Interferon-γ release assays (IGRAs) are now established for the immunodiagnosis of latent infection with Mycobacterium tuberculosis in many countries. However, the role of IGRAs for the diagnosis of ...active tuberculosis (TB) remains unclear. Following preferred reporting items for systematic reviews and meta-analyses (PRISMA) and quality assessment of diagnostic accuracy studies (QUADAS) guidelines, we searched PubMed, EMBASE and Cochrane databases to identify studies published in January 2001-November 2009 that evaluated the evidence of using QuantiFERON-TB® Gold in-tube (QFT-G-IT) and T-SPOT.TB® directly on blood or extrasanguinous specimens for the diagnosis of active TB. The literature search yielded 844 studies and 27 met the inclusion criteria. In blood and extrasanguinous fluids, the pooled sensitivity for the diagnosis of active TB was 80% (95% CI 75-84%) and 48% (95% CI 39-58%) for QFT-G-IT, and 81% (95% CI 78-84%) and 88% (confirmed and unconfirmed cases) (95% CI 82-92%) for T-SPOT.TB®, respectively. In blood and extrasanguinous fluids, the pooled specificity was 79% (95% CI 75-82%) and 82% (95% CI 70-91%) for QFT-G-IT, and 59% (95% CI 56-62%) and 82% (95% CI 78-86%) for T-SPOT.TB®, respectively. Although the diagnostic sensitivities of both IGRAs were higher than that of tuberculin skin tests, it was still not high enough to use as a rule out test for TB. Positive evidence for the use of IGRAs in compartments other than blood will require more independent and carefully designed prospective studies.
ABSTRACT
According to radiative models, radio galaxies and quasars are predicted to produce gamma rays from the earliest stages of their evolution. Exploring their high-energy emission is crucial for ...providing information on the most energetic processes, the origin and the structure of the newly born radio jets. Taking advantage of more than 11 yr of Fermi-LAT data, we investigate the gamma-ray emission of 162 young radio sources (103 galaxies and 59 quasars), the largest sample of young radio sources used so far for such a gamma-ray study. We separately analyse each source and perform the first stacking analysis of this class of sources to investigate the gamma-ray emission of the undetected sources. We detect significant gamma-ray emission from 11 young radio sources, 4 galaxies, and 7 quasars, including the discovery of significant gamma-ray emission from the compact radio galaxy PKS 1007+142 (z = 0.213). The cumulative signal of below-threshold young radio sources is not significantly detected. However, it is about one order of magnitude lower than those derived from the individual sources, providing stringent upper limits on the gamma-ray emission from young radio galaxies (Fγ < 4.6 × 10−11 ph cm−2 s−1) and quasars (Fγ < 10.1 × 10−11 ph cm−2 s−1), and enabling a comparison with the models proposed. With this analysis of more than a decade of Fermi-LAT observations, we can conclude that while individual young radio sources can be bright gamma-ray emitters, the collective gamma-ray emission of this class of sources is not bright enough to be detected by Fermi-LAT.
We present radio, optical/NIR, and X-ray observations of the afterglow of the short-duration Swift and Konus-Wind GRB 130603B, and uncover a break in the radio and optical bands at approximately 0.5 ...day after the burst, best explained as a jet break with an inferred jet opening angle of approximately 4degrees-8degrees. GRB 130603B is only the third short GRB with a radio afterglow detection to date, and represents the first time that a jet break has been evident in the radio band. We model the temporal evolution of the spectral energy distribution to determine the burst explosion properties and find an isotropic-equivalent kinetic energy of approximately (0.6-1.7)x 10 super(51) erg and a circumburst density of approximately 5 x 10 super(-3)-30cm super(-3). From the inferred opening angle of GRB 130603B, we calculate beaming-corrected energies of E sub( gamma ) approximately (0.5-2) x 10 super(49) erg and E sub(K) approximately (0.1-1.6) x 10 super(49) erg. Along with previous measurements and lower limits we find a median opening angle of approximately 10degrees. Using the all-sky observed rate of 10 Gpc super(-3) yr super(-1), this implies a true short GRB rate of approximately 20 yr super(-1) within 200 Mpc, the Advanced LIGO/VIRGO sensitivity range for neutron star binary mergers. Finally, we uncover evidence for significant excess emission in the X-ray afterglow of GRB 130603B at > ~ 1 day and conclude that the additional energy component could be due to fail-back accretion or spin-down energy from a magnetar formed following the merger.
Evidence is accumulating on the interaction between tuberculosis (TB) and COVID-19.
The aim of the present review is to report the available evidence on the interaction between these two infections. ...Differences and similarities of TB and COVID-19, their immunological features, diagnostics, epidemiological and clinical characteristics and public health implications are discussed. The key published documents and guidelines on the topic have been reviewed.
Based on the immunological mechanism involved, a shared dysregulation of immune responses in COVID-19 and TB has been found, suggesting a dual risk posed by co-infection worsening COVID-19 severity and favouring TB disease progression.
The available evidence on clinical aspects suggests that COVID-19 happens regardless of TB occurrence either before, during or after an active TB diagnosis. More evidence is required to determine if COVID-19 may reactivate or worsen active TB disease. The role of sequeale and the need for further rehabilitation must be further studied
Similarly, the potential role of drugs prescribed during the initial phase to treat COVID-19 and their interaction with anti-TB drugs require caution. Regarding risk of morbidity and mortality, several risk scores for COVID-19 and independent risk factors for TB have been identified: including, among others, age, poverty, malnutrition and co-morbidities (HIV co-infection, diabetes, etc.). Additional evidence is expected to be provided by the ongoing global TB/COVID-19 study.
Context.
According to radiative models, radio galaxies may produce
γ
-ray emission from the first stages of their evolution. However, very few such galaxies have been detected by the
Fermi
Large Area ...Telescope (LAT) so far.
Aims.
NGC 3894 is a nearby (
z
= 0.0108) object that belongs to the class of compact symmetric objects (CSOs, i.e., the most compact and youngest radio galaxies), which is associated with a
γ
-ray counterpart in the Fourth
Fermi
-LAT source catalog. Here we present a study of the source in the
γ
-ray and radio bands aimed at investigating its high-energy emission and assess its young nature.
Methods.
We analyzed 10.8 years of
Fermi
-LAT data between 100 MeV and 300 GeV and determined the spectral and variability characteristics of the source. Multi-epoch very long baseline array (VLBA) observations between 5 and 15 GHz over a period of 35years were used to study the radio morphology of NGC 3894 and its evolution.
Results.
NGC 3894 is detected in
γ
-rays with a significance >9
σ
over the full period, and no significant variability has been observed in the
γ
-ray flux on a yearly time-scale. The spectrum is modeled with a flat power law (Γ = 2.0 ± 0.1) and a flux on the order of 2.2 × 10
−9
ph cm
−2
s
−1
. For the first time, the VLBA data allow us to constrain with high precision the apparent velocity of the jet and counter-jet side to be
β
app, NW
= 0.132 ± 0.004 and
β
app, SE
= 0.065 ± 0.003, respectively.
Conclusions.
Fermi
-LAT and VLBA results favor the youth scenario for the inner structure of this object, with an estimated dynamical age of 59 ± 5 years. The estimated range of viewing angle (10° <
θ
< 21°) does not exclude a possible jet-like origin of the
γ
-ray emission.
We present the results from a sensitive X-ray survey of 26 nearby hydrogen-poor superluminous supernovae (SLSNe-I) with Swift, Chandra, and XMM. This data set constrains the SLSN evolution from a few ...days until ∼2000 days after explosion, reaching a luminosity limit Lx ∼ 1040 erg s−1 and revealing the presence of significant X-ray emission possibly associated with PTF 12dam. No SLSN-I is detected above , suggesting that the luminous X-ray emission Lx ∼ 1045 erg s−1 associated with SCP 60F6 is not common among SLSNe-I. We constrain the presence of off-axis gamma-ray burst (GRB) jets, ionization breakouts from magnetar engines and the density in the sub-parsec environments of SLSNe-I through inverse Compton emission. The deepest limits rule out the weakest uncollimated GRB outflows, suggesting that if the similarity of SLSNe-I with GRB/SNe extends to their fastest ejecta, then SLSNe-I are either powered by energetic jets pointed far away from our line of sight (θ > 30°), or harbor failed jets that do not successfully break through the stellar envelope. Furthermore, if a magnetar central engine is responsible for the exceptional luminosity of SLSNe-I, our X-ray analysis favors large magnetic fields G and ejecta masses , in agreement with optical/UV studies. Finally, we constrain the pre-explosion mass-loss rate of stellar progenitors of SLSNe-I. For PTF 12dam we infer , suggesting that the SN shock interaction with an extended circumstellar medium is unlikely to supply the main source of energy powering the optical transient and that some SLSN-I progenitors end their lives as compact stars surrounded by a low-density medium similar to long GRBs and type Ib/c SNe.
Alpha-1 deficiency in severe asthma patients Zappa, M.; Grossi, S.; Pignatti, P. ...
The international journal of tuberculosis and lung disease,
05/2024, Letnik:
28, Številka:
5
Journal Article
Recenzirano
INTRODUCTION Alpha-1 antitrypsin (AAT) deficiency, an autosomal co-dominant condition, decreases protein concentration and activity at both serum and tissue levels. Few studies investigated whether ...the type of SERPINA1 gene phenotype
in patients with severe asthma can influence symptoms and disease control during follow-up. OBJECTIVE To assess whether the presence of a non-MM genotype of SERPINA1 in patients with severe asthma is associated with disease
control, systemic and airway inflammation, lung function and comorbidities prevalence compared to severe asthma patients with a homozygous genotype (MM). METHODS Asthmatic patients belonging to Global Initiative for Asthma (GINA)
step 5 were retrospectively analysed in an Italian reference asthma clinic. We collected clinical, biological and functional variables at baseline and for the three following years. RESULTS Out of 73 patients enrolled, 14 (19.18%)
were non-MM and 59 (80.8%) were MM. Asthmatics with non-MM genotype had lower serum AAT concentration (P = 0.004) and higher emphysema prevalence than the MM group (P = 0.003) at baseline. During follow up, only MM patients showed a significant improvement of both ACQ-6 score
(P < 0.0001) and eosinophilic systemic inflammation (P < 0.0001). CONCLUSIONS Our findings emphasise the importance of a screening for AAT deficiency in severe asthma, as alleles mutation may influence patient's
follow-up.
The fourth catalog of active galactic nuclei (AGNs) detected by the Fermi Gamma-ray Space Telescope Large Area Telescope (4LAC) between 2008 August 4 and 2016 August 2 contains objects located at ...high Galactic latitudes ( ). It includes 85% more sources than the previous 3LAC catalog based on 4 yr of data. AGNs represent at least 79% of the high-latitude sources in the fourth Fermi-Large Area Telescope Source Catalog (4FGL), which covers the energy range from 50 MeV to 1 TeV. In addition, gamma-ray AGNs are found at low Galactic latitudes. Most of the 4LAC AGNs are blazars (98%), while the remainder are other types of AGNs. The blazar population consists of 24% Flat Spectrum Radio Quasars (FSRQs), 38% BL Lac-type objects, and 38% blazar candidates of unknown types (BCUs). On average, FSRQs display softer spectra and stronger variability in the gamma-ray band than BL Lacs do, confirming previous findings. All AGNs detected by ground-based atmospheric Cerenkov telescopes are also found in the 4LAC.
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