1,166 research outputs found

    The 'Antibiotic Apocalypse' - scaremongering or scientific reporting?

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    Antimicrobial resistance is dominating scientific media. We are warned of an impending 'antibiotic apocalypse', where mankind faces its biggest threat, untreatable microbes. However, the world is not ending. Scientists are responding to the threat; new knowledge and chemotherapeutics are being created to safeguard our future. The future is bright, not gloomy

    Role of tumour necrosis factor gene polymorphisms (-308 and -238) in breast cancer susceptibility and severity

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    Introduction Genetic polymorphisms in the promoter region of the tumour necrosis factor (TNF) gene can regulate gene expression and have been associated with inflammatory and malignant conditions. We have investigated two polymorphisms in the promoter of the TNF gene (-308 G>A and -238 G>A) for their role in breast cancer susceptibility and severity by means of an allelic association study. Methods Using a case–control study design, breast cancer patients (n = 709) and appropriate age-matched and sex-matched controls obtained from the Breast Screening Unit (n = 498) were genotyped for these TNF polymorphisms, using a high-throughput allelic discrimination method. Results Allele frequencies for both polymorphisms were similar in both breast cancer cases and controls. However, the -308 polymorphism was found to be associated with vascular invasion in breast tumours (P = 0.024). Comparison with other standard prognostic indices did not show any association for either genotype. Conclusions We demonstrated no association between the -308G>A polymorphism and the -238G>A polymorphism in the promoter region of TNF and susceptibility to breast cancer, in a large North European population. However, the -308 G>A polymorphism was found to be associated with the presence of vascular invasion in breast tumours

    Modelling a silent epidemic:A review of the in vitro models of latent tuberculosis

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    Tuberculosis (TB) is the primary cause of death by a single infectious agent; responsible for around two million deaths in 2016. A major virulence factor of TB is the ability to enter a latent or Non-Replicating Persistent (NRP) state which is presumed untreatable. Approximately 1.7 billion people are latently infected with TB and on reactivation many of these infections are drug resistant. As the current treatment is ineffective and diagnosis remains poor, millions of people have the potential to reactivate into active TB disease. The immune system seeks to control the TB infection by containing the bacteria in a granuloma, where it is exposed to stressful anaerobic and nutrient deprived conditions. It is thought to be these environmental conditions that trigger the NRP state. A number of in vitro models have been developed that mimic conditions within the granuloma to a lesser or greater extent. These different models have all been utilised for the research of different characteristics of NRP Mycobacterium tuberculosis, however their disparity in approach and physiological relevance often results in inconsistencies and a lack of consensus between studies. This review provides a summation of the different NRP models and a critical analysis of their respective advantages and disadvantages relating to their physiological relevance

    Modular Decomposition Numbers of Cyclotomic Hecke and Diagrammatic Cherednik Algebras: a Path Theoretic Approach

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    We introduce a path theoretic framework for understanding the representation theory of (quantum) symmetric and general linear groups and their higher-level generalizations over fields of arbitrary characteristic. Our first main result is a ‘super-strong linkage principle’ which provides degree-wise upper bounds for graded decomposition numbers (this is new even in the case of symmetric groups). Next, we generalize the notion of homomorphisms between Weyl/Specht modules which are ‘generically’ placed (within the associated alcove geometries) to cyclotomic Hecke and diagrammatic Cherednik algebras. Finally, we provide evidence for a higher-level analogue of the classical Lusztig conjecture over fields of sufficiently large characteristic

    Decomposition numbers for the cyclotomic Brauer algebras in characteristic zero

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    We study the representation theory of the cyclotomic Brauer algebra via truncation to idempotent subalgebras which are isomorphic to a product of walled and classical Brauer algebras. In particular, we determine the block structure and decomposition numbers in characteristic zero.Comment: 20 pages, 12 figure

    Effect of Amoxicillin in combination with Imipenem-Relebactam against Mycobacterium abscessus

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    Infections caused by Mycobacterium abscessus are increasing in prevalence in cystic fibrosis patients. This opportunistic pathogen′s intrinsic resistance to most antibiotics has perpetuated an urgent demand for new, more effective therapeutic interventions. Here we report a prospective advance in the treatment of M. abscessus infection; increasing the susceptibility of the organism to amoxicillin, by repurposing the β-lactamase inhibitor, relebactam, in combination with the front line M. abscessus drug imipenem. We establish by multiple in vitro methods that this combination works synergistically to inhibit M. abscessus. We also show the direct competitive inhibition of the M. abscessus β-lactamase, BlaMab, using a novel assay, which is validated kinetically using the nitrocefin reporter assay and in silico binding studies. Furthermore, we reverse the susceptibility by overexpressing BlaMab in M. abscessus, demonstrating relebactam-BlaMab target engagement. Finally, we highlight the in vitro efficacy of this combination against a panel of M. abscessus clinical isolates, revealing the therapeutic potential of the amoxicillin-imipenem-relebactam combination

    In vitro synergy between manuka honey and amikacin against Mycobacteria abscessus complex shows potential for nebulisation therapy

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    Mycobacterium abscessusis an opportunistic human pathogen of increasing concern, due to its ability to cause aggressive pulmonary infections (especially in cystic fibrosis patients), as well as skin and soft tissue infections. M. abscessus is intrinsically drug resistant and treatment regimens are lengthy, consisting of multiple antibiotics with severe side effects and poor patient success rates. New and novel strategies are urgently required to combat these infections. One such strategy thus far overlooked for mycobacteria is manuka honey. For millennia manuka honey has been shown to have wide ranging medicinal properties, which have more recently been identified for its broad spectrum of antimicrobial activity. Here we demonstrate that manuka honey can be used to inhibit M. abscessus and a variety of drug resistant clinical isolates in vitro. We also demonstrate using a microbroth dilution checkerboard assay that manuka honey works synergistically with amikacin, which is one of the current front line antibiotics used for treatment of M. abscessus infections. This was further validated using an in vitro inhalation model, where we showed that with the addition of manuka honey, the amikacin dosage can be lowered whilst increasing its efficacy. These findings demonstrate the utility of manuka honey for incorporation into nebulised antibiotic treatment for respiratory infections, in particular M. abscessus. These results pave the way for a change of strategy for M. abscessus management, offering new therapeutic options for this deadly infection

    Crystal structure of Mycobacterium tuberculosis FadB2 implicated in mycobacterial β-oxidation

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    The intracellular pathogen Mycobacterium tuberculosis is the causative agent of tuberculosis, which is a leading cause of mortality worldwide. The survival of M. tuberculosis in host macrophages through long-lasting periods of persistence depends, in part, on breaking down host cell lipids as a carbon source. The critical role of fatty-acid catabolism in this organism is underscored by the extensive redundancy of the genes implicated in β-oxidation (∼100 genes). In a previous study, the enzymology of the M. tuberculosisl-3-hydroxyacyl-CoA dehydrogenase FadB2 was characterized. Here, the crystal structure of this enzyme in a ligand-free form is reported at 2.1 Å resolution. FadB2 crystallized as a dimer with three unique dimer copies per asymmetric unit. The structure of the monomer reveals a dual Rossmann-fold motif in the N-terminal domain, while the helical C-terminal domain mediates dimer formation. Comparison with the CoA- and NAD + -bound human orthologue mitochondrial hydroxyacyl-CoA dehydrogenase shows extensive conservation of the residues that mediate substrate and cofactor binding. Superposition with the multi-catalytic homologue M. tuberculosis FadB, which forms a trifunctional complex with the thiolase FadA, indicates that FadB has developed structural features that prevent its self-association as a dimer. Conversely, FadB2 is unable to substitute for FadB in the tetrameric FadA–FadB complex as it lacks the N-terminal hydratase domain of FadB. Instead, FadB2 may functionally (or physically) associate with the enoyl-CoA hydratase EchA8 and the thiolases FadA2, FadA3, FadA4 or FadA6 as suggested by interrogation of the STRING protein-network database

    Model of hopping dc conductivity via nearest neighbor boron atoms in moderately compensated diamond crystals

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    Expressions for dependences of the pre-exponential factor \sigma_3 and the thermal activation energy \epsilon_3 of hopping electric conductivity of holes via boron atoms on the boron atom concentration N and the compensation ratio K are obtained in the quasiclassical approximation. It is assumed that the acceptors (boron atoms) in charge states (0) and (-1) and the donors that compensate them in the charge state (+1) form a nonstoichiometric simple cubic lattice with translational period R_h = [(1 + K)N]^{-1/3} within the crystalline matrix. A hopping event occurs only over the distance R_h at a thermally activated accidental coincidence of the acceptor levels in charge states (0) and (-1). Donors block the fraction K/(1 - K) of impurity lattice sites. The hole hopping conductivity is averaged over all possible orientations of the lattice with respect to the external electric field direction. It is supposed that an acceptor band is formed by Gaussian fluctuations of the potential energy of boron atoms in charge state (-1) due to Coulomb interaction only between the ions at distance R_h. The shift of the acceptor band towards the top of the valence band with increasing N due to screening (in the Debye--H\"uckel approximation) of the impurity ions by holes hopping via acceptor states was taken into account. The calculated values of \sigma_3(N) and \epsilon_3(N) for K \approx 0.25 agree well with known experimental data at the insulator side of the insulator--metal phase transition. The calculation is carried out at a temperature two times lower than the transition temperature from hole transport in v-band of diamond to hopping conductance via boron atoms.Comment: 6 pages, 2 figure

    Aston University's Antimicrobial Resistance (AMR) Roadshow: raising awareness and embedding knowledge of AMR in key stage 4 learners:raising awareness and embedding knowledge of AMR in key stage 4 learners

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    Antimicrobial resistance (AMR) is a global healthcare problem and therefore raising awareness within young learners is imperative. An AMR roadshow was designed to take key stage 4 students' learning ‘out of the classroom’, assess pre-existing knowledge of AMR and determine the impact of the roadshow on knowledge retention. Knowledge and subsequent retention were measured pre- and post-event through a standardised questionnaire. The roadshow significantly improved knowledge and understanding of AMR, which was retained for a minimum of twelve weeks. Engaging and interactive strategies addressing key health issues provide a positive learning experience which contributes to retained knowledge in young learners
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