The predictive values of the tuberculin skin test and interferon-γ release assays for active tuberculosis development

A multistage Sendai virus vaccine incorporating latency-associated antigens induces protection against acute and latent tuberculosis

One-quarter of the world's population is infected with Mycobacterium tuberculosis (Mtb). After initial exposure, more immune-competent persons develop asymptomatic latent tuberculosis infection (LTBI) but not active diseases, creates an extensive reservoir at risk of developing active tuberculosis. Previously, we constructed a novel recombinant Sendai virus (SeV)-vectored vaccine encoding two dominant antigens of Mtb, which elicited immune protection against acute Mtb infection. In this study, nine Mtb latency-associated antigens were screened as potential supplementary vaccine candidate antigens, and three antigens (Rv2029c, Rv2028c, and Rv3126c) were selected based on their immune-therapeutic effect in mice, and their elevated immune responses in LTBI human populations. Then, a recombinant SeV-vectored vaccine, termed SeV986A, that expresses three latency-associated antigens and Ag85A was constructed. In murine models, the doses, titers, and inoculation sites of SeV986A were optimized, and its immunogenicity in BCG-primed and BCG-naive mice were determined. Enhanced immune protection against the Mtb challenge was shown in both acute-infection and latent-infection murine models. The expression levels of several T-cell exhaustion markers were significantly lower in the SeV986A-vaccinated group, suggesting that the expression of latency-associated antigens inhibited the T-cell exhaustion process in LTBI infection. Hence, the multistage quarter-antigenic SeV986A vaccine holds considerable promise as a novel post-exposure prophylaxis vaccine against tuberculosis.

Does social pension buy improved mental health and mortality outcomes for senior citizens? Evidence from South Africa's 2008 pension reform

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The 2008 pension reform in South Africa improved access to healthcare.

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The 2008 pension reform improved mental health and 60-year-old deaths.

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The impact of the 2008 pension reform in averting 60-year-old deaths is higher in urban regions than rural regions.

In South Africa, men were traditionally eligible to receive government pensions at 65 years. However, that eligibility criterion was changed in 2008 to allow men to receive a pension payout at 60 years. This study is designed to quantify the impact of the 2008 pension reform on mental health outcomes (depression and traumatic stress) and deaths among 60-year-old men from disadvantaged households without advanced education. This analysis used secondary data issued by Statistic South Africa- General Household Survey. Men who reported earning a pension at 60 years from 2008 to 2014 were exposed to the 2008 pension reform and thus were classified as the treatment group. The 60-year-old men during 2002–2007 were ineligible to earn the pension, therefore considered the control group. We then used a Two-stage Least Squared Model (2SLS) to quantify the impact of the 2008 pension reform on healthcare utilization, depression cases, traumatic stress cases, and deaths among 60-year-old men. The model shows that the 2008 pension reform improved healthcare utilization by 3 % in the cohorts of men who benefitted from the 2008 reform. The 2008 pension reform averted depression cases, traumatic stress cases, and deaths among 60-year-old men by 3 %, 4 %, and 5 %, respectively. The impact of the 2008 pension reform in averting deaths among 60-year-old men was higher in urban regions than rural regions. We concluded that the 2008 pension reform successfully bought improved mental health outcomes and prevented depression, traumatic stress, and deaths among 60-year-old men.

Mycobacterium tuberculosis piezoelectric sensor based on AuNPs-mediated enzyme assisted signal amplification

Rapid diagnosis of tuberculosis disease (TB) still remained a pressing need for TB control efforts all over the world. However, the existing detection approaches cannot satisfy demand of rapid detection of clinical Mycobacterium tuberculosis (M. tuberculosis) because of the long detection time and high cost. Herein, we proposed a new M. tuberculosis piezoelectric sensor based on AuNPs-mediated enzyme assisted signal amplification. A hairpin-shaped DNA duplex with a protrusion of the 3' end was designed. In the presence of specific 16 S rDNA fragment of M. tuberculosis, the hairpin probe was opened, which triggered the selective cleavage of hairpin probe by Exonuclease III (Exo III), resulting in the release of uncut DNA probe and target DNA. The released target DNA hybridized with another hairpin-shaped DNA duplex, and a new digestion cycle was started, thus generating large amounts of uncut DNA probes. The uncut DNA was pulled to the electrode surface by the hybridization with capture probe modified on the electrode. Subsequently detection probe labeled AuNPs was hybridized with uncut DNA and entered between the two electrodes. The AuNPs linked to hybridized detection probe were grown in the HAuCl₄ and Nicotinamide adenine dinucleotide (NADH) solution and offered the conductive connection between the gaps of electrode. The changes were monitored by the piezoelectric sensor. The piezoelectric biosensor could achieve a detection of M. tuberculosis (10²-10⁸ CFU mL^-1) within 3 h, the detection limit (LOD) was 30 CFU mL^-1. The methodology could be transformed into different microbial targets, which is suitable for further development of small portable equipment and multifunctional detection.