Assay strategies for the discovery and validation of therapeutics targeting <i>Brugia pahangi</i> Hsp90

The chemotherapy of lymphatic filariasis relies upon drugs such as diethylcarbamazine and ivermectin that largely target the microfilarial stages of the parasite, necessitating continued treatment over the long reproductive life span of the adult worm. The identification of compounds that target adult worms has been a long-term goal of WHO. Here we describe a fluorescence polarization assay for the identification of compounds that target Hsp90 in adult filarial worms. The assay was originally developed to identify inhibitors of Hsp90 in tumor cells, and relies upon the ability of small molecules to inhibit the binding of fluorescently labelled geldanamycin to Hsp90. We demonstrate that the assay works well with soluble extracts of Brugia, while extracts of the free-living nematode C. elegans fail to bind the probe, in agreement with data from other experiments. The assay was validated using known inhibitors of Hsp90 that compete with geldanamycin for binding to Hsp90, including members of the synthetic purine-scaffold series of compounds. The efficacy of some of these compounds against adult worms was confirmed in vitro. Moreover, the assay is sufficiently sensitive to differentiate between binding of purine-scaffold compounds to human and Brugia Hsp90. The assay is suitable for high-throughput screening and provides the first example of a format with the potential to identify novel inhibitors of Hsp90 in filarial worms and in other parasitic species where Hsp90 may be a target

Observer performance in Computed Tomography head reporting

Aim: To audit the reporting results of a cohort of radiographers (n=6) completing an accredited academic programme in clinical reporting of Computed Tomography (CT) head examinations. Methods: An audit of retrospective academic image case banks and prospective random clinical workload case banks. Both the academic test banks and clinical workload banks included a wide range of normal and abnormal cases of different levels of difficulty and pathology. Abnormalities included: haemorrhage, fractures, lesions, infarctions, degeneration, and normal variants from a variety of referral sources. True positive and negative, as well as false positive and negative fractions were used to mark the reports, which were analysed for accuracy against a reference standard. Further interobserver variability was assessed using Cohens Kappa, one-way analysis of variance and Tukey for multiple comparisons and significance testing at 95% confidence intervals. Results: The mean accuracy score for all radiographers (n=6) and reports (n=3,008) was 90.7% (95%CI 88.3%-93.0%). Mean sensitivity and specificity rate was 86.9% (95%CI 85.8%-88.2%), and 94% (95%CI 89.6%-98.3%) respectively. The most common errors were associated with herniation, lacunar infarctions and subtle fractures (false negatives) and involutional changes, subtle infarctions, and ventricular dilation (false positives). Conclusions: The results suggest appropriately trained radiographers can successfully undertake to report CT head examinations to a high standard. The adoption of both academic and clinical workload image banks that reflect disease examples and the prevalence that may logically be encountered in practice offers the potential for an accurate measure of performance of radiographer’s abilities

CT head reporting by radiographers: results of an accredited postgraduate programme

Aim: To evaluate the results of the summative objective structured examination (OSE) for the first four cohorts of radiographers (n ¼ 24) undertaking an accredited postgraduate course in reporting computer tomography (CT) head examinations. Method: The construction of a summative OSE contained twenty five CT head examinations that incorporated 1:1 normal to abnormal pathological examples. All cases were blind reported by three consultant radiologists to produce a valid reference standard report for comparison with the radiographer's interpretation. The radiographers (n ¼ 24) final reports (n ¼ 600) were analysed to determine the sensitivity, specificity and agreement values and concordance for the four cohorts. Results: The four cohorts (2007e2013) of postgraduate radiography students' collective OSE results established a mean sensitivity rate of 99%, specificity 95% and agreement concordance rates of 90%. The final grades indicate that within an academic environment, trained radiographers possess high levels of diagnostic performance accuracy in the interpretation of CT head examinations

Small but crucial : the novel small heat shock protein Hsp21 mediates stress adaptation and virulence in Candida albicans

Peer reviewedPublisher PD

AFROC analysis of reporting radiographer’s performance in CT head interpretation

Aim: A preliminary small scale study to assess the diagnostic performance of a limited group of reporting radiographers and consultant radiologists in clinical practice undertaking computer tomography (CT) head interpretation . Method: A multiple reader multiple case (MRMC) alternative free response receiver operating characteristic (AFROC) methodology was applied. Utilising an image bank of 30 CT head examinations, with a 1:1 ratio of normal to abnormal cases. A reference standard was established by double reporting the original reports using two additional independent consultant radiologists with arbitration of discordance by the researcher. Twelve observers from six southern National Health Service (NHS) trusts were invited to participate. The results were compared for accuracy, agreement, sensitivity, specificity. Data analysis used AFROC and area under the curve (AUC) with standard error. Results: The reporting radiographers results demonstrated a mean sensitivity rate of 88.7% (95% CI 82.3 to 95.1%), specificity 95.6% (96% CI 90.1 to 100%) and accuracy of 92.2% (95% CI 89.3 to 95%). The consultant radiologists mean sensitivity rate was 83.35% (95% CI 80 to 86.7%), specificity 90% (95% CI 86.7 to 93.3%) and accuracy of 86.65% (95% CI 83.3 to 90%). Observer performance between the two groups was compared with AFROC, AUC, and standard error analysis (p=0.94, SE 0.202). Conclusion: The findings of this research indicate that within a limited study, a small group of reporting radiographers demonstrated high levels of diagnostic accuracy in the interpretation of CT head examinations that was equivalent to a small selection of consultant radiologists

Origin and geochemical evolution of the Madeira-Tore Rise (eastern North Atlantic)

The Madeira-Tore Rise, located ∼700 km off the NW African coast, forms a prominent ridge in the east Atlantic. The age and origin of the rise are controversial. This study presents major and trace element, Sr, Nd, Pb, Hf isotope and 40Ar/39Ar age determinations from volcanic rocks dredged from different sites along the rise. In addition, isotopic compositions of rock samples from Great Meteor Seamount in the central Atlantic are presented. The new radiometric and paleontologically constrained ages identify two major episodes of volcanism: The first is the base of the rise (circa 80 to >95 Ma) and the second is seamounts on the rise (0.5–16 Ma). It is proposed that interaction of the Canary hot spot with the Mid-Atlantic spreading center formed the deep basement of the Madeira-Tore Rise and the J-Anomaly Ridge west of the Atlantic spreading center in the Mid-Cretaceous. Age and geochemical data and plate tectonic reconstructions suggest, however, that the recovered Late Cretaceous volcanic rocks represent late stage volcanism from the time when the Madeira-Tore Rise was still close to the Canary hot spot. Long after moving away from the influence of the Canary hot spot, the Madeira-Tore Rise was overprinted by late Cenozoic volcanism. Miocene to Pleistocene volcanism at the northern end of the rise can be best explained by decompression mantle melting beneath extensional sectors of the Azores-Gibraltar Fracture Zone (African-Eurasian plate boundary). The geochemical compositions of these volcanic rocks suggest that the magmas were variably contaminated by enriched material within or derived by melting of enriched material underplated at the base of the lithosphere, possibly originating from the Cretaceous Canary plume. Alternatively, these late Cenozoic volcanic rocks may have derived from decompression melting of enriched pyroxenitic/eclogitic material in the upper mantle. Isotopically more depleted Pliocene to Pleistocene volcanism at the southern end of the Madeira-Tore Rise may be related to the nearby Madeira hot spot

Methodological quality of systematic reviews of animal studies: a survey of reviews of basic research

BACKGROUND: Systematic reviews can serve as a tool in translation of basic life sciences research from laboratory to human research and healthcare. The extent to which reviews of animal research are systematic and unbiased is not known. METHODS: We searched, without language restrictions, Medline, Embase, bibliographies of known reviews (1996–2004) and contacted experts to identify citations of reviews of basic science literature which, as a minimum, performed search of a publicly available resource. From these we identified reviews of animal studies where laboratory variables were measured or where treatments were administered to live animals to examine their effects, and compared them with reviews of bench studies in which human or animal tissues, cell systems or organ preparations were examined in laboratories to better understand mechanisms of diseases. RESULTS: Systematic reviews of animal studies often lacked methodological features such as specification of a testable hypothesis (9/30, 30%); literature search without language restriction (8/30, 26.6%); assessment of publication bias (5/30, 16.6%), study validity (15/30, 50%) and heterogeneity (10/30, 33.3%); and meta-analysis for quantitative synthesis (12/30, 40%). Compared to reviews of bench studies, they were less prone to bias as they specified the question (96.6% vs. 80%, p = 0.04), searched multiple databases (60% vs. 26.6%, p = 0.01), assessed study quality (50% vs. 20%, p = 0.01), and explored heterogeneity (33.3% vs. 2.2%, p = 0.001) more often. CONCLUSION: There seems to be a gradient of frequency of methodological weaknesses among reviews: Attempted systematic reviews of whole animal research tend to be better than those of bench studies, though compared to systematic reviews of human clinical trials they are apparently poorer. There is a need for rigour when reviewing animal research

Measurement of the ratios of the Z/G* + >= n jet production cross sections to the total inclusive Z/G* cross section in ppbar collisions at sqrt(s) = 1.96 TeV

We present a study of events with Z bosons and jets produced at the Fermilab Tevatron Collider in ppbar collisions at a center of mass energy of 1.96 TeV. The data sample consists of nearly 14,000 Z/G* -> e+e- candidates corresponding to the integrated luminosity of 0.4 fb-1 collected using the D0 detector. Ratios of the Z/G* + >= n jet cross sections to the total inclusive Z/G* cross section have been measured for n = 1 to 4 jet events. Our measurements are found to be in good agreement with a next-to-leading order QCD calculation and with a tree-level QCD prediction with parton shower simulation and hadronization.Comment: 7 pages, 2 figures, slightly modified, submitted to Phys. Lett.

Measurement of the ppbar to ttbar production cross section at sqrt(s)=1.96 TeV in the fully hadronic decay channel

A measurement of the top quark pair production cross section in proton anti-proton collisions at an interaction energy of sqrt(s)=1.96 TeV is presented. This analysis uses 405 pb-1 of data collected with the D0 detector at the Fermilab Tevatron Collider. Fully hadronic ttbar decays with final states of six or more jets are separated from the multijet background using secondary vertex tagging and a neural network. The ttbar cross section is measured as sigma(ttbar)=4.5 -1.9 +2.0 (stat) -1.1 +1.4 (syst) +/- 0.3 (lumi) pb for a top quark mass of m(t) = 175 GeV/c^2.Comment: 10 pages, 10 figures, submitted to Phys. Rev.

Anaesthesiological strategies in elective craniotomy: randomized, equivalence, open trial – The NeuroMorfeo trial

<p>Abstract</p> <p>Background</p> <p>Many studies have attempted to determine the <it>"best" </it>anaesthetic technique for neurosurgical procedures in patients without intracranial hypertension. So far, no study comparing intravenous (IA) with volatile-based neuroanaesthesia (VA) has been able to demonstrate major outcome differences nor a superiority of one of the two strategies in patients undergoing elective supratentorial neurosurgery. Therefore, current practice varies and includes the use of either volatile or intravenous anaesthetics in addition to narcotics. Actually the choice of the anaestesiological strategy depends only on the anaesthetists' preferences or institutional policies.</p> <p>This trial, named NeuroMorfeo, aims to assess the equivalence between volatile and intravenous anaesthetics for neurosurgical procedures.</p> <p>Methods/Design</p> <p>NeuroMorfeo is a multicenter, randomized, open label, controlled trial, based on an equivalence design. Patients aged between 18 and 75 years, scheduled for elective craniotomy for supratentorial lesion without signs of intracranial hypertension, in good physical state (ASA I-III) and Glasgow Coma Scale (GCS) equal to 15, are randomly assigned to one of three anaesthesiological strategies (two VA arms, sevoflurane + fentanyl or sevoflurane + remifentanil, and one IA, propofol + remifentanil). The equivalence between intravenous and volatile-based neuroanaesthesia will be evaluated by comparing the intervals required to reach, after anaesthesia discontinuation, a modified Aldrete score ≥ 9 (primary end-point). Two statistical comparisons have been planned:</p> <p>1) sevoflurane + fentanyl vs. propofol + remifentanil;</p> <p>2) sevoflurane + remifentanil vs. propofol + remifentanil.</p> <p>Secondary end-points include: an assessment of neurovegetative stress based on (a) measurement of urinary catecholamines and plasma and urinary cortisol and (b) estimate of sympathetic/parasympathetic balance by power spectrum analyses of electrocardiographic tracings recorded during anaesthesia; intraoperative adverse events; evaluation of surgical field; postoperative adverse events; patient's satisfaction and analysis of costs.</p> <p>411 patients will be recruited in 14 Italian centers during an 18-month period.</p> <p>Discussion</p> <p>We presented the development phase of this anaesthesiological on-going trial. The recruitment started December 4^th, 2007 and up to 4^th, December 2008, 314 patients have been enrolled.</p