Structural and dynamic insights into the energetics of activation loop rearrangement in FGFR1 kinase

Protein tyrosine kinases differ widely in their propensity to undergo rearrangements of the N-terminal Asp- Phe-Gly motif of the activation loop, with some, including FGFR1 kinase, appearing refractory to this so called ‘DFG flip’. Recent inhibitor-bound structures have unexpectedly revealed FGFR1 for the first time in a ‘DFG-out’ state. Here, we use conformationally-selective inhibitors as chemical probes for interrogation of the structural and dynamic features that appear to govern the DFG flip in FGFR1. Our detailed structural and biophysical insights identify contributions from altered dynamics in distal elements, including the ?H helix towards the outstanding stability of the DFG-out complex with the inhibitor ponatinib. We conclude that the ?C-?4 loop and ‘molecular brake’ regions together impose a high energy barrier for this conformational rearrangement, and that this may have significance for maintaining autoinhibition in the non-phosphorylated basal state of FGFR1

Structural and functional responses of macroinvertebrate assemblages to long‐term flow variability at perennial and nonperennial sites

Temporary streams constitute a significant proportion of rivers globally and are common in wet, cool, temperate regions. These heterogeneous ecosystems harbour high biodiversity associated with the dynamic turnover of taxa. Despite flow permanence being widely recognised as an important environmental control, few studies have characterised biotic responses to long‐term hydrological variability in temporary streams. We examined taxonomic and functional macroinvertebrate communities of perennial and nonperennial river reaches over a 26‐year period. Flow permanence resulted in spatial variation in taxonomic and functional macroinvertebrate communities. Nonperennial river reaches, which were characterised by dynamic habitat provision (lotic, lentic, and dry states) over the study period, supported more heterogeneous communities than perennial river reaches. Hydrological variables, in particular wetted width, water depth, and zero‐flow states, were instrumental in structuring taxonomic and functional communities, although the importance of substrate conditions increased in autumn. Hydrological conditions resulted in separation of perennial and nonperennial taxonomic communities regardless of season, whereas functional communities differed only in spring. Our results emphasise that understanding of community responses to hydrological variability is enhanced by analyses that concurrently explore taxonomic and functional responses to long‐term intraannual and interannual hydrological variability. Moreover, functional responses represent a robust method to test ecological responses to hydrological drivers. Further research that builds on our work is needed to inform the protection of both perennial and nonperennial streams as they adapt to ongoing environmental change

Acupuncture as analgesia for low back pain, ankle sprain and migraine in emergency departments: Study protocol for a randomized controlled trial

BACKGROUND: Pain is the most common reason that patients present to an emergency department (ED) and is often inadequately managed. Evidence suggests that acupuncture is effective for pain relief, yet it is rarely practiced in the ED. The current study aims to assess the efficacy of acupuncture for providing effective analgesia to patients presenting with acute low back pain, migraine and ankle sprain at the EDs of four hospitals in Melbourne, Australia. METHOD: The study is a multi-site, randomized, assessor-blinded, controlled trial of acupuncture analgesia in patients who present to an ED with low back pain, migraine or ankle sprain. Patients will be block randomized to receive either acupuncture alone, acupuncture as an adjunct to pharmacotherapy or pharmacotherapy alone. Acupuncture will be applied according to Standards for Reporting Interventions in Clinical Trials of Acupuncture (STRICTA). Pain after one hour, measured using a visual analogue scale (VAS), is the primary outcome. Secondary outcomes measures include the following instruments; the Oswestry low back pain disability questionnaire, 24-hour Migraine Quality of Life questionnaire and Patient's Global Assessment of Ankle Injury Scale. These measures will be recorded at baseline, 1 hour after intervention, each hour until discharge and 48±12 hours of ED discharge. Data will also be collected on the safety and acceptability of acupuncture and health resource utilization. DISCUSSION: The results of this study will determine if acupuncture, alone or as an adjunct to pharmacotherapy provides effective, safe and acceptable pain relief for patients presenting to EDs with acute back pain, migraine or ankle sprain. The results will also identify the impact that acupuncture treatment may have upon health resource utilisation in the ED setting. TRIAL REGISTRATION: Australia and New Zealand Clinical Trials Register (ANZCTR): ACTRN12609000989246

A two-in-one superhydrophobic and anti-reflective nanodevice in the grey cicada Cicada orni (Hemiptera)

Two separated levels of functionality are identified in the nanostructure which covers the wings of the grey cicada $\textit{Cicada orni}$ (Hemiptera). The upper level is responsible for superhydrophobic character of the wing while the lower level enhances its anti-reflective behavior. Extensive wetting experiments with various chemical species and optical measurements were performed in order to assess the bi-functionality. Scanning electron microscopy imaging was used to identify the nanostructure morphology. Numerical optical simulations and analytical wetting models were used to prove the roles of both levels of the nanostructure. In addition, the complex refractive index of the chitinous material of the wing was determined from measurements.Comment: 8 pages, 10 figures, final version published in Journal of Applied Physic

Exploiting bacterial DNA gyrase as a drug target: current state and perspectives

DNA gyrase is a type II topoisomerase that can introduce negative supercoils into DNA at the expense of ATP hydrolysis. It is essential in all bacteria but absent from higher eukaryotes, making it an attractive target for antibacterials. The fluoroquinolones are examples of very successful gyrase-targeted drugs, but the rise in bacterial resistance to these agents means that we not only need to seek new compounds, but also new modes of inhibition of this enzyme. We review known gyrase-specific drugs and toxins and assess the prospects for developing new antibacterials targeted to this enzyme

Characterisation of radioiodinated flavonoid derivatives for SPECT imaging of cerebral prion deposits

Prion diseases are fatal neurodegenerative diseases characterised by deposition of amyloid plaques containing abnormal prion protein aggregates (PrPSc). This study aimed to evaluate the potential of radioiodinated flavonoid derivatives for single photon emission computed tomography (SPECT) imaging of PrPSc. In vitro binding assays using recombinant mouse PrP (rMoPrP) aggregates revealed that the 4-dimethylamino-substituted styrylchromone derivative (SC-NMe2) had higher in vitro binding affinity (Kd = 24.5 nM) and capacity (Bmax = 36.3 pmol/nmol protein) than three other flavonoid derivatives (flavone, chalcone, and aurone). Fluorescent imaging using brain sections from mouse-adapted bovine spongiform encephalopathy (mBSE)-infected mice demonstrated that SC-NMe2 clearly labelled PrPSc-positive prion deposits in the mice brain. Two methoxy SC derivatives, SC-OMe and SC-(OMe)2, also showed high binding affinity for rMoPrP aggregates with Ki values of 20.8 and 26.6 nM, respectively. In vitro fluorescence and autoradiography experiments demonstrated high accumulation of [125I]SC-OMe and [125I]SC-(OMe)2 in prion deposit-rich regions of the mBSE-infected mouse brain. SPECT/computed tomography (CT) imaging and ex vivo autoradiography demonstrated that [123I]SC-OMe showed consistent brain distribution with the presence of PrPSc deposits in the mBSE-infected mice brain. In conclusion, [123I]SC-OMe appears a promising SPECT radioligand for monitoring prion deposit levels in the living brain