Moral reasoning behind the veil of ignorance: An investigation into perspective-taking accessibility in the context of autonomous vehicles

Perspective-taking (PT) accessibility has been recognized as an important factor in affecting moral reasoning, also playing a non-trivial role in moral investigation towards autonomous vehicles (AVs). A new proposal to deepen this effect leverages the principles of the veil of ignorance (VOI), as a moral reasoning device aimed to control self-interested decisions by limiting the access to specific perspectives and to potentially biased information. Throughout two studies, we deepen the role of VOI reasoning in the moral perception of AVs, disclosing personal and contingent information progressively throughout the experiment. With the use of the moral trilemma paradigm, two different VOI conditions were operationalized, inspired by the Original Position theory by John Rawls and the Equiprobability Model by John Harsanyi. Evidence suggests a significant role of VOI reasoning in affecting moral reasoning, which seems not independent from the order in which information is revealed. Coherently, a detrimental effect of self-involvement on utilitarian behaviours was detected. These results highlight the importance of considering PT accessibility and self-involvement when investigating moral attitudes towards AVs, since it can help the intelligibility of general concerns and hesitations towards this new technology.

Constrained chromatin accessibility in PU.1-mutated agammaglobulinemia patients

The pioneer transcription factor (TF) PU.1 controls hematopoietic cell fate by decompacting stem cell heterochromatin and allowing nonpioneer TFs to enter otherwise inaccessible genomic sites. PU.1 deficiency fatally arrests lymphopoiesis and myelopoiesis in mice, but human congenital PU.1 disorders have not previously been described. We studied six unrelated agammaglobulinemic patients, each harboring a heterozygous mutation (four de novo, two unphased) of SPI1, the gene encoding PU.1. Affected patients lacked circulating B cells and possessed few conventional dendritic cells. Introducing disease-similar SPI1 mutations into human hematopoietic stem and progenitor cells impaired early in vitro B cell and myeloid cell differentiation. Patient SPI1 mutations encoded destabilized PU.1 proteins unable to nuclear localize or bind target DNA. In PU.1-haploinsufficient pro–B cell lines, euchromatin was less accessible to nonpioneer TFs critical for B cell development, and gene expression patterns associated with the pro– to pre–B cell transition were undermined. Our findings molecularly describe a novel form of agammaglobulinemia and underscore PU.1’s critical, dose-dependent role as a hematopoietic euchromatin gatekeeper.

Timed inhibition of CDC7 increases CRISPR-Cas9 mediated templated repair

Repair of double strand DNA breaks (DSBs) can result in gene disruption or gene modification via homology directed repair (HDR) from donor DNA. Altering cellular responses to DSBs may rebalance editing outcomes towards HDR and away from other repair outcomes. Here, we utilize a pooled CRISPR screen to define host cell involvement in HDR between a Cas9 DSB and a plasmid double stranded donor DNA (dsDonor). We find that the Fanconi Anemia (FA) pathway is required for dsDonor HDR and that other genes act to repress HDR. Small molecule inhibition of one of these repressors, CDC7, by XL413 and other inhibitors increases the efficiency of HDR by up to 3.5 fold in many contexts, including primary T cells. XL413 stimulates HDR during a reversible slowing of S-phase that is unexplored for Cas9-induced HDR. We anticipate that XL413 and other such rationally developed inhibitors will be useful tools for gene modification.

IMMU-38. CRISPR BASED GENOME EDITING OF HUMAN T CELLS TO TARGET H3.3K27M MUTATION IN GLIOMAS

We recently identified an HLA-A*02:01-restricted CD8 T cell epitope encompassing the H3.3K27M mutation, which is common in diffuse midline glioma, and a corresponding high-affinity T cell receptor (TCR) that recognizes the epitope. While recombinant viral vectors have been widely used for genetic reprogramming of T cells, viral vectors are far from ideal as they typically integrate randomly into the genome and are not governed by the molecular regulatory mechanisms of the cell. We used a non-viral, CRISPR-Cas9-based approach to replace the endogenous TCR with H3.3K27M TCR at the TCR a constant region (TRAC) in human T cells. Co-electroporation of healthy donor-derived T cells with homology-directed repair (HDR) templates encoding the full-length sequence of H3.3K27M TCR along with CRISPR-Cas9 ribonucleoprotein (RNP) resulted in the integration of the new TCR into the TRAC locus by HDR. Antibody staining of TCR α/β and H3.3K27M dextramer showed replacement of endogenous TCR with H.3.3K27M TCR in ~5–10% of TCR+ CD8 T cells. Modifying the HDR template to include a binding site for Cas9, which contains the nuclear localization signal that acts as a “shuttle”, further enhanced the integration efficiency (~15% of TCR+ CD8 T cells). Furthermore, HLA-A2+ H3.3K27M TCR-engineered T cells selectively killed U87 glioma cells expressing the H3.3K27M epitope. In addition, the engineered T cells exhibited a stem memory-like phenotype when expanded in the presence of a cocktail of IL-2, IL-7 and IL-15. Taken together, these data provide evidence for non-viral genome editing as a strategy to engineer T cells with specific TCR for cancer immunotherapy.

The evaluation of vesicoureteral reflux among children using contrast-enhanced ultrasound: a literature review

INTRODUCTION

Voiding cystourethrogram (VCUG) with fluoroscopy remains the gold standard for detection and evaluation of vesicoureteral reflux (VUR) among children. However, the ionizing radiation exposure remains a concern for this diagnostic modality. Recent studies have proposed using contrast-enhanced ultrasound as an alternative option for VUR screening and follow-up in children. The aim of the study was to review the literature of comparative studies that assessed the diagnostic accuracy of contrast-enhanced ultrasound compared with VCUG.

METHODOLOGY

A systematic literature search was performed on electronic medical literature databases in July 2017. Literature identification, screening, and assessment of eligibility were performed by five reviewers with a pediatric radiologist. Literature was summarized for the study population, contrast used, and ultrasound mode as well as the timing of comparative reference study being performed. The studies were clustered according to the kind of contrast used. Reported diagnostic accuracy was extracted from individual studies and summarized across the included studies using descriptive statistics of median and interquartile range (IQR).

RESULT

A total of 45 comparative studies were identified as eligible for the summary of the literature. Two generations of ultrasound contrast were identified in the available studies (first generation, Levovist and second generation, SonoVue). For the ultrasound studies using the first-generation contrast, the median sensitivity, regardless of the ultrasound mode, was 90.25 (IQR 83.25-97), and the median specificity was 93 (IQR 91.3-95.25). Among studies using the second-generation contrast, the median sensitivity was 86.26 (IQR 81.13-97), and the median specificity was 90.99 (IQR 84-98). No serious adverse events were reported in any of the studies.

CONCLUSION

Overall, this review highlights the application of contrast-enhanced ultrasound for its advantage of no exposure to ionizing radiation and diagnostic accuracy relatively comparable to VCUG in the evaluation of VUR. In addition to the functional evaluation of the VUR, it also provides an anatomic evaluation of the kidneys and bladder with ultrasound imaging. However, one should also note that this alternate procedure is highly operator dependent where diagnostic accuracy is excellent when the expertise is available.

The clinical effectiveness and cost-effectiveness of technologies used to visualise the seizure focus in people with refractory epilepsy being considered for surgery: a systematic review and decision-analytical model

BACKGROUND

For patients who continue to have seizures despite ongoing treatment, surgical resection of the epileptic focus may be considered, and can result in seizure-freedom. Currently, non-invasive tests provide information to inform the scope and positioning of invasive electroencephalography (EEG) electrodes. However, these technologies could replace intracranial EEG in at least some patients if their ability to accurately locate a seizure focus could be established. In order to inform clinical practice, studies need to investigate the clinical value of a test, and the impact of the results of that test on the decision-making process and subsequently on clinical outcomes.

OBJECTIVES

The aims of this systematic review were to determine the diagnostic accuracy of non-invasive technologies, how these technologies impact on the decision-making process, associations with surgical outcome, and the gaps in the current evidence base. In addition, a decision-analytical model was designed to consider the potential use of existing data to determine the cost-effectiveness of options for presurgical work-up.

DATA SOURCES

Eighteen electronic databases were searched without language restrictions [including MEDLINE, EMBASE, BIOSIS Previews, PASCAL, ClinicalTrials.gov, Cochrane Database of Systematic Reviews (CDSR), Cochrane Central Register of Controlled Trials (CENTRAL) and the Cochrane Register of Diagnostic Studies] from 2003 to July 2010. A prior, wider-ranging HTA review in this area conducted by the Centre for Reviews and Dissemination was used as the source for studies prior to 2003. Reference lists of included studies and relevant reviews were also searched, and a citation search of key papers undertaken.

REVIEW METHODS

Systematic reviews of the diagnostic accuracy, clinical utility and cost-effectiveness of non-invasive technologies used to define the seizure focus in patients with refractory epilepsy being considered for surgery were undertaken according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Thirteen diagnostic accuracy studies, seven outcome prediction studies and one study reporting the impact of test results on the decision-making process ('decision study') were included. The decision study was used to aid the development of a decision-analytical model to illustrate how data from appropriately designed clinical studies can be utilised.

RESULTS

Data from the diagnostic accuracy studies could not determine the contribution of the tests to the decision-making process. The number of index tests that could not be classified as correctly, non- or wrongly localising as indicated by a surgical outcome was high, up to 53%. The decision study reported fluorodeoxyglucose positron emission tomography influencing the decision for or against surgery in 78 of the 110 patients. The constructed decision-analytical model provided provisional cost-effectiveness results from the included diagnostic strategies. It demonstrated the feasibility of extending such analysis to all diagnostic strategies if suitable data were to become available.

LIMITATIONS

There were a number of limitations of the available evidence, and overall, the quality of the available evidence was poor; only one study met the inclusion criteria that evaluated the use an index test on the decision-making process. Most of the available data was from the diagnostic accuracy studies; those currently available did not provide information on either the diagnostic accuracy or clinical utility of the tests being evaluated. Further limitations were the generally small study sizes, patient selection bias and the substantial clinical heterogeneity across the studies.

CONCLUSIONS

The current evidence base is abundant but not adequately informative; there is no acceptable reference standard, reporting of clinical outcomes tends to be only following surgery, and decision level and clinical effectiveness studies are lacking. The additional value of diagnostic technologies for the localisation of epileptic foci is related to the impact on treatment decisions and the value of the treatments themselves; this needs to be considered fully in informing cost-effectiveness. Appropriately designed studies are needed to determine the added value of diagnostic regimens. Ultimately, how research informs the actual decision problem(s) faced by clinicians and the NHS needs to be considered; decision modelling is central to this issue.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Immunoisolating semi-permeable membranes for cell encapsulation: focus on hydrogels

Cell-based medicine has recently emerged as a promising cure for patients suffering from various diseases and disorders that cannot be cured/treated using technologies currently available. Encapsulation within semi-permeable membranes offers transplanted cell protection from the surrounding host environment to achieve successful therapeutic function following in vivo implantation. Apart from the immunoisolation requirements, the encapsulating material must allow for cell survival and differentiation while maintaining its physico-mechanical properties throughout the required implantation period. Here we review the progress made in the development of cell encapsulation technologies from the mass transport side, highlighting the essential requirements of materials comprising immunoisolating membranes. The review will focus on hydrogels, the most common polymers used in cell encapsulation, and discuss the advantages of these materials and the challenges faced in the modification of their immunoisolating and permeability characteristics in order to optimize their function.

Quality of life outcomes of immediate or delayed treatment of early epilepsy and single seizures

OBJECTIVE

To compare the impact of policies of immediate vs deferred treatment in patients with few or infrequent seizures on quality of life (QoL) outcomes.

METHODS

We conducted a multicenter, randomized, unblinded study of immediate and deferred treatment. QoL data were collected by mail, using validated measures, for participants living in the UK and without major learning disability. Baseline questionnaires were returned by 441 adult patients; 333 returned 2-year follow-up questionnaires. This analysis is based on 331 patients (162 randomized to immediate, 169 to deferred treatment) returning both baseline and 2-year questionnaires.

RESULTS

There were no significant differences at 2 years in QoL outcomes by treatment group. Patients randomized to deferred treatment were no more likely to report impairments in general health, cognitive function, psychological well-being, or social function. The one area of functioning affected was driving, where those randomized to deferred treatment were disadvantaged. There were clear QoL impacts both of taking antiepileptic drugs and, to an even greater extent, of continuing seizures.

CONCLUSIONS

In treatment uncertain patients, there is a clear trade-off between adverse effects of seizures and adverse effects of taking antiepileptic drugs, i.e., neither policy examined in our study was associated with overall quality of life gains or losses longer term.

An association between type 1 diabetes and idiopathic generalized epilepsy

OBJECTIVE

Idiopathic generalized epilepsies (IGEs) account for approximately 30% of all patients with epilepsy. Both the IGEs and type 1 diabetes mellitus (T1D) represent serious worldwide problems, because of related medical and social management costs. Clinical experience suggested the two conditions were seen in individuals more frequently than might be expected by chance.

METHODS

We compared the population prevalence of T1D in 15- to 30-year-olds to a cohort of 518 15- to 30-year-olds with IGE.

RESULTS

We found a highly significant excess of T1D in our IGE cohort, with an odds ratio of 4.4 (95% confidence interval, 2.1-9.2).

INTERPRETATION

Our results suggest that the prevalence of T1D is increased by a factor of four in young adults with IGE. To our knowledge, this is the first published association between the two conditions and expands the diseases known to be associated with T1D.

A systematic review of the effectiveness and cost-effectiveness of neuroimaging assessments used to visualise the seizure focus in people with refractory epilepsy being considered for surgery

OBJECTIVE

To review the effectiveness and/or accuracy, cost-effectiveness, and predictive value of neuroimaging of the cerebral cortex to visualise the seizure focus in people with refractory epilepsy being considered for surgery.

DATA SOURCES

Electronic databases, Internet searches, hand searching and consultation with experts.

METHODS

A systematic review was undertaken according to published guidelines. Results of diagnostic accuracy studies were analysed according to the imaging test evaluated. For each study the proportion of patients who were correctly localised, not localised, partially localised or incorrectly localised by the index test was calculated. Due to the heterogeneity present between studies, statistical pooling was not performed. Instead, a narrative synthesis of results is presented. For studies using multivariate analysis to look at the association of neuroimaging findings and outcome following surgery, all factors considered in the analyses were presented. Studies were grouped according to the neuroimaging technique investigated and the findings discussed with reference to possible sources of heterogeneity between studies.

RESULTS

No randomised controlled trials (RCTs) were identified, with the majority of studies evaluating the diagnostic accuracy of various imaging techniques in the localisation of epileptic seizure foci. There was significant heterogeneity (p<0.05) between studies for at least one of the localisation categories (correctly localised, not localised, partially localised and incorrectly localised) for all imaging techniques. Possible explanations for this heterogeneity include differing study designs, index test characteristics, reference standards and population characteristics. Test performance was more promising in studies restricted to patients with temporal lobe epilepsy. Ictal single photon emission computed tomography (SPECT) generally had more correctly localising (70--100%) and fewer non-localising (0--7%) scans than other techniques evaluated in patients with temporal lobe epilepsy. Results for computed tomography and interictal SPECT suggest that these tests are relatively poor at localising the seizure focus. Volumeric magnetic resonance imaging (MRI) and position emission tomography (PET) appear promising, and subtraction ictal single photon emission computed tomography co-registered to magnetic resonance imaging (SISCOM) and magnetic resonance spectrosopy (MRS) less promising than ictal SPECT, but these technologies have been assessed in fewer studies. T2 relaxometry was reported in only one small study with inconclusive results. Seventeen studies (33 evaluations) provided sufficient data on the association of a localised scan with outcome following surgery to calculate a relative risk. The majority of evaluations (24/33) suggested that patients with a correctly or partially localised scan had a better outcome following surgery than those with an incorrectly localised or non-localised scan. However, this association was statistically significant in only three studies, two evaluating routine MRI [(relative risk (RR) 2.74, 95% confidence interval (CI): 1.32 to 5.67; RR 1.28, 95% CI: 1.00 to 1.63] and the other SISCOM (RR 2.12, 95% CI: 1.01, 4.44). Nine studies used multivariate analysis to investigate the association of MRI (7 studies), MRS and volumetric MRI (1 study), PET (3 studies), SPECT (1 study) and SISCOM (3 studies) with the outcome following surgery. There was a trend for localisation of abnormalities to be associated with a beneficial outcome.

CONCLUSIONS

Due to the limitations of the included studies, the results of this review do little to inform clinical practice, with insufficient evidence regarding effectiveness and cost-effectiveness of imaging techniques in the work-up for epilepsy surgery. Given the inadequacy of existing data, there is a pressing need for studies investigating the utility of imaging techniques in the work up for epilepsy surgery. The most reliable method to achieve this is the RCT, which could examine the single tests or combinations of tests on patient outcome. The authors suggest that it is important that clinicians, patient groups, policy makers and healthcare/research funders meet and debate the most appropriate way to investigate these technologies.

Immediate versus deferred antiepileptic drug treatment for early epilepsy and single seizures: a randomised controlled trial

BACKGROUND

The relative risks and benefits of starting or withholding antiepileptic drug treatment in patients with few or infrequent seizures are unclear. We sought to compare policies of immediate versus deferred treatment in such patients and to assess the effects of these policies on short-term recurrence and long-term outcomes.

METHODS

We undertook an unmasked, multicentre, randomised study of immediate and deferred antiepileptic drug treatment in 1847 patients with single seizures and early epilepsy. Outcomes comprised time to first, second, and fifth seizures; time to 2-year remission; no seizures between years 1 and 3 and between years 3 and 5 after randomisation; and quality of life. Analysis was by intention to treat.

FINDINGS

404 patients invited to join the trial did not consent to randomisation; 722 were subsequently assigned immediate treatment with antiepileptic drugs and 721 were assigned deferred treatment. Immediate treatment increased time to first seizure (hazard ratio 1.4 [95% CI 1.2 to 1.7]), second seizure (1.3 [1.1 to 1.6]), and first tonic-clonic seizure (1.5 [1.2 to 1.8]). It also reduced the time to achieve 2-year remission of seizures (p=0.023). At 5-years follow-up, 76% of patients in the immediate treatment group and 77% of those in the deferred treatment group were seizure free between 3 and 5 years after randomisation (difference -0.2% [95% CI -5.8% to 5.5%]). The two policies did not differ with respect to quality of life outcomes or serious complications.

INTERPRETATION

Immediate antiepileptic drug treatment reduces the occurrence of seizures in the next 1-2 years, but does not affect long-term remission in individuals with single or infrequent seizures.

The Wuchereria bancrofti orthologue of Brugia malayi SXP1 and the diagnosis of bancroftian filariasis

The gene encoding the Wuchereria bancrofti orthologue of the Brugia malayi-derived diagnostic antigen SXP1 was identified from a W. bancrofti L3 cDNA library and characterized. The Wb-sxp-1 cDNA encoded a basic protein with a calculated molecular mass of 20.8 kDa. Wb-SXP-1 was 85% identical to the SXP1 protein described from B. malayi (Bm-SXP-1). The Wb-SXP-1 sequence also showed significant identity with proteins described from B. pahangi, Onchocerca volvulus, Acanthochilonema vitea, Ascaris suum, Loa loa, Litomosoides sigmodontis and Caenorhabditis elegans. The presence of a number of invariant and conserved residues in all of these nematode-derived molecules suggests that Wb-SXP-1 is a member of a new protein family. A recombinant form of Wb-SXP-1 was produced and it was determined that the anti-Wb-SXP-1 antibody response in patients with W. bancrofti infections was restricted to the IgG4 subclass. An anti-Wb-SXP-1 IgG4 ELISA was developed and this assay was found to be 100% sensitive for patients with patent W. bancrofti infection. Sera from individuals experiencing chronic pathology, endemic normals or patients with non-filarial nematode infections had no detectable IgG4 against Wb-SXP-1. While patients with patent Onchocerca volvulus infections were uniformly negative in the Wb-SXP-1 assay, 40% of sera from patent Loa loa infections were positive. When Bm-SXP-1 was used as the antigen under identical conditions, the assay was 88% specific for patent W. bancrofti infections and the antigen was recognized by antibodies from both O. volvulus and L. loa infections. The results strongly suggested that, for certain diagnostic filarial antigens, the use of same-species molecules can enhance the specificity of diagnostic tests.

Genetical variation for enzyme activity in a population of Drosophila melanogaster. VI. Molecular variation in the control of alcohol dehydrogenase (ADH) activity

Four characters, ADH activity at 25 degrees, immunologically determined ADH protein level, total protein and body weight were measured upon 72 hour old adult female and male Drosophila melanogaster from 16 highly inbred lines, derived from the laboratory population, "Texas" (established 1966). The highest levels of ADH activity and ADH protein level were observed in the 2 lined homozygous for the AdhF allele. Amongst the 14 AdhS/S lines variation for ADH protein level was associated with genetical variation for ADH activity (r = 0.6). The genetical association between ADH activity or ADH protein level and either body weight or total protein in the 16 inbred lines was not statistically significant. A study of ADH activity, ADH protein and total protein in 8 lines representing all homozygous combinations of chromosomes I, II and III and derived from two inbred AdhS/S lines, chosen for their respective high and low ADH activities, showed that ADH activity was considerably modified by a post-translational event controlled from chromosome III. Total protein was controlled by different chromosomal effects from those controlling ADH activity. Michaelis constants for crude fly extracts of the two AdhF/F and the above two AdhS/S lines showed clear differences in affinity for isopropanol.

Genetical variation for enzyme activity in a population of Drosophila melanogaster. VII. Genotype-environment interaction for alcohol dehydrogenase (ADH) activity

Genotype-environment interaction was detected for ADH activity amongst a set of 18 highly inbred lines of Drosophila melanogaster which had been extracted from the laboratory population, "Texas". The genotype-environment interaction for ADH activity was not wholly associated with genotype-environment interaction for body weight or total protein level. Detailed analyses of the responses of the individual inbred lines in ADH activity in relation to the environmental index, ej and following the procedure of Jinks and Pooni (1979), showed substantial diversity in the form of response. Lines homozygous for the AdhF allele were more environmentally sensitive than AdhS/S lines. Amongst the 16 AdhS/S lines, models of linear, quadratic or two intersecting-straight-lines were used to illustrate the varied responses of genotypes to the environment. The heterogeneity in the response characteristics of the inbred lines was attributed to variations in the conditions of culture media normally present within populations and laboratories. Moreover the non-linear responses shown by some lines to the environment are consistent with a model of genotype-environment interaction for ADH activity mediated by varied genotype-specific sensitivities to different environmental factors.

Genetical variation for enzyme activity in a population of Drosophila melanogaster. V. The genetical architecture, as shown by diallel analysis, of alcohol dehydrogenase (ADH) activity

Fifteen highly inbred lines extracted by sib-mating from the laboratory cage population, "Texas", of Drosophila melanogaster were crossed in a half-diallel mating design. Female progeny were assayed individually for ADH activity at 25 degrees and 35 degrees C and for total protein. At 25 degrees C there was considerable additive genetical variation and the dominance variation was attributable to specific parents and to specific crosses at random in the diallel table. The character total protein also showed considerable additive variation but less dominance variation. Largely independent gene action was shown by the characters ADH activity and total protein. There were strong genotype-environment interactions for heat-stability. At 35 degrees C most of the genetical variation was additive and mainly due to modifier loci. It was concluded that at 25 degrees C dominance was ambidirectional and almost complete. This genetical architecture was compatible with a past history of stabilising selection for ADH activity in the "Texas" population.

The effects of surfactants on cell aggregation

Trypsin-dissociated HeLa and human amnion cells were employed to investigate the effects of an anionic, a cationic, and a non-ionic surfactant on cell reaggregation. All the surfactants inhibited the reaggregation process, the effect increasing with surfactant concentration, and becoming significant at concentrations of about 10(−6) M for the anionic surfactant and about 10(−5) M for the others. The effects of temperature and ionic strength on HeLa cell aggregation, and of surfactants on the electrophoretic mobility of HeLa cells and the release of sialic acid from their surfaces by neuraminidase, were also examined. The results indicate that although electrostatic effects occur and are likely to be of importance in cell reaggregation, the effect of surfactants cannot be accounted for on this basis alone, and it is suggested that interactions involving the cell-surface glycoproteins, possibly indirectly via effects on the fluidity of the cell membrane, are also significant in this respect.

Evaluation of the non-randomness of protein compositions

A method is described for assessing the non-randomness of protein compositions, based on the chi-squared statistic for the differences between the observed numbers of residues of each type and the numbers expected for a random distribution of codons. The analysis indicates that changes in at least 30% of the residues in natural proteins are selected against.