Bedaquiline is recommended by the World Health Organization for the treatment of multidrug-resistant (MDR) and extensively drug-resistant (XDR) tuberculosis (TB). We pooled data from 5 cohorts of ...patients treated with bedaquiline in France, Georgia, Armenia, and South Africa and in a multicountry study. The rate of culture conversion to negative at 6 months (by the end of 6 months of treatment) was 78% (95% CI 73.5%-81.9%), and the treatment success rate was 65.8% (95% CI 59.9%-71.3%). Death rate was 11.7% (95% CI 7.0%-19.1%). Up to 91.1% (95% CI 82.2%-95.8%) of the patients experienced >1 adverse event, and 11.2% (95% CI 5.0%-23.2%) experienced a serious adverse event. Lung cavitations were consistently associated with unfavorable outcomes. The use of bedaquiline in MDR and XDR TB treatment regimens appears to be effective and safe across different settings, although the certainty of evidence was assessed as very low.
We study the impact of a spatially homogeneous yet non-stationary dielectric permittivity on the dynamical and spectral properties of light. Our choice of potential is motivated by the interest in ... -symmetric systems as an extension of quantum mechanics. Because we consider a homogeneous and non-stationary medium, symmetry reduces to time-reversal symmetry in the presence of balanced gain and loss. We construct the instantaneous amplitude and angular frequency of waves within the framework of Maxwell's equations and demonstrate the modulation of light amplification and attenuation associated with the well-defined temporal domains of gain and loss, respectively. Moreover, we predict the splitting of extrema of the angular frequency modulation and demonstrate the associated shrinkage of the modulation period. Our theory can be extended for investigating similar time-dependent effects with matter and acoustic waves in -symmetric structures.
Delamanid, recently available for the treatment of multidrug-resistant tuberculosis (MDR TB), has had limited use outside clinical trials. We present the early treatment results for 53 patients from ...7 countries who received a delamanid-containing treatment for MDR TB. Results show good tolerability and treatment response at 6 months.
The emergence of resistance to anti-tuberculosis (DR-TB) drugs and the HIV epidemic represent a serious threat for reducing the global burden of TB. Although data on HIV-negative DR-TB treatment ...outcomes are well published, few data on DR-TB outcomes among HIV co-infected people is available despite the great public health importance.
We retrospectively reported and compared the DR-TB treatment outcomes of HIV-positive and HIV-negative patients treated with an individualized regimen based on WHO guidelines in seven countries: Abkhazia, Armenia, Colombia, Kenya, Kyrgyzstan, Swaziland and Uzbekistan.
Of the 1,369 patients started DRTB treatment, 809 (59.1%) were multi-drug resistant (MDR-TB) and 418 (30.5%) were HIV-positive. HIV-positive patients were mainly from African countries (90.1%) while HIV-negative originated from Former Soviet Union (FSU) countries. Despite a higher case fatality rate (19.0% vs 9.4%), HIV-positive MDR-TB patients had a 10% higher success rate than HIV-negative patients (64.0% vs 53.2%, p = 0.007). No difference in treatment success was found among polydrug-resistant (PDR-TB) patients. Overall, lost to follow-up rate was much higher among HIV-negative (22.0% vs. 8.4%). Older age and not receiving ART were the only factors associated with unfavorable treatment outcome among HIV-positive patients.
As already known for HIV-negative patients, success rate of DR-TB HIV-positive patients remains low and requires more effective DR-TB regimen using new drugs also suitable to HIV-infected patients on ART. The study also confirms the need of ART introduction in HIV co-infected patients.
We study Bessel beams of two-level atoms that are driven by a linearly polarized laser field. Starting from the Schrödinger equation, we determine the states of two-level atoms in a plane-wave field ...respecting propagation directions both of the atom and the field. For such laser-driven two-level atoms, we construct Bessel beams beyond the typical paraxial approximation. We show that the probability density of these atomic beams obtains a non-trivial, Bessel-squared-type behavior and can be tuned under the special choice of the atom and laser parameters, such as the nuclear charge, atom velocity, laser frequency, and propagation geometry of the atom and laser beams. Moreover, we spatially and temporally characterize the beam of hydrogen and selected (neutral) alkali-metal atoms that carry non-zero orbital angular momentum (OAM). The proposed spatiotemporal Bessel states (i) are able to describe, in principle,
twisted
states of any two-level system which is driven by the radiation field and (ii) have potential applications in atomic and nuclear processes as well as in quantum communication.
Kapitza-Dirac effect with traveling waves Hayrapetyan, Armen G; Grigoryan, Karen K; Götte, Jörg B ...
New journal of physics,
08/2015, Volume:
17, Issue:
8
Journal Article
Peer reviewed
Open access
We report on the possibility of diffracting electrons from light waves traveling inside a dielectric medium. We show that, in the frame of reference which moves with the group velocity of light, the ...traveling wave acts as a stationary diffraction grating from which electrons can diffract, similar to the conventional Kapitza-Dirac effect. To characterize the Kapitza-Dirac effect with traveling light waves, we make use of the Hamiltonian Analogy between electron optics and quantum mechanics and apply the Helmholtz-Kirchhoff theory of diffraction.
We explore the propagation and transformation of electromagnetic waves through spatially homogeneous yet smoothly time-dependent media within the framework of classical electrodynamics. By modelling ...the smooth transition, occurring during a finite period τ, as a phenomenologically realistic and sigmoidal change of the dielectric permittivity, an analytically exact solution to Maxwell׳s equations is derived for the electric displacement in terms of hypergeometric functions. Using this solution, we show the possibility of amplification and attenuation of waves and associate this with the decrease and increase of the time-dependent permittivity. We demonstrate, moreover, that such an energy exchange between waves and non-stationary media leads to the transformation (or conversion) of frequencies. Our results may pave the way towards controllable light–matter interaction in time-varying structures.
•Wave transformation in smoothly time-varying dielectric media is considered.•Analytically exact solutions to time-dependent Maxwell׳s equations are found.•Amplification and attenuation of waves in non-stationary media is demonstrated.•Energy exchange between waves and non-stationary media leads to frequency conversion.
The GenoType MTBDRsl test rapidly detects resistance to ethambutol, fluoroquinolones, second-line aminoglycosides (amikacin AMK and kanamycin KAN), and cyclic peptides (capreomycin CAP) in ...Mycobacterium tuberculosis. According to data from Global Drug Resistance Surveillance Report (2007), Armenia is counted as a high-burden country for multidrug-resistant tuberculosis (MDR-TB). The estimated burden of MDR-TB in 2012 was 9.4 (7–12) and 43 (38–49) among retreatment TB cases. A total of 92 laboratory confirmed cases were reported to the World Health Organization (57 new and 35 previously treated) out of 511 cases tested for MDR-TB.
A set of 77 drug-resistant TB isolates during 2011 and 2012 period, being either acid-fast bacterium positive or negative but culture-positive resistant to isoniazid, rifampin, or both according to the GenoType MTBDR plus assay, were consecutively tested using GenoType MTBDRsl. rrs gene analysis and the results from GenoType MTBDRsl were compared with phenotypic drug resistance testing. The DNA preparation method was performed as recommended by the manufacturer (Genotype MTBDR plus version 1.0 and Genotype MTBDRsl version 2.0 Hain Lifescience Nehren, Germany).
Aminoglycosides are key drugs for the treatment of MDR-TB. A total of 77 drug-resistant TB and four extensively drug-resistant M. tuberculosis isolates from Armenian TB patients were analyzed to characterize mutations within rrs and to compare with phenotypic drug resistance testing. Simultaneously, the following were identified: 65 (84.41%) rrs wild type (WT), 1 (1.3%) rrs WT MUT1 and MUT2 (WT; A1401G and G1484T), 1 (1.3%) rrs WT1, MUT1 (A1401G), 9 (11.7%) rrs WT1, MUT1 (A1401G), and 1 (1.3%) rrs WT1, MUT1. Mutation at position 1401 in rrs leads to resistance to KAN (7/77=9%), AMK (9/77=11.68%), and CAP (5/77=6.49%). Eleven (14.28%) streptomycin-resistant strains had a rrs mutation.
Isolates with rrs structural gene mutations were cross-resistant to streptomycin, KAN, CAP, and AMK. Detection of the A1401G mutation appeared to be 100% specific for the detection of resistance to KAN and AMK. Being the first assessment, these data establish the presence of phenotypic drug-resistant and extensively drug-resistant strains using molecular profiling and are helpful in understanding aminoglycoside resistance on a molecular level.
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