolved collision cross sections (CCSs) of mycolic acids originating from the strict human pathogen M. tuberculosis, the opportunistic strains M. abscessus, M. marinum and M. avium, and the nonpathogenic strain M. smegmatis. Primary differences between the mycolic acid profiles could be observed between mycobacterial species. Acyl tail length and modifications were the primary structural descriptors determining CCS magnitude. As a resource for researchers, this work provides a detailed catalogue of the mass-resolved collision cross sections for mycolic acids along with a workflow to generate and analyse the dataset generated