A phenotypic screen of the Global Health Priority Box identifies an insecticide with anthelmintic activity.

BACKGROUND: Infection with parasitic nematodes (helminths), particularly those of the order Strongylida (such as Haemonchus contortus), can cause significant and burdensome diseases in humans and animals. Widespread drug (anthelmintic) resistance in livestock parasites, the absence of vaccines against most of these nematodes, and a lack of new and effective chemical entities on the commercial market demands the discovery of new anthelmintics. In the present study, we searched the Global Health Priority Box (Medicines for Malaria Venture) for new candidates for anthelmintic development. METHODS: We employed a whole-organism, motility-based phenotypic screening assay to identify compounds from the Global Health Priority Box with activity against larvae of the model parasite H. contortus, and the free-living comparator nematode Caenorhabditis elegans. Hit compounds were further validated via dose-response assays, with lead candidates then assessed for nematocidal activity against H. contortus adult worms, and additionally, for cytotoxic and mitotoxic effects on human hepatoma (HepG2) cells. RESULTS: The primary screen against H. contortus and C. elegans revealed or reidentified 16 hit compounds; further validation established MMV1794206, otherwise known as 'flufenerim', as a significant inhibitor of H. contortus larval motility (half-maximal inhibitory concentration [IC50] = 18 µM) and development (IC50 = 1.2 µM), H. contortus adult female motility (100% after 12 h of incubation) and C. elegans larval motility (IC50 = 0.22 µM). Further testing on a mammalian cell line (human hepatoma HepG2 cells), however, identified flufenerim to be both cytotoxic (half-maximal cytotoxic concentration [CC50] < 0.7 µM) and mitotoxic (half-maximal mitotoxic concentration [MC50] < 0.7 µM). CONCLUSIONS: The in vitro efficacy of MMV1794206 against the most pathogenic stages of H. contortus, as well as the free-living C. elegans, suggests the potential for development as a broad-spectrum anthelmintic compound; however, the high toxicity towards mammalian cells presents a significant hindrance. Further work should seek to establish the protein-drug interactions of MMV1794206 in a nematode model, to unravel the mechanism of action, in addition to an advanced structure-activity relationship investigation to optimise anthelmintic activity and eliminate mammalian cell toxicity.

Structure-activity relationship and target investigation of 2-aryl quinolines with nematocidal activity.

Within the context of our anthelmintic discovery program, we recently identified and evaluated a quinoline derivative, called ABX464 or obefazimod, as a nematocidal candidate; synthesised a series of analogues which were assessed for activity against the free-living nematode Caenorhabditis elegans; and predicted compound-target relationships by thermal proteome profiling (TPP) and in silico docking. Here, we logically extended this work and critically evaluated the anthelmintic activity of ABX464 analogues on Haemonchus contortus (barber's pole worm) - a highly pathogenic nematode of ruminant livestock. First, we tested a series of 44 analogues on H. contortus (larvae and adults) to investigate the nematocidal pharmacophore of ABX464, and identified one compound with greater potency than the parent compound and showed moderate activity against a select number of other parasitic nematodes (including Ancylostoma, Heligmosomoides and Strongyloides species). Using TPP and in silico modelling studies, we predicted protein HCON_00074590 (a predicted aldo-keto reductase) as a target candidate for ABX464 in H. contortus. Future work aims to optimise this compound as a nematocidal candidate and investigate its pharmacokinetic properties. Overall, this study presents a first step toward the development of a new nematocide.

Structure activity relationship and target prediction for ABX464 analogues in Caenorhabditis elegans.

Global challenges with treatment failures and/or widespread resistance in parasitic worms against commercially available anthelmintics lend impetus to the development of new anthelmintics with novel mechanism(s) of action. The free-living nematode Caenorhabditis elegans is an important model organism used for drug discovery, including the screening and structure-activity investigation of new compounds, and target deconvolution. Previously, we conducted a whole-organism phenotypic screen of the 'Pandemic Response Box' (from Medicines for Malaria Venture, MMV) and identified a hit compound, called ABX464, with activity against C. elegans and a related, parasitic nematode, Haemonchus contortus. Here, we tested a series of 44 synthesized analogues to explore the pharmacophore of activity on C. elegans and revealed five compounds whose potency was similar or greater than that of ABX464, but which were not toxic to human hepatoma (HepG2) cells. Subsequently, we employed thermal proteome profiling (TPP), protein structure prediction and an in silico-docking algorithm to predict ABX464-target candidates. Taken together, the findings from this study contribute significantly to the early-stage drug discovery of a new nematocide based on ABX464. Future work is aimed at validating the ABX464-protein interactions identified here, and at assessing ABX464 and associated analogues against a panel of parasitic nematodes, towards developing a new anthelmintic with a mechanism of action that is distinct from any of the compounds currently-available commercially.

The everolimus eluting Synergy MegatronTM drug-eluting stent platform: Early outcomes from the European Synergy MegatronTM Implanters' Registry.

BACKGROUND: The Synergy MegatronTM is an everolimus-drug eluting stent that may offer advantages in the treatment of aorto-ostial disease and large proximal vessels. AIMS: To report the short- to medium-term clinical outcomes from the European Synergy MegatronTM Implanters' Registry. METHODS: This registry was an investigator-initiated study conducted at 14 European centers. The primary outcome was target lesion failure (TLF), defined as the composite of cardiovascular death, target vessel myocardial infarction (MI), and target lesion revascularisation. RESULTS: Five hundred seventy-five patients underwent PCI with MegatronTM between 2019 and 2021. Patients were 69 ± 12 years old, 26% had diabetes mellitus, 24% had moderate-severe left ventricular impairment and 59% presented with an acute coronary syndrome. 15% were deemed prohibitively high risk for surgical revascularisation. The target vessel involved the left main stem in 55%, the ostium of the RCA in 13% and was a true bifurcation (Medina 1,1,1) in 50%.  At 1 year, TLF was observed in 40 patients, with 26 (65%) occurring within the first 30 days. The cumulative incidence of TLF was 4.5% at 30 days and 8.6% (95% CI 6.3-11.7) at 1 year. The incidence of stent thrombosis was 0.5% with no late stent thromboses. By multivariate analysis, the strongest independent predictors of TLF were severe left ventricular impairment (HR 3.43, 95% CI: 1.67-6.76, p < 0.001) and a target vessel involving the left main (HR 4.00 95% CI 1.81-10.15 p = 0.001). CONCLUSIONS: Use of the Synergy MegatronTM everolimus eluting stent in a 'real-world' setting shows favorable outcomes at 30 days and 1 year.

A High-Throughput Phenotypic Screen of the 'Pandemic Response Box' Identifies a Quinoline Derivative with Significant Anthelmintic Activity.

Parasitic nematodes cause diseases in livestock animals and major economic losses to the agricultural industry worldwide. Nematodes of the order Strongylida, including Haemonchus contortus, are particularly important. The excessive use of anthelmintic compounds to treat infections and disease has led to widespread resistance to these compounds in nematodes, such that there is a need for new anthelmintics with distinctive mechanisms of action. With a focus on discovering new anthelmintic entities, we screened 400 chemically diverse compounds within the 'Pandemic Response Box' (from Medicines for Malaria Venture, MMV) for activity against H. contortus and its free-living relative, Caenorhabditis elegans-a model organism. Using established phenotypic assays, test compounds were evaluated in vitro for their ability to inhibit the motility and/or development of H. contortus and C. elegans. Dose-response evaluations identified a compound, MMV1581032, that significantly the motility of H. contortus larvae (IC50 = 3.4 ± 1.1 µM) and young adults of C. elegans (IC50 = 7.1 ± 4.6 µM), and the development of H. contortus larvae (IC50 = 2.2 ± 0.7 µM). The favourable characteristics of MMV1581032, such as suitable physicochemical properties and an efficient, cost-effective pathway to analogue synthesis, indicates a promising candidate for further evaluation as a nematocide. Future work will focus on a structure-activity relationship investigation of this chemical scaffold, a toxicity assessment of potent analogues and a mechanism/mode of action investigation.

MRI rectal cancer in Australia and New Zealand: An audit from the PETACC-6 trial.

INTRODUCTION: An MRI audit substudy was conducted in patients who underwent an MRI prior to treatment in Australia and New Zealand as part of the PETACC-6 trial in locally advanced rectal cancer. METHODS: A total of 82 patients from 15 centres had rectal MRI scans reviewed for technique, data included in reports and comparison of reports with blinded central reporting by two experienced radiologists. RESULTS: In total, 82% performed minimum T2 sagittal and T2 axial oblique sequences. The high-resolution T2 sequence parameters varied significantly with only 33% obtaining a voxel size of <1.3 mm3 . The rate of inclusion of relevant findings in the reports was T3 distance in mm 21%, N stage 84%, circumferential resection margin (CRM) status 72%, extramural venous invasion (EMVI) status 29% and distance from the puborectalis sling 17%. In total, 31% reports included all of T stage with T3 substage, N stage and CRM involvement. In total, 17% reports included these 3 findings and EMVI. Eleven reports used a template with 82% of these including the first 3 findings. The agreement with central reporters was T stage 76%, N stage 70%, CRM status 57% and EMVI 16%. CONCLUSION: There is significant variation in scan quality and low rates of including all relevant findings in rectal MRI reports in the audit. The authors recommend adoption of routine sequences and template reports in both trial settings and routine practice to improve scan technique and adequacy of reports in rectal cancer MRI staging scans across Australia and New Zealand.

Orbital Varix Thrombosis and Review of Orbital Vascular Anomalies in Blue Rubber Bleb Nevus Syndrome.

A 57-year-old woman with cutaneous manifestations of (BRBNS) presented with acute left proptosis and venous congestion secondary to thrombosis within a superior ophthalmic vein varix. Multiple phleboliths were noted in the contralateral right orbit, and an incidental right middle cerebral artery aneurysm. Her symptoms spontaneously resolved within a few days. An English literature review found 7 reported cases of orbital vascular lesions in association with BRBNS from 1950 to 2012. All lesions showed contrast enhancement on CT or MRI: 4 had small orbital calcifications and 3 were distensible with raised venous pressure. The occurrence of a thrombosed orbital varix or cerebral artery aneurysm in BRBNS, to the best of the authors' knowledge, has not been previously reported. Although orbital vascular lesions in BRBNS have been described as hemangiomas, the biologic behavior and histology of most of the reported orbital lesions are most compatible with venous malformations.

Beyond the balloon: excimer coronary laser atherectomy used alone or in combination with rotational atherectomy in the treatment of chronic total occlusions, non-crossable and non-expansible coronary lesions.

AIMS: To establish success and complication rates of excimer laser coronary atherectomy (ELCA) in a contemporary series of patients with balloon failure during percutaneous coronary intervention (PCI) of both chronic total occlusions (CTO) and lesions with distal TIMI 3 flow. METHODS AND RESULTS: We identified 58 cases of balloon failure treated with ELCA±rotational atherectomy (RA) over four years, representing 0.84% of all PCI performed in our centre during this period. Balloon failures were classified according to: (i) mechanism of balloon failure; and (ii) whether this occurred in the context of treating a CTO. ELCA was performed following balloon failure using the CVX-300 Excimer Laser System and a 0.9 mm catheter with saline flush. For the entire cohort, procedure success was achieved in 91% (with ELCA successful: alone in 76.1%, after RA failure in 6.8% and in combination with RA for 8.6%). Only in one case did RA succeed where ELCA had failed. There were four procedure-related complications, including transient no-reflow, side branch occlusion and two coronary perforations, of which one was directly attributable to ELCA and led to subsequent mortality. CONCLUSIONS: ELCA provides safe and effective adjunctive therapy in contemporary PCI to treat lesions associated with balloon failure due to an inability either to cross the lesion or to expand a balloon sufficiently to permit stenting. ELCA was successful in the majority of these selected cases when used independently with further effectiveness achieved when combined with RA or after RA failure.

Rodent Aanat: intronic E-box sequences control tissue specificity but not rhythmic expression in the pineal gland.

Arylalkylamine N-acetyltransferase (Aanat) is the penultimate enzyme in the serotonin-N-acetylserotonin-melatonin pathway. It is nearly exclusively expressed in the pineal gland and the retina. A marked rhythm of Aanat gene expression in the rat pineal is mediated by cyclic AMP response elements located in the promoter and first intron. Intron 1 also contains E-box elements, which mediate circadian gene expression in other cells. Here we examined whether these elements contribute to rhythmic Aanat expression in the pineal gland. This was done using transgenic rats carrying Aanat transgenes with mutant E-box elements. Circadian expression of Aanat transgenes was not altered by these mutations. However, these mutations enhanced ectopic expression establishing that the intronic Aanat E-box elements contribute to the gene's pineal specific expression. A similar role of the Aanat E-box has been reported in zebrafish, indicating that Aanat E-box mediated silencing is a conserved feature of vertebrate biology.

The management of acute endocarditis.

Infective endocarditis (IE) is an infection, usually of bacterial aetiology, which can affect any part of the endovascular surface of the heart or large intrathoracic vessels but most commonly affects cardiac valves. Without treatment this condition is invariably fatal and even with treatment is associated with a high incidence of morbidity and mortality. This article looks at the difficulties in diagnosing IE and the investigations used to confirm the diagnosis. It also lists the major causes of IE and its management.

Plasma concentrations and role of macrophage inflammatory protein-1alpha during chronic Schistosoma mansoni infection in humans.

Chemokines play an important role during granulomatous inflammation in murine models of Schistosoma mansoni infection. Here, the expression and possible roles of chemokines during human S. mansoni infection were examined. Compared with uninfected individuals, infected patients had elevated plasma concentrations of macrophage inflammatory protein (MIP)-1alpha, RANTES (regulated on activation, normally T cell-expressed and secreted), and eotaxin. Concentrations of macrophage-derived chemokine, eotaxin-2, monocyte chemotactic protein-1, growth-related oncogene, and interleukin-8 were similar between the 2 groups. When subjects were grouped according to disease severity, individuals with a plasma MIP-1alpha concentration >400 pM had a 10-times greater risk of having the more severe hepatosplenic form of disease. In the in vitro granuloma reaction, greater concentrations of MIP-1alpha were produced by cells of patients with hepatosplenic disease than cells of patients with intestinal disease. Pretreatment with a chemokine receptor antagonist attenuated the enhanced in vitro reaction seen with cells derived from patients with hepatosplenic disease. MIP-1alpha may not only mark a subset of patients with a greater risk of having more severe disease but also play a relevant pathophysiological role in human schistosomiasis.