Correspondence - Further reflections of the role of artificial intelligence in acute medicine.

We read with great interest the article "Artificial Intelligence: its Future and Impact on Acute Medicine". Regarding the historical perspective on artificial intelligence (AI) origins, we believe the role of John von Neumann (1903-1957) also deserves emphasis.

Pharmacologic profiling reveals lapatinib as a novel antiviral against SARS-CoV-2 in vitro.

The emergence of SARS-CoV-2 virus has resulted in a worldwide pandemic, but effective antiviral therapies are not widely available. To improve treatment options, we conducted a high-throughput screen to uncover compounds that block SARS-CoV-2 infection. A minimally pathogenic human betacoronavirus (OC43) was used to infect physiologically-relevant human pulmonary fibroblasts (MRC5) to facilitate rapid antiviral discovery in a preclinical model. Comprehensive profiling was conducted on more than 600 compounds, with each compound arrayed across 10 dose points. Our screening revealed several FDA-approved agents that can attenuate both OC43 and SARS-CoV-2 viral replication, including lapatinib, doramapimod, and 17-AAG. Importantly, lapatinib inhibited SARS-CoV-2 RNA replication by over 50,000-fold. Further, both lapatinib and doramapimod could be combined with remdesivir to improve antiviral activity in cells. These findings reveal novel therapeutic avenues that could limit SARS-CoV-2 infection.

An actuatable soft reservoir modulates host foreign body response.

The performance of indwelling medical devices that depend on an interface with soft tissue is plagued by complex, unpredictable foreign body responses. Such devices-including breast implants, biosensors, and drug delivery devices-are often subject to a collection of biological host responses, including fibrosis, which can impair device functionality. This work describes a milliscale dynamic soft reservoir (DSR) that actively modulates the biomechanics of the biotic-abiotic interface by altering strain, fluid flow, and cellular activity in the peri-implant tissue. We performed cyclical actuation of the DSR in a preclinical rodent model. Evaluation of the resulting host response showed a significant reduction in fibrous capsule thickness (P = 0.0005) in the actuated DSR compared with non-actuated controls, whereas the collagen density and orientation were not changed. We also show a significant reduction in myofibroblasts (P = 0.0036) in the actuated group and propose that actuation-mediated strain reduces differentiation and proliferation of myofibroblasts and therefore extracellular matrix production. Computational models quantified the effect of actuation on the reservoir and surrounding fluid. By adding a porous membrane and a therapy reservoir to the DSR, we demonstrate that, with actuation, we could (i) increase transport of a therapy analog and (ii) enhance pharmacokinetics and time to functional effect of an inotropic agent. The dynamic reservoirs presented here may act as a versatile tool to further understand, and ultimately to ameliorate, the host response to implantable biomaterials.

Impact of 3D echocardiography on grading of mitral stenosis and prediction of clinical events

Background: The mitral valve orifice area (MVOA) is difficult to assess accurately by 2D echocardiography because of geometric assumptions; therefore, 3D planimetry may offer advantages. We studied the differences in MVOA measurements between the most frequently used methods, to determine if 3D planimetry would result in the re-grading of severity in any cases, and whether it was a more accurate predictor of clinical outcomes. Methods: This was a head-to-head comparison of the three most commonly used techniques to grade mitral stenosis (MS) by orifice area and to assess their impact on clinical outcomes. 2D measurements (pressure half-time (PHT), planimetry) and 3D planimetry were performed retrospectively on patients with at least mild MS. The clinical primary endpoint was defined as a composite of MV balloon valvotomy, mitral valve repair or replacement (MVR) and/or acute heart failure (HF) admissions. Results: Forty-one consecutive patients were included; the majority were female (35; 85.4%), average age 55 (17) years. Mean and peak MV gradients were 9.4 (4) mmHg and 19 (6) mmHg, respectively. 2D and 3D measures of MVOA differed significantly; mean 2D planimetry MVOA was 1.28 (0.40) cm2, mean 3D planimetry MVOA 1.15 (0.29) cm2 (P = 0.003). Mean PHT MVOA was 1.43 (0.44) cm2 (P = 0.046 and P < 0.001 in comparison to 2D and 3D planimetry methods, respectively). 3D planimetry reclassified 7 (17%) patients from mild-to-moderate MS, and 1 (2.4%) from moderate to severe. Overall, differences between the two methods were significant (X2, P < 0.001). Only cases graded as severe by 3D predicted the primary outcome measure compared with mild or moderate cases (odds ratio 5.7). Conclusion: 3D planimetry in MS returns significantly smaller measurements, which in some cases results in the reclassification of severity. Routine use of 3D may significantly influence the management of MS, with a degree of prediction of clinical outcomes.

Prominent inter-scallop separations of the posterior leaflet of the mitral valve: an important cause of 'pathological' mitral regurgitation.

The 2012 World Heart Federation (WHF) criteria for echocardiographic diagnosis of rheumatic heart disease (RHD) identify that the finding of 'pathological' mitral regurgitation (MR) in a screened individual increases the likelihood of detecting underlying RHD. Cases of isolated "pathological MR are thus identified as 'borderline RHD'. A large-scale echocardiographic screening program (Echo in Africa) in South Africa has identified that inter-scallop separations of the posterior mitral valve leaflet (PMVL) can give rise to 'pathological' MR. The authors propose that this finding when associated with isolated 'pathological' MR is unrelated to the rheumatic disease process. In this case report, we present two examples of 'pathological' MR related to inter-scallop separation from the Echo in Africa image database. We provide additional screening tips to accurately identify this entity.

Network geometry of evidence from randomised controlled trials addressing donor selection and source of haematopoietic progenitor cells used in allogeneic transplantation: a systematic scoping review.

BACKGROUND AND METHODS: A scoping review of randomised controlled trials (RCTs) addressing source of cells and choice of donor for allogeneic haematopoietic cell transplantation (HCT) was performed to create a network of best evidence that allows us to identify new potential indirect comparisons for the strategic development of future studies that connect to the existing evidence network. RESULTS: A total of 19 eligible RCTs (2589 total patients) were identified. Nine studies (1566 patients) compared clinical outcomes following the use of peripheral blood progenitor cells (PBPCs) with bone marrow (BM) from matched related donors (eight studies) or matched unrelated donors (one study). The remaining studies compared BM or PBPCs with various methods of BM stimulation or manipulation (six studies), compared different methods of surface molecule-based selection and/or depletion of grafts (two studies) or compared the optimal number of units for paediatric cord blood transplantation (two studies). No published RCTs compared different types of donors. The geometry of the evidence network was analysed to identify opportunities for potential novel indirect comparisons and to identify opportunities to expand the network. Few indirect comparisons are currently feasible due to small sample size and heterogeneity in patient diagnoses and demographics between treatment nodes in the network. CONCLUSION: More RCTs that enrol greater numbers of similar patients are needed to leverage the current evidence network concerning donor choice and source of cells used in allogeneic HCT.

Screening for rheumatic heart disease: is a paradigm shift required?

This focused review presents a critical appraisal of the World Heart Federation criteria for the echocardiographic diagnosis of rheumatic heart disease (RHD) and its performance in African RHD screening programmes. It identifies various logistical and methodological problems that negatively influence the current guideline's performance. The authors explore novel RHD screening methodology that could address some of these shortcomings and if proven to be of merit, would require a paradigm shift in the approach to the echocardiographic diagnosis of subclinical RHD.

Contrast echocardiography in daily clinical practice.

Ultrasound contrast agents have unique acoustic properties that enable them to enhance the cardiac blood flow and thus are used broadly in modern echocardiography laboratories for salvage of nondiagnostic studies, improving accuracy and reducing variability even in the presence of adequate image quality. Contrast echocardiography is also used as an adjunctive technique when unenhanced echocardiography falls short in the differentiation of cardiac structural abnormalities such as cardiac masses. Ultrasound contrast agents are pure intravascular tracers. Development of innovative ultrasound imaging techniques has led to myocardial perfusion imaging with contrast echocardiography. Although currently an off-label indication, it has been shown that perfusion imaging with contrast echocardiography adds incremental value to stress echocardiography in the detection of coronary artery disease. Moreover, it can be used for assessment of myocardial viability. In this paper we briefly discuss the basics of contrast echocardiography and its use in daily clinical practice.

Impact of co-facilitated information programmes on outcomes for service users and family members: the EOLAS programmes (paper 2).

OBJECTIVE: The present study evaluated the impact on psychosocial outcome of parallel clinician and peer-led information programmes for people with a diagnosis of schizophrenia and bipolar disorder and for family members within an Irish context. METHODS: A sequential mixed method design was used. Quantitative data were collected using pre- and post-programme questionnaires followed by an integrated qualitative component involving semi-structured interviews after the programme. The questionnaires assessed knowledge, attitudes towards recovery, hope, support, advocacy and well-being. Interviews with participants, facilitators and project workers explored their experiences and views of the programme. Findings While a number of the questionnaires did not show a statistically significant change, findings from the interviews suggest that the1 programmes had a number of positive outcomes, including increases in perceived knowledge, empowerment and support. Participants in both programmes valued the opportunity to meet people in similar circumstances, share their experiences, learn from each other and provide mutual support. CONCLUSION: The EOLAS programmes offer a novel template for communication and information sharing in a way that embodies the principles of collaboration and offers users and families a meaningful opportunity to become involved in service design, delivery and evaluation.

Impact of mitral geometry and global afterload on improvement of mitral regurgitation after trans-catheter aortic valve implantation.

OBJECTIVE: To assess the impact of mitral geometry, left ventricular (LV) remodelling and global LV afterload on mitral regurgitation (MR) after trans-catheter aortic valve implantation (TAVI). METHODS: In this study, 60 patients who underwent TAVI were evaluated by 3D echocardiography at baseline, 1 month and 6 months after procedure. The proportional change in MR following TAVI was determined by examining the percentage change in vena contracta (VC) at 6 months. Patients having a significant reduction of at least 30% in VC were defined as good responders (GR) and the remaining patients were defined as poor responders (PR). RESULTS: After 6 months of TAVI, 27 (45%) patients were GR and 33 (55%) were PR. There was a significant decrease in 3DE-derived mitral annular diameter and area (P = 0.001), mitral valve tenting area (TA) (P = 0.05), and mitral papillary muscle dyssynchrony index (DSI) (P = 0.05) in the GR group. 3DE-derived LVESV (P = 0.016), LV mass (P = 0.001) and LV DSI, (P = 0.001) were also improved 6 months after TAVI. In addition, valvulo-arterial impedance (ZVA) was significantly higher at baseline in patients with PR (P = 0.028). 3DE-derived mitral annular area (ß: 0.47, P = 0.04), mitral papillary DSI (ß: -0.65, P = 0.012) and ZVA (ß: 0.45, P = 0.028) were the strongest independent parameters that could predict the reduction of functional MR after TAVI. CONCLUSION: GR patients demonstrate more regression in mitral annulus area and diameter after significant decrease in high LVEDP and trans-aortic gradients with TAVI. PR patients appear to have increased baseline ZVA, mitral valve tenting and restriction in mitral valve coaptation. These factors are important for predicting the impact of TAVI on pre-existing MR.

Stabilizing interactions between D666-S1787 and T657-Y1792 at the A2-A3 interface support factor VIIIa stability in the blood clotting pathway.

UNLABELLED: Essentials Factor VIIIa (FVIIIa) is unstable due to loss of A2; D666 and Y1792 contribute to its stability. We conducted a study to identify the interactions made at these residues at the A2-A3 interface. We present evidence for stabilizing interactions between D666-S1787 and T657-Y1792 in FVIIIa. A D666C/S1788C variant with a disulfide A2-A3 linkage has a FVIIIa decay rate that is 1% of wild-type. SUMMARY: Background Factor (F)VIIIa activity and stability depends on the non-covalent association of the A2 subunit with the A1/A3C1C2 dimer, but the interactions that contribute to A2 association are not well defined. Previous work had shown that D666A and Y1792F mutations at the A2-A3 interface resulted in increased FVIIIa decay, suggesting that the residues were involved in bonding interactions important for FVIIIa stability. Objectives Several potential hydrogen bonding partners of D666 and Y1792 across the A2-A3 interface were selected from the low-resolution FVIII crystal structure, and we used mutagenesis and biochemical analysis to examine the bonding interactions occurring at D666 and Y1792. Methods Using a series of stability and functional analyses, we analyzed FVIII variants in which D666 and Y1792 were each swapped with the residues of potential bonding partners. Results and conclusions We present evidence for hydrogen bonds between D666 and S1787 and between Y1792 and T657 that are important for FVIIIa stability. D666S/S1787D and T657Y/Y1792T variants each displayed wild-type (WT)-like FVIIIa stability and performed like WT FVIII in a series of functional analyses, whereas D666S, S1787D, and Y1792T single variants showed increased FVIIIa decay and a T657Y variant had little FVIIIa activity. These results suggest that WT hydrogen bonds are disrupted with the single mutations but maintained in the swap variants. Furthermore, mutation of D666 and S1788 to cysteine resulted in disulfide bond formation across the A2-A3 interface, confirming the close proximity of D666 and S1787, and this covalent attachment of the A2 subunit significantly increased FVIIIa stability.

Impedance spectroscopy for the non-destructive evaluation of in vitro epidermal models.

PURPOSE: Reconstructed human epidermis (RHE) is standardly used for the risk assessment of chemical compounds. However, analysis is dependent on invasive methods such as histological processing or 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) staining. METHODS: As an alternative, we have developed a non-destructive technology to analyze the integrity of epidermal equivalents based on impedance spectroscopy. RHEs were generated and impedance spectra were recorded. from these spectra, we extrapolated electrical characteristics such as the capacitance and the ohmic resistance. Furthermore, the measurable electrical parameters were used to quantify the effects of mechanical and chemical disruption of the epidermal integrity. RESULTS: A fully matured RHE exhibits typical impedance spectra in a frequency ranging between 1 Hz and 100 kHz, which is comparable to the spectra of freshly isolated human epidermal biopsies. We could show that, during RHE maturation, these characteristics change significantly. Thus, capacitance and ohmic resistance can be employed as a criterion for the quality control of skin equivalents. Additionally, our application of impedance spectroscopy reveals sufficient sensitivity to detect a transient decreased ohmic resistance caused by 2-propanol, which is classified as a non-irritant by MTT assays. CONCLUSION: These results indicate that impedance spectroscopy can be employed as a non-destructive complementary method to assess mild irritative effects, which is currently not possible.

Enhanced factor VIIIa stability of A2 domain interface variants results from an increased apparent affinity for the A2 subunit. Results from an increased apparent affinity for the A2 subunit.

Factor (F)VIIIa, a heterotrimer comprised of A1, A2, and A3C1C2 subunits, is labile due to the tendency of the A2 subunit to dissociate from the A1/A3C1C2 dimer. As dissociation of the A2 subunit inactivates FVIIIa activity, retention of A2 defines FVIIIa stability and thus, FXase activity. Earlier results showed that replacing residues D519, E665, and E1984 at the A2 domain interface with Ala or Val reduced rates of FVIIIa decay, increasing FXa and thrombin generation. We now show the enhanced FVIIIa stability of these variants results from increases in inter-A2 subunit affinity. Using a FVIIIa reconstitution assay to monitor inter-subunit affinity by activity regeneration, the apparent Kd value for the interaction of wild-type (WT) A2 subunit with WT A1/A3C1C2 dimer (43 ± 2 nM) was significantly higher than values observed for the A2 point mutants D519A/V, E665A/V, and E1984A/V which ranged from ~5 to ~19 nM. Val was determined to be the optimal hydrophobic residue at position 665 (apparent Kd = 5.1 ± 0.7 nM) as substitutions with Ile or Leu at this position increased the apparent Kd value by ~3- and ~7-fold, respectively. Furthermore, the double mutant (D519V/E665V) showed an ~47-fold lower apparent Kd value (0.9 ± 0.6 nM) than WT. Thus these hydrophobic mutations at the A2 subunit interfaces result in high binding affinities for the A2 subunit and correlate well with previously observed reductions in rates in FVIIIa decay.

Spatial heterogeneity in the Mediterranean Biodiversity Hotspot affects barcoding accuracy of its freshwater fishes.

Incomplete knowledge of biodiversity remains a stumbling block for conservation planning and even occurs within globally important Biodiversity Hotspots (BH). Although technical advances have boosted the power of molecular biodiversity assessments, the link between DNA sequences and species and the analytics to discriminate entities remain crucial. Here, we present an analysis of the first DNA barcode library for the freshwater fish fauna of the Mediterranean BH (526 spp.), with virtually complete species coverage (498 spp., 98% extant species). In order to build an identification system supporting conservation, we compared species determination by taxonomists to multiple clustering analyses of DNA barcodes for 3165 specimens. The congruence of barcode clusters with morphological determination was strongly dependent on the method of cluster delineation, but was highest with the general mixed Yule-coalescent (GMYC) model-based approach (83% of all species recovered as GMYC entity). Overall, genetic morphological discontinuities suggest the existence of up to 64 previously unrecognized candidate species. We found reduced identification accuracy when using the entire DNA-barcode database, compared with analyses on databases for individual river catchments. This scale effect has important implications for barcoding assessments and suggests that fairly simple identification pipelines provide sufficient resolution in local applications. We calculated Evolutionarily Distinct and Globally Endangered scores in order to identify candidate species for conservation priority and argue that the evolutionary content of barcode data can be used to detect priority species for future IUCN assessments. We show that large-scale barcoding inventories of complex biotas are feasible and contribute directly to the evaluation of conservation priorities.

Occurrence and host preferences of Anopheles maculipennis group mosquitoes in England and Wales.

Mosquitoes of the Anopheles maculipennis Meigen (Diptera: Culicidae) group are of public health concern: five of the 11 morphologically indistinct species have been historically considered as vectors of malaria in Europe. Three members of the An. maculipennis group have been reported in the U.K.: Anopheles atroparvus van Thiel; Anopheles messeae Falleroni, and Anopheles daciae Linton, Nicolescu & Harbach. To study the distribution of the three U.K. species, particularly that of An. daciae, we developed a polymerase chain reaction-Restriction fragment length polymorphism (PCR-RFLP) assay using the nuclear ribosomal internal transcribed spacer 2 (ITS-2) gene. Anopheles daciae was found to be widespread, occurring in four of the five counties surveyed in southern England and on the Welsh island of Anglesey, often in sympatry with the closely related species An. messeae. The host preferences of 237 blood-fed females were determined using either direct sequencing or PCR-based fragment analysis of the mitochondrial cytochrome oxidase b gene with DNA from females' abdomens. All three species were found to be opportunistic, having fed on at least three different hosts. Seventeen individuals contained multiple bloodmeals, including two An. daciae that had fed on humans and birds. Our results show that An. daciae is widespread in England and Wales, occurs in sympatry with other members of the An. maculipennis group, and feeds on humans, which suggests it is a potential vector of disease in the U.K.

An antibody fragment functionalized dendritic PEGylated poly(2-(dimethylamino)ethyl diacrylate) as a vehicle of exogenous microRNA.

The translation of interfering RNA to the clinic requires more effective delivery agents to enable safe and efficient delivery. The aim of this work was to create a multi-functional delivery agent using deactivation enhanced ATRP synthesis of poly(dimethylamino)ethyl methacrylate (pDMAEMA)-co-PEGMEA/PEGDA (pD-b-P/DA) with linear pDMAEMA as a macro-initiator. The pD-b-P/DA was characterized for its potential to bind synthetic microRNA mimics to form structures and reacted with antibody-derived fragments (Fabs) using Michael-type addition. Conjugation of antibody fragments was verified using SDS-PAGE. Functional delivery of these interfering RNA complexes was proven using a dual luciferase reporter assay. Functional silencing of a reporter gene was improved by complexation of microRNA mimics with pD-b-P/DA alone and with Fab-decorated pD-b-P/DA. The improved silencing with Fab-decorated pD-b-P/DA was evident at 48 h but disappeared at 96 h. The resultant agent enables complexation of nucleic acid (microRNA mimic) and facile conjugation of antibody fragments via a Michael-type addition. In conclusion, this platform is effective at silencing in this reporter system and has potential as an effective delivery system of interfering RNA.

The combined treatment of aortic stenosis and abdominal aortic aneurysm using transcatheter techniques: a case report.

We describe the case of an 85 year old lady with symptomatic aortic stenosis (AS) with a history of previous coronary artery bypass grafting (CABG), who was referred for consideration of aortic valve replacement (AVR). Echocardiography revealed severe AS with peak gradient of 92 mmHg, orifice area of 0.6 cm2 and preserved left ventricular function. Computed tomography (CT) aortogram revealed a diffusely calcified aorta and an infrarenal abdominal aortic aneurysm (AAA) measuring 6.5 cm. For symptomatic and prognostic reasons she needed treatment of both the AAA and AS. Her calculated logistic EuroSCORE for AVR was 39%. Following discussion at a multidisciplinary forum, it was agreed that the best way to offer her treatment with the lowest risk was by using transcatheter techniques for both pathologies. She subsequently underwent transcatheter aortic valve implantation (TAVI) via the transapical approach to treat her AS, and 3 months later, endovascular stenting of her infrarenal AAA. She recovered well from both procedures. At 6 week follow up, her cardiac symptoms had improved considerably, and echocardiography revealed a mean AV gradient of 7 mmHg with good left ventricular function. Ultrasound of her abdomen revealed exclusion of the aneurysm sac with no endoleak. This is the first described case of TAVI and endovascular treatment of an AAA as a staged procedure.